1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 */ 8 #ifndef _UAPI__LINUX_BPF_H__ 9 #define _UAPI__LINUX_BPF_H__ 10 11 #include <linux/types.h> 12 #include <linux/bpf_common.h> 13 14 /* Extended instruction set based on top of classic BPF */ 15 16 /* instruction classes */ 17 #define BPF_JMP32 0x06 /* jmp mode in word width */ 18 #define BPF_ALU64 0x07 /* alu mode in double word width */ 19 20 /* ld/ldx fields */ 21 #define BPF_DW 0x18 /* double word (64-bit) */ 22 #define BPF_MEMSX 0x80 /* load with sign extension */ 23 #define BPF_ATOMIC 0xc0 /* atomic memory ops - op type in immediate */ 24 #define BPF_XADD 0xc0 /* exclusive add - legacy name */ 25 26 /* alu/jmp fields */ 27 #define BPF_MOV 0xb0 /* mov reg to reg */ 28 #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */ 29 30 /* change endianness of a register */ 31 #define BPF_END 0xd0 /* flags for endianness conversion: */ 32 #define BPF_TO_LE 0x00 /* convert to little-endian */ 33 #define BPF_TO_BE 0x08 /* convert to big-endian */ 34 #define BPF_FROM_LE BPF_TO_LE 35 #define BPF_FROM_BE BPF_TO_BE 36 37 /* jmp encodings */ 38 #define BPF_JNE 0x50 /* jump != */ 39 #define BPF_JLT 0xa0 /* LT is unsigned, '<' */ 40 #define BPF_JLE 0xb0 /* LE is unsigned, '<=' */ 41 #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */ 42 #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */ 43 #define BPF_JSLT 0xc0 /* SLT is signed, '<' */ 44 #define BPF_JSLE 0xd0 /* SLE is signed, '<=' */ 45 #define BPF_CALL 0x80 /* function call */ 46 #define BPF_EXIT 0x90 /* function return */ 47 48 /* atomic op type fields (stored in immediate) */ 49 #define BPF_FETCH 0x01 /* not an opcode on its own, used to build others */ 50 #define BPF_XCHG (0xe0 | BPF_FETCH) /* atomic exchange */ 51 #define BPF_CMPXCHG (0xf0 | BPF_FETCH) /* atomic compare-and-write */ 52 53 /* Register numbers */ 54 enum { 55 BPF_REG_0 = 0, 56 BPF_REG_1, 57 BPF_REG_2, 58 BPF_REG_3, 59 BPF_REG_4, 60 BPF_REG_5, 61 BPF_REG_6, 62 BPF_REG_7, 63 BPF_REG_8, 64 BPF_REG_9, 65 BPF_REG_10, 66 __MAX_BPF_REG, 67 }; 68 69 /* BPF has 10 general purpose 64-bit registers and stack frame. */ 70 #define MAX_BPF_REG __MAX_BPF_REG 71 72 struct bpf_insn { 73 __u8 code; /* opcode */ 74 __u8 dst_reg:4; /* dest register */ 75 __u8 src_reg:4; /* source register */ 76 __s16 off; /* signed offset */ 77 __s32 imm; /* signed immediate constant */ 78 }; 79 80 /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */ 81 struct bpf_lpm_trie_key { 82 __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ 83 __u8 data[0]; /* Arbitrary size */ 84 }; 85 86 struct bpf_cgroup_storage_key { 87 __u64 cgroup_inode_id; /* cgroup inode id */ 88 __u32 attach_type; /* program attach type (enum bpf_attach_type) */ 89 }; 90 91 enum bpf_cgroup_iter_order { 92 BPF_CGROUP_ITER_ORDER_UNSPEC = 0, 93 BPF_CGROUP_ITER_SELF_ONLY, /* process only a single object. */ 94 BPF_CGROUP_ITER_DESCENDANTS_PRE, /* walk descendants in pre-order. */ 95 BPF_CGROUP_ITER_DESCENDANTS_POST, /* walk descendants in post-order. */ 96 BPF_CGROUP_ITER_ANCESTORS_UP, /* walk ancestors upward. */ 97 }; 98 99 union bpf_iter_link_info { 100 struct { 101 __u32 map_fd; 102 } map; 103 struct { 104 enum bpf_cgroup_iter_order order; 105 106 /* At most one of cgroup_fd and cgroup_id can be non-zero. If 107 * both are zero, the walk starts from the default cgroup v2 108 * root. For walking v1 hierarchy, one should always explicitly 109 * specify cgroup_fd. 110 */ 111 __u32 cgroup_fd; 112 __u64 cgroup_id; 113 } cgroup; 114 /* Parameters of task iterators. */ 115 struct { 116 __u32 tid; 117 __u32 pid; 118 __u32 pid_fd; 119 } task; 120 }; 121 122 /* BPF syscall commands, see bpf(2) man-page for more details. */ 123 /** 124 * DOC: eBPF Syscall Preamble 125 * 126 * The operation to be performed by the **bpf**\ () system call is determined 127 * by the *cmd* argument. Each operation takes an accompanying argument, 128 * provided via *attr*, which is a pointer to a union of type *bpf_attr* (see 129 * below). The size argument is the size of the union pointed to by *attr*. 130 */ 131 /** 132 * DOC: eBPF Syscall Commands 133 * 134 * BPF_MAP_CREATE 135 * Description 136 * Create a map and return a file descriptor that refers to the 137 * map. The close-on-exec file descriptor flag (see **fcntl**\ (2)) 138 * is automatically enabled for the new file descriptor. 139 * 140 * Applying **close**\ (2) to the file descriptor returned by 141 * **BPF_MAP_CREATE** will delete the map (but see NOTES). 142 * 143 * Return 144 * A new file descriptor (a nonnegative integer), or -1 if an 145 * error occurred (in which case, *errno* is set appropriately). 146 * 147 * BPF_MAP_LOOKUP_ELEM 148 * Description 149 * Look up an element with a given *key* in the map referred to 150 * by the file descriptor *map_fd*. 151 * 152 * The *flags* argument may be specified as one of the 153 * following: 154 * 155 * **BPF_F_LOCK** 156 * Look up the value of a spin-locked map without 157 * returning the lock. This must be specified if the 158 * elements contain a spinlock. 159 * 160 * Return 161 * Returns zero on success. On error, -1 is returned and *errno* 162 * is set appropriately. 163 * 164 * BPF_MAP_UPDATE_ELEM 165 * Description 166 * Create or update an element (key/value pair) in a specified map. 167 * 168 * The *flags* argument should be specified as one of the 169 * following: 170 * 171 * **BPF_ANY** 172 * Create a new element or update an existing element. 173 * **BPF_NOEXIST** 174 * Create a new element only if it did not exist. 175 * **BPF_EXIST** 176 * Update an existing element. 177 * **BPF_F_LOCK** 178 * Update a spin_lock-ed map element. 179 * 180 * Return 181 * Returns zero on success. On error, -1 is returned and *errno* 182 * is set appropriately. 183 * 184 * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, 185 * **E2BIG**, **EEXIST**, or **ENOENT**. 186 * 187 * **E2BIG** 188 * The number of elements in the map reached the 189 * *max_entries* limit specified at map creation time. 190 * **EEXIST** 191 * If *flags* specifies **BPF_NOEXIST** and the element 192 * with *key* already exists in the map. 193 * **ENOENT** 194 * If *flags* specifies **BPF_EXIST** and the element with 195 * *key* does not exist in the map. 196 * 197 * BPF_MAP_DELETE_ELEM 198 * Description 199 * Look up and delete an element by key in a specified map. 200 * 201 * Return 202 * Returns zero on success. On error, -1 is returned and *errno* 203 * is set appropriately. 204 * 205 * BPF_MAP_GET_NEXT_KEY 206 * Description 207 * Look up an element by key in a specified map and return the key 208 * of the next element. Can be used to iterate over all elements 209 * in the map. 210 * 211 * Return 212 * Returns zero on success. On error, -1 is returned and *errno* 213 * is set appropriately. 214 * 215 * The following cases can be used to iterate over all elements of 216 * the map: 217 * 218 * * If *key* is not found, the operation returns zero and sets 219 * the *next_key* pointer to the key of the first element. 220 * * If *key* is found, the operation returns zero and sets the 221 * *next_key* pointer to the key of the next element. 222 * * If *key* is the last element, returns -1 and *errno* is set 223 * to **ENOENT**. 224 * 225 * May set *errno* to **ENOMEM**, **EFAULT**, **EPERM**, or 226 * **EINVAL** on error. 227 * 228 * BPF_PROG_LOAD 229 * Description 230 * Verify and load an eBPF program, returning a new file 231 * descriptor associated with the program. 232 * 233 * Applying **close**\ (2) to the file descriptor returned by 234 * **BPF_PROG_LOAD** will unload the eBPF program (but see NOTES). 235 * 236 * The close-on-exec file descriptor flag (see **fcntl**\ (2)) is 237 * automatically enabled for the new file descriptor. 238 * 239 * Return 240 * A new file descriptor (a nonnegative integer), or -1 if an 241 * error occurred (in which case, *errno* is set appropriately). 242 * 243 * BPF_OBJ_PIN 244 * Description 245 * Pin an eBPF program or map referred by the specified *bpf_fd* 246 * to the provided *pathname* on the filesystem. 247 * 248 * The *pathname* argument must not contain a dot ("."). 249 * 250 * On success, *pathname* retains a reference to the eBPF object, 251 * preventing deallocation of the object when the original 252 * *bpf_fd* is closed. This allow the eBPF object to live beyond 253 * **close**\ (\ *bpf_fd*\ ), and hence the lifetime of the parent 254 * process. 255 * 256 * Applying **unlink**\ (2) or similar calls to the *pathname* 257 * unpins the object from the filesystem, removing the reference. 258 * If no other file descriptors or filesystem nodes refer to the 259 * same object, it will be deallocated (see NOTES). 260 * 261 * The filesystem type for the parent directory of *pathname* must 262 * be **BPF_FS_MAGIC**. 263 * 264 * Return 265 * Returns zero on success. On error, -1 is returned and *errno* 266 * is set appropriately. 267 * 268 * BPF_OBJ_GET 269 * Description 270 * Open a file descriptor for the eBPF object pinned to the 271 * specified *pathname*. 272 * 273 * Return 274 * A new file descriptor (a nonnegative integer), or -1 if an 275 * error occurred (in which case, *errno* is set appropriately). 276 * 277 * BPF_PROG_ATTACH 278 * Description 279 * Attach an eBPF program to a *target_fd* at the specified 280 * *attach_type* hook. 281 * 282 * The *attach_type* specifies the eBPF attachment point to 283 * attach the program to, and must be one of *bpf_attach_type* 284 * (see below). 285 * 286 * The *attach_bpf_fd* must be a valid file descriptor for a 287 * loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap 288 * or sock_ops type corresponding to the specified *attach_type*. 289 * 290 * The *target_fd* must be a valid file descriptor for a kernel 291 * object which depends on the attach type of *attach_bpf_fd*: 292 * 293 * **BPF_PROG_TYPE_CGROUP_DEVICE**, 294 * **BPF_PROG_TYPE_CGROUP_SKB**, 295 * **BPF_PROG_TYPE_CGROUP_SOCK**, 296 * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, 297 * **BPF_PROG_TYPE_CGROUP_SOCKOPT**, 298 * **BPF_PROG_TYPE_CGROUP_SYSCTL**, 299 * **BPF_PROG_TYPE_SOCK_OPS** 300 * 301 * Control Group v2 hierarchy with the eBPF controller 302 * enabled. Requires the kernel to be compiled with 303 * **CONFIG_CGROUP_BPF**. 304 * 305 * **BPF_PROG_TYPE_FLOW_DISSECTOR** 306 * 307 * Network namespace (eg /proc/self/ns/net). 308 * 309 * **BPF_PROG_TYPE_LIRC_MODE2** 310 * 311 * LIRC device path (eg /dev/lircN). Requires the kernel 312 * to be compiled with **CONFIG_BPF_LIRC_MODE2**. 313 * 314 * **BPF_PROG_TYPE_SK_SKB**, 315 * **BPF_PROG_TYPE_SK_MSG** 316 * 317 * eBPF map of socket type (eg **BPF_MAP_TYPE_SOCKHASH**). 318 * 319 * Return 320 * Returns zero on success. On error, -1 is returned and *errno* 321 * is set appropriately. 322 * 323 * BPF_PROG_DETACH 324 * Description 325 * Detach the eBPF program associated with the *target_fd* at the 326 * hook specified by *attach_type*. The program must have been 327 * previously attached using **BPF_PROG_ATTACH**. 328 * 329 * Return 330 * Returns zero on success. On error, -1 is returned and *errno* 331 * is set appropriately. 332 * 333 * BPF_PROG_TEST_RUN 334 * Description 335 * Run the eBPF program associated with the *prog_fd* a *repeat* 336 * number of times against a provided program context *ctx_in* and 337 * data *data_in*, and return the modified program context 338 * *ctx_out*, *data_out* (for example, packet data), result of the 339 * execution *retval*, and *duration* of the test run. 340 * 341 * The sizes of the buffers provided as input and output 342 * parameters *ctx_in*, *ctx_out*, *data_in*, and *data_out* must 343 * be provided in the corresponding variables *ctx_size_in*, 344 * *ctx_size_out*, *data_size_in*, and/or *data_size_out*. If any 345 * of these parameters are not provided (ie set to NULL), the 346 * corresponding size field must be zero. 347 * 348 * Some program types have particular requirements: 349 * 350 * **BPF_PROG_TYPE_SK_LOOKUP** 351 * *data_in* and *data_out* must be NULL. 352 * 353 * **BPF_PROG_TYPE_RAW_TRACEPOINT**, 354 * **BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE** 355 * 356 * *ctx_out*, *data_in* and *data_out* must be NULL. 357 * *repeat* must be zero. 358 * 359 * BPF_PROG_RUN is an alias for BPF_PROG_TEST_RUN. 360 * 361 * Return 362 * Returns zero on success. On error, -1 is returned and *errno* 363 * is set appropriately. 364 * 365 * **ENOSPC** 366 * Either *data_size_out* or *ctx_size_out* is too small. 367 * **ENOTSUPP** 368 * This command is not supported by the program type of 369 * the program referred to by *prog_fd*. 370 * 371 * BPF_PROG_GET_NEXT_ID 372 * Description 373 * Fetch the next eBPF program currently loaded into the kernel. 374 * 375 * Looks for the eBPF program with an id greater than *start_id* 376 * and updates *next_id* on success. If no other eBPF programs 377 * remain with ids higher than *start_id*, returns -1 and sets 378 * *errno* to **ENOENT**. 379 * 380 * Return 381 * Returns zero on success. On error, or when no id remains, -1 382 * is returned and *errno* is set appropriately. 383 * 384 * BPF_MAP_GET_NEXT_ID 385 * Description 386 * Fetch the next eBPF map currently loaded into the kernel. 387 * 388 * Looks for the eBPF map with an id greater than *start_id* 389 * and updates *next_id* on success. If no other eBPF maps 390 * remain with ids higher than *start_id*, returns -1 and sets 391 * *errno* to **ENOENT**. 392 * 393 * Return 394 * Returns zero on success. On error, or when no id remains, -1 395 * is returned and *errno* is set appropriately. 396 * 397 * BPF_PROG_GET_FD_BY_ID 398 * Description 399 * Open a file descriptor for the eBPF program corresponding to 400 * *prog_id*. 401 * 402 * Return 403 * A new file descriptor (a nonnegative integer), or -1 if an 404 * error occurred (in which case, *errno* is set appropriately). 405 * 406 * BPF_MAP_GET_FD_BY_ID 407 * Description 408 * Open a file descriptor for the eBPF map corresponding to 409 * *map_id*. 410 * 411 * Return 412 * A new file descriptor (a nonnegative integer), or -1 if an 413 * error occurred (in which case, *errno* is set appropriately). 414 * 415 * BPF_OBJ_GET_INFO_BY_FD 416 * Description 417 * Obtain information about the eBPF object corresponding to 418 * *bpf_fd*. 419 * 420 * Populates up to *info_len* bytes of *info*, which will be in 421 * one of the following formats depending on the eBPF object type 422 * of *bpf_fd*: 423 * 424 * * **struct bpf_prog_info** 425 * * **struct bpf_map_info** 426 * * **struct bpf_btf_info** 427 * * **struct bpf_link_info** 428 * 429 * Return 430 * Returns zero on success. On error, -1 is returned and *errno* 431 * is set appropriately. 432 * 433 * BPF_PROG_QUERY 434 * Description 435 * Obtain information about eBPF programs associated with the 436 * specified *attach_type* hook. 437 * 438 * The *target_fd* must be a valid file descriptor for a kernel 439 * object which depends on the attach type of *attach_bpf_fd*: 440 * 441 * **BPF_PROG_TYPE_CGROUP_DEVICE**, 442 * **BPF_PROG_TYPE_CGROUP_SKB**, 443 * **BPF_PROG_TYPE_CGROUP_SOCK**, 444 * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, 445 * **BPF_PROG_TYPE_CGROUP_SOCKOPT**, 446 * **BPF_PROG_TYPE_CGROUP_SYSCTL**, 447 * **BPF_PROG_TYPE_SOCK_OPS** 448 * 449 * Control Group v2 hierarchy with the eBPF controller 450 * enabled. Requires the kernel to be compiled with 451 * **CONFIG_CGROUP_BPF**. 452 * 453 * **BPF_PROG_TYPE_FLOW_DISSECTOR** 454 * 455 * Network namespace (eg /proc/self/ns/net). 456 * 457 * **BPF_PROG_TYPE_LIRC_MODE2** 458 * 459 * LIRC device path (eg /dev/lircN). Requires the kernel 460 * to be compiled with **CONFIG_BPF_LIRC_MODE2**. 461 * 462 * **BPF_PROG_QUERY** always fetches the number of programs 463 * attached and the *attach_flags* which were used to attach those 464 * programs. Additionally, if *prog_ids* is nonzero and the number 465 * of attached programs is less than *prog_cnt*, populates 466 * *prog_ids* with the eBPF program ids of the programs attached 467 * at *target_fd*. 468 * 469 * The following flags may alter the result: 470 * 471 * **BPF_F_QUERY_EFFECTIVE** 472 * Only return information regarding programs which are 473 * currently effective at the specified *target_fd*. 474 * 475 * Return 476 * Returns zero on success. On error, -1 is returned and *errno* 477 * is set appropriately. 478 * 479 * BPF_RAW_TRACEPOINT_OPEN 480 * Description 481 * Attach an eBPF program to a tracepoint *name* to access kernel 482 * internal arguments of the tracepoint in their raw form. 483 * 484 * The *prog_fd* must be a valid file descriptor associated with 485 * a loaded eBPF program of type **BPF_PROG_TYPE_RAW_TRACEPOINT**. 486 * 487 * No ABI guarantees are made about the content of tracepoint 488 * arguments exposed to the corresponding eBPF program. 489 * 490 * Applying **close**\ (2) to the file descriptor returned by 491 * **BPF_RAW_TRACEPOINT_OPEN** will delete the map (but see NOTES). 492 * 493 * Return 494 * A new file descriptor (a nonnegative integer), or -1 if an 495 * error occurred (in which case, *errno* is set appropriately). 496 * 497 * BPF_BTF_LOAD 498 * Description 499 * Verify and load BPF Type Format (BTF) metadata into the kernel, 500 * returning a new file descriptor associated with the metadata. 501 * BTF is described in more detail at 502 * https://www.kernel.org/doc/html/latest/bpf/btf.html. 503 * 504 * The *btf* parameter must point to valid memory providing 505 * *btf_size* bytes of BTF binary metadata. 506 * 507 * The returned file descriptor can be passed to other **bpf**\ () 508 * subcommands such as **BPF_PROG_LOAD** or **BPF_MAP_CREATE** to 509 * associate the BTF with those objects. 510 * 511 * Similar to **BPF_PROG_LOAD**, **BPF_BTF_LOAD** has optional 512 * parameters to specify a *btf_log_buf*, *btf_log_size* and 513 * *btf_log_level* which allow the kernel to return freeform log 514 * output regarding the BTF verification process. 515 * 516 * Return 517 * A new file descriptor (a nonnegative integer), or -1 if an 518 * error occurred (in which case, *errno* is set appropriately). 519 * 520 * BPF_BTF_GET_FD_BY_ID 521 * Description 522 * Open a file descriptor for the BPF Type Format (BTF) 523 * corresponding to *btf_id*. 524 * 525 * Return 526 * A new file descriptor (a nonnegative integer), or -1 if an 527 * error occurred (in which case, *errno* is set appropriately). 528 * 529 * BPF_TASK_FD_QUERY 530 * Description 531 * Obtain information about eBPF programs associated with the 532 * target process identified by *pid* and *fd*. 533 * 534 * If the *pid* and *fd* are associated with a tracepoint, kprobe 535 * or uprobe perf event, then the *prog_id* and *fd_type* will 536 * be populated with the eBPF program id and file descriptor type 537 * of type **bpf_task_fd_type**. If associated with a kprobe or 538 * uprobe, the *probe_offset* and *probe_addr* will also be 539 * populated. Optionally, if *buf* is provided, then up to 540 * *buf_len* bytes of *buf* will be populated with the name of 541 * the tracepoint, kprobe or uprobe. 542 * 543 * The resulting *prog_id* may be introspected in deeper detail 544 * using **BPF_PROG_GET_FD_BY_ID** and **BPF_OBJ_GET_INFO_BY_FD**. 545 * 546 * Return 547 * Returns zero on success. On error, -1 is returned and *errno* 548 * is set appropriately. 549 * 550 * BPF_MAP_LOOKUP_AND_DELETE_ELEM 551 * Description 552 * Look up an element with the given *key* in the map referred to 553 * by the file descriptor *fd*, and if found, delete the element. 554 * 555 * For **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map 556 * types, the *flags* argument needs to be set to 0, but for other 557 * map types, it may be specified as: 558 * 559 * **BPF_F_LOCK** 560 * Look up and delete the value of a spin-locked map 561 * without returning the lock. This must be specified if 562 * the elements contain a spinlock. 563 * 564 * The **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map types 565 * implement this command as a "pop" operation, deleting the top 566 * element rather than one corresponding to *key*. 567 * The *key* and *key_len* parameters should be zeroed when 568 * issuing this operation for these map types. 569 * 570 * This command is only valid for the following map types: 571 * * **BPF_MAP_TYPE_QUEUE** 572 * * **BPF_MAP_TYPE_STACK** 573 * * **BPF_MAP_TYPE_HASH** 574 * * **BPF_MAP_TYPE_PERCPU_HASH** 575 * * **BPF_MAP_TYPE_LRU_HASH** 576 * * **BPF_MAP_TYPE_LRU_PERCPU_HASH** 577 * 578 * Return 579 * Returns zero on success. On error, -1 is returned and *errno* 580 * is set appropriately. 581 * 582 * BPF_MAP_FREEZE 583 * Description 584 * Freeze the permissions of the specified map. 585 * 586 * Write permissions may be frozen by passing zero *flags*. 587 * Upon success, no future syscall invocations may alter the 588 * map state of *map_fd*. Write operations from eBPF programs 589 * are still possible for a frozen map. 590 * 591 * Not supported for maps of type **BPF_MAP_TYPE_STRUCT_OPS**. 592 * 593 * Return 594 * Returns zero on success. On error, -1 is returned and *errno* 595 * is set appropriately. 596 * 597 * BPF_BTF_GET_NEXT_ID 598 * Description 599 * Fetch the next BPF Type Format (BTF) object currently loaded 600 * into the kernel. 601 * 602 * Looks for the BTF object with an id greater than *start_id* 603 * and updates *next_id* on success. If no other BTF objects 604 * remain with ids higher than *start_id*, returns -1 and sets 605 * *errno* to **ENOENT**. 606 * 607 * Return 608 * Returns zero on success. On error, or when no id remains, -1 609 * is returned and *errno* is set appropriately. 610 * 611 * BPF_MAP_LOOKUP_BATCH 612 * Description 613 * Iterate and fetch multiple elements in a map. 614 * 615 * Two opaque values are used to manage batch operations, 616 * *in_batch* and *out_batch*. Initially, *in_batch* must be set 617 * to NULL to begin the batched operation. After each subsequent 618 * **BPF_MAP_LOOKUP_BATCH**, the caller should pass the resultant 619 * *out_batch* as the *in_batch* for the next operation to 620 * continue iteration from the current point. 621 * 622 * The *keys* and *values* are output parameters which must point 623 * to memory large enough to hold *count* items based on the key 624 * and value size of the map *map_fd*. The *keys* buffer must be 625 * of *key_size* * *count*. The *values* buffer must be of 626 * *value_size* * *count*. 627 * 628 * The *elem_flags* argument may be specified as one of the 629 * following: 630 * 631 * **BPF_F_LOCK** 632 * Look up the value of a spin-locked map without 633 * returning the lock. This must be specified if the 634 * elements contain a spinlock. 635 * 636 * On success, *count* elements from the map are copied into the 637 * user buffer, with the keys copied into *keys* and the values 638 * copied into the corresponding indices in *values*. 639 * 640 * If an error is returned and *errno* is not **EFAULT**, *count* 641 * is set to the number of successfully processed elements. 642 * 643 * Return 644 * Returns zero on success. On error, -1 is returned and *errno* 645 * is set appropriately. 646 * 647 * May set *errno* to **ENOSPC** to indicate that *keys* or 648 * *values* is too small to dump an entire bucket during 649 * iteration of a hash-based map type. 650 * 651 * BPF_MAP_LOOKUP_AND_DELETE_BATCH 652 * Description 653 * Iterate and delete all elements in a map. 654 * 655 * This operation has the same behavior as 656 * **BPF_MAP_LOOKUP_BATCH** with two exceptions: 657 * 658 * * Every element that is successfully returned is also deleted 659 * from the map. This is at least *count* elements. Note that 660 * *count* is both an input and an output parameter. 661 * * Upon returning with *errno* set to **EFAULT**, up to 662 * *count* elements may be deleted without returning the keys 663 * and values of the deleted elements. 664 * 665 * Return 666 * Returns zero on success. On error, -1 is returned and *errno* 667 * is set appropriately. 668 * 669 * BPF_MAP_UPDATE_BATCH 670 * Description 671 * Update multiple elements in a map by *key*. 672 * 673 * The *keys* and *values* are input parameters which must point 674 * to memory large enough to hold *count* items based on the key 675 * and value size of the map *map_fd*. The *keys* buffer must be 676 * of *key_size* * *count*. The *values* buffer must be of 677 * *value_size* * *count*. 678 * 679 * Each element specified in *keys* is sequentially updated to the 680 * value in the corresponding index in *values*. The *in_batch* 681 * and *out_batch* parameters are ignored and should be zeroed. 682 * 683 * The *elem_flags* argument should be specified as one of the 684 * following: 685 * 686 * **BPF_ANY** 687 * Create new elements or update a existing elements. 688 * **BPF_NOEXIST** 689 * Create new elements only if they do not exist. 690 * **BPF_EXIST** 691 * Update existing elements. 692 * **BPF_F_LOCK** 693 * Update spin_lock-ed map elements. This must be 694 * specified if the map value contains a spinlock. 695 * 696 * On success, *count* elements from the map are updated. 697 * 698 * If an error is returned and *errno* is not **EFAULT**, *count* 699 * is set to the number of successfully processed elements. 700 * 701 * Return 702 * Returns zero on success. On error, -1 is returned and *errno* 703 * is set appropriately. 704 * 705 * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, or 706 * **E2BIG**. **E2BIG** indicates that the number of elements in 707 * the map reached the *max_entries* limit specified at map 708 * creation time. 709 * 710 * May set *errno* to one of the following error codes under 711 * specific circumstances: 712 * 713 * **EEXIST** 714 * If *flags* specifies **BPF_NOEXIST** and the element 715 * with *key* already exists in the map. 716 * **ENOENT** 717 * If *flags* specifies **BPF_EXIST** and the element with 718 * *key* does not exist in the map. 719 * 720 * BPF_MAP_DELETE_BATCH 721 * Description 722 * Delete multiple elements in a map by *key*. 723 * 724 * The *keys* parameter is an input parameter which must point 725 * to memory large enough to hold *count* items based on the key 726 * size of the map *map_fd*, that is, *key_size* * *count*. 727 * 728 * Each element specified in *keys* is sequentially deleted. The 729 * *in_batch*, *out_batch*, and *values* parameters are ignored 730 * and should be zeroed. 731 * 732 * The *elem_flags* argument may be specified as one of the 733 * following: 734 * 735 * **BPF_F_LOCK** 736 * Look up the value of a spin-locked map without 737 * returning the lock. This must be specified if the 738 * elements contain a spinlock. 739 * 740 * On success, *count* elements from the map are updated. 741 * 742 * If an error is returned and *errno* is not **EFAULT**, *count* 743 * is set to the number of successfully processed elements. If 744 * *errno* is **EFAULT**, up to *count* elements may be been 745 * deleted. 746 * 747 * Return 748 * Returns zero on success. On error, -1 is returned and *errno* 749 * is set appropriately. 750 * 751 * BPF_LINK_CREATE 752 * Description 753 * Attach an eBPF program to a *target_fd* at the specified 754 * *attach_type* hook and return a file descriptor handle for 755 * managing the link. 756 * 757 * Return 758 * A new file descriptor (a nonnegative integer), or -1 if an 759 * error occurred (in which case, *errno* is set appropriately). 760 * 761 * BPF_LINK_UPDATE 762 * Description 763 * Update the eBPF program in the specified *link_fd* to 764 * *new_prog_fd*. 765 * 766 * Return 767 * Returns zero on success. On error, -1 is returned and *errno* 768 * is set appropriately. 769 * 770 * BPF_LINK_GET_FD_BY_ID 771 * Description 772 * Open a file descriptor for the eBPF Link corresponding to 773 * *link_id*. 774 * 775 * Return 776 * A new file descriptor (a nonnegative integer), or -1 if an 777 * error occurred (in which case, *errno* is set appropriately). 778 * 779 * BPF_LINK_GET_NEXT_ID 780 * Description 781 * Fetch the next eBPF link currently loaded into the kernel. 782 * 783 * Looks for the eBPF link with an id greater than *start_id* 784 * and updates *next_id* on success. If no other eBPF links 785 * remain with ids higher than *start_id*, returns -1 and sets 786 * *errno* to **ENOENT**. 787 * 788 * Return 789 * Returns zero on success. On error, or when no id remains, -1 790 * is returned and *errno* is set appropriately. 791 * 792 * BPF_ENABLE_STATS 793 * Description 794 * Enable eBPF runtime statistics gathering. 795 * 796 * Runtime statistics gathering for the eBPF runtime is disabled 797 * by default to minimize the corresponding performance overhead. 798 * This command enables statistics globally. 799 * 800 * Multiple programs may independently enable statistics. 801 * After gathering the desired statistics, eBPF runtime statistics 802 * may be disabled again by calling **close**\ (2) for the file 803 * descriptor returned by this function. Statistics will only be 804 * disabled system-wide when all outstanding file descriptors 805 * returned by prior calls for this subcommand are closed. 806 * 807 * Return 808 * A new file descriptor (a nonnegative integer), or -1 if an 809 * error occurred (in which case, *errno* is set appropriately). 810 * 811 * BPF_ITER_CREATE 812 * Description 813 * Create an iterator on top of the specified *link_fd* (as 814 * previously created using **BPF_LINK_CREATE**) and return a 815 * file descriptor that can be used to trigger the iteration. 816 * 817 * If the resulting file descriptor is pinned to the filesystem 818 * using **BPF_OBJ_PIN**, then subsequent **read**\ (2) syscalls 819 * for that path will trigger the iterator to read kernel state 820 * using the eBPF program attached to *link_fd*. 821 * 822 * Return 823 * A new file descriptor (a nonnegative integer), or -1 if an 824 * error occurred (in which case, *errno* is set appropriately). 825 * 826 * BPF_LINK_DETACH 827 * Description 828 * Forcefully detach the specified *link_fd* from its 829 * corresponding attachment point. 830 * 831 * Return 832 * Returns zero on success. On error, -1 is returned and *errno* 833 * is set appropriately. 834 * 835 * BPF_PROG_BIND_MAP 836 * Description 837 * Bind a map to the lifetime of an eBPF program. 838 * 839 * The map identified by *map_fd* is bound to the program 840 * identified by *prog_fd* and only released when *prog_fd* is 841 * released. This may be used in cases where metadata should be 842 * associated with a program which otherwise does not contain any 843 * references to the map (for example, embedded in the eBPF 844 * program instructions). 845 * 846 * Return 847 * Returns zero on success. On error, -1 is returned and *errno* 848 * is set appropriately. 849 * 850 * NOTES 851 * eBPF objects (maps and programs) can be shared between processes. 852 * 853 * * After **fork**\ (2), the child inherits file descriptors 854 * referring to the same eBPF objects. 855 * * File descriptors referring to eBPF objects can be transferred over 856 * **unix**\ (7) domain sockets. 857 * * File descriptors referring to eBPF objects can be duplicated in the 858 * usual way, using **dup**\ (2) and similar calls. 859 * * File descriptors referring to eBPF objects can be pinned to the 860 * filesystem using the **BPF_OBJ_PIN** command of **bpf**\ (2). 861 * 862 * An eBPF object is deallocated only after all file descriptors referring 863 * to the object have been closed and no references remain pinned to the 864 * filesystem or attached (for example, bound to a program or device). 865 */ 866 enum bpf_cmd { 867 BPF_MAP_CREATE, 868 BPF_MAP_LOOKUP_ELEM, 869 BPF_MAP_UPDATE_ELEM, 870 BPF_MAP_DELETE_ELEM, 871 BPF_MAP_GET_NEXT_KEY, 872 BPF_PROG_LOAD, 873 BPF_OBJ_PIN, 874 BPF_OBJ_GET, 875 BPF_PROG_ATTACH, 876 BPF_PROG_DETACH, 877 BPF_PROG_TEST_RUN, 878 BPF_PROG_RUN = BPF_PROG_TEST_RUN, 879 BPF_PROG_GET_NEXT_ID, 880 BPF_MAP_GET_NEXT_ID, 881 BPF_PROG_GET_FD_BY_ID, 882 BPF_MAP_GET_FD_BY_ID, 883 BPF_OBJ_GET_INFO_BY_FD, 884 BPF_PROG_QUERY, 885 BPF_RAW_TRACEPOINT_OPEN, 886 BPF_BTF_LOAD, 887 BPF_BTF_GET_FD_BY_ID, 888 BPF_TASK_FD_QUERY, 889 BPF_MAP_LOOKUP_AND_DELETE_ELEM, 890 BPF_MAP_FREEZE, 891 BPF_BTF_GET_NEXT_ID, 892 BPF_MAP_LOOKUP_BATCH, 893 BPF_MAP_LOOKUP_AND_DELETE_BATCH, 894 BPF_MAP_UPDATE_BATCH, 895 BPF_MAP_DELETE_BATCH, 896 BPF_LINK_CREATE, 897 BPF_LINK_UPDATE, 898 BPF_LINK_GET_FD_BY_ID, 899 BPF_LINK_GET_NEXT_ID, 900 BPF_ENABLE_STATS, 901 BPF_ITER_CREATE, 902 BPF_LINK_DETACH, 903 BPF_PROG_BIND_MAP, 904 }; 905 906 enum bpf_map_type { 907 BPF_MAP_TYPE_UNSPEC, 908 BPF_MAP_TYPE_HASH, 909 BPF_MAP_TYPE_ARRAY, 910 BPF_MAP_TYPE_PROG_ARRAY, 911 BPF_MAP_TYPE_PERF_EVENT_ARRAY, 912 BPF_MAP_TYPE_PERCPU_HASH, 913 BPF_MAP_TYPE_PERCPU_ARRAY, 914 BPF_MAP_TYPE_STACK_TRACE, 915 BPF_MAP_TYPE_CGROUP_ARRAY, 916 BPF_MAP_TYPE_LRU_HASH, 917 BPF_MAP_TYPE_LRU_PERCPU_HASH, 918 BPF_MAP_TYPE_LPM_TRIE, 919 BPF_MAP_TYPE_ARRAY_OF_MAPS, 920 BPF_MAP_TYPE_HASH_OF_MAPS, 921 BPF_MAP_TYPE_DEVMAP, 922 BPF_MAP_TYPE_SOCKMAP, 923 BPF_MAP_TYPE_CPUMAP, 924 BPF_MAP_TYPE_XSKMAP, 925 BPF_MAP_TYPE_SOCKHASH, 926 BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, 927 /* BPF_MAP_TYPE_CGROUP_STORAGE is available to bpf programs attaching 928 * to a cgroup. The newer BPF_MAP_TYPE_CGRP_STORAGE is available to 929 * both cgroup-attached and other progs and supports all functionality 930 * provided by BPF_MAP_TYPE_CGROUP_STORAGE. So mark 931 * BPF_MAP_TYPE_CGROUP_STORAGE deprecated. 932 */ 933 BPF_MAP_TYPE_CGROUP_STORAGE = BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, 934 BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, 935 BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, 936 BPF_MAP_TYPE_QUEUE, 937 BPF_MAP_TYPE_STACK, 938 BPF_MAP_TYPE_SK_STORAGE, 939 BPF_MAP_TYPE_DEVMAP_HASH, 940 BPF_MAP_TYPE_STRUCT_OPS, 941 BPF_MAP_TYPE_RINGBUF, 942 BPF_MAP_TYPE_INODE_STORAGE, 943 BPF_MAP_TYPE_TASK_STORAGE, 944 BPF_MAP_TYPE_BLOOM_FILTER, 945 BPF_MAP_TYPE_USER_RINGBUF, 946 BPF_MAP_TYPE_CGRP_STORAGE, 947 }; 948 949 /* Note that tracing related programs such as 950 * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT} 951 * are not subject to a stable API since kernel internal data 952 * structures can change from release to release and may 953 * therefore break existing tracing BPF programs. Tracing BPF 954 * programs correspond to /a/ specific kernel which is to be 955 * analyzed, and not /a/ specific kernel /and/ all future ones. 956 */ 957 enum bpf_prog_type { 958 BPF_PROG_TYPE_UNSPEC, 959 BPF_PROG_TYPE_SOCKET_FILTER, 960 BPF_PROG_TYPE_KPROBE, 961 BPF_PROG_TYPE_SCHED_CLS, 962 BPF_PROG_TYPE_SCHED_ACT, 963 BPF_PROG_TYPE_TRACEPOINT, 964 BPF_PROG_TYPE_XDP, 965 BPF_PROG_TYPE_PERF_EVENT, 966 BPF_PROG_TYPE_CGROUP_SKB, 967 BPF_PROG_TYPE_CGROUP_SOCK, 968 BPF_PROG_TYPE_LWT_IN, 969 BPF_PROG_TYPE_LWT_OUT, 970 BPF_PROG_TYPE_LWT_XMIT, 971 BPF_PROG_TYPE_SOCK_OPS, 972 BPF_PROG_TYPE_SK_SKB, 973 BPF_PROG_TYPE_CGROUP_DEVICE, 974 BPF_PROG_TYPE_SK_MSG, 975 BPF_PROG_TYPE_RAW_TRACEPOINT, 976 BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 977 BPF_PROG_TYPE_LWT_SEG6LOCAL, 978 BPF_PROG_TYPE_LIRC_MODE2, 979 BPF_PROG_TYPE_SK_REUSEPORT, 980 BPF_PROG_TYPE_FLOW_DISSECTOR, 981 BPF_PROG_TYPE_CGROUP_SYSCTL, 982 BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, 983 BPF_PROG_TYPE_CGROUP_SOCKOPT, 984 BPF_PROG_TYPE_TRACING, 985 BPF_PROG_TYPE_STRUCT_OPS, 986 BPF_PROG_TYPE_EXT, 987 BPF_PROG_TYPE_LSM, 988 BPF_PROG_TYPE_SK_LOOKUP, 989 BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */ 990 BPF_PROG_TYPE_NETFILTER, 991 }; 992 993 enum bpf_attach_type { 994 BPF_CGROUP_INET_INGRESS, 995 BPF_CGROUP_INET_EGRESS, 996 BPF_CGROUP_INET_SOCK_CREATE, 997 BPF_CGROUP_SOCK_OPS, 998 BPF_SK_SKB_STREAM_PARSER, 999 BPF_SK_SKB_STREAM_VERDICT, 1000 BPF_CGROUP_DEVICE, 1001 BPF_SK_MSG_VERDICT, 1002 BPF_CGROUP_INET4_BIND, 1003 BPF_CGROUP_INET6_BIND, 1004 BPF_CGROUP_INET4_CONNECT, 1005 BPF_CGROUP_INET6_CONNECT, 1006 BPF_CGROUP_INET4_POST_BIND, 1007 BPF_CGROUP_INET6_POST_BIND, 1008 BPF_CGROUP_UDP4_SENDMSG, 1009 BPF_CGROUP_UDP6_SENDMSG, 1010 BPF_LIRC_MODE2, 1011 BPF_FLOW_DISSECTOR, 1012 BPF_CGROUP_SYSCTL, 1013 BPF_CGROUP_UDP4_RECVMSG, 1014 BPF_CGROUP_UDP6_RECVMSG, 1015 BPF_CGROUP_GETSOCKOPT, 1016 BPF_CGROUP_SETSOCKOPT, 1017 BPF_TRACE_RAW_TP, 1018 BPF_TRACE_FENTRY, 1019 BPF_TRACE_FEXIT, 1020 BPF_MODIFY_RETURN, 1021 BPF_LSM_MAC, 1022 BPF_TRACE_ITER, 1023 BPF_CGROUP_INET4_GETPEERNAME, 1024 BPF_CGROUP_INET6_GETPEERNAME, 1025 BPF_CGROUP_INET4_GETSOCKNAME, 1026 BPF_CGROUP_INET6_GETSOCKNAME, 1027 BPF_XDP_DEVMAP, 1028 BPF_CGROUP_INET_SOCK_RELEASE, 1029 BPF_XDP_CPUMAP, 1030 BPF_SK_LOOKUP, 1031 BPF_XDP, 1032 BPF_SK_SKB_VERDICT, 1033 BPF_SK_REUSEPORT_SELECT, 1034 BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, 1035 BPF_PERF_EVENT, 1036 BPF_TRACE_KPROBE_MULTI, 1037 BPF_LSM_CGROUP, 1038 BPF_STRUCT_OPS, 1039 BPF_NETFILTER, 1040 BPF_TCX_INGRESS, 1041 BPF_TCX_EGRESS, 1042 BPF_TRACE_UPROBE_MULTI, 1043 __MAX_BPF_ATTACH_TYPE 1044 }; 1045 1046 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE 1047 1048 enum bpf_link_type { 1049 BPF_LINK_TYPE_UNSPEC = 0, 1050 BPF_LINK_TYPE_RAW_TRACEPOINT = 1, 1051 BPF_LINK_TYPE_TRACING = 2, 1052 BPF_LINK_TYPE_CGROUP = 3, 1053 BPF_LINK_TYPE_ITER = 4, 1054 BPF_LINK_TYPE_NETNS = 5, 1055 BPF_LINK_TYPE_XDP = 6, 1056 BPF_LINK_TYPE_PERF_EVENT = 7, 1057 BPF_LINK_TYPE_KPROBE_MULTI = 8, 1058 BPF_LINK_TYPE_STRUCT_OPS = 9, 1059 BPF_LINK_TYPE_NETFILTER = 10, 1060 BPF_LINK_TYPE_TCX = 11, 1061 BPF_LINK_TYPE_UPROBE_MULTI = 12, 1062 MAX_BPF_LINK_TYPE, 1063 }; 1064 1065 enum bpf_perf_event_type { 1066 BPF_PERF_EVENT_UNSPEC = 0, 1067 BPF_PERF_EVENT_UPROBE = 1, 1068 BPF_PERF_EVENT_URETPROBE = 2, 1069 BPF_PERF_EVENT_KPROBE = 3, 1070 BPF_PERF_EVENT_KRETPROBE = 4, 1071 BPF_PERF_EVENT_TRACEPOINT = 5, 1072 BPF_PERF_EVENT_EVENT = 6, 1073 }; 1074 1075 /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command 1076 * 1077 * NONE(default): No further bpf programs allowed in the subtree. 1078 * 1079 * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, 1080 * the program in this cgroup yields to sub-cgroup program. 1081 * 1082 * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, 1083 * that cgroup program gets run in addition to the program in this cgroup. 1084 * 1085 * Only one program is allowed to be attached to a cgroup with 1086 * NONE or BPF_F_ALLOW_OVERRIDE flag. 1087 * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will 1088 * release old program and attach the new one. Attach flags has to match. 1089 * 1090 * Multiple programs are allowed to be attached to a cgroup with 1091 * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order 1092 * (those that were attached first, run first) 1093 * The programs of sub-cgroup are executed first, then programs of 1094 * this cgroup and then programs of parent cgroup. 1095 * When children program makes decision (like picking TCP CA or sock bind) 1096 * parent program has a chance to override it. 1097 * 1098 * With BPF_F_ALLOW_MULTI a new program is added to the end of the list of 1099 * programs for a cgroup. Though it's possible to replace an old program at 1100 * any position by also specifying BPF_F_REPLACE flag and position itself in 1101 * replace_bpf_fd attribute. Old program at this position will be released. 1102 * 1103 * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups. 1104 * A cgroup with NONE doesn't allow any programs in sub-cgroups. 1105 * Ex1: 1106 * cgrp1 (MULTI progs A, B) -> 1107 * cgrp2 (OVERRIDE prog C) -> 1108 * cgrp3 (MULTI prog D) -> 1109 * cgrp4 (OVERRIDE prog E) -> 1110 * cgrp5 (NONE prog F) 1111 * the event in cgrp5 triggers execution of F,D,A,B in that order. 1112 * if prog F is detached, the execution is E,D,A,B 1113 * if prog F and D are detached, the execution is E,A,B 1114 * if prog F, E and D are detached, the execution is C,A,B 1115 * 1116 * All eligible programs are executed regardless of return code from 1117 * earlier programs. 1118 */ 1119 #define BPF_F_ALLOW_OVERRIDE (1U << 0) 1120 #define BPF_F_ALLOW_MULTI (1U << 1) 1121 /* Generic attachment flags. */ 1122 #define BPF_F_REPLACE (1U << 2) 1123 #define BPF_F_BEFORE (1U << 3) 1124 #define BPF_F_AFTER (1U << 4) 1125 #define BPF_F_ID (1U << 5) 1126 #define BPF_F_LINK BPF_F_LINK /* 1 << 13 */ 1127 1128 /* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the 1129 * verifier will perform strict alignment checking as if the kernel 1130 * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set, 1131 * and NET_IP_ALIGN defined to 2. 1132 */ 1133 #define BPF_F_STRICT_ALIGNMENT (1U << 0) 1134 1135 /* If BPF_F_ANY_ALIGNMENT is used in BPF_PROG_LOAD command, the 1136 * verifier will allow any alignment whatsoever. On platforms 1137 * with strict alignment requirements for loads ands stores (such 1138 * as sparc and mips) the verifier validates that all loads and 1139 * stores provably follow this requirement. This flag turns that 1140 * checking and enforcement off. 1141 * 1142 * It is mostly used for testing when we want to validate the 1143 * context and memory access aspects of the verifier, but because 1144 * of an unaligned access the alignment check would trigger before 1145 * the one we are interested in. 1146 */ 1147 #define BPF_F_ANY_ALIGNMENT (1U << 1) 1148 1149 /* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose. 1150 * Verifier does sub-register def/use analysis and identifies instructions whose 1151 * def only matters for low 32-bit, high 32-bit is never referenced later 1152 * through implicit zero extension. Therefore verifier notifies JIT back-ends 1153 * that it is safe to ignore clearing high 32-bit for these instructions. This 1154 * saves some back-ends a lot of code-gen. However such optimization is not 1155 * necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends 1156 * hence hasn't used verifier's analysis result. But, we really want to have a 1157 * way to be able to verify the correctness of the described optimization on 1158 * x86_64 on which testsuites are frequently exercised. 1159 * 1160 * So, this flag is introduced. Once it is set, verifier will randomize high 1161 * 32-bit for those instructions who has been identified as safe to ignore them. 1162 * Then, if verifier is not doing correct analysis, such randomization will 1163 * regress tests to expose bugs. 1164 */ 1165 #define BPF_F_TEST_RND_HI32 (1U << 2) 1166 1167 /* The verifier internal test flag. Behavior is undefined */ 1168 #define BPF_F_TEST_STATE_FREQ (1U << 3) 1169 1170 /* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will 1171 * restrict map and helper usage for such programs. Sleepable BPF programs can 1172 * only be attached to hooks where kernel execution context allows sleeping. 1173 * Such programs are allowed to use helpers that may sleep like 1174 * bpf_copy_from_user(). 1175 */ 1176 #define BPF_F_SLEEPABLE (1U << 4) 1177 1178 /* If BPF_F_XDP_HAS_FRAGS is used in BPF_PROG_LOAD command, the loaded program 1179 * fully support xdp frags. 1180 */ 1181 #define BPF_F_XDP_HAS_FRAGS (1U << 5) 1182 1183 /* If BPF_F_XDP_DEV_BOUND_ONLY is used in BPF_PROG_LOAD command, the loaded 1184 * program becomes device-bound but can access XDP metadata. 1185 */ 1186 #define BPF_F_XDP_DEV_BOUND_ONLY (1U << 6) 1187 1188 /* link_create.kprobe_multi.flags used in LINK_CREATE command for 1189 * BPF_TRACE_KPROBE_MULTI attach type to create return probe. 1190 */ 1191 enum { 1192 BPF_F_KPROBE_MULTI_RETURN = (1U << 0) 1193 }; 1194 1195 /* link_create.uprobe_multi.flags used in LINK_CREATE command for 1196 * BPF_TRACE_UPROBE_MULTI attach type to create return probe. 1197 */ 1198 enum { 1199 BPF_F_UPROBE_MULTI_RETURN = (1U << 0) 1200 }; 1201 1202 /* link_create.netfilter.flags used in LINK_CREATE command for 1203 * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation. 1204 */ 1205 #define BPF_F_NETFILTER_IP_DEFRAG (1U << 0) 1206 1207 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have 1208 * the following extensions: 1209 * 1210 * insn[0].src_reg: BPF_PSEUDO_MAP_[FD|IDX] 1211 * insn[0].imm: map fd or fd_idx 1212 * insn[1].imm: 0 1213 * insn[0].off: 0 1214 * insn[1].off: 0 1215 * ldimm64 rewrite: address of map 1216 * verifier type: CONST_PTR_TO_MAP 1217 */ 1218 #define BPF_PSEUDO_MAP_FD 1 1219 #define BPF_PSEUDO_MAP_IDX 5 1220 1221 /* insn[0].src_reg: BPF_PSEUDO_MAP_[IDX_]VALUE 1222 * insn[0].imm: map fd or fd_idx 1223 * insn[1].imm: offset into value 1224 * insn[0].off: 0 1225 * insn[1].off: 0 1226 * ldimm64 rewrite: address of map[0]+offset 1227 * verifier type: PTR_TO_MAP_VALUE 1228 */ 1229 #define BPF_PSEUDO_MAP_VALUE 2 1230 #define BPF_PSEUDO_MAP_IDX_VALUE 6 1231 1232 /* insn[0].src_reg: BPF_PSEUDO_BTF_ID 1233 * insn[0].imm: kernel btd id of VAR 1234 * insn[1].imm: 0 1235 * insn[0].off: 0 1236 * insn[1].off: 0 1237 * ldimm64 rewrite: address of the kernel variable 1238 * verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var 1239 * is struct/union. 1240 */ 1241 #define BPF_PSEUDO_BTF_ID 3 1242 /* insn[0].src_reg: BPF_PSEUDO_FUNC 1243 * insn[0].imm: insn offset to the func 1244 * insn[1].imm: 0 1245 * insn[0].off: 0 1246 * insn[1].off: 0 1247 * ldimm64 rewrite: address of the function 1248 * verifier type: PTR_TO_FUNC. 1249 */ 1250 #define BPF_PSEUDO_FUNC 4 1251 1252 /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative 1253 * offset to another bpf function 1254 */ 1255 #define BPF_PSEUDO_CALL 1 1256 /* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL, 1257 * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel 1258 */ 1259 #define BPF_PSEUDO_KFUNC_CALL 2 1260 1261 /* flags for BPF_MAP_UPDATE_ELEM command */ 1262 enum { 1263 BPF_ANY = 0, /* create new element or update existing */ 1264 BPF_NOEXIST = 1, /* create new element if it didn't exist */ 1265 BPF_EXIST = 2, /* update existing element */ 1266 BPF_F_LOCK = 4, /* spin_lock-ed map_lookup/map_update */ 1267 }; 1268 1269 /* flags for BPF_MAP_CREATE command */ 1270 enum { 1271 BPF_F_NO_PREALLOC = (1U << 0), 1272 /* Instead of having one common LRU list in the 1273 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list 1274 * which can scale and perform better. 1275 * Note, the LRU nodes (including free nodes) cannot be moved 1276 * across different LRU lists. 1277 */ 1278 BPF_F_NO_COMMON_LRU = (1U << 1), 1279 /* Specify numa node during map creation */ 1280 BPF_F_NUMA_NODE = (1U << 2), 1281 1282 /* Flags for accessing BPF object from syscall side. */ 1283 BPF_F_RDONLY = (1U << 3), 1284 BPF_F_WRONLY = (1U << 4), 1285 1286 /* Flag for stack_map, store build_id+offset instead of pointer */ 1287 BPF_F_STACK_BUILD_ID = (1U << 5), 1288 1289 /* Zero-initialize hash function seed. This should only be used for testing. */ 1290 BPF_F_ZERO_SEED = (1U << 6), 1291 1292 /* Flags for accessing BPF object from program side. */ 1293 BPF_F_RDONLY_PROG = (1U << 7), 1294 BPF_F_WRONLY_PROG = (1U << 8), 1295 1296 /* Clone map from listener for newly accepted socket */ 1297 BPF_F_CLONE = (1U << 9), 1298 1299 /* Enable memory-mapping BPF map */ 1300 BPF_F_MMAPABLE = (1U << 10), 1301 1302 /* Share perf_event among processes */ 1303 BPF_F_PRESERVE_ELEMS = (1U << 11), 1304 1305 /* Create a map that is suitable to be an inner map with dynamic max entries */ 1306 BPF_F_INNER_MAP = (1U << 12), 1307 1308 /* Create a map that will be registered/unregesitered by the backed bpf_link */ 1309 BPF_F_LINK = (1U << 13), 1310 1311 /* Get path from provided FD in BPF_OBJ_PIN/BPF_OBJ_GET commands */ 1312 BPF_F_PATH_FD = (1U << 14), 1313 }; 1314 1315 /* Flags for BPF_PROG_QUERY. */ 1316 1317 /* Query effective (directly attached + inherited from ancestor cgroups) 1318 * programs that will be executed for events within a cgroup. 1319 * attach_flags with this flag are always returned 0. 1320 */ 1321 #define BPF_F_QUERY_EFFECTIVE (1U << 0) 1322 1323 /* Flags for BPF_PROG_TEST_RUN */ 1324 1325 /* If set, run the test on the cpu specified by bpf_attr.test.cpu */ 1326 #define BPF_F_TEST_RUN_ON_CPU (1U << 0) 1327 /* If set, XDP frames will be transmitted after processing */ 1328 #define BPF_F_TEST_XDP_LIVE_FRAMES (1U << 1) 1329 1330 /* type for BPF_ENABLE_STATS */ 1331 enum bpf_stats_type { 1332 /* enabled run_time_ns and run_cnt */ 1333 BPF_STATS_RUN_TIME = 0, 1334 }; 1335 1336 enum bpf_stack_build_id_status { 1337 /* user space need an empty entry to identify end of a trace */ 1338 BPF_STACK_BUILD_ID_EMPTY = 0, 1339 /* with valid build_id and offset */ 1340 BPF_STACK_BUILD_ID_VALID = 1, 1341 /* couldn't get build_id, fallback to ip */ 1342 BPF_STACK_BUILD_ID_IP = 2, 1343 }; 1344 1345 #define BPF_BUILD_ID_SIZE 20 1346 struct bpf_stack_build_id { 1347 __s32 status; 1348 unsigned char build_id[BPF_BUILD_ID_SIZE]; 1349 union { 1350 __u64 offset; 1351 __u64 ip; 1352 }; 1353 }; 1354 1355 #define BPF_OBJ_NAME_LEN 16U 1356 1357 union bpf_attr { 1358 struct { /* anonymous struct used by BPF_MAP_CREATE command */ 1359 __u32 map_type; /* one of enum bpf_map_type */ 1360 __u32 key_size; /* size of key in bytes */ 1361 __u32 value_size; /* size of value in bytes */ 1362 __u32 max_entries; /* max number of entries in a map */ 1363 __u32 map_flags; /* BPF_MAP_CREATE related 1364 * flags defined above. 1365 */ 1366 __u32 inner_map_fd; /* fd pointing to the inner map */ 1367 __u32 numa_node; /* numa node (effective only if 1368 * BPF_F_NUMA_NODE is set). 1369 */ 1370 char map_name[BPF_OBJ_NAME_LEN]; 1371 __u32 map_ifindex; /* ifindex of netdev to create on */ 1372 __u32 btf_fd; /* fd pointing to a BTF type data */ 1373 __u32 btf_key_type_id; /* BTF type_id of the key */ 1374 __u32 btf_value_type_id; /* BTF type_id of the value */ 1375 __u32 btf_vmlinux_value_type_id;/* BTF type_id of a kernel- 1376 * struct stored as the 1377 * map value 1378 */ 1379 /* Any per-map-type extra fields 1380 * 1381 * BPF_MAP_TYPE_BLOOM_FILTER - the lowest 4 bits indicate the 1382 * number of hash functions (if 0, the bloom filter will default 1383 * to using 5 hash functions). 1384 */ 1385 __u64 map_extra; 1386 }; 1387 1388 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */ 1389 __u32 map_fd; 1390 __aligned_u64 key; 1391 union { 1392 __aligned_u64 value; 1393 __aligned_u64 next_key; 1394 }; 1395 __u64 flags; 1396 }; 1397 1398 struct { /* struct used by BPF_MAP_*_BATCH commands */ 1399 __aligned_u64 in_batch; /* start batch, 1400 * NULL to start from beginning 1401 */ 1402 __aligned_u64 out_batch; /* output: next start batch */ 1403 __aligned_u64 keys; 1404 __aligned_u64 values; 1405 __u32 count; /* input/output: 1406 * input: # of key/value 1407 * elements 1408 * output: # of filled elements 1409 */ 1410 __u32 map_fd; 1411 __u64 elem_flags; 1412 __u64 flags; 1413 } batch; 1414 1415 struct { /* anonymous struct used by BPF_PROG_LOAD command */ 1416 __u32 prog_type; /* one of enum bpf_prog_type */ 1417 __u32 insn_cnt; 1418 __aligned_u64 insns; 1419 __aligned_u64 license; 1420 __u32 log_level; /* verbosity level of verifier */ 1421 __u32 log_size; /* size of user buffer */ 1422 __aligned_u64 log_buf; /* user supplied buffer */ 1423 __u32 kern_version; /* not used */ 1424 __u32 prog_flags; 1425 char prog_name[BPF_OBJ_NAME_LEN]; 1426 __u32 prog_ifindex; /* ifindex of netdev to prep for */ 1427 /* For some prog types expected attach type must be known at 1428 * load time to verify attach type specific parts of prog 1429 * (context accesses, allowed helpers, etc). 1430 */ 1431 __u32 expected_attach_type; 1432 __u32 prog_btf_fd; /* fd pointing to BTF type data */ 1433 __u32 func_info_rec_size; /* userspace bpf_func_info size */ 1434 __aligned_u64 func_info; /* func info */ 1435 __u32 func_info_cnt; /* number of bpf_func_info records */ 1436 __u32 line_info_rec_size; /* userspace bpf_line_info size */ 1437 __aligned_u64 line_info; /* line info */ 1438 __u32 line_info_cnt; /* number of bpf_line_info records */ 1439 __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ 1440 union { 1441 /* valid prog_fd to attach to bpf prog */ 1442 __u32 attach_prog_fd; 1443 /* or valid module BTF object fd or 0 to attach to vmlinux */ 1444 __u32 attach_btf_obj_fd; 1445 }; 1446 __u32 core_relo_cnt; /* number of bpf_core_relo */ 1447 __aligned_u64 fd_array; /* array of FDs */ 1448 __aligned_u64 core_relos; 1449 __u32 core_relo_rec_size; /* sizeof(struct bpf_core_relo) */ 1450 /* output: actual total log contents size (including termintaing zero). 1451 * It could be both larger than original log_size (if log was 1452 * truncated), or smaller (if log buffer wasn't filled completely). 1453 */ 1454 __u32 log_true_size; 1455 }; 1456 1457 struct { /* anonymous struct used by BPF_OBJ_* commands */ 1458 __aligned_u64 pathname; 1459 __u32 bpf_fd; 1460 __u32 file_flags; 1461 /* Same as dirfd in openat() syscall; see openat(2) 1462 * manpage for details of path FD and pathname semantics; 1463 * path_fd should accompanied by BPF_F_PATH_FD flag set in 1464 * file_flags field, otherwise it should be set to zero; 1465 * if BPF_F_PATH_FD flag is not set, AT_FDCWD is assumed. 1466 */ 1467 __s32 path_fd; 1468 }; 1469 1470 struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */ 1471 union { 1472 __u32 target_fd; /* target object to attach to or ... */ 1473 __u32 target_ifindex; /* target ifindex */ 1474 }; 1475 __u32 attach_bpf_fd; 1476 __u32 attach_type; 1477 __u32 attach_flags; 1478 __u32 replace_bpf_fd; 1479 union { 1480 __u32 relative_fd; 1481 __u32 relative_id; 1482 }; 1483 __u64 expected_revision; 1484 }; 1485 1486 struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */ 1487 __u32 prog_fd; 1488 __u32 retval; 1489 __u32 data_size_in; /* input: len of data_in */ 1490 __u32 data_size_out; /* input/output: len of data_out 1491 * returns ENOSPC if data_out 1492 * is too small. 1493 */ 1494 __aligned_u64 data_in; 1495 __aligned_u64 data_out; 1496 __u32 repeat; 1497 __u32 duration; 1498 __u32 ctx_size_in; /* input: len of ctx_in */ 1499 __u32 ctx_size_out; /* input/output: len of ctx_out 1500 * returns ENOSPC if ctx_out 1501 * is too small. 1502 */ 1503 __aligned_u64 ctx_in; 1504 __aligned_u64 ctx_out; 1505 __u32 flags; 1506 __u32 cpu; 1507 __u32 batch_size; 1508 } test; 1509 1510 struct { /* anonymous struct used by BPF_*_GET_*_ID */ 1511 union { 1512 __u32 start_id; 1513 __u32 prog_id; 1514 __u32 map_id; 1515 __u32 btf_id; 1516 __u32 link_id; 1517 }; 1518 __u32 next_id; 1519 __u32 open_flags; 1520 }; 1521 1522 struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */ 1523 __u32 bpf_fd; 1524 __u32 info_len; 1525 __aligned_u64 info; 1526 } info; 1527 1528 struct { /* anonymous struct used by BPF_PROG_QUERY command */ 1529 union { 1530 __u32 target_fd; /* target object to query or ... */ 1531 __u32 target_ifindex; /* target ifindex */ 1532 }; 1533 __u32 attach_type; 1534 __u32 query_flags; 1535 __u32 attach_flags; 1536 __aligned_u64 prog_ids; 1537 union { 1538 __u32 prog_cnt; 1539 __u32 count; 1540 }; 1541 __u32 :32; 1542 /* output: per-program attach_flags. 1543 * not allowed to be set during effective query. 1544 */ 1545 __aligned_u64 prog_attach_flags; 1546 __aligned_u64 link_ids; 1547 __aligned_u64 link_attach_flags; 1548 __u64 revision; 1549 } query; 1550 1551 struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ 1552 __u64 name; 1553 __u32 prog_fd; 1554 } raw_tracepoint; 1555 1556 struct { /* anonymous struct for BPF_BTF_LOAD */ 1557 __aligned_u64 btf; 1558 __aligned_u64 btf_log_buf; 1559 __u32 btf_size; 1560 __u32 btf_log_size; 1561 __u32 btf_log_level; 1562 /* output: actual total log contents size (including termintaing zero). 1563 * It could be both larger than original log_size (if log was 1564 * truncated), or smaller (if log buffer wasn't filled completely). 1565 */ 1566 __u32 btf_log_true_size; 1567 }; 1568 1569 struct { 1570 __u32 pid; /* input: pid */ 1571 __u32 fd; /* input: fd */ 1572 __u32 flags; /* input: flags */ 1573 __u32 buf_len; /* input/output: buf len */ 1574 __aligned_u64 buf; /* input/output: 1575 * tp_name for tracepoint 1576 * symbol for kprobe 1577 * filename for uprobe 1578 */ 1579 __u32 prog_id; /* output: prod_id */ 1580 __u32 fd_type; /* output: BPF_FD_TYPE_* */ 1581 __u64 probe_offset; /* output: probe_offset */ 1582 __u64 probe_addr; /* output: probe_addr */ 1583 } task_fd_query; 1584 1585 struct { /* struct used by BPF_LINK_CREATE command */ 1586 union { 1587 __u32 prog_fd; /* eBPF program to attach */ 1588 __u32 map_fd; /* struct_ops to attach */ 1589 }; 1590 union { 1591 __u32 target_fd; /* target object to attach to or ... */ 1592 __u32 target_ifindex; /* target ifindex */ 1593 }; 1594 __u32 attach_type; /* attach type */ 1595 __u32 flags; /* extra flags */ 1596 union { 1597 __u32 target_btf_id; /* btf_id of target to attach to */ 1598 struct { 1599 __aligned_u64 iter_info; /* extra bpf_iter_link_info */ 1600 __u32 iter_info_len; /* iter_info length */ 1601 }; 1602 struct { 1603 /* black box user-provided value passed through 1604 * to BPF program at the execution time and 1605 * accessible through bpf_get_attach_cookie() BPF helper 1606 */ 1607 __u64 bpf_cookie; 1608 } perf_event; 1609 struct { 1610 __u32 flags; 1611 __u32 cnt; 1612 __aligned_u64 syms; 1613 __aligned_u64 addrs; 1614 __aligned_u64 cookies; 1615 } kprobe_multi; 1616 struct { 1617 /* this is overlaid with the target_btf_id above. */ 1618 __u32 target_btf_id; 1619 /* black box user-provided value passed through 1620 * to BPF program at the execution time and 1621 * accessible through bpf_get_attach_cookie() BPF helper 1622 */ 1623 __u64 cookie; 1624 } tracing; 1625 struct { 1626 __u32 pf; 1627 __u32 hooknum; 1628 __s32 priority; 1629 __u32 flags; 1630 } netfilter; 1631 struct { 1632 union { 1633 __u32 relative_fd; 1634 __u32 relative_id; 1635 }; 1636 __u64 expected_revision; 1637 } tcx; 1638 struct { 1639 __aligned_u64 path; 1640 __aligned_u64 offsets; 1641 __aligned_u64 ref_ctr_offsets; 1642 __aligned_u64 cookies; 1643 __u32 cnt; 1644 __u32 flags; 1645 __u32 pid; 1646 } uprobe_multi; 1647 }; 1648 } link_create; 1649 1650 struct { /* struct used by BPF_LINK_UPDATE command */ 1651 __u32 link_fd; /* link fd */ 1652 union { 1653 /* new program fd to update link with */ 1654 __u32 new_prog_fd; 1655 /* new struct_ops map fd to update link with */ 1656 __u32 new_map_fd; 1657 }; 1658 __u32 flags; /* extra flags */ 1659 union { 1660 /* expected link's program fd; is specified only if 1661 * BPF_F_REPLACE flag is set in flags. 1662 */ 1663 __u32 old_prog_fd; 1664 /* expected link's map fd; is specified only 1665 * if BPF_F_REPLACE flag is set. 1666 */ 1667 __u32 old_map_fd; 1668 }; 1669 } link_update; 1670 1671 struct { 1672 __u32 link_fd; 1673 } link_detach; 1674 1675 struct { /* struct used by BPF_ENABLE_STATS command */ 1676 __u32 type; 1677 } enable_stats; 1678 1679 struct { /* struct used by BPF_ITER_CREATE command */ 1680 __u32 link_fd; 1681 __u32 flags; 1682 } iter_create; 1683 1684 struct { /* struct used by BPF_PROG_BIND_MAP command */ 1685 __u32 prog_fd; 1686 __u32 map_fd; 1687 __u32 flags; /* extra flags */ 1688 } prog_bind_map; 1689 1690 } __attribute__((aligned(8))); 1691 1692 /* The description below is an attempt at providing documentation to eBPF 1693 * developers about the multiple available eBPF helper functions. It can be 1694 * parsed and used to produce a manual page. The workflow is the following, 1695 * and requires the rst2man utility: 1696 * 1697 * $ ./scripts/bpf_doc.py \ 1698 * --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst 1699 * $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7 1700 * $ man /tmp/bpf-helpers.7 1701 * 1702 * Note that in order to produce this external documentation, some RST 1703 * formatting is used in the descriptions to get "bold" and "italics" in 1704 * manual pages. Also note that the few trailing white spaces are 1705 * intentional, removing them would break paragraphs for rst2man. 1706 * 1707 * Start of BPF helper function descriptions: 1708 * 1709 * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key) 1710 * Description 1711 * Perform a lookup in *map* for an entry associated to *key*. 1712 * Return 1713 * Map value associated to *key*, or **NULL** if no entry was 1714 * found. 1715 * 1716 * long bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags) 1717 * Description 1718 * Add or update the value of the entry associated to *key* in 1719 * *map* with *value*. *flags* is one of: 1720 * 1721 * **BPF_NOEXIST** 1722 * The entry for *key* must not exist in the map. 1723 * **BPF_EXIST** 1724 * The entry for *key* must already exist in the map. 1725 * **BPF_ANY** 1726 * No condition on the existence of the entry for *key*. 1727 * 1728 * Flag value **BPF_NOEXIST** cannot be used for maps of types 1729 * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all 1730 * elements always exist), the helper would return an error. 1731 * Return 1732 * 0 on success, or a negative error in case of failure. 1733 * 1734 * long bpf_map_delete_elem(struct bpf_map *map, const void *key) 1735 * Description 1736 * Delete entry with *key* from *map*. 1737 * Return 1738 * 0 on success, or a negative error in case of failure. 1739 * 1740 * long bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr) 1741 * Description 1742 * For tracing programs, safely attempt to read *size* bytes from 1743 * kernel space address *unsafe_ptr* and store the data in *dst*. 1744 * 1745 * Generally, use **bpf_probe_read_user**\ () or 1746 * **bpf_probe_read_kernel**\ () instead. 1747 * Return 1748 * 0 on success, or a negative error in case of failure. 1749 * 1750 * u64 bpf_ktime_get_ns(void) 1751 * Description 1752 * Return the time elapsed since system boot, in nanoseconds. 1753 * Does not include time the system was suspended. 1754 * See: **clock_gettime**\ (**CLOCK_MONOTONIC**) 1755 * Return 1756 * Current *ktime*. 1757 * 1758 * long bpf_trace_printk(const char *fmt, u32 fmt_size, ...) 1759 * Description 1760 * This helper is a "printk()-like" facility for debugging. It 1761 * prints a message defined by format *fmt* (of size *fmt_size*) 1762 * to file *\/sys/kernel/tracing/trace* from TraceFS, if 1763 * available. It can take up to three additional **u64** 1764 * arguments (as an eBPF helpers, the total number of arguments is 1765 * limited to five). 1766 * 1767 * Each time the helper is called, it appends a line to the trace. 1768 * Lines are discarded while *\/sys/kernel/tracing/trace* is 1769 * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. 1770 * The format of the trace is customizable, and the exact output 1771 * one will get depends on the options set in 1772 * *\/sys/kernel/tracing/trace_options* (see also the 1773 * *README* file under the same directory). However, it usually 1774 * defaults to something like: 1775 * 1776 * :: 1777 * 1778 * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> 1779 * 1780 * In the above: 1781 * 1782 * * ``telnet`` is the name of the current task. 1783 * * ``470`` is the PID of the current task. 1784 * * ``001`` is the CPU number on which the task is 1785 * running. 1786 * * In ``.N..``, each character refers to a set of 1787 * options (whether irqs are enabled, scheduling 1788 * options, whether hard/softirqs are running, level of 1789 * preempt_disabled respectively). **N** means that 1790 * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED** 1791 * are set. 1792 * * ``419421.045894`` is a timestamp. 1793 * * ``0x00000001`` is a fake value used by BPF for the 1794 * instruction pointer register. 1795 * * ``<formatted msg>`` is the message formatted with 1796 * *fmt*. 1797 * 1798 * The conversion specifiers supported by *fmt* are similar, but 1799 * more limited than for printk(). They are **%d**, **%i**, 1800 * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**, 1801 * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size 1802 * of field, padding with zeroes, etc.) is available, and the 1803 * helper will return **-EINVAL** (but print nothing) if it 1804 * encounters an unknown specifier. 1805 * 1806 * Also, note that **bpf_trace_printk**\ () is slow, and should 1807 * only be used for debugging purposes. For this reason, a notice 1808 * block (spanning several lines) is printed to kernel logs and 1809 * states that the helper should not be used "for production use" 1810 * the first time this helper is used (or more precisely, when 1811 * **trace_printk**\ () buffers are allocated). For passing values 1812 * to user space, perf events should be preferred. 1813 * Return 1814 * The number of bytes written to the buffer, or a negative error 1815 * in case of failure. 1816 * 1817 * u32 bpf_get_prandom_u32(void) 1818 * Description 1819 * Get a pseudo-random number. 1820 * 1821 * From a security point of view, this helper uses its own 1822 * pseudo-random internal state, and cannot be used to infer the 1823 * seed of other random functions in the kernel. However, it is 1824 * essential to note that the generator used by the helper is not 1825 * cryptographically secure. 1826 * Return 1827 * A random 32-bit unsigned value. 1828 * 1829 * u32 bpf_get_smp_processor_id(void) 1830 * Description 1831 * Get the SMP (symmetric multiprocessing) processor id. Note that 1832 * all programs run with migration disabled, which means that the 1833 * SMP processor id is stable during all the execution of the 1834 * program. 1835 * Return 1836 * The SMP id of the processor running the program. 1837 * 1838 * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags) 1839 * Description 1840 * Store *len* bytes from address *from* into the packet 1841 * associated to *skb*, at *offset*. *flags* are a combination of 1842 * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the 1843 * checksum for the packet after storing the bytes) and 1844 * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\ 1845 * **->swhash** and *skb*\ **->l4hash** to 0). 1846 * 1847 * A call to this helper is susceptible to change the underlying 1848 * packet buffer. Therefore, at load time, all checks on pointers 1849 * previously done by the verifier are invalidated and must be 1850 * performed again, if the helper is used in combination with 1851 * direct packet access. 1852 * Return 1853 * 0 on success, or a negative error in case of failure. 1854 * 1855 * long bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size) 1856 * Description 1857 * Recompute the layer 3 (e.g. IP) checksum for the packet 1858 * associated to *skb*. Computation is incremental, so the helper 1859 * must know the former value of the header field that was 1860 * modified (*from*), the new value of this field (*to*), and the 1861 * number of bytes (2 or 4) for this field, stored in *size*. 1862 * Alternatively, it is possible to store the difference between 1863 * the previous and the new values of the header field in *to*, by 1864 * setting *from* and *size* to 0. For both methods, *offset* 1865 * indicates the location of the IP checksum within the packet. 1866 * 1867 * This helper works in combination with **bpf_csum_diff**\ (), 1868 * which does not update the checksum in-place, but offers more 1869 * flexibility and can handle sizes larger than 2 or 4 for the 1870 * checksum to update. 1871 * 1872 * A call to this helper is susceptible to change the underlying 1873 * packet buffer. Therefore, at load time, all checks on pointers 1874 * previously done by the verifier are invalidated and must be 1875 * performed again, if the helper is used in combination with 1876 * direct packet access. 1877 * Return 1878 * 0 on success, or a negative error in case of failure. 1879 * 1880 * long bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags) 1881 * Description 1882 * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the 1883 * packet associated to *skb*. Computation is incremental, so the 1884 * helper must know the former value of the header field that was 1885 * modified (*from*), the new value of this field (*to*), and the 1886 * number of bytes (2 or 4) for this field, stored on the lowest 1887 * four bits of *flags*. Alternatively, it is possible to store 1888 * the difference between the previous and the new values of the 1889 * header field in *to*, by setting *from* and the four lowest 1890 * bits of *flags* to 0. For both methods, *offset* indicates the 1891 * location of the IP checksum within the packet. In addition to 1892 * the size of the field, *flags* can be added (bitwise OR) actual 1893 * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left 1894 * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and 1895 * for updates resulting in a null checksum the value is set to 1896 * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates 1897 * the checksum is to be computed against a pseudo-header. 1898 * 1899 * This helper works in combination with **bpf_csum_diff**\ (), 1900 * which does not update the checksum in-place, but offers more 1901 * flexibility and can handle sizes larger than 2 or 4 for the 1902 * checksum to update. 1903 * 1904 * A call to this helper is susceptible to change the underlying 1905 * packet buffer. Therefore, at load time, all checks on pointers 1906 * previously done by the verifier are invalidated and must be 1907 * performed again, if the helper is used in combination with 1908 * direct packet access. 1909 * Return 1910 * 0 on success, or a negative error in case of failure. 1911 * 1912 * long bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index) 1913 * Description 1914 * This special helper is used to trigger a "tail call", or in 1915 * other words, to jump into another eBPF program. The same stack 1916 * frame is used (but values on stack and in registers for the 1917 * caller are not accessible to the callee). This mechanism allows 1918 * for program chaining, either for raising the maximum number of 1919 * available eBPF instructions, or to execute given programs in 1920 * conditional blocks. For security reasons, there is an upper 1921 * limit to the number of successive tail calls that can be 1922 * performed. 1923 * 1924 * Upon call of this helper, the program attempts to jump into a 1925 * program referenced at index *index* in *prog_array_map*, a 1926 * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes 1927 * *ctx*, a pointer to the context. 1928 * 1929 * If the call succeeds, the kernel immediately runs the first 1930 * instruction of the new program. This is not a function call, 1931 * and it never returns to the previous program. If the call 1932 * fails, then the helper has no effect, and the caller continues 1933 * to run its subsequent instructions. A call can fail if the 1934 * destination program for the jump does not exist (i.e. *index* 1935 * is superior to the number of entries in *prog_array_map*), or 1936 * if the maximum number of tail calls has been reached for this 1937 * chain of programs. This limit is defined in the kernel by the 1938 * macro **MAX_TAIL_CALL_CNT** (not accessible to user space), 1939 * which is currently set to 33. 1940 * Return 1941 * 0 on success, or a negative error in case of failure. 1942 * 1943 * long bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags) 1944 * Description 1945 * Clone and redirect the packet associated to *skb* to another 1946 * net device of index *ifindex*. Both ingress and egress 1947 * interfaces can be used for redirection. The **BPF_F_INGRESS** 1948 * value in *flags* is used to make the distinction (ingress path 1949 * is selected if the flag is present, egress path otherwise). 1950 * This is the only flag supported for now. 1951 * 1952 * In comparison with **bpf_redirect**\ () helper, 1953 * **bpf_clone_redirect**\ () has the associated cost of 1954 * duplicating the packet buffer, but this can be executed out of 1955 * the eBPF program. Conversely, **bpf_redirect**\ () is more 1956 * efficient, but it is handled through an action code where the 1957 * redirection happens only after the eBPF program has returned. 1958 * 1959 * A call to this helper is susceptible to change the underlying 1960 * packet buffer. Therefore, at load time, all checks on pointers 1961 * previously done by the verifier are invalidated and must be 1962 * performed again, if the helper is used in combination with 1963 * direct packet access. 1964 * Return 1965 * 0 on success, or a negative error in case of failure. Positive 1966 * error indicates a potential drop or congestion in the target 1967 * device. The particular positive error codes are not defined. 1968 * 1969 * u64 bpf_get_current_pid_tgid(void) 1970 * Description 1971 * Get the current pid and tgid. 1972 * Return 1973 * A 64-bit integer containing the current tgid and pid, and 1974 * created as such: 1975 * *current_task*\ **->tgid << 32 \|** 1976 * *current_task*\ **->pid**. 1977 * 1978 * u64 bpf_get_current_uid_gid(void) 1979 * Description 1980 * Get the current uid and gid. 1981 * Return 1982 * A 64-bit integer containing the current GID and UID, and 1983 * created as such: *current_gid* **<< 32 \|** *current_uid*. 1984 * 1985 * long bpf_get_current_comm(void *buf, u32 size_of_buf) 1986 * Description 1987 * Copy the **comm** attribute of the current task into *buf* of 1988 * *size_of_buf*. The **comm** attribute contains the name of 1989 * the executable (excluding the path) for the current task. The 1990 * *size_of_buf* must be strictly positive. On success, the 1991 * helper makes sure that the *buf* is NUL-terminated. On failure, 1992 * it is filled with zeroes. 1993 * Return 1994 * 0 on success, or a negative error in case of failure. 1995 * 1996 * u32 bpf_get_cgroup_classid(struct sk_buff *skb) 1997 * Description 1998 * Retrieve the classid for the current task, i.e. for the net_cls 1999 * cgroup to which *skb* belongs. 2000 * 2001 * This helper can be used on TC egress path, but not on ingress. 2002 * 2003 * The net_cls cgroup provides an interface to tag network packets 2004 * based on a user-provided identifier for all traffic coming from 2005 * the tasks belonging to the related cgroup. See also the related 2006 * kernel documentation, available from the Linux sources in file 2007 * *Documentation/admin-guide/cgroup-v1/net_cls.rst*. 2008 * 2009 * The Linux kernel has two versions for cgroups: there are 2010 * cgroups v1 and cgroups v2. Both are available to users, who can 2011 * use a mixture of them, but note that the net_cls cgroup is for 2012 * cgroup v1 only. This makes it incompatible with BPF programs 2013 * run on cgroups, which is a cgroup-v2-only feature (a socket can 2014 * only hold data for one version of cgroups at a time). 2015 * 2016 * This helper is only available is the kernel was compiled with 2017 * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to 2018 * "**y**" or to "**m**". 2019 * Return 2020 * The classid, or 0 for the default unconfigured classid. 2021 * 2022 * long bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) 2023 * Description 2024 * Push a *vlan_tci* (VLAN tag control information) of protocol 2025 * *vlan_proto* to the packet associated to *skb*, then update 2026 * the checksum. Note that if *vlan_proto* is different from 2027 * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to 2028 * be **ETH_P_8021Q**. 2029 * 2030 * A call to this helper is susceptible to change the underlying 2031 * packet buffer. Therefore, at load time, all checks on pointers 2032 * previously done by the verifier are invalidated and must be 2033 * performed again, if the helper is used in combination with 2034 * direct packet access. 2035 * Return 2036 * 0 on success, or a negative error in case of failure. 2037 * 2038 * long bpf_skb_vlan_pop(struct sk_buff *skb) 2039 * Description 2040 * Pop a VLAN header from the packet associated to *skb*. 2041 * 2042 * A call to this helper is susceptible to change the underlying 2043 * packet buffer. Therefore, at load time, all checks on pointers 2044 * previously done by the verifier are invalidated and must be 2045 * performed again, if the helper is used in combination with 2046 * direct packet access. 2047 * Return 2048 * 0 on success, or a negative error in case of failure. 2049 * 2050 * long bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) 2051 * Description 2052 * Get tunnel metadata. This helper takes a pointer *key* to an 2053 * empty **struct bpf_tunnel_key** of **size**, that will be 2054 * filled with tunnel metadata for the packet associated to *skb*. 2055 * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which 2056 * indicates that the tunnel is based on IPv6 protocol instead of 2057 * IPv4. 2058 * 2059 * The **struct bpf_tunnel_key** is an object that generalizes the 2060 * principal parameters used by various tunneling protocols into a 2061 * single struct. This way, it can be used to easily make a 2062 * decision based on the contents of the encapsulation header, 2063 * "summarized" in this struct. In particular, it holds the IP 2064 * address of the remote end (IPv4 or IPv6, depending on the case) 2065 * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also, 2066 * this struct exposes the *key*\ **->tunnel_id**, which is 2067 * generally mapped to a VNI (Virtual Network Identifier), making 2068 * it programmable together with the **bpf_skb_set_tunnel_key**\ 2069 * () helper. 2070 * 2071 * Let's imagine that the following code is part of a program 2072 * attached to the TC ingress interface, on one end of a GRE 2073 * tunnel, and is supposed to filter out all messages coming from 2074 * remote ends with IPv4 address other than 10.0.0.1: 2075 * 2076 * :: 2077 * 2078 * int ret; 2079 * struct bpf_tunnel_key key = {}; 2080 * 2081 * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0); 2082 * if (ret < 0) 2083 * return TC_ACT_SHOT; // drop packet 2084 * 2085 * if (key.remote_ipv4 != 0x0a000001) 2086 * return TC_ACT_SHOT; // drop packet 2087 * 2088 * return TC_ACT_OK; // accept packet 2089 * 2090 * This interface can also be used with all encapsulation devices 2091 * that can operate in "collect metadata" mode: instead of having 2092 * one network device per specific configuration, the "collect 2093 * metadata" mode only requires a single device where the 2094 * configuration can be extracted from this helper. 2095 * 2096 * This can be used together with various tunnels such as VXLan, 2097 * Geneve, GRE or IP in IP (IPIP). 2098 * Return 2099 * 0 on success, or a negative error in case of failure. 2100 * 2101 * long bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) 2102 * Description 2103 * Populate tunnel metadata for packet associated to *skb.* The 2104 * tunnel metadata is set to the contents of *key*, of *size*. The 2105 * *flags* can be set to a combination of the following values: 2106 * 2107 * **BPF_F_TUNINFO_IPV6** 2108 * Indicate that the tunnel is based on IPv6 protocol 2109 * instead of IPv4. 2110 * **BPF_F_ZERO_CSUM_TX** 2111 * For IPv4 packets, add a flag to tunnel metadata 2112 * indicating that checksum computation should be skipped 2113 * and checksum set to zeroes. 2114 * **BPF_F_DONT_FRAGMENT** 2115 * Add a flag to tunnel metadata indicating that the 2116 * packet should not be fragmented. 2117 * **BPF_F_SEQ_NUMBER** 2118 * Add a flag to tunnel metadata indicating that a 2119 * sequence number should be added to tunnel header before 2120 * sending the packet. This flag was added for GRE 2121 * encapsulation, but might be used with other protocols 2122 * as well in the future. 2123 * **BPF_F_NO_TUNNEL_KEY** 2124 * Add a flag to tunnel metadata indicating that no tunnel 2125 * key should be set in the resulting tunnel header. 2126 * 2127 * Here is a typical usage on the transmit path: 2128 * 2129 * :: 2130 * 2131 * struct bpf_tunnel_key key; 2132 * populate key ... 2133 * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0); 2134 * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); 2135 * 2136 * See also the description of the **bpf_skb_get_tunnel_key**\ () 2137 * helper for additional information. 2138 * Return 2139 * 0 on success, or a negative error in case of failure. 2140 * 2141 * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags) 2142 * Description 2143 * Read the value of a perf event counter. This helper relies on a 2144 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of 2145 * the perf event counter is selected when *map* is updated with 2146 * perf event file descriptors. The *map* is an array whose size 2147 * is the number of available CPUs, and each cell contains a value 2148 * relative to one CPU. The value to retrieve is indicated by 2149 * *flags*, that contains the index of the CPU to look up, masked 2150 * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to 2151 * **BPF_F_CURRENT_CPU** to indicate that the value for the 2152 * current CPU should be retrieved. 2153 * 2154 * Note that before Linux 4.13, only hardware perf event can be 2155 * retrieved. 2156 * 2157 * Also, be aware that the newer helper 2158 * **bpf_perf_event_read_value**\ () is recommended over 2159 * **bpf_perf_event_read**\ () in general. The latter has some ABI 2160 * quirks where error and counter value are used as a return code 2161 * (which is wrong to do since ranges may overlap). This issue is 2162 * fixed with **bpf_perf_event_read_value**\ (), which at the same 2163 * time provides more features over the **bpf_perf_event_read**\ 2164 * () interface. Please refer to the description of 2165 * **bpf_perf_event_read_value**\ () for details. 2166 * Return 2167 * The value of the perf event counter read from the map, or a 2168 * negative error code in case of failure. 2169 * 2170 * long bpf_redirect(u32 ifindex, u64 flags) 2171 * Description 2172 * Redirect the packet to another net device of index *ifindex*. 2173 * This helper is somewhat similar to **bpf_clone_redirect**\ 2174 * (), except that the packet is not cloned, which provides 2175 * increased performance. 2176 * 2177 * Except for XDP, both ingress and egress interfaces can be used 2178 * for redirection. The **BPF_F_INGRESS** value in *flags* is used 2179 * to make the distinction (ingress path is selected if the flag 2180 * is present, egress path otherwise). Currently, XDP only 2181 * supports redirection to the egress interface, and accepts no 2182 * flag at all. 2183 * 2184 * The same effect can also be attained with the more generic 2185 * **bpf_redirect_map**\ (), which uses a BPF map to store the 2186 * redirect target instead of providing it directly to the helper. 2187 * Return 2188 * For XDP, the helper returns **XDP_REDIRECT** on success or 2189 * **XDP_ABORTED** on error. For other program types, the values 2190 * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on 2191 * error. 2192 * 2193 * u32 bpf_get_route_realm(struct sk_buff *skb) 2194 * Description 2195 * Retrieve the realm or the route, that is to say the 2196 * **tclassid** field of the destination for the *skb*. The 2197 * identifier retrieved is a user-provided tag, similar to the 2198 * one used with the net_cls cgroup (see description for 2199 * **bpf_get_cgroup_classid**\ () helper), but here this tag is 2200 * held by a route (a destination entry), not by a task. 2201 * 2202 * Retrieving this identifier works with the clsact TC egress hook 2203 * (see also **tc-bpf(8)**), or alternatively on conventional 2204 * classful egress qdiscs, but not on TC ingress path. In case of 2205 * clsact TC egress hook, this has the advantage that, internally, 2206 * the destination entry has not been dropped yet in the transmit 2207 * path. Therefore, the destination entry does not need to be 2208 * artificially held via **netif_keep_dst**\ () for a classful 2209 * qdisc until the *skb* is freed. 2210 * 2211 * This helper is available only if the kernel was compiled with 2212 * **CONFIG_IP_ROUTE_CLASSID** configuration option. 2213 * Return 2214 * The realm of the route for the packet associated to *skb*, or 0 2215 * if none was found. 2216 * 2217 * long bpf_perf_event_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) 2218 * Description 2219 * Write raw *data* blob into a special BPF perf event held by 2220 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf 2221 * event must have the following attributes: **PERF_SAMPLE_RAW** 2222 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and 2223 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. 2224 * 2225 * The *flags* are used to indicate the index in *map* for which 2226 * the value must be put, masked with **BPF_F_INDEX_MASK**. 2227 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** 2228 * to indicate that the index of the current CPU core should be 2229 * used. 2230 * 2231 * The value to write, of *size*, is passed through eBPF stack and 2232 * pointed by *data*. 2233 * 2234 * The context of the program *ctx* needs also be passed to the 2235 * helper. 2236 * 2237 * On user space, a program willing to read the values needs to 2238 * call **perf_event_open**\ () on the perf event (either for 2239 * one or for all CPUs) and to store the file descriptor into the 2240 * *map*. This must be done before the eBPF program can send data 2241 * into it. An example is available in file 2242 * *samples/bpf/trace_output_user.c* in the Linux kernel source 2243 * tree (the eBPF program counterpart is in 2244 * *samples/bpf/trace_output_kern.c*). 2245 * 2246 * **bpf_perf_event_output**\ () achieves better performance 2247 * than **bpf_trace_printk**\ () for sharing data with user 2248 * space, and is much better suitable for streaming data from eBPF 2249 * programs. 2250 * 2251 * Note that this helper is not restricted to tracing use cases 2252 * and can be used with programs attached to TC or XDP as well, 2253 * where it allows for passing data to user space listeners. Data 2254 * can be: 2255 * 2256 * * Only custom structs, 2257 * * Only the packet payload, or 2258 * * A combination of both. 2259 * Return 2260 * 0 on success, or a negative error in case of failure. 2261 * 2262 * long bpf_skb_load_bytes(const void *skb, u32 offset, void *to, u32 len) 2263 * Description 2264 * This helper was provided as an easy way to load data from a 2265 * packet. It can be used to load *len* bytes from *offset* from 2266 * the packet associated to *skb*, into the buffer pointed by 2267 * *to*. 2268 * 2269 * Since Linux 4.7, usage of this helper has mostly been replaced 2270 * by "direct packet access", enabling packet data to be 2271 * manipulated with *skb*\ **->data** and *skb*\ **->data_end** 2272 * pointing respectively to the first byte of packet data and to 2273 * the byte after the last byte of packet data. However, it 2274 * remains useful if one wishes to read large quantities of data 2275 * at once from a packet into the eBPF stack. 2276 * Return 2277 * 0 on success, or a negative error in case of failure. 2278 * 2279 * long bpf_get_stackid(void *ctx, struct bpf_map *map, u64 flags) 2280 * Description 2281 * Walk a user or a kernel stack and return its id. To achieve 2282 * this, the helper needs *ctx*, which is a pointer to the context 2283 * on which the tracing program is executed, and a pointer to a 2284 * *map* of type **BPF_MAP_TYPE_STACK_TRACE**. 2285 * 2286 * The last argument, *flags*, holds the number of stack frames to 2287 * skip (from 0 to 255), masked with 2288 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set 2289 * a combination of the following flags: 2290 * 2291 * **BPF_F_USER_STACK** 2292 * Collect a user space stack instead of a kernel stack. 2293 * **BPF_F_FAST_STACK_CMP** 2294 * Compare stacks by hash only. 2295 * **BPF_F_REUSE_STACKID** 2296 * If two different stacks hash into the same *stackid*, 2297 * discard the old one. 2298 * 2299 * The stack id retrieved is a 32 bit long integer handle which 2300 * can be further combined with other data (including other stack 2301 * ids) and used as a key into maps. This can be useful for 2302 * generating a variety of graphs (such as flame graphs or off-cpu 2303 * graphs). 2304 * 2305 * For walking a stack, this helper is an improvement over 2306 * **bpf_probe_read**\ (), which can be used with unrolled loops 2307 * but is not efficient and consumes a lot of eBPF instructions. 2308 * Instead, **bpf_get_stackid**\ () can collect up to 2309 * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that 2310 * this limit can be controlled with the **sysctl** program, and 2311 * that it should be manually increased in order to profile long 2312 * user stacks (such as stacks for Java programs). To do so, use: 2313 * 2314 * :: 2315 * 2316 * # sysctl kernel.perf_event_max_stack=<new value> 2317 * Return 2318 * The positive or null stack id on success, or a negative error 2319 * in case of failure. 2320 * 2321 * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed) 2322 * Description 2323 * Compute a checksum difference, from the raw buffer pointed by 2324 * *from*, of length *from_size* (that must be a multiple of 4), 2325 * towards the raw buffer pointed by *to*, of size *to_size* 2326 * (same remark). An optional *seed* can be added to the value 2327 * (this can be cascaded, the seed may come from a previous call 2328 * to the helper). 2329 * 2330 * This is flexible enough to be used in several ways: 2331 * 2332 * * With *from_size* == 0, *to_size* > 0 and *seed* set to 2333 * checksum, it can be used when pushing new data. 2334 * * With *from_size* > 0, *to_size* == 0 and *seed* set to 2335 * checksum, it can be used when removing data from a packet. 2336 * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it 2337 * can be used to compute a diff. Note that *from_size* and 2338 * *to_size* do not need to be equal. 2339 * 2340 * This helper can be used in combination with 2341 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to 2342 * which one can feed in the difference computed with 2343 * **bpf_csum_diff**\ (). 2344 * Return 2345 * The checksum result, or a negative error code in case of 2346 * failure. 2347 * 2348 * long bpf_skb_get_tunnel_opt(struct sk_buff *skb, void *opt, u32 size) 2349 * Description 2350 * Retrieve tunnel options metadata for the packet associated to 2351 * *skb*, and store the raw tunnel option data to the buffer *opt* 2352 * of *size*. 2353 * 2354 * This helper can be used with encapsulation devices that can 2355 * operate in "collect metadata" mode (please refer to the related 2356 * note in the description of **bpf_skb_get_tunnel_key**\ () for 2357 * more details). A particular example where this can be used is 2358 * in combination with the Geneve encapsulation protocol, where it 2359 * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper) 2360 * and retrieving arbitrary TLVs (Type-Length-Value headers) from 2361 * the eBPF program. This allows for full customization of these 2362 * headers. 2363 * Return 2364 * The size of the option data retrieved. 2365 * 2366 * long bpf_skb_set_tunnel_opt(struct sk_buff *skb, void *opt, u32 size) 2367 * Description 2368 * Set tunnel options metadata for the packet associated to *skb* 2369 * to the option data contained in the raw buffer *opt* of *size*. 2370 * 2371 * See also the description of the **bpf_skb_get_tunnel_opt**\ () 2372 * helper for additional information. 2373 * Return 2374 * 0 on success, or a negative error in case of failure. 2375 * 2376 * long bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags) 2377 * Description 2378 * Change the protocol of the *skb* to *proto*. Currently 2379 * supported are transition from IPv4 to IPv6, and from IPv6 to 2380 * IPv4. The helper takes care of the groundwork for the 2381 * transition, including resizing the socket buffer. The eBPF 2382 * program is expected to fill the new headers, if any, via 2383 * **skb_store_bytes**\ () and to recompute the checksums with 2384 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ 2385 * (). The main case for this helper is to perform NAT64 2386 * operations out of an eBPF program. 2387 * 2388 * Internally, the GSO type is marked as dodgy so that headers are 2389 * checked and segments are recalculated by the GSO/GRO engine. 2390 * The size for GSO target is adapted as well. 2391 * 2392 * All values for *flags* are reserved for future usage, and must 2393 * be left at zero. 2394 * 2395 * A call to this helper is susceptible to change the underlying 2396 * packet buffer. Therefore, at load time, all checks on pointers 2397 * previously done by the verifier are invalidated and must be 2398 * performed again, if the helper is used in combination with 2399 * direct packet access. 2400 * Return 2401 * 0 on success, or a negative error in case of failure. 2402 * 2403 * long bpf_skb_change_type(struct sk_buff *skb, u32 type) 2404 * Description 2405 * Change the packet type for the packet associated to *skb*. This 2406 * comes down to setting *skb*\ **->pkt_type** to *type*, except 2407 * the eBPF program does not have a write access to *skb*\ 2408 * **->pkt_type** beside this helper. Using a helper here allows 2409 * for graceful handling of errors. 2410 * 2411 * The major use case is to change incoming *skb*s to 2412 * **PACKET_HOST** in a programmatic way instead of having to 2413 * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for 2414 * example. 2415 * 2416 * Note that *type* only allows certain values. At this time, they 2417 * are: 2418 * 2419 * **PACKET_HOST** 2420 * Packet is for us. 2421 * **PACKET_BROADCAST** 2422 * Send packet to all. 2423 * **PACKET_MULTICAST** 2424 * Send packet to group. 2425 * **PACKET_OTHERHOST** 2426 * Send packet to someone else. 2427 * Return 2428 * 0 on success, or a negative error in case of failure. 2429 * 2430 * long bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index) 2431 * Description 2432 * Check whether *skb* is a descendant of the cgroup2 held by 2433 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. 2434 * Return 2435 * The return value depends on the result of the test, and can be: 2436 * 2437 * * 0, if the *skb* failed the cgroup2 descendant test. 2438 * * 1, if the *skb* succeeded the cgroup2 descendant test. 2439 * * A negative error code, if an error occurred. 2440 * 2441 * u32 bpf_get_hash_recalc(struct sk_buff *skb) 2442 * Description 2443 * Retrieve the hash of the packet, *skb*\ **->hash**. If it is 2444 * not set, in particular if the hash was cleared due to mangling, 2445 * recompute this hash. Later accesses to the hash can be done 2446 * directly with *skb*\ **->hash**. 2447 * 2448 * Calling **bpf_set_hash_invalid**\ (), changing a packet 2449 * prototype with **bpf_skb_change_proto**\ (), or calling 2450 * **bpf_skb_store_bytes**\ () with the 2451 * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear 2452 * the hash and to trigger a new computation for the next call to 2453 * **bpf_get_hash_recalc**\ (). 2454 * Return 2455 * The 32-bit hash. 2456 * 2457 * u64 bpf_get_current_task(void) 2458 * Description 2459 * Get the current task. 2460 * Return 2461 * A pointer to the current task struct. 2462 * 2463 * long bpf_probe_write_user(void *dst, const void *src, u32 len) 2464 * Description 2465 * Attempt in a safe way to write *len* bytes from the buffer 2466 * *src* to *dst* in memory. It only works for threads that are in 2467 * user context, and *dst* must be a valid user space address. 2468 * 2469 * This helper should not be used to implement any kind of 2470 * security mechanism because of TOC-TOU attacks, but rather to 2471 * debug, divert, and manipulate execution of semi-cooperative 2472 * processes. 2473 * 2474 * Keep in mind that this feature is meant for experiments, and it 2475 * has a risk of crashing the system and running programs. 2476 * Therefore, when an eBPF program using this helper is attached, 2477 * a warning including PID and process name is printed to kernel 2478 * logs. 2479 * Return 2480 * 0 on success, or a negative error in case of failure. 2481 * 2482 * long bpf_current_task_under_cgroup(struct bpf_map *map, u32 index) 2483 * Description 2484 * Check whether the probe is being run is the context of a given 2485 * subset of the cgroup2 hierarchy. The cgroup2 to test is held by 2486 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. 2487 * Return 2488 * The return value depends on the result of the test, and can be: 2489 * 2490 * * 1, if current task belongs to the cgroup2. 2491 * * 0, if current task does not belong to the cgroup2. 2492 * * A negative error code, if an error occurred. 2493 * 2494 * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags) 2495 * Description 2496 * Resize (trim or grow) the packet associated to *skb* to the 2497 * new *len*. The *flags* are reserved for future usage, and must 2498 * be left at zero. 2499 * 2500 * The basic idea is that the helper performs the needed work to 2501 * change the size of the packet, then the eBPF program rewrites 2502 * the rest via helpers like **bpf_skb_store_bytes**\ (), 2503 * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ () 2504 * and others. This helper is a slow path utility intended for 2505 * replies with control messages. And because it is targeted for 2506 * slow path, the helper itself can afford to be slow: it 2507 * implicitly linearizes, unclones and drops offloads from the 2508 * *skb*. 2509 * 2510 * A call to this helper is susceptible to change the underlying 2511 * packet buffer. Therefore, at load time, all checks on pointers 2512 * previously done by the verifier are invalidated and must be 2513 * performed again, if the helper is used in combination with 2514 * direct packet access. 2515 * Return 2516 * 0 on success, or a negative error in case of failure. 2517 * 2518 * long bpf_skb_pull_data(struct sk_buff *skb, u32 len) 2519 * Description 2520 * Pull in non-linear data in case the *skb* is non-linear and not 2521 * all of *len* are part of the linear section. Make *len* bytes 2522 * from *skb* readable and writable. If a zero value is passed for 2523 * *len*, then all bytes in the linear part of *skb* will be made 2524 * readable and writable. 2525 * 2526 * This helper is only needed for reading and writing with direct 2527 * packet access. 2528 * 2529 * For direct packet access, testing that offsets to access 2530 * are within packet boundaries (test on *skb*\ **->data_end**) is 2531 * susceptible to fail if offsets are invalid, or if the requested 2532 * data is in non-linear parts of the *skb*. On failure the 2533 * program can just bail out, or in the case of a non-linear 2534 * buffer, use a helper to make the data available. The 2535 * **bpf_skb_load_bytes**\ () helper is a first solution to access 2536 * the data. Another one consists in using **bpf_skb_pull_data** 2537 * to pull in once the non-linear parts, then retesting and 2538 * eventually access the data. 2539 * 2540 * At the same time, this also makes sure the *skb* is uncloned, 2541 * which is a necessary condition for direct write. As this needs 2542 * to be an invariant for the write part only, the verifier 2543 * detects writes and adds a prologue that is calling 2544 * **bpf_skb_pull_data()** to effectively unclone the *skb* from 2545 * the very beginning in case it is indeed cloned. 2546 * 2547 * A call to this helper is susceptible to change the underlying 2548 * packet buffer. Therefore, at load time, all checks on pointers 2549 * previously done by the verifier are invalidated and must be 2550 * performed again, if the helper is used in combination with 2551 * direct packet access. 2552 * Return 2553 * 0 on success, or a negative error in case of failure. 2554 * 2555 * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum) 2556 * Description 2557 * Add the checksum *csum* into *skb*\ **->csum** in case the 2558 * driver has supplied a checksum for the entire packet into that 2559 * field. Return an error otherwise. This helper is intended to be 2560 * used in combination with **bpf_csum_diff**\ (), in particular 2561 * when the checksum needs to be updated after data has been 2562 * written into the packet through direct packet access. 2563 * Return 2564 * The checksum on success, or a negative error code in case of 2565 * failure. 2566 * 2567 * void bpf_set_hash_invalid(struct sk_buff *skb) 2568 * Description 2569 * Invalidate the current *skb*\ **->hash**. It can be used after 2570 * mangling on headers through direct packet access, in order to 2571 * indicate that the hash is outdated and to trigger a 2572 * recalculation the next time the kernel tries to access this 2573 * hash or when the **bpf_get_hash_recalc**\ () helper is called. 2574 * Return 2575 * void. 2576 * 2577 * long bpf_get_numa_node_id(void) 2578 * Description 2579 * Return the id of the current NUMA node. The primary use case 2580 * for this helper is the selection of sockets for the local NUMA 2581 * node, when the program is attached to sockets using the 2582 * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**), 2583 * but the helper is also available to other eBPF program types, 2584 * similarly to **bpf_get_smp_processor_id**\ (). 2585 * Return 2586 * The id of current NUMA node. 2587 * 2588 * long bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags) 2589 * Description 2590 * Grows headroom of packet associated to *skb* and adjusts the 2591 * offset of the MAC header accordingly, adding *len* bytes of 2592 * space. It automatically extends and reallocates memory as 2593 * required. 2594 * 2595 * This helper can be used on a layer 3 *skb* to push a MAC header 2596 * for redirection into a layer 2 device. 2597 * 2598 * All values for *flags* are reserved for future usage, and must 2599 * be left at zero. 2600 * 2601 * A call to this helper is susceptible to change the underlying 2602 * packet buffer. Therefore, at load time, all checks on pointers 2603 * previously done by the verifier are invalidated and must be 2604 * performed again, if the helper is used in combination with 2605 * direct packet access. 2606 * Return 2607 * 0 on success, or a negative error in case of failure. 2608 * 2609 * long bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta) 2610 * Description 2611 * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that 2612 * it is possible to use a negative value for *delta*. This helper 2613 * can be used to prepare the packet for pushing or popping 2614 * headers. 2615 * 2616 * A call to this helper is susceptible to change the underlying 2617 * packet buffer. Therefore, at load time, all checks on pointers 2618 * previously done by the verifier are invalidated and must be 2619 * performed again, if the helper is used in combination with 2620 * direct packet access. 2621 * Return 2622 * 0 on success, or a negative error in case of failure. 2623 * 2624 * long bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr) 2625 * Description 2626 * Copy a NUL terminated string from an unsafe kernel address 2627 * *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for 2628 * more details. 2629 * 2630 * Generally, use **bpf_probe_read_user_str**\ () or 2631 * **bpf_probe_read_kernel_str**\ () instead. 2632 * Return 2633 * On success, the strictly positive length of the string, 2634 * including the trailing NUL character. On error, a negative 2635 * value. 2636 * 2637 * u64 bpf_get_socket_cookie(struct sk_buff *skb) 2638 * Description 2639 * If the **struct sk_buff** pointed by *skb* has a known socket, 2640 * retrieve the cookie (generated by the kernel) of this socket. 2641 * If no cookie has been set yet, generate a new cookie. Once 2642 * generated, the socket cookie remains stable for the life of the 2643 * socket. This helper can be useful for monitoring per socket 2644 * networking traffic statistics as it provides a global socket 2645 * identifier that can be assumed unique. 2646 * Return 2647 * A 8-byte long unique number on success, or 0 if the socket 2648 * field is missing inside *skb*. 2649 * 2650 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx) 2651 * Description 2652 * Equivalent to bpf_get_socket_cookie() helper that accepts 2653 * *skb*, but gets socket from **struct bpf_sock_addr** context. 2654 * Return 2655 * A 8-byte long unique number. 2656 * 2657 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx) 2658 * Description 2659 * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts 2660 * *skb*, but gets socket from **struct bpf_sock_ops** context. 2661 * Return 2662 * A 8-byte long unique number. 2663 * 2664 * u64 bpf_get_socket_cookie(struct sock *sk) 2665 * Description 2666 * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts 2667 * *sk*, but gets socket from a BTF **struct sock**. This helper 2668 * also works for sleepable programs. 2669 * Return 2670 * A 8-byte long unique number or 0 if *sk* is NULL. 2671 * 2672 * u32 bpf_get_socket_uid(struct sk_buff *skb) 2673 * Description 2674 * Get the owner UID of the socked associated to *skb*. 2675 * Return 2676 * The owner UID of the socket associated to *skb*. If the socket 2677 * is **NULL**, or if it is not a full socket (i.e. if it is a 2678 * time-wait or a request socket instead), **overflowuid** value 2679 * is returned (note that **overflowuid** might also be the actual 2680 * UID value for the socket). 2681 * 2682 * long bpf_set_hash(struct sk_buff *skb, u32 hash) 2683 * Description 2684 * Set the full hash for *skb* (set the field *skb*\ **->hash**) 2685 * to value *hash*. 2686 * Return 2687 * 0 2688 * 2689 * long bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) 2690 * Description 2691 * Emulate a call to **setsockopt()** on the socket associated to 2692 * *bpf_socket*, which must be a full socket. The *level* at 2693 * which the option resides and the name *optname* of the option 2694 * must be specified, see **setsockopt(2)** for more information. 2695 * The option value of length *optlen* is pointed by *optval*. 2696 * 2697 * *bpf_socket* should be one of the following: 2698 * 2699 * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. 2700 * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** 2701 * and **BPF_CGROUP_INET6_CONNECT**. 2702 * 2703 * This helper actually implements a subset of **setsockopt()**. 2704 * It supports the following *level*\ s: 2705 * 2706 * * **SOL_SOCKET**, which supports the following *optname*\ s: 2707 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, 2708 * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**, 2709 * **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**, 2710 * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**. 2711 * * **IPPROTO_TCP**, which supports the following *optname*\ s: 2712 * **TCP_CONGESTION**, **TCP_BPF_IW**, 2713 * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, 2714 * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**, 2715 * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**, 2716 * **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**, 2717 * **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**, 2718 * **TCP_BPF_RTO_MIN**. 2719 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. 2720 * * **IPPROTO_IPV6**, which supports the following *optname*\ s: 2721 * **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**. 2722 * Return 2723 * 0 on success, or a negative error in case of failure. 2724 * 2725 * long bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags) 2726 * Description 2727 * Grow or shrink the room for data in the packet associated to 2728 * *skb* by *len_diff*, and according to the selected *mode*. 2729 * 2730 * By default, the helper will reset any offloaded checksum 2731 * indicator of the skb to CHECKSUM_NONE. This can be avoided 2732 * by the following flag: 2733 * 2734 * * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded 2735 * checksum data of the skb to CHECKSUM_NONE. 2736 * 2737 * There are two supported modes at this time: 2738 * 2739 * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer 2740 * (room space is added or removed between the layer 2 and 2741 * layer 3 headers). 2742 * 2743 * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer 2744 * (room space is added or removed between the layer 3 and 2745 * layer 4 headers). 2746 * 2747 * The following flags are supported at this time: 2748 * 2749 * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size. 2750 * Adjusting mss in this way is not allowed for datagrams. 2751 * 2752 * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**, 2753 * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**: 2754 * Any new space is reserved to hold a tunnel header. 2755 * Configure skb offsets and other fields accordingly. 2756 * 2757 * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**, 2758 * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**: 2759 * Use with ENCAP_L3 flags to further specify the tunnel type. 2760 * 2761 * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*): 2762 * Use with ENCAP_L3/L4 flags to further specify the tunnel 2763 * type; *len* is the length of the inner MAC header. 2764 * 2765 * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**: 2766 * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the 2767 * L2 type as Ethernet. 2768 * 2769 * * **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**, 2770 * **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**: 2771 * Indicate the new IP header version after decapsulating the outer 2772 * IP header. Used when the inner and outer IP versions are different. 2773 * 2774 * A call to this helper is susceptible to change the underlying 2775 * packet buffer. Therefore, at load time, all checks on pointers 2776 * previously done by the verifier are invalidated and must be 2777 * performed again, if the helper is used in combination with 2778 * direct packet access. 2779 * Return 2780 * 0 on success, or a negative error in case of failure. 2781 * 2782 * long bpf_redirect_map(struct bpf_map *map, u64 key, u64 flags) 2783 * Description 2784 * Redirect the packet to the endpoint referenced by *map* at 2785 * index *key*. Depending on its type, this *map* can contain 2786 * references to net devices (for forwarding packets through other 2787 * ports), or to CPUs (for redirecting XDP frames to another CPU; 2788 * but this is only implemented for native XDP (with driver 2789 * support) as of this writing). 2790 * 2791 * The lower two bits of *flags* are used as the return code if 2792 * the map lookup fails. This is so that the return value can be 2793 * one of the XDP program return codes up to **XDP_TX**, as chosen 2794 * by the caller. The higher bits of *flags* can be set to 2795 * BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below. 2796 * 2797 * With BPF_F_BROADCAST the packet will be broadcasted to all the 2798 * interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress 2799 * interface will be excluded when do broadcasting. 2800 * 2801 * See also **bpf_redirect**\ (), which only supports redirecting 2802 * to an ifindex, but doesn't require a map to do so. 2803 * Return 2804 * **XDP_REDIRECT** on success, or the value of the two lower bits 2805 * of the *flags* argument on error. 2806 * 2807 * long bpf_sk_redirect_map(struct sk_buff *skb, struct bpf_map *map, u32 key, u64 flags) 2808 * Description 2809 * Redirect the packet to the socket referenced by *map* (of type 2810 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and 2811 * egress interfaces can be used for redirection. The 2812 * **BPF_F_INGRESS** value in *flags* is used to make the 2813 * distinction (ingress path is selected if the flag is present, 2814 * egress path otherwise). This is the only flag supported for now. 2815 * Return 2816 * **SK_PASS** on success, or **SK_DROP** on error. 2817 * 2818 * long bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) 2819 * Description 2820 * Add an entry to, or update a *map* referencing sockets. The 2821 * *skops* is used as a new value for the entry associated to 2822 * *key*. *flags* is one of: 2823 * 2824 * **BPF_NOEXIST** 2825 * The entry for *key* must not exist in the map. 2826 * **BPF_EXIST** 2827 * The entry for *key* must already exist in the map. 2828 * **BPF_ANY** 2829 * No condition on the existence of the entry for *key*. 2830 * 2831 * If the *map* has eBPF programs (parser and verdict), those will 2832 * be inherited by the socket being added. If the socket is 2833 * already attached to eBPF programs, this results in an error. 2834 * Return 2835 * 0 on success, or a negative error in case of failure. 2836 * 2837 * long bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta) 2838 * Description 2839 * Adjust the address pointed by *xdp_md*\ **->data_meta** by 2840 * *delta* (which can be positive or negative). Note that this 2841 * operation modifies the address stored in *xdp_md*\ **->data**, 2842 * so the latter must be loaded only after the helper has been 2843 * called. 2844 * 2845 * The use of *xdp_md*\ **->data_meta** is optional and programs 2846 * are not required to use it. The rationale is that when the 2847 * packet is processed with XDP (e.g. as DoS filter), it is 2848 * possible to push further meta data along with it before passing 2849 * to the stack, and to give the guarantee that an ingress eBPF 2850 * program attached as a TC classifier on the same device can pick 2851 * this up for further post-processing. Since TC works with socket 2852 * buffers, it remains possible to set from XDP the **mark** or 2853 * **priority** pointers, or other pointers for the socket buffer. 2854 * Having this scratch space generic and programmable allows for 2855 * more flexibility as the user is free to store whatever meta 2856 * data they need. 2857 * 2858 * A call to this helper is susceptible to change the underlying 2859 * packet buffer. Therefore, at load time, all checks on pointers 2860 * previously done by the verifier are invalidated and must be 2861 * performed again, if the helper is used in combination with 2862 * direct packet access. 2863 * Return 2864 * 0 on success, or a negative error in case of failure. 2865 * 2866 * long bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size) 2867 * Description 2868 * Read the value of a perf event counter, and store it into *buf* 2869 * of size *buf_size*. This helper relies on a *map* of type 2870 * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event 2871 * counter is selected when *map* is updated with perf event file 2872 * descriptors. The *map* is an array whose size is the number of 2873 * available CPUs, and each cell contains a value relative to one 2874 * CPU. The value to retrieve is indicated by *flags*, that 2875 * contains the index of the CPU to look up, masked with 2876 * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to 2877 * **BPF_F_CURRENT_CPU** to indicate that the value for the 2878 * current CPU should be retrieved. 2879 * 2880 * This helper behaves in a way close to 2881 * **bpf_perf_event_read**\ () helper, save that instead of 2882 * just returning the value observed, it fills the *buf* 2883 * structure. This allows for additional data to be retrieved: in 2884 * particular, the enabled and running times (in *buf*\ 2885 * **->enabled** and *buf*\ **->running**, respectively) are 2886 * copied. In general, **bpf_perf_event_read_value**\ () is 2887 * recommended over **bpf_perf_event_read**\ (), which has some 2888 * ABI issues and provides fewer functionalities. 2889 * 2890 * These values are interesting, because hardware PMU (Performance 2891 * Monitoring Unit) counters are limited resources. When there are 2892 * more PMU based perf events opened than available counters, 2893 * kernel will multiplex these events so each event gets certain 2894 * percentage (but not all) of the PMU time. In case that 2895 * multiplexing happens, the number of samples or counter value 2896 * will not reflect the case compared to when no multiplexing 2897 * occurs. This makes comparison between different runs difficult. 2898 * Typically, the counter value should be normalized before 2899 * comparing to other experiments. The usual normalization is done 2900 * as follows. 2901 * 2902 * :: 2903 * 2904 * normalized_counter = counter * t_enabled / t_running 2905 * 2906 * Where t_enabled is the time enabled for event and t_running is 2907 * the time running for event since last normalization. The 2908 * enabled and running times are accumulated since the perf event 2909 * open. To achieve scaling factor between two invocations of an 2910 * eBPF program, users can use CPU id as the key (which is 2911 * typical for perf array usage model) to remember the previous 2912 * value and do the calculation inside the eBPF program. 2913 * Return 2914 * 0 on success, or a negative error in case of failure. 2915 * 2916 * long bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size) 2917 * Description 2918 * For an eBPF program attached to a perf event, retrieve the 2919 * value of the event counter associated to *ctx* and store it in 2920 * the structure pointed by *buf* and of size *buf_size*. Enabled 2921 * and running times are also stored in the structure (see 2922 * description of helper **bpf_perf_event_read_value**\ () for 2923 * more details). 2924 * Return 2925 * 0 on success, or a negative error in case of failure. 2926 * 2927 * long bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) 2928 * Description 2929 * Emulate a call to **getsockopt()** on the socket associated to 2930 * *bpf_socket*, which must be a full socket. The *level* at 2931 * which the option resides and the name *optname* of the option 2932 * must be specified, see **getsockopt(2)** for more information. 2933 * The retrieved value is stored in the structure pointed by 2934 * *opval* and of length *optlen*. 2935 * 2936 * *bpf_socket* should be one of the following: 2937 * 2938 * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. 2939 * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** 2940 * and **BPF_CGROUP_INET6_CONNECT**. 2941 * 2942 * This helper actually implements a subset of **getsockopt()**. 2943 * It supports the same set of *optname*\ s that is supported by 2944 * the **bpf_setsockopt**\ () helper. The exceptions are 2945 * **TCP_BPF_*** is **bpf_setsockopt**\ () only and 2946 * **TCP_SAVED_SYN** is **bpf_getsockopt**\ () only. 2947 * Return 2948 * 0 on success, or a negative error in case of failure. 2949 * 2950 * long bpf_override_return(struct pt_regs *regs, u64 rc) 2951 * Description 2952 * Used for error injection, this helper uses kprobes to override 2953 * the return value of the probed function, and to set it to *rc*. 2954 * The first argument is the context *regs* on which the kprobe 2955 * works. 2956 * 2957 * This helper works by setting the PC (program counter) 2958 * to an override function which is run in place of the original 2959 * probed function. This means the probed function is not run at 2960 * all. The replacement function just returns with the required 2961 * value. 2962 * 2963 * This helper has security implications, and thus is subject to 2964 * restrictions. It is only available if the kernel was compiled 2965 * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration 2966 * option, and in this case it only works on functions tagged with 2967 * **ALLOW_ERROR_INJECTION** in the kernel code. 2968 * 2969 * Also, the helper is only available for the architectures having 2970 * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing, 2971 * x86 architecture is the only one to support this feature. 2972 * Return 2973 * 0 2974 * 2975 * long bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval) 2976 * Description 2977 * Attempt to set the value of the **bpf_sock_ops_cb_flags** field 2978 * for the full TCP socket associated to *bpf_sock_ops* to 2979 * *argval*. 2980 * 2981 * The primary use of this field is to determine if there should 2982 * be calls to eBPF programs of type 2983 * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP 2984 * code. A program of the same type can change its value, per 2985 * connection and as necessary, when the connection is 2986 * established. This field is directly accessible for reading, but 2987 * this helper must be used for updates in order to return an 2988 * error if an eBPF program tries to set a callback that is not 2989 * supported in the current kernel. 2990 * 2991 * *argval* is a flag array which can combine these flags: 2992 * 2993 * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out) 2994 * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission) 2995 * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change) 2996 * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT) 2997 * 2998 * Therefore, this function can be used to clear a callback flag by 2999 * setting the appropriate bit to zero. e.g. to disable the RTO 3000 * callback: 3001 * 3002 * **bpf_sock_ops_cb_flags_set(bpf_sock,** 3003 * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)** 3004 * 3005 * Here are some examples of where one could call such eBPF 3006 * program: 3007 * 3008 * * When RTO fires. 3009 * * When a packet is retransmitted. 3010 * * When the connection terminates. 3011 * * When a packet is sent. 3012 * * When a packet is received. 3013 * Return 3014 * Code **-EINVAL** if the socket is not a full TCP socket; 3015 * otherwise, a positive number containing the bits that could not 3016 * be set is returned (which comes down to 0 if all bits were set 3017 * as required). 3018 * 3019 * long bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags) 3020 * Description 3021 * This helper is used in programs implementing policies at the 3022 * socket level. If the message *msg* is allowed to pass (i.e. if 3023 * the verdict eBPF program returns **SK_PASS**), redirect it to 3024 * the socket referenced by *map* (of type 3025 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and 3026 * egress interfaces can be used for redirection. The 3027 * **BPF_F_INGRESS** value in *flags* is used to make the 3028 * distinction (ingress path is selected if the flag is present, 3029 * egress path otherwise). This is the only flag supported for now. 3030 * Return 3031 * **SK_PASS** on success, or **SK_DROP** on error. 3032 * 3033 * long bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes) 3034 * Description 3035 * For socket policies, apply the verdict of the eBPF program to 3036 * the next *bytes* (number of bytes) of message *msg*. 3037 * 3038 * For example, this helper can be used in the following cases: 3039 * 3040 * * A single **sendmsg**\ () or **sendfile**\ () system call 3041 * contains multiple logical messages that the eBPF program is 3042 * supposed to read and for which it should apply a verdict. 3043 * * An eBPF program only cares to read the first *bytes* of a 3044 * *msg*. If the message has a large payload, then setting up 3045 * and calling the eBPF program repeatedly for all bytes, even 3046 * though the verdict is already known, would create unnecessary 3047 * overhead. 3048 * 3049 * When called from within an eBPF program, the helper sets a 3050 * counter internal to the BPF infrastructure, that is used to 3051 * apply the last verdict to the next *bytes*. If *bytes* is 3052 * smaller than the current data being processed from a 3053 * **sendmsg**\ () or **sendfile**\ () system call, the first 3054 * *bytes* will be sent and the eBPF program will be re-run with 3055 * the pointer for start of data pointing to byte number *bytes* 3056 * **+ 1**. If *bytes* is larger than the current data being 3057 * processed, then the eBPF verdict will be applied to multiple 3058 * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are 3059 * consumed. 3060 * 3061 * Note that if a socket closes with the internal counter holding 3062 * a non-zero value, this is not a problem because data is not 3063 * being buffered for *bytes* and is sent as it is received. 3064 * Return 3065 * 0 3066 * 3067 * long bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes) 3068 * Description 3069 * For socket policies, prevent the execution of the verdict eBPF 3070 * program for message *msg* until *bytes* (byte number) have been 3071 * accumulated. 3072 * 3073 * This can be used when one needs a specific number of bytes 3074 * before a verdict can be assigned, even if the data spans 3075 * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme 3076 * case would be a user calling **sendmsg**\ () repeatedly with 3077 * 1-byte long message segments. Obviously, this is bad for 3078 * performance, but it is still valid. If the eBPF program needs 3079 * *bytes* bytes to validate a header, this helper can be used to 3080 * prevent the eBPF program to be called again until *bytes* have 3081 * been accumulated. 3082 * Return 3083 * 0 3084 * 3085 * long bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags) 3086 * Description 3087 * For socket policies, pull in non-linear data from user space 3088 * for *msg* and set pointers *msg*\ **->data** and *msg*\ 3089 * **->data_end** to *start* and *end* bytes offsets into *msg*, 3090 * respectively. 3091 * 3092 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a 3093 * *msg* it can only parse data that the (**data**, **data_end**) 3094 * pointers have already consumed. For **sendmsg**\ () hooks this 3095 * is likely the first scatterlist element. But for calls relying 3096 * on the **sendpage** handler (e.g. **sendfile**\ ()) this will 3097 * be the range (**0**, **0**) because the data is shared with 3098 * user space and by default the objective is to avoid allowing 3099 * user space to modify data while (or after) eBPF verdict is 3100 * being decided. This helper can be used to pull in data and to 3101 * set the start and end pointer to given values. Data will be 3102 * copied if necessary (i.e. if data was not linear and if start 3103 * and end pointers do not point to the same chunk). 3104 * 3105 * A call to this helper is susceptible to change the underlying 3106 * packet buffer. Therefore, at load time, all checks on pointers 3107 * previously done by the verifier are invalidated and must be 3108 * performed again, if the helper is used in combination with 3109 * direct packet access. 3110 * 3111 * All values for *flags* are reserved for future usage, and must 3112 * be left at zero. 3113 * Return 3114 * 0 on success, or a negative error in case of failure. 3115 * 3116 * long bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) 3117 * Description 3118 * Bind the socket associated to *ctx* to the address pointed by 3119 * *addr*, of length *addr_len*. This allows for making outgoing 3120 * connection from the desired IP address, which can be useful for 3121 * example when all processes inside a cgroup should use one 3122 * single IP address on a host that has multiple IP configured. 3123 * 3124 * This helper works for IPv4 and IPv6, TCP and UDP sockets. The 3125 * domain (*addr*\ **->sa_family**) must be **AF_INET** (or 3126 * **AF_INET6**). It's advised to pass zero port (**sin_port** 3127 * or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like 3128 * behavior and lets the kernel efficiently pick up an unused 3129 * port as long as 4-tuple is unique. Passing non-zero port might 3130 * lead to degraded performance. 3131 * Return 3132 * 0 on success, or a negative error in case of failure. 3133 * 3134 * long bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta) 3135 * Description 3136 * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is 3137 * possible to both shrink and grow the packet tail. 3138 * Shrink done via *delta* being a negative integer. 3139 * 3140 * A call to this helper is susceptible to change the underlying 3141 * packet buffer. Therefore, at load time, all checks on pointers 3142 * previously done by the verifier are invalidated and must be 3143 * performed again, if the helper is used in combination with 3144 * direct packet access. 3145 * Return 3146 * 0 on success, or a negative error in case of failure. 3147 * 3148 * long bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags) 3149 * Description 3150 * Retrieve the XFRM state (IP transform framework, see also 3151 * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*. 3152 * 3153 * The retrieved value is stored in the **struct bpf_xfrm_state** 3154 * pointed by *xfrm_state* and of length *size*. 3155 * 3156 * All values for *flags* are reserved for future usage, and must 3157 * be left at zero. 3158 * 3159 * This helper is available only if the kernel was compiled with 3160 * **CONFIG_XFRM** configuration option. 3161 * Return 3162 * 0 on success, or a negative error in case of failure. 3163 * 3164 * long bpf_get_stack(void *ctx, void *buf, u32 size, u64 flags) 3165 * Description 3166 * Return a user or a kernel stack in bpf program provided buffer. 3167 * To achieve this, the helper needs *ctx*, which is a pointer 3168 * to the context on which the tracing program is executed. 3169 * To store the stacktrace, the bpf program provides *buf* with 3170 * a nonnegative *size*. 3171 * 3172 * The last argument, *flags*, holds the number of stack frames to 3173 * skip (from 0 to 255), masked with 3174 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set 3175 * the following flags: 3176 * 3177 * **BPF_F_USER_STACK** 3178 * Collect a user space stack instead of a kernel stack. 3179 * **BPF_F_USER_BUILD_ID** 3180 * Collect (build_id, file_offset) instead of ips for user 3181 * stack, only valid if **BPF_F_USER_STACK** is also 3182 * specified. 3183 * 3184 * *file_offset* is an offset relative to the beginning 3185 * of the executable or shared object file backing the vma 3186 * which the *ip* falls in. It is *not* an offset relative 3187 * to that object's base address. Accordingly, it must be 3188 * adjusted by adding (sh_addr - sh_offset), where 3189 * sh_{addr,offset} correspond to the executable section 3190 * containing *file_offset* in the object, for comparisons 3191 * to symbols' st_value to be valid. 3192 * 3193 * **bpf_get_stack**\ () can collect up to 3194 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject 3195 * to sufficient large buffer size. Note that 3196 * this limit can be controlled with the **sysctl** program, and 3197 * that it should be manually increased in order to profile long 3198 * user stacks (such as stacks for Java programs). To do so, use: 3199 * 3200 * :: 3201 * 3202 * # sysctl kernel.perf_event_max_stack=<new value> 3203 * Return 3204 * The non-negative copied *buf* length equal to or less than 3205 * *size* on success, or a negative error in case of failure. 3206 * 3207 * long bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header) 3208 * Description 3209 * This helper is similar to **bpf_skb_load_bytes**\ () in that 3210 * it provides an easy way to load *len* bytes from *offset* 3211 * from the packet associated to *skb*, into the buffer pointed 3212 * by *to*. The difference to **bpf_skb_load_bytes**\ () is that 3213 * a fifth argument *start_header* exists in order to select a 3214 * base offset to start from. *start_header* can be one of: 3215 * 3216 * **BPF_HDR_START_MAC** 3217 * Base offset to load data from is *skb*'s mac header. 3218 * **BPF_HDR_START_NET** 3219 * Base offset to load data from is *skb*'s network header. 3220 * 3221 * In general, "direct packet access" is the preferred method to 3222 * access packet data, however, this helper is in particular useful 3223 * in socket filters where *skb*\ **->data** does not always point 3224 * to the start of the mac header and where "direct packet access" 3225 * is not available. 3226 * Return 3227 * 0 on success, or a negative error in case of failure. 3228 * 3229 * long bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) 3230 * Description 3231 * Do FIB lookup in kernel tables using parameters in *params*. 3232 * If lookup is successful and result shows packet is to be 3233 * forwarded, the neighbor tables are searched for the nexthop. 3234 * If successful (ie., FIB lookup shows forwarding and nexthop 3235 * is resolved), the nexthop address is returned in ipv4_dst 3236 * or ipv6_dst based on family, smac is set to mac address of 3237 * egress device, dmac is set to nexthop mac address, rt_metric 3238 * is set to metric from route (IPv4/IPv6 only), and ifindex 3239 * is set to the device index of the nexthop from the FIB lookup. 3240 * 3241 * *plen* argument is the size of the passed in struct. 3242 * *flags* argument can be a combination of one or more of the 3243 * following values: 3244 * 3245 * **BPF_FIB_LOOKUP_DIRECT** 3246 * Do a direct table lookup vs full lookup using FIB 3247 * rules. 3248 * **BPF_FIB_LOOKUP_TBID** 3249 * Used with BPF_FIB_LOOKUP_DIRECT. 3250 * Use the routing table ID present in *params*->tbid 3251 * for the fib lookup. 3252 * **BPF_FIB_LOOKUP_OUTPUT** 3253 * Perform lookup from an egress perspective (default is 3254 * ingress). 3255 * **BPF_FIB_LOOKUP_SKIP_NEIGH** 3256 * Skip the neighbour table lookup. *params*->dmac 3257 * and *params*->smac will not be set as output. A common 3258 * use case is to call **bpf_redirect_neigh**\ () after 3259 * doing **bpf_fib_lookup**\ (). 3260 * **BPF_FIB_LOOKUP_SRC** 3261 * Derive and set source IP addr in *params*->ipv{4,6}_src 3262 * for the nexthop. If the src addr cannot be derived, 3263 * **BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this 3264 * case, *params*->dmac and *params*->smac are not set either. 3265 * 3266 * *ctx* is either **struct xdp_md** for XDP programs or 3267 * **struct sk_buff** tc cls_act programs. 3268 * Return 3269 * * < 0 if any input argument is invalid 3270 * * 0 on success (packet is forwarded, nexthop neighbor exists) 3271 * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the 3272 * packet is not forwarded or needs assist from full stack 3273 * 3274 * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU 3275 * was exceeded and output params->mtu_result contains the MTU. 3276 * 3277 * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) 3278 * Description 3279 * Add an entry to, or update a sockhash *map* referencing sockets. 3280 * The *skops* is used as a new value for the entry associated to 3281 * *key*. *flags* is one of: 3282 * 3283 * **BPF_NOEXIST** 3284 * The entry for *key* must not exist in the map. 3285 * **BPF_EXIST** 3286 * The entry for *key* must already exist in the map. 3287 * **BPF_ANY** 3288 * No condition on the existence of the entry for *key*. 3289 * 3290 * If the *map* has eBPF programs (parser and verdict), those will 3291 * be inherited by the socket being added. If the socket is 3292 * already attached to eBPF programs, this results in an error. 3293 * Return 3294 * 0 on success, or a negative error in case of failure. 3295 * 3296 * long bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags) 3297 * Description 3298 * This helper is used in programs implementing policies at the 3299 * socket level. If the message *msg* is allowed to pass (i.e. if 3300 * the verdict eBPF program returns **SK_PASS**), redirect it to 3301 * the socket referenced by *map* (of type 3302 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and 3303 * egress interfaces can be used for redirection. The 3304 * **BPF_F_INGRESS** value in *flags* is used to make the 3305 * distinction (ingress path is selected if the flag is present, 3306 * egress path otherwise). This is the only flag supported for now. 3307 * Return 3308 * **SK_PASS** on success, or **SK_DROP** on error. 3309 * 3310 * long bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags) 3311 * Description 3312 * This helper is used in programs implementing policies at the 3313 * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. 3314 * if the verdict eBPF program returns **SK_PASS**), redirect it 3315 * to the socket referenced by *map* (of type 3316 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and 3317 * egress interfaces can be used for redirection. The 3318 * **BPF_F_INGRESS** value in *flags* is used to make the 3319 * distinction (ingress path is selected if the flag is present, 3320 * egress otherwise). This is the only flag supported for now. 3321 * Return 3322 * **SK_PASS** on success, or **SK_DROP** on error. 3323 * 3324 * long bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) 3325 * Description 3326 * Encapsulate the packet associated to *skb* within a Layer 3 3327 * protocol header. This header is provided in the buffer at 3328 * address *hdr*, with *len* its size in bytes. *type* indicates 3329 * the protocol of the header and can be one of: 3330 * 3331 * **BPF_LWT_ENCAP_SEG6** 3332 * IPv6 encapsulation with Segment Routing Header 3333 * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, 3334 * the IPv6 header is computed by the kernel. 3335 * **BPF_LWT_ENCAP_SEG6_INLINE** 3336 * Only works if *skb* contains an IPv6 packet. Insert a 3337 * Segment Routing Header (**struct ipv6_sr_hdr**) inside 3338 * the IPv6 header. 3339 * **BPF_LWT_ENCAP_IP** 3340 * IP encapsulation (GRE/GUE/IPIP/etc). The outer header 3341 * must be IPv4 or IPv6, followed by zero or more 3342 * additional headers, up to **LWT_BPF_MAX_HEADROOM** 3343 * total bytes in all prepended headers. Please note that 3344 * if **skb_is_gso**\ (*skb*) is true, no more than two 3345 * headers can be prepended, and the inner header, if 3346 * present, should be either GRE or UDP/GUE. 3347 * 3348 * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs 3349 * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can 3350 * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and 3351 * **BPF_PROG_TYPE_LWT_XMIT**. 3352 * 3353 * A call to this helper is susceptible to change the underlying 3354 * packet buffer. Therefore, at load time, all checks on pointers 3355 * previously done by the verifier are invalidated and must be 3356 * performed again, if the helper is used in combination with 3357 * direct packet access. 3358 * Return 3359 * 0 on success, or a negative error in case of failure. 3360 * 3361 * long bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len) 3362 * Description 3363 * Store *len* bytes from address *from* into the packet 3364 * associated to *skb*, at *offset*. Only the flags, tag and TLVs 3365 * inside the outermost IPv6 Segment Routing Header can be 3366 * modified through this helper. 3367 * 3368 * A call to this helper is susceptible to change the underlying 3369 * packet buffer. Therefore, at load time, all checks on pointers 3370 * previously done by the verifier are invalidated and must be 3371 * performed again, if the helper is used in combination with 3372 * direct packet access. 3373 * Return 3374 * 0 on success, or a negative error in case of failure. 3375 * 3376 * long bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta) 3377 * Description 3378 * Adjust the size allocated to TLVs in the outermost IPv6 3379 * Segment Routing Header contained in the packet associated to 3380 * *skb*, at position *offset* by *delta* bytes. Only offsets 3381 * after the segments are accepted. *delta* can be as well 3382 * positive (growing) as negative (shrinking). 3383 * 3384 * A call to this helper is susceptible to change the underlying 3385 * packet buffer. Therefore, at load time, all checks on pointers 3386 * previously done by the verifier are invalidated and must be 3387 * performed again, if the helper is used in combination with 3388 * direct packet access. 3389 * Return 3390 * 0 on success, or a negative error in case of failure. 3391 * 3392 * long bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len) 3393 * Description 3394 * Apply an IPv6 Segment Routing action of type *action* to the 3395 * packet associated to *skb*. Each action takes a parameter 3396 * contained at address *param*, and of length *param_len* bytes. 3397 * *action* can be one of: 3398 * 3399 * **SEG6_LOCAL_ACTION_END_X** 3400 * End.X action: Endpoint with Layer-3 cross-connect. 3401 * Type of *param*: **struct in6_addr**. 3402 * **SEG6_LOCAL_ACTION_END_T** 3403 * End.T action: Endpoint with specific IPv6 table lookup. 3404 * Type of *param*: **int**. 3405 * **SEG6_LOCAL_ACTION_END_B6** 3406 * End.B6 action: Endpoint bound to an SRv6 policy. 3407 * Type of *param*: **struct ipv6_sr_hdr**. 3408 * **SEG6_LOCAL_ACTION_END_B6_ENCAP** 3409 * End.B6.Encap action: Endpoint bound to an SRv6 3410 * encapsulation policy. 3411 * Type of *param*: **struct ipv6_sr_hdr**. 3412 * 3413 * A call to this helper is susceptible to change the underlying 3414 * packet buffer. Therefore, at load time, all checks on pointers 3415 * previously done by the verifier are invalidated and must be 3416 * performed again, if the helper is used in combination with 3417 * direct packet access. 3418 * Return 3419 * 0 on success, or a negative error in case of failure. 3420 * 3421 * long bpf_rc_repeat(void *ctx) 3422 * Description 3423 * This helper is used in programs implementing IR decoding, to 3424 * report a successfully decoded repeat key message. This delays 3425 * the generation of a key up event for previously generated 3426 * key down event. 3427 * 3428 * Some IR protocols like NEC have a special IR message for 3429 * repeating last button, for when a button is held down. 3430 * 3431 * The *ctx* should point to the lirc sample as passed into 3432 * the program. 3433 * 3434 * This helper is only available is the kernel was compiled with 3435 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 3436 * "**y**". 3437 * Return 3438 * 0 3439 * 3440 * long bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle) 3441 * Description 3442 * This helper is used in programs implementing IR decoding, to 3443 * report a successfully decoded key press with *scancode*, 3444 * *toggle* value in the given *protocol*. The scancode will be 3445 * translated to a keycode using the rc keymap, and reported as 3446 * an input key down event. After a period a key up event is 3447 * generated. This period can be extended by calling either 3448 * **bpf_rc_keydown**\ () again with the same values, or calling 3449 * **bpf_rc_repeat**\ (). 3450 * 3451 * Some protocols include a toggle bit, in case the button was 3452 * released and pressed again between consecutive scancodes. 3453 * 3454 * The *ctx* should point to the lirc sample as passed into 3455 * the program. 3456 * 3457 * The *protocol* is the decoded protocol number (see 3458 * **enum rc_proto** for some predefined values). 3459 * 3460 * This helper is only available is the kernel was compiled with 3461 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 3462 * "**y**". 3463 * Return 3464 * 0 3465 * 3466 * u64 bpf_skb_cgroup_id(struct sk_buff *skb) 3467 * Description 3468 * Return the cgroup v2 id of the socket associated with the *skb*. 3469 * This is roughly similar to the **bpf_get_cgroup_classid**\ () 3470 * helper for cgroup v1 by providing a tag resp. identifier that 3471 * can be matched on or used for map lookups e.g. to implement 3472 * policy. The cgroup v2 id of a given path in the hierarchy is 3473 * exposed in user space through the f_handle API in order to get 3474 * to the same 64-bit id. 3475 * 3476 * This helper can be used on TC egress path, but not on ingress, 3477 * and is available only if the kernel was compiled with the 3478 * **CONFIG_SOCK_CGROUP_DATA** configuration option. 3479 * Return 3480 * The id is returned or 0 in case the id could not be retrieved. 3481 * 3482 * u64 bpf_get_current_cgroup_id(void) 3483 * Description 3484 * Get the current cgroup id based on the cgroup within which 3485 * the current task is running. 3486 * Return 3487 * A 64-bit integer containing the current cgroup id based 3488 * on the cgroup within which the current task is running. 3489 * 3490 * void *bpf_get_local_storage(void *map, u64 flags) 3491 * Description 3492 * Get the pointer to the local storage area. 3493 * The type and the size of the local storage is defined 3494 * by the *map* argument. 3495 * The *flags* meaning is specific for each map type, 3496 * and has to be 0 for cgroup local storage. 3497 * 3498 * Depending on the BPF program type, a local storage area 3499 * can be shared between multiple instances of the BPF program, 3500 * running simultaneously. 3501 * 3502 * A user should care about the synchronization by himself. 3503 * For example, by using the **BPF_ATOMIC** instructions to alter 3504 * the shared data. 3505 * Return 3506 * A pointer to the local storage area. 3507 * 3508 * long bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags) 3509 * Description 3510 * Select a **SO_REUSEPORT** socket from a 3511 * **BPF_MAP_TYPE_REUSEPORT_SOCKARRAY** *map*. 3512 * It checks the selected socket is matching the incoming 3513 * request in the socket buffer. 3514 * Return 3515 * 0 on success, or a negative error in case of failure. 3516 * 3517 * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level) 3518 * Description 3519 * Return id of cgroup v2 that is ancestor of cgroup associated 3520 * with the *skb* at the *ancestor_level*. The root cgroup is at 3521 * *ancestor_level* zero and each step down the hierarchy 3522 * increments the level. If *ancestor_level* == level of cgroup 3523 * associated with *skb*, then return value will be same as that 3524 * of **bpf_skb_cgroup_id**\ (). 3525 * 3526 * The helper is useful to implement policies based on cgroups 3527 * that are upper in hierarchy than immediate cgroup associated 3528 * with *skb*. 3529 * 3530 * The format of returned id and helper limitations are same as in 3531 * **bpf_skb_cgroup_id**\ (). 3532 * Return 3533 * The id is returned or 0 in case the id could not be retrieved. 3534 * 3535 * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 3536 * Description 3537 * Look for TCP socket matching *tuple*, optionally in a child 3538 * network namespace *netns*. The return value must be checked, 3539 * and if non-**NULL**, released via **bpf_sk_release**\ (). 3540 * 3541 * The *ctx* should point to the context of the program, such as 3542 * the skb or socket (depending on the hook in use). This is used 3543 * to determine the base network namespace for the lookup. 3544 * 3545 * *tuple_size* must be one of: 3546 * 3547 * **sizeof**\ (*tuple*\ **->ipv4**) 3548 * Look for an IPv4 socket. 3549 * **sizeof**\ (*tuple*\ **->ipv6**) 3550 * Look for an IPv6 socket. 3551 * 3552 * If the *netns* is a negative signed 32-bit integer, then the 3553 * socket lookup table in the netns associated with the *ctx* 3554 * will be used. For the TC hooks, this is the netns of the device 3555 * in the skb. For socket hooks, this is the netns of the socket. 3556 * If *netns* is any other signed 32-bit value greater than or 3557 * equal to zero then it specifies the ID of the netns relative to 3558 * the netns associated with the *ctx*. *netns* values beyond the 3559 * range of 32-bit integers are reserved for future use. 3560 * 3561 * All values for *flags* are reserved for future usage, and must 3562 * be left at zero. 3563 * 3564 * This helper is available only if the kernel was compiled with 3565 * **CONFIG_NET** configuration option. 3566 * Return 3567 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 3568 * For sockets with reuseport option, the **struct bpf_sock** 3569 * result is from *reuse*\ **->socks**\ [] using the hash of the 3570 * tuple. 3571 * 3572 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 3573 * Description 3574 * Look for UDP socket matching *tuple*, optionally in a child 3575 * network namespace *netns*. The return value must be checked, 3576 * and if non-**NULL**, released via **bpf_sk_release**\ (). 3577 * 3578 * The *ctx* should point to the context of the program, such as 3579 * the skb or socket (depending on the hook in use). This is used 3580 * to determine the base network namespace for the lookup. 3581 * 3582 * *tuple_size* must be one of: 3583 * 3584 * **sizeof**\ (*tuple*\ **->ipv4**) 3585 * Look for an IPv4 socket. 3586 * **sizeof**\ (*tuple*\ **->ipv6**) 3587 * Look for an IPv6 socket. 3588 * 3589 * If the *netns* is a negative signed 32-bit integer, then the 3590 * socket lookup table in the netns associated with the *ctx* 3591 * will be used. For the TC hooks, this is the netns of the device 3592 * in the skb. For socket hooks, this is the netns of the socket. 3593 * If *netns* is any other signed 32-bit value greater than or 3594 * equal to zero then it specifies the ID of the netns relative to 3595 * the netns associated with the *ctx*. *netns* values beyond the 3596 * range of 32-bit integers are reserved for future use. 3597 * 3598 * All values for *flags* are reserved for future usage, and must 3599 * be left at zero. 3600 * 3601 * This helper is available only if the kernel was compiled with 3602 * **CONFIG_NET** configuration option. 3603 * Return 3604 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 3605 * For sockets with reuseport option, the **struct bpf_sock** 3606 * result is from *reuse*\ **->socks**\ [] using the hash of the 3607 * tuple. 3608 * 3609 * long bpf_sk_release(void *sock) 3610 * Description 3611 * Release the reference held by *sock*. *sock* must be a 3612 * non-**NULL** pointer that was returned from 3613 * **bpf_sk_lookup_xxx**\ (). 3614 * Return 3615 * 0 on success, or a negative error in case of failure. 3616 * 3617 * long bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags) 3618 * Description 3619 * Push an element *value* in *map*. *flags* is one of: 3620 * 3621 * **BPF_EXIST** 3622 * If the queue/stack is full, the oldest element is 3623 * removed to make room for this. 3624 * Return 3625 * 0 on success, or a negative error in case of failure. 3626 * 3627 * long bpf_map_pop_elem(struct bpf_map *map, void *value) 3628 * Description 3629 * Pop an element from *map*. 3630 * Return 3631 * 0 on success, or a negative error in case of failure. 3632 * 3633 * long bpf_map_peek_elem(struct bpf_map *map, void *value) 3634 * Description 3635 * Get an element from *map* without removing it. 3636 * Return 3637 * 0 on success, or a negative error in case of failure. 3638 * 3639 * long bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags) 3640 * Description 3641 * For socket policies, insert *len* bytes into *msg* at offset 3642 * *start*. 3643 * 3644 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a 3645 * *msg* it may want to insert metadata or options into the *msg*. 3646 * This can later be read and used by any of the lower layer BPF 3647 * hooks. 3648 * 3649 * This helper may fail if under memory pressure (a malloc 3650 * fails) in these cases BPF programs will get an appropriate 3651 * error and BPF programs will need to handle them. 3652 * Return 3653 * 0 on success, or a negative error in case of failure. 3654 * 3655 * long bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags) 3656 * Description 3657 * Will remove *len* bytes from a *msg* starting at byte *start*. 3658 * This may result in **ENOMEM** errors under certain situations if 3659 * an allocation and copy are required due to a full ring buffer. 3660 * However, the helper will try to avoid doing the allocation 3661 * if possible. Other errors can occur if input parameters are 3662 * invalid either due to *start* byte not being valid part of *msg* 3663 * payload and/or *pop* value being to large. 3664 * Return 3665 * 0 on success, or a negative error in case of failure. 3666 * 3667 * long bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y) 3668 * Description 3669 * This helper is used in programs implementing IR decoding, to 3670 * report a successfully decoded pointer movement. 3671 * 3672 * The *ctx* should point to the lirc sample as passed into 3673 * the program. 3674 * 3675 * This helper is only available is the kernel was compiled with 3676 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 3677 * "**y**". 3678 * Return 3679 * 0 3680 * 3681 * long bpf_spin_lock(struct bpf_spin_lock *lock) 3682 * Description 3683 * Acquire a spinlock represented by the pointer *lock*, which is 3684 * stored as part of a value of a map. Taking the lock allows to 3685 * safely update the rest of the fields in that value. The 3686 * spinlock can (and must) later be released with a call to 3687 * **bpf_spin_unlock**\ (\ *lock*\ ). 3688 * 3689 * Spinlocks in BPF programs come with a number of restrictions 3690 * and constraints: 3691 * 3692 * * **bpf_spin_lock** objects are only allowed inside maps of 3693 * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this 3694 * list could be extended in the future). 3695 * * BTF description of the map is mandatory. 3696 * * The BPF program can take ONE lock at a time, since taking two 3697 * or more could cause dead locks. 3698 * * Only one **struct bpf_spin_lock** is allowed per map element. 3699 * * When the lock is taken, calls (either BPF to BPF or helpers) 3700 * are not allowed. 3701 * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not 3702 * allowed inside a spinlock-ed region. 3703 * * The BPF program MUST call **bpf_spin_unlock**\ () to release 3704 * the lock, on all execution paths, before it returns. 3705 * * The BPF program can access **struct bpf_spin_lock** only via 3706 * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ () 3707 * helpers. Loading or storing data into the **struct 3708 * bpf_spin_lock** *lock*\ **;** field of a map is not allowed. 3709 * * To use the **bpf_spin_lock**\ () helper, the BTF description 3710 * of the map value must be a struct and have **struct 3711 * bpf_spin_lock** *anyname*\ **;** field at the top level. 3712 * Nested lock inside another struct is not allowed. 3713 * * The **struct bpf_spin_lock** *lock* field in a map value must 3714 * be aligned on a multiple of 4 bytes in that value. 3715 * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy 3716 * the **bpf_spin_lock** field to user space. 3717 * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from 3718 * a BPF program, do not update the **bpf_spin_lock** field. 3719 * * **bpf_spin_lock** cannot be on the stack or inside a 3720 * networking packet (it can only be inside of a map values). 3721 * * **bpf_spin_lock** is available to root only. 3722 * * Tracing programs and socket filter programs cannot use 3723 * **bpf_spin_lock**\ () due to insufficient preemption checks 3724 * (but this may change in the future). 3725 * * **bpf_spin_lock** is not allowed in inner maps of map-in-map. 3726 * Return 3727 * 0 3728 * 3729 * long bpf_spin_unlock(struct bpf_spin_lock *lock) 3730 * Description 3731 * Release the *lock* previously locked by a call to 3732 * **bpf_spin_lock**\ (\ *lock*\ ). 3733 * Return 3734 * 0 3735 * 3736 * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk) 3737 * Description 3738 * This helper gets a **struct bpf_sock** pointer such 3739 * that all the fields in this **bpf_sock** can be accessed. 3740 * Return 3741 * A **struct bpf_sock** pointer on success, or **NULL** in 3742 * case of failure. 3743 * 3744 * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk) 3745 * Description 3746 * This helper gets a **struct bpf_tcp_sock** pointer from a 3747 * **struct bpf_sock** pointer. 3748 * Return 3749 * A **struct bpf_tcp_sock** pointer on success, or **NULL** in 3750 * case of failure. 3751 * 3752 * long bpf_skb_ecn_set_ce(struct sk_buff *skb) 3753 * Description 3754 * Set ECN (Explicit Congestion Notification) field of IP header 3755 * to **CE** (Congestion Encountered) if current value is **ECT** 3756 * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6 3757 * and IPv4. 3758 * Return 3759 * 1 if the **CE** flag is set (either by the current helper call 3760 * or because it was already present), 0 if it is not set. 3761 * 3762 * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk) 3763 * Description 3764 * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state. 3765 * **bpf_sk_release**\ () is unnecessary and not allowed. 3766 * Return 3767 * A **struct bpf_sock** pointer on success, or **NULL** in 3768 * case of failure. 3769 * 3770 * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 3771 * Description 3772 * Look for TCP socket matching *tuple*, optionally in a child 3773 * network namespace *netns*. The return value must be checked, 3774 * and if non-**NULL**, released via **bpf_sk_release**\ (). 3775 * 3776 * This function is identical to **bpf_sk_lookup_tcp**\ (), except 3777 * that it also returns timewait or request sockets. Use 3778 * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the 3779 * full structure. 3780 * 3781 * This helper is available only if the kernel was compiled with 3782 * **CONFIG_NET** configuration option. 3783 * Return 3784 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 3785 * For sockets with reuseport option, the **struct bpf_sock** 3786 * result is from *reuse*\ **->socks**\ [] using the hash of the 3787 * tuple. 3788 * 3789 * long bpf_tcp_check_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) 3790 * Description 3791 * Check whether *iph* and *th* contain a valid SYN cookie ACK for 3792 * the listening socket in *sk*. 3793 * 3794 * *iph* points to the start of the IPv4 or IPv6 header, while 3795 * *iph_len* contains **sizeof**\ (**struct iphdr**) or 3796 * **sizeof**\ (**struct ipv6hdr**). 3797 * 3798 * *th* points to the start of the TCP header, while *th_len* 3799 * contains the length of the TCP header (at least 3800 * **sizeof**\ (**struct tcphdr**)). 3801 * Return 3802 * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative 3803 * error otherwise. 3804 * 3805 * long bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags) 3806 * Description 3807 * Get name of sysctl in /proc/sys/ and copy it into provided by 3808 * program buffer *buf* of size *buf_len*. 3809 * 3810 * The buffer is always NUL terminated, unless it's zero-sized. 3811 * 3812 * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is 3813 * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name 3814 * only (e.g. "tcp_mem"). 3815 * Return 3816 * Number of character copied (not including the trailing NUL). 3817 * 3818 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 3819 * truncated name in this case). 3820 * 3821 * long bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) 3822 * Description 3823 * Get current value of sysctl as it is presented in /proc/sys 3824 * (incl. newline, etc), and copy it as a string into provided 3825 * by program buffer *buf* of size *buf_len*. 3826 * 3827 * The whole value is copied, no matter what file position user 3828 * space issued e.g. sys_read at. 3829 * 3830 * The buffer is always NUL terminated, unless it's zero-sized. 3831 * Return 3832 * Number of character copied (not including the trailing NUL). 3833 * 3834 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 3835 * truncated name in this case). 3836 * 3837 * **-EINVAL** if current value was unavailable, e.g. because 3838 * sysctl is uninitialized and read returns -EIO for it. 3839 * 3840 * long bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) 3841 * Description 3842 * Get new value being written by user space to sysctl (before 3843 * the actual write happens) and copy it as a string into 3844 * provided by program buffer *buf* of size *buf_len*. 3845 * 3846 * User space may write new value at file position > 0. 3847 * 3848 * The buffer is always NUL terminated, unless it's zero-sized. 3849 * Return 3850 * Number of character copied (not including the trailing NUL). 3851 * 3852 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 3853 * truncated name in this case). 3854 * 3855 * **-EINVAL** if sysctl is being read. 3856 * 3857 * long bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len) 3858 * Description 3859 * Override new value being written by user space to sysctl with 3860 * value provided by program in buffer *buf* of size *buf_len*. 3861 * 3862 * *buf* should contain a string in same form as provided by user 3863 * space on sysctl write. 3864 * 3865 * User space may write new value at file position > 0. To override 3866 * the whole sysctl value file position should be set to zero. 3867 * Return 3868 * 0 on success. 3869 * 3870 * **-E2BIG** if the *buf_len* is too big. 3871 * 3872 * **-EINVAL** if sysctl is being read. 3873 * 3874 * long bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res) 3875 * Description 3876 * Convert the initial part of the string from buffer *buf* of 3877 * size *buf_len* to a long integer according to the given base 3878 * and save the result in *res*. 3879 * 3880 * The string may begin with an arbitrary amount of white space 3881 * (as determined by **isspace**\ (3)) followed by a single 3882 * optional '**-**' sign. 3883 * 3884 * Five least significant bits of *flags* encode base, other bits 3885 * are currently unused. 3886 * 3887 * Base must be either 8, 10, 16 or 0 to detect it automatically 3888 * similar to user space **strtol**\ (3). 3889 * Return 3890 * Number of characters consumed on success. Must be positive but 3891 * no more than *buf_len*. 3892 * 3893 * **-EINVAL** if no valid digits were found or unsupported base 3894 * was provided. 3895 * 3896 * **-ERANGE** if resulting value was out of range. 3897 * 3898 * long bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res) 3899 * Description 3900 * Convert the initial part of the string from buffer *buf* of 3901 * size *buf_len* to an unsigned long integer according to the 3902 * given base and save the result in *res*. 3903 * 3904 * The string may begin with an arbitrary amount of white space 3905 * (as determined by **isspace**\ (3)). 3906 * 3907 * Five least significant bits of *flags* encode base, other bits 3908 * are currently unused. 3909 * 3910 * Base must be either 8, 10, 16 or 0 to detect it automatically 3911 * similar to user space **strtoul**\ (3). 3912 * Return 3913 * Number of characters consumed on success. Must be positive but 3914 * no more than *buf_len*. 3915 * 3916 * **-EINVAL** if no valid digits were found or unsupported base 3917 * was provided. 3918 * 3919 * **-ERANGE** if resulting value was out of range. 3920 * 3921 * void *bpf_sk_storage_get(struct bpf_map *map, void *sk, void *value, u64 flags) 3922 * Description 3923 * Get a bpf-local-storage from a *sk*. 3924 * 3925 * Logically, it could be thought of getting the value from 3926 * a *map* with *sk* as the **key**. From this 3927 * perspective, the usage is not much different from 3928 * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this 3929 * helper enforces the key must be a full socket and the map must 3930 * be a **BPF_MAP_TYPE_SK_STORAGE** also. 3931 * 3932 * Underneath, the value is stored locally at *sk* instead of 3933 * the *map*. The *map* is used as the bpf-local-storage 3934 * "type". The bpf-local-storage "type" (i.e. the *map*) is 3935 * searched against all bpf-local-storages residing at *sk*. 3936 * 3937 * *sk* is a kernel **struct sock** pointer for LSM program. 3938 * *sk* is a **struct bpf_sock** pointer for other program types. 3939 * 3940 * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be 3941 * used such that a new bpf-local-storage will be 3942 * created if one does not exist. *value* can be used 3943 * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify 3944 * the initial value of a bpf-local-storage. If *value* is 3945 * **NULL**, the new bpf-local-storage will be zero initialized. 3946 * Return 3947 * A bpf-local-storage pointer is returned on success. 3948 * 3949 * **NULL** if not found or there was an error in adding 3950 * a new bpf-local-storage. 3951 * 3952 * long bpf_sk_storage_delete(struct bpf_map *map, void *sk) 3953 * Description 3954 * Delete a bpf-local-storage from a *sk*. 3955 * Return 3956 * 0 on success. 3957 * 3958 * **-ENOENT** if the bpf-local-storage cannot be found. 3959 * **-EINVAL** if sk is not a fullsock (e.g. a request_sock). 3960 * 3961 * long bpf_send_signal(u32 sig) 3962 * Description 3963 * Send signal *sig* to the process of the current task. 3964 * The signal may be delivered to any of this process's threads. 3965 * Return 3966 * 0 on success or successfully queued. 3967 * 3968 * **-EBUSY** if work queue under nmi is full. 3969 * 3970 * **-EINVAL** if *sig* is invalid. 3971 * 3972 * **-EPERM** if no permission to send the *sig*. 3973 * 3974 * **-EAGAIN** if bpf program can try again. 3975 * 3976 * s64 bpf_tcp_gen_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) 3977 * Description 3978 * Try to issue a SYN cookie for the packet with corresponding 3979 * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*. 3980 * 3981 * *iph* points to the start of the IPv4 or IPv6 header, while 3982 * *iph_len* contains **sizeof**\ (**struct iphdr**) or 3983 * **sizeof**\ (**struct ipv6hdr**). 3984 * 3985 * *th* points to the start of the TCP header, while *th_len* 3986 * contains the length of the TCP header with options (at least 3987 * **sizeof**\ (**struct tcphdr**)). 3988 * Return 3989 * On success, lower 32 bits hold the generated SYN cookie in 3990 * followed by 16 bits which hold the MSS value for that cookie, 3991 * and the top 16 bits are unused. 3992 * 3993 * On failure, the returned value is one of the following: 3994 * 3995 * **-EINVAL** SYN cookie cannot be issued due to error 3996 * 3997 * **-ENOENT** SYN cookie should not be issued (no SYN flood) 3998 * 3999 * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies 4000 * 4001 * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 4002 * 4003 * long bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) 4004 * Description 4005 * Write raw *data* blob into a special BPF perf event held by 4006 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf 4007 * event must have the following attributes: **PERF_SAMPLE_RAW** 4008 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and 4009 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. 4010 * 4011 * The *flags* are used to indicate the index in *map* for which 4012 * the value must be put, masked with **BPF_F_INDEX_MASK**. 4013 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** 4014 * to indicate that the index of the current CPU core should be 4015 * used. 4016 * 4017 * The value to write, of *size*, is passed through eBPF stack and 4018 * pointed by *data*. 4019 * 4020 * *ctx* is a pointer to in-kernel struct sk_buff. 4021 * 4022 * This helper is similar to **bpf_perf_event_output**\ () but 4023 * restricted to raw_tracepoint bpf programs. 4024 * Return 4025 * 0 on success, or a negative error in case of failure. 4026 * 4027 * long bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr) 4028 * Description 4029 * Safely attempt to read *size* bytes from user space address 4030 * *unsafe_ptr* and store the data in *dst*. 4031 * Return 4032 * 0 on success, or a negative error in case of failure. 4033 * 4034 * long bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) 4035 * Description 4036 * Safely attempt to read *size* bytes from kernel space address 4037 * *unsafe_ptr* and store the data in *dst*. 4038 * Return 4039 * 0 on success, or a negative error in case of failure. 4040 * 4041 * long bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr) 4042 * Description 4043 * Copy a NUL terminated string from an unsafe user address 4044 * *unsafe_ptr* to *dst*. The *size* should include the 4045 * terminating NUL byte. In case the string length is smaller than 4046 * *size*, the target is not padded with further NUL bytes. If the 4047 * string length is larger than *size*, just *size*-1 bytes are 4048 * copied and the last byte is set to NUL. 4049 * 4050 * On success, returns the number of bytes that were written, 4051 * including the terminal NUL. This makes this helper useful in 4052 * tracing programs for reading strings, and more importantly to 4053 * get its length at runtime. See the following snippet: 4054 * 4055 * :: 4056 * 4057 * SEC("kprobe/sys_open") 4058 * void bpf_sys_open(struct pt_regs *ctx) 4059 * { 4060 * char buf[PATHLEN]; // PATHLEN is defined to 256 4061 * int res = bpf_probe_read_user_str(buf, sizeof(buf), 4062 * ctx->di); 4063 * 4064 * // Consume buf, for example push it to 4065 * // userspace via bpf_perf_event_output(); we 4066 * // can use res (the string length) as event 4067 * // size, after checking its boundaries. 4068 * } 4069 * 4070 * In comparison, using **bpf_probe_read_user**\ () helper here 4071 * instead to read the string would require to estimate the length 4072 * at compile time, and would often result in copying more memory 4073 * than necessary. 4074 * 4075 * Another useful use case is when parsing individual process 4076 * arguments or individual environment variables navigating 4077 * *current*\ **->mm->arg_start** and *current*\ 4078 * **->mm->env_start**: using this helper and the return value, 4079 * one can quickly iterate at the right offset of the memory area. 4080 * Return 4081 * On success, the strictly positive length of the output string, 4082 * including the trailing NUL character. On error, a negative 4083 * value. 4084 * 4085 * long bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr) 4086 * Description 4087 * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr* 4088 * to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply. 4089 * Return 4090 * On success, the strictly positive length of the string, including 4091 * the trailing NUL character. On error, a negative value. 4092 * 4093 * long bpf_tcp_send_ack(void *tp, u32 rcv_nxt) 4094 * Description 4095 * Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**. 4096 * *rcv_nxt* is the ack_seq to be sent out. 4097 * Return 4098 * 0 on success, or a negative error in case of failure. 4099 * 4100 * long bpf_send_signal_thread(u32 sig) 4101 * Description 4102 * Send signal *sig* to the thread corresponding to the current task. 4103 * Return 4104 * 0 on success or successfully queued. 4105 * 4106 * **-EBUSY** if work queue under nmi is full. 4107 * 4108 * **-EINVAL** if *sig* is invalid. 4109 * 4110 * **-EPERM** if no permission to send the *sig*. 4111 * 4112 * **-EAGAIN** if bpf program can try again. 4113 * 4114 * u64 bpf_jiffies64(void) 4115 * Description 4116 * Obtain the 64bit jiffies 4117 * Return 4118 * The 64 bit jiffies 4119 * 4120 * long bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags) 4121 * Description 4122 * For an eBPF program attached to a perf event, retrieve the 4123 * branch records (**struct perf_branch_entry**) associated to *ctx* 4124 * and store it in the buffer pointed by *buf* up to size 4125 * *size* bytes. 4126 * Return 4127 * On success, number of bytes written to *buf*. On error, a 4128 * negative value. 4129 * 4130 * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to 4131 * instead return the number of bytes required to store all the 4132 * branch entries. If this flag is set, *buf* may be NULL. 4133 * 4134 * **-EINVAL** if arguments invalid or **size** not a multiple 4135 * of **sizeof**\ (**struct perf_branch_entry**\ ). 4136 * 4137 * **-ENOENT** if architecture does not support branch records. 4138 * 4139 * long bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) 4140 * Description 4141 * Returns 0 on success, values for *pid* and *tgid* as seen from the current 4142 * *namespace* will be returned in *nsdata*. 4143 * Return 4144 * 0 on success, or one of the following in case of failure: 4145 * 4146 * **-EINVAL** if dev and inum supplied don't match dev_t and inode number 4147 * with nsfs of current task, or if dev conversion to dev_t lost high bits. 4148 * 4149 * **-ENOENT** if pidns does not exists for the current task. 4150 * 4151 * long bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) 4152 * Description 4153 * Write raw *data* blob into a special BPF perf event held by 4154 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf 4155 * event must have the following attributes: **PERF_SAMPLE_RAW** 4156 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and 4157 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. 4158 * 4159 * The *flags* are used to indicate the index in *map* for which 4160 * the value must be put, masked with **BPF_F_INDEX_MASK**. 4161 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** 4162 * to indicate that the index of the current CPU core should be 4163 * used. 4164 * 4165 * The value to write, of *size*, is passed through eBPF stack and 4166 * pointed by *data*. 4167 * 4168 * *ctx* is a pointer to in-kernel struct xdp_buff. 4169 * 4170 * This helper is similar to **bpf_perf_eventoutput**\ () but 4171 * restricted to raw_tracepoint bpf programs. 4172 * Return 4173 * 0 on success, or a negative error in case of failure. 4174 * 4175 * u64 bpf_get_netns_cookie(void *ctx) 4176 * Description 4177 * Retrieve the cookie (generated by the kernel) of the network 4178 * namespace the input *ctx* is associated with. The network 4179 * namespace cookie remains stable for its lifetime and provides 4180 * a global identifier that can be assumed unique. If *ctx* is 4181 * NULL, then the helper returns the cookie for the initial 4182 * network namespace. The cookie itself is very similar to that 4183 * of **bpf_get_socket_cookie**\ () helper, but for network 4184 * namespaces instead of sockets. 4185 * Return 4186 * A 8-byte long opaque number. 4187 * 4188 * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level) 4189 * Description 4190 * Return id of cgroup v2 that is ancestor of the cgroup associated 4191 * with the current task at the *ancestor_level*. The root cgroup 4192 * is at *ancestor_level* zero and each step down the hierarchy 4193 * increments the level. If *ancestor_level* == level of cgroup 4194 * associated with the current task, then return value will be the 4195 * same as that of **bpf_get_current_cgroup_id**\ (). 4196 * 4197 * The helper is useful to implement policies based on cgroups 4198 * that are upper in hierarchy than immediate cgroup associated 4199 * with the current task. 4200 * 4201 * The format of returned id and helper limitations are same as in 4202 * **bpf_get_current_cgroup_id**\ (). 4203 * Return 4204 * The id is returned or 0 in case the id could not be retrieved. 4205 * 4206 * long bpf_sk_assign(struct sk_buff *skb, void *sk, u64 flags) 4207 * Description 4208 * Helper is overloaded depending on BPF program type. This 4209 * description applies to **BPF_PROG_TYPE_SCHED_CLS** and 4210 * **BPF_PROG_TYPE_SCHED_ACT** programs. 4211 * 4212 * Assign the *sk* to the *skb*. When combined with appropriate 4213 * routing configuration to receive the packet towards the socket, 4214 * will cause *skb* to be delivered to the specified socket. 4215 * Subsequent redirection of *skb* via **bpf_redirect**\ (), 4216 * **bpf_clone_redirect**\ () or other methods outside of BPF may 4217 * interfere with successful delivery to the socket. 4218 * 4219 * This operation is only valid from TC ingress path. 4220 * 4221 * The *flags* argument must be zero. 4222 * Return 4223 * 0 on success, or a negative error in case of failure: 4224 * 4225 * **-EINVAL** if specified *flags* are not supported. 4226 * 4227 * **-ENOENT** if the socket is unavailable for assignment. 4228 * 4229 * **-ENETUNREACH** if the socket is unreachable (wrong netns). 4230 * 4231 * **-EOPNOTSUPP** if the operation is not supported, for example 4232 * a call from outside of TC ingress. 4233 * 4234 * long bpf_sk_assign(struct bpf_sk_lookup *ctx, struct bpf_sock *sk, u64 flags) 4235 * Description 4236 * Helper is overloaded depending on BPF program type. This 4237 * description applies to **BPF_PROG_TYPE_SK_LOOKUP** programs. 4238 * 4239 * Select the *sk* as a result of a socket lookup. 4240 * 4241 * For the operation to succeed passed socket must be compatible 4242 * with the packet description provided by the *ctx* object. 4243 * 4244 * L4 protocol (**IPPROTO_TCP** or **IPPROTO_UDP**) must 4245 * be an exact match. While IP family (**AF_INET** or 4246 * **AF_INET6**) must be compatible, that is IPv6 sockets 4247 * that are not v6-only can be selected for IPv4 packets. 4248 * 4249 * Only TCP listeners and UDP unconnected sockets can be 4250 * selected. *sk* can also be NULL to reset any previous 4251 * selection. 4252 * 4253 * *flags* argument can combination of following values: 4254 * 4255 * * **BPF_SK_LOOKUP_F_REPLACE** to override the previous 4256 * socket selection, potentially done by a BPF program 4257 * that ran before us. 4258 * 4259 * * **BPF_SK_LOOKUP_F_NO_REUSEPORT** to skip 4260 * load-balancing within reuseport group for the socket 4261 * being selected. 4262 * 4263 * On success *ctx->sk* will point to the selected socket. 4264 * 4265 * Return 4266 * 0 on success, or a negative errno in case of failure. 4267 * 4268 * * **-EAFNOSUPPORT** if socket family (*sk->family*) is 4269 * not compatible with packet family (*ctx->family*). 4270 * 4271 * * **-EEXIST** if socket has been already selected, 4272 * potentially by another program, and 4273 * **BPF_SK_LOOKUP_F_REPLACE** flag was not specified. 4274 * 4275 * * **-EINVAL** if unsupported flags were specified. 4276 * 4277 * * **-EPROTOTYPE** if socket L4 protocol 4278 * (*sk->protocol*) doesn't match packet protocol 4279 * (*ctx->protocol*). 4280 * 4281 * * **-ESOCKTNOSUPPORT** if socket is not in allowed 4282 * state (TCP listening or UDP unconnected). 4283 * 4284 * u64 bpf_ktime_get_boot_ns(void) 4285 * Description 4286 * Return the time elapsed since system boot, in nanoseconds. 4287 * Does include the time the system was suspended. 4288 * See: **clock_gettime**\ (**CLOCK_BOOTTIME**) 4289 * Return 4290 * Current *ktime*. 4291 * 4292 * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len) 4293 * Description 4294 * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print 4295 * out the format string. 4296 * The *m* represents the seq_file. The *fmt* and *fmt_size* are for 4297 * the format string itself. The *data* and *data_len* are format string 4298 * arguments. The *data* are a **u64** array and corresponding format string 4299 * values are stored in the array. For strings and pointers where pointees 4300 * are accessed, only the pointer values are stored in the *data* array. 4301 * The *data_len* is the size of *data* in bytes - must be a multiple of 8. 4302 * 4303 * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory. 4304 * Reading kernel memory may fail due to either invalid address or 4305 * valid address but requiring a major memory fault. If reading kernel memory 4306 * fails, the string for **%s** will be an empty string, and the ip 4307 * address for **%p{i,I}{4,6}** will be 0. Not returning error to 4308 * bpf program is consistent with what **bpf_trace_printk**\ () does for now. 4309 * Return 4310 * 0 on success, or a negative error in case of failure: 4311 * 4312 * **-EBUSY** if per-CPU memory copy buffer is busy, can try again 4313 * by returning 1 from bpf program. 4314 * 4315 * **-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported. 4316 * 4317 * **-E2BIG** if *fmt* contains too many format specifiers. 4318 * 4319 * **-EOVERFLOW** if an overflow happened: The same object will be tried again. 4320 * 4321 * long bpf_seq_write(struct seq_file *m, const void *data, u32 len) 4322 * Description 4323 * **bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data. 4324 * The *m* represents the seq_file. The *data* and *len* represent the 4325 * data to write in bytes. 4326 * Return 4327 * 0 on success, or a negative error in case of failure: 4328 * 4329 * **-EOVERFLOW** if an overflow happened: The same object will be tried again. 4330 * 4331 * u64 bpf_sk_cgroup_id(void *sk) 4332 * Description 4333 * Return the cgroup v2 id of the socket *sk*. 4334 * 4335 * *sk* must be a non-**NULL** pointer to a socket, e.g. one 4336 * returned from **bpf_sk_lookup_xxx**\ (), 4337 * **bpf_sk_fullsock**\ (), etc. The format of returned id is 4338 * same as in **bpf_skb_cgroup_id**\ (). 4339 * 4340 * This helper is available only if the kernel was compiled with 4341 * the **CONFIG_SOCK_CGROUP_DATA** configuration option. 4342 * Return 4343 * The id is returned or 0 in case the id could not be retrieved. 4344 * 4345 * u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level) 4346 * Description 4347 * Return id of cgroup v2 that is ancestor of cgroup associated 4348 * with the *sk* at the *ancestor_level*. The root cgroup is at 4349 * *ancestor_level* zero and each step down the hierarchy 4350 * increments the level. If *ancestor_level* == level of cgroup 4351 * associated with *sk*, then return value will be same as that 4352 * of **bpf_sk_cgroup_id**\ (). 4353 * 4354 * The helper is useful to implement policies based on cgroups 4355 * that are upper in hierarchy than immediate cgroup associated 4356 * with *sk*. 4357 * 4358 * The format of returned id and helper limitations are same as in 4359 * **bpf_sk_cgroup_id**\ (). 4360 * Return 4361 * The id is returned or 0 in case the id could not be retrieved. 4362 * 4363 * long bpf_ringbuf_output(void *ringbuf, void *data, u64 size, u64 flags) 4364 * Description 4365 * Copy *size* bytes from *data* into a ring buffer *ringbuf*. 4366 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification 4367 * of new data availability is sent. 4368 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification 4369 * of new data availability is sent unconditionally. 4370 * If **0** is specified in *flags*, an adaptive notification 4371 * of new data availability is sent. 4372 * 4373 * An adaptive notification is a notification sent whenever the user-space 4374 * process has caught up and consumed all available payloads. In case the user-space 4375 * process is still processing a previous payload, then no notification is needed 4376 * as it will process the newly added payload automatically. 4377 * Return 4378 * 0 on success, or a negative error in case of failure. 4379 * 4380 * void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags) 4381 * Description 4382 * Reserve *size* bytes of payload in a ring buffer *ringbuf*. 4383 * *flags* must be 0. 4384 * Return 4385 * Valid pointer with *size* bytes of memory available; NULL, 4386 * otherwise. 4387 * 4388 * void bpf_ringbuf_submit(void *data, u64 flags) 4389 * Description 4390 * Submit reserved ring buffer sample, pointed to by *data*. 4391 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification 4392 * of new data availability is sent. 4393 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification 4394 * of new data availability is sent unconditionally. 4395 * If **0** is specified in *flags*, an adaptive notification 4396 * of new data availability is sent. 4397 * 4398 * See 'bpf_ringbuf_output()' for the definition of adaptive notification. 4399 * Return 4400 * Nothing. Always succeeds. 4401 * 4402 * void bpf_ringbuf_discard(void *data, u64 flags) 4403 * Description 4404 * Discard reserved ring buffer sample, pointed to by *data*. 4405 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification 4406 * of new data availability is sent. 4407 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification 4408 * of new data availability is sent unconditionally. 4409 * If **0** is specified in *flags*, an adaptive notification 4410 * of new data availability is sent. 4411 * 4412 * See 'bpf_ringbuf_output()' for the definition of adaptive notification. 4413 * Return 4414 * Nothing. Always succeeds. 4415 * 4416 * u64 bpf_ringbuf_query(void *ringbuf, u64 flags) 4417 * Description 4418 * Query various characteristics of provided ring buffer. What 4419 * exactly is queries is determined by *flags*: 4420 * 4421 * * **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed. 4422 * * **BPF_RB_RING_SIZE**: The size of ring buffer. 4423 * * **BPF_RB_CONS_POS**: Consumer position (can wrap around). 4424 * * **BPF_RB_PROD_POS**: Producer(s) position (can wrap around). 4425 * 4426 * Data returned is just a momentary snapshot of actual values 4427 * and could be inaccurate, so this facility should be used to 4428 * power heuristics and for reporting, not to make 100% correct 4429 * calculation. 4430 * Return 4431 * Requested value, or 0, if *flags* are not recognized. 4432 * 4433 * long bpf_csum_level(struct sk_buff *skb, u64 level) 4434 * Description 4435 * Change the skbs checksum level by one layer up or down, or 4436 * reset it entirely to none in order to have the stack perform 4437 * checksum validation. The level is applicable to the following 4438 * protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of 4439 * | ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP | 4440 * through **bpf_skb_adjust_room**\ () helper with passing in 4441 * **BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one call 4442 * to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since 4443 * the UDP header is removed. Similarly, an encap of the latter 4444 * into the former could be accompanied by a helper call to 4445 * **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the 4446 * skb is still intended to be processed in higher layers of the 4447 * stack instead of just egressing at tc. 4448 * 4449 * There are three supported level settings at this time: 4450 * 4451 * * **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs 4452 * with CHECKSUM_UNNECESSARY. 4453 * * **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs 4454 * with CHECKSUM_UNNECESSARY. 4455 * * **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and 4456 * sets CHECKSUM_NONE to force checksum validation by the stack. 4457 * * **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current 4458 * skb->csum_level. 4459 * Return 4460 * 0 on success, or a negative error in case of failure. In the 4461 * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level 4462 * is returned or the error code -EACCES in case the skb is not 4463 * subject to CHECKSUM_UNNECESSARY. 4464 * 4465 * struct tcp6_sock *bpf_skc_to_tcp6_sock(void *sk) 4466 * Description 4467 * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. 4468 * Return 4469 * *sk* if casting is valid, or **NULL** otherwise. 4470 * 4471 * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk) 4472 * Description 4473 * Dynamically cast a *sk* pointer to a *tcp_sock* pointer. 4474 * Return 4475 * *sk* if casting is valid, or **NULL** otherwise. 4476 * 4477 * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk) 4478 * Description 4479 * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer. 4480 * Return 4481 * *sk* if casting is valid, or **NULL** otherwise. 4482 * 4483 * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk) 4484 * Description 4485 * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. 4486 * Return 4487 * *sk* if casting is valid, or **NULL** otherwise. 4488 * 4489 * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) 4490 * Description 4491 * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. 4492 * Return 4493 * *sk* if casting is valid, or **NULL** otherwise. 4494 * 4495 * long bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, u64 flags) 4496 * Description 4497 * Return a user or a kernel stack in bpf program provided buffer. 4498 * Note: the user stack will only be populated if the *task* is 4499 * the current task; all other tasks will return -EOPNOTSUPP. 4500 * To achieve this, the helper needs *task*, which is a valid 4501 * pointer to **struct task_struct**. To store the stacktrace, the 4502 * bpf program provides *buf* with a nonnegative *size*. 4503 * 4504 * The last argument, *flags*, holds the number of stack frames to 4505 * skip (from 0 to 255), masked with 4506 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set 4507 * the following flags: 4508 * 4509 * **BPF_F_USER_STACK** 4510 * Collect a user space stack instead of a kernel stack. 4511 * The *task* must be the current task. 4512 * **BPF_F_USER_BUILD_ID** 4513 * Collect buildid+offset instead of ips for user stack, 4514 * only valid if **BPF_F_USER_STACK** is also specified. 4515 * 4516 * **bpf_get_task_stack**\ () can collect up to 4517 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject 4518 * to sufficient large buffer size. Note that 4519 * this limit can be controlled with the **sysctl** program, and 4520 * that it should be manually increased in order to profile long 4521 * user stacks (such as stacks for Java programs). To do so, use: 4522 * 4523 * :: 4524 * 4525 * # sysctl kernel.perf_event_max_stack=<new value> 4526 * Return 4527 * The non-negative copied *buf* length equal to or less than 4528 * *size* on success, or a negative error in case of failure. 4529 * 4530 * long bpf_load_hdr_opt(struct bpf_sock_ops *skops, void *searchby_res, u32 len, u64 flags) 4531 * Description 4532 * Load header option. Support reading a particular TCP header 4533 * option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**). 4534 * 4535 * If *flags* is 0, it will search the option from the 4536 * *skops*\ **->skb_data**. The comment in **struct bpf_sock_ops** 4537 * has details on what skb_data contains under different 4538 * *skops*\ **->op**. 4539 * 4540 * The first byte of the *searchby_res* specifies the 4541 * kind that it wants to search. 4542 * 4543 * If the searching kind is an experimental kind 4544 * (i.e. 253 or 254 according to RFC6994). It also 4545 * needs to specify the "magic" which is either 4546 * 2 bytes or 4 bytes. It then also needs to 4547 * specify the size of the magic by using 4548 * the 2nd byte which is "kind-length" of a TCP 4549 * header option and the "kind-length" also 4550 * includes the first 2 bytes "kind" and "kind-length" 4551 * itself as a normal TCP header option also does. 4552 * 4553 * For example, to search experimental kind 254 with 4554 * 2 byte magic 0xeB9F, the searchby_res should be 4555 * [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ]. 4556 * 4557 * To search for the standard window scale option (3), 4558 * the *searchby_res* should be [ 3, 0, 0, .... 0 ]. 4559 * Note, kind-length must be 0 for regular option. 4560 * 4561 * Searching for No-Op (0) and End-of-Option-List (1) are 4562 * not supported. 4563 * 4564 * *len* must be at least 2 bytes which is the minimal size 4565 * of a header option. 4566 * 4567 * Supported flags: 4568 * 4569 * * **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the 4570 * saved_syn packet or the just-received syn packet. 4571 * 4572 * Return 4573 * > 0 when found, the header option is copied to *searchby_res*. 4574 * The return value is the total length copied. On failure, a 4575 * negative error code is returned: 4576 * 4577 * **-EINVAL** if a parameter is invalid. 4578 * 4579 * **-ENOMSG** if the option is not found. 4580 * 4581 * **-ENOENT** if no syn packet is available when 4582 * **BPF_LOAD_HDR_OPT_TCP_SYN** is used. 4583 * 4584 * **-ENOSPC** if there is not enough space. Only *len* number of 4585 * bytes are copied. 4586 * 4587 * **-EFAULT** on failure to parse the header options in the 4588 * packet. 4589 * 4590 * **-EPERM** if the helper cannot be used under the current 4591 * *skops*\ **->op**. 4592 * 4593 * long bpf_store_hdr_opt(struct bpf_sock_ops *skops, const void *from, u32 len, u64 flags) 4594 * Description 4595 * Store header option. The data will be copied 4596 * from buffer *from* with length *len* to the TCP header. 4597 * 4598 * The buffer *from* should have the whole option that 4599 * includes the kind, kind-length, and the actual 4600 * option data. The *len* must be at least kind-length 4601 * long. The kind-length does not have to be 4 byte 4602 * aligned. The kernel will take care of the padding 4603 * and setting the 4 bytes aligned value to th->doff. 4604 * 4605 * This helper will check for duplicated option 4606 * by searching the same option in the outgoing skb. 4607 * 4608 * This helper can only be called during 4609 * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. 4610 * 4611 * Return 4612 * 0 on success, or negative error in case of failure: 4613 * 4614 * **-EINVAL** If param is invalid. 4615 * 4616 * **-ENOSPC** if there is not enough space in the header. 4617 * Nothing has been written 4618 * 4619 * **-EEXIST** if the option already exists. 4620 * 4621 * **-EFAULT** on failure to parse the existing header options. 4622 * 4623 * **-EPERM** if the helper cannot be used under the current 4624 * *skops*\ **->op**. 4625 * 4626 * long bpf_reserve_hdr_opt(struct bpf_sock_ops *skops, u32 len, u64 flags) 4627 * Description 4628 * Reserve *len* bytes for the bpf header option. The 4629 * space will be used by **bpf_store_hdr_opt**\ () later in 4630 * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. 4631 * 4632 * If **bpf_reserve_hdr_opt**\ () is called multiple times, 4633 * the total number of bytes will be reserved. 4634 * 4635 * This helper can only be called during 4636 * **BPF_SOCK_OPS_HDR_OPT_LEN_CB**. 4637 * 4638 * Return 4639 * 0 on success, or negative error in case of failure: 4640 * 4641 * **-EINVAL** if a parameter is invalid. 4642 * 4643 * **-ENOSPC** if there is not enough space in the header. 4644 * 4645 * **-EPERM** if the helper cannot be used under the current 4646 * *skops*\ **->op**. 4647 * 4648 * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags) 4649 * Description 4650 * Get a bpf_local_storage from an *inode*. 4651 * 4652 * Logically, it could be thought of as getting the value from 4653 * a *map* with *inode* as the **key**. From this 4654 * perspective, the usage is not much different from 4655 * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this 4656 * helper enforces the key must be an inode and the map must also 4657 * be a **BPF_MAP_TYPE_INODE_STORAGE**. 4658 * 4659 * Underneath, the value is stored locally at *inode* instead of 4660 * the *map*. The *map* is used as the bpf-local-storage 4661 * "type". The bpf-local-storage "type" (i.e. the *map*) is 4662 * searched against all bpf_local_storage residing at *inode*. 4663 * 4664 * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be 4665 * used such that a new bpf_local_storage will be 4666 * created if one does not exist. *value* can be used 4667 * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify 4668 * the initial value of a bpf_local_storage. If *value* is 4669 * **NULL**, the new bpf_local_storage will be zero initialized. 4670 * Return 4671 * A bpf_local_storage pointer is returned on success. 4672 * 4673 * **NULL** if not found or there was an error in adding 4674 * a new bpf_local_storage. 4675 * 4676 * int bpf_inode_storage_delete(struct bpf_map *map, void *inode) 4677 * Description 4678 * Delete a bpf_local_storage from an *inode*. 4679 * Return 4680 * 0 on success. 4681 * 4682 * **-ENOENT** if the bpf_local_storage cannot be found. 4683 * 4684 * long bpf_d_path(struct path *path, char *buf, u32 sz) 4685 * Description 4686 * Return full path for given **struct path** object, which 4687 * needs to be the kernel BTF *path* object. The path is 4688 * returned in the provided buffer *buf* of size *sz* and 4689 * is zero terminated. 4690 * 4691 * Return 4692 * On success, the strictly positive length of the string, 4693 * including the trailing NUL character. On error, a negative 4694 * value. 4695 * 4696 * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr) 4697 * Description 4698 * Read *size* bytes from user space address *user_ptr* and store 4699 * the data in *dst*. This is a wrapper of **copy_from_user**\ (). 4700 * Return 4701 * 0 on success, or a negative error in case of failure. 4702 * 4703 * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags) 4704 * Description 4705 * Use BTF to store a string representation of *ptr*->ptr in *str*, 4706 * using *ptr*->type_id. This value should specify the type 4707 * that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1) 4708 * can be used to look up vmlinux BTF type ids. Traversing the 4709 * data structure using BTF, the type information and values are 4710 * stored in the first *str_size* - 1 bytes of *str*. Safe copy of 4711 * the pointer data is carried out to avoid kernel crashes during 4712 * operation. Smaller types can use string space on the stack; 4713 * larger programs can use map data to store the string 4714 * representation. 4715 * 4716 * The string can be subsequently shared with userspace via 4717 * bpf_perf_event_output() or ring buffer interfaces. 4718 * bpf_trace_printk() is to be avoided as it places too small 4719 * a limit on string size to be useful. 4720 * 4721 * *flags* is a combination of 4722 * 4723 * **BTF_F_COMPACT** 4724 * no formatting around type information 4725 * **BTF_F_NONAME** 4726 * no struct/union member names/types 4727 * **BTF_F_PTR_RAW** 4728 * show raw (unobfuscated) pointer values; 4729 * equivalent to printk specifier %px. 4730 * **BTF_F_ZERO** 4731 * show zero-valued struct/union members; they 4732 * are not displayed by default 4733 * 4734 * Return 4735 * The number of bytes that were written (or would have been 4736 * written if output had to be truncated due to string size), 4737 * or a negative error in cases of failure. 4738 * 4739 * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags) 4740 * Description 4741 * Use BTF to write to seq_write a string representation of 4742 * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf(). 4743 * *flags* are identical to those used for bpf_snprintf_btf. 4744 * Return 4745 * 0 on success or a negative error in case of failure. 4746 * 4747 * u64 bpf_skb_cgroup_classid(struct sk_buff *skb) 4748 * Description 4749 * See **bpf_get_cgroup_classid**\ () for the main description. 4750 * This helper differs from **bpf_get_cgroup_classid**\ () in that 4751 * the cgroup v1 net_cls class is retrieved only from the *skb*'s 4752 * associated socket instead of the current process. 4753 * Return 4754 * The id is returned or 0 in case the id could not be retrieved. 4755 * 4756 * long bpf_redirect_neigh(u32 ifindex, struct bpf_redir_neigh *params, int plen, u64 flags) 4757 * Description 4758 * Redirect the packet to another net device of index *ifindex* 4759 * and fill in L2 addresses from neighboring subsystem. This helper 4760 * is somewhat similar to **bpf_redirect**\ (), except that it 4761 * populates L2 addresses as well, meaning, internally, the helper 4762 * relies on the neighbor lookup for the L2 address of the nexthop. 4763 * 4764 * The helper will perform a FIB lookup based on the skb's 4765 * networking header to get the address of the next hop, unless 4766 * this is supplied by the caller in the *params* argument. The 4767 * *plen* argument indicates the len of *params* and should be set 4768 * to 0 if *params* is NULL. 4769 * 4770 * The *flags* argument is reserved and must be 0. The helper is 4771 * currently only supported for tc BPF program types, and enabled 4772 * for IPv4 and IPv6 protocols. 4773 * Return 4774 * The helper returns **TC_ACT_REDIRECT** on success or 4775 * **TC_ACT_SHOT** on error. 4776 * 4777 * void *bpf_per_cpu_ptr(const void *percpu_ptr, u32 cpu) 4778 * Description 4779 * Take a pointer to a percpu ksym, *percpu_ptr*, and return a 4780 * pointer to the percpu kernel variable on *cpu*. A ksym is an 4781 * extern variable decorated with '__ksym'. For ksym, there is a 4782 * global var (either static or global) defined of the same name 4783 * in the kernel. The ksym is percpu if the global var is percpu. 4784 * The returned pointer points to the global percpu var on *cpu*. 4785 * 4786 * bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the 4787 * kernel, except that bpf_per_cpu_ptr() may return NULL. This 4788 * happens if *cpu* is larger than nr_cpu_ids. The caller of 4789 * bpf_per_cpu_ptr() must check the returned value. 4790 * Return 4791 * A pointer pointing to the kernel percpu variable on *cpu*, or 4792 * NULL, if *cpu* is invalid. 4793 * 4794 * void *bpf_this_cpu_ptr(const void *percpu_ptr) 4795 * Description 4796 * Take a pointer to a percpu ksym, *percpu_ptr*, and return a 4797 * pointer to the percpu kernel variable on this cpu. See the 4798 * description of 'ksym' in **bpf_per_cpu_ptr**\ (). 4799 * 4800 * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in 4801 * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would 4802 * never return NULL. 4803 * Return 4804 * A pointer pointing to the kernel percpu variable on this cpu. 4805 * 4806 * long bpf_redirect_peer(u32 ifindex, u64 flags) 4807 * Description 4808 * Redirect the packet to another net device of index *ifindex*. 4809 * This helper is somewhat similar to **bpf_redirect**\ (), except 4810 * that the redirection happens to the *ifindex*' peer device and 4811 * the netns switch takes place from ingress to ingress without 4812 * going through the CPU's backlog queue. 4813 * 4814 * The *flags* argument is reserved and must be 0. The helper is 4815 * currently only supported for tc BPF program types at the ingress 4816 * hook and for veth device types. The peer device must reside in a 4817 * different network namespace. 4818 * Return 4819 * The helper returns **TC_ACT_REDIRECT** on success or 4820 * **TC_ACT_SHOT** on error. 4821 * 4822 * void *bpf_task_storage_get(struct bpf_map *map, struct task_struct *task, void *value, u64 flags) 4823 * Description 4824 * Get a bpf_local_storage from the *task*. 4825 * 4826 * Logically, it could be thought of as getting the value from 4827 * a *map* with *task* as the **key**. From this 4828 * perspective, the usage is not much different from 4829 * **bpf_map_lookup_elem**\ (*map*, **&**\ *task*) except this 4830 * helper enforces the key must be a task_struct and the map must also 4831 * be a **BPF_MAP_TYPE_TASK_STORAGE**. 4832 * 4833 * Underneath, the value is stored locally at *task* instead of 4834 * the *map*. The *map* is used as the bpf-local-storage 4835 * "type". The bpf-local-storage "type" (i.e. the *map*) is 4836 * searched against all bpf_local_storage residing at *task*. 4837 * 4838 * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be 4839 * used such that a new bpf_local_storage will be 4840 * created if one does not exist. *value* can be used 4841 * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify 4842 * the initial value of a bpf_local_storage. If *value* is 4843 * **NULL**, the new bpf_local_storage will be zero initialized. 4844 * Return 4845 * A bpf_local_storage pointer is returned on success. 4846 * 4847 * **NULL** if not found or there was an error in adding 4848 * a new bpf_local_storage. 4849 * 4850 * long bpf_task_storage_delete(struct bpf_map *map, struct task_struct *task) 4851 * Description 4852 * Delete a bpf_local_storage from a *task*. 4853 * Return 4854 * 0 on success. 4855 * 4856 * **-ENOENT** if the bpf_local_storage cannot be found. 4857 * 4858 * struct task_struct *bpf_get_current_task_btf(void) 4859 * Description 4860 * Return a BTF pointer to the "current" task. 4861 * This pointer can also be used in helpers that accept an 4862 * *ARG_PTR_TO_BTF_ID* of type *task_struct*. 4863 * Return 4864 * Pointer to the current task. 4865 * 4866 * long bpf_bprm_opts_set(struct linux_binprm *bprm, u64 flags) 4867 * Description 4868 * Set or clear certain options on *bprm*: 4869 * 4870 * **BPF_F_BPRM_SECUREEXEC** Set the secureexec bit 4871 * which sets the **AT_SECURE** auxv for glibc. The bit 4872 * is cleared if the flag is not specified. 4873 * Return 4874 * **-EINVAL** if invalid *flags* are passed, zero otherwise. 4875 * 4876 * u64 bpf_ktime_get_coarse_ns(void) 4877 * Description 4878 * Return a coarse-grained version of the time elapsed since 4879 * system boot, in nanoseconds. Does not include time the system 4880 * was suspended. 4881 * 4882 * See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**) 4883 * Return 4884 * Current *ktime*. 4885 * 4886 * long bpf_ima_inode_hash(struct inode *inode, void *dst, u32 size) 4887 * Description 4888 * Returns the stored IMA hash of the *inode* (if it's available). 4889 * If the hash is larger than *size*, then only *size* 4890 * bytes will be copied to *dst* 4891 * Return 4892 * The **hash_algo** is returned on success, 4893 * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if 4894 * invalid arguments are passed. 4895 * 4896 * struct socket *bpf_sock_from_file(struct file *file) 4897 * Description 4898 * If the given file represents a socket, returns the associated 4899 * socket. 4900 * Return 4901 * A pointer to a struct socket on success or NULL if the file is 4902 * not a socket. 4903 * 4904 * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags) 4905 * Description 4906 * Check packet size against exceeding MTU of net device (based 4907 * on *ifindex*). This helper will likely be used in combination 4908 * with helpers that adjust/change the packet size. 4909 * 4910 * The argument *len_diff* can be used for querying with a planned 4911 * size change. This allows to check MTU prior to changing packet 4912 * ctx. Providing a *len_diff* adjustment that is larger than the 4913 * actual packet size (resulting in negative packet size) will in 4914 * principle not exceed the MTU, which is why it is not considered 4915 * a failure. Other BPF helpers are needed for performing the 4916 * planned size change; therefore the responsibility for catching 4917 * a negative packet size belongs in those helpers. 4918 * 4919 * Specifying *ifindex* zero means the MTU check is performed 4920 * against the current net device. This is practical if this isn't 4921 * used prior to redirect. 4922 * 4923 * On input *mtu_len* must be a valid pointer, else verifier will 4924 * reject BPF program. If the value *mtu_len* is initialized to 4925 * zero then the ctx packet size is use. When value *mtu_len* is 4926 * provided as input this specify the L3 length that the MTU check 4927 * is done against. Remember XDP and TC length operate at L2, but 4928 * this value is L3 as this correlate to MTU and IP-header tot_len 4929 * values which are L3 (similar behavior as bpf_fib_lookup). 4930 * 4931 * The Linux kernel route table can configure MTUs on a more 4932 * specific per route level, which is not provided by this helper. 4933 * For route level MTU checks use the **bpf_fib_lookup**\ () 4934 * helper. 4935 * 4936 * *ctx* is either **struct xdp_md** for XDP programs or 4937 * **struct sk_buff** for tc cls_act programs. 4938 * 4939 * The *flags* argument can be a combination of one or more of the 4940 * following values: 4941 * 4942 * **BPF_MTU_CHK_SEGS** 4943 * This flag will only works for *ctx* **struct sk_buff**. 4944 * If packet context contains extra packet segment buffers 4945 * (often knows as GSO skb), then MTU check is harder to 4946 * check at this point, because in transmit path it is 4947 * possible for the skb packet to get re-segmented 4948 * (depending on net device features). This could still be 4949 * a MTU violation, so this flag enables performing MTU 4950 * check against segments, with a different violation 4951 * return code to tell it apart. Check cannot use len_diff. 4952 * 4953 * On return *mtu_len* pointer contains the MTU value of the net 4954 * device. Remember the net device configured MTU is the L3 size, 4955 * which is returned here and XDP and TC length operate at L2. 4956 * Helper take this into account for you, but remember when using 4957 * MTU value in your BPF-code. 4958 * 4959 * Return 4960 * * 0 on success, and populate MTU value in *mtu_len* pointer. 4961 * 4962 * * < 0 if any input argument is invalid (*mtu_len* not updated) 4963 * 4964 * MTU violations return positive values, but also populate MTU 4965 * value in *mtu_len* pointer, as this can be needed for 4966 * implementing PMTU handing: 4967 * 4968 * * **BPF_MTU_CHK_RET_FRAG_NEEDED** 4969 * * **BPF_MTU_CHK_RET_SEGS_TOOBIG** 4970 * 4971 * long bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn, void *callback_ctx, u64 flags) 4972 * Description 4973 * For each element in **map**, call **callback_fn** function with 4974 * **map**, **callback_ctx** and other map-specific parameters. 4975 * The **callback_fn** should be a static function and 4976 * the **callback_ctx** should be a pointer to the stack. 4977 * The **flags** is used to control certain aspects of the helper. 4978 * Currently, the **flags** must be 0. 4979 * 4980 * The following are a list of supported map types and their 4981 * respective expected callback signatures: 4982 * 4983 * BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH, 4984 * BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH, 4985 * BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY 4986 * 4987 * long (\*callback_fn)(struct bpf_map \*map, const void \*key, void \*value, void \*ctx); 4988 * 4989 * For per_cpu maps, the map_value is the value on the cpu where the 4990 * bpf_prog is running. 4991 * 4992 * If **callback_fn** return 0, the helper will continue to the next 4993 * element. If return value is 1, the helper will skip the rest of 4994 * elements and return. Other return values are not used now. 4995 * 4996 * Return 4997 * The number of traversed map elements for success, **-EINVAL** for 4998 * invalid **flags**. 4999 * 5000 * long bpf_snprintf(char *str, u32 str_size, const char *fmt, u64 *data, u32 data_len) 5001 * Description 5002 * Outputs a string into the **str** buffer of size **str_size** 5003 * based on a format string stored in a read-only map pointed by 5004 * **fmt**. 5005 * 5006 * Each format specifier in **fmt** corresponds to one u64 element 5007 * in the **data** array. For strings and pointers where pointees 5008 * are accessed, only the pointer values are stored in the *data* 5009 * array. The *data_len* is the size of *data* in bytes - must be 5010 * a multiple of 8. 5011 * 5012 * Formats **%s** and **%p{i,I}{4,6}** require to read kernel 5013 * memory. Reading kernel memory may fail due to either invalid 5014 * address or valid address but requiring a major memory fault. If 5015 * reading kernel memory fails, the string for **%s** will be an 5016 * empty string, and the ip address for **%p{i,I}{4,6}** will be 0. 5017 * Not returning error to bpf program is consistent with what 5018 * **bpf_trace_printk**\ () does for now. 5019 * 5020 * Return 5021 * The strictly positive length of the formatted string, including 5022 * the trailing zero character. If the return value is greater than 5023 * **str_size**, **str** contains a truncated string, guaranteed to 5024 * be zero-terminated except when **str_size** is 0. 5025 * 5026 * Or **-EBUSY** if the per-CPU memory copy buffer is busy. 5027 * 5028 * long bpf_sys_bpf(u32 cmd, void *attr, u32 attr_size) 5029 * Description 5030 * Execute bpf syscall with given arguments. 5031 * Return 5032 * A syscall result. 5033 * 5034 * long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags) 5035 * Description 5036 * Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. 5037 * Return 5038 * Returns btf_id and btf_obj_fd in lower and upper 32 bits. 5039 * 5040 * long bpf_sys_close(u32 fd) 5041 * Description 5042 * Execute close syscall for given FD. 5043 * Return 5044 * A syscall result. 5045 * 5046 * long bpf_timer_init(struct bpf_timer *timer, struct bpf_map *map, u64 flags) 5047 * Description 5048 * Initialize the timer. 5049 * First 4 bits of *flags* specify clockid. 5050 * Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed. 5051 * All other bits of *flags* are reserved. 5052 * The verifier will reject the program if *timer* is not from 5053 * the same *map*. 5054 * Return 5055 * 0 on success. 5056 * **-EBUSY** if *timer* is already initialized. 5057 * **-EINVAL** if invalid *flags* are passed. 5058 * **-EPERM** if *timer* is in a map that doesn't have any user references. 5059 * The user space should either hold a file descriptor to a map with timers 5060 * or pin such map in bpffs. When map is unpinned or file descriptor is 5061 * closed all timers in the map will be cancelled and freed. 5062 * 5063 * long bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn) 5064 * Description 5065 * Configure the timer to call *callback_fn* static function. 5066 * Return 5067 * 0 on success. 5068 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. 5069 * **-EPERM** if *timer* is in a map that doesn't have any user references. 5070 * The user space should either hold a file descriptor to a map with timers 5071 * or pin such map in bpffs. When map is unpinned or file descriptor is 5072 * closed all timers in the map will be cancelled and freed. 5073 * 5074 * long bpf_timer_start(struct bpf_timer *timer, u64 nsecs, u64 flags) 5075 * Description 5076 * Set timer expiration N nanoseconds from the current time. The 5077 * configured callback will be invoked in soft irq context on some cpu 5078 * and will not repeat unless another bpf_timer_start() is made. 5079 * In such case the next invocation can migrate to a different cpu. 5080 * Since struct bpf_timer is a field inside map element the map 5081 * owns the timer. The bpf_timer_set_callback() will increment refcnt 5082 * of BPF program to make sure that callback_fn code stays valid. 5083 * When user space reference to a map reaches zero all timers 5084 * in a map are cancelled and corresponding program's refcnts are 5085 * decremented. This is done to make sure that Ctrl-C of a user 5086 * process doesn't leave any timers running. If map is pinned in 5087 * bpffs the callback_fn can re-arm itself indefinitely. 5088 * bpf_map_update/delete_elem() helpers and user space sys_bpf commands 5089 * cancel and free the timer in the given map element. 5090 * The map can contain timers that invoke callback_fn-s from different 5091 * programs. The same callback_fn can serve different timers from 5092 * different maps if key/value layout matches across maps. 5093 * Every bpf_timer_set_callback() can have different callback_fn. 5094 * 5095 * *flags* can be one of: 5096 * 5097 * **BPF_F_TIMER_ABS** 5098 * Start the timer in absolute expire value instead of the 5099 * default relative one. 5100 * 5101 * Return 5102 * 0 on success. 5103 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier 5104 * or invalid *flags* are passed. 5105 * 5106 * long bpf_timer_cancel(struct bpf_timer *timer) 5107 * Description 5108 * Cancel the timer and wait for callback_fn to finish if it was running. 5109 * Return 5110 * 0 if the timer was not active. 5111 * 1 if the timer was active. 5112 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. 5113 * **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its 5114 * own timer which would have led to a deadlock otherwise. 5115 * 5116 * u64 bpf_get_func_ip(void *ctx) 5117 * Description 5118 * Get address of the traced function (for tracing and kprobe programs). 5119 * 5120 * When called for kprobe program attached as uprobe it returns 5121 * probe address for both entry and return uprobe. 5122 * 5123 * Return 5124 * Address of the traced function for kprobe. 5125 * 0 for kprobes placed within the function (not at the entry). 5126 * Address of the probe for uprobe and return uprobe. 5127 * 5128 * u64 bpf_get_attach_cookie(void *ctx) 5129 * Description 5130 * Get bpf_cookie value provided (optionally) during the program 5131 * attachment. It might be different for each individual 5132 * attachment, even if BPF program itself is the same. 5133 * Expects BPF program context *ctx* as a first argument. 5134 * 5135 * Supported for the following program types: 5136 * - kprobe/uprobe; 5137 * - tracepoint; 5138 * - perf_event. 5139 * Return 5140 * Value specified by user at BPF link creation/attachment time 5141 * or 0, if it was not specified. 5142 * 5143 * long bpf_task_pt_regs(struct task_struct *task) 5144 * Description 5145 * Get the struct pt_regs associated with **task**. 5146 * Return 5147 * A pointer to struct pt_regs. 5148 * 5149 * long bpf_get_branch_snapshot(void *entries, u32 size, u64 flags) 5150 * Description 5151 * Get branch trace from hardware engines like Intel LBR. The 5152 * hardware engine is stopped shortly after the helper is 5153 * called. Therefore, the user need to filter branch entries 5154 * based on the actual use case. To capture branch trace 5155 * before the trigger point of the BPF program, the helper 5156 * should be called at the beginning of the BPF program. 5157 * 5158 * The data is stored as struct perf_branch_entry into output 5159 * buffer *entries*. *size* is the size of *entries* in bytes. 5160 * *flags* is reserved for now and must be zero. 5161 * 5162 * Return 5163 * On success, number of bytes written to *buf*. On error, a 5164 * negative value. 5165 * 5166 * **-EINVAL** if *flags* is not zero. 5167 * 5168 * **-ENOENT** if architecture does not support branch records. 5169 * 5170 * long bpf_trace_vprintk(const char *fmt, u32 fmt_size, const void *data, u32 data_len) 5171 * Description 5172 * Behaves like **bpf_trace_printk**\ () helper, but takes an array of u64 5173 * to format and can handle more format args as a result. 5174 * 5175 * Arguments are to be used as in **bpf_seq_printf**\ () helper. 5176 * Return 5177 * The number of bytes written to the buffer, or a negative error 5178 * in case of failure. 5179 * 5180 * struct unix_sock *bpf_skc_to_unix_sock(void *sk) 5181 * Description 5182 * Dynamically cast a *sk* pointer to a *unix_sock* pointer. 5183 * Return 5184 * *sk* if casting is valid, or **NULL** otherwise. 5185 * 5186 * long bpf_kallsyms_lookup_name(const char *name, int name_sz, int flags, u64 *res) 5187 * Description 5188 * Get the address of a kernel symbol, returned in *res*. *res* is 5189 * set to 0 if the symbol is not found. 5190 * Return 5191 * On success, zero. On error, a negative value. 5192 * 5193 * **-EINVAL** if *flags* is not zero. 5194 * 5195 * **-EINVAL** if string *name* is not the same size as *name_sz*. 5196 * 5197 * **-ENOENT** if symbol is not found. 5198 * 5199 * **-EPERM** if caller does not have permission to obtain kernel address. 5200 * 5201 * long bpf_find_vma(struct task_struct *task, u64 addr, void *callback_fn, void *callback_ctx, u64 flags) 5202 * Description 5203 * Find vma of *task* that contains *addr*, call *callback_fn* 5204 * function with *task*, *vma*, and *callback_ctx*. 5205 * The *callback_fn* should be a static function and 5206 * the *callback_ctx* should be a pointer to the stack. 5207 * The *flags* is used to control certain aspects of the helper. 5208 * Currently, the *flags* must be 0. 5209 * 5210 * The expected callback signature is 5211 * 5212 * long (\*callback_fn)(struct task_struct \*task, struct vm_area_struct \*vma, void \*callback_ctx); 5213 * 5214 * Return 5215 * 0 on success. 5216 * **-ENOENT** if *task->mm* is NULL, or no vma contains *addr*. 5217 * **-EBUSY** if failed to try lock mmap_lock. 5218 * **-EINVAL** for invalid **flags**. 5219 * 5220 * long bpf_loop(u32 nr_loops, void *callback_fn, void *callback_ctx, u64 flags) 5221 * Description 5222 * For **nr_loops**, call **callback_fn** function 5223 * with **callback_ctx** as the context parameter. 5224 * The **callback_fn** should be a static function and 5225 * the **callback_ctx** should be a pointer to the stack. 5226 * The **flags** is used to control certain aspects of the helper. 5227 * Currently, the **flags** must be 0. Currently, nr_loops is 5228 * limited to 1 << 23 (~8 million) loops. 5229 * 5230 * long (\*callback_fn)(u32 index, void \*ctx); 5231 * 5232 * where **index** is the current index in the loop. The index 5233 * is zero-indexed. 5234 * 5235 * If **callback_fn** returns 0, the helper will continue to the next 5236 * loop. If return value is 1, the helper will skip the rest of 5237 * the loops and return. Other return values are not used now, 5238 * and will be rejected by the verifier. 5239 * 5240 * Return 5241 * The number of loops performed, **-EINVAL** for invalid **flags**, 5242 * **-E2BIG** if **nr_loops** exceeds the maximum number of loops. 5243 * 5244 * long bpf_strncmp(const char *s1, u32 s1_sz, const char *s2) 5245 * Description 5246 * Do strncmp() between **s1** and **s2**. **s1** doesn't need 5247 * to be null-terminated and **s1_sz** is the maximum storage 5248 * size of **s1**. **s2** must be a read-only string. 5249 * Return 5250 * An integer less than, equal to, or greater than zero 5251 * if the first **s1_sz** bytes of **s1** is found to be 5252 * less than, to match, or be greater than **s2**. 5253 * 5254 * long bpf_get_func_arg(void *ctx, u32 n, u64 *value) 5255 * Description 5256 * Get **n**-th argument register (zero based) of the traced function (for tracing programs) 5257 * returned in **value**. 5258 * 5259 * Return 5260 * 0 on success. 5261 * **-EINVAL** if n >= argument register count of traced function. 5262 * 5263 * long bpf_get_func_ret(void *ctx, u64 *value) 5264 * Description 5265 * Get return value of the traced function (for tracing programs) 5266 * in **value**. 5267 * 5268 * Return 5269 * 0 on success. 5270 * **-EOPNOTSUPP** for tracing programs other than BPF_TRACE_FEXIT or BPF_MODIFY_RETURN. 5271 * 5272 * long bpf_get_func_arg_cnt(void *ctx) 5273 * Description 5274 * Get number of registers of the traced function (for tracing programs) where 5275 * function arguments are stored in these registers. 5276 * 5277 * Return 5278 * The number of argument registers of the traced function. 5279 * 5280 * int bpf_get_retval(void) 5281 * Description 5282 * Get the BPF program's return value that will be returned to the upper layers. 5283 * 5284 * This helper is currently supported by cgroup programs and only by the hooks 5285 * where BPF program's return value is returned to the userspace via errno. 5286 * Return 5287 * The BPF program's return value. 5288 * 5289 * int bpf_set_retval(int retval) 5290 * Description 5291 * Set the BPF program's return value that will be returned to the upper layers. 5292 * 5293 * This helper is currently supported by cgroup programs and only by the hooks 5294 * where BPF program's return value is returned to the userspace via errno. 5295 * 5296 * Note that there is the following corner case where the program exports an error 5297 * via bpf_set_retval but signals success via 'return 1': 5298 * 5299 * bpf_set_retval(-EPERM); 5300 * return 1; 5301 * 5302 * In this case, the BPF program's return value will use helper's -EPERM. This 5303 * still holds true for cgroup/bind{4,6} which supports extra 'return 3' success case. 5304 * 5305 * Return 5306 * 0 on success, or a negative error in case of failure. 5307 * 5308 * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md) 5309 * Description 5310 * Get the total size of a given xdp buff (linear and paged area) 5311 * Return 5312 * The total size of a given xdp buffer. 5313 * 5314 * long bpf_xdp_load_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len) 5315 * Description 5316 * This helper is provided as an easy way to load data from a 5317 * xdp buffer. It can be used to load *len* bytes from *offset* from 5318 * the frame associated to *xdp_md*, into the buffer pointed by 5319 * *buf*. 5320 * Return 5321 * 0 on success, or a negative error in case of failure. 5322 * 5323 * long bpf_xdp_store_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len) 5324 * Description 5325 * Store *len* bytes from buffer *buf* into the frame 5326 * associated to *xdp_md*, at *offset*. 5327 * Return 5328 * 0 on success, or a negative error in case of failure. 5329 * 5330 * long bpf_copy_from_user_task(void *dst, u32 size, const void *user_ptr, struct task_struct *tsk, u64 flags) 5331 * Description 5332 * Read *size* bytes from user space address *user_ptr* in *tsk*'s 5333 * address space, and stores the data in *dst*. *flags* is not 5334 * used yet and is provided for future extensibility. This helper 5335 * can only be used by sleepable programs. 5336 * Return 5337 * 0 on success, or a negative error in case of failure. On error 5338 * *dst* buffer is zeroed out. 5339 * 5340 * long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type) 5341 * Description 5342 * Change the __sk_buff->tstamp_type to *tstamp_type* 5343 * and set *tstamp* to the __sk_buff->tstamp together. 5344 * 5345 * If there is no need to change the __sk_buff->tstamp_type, 5346 * the tstamp value can be directly written to __sk_buff->tstamp 5347 * instead. 5348 * 5349 * BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that 5350 * will be kept during bpf_redirect_*(). A non zero 5351 * *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO 5352 * *tstamp_type*. 5353 * 5354 * A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used 5355 * with a zero *tstamp*. 5356 * 5357 * Only IPv4 and IPv6 skb->protocol are supported. 5358 * 5359 * This function is most useful when it needs to set a 5360 * mono delivery time to __sk_buff->tstamp and then 5361 * bpf_redirect_*() to the egress of an iface. For example, 5362 * changing the (rcv) timestamp in __sk_buff->tstamp at 5363 * ingress to a mono delivery time and then bpf_redirect_*() 5364 * to sch_fq@phy-dev. 5365 * Return 5366 * 0 on success. 5367 * **-EINVAL** for invalid input 5368 * **-EOPNOTSUPP** for unsupported protocol 5369 * 5370 * long bpf_ima_file_hash(struct file *file, void *dst, u32 size) 5371 * Description 5372 * Returns a calculated IMA hash of the *file*. 5373 * If the hash is larger than *size*, then only *size* 5374 * bytes will be copied to *dst* 5375 * Return 5376 * The **hash_algo** is returned on success, 5377 * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if 5378 * invalid arguments are passed. 5379 * 5380 * void *bpf_kptr_xchg(void *map_value, void *ptr) 5381 * Description 5382 * Exchange kptr at pointer *map_value* with *ptr*, and return the 5383 * old value. *ptr* can be NULL, otherwise it must be a referenced 5384 * pointer which will be released when this helper is called. 5385 * Return 5386 * The old value of kptr (which can be NULL). The returned pointer 5387 * if not NULL, is a reference which must be released using its 5388 * corresponding release function, or moved into a BPF map before 5389 * program exit. 5390 * 5391 * void *bpf_map_lookup_percpu_elem(struct bpf_map *map, const void *key, u32 cpu) 5392 * Description 5393 * Perform a lookup in *percpu map* for an entry associated to 5394 * *key* on *cpu*. 5395 * Return 5396 * Map value associated to *key* on *cpu*, or **NULL** if no entry 5397 * was found or *cpu* is invalid. 5398 * 5399 * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk) 5400 * Description 5401 * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer. 5402 * Return 5403 * *sk* if casting is valid, or **NULL** otherwise. 5404 * 5405 * long bpf_dynptr_from_mem(void *data, u32 size, u64 flags, struct bpf_dynptr *ptr) 5406 * Description 5407 * Get a dynptr to local memory *data*. 5408 * 5409 * *data* must be a ptr to a map value. 5410 * The maximum *size* supported is DYNPTR_MAX_SIZE. 5411 * *flags* is currently unused. 5412 * Return 5413 * 0 on success, -E2BIG if the size exceeds DYNPTR_MAX_SIZE, 5414 * -EINVAL if flags is not 0. 5415 * 5416 * long bpf_ringbuf_reserve_dynptr(void *ringbuf, u32 size, u64 flags, struct bpf_dynptr *ptr) 5417 * Description 5418 * Reserve *size* bytes of payload in a ring buffer *ringbuf* 5419 * through the dynptr interface. *flags* must be 0. 5420 * 5421 * Please note that a corresponding bpf_ringbuf_submit_dynptr or 5422 * bpf_ringbuf_discard_dynptr must be called on *ptr*, even if the 5423 * reservation fails. This is enforced by the verifier. 5424 * Return 5425 * 0 on success, or a negative error in case of failure. 5426 * 5427 * void bpf_ringbuf_submit_dynptr(struct bpf_dynptr *ptr, u64 flags) 5428 * Description 5429 * Submit reserved ring buffer sample, pointed to by *data*, 5430 * through the dynptr interface. This is a no-op if the dynptr is 5431 * invalid/null. 5432 * 5433 * For more information on *flags*, please see 5434 * 'bpf_ringbuf_submit'. 5435 * Return 5436 * Nothing. Always succeeds. 5437 * 5438 * void bpf_ringbuf_discard_dynptr(struct bpf_dynptr *ptr, u64 flags) 5439 * Description 5440 * Discard reserved ring buffer sample through the dynptr 5441 * interface. This is a no-op if the dynptr is invalid/null. 5442 * 5443 * For more information on *flags*, please see 5444 * 'bpf_ringbuf_discard'. 5445 * Return 5446 * Nothing. Always succeeds. 5447 * 5448 * long bpf_dynptr_read(void *dst, u32 len, const struct bpf_dynptr *src, u32 offset, u64 flags) 5449 * Description 5450 * Read *len* bytes from *src* into *dst*, starting from *offset* 5451 * into *src*. 5452 * *flags* is currently unused. 5453 * Return 5454 * 0 on success, -E2BIG if *offset* + *len* exceeds the length 5455 * of *src*'s data, -EINVAL if *src* is an invalid dynptr or if 5456 * *flags* is not 0. 5457 * 5458 * long bpf_dynptr_write(const struct bpf_dynptr *dst, u32 offset, void *src, u32 len, u64 flags) 5459 * Description 5460 * Write *len* bytes from *src* into *dst*, starting from *offset* 5461 * into *dst*. 5462 * 5463 * *flags* must be 0 except for skb-type dynptrs. 5464 * 5465 * For skb-type dynptrs: 5466 * * All data slices of the dynptr are automatically 5467 * invalidated after **bpf_dynptr_write**\ (). This is 5468 * because writing may pull the skb and change the 5469 * underlying packet buffer. 5470 * 5471 * * For *flags*, please see the flags accepted by 5472 * **bpf_skb_store_bytes**\ (). 5473 * Return 5474 * 0 on success, -E2BIG if *offset* + *len* exceeds the length 5475 * of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst* 5476 * is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs, 5477 * other errors correspond to errors returned by **bpf_skb_store_bytes**\ (). 5478 * 5479 * void *bpf_dynptr_data(const struct bpf_dynptr *ptr, u32 offset, u32 len) 5480 * Description 5481 * Get a pointer to the underlying dynptr data. 5482 * 5483 * *len* must be a statically known value. The returned data slice 5484 * is invalidated whenever the dynptr is invalidated. 5485 * 5486 * skb and xdp type dynptrs may not use bpf_dynptr_data. They should 5487 * instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr. 5488 * Return 5489 * Pointer to the underlying dynptr data, NULL if the dynptr is 5490 * read-only, if the dynptr is invalid, or if the offset and length 5491 * is out of bounds. 5492 * 5493 * s64 bpf_tcp_raw_gen_syncookie_ipv4(struct iphdr *iph, struct tcphdr *th, u32 th_len) 5494 * Description 5495 * Try to issue a SYN cookie for the packet with corresponding 5496 * IPv4/TCP headers, *iph* and *th*, without depending on a 5497 * listening socket. 5498 * 5499 * *iph* points to the IPv4 header. 5500 * 5501 * *th* points to the start of the TCP header, while *th_len* 5502 * contains the length of the TCP header (at least 5503 * **sizeof**\ (**struct tcphdr**)). 5504 * Return 5505 * On success, lower 32 bits hold the generated SYN cookie in 5506 * followed by 16 bits which hold the MSS value for that cookie, 5507 * and the top 16 bits are unused. 5508 * 5509 * On failure, the returned value is one of the following: 5510 * 5511 * **-EINVAL** if *th_len* is invalid. 5512 * 5513 * s64 bpf_tcp_raw_gen_syncookie_ipv6(struct ipv6hdr *iph, struct tcphdr *th, u32 th_len) 5514 * Description 5515 * Try to issue a SYN cookie for the packet with corresponding 5516 * IPv6/TCP headers, *iph* and *th*, without depending on a 5517 * listening socket. 5518 * 5519 * *iph* points to the IPv6 header. 5520 * 5521 * *th* points to the start of the TCP header, while *th_len* 5522 * contains the length of the TCP header (at least 5523 * **sizeof**\ (**struct tcphdr**)). 5524 * Return 5525 * On success, lower 32 bits hold the generated SYN cookie in 5526 * followed by 16 bits which hold the MSS value for that cookie, 5527 * and the top 16 bits are unused. 5528 * 5529 * On failure, the returned value is one of the following: 5530 * 5531 * **-EINVAL** if *th_len* is invalid. 5532 * 5533 * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. 5534 * 5535 * long bpf_tcp_raw_check_syncookie_ipv4(struct iphdr *iph, struct tcphdr *th) 5536 * Description 5537 * Check whether *iph* and *th* contain a valid SYN cookie ACK 5538 * without depending on a listening socket. 5539 * 5540 * *iph* points to the IPv4 header. 5541 * 5542 * *th* points to the TCP header. 5543 * Return 5544 * 0 if *iph* and *th* are a valid SYN cookie ACK. 5545 * 5546 * On failure, the returned value is one of the following: 5547 * 5548 * **-EACCES** if the SYN cookie is not valid. 5549 * 5550 * long bpf_tcp_raw_check_syncookie_ipv6(struct ipv6hdr *iph, struct tcphdr *th) 5551 * Description 5552 * Check whether *iph* and *th* contain a valid SYN cookie ACK 5553 * without depending on a listening socket. 5554 * 5555 * *iph* points to the IPv6 header. 5556 * 5557 * *th* points to the TCP header. 5558 * Return 5559 * 0 if *iph* and *th* are a valid SYN cookie ACK. 5560 * 5561 * On failure, the returned value is one of the following: 5562 * 5563 * **-EACCES** if the SYN cookie is not valid. 5564 * 5565 * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. 5566 * 5567 * u64 bpf_ktime_get_tai_ns(void) 5568 * Description 5569 * A nonsettable system-wide clock derived from wall-clock time but 5570 * ignoring leap seconds. This clock does not experience 5571 * discontinuities and backwards jumps caused by NTP inserting leap 5572 * seconds as CLOCK_REALTIME does. 5573 * 5574 * See: **clock_gettime**\ (**CLOCK_TAI**) 5575 * Return 5576 * Current *ktime*. 5577 * 5578 * long bpf_user_ringbuf_drain(struct bpf_map *map, void *callback_fn, void *ctx, u64 flags) 5579 * Description 5580 * Drain samples from the specified user ring buffer, and invoke 5581 * the provided callback for each such sample: 5582 * 5583 * long (\*callback_fn)(const struct bpf_dynptr \*dynptr, void \*ctx); 5584 * 5585 * If **callback_fn** returns 0, the helper will continue to try 5586 * and drain the next sample, up to a maximum of 5587 * BPF_MAX_USER_RINGBUF_SAMPLES samples. If the return value is 1, 5588 * the helper will skip the rest of the samples and return. Other 5589 * return values are not used now, and will be rejected by the 5590 * verifier. 5591 * Return 5592 * The number of drained samples if no error was encountered while 5593 * draining samples, or 0 if no samples were present in the ring 5594 * buffer. If a user-space producer was epoll-waiting on this map, 5595 * and at least one sample was drained, they will receive an event 5596 * notification notifying them of available space in the ring 5597 * buffer. If the BPF_RB_NO_WAKEUP flag is passed to this 5598 * function, no wakeup notification will be sent. If the 5599 * BPF_RB_FORCE_WAKEUP flag is passed, a wakeup notification will 5600 * be sent even if no sample was drained. 5601 * 5602 * On failure, the returned value is one of the following: 5603 * 5604 * **-EBUSY** if the ring buffer is contended, and another calling 5605 * context was concurrently draining the ring buffer. 5606 * 5607 * **-EINVAL** if user-space is not properly tracking the ring 5608 * buffer due to the producer position not being aligned to 8 5609 * bytes, a sample not being aligned to 8 bytes, or the producer 5610 * position not matching the advertised length of a sample. 5611 * 5612 * **-E2BIG** if user-space has tried to publish a sample which is 5613 * larger than the size of the ring buffer, or which cannot fit 5614 * within a struct bpf_dynptr. 5615 * 5616 * void *bpf_cgrp_storage_get(struct bpf_map *map, struct cgroup *cgroup, void *value, u64 flags) 5617 * Description 5618 * Get a bpf_local_storage from the *cgroup*. 5619 * 5620 * Logically, it could be thought of as getting the value from 5621 * a *map* with *cgroup* as the **key**. From this 5622 * perspective, the usage is not much different from 5623 * **bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this 5624 * helper enforces the key must be a cgroup struct and the map must also 5625 * be a **BPF_MAP_TYPE_CGRP_STORAGE**. 5626 * 5627 * In reality, the local-storage value is embedded directly inside of the 5628 * *cgroup* object itself, rather than being located in the 5629 * **BPF_MAP_TYPE_CGRP_STORAGE** map. When the local-storage value is 5630 * queried for some *map* on a *cgroup* object, the kernel will perform an 5631 * O(n) iteration over all of the live local-storage values for that 5632 * *cgroup* object until the local-storage value for the *map* is found. 5633 * 5634 * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be 5635 * used such that a new bpf_local_storage will be 5636 * created if one does not exist. *value* can be used 5637 * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify 5638 * the initial value of a bpf_local_storage. If *value* is 5639 * **NULL**, the new bpf_local_storage will be zero initialized. 5640 * Return 5641 * A bpf_local_storage pointer is returned on success. 5642 * 5643 * **NULL** if not found or there was an error in adding 5644 * a new bpf_local_storage. 5645 * 5646 * long bpf_cgrp_storage_delete(struct bpf_map *map, struct cgroup *cgroup) 5647 * Description 5648 * Delete a bpf_local_storage from a *cgroup*. 5649 * Return 5650 * 0 on success. 5651 * 5652 * **-ENOENT** if the bpf_local_storage cannot be found. 5653 */ 5654 #define ___BPF_FUNC_MAPPER(FN, ctx...) \ 5655 FN(unspec, 0, ##ctx) \ 5656 FN(map_lookup_elem, 1, ##ctx) \ 5657 FN(map_update_elem, 2, ##ctx) \ 5658 FN(map_delete_elem, 3, ##ctx) \ 5659 FN(probe_read, 4, ##ctx) \ 5660 FN(ktime_get_ns, 5, ##ctx) \ 5661 FN(trace_printk, 6, ##ctx) \ 5662 FN(get_prandom_u32, 7, ##ctx) \ 5663 FN(get_smp_processor_id, 8, ##ctx) \ 5664 FN(skb_store_bytes, 9, ##ctx) \ 5665 FN(l3_csum_replace, 10, ##ctx) \ 5666 FN(l4_csum_replace, 11, ##ctx) \ 5667 FN(tail_call, 12, ##ctx) \ 5668 FN(clone_redirect, 13, ##ctx) \ 5669 FN(get_current_pid_tgid, 14, ##ctx) \ 5670 FN(get_current_uid_gid, 15, ##ctx) \ 5671 FN(get_current_comm, 16, ##ctx) \ 5672 FN(get_cgroup_classid, 17, ##ctx) \ 5673 FN(skb_vlan_push, 18, ##ctx) \ 5674 FN(skb_vlan_pop, 19, ##ctx) \ 5675 FN(skb_get_tunnel_key, 20, ##ctx) \ 5676 FN(skb_set_tunnel_key, 21, ##ctx) \ 5677 FN(perf_event_read, 22, ##ctx) \ 5678 FN(redirect, 23, ##ctx) \ 5679 FN(get_route_realm, 24, ##ctx) \ 5680 FN(perf_event_output, 25, ##ctx) \ 5681 FN(skb_load_bytes, 26, ##ctx) \ 5682 FN(get_stackid, 27, ##ctx) \ 5683 FN(csum_diff, 28, ##ctx) \ 5684 FN(skb_get_tunnel_opt, 29, ##ctx) \ 5685 FN(skb_set_tunnel_opt, 30, ##ctx) \ 5686 FN(skb_change_proto, 31, ##ctx) \ 5687 FN(skb_change_type, 32, ##ctx) \ 5688 FN(skb_under_cgroup, 33, ##ctx) \ 5689 FN(get_hash_recalc, 34, ##ctx) \ 5690 FN(get_current_task, 35, ##ctx) \ 5691 FN(probe_write_user, 36, ##ctx) \ 5692 FN(current_task_under_cgroup, 37, ##ctx) \ 5693 FN(skb_change_tail, 38, ##ctx) \ 5694 FN(skb_pull_data, 39, ##ctx) \ 5695 FN(csum_update, 40, ##ctx) \ 5696 FN(set_hash_invalid, 41, ##ctx) \ 5697 FN(get_numa_node_id, 42, ##ctx) \ 5698 FN(skb_change_head, 43, ##ctx) \ 5699 FN(xdp_adjust_head, 44, ##ctx) \ 5700 FN(probe_read_str, 45, ##ctx) \ 5701 FN(get_socket_cookie, 46, ##ctx) \ 5702 FN(get_socket_uid, 47, ##ctx) \ 5703 FN(set_hash, 48, ##ctx) \ 5704 FN(setsockopt, 49, ##ctx) \ 5705 FN(skb_adjust_room, 50, ##ctx) \ 5706 FN(redirect_map, 51, ##ctx) \ 5707 FN(sk_redirect_map, 52, ##ctx) \ 5708 FN(sock_map_update, 53, ##ctx) \ 5709 FN(xdp_adjust_meta, 54, ##ctx) \ 5710 FN(perf_event_read_value, 55, ##ctx) \ 5711 FN(perf_prog_read_value, 56, ##ctx) \ 5712 FN(getsockopt, 57, ##ctx) \ 5713 FN(override_return, 58, ##ctx) \ 5714 FN(sock_ops_cb_flags_set, 59, ##ctx) \ 5715 FN(msg_redirect_map, 60, ##ctx) \ 5716 FN(msg_apply_bytes, 61, ##ctx) \ 5717 FN(msg_cork_bytes, 62, ##ctx) \ 5718 FN(msg_pull_data, 63, ##ctx) \ 5719 FN(bind, 64, ##ctx) \ 5720 FN(xdp_adjust_tail, 65, ##ctx) \ 5721 FN(skb_get_xfrm_state, 66, ##ctx) \ 5722 FN(get_stack, 67, ##ctx) \ 5723 FN(skb_load_bytes_relative, 68, ##ctx) \ 5724 FN(fib_lookup, 69, ##ctx) \ 5725 FN(sock_hash_update, 70, ##ctx) \ 5726 FN(msg_redirect_hash, 71, ##ctx) \ 5727 FN(sk_redirect_hash, 72, ##ctx) \ 5728 FN(lwt_push_encap, 73, ##ctx) \ 5729 FN(lwt_seg6_store_bytes, 74, ##ctx) \ 5730 FN(lwt_seg6_adjust_srh, 75, ##ctx) \ 5731 FN(lwt_seg6_action, 76, ##ctx) \ 5732 FN(rc_repeat, 77, ##ctx) \ 5733 FN(rc_keydown, 78, ##ctx) \ 5734 FN(skb_cgroup_id, 79, ##ctx) \ 5735 FN(get_current_cgroup_id, 80, ##ctx) \ 5736 FN(get_local_storage, 81, ##ctx) \ 5737 FN(sk_select_reuseport, 82, ##ctx) \ 5738 FN(skb_ancestor_cgroup_id, 83, ##ctx) \ 5739 FN(sk_lookup_tcp, 84, ##ctx) \ 5740 FN(sk_lookup_udp, 85, ##ctx) \ 5741 FN(sk_release, 86, ##ctx) \ 5742 FN(map_push_elem, 87, ##ctx) \ 5743 FN(map_pop_elem, 88, ##ctx) \ 5744 FN(map_peek_elem, 89, ##ctx) \ 5745 FN(msg_push_data, 90, ##ctx) \ 5746 FN(msg_pop_data, 91, ##ctx) \ 5747 FN(rc_pointer_rel, 92, ##ctx) \ 5748 FN(spin_lock, 93, ##ctx) \ 5749 FN(spin_unlock, 94, ##ctx) \ 5750 FN(sk_fullsock, 95, ##ctx) \ 5751 FN(tcp_sock, 96, ##ctx) \ 5752 FN(skb_ecn_set_ce, 97, ##ctx) \ 5753 FN(get_listener_sock, 98, ##ctx) \ 5754 FN(skc_lookup_tcp, 99, ##ctx) \ 5755 FN(tcp_check_syncookie, 100, ##ctx) \ 5756 FN(sysctl_get_name, 101, ##ctx) \ 5757 FN(sysctl_get_current_value, 102, ##ctx) \ 5758 FN(sysctl_get_new_value, 103, ##ctx) \ 5759 FN(sysctl_set_new_value, 104, ##ctx) \ 5760 FN(strtol, 105, ##ctx) \ 5761 FN(strtoul, 106, ##ctx) \ 5762 FN(sk_storage_get, 107, ##ctx) \ 5763 FN(sk_storage_delete, 108, ##ctx) \ 5764 FN(send_signal, 109, ##ctx) \ 5765 FN(tcp_gen_syncookie, 110, ##ctx) \ 5766 FN(skb_output, 111, ##ctx) \ 5767 FN(probe_read_user, 112, ##ctx) \ 5768 FN(probe_read_kernel, 113, ##ctx) \ 5769 FN(probe_read_user_str, 114, ##ctx) \ 5770 FN(probe_read_kernel_str, 115, ##ctx) \ 5771 FN(tcp_send_ack, 116, ##ctx) \ 5772 FN(send_signal_thread, 117, ##ctx) \ 5773 FN(jiffies64, 118, ##ctx) \ 5774 FN(read_branch_records, 119, ##ctx) \ 5775 FN(get_ns_current_pid_tgid, 120, ##ctx) \ 5776 FN(xdp_output, 121, ##ctx) \ 5777 FN(get_netns_cookie, 122, ##ctx) \ 5778 FN(get_current_ancestor_cgroup_id, 123, ##ctx) \ 5779 FN(sk_assign, 124, ##ctx) \ 5780 FN(ktime_get_boot_ns, 125, ##ctx) \ 5781 FN(seq_printf, 126, ##ctx) \ 5782 FN(seq_write, 127, ##ctx) \ 5783 FN(sk_cgroup_id, 128, ##ctx) \ 5784 FN(sk_ancestor_cgroup_id, 129, ##ctx) \ 5785 FN(ringbuf_output, 130, ##ctx) \ 5786 FN(ringbuf_reserve, 131, ##ctx) \ 5787 FN(ringbuf_submit, 132, ##ctx) \ 5788 FN(ringbuf_discard, 133, ##ctx) \ 5789 FN(ringbuf_query, 134, ##ctx) \ 5790 FN(csum_level, 135, ##ctx) \ 5791 FN(skc_to_tcp6_sock, 136, ##ctx) \ 5792 FN(skc_to_tcp_sock, 137, ##ctx) \ 5793 FN(skc_to_tcp_timewait_sock, 138, ##ctx) \ 5794 FN(skc_to_tcp_request_sock, 139, ##ctx) \ 5795 FN(skc_to_udp6_sock, 140, ##ctx) \ 5796 FN(get_task_stack, 141, ##ctx) \ 5797 FN(load_hdr_opt, 142, ##ctx) \ 5798 FN(store_hdr_opt, 143, ##ctx) \ 5799 FN(reserve_hdr_opt, 144, ##ctx) \ 5800 FN(inode_storage_get, 145, ##ctx) \ 5801 FN(inode_storage_delete, 146, ##ctx) \ 5802 FN(d_path, 147, ##ctx) \ 5803 FN(copy_from_user, 148, ##ctx) \ 5804 FN(snprintf_btf, 149, ##ctx) \ 5805 FN(seq_printf_btf, 150, ##ctx) \ 5806 FN(skb_cgroup_classid, 151, ##ctx) \ 5807 FN(redirect_neigh, 152, ##ctx) \ 5808 FN(per_cpu_ptr, 153, ##ctx) \ 5809 FN(this_cpu_ptr, 154, ##ctx) \ 5810 FN(redirect_peer, 155, ##ctx) \ 5811 FN(task_storage_get, 156, ##ctx) \ 5812 FN(task_storage_delete, 157, ##ctx) \ 5813 FN(get_current_task_btf, 158, ##ctx) \ 5814 FN(bprm_opts_set, 159, ##ctx) \ 5815 FN(ktime_get_coarse_ns, 160, ##ctx) \ 5816 FN(ima_inode_hash, 161, ##ctx) \ 5817 FN(sock_from_file, 162, ##ctx) \ 5818 FN(check_mtu, 163, ##ctx) \ 5819 FN(for_each_map_elem, 164, ##ctx) \ 5820 FN(snprintf, 165, ##ctx) \ 5821 FN(sys_bpf, 166, ##ctx) \ 5822 FN(btf_find_by_name_kind, 167, ##ctx) \ 5823 FN(sys_close, 168, ##ctx) \ 5824 FN(timer_init, 169, ##ctx) \ 5825 FN(timer_set_callback, 170, ##ctx) \ 5826 FN(timer_start, 171, ##ctx) \ 5827 FN(timer_cancel, 172, ##ctx) \ 5828 FN(get_func_ip, 173, ##ctx) \ 5829 FN(get_attach_cookie, 174, ##ctx) \ 5830 FN(task_pt_regs, 175, ##ctx) \ 5831 FN(get_branch_snapshot, 176, ##ctx) \ 5832 FN(trace_vprintk, 177, ##ctx) \ 5833 FN(skc_to_unix_sock, 178, ##ctx) \ 5834 FN(kallsyms_lookup_name, 179, ##ctx) \ 5835 FN(find_vma, 180, ##ctx) \ 5836 FN(loop, 181, ##ctx) \ 5837 FN(strncmp, 182, ##ctx) \ 5838 FN(get_func_arg, 183, ##ctx) \ 5839 FN(get_func_ret, 184, ##ctx) \ 5840 FN(get_func_arg_cnt, 185, ##ctx) \ 5841 FN(get_retval, 186, ##ctx) \ 5842 FN(set_retval, 187, ##ctx) \ 5843 FN(xdp_get_buff_len, 188, ##ctx) \ 5844 FN(xdp_load_bytes, 189, ##ctx) \ 5845 FN(xdp_store_bytes, 190, ##ctx) \ 5846 FN(copy_from_user_task, 191, ##ctx) \ 5847 FN(skb_set_tstamp, 192, ##ctx) \ 5848 FN(ima_file_hash, 193, ##ctx) \ 5849 FN(kptr_xchg, 194, ##ctx) \ 5850 FN(map_lookup_percpu_elem, 195, ##ctx) \ 5851 FN(skc_to_mptcp_sock, 196, ##ctx) \ 5852 FN(dynptr_from_mem, 197, ##ctx) \ 5853 FN(ringbuf_reserve_dynptr, 198, ##ctx) \ 5854 FN(ringbuf_submit_dynptr, 199, ##ctx) \ 5855 FN(ringbuf_discard_dynptr, 200, ##ctx) \ 5856 FN(dynptr_read, 201, ##ctx) \ 5857 FN(dynptr_write, 202, ##ctx) \ 5858 FN(dynptr_data, 203, ##ctx) \ 5859 FN(tcp_raw_gen_syncookie_ipv4, 204, ##ctx) \ 5860 FN(tcp_raw_gen_syncookie_ipv6, 205, ##ctx) \ 5861 FN(tcp_raw_check_syncookie_ipv4, 206, ##ctx) \ 5862 FN(tcp_raw_check_syncookie_ipv6, 207, ##ctx) \ 5863 FN(ktime_get_tai_ns, 208, ##ctx) \ 5864 FN(user_ringbuf_drain, 209, ##ctx) \ 5865 FN(cgrp_storage_get, 210, ##ctx) \ 5866 FN(cgrp_storage_delete, 211, ##ctx) \ 5867 /* */ 5868 5869 /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't 5870 * know or care about integer value that is now passed as second argument 5871 */ 5872 #define __BPF_FUNC_MAPPER_APPLY(name, value, FN) FN(name), 5873 #define __BPF_FUNC_MAPPER(FN) ___BPF_FUNC_MAPPER(__BPF_FUNC_MAPPER_APPLY, FN) 5874 5875 /* integer value in 'imm' field of BPF_CALL instruction selects which helper 5876 * function eBPF program intends to call 5877 */ 5878 #define __BPF_ENUM_FN(x, y) BPF_FUNC_ ## x = y, 5879 enum bpf_func_id { 5880 ___BPF_FUNC_MAPPER(__BPF_ENUM_FN) 5881 __BPF_FUNC_MAX_ID, 5882 }; 5883 #undef __BPF_ENUM_FN 5884 5885 /* All flags used by eBPF helper functions, placed here. */ 5886 5887 /* BPF_FUNC_skb_store_bytes flags. */ 5888 enum { 5889 BPF_F_RECOMPUTE_CSUM = (1ULL << 0), 5890 BPF_F_INVALIDATE_HASH = (1ULL << 1), 5891 }; 5892 5893 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags. 5894 * First 4 bits are for passing the header field size. 5895 */ 5896 enum { 5897 BPF_F_HDR_FIELD_MASK = 0xfULL, 5898 }; 5899 5900 /* BPF_FUNC_l4_csum_replace flags. */ 5901 enum { 5902 BPF_F_PSEUDO_HDR = (1ULL << 4), 5903 BPF_F_MARK_MANGLED_0 = (1ULL << 5), 5904 BPF_F_MARK_ENFORCE = (1ULL << 6), 5905 }; 5906 5907 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */ 5908 enum { 5909 BPF_F_INGRESS = (1ULL << 0), 5910 }; 5911 5912 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */ 5913 enum { 5914 BPF_F_TUNINFO_IPV6 = (1ULL << 0), 5915 }; 5916 5917 /* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */ 5918 enum { 5919 BPF_F_SKIP_FIELD_MASK = 0xffULL, 5920 BPF_F_USER_STACK = (1ULL << 8), 5921 /* flags used by BPF_FUNC_get_stackid only. */ 5922 BPF_F_FAST_STACK_CMP = (1ULL << 9), 5923 BPF_F_REUSE_STACKID = (1ULL << 10), 5924 /* flags used by BPF_FUNC_get_stack only. */ 5925 BPF_F_USER_BUILD_ID = (1ULL << 11), 5926 }; 5927 5928 /* BPF_FUNC_skb_set_tunnel_key flags. */ 5929 enum { 5930 BPF_F_ZERO_CSUM_TX = (1ULL << 1), 5931 BPF_F_DONT_FRAGMENT = (1ULL << 2), 5932 BPF_F_SEQ_NUMBER = (1ULL << 3), 5933 BPF_F_NO_TUNNEL_KEY = (1ULL << 4), 5934 }; 5935 5936 /* BPF_FUNC_skb_get_tunnel_key flags. */ 5937 enum { 5938 BPF_F_TUNINFO_FLAGS = (1ULL << 4), 5939 }; 5940 5941 /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and 5942 * BPF_FUNC_perf_event_read_value flags. 5943 */ 5944 enum { 5945 BPF_F_INDEX_MASK = 0xffffffffULL, 5946 BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK, 5947 /* BPF_FUNC_perf_event_output for sk_buff input context. */ 5948 BPF_F_CTXLEN_MASK = (0xfffffULL << 32), 5949 }; 5950 5951 /* Current network namespace */ 5952 enum { 5953 BPF_F_CURRENT_NETNS = (-1L), 5954 }; 5955 5956 /* BPF_FUNC_csum_level level values. */ 5957 enum { 5958 BPF_CSUM_LEVEL_QUERY, 5959 BPF_CSUM_LEVEL_INC, 5960 BPF_CSUM_LEVEL_DEC, 5961 BPF_CSUM_LEVEL_RESET, 5962 }; 5963 5964 /* BPF_FUNC_skb_adjust_room flags. */ 5965 enum { 5966 BPF_F_ADJ_ROOM_FIXED_GSO = (1ULL << 0), 5967 BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 = (1ULL << 1), 5968 BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 = (1ULL << 2), 5969 BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (1ULL << 3), 5970 BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (1ULL << 4), 5971 BPF_F_ADJ_ROOM_NO_CSUM_RESET = (1ULL << 5), 5972 BPF_F_ADJ_ROOM_ENCAP_L2_ETH = (1ULL << 6), 5973 BPF_F_ADJ_ROOM_DECAP_L3_IPV4 = (1ULL << 7), 5974 BPF_F_ADJ_ROOM_DECAP_L3_IPV6 = (1ULL << 8), 5975 }; 5976 5977 enum { 5978 BPF_ADJ_ROOM_ENCAP_L2_MASK = 0xff, 5979 BPF_ADJ_ROOM_ENCAP_L2_SHIFT = 56, 5980 }; 5981 5982 #define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \ 5983 BPF_ADJ_ROOM_ENCAP_L2_MASK) \ 5984 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT) 5985 5986 /* BPF_FUNC_sysctl_get_name flags. */ 5987 enum { 5988 BPF_F_SYSCTL_BASE_NAME = (1ULL << 0), 5989 }; 5990 5991 /* BPF_FUNC_<kernel_obj>_storage_get flags */ 5992 enum { 5993 BPF_LOCAL_STORAGE_GET_F_CREATE = (1ULL << 0), 5994 /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility 5995 * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead. 5996 */ 5997 BPF_SK_STORAGE_GET_F_CREATE = BPF_LOCAL_STORAGE_GET_F_CREATE, 5998 }; 5999 6000 /* BPF_FUNC_read_branch_records flags. */ 6001 enum { 6002 BPF_F_GET_BRANCH_RECORDS_SIZE = (1ULL << 0), 6003 }; 6004 6005 /* BPF_FUNC_bpf_ringbuf_commit, BPF_FUNC_bpf_ringbuf_discard, and 6006 * BPF_FUNC_bpf_ringbuf_output flags. 6007 */ 6008 enum { 6009 BPF_RB_NO_WAKEUP = (1ULL << 0), 6010 BPF_RB_FORCE_WAKEUP = (1ULL << 1), 6011 }; 6012 6013 /* BPF_FUNC_bpf_ringbuf_query flags */ 6014 enum { 6015 BPF_RB_AVAIL_DATA = 0, 6016 BPF_RB_RING_SIZE = 1, 6017 BPF_RB_CONS_POS = 2, 6018 BPF_RB_PROD_POS = 3, 6019 }; 6020 6021 /* BPF ring buffer constants */ 6022 enum { 6023 BPF_RINGBUF_BUSY_BIT = (1U << 31), 6024 BPF_RINGBUF_DISCARD_BIT = (1U << 30), 6025 BPF_RINGBUF_HDR_SZ = 8, 6026 }; 6027 6028 /* BPF_FUNC_sk_assign flags in bpf_sk_lookup context. */ 6029 enum { 6030 BPF_SK_LOOKUP_F_REPLACE = (1ULL << 0), 6031 BPF_SK_LOOKUP_F_NO_REUSEPORT = (1ULL << 1), 6032 }; 6033 6034 /* Mode for BPF_FUNC_skb_adjust_room helper. */ 6035 enum bpf_adj_room_mode { 6036 BPF_ADJ_ROOM_NET, 6037 BPF_ADJ_ROOM_MAC, 6038 }; 6039 6040 /* Mode for BPF_FUNC_skb_load_bytes_relative helper. */ 6041 enum bpf_hdr_start_off { 6042 BPF_HDR_START_MAC, 6043 BPF_HDR_START_NET, 6044 }; 6045 6046 /* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */ 6047 enum bpf_lwt_encap_mode { 6048 BPF_LWT_ENCAP_SEG6, 6049 BPF_LWT_ENCAP_SEG6_INLINE, 6050 BPF_LWT_ENCAP_IP, 6051 }; 6052 6053 /* Flags for bpf_bprm_opts_set helper */ 6054 enum { 6055 BPF_F_BPRM_SECUREEXEC = (1ULL << 0), 6056 }; 6057 6058 /* Flags for bpf_redirect_map helper */ 6059 enum { 6060 BPF_F_BROADCAST = (1ULL << 3), 6061 BPF_F_EXCLUDE_INGRESS = (1ULL << 4), 6062 }; 6063 6064 #define __bpf_md_ptr(type, name) \ 6065 union { \ 6066 type name; \ 6067 __u64 :64; \ 6068 } __attribute__((aligned(8))) 6069 6070 enum { 6071 BPF_SKB_TSTAMP_UNSPEC, 6072 BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ 6073 /* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle, 6074 * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC 6075 * and try to deduce it by ingress, egress or skb->sk->sk_clockid. 6076 */ 6077 }; 6078 6079 /* user accessible mirror of in-kernel sk_buff. 6080 * new fields can only be added to the end of this structure 6081 */ 6082 struct __sk_buff { 6083 __u32 len; 6084 __u32 pkt_type; 6085 __u32 mark; 6086 __u32 queue_mapping; 6087 __u32 protocol; 6088 __u32 vlan_present; 6089 __u32 vlan_tci; 6090 __u32 vlan_proto; 6091 __u32 priority; 6092 __u32 ingress_ifindex; 6093 __u32 ifindex; 6094 __u32 tc_index; 6095 __u32 cb[5]; 6096 __u32 hash; 6097 __u32 tc_classid; 6098 __u32 data; 6099 __u32 data_end; 6100 __u32 napi_id; 6101 6102 /* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */ 6103 __u32 family; 6104 __u32 remote_ip4; /* Stored in network byte order */ 6105 __u32 local_ip4; /* Stored in network byte order */ 6106 __u32 remote_ip6[4]; /* Stored in network byte order */ 6107 __u32 local_ip6[4]; /* Stored in network byte order */ 6108 __u32 remote_port; /* Stored in network byte order */ 6109 __u32 local_port; /* stored in host byte order */ 6110 /* ... here. */ 6111 6112 __u32 data_meta; 6113 __bpf_md_ptr(struct bpf_flow_keys *, flow_keys); 6114 __u64 tstamp; 6115 __u32 wire_len; 6116 __u32 gso_segs; 6117 __bpf_md_ptr(struct bpf_sock *, sk); 6118 __u32 gso_size; 6119 __u8 tstamp_type; 6120 __u32 :24; /* Padding, future use. */ 6121 __u64 hwtstamp; 6122 }; 6123 6124 struct bpf_tunnel_key { 6125 __u32 tunnel_id; 6126 union { 6127 __u32 remote_ipv4; 6128 __u32 remote_ipv6[4]; 6129 }; 6130 __u8 tunnel_tos; 6131 __u8 tunnel_ttl; 6132 union { 6133 __u16 tunnel_ext; /* compat */ 6134 __be16 tunnel_flags; 6135 }; 6136 __u32 tunnel_label; 6137 union { 6138 __u32 local_ipv4; 6139 __u32 local_ipv6[4]; 6140 }; 6141 }; 6142 6143 /* user accessible mirror of in-kernel xfrm_state. 6144 * new fields can only be added to the end of this structure 6145 */ 6146 struct bpf_xfrm_state { 6147 __u32 reqid; 6148 __u32 spi; /* Stored in network byte order */ 6149 __u16 family; 6150 __u16 ext; /* Padding, future use. */ 6151 union { 6152 __u32 remote_ipv4; /* Stored in network byte order */ 6153 __u32 remote_ipv6[4]; /* Stored in network byte order */ 6154 }; 6155 }; 6156 6157 /* Generic BPF return codes which all BPF program types may support. 6158 * The values are binary compatible with their TC_ACT_* counter-part to 6159 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT 6160 * programs. 6161 * 6162 * XDP is handled seprately, see XDP_*. 6163 */ 6164 enum bpf_ret_code { 6165 BPF_OK = 0, 6166 /* 1 reserved */ 6167 BPF_DROP = 2, 6168 /* 3-6 reserved */ 6169 BPF_REDIRECT = 7, 6170 /* >127 are reserved for prog type specific return codes. 6171 * 6172 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and 6173 * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been 6174 * changed and should be routed based on its new L3 header. 6175 * (This is an L3 redirect, as opposed to L2 redirect 6176 * represented by BPF_REDIRECT above). 6177 */ 6178 BPF_LWT_REROUTE = 128, 6179 /* BPF_FLOW_DISSECTOR_CONTINUE: used by BPF_PROG_TYPE_FLOW_DISSECTOR 6180 * to indicate that no custom dissection was performed, and 6181 * fallback to standard dissector is requested. 6182 */ 6183 BPF_FLOW_DISSECTOR_CONTINUE = 129, 6184 }; 6185 6186 struct bpf_sock { 6187 __u32 bound_dev_if; 6188 __u32 family; 6189 __u32 type; 6190 __u32 protocol; 6191 __u32 mark; 6192 __u32 priority; 6193 /* IP address also allows 1 and 2 bytes access */ 6194 __u32 src_ip4; 6195 __u32 src_ip6[4]; 6196 __u32 src_port; /* host byte order */ 6197 __be16 dst_port; /* network byte order */ 6198 __u16 :16; /* zero padding */ 6199 __u32 dst_ip4; 6200 __u32 dst_ip6[4]; 6201 __u32 state; 6202 __s32 rx_queue_mapping; 6203 }; 6204 6205 struct bpf_tcp_sock { 6206 __u32 snd_cwnd; /* Sending congestion window */ 6207 __u32 srtt_us; /* smoothed round trip time << 3 in usecs */ 6208 __u32 rtt_min; 6209 __u32 snd_ssthresh; /* Slow start size threshold */ 6210 __u32 rcv_nxt; /* What we want to receive next */ 6211 __u32 snd_nxt; /* Next sequence we send */ 6212 __u32 snd_una; /* First byte we want an ack for */ 6213 __u32 mss_cache; /* Cached effective mss, not including SACKS */ 6214 __u32 ecn_flags; /* ECN status bits. */ 6215 __u32 rate_delivered; /* saved rate sample: packets delivered */ 6216 __u32 rate_interval_us; /* saved rate sample: time elapsed */ 6217 __u32 packets_out; /* Packets which are "in flight" */ 6218 __u32 retrans_out; /* Retransmitted packets out */ 6219 __u32 total_retrans; /* Total retransmits for entire connection */ 6220 __u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn 6221 * total number of segments in. 6222 */ 6223 __u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn 6224 * total number of data segments in. 6225 */ 6226 __u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut 6227 * The total number of segments sent. 6228 */ 6229 __u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut 6230 * total number of data segments sent. 6231 */ 6232 __u32 lost_out; /* Lost packets */ 6233 __u32 sacked_out; /* SACK'd packets */ 6234 __u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived 6235 * sum(delta(rcv_nxt)), or how many bytes 6236 * were acked. 6237 */ 6238 __u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked 6239 * sum(delta(snd_una)), or how many bytes 6240 * were acked. 6241 */ 6242 __u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups 6243 * total number of DSACK blocks received 6244 */ 6245 __u32 delivered; /* Total data packets delivered incl. rexmits */ 6246 __u32 delivered_ce; /* Like the above but only ECE marked packets */ 6247 __u32 icsk_retransmits; /* Number of unrecovered [RTO] timeouts */ 6248 }; 6249 6250 struct bpf_sock_tuple { 6251 union { 6252 struct { 6253 __be32 saddr; 6254 __be32 daddr; 6255 __be16 sport; 6256 __be16 dport; 6257 } ipv4; 6258 struct { 6259 __be32 saddr[4]; 6260 __be32 daddr[4]; 6261 __be16 sport; 6262 __be16 dport; 6263 } ipv6; 6264 }; 6265 }; 6266 6267 /* (Simplified) user return codes for tcx prog type. 6268 * A valid tcx program must return one of these defined values. All other 6269 * return codes are reserved for future use. Must remain compatible with 6270 * their TC_ACT_* counter-parts. For compatibility in behavior, unknown 6271 * return codes are mapped to TCX_NEXT. 6272 */ 6273 enum tcx_action_base { 6274 TCX_NEXT = -1, 6275 TCX_PASS = 0, 6276 TCX_DROP = 2, 6277 TCX_REDIRECT = 7, 6278 }; 6279 6280 struct bpf_xdp_sock { 6281 __u32 queue_id; 6282 }; 6283 6284 #define XDP_PACKET_HEADROOM 256 6285 6286 /* User return codes for XDP prog type. 6287 * A valid XDP program must return one of these defined values. All other 6288 * return codes are reserved for future use. Unknown return codes will 6289 * result in packet drops and a warning via bpf_warn_invalid_xdp_action(). 6290 */ 6291 enum xdp_action { 6292 XDP_ABORTED = 0, 6293 XDP_DROP, 6294 XDP_PASS, 6295 XDP_TX, 6296 XDP_REDIRECT, 6297 }; 6298 6299 /* user accessible metadata for XDP packet hook 6300 * new fields must be added to the end of this structure 6301 */ 6302 struct xdp_md { 6303 __u32 data; 6304 __u32 data_end; 6305 __u32 data_meta; 6306 /* Below access go through struct xdp_rxq_info */ 6307 __u32 ingress_ifindex; /* rxq->dev->ifindex */ 6308 __u32 rx_queue_index; /* rxq->queue_index */ 6309 6310 __u32 egress_ifindex; /* txq->dev->ifindex */ 6311 }; 6312 6313 /* DEVMAP map-value layout 6314 * 6315 * The struct data-layout of map-value is a configuration interface. 6316 * New members can only be added to the end of this structure. 6317 */ 6318 struct bpf_devmap_val { 6319 __u32 ifindex; /* device index */ 6320 union { 6321 int fd; /* prog fd on map write */ 6322 __u32 id; /* prog id on map read */ 6323 } bpf_prog; 6324 }; 6325 6326 /* CPUMAP map-value layout 6327 * 6328 * The struct data-layout of map-value is a configuration interface. 6329 * New members can only be added to the end of this structure. 6330 */ 6331 struct bpf_cpumap_val { 6332 __u32 qsize; /* queue size to remote target CPU */ 6333 union { 6334 int fd; /* prog fd on map write */ 6335 __u32 id; /* prog id on map read */ 6336 } bpf_prog; 6337 }; 6338 6339 enum sk_action { 6340 SK_DROP = 0, 6341 SK_PASS, 6342 }; 6343 6344 /* user accessible metadata for SK_MSG packet hook, new fields must 6345 * be added to the end of this structure 6346 */ 6347 struct sk_msg_md { 6348 __bpf_md_ptr(void *, data); 6349 __bpf_md_ptr(void *, data_end); 6350 6351 __u32 family; 6352 __u32 remote_ip4; /* Stored in network byte order */ 6353 __u32 local_ip4; /* Stored in network byte order */ 6354 __u32 remote_ip6[4]; /* Stored in network byte order */ 6355 __u32 local_ip6[4]; /* Stored in network byte order */ 6356 __u32 remote_port; /* Stored in network byte order */ 6357 __u32 local_port; /* stored in host byte order */ 6358 __u32 size; /* Total size of sk_msg */ 6359 6360 __bpf_md_ptr(struct bpf_sock *, sk); /* current socket */ 6361 }; 6362 6363 struct sk_reuseport_md { 6364 /* 6365 * Start of directly accessible data. It begins from 6366 * the tcp/udp header. 6367 */ 6368 __bpf_md_ptr(void *, data); 6369 /* End of directly accessible data */ 6370 __bpf_md_ptr(void *, data_end); 6371 /* 6372 * Total length of packet (starting from the tcp/udp header). 6373 * Note that the directly accessible bytes (data_end - data) 6374 * could be less than this "len". Those bytes could be 6375 * indirectly read by a helper "bpf_skb_load_bytes()". 6376 */ 6377 __u32 len; 6378 /* 6379 * Eth protocol in the mac header (network byte order). e.g. 6380 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD) 6381 */ 6382 __u32 eth_protocol; 6383 __u32 ip_protocol; /* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */ 6384 __u32 bind_inany; /* Is sock bound to an INANY address? */ 6385 __u32 hash; /* A hash of the packet 4 tuples */ 6386 /* When reuse->migrating_sk is NULL, it is selecting a sk for the 6387 * new incoming connection request (e.g. selecting a listen sk for 6388 * the received SYN in the TCP case). reuse->sk is one of the sk 6389 * in the reuseport group. The bpf prog can use reuse->sk to learn 6390 * the local listening ip/port without looking into the skb. 6391 * 6392 * When reuse->migrating_sk is not NULL, reuse->sk is closed and 6393 * reuse->migrating_sk is the socket that needs to be migrated 6394 * to another listening socket. migrating_sk could be a fullsock 6395 * sk that is fully established or a reqsk that is in-the-middle 6396 * of 3-way handshake. 6397 */ 6398 __bpf_md_ptr(struct bpf_sock *, sk); 6399 __bpf_md_ptr(struct bpf_sock *, migrating_sk); 6400 }; 6401 6402 #define BPF_TAG_SIZE 8 6403 6404 struct bpf_prog_info { 6405 __u32 type; 6406 __u32 id; 6407 __u8 tag[BPF_TAG_SIZE]; 6408 __u32 jited_prog_len; 6409 __u32 xlated_prog_len; 6410 __aligned_u64 jited_prog_insns; 6411 __aligned_u64 xlated_prog_insns; 6412 __u64 load_time; /* ns since boottime */ 6413 __u32 created_by_uid; 6414 __u32 nr_map_ids; 6415 __aligned_u64 map_ids; 6416 char name[BPF_OBJ_NAME_LEN]; 6417 __u32 ifindex; 6418 __u32 gpl_compatible:1; 6419 __u32 :31; /* alignment pad */ 6420 __u64 netns_dev; 6421 __u64 netns_ino; 6422 __u32 nr_jited_ksyms; 6423 __u32 nr_jited_func_lens; 6424 __aligned_u64 jited_ksyms; 6425 __aligned_u64 jited_func_lens; 6426 __u32 btf_id; 6427 __u32 func_info_rec_size; 6428 __aligned_u64 func_info; 6429 __u32 nr_func_info; 6430 __u32 nr_line_info; 6431 __aligned_u64 line_info; 6432 __aligned_u64 jited_line_info; 6433 __u32 nr_jited_line_info; 6434 __u32 line_info_rec_size; 6435 __u32 jited_line_info_rec_size; 6436 __u32 nr_prog_tags; 6437 __aligned_u64 prog_tags; 6438 __u64 run_time_ns; 6439 __u64 run_cnt; 6440 __u64 recursion_misses; 6441 __u32 verified_insns; 6442 __u32 attach_btf_obj_id; 6443 __u32 attach_btf_id; 6444 } __attribute__((aligned(8))); 6445 6446 struct bpf_map_info { 6447 __u32 type; 6448 __u32 id; 6449 __u32 key_size; 6450 __u32 value_size; 6451 __u32 max_entries; 6452 __u32 map_flags; 6453 char name[BPF_OBJ_NAME_LEN]; 6454 __u32 ifindex; 6455 __u32 btf_vmlinux_value_type_id; 6456 __u64 netns_dev; 6457 __u64 netns_ino; 6458 __u32 btf_id; 6459 __u32 btf_key_type_id; 6460 __u32 btf_value_type_id; 6461 __u32 :32; /* alignment pad */ 6462 __u64 map_extra; 6463 } __attribute__((aligned(8))); 6464 6465 struct bpf_btf_info { 6466 __aligned_u64 btf; 6467 __u32 btf_size; 6468 __u32 id; 6469 __aligned_u64 name; 6470 __u32 name_len; 6471 __u32 kernel_btf; 6472 } __attribute__((aligned(8))); 6473 6474 struct bpf_link_info { 6475 __u32 type; 6476 __u32 id; 6477 __u32 prog_id; 6478 union { 6479 struct { 6480 __aligned_u64 tp_name; /* in/out: tp_name buffer ptr */ 6481 __u32 tp_name_len; /* in/out: tp_name buffer len */ 6482 } raw_tracepoint; 6483 struct { 6484 __u32 attach_type; 6485 __u32 target_obj_id; /* prog_id for PROG_EXT, otherwise btf object id */ 6486 __u32 target_btf_id; /* BTF type id inside the object */ 6487 } tracing; 6488 struct { 6489 __u64 cgroup_id; 6490 __u32 attach_type; 6491 } cgroup; 6492 struct { 6493 __aligned_u64 target_name; /* in/out: target_name buffer ptr */ 6494 __u32 target_name_len; /* in/out: target_name buffer len */ 6495 6496 /* If the iter specific field is 32 bits, it can be put 6497 * in the first or second union. Otherwise it should be 6498 * put in the second union. 6499 */ 6500 union { 6501 struct { 6502 __u32 map_id; 6503 } map; 6504 }; 6505 union { 6506 struct { 6507 __u64 cgroup_id; 6508 __u32 order; 6509 } cgroup; 6510 struct { 6511 __u32 tid; 6512 __u32 pid; 6513 } task; 6514 }; 6515 } iter; 6516 struct { 6517 __u32 netns_ino; 6518 __u32 attach_type; 6519 } netns; 6520 struct { 6521 __u32 ifindex; 6522 } xdp; 6523 struct { 6524 __u32 map_id; 6525 } struct_ops; 6526 struct { 6527 __u32 pf; 6528 __u32 hooknum; 6529 __s32 priority; 6530 __u32 flags; 6531 } netfilter; 6532 struct { 6533 __aligned_u64 addrs; 6534 __u32 count; /* in/out: kprobe_multi function count */ 6535 __u32 flags; 6536 } kprobe_multi; 6537 struct { 6538 __u32 type; /* enum bpf_perf_event_type */ 6539 __u32 :32; 6540 union { 6541 struct { 6542 __aligned_u64 file_name; /* in/out */ 6543 __u32 name_len; 6544 __u32 offset; /* offset from file_name */ 6545 } uprobe; /* BPF_PERF_EVENT_UPROBE, BPF_PERF_EVENT_URETPROBE */ 6546 struct { 6547 __aligned_u64 func_name; /* in/out */ 6548 __u32 name_len; 6549 __u32 offset; /* offset from func_name */ 6550 __u64 addr; 6551 } kprobe; /* BPF_PERF_EVENT_KPROBE, BPF_PERF_EVENT_KRETPROBE */ 6552 struct { 6553 __aligned_u64 tp_name; /* in/out */ 6554 __u32 name_len; 6555 } tracepoint; /* BPF_PERF_EVENT_TRACEPOINT */ 6556 struct { 6557 __u64 config; 6558 __u32 type; 6559 } event; /* BPF_PERF_EVENT_EVENT */ 6560 }; 6561 } perf_event; 6562 struct { 6563 __u32 ifindex; 6564 __u32 attach_type; 6565 } tcx; 6566 }; 6567 } __attribute__((aligned(8))); 6568 6569 /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed 6570 * by user and intended to be used by socket (e.g. to bind to, depends on 6571 * attach type). 6572 */ 6573 struct bpf_sock_addr { 6574 __u32 user_family; /* Allows 4-byte read, but no write. */ 6575 __u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write. 6576 * Stored in network byte order. 6577 */ 6578 __u32 user_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write. 6579 * Stored in network byte order. 6580 */ 6581 __u32 user_port; /* Allows 1,2,4-byte read and 4-byte write. 6582 * Stored in network byte order 6583 */ 6584 __u32 family; /* Allows 4-byte read, but no write */ 6585 __u32 type; /* Allows 4-byte read, but no write */ 6586 __u32 protocol; /* Allows 4-byte read, but no write */ 6587 __u32 msg_src_ip4; /* Allows 1,2,4-byte read and 4-byte write. 6588 * Stored in network byte order. 6589 */ 6590 __u32 msg_src_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write. 6591 * Stored in network byte order. 6592 */ 6593 __bpf_md_ptr(struct bpf_sock *, sk); 6594 }; 6595 6596 /* User bpf_sock_ops struct to access socket values and specify request ops 6597 * and their replies. 6598 * Some of this fields are in network (bigendian) byte order and may need 6599 * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h). 6600 * New fields can only be added at the end of this structure 6601 */ 6602 struct bpf_sock_ops { 6603 __u32 op; 6604 union { 6605 __u32 args[4]; /* Optionally passed to bpf program */ 6606 __u32 reply; /* Returned by bpf program */ 6607 __u32 replylong[4]; /* Optionally returned by bpf prog */ 6608 }; 6609 __u32 family; 6610 __u32 remote_ip4; /* Stored in network byte order */ 6611 __u32 local_ip4; /* Stored in network byte order */ 6612 __u32 remote_ip6[4]; /* Stored in network byte order */ 6613 __u32 local_ip6[4]; /* Stored in network byte order */ 6614 __u32 remote_port; /* Stored in network byte order */ 6615 __u32 local_port; /* stored in host byte order */ 6616 __u32 is_fullsock; /* Some TCP fields are only valid if 6617 * there is a full socket. If not, the 6618 * fields read as zero. 6619 */ 6620 __u32 snd_cwnd; 6621 __u32 srtt_us; /* Averaged RTT << 3 in usecs */ 6622 __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ 6623 __u32 state; 6624 __u32 rtt_min; 6625 __u32 snd_ssthresh; 6626 __u32 rcv_nxt; 6627 __u32 snd_nxt; 6628 __u32 snd_una; 6629 __u32 mss_cache; 6630 __u32 ecn_flags; 6631 __u32 rate_delivered; 6632 __u32 rate_interval_us; 6633 __u32 packets_out; 6634 __u32 retrans_out; 6635 __u32 total_retrans; 6636 __u32 segs_in; 6637 __u32 data_segs_in; 6638 __u32 segs_out; 6639 __u32 data_segs_out; 6640 __u32 lost_out; 6641 __u32 sacked_out; 6642 __u32 sk_txhash; 6643 __u64 bytes_received; 6644 __u64 bytes_acked; 6645 __bpf_md_ptr(struct bpf_sock *, sk); 6646 /* [skb_data, skb_data_end) covers the whole TCP header. 6647 * 6648 * BPF_SOCK_OPS_PARSE_HDR_OPT_CB: The packet received 6649 * BPF_SOCK_OPS_HDR_OPT_LEN_CB: Not useful because the 6650 * header has not been written. 6651 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB: The header and options have 6652 * been written so far. 6653 * BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: The SYNACK that concludes 6654 * the 3WHS. 6655 * BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: The ACK that concludes 6656 * the 3WHS. 6657 * 6658 * bpf_load_hdr_opt() can also be used to read a particular option. 6659 */ 6660 __bpf_md_ptr(void *, skb_data); 6661 __bpf_md_ptr(void *, skb_data_end); 6662 __u32 skb_len; /* The total length of a packet. 6663 * It includes the header, options, 6664 * and payload. 6665 */ 6666 __u32 skb_tcp_flags; /* tcp_flags of the header. It provides 6667 * an easy way to check for tcp_flags 6668 * without parsing skb_data. 6669 * 6670 * In particular, the skb_tcp_flags 6671 * will still be available in 6672 * BPF_SOCK_OPS_HDR_OPT_LEN even though 6673 * the outgoing header has not 6674 * been written yet. 6675 */ 6676 __u64 skb_hwtstamp; 6677 }; 6678 6679 /* Definitions for bpf_sock_ops_cb_flags */ 6680 enum { 6681 BPF_SOCK_OPS_RTO_CB_FLAG = (1<<0), 6682 BPF_SOCK_OPS_RETRANS_CB_FLAG = (1<<1), 6683 BPF_SOCK_OPS_STATE_CB_FLAG = (1<<2), 6684 BPF_SOCK_OPS_RTT_CB_FLAG = (1<<3), 6685 /* Call bpf for all received TCP headers. The bpf prog will be 6686 * called under sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB 6687 * 6688 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB 6689 * for the header option related helpers that will be useful 6690 * to the bpf programs. 6691 * 6692 * It could be used at the client/active side (i.e. connect() side) 6693 * when the server told it that the server was in syncookie 6694 * mode and required the active side to resend the bpf-written 6695 * options. The active side can keep writing the bpf-options until 6696 * it received a valid packet from the server side to confirm 6697 * the earlier packet (and options) has been received. The later 6698 * example patch is using it like this at the active side when the 6699 * server is in syncookie mode. 6700 * 6701 * The bpf prog will usually turn this off in the common cases. 6702 */ 6703 BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG = (1<<4), 6704 /* Call bpf when kernel has received a header option that 6705 * the kernel cannot handle. The bpf prog will be called under 6706 * sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB. 6707 * 6708 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB 6709 * for the header option related helpers that will be useful 6710 * to the bpf programs. 6711 */ 6712 BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG = (1<<5), 6713 /* Call bpf when the kernel is writing header options for the 6714 * outgoing packet. The bpf prog will first be called 6715 * to reserve space in a skb under 6716 * sock_ops->op == BPF_SOCK_OPS_HDR_OPT_LEN_CB. Then 6717 * the bpf prog will be called to write the header option(s) 6718 * under sock_ops->op == BPF_SOCK_OPS_WRITE_HDR_OPT_CB. 6719 * 6720 * Please refer to the comment in BPF_SOCK_OPS_HDR_OPT_LEN_CB 6721 * and BPF_SOCK_OPS_WRITE_HDR_OPT_CB for the header option 6722 * related helpers that will be useful to the bpf programs. 6723 * 6724 * The kernel gets its chance to reserve space and write 6725 * options first before the BPF program does. 6726 */ 6727 BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG = (1<<6), 6728 /* Mask of all currently supported cb flags */ 6729 BPF_SOCK_OPS_ALL_CB_FLAGS = 0x7F, 6730 }; 6731 6732 /* List of known BPF sock_ops operators. 6733 * New entries can only be added at the end 6734 */ 6735 enum { 6736 BPF_SOCK_OPS_VOID, 6737 BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or 6738 * -1 if default value should be used 6739 */ 6740 BPF_SOCK_OPS_RWND_INIT, /* Should return initial advertized 6741 * window (in packets) or -1 if default 6742 * value should be used 6743 */ 6744 BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an 6745 * active connection is initialized 6746 */ 6747 BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an 6748 * active connection is 6749 * established 6750 */ 6751 BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a 6752 * passive connection is 6753 * established 6754 */ 6755 BPF_SOCK_OPS_NEEDS_ECN, /* If connection's congestion control 6756 * needs ECN 6757 */ 6758 BPF_SOCK_OPS_BASE_RTT, /* Get base RTT. The correct value is 6759 * based on the path and may be 6760 * dependent on the congestion control 6761 * algorithm. In general it indicates 6762 * a congestion threshold. RTTs above 6763 * this indicate congestion 6764 */ 6765 BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered. 6766 * Arg1: value of icsk_retransmits 6767 * Arg2: value of icsk_rto 6768 * Arg3: whether RTO has expired 6769 */ 6770 BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. 6771 * Arg1: sequence number of 1st byte 6772 * Arg2: # segments 6773 * Arg3: return value of 6774 * tcp_transmit_skb (0 => success) 6775 */ 6776 BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state. 6777 * Arg1: old_state 6778 * Arg2: new_state 6779 */ 6780 BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after 6781 * socket transition to LISTEN state. 6782 */ 6783 BPF_SOCK_OPS_RTT_CB, /* Called on every RTT. 6784 */ 6785 BPF_SOCK_OPS_PARSE_HDR_OPT_CB, /* Parse the header option. 6786 * It will be called to handle 6787 * the packets received at 6788 * an already established 6789 * connection. 6790 * 6791 * sock_ops->skb_data: 6792 * Referring to the received skb. 6793 * It covers the TCP header only. 6794 * 6795 * bpf_load_hdr_opt() can also 6796 * be used to search for a 6797 * particular option. 6798 */ 6799 BPF_SOCK_OPS_HDR_OPT_LEN_CB, /* Reserve space for writing the 6800 * header option later in 6801 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB. 6802 * Arg1: bool want_cookie. (in 6803 * writing SYNACK only) 6804 * 6805 * sock_ops->skb_data: 6806 * Not available because no header has 6807 * been written yet. 6808 * 6809 * sock_ops->skb_tcp_flags: 6810 * The tcp_flags of the 6811 * outgoing skb. (e.g. SYN, ACK, FIN). 6812 * 6813 * bpf_reserve_hdr_opt() should 6814 * be used to reserve space. 6815 */ 6816 BPF_SOCK_OPS_WRITE_HDR_OPT_CB, /* Write the header options 6817 * Arg1: bool want_cookie. (in 6818 * writing SYNACK only) 6819 * 6820 * sock_ops->skb_data: 6821 * Referring to the outgoing skb. 6822 * It covers the TCP header 6823 * that has already been written 6824 * by the kernel and the 6825 * earlier bpf-progs. 6826 * 6827 * sock_ops->skb_tcp_flags: 6828 * The tcp_flags of the outgoing 6829 * skb. (e.g. SYN, ACK, FIN). 6830 * 6831 * bpf_store_hdr_opt() should 6832 * be used to write the 6833 * option. 6834 * 6835 * bpf_load_hdr_opt() can also 6836 * be used to search for a 6837 * particular option that 6838 * has already been written 6839 * by the kernel or the 6840 * earlier bpf-progs. 6841 */ 6842 }; 6843 6844 /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect 6845 * changes between the TCP and BPF versions. Ideally this should never happen. 6846 * If it does, we need to add code to convert them before calling 6847 * the BPF sock_ops function. 6848 */ 6849 enum { 6850 BPF_TCP_ESTABLISHED = 1, 6851 BPF_TCP_SYN_SENT, 6852 BPF_TCP_SYN_RECV, 6853 BPF_TCP_FIN_WAIT1, 6854 BPF_TCP_FIN_WAIT2, 6855 BPF_TCP_TIME_WAIT, 6856 BPF_TCP_CLOSE, 6857 BPF_TCP_CLOSE_WAIT, 6858 BPF_TCP_LAST_ACK, 6859 BPF_TCP_LISTEN, 6860 BPF_TCP_CLOSING, /* Now a valid state */ 6861 BPF_TCP_NEW_SYN_RECV, 6862 6863 BPF_TCP_MAX_STATES /* Leave at the end! */ 6864 }; 6865 6866 enum { 6867 TCP_BPF_IW = 1001, /* Set TCP initial congestion window */ 6868 TCP_BPF_SNDCWND_CLAMP = 1002, /* Set sndcwnd_clamp */ 6869 TCP_BPF_DELACK_MAX = 1003, /* Max delay ack in usecs */ 6870 TCP_BPF_RTO_MIN = 1004, /* Min delay ack in usecs */ 6871 /* Copy the SYN pkt to optval 6872 * 6873 * BPF_PROG_TYPE_SOCK_OPS only. It is similar to the 6874 * bpf_getsockopt(TCP_SAVED_SYN) but it does not limit 6875 * to only getting from the saved_syn. It can either get the 6876 * syn packet from: 6877 * 6878 * 1. the just-received SYN packet (only available when writing the 6879 * SYNACK). It will be useful when it is not necessary to 6880 * save the SYN packet for latter use. It is also the only way 6881 * to get the SYN during syncookie mode because the syn 6882 * packet cannot be saved during syncookie. 6883 * 6884 * OR 6885 * 6886 * 2. the earlier saved syn which was done by 6887 * bpf_setsockopt(TCP_SAVE_SYN). 6888 * 6889 * The bpf_getsockopt(TCP_BPF_SYN*) option will hide where the 6890 * SYN packet is obtained. 6891 * 6892 * If the bpf-prog does not need the IP[46] header, the 6893 * bpf-prog can avoid parsing the IP header by using 6894 * TCP_BPF_SYN. Otherwise, the bpf-prog can get both 6895 * IP[46] and TCP header by using TCP_BPF_SYN_IP. 6896 * 6897 * >0: Total number of bytes copied 6898 * -ENOSPC: Not enough space in optval. Only optlen number of 6899 * bytes is copied. 6900 * -ENOENT: The SYN skb is not available now and the earlier SYN pkt 6901 * is not saved by setsockopt(TCP_SAVE_SYN). 6902 */ 6903 TCP_BPF_SYN = 1005, /* Copy the TCP header */ 6904 TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */ 6905 TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */ 6906 }; 6907 6908 enum { 6909 BPF_LOAD_HDR_OPT_TCP_SYN = (1ULL << 0), 6910 }; 6911 6912 /* args[0] value during BPF_SOCK_OPS_HDR_OPT_LEN_CB and 6913 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB. 6914 */ 6915 enum { 6916 BPF_WRITE_HDR_TCP_CURRENT_MSS = 1, /* Kernel is finding the 6917 * total option spaces 6918 * required for an established 6919 * sk in order to calculate the 6920 * MSS. No skb is actually 6921 * sent. 6922 */ 6923 BPF_WRITE_HDR_TCP_SYNACK_COOKIE = 2, /* Kernel is in syncookie mode 6924 * when sending a SYN. 6925 */ 6926 }; 6927 6928 struct bpf_perf_event_value { 6929 __u64 counter; 6930 __u64 enabled; 6931 __u64 running; 6932 }; 6933 6934 enum { 6935 BPF_DEVCG_ACC_MKNOD = (1ULL << 0), 6936 BPF_DEVCG_ACC_READ = (1ULL << 1), 6937 BPF_DEVCG_ACC_WRITE = (1ULL << 2), 6938 }; 6939 6940 enum { 6941 BPF_DEVCG_DEV_BLOCK = (1ULL << 0), 6942 BPF_DEVCG_DEV_CHAR = (1ULL << 1), 6943 }; 6944 6945 struct bpf_cgroup_dev_ctx { 6946 /* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */ 6947 __u32 access_type; 6948 __u32 major; 6949 __u32 minor; 6950 }; 6951 6952 struct bpf_raw_tracepoint_args { 6953 __u64 args[0]; 6954 }; 6955 6956 /* DIRECT: Skip the FIB rules and go to FIB table associated with device 6957 * OUTPUT: Do lookup from egress perspective; default is ingress 6958 */ 6959 enum { 6960 BPF_FIB_LOOKUP_DIRECT = (1U << 0), 6961 BPF_FIB_LOOKUP_OUTPUT = (1U << 1), 6962 BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2), 6963 BPF_FIB_LOOKUP_TBID = (1U << 3), 6964 BPF_FIB_LOOKUP_SRC = (1U << 4), 6965 }; 6966 6967 enum { 6968 BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */ 6969 BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */ 6970 BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */ 6971 BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */ 6972 BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */ 6973 BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */ 6974 BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */ 6975 BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */ 6976 BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */ 6977 BPF_FIB_LKUP_RET_NO_SRC_ADDR, /* failed to derive IP src addr */ 6978 }; 6979 6980 struct bpf_fib_lookup { 6981 /* input: network family for lookup (AF_INET, AF_INET6) 6982 * output: network family of egress nexthop 6983 */ 6984 __u8 family; 6985 6986 /* set if lookup is to consider L4 data - e.g., FIB rules */ 6987 __u8 l4_protocol; 6988 __be16 sport; 6989 __be16 dport; 6990 6991 union { /* used for MTU check */ 6992 /* input to lookup */ 6993 __u16 tot_len; /* L3 length from network hdr (iph->tot_len) */ 6994 6995 /* output: MTU value */ 6996 __u16 mtu_result; 6997 } __attribute__((packed, aligned(2))); 6998 /* input: L3 device index for lookup 6999 * output: device index from FIB lookup 7000 */ 7001 __u32 ifindex; 7002 7003 union { 7004 /* inputs to lookup */ 7005 __u8 tos; /* AF_INET */ 7006 __be32 flowinfo; /* AF_INET6, flow_label + priority */ 7007 7008 /* output: metric of fib result (IPv4/IPv6 only) */ 7009 __u32 rt_metric; 7010 }; 7011 7012 /* input: source address to consider for lookup 7013 * output: source address result from lookup 7014 */ 7015 union { 7016 __be32 ipv4_src; 7017 __u32 ipv6_src[4]; /* in6_addr; network order */ 7018 }; 7019 7020 /* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in 7021 * network header. output: bpf_fib_lookup sets to gateway address 7022 * if FIB lookup returns gateway route 7023 */ 7024 union { 7025 __be32 ipv4_dst; 7026 __u32 ipv6_dst[4]; /* in6_addr; network order */ 7027 }; 7028 7029 union { 7030 struct { 7031 /* output */ 7032 __be16 h_vlan_proto; 7033 __be16 h_vlan_TCI; 7034 }; 7035 /* input: when accompanied with the 7036 * 'BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID` flags, a 7037 * specific routing table to use for the fib lookup. 7038 */ 7039 __u32 tbid; 7040 }; 7041 7042 __u8 smac[6]; /* ETH_ALEN */ 7043 __u8 dmac[6]; /* ETH_ALEN */ 7044 }; 7045 7046 struct bpf_redir_neigh { 7047 /* network family for lookup (AF_INET, AF_INET6) */ 7048 __u32 nh_family; 7049 /* network address of nexthop; skips fib lookup to find gateway */ 7050 union { 7051 __be32 ipv4_nh; 7052 __u32 ipv6_nh[4]; /* in6_addr; network order */ 7053 }; 7054 }; 7055 7056 /* bpf_check_mtu flags*/ 7057 enum bpf_check_mtu_flags { 7058 BPF_MTU_CHK_SEGS = (1U << 0), 7059 }; 7060 7061 enum bpf_check_mtu_ret { 7062 BPF_MTU_CHK_RET_SUCCESS, /* check and lookup successful */ 7063 BPF_MTU_CHK_RET_FRAG_NEEDED, /* fragmentation required to fwd */ 7064 BPF_MTU_CHK_RET_SEGS_TOOBIG, /* GSO re-segmentation needed to fwd */ 7065 }; 7066 7067 enum bpf_task_fd_type { 7068 BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */ 7069 BPF_FD_TYPE_TRACEPOINT, /* tp name */ 7070 BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */ 7071 BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */ 7072 BPF_FD_TYPE_UPROBE, /* filename + offset */ 7073 BPF_FD_TYPE_URETPROBE, /* filename + offset */ 7074 }; 7075 7076 enum { 7077 BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG = (1U << 0), 7078 BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL = (1U << 1), 7079 BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP = (1U << 2), 7080 }; 7081 7082 struct bpf_flow_keys { 7083 __u16 nhoff; 7084 __u16 thoff; 7085 __u16 addr_proto; /* ETH_P_* of valid addrs */ 7086 __u8 is_frag; 7087 __u8 is_first_frag; 7088 __u8 is_encap; 7089 __u8 ip_proto; 7090 __be16 n_proto; 7091 __be16 sport; 7092 __be16 dport; 7093 union { 7094 struct { 7095 __be32 ipv4_src; 7096 __be32 ipv4_dst; 7097 }; 7098 struct { 7099 __u32 ipv6_src[4]; /* in6_addr; network order */ 7100 __u32 ipv6_dst[4]; /* in6_addr; network order */ 7101 }; 7102 }; 7103 __u32 flags; 7104 __be32 flow_label; 7105 }; 7106 7107 struct bpf_func_info { 7108 __u32 insn_off; 7109 __u32 type_id; 7110 }; 7111 7112 #define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10) 7113 #define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff) 7114 7115 struct bpf_line_info { 7116 __u32 insn_off; 7117 __u32 file_name_off; 7118 __u32 line_off; 7119 __u32 line_col; 7120 }; 7121 7122 struct bpf_spin_lock { 7123 __u32 val; 7124 }; 7125 7126 struct bpf_timer { 7127 __u64 :64; 7128 __u64 :64; 7129 } __attribute__((aligned(8))); 7130 7131 struct bpf_dynptr { 7132 __u64 :64; 7133 __u64 :64; 7134 } __attribute__((aligned(8))); 7135 7136 struct bpf_list_head { 7137 __u64 :64; 7138 __u64 :64; 7139 } __attribute__((aligned(8))); 7140 7141 struct bpf_list_node { 7142 __u64 :64; 7143 __u64 :64; 7144 __u64 :64; 7145 } __attribute__((aligned(8))); 7146 7147 struct bpf_rb_root { 7148 __u64 :64; 7149 __u64 :64; 7150 } __attribute__((aligned(8))); 7151 7152 struct bpf_rb_node { 7153 __u64 :64; 7154 __u64 :64; 7155 __u64 :64; 7156 __u64 :64; 7157 } __attribute__((aligned(8))); 7158 7159 struct bpf_refcount { 7160 __u32 :32; 7161 } __attribute__((aligned(4))); 7162 7163 struct bpf_sysctl { 7164 __u32 write; /* Sysctl is being read (= 0) or written (= 1). 7165 * Allows 1,2,4-byte read, but no write. 7166 */ 7167 __u32 file_pos; /* Sysctl file position to read from, write to. 7168 * Allows 1,2,4-byte read an 4-byte write. 7169 */ 7170 }; 7171 7172 struct bpf_sockopt { 7173 __bpf_md_ptr(struct bpf_sock *, sk); 7174 __bpf_md_ptr(void *, optval); 7175 __bpf_md_ptr(void *, optval_end); 7176 7177 __s32 level; 7178 __s32 optname; 7179 __s32 optlen; 7180 __s32 retval; 7181 }; 7182 7183 struct bpf_pidns_info { 7184 __u32 pid; 7185 __u32 tgid; 7186 }; 7187 7188 /* User accessible data for SK_LOOKUP programs. Add new fields at the end. */ 7189 struct bpf_sk_lookup { 7190 union { 7191 __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */ 7192 __u64 cookie; /* Non-zero if socket was selected in PROG_TEST_RUN */ 7193 }; 7194 7195 __u32 family; /* Protocol family (AF_INET, AF_INET6) */ 7196 __u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */ 7197 __u32 remote_ip4; /* Network byte order */ 7198 __u32 remote_ip6[4]; /* Network byte order */ 7199 __be16 remote_port; /* Network byte order */ 7200 __u16 :16; /* Zero padding */ 7201 __u32 local_ip4; /* Network byte order */ 7202 __u32 local_ip6[4]; /* Network byte order */ 7203 __u32 local_port; /* Host byte order */ 7204 __u32 ingress_ifindex; /* The arriving interface. Determined by inet_iif. */ 7205 }; 7206 7207 /* 7208 * struct btf_ptr is used for typed pointer representation; the 7209 * type id is used to render the pointer data as the appropriate type 7210 * via the bpf_snprintf_btf() helper described above. A flags field - 7211 * potentially to specify additional details about the BTF pointer 7212 * (rather than its mode of display) - is included for future use. 7213 * Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately. 7214 */ 7215 struct btf_ptr { 7216 void *ptr; 7217 __u32 type_id; 7218 __u32 flags; /* BTF ptr flags; unused at present. */ 7219 }; 7220 7221 /* 7222 * Flags to control bpf_snprintf_btf() behaviour. 7223 * - BTF_F_COMPACT: no formatting around type information 7224 * - BTF_F_NONAME: no struct/union member names/types 7225 * - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values; 7226 * equivalent to %px. 7227 * - BTF_F_ZERO: show zero-valued struct/union members; they 7228 * are not displayed by default 7229 */ 7230 enum { 7231 BTF_F_COMPACT = (1ULL << 0), 7232 BTF_F_NONAME = (1ULL << 1), 7233 BTF_F_PTR_RAW = (1ULL << 2), 7234 BTF_F_ZERO = (1ULL << 3), 7235 }; 7236 7237 /* bpf_core_relo_kind encodes which aspect of captured field/type/enum value 7238 * has to be adjusted by relocations. It is emitted by llvm and passed to 7239 * libbpf and later to the kernel. 7240 */ 7241 enum bpf_core_relo_kind { 7242 BPF_CORE_FIELD_BYTE_OFFSET = 0, /* field byte offset */ 7243 BPF_CORE_FIELD_BYTE_SIZE = 1, /* field size in bytes */ 7244 BPF_CORE_FIELD_EXISTS = 2, /* field existence in target kernel */ 7245 BPF_CORE_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */ 7246 BPF_CORE_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */ 7247 BPF_CORE_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */ 7248 BPF_CORE_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */ 7249 BPF_CORE_TYPE_ID_TARGET = 7, /* type ID in target kernel */ 7250 BPF_CORE_TYPE_EXISTS = 8, /* type existence in target kernel */ 7251 BPF_CORE_TYPE_SIZE = 9, /* type size in bytes */ 7252 BPF_CORE_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ 7253 BPF_CORE_ENUMVAL_VALUE = 11, /* enum value integer value */ 7254 BPF_CORE_TYPE_MATCHES = 12, /* type match in target kernel */ 7255 }; 7256 7257 /* 7258 * "struct bpf_core_relo" is used to pass relocation data form LLVM to libbpf 7259 * and from libbpf to the kernel. 7260 * 7261 * CO-RE relocation captures the following data: 7262 * - insn_off - instruction offset (in bytes) within a BPF program that needs 7263 * its insn->imm field to be relocated with actual field info; 7264 * - type_id - BTF type ID of the "root" (containing) entity of a relocatable 7265 * type or field; 7266 * - access_str_off - offset into corresponding .BTF string section. String 7267 * interpretation depends on specific relocation kind: 7268 * - for field-based relocations, string encodes an accessed field using 7269 * a sequence of field and array indices, separated by colon (:). It's 7270 * conceptually very close to LLVM's getelementptr ([0]) instruction's 7271 * arguments for identifying offset to a field. 7272 * - for type-based relocations, strings is expected to be just "0"; 7273 * - for enum value-based relocations, string contains an index of enum 7274 * value within its enum type; 7275 * - kind - one of enum bpf_core_relo_kind; 7276 * 7277 * Example: 7278 * struct sample { 7279 * int a; 7280 * struct { 7281 * int b[10]; 7282 * }; 7283 * }; 7284 * 7285 * struct sample *s = ...; 7286 * int *x = &s->a; // encoded as "0:0" (a is field #0) 7287 * int *y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1, 7288 * // b is field #0 inside anon struct, accessing elem #5) 7289 * int *z = &s[10]->b; // encoded as "10:1" (ptr is used as an array) 7290 * 7291 * type_id for all relocs in this example will capture BTF type id of 7292 * `struct sample`. 7293 * 7294 * Such relocation is emitted when using __builtin_preserve_access_index() 7295 * Clang built-in, passing expression that captures field address, e.g.: 7296 * 7297 * bpf_probe_read(&dst, sizeof(dst), 7298 * __builtin_preserve_access_index(&src->a.b.c)); 7299 * 7300 * In this case Clang will emit field relocation recording necessary data to 7301 * be able to find offset of embedded `a.b.c` field within `src` struct. 7302 * 7303 * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction 7304 */ 7305 struct bpf_core_relo { 7306 __u32 insn_off; 7307 __u32 type_id; 7308 __u32 access_str_off; 7309 enum bpf_core_relo_kind kind; 7310 }; 7311 7312 /* 7313 * Flags to control bpf_timer_start() behaviour. 7314 * - BPF_F_TIMER_ABS: Timeout passed is absolute time, by default it is 7315 * relative to current time. 7316 */ 7317 enum { 7318 BPF_F_TIMER_ABS = (1ULL << 0), 7319 }; 7320 7321 /* BPF numbers iterator state */ 7322 struct bpf_iter_num { 7323 /* opaque iterator state; having __u64 here allows to preserve correct 7324 * alignment requirements in vmlinux.h, generated from BTF 7325 */ 7326 __u64 __opaque[1]; 7327 } __attribute__((aligned(8))); 7328 7329 #endif /* _UAPI__LINUX_BPF_H__ */ 7330