xref: /freebsd/usr.sbin/ppp/hdlc.h (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
5  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
6  *                           Internet Initiative Japan, Inc (IIJ)
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 /*
34  *  Definition for Async HDLC
35  */
36 #define HDLC_SYN 0x7e		/* SYNC character */
37 #define HDLC_ESC 0x7d		/* Escape character */
38 #define HDLC_XOR 0x20		/* Modifier value */
39 
40 #define	HDLC_ADDR 0xff
41 #define	HDLC_UI	  0x03
42 /*
43  *  Definition for HDLC Frame Check Sequence
44  */
45 #define INITFCS 0xffff		/* Initial value for FCS computation */
46 #define GOODFCS 0xf0b8		/* Good FCS value */
47 
48 #define	DEF_MRU		1500
49 #define	MAX_MRU		2048
50 #define	MIN_MRU		296
51 
52 #define	DEF_MTU		0	/* whatever peer says */
53 #define	MAX_MTU		2048
54 #define	MIN_MTU		296
55 
56 struct physical;
57 struct link;
58 struct lcp;
59 struct bundle;
60 struct mbuf;
61 struct cmdargs;
62 
63 struct hdlc {
64   struct pppTimer ReportTimer;
65 
66   struct {
67     int badfcs;
68     int badaddr;
69     int badcommand;
70     int unknownproto;
71   } laststats, stats;
72 
73   struct {
74     struct lcp *owner;			/* parent LCP */
75     struct pppTimer timer;		/* When to send */
76     int method;				/* bit-mask for LQM_* from lqr.h */
77 
78     u_int32_t ifOutUniPackets;		/* Packets sent by me */
79     u_int32_t ifOutOctets;		/* Octets sent by me */
80     u_int32_t ifInUniPackets;		/* Packets received from peer */
81     u_int32_t ifInDiscards;		/* Discards */
82     u_int32_t ifInErrors;		/* Errors */
83     u_int32_t ifInOctets;		/* Octets received from peer (unused) */
84 
85     struct {
86       u_int32_t InGoodOctets;		/* Good octets received from peer */
87       u_int32_t OutLQRs;		/* LQRs sent by me */
88       u_int32_t InLQRs;			/* LQRs received from peer */
89 
90       struct lqrsavedata Save;		/* Our last LQR */
91       struct lqrsavedata prevSave;	/* Our last-but-one LQR (analysis) */
92 
93       struct lqrdata peer;		/* Last LQR from peer */
94       int peer_timeout;			/* peers max lqr timeout */
95       int resent;			/* Resent last packet `resent' times */
96     } lqr;
97 
98     struct {
99       u_int32_t seq_sent;		/* last echo sent */
100       u_int32_t seq_recv;		/* last echo received */
101     } echo;
102   } lqm;
103 };
104 
105 
106 extern void hdlc_Init(struct hdlc *, struct lcp *);
107 extern void hdlc_StartTimer(struct hdlc *);
108 extern void hdlc_StopTimer(struct hdlc *);
109 extern int hdlc_ReportStatus(struct cmdargs const *);
110 extern const char *hdlc_Protocol2Nam(u_short);
111 extern void hdlc_DecodePacket(struct bundle *, u_short, struct mbuf *,
112                               struct link *);
113 
114 extern u_short hdlc_Fcs(u_char *, size_t);
115 extern int hdlc_Detect(u_char const **, unsigned, int);
116 #define hdlc_WrapperOctets() (2)
117 
118 extern struct layer hdlclayer;
119