+diff -Nur openswan-2.4.4/linux/include/openswan.h openswan-2.4.4.patched/linux/include/openswan.h
+--- openswan-2.4.4/linux/include/openswan.h 2005-04-14 22:21:51.000000000 +0200
++++ openswan-2.4.4.patched/linux/include/openswan.h 2005-12-23 20:31:58.248159750 +0100
+@@ -78,6 +78,10 @@
+ #define NET_21
+ #endif
+
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
++#define KERNEL_2615
++#endif
++
+ #ifndef IPPROTO_COMP
+ # define IPPROTO_COMP 108
+ #endif /* !IPPROTO_COMP */