1/*	$OpenBSD: fsm.h,v 1.5 2002/07/01 19:31:37 deraadt Exp $	*/
2
3/*
4 * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
5 *
6 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. The name "Carnegie Mellon University" must not be used to
21 *    endorse or promote products derived from this software without
22 *    prior written permission. For permission or any legal
23 *    details, please contact
24 *      Office of Technology Transfer
25 *      Carnegie Mellon University
26 *      5000 Forbes Avenue
27 *      Pittsburgh, PA  15213-3890
28 *      (412) 268-4387, fax: (412) 268-7395
29 *      tech-transfer@andrew.cmu.edu
30 *
31 * 4. Redistributions of any form whatsoever must retain the following
32 *    acknowledgment:
33 *    "This product includes software developed by Computing Services
34 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35 *
36 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43 */
44
45/*
46 * Packet header = Code, id, length.
47 */
48#define HEADERLEN	(sizeof (u_char) + sizeof (u_char) + sizeof (u_short))
49
50
51/*
52 *  CP (LCP, IPCP, etc.) codes.
53 */
54#define CONFREQ		1	/* Configuration Request */
55#define CONFACK		2	/* Configuration Ack */
56#define CONFNAK		3	/* Configuration Nak */
57#define CONFREJ		4	/* Configuration Reject */
58#define TERMREQ		5	/* Termination Request */
59#define TERMACK		6	/* Termination Ack */
60#define CODEREJ		7	/* Code Reject */
61
62
63/*
64 * Each FSM is described by an fsm structure and fsm callbacks.
65 */
66typedef struct fsm {
67    int unit;			/* Interface unit number */
68    int protocol;		/* Data Link Layer Protocol field value */
69    int state;			/* State */
70    int flags;			/* Contains option bits */
71    u_char id;			/* Current id */
72    u_char reqid;		/* Current request id */
73    u_char seen_ack;		/* Have received valid Ack/Nak/Rej to Req */
74    int timeouttime;		/* Timeout time in milliseconds */
75    int maxconfreqtransmits;	/* Maximum Configure-Request transmissions */
76    int retransmits;		/* Number of retransmissions left */
77    int maxtermtransmits;	/* Maximum Terminate-Request transmissions */
78    int nakloops;		/* Number of nak loops since last ack */
79    int maxnakloops;		/* Maximum number of nak loops tolerated */
80    struct fsm_callbacks *callbacks;	/* Callback routines */
81    char *term_reason;		/* Reason for closing protocol */
82    int term_reason_len;	/* Length of term_reason */
83} fsm;
84
85
86typedef struct fsm_callbacks {
87    void (*resetci)		/* Reset our Configuration Information */
88(fsm *);
89    int  (*cilen)		/* Length of our Configuration Information */
90(fsm *);
91    void (*addci) 		/* Add our Configuration Information */
92(fsm *, u_char *, int *);
93    int  (*ackci)		/* ACK our Configuration Information */
94(fsm *, u_char *, int);
95    int  (*nakci)		/* NAK our Configuration Information */
96(fsm *, u_char *, int);
97    int  (*rejci)		/* Reject our Configuration Information */
98(fsm *, u_char *, int);
99    int  (*reqci)		/* Request peer's Configuration Information */
100(fsm *, u_char *, int *, int);
101    void (*up)			/* Called when fsm reaches OPENED state */
102(fsm *);
103    void (*down)		/* Called when fsm leaves OPENED state */
104(fsm *);
105    void (*starting)		/* Called when we want the lower layer */
106(fsm *);
107    void (*finished)		/* Called when we don't want the lower layer */
108(fsm *);
109    void (*protreject)		/* Called when Protocol-Reject received */
110(int);
111    void (*retransmit)		/* Retransmission is necessary */
112(fsm *);
113    int  (*extcode)		/* Called when unknown code received */
114(fsm *, int, int, u_char *, int);
115    char *proto_name;		/* String name for protocol (for messages) */
116} fsm_callbacks;
117
118
119/*
120 * Link states.
121 */
122#define INITIAL		0	/* Down, hasn't been opened */
123#define STARTING	1	/* Down, been opened */
124#define CLOSED		2	/* Up, hasn't been opened */
125#define STOPPED		3	/* Open, waiting for down event */
126#define CLOSING		4	/* Terminating the connection, not open */
127#define STOPPING	5	/* Terminating, but open */
128#define REQSENT		6	/* We've sent a Config Request */
129#define ACKRCVD		7	/* We've received a Config Ack */
130#define ACKSENT		8	/* We've sent a Config Ack */
131#define OPENED		9	/* Connection available */
132
133
134/*
135 * Flags - indicate options controlling FSM operation
136 */
137#define OPT_PASSIVE	1	/* Don't die if we don't get a response */
138#define OPT_RESTART	2	/* Treat 2nd OPEN as DOWN, UP */
139#define OPT_SILENT	4	/* Wait for peer to speak first */
140
141
142/*
143 * Timeouts.
144 */
145#define DEFTIMEOUT	3	/* Timeout time in seconds */
146#define DEFMAXTERMREQS	2	/* Maximum Terminate-Request transmissions */
147#define DEFMAXCONFREQS	10	/* Maximum Configure-Request transmissions */
148#define DEFMAXNAKLOOPS	5	/* Maximum number of nak loops */
149
150
151/*
152 * Prototypes
153 */
154void fsm_init(fsm *);
155void fsm_lowerup(fsm *);
156void fsm_lowerdown(fsm *);
157void fsm_open(fsm *);
158void fsm_close(fsm *, char *);
159void fsm_input(fsm *, u_char *, int);
160void fsm_protreject(fsm *);
161void fsm_sdata(fsm *, int, int, u_char *, int);
162
163
164/*
165 * Variables
166 */
167extern int peer_mru[];		/* currently negotiated peer MRU (per unit) */
168