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Commit d5148d85 authored by Joe Stringer's avatar Joe Stringer Committed by Arnaldo Carvalho de Melo
Browse files

tools lib bpf: Add bpf_object__pin() 



Add a new API to pin a BPF object to the filesystem. The user can
specify the path within a BPF filesystem to pin the object.
Programs will be pinned under a subdirectory named the same as the
program, with each instance appearing as a numbered file under that
directory, and maps will be pinned under the path using the name of
the map as the file basename.

For example, with the directory '/sys/fs/bpf/foo' and a BPF object which
contains two instances of a program named 'bar', and a map named 'baz':

/sys/fs/bpf/foo/bar/0
/sys/fs/bpf/foo/bar/1
/sys/fs/bpf/foo/baz

Signed-off-by: default avatarJoe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-4-joe@ovn.org


[ Check snprintf >= for truncation, as snprintf(bf, size, ...) == size also means truncation ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b6989f35

tools/lib/bpf/libbpf.c

+53 −0
Original line number Diff line number Diff line
@@ -1379,6 +1379,59 @@ int bpf_map__pin(struct bpf_map *map, const char *path) 
	return 0;

}



int bpf_object__pin(struct bpf_object *obj, const char *path)

{

	struct bpf_program *prog;

	struct bpf_map *map;

	int err;



	if (!obj)

		return -ENOENT;



	if (!obj->loaded) {

		pr_warning("object not yet loaded; load it first\n");

		return -ENOENT;

	}



	err = make_dir(path);

	if (err)

		return err;



	bpf_map__for_each(map, obj) {

		char buf[PATH_MAX];

		int len;



		len = snprintf(buf, PATH_MAX, "%s/%s", path,

			       bpf_map__name(map));

		if (len < 0)

			return -EINVAL;

		else if (len >= PATH_MAX)

			return -ENAMETOOLONG;



		err = bpf_map__pin(map, buf);

		if (err)

			return err;

	}



	bpf_object__for_each_program(prog, obj) {

		char buf[PATH_MAX];

		int len;



		len = snprintf(buf, PATH_MAX, "%s/%s", path,

			       prog->section_name);

		if (len < 0)

			return -EINVAL;

		else if (len >= PATH_MAX)

			return -ENAMETOOLONG;



		err = bpf_program__pin(prog, buf);

		if (err)

			return err;

	}



	return 0;

}



void bpf_object__close(struct bpf_object *obj)

{

	size_t i;

tools/lib/bpf/libbpf.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct bpf_object *bpf_object__open(const char *path); 
struct bpf_object *bpf_object__open_buffer(void *obj_buf,

					   size_t obj_buf_sz,

					   const char *name);

int bpf_object__pin(struct bpf_object *object, const char *path);

void bpf_object__close(struct bpf_object *object);



/* Load/unload object into/from kernel */