From: Herbert Xu Date: Tue, 15 Jun 2010 01:52:25 +0000 (+0000) Subject: udp: Fix bogus UFO packet generation X-Git-Tag: v2.6.32.40~130 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=548a4a8c2bffd5748f88aff92cea844a842535b8;p=karo-tx-linux.git 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: David S. Miller Cc: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 2ef9026526b8..44b79107866f 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -867,8 +867,10 @@ 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, @@ -886,7 +888,7 @@ 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) { @@ -1115,7 +1117,8 @@ 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;