libbpf: Add a helper for retrieving a map fd for a given name (f3cea32d) · Commits · 戴 / test

XDP samples are mostly cooperating with eBPF maps through their file descriptors. In case of a eBPF program that contains multiple maps it might be tiresome to iterate through them and call bpf_map__fd for each one. Add a helper mostly based on bpf_object__find_map_by_name, but instead of returning the struct bpf_map pointer, return map fd. Suggested-by:

Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:

Maciej Fijalkowski <maciej.fijalkowski@intel.com> Reviewed-by:

Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by:

John Fastabend <john.fastabend@gmail.com> Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net>

tools/lib/bpf/libbpf.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -2884,6 +2884,12 @@ bpf_object__find_map_by_name(struct bpf_object obj, const char name)
		return NULL;
		}

		int
		bpf_object__find_map_fd_by_name(struct bpf_object obj, const char name)
		{
		return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
		}

		struct bpf_map *
		bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
		{

tools/lib/bpf/libbpf.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -264,6 +264,9 @@ struct bpf_map;
		LIBBPF_API struct bpf_map *
		bpf_object__find_map_by_name(struct bpf_object obj, const char name);

		LIBBPF_API int
		bpf_object__find_map_fd_by_name(struct bpf_object obj, const char name);

		/*
		* Get bpf_map through the offset of corresponding struct bpf_map_def
		* in the BPF object file.

tools/lib/bpf/libbpf.map

+1 −0

Original line number	Diff line number	Diff line
		@@ -131,4 +131,5 @@ LIBBPF_0.0.2 {
		bpf_probe_map_type;
		bpf_probe_prog_type;
		bpf_map_lookup_elem_flags;
		bpf_object__find_map_fd_by_name;
		} LIBBPF_0.0.1;

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