From 1ee1cfe7d3df00bff11dd28576eeac1875d7d51f Mon Sep 17 00:00:00 2001
From: Vlad Yasevich <vyasevich@gmail.com>
Date: Mon, 25 Aug 2014 10:34:55 -0400
Subject: qlge: Fix TSO for non-accelerated vlan traffic

This device claims TSO support for vlans.  It also allows a user to
control vlan acceleration offloading.  As such, it is possible to turn
off vlan acceleration and configure a vlan which will continue to send
TSO traffic.

In such situation the packet passed down the the device will contain
a vlan header and skb->protocol will be set to ETH_P_8021Q.
The device assumes that skb->protocol contains network protocol
value and uses that value to set up TSO information.
This results in corrupted frames sent on the wire.

This patch extracts the protocol value correctly by using a
vlan_get_protocol() helper and corrects corrupt TSO frames.

CC: Shahed Shaikh <shahed.shaikh@qlogic.com>
CC: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
CC: Ron Mercer <ron.mercer@qlogic.com>
CC: linux-driver@qlogic.com
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Shahed Shaikh <shahed.shaikh@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_main.c b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
index 188626e..3e96f26 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge_main.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
@@ -2556,6 +2556,7 @@ static int ql_tso(struct sk_buff *skb, struct ob_mac_tso_iocb_req *mac_iocb_ptr)
 
 	if (skb_is_gso(skb)) {
 		int err;
+		__be16 l3_proto = vlan_get_protocol(skb);
 
 		err = skb_cow_head(skb, 0);
 		if (err < 0)
@@ -2572,7 +2573,7 @@ static int ql_tso(struct sk_buff *skb, struct ob_mac_tso_iocb_req *mac_iocb_ptr)
 				<< OB_MAC_TRANSPORT_HDR_SHIFT);
 		mac_iocb_ptr->mss = cpu_to_le16(skb_shinfo(skb)->gso_size);
 		mac_iocb_ptr->flags2 |= OB_MAC_TSO_IOCB_LSO;
-		if (likely(skb->protocol == htons(ETH_P_IP))) {
+		if (likely(l3_proto == htons(ETH_P_IP))) {
 			struct iphdr *iph = ip_hdr(skb);
 			iph->check = 0;
 			mac_iocb_ptr->flags1 |= OB_MAC_TSO_IOCB_IP4;
@@ -2580,7 +2581,7 @@ static int ql_tso(struct sk_buff *skb, struct ob_mac_tso_iocb_req *mac_iocb_ptr)
 								 iph->daddr, 0,
 								 IPPROTO_TCP,
 								 0);
-		} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		} else if (l3_proto == htons(ETH_P_IPV6)) {
 			mac_iocb_ptr->flags1 |= OB_MAC_TSO_IOCB_IP6;
 			tcp_hdr(skb)->check =
 			    ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-- 
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