// 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(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 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, excl_prog_hash_size);

  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);

  attr.excl_prog_hash = ptr_to_u64(OPTS_GET(opts, excl_prog_hash, NULL));

  attr.excl_prog_hash_size = OPTS_GET(opts, excl_prog_hash_size, 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, keyring_id);

  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));

  attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0);

  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:

  case BPF_TRACE_UPROBE_SESSION:

    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;

  case BPF_CGROUP_INET_INGRESS:

  case BPF_CGROUP_INET_EGRESS:

  case BPF_CGROUP_INET_SOCK_CREATE:

  case BPF_CGROUP_INET_SOCK_RELEASE:

  case BPF_CGROUP_INET4_BIND:

  case BPF_CGROUP_INET6_BIND:

  case BPF_CGROUP_INET4_POST_BIND:

  case BPF_CGROUP_INET6_POST_BIND:

  case BPF_CGROUP_INET4_CONNECT:

  case BPF_CGROUP_INET6_CONNECT:

  case BPF_CGROUP_UNIX_CONNECT:

  case BPF_CGROUP_INET4_GETPEERNAME:

  case BPF_CGROUP_INET6_GETPEERNAME:

  case BPF_CGROUP_UNIX_GETPEERNAME:

  case BPF_CGROUP_INET4_GETSOCKNAME:

  case BPF_CGROUP_INET6_GETSOCKNAME:

  case BPF_CGROUP_UNIX_GETSOCKNAME:

  case BPF_CGROUP_UDP4_SENDMSG:

  case BPF_CGROUP_UDP6_SENDMSG:

  case BPF_CGROUP_UNIX_SENDMSG:

  case BPF_CGROUP_UDP4_RECVMSG:

  case BPF_CGROUP_UDP6_RECVMSG:

  case BPF_CGROUP_UNIX_RECVMSG:

  case BPF_CGROUP_SOCK_OPS:

  case BPF_CGROUP_DEVICE:

  case BPF_CGROUP_SYSCTL:

  case BPF_CGROUP_GETSOCKOPT:

  case BPF_CGROUP_SETSOCKOPT:

  case BPF_LSM_CGROUP:

    relative_fd = OPTS_GET(opts, cgroup.relative_fd, 0);

    relative_id = OPTS_GET(opts, cgroup.relative_id, 0);

    if (relative_fd && relative_id)