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#ifndef _CONNTRACK_PROTO_GRE_H
#define _CONNTRACK_PROTO_GRE_H
#include <asm/byteorder.h>
/* GRE PROTOCOL HEADER */
/* GRE Version field */
#define GRE_VERSION_1701 0x0
#define GRE_VERSION_PPTP 0x1
/* GRE Protocol field */
#define GRE_PROTOCOL_PPTP 0x880B
/* GRE Flags */
#define GRE_FLAG_C 0x80
#define GRE_FLAG_R 0x40
#define GRE_FLAG_K 0x20
#define GRE_FLAG_S 0x10
#define GRE_FLAG_A 0x80
#define GRE_IS_C(f) ((f)&GRE_FLAG_C)
#define GRE_IS_R(f) ((f)&GRE_FLAG_R)
#define GRE_IS_K(f) ((f)&GRE_FLAG_K)
#define GRE_IS_S(f) ((f)&GRE_FLAG_S)
#define GRE_IS_A(f) ((f)&GRE_FLAG_A)
/* GRE is a mess: Four different standards */
struct gre_hdr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u16 rec:3,
srr:1,
seq:1,
key:1,
routing:1,
csum:1,
version:3,
reserved:4,
ack:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u16 csum:1,
routing:1,
key:1,
seq:1,
srr:1,
rec:3,
ack:1,
reserved:4,
version:3;
#else
#error "Adjust your <asm/byteorder.h> defines"
#endif
__be16 protocol;
};
/* modified GRE header for PPTP */
struct gre_hdr_pptp {
__u8 flags; /* bitfield */
__u8 version; /* should be GRE_VERSION_PPTP */
__be16 protocol; /* should be GRE_PROTOCOL_PPTP */
__be16 payload_len; /* size of ppp payload, not inc. gre header */
__be16 call_id; /* peer's call_id for this session */
__be32 seq; /* sequence number. Present if S==1 */
__be32 ack; /* seq number of highest packet received by */
/* sender in this session */
};
struct nf_ct_gre {
unsigned int stream_timeout;
unsigned int timeout;
};
#ifdef __KERNEL__
#include <net/netfilter/nf_conntrack_tuple.h>
struct nf_conn;
/* structure for original <-> reply keymap */
struct nf_ct_gre_keymap {
struct list_head list;
struct nf_conntrack_tuple tuple;
};
/* add new tuple->key_reply pair to keymap */
int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
struct nf_conntrack_tuple *t);
/* delete keymap entries */
void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
extern void nf_ct_gre_keymap_flush(struct net *net);
extern void nf_nat_need_gre(void);
#endif /* __KERNEL__ */
#endif /* _CONNTRACK_PROTO_GRE_H */
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