diff options
Diffstat (limited to 'include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h')
-rw-r--r-- | include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h new file mode 100644 index 00000000000..8d090ef82f5 --- /dev/null +++ b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h @@ -0,0 +1,114 @@ +#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 + __u16 protocol; +}; + +/* modified GRE header for PPTP */ +struct gre_hdr_pptp { + __u8 flags; /* bitfield */ + __u8 version; /* should be GRE_VERSION_PPTP */ + __u16 protocol; /* should be GRE_PROTOCOL_PPTP */ + __u16 payload_len; /* size of ppp payload, not inc. gre header */ + __u16 call_id; /* peer's call_id for this session */ + __u32 seq; /* sequence number. Present if S==1 */ + __u32 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 u_int32_t *gre_key(struct gre_hdr *greh) +{ + if (!greh->key) + return NULL; + if (greh->csum || greh->routing) + return (u_int32_t *) (greh+sizeof(*greh)+4); + return (u_int32_t *) (greh+sizeof(*greh)); +} + +/* get pointer ot gre csum, if present */ +static inline u_int16_t *gre_csum(struct gre_hdr *greh) +{ + if (!greh->csum) + return NULL; + return (u_int16_t *) (greh+sizeof(*greh)); +} + +#endif /* __KERNEL__ */ + +#endif /* _CONNTRACK_PROTO_GRE_H */ |