Merge branch 'inet_csums_part2'

Tom Herbert says:

====================
net: Checksum offload changes - Part II

I am working on overhauling RX checksum offload. Goals of this effort
are:

- Specify what exactly it means when driver returns CHECKSUM_UNNECESSARY
- Preserve CHECKSUM_COMPLETE through encapsulation layers
- Don't do skb_checksum more than once per packet
- Unify GRO and non-GRO csum verification as much as possible
- Unify the checksum functions (checksum_init)
- Simply code

What is in this second patch set:

- Call common inet checksum validation functions in ICMP{4,6},
  GRE{4,6}, and IGMP.
- In UDP, verify checksum before handing off to encap_rcv.
- Remove custom UDP checksum validation code in L2TP.

Please review carefully and test if possible, mucking with basic
checksum functions is always a little precarious :-)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index fc2be63e32d5..7edf096867c4 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -634,6 +634,10 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
 			int ret;
 
+			/* Verify checksum before giving to encap */
+			if (udp_lib_checksum_complete(skb))
+				goto csum_error;
+
 			ret = encap_rcv(sk, skb);
 			if (ret <= 0) {
 				UDP_INC_STATS_BH(sock_net(sk),