1 #ifndef _CONNTRACK_PROTO_GRE_H
2 #define _CONNTRACK_PROTO_GRE_H
3 #include <asm/byteorder.h>
5 /* GRE PROTOCOL HEADER */
7 /* GRE Version field */
8 #define GRE_VERSION_1701 0x0
9 #define GRE_VERSION_PPTP 0x1
11 /* GRE Protocol field */
12 #define GRE_PROTOCOL_PPTP 0x880B
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
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)
27 /* GRE is a mess: Four different standards */
29 #if defined(__LITTLE_ENDIAN_BITFIELD)
39 #elif defined(__BIG_ENDIAN_BITFIELD)
50 #error "Adjust your <asm/byteorder.h> defines"
55 /* modified GRE header for 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 received by */
64 /* sender in this session */
68 unsigned int stream_timeout;
73 #include <net/netfilter/nf_conntrack_tuple.h>
77 /* structure for original <-> reply keymap */
78 struct nf_ct_gre_keymap {
79 struct list_head list;
80 struct nf_conntrack_tuple tuple;
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);
87 /* delete keymap entries */
88 void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
90 extern void nf_ct_gre_keymap_flush(struct net *net);
91 extern void nf_nat_need_gre(void);
93 #endif /* __KERNEL__ */
94 #endif /* _CONNTRACK_PROTO_GRE_H */