From: Mark Huang <mlhuang@cs.princeton.edu>
Date: Mon, 10 Jan 2005 19:31:58 +0000 (+0000)
Subject: - backport 2.6.9 addition of skb_header_pointer() macro to support
X-Git-Tag: before-shares_write_debug-merge~4
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=904e3609366f1e3446ce08d9967ef63ddf4f5bf0;p=linux-2.6.git

- backport 2.6.9 addition of skb_header_pointer() macro to support
  pptp-conntrack-nat patch
---

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 111bb7367..5156e432d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1106,6 +1106,20 @@ extern void	       skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
 extern void	       skb_split(struct sk_buff *skb,
 				 struct sk_buff *skb1, const u32 len);
 
+static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
+				       int len, void *buffer)
+{
+	int hlen = skb_headlen(skb);
+
+	if (offset + len <= hlen)
+		return skb->data + offset;
+
+	if (skb_copy_bits(skb, offset, buffer, len) < 0)
+		return NULL;
+
+	return buffer;
+}
+
 extern void skb_init(void);
 extern void skb_add_mtu(int mtu);