From: t_jeang <devnull@localhost>
Date: Tue, 6 Jan 2009 12:06:02 +0000 (+0000)
Subject: Ensure that packet csums are computed correctly when sending a GSO
X-Git-Tag: netback-increase-pullup
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a90b2b155218d3ad21732fd6b0ec463506f1727d;p=xenclient%2Fkernel.git

Ensure that packet csums are computed correctly when sending a GSO
packet to an interface which supports scatter-gather but not transmit
checksum offloads.

Signed-off-by: Steven Smith <ssmith@xensource.com>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index 82d94393..dc304209 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1369,6 +1369,18 @@ gso:
 
 		skb->next = nskb->next;
 		nskb->next = NULL;
+
+		if (nskb->ip_summed == CHECKSUM_HW &&
+		    (!(dev->features & NETIF_F_GEN_CSUM) &&
+		     (!(dev->features & NETIF_F_IP_CSUM) ||
+		      nskb->protocol != htons(ETH_P_IP)))) {
+			if (skb_checksum_help(nskb, 0)) {
+				nskb->next = skb->next;
+				skb->next = nskb;
+				return NETDEV_TX_BUSY;
+			}
+		}
+
 		rc = dev->hard_start_xmit(nskb, dev);
 		if (unlikely(rc)) {
 			nskb->next = skb->next;