// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/*
* common eBPF ELF operations.
*
* Copyright (C) 2013-2015 Alexei Starovoitov <[email protected]>
* Copyright (C) 2015 Wang Nan <[email protected]>
* 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/[email protected]/
* [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, prog_token_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:
case BPF_TRACE_KPROBE_SESSION:
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_RAW_TP:
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_opts(int prog_fd, struct bpf_raw_tp_opts *opts)
{
const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint);
union bpf_attr attr;
int fd;
if (!OPTS_VALID(opts, bpf_raw_tp_opts))
return libbpf_err(-EINVAL);
memset(&attr, 0, attr_sz);
attr.raw_tracepoint.prog_fd = prog_fd;
attr.raw_tracepoint.name = ptr_to_u64(OPTS_GET(opts, tp_name, NULL));
attr.raw_tracepoint.cookie = OPTS_GET(opts, cookie, 0);
fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz);
return libbpf_err_errno(fd);
}
int bpf_raw_tracepoint_open(const char *name, int prog_fd)
{
LIBBPF_OPTS(bpf_raw_tp_opts, opts, .tp_name = name);
return bpf_raw_tracepoint_open_opts(prog_fd, &opts);
}
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);
}
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