From: Tom Herbert <therbert@google.com>
Date: Fri, 3 Oct 2014 22:48:07 +0000 (-0700)
Subject: ip_tunnel: Account for secondary encapsulation header in max_headroom
X-Git-Tag: v3.18-rc1~115^2~49^2~3
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=7371e0221c7721a1486fef745abaa8ae84571621;p=~emulex%2Finfiniband.git

ip_tunnel: Account for secondary encapsulation header in max_headroom

When adjusting max_header for the tunnel interface based on egress
device we need to account for any extra bytes in secondary encapsulation
(e.g. FOU).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 2272de90c2d..d9c9dc4ffea 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -759,7 +759,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 		df |= (inner_iph->frag_off&htons(IP_DF));
 
 	max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
-			+ rt->dst.header_len;
+			+ rt->dst.header_len + ip_encap_hlen(&tunnel->encap);
 	if (max_headroom > dev->needed_headroom)
 		dev->needed_headroom = max_headroom;