src/shared/bpf-link.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include "bpf-link.h"
   4 #include "serialize.h"
   5
   6 bool can_link_bpf_program(struct bpf_program *prog) {
   7         _cleanup_(bpf_link_freep) struct bpf_link *link = NULL;
   8
   9         assert(prog);
  10
  11         /* Pass invalid cgroup fd intentionally. */
  12         link = bpf_program__attach_cgroup(prog, /*cgroup_fd=*/-1);
  13
  14         /* EBADF indicates that bpf_link is supported by kernel. */
  15         return libbpf_get_error(link) == -EBADF;
  16 }
  17
  18 int serialize_bpf_link(FILE *f, FDSet *fds, const char *key, struct bpf_link *link) {
  19         int fd;
  20
  21         assert(key);
  22
  23         if (!link)
  24                 return -ENOENT;
  25
  26         if (libbpf_get_error(link) != 0)
  27                 return -EINVAL;
  28
  29         fd = bpf_link__fd(link);
  30         return serialize_fd(f, fds, key, fd);
  31 }
  32
  33 struct bpf_link *bpf_link_free(struct bpf_link *link) {
  34         /* bpf_link__destroy handles link == NULL case */
  35         (void) bpf_link__destroy(link);
  36
  37         return NULL;
  38 }