1 // SPDX-License-Identifier: LGPL-2.1 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 <memory.h> 26 #include <unistd.h> 27 #include <asm/unistd.h> 28 #include <linux/bpf.h> 29 #include "bpf.h" 30 #include "libbpf.h" 31 #include "nlattr.h" 32 #include <linux/rtnetlink.h> 33 #include <linux/if_link.h> 34 #include <sys/socket.h> 35 #include <errno.h> 36 37 #ifndef SOL_NETLINK 38 #define SOL_NETLINK 270 39 #endif 40 41 /* 42 * When building perf, unistd.h is overridden. __NR_bpf is 43 * required to be defined explicitly. 44 */ 45 #ifndef __NR_bpf 46 # if defined(__i386__) 47 # define __NR_bpf 357 48 # elif defined(__x86_64__) 49 # define __NR_bpf 321 50 # elif defined(__aarch64__) 51 # define __NR_bpf 280 52 # elif defined(__sparc__) 53 # define __NR_bpf 349 54 # elif defined(__s390__) 55 # define __NR_bpf 351 56 # else 57 # error __NR_bpf not defined. libbpf does not support your arch. 58 # endif 59 #endif 60 61 #ifndef min 62 #define min(x, y) ((x) < (y) ? (x) : (y)) 63 #endif 64 65 static inline __u64 ptr_to_u64(const void *ptr) 66 { 67 return (__u64) (unsigned long) ptr; 68 } 69 70 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 71 unsigned int size) 72 { 73 return syscall(__NR_bpf, cmd, attr, size); 74 } 75 76 int bpf_create_map_node(enum bpf_map_type map_type, const char *name, 77 int key_size, int value_size, int max_entries, 78 __u32 map_flags, int node) 79 { 80 __u32 name_len = name ? strlen(name) : 0; 81 union bpf_attr attr; 82 83 memset(&attr, '\0', sizeof(attr)); 84 85 attr.map_type = map_type; 86 attr.key_size = key_size; 87 attr.value_size = value_size; 88 attr.max_entries = max_entries; 89 attr.map_flags = map_flags; 90 memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1)); 91 92 if (node >= 0) { 93 attr.map_flags |= BPF_F_NUMA_NODE; 94 attr.numa_node = node; 95 } 96 97 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 98 } 99 100 int bpf_create_map(enum bpf_map_type map_type, int key_size, 101 int value_size, int max_entries, __u32 map_flags) 102 { 103 return bpf_create_map_node(map_type, NULL, key_size, value_size, 104 max_entries, map_flags, -1); 105 } 106 107 int bpf_create_map_name(enum bpf_map_type map_type, const char *name, 108 int key_size, int value_size, int max_entries, 109 __u32 map_flags) 110 { 111 return bpf_create_map_node(map_type, name, key_size, value_size, 112 max_entries, map_flags, -1); 113 } 114 115 int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, 116 int key_size, int inner_map_fd, int max_entries, 117 __u32 map_flags, int node) 118 { 119 __u32 name_len = name ? strlen(name) : 0; 120 union bpf_attr attr; 121 122 memset(&attr, '\0', sizeof(attr)); 123 124 attr.map_type = map_type; 125 attr.key_size = key_size; 126 attr.value_size = 4; 127 attr.inner_map_fd = inner_map_fd; 128 attr.max_entries = max_entries; 129 attr.map_flags = map_flags; 130 memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1)); 131 132 if (node >= 0) { 133 attr.map_flags |= BPF_F_NUMA_NODE; 134 attr.numa_node = node; 135 } 136 137 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 138 } 139 140 int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name, 141 int key_size, int inner_map_fd, int max_entries, 142 __u32 map_flags) 143 { 144 return bpf_create_map_in_map_node(map_type, name, key_size, 145 inner_map_fd, max_entries, map_flags, 146 -1); 147 } 148 149 int bpf_load_program_name(enum bpf_prog_type type, const char *name, 150 const struct bpf_insn *insns, 151 size_t insns_cnt, const char *license, 152 __u32 kern_version, char *log_buf, 153 size_t log_buf_sz) 154 { 155 int fd; 156 union bpf_attr attr; 157 __u32 name_len = name ? strlen(name) : 0; 158 159 bzero(&attr, sizeof(attr)); 160 attr.prog_type = type; 161 attr.insn_cnt = (__u32)insns_cnt; 162 attr.insns = ptr_to_u64(insns); 163 attr.license = ptr_to_u64(license); 164 attr.log_buf = ptr_to_u64(NULL); 165 attr.log_size = 0; 166 attr.log_level = 0; 167 attr.kern_version = kern_version; 168 memcpy(attr.prog_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1)); 169 170 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 171 if (fd >= 0 || !log_buf || !log_buf_sz) 172 return fd; 173 174 /* Try again with log */ 175 attr.log_buf = ptr_to_u64(log_buf); 176 attr.log_size = log_buf_sz; 177 attr.log_level = 1; 178 log_buf[0] = 0; 179 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 180 } 181 182 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 183 size_t insns_cnt, const char *license, 184 __u32 kern_version, char *log_buf, 185 size_t log_buf_sz) 186 { 187 return bpf_load_program_name(type, NULL, insns, insns_cnt, license, 188 kern_version, log_buf, log_buf_sz); 189 } 190 191 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, 192 size_t insns_cnt, int strict_alignment, 193 const char *license, __u32 kern_version, 194 char *log_buf, size_t log_buf_sz, int log_level) 195 { 196 union bpf_attr attr; 197 198 bzero(&attr, sizeof(attr)); 199 attr.prog_type = type; 200 attr.insn_cnt = (__u32)insns_cnt; 201 attr.insns = ptr_to_u64(insns); 202 attr.license = ptr_to_u64(license); 203 attr.log_buf = ptr_to_u64(log_buf); 204 attr.log_size = log_buf_sz; 205 attr.log_level = log_level; 206 log_buf[0] = 0; 207 attr.kern_version = kern_version; 208 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0; 209 210 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 211 } 212 213 int bpf_map_update_elem(int fd, const void *key, const void *value, 214 __u64 flags) 215 { 216 union bpf_attr attr; 217 218 bzero(&attr, sizeof(attr)); 219 attr.map_fd = fd; 220 attr.key = ptr_to_u64(key); 221 attr.value = ptr_to_u64(value); 222 attr.flags = flags; 223 224 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 225 } 226 227 int bpf_map_lookup_elem(int fd, const void *key, void *value) 228 { 229 union bpf_attr attr; 230 231 bzero(&attr, sizeof(attr)); 232 attr.map_fd = fd; 233 attr.key = ptr_to_u64(key); 234 attr.value = ptr_to_u64(value); 235 236 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 237 } 238 239 int bpf_map_delete_elem(int fd, const void *key) 240 { 241 union bpf_attr attr; 242 243 bzero(&attr, sizeof(attr)); 244 attr.map_fd = fd; 245 attr.key = ptr_to_u64(key); 246 247 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 248 } 249 250 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 251 { 252 union bpf_attr attr; 253 254 bzero(&attr, sizeof(attr)); 255 attr.map_fd = fd; 256 attr.key = ptr_to_u64(key); 257 attr.next_key = ptr_to_u64(next_key); 258 259 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 260 } 261 262 int bpf_obj_pin(int fd, const char *pathname) 263 { 264 union bpf_attr attr; 265 266 bzero(&attr, sizeof(attr)); 267 attr.pathname = ptr_to_u64((void *)pathname); 268 attr.bpf_fd = fd; 269 270 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 271 } 272 273 int bpf_obj_get(const char *pathname) 274 { 275 union bpf_attr attr; 276 277 bzero(&attr, sizeof(attr)); 278 attr.pathname = ptr_to_u64((void *)pathname); 279 280 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 281 } 282 283 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 284 unsigned int flags) 285 { 286 union bpf_attr attr; 287 288 bzero(&attr, sizeof(attr)); 289 attr.target_fd = target_fd; 290 attr.attach_bpf_fd = prog_fd; 291 attr.attach_type = type; 292 attr.attach_flags = flags; 293 294 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 295 } 296 297 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 298 { 299 union bpf_attr attr; 300 301 bzero(&attr, sizeof(attr)); 302 attr.target_fd = target_fd; 303 attr.attach_type = type; 304 305 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 306 } 307 308 int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) 309 { 310 union bpf_attr attr; 311 312 bzero(&attr, sizeof(attr)); 313 attr.target_fd = target_fd; 314 attr.attach_bpf_fd = prog_fd; 315 attr.attach_type = type; 316 317 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 318 } 319 320 int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, 321 __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) 322 { 323 union bpf_attr attr; 324 int ret; 325 326 bzero(&attr, sizeof(attr)); 327 attr.query.target_fd = target_fd; 328 attr.query.attach_type = type; 329 attr.query.query_flags = query_flags; 330 attr.query.prog_cnt = *prog_cnt; 331 attr.query.prog_ids = ptr_to_u64(prog_ids); 332 333 ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr)); 334 if (attach_flags) 335 *attach_flags = attr.query.attach_flags; 336 *prog_cnt = attr.query.prog_cnt; 337 return ret; 338 } 339 340 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 341 void *data_out, __u32 *size_out, __u32 *retval, 342 __u32 *duration) 343 { 344 union bpf_attr attr; 345 int ret; 346 347 bzero(&attr, sizeof(attr)); 348 attr.test.prog_fd = prog_fd; 349 attr.test.data_in = ptr_to_u64(data); 350 attr.test.data_out = ptr_to_u64(data_out); 351 attr.test.data_size_in = size; 352 attr.test.repeat = repeat; 353 354 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 355 if (size_out) 356 *size_out = attr.test.data_size_out; 357 if (retval) 358 *retval = attr.test.retval; 359 if (duration) 360 *duration = attr.test.duration; 361 return ret; 362 } 363 364 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 365 { 366 union bpf_attr attr; 367 int err; 368 369 bzero(&attr, sizeof(attr)); 370 attr.start_id = start_id; 371 372 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); 373 if (!err) 374 *next_id = attr.next_id; 375 376 return err; 377 } 378 379 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 380 { 381 union bpf_attr attr; 382 int err; 383 384 bzero(&attr, sizeof(attr)); 385 attr.start_id = start_id; 386 387 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr)); 388 if (!err) 389 *next_id = attr.next_id; 390 391 return err; 392 } 393 394 int bpf_prog_get_fd_by_id(__u32 id) 395 { 396 union bpf_attr attr; 397 398 bzero(&attr, sizeof(attr)); 399 attr.prog_id = id; 400 401 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); 402 } 403 404 int bpf_map_get_fd_by_id(__u32 id) 405 { 406 union bpf_attr attr; 407 408 bzero(&attr, sizeof(attr)); 409 attr.map_id = id; 410 411 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); 412 } 413 414 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) 415 { 416 union bpf_attr attr; 417 int err; 418 419 bzero(&attr, sizeof(attr)); 420 attr.info.bpf_fd = prog_fd; 421 attr.info.info_len = *info_len; 422 attr.info.info = ptr_to_u64(info); 423 424 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); 425 if (!err) 426 *info_len = attr.info.info_len; 427 428 return err; 429 } 430 431 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) 432 { 433 struct sockaddr_nl sa; 434 int sock, seq = 0, len, ret = -1; 435 char buf[4096]; 436 struct nlattr *nla, *nla_xdp; 437 struct { 438 struct nlmsghdr nh; 439 struct ifinfomsg ifinfo; 440 char attrbuf[64]; 441 } req; 442 struct nlmsghdr *nh; 443 struct nlmsgerr *err; 444 socklen_t addrlen; 445 int one = 1; 446 447 memset(&sa, 0, sizeof(sa)); 448 sa.nl_family = AF_NETLINK; 449 450 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 451 if (sock < 0) { 452 return -errno; 453 } 454 455 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 456 &one, sizeof(one)) < 0) { 457 fprintf(stderr, "Netlink error reporting not supported\n"); 458 } 459 460 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 461 ret = -errno; 462 goto cleanup; 463 } 464 465 addrlen = sizeof(sa); 466 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 467 ret = -errno; 468 goto cleanup; 469 } 470 471 if (addrlen != sizeof(sa)) { 472 ret = -LIBBPF_ERRNO__INTERNAL; 473 goto cleanup; 474 } 475 476 memset(&req, 0, sizeof(req)); 477 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); 478 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 479 req.nh.nlmsg_type = RTM_SETLINK; 480 req.nh.nlmsg_pid = 0; 481 req.nh.nlmsg_seq = ++seq; 482 req.ifinfo.ifi_family = AF_UNSPEC; 483 req.ifinfo.ifi_index = ifindex; 484 485 /* started nested attribute for XDP */ 486 nla = (struct nlattr *)(((char *)&req) 487 + NLMSG_ALIGN(req.nh.nlmsg_len)); 488 nla->nla_type = NLA_F_NESTED | IFLA_XDP; 489 nla->nla_len = NLA_HDRLEN; 490 491 /* add XDP fd */ 492 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len); 493 nla_xdp->nla_type = IFLA_XDP_FD; 494 nla_xdp->nla_len = NLA_HDRLEN + sizeof(int); 495 memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd)); 496 nla->nla_len += nla_xdp->nla_len; 497 498 /* if user passed in any flags, add those too */ 499 if (flags) { 500 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len); 501 nla_xdp->nla_type = IFLA_XDP_FLAGS; 502 nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags); 503 memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags)); 504 nla->nla_len += nla_xdp->nla_len; 505 } 506 507 req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len); 508 509 if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) { 510 ret = -errno; 511 goto cleanup; 512 } 513 514 len = recv(sock, buf, sizeof(buf), 0); 515 if (len < 0) { 516 ret = -errno; 517 goto cleanup; 518 } 519 520 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); 521 nh = NLMSG_NEXT(nh, len)) { 522 if (nh->nlmsg_pid != sa.nl_pid) { 523 ret = -LIBBPF_ERRNO__WRNGPID; 524 goto cleanup; 525 } 526 if (nh->nlmsg_seq != seq) { 527 ret = -LIBBPF_ERRNO__INVSEQ; 528 goto cleanup; 529 } 530 switch (nh->nlmsg_type) { 531 case NLMSG_ERROR: 532 err = (struct nlmsgerr *)NLMSG_DATA(nh); 533 if (!err->error) 534 continue; 535 ret = err->error; 536 nla_dump_errormsg(nh); 537 goto cleanup; 538 case NLMSG_DONE: 539 break; 540 default: 541 break; 542 } 543 } 544 545 ret = 0; 546 547 cleanup: 548 close(sock); 549 return ret; 550 } 551