release/src-rt-6.x/linux/linux-2.6/include/linux/netfilter/nf_conntrack_proto_gre.h

   1 #ifndef _CONNTRACK_PROTO_GRE_H
   2 #define _CONNTRACK_PROTO_GRE_H
   3 #include <asm/byteorder.h>
   4
   5 /* GRE PROTOCOL HEADER */
   6
   7 /* GRE Version field */
   8 #define GRE_VERSION_1701        0x0
   9 #define GRE_VERSION_PPTP        0x1
  10
  11 /* GRE Protocol field */
  12 #define GRE_PROTOCOL_PPTP       0x880B
  13
  14 /* GRE Flags */
  15 #define GRE_FLAG_C              0x80
  16 #define GRE_FLAG_R              0x40
  17 #define GRE_FLAG_K              0x20
  18 #define GRE_FLAG_S              0x10
  19 #define GRE_FLAG_A              0x80
  20
  21 #define GRE_IS_C(f)     ((f)&GRE_FLAG_C)
  22 #define GRE_IS_R(f)     ((f)&GRE_FLAG_R)
  23 #define GRE_IS_K(f)     ((f)&GRE_FLAG_K)
  24 #define GRE_IS_S(f)     ((f)&GRE_FLAG_S)
  25 #define GRE_IS_A(f)     ((f)&GRE_FLAG_A)
  26
  27 /* GRE is a mess: Four different standards */
  28 struct gre_hdr {
  29 #if defined(__LITTLE_ENDIAN_BITFIELD)
  30         __u16   rec:3,
  31                 srr:1,
  32                 seq:1,
  33                 key:1,
  34                 routing:1,
  35                 csum:1,
  36                 version:3,
  37                 reserved:4,
  38                 ack:1;
  39 #elif defined(__BIG_ENDIAN_BITFIELD)
  40         __u16   csum:1,
  41                 routing:1,
  42                 key:1,
  43                 seq:1,
  44                 srr:1,
  45                 rec:3,
  46                 ack:1,
  47                 reserved:4,
  48                 version:3;
  49 #else
  50 #error "Adjust your <asm/byteorder.h> defines"
  51 #endif
  52         __be16  protocol;
  53 };
  54
  55 /* modified GRE header for PPTP */
  56 struct gre_hdr_pptp {
  57         __u8   flags;           /* bitfield */
  58         __u8   version;         /* should be GRE_VERSION_PPTP */
  59         __be16 protocol;        /* should be GRE_PROTOCOL_PPTP */
  60         __be16 payload_len;     /* size of ppp payload, not inc. gre header */
  61         __be16 call_id;         /* peer's call_id for this session */
  62         __be32 seq;             /* sequence number.  Present if S==1 */
  63         __be32 ack;             /* seq number of highest packet recieved by */
  64                                 /*  sender in this session */
  65 };
  66
  67 struct nf_ct_gre {
  68         unsigned int stream_timeout;
  69         unsigned int timeout;
  70 };
  71
  72 #ifdef __KERNEL__
  73 #include <net/netfilter/nf_conntrack_tuple.h>
  74
  75 struct nf_conn;
  76
  77 /* structure for original <-> reply keymap */
  78 struct nf_ct_gre_keymap {
  79         struct list_head list;
  80         struct nf_conntrack_tuple tuple;
  81 };
  82
  83 /* add new tuple->key_reply pair to keymap */
  84 int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
  85                          struct nf_conntrack_tuple *t);
  86
  87 /* delete keymap entries */
  88 void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
  89
  90 extern void nf_ct_gre_keymap_flush(void);
  91 extern void nf_nat_need_gre(void);
  92
  93 #endif /* __KERNEL__ */
  94 #endif /* _CONNTRACK_PROTO_GRE_H */