ipv4: no CHECKSUM_PARTIAL on MSG_MORE corked sockets

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 <[email protected]>
Cc: Vlad Yasevich <[email protected]>
Cc: Benjamin Coddington <[email protected]>
Cc: Tom Herbert <[email protected]>
Signed-off-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 50e29737b584624b6d338630622e87634961612e..0b024178edd39a6bc460892ac190095b4dfabbd9 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -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;