[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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 35021eb..944189d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -472,6 +472,9 @@
#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 @@
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 @@
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 @@
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 @@
*
* 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 @@
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 @@
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;
}