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 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 gre_csum)
  41 {
  42         return iptunnel_handle_offloads(skb, gre_csum, SKB_GSO_GRE);
  43 }
  44
  45
  46 static inline int ip_gre_calc_hlen(__be16 o_flags)
  47 {
  48         int addend = 4;
  49
  50         if (o_flags&TUNNEL_CSUM)
  51                 addend += 4;
  52         if (o_flags&TUNNEL_KEY)
  53                 addend += 4;
  54         if (o_flags&TUNNEL_SEQ)
  55                 addend += 4;
  56         return addend;
  57 }
  58
  59 static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
  60 {
  61         __be16 tflags = 0;
  62
  63         if (flags & GRE_CSUM)
  64                 tflags |= TUNNEL_CSUM;
  65         if (flags & GRE_ROUTING)
  66                 tflags |= TUNNEL_ROUTING;
  67         if (flags & GRE_KEY)
  68                 tflags |= TUNNEL_KEY;
  69         if (flags & GRE_SEQ)
  70                 tflags |= TUNNEL_SEQ;
  71         if (flags & GRE_STRICT)
  72                 tflags |= TUNNEL_STRICT;
  73         if (flags & GRE_REC)
  74                 tflags |= TUNNEL_REC;
  75         if (flags & GRE_VERSION)
  76                 tflags |= TUNNEL_VERSION;
  77
  78         return tflags;
  79 }
  80
  81 static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
  82 {
  83         __be16 flags = 0;
  84
  85         if (tflags & TUNNEL_CSUM)
  86                 flags |= GRE_CSUM;
  87         if (tflags & TUNNEL_ROUTING)
  88                 flags |= GRE_ROUTING;
  89         if (tflags & TUNNEL_KEY)
  90                 flags |= GRE_KEY;
  91         if (tflags & TUNNEL_SEQ)
  92                 flags |= GRE_SEQ;
  93         if (tflags & TUNNEL_STRICT)
  94                 flags |= GRE_STRICT;
  95         if (tflags & TUNNEL_REC)
  96                 flags |= GRE_REC;
  97         if (tflags & TUNNEL_VERSION)
  98                 flags |= GRE_VERSION;
  99
 100         return flags;
 101 }
 102
 103 #endif