From 6602cebb5bcac1fccf2850541f8bf9fcc8c86dee Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 1 Sep 2010 05:25:10 +0000 Subject: [PATCH] net: skbuff.c cleanup (skb->data - skb->head) can be changed by skb_headroom(skb) Remove some uses of NET_SKBUFF_DATA_USES_OFFSET, using (skb_end_pointer(skb) - skb->head) or (skb_tail_pointer(skb) - skb->head) : compiler does the right thing, and this is more readable for us ;) (struct skb_shared_info *) casts in pskb_expand_head() to help memcpy() to use aligned moves. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/skbuff.c | 47 +++++++++++++++-------------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e2535fb4985..231dff0dde2 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -685,16 +685,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) { - int headerlen = skb->data - skb->head; - /* - * Allocate the copy buffer - */ - struct sk_buff *n; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - n = alloc_skb(skb->end + skb->data_len, gfp_mask); -#else - n = alloc_skb(skb->end - skb->head + skb->data_len, gfp_mask); -#endif + int headerlen = skb_headroom(skb); + unsigned int size = (skb_end_pointer(skb) - skb->head) + skb->data_len; + struct sk_buff *n = alloc_skb(size, gfp_mask); + if (!n) return NULL; @@ -726,20 +720,14 @@ EXPORT_SYMBOL(skb_copy); struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) { - /* - * Allocate the copy buffer - */ - struct sk_buff *n; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - n = alloc_skb(skb->end, gfp_mask); -#else - n = alloc_skb(skb->end - skb->head, gfp_mask); -#endif + unsigned int size = skb_end_pointer(skb) - skb->head; + struct sk_buff *n = alloc_skb(size, gfp_mask); + if (!n) goto out; /* Set the data pointer */ - skb_reserve(n, skb->data - skb->head); + skb_reserve(n, skb_headroom(skb)); /* Set the tail pointer and length */ skb_put(n, skb_headlen(skb)); /* Copy the bytes */ @@ -791,11 +779,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, { int i; u8 *data; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - int size = nhead + skb->end + ntail; -#else - int size = nhead + (skb->end - skb->head) + ntail; -#endif + int size = nhead + (skb_end_pointer(skb) - skb->head) + ntail; long off; BUG_ON(nhead < 0); @@ -810,13 +794,12 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, goto nodata; /* Copy only real data... and, alas, header. This should be - * optimized for the cases when header is void. */ -#ifdef NET_SKBUFF_DATA_USES_OFFSET - memcpy(data + nhead, skb->head, skb->tail); -#else - memcpy(data + nhead, skb->head, skb->tail - skb->head); -#endif - memcpy(data + size, skb_end_pointer(skb), + * optimized for the cases when header is void. + */ + memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head); + + memcpy((struct skb_shared_info *)(data + size), + skb_shinfo(skb), offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags])); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) -- 2.20.1