1#ifndef __LINUX_GRE_H 2#define __LINUX_GRE_H 3 4#include <linux/skbuff.h> 5 6#define GREPROTO_CISCO 0 7#define GREPROTO_PPTP 1 8#define GREPROTO_MAX 2 9 10struct gre_protocol { 11 int (*handler)(struct sk_buff *skb); 12 void (*err_handler)(struct sk_buff *skb, u32 info); 13}; 14 15int gre_add_protocol(const struct gre_protocol *proto, u8 version); 16int gre_del_protocol(const struct gre_protocol *proto, u8 version); 17 18#endif 19