[SRU][lts-linux-vivid][PATCH 1/3] ip_vti/ip6_vti: Do not touch skb->mark on xmit

[Joseph Salisbury]

From: Alexander Duyck <alexander.h.duyck at redhat.com>

BugLink: http://bugs.launchpad.net/bugs/1541330

Instead of modifying skb->mark we can simply modify the flowi_mark that is
generated as a result of the xfrm_decode_session.  By doing this we don't
need to actually touch the skb->mark and it can be preserved as it passes
out through the tunnel.

Signed-off-by: Alexander Duyck <alexander.h.duyck at redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert at secunet.com>
(cherry picked from commit cd5279c194f89c9b97c294af4aaf4ea8c5e3c704)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 net/ipv4/ip_vti.c  | 5 +++--
 net/ipv6/ip6_vti.c | 4 +++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 1a7e979..669e4086 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -216,8 +216,6 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	memset(&fl, 0, sizeof(fl));
 
-	skb->mark = be32_to_cpu(tunnel->parms.o_key);
-
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
 		xfrm_decode_session(skb, &fl, AF_INET);
@@ -233,6 +231,9 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_OK;
 	}
 
+	/* override mark with tunnel output key */
+	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
+
 	return vti_xmit(skb, dev, &fl);
 }
 
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index ace10d0..b0a1ea0 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -496,7 +496,6 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	int ret;
 
 	memset(&fl, 0, sizeof(fl));
-	skb->mark = be32_to_cpu(t->parms.o_key);
 
 	switch (skb->protocol) {
 	case htons(ETH_P_IPV6):
@@ -517,6 +516,9 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto tx_err;
 	}
 
+	/* override mark with tunnel output key */
+	fl.flowi_mark = be32_to_cpu(t->parms.o_key);
+
 	ret = vti6_xmit(skb, dev, &fl);
 	if (ret < 0)
 		goto tx_err;
-- 
1.9.1