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authorHerbert Xu <herbert@gondor.apana.org.au>2010-06-15 01:52:25 +0000
committerPaul Gortmaker <paul.gortmaker@windriver.com>2011-06-26 12:47:16 -0400
commit8d988d390bbfd5ede742e9cab66916cb372e7829 (patch)
treef4fceb8c0496979595c55ad2b9266b03f6891f15
parentbbfbf1663c6a191f4020e3a6aadd0917dc0f0d8e (diff)
downloadlinux-rt-8d988d390bbfd5ede742e9cab66916cb372e7829.tar.gz
udp: Fix bogus UFO packet generation
commit 26cde9f7e2747b6d254b704594eed87ab959afa5 upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--net/ipv4/ip_output.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index e8a6860128d4..d52fe4bd573f 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -871,8 +871,10 @@ int ip_append_data(struct sock *sk,
!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,
@@ -890,7 +892,7 @@ int ip_append_data(struct sock *sk,
* adding appropriate IP header.
*/
- if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ if (!skb)
goto alloc_new_skb;
while (length > 0) {
@@ -1119,7 +1121,8 @@ ssize_t ip_append_page(struct sock *sk, struct page *page,
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;