diff options
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 76 |
1 files changed, 44 insertions, 32 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ad7cc22bd424..c4619a428d9b 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -270,7 +270,6 @@ struct sk_buff { void (*destructor)(struct sk_buff *skb); #ifdef CONFIG_NETFILTER - __u32 nfmark; struct nf_conntrack *nfct; #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) struct sk_buff *nfct_reasm; @@ -278,6 +277,7 @@ struct sk_buff { #ifdef CONFIG_BRIDGE_NETFILTER struct nf_bridge_info *nf_bridge; #endif + __u32 nfmark; #endif /* CONFIG_NETFILTER */ #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ @@ -304,6 +304,7 @@ struct sk_buff { #include <asm/system.h> +extern void kfree_skb(struct sk_buff *skb); extern void __kfree_skb(struct sk_buff *skb); extern struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int fclone); @@ -404,22 +405,6 @@ static inline struct sk_buff *skb_get(struct sk_buff *skb) */ /** - * kfree_skb - free an sk_buff - * @skb: buffer to free - * - * Drop a reference to the buffer and free it if the usage count has - * hit zero. - */ -static inline void kfree_skb(struct sk_buff *skb) -{ - if (likely(atomic_read(&skb->users) == 1)) - smp_rmb(); - else if (likely(!atomic_dec_and_test(&skb->users))) - return; - __kfree_skb(skb); -} - -/** * skb_cloned - is the buffer a clone * @skb: buffer to check * @@ -956,6 +941,25 @@ static inline void skb_reserve(struct sk_buff *skb, int len) #define NET_IP_ALIGN 2 #endif +/* + * The networking layer reserves some headroom in skb data (via + * dev_alloc_skb). This is used to avoid having to reallocate skb data when + * the header has to grow. In the default case, if the header has to grow + * 16 bytes or less we avoid the reallocation. + * + * Unfortunately this headroom changes the DMA alignment of the resulting + * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive + * on some architectures. An architecture can override this value, + * perhaps setting it to a cacheline in size (since that will maintain + * cacheline alignment of the DMA). It must be a power of 2. + * + * Various parts of the networking layer expect at least 16 bytes of + * headroom, you should not reduce this. + */ +#ifndef NET_SKB_PAD +#define NET_SKB_PAD 16 +#endif + extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc); static inline void __skb_trim(struct sk_buff *skb, unsigned int len) @@ -1045,9 +1049,9 @@ static inline void __skb_queue_purge(struct sk_buff_head *list) static inline struct sk_buff *__dev_alloc_skb(unsigned int length, gfp_t gfp_mask) { - struct sk_buff *skb = alloc_skb(length + 16, gfp_mask); + struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); if (likely(skb)) - skb_reserve(skb, 16); + skb_reserve(skb, NET_SKB_PAD); return skb; } #else @@ -1085,13 +1089,15 @@ static inline struct sk_buff *dev_alloc_skb(unsigned int length) */ static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) { - int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb); + int delta = (headroom > NET_SKB_PAD ? headroom : NET_SKB_PAD) - + skb_headroom(skb); if (delta < 0) delta = 0; if (delta || skb_cloned(skb)) - return pskb_expand_head(skb, (delta + 15) & ~15, 0, GFP_ATOMIC); + return pskb_expand_head(skb, (delta + (NET_SKB_PAD-1)) & + ~(NET_SKB_PAD-1), 0, GFP_ATOMIC); return 0; } @@ -1174,12 +1180,14 @@ static inline int skb_linearize(struct sk_buff *skb, gfp_t gfp) */ static inline void skb_postpull_rcsum(struct sk_buff *skb, - const void *start, int len) + const void *start, unsigned int len) { if (skb->ip_summed == CHECKSUM_HW) skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); } +unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); + /** * pskb_trim_rcsum - trim received skb and update checksum * @skb: buffer to trim @@ -1351,16 +1359,6 @@ static inline void nf_conntrack_put_reasm(struct sk_buff *skb) kfree_skb(skb); } #endif -static inline void nf_reset(struct sk_buff *skb) -{ - nf_conntrack_put(skb->nfct); - skb->nfct = NULL; -#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) - nf_conntrack_put_reasm(skb->nfct_reasm); - skb->nfct_reasm = NULL; -#endif -} - #ifdef CONFIG_BRIDGE_NETFILTER static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) { @@ -1373,6 +1371,20 @@ static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) atomic_inc(&nf_bridge->use); } #endif /* CONFIG_BRIDGE_NETFILTER */ +static inline void nf_reset(struct sk_buff *skb) +{ + nf_conntrack_put(skb->nfct); + skb->nfct = NULL; +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + nf_conntrack_put_reasm(skb->nfct_reasm); + skb->nfct_reasm = NULL; +#endif +#ifdef CONFIG_BRIDGE_NETFILTER + nf_bridge_put(skb->nf_bridge); + skb->nf_bridge = NULL; +#endif +} + #else /* CONFIG_NETFILTER */ static inline void nf_reset(struct sk_buff *skb) {} #endif /* CONFIG_NETFILTER */ |