51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include "bpf-dlopen.h"
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#include "bpf-link.h"
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#include "serialize.h"
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bool bpf_can_link_program(struct bpf_program *prog) {
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_cleanup_(bpf_link_freep) struct bpf_link *link = NULL;
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assert(prog);
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if (dlopen_bpf() < 0)
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return false;
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/* Pass invalid cgroup fd intentionally. */
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link = sym_bpf_program__attach_cgroup(prog, /*cgroup_fd=*/-1);
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/* EBADF indicates that bpf_link is supported by kernel. */
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return bpf_get_error_translated(link) == -EBADF;
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}
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int bpf_serialize_link(FILE *f, FDSet *fds, const char *key, struct bpf_link *link) {
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assert(key);
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if (!link)
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return -ENOENT;
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if (bpf_get_error_translated(link) != 0)
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return -EINVAL;
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return serialize_fd(f, fds, key, sym_bpf_link__fd(link));
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}
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struct bpf_link* bpf_link_free(struct bpf_link *link) {
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/* If libbpf wasn't dlopen()ed, sym_bpf_link__destroy might be unresolved (NULL), so let's not try to
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* call it if link is NULL. link might also be a non-null "error pointer", but such a value can only
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* originate from a call to libbpf, but that means that libbpf is available, and we can let
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* bpf_link__destroy() handle it. */
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if (link)
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(void) sym_bpf_link__destroy(link);
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return NULL;
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}
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struct ring_buffer* bpf_ring_buffer_free(struct ring_buffer *rb) {
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if (rb) /* See the comment in bpf_link_free(). */
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sym_ring_buffer__free(rb);
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return NULL;
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}
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