From 649c5b8bdd8d5c8c9c50882e3a789030fb99b75c Mon Sep 17 00:00:00 2001
From: Pravin B Shelar <pshelar@nicira.com>
Date: Mon, 19 Aug 2013 11:23:22 -0700
Subject: [PATCH] vxlan: Improve vxlan headroom calculation.
Rather than having static headroom calculation, adjust headroom
according to target device.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/vxlan.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index f3496e9953025..73e255788faec 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1130,6 +1130,7 @@ int vxlan_xmit_skb(struct net *net, struct vxlan_sock *vs,
{
struct vxlanhdr *vxh;
struct udphdr *uh;
+ int min_headroom;
int err;
if (!skb->encapsulation) {
@@ -1137,6 +1138,14 @@ int vxlan_xmit_skb(struct net *net, struct vxlan_sock *vs,
skb->encapsulation = 1;
}
+ min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ + VXLAN_HLEN + sizeof(struct iphdr);
+
+ /* Need space for new headers (invalidates iph ptr) */
+ err = skb_cow_head(skb, min_headroom);
+ if (unlikely(err))
+ return err;
+
vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
vxh->vx_flags = htonl(VXLAN_FLAGS);
vxh->vx_vni = vni;
@@ -1220,10 +1229,6 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
goto drop;
}
- /* Need space for new headers (invalidates iph ptr) */
- if (skb_cow_head(skb, VXLAN_HEADROOM))
- goto drop;
-
old_iph = ip_hdr(skb);
ttl = vxlan->ttl;