1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 3 /* 4 * common eBPF ELF operations. 5 * 6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 8 * Copyright (C) 2015 Huawei Inc. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU Lesser General Public 12 * License as published by the Free Software Foundation; 13 * version 2.1 of the License (not later!) 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License for more details. 19 * 20 * You should have received a copy of the GNU Lesser General Public 21 * License along with this program; if not, see <http://www.gnu.org/licenses> 22 */ 23 24 #include <stdlib.h> 25 #include <string.h> 26 #include <memory.h> 27 #include <unistd.h> 28 #include <asm/unistd.h> 29 #include <errno.h> 30 #include <linux/bpf.h> 31 #include <linux/filter.h> 32 #include <linux/kernel.h> 33 #include <limits.h> 34 #include <sys/resource.h> 35 #include "bpf.h" 36 #include "libbpf.h" 37 #include "libbpf_internal.h" 38 39 /* 40 * When building perf, unistd.h is overridden. __NR_bpf is 41 * required to be defined explicitly. 42 */ 43 #ifndef __NR_bpf 44 # if defined(__i386__) 45 # define __NR_bpf 357 46 # elif defined(__x86_64__) 47 # define __NR_bpf 321 48 # elif defined(__aarch64__) 49 # define __NR_bpf 280 50 # elif defined(__sparc__) 51 # define __NR_bpf 349 52 # elif defined(__s390__) 53 # define __NR_bpf 351 54 # elif defined(__arc__) 55 # define __NR_bpf 280 56 # elif defined(__mips__) && defined(_ABIO32) 57 # define __NR_bpf 4355 58 # elif defined(__mips__) && defined(_ABIN32) 59 # define __NR_bpf 6319 60 # elif defined(__mips__) && defined(_ABI64) 61 # define __NR_bpf 5315 62 # else 63 # error __NR_bpf not defined. libbpf does not support your arch. 64 # endif 65 #endif 66 67 static inline __u64 ptr_to_u64(const void *ptr) 68 { 69 return (__u64) (unsigned long) ptr; 70 } 71 72 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 73 unsigned int size) 74 { 75 return syscall(__NR_bpf, cmd, attr, size); 76 } 77 78 static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr, 79 unsigned int size) 80 { 81 int fd; 82 83 fd = sys_bpf(cmd, attr, size); 84 return ensure_good_fd(fd); 85 } 86 87 int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts) 88 { 89 int fd; 90 91 do { 92 fd = sys_bpf_fd(BPF_PROG_LOAD, attr, size); 93 } while (fd < 0 && errno == EAGAIN && --attempts > 0); 94 95 return fd; 96 } 97 98 /* Probe whether kernel switched from memlock-based (RLIMIT_MEMLOCK) to 99 * memcg-based memory accounting for BPF maps and progs. This was done in [0]. 100 * We use the support for bpf_ktime_get_coarse_ns() helper, which was added in 101 * the same 5.11 Linux release ([1]), to detect memcg-based accounting for BPF. 102 * 103 * [0] https://lore.kernel.org/bpf/20201201215900.3569844-1-guro@fb.com/ 104 * [1] d05512618056 ("bpf: Add bpf_ktime_get_coarse_ns helper") 105 */ 106 int probe_memcg_account(void) 107 { 108 const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd); 109 struct bpf_insn insns[] = { 110 BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns), 111 BPF_EXIT_INSN(), 112 }; 113 size_t insn_cnt = ARRAY_SIZE(insns); 114 union bpf_attr attr; 115 int prog_fd; 116 117 /* attempt loading freplace trying to use custom BTF */ 118 memset(&attr, 0, attr_sz); 119 attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; 120 attr.insns = ptr_to_u64(insns); 121 attr.insn_cnt = insn_cnt; 122 attr.license = ptr_to_u64("GPL"); 123 124 prog_fd = sys_bpf_fd(BPF_PROG_LOAD, &attr, attr_sz); 125 if (prog_fd >= 0) { 126 close(prog_fd); 127 return 1; 128 } 129 return 0; 130 } 131 132 static bool memlock_bumped; 133 static rlim_t memlock_rlim = RLIM_INFINITY; 134 135 int libbpf_set_memlock_rlim(size_t memlock_bytes) 136 { 137 if (memlock_bumped) 138 return libbpf_err(-EBUSY); 139 140 memlock_rlim = memlock_bytes; 141 return 0; 142 } 143 144 int bump_rlimit_memlock(void) 145 { 146 struct rlimit rlim; 147 148 /* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLOCK */ 149 if (memlock_bumped || kernel_supports(NULL, FEAT_MEMCG_ACCOUNT)) 150 return 0; 151 152 memlock_bumped = true; 153 154 /* zero memlock_rlim_max disables auto-bumping RLIMIT_MEMLOCK */ 155 if (memlock_rlim == 0) 156 return 0; 157 158 rlim.rlim_cur = rlim.rlim_max = memlock_rlim; 159 if (setrlimit(RLIMIT_MEMLOCK, &rlim)) 160 return -errno; 161 162 return 0; 163 } 164 165 int bpf_map_create(enum bpf_map_type map_type, 166 const char *map_name, 167 __u32 key_size, 168 __u32 value_size, 169 __u32 max_entries, 170 const struct bpf_map_create_opts *opts) 171 { 172 const size_t attr_sz = offsetofend(union bpf_attr, map_extra); 173 union bpf_attr attr; 174 int fd; 175 176 bump_rlimit_memlock(); 177 178 memset(&attr, 0, attr_sz); 179 180 if (!OPTS_VALID(opts, bpf_map_create_opts)) 181 return libbpf_err(-EINVAL); 182 183 attr.map_type = map_type; 184 if (map_name && kernel_supports(NULL, FEAT_PROG_NAME)) 185 libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name)); 186 attr.key_size = key_size; 187 attr.value_size = value_size; 188 attr.max_entries = max_entries; 189 190 attr.btf_fd = OPTS_GET(opts, btf_fd, 0); 191 attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0); 192 attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0); 193 attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0); 194 195 attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0); 196 attr.map_flags = OPTS_GET(opts, map_flags, 0); 197 attr.map_extra = OPTS_GET(opts, map_extra, 0); 198 attr.numa_node = OPTS_GET(opts, numa_node, 0); 199 attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0); 200 201 fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz); 202 return libbpf_err_errno(fd); 203 } 204 205 static void * 206 alloc_zero_tailing_info(const void *orecord, __u32 cnt, 207 __u32 actual_rec_size, __u32 expected_rec_size) 208 { 209 __u64 info_len = (__u64)actual_rec_size * cnt; 210 void *info, *nrecord; 211 int i; 212 213 info = malloc(info_len); 214 if (!info) 215 return NULL; 216 217 /* zero out bytes kernel does not understand */ 218 nrecord = info; 219 for (i = 0; i < cnt; i++) { 220 memcpy(nrecord, orecord, expected_rec_size); 221 memset(nrecord + expected_rec_size, 0, 222 actual_rec_size - expected_rec_size); 223 orecord += actual_rec_size; 224 nrecord += actual_rec_size; 225 } 226 227 return info; 228 } 229 230 int bpf_prog_load(enum bpf_prog_type prog_type, 231 const char *prog_name, const char *license, 232 const struct bpf_insn *insns, size_t insn_cnt, 233 const struct bpf_prog_load_opts *opts) 234 { 235 const size_t attr_sz = offsetofend(union bpf_attr, fd_array); 236 void *finfo = NULL, *linfo = NULL; 237 const char *func_info, *line_info; 238 __u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd; 239 __u32 func_info_rec_size, line_info_rec_size; 240 int fd, attempts; 241 union bpf_attr attr; 242 char *log_buf; 243 244 bump_rlimit_memlock(); 245 246 if (!OPTS_VALID(opts, bpf_prog_load_opts)) 247 return libbpf_err(-EINVAL); 248 249 attempts = OPTS_GET(opts, attempts, 0); 250 if (attempts < 0) 251 return libbpf_err(-EINVAL); 252 if (attempts == 0) 253 attempts = PROG_LOAD_ATTEMPTS; 254 255 memset(&attr, 0, attr_sz); 256 257 attr.prog_type = prog_type; 258 attr.expected_attach_type = OPTS_GET(opts, expected_attach_type, 0); 259 260 attr.prog_btf_fd = OPTS_GET(opts, prog_btf_fd, 0); 261 attr.prog_flags = OPTS_GET(opts, prog_flags, 0); 262 attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0); 263 attr.kern_version = OPTS_GET(opts, kern_version, 0); 264 265 if (prog_name && kernel_supports(NULL, FEAT_PROG_NAME)) 266 libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name)); 267 attr.license = ptr_to_u64(license); 268 269 if (insn_cnt > UINT_MAX) 270 return libbpf_err(-E2BIG); 271 272 attr.insns = ptr_to_u64(insns); 273 attr.insn_cnt = (__u32)insn_cnt; 274 275 attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0); 276 attach_btf_obj_fd = OPTS_GET(opts, attach_btf_obj_fd, 0); 277 278 if (attach_prog_fd && attach_btf_obj_fd) 279 return libbpf_err(-EINVAL); 280 281 attr.attach_btf_id = OPTS_GET(opts, attach_btf_id, 0); 282 if (attach_prog_fd) 283 attr.attach_prog_fd = attach_prog_fd; 284 else 285 attr.attach_btf_obj_fd = attach_btf_obj_fd; 286 287 log_buf = OPTS_GET(opts, log_buf, NULL); 288 log_size = OPTS_GET(opts, log_size, 0); 289 log_level = OPTS_GET(opts, log_level, 0); 290 291 if (!!log_buf != !!log_size) 292 return libbpf_err(-EINVAL); 293 if (log_level > (4 | 2 | 1)) 294 return libbpf_err(-EINVAL); 295 if (log_level && !log_buf) 296 return libbpf_err(-EINVAL); 297 298 func_info_rec_size = OPTS_GET(opts, func_info_rec_size, 0); 299 func_info = OPTS_GET(opts, func_info, NULL); 300 attr.func_info_rec_size = func_info_rec_size; 301 attr.func_info = ptr_to_u64(func_info); 302 attr.func_info_cnt = OPTS_GET(opts, func_info_cnt, 0); 303 304 line_info_rec_size = OPTS_GET(opts, line_info_rec_size, 0); 305 line_info = OPTS_GET(opts, line_info, NULL); 306 attr.line_info_rec_size = line_info_rec_size; 307 attr.line_info = ptr_to_u64(line_info); 308 attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0); 309 310 attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL)); 311 312 if (log_level) { 313 attr.log_buf = ptr_to_u64(log_buf); 314 attr.log_size = log_size; 315 attr.log_level = log_level; 316 } 317 318 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 319 if (fd >= 0) 320 return fd; 321 322 /* After bpf_prog_load, the kernel may modify certain attributes 323 * to give user space a hint how to deal with loading failure. 324 * Check to see whether we can make some changes and load again. 325 */ 326 while (errno == E2BIG && (!finfo || !linfo)) { 327 if (!finfo && attr.func_info_cnt && 328 attr.func_info_rec_size < func_info_rec_size) { 329 /* try with corrected func info records */ 330 finfo = alloc_zero_tailing_info(func_info, 331 attr.func_info_cnt, 332 func_info_rec_size, 333 attr.func_info_rec_size); 334 if (!finfo) { 335 errno = E2BIG; 336 goto done; 337 } 338 339 attr.func_info = ptr_to_u64(finfo); 340 attr.func_info_rec_size = func_info_rec_size; 341 } else if (!linfo && attr.line_info_cnt && 342 attr.line_info_rec_size < line_info_rec_size) { 343 linfo = alloc_zero_tailing_info(line_info, 344 attr.line_info_cnt, 345 line_info_rec_size, 346 attr.line_info_rec_size); 347 if (!linfo) { 348 errno = E2BIG; 349 goto done; 350 } 351 352 attr.line_info = ptr_to_u64(linfo); 353 attr.line_info_rec_size = line_info_rec_size; 354 } else { 355 break; 356 } 357 358 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 359 if (fd >= 0) 360 goto done; 361 } 362 363 if (log_level == 0 && log_buf) { 364 /* log_level == 0 with non-NULL log_buf requires retrying on error 365 * with log_level == 1 and log_buf/log_buf_size set, to get details of 366 * failure 367 */ 368 attr.log_buf = ptr_to_u64(log_buf); 369 attr.log_size = log_size; 370 attr.log_level = 1; 371 372 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 373 } 374 done: 375 /* free() doesn't affect errno, so we don't need to restore it */ 376 free(finfo); 377 free(linfo); 378 return libbpf_err_errno(fd); 379 } 380 381 int bpf_map_update_elem(int fd, const void *key, const void *value, 382 __u64 flags) 383 { 384 const size_t attr_sz = offsetofend(union bpf_attr, flags); 385 union bpf_attr attr; 386 int ret; 387 388 memset(&attr, 0, attr_sz); 389 attr.map_fd = fd; 390 attr.key = ptr_to_u64(key); 391 attr.value = ptr_to_u64(value); 392 attr.flags = flags; 393 394 ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz); 395 return libbpf_err_errno(ret); 396 } 397 398 int bpf_map_lookup_elem(int fd, const void *key, void *value) 399 { 400 const size_t attr_sz = offsetofend(union bpf_attr, flags); 401 union bpf_attr attr; 402 int ret; 403 404 memset(&attr, 0, attr_sz); 405 attr.map_fd = fd; 406 attr.key = ptr_to_u64(key); 407 attr.value = ptr_to_u64(value); 408 409 ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); 410 return libbpf_err_errno(ret); 411 } 412 413 int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) 414 { 415 const size_t attr_sz = offsetofend(union bpf_attr, flags); 416 union bpf_attr attr; 417 int ret; 418 419 memset(&attr, 0, attr_sz); 420 attr.map_fd = fd; 421 attr.key = ptr_to_u64(key); 422 attr.value = ptr_to_u64(value); 423 attr.flags = flags; 424 425 ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); 426 return libbpf_err_errno(ret); 427 } 428 429 int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) 430 { 431 const size_t attr_sz = offsetofend(union bpf_attr, flags); 432 union bpf_attr attr; 433 int ret; 434 435 memset(&attr, 0, attr_sz); 436 attr.map_fd = fd; 437 attr.key = ptr_to_u64(key); 438 attr.value = ptr_to_u64(value); 439 440 ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); 441 return libbpf_err_errno(ret); 442 } 443 444 int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags) 445 { 446 const size_t attr_sz = offsetofend(union bpf_attr, flags); 447 union bpf_attr attr; 448 int ret; 449 450 memset(&attr, 0, attr_sz); 451 attr.map_fd = fd; 452 attr.key = ptr_to_u64(key); 453 attr.value = ptr_to_u64(value); 454 attr.flags = flags; 455 456 ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); 457 return libbpf_err_errno(ret); 458 } 459 460 int bpf_map_delete_elem(int fd, const void *key) 461 { 462 const size_t attr_sz = offsetofend(union bpf_attr, flags); 463 union bpf_attr attr; 464 int ret; 465 466 memset(&attr, 0, attr_sz); 467 attr.map_fd = fd; 468 attr.key = ptr_to_u64(key); 469 470 ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); 471 return libbpf_err_errno(ret); 472 } 473 474 int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags) 475 { 476 const size_t attr_sz = offsetofend(union bpf_attr, flags); 477 union bpf_attr attr; 478 int ret; 479 480 memset(&attr, 0, attr_sz); 481 attr.map_fd = fd; 482 attr.key = ptr_to_u64(key); 483 attr.flags = flags; 484 485 ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); 486 return libbpf_err_errno(ret); 487 } 488 489 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 490 { 491 const size_t attr_sz = offsetofend(union bpf_attr, next_key); 492 union bpf_attr attr; 493 int ret; 494 495 memset(&attr, 0, attr_sz); 496 attr.map_fd = fd; 497 attr.key = ptr_to_u64(key); 498 attr.next_key = ptr_to_u64(next_key); 499 500 ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, attr_sz); 501 return libbpf_err_errno(ret); 502 } 503 504 int bpf_map_freeze(int fd) 505 { 506 const size_t attr_sz = offsetofend(union bpf_attr, map_fd); 507 union bpf_attr attr; 508 int ret; 509 510 memset(&attr, 0, attr_sz); 511 attr.map_fd = fd; 512 513 ret = sys_bpf(BPF_MAP_FREEZE, &attr, attr_sz); 514 return libbpf_err_errno(ret); 515 } 516 517 static int bpf_map_batch_common(int cmd, int fd, void *in_batch, 518 void *out_batch, void *keys, void *values, 519 __u32 *count, 520 const struct bpf_map_batch_opts *opts) 521 { 522 const size_t attr_sz = offsetofend(union bpf_attr, batch); 523 union bpf_attr attr; 524 int ret; 525 526 if (!OPTS_VALID(opts, bpf_map_batch_opts)) 527 return libbpf_err(-EINVAL); 528 529 memset(&attr, 0, attr_sz); 530 attr.batch.map_fd = fd; 531 attr.batch.in_batch = ptr_to_u64(in_batch); 532 attr.batch.out_batch = ptr_to_u64(out_batch); 533 attr.batch.keys = ptr_to_u64(keys); 534 attr.batch.values = ptr_to_u64(values); 535 attr.batch.count = *count; 536 attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0); 537 attr.batch.flags = OPTS_GET(opts, flags, 0); 538 539 ret = sys_bpf(cmd, &attr, attr_sz); 540 *count = attr.batch.count; 541 542 return libbpf_err_errno(ret); 543 } 544 545 int bpf_map_delete_batch(int fd, const void *keys, __u32 *count, 546 const struct bpf_map_batch_opts *opts) 547 { 548 return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL, 549 NULL, (void *)keys, NULL, count, opts); 550 } 551 552 int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys, 553 void *values, __u32 *count, 554 const struct bpf_map_batch_opts *opts) 555 { 556 return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch, 557 out_batch, keys, values, count, opts); 558 } 559 560 int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch, 561 void *keys, void *values, __u32 *count, 562 const struct bpf_map_batch_opts *opts) 563 { 564 return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH, 565 fd, in_batch, out_batch, keys, values, 566 count, opts); 567 } 568 569 int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *count, 570 const struct bpf_map_batch_opts *opts) 571 { 572 return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL, 573 (void *)keys, (void *)values, count, opts); 574 } 575 576 int bpf_obj_pin(int fd, const char *pathname) 577 { 578 const size_t attr_sz = offsetofend(union bpf_attr, file_flags); 579 union bpf_attr attr; 580 int ret; 581 582 memset(&attr, 0, attr_sz); 583 attr.pathname = ptr_to_u64((void *)pathname); 584 attr.bpf_fd = fd; 585 586 ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz); 587 return libbpf_err_errno(ret); 588 } 589 590 int bpf_obj_get(const char *pathname) 591 { 592 return bpf_obj_get_opts(pathname, NULL); 593 } 594 595 int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) 596 { 597 const size_t attr_sz = offsetofend(union bpf_attr, file_flags); 598 union bpf_attr attr; 599 int fd; 600 601 if (!OPTS_VALID(opts, bpf_obj_get_opts)) 602 return libbpf_err(-EINVAL); 603 604 memset(&attr, 0, attr_sz); 605 attr.pathname = ptr_to_u64((void *)pathname); 606 attr.file_flags = OPTS_GET(opts, file_flags, 0); 607 608 fd = sys_bpf_fd(BPF_OBJ_GET, &attr, attr_sz); 609 return libbpf_err_errno(fd); 610 } 611 612 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 613 unsigned int flags) 614 { 615 DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, opts, 616 .flags = flags, 617 ); 618 619 return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts); 620 } 621 622 int bpf_prog_attach_opts(int prog_fd, int target_fd, 623 enum bpf_attach_type type, 624 const struct bpf_prog_attach_opts *opts) 625 { 626 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 627 union bpf_attr attr; 628 int ret; 629 630 if (!OPTS_VALID(opts, bpf_prog_attach_opts)) 631 return libbpf_err(-EINVAL); 632 633 memset(&attr, 0, attr_sz); 634 attr.target_fd = target_fd; 635 attr.attach_bpf_fd = prog_fd; 636 attr.attach_type = type; 637 attr.attach_flags = OPTS_GET(opts, flags, 0); 638 attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0); 639 640 ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz); 641 return libbpf_err_errno(ret); 642 } 643 644 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 645 { 646 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 647 union bpf_attr attr; 648 int ret; 649 650 memset(&attr, 0, attr_sz); 651 attr.target_fd = target_fd; 652 attr.attach_type = type; 653 654 ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); 655 return libbpf_err_errno(ret); 656 } 657 658 int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) 659 { 660 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 661 union bpf_attr attr; 662 int ret; 663 664 memset(&attr, 0, attr_sz); 665 attr.target_fd = target_fd; 666 attr.attach_bpf_fd = prog_fd; 667 attr.attach_type = type; 668 669 ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); 670 return libbpf_err_errno(ret); 671 } 672 673 int bpf_link_create(int prog_fd, int target_fd, 674 enum bpf_attach_type attach_type, 675 const struct bpf_link_create_opts *opts) 676 { 677 const size_t attr_sz = offsetofend(union bpf_attr, link_create); 678 __u32 target_btf_id, iter_info_len; 679 union bpf_attr attr; 680 int fd, err; 681 682 if (!OPTS_VALID(opts, bpf_link_create_opts)) 683 return libbpf_err(-EINVAL); 684 685 iter_info_len = OPTS_GET(opts, iter_info_len, 0); 686 target_btf_id = OPTS_GET(opts, target_btf_id, 0); 687 688 /* validate we don't have unexpected combinations of non-zero fields */ 689 if (iter_info_len || target_btf_id) { 690 if (iter_info_len && target_btf_id) 691 return libbpf_err(-EINVAL); 692 if (!OPTS_ZEROED(opts, target_btf_id)) 693 return libbpf_err(-EINVAL); 694 } 695 696 memset(&attr, 0, attr_sz); 697 attr.link_create.prog_fd = prog_fd; 698 attr.link_create.target_fd = target_fd; 699 attr.link_create.attach_type = attach_type; 700 attr.link_create.flags = OPTS_GET(opts, flags, 0); 701 702 if (target_btf_id) { 703 attr.link_create.target_btf_id = target_btf_id; 704 goto proceed; 705 } 706 707 switch (attach_type) { 708 case BPF_TRACE_ITER: 709 attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); 710 attr.link_create.iter_info_len = iter_info_len; 711 break; 712 case BPF_PERF_EVENT: 713 attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0); 714 if (!OPTS_ZEROED(opts, perf_event)) 715 return libbpf_err(-EINVAL); 716 break; 717 case BPF_TRACE_KPROBE_MULTI: 718 attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0); 719 attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0); 720 attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0)); 721 attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0)); 722 attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0)); 723 if (!OPTS_ZEROED(opts, kprobe_multi)) 724 return libbpf_err(-EINVAL); 725 break; 726 case BPF_TRACE_FENTRY: 727 case BPF_TRACE_FEXIT: 728 case BPF_MODIFY_RETURN: 729 case BPF_LSM_MAC: 730 attr.link_create.tracing.cookie = OPTS_GET(opts, tracing.cookie, 0); 731 if (!OPTS_ZEROED(opts, tracing)) 732 return libbpf_err(-EINVAL); 733 break; 734 default: 735 if (!OPTS_ZEROED(opts, flags)) 736 return libbpf_err(-EINVAL); 737 break; 738 } 739 proceed: 740 fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, attr_sz); 741 if (fd >= 0) 742 return fd; 743 /* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry 744 * and other similar programs 745 */ 746 err = -errno; 747 if (err != -EINVAL) 748 return libbpf_err(err); 749 750 /* if user used features not supported by 751 * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately 752 */ 753 if (attr.link_create.target_fd || attr.link_create.target_btf_id) 754 return libbpf_err(err); 755 if (!OPTS_ZEROED(opts, sz)) 756 return libbpf_err(err); 757 758 /* otherwise, for few select kinds of programs that can be 759 * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as 760 * a fallback for older kernels 761 */ 762 switch (attach_type) { 763 case BPF_TRACE_RAW_TP: 764 case BPF_LSM_MAC: 765 case BPF_TRACE_FENTRY: 766 case BPF_TRACE_FEXIT: 767 case BPF_MODIFY_RETURN: 768 return bpf_raw_tracepoint_open(NULL, prog_fd); 769 default: 770 return libbpf_err(err); 771 } 772 } 773 774 int bpf_link_detach(int link_fd) 775 { 776 const size_t attr_sz = offsetofend(union bpf_attr, link_detach); 777 union bpf_attr attr; 778 int ret; 779 780 memset(&attr, 0, attr_sz); 781 attr.link_detach.link_fd = link_fd; 782 783 ret = sys_bpf(BPF_LINK_DETACH, &attr, attr_sz); 784 return libbpf_err_errno(ret); 785 } 786 787 int bpf_link_update(int link_fd, int new_prog_fd, 788 const struct bpf_link_update_opts *opts) 789 { 790 const size_t attr_sz = offsetofend(union bpf_attr, link_update); 791 union bpf_attr attr; 792 int ret; 793 794 if (!OPTS_VALID(opts, bpf_link_update_opts)) 795 return libbpf_err(-EINVAL); 796 797 memset(&attr, 0, attr_sz); 798 attr.link_update.link_fd = link_fd; 799 attr.link_update.new_prog_fd = new_prog_fd; 800 attr.link_update.flags = OPTS_GET(opts, flags, 0); 801 attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0); 802 803 ret = sys_bpf(BPF_LINK_UPDATE, &attr, attr_sz); 804 return libbpf_err_errno(ret); 805 } 806 807 int bpf_iter_create(int link_fd) 808 { 809 const size_t attr_sz = offsetofend(union bpf_attr, iter_create); 810 union bpf_attr attr; 811 int fd; 812 813 memset(&attr, 0, attr_sz); 814 attr.iter_create.link_fd = link_fd; 815 816 fd = sys_bpf_fd(BPF_ITER_CREATE, &attr, attr_sz); 817 return libbpf_err_errno(fd); 818 } 819 820 int bpf_prog_query_opts(int target_fd, 821 enum bpf_attach_type type, 822 struct bpf_prog_query_opts *opts) 823 { 824 const size_t attr_sz = offsetofend(union bpf_attr, query); 825 union bpf_attr attr; 826 int ret; 827 828 if (!OPTS_VALID(opts, bpf_prog_query_opts)) 829 return libbpf_err(-EINVAL); 830 831 memset(&attr, 0, attr_sz); 832 833 attr.query.target_fd = target_fd; 834 attr.query.attach_type = type; 835 attr.query.query_flags = OPTS_GET(opts, query_flags, 0); 836 attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0); 837 attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); 838 attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); 839 840 ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz); 841 842 OPTS_SET(opts, attach_flags, attr.query.attach_flags); 843 OPTS_SET(opts, prog_cnt, attr.query.prog_cnt); 844 845 return libbpf_err_errno(ret); 846 } 847 848 int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, 849 __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) 850 { 851 LIBBPF_OPTS(bpf_prog_query_opts, opts); 852 int ret; 853 854 opts.query_flags = query_flags; 855 opts.prog_ids = prog_ids; 856 opts.prog_cnt = *prog_cnt; 857 858 ret = bpf_prog_query_opts(target_fd, type, &opts); 859 860 if (attach_flags) 861 *attach_flags = opts.attach_flags; 862 *prog_cnt = opts.prog_cnt; 863 864 return libbpf_err_errno(ret); 865 } 866 867 int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) 868 { 869 const size_t attr_sz = offsetofend(union bpf_attr, test); 870 union bpf_attr attr; 871 int ret; 872 873 if (!OPTS_VALID(opts, bpf_test_run_opts)) 874 return libbpf_err(-EINVAL); 875 876 memset(&attr, 0, attr_sz); 877 attr.test.prog_fd = prog_fd; 878 attr.test.batch_size = OPTS_GET(opts, batch_size, 0); 879 attr.test.cpu = OPTS_GET(opts, cpu, 0); 880 attr.test.flags = OPTS_GET(opts, flags, 0); 881 attr.test.repeat = OPTS_GET(opts, repeat, 0); 882 attr.test.duration = OPTS_GET(opts, duration, 0); 883 attr.test.ctx_size_in = OPTS_GET(opts, ctx_size_in, 0); 884 attr.test.ctx_size_out = OPTS_GET(opts, ctx_size_out, 0); 885 attr.test.data_size_in = OPTS_GET(opts, data_size_in, 0); 886 attr.test.data_size_out = OPTS_GET(opts, data_size_out, 0); 887 attr.test.ctx_in = ptr_to_u64(OPTS_GET(opts, ctx_in, NULL)); 888 attr.test.ctx_out = ptr_to_u64(OPTS_GET(opts, ctx_out, NULL)); 889 attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL)); 890 attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL)); 891 892 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, attr_sz); 893 894 OPTS_SET(opts, data_size_out, attr.test.data_size_out); 895 OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out); 896 OPTS_SET(opts, duration, attr.test.duration); 897 OPTS_SET(opts, retval, attr.test.retval); 898 899 return libbpf_err_errno(ret); 900 } 901 902 static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) 903 { 904 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 905 union bpf_attr attr; 906 int err; 907 908 memset(&attr, 0, attr_sz); 909 attr.start_id = start_id; 910 911 err = sys_bpf(cmd, &attr, attr_sz); 912 if (!err) 913 *next_id = attr.next_id; 914 915 return libbpf_err_errno(err); 916 } 917 918 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 919 { 920 return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID); 921 } 922 923 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 924 { 925 return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID); 926 } 927 928 int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id) 929 { 930 return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID); 931 } 932 933 int bpf_link_get_next_id(__u32 start_id, __u32 *next_id) 934 { 935 return bpf_obj_get_next_id(start_id, next_id, BPF_LINK_GET_NEXT_ID); 936 } 937 938 int bpf_prog_get_fd_by_id_opts(__u32 id, 939 const struct bpf_get_fd_by_id_opts *opts) 940 { 941 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 942 union bpf_attr attr; 943 int fd; 944 945 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 946 return libbpf_err(-EINVAL); 947 948 memset(&attr, 0, attr_sz); 949 attr.prog_id = id; 950 attr.open_flags = OPTS_GET(opts, open_flags, 0); 951 952 fd = sys_bpf_fd(BPF_PROG_GET_FD_BY_ID, &attr, attr_sz); 953 return libbpf_err_errno(fd); 954 } 955 956 int bpf_prog_get_fd_by_id(__u32 id) 957 { 958 return bpf_prog_get_fd_by_id_opts(id, NULL); 959 } 960 961 int bpf_map_get_fd_by_id_opts(__u32 id, 962 const struct bpf_get_fd_by_id_opts *opts) 963 { 964 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 965 union bpf_attr attr; 966 int fd; 967 968 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 969 return libbpf_err(-EINVAL); 970 971 memset(&attr, 0, attr_sz); 972 attr.map_id = id; 973 attr.open_flags = OPTS_GET(opts, open_flags, 0); 974 975 fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz); 976 return libbpf_err_errno(fd); 977 } 978 979 int bpf_map_get_fd_by_id(__u32 id) 980 { 981 return bpf_map_get_fd_by_id_opts(id, NULL); 982 } 983 984 int bpf_btf_get_fd_by_id_opts(__u32 id, 985 const struct bpf_get_fd_by_id_opts *opts) 986 { 987 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 988 union bpf_attr attr; 989 int fd; 990 991 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 992 return libbpf_err(-EINVAL); 993 994 memset(&attr, 0, attr_sz); 995 attr.btf_id = id; 996 attr.open_flags = OPTS_GET(opts, open_flags, 0); 997 998 fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, attr_sz); 999 return libbpf_err_errno(fd); 1000 } 1001 1002 int bpf_btf_get_fd_by_id(__u32 id) 1003 { 1004 return bpf_btf_get_fd_by_id_opts(id, NULL); 1005 } 1006 1007 int bpf_link_get_fd_by_id_opts(__u32 id, 1008 const struct bpf_get_fd_by_id_opts *opts) 1009 { 1010 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 1011 union bpf_attr attr; 1012 int fd; 1013 1014 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 1015 return libbpf_err(-EINVAL); 1016 1017 memset(&attr, 0, attr_sz); 1018 attr.link_id = id; 1019 attr.open_flags = OPTS_GET(opts, open_flags, 0); 1020 1021 fd = sys_bpf_fd(BPF_LINK_GET_FD_BY_ID, &attr, attr_sz); 1022 return libbpf_err_errno(fd); 1023 } 1024 1025 int bpf_link_get_fd_by_id(__u32 id) 1026 { 1027 return bpf_link_get_fd_by_id_opts(id, NULL); 1028 } 1029 1030 int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) 1031 { 1032 const size_t attr_sz = offsetofend(union bpf_attr, info); 1033 union bpf_attr attr; 1034 int err; 1035 1036 memset(&attr, 0, attr_sz); 1037 attr.info.bpf_fd = bpf_fd; 1038 attr.info.info_len = *info_len; 1039 attr.info.info = ptr_to_u64(info); 1040 1041 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, attr_sz); 1042 if (!err) 1043 *info_len = attr.info.info_len; 1044 return libbpf_err_errno(err); 1045 } 1046 1047 int bpf_raw_tracepoint_open(const char *name, int prog_fd) 1048 { 1049 const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint); 1050 union bpf_attr attr; 1051 int fd; 1052 1053 memset(&attr, 0, attr_sz); 1054 attr.raw_tracepoint.name = ptr_to_u64(name); 1055 attr.raw_tracepoint.prog_fd = prog_fd; 1056 1057 fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz); 1058 return libbpf_err_errno(fd); 1059 } 1060 1061 int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_load_opts *opts) 1062 { 1063 const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level); 1064 union bpf_attr attr; 1065 char *log_buf; 1066 size_t log_size; 1067 __u32 log_level; 1068 int fd; 1069 1070 bump_rlimit_memlock(); 1071 1072 memset(&attr, 0, attr_sz); 1073 1074 if (!OPTS_VALID(opts, bpf_btf_load_opts)) 1075 return libbpf_err(-EINVAL); 1076 1077 log_buf = OPTS_GET(opts, log_buf, NULL); 1078 log_size = OPTS_GET(opts, log_size, 0); 1079 log_level = OPTS_GET(opts, log_level, 0); 1080 1081 if (log_size > UINT_MAX) 1082 return libbpf_err(-EINVAL); 1083 if (log_size && !log_buf) 1084 return libbpf_err(-EINVAL); 1085 1086 attr.btf = ptr_to_u64(btf_data); 1087 attr.btf_size = btf_size; 1088 /* log_level == 0 and log_buf != NULL means "try loading without 1089 * log_buf, but retry with log_buf and log_level=1 on error", which is 1090 * consistent across low-level and high-level BTF and program loading 1091 * APIs within libbpf and provides a sensible behavior in practice 1092 */ 1093 if (log_level) { 1094 attr.btf_log_buf = ptr_to_u64(log_buf); 1095 attr.btf_log_size = (__u32)log_size; 1096 attr.btf_log_level = log_level; 1097 } 1098 1099 fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); 1100 if (fd < 0 && log_buf && log_level == 0) { 1101 attr.btf_log_buf = ptr_to_u64(log_buf); 1102 attr.btf_log_size = (__u32)log_size; 1103 attr.btf_log_level = 1; 1104 fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); 1105 } 1106 return libbpf_err_errno(fd); 1107 } 1108 1109 int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, 1110 __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, 1111 __u64 *probe_addr) 1112 { 1113 const size_t attr_sz = offsetofend(union bpf_attr, task_fd_query); 1114 union bpf_attr attr; 1115 int err; 1116 1117 memset(&attr, 0, attr_sz); 1118 attr.task_fd_query.pid = pid; 1119 attr.task_fd_query.fd = fd; 1120 attr.task_fd_query.flags = flags; 1121 attr.task_fd_query.buf = ptr_to_u64(buf); 1122 attr.task_fd_query.buf_len = *buf_len; 1123 1124 err = sys_bpf(BPF_TASK_FD_QUERY, &attr, attr_sz); 1125 1126 *buf_len = attr.task_fd_query.buf_len; 1127 *prog_id = attr.task_fd_query.prog_id; 1128 *fd_type = attr.task_fd_query.fd_type; 1129 *probe_offset = attr.task_fd_query.probe_offset; 1130 *probe_addr = attr.task_fd_query.probe_addr; 1131 1132 return libbpf_err_errno(err); 1133 } 1134 1135 int bpf_enable_stats(enum bpf_stats_type type) 1136 { 1137 const size_t attr_sz = offsetofend(union bpf_attr, enable_stats); 1138 union bpf_attr attr; 1139 int fd; 1140 1141 memset(&attr, 0, attr_sz); 1142 attr.enable_stats.type = type; 1143 1144 fd = sys_bpf_fd(BPF_ENABLE_STATS, &attr, attr_sz); 1145 return libbpf_err_errno(fd); 1146 } 1147 1148 int bpf_prog_bind_map(int prog_fd, int map_fd, 1149 const struct bpf_prog_bind_opts *opts) 1150 { 1151 const size_t attr_sz = offsetofend(union bpf_attr, prog_bind_map); 1152 union bpf_attr attr; 1153 int ret; 1154 1155 if (!OPTS_VALID(opts, bpf_prog_bind_opts)) 1156 return libbpf_err(-EINVAL); 1157 1158 memset(&attr, 0, attr_sz); 1159 attr.prog_bind_map.prog_fd = prog_fd; 1160 attr.prog_bind_map.map_fd = map_fd; 1161 attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0); 1162 1163 ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, attr_sz); 1164 return libbpf_err_errno(ret); 1165 } 1166