From: Aubrey Li <aubreylee@gmail.com>
Date: Thu, 19 Apr 2007 23:40:19 +0000 (+0200)
Subject: [NET]: Fix UDP checksum issue in net poll mode.
X-Git-Tag: v2.6.16.49-rc1~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=691d4b9f4f4479edb4c3c63c7dbf5c5fa1ce0979;p=thirdparty%2Fkernel%2Fstable.git

[NET]: Fix UDP checksum issue in net poll mode.

In net poll mode, the current checksum function doesn't consider the
kind of packet which is padded to reach a specific minimum length. I
believe that's the problem causing my test case failed. The following
patch fixed this issue.

Signed-off-by: Aubrey Li <aubreylee@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
---

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index ea51f8d02eb86..62753d3afc720 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -485,6 +485,13 @@ int __netpoll_rx(struct sk_buff *skb)
 	if (skb->len < len || len < iph->ihl*4)
 		goto out;
 
+	/*
+	 * Our transport medium may have padded the buffer out.
+	 * Now We trim to the true length of the frame.
+	 */
+	if (pskb_trim_rcsum(skb, len))
+		goto out;
+
 	if (iph->protocol != IPPROTO_UDP)
 		goto out;