netlink: fix monitor trace crash with netdev family

nft monitor trace crashes on first packet with:

table netdev filter {
  chain foobar {
    type filter hook ingress device eth0 priority 0;
    udp sport 53 meta nftrace set 1
  }
}

We did not handle netdev family and thus generated bogus payload
statements without data types.

Netfilter Bugzilla: http://bugzilla.netfilter.org/show_bug.cgi?id=1092
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/src/netlink.c b/src/netlink.c
index f8da2a6b4fbbbba6889980aa0284f4385653aa66..f8e600ff6f8117939995baa77418254d5ca952db 100644 (file)
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -2340,6 +2340,7 @@ next:
 static void trace_print_packet(const struct nftnl_trace *nlt)
 {
        struct list_head stmts = LIST_HEAD_INIT(stmts);
+       const struct proto_desc *ll_desc;
        struct payload_dep_ctx pctx = {};
        struct proto_ctx ctx;
        uint16_t dev_type;
@@ -2359,12 +2360,14 @@ static void trace_print_packet(const struct nftnl_trace *nlt)
                                                 NFT_META_OIF));
 
        proto_ctx_init(&ctx, nftnl_trace_get_u32(nlt, NFTNL_TRACE_FAMILY));
-       if (ctx.protocol[PROTO_BASE_LL_HDR].desc == &proto_inet &&
+       ll_desc = ctx.protocol[PROTO_BASE_LL_HDR].desc;
+       if ((ll_desc == &proto_inet || ll_desc  == &proto_netdev) &&
            nftnl_trace_is_set(nlt, NFTNL_TRACE_NFPROTO)) {
                nfproto = nftnl_trace_get_u32(nlt, NFTNL_TRACE_NFPROTO);
+
                proto_ctx_update(&ctx, PROTO_BASE_LL_HDR, &netlink_location, NULL);
                proto_ctx_update(&ctx, PROTO_BASE_NETWORK_HDR, &netlink_location,
-                                proto_find_upper(&proto_inet, nfproto));
+                                proto_find_upper(ll_desc, nfproto));
        }
        if (ctx.protocol[PROTO_BASE_LL_HDR].desc == NULL &&
            nftnl_trace_is_set(nlt, NFTNL_TRACE_IIFTYPE)) {