hdlc.h revision 28679 
1/*
2 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
3 *
4 *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
5 *
6 * Redistribution and use in source and binary forms are permitted
7 * provided that the above copyright notice and this paragraph are
8 * duplicated in all such forms and that any documentation,
9 * advertising materials, and other materials related to such
10 * distribution and use acknowledge that the software was developed
11 * by the Internet Initiative Japan.  The name of the
12 * IIJ may not be used to endorse or promote products derived
13 * from this software without specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
17 *
18 * $Id: hdlc.h,v 1.9 1997/06/09 03:27:22 brian Exp $
19 *
20 *	TODO:
21 */
22
23#ifndef _HDLC_H_
24#define _HDLC_H_
25
26/*
27 *  Definition for Async HDLC
28 */
29#define HDLC_SYN 0x7e		/* SYNC character */
30#define HDLC_ESC 0x7d		/* Escape character */
31#define HDLC_XOR 0x20		/* Modifier value */
32
33#define	HDLC_ADDR 0xff
34#define	HDLC_UI	  0x03
35/*
36 *  Definition for HDLC Frame Check Sequence
37 */
38#define INITFCS 0xffff		/* Initial value for FCS computation */
39#define GOODFCS 0xf0b8		/* Good FCS value */
40
41#define	DEF_MRU		1500
42#define	MAX_MRU		2048
43#define	MIN_MRU		296
44
45#define	DEF_MTU		0	/* whatever peer says */
46#define	MAX_MTU		2048
47#define	MIN_MTU		296
48
49/*
50 *  Output priority
51 */
52/* PRI_NORMAL and PRI_FAST have meaning only on the IP queue.
53 * All IP frames have the same priority once they are compressed.
54 * IP frames stay on the IP queue till they can be sent on the
55 * link. They are compressed at that time.
56*/
57#define	PRI_NORMAL	0	/* Normal priority */
58#define	PRI_FAST	1	/* Fast (interractive) */
59#define	PRI_LINK	1	/* Urgent (LQR packets) */
60
61extern u_char EscMap[33];
62
63void HdlcInit(void);
64void HdlcErrorCheck(void);
65void HdlcInput(struct mbuf * bp);
66void HdlcOutput(int pri, u_short proto, struct mbuf * bp);
67void AsyncOutput(int pri, struct mbuf * bp, int proto);
68u_short HdlcFcs(u_short, u_char *, int);
69void DecodePacket(u_short, struct mbuf *);
70
71#endif
72