#ifndef _NET_PPTP_H
#define _NET_PPTP_H

#define PPP_LCP_ECHOREQ 0x09
#define PPP_LCP_ECHOREP 0x0A
#define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)

#define MISSING_WINDOW 20
#define WRAPPED(curseq, lastseq)\
	((((curseq) & 0xffffff00) == 0) &&\
	(((lastseq) & 0xffffff00) == 0xffffff00))

#define PPTP_GRE_PROTO  0x880B
#define PPTP_GRE_VER    0x1

#define PPTP_GRE_FLAG_C 0x80
#define PPTP_GRE_FLAG_R 0x40
#define PPTP_GRE_FLAG_K 0x20
#define PPTP_GRE_FLAG_S 0x10
#define PPTP_GRE_FLAG_A 0x80

#define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C)
#define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R)
#define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K)
#define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S)
#define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A)

#define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header))
struct pptp_gre_header {
	u8  flags;
	u8  ver;
	__be16 protocol;
	__be16 payload_len;
	__be16 call_id;
	__be32 seq;
	__be32 ack;
} __packed;


#endif