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 received 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(struct net *net); 91 extern void nf_nat_need_gre(void); 92 93 #endif /* __KERNEL__ */ 94 #endif /* _CONNTRACK_PROTO_GRE_H */ 95