From 52886051ffdc087a4f7f11540395fd64040101ad Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 16 Sep 2007 16:32:11 -0700 Subject: [PATCH] [SKBUFF]: Fix up csum_start when head room changes Thanks for noticing the bug where csum_start is not updated when the head room changes. This patch fixes that. It also moves the csum/ip_summed copying into copy_skb_header so that skb_copy_expand gets it too. I've checked its callers and no one should be upset by this. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/skbuff.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 35021eb3ed..944189d963 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -472,6 +472,9 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) #ifdef CONFIG_INET new->sp = secpath_get(old->sp); #endif + new->csum_start = old->csum_start; + new->csum_offset = old->csum_offset; + new->ip_summed = old->ip_summed; new->transport_header = old->transport_header; new->network_header = old->network_header; new->mac_header = old->mac_header; @@ -545,8 +548,6 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) skb_reserve(n, headerlen); /* Set the tail pointer and length */ skb_put(n, skb->len); - n->csum = skb->csum; - n->ip_summed = skb->ip_summed; if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) BUG(); @@ -589,8 +590,6 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) skb_put(n, skb_headlen(skb)); /* Copy the bytes */ skb_copy_from_linear_data(skb, n->data, n->len); - n->csum = skb->csum; - n->ip_summed = skb->ip_summed; n->truesize += skb->data_len; n->data_len = skb->data_len; @@ -686,6 +685,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, skb->transport_header += off; skb->network_header += off; skb->mac_header += off; + skb->csum_start += off; skb->cloned = 0; skb->hdr_len = 0; skb->nohdr = 0; @@ -734,9 +734,6 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) * * You must pass %GFP_ATOMIC as the allocation priority if this function * is called from an interrupt. - * - * BUG ALERT: ip_summed is not copied. Why does this work? Is it used - * only by netfilter in the cases when checksum is recalculated? --ANK */ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, int newtailroom, @@ -749,7 +746,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, gfp_mask); int oldheadroom = skb_headroom(skb); int head_copy_len, head_copy_off; - int off = 0; + int off; if (!n) return NULL; @@ -773,12 +770,13 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, copy_skb_header(n, skb); -#ifdef NET_SKBUFF_DATA_USES_OFFSET off = newheadroom - oldheadroom; -#endif + n->csum_start += off; +#ifdef NET_SKBUFF_DATA_USES_OFFSET n->transport_header += off; n->network_header += off; n->mac_header += off; +#endif return n; } -- 2.39.5