udp: Fix bogus UFO packet generation
It has been reported that the new UFO software fallback path
fails under certain conditions with NFS. I tracked the problem
down to the generation of UFO packets that are smaller than the
MTU. The software fallback path simply discards these packets.
This patch fixes the problem by not generating such packets on
the UFO path.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 9a4a6c9..041d41d 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -873,8 +873,10 @@
!exthdrlen)
csummode = CHECKSUM_PARTIAL;
+ skb = skb_peek_tail(&sk->sk_write_queue);
+
inet->cork.length += length;
- if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) &&
+ if (((length > mtu) || (skb && skb_is_gso(skb))) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->u.dst.dev->features & NETIF_F_UFO)) {
err = ip_ufo_append_data(sk, getfrag, from, length, hh_len,
@@ -892,7 +894,7 @@
* adding appropriate IP header.
*/
- if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ if (!skb)
goto alloc_new_skb;
while (length > 0) {
@@ -1121,7 +1123,8 @@
return -EINVAL;
inet->cork.length += size;
- if ((sk->sk_protocol == IPPROTO_UDP) &&
+ if ((size + skb->len > mtu) &&
+ (sk->sk_protocol == IPPROTO_UDP) &&
(rt->u.dst.dev->features & NETIF_F_UFO)) {
skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;