// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) /* * common eBPF ELF operations. * * Copyright (C) 2013-2015 Alexei Starovoitov * Copyright (C) 2015 Wang Nan * Copyright (C) 2015 Huawei Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License (not later!) * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see */ #include #include #include #include #include #include #include #include #include #include #include #include "bpf.h" #include "libbpf.h" #include "libbpf_internal.h" /* * When building perf, unistd.h is overridden. __NR_bpf is * required to be defined explicitly. */ #ifndef __NR_bpf # if defined(__i386__) # define __NR_bpf 357 # elif defined(__x86_64__) # define __NR_bpf 321 # elif defined(__aarch64__) # define __NR_bpf 280 # elif defined(__sparc__) # define __NR_bpf 349 # elif defined(__s390__) # define __NR_bpf 351 # elif defined(__arc__) # define __NR_bpf 280 # elif defined(__mips__) && defined(_ABIO32) # define __NR_bpf 4355 # elif defined(__mips__) && defined(_ABIN32) # define __NR_bpf 6319 # elif defined(__mips__) && defined(_ABI64) # define __NR_bpf 5315 # else # error __NR_bpf not defined. libbpf does not support your arch. # endif #endif static inline __u64 ptr_to_u64(const void *ptr) { return (__u64) (unsigned long) ptr; } static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, unsigned int size) { return syscall(__NR_bpf, cmd, attr, size); } static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr, unsigned int size) { int fd; fd = sys_bpf(cmd, attr, size); return ensure_good_fd(fd); } int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts) { int fd; do { fd = sys_bpf_fd(BPF_PROG_LOAD, attr, size); } while (fd < 0 && errno == EAGAIN && --attempts > 0); return fd; } /* Probe whether kernel switched from memlock-based (RLIMIT_MEMLOCK) to * memcg-based memory accounting for BPF maps and progs. This was done in [0]. * We use the support for bpf_ktime_get_coarse_ns() helper, which was added in * the same 5.11 Linux release ([1]), to detect memcg-based accounting for BPF. * * [0] https://lore.kernel.org/bpf/20201201215900.3569844-1-guro@fb.com/ * [1] d05512618056 ("bpf: Add bpf_ktime_get_coarse_ns helper") */ int probe_memcg_account(int token_fd) { const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd); struct bpf_insn insns[] = { BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns), BPF_EXIT_INSN(), }; size_t insn_cnt = ARRAY_SIZE(insns); union bpf_attr attr; int prog_fd; /* attempt loading freplace trying to use custom BTF */ memset(&attr, 0, attr_sz); attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; attr.insns = ptr_to_u64(insns); attr.insn_cnt = insn_cnt; attr.license = ptr_to_u64("GPL"); attr.prog_token_fd = token_fd; if (token_fd) attr.prog_flags |= BPF_F_TOKEN_FD; prog_fd = sys_bpf_fd(BPF_PROG_LOAD, &attr, attr_sz); if (prog_fd >= 0) { close(prog_fd); return 1; } return 0; } static bool memlock_bumped; static rlim_t memlock_rlim = RLIM_INFINITY; int libbpf_set_memlock_rlim(size_t memlock_bytes) { if (memlock_bumped) return libbpf_err(-EBUSY); memlock_rlim = memlock_bytes; return 0; } int bump_rlimit_memlock(void) { struct rlimit rlim; /* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLOCK */ if (memlock_bumped || feat_supported(NULL, FEAT_MEMCG_ACCOUNT)) return 0; memlock_bumped = true; /* zero memlock_rlim_max disables auto-bumping RLIMIT_MEMLOCK */ if (memlock_rlim == 0) return 0; rlim.rlim_cur = rlim.rlim_max = memlock_rlim; if (setrlimit(RLIMIT_MEMLOCK, &rlim)) return -errno; return 0; } int bpf_map_create(enum bpf_map_type map_type, const char *map_name, __u32 key_size, __u32 value_size, __u32 max_entries, const struct bpf_map_create_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, map_token_fd); union bpf_attr attr; int fd; bump_rlimit_memlock(); memset(&attr, 0, attr_sz); if (!OPTS_VALID(opts, bpf_map_create_opts)) return libbpf_err(-EINVAL); attr.map_type = map_type; if (map_name && feat_supported(NULL, FEAT_PROG_NAME)) libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name)); attr.key_size = key_size; attr.value_size = value_size; attr.max_entries = max_entries; attr.btf_fd = OPTS_GET(opts, btf_fd, 0); attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0); attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0); attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0); attr.value_type_btf_obj_fd = OPTS_GET(opts, value_type_btf_obj_fd, 0); attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0); attr.map_flags = OPTS_GET(opts, map_flags, 0); attr.map_extra = OPTS_GET(opts, map_extra, 0); attr.numa_node = OPTS_GET(opts, numa_node, 0); attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0); attr.map_token_fd = OPTS_GET(opts, token_fd, 0); fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz); return libbpf_err_errno(fd); } static void * alloc_zero_tailing_info(const void *orecord, __u32 cnt, __u32 actual_rec_size, __u32 expected_rec_size) { __u64 info_len = (__u64)actual_rec_size * cnt; void *info, *nrecord; int i; info = malloc(info_len); if (!info) return NULL; /* zero out bytes kernel does not understand */ nrecord = info; for (i = 0; i < cnt; i++) { memcpy(nrecord, orecord, expected_rec_size); memset(nrecord + expected_rec_size, 0, actual_rec_size - expected_rec_size); orecord += actual_rec_size; nrecord += actual_rec_size; } return info; } int bpf_prog_load(enum bpf_prog_type prog_type, const char *prog_name, const char *license, const struct bpf_insn *insns, size_t insn_cnt, struct bpf_prog_load_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd); void *finfo = NULL, *linfo = NULL; const char *func_info, *line_info; __u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd; __u32 func_info_rec_size, line_info_rec_size; int fd, attempts; union bpf_attr attr; char *log_buf; bump_rlimit_memlock(); if (!OPTS_VALID(opts, bpf_prog_load_opts)) return libbpf_err(-EINVAL); attempts = OPTS_GET(opts, attempts, 0); if (attempts < 0) return libbpf_err(-EINVAL); if (attempts == 0) attempts = PROG_LOAD_ATTEMPTS; memset(&attr, 0, attr_sz); attr.prog_type = prog_type; attr.expected_attach_type = OPTS_GET(opts, expected_attach_type, 0); attr.prog_btf_fd = OPTS_GET(opts, prog_btf_fd, 0); attr.prog_flags = OPTS_GET(opts, prog_flags, 0); attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0); attr.kern_version = OPTS_GET(opts, kern_version, 0); attr.prog_token_fd = OPTS_GET(opts, token_fd, 0); if (prog_name && feat_supported(NULL, FEAT_PROG_NAME)) libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name)); attr.license = ptr_to_u64(license); if (insn_cnt > UINT_MAX) return libbpf_err(-E2BIG); attr.insns = ptr_to_u64(insns); attr.insn_cnt = (__u32)insn_cnt; attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0); attach_btf_obj_fd = OPTS_GET(opts, attach_btf_obj_fd, 0); if (attach_prog_fd && attach_btf_obj_fd) return libbpf_err(-EINVAL); attr.attach_btf_id = OPTS_GET(opts, attach_btf_id, 0); if (attach_prog_fd) attr.attach_prog_fd = attach_prog_fd; else attr.attach_btf_obj_fd = attach_btf_obj_fd; log_buf = OPTS_GET(opts, log_buf, NULL); log_size = OPTS_GET(opts, log_size, 0); log_level = OPTS_GET(opts, log_level, 0); if (!!log_buf != !!log_size) return libbpf_err(-EINVAL); func_info_rec_size = OPTS_GET(opts, func_info_rec_size, 0); func_info = OPTS_GET(opts, func_info, NULL); attr.func_info_rec_size = func_info_rec_size; attr.func_info = ptr_to_u64(func_info); attr.func_info_cnt = OPTS_GET(opts, func_info_cnt, 0); line_info_rec_size = OPTS_GET(opts, line_info_rec_size, 0); line_info = OPTS_GET(opts, line_info, NULL); attr.line_info_rec_size = line_info_rec_size; attr.line_info = ptr_to_u64(line_info); attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0); attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL)); if (log_level) { attr.log_buf = ptr_to_u64(log_buf); attr.log_size = log_size; attr.log_level = log_level; } fd = sys_bpf_prog_load(&attr, attr_sz, attempts); OPTS_SET(opts, log_true_size, attr.log_true_size); if (fd >= 0) return fd; /* After bpf_prog_load, the kernel may modify certain attributes * to give user space a hint how to deal with loading failure. * Check to see whether we can make some changes and load again. */ while (errno == E2BIG && (!finfo || !linfo)) { if (!finfo && attr.func_info_cnt && attr.func_info_rec_size < func_info_rec_size) { /* try with corrected func info records */ finfo = alloc_zero_tailing_info(func_info, attr.func_info_cnt, func_info_rec_size, attr.func_info_rec_size); if (!finfo) { errno = E2BIG; goto done; } attr.func_info = ptr_to_u64(finfo); attr.func_info_rec_size = func_info_rec_size; } else if (!linfo && attr.line_info_cnt && attr.line_info_rec_size < line_info_rec_size) { linfo = alloc_zero_tailing_info(line_info, attr.line_info_cnt, line_info_rec_size, attr.line_info_rec_size); if (!linfo) { errno = E2BIG; goto done; } attr.line_info = ptr_to_u64(linfo); attr.line_info_rec_size = line_info_rec_size; } else { break; } fd = sys_bpf_prog_load(&attr, attr_sz, attempts); OPTS_SET(opts, log_true_size, attr.log_true_size); if (fd >= 0) goto done; } if (log_level == 0 && log_buf) { /* log_level == 0 with non-NULL log_buf requires retrying on error * with log_level == 1 and log_buf/log_buf_size set, to get details of * failure */ attr.log_buf = ptr_to_u64(log_buf); attr.log_size = log_size; attr.log_level = 1; fd = sys_bpf_prog_load(&attr, attr_sz, attempts); OPTS_SET(opts, log_true_size, attr.log_true_size); } done: /* free() doesn't affect errno, so we don't need to restore it */ free(finfo); free(linfo); return libbpf_err_errno(fd); } int bpf_map_update_elem(int fd, const void *key, const void *value, __u64 flags) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); attr.flags = flags; ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_lookup_elem(int fd, const void *key, void *value) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); attr.flags = flags; ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); attr.flags = flags; ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_delete_elem(int fd, const void *key) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags) { const size_t attr_sz = offsetofend(union bpf_attr, flags); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.flags = flags; ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_get_next_key(int fd, const void *key, void *next_key) { const size_t attr_sz = offsetofend(union bpf_attr, next_key); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.next_key = ptr_to_u64(next_key); ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_map_freeze(int fd) { const size_t attr_sz = offsetofend(union bpf_attr, map_fd); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.map_fd = fd; ret = sys_bpf(BPF_MAP_FREEZE, &attr, attr_sz); return libbpf_err_errno(ret); } static int bpf_map_batch_common(int cmd, int fd, void *in_batch, void *out_batch, void *keys, void *values, __u32 *count, const struct bpf_map_batch_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, batch); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_map_batch_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.batch.map_fd = fd; attr.batch.in_batch = ptr_to_u64(in_batch); attr.batch.out_batch = ptr_to_u64(out_batch); attr.batch.keys = ptr_to_u64(keys); attr.batch.values = ptr_to_u64(values); attr.batch.count = *count; attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0); attr.batch.flags = OPTS_GET(opts, flags, 0); ret = sys_bpf(cmd, &attr, attr_sz); *count = attr.batch.count; return libbpf_err_errno(ret); } int bpf_map_delete_batch(int fd, const void *keys, __u32 *count, const struct bpf_map_batch_opts *opts) { return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL, NULL, (void *)keys, NULL, count, opts); } int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys, void *values, __u32 *count, const struct bpf_map_batch_opts *opts) { return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch, out_batch, keys, values, count, opts); } int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch, void *keys, void *values, __u32 *count, const struct bpf_map_batch_opts *opts) { return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH, fd, in_batch, out_batch, keys, values, count, opts); } int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *count, const struct bpf_map_batch_opts *opts) { return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL, (void *)keys, (void *)values, count, opts); } int bpf_obj_pin_opts(int fd, const char *pathname, const struct bpf_obj_pin_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, path_fd); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_obj_pin_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.path_fd = OPTS_GET(opts, path_fd, 0); attr.pathname = ptr_to_u64((void *)pathname); attr.file_flags = OPTS_GET(opts, file_flags, 0); attr.bpf_fd = fd; ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_obj_pin(int fd, const char *pathname) { return bpf_obj_pin_opts(fd, pathname, NULL); } int bpf_obj_get(const char *pathname) { return bpf_obj_get_opts(pathname, NULL); } int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, path_fd); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_obj_get_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.path_fd = OPTS_GET(opts, path_fd, 0); attr.pathname = ptr_to_u64((void *)pathname); attr.file_flags = OPTS_GET(opts, file_flags, 0); fd = sys_bpf_fd(BPF_OBJ_GET, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, unsigned int flags) { DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, opts, .flags = flags, ); return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts); } int bpf_prog_attach_opts(int prog_fd, int target, enum bpf_attach_type type, const struct bpf_prog_attach_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, expected_revision); __u32 relative_id, flags; int ret, relative_fd; union bpf_attr attr; if (!OPTS_VALID(opts, bpf_prog_attach_opts)) return libbpf_err(-EINVAL); relative_id = OPTS_GET(opts, relative_id, 0); relative_fd = OPTS_GET(opts, relative_fd, 0); flags = OPTS_GET(opts, flags, 0); /* validate we don't have unexpected combinations of non-zero fields */ if (relative_fd && relative_id) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.target_fd = target; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; attr.replace_bpf_fd = OPTS_GET(opts, replace_fd, 0); attr.expected_revision = OPTS_GET(opts, expected_revision, 0); if (relative_id) { attr.attach_flags = flags | BPF_F_ID; attr.relative_id = relative_id; } else { attr.attach_flags = flags; attr.relative_fd = relative_fd; } ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_prog_detach_opts(int prog_fd, int target, enum bpf_attach_type type, const struct bpf_prog_detach_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, expected_revision); __u32 relative_id, flags; int ret, relative_fd; union bpf_attr attr; if (!OPTS_VALID(opts, bpf_prog_detach_opts)) return libbpf_err(-EINVAL); relative_id = OPTS_GET(opts, relative_id, 0); relative_fd = OPTS_GET(opts, relative_fd, 0); flags = OPTS_GET(opts, flags, 0); /* validate we don't have unexpected combinations of non-zero fields */ if (relative_fd && relative_id) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.target_fd = target; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; attr.expected_revision = OPTS_GET(opts, expected_revision, 0); if (relative_id) { attr.attach_flags = flags | BPF_F_ID; attr.relative_id = relative_id; } else { attr.attach_flags = flags; attr.relative_fd = relative_fd; } ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_prog_detach(int target_fd, enum bpf_attach_type type) { return bpf_prog_detach_opts(0, target_fd, type, NULL); } int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) { return bpf_prog_detach_opts(prog_fd, target_fd, type, NULL); } int bpf_link_create(int prog_fd, int target_fd, enum bpf_attach_type attach_type, const struct bpf_link_create_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, link_create); __u32 target_btf_id, iter_info_len, relative_id; int fd, err, relative_fd; union bpf_attr attr; if (!OPTS_VALID(opts, bpf_link_create_opts)) return libbpf_err(-EINVAL); iter_info_len = OPTS_GET(opts, iter_info_len, 0); target_btf_id = OPTS_GET(opts, target_btf_id, 0); /* validate we don't have unexpected combinations of non-zero fields */ if (iter_info_len || target_btf_id) { if (iter_info_len && target_btf_id) return libbpf_err(-EINVAL); if (!OPTS_ZEROED(opts, target_btf_id)) return libbpf_err(-EINVAL); } memset(&attr, 0, attr_sz); attr.link_create.prog_fd = prog_fd; attr.link_create.target_fd = target_fd; attr.link_create.attach_type = attach_type; attr.link_create.flags = OPTS_GET(opts, flags, 0); if (target_btf_id) { attr.link_create.target_btf_id = target_btf_id; goto proceed; } switch (attach_type) { case BPF_TRACE_ITER: attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); attr.link_create.iter_info_len = iter_info_len; break; case BPF_PERF_EVENT: attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0); if (!OPTS_ZEROED(opts, perf_event)) return libbpf_err(-EINVAL); break; case BPF_TRACE_KPROBE_MULTI: attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0); attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0); attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0)); attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0)); attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0)); if (!OPTS_ZEROED(opts, kprobe_multi)) return libbpf_err(-EINVAL); break; case BPF_TRACE_UPROBE_MULTI: attr.link_create.uprobe_multi.flags = OPTS_GET(opts, uprobe_multi.flags, 0); attr.link_create.uprobe_multi.cnt = OPTS_GET(opts, uprobe_multi.cnt, 0); attr.link_create.uprobe_multi.path = ptr_to_u64(OPTS_GET(opts, uprobe_multi.path, 0)); attr.link_create.uprobe_multi.offsets = ptr_to_u64(OPTS_GET(opts, uprobe_multi.offsets, 0)); attr.link_create.uprobe_multi.ref_ctr_offsets = ptr_to_u64(OPTS_GET(opts, uprobe_multi.ref_ctr_offsets, 0)); attr.link_create.uprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, uprobe_multi.cookies, 0)); attr.link_create.uprobe_multi.pid = OPTS_GET(opts, uprobe_multi.pid, 0); if (!OPTS_ZEROED(opts, uprobe_multi)) return libbpf_err(-EINVAL); break; case BPF_TRACE_FENTRY: case BPF_TRACE_FEXIT: case BPF_MODIFY_RETURN: case BPF_LSM_MAC: attr.link_create.tracing.cookie = OPTS_GET(opts, tracing.cookie, 0); if (!OPTS_ZEROED(opts, tracing)) return libbpf_err(-EINVAL); break; case BPF_NETFILTER: attr.link_create.netfilter.pf = OPTS_GET(opts, netfilter.pf, 0); attr.link_create.netfilter.hooknum = OPTS_GET(opts, netfilter.hooknum, 0); attr.link_create.netfilter.priority = OPTS_GET(opts, netfilter.priority, 0); attr.link_create.netfilter.flags = OPTS_GET(opts, netfilter.flags, 0); if (!OPTS_ZEROED(opts, netfilter)) return libbpf_err(-EINVAL); break; case BPF_TCX_INGRESS: case BPF_TCX_EGRESS: relative_fd = OPTS_GET(opts, tcx.relative_fd, 0); relative_id = OPTS_GET(opts, tcx.relative_id, 0); if (relative_fd && relative_id) return libbpf_err(-EINVAL); if (relative_id) { attr.link_create.tcx.relative_id = relative_id; attr.link_create.flags |= BPF_F_ID; } else { attr.link_create.tcx.relative_fd = relative_fd; } attr.link_create.tcx.expected_revision = OPTS_GET(opts, tcx.expected_revision, 0); if (!OPTS_ZEROED(opts, tcx)) return libbpf_err(-EINVAL); break; case BPF_NETKIT_PRIMARY: case BPF_NETKIT_PEER: relative_fd = OPTS_GET(opts, netkit.relative_fd, 0); relative_id = OPTS_GET(opts, netkit.relative_id, 0); if (relative_fd && relative_id) return libbpf_err(-EINVAL); if (relative_id) { attr.link_create.netkit.relative_id = relative_id; attr.link_create.flags |= BPF_F_ID; } else { attr.link_create.netkit.relative_fd = relative_fd; } attr.link_create.netkit.expected_revision = OPTS_GET(opts, netkit.expected_revision, 0); if (!OPTS_ZEROED(opts, netkit)) return libbpf_err(-EINVAL); break; default: if (!OPTS_ZEROED(opts, flags)) return libbpf_err(-EINVAL); break; } proceed: fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, attr_sz); if (fd >= 0) return fd; /* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry * and other similar programs */ err = -errno; if (err != -EINVAL) return libbpf_err(err); /* if user used features not supported by * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately */ if (attr.link_create.target_fd || attr.link_create.target_btf_id) return libbpf_err(err); if (!OPTS_ZEROED(opts, sz)) return libbpf_err(err); /* otherwise, for few select kinds of programs that can be * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as * a fallback for older kernels */ switch (attach_type) { case BPF_TRACE_RAW_TP: case BPF_LSM_MAC: case BPF_TRACE_FENTRY: case BPF_TRACE_FEXIT: case BPF_MODIFY_RETURN: return bpf_raw_tracepoint_open(NULL, prog_fd); default: return libbpf_err(err); } } int bpf_link_detach(int link_fd) { const size_t attr_sz = offsetofend(union bpf_attr, link_detach); union bpf_attr attr; int ret; memset(&attr, 0, attr_sz); attr.link_detach.link_fd = link_fd; ret = sys_bpf(BPF_LINK_DETACH, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_link_update(int link_fd, int new_prog_fd, const struct bpf_link_update_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, link_update); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_link_update_opts)) return libbpf_err(-EINVAL); if (OPTS_GET(opts, old_prog_fd, 0) && OPTS_GET(opts, old_map_fd, 0)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.link_update.link_fd = link_fd; attr.link_update.new_prog_fd = new_prog_fd; attr.link_update.flags = OPTS_GET(opts, flags, 0); if (OPTS_GET(opts, old_prog_fd, 0)) attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0); else if (OPTS_GET(opts, old_map_fd, 0)) attr.link_update.old_map_fd = OPTS_GET(opts, old_map_fd, 0); ret = sys_bpf(BPF_LINK_UPDATE, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_iter_create(int link_fd) { const size_t attr_sz = offsetofend(union bpf_attr, iter_create); union bpf_attr attr; int fd; memset(&attr, 0, attr_sz); attr.iter_create.link_fd = link_fd; fd = sys_bpf_fd(BPF_ITER_CREATE, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_prog_query_opts(int target, enum bpf_attach_type type, struct bpf_prog_query_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, query); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_prog_query_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.query.target_fd = target; attr.query.attach_type = type; attr.query.query_flags = OPTS_GET(opts, query_flags, 0); attr.query.count = OPTS_GET(opts, count, 0); attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); attr.query.link_ids = ptr_to_u64(OPTS_GET(opts, link_ids, NULL)); attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); attr.query.link_attach_flags = ptr_to_u64(OPTS_GET(opts, link_attach_flags, NULL)); ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz); OPTS_SET(opts, attach_flags, attr.query.attach_flags); OPTS_SET(opts, revision, attr.query.revision); OPTS_SET(opts, count, attr.query.count); return libbpf_err_errno(ret); } int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) { LIBBPF_OPTS(bpf_prog_query_opts, opts); int ret; opts.query_flags = query_flags; opts.prog_ids = prog_ids; opts.prog_cnt = *prog_cnt; ret = bpf_prog_query_opts(target_fd, type, &opts); if (attach_flags) *attach_flags = opts.attach_flags; *prog_cnt = opts.prog_cnt; return libbpf_err_errno(ret); } int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, test); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_test_run_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.test.prog_fd = prog_fd; attr.test.batch_size = OPTS_GET(opts, batch_size, 0); attr.test.cpu = OPTS_GET(opts, cpu, 0); attr.test.flags = OPTS_GET(opts, flags, 0); attr.test.repeat = OPTS_GET(opts, repeat, 0); attr.test.duration = OPTS_GET(opts, duration, 0); attr.test.ctx_size_in = OPTS_GET(opts, ctx_size_in, 0); attr.test.ctx_size_out = OPTS_GET(opts, ctx_size_out, 0); attr.test.data_size_in = OPTS_GET(opts, data_size_in, 0); attr.test.data_size_out = OPTS_GET(opts, data_size_out, 0); attr.test.ctx_in = ptr_to_u64(OPTS_GET(opts, ctx_in, NULL)); attr.test.ctx_out = ptr_to_u64(OPTS_GET(opts, ctx_out, NULL)); attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL)); attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL)); ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, attr_sz); OPTS_SET(opts, data_size_out, attr.test.data_size_out); OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out); OPTS_SET(opts, duration, attr.test.duration); OPTS_SET(opts, retval, attr.test.retval); return libbpf_err_errno(ret); } static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int err; memset(&attr, 0, attr_sz); attr.start_id = start_id; err = sys_bpf(cmd, &attr, attr_sz); if (!err) *next_id = attr.next_id; return libbpf_err_errno(err); } int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) { return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID); } int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) { return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID); } int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id) { return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID); } int bpf_link_get_next_id(__u32 start_id, __u32 *next_id) { return bpf_obj_get_next_id(start_id, next_id, BPF_LINK_GET_NEXT_ID); } int bpf_prog_get_fd_by_id_opts(__u32 id, const struct bpf_get_fd_by_id_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.prog_id = id; attr.open_flags = OPTS_GET(opts, open_flags, 0); fd = sys_bpf_fd(BPF_PROG_GET_FD_BY_ID, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_prog_get_fd_by_id(__u32 id) { return bpf_prog_get_fd_by_id_opts(id, NULL); } int bpf_map_get_fd_by_id_opts(__u32 id, const struct bpf_get_fd_by_id_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.map_id = id; attr.open_flags = OPTS_GET(opts, open_flags, 0); fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_map_get_fd_by_id(__u32 id) { return bpf_map_get_fd_by_id_opts(id, NULL); } int bpf_btf_get_fd_by_id_opts(__u32 id, const struct bpf_get_fd_by_id_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.btf_id = id; attr.open_flags = OPTS_GET(opts, open_flags, 0); fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_btf_get_fd_by_id(__u32 id) { return bpf_btf_get_fd_by_id_opts(id, NULL); } int bpf_link_get_fd_by_id_opts(__u32 id, const struct bpf_get_fd_by_id_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, open_flags); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_get_fd_by_id_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.link_id = id; attr.open_flags = OPTS_GET(opts, open_flags, 0); fd = sys_bpf_fd(BPF_LINK_GET_FD_BY_ID, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_link_get_fd_by_id(__u32 id) { return bpf_link_get_fd_by_id_opts(id, NULL); } int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) { const size_t attr_sz = offsetofend(union bpf_attr, info); union bpf_attr attr; int err; memset(&attr, 0, attr_sz); attr.info.bpf_fd = bpf_fd; attr.info.info_len = *info_len; attr.info.info = ptr_to_u64(info); err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, attr_sz); if (!err) *info_len = attr.info.info_len; return libbpf_err_errno(err); } int bpf_prog_get_info_by_fd(int prog_fd, struct bpf_prog_info *info, __u32 *info_len) { return bpf_obj_get_info_by_fd(prog_fd, info, info_len); } int bpf_map_get_info_by_fd(int map_fd, struct bpf_map_info *info, __u32 *info_len) { return bpf_obj_get_info_by_fd(map_fd, info, info_len); } int bpf_btf_get_info_by_fd(int btf_fd, struct bpf_btf_info *info, __u32 *info_len) { return bpf_obj_get_info_by_fd(btf_fd, info, info_len); } int bpf_link_get_info_by_fd(int link_fd, struct bpf_link_info *info, __u32 *info_len) { return bpf_obj_get_info_by_fd(link_fd, info, info_len); } int bpf_raw_tracepoint_open(const char *name, int prog_fd) { const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint); union bpf_attr attr; int fd; memset(&attr, 0, attr_sz); attr.raw_tracepoint.name = ptr_to_u64(name); attr.raw_tracepoint.prog_fd = prog_fd; fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, btf_token_fd); union bpf_attr attr; char *log_buf; size_t log_size; __u32 log_level; int fd; bump_rlimit_memlock(); memset(&attr, 0, attr_sz); if (!OPTS_VALID(opts, bpf_btf_load_opts)) return libbpf_err(-EINVAL); log_buf = OPTS_GET(opts, log_buf, NULL); log_size = OPTS_GET(opts, log_size, 0); log_level = OPTS_GET(opts, log_level, 0); if (log_size > UINT_MAX) return libbpf_err(-EINVAL); if (log_size && !log_buf) return libbpf_err(-EINVAL); attr.btf = ptr_to_u64(btf_data); attr.btf_size = btf_size; attr.btf_flags = OPTS_GET(opts, btf_flags, 0); attr.btf_token_fd = OPTS_GET(opts, token_fd, 0); /* log_level == 0 and log_buf != NULL means "try loading without * log_buf, but retry with log_buf and log_level=1 on error", which is * consistent across low-level and high-level BTF and program loading * APIs within libbpf and provides a sensible behavior in practice */ if (log_level) { attr.btf_log_buf = ptr_to_u64(log_buf); attr.btf_log_size = (__u32)log_size; attr.btf_log_level = log_level; } fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); if (fd < 0 && log_buf && log_level == 0) { attr.btf_log_buf = ptr_to_u64(log_buf); attr.btf_log_size = (__u32)log_size; attr.btf_log_level = 1; fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz); } OPTS_SET(opts, log_true_size, attr.btf_log_true_size); return libbpf_err_errno(fd); } int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, __u64 *probe_addr) { const size_t attr_sz = offsetofend(union bpf_attr, task_fd_query); union bpf_attr attr; int err; memset(&attr, 0, attr_sz); attr.task_fd_query.pid = pid; attr.task_fd_query.fd = fd; attr.task_fd_query.flags = flags; attr.task_fd_query.buf = ptr_to_u64(buf); attr.task_fd_query.buf_len = *buf_len; err = sys_bpf(BPF_TASK_FD_QUERY, &attr, attr_sz); *buf_len = attr.task_fd_query.buf_len; *prog_id = attr.task_fd_query.prog_id; *fd_type = attr.task_fd_query.fd_type; *probe_offset = attr.task_fd_query.probe_offset; *probe_addr = attr.task_fd_query.probe_addr; return libbpf_err_errno(err); } int bpf_enable_stats(enum bpf_stats_type type) { const size_t attr_sz = offsetofend(union bpf_attr, enable_stats); union bpf_attr attr; int fd; memset(&attr, 0, attr_sz); attr.enable_stats.type = type; fd = sys_bpf_fd(BPF_ENABLE_STATS, &attr, attr_sz); return libbpf_err_errno(fd); } int bpf_prog_bind_map(int prog_fd, int map_fd, const struct bpf_prog_bind_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, prog_bind_map); union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_prog_bind_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.prog_bind_map.prog_fd = prog_fd; attr.prog_bind_map.map_fd = map_fd; attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0); ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, attr_sz); return libbpf_err_errno(ret); } int bpf_token_create(int bpffs_fd, struct bpf_token_create_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, token_create); union bpf_attr attr; int fd; if (!OPTS_VALID(opts, bpf_token_create_opts)) return libbpf_err(-EINVAL); memset(&attr, 0, attr_sz); attr.token_create.bpffs_fd = bpffs_fd; attr.token_create.flags = OPTS_GET(opts, flags, 0); fd = sys_bpf_fd(BPF_TOKEN_CREATE, &attr, attr_sz); return libbpf_err_errno(fd); }