From 26cde9f7e2747b6d254b704594eed87ab959afa5 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 15 Jun 2010 01:52:25 +0000 Subject: 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- net/ipv4/ip_output.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 9a4a6c96cb0..041d41df122 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -873,8 +873,10 @@ 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, @@ -892,7 +894,7 @@ 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) { @@ -1121,7 +1123,8 @@ 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; -- cgit v1.2.3