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 */ 28struct 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 */ 56struct 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 67struct 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 75struct nf_conn; 76 77/* structure for original <-> reply keymap */ 78struct 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 */ 84int 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 */ 88void nf_ct_gre_keymap_destroy(struct nf_conn *ct); 89 90extern void nf_ct_gre_keymap_flush(void); 91extern void nf_nat_need_gre(void); 92 93#endif /* __KERNEL__ */ 94#endif /* _CONNTRACK_PROTO_GRE_H */ 95