include/net/gre.h

   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 int gre_offload_init(void);
  37 void gre_offload_exit(void);
  38
  39 void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
  40                       int hdr_len);
  41 struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum);
  42
  43 static inline int ip_gre_calc_hlen(__be16 o_flags)
  44 {
  45         int addend = 4;
  46
  47         if (o_flags&TUNNEL_CSUM)
  48                 addend += 4;
  49         if (o_flags&TUNNEL_KEY)
  50                 addend += 4;
  51         if (o_flags&TUNNEL_SEQ)
  52                 addend += 4;
  53         return addend;
  54 }
  55
  56 static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
  57 {
  58         __be16 tflags = 0;
  59
  60         if (flags & GRE_CSUM)
  61                 tflags |= TUNNEL_CSUM;
  62         if (flags & GRE_ROUTING)
  63                 tflags |= TUNNEL_ROUTING;
  64         if (flags & GRE_KEY)
  65                 tflags |= TUNNEL_KEY;
  66         if (flags & GRE_SEQ)
  67                 tflags |= TUNNEL_SEQ;
  68         if (flags & GRE_STRICT)
  69                 tflags |= TUNNEL_STRICT;
  70         if (flags & GRE_REC)
  71                 tflags |= TUNNEL_REC;
  72         if (flags & GRE_VERSION)
  73                 tflags |= TUNNEL_VERSION;
  74
  75         return tflags;
  76 }
  77
  78 static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
  79 {
  80         __be16 flags = 0;
  81
  82         if (tflags & TUNNEL_CSUM)
  83                 flags |= GRE_CSUM;
  84         if (tflags & TUNNEL_ROUTING)
  85                 flags |= GRE_ROUTING;
  86         if (tflags & TUNNEL_KEY)
  87                 flags |= GRE_KEY;
  88         if (tflags & TUNNEL_SEQ)
  89                 flags |= GRE_SEQ;
  90         if (tflags & TUNNEL_STRICT)
  91                 flags |= GRE_STRICT;
  92         if (tflags & TUNNEL_REC)
  93                 flags |= GRE_REC;
  94         if (tflags & TUNNEL_VERSION)
  95                 flags |= GRE_VERSION;
  96
  97         return flags;
  98 }
  99
 100 #endif