ip6_udp_tunnel: Fix checksum calculation

The UDP checksum calculation for VXLAN tunnels is currently using the
socket addresses instead of the actual packet source and destination
addresses.  As a result the checksum calculated is incorrect in some
cases.

Also uh->check was being set twice, first it was set to 0, and then it is
set again in udp6_set_csum.  This change removes the redundant assignment
to 0.

Fixes: acbf74a7 ("vxlan: Refactor vxlan driver to make use of the common UDP tunnel functions.")

Cc: Andy Zhou <azhou@nicira.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 3 deletions

diff --git a/net/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c
index b04ed72c4542..8db6c98fe218 100644
--- a/net/ipv6/ip6_udp_tunnel.c
+++ b/net/ipv6/ip6_udp_tunnel.c
@@ -79,15 +79,13 @@ int udp_tunnel6_xmit_skb(struct socket *sock, struct dst_entry *dst,
         uh->source = src_port;
 
         uh->len = htons(skb->len);
-        uh->check = 0;
 
         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED
                             | IPSKB_REROUTED);
         skb_dst_set(skb, dst);
 
-        udp6_set_csum(udp_get_no_check6_tx(sk), skb, &inet6_sk(sk)->saddr,
-                      &sk->sk_v6_daddr, skb->len);
+        udp6_set_csum(udp_get_no_check6_tx(sk), skb, saddr, daddr, skb->len);
 
         __skb_push(skb, sizeof(*ip6h));
         skb_reset_network_header(skb);