[NET]: Treat CHECKSUM_PARTIAL as CHECKSUM_UNNECESSARY

When a transmitted packet is looped back directly, CHECKSUM_PARTIAL
maps to the semantics of CHECKSUM_UNNECESSARY.  Therefore we should
treat it as such in the stack.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 2 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7e824b97126d..2b668a6ae698 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1707,8 +1707,7 @@ static int tcp_v6_rcv(struct sk_buff **pskb)
         if (!pskb_may_pull(skb, th->doff*4))
                 goto discard_it;
 
-        if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
-             tcp_v6_checksum_init(skb)))
+        if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
                 goto bad_packet;
 
         th = tcp_hdr(skb);