| #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 recieved by */ |
| /* sender in this session */ |
| }; |
| |
| |
| /* this is part of ip_conntrack */ |
| struct ip_ct_gre { |
| unsigned int stream_timeout; |
| unsigned int timeout; |
| }; |
| |
| #ifdef __KERNEL__ |
| struct ip_conntrack_expect; |
| struct ip_conntrack; |
| |
| /* structure for original <-> reply keymap */ |
| struct ip_ct_gre_keymap { |
| struct list_head list; |
| |
| struct ip_conntrack_tuple tuple; |
| }; |
| |
| /* add new tuple->key_reply pair to keymap */ |
| int ip_ct_gre_keymap_add(struct ip_conntrack *ct, |
| struct ip_conntrack_tuple *t, |
| int reply); |
| |
| /* delete keymap entries */ |
| void ip_ct_gre_keymap_destroy(struct ip_conntrack *ct); |
| |
| |
| /* get pointer to gre key, if present */ |
| static inline __be32 *gre_key(struct gre_hdr *greh) |
| { |
| if (!greh->key) |
| return NULL; |
| if (greh->csum || greh->routing) |
| return (__be32 *) (greh+sizeof(*greh)+4); |
| return (__be32 *) (greh+sizeof(*greh)); |
| } |
| |
| /* get pointer ot gre csum, if present */ |
| static inline __sum16 *gre_csum(struct gre_hdr *greh) |
| { |
| if (!greh->csum) |
| return NULL; |
| return (__sum16 *) (greh+sizeof(*greh)); |
| } |
| |
| #endif /* __KERNEL__ */ |
| |
| #endif /* _CONNTRACK_PROTO_GRE_H */ |