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| author | Patrick McHardy <kaber@trash.net> | 2008-07-08 15:36:57 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-07-08 15:36:57 -0700 |
| commit | 11a100f844f6096787ab20e19f17d72abc957a8f (patch) | |
| tree | 9dd9f8578727783dc1d321a822402ee6ca83cd10 /include | |
| parent | 9bb8582efb555521c7eec595ebd34e835ddc34b8 (diff) | |
| download | linux-3.10-11a100f844f6096787ab20e19f17d72abc957a8f.tar.gz linux-3.10-11a100f844f6096787ab20e19f17d72abc957a8f.tar.bz2 linux-3.10-11a100f844f6096787ab20e19f17d72abc957a8f.zip | |
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')
| -rw-r--r-- | include/linux/if_vlan.h | 18 |
1 files changed, 3 insertions, 15 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index d36515dae62..93f5d9b0e9f 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. */ |