LXR linux/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
  12struct gre_protocol {
  13        int  (*handler)(struct sk_buff *skb);
  14        void (*err_handler)(struct sk_buff *skb, u32 info);
  15};
  16
  17struct gre_base_hdr {
  18        __be16 flags;
  19        __be16 protocol;
  20};
  21#define GRE_HEADER_SECTION 4
  22
  23int gre_add_protocol(const struct gre_protocol *proto, u8 version);
  24int gre_del_protocol(const struct gre_protocol *proto, u8 version);
  25
  26struct 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
  33int gre_cisco_register(struct gre_cisco_protocol *proto);
  34int gre_cisco_unregister(struct gre_cisco_protocol *proto);
  35
  36void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
  37                      int hdr_len);
  38
  39static 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
  47static 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
  60static 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
  82static 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