1 #ifndef __LINUX_GRE_H 2 #define __LINUX_GRE_H 3 4 #include <linux/skbuff.h> 5 #include <net/ip_tunnels.h> 6 7 #define GREPROTO_CISCO 0 8 #define GREPROTO_PPTP 1 9 #define GREPROTO_MAX 2 10 #define GRE_IP_PROTO_MAX 2 11 12 struct gre_protocol { 13 int (*handler)(struct sk_buff *skb); 14 void (*err_handler)(struct sk_buff *skb, u32 info); 15 }; 16 17 struct gre_base_hdr { 18 __be16 flags; 19 __be16 protocol; 20 }; 21 #define GRE_HEADER_SECTION 4 22 23 int gre_add_protocol(const struct gre_protocol *proto, u8 version); 24 int gre_del_protocol(const struct gre_protocol *proto, u8 version); 25 26 struct gre_cisco_protocol { 27 int (*handler)(struct sk_buff *skb, const struct tnl_ptk_info *tpi); 28 int (*err_handler)(struct sk_buff *skb, u32 info, 29 const struct tnl_ptk_info *tpi); 30 u8 priority; 31 }; 32 33 int gre_cisco_register(struct gre_cisco_protocol *proto); 34 int gre_cisco_unregister(struct gre_cisco_protocol *proto); 35 36 void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 37 int hdr_len); 38 39 static inline struct sk_buff *gre_handle_offloads(struct sk_buff *skb, 40 bool csum) 41 { 42 return iptunnel_handle_offloads(skb, csum, 43 csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 44 } 45 46 47 static inline int ip_gre_calc_hlen(__be16 o_flags) 48 { 49 int addend = 4; 50 51 if (o_flags&TUNNEL_CSUM) 52 addend += 4; 53 if (o_flags&TUNNEL_KEY) 54 addend += 4; 55 if (o_flags&TUNNEL_SEQ) 56 addend += 4; 57 return addend; 58 } 59 60 static inline __be16 gre_flags_to_tnl_flags(__be16 flags) 61 { 62 __be16 tflags = 0; 63 64 if (flags & GRE_CSUM) 65 tflags |= TUNNEL_CSUM; 66 if (flags & GRE_ROUTING) 67 tflags |= TUNNEL_ROUTING; 68 if (flags & GRE_KEY) 69 tflags |= TUNNEL_KEY; 70 if (flags & GRE_SEQ) 71 tflags |= TUNNEL_SEQ; 72 if (flags & GRE_STRICT) 73 tflags |= TUNNEL_STRICT; 74 if (flags & GRE_REC) 75 tflags |= TUNNEL_REC; 76 if (flags & GRE_VERSION) 77 tflags |= TUNNEL_VERSION; 78 79 return tflags; 80 } 81 82 static inline __be16 tnl_flags_to_gre_flags(__be16 tflags) 83 { 84 __be16 flags = 0; 85 86 if (tflags & TUNNEL_CSUM) 87 flags |= GRE_CSUM; 88 if (tflags & TUNNEL_ROUTING) 89 flags |= GRE_ROUTING; 90 if (tflags & TUNNEL_KEY) 91 flags |= GRE_KEY; 92 if (tflags & TUNNEL_SEQ) 93 flags |= GRE_SEQ; 94 if (tflags & TUNNEL_STRICT) 95 flags |= GRE_STRICT; 96 if (tflags & TUNNEL_REC) 97 flags |= GRE_REC; 98 if (tflags & TUNNEL_VERSION) 99 flags |= GRE_VERSION; 100 101 return flags; 102 } 103 104 #endif 105