udp6: fix UDP/IPv6 encap resubmit path
IPv4 interprets a negative return value from a protocol handler as a
request to redispatch to a new protocol. In contrast, IPv6 interprets a
negative value as an error, and interprets a positive value as a request
for redispatch.
UDP for IPv6 was unaware of this difference. Change __udp6_lib_rcv() to
return a positive value for redispatch. Note that the socket's
encap_rcv hook still needs to return a negative value to request
dispatch, and in the case of IPv6 packets, adjust IP6CB(skb)->nhoff to
identify the byte containing the next protocol.
Signed-off-by: Bill Sommerfeld <wsommerfeld@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 22e28a4..422dd01 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -962,11 +962,9 @@
ret = udpv6_queue_rcv_skb(sk, skb);
sock_put(sk);
- /* a return value > 0 means to resubmit the input, but
- * it wants the return to be -protocol, or 0
- */
+ /* a return value > 0 means to resubmit the input */
if (ret > 0)
- return -ret;
+ return ret;
return 0;
}