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Commit 52886051 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
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[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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0cfad075

net/core/skbuff.c

+8 −10
Original line number Original line Diff line number Diff line
@@ -472,6 +472,9 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 
#ifdef CONFIG_INET

#ifdef CONFIG_INET

	new->sp		= secpath_get(old->sp);

	new->sp		= secpath_get(old->sp);

#endif

#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->transport_header = old->transport_header;

	new->network_header   = old->network_header;

	new->network_header   = old->network_header;

	new->mac_header	      = old->mac_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);

	skb_reserve(n, headerlen);

	/* Set the tail pointer and length */

	/* Set the tail pointer and length */

	skb_put(n, skb->len);

	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))

	if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))

		BUG();

		BUG();
@@ -589,8 +590,6 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) 
	skb_put(n, skb_headlen(skb));

	skb_put(n, skb_headlen(skb));

	/* Copy the bytes */

	/* Copy the bytes */

	skb_copy_from_linear_data(skb, n->data, n->len);

	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->truesize += skb->data_len;

	n->data_len  = 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->transport_header += off;

	skb->network_header   += off;

	skb->network_header   += off;

	skb->mac_header	      += off;

	skb->mac_header	      += off;

	skb->csum_start       += off;

	skb->cloned   = 0;

	skb->cloned   = 0;

	skb->hdr_len  = 0;

	skb->hdr_len  = 0;

	skb->nohdr    = 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

 *	You must pass %GFP_ATOMIC as the allocation priority if this function

 *	is called from an interrupt.

 *	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,

struct sk_buff *skb_copy_expand(const struct sk_buff *skb,

				int newheadroom, int newtailroom,

				int newheadroom, int newtailroom,
@@ -749,7 +746,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 
				      gfp_mask);

				      gfp_mask);

	int oldheadroom = skb_headroom(skb);

	int oldheadroom = skb_headroom(skb);

	int head_copy_len, head_copy_off;

	int head_copy_len, head_copy_off;

	int off = 0;

	int off;





	if (!n)

	if (!n)

		return NULL;

		return NULL;
@@ -773,12 +770,13 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 




	copy_skb_header(n, skb);

	copy_skb_header(n, skb);





#ifdef NET_SKBUFF_DATA_USES_OFFSET

	off                  = newheadroom - oldheadroom;

	off                  = newheadroom - oldheadroom;

#endif

	n->csum_start       += off;

#ifdef NET_SKBUFF_DATA_USES_OFFSET

	n->transport_header += off;

	n->transport_header += off;

	n->network_header   += off;

	n->network_header   += off;

	n->mac_header	    += off;

	n->mac_header	    += off;

#endif





	return n;

	return n;

}

}