tools lib bpf: Add bpf_map__pin()

Add a new API to pin a BPF map to the filesystem. The user can specify
the path full path within a BPF filesystem to pin the map.

Signed-off-by: Joe 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/20170126212001.14103-3-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c4465b2fddf6..6a8c8beeb291 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1357,6 +1357,28 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
         return 0;
 }
 
+int bpf_map__pin(struct bpf_map *map, const char *path)
+{
+        int err;
+
+        err = check_path(path);
+        if (err)
+                return err;
+
+        if (map == NULL) {
+                pr_warning("invalid map pointer\n");
+                return -EINVAL;
+        }
+
+        if (bpf_obj_pin(map->fd, path)) {
+                pr_warning("failed to pin map: %s\n", strerror(errno));
+                return -errno;
+        }
+
+        pr_debug("pinned map '%s'\n", path);
+        return 0;
+}
+
 void bpf_object__close(struct bpf_object *obj)
 {
         size_t i;