mpls: fix sending of local encapped packets

Locally generated IPv4 and (probably) IPv6 packets are dropped because
skb->protocol isn't set. We could write wrappers to lwtunnel_output
for IPv4 and IPv6 that set the protocol accordingly and then call
lwtunnel_output, but mpls_output relies on the AF-specific type of dst
anyway to get the via address.

Therefore, make use of dst->dst_ops->family in mpls_output to
determine the type of nexthop and thus protocol of the packet instead
of checking skb->protocol.

Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Reported-by: Sam Russell <sam.h.russell@gmail.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 67591aef9cae6fb203ef802272baad6e5b191000..64afd3d0b14407c252a766ab2280a30452a684c5 100644 (file)
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -54,10 +54,10 @@ int mpls_output(struct net *net, struct sock *sk, struct sk_buff *skb)
        unsigned int ttl;
 
        /* Obtain the ttl */
-       if (skb->protocol == htons(ETH_P_IP)) {
+       if (dst->ops->family == AF_INET) {
                ttl = ip_hdr(skb)->ttl;
                rt = (struct rtable *)dst;
-       } else if (skb->protocol == htons(ETH_P_IPV6)) {
+       } else if (dst->ops->family == AF_INET6) {
                ttl = ipv6_hdr(skb)->hop_limit;
                rt6 = (struct rt6_info *)dst;
        } else {