ipv6: Fix nexthdr for reinjection

In ip6_input_finish the nexthdr protocol is retrieved from the
next header offset that is returned in the cb of the skb.
This method does not work for UDP encapsulation that may not
even have a concept of a nexthdr field (e.g. FOU).

This patch checks for a final protocol (INET6_PROTO_FINAL) when a
protocol handler returns > 0. If the protocol is not final then
resubmission is performed on nhoff value. If the protocol is final
then the nexthdr is taken to be the return value.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index f185cbcda1144f02f81657b052f39f2fba8e3e20..d35dff23f609bcc26e97229ad22a8f33ba6596d2 100644 (file)
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -236,6 +236,7 @@ resubmit:
        nhoff = IP6CB(skb)->nhoff;
        nexthdr = skb_network_header(skb)[nhoff];
 
+resubmit_final:
        raw = raw6_local_deliver(skb, nexthdr);
        ipprot = rcu_dereference(inet6_protos[nexthdr]);
        if (ipprot) {
@@ -263,10 +264,21 @@ resubmit:
                        goto discard;
 
                ret = ipprot->handler(skb);
-               if (ret > 0)
-                       goto resubmit;
-               else if (ret == 0)
+               if (ret > 0) {
+                       if (ipprot->flags & INET6_PROTO_FINAL) {
+                               /* Not an extension header, most likely UDP
+                                * encapsulation. Use return value as nexthdr
+                                * protocol not nhoff (which presumably is
+                                * not set by handler).
+                                */
+                               nexthdr = ret;
+                               goto resubmit_final;
+                       } else {
+                               goto resubmit;
+                       }
+               } else if (ret == 0) {
                        __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
+               }
        } else {
                if (!raw) {
                        if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {