datapath: Fix warning building datapath on pre-2.6.24 kernels.

[openvswitch] / datapath / linux-2.6 / compat-2.6 / include / linux / skbuff.h

diff --git a/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h b/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
index 666ef85046360e89dfcd64b7179f4f311d66eba0..dd9bfa37272d5e0f1eaef9476c683689776447e5 100644 (file)
--- a/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
+++ b/datapath/linux-2.6/compat-2.6/include/linux/skbuff.h
@@ -5,6 +5,17 @@
 
 #include <linux/version.h>
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
+/* In version 2.6.24 the return type of skb_headroom() changed from 'int' to
+ * 'unsigned int'.  We use skb_headroom() as one arm of a min(a,b) invocation
+ * in make_writable() in actions.c, so we need the correct type. */
+#define skb_headroom rpl_skb_headroom
+static inline unsigned int rpl_skb_headroom(const struct sk_buff *skb)
+{
+       return skb->data - skb->head;
+}
+#endif
+
 #ifndef HAVE_SKB_COPY_FROM_LINEAR_DATA_OFFSET
 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
                                                     const int offset, void *to,
@@ -42,7 +53,7 @@ static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
 #define NET_SKB_PAD    16
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+#ifndef HAVE_SKB_COW
 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
                             int cloned)
 {
@@ -63,7 +74,7 @@ static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
 {
        return __skb_cow(skb, headroom, skb_header_cloned(skb));
 }
-#endif  /* linux < 2.6.23 */
+#endif  /* !HAVE_SKB_COW */
 
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)