ipv4: no CHECKSUM_PARTIAL on MSG_MORE corked sockets
authorHannes Frederic Sowa <hannes@stressinduktion.org>
Tue, 27 Oct 2015 21:40:39 +0000 (22:40 +0100)
committerDavid S. Miller <davem@davemloft.net>
Sun, 1 Nov 2015 17:01:27 +0000 (12:01 -0500)
We cannot reliable calculate packet size on MSG_MORE corked sockets
and thus cannot decide if they are going to be fragmented later on,
so better not use CHECKSUM_PARTIAL in the first place.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/ip_output.c

index 50e29737b584624b6d338630622e87634961612e..0b024178edd39a6bc460892ac190095b4dfabbd9 100644 (file)
@@ -911,6 +911,7 @@ static int __ip_append_data(struct sock *sk,
        if (transhdrlen &&
            length + fragheaderlen <= mtu &&
            rt->dst.dev->features & NETIF_F_V4_CSUM &&
+           !(flags & MSG_MORE) &&
            !exthdrlen)
                csummode = CHECKSUM_PARTIAL;