[PATCH] Provide compatibility for older kernels in a separate file

Remove all Linux 2.6.21 compatibility from the driver - it shouldn't be
there for kernel submission.  Move all compatibility code to a separate
file compat.h.  Include it forcedly with the "-include" option.  Add
a makefile option to disable config.h inclusion.

Provide compatibility as far back as Linux 2.6.19 - it's not really hard
once the infrastructure is in place.

Signed-off-by: Pavel Roskin <proski@gnu.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/compat.h b/compat.h
new file mode 100644
index 0000000..32a66c7
--- /dev/null
+++ b/compat.h
@@ -0,0 +1,43 @@
+/* Compatibility layer for older kernels */
+
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
+#include <linux/skbuff.h>
+static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
+{
+	return skb->mac.raw;
+}
+
+static inline void skb_reset_mac_header(struct sk_buff *skb)
+{
+	skb->mac.raw = skb->data;
+}
+
+static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
+{
+	skb->mac.raw = skb->data + offset;
+}
+
+static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
+{
+	return skb->end;
+}
+
+static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
+{
+	return skb->tail;
+}
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
+#undef INIT_WORK
+#define INIT_WORK(_work, _func)						\
+	do {								\
+		INIT_LIST_HEAD(&(_work)->entry);			\
+		(_work)->pending = 0;					\
+		PREPARE_WORK((_work), (void (*)(void *))(_func),	\
+			     (void *)(_work));				\
+		init_timer(&(_work)->timer);				\
+	} while (0)
+#endif