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 struct bpf_prog_load_opts *opts) 234 { 235 const size_t attr_sz = offsetofend(union bpf_attr, log_true_size); 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); 293 294 func_info_rec_size = OPTS_GET(opts, func_info_rec_size, 0); 295 func_info = OPTS_GET(opts, func_info, NULL); 296 attr.func_info_rec_size = func_info_rec_size; 297 attr.func_info = ptr_to_u64(func_info); 298 attr.func_info_cnt = OPTS_GET(opts, func_info_cnt, 0); 299 300 line_info_rec_size = OPTS_GET(opts, line_info_rec_size, 0); 301 line_info = OPTS_GET(opts, line_info, NULL); 302 attr.line_info_rec_size = line_info_rec_size; 303 attr.line_info = ptr_to_u64(line_info); 304 attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0); 305 306 attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL)); 307 308 if (log_level) { 309 attr.log_buf = ptr_to_u64(log_buf); 310 attr.log_size = log_size; 311 attr.log_level = log_level; 312 } 313 314 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 315 OPTS_SET(opts, log_true_size, attr.log_true_size); 316 if (fd >= 0) 317 return fd; 318 319 /* After bpf_prog_load, the kernel may modify certain attributes 320 * to give user space a hint how to deal with loading failure. 321 * Check to see whether we can make some changes and load again. 322 */ 323 while (errno == E2BIG && (!finfo || !linfo)) { 324 if (!finfo && attr.func_info_cnt && 325 attr.func_info_rec_size < func_info_rec_size) { 326 /* try with corrected func info records */ 327 finfo = alloc_zero_tailing_info(func_info, 328 attr.func_info_cnt, 329 func_info_rec_size, 330 attr.func_info_rec_size); 331 if (!finfo) { 332 errno = E2BIG; 333 goto done; 334 } 335 336 attr.func_info = ptr_to_u64(finfo); 337 attr.func_info_rec_size = func_info_rec_size; 338 } else if (!linfo && attr.line_info_cnt && 339 attr.line_info_rec_size < line_info_rec_size) { 340 linfo = alloc_zero_tailing_info(line_info, 341 attr.line_info_cnt, 342 line_info_rec_size, 343 attr.line_info_rec_size); 344 if (!linfo) { 345 errno = E2BIG; 346 goto done; 347 } 348 349 attr.line_info = ptr_to_u64(linfo); 350 attr.line_info_rec_size = line_info_rec_size; 351 } else { 352 break; 353 } 354 355 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 356 OPTS_SET(opts, log_true_size, attr.log_true_size); 357 if (fd >= 0) 358 goto done; 359 } 360 361 if (log_level == 0 && log_buf) { 362 /* log_level == 0 with non-NULL log_buf requires retrying on error 363 * with log_level == 1 and log_buf/log_buf_size set, to get details of 364 * failure 365 */ 366 attr.log_buf = ptr_to_u64(log_buf); 367 attr.log_size = log_size; 368 attr.log_level = 1; 369 370 fd = sys_bpf_prog_load(&attr, attr_sz, attempts); 371 OPTS_SET(opts, log_true_size, attr.log_true_size); 372 } 373 done: 374 /* free() doesn't affect errno, so we don't need to restore it */ 375 free(finfo); 376 free(linfo); 377 return libbpf_err_errno(fd); 378 } 379 380 int bpf_map_update_elem(int fd, const void *key, const void *value, 381 __u64 flags) 382 { 383 const size_t attr_sz = offsetofend(union bpf_attr, flags); 384 union bpf_attr attr; 385 int ret; 386 387 memset(&attr, 0, attr_sz); 388 attr.map_fd = fd; 389 attr.key = ptr_to_u64(key); 390 attr.value = ptr_to_u64(value); 391 attr.flags = flags; 392 393 ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz); 394 return libbpf_err_errno(ret); 395 } 396 397 int bpf_map_lookup_elem(int fd, const void *key, void *value) 398 { 399 const size_t attr_sz = offsetofend(union bpf_attr, flags); 400 union bpf_attr attr; 401 int ret; 402 403 memset(&attr, 0, attr_sz); 404 attr.map_fd = fd; 405 attr.key = ptr_to_u64(key); 406 attr.value = ptr_to_u64(value); 407 408 ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); 409 return libbpf_err_errno(ret); 410 } 411 412 int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) 413 { 414 const size_t attr_sz = offsetofend(union bpf_attr, flags); 415 union bpf_attr attr; 416 int ret; 417 418 memset(&attr, 0, attr_sz); 419 attr.map_fd = fd; 420 attr.key = ptr_to_u64(key); 421 attr.value = ptr_to_u64(value); 422 attr.flags = flags; 423 424 ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); 425 return libbpf_err_errno(ret); 426 } 427 428 int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) 429 { 430 const size_t attr_sz = offsetofend(union bpf_attr, flags); 431 union bpf_attr attr; 432 int ret; 433 434 memset(&attr, 0, attr_sz); 435 attr.map_fd = fd; 436 attr.key = ptr_to_u64(key); 437 attr.value = ptr_to_u64(value); 438 439 ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); 440 return libbpf_err_errno(ret); 441 } 442 443 int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags) 444 { 445 const size_t attr_sz = offsetofend(union bpf_attr, flags); 446 union bpf_attr attr; 447 int ret; 448 449 memset(&attr, 0, attr_sz); 450 attr.map_fd = fd; 451 attr.key = ptr_to_u64(key); 452 attr.value = ptr_to_u64(value); 453 attr.flags = flags; 454 455 ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); 456 return libbpf_err_errno(ret); 457 } 458 459 int bpf_map_delete_elem(int fd, const void *key) 460 { 461 const size_t attr_sz = offsetofend(union bpf_attr, flags); 462 union bpf_attr attr; 463 int ret; 464 465 memset(&attr, 0, attr_sz); 466 attr.map_fd = fd; 467 attr.key = ptr_to_u64(key); 468 469 ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); 470 return libbpf_err_errno(ret); 471 } 472 473 int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags) 474 { 475 const size_t attr_sz = offsetofend(union bpf_attr, flags); 476 union bpf_attr attr; 477 int ret; 478 479 memset(&attr, 0, attr_sz); 480 attr.map_fd = fd; 481 attr.key = ptr_to_u64(key); 482 attr.flags = flags; 483 484 ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); 485 return libbpf_err_errno(ret); 486 } 487 488 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 489 { 490 const size_t attr_sz = offsetofend(union bpf_attr, next_key); 491 union bpf_attr attr; 492 int ret; 493 494 memset(&attr, 0, attr_sz); 495 attr.map_fd = fd; 496 attr.key = ptr_to_u64(key); 497 attr.next_key = ptr_to_u64(next_key); 498 499 ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, attr_sz); 500 return libbpf_err_errno(ret); 501 } 502 503 int bpf_map_freeze(int fd) 504 { 505 const size_t attr_sz = offsetofend(union bpf_attr, map_fd); 506 union bpf_attr attr; 507 int ret; 508 509 memset(&attr, 0, attr_sz); 510 attr.map_fd = fd; 511 512 ret = sys_bpf(BPF_MAP_FREEZE, &attr, attr_sz); 513 return libbpf_err_errno(ret); 514 } 515 516 static int bpf_map_batch_common(int cmd, int fd, void *in_batch, 517 void *out_batch, void *keys, void *values, 518 __u32 *count, 519 const struct bpf_map_batch_opts *opts) 520 { 521 const size_t attr_sz = offsetofend(union bpf_attr, batch); 522 union bpf_attr attr; 523 int ret; 524 525 if (!OPTS_VALID(opts, bpf_map_batch_opts)) 526 return libbpf_err(-EINVAL); 527 528 memset(&attr, 0, attr_sz); 529 attr.batch.map_fd = fd; 530 attr.batch.in_batch = ptr_to_u64(in_batch); 531 attr.batch.out_batch = ptr_to_u64(out_batch); 532 attr.batch.keys = ptr_to_u64(keys); 533 attr.batch.values = ptr_to_u64(values); 534 attr.batch.count = *count; 535 attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0); 536 attr.batch.flags = OPTS_GET(opts, flags, 0); 537 538 ret = sys_bpf(cmd, &attr, attr_sz); 539 *count = attr.batch.count; 540 541 return libbpf_err_errno(ret); 542 } 543 544 int bpf_map_delete_batch(int fd, const void *keys, __u32 *count, 545 const struct bpf_map_batch_opts *opts) 546 { 547 return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL, 548 NULL, (void *)keys, NULL, count, opts); 549 } 550 551 int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys, 552 void *values, __u32 *count, 553 const struct bpf_map_batch_opts *opts) 554 { 555 return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch, 556 out_batch, keys, values, count, opts); 557 } 558 559 int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch, 560 void *keys, void *values, __u32 *count, 561 const struct bpf_map_batch_opts *opts) 562 { 563 return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH, 564 fd, in_batch, out_batch, keys, values, 565 count, opts); 566 } 567 568 int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *count, 569 const struct bpf_map_batch_opts *opts) 570 { 571 return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL, 572 (void *)keys, (void *)values, count, opts); 573 } 574 575 int bpf_obj_pin_opts(int fd, const char *pathname, const struct bpf_obj_pin_opts *opts) 576 { 577 const size_t attr_sz = offsetofend(union bpf_attr, path_fd); 578 union bpf_attr attr; 579 int ret; 580 581 if (!OPTS_VALID(opts, bpf_obj_pin_opts)) 582 return libbpf_err(-EINVAL); 583 584 memset(&attr, 0, attr_sz); 585 attr.path_fd = OPTS_GET(opts, path_fd, 0); 586 attr.pathname = ptr_to_u64((void *)pathname); 587 attr.file_flags = OPTS_GET(opts, file_flags, 0); 588 attr.bpf_fd = fd; 589 590 ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz); 591 return libbpf_err_errno(ret); 592 } 593 594 int bpf_obj_pin(int fd, const char *pathname) 595 { 596 return bpf_obj_pin_opts(fd, pathname, NULL); 597 } 598 599 int bpf_obj_get(const char *pathname) 600 { 601 return bpf_obj_get_opts(pathname, NULL); 602 } 603 604 int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) 605 { 606 const size_t attr_sz = offsetofend(union bpf_attr, path_fd); 607 union bpf_attr attr; 608 int fd; 609 610 if (!OPTS_VALID(opts, bpf_obj_get_opts)) 611 return libbpf_err(-EINVAL); 612 613 memset(&attr, 0, attr_sz); 614 attr.path_fd = OPTS_GET(opts, path_fd, 0); 615 attr.pathname = ptr_to_u64((void *)pathname); 616 attr.file_flags = OPTS_GET(opts, file_flags, 0); 617 618 fd = sys_bpf_fd(BPF_OBJ_GET, &attr, attr_sz); 619 return libbpf_err_errno(fd); 620 } 621 622 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 623 unsigned int flags) 624 { 625 DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, opts, 626 .flags = flags, 627 ); 628 629 return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts); 630 } 631 632 int bpf_prog_attach_opts(int prog_fd, int target_fd, 633 enum bpf_attach_type type, 634 const struct bpf_prog_attach_opts *opts) 635 { 636 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 637 union bpf_attr attr; 638 int ret; 639 640 if (!OPTS_VALID(opts, bpf_prog_attach_opts)) 641 return libbpf_err(-EINVAL); 642 643 memset(&attr, 0, attr_sz); 644 attr.target_fd = target_fd; 645 attr.attach_bpf_fd = prog_fd; 646 attr.attach_type = type; 647 attr.attach_flags = OPTS_GET(opts, flags, 0); 648 attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0); 649 650 ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz); 651 return libbpf_err_errno(ret); 652 } 653 654 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 655 { 656 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 657 union bpf_attr attr; 658 int ret; 659 660 memset(&attr, 0, attr_sz); 661 attr.target_fd = target_fd; 662 attr.attach_type = type; 663 664 ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); 665 return libbpf_err_errno(ret); 666 } 667 668 int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) 669 { 670 const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); 671 union bpf_attr attr; 672 int ret; 673 674 memset(&attr, 0, attr_sz); 675 attr.target_fd = target_fd; 676 attr.attach_bpf_fd = prog_fd; 677 attr.attach_type = type; 678 679 ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); 680 return libbpf_err_errno(ret); 681 } 682 683 int bpf_link_create(int prog_fd, int target_fd, 684 enum bpf_attach_type attach_type, 685 const struct bpf_link_create_opts *opts) 686 { 687 const size_t attr_sz = offsetofend(union bpf_attr, link_create); 688 __u32 target_btf_id, iter_info_len; 689 union bpf_attr attr; 690 int fd, err; 691 692 if (!OPTS_VALID(opts, bpf_link_create_opts)) 693 return libbpf_err(-EINVAL); 694 695 iter_info_len = OPTS_GET(opts, iter_info_len, 0); 696 target_btf_id = OPTS_GET(opts, target_btf_id, 0); 697 698 /* validate we don't have unexpected combinations of non-zero fields */ 699 if (iter_info_len || target_btf_id) { 700 if (iter_info_len && target_btf_id) 701 return libbpf_err(-EINVAL); 702 if (!OPTS_ZEROED(opts, target_btf_id)) 703 return libbpf_err(-EINVAL); 704 } 705 706 memset(&attr, 0, attr_sz); 707 attr.link_create.prog_fd = prog_fd; 708 attr.link_create.target_fd = target_fd; 709 attr.link_create.attach_type = attach_type; 710 attr.link_create.flags = OPTS_GET(opts, flags, 0); 711 712 if (target_btf_id) { 713 attr.link_create.target_btf_id = target_btf_id; 714 goto proceed; 715 } 716 717 switch (attach_type) { 718 case BPF_TRACE_ITER: 719 attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); 720 attr.link_create.iter_info_len = iter_info_len; 721 break; 722 case BPF_PERF_EVENT: 723 attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0); 724 if (!OPTS_ZEROED(opts, perf_event)) 725 return libbpf_err(-EINVAL); 726 break; 727 case BPF_TRACE_KPROBE_MULTI: 728 attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0); 729 attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0); 730 attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0)); 731 attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0)); 732 attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0)); 733 if (!OPTS_ZEROED(opts, kprobe_multi)) 734 return libbpf_err(-EINVAL); 735 break; 736 case BPF_TRACE_FENTRY: 737 case BPF_TRACE_FEXIT: 738 case BPF_MODIFY_RETURN: 739 case BPF_LSM_MAC: 740 attr.link_create.tracing.cookie = OPTS_GET(opts, tracing.cookie, 0); 741 if (!OPTS_ZEROED(opts, tracing)) 742 return libbpf_err(-EINVAL); 743 break; 744 default: 745 if (!OPTS_ZEROED(opts, flags)) 746 return libbpf_err(-EINVAL); 747 break; 748 } 749 proceed: 750 fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, attr_sz); 751 if (fd >= 0) 752 return fd; 753 /* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry 754 * and other similar programs 755 */ 756 err = -errno; 757 if (err != -EINVAL) 758 return libbpf_err(err); 759 760 /* if user used features not supported by 761 * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately 762 */ 763 if (attr.link_create.target_fd || attr.link_create.target_btf_id) 764 return libbpf_err(err); 765 if (!OPTS_ZEROED(opts, sz)) 766 return libbpf_err(err); 767 768 /* otherwise, for few select kinds of programs that can be 769 * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as 770 * a fallback for older kernels 771 */ 772 switch (attach_type) { 773 case BPF_TRACE_RAW_TP: 774 case BPF_LSM_MAC: 775 case BPF_TRACE_FENTRY: 776 case BPF_TRACE_FEXIT: 777 case BPF_MODIFY_RETURN: 778 return bpf_raw_tracepoint_open(NULL, prog_fd); 779 default: 780 return libbpf_err(err); 781 } 782 } 783 784 int bpf_link_detach(int link_fd) 785 { 786 const size_t attr_sz = offsetofend(union bpf_attr, link_detach); 787 union bpf_attr attr; 788 int ret; 789 790 memset(&attr, 0, attr_sz); 791 attr.link_detach.link_fd = link_fd; 792 793 ret = sys_bpf(BPF_LINK_DETACH, &attr, attr_sz); 794 return libbpf_err_errno(ret); 795 } 796 797 int bpf_link_update(int link_fd, int new_prog_fd, 798 const struct bpf_link_update_opts *opts) 799 { 800 const size_t attr_sz = offsetofend(union bpf_attr, link_update); 801 union bpf_attr attr; 802 int ret; 803 804 if (!OPTS_VALID(opts, bpf_link_update_opts)) 805 return libbpf_err(-EINVAL); 806 807 if (OPTS_GET(opts, old_prog_fd, 0) && OPTS_GET(opts, old_map_fd, 0)) 808 return libbpf_err(-EINVAL); 809 810 memset(&attr, 0, attr_sz); 811 attr.link_update.link_fd = link_fd; 812 attr.link_update.new_prog_fd = new_prog_fd; 813 attr.link_update.flags = OPTS_GET(opts, flags, 0); 814 if (OPTS_GET(opts, old_prog_fd, 0)) 815 attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0); 816 else if (OPTS_GET(opts, old_map_fd, 0)) 817 attr.link_update.old_map_fd = OPTS_GET(opts, old_map_fd, 0); 818 819 ret = sys_bpf(BPF_LINK_UPDATE, &attr, attr_sz); 820 return libbpf_err_errno(ret); 821 } 822 823 int bpf_iter_create(int link_fd) 824 { 825 const size_t attr_sz = offsetofend(union bpf_attr, iter_create); 826 union bpf_attr attr; 827 int fd; 828 829 memset(&attr, 0, attr_sz); 830 attr.iter_create.link_fd = link_fd; 831 832 fd = sys_bpf_fd(BPF_ITER_CREATE, &attr, attr_sz); 833 return libbpf_err_errno(fd); 834 } 835 836 int bpf_prog_query_opts(int target_fd, 837 enum bpf_attach_type type, 838 struct bpf_prog_query_opts *opts) 839 { 840 const size_t attr_sz = offsetofend(union bpf_attr, query); 841 union bpf_attr attr; 842 int ret; 843 844 if (!OPTS_VALID(opts, bpf_prog_query_opts)) 845 return libbpf_err(-EINVAL); 846 847 memset(&attr, 0, attr_sz); 848 849 attr.query.target_fd = target_fd; 850 attr.query.attach_type = type; 851 attr.query.query_flags = OPTS_GET(opts, query_flags, 0); 852 attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0); 853 attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); 854 attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); 855 856 ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz); 857 858 OPTS_SET(opts, attach_flags, attr.query.attach_flags); 859 OPTS_SET(opts, prog_cnt, attr.query.prog_cnt); 860 861 return libbpf_err_errno(ret); 862 } 863 864 int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, 865 __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) 866 { 867 LIBBPF_OPTS(bpf_prog_query_opts, opts); 868 int ret; 869 870 opts.query_flags = query_flags; 871 opts.prog_ids = prog_ids; 872 opts.prog_cnt = *prog_cnt; 873 874 ret = bpf_prog_query_opts(target_fd, type, &opts); 875 876 if (attach_flags) 877 *attach_flags = opts.attach_flags; 878 *prog_cnt = opts.prog_cnt; 879 880 return libbpf_err_errno(ret); 881 } 882 883 int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) 884 { 885 const size_t attr_sz = offsetofend(union bpf_attr, test); 886 union bpf_attr attr; 887 int ret; 888 889 if (!OPTS_VALID(opts, bpf_test_run_opts)) 890 return libbpf_err(-EINVAL); 891 892 memset(&attr, 0, attr_sz); 893 attr.test.prog_fd = prog_fd; 894 attr.test.batch_size = OPTS_GET(opts, batch_size, 0); 895 attr.test.cpu = OPTS_GET(opts, cpu, 0); 896 attr.test.flags = OPTS_GET(opts, flags, 0); 897 attr.test.repeat = OPTS_GET(opts, repeat, 0); 898 attr.test.duration = OPTS_GET(opts, duration, 0); 899 attr.test.ctx_size_in = OPTS_GET(opts, ctx_size_in, 0); 900 attr.test.ctx_size_out = OPTS_GET(opts, ctx_size_out, 0); 901 attr.test.data_size_in = OPTS_GET(opts, data_size_in, 0); 902 attr.test.data_size_out = OPTS_GET(opts, data_size_out, 0); 903 attr.test.ctx_in = ptr_to_u64(OPTS_GET(opts, ctx_in, NULL)); 904 attr.test.ctx_out = ptr_to_u64(OPTS_GET(opts, ctx_out, NULL)); 905 attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL)); 906 attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL)); 907 908 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, attr_sz); 909 910 OPTS_SET(opts, data_size_out, attr.test.data_size_out); 911 OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out); 912 OPTS_SET(opts, duration, attr.test.duration); 913 OPTS_SET(opts, retval, attr.test.retval); 914 915 return libbpf_err_errno(ret); 916 } 917 918 static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) 919 { 920 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 921 union bpf_attr attr; 922 int err; 923 924 memset(&attr, 0, attr_sz); 925 attr.start_id = start_id; 926 927 err = sys_bpf(cmd, &attr, attr_sz); 928 if (!err) 929 *next_id = attr.next_id; 930 931 return libbpf_err_errno(err); 932 } 933 934 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 935 { 936 return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID); 937 } 938 939 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 940 { 941 return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID); 942 } 943 944 int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id) 945 { 946 return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID); 947 } 948 949 int bpf_link_get_next_id(__u32 start_id, __u32 *next_id) 950 { 951 return bpf_obj_get_next_id(start_id, next_id, BPF_LINK_GET_NEXT_ID); 952 } 953 954 int bpf_prog_get_fd_by_id_opts(__u32 id, 955 const struct bpf_get_fd_by_id_opts *opts) 956 { 957 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 958 union bpf_attr attr; 959 int fd; 960 961 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 962 return libbpf_err(-EINVAL); 963 964 memset(&attr, 0, attr_sz); 965 attr.prog_id = id; 966 attr.open_flags = OPTS_GET(opts, open_flags, 0); 967 968 fd = sys_bpf_fd(BPF_PROG_GET_FD_BY_ID, &attr, attr_sz); 969 return libbpf_err_errno(fd); 970 } 971 972 int bpf_prog_get_fd_by_id(__u32 id) 973 { 974 return bpf_prog_get_fd_by_id_opts(id, NULL); 975 } 976 977 int bpf_map_get_fd_by_id_opts(__u32 id, 978 const struct bpf_get_fd_by_id_opts *opts) 979 { 980 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 981 union bpf_attr attr; 982 int fd; 983 984 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 985 return libbpf_err(-EINVAL); 986 987 memset(&attr, 0, attr_sz); 988 attr.map_id = id; 989 attr.open_flags = OPTS_GET(opts, open_flags, 0); 990 991 fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz); 992 return libbpf_err_errno(fd); 993 } 994 995 int bpf_map_get_fd_by_id(__u32 id) 996 { 997 return bpf_map_get_fd_by_id_opts(id, NULL); 998 } 999 1000 int bpf_btf_get_fd_by_id_opts(__u32 id, 1001 const struct bpf_get_fd_by_id_opts *opts) 1002 { 1003 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 1004 union bpf_attr attr; 1005 int fd; 1006 1007 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 1008 return libbpf_err(-EINVAL); 1009 1010 memset(&attr, 0, attr_sz); 1011 attr.btf_id = id; 1012 attr.open_flags = OPTS_GET(opts, open_flags, 0); 1013 1014 fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, attr_sz); 1015 return libbpf_err_errno(fd); 1016 } 1017 1018 int bpf_btf_get_fd_by_id(__u32 id) 1019 { 1020 return bpf_btf_get_fd_by_id_opts(id, NULL); 1021 } 1022 1023 int bpf_link_get_fd_by_id_opts(__u32 id, 1024 const struct bpf_get_fd_by_id_opts *opts) 1025 { 1026 const size_t attr_sz = offsetofend(union bpf_attr, open_flags); 1027 union bpf_attr attr; 1028 int fd; 1029 1030 if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) 1031 return libbpf_err(-EINVAL); 1032 1033 memset(&attr, 0, attr_sz); 1034 attr.link_id = id; 1035 attr.open_flags = OPTS_GET(opts, open_flags, 0); 1036 1037 fd = sys_bpf_fd(BPF_LINK_GET_FD_BY_ID, &attr, attr_sz); 1038 return libbpf_err_errno(fd); 1039 } 1040 1041 int bpf_link_get_fd_by_id(__u32 id) 1042 { 1043 return bpf_link_get_fd_by_id_opts(id, NULL); 1044 } 1045 1046 int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) 1047 { 1048 const size_t attr_sz = offsetofend(union bpf_attr, info); 1049 union bpf_attr attr; 1050 int err; 1051 1052 memset(&attr, 0, attr_sz); 1053 attr.info.bpf_fd = bpf_fd; 1054 attr.info.info_len = *info_len; 1055 attr.info.info = ptr_to_u64(info); 1056 1057 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, attr_sz); 1058 if (!err) 1059 *info_len = attr.info.info_len; 1060 return libbpf_err_errno(err); 1061 } 1062 1063 int bpf_prog_get_info_by_fd(int prog_fd, struct bpf_prog_info *info, __u32 *info_len) 1064 { 1065 return bpf_obj_get_info_by_fd(prog_fd, info, info_len); 1066 } 1067 1068 int bpf_map_get_info_by_fd(int map_fd, struct bpf_map_info *info, __u32 *info_len) 1069 { 1070 return bpf_obj_get_info_by_fd(map_fd, info, info_len); 1071 } 1072 1073 int bpf_btf_get_info_by_fd(int btf_fd, struct bpf_btf_info *info, __u32 *info_len) 1074 { 1075 return bpf_obj_get_info_by_fd(btf_fd, info, info_len); 1076 } 1077 1078 int bpf_link_get_info_by_fd(int link_fd, struct bpf_link_info *info, __u32 *info_len) 1079 { 1080 return bpf_obj_get_info_by_fd(link_fd, info, info_len); 1081 } 1082 1083 int bpf_raw_tracepoint_open(const char *name, int prog_fd) 1084 { 1085 const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint); 1086 union bpf_attr attr; 1087 int fd; 1088 1089 memset(&attr, 0, attr_sz); 1090 attr.raw_tracepoint.name = ptr_to_u64(name); 1091 attr.raw_tracepoint.prog_fd = prog_fd; 1092 1093 fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz); 1094 return libbpf_err_errno(fd); 1095 } 1096 1097 int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts) 1098 { 1099 const size_t attr_sz = offsetofend(union bpf_attr, btf_log_true_size); 1100 union bpf_attr attr; 1101 char *log_buf; 1102 size_t log_size; 1103 __u32 log_level; 1104 int fd; 1105 1106 bump_rlimit_memlock(); 1107 1108 memset(&attr, 0, attr_sz); 1109 1110 if (!OPTS_VALID(opts, bpf_btf_load_opts)) 1111 return libbpf_err(-EINVAL); 1112 1113 log_buf = OPTS_GET(opts, log_buf, NULL); 1114 log_size = OPTS_GET(opts, log_size, 0); 1115 log_level = OPTS_GET(opts, log_level, 0); 1116 1117 if (log_size > UINT_MAX) 1118 return libbpf_err(-EINVAL); 1119 if (log_size && !log_buf) 1120 return libbpf_err(-EINVAL); 1121 1122 attr.btf = ptr_to_u64(btf_data); 1123 attr.btf_size = btf_size; 1124 /* log_level == 0 and log_buf != NULL means "try loading without 1125 * log_buf, but retry with log_buf and log_level=1 on error", which is 1126 * consistent across low-level and high-level BTF and program loading 1127 * APIs within libbpf and provides a sensible behavior in practice 1128 */ 1129 if (log_level) { 1130 attr.btf_log_buf = ptr_to_u64(log_buf); 1131 attr.btf_log_size = (__u32)log_size; 1132 attr.btf_log_level = log_level; 1133 } 1134 1135 fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); 1136 if (fd < 0 && log_buf && log_level == 0) { 1137 attr.btf_log_buf = ptr_to_u64(log_buf); 1138 attr.btf_log_size = (__u32)log_size; 1139 attr.btf_log_level = 1; 1140 fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); 1141 } 1142 1143 OPTS_SET(opts, log_true_size, attr.btf_log_true_size); 1144 return libbpf_err_errno(fd); 1145 } 1146 1147 int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, 1148 __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, 1149 __u64 *probe_addr) 1150 { 1151 const size_t attr_sz = offsetofend(union bpf_attr, task_fd_query); 1152 union bpf_attr attr; 1153 int err; 1154 1155 memset(&attr, 0, attr_sz); 1156 attr.task_fd_query.pid = pid; 1157 attr.task_fd_query.fd = fd; 1158 attr.task_fd_query.flags = flags; 1159 attr.task_fd_query.buf = ptr_to_u64(buf); 1160 attr.task_fd_query.buf_len = *buf_len; 1161 1162 err = sys_bpf(BPF_TASK_FD_QUERY, &attr, attr_sz); 1163 1164 *buf_len = attr.task_fd_query.buf_len; 1165 *prog_id = attr.task_fd_query.prog_id; 1166 *fd_type = attr.task_fd_query.fd_type; 1167 *probe_offset = attr.task_fd_query.probe_offset; 1168 *probe_addr = attr.task_fd_query.probe_addr; 1169 1170 return libbpf_err_errno(err); 1171 } 1172 1173 int bpf_enable_stats(enum bpf_stats_type type) 1174 { 1175 const size_t attr_sz = offsetofend(union bpf_attr, enable_stats); 1176 union bpf_attr attr; 1177 int fd; 1178 1179 memset(&attr, 0, attr_sz); 1180 attr.enable_stats.type = type; 1181 1182 fd = sys_bpf_fd(BPF_ENABLE_STATS, &attr, attr_sz); 1183 return libbpf_err_errno(fd); 1184 } 1185 1186 int bpf_prog_bind_map(int prog_fd, int map_fd, 1187 const struct bpf_prog_bind_opts *opts) 1188 { 1189 const size_t attr_sz = offsetofend(union bpf_attr, prog_bind_map); 1190 union bpf_attr attr; 1191 int ret; 1192 1193 if (!OPTS_VALID(opts, bpf_prog_bind_opts)) 1194 return libbpf_err(-EINVAL); 1195 1196 memset(&attr, 0, attr_sz); 1197 attr.prog_bind_map.prog_fd = prog_fd; 1198 attr.prog_bind_map.map_fd = map_fd; 1199 attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0); 1200 1201 ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, attr_sz); 1202 return libbpf_err_errno(ret); 1203 } 1204