Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1729769 > unrolled thread

[PATCH 3.16 214/233] ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 3.16 214/233] ipv4: Should use consistent conditional  judgement for ip fragment in __ip_append_data and ip_finish_output Ben Hutchings <ben@decadent.org.uk> - 2017-09-10 01:20 +0200

#1729769 — [PATCH 3.16 214/233] ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output

3.16.48-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: zheng li <james.z.li@ericsson.com>

commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 upstream.

There is an inconsistent conditional judgement in __ip_append_data and
ip_finish_output functions, the variable length in __ip_append_data just
include the length of application's payload and udp header, don't include
the length of ip header, but in ip_finish_output use
(skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the
length of ip header.

That causes some particular application's udp payload whose length is
between (MTU - IP Header) and MTU were fragmented by ip_fragment even
though the rst->dev support UFO feature.

Add the length of ip header to length in __ip_append_data to keep
consistent conditional judgement as ip_finish_output for ip fragment.

Signed-off-by: Zheng Li <james.z.li@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context to apply after "udp: consistently apply
 ufo or fragmentation"]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 net/ipv4/ip_output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -886,7 +886,7 @@ static int __ip_append_data(struct sock
 
 	cork->length += length;
 	if ((skb && skb_is_gso(skb)) ||
-	    ((length > mtu) &&
+	    (((length + fragheaderlen) > mtu) &&
 	    (skb_queue_len(queue) <= 1) &&
 	    (sk->sk_protocol == IPPROTO_UDP) &&
 	    (rt->dst.dev->features & NETIF_F_UFO) && !dst_xfrm(&rt->dst) &&

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web