[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

[Patrick McHardy]

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[-- Attachment #2: 02.diff --]
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[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 <kaber@trash.net>

---
commit 9cb76fae709a9303777286998baa457b0730a225
tree 2ea619c7daf9c5e6829dad6d502386eb9c922700
parent fb98b03719ad23840ca005edbba3c86ef1e3282c
author Patrick McHardy <kaber@trash.net> Sun, 08 Apr 2007 03:36:49 +0200
committer Patrick McHardy <kaber@trash.net> Sun, 08 Apr 2007 03:36:49 +0200

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

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 5c9ee94..f2cffd4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -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;
 }
 

Re: [SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

[Patrick McHardy]

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Hi Dave,

Patrick McHardy wrote:
> [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.



[-- Attachment #2: 02.diff --]
[-- Type: text/x-diff, Size: 1671 bytes --]

[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 <kaber@trash.net>

---
commit 9cb76fae709a9303777286998baa457b0730a225
tree 2ea619c7daf9c5e6829dad6d502386eb9c922700
parent fb98b03719ad23840ca005edbba3c86ef1e3282c
author Patrick McHardy <kaber@trash.net> Sun, 08 Apr 2007 03:36:49 +0200
committer Patrick McHardy <kaber@trash.net> Sun, 08 Apr 2007 03:36:49 +0200

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

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 5c9ee94..f2cffd4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -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;
 }
 

Re: [SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

[David Miller]

From: Patrick McHardy <kaber@trash.net>
Date: Wed, 11 Apr 2007 02:42:59 +0200

> Hi Dave,
> 
> Patrick McHardy wrote:
> > [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!