libbpf: Fix bpf_xdp_query() in old kernels

[platform/kernel/linux-rpi.git] / tools / lib / bpf / netlink.c

diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index 1653e7a..84dd5fa 100644 (file)
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -468,8 +468,13 @@ int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
                return 0;
 
        err = libbpf_netlink_resolve_genl_family_id("netdev", sizeof("netdev"), &id);
-       if (err < 0)
+       if (err < 0) {
+               if (err == -ENOENT) {
+                       opts->feature_flags = 0;
+                       goto skip_feature_flags;
+               }
                return libbpf_err(err);
+       }
 
        memset(&req, 0, sizeof(req));
        req.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
@@ -489,6 +494,7 @@ int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
 
        opts->feature_flags = md.flags;
 
+skip_feature_flags:
        return 0;
 }