diff options
| -rw-r--r-- | drivers/net/pppoe.c | 2 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 40 | ||||
| -rw-r--r-- | net/bridge/br_netfilter.c | 2 |
3 files changed, 33 insertions, 11 deletions
diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c index bac36546e0b..0d7f570b9a5 100644 --- a/drivers/net/pppoe.c +++ b/drivers/net/pppoe.c @@ -860,7 +860,7 @@ static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) /* Copy the data if there is no space for the header or if it's * read-only. */ - if (skb_cow(skb, sizeof(*ph) + dev->hard_header_len)) + if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len)) goto abort; __skb_push(skb, sizeof(*ph)); diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 93c27f71122..a656cecd373 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1352,6 +1352,22 @@ static inline int skb_clone_writable(struct sk_buff *skb, int len) skb_headroom(skb) + len <= skb->hdr_len; } +static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, + int cloned) +{ + int delta = 0; + + if (headroom < NET_SKB_PAD) + headroom = NET_SKB_PAD; + if (headroom > skb_headroom(skb)) + delta = headroom - skb_headroom(skb); + + if (delta || cloned) + return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, + GFP_ATOMIC); + return 0; +} + /** * skb_cow - copy header of skb when it is required * @skb: buffer to cow @@ -1366,16 +1382,22 @@ static inline int skb_clone_writable(struct sk_buff *skb, int len) */ static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) { - int delta = (headroom > NET_SKB_PAD ? headroom : NET_SKB_PAD) - - skb_headroom(skb); - - if (delta < 0) - delta = 0; + return __skb_cow(skb, headroom, skb_cloned(skb)); +} - if (delta || skb_cloned(skb)) - return pskb_expand_head(skb, (delta + (NET_SKB_PAD-1)) & - ~(NET_SKB_PAD-1), 0, GFP_ATOMIC); - return 0; +/** + * skb_cow_head - skb_cow but only making the head writable + * @skb: buffer to cow + * @headroom: needed headroom + * + * This function is identical to skb_cow except that we replace the + * skb_cloned check by skb_header_cloned. It should be used when + * you only need to push on some header and do not need to modify + * the data. + */ +static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) +{ + return __skb_cow(skb, headroom, skb_header_cloned(skb)); } /** diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 3ee2022928e..fc13130035e 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -183,7 +183,7 @@ int nf_bridge_copy_header(struct sk_buff *skb) int err; int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb); - err = skb_cow(skb, header_size); + err = skb_cow_head(skb, header_size); if (err) return err; |