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authorPatrick McHardy <kaber@trash.net>2008-07-08 15:36:57 -0700
committerDavid S. Miller <davem@davemloft.net>2008-07-08 15:36:57 -0700
commit11a100f844f6096787ab20e19f17d72abc957a8f (patch)
tree9dd9f8578727783dc1d321a822402ee6ca83cd10 /include/linux/if_vlan.h
parent9bb8582efb555521c7eec595ebd34e835ddc34b8 (diff)
vlan: avoid header copying and linearisation where possible
- vlan_dev_reorder_header() is only called on the receive path after calling skb_share_check(). This means we can use skb_cow() since all we need is a writable header. - vlan_dev_hard_header() includes a work-around for some apparently broken out of tree MPLS code. The hard_header functions can expect to always have a headroom of at least there own hard_header_len available, so the reallocation check is unnecessary. - __vlan_put_tag() can use skb_cow_head() to avoid the skb_unshare() copy when the header is writable. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/if_vlan.h')
-rw-r--r--include/linux/if_vlan.h18
1 files changed, 3 insertions, 15 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index d36515dae62f..93f5d9b0e9f9 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -185,22 +185,10 @@ static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
{
struct vlan_ethhdr *veth;
- if (skb_headroom(skb) < VLAN_HLEN) {
- struct sk_buff *sk_tmp = skb;
- skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
- kfree_skb(sk_tmp);
- if (!skb) {
- printk(KERN_ERR "vlan: failed to realloc headroom\n");
- return NULL;
- }
- } else {
- skb = skb_unshare(skb, GFP_ATOMIC);
- if (!skb) {
- printk(KERN_ERR "vlan: failed to unshare skbuff\n");
- return NULL;
- }
+ if (skb_cow_head(skb, VLAN_HLEN) < 0) {
+ kfree_skb(skb);
+ return NULL;
}
-
veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
/* Move the mac addresses to the beginning of the new header. */