From: Aubrey.Li <aubreylee@gmail.com>
Date: Tue, 17 Apr 2007 19:40:20 +0000 (-0700)
Subject: [NET]: Fix UDP checksum issue in net poll mode.
X-Git-Tag: firefly_0821_release~30345^2~4
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5e7d7fa57323dfb48fb09464cf4542daa7ce8a72;p=firefly-linux-kernel-4.4.55.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>
---

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index da1019451ccb..4581ece48bb2 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -471,6 +471,13 @@ 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;