4 #define GRE_FLAG_CKSUM htons(0x8000) /* Checksum Present */
5 #define GRE_FLAG_ROUTE htons(0x4000) /* Routing Present */
6 #define GRE_FLAG_KEY htons(0x2000) /* Key Present */
7 #define GRE_FLAG_SEQ htons(0x1000) /* Sequence Present */
8 #define GRE_FLAG_SSR htons(0x0800) /* Strict Source Route */
9 #define GRE_FLAG_RECUR htons(0x0700) /* Recursion Control */
10 #define GRE_FLAG_ACK htons(0x0080) /* Acknowledgement Present (PPTP only) */
11 #define GRE_FLAG_FLAGS htons(0x0078) /* Additional Flags */
12 #define GRE_FLAG_VER htons(0x0007) /* Version Number */
13 #define GRE_VER_GRE htons(0x0000) /* GRE version 0 (RFC1701 GRE) */
14 #define GRE_VER_PPTP htons(0x0001) /* Enhanced GRE (RFC2637 PPTP) */
17 u_int16_t flags_ver; /* See above */
18 u_int16_t protocol; /* Ethernet protocol type */
19 u_int16_t cksum; /* present if (flags_ver & GRE_FLAG_CKSUM) */
20 u_int16_t reserved1; /* present if (flags_ver & GRE_FLAG_CKSUM) */
21 u_int32_t key; /* present if (flags_ver & GRE_FLAG_KEY) */
22 u_int32_t seq; /* present if (flags_ver & GRE_FLAG_SEQ) */
26 u_int16_t flags_ver; /* See above */
27 u_int16_t protocol; /* Ethernet protocol type */
28 u_int16_t payload_len; /* following payload length (not including this header) */
29 u_int16_t call_id; /* peer call ID */
30 u_int32_t seq; /* present if (flags_ver & GRE_FLAG_SEQ) */
31 u_int32_t ack; /* present if (flags_ver & GRE_FLAG_ACK) */
34 #endif /* _ULOGD_GRE_H_ */