: Fix missing offset adjustment in skb_copy_expand

SK_BUFF Patrick McHardy 2 participants 3 messages Apr 8, 2007 – Apr 11, 2007

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Patrick McHardy

author

2007-04-08 01:47 UTC #0 lore raw

[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

skb_copy_expand changes the headroom, so it needs to adjust the header offsets by the difference between the old and the new value.

Signed-off-by Patrick McHardy <[email protected]>

---
commit 9cb76fae709a9303777286998baa457b0730a225
tree 2ea619c7daf9c5e6829dad6d502386eb9c922700
parent fb98b03719ad23840ca005edbba3c86ef1e3282c
author Patrick McHardy <[email protected]> Sun, 08 Apr 2007 03:36:49 +0200 committer Patrick McHardy <[email protected]> Sun, 08 Apr 2007 03:36:49 +0200

 net/core/skbuff.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

net/core/skbuff.c +10 -1

index 5c9ee94..f2cffd4 100644
@@ -794,7 +794,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 	 */
 	struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
 				      gfp_mask);
+	int oldheadroom = skb_headroom(skb);
 	int head_copy_len, head_copy_off;
+	int off = 0;
 
 	if (!n)
 		return NULL;

@@ -804,7 +806,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 	/* Set the tail pointer and length */
 	skb_put(n, skb->len);
 
-	head_copy_len = skb_headroom(skb);
+	head_copy_len = oldheadroom;
 	head_copy_off = 0;
 	if (newheadroom <= head_copy_len)
 		head_copy_len = newheadroom;

@@ -818,6 +820,13 @@ 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->transport_header += off;
+	n->network_header   += off;
+	n->mac_header	    += off;
+
 	return n;
 }

Patrick McHardy

author

2007-04-11 00:43 UTC #1 lore raw

Hi Dave,

Quoted 4 lines · Patrick McHardy

[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand
skb_copy_expand changes the headroom, so it needs to adjust the header offsets by the difference between the old and the new value.

it seems like you missed this one. Attached again for your convenience.

[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

skb_copy_expand changes the headroom, so it needs to adjust the header offsets by the difference between the old and the new value.

Signed-off-by Patrick McHardy <[email protected]>

 net/core/skbuff.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

net/core/skbuff.c +10 -1

index 5c9ee94..f2cffd4 100644
@@ -794,7 +794,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 	 */
 	struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
 				      gfp_mask);
+	int oldheadroom = skb_headroom(skb);
 	int head_copy_len, head_copy_off;
+	int off = 0;
 
 	if (!n)
 		return NULL;

@@ -804,7 +806,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 	/* Set the tail pointer and length */
 	skb_put(n, skb->len);
 
-	head_copy_len = skb_headroom(skb);
+	head_copy_len = oldheadroom;
 	head_copy_off = 0;
 	if (newheadroom <= head_copy_len)
 		head_copy_len = newheadroom;

@@ -818,6 +820,13 @@ 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->transport_header += off;
+	n->network_header   += off;
+	n->mac_header	    += off;
+
 	return n;
 }

David Miller

maintainer

2007-04-11 01:31 UTC #2 lore raw

From: Patrick McHardy <[email protected]>
Date: Wed, 11 Apr 2007 02:42:59 +0200

Quoted 10 lines

Hi Dave,
Quoted 4 lines · Patrick McHardy
[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand
skb_copy_expand changes the headroom, so it needs to adjust the header offsets by the difference between the old and the new value.
it seems like you missed this one. Attached again for your convenience.

Thanks a lot Patrick, applied.

I know what happened, I applied the pskb_copy_expand() patch and then deleted this one by accident since the subject lines looked so similar and I figured I was just getting a second copy of the same patch :-)

Thanks again!