[NET]: Avoid copying writable clones in tunnel drivers

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 6328293..5c14ed6 100644 (file)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -809,7 +809,8 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 
        max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
 
-       if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
+       if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
+           (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
                if (!new_skb) {
                        ip_rt_put(rt);

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index ebd2f2d..3964372 100644 (file)
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -595,7 +595,8 @@ static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
         */
        max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
 
-       if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
+       if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+           (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
                if (!new_skb) {
                        ip_rt_put(rt);

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index a0902fb..281aee4 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -883,8 +883,8 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
         */
        max_headroom += LL_RESERVED_SPACE(tdev);
 
-       if (skb_headroom(skb) < max_headroom ||
-           skb_cloned(skb) || skb_shared(skb)) {
+       if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+           (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
                struct sk_buff *new_skb;
 
                if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 1efa95a..eb20bb6 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -532,7 +532,8 @@ static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
         */
        max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
 
-       if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
+       if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+           (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
                if (!new_skb) {
                        ip_rt_put(rt);