diff options
Diffstat (limited to '')
| -rw-r--r-- | src/bpf.c | 1165 |
1 files changed, 1165 insertions, 0 deletions
diff --git a/src/bpf.c b/src/bpf.c new file mode 100644 index 0000000..9aff98f --- /dev/null +++ b/src/bpf.c @@ -0,0 +1,1165 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * common eBPF ELF operations. + * + * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> + * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> + * 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 <http://www.gnu.org/licenses> + */ + +#include <stdlib.h> +#include <string.h> +#include <memory.h> +#include <unistd.h> +#include <asm/unistd.h> +#include <errno.h> +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/kernel.h> +#include <limits.h> +#include <sys/resource.h> +#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(void) +{ + 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"); + + 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 || kernel_supports(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_extra); + 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 && kernel_supports(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.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); + + 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, + const struct bpf_prog_load_opts *opts) +{ + const size_t attr_sz = offsetofend(union bpf_attr, fd_array); + 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); + + if (prog_name && kernel_supports(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); + if (log_level > (4 | 2 | 1)) + return libbpf_err(-EINVAL); + if (log_level && !log_buf) + 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); + 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); + 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); + } +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(int fd, const char *pathname) +{ + const size_t attr_sz = offsetofend(union bpf_attr, file_flags); + union bpf_attr attr; + int ret; + + memset(&attr, 0, attr_sz); + attr.pathname = ptr_to_u64((void *)pathname); + attr.bpf_fd = fd; + + ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz); + return libbpf_err_errno(ret); +} + +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, file_flags); + union bpf_attr attr; + int fd; + + if (!OPTS_VALID(opts, bpf_obj_get_opts)) + return libbpf_err(-EINVAL); + + memset(&attr, 0, attr_sz); + 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_fd, + enum bpf_attach_type type, + const struct bpf_prog_attach_opts *opts) +{ + const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); + union bpf_attr attr; + int ret; + + if (!OPTS_VALID(opts, bpf_prog_attach_opts)) + return libbpf_err(-EINVAL); + + memset(&attr, 0, attr_sz); + attr.target_fd = target_fd; + attr.attach_bpf_fd = prog_fd; + attr.attach_type = type; + attr.attach_flags = OPTS_GET(opts, flags, 0); + attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0); + + ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz); + return libbpf_err_errno(ret); +} + +int bpf_prog_detach(int target_fd, enum bpf_attach_type type) +{ + const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); + union bpf_attr attr; + int ret; + + memset(&attr, 0, attr_sz); + attr.target_fd = target_fd; + attr.attach_type = type; + + ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); + return libbpf_err_errno(ret); +} + +int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) +{ + const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd); + union bpf_attr attr; + int ret; + + memset(&attr, 0, attr_sz); + attr.target_fd = target_fd; + attr.attach_bpf_fd = prog_fd; + attr.attach_type = type; + + ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz); + return libbpf_err_errno(ret); +} + +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; + union bpf_attr attr; + int fd, err; + + 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_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; + 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); + + 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); + attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_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_fd, + 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_fd; + attr.query.attach_type = type; + attr.query.query_flags = OPTS_GET(opts, query_flags, 0); + attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0); + attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); + attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); + + ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz); + + OPTS_SET(opts, attach_flags, attr.query.attach_flags); + OPTS_SET(opts, prog_cnt, attr.query.prog_cnt); + + 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_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, const struct bpf_btf_load_opts *opts) +{ + const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level); + 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; + /* 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); + } + 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); +} |