tcp: Fix ipv6 checksumming on response packets for real.

Commit 6651ffc8e8bdd5fb4b7d1867c6cfebb4f309512c
("ipv6: Fix tcp_v6_send_response transport header setting.")
fixed one half of why ipv6 tcp response checksums were
invalid, but it's not the whole story.

If we're going to use CHECKSUM_PARTIAL for these things (which we are
since commit 2e8e18ef52e7dd1af0a3bd1f7d990a1d0b249586 "tcp: Set
CHECKSUM_UNNECESSARY in tcp_init_nondata_skb"), we can't be setting
buff->csum as we always have been here in tcp_v6_send_response.  We
need to leave it at zero.

Kill that line and checksums are good again.

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

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 78480f410a9b7b475d3b5c8a110dd6be1601ada3..5d2e4301e2462865b92fd67b66def08080adb167 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1050,8 +1050,6 @@ static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
        }
 #endif
 
-       buff->csum = csum_partial(t1, tot_len, 0);
-
        memset(&fl, 0, sizeof(fl));
        ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
        ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);