From: Herbert Xu Date: Tue, 15 Jun 2010 01:52:25 +0000 (+0000) Subject: udp: Fix bogus UFO packet generation X-Git-Tag: v2.6.35-rc4~54^2~19 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=26cde9f7e2747b6d254b704594eed87ab959afa5;p=linux.git 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 --- diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 9a4a6c96cb0d..041d41df1224 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;