xref: /netbsd/external/bsd/ppp/dist/pppd/fsm.h (revision 3dce80e5)
1 /*	$NetBSD: fsm.h,v 1.5 2021/01/09 16:39:28 christos 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  * Id: fsm.h,v 1.10 2004/11/13 02:28:15 paulus Exp
45  */
46 
47 /*
48  * Packet header = Code, id, length.
49  */
50 #define HEADERLEN	4
51 
52 
53 /*
54  *  CP (LCP, IPCP, etc.) codes.
55  */
56 #define CONFREQ		1	/* Configuration Request */
57 #define CONFACK		2	/* Configuration Ack */
58 #define CONFNAK		3	/* Configuration Nak */
59 #define CONFREJ		4	/* Configuration Reject */
60 #define TERMREQ		5	/* Termination Request */
61 #define TERMACK		6	/* Termination Ack */
62 #define CODEREJ		7	/* Code Reject */
63 
64 
65 /*
66  * Each FSM is described by an fsm structure and fsm callbacks.
67  */
68 typedef struct fsm {
69     int unit;			/* Interface unit number */
70     int protocol;		/* Data Link Layer Protocol field value */
71     int state;			/* State */
72     int flags;			/* Contains option bits */
73     u_char id;			/* Current id */
74     u_char reqid;		/* Current request id */
75     u_char seen_ack;		/* Have received valid Ack/Nak/Rej to Req */
76     int timeouttime;		/* Timeout time in milliseconds */
77     int maxconfreqtransmits;	/* Maximum Configure-Request transmissions */
78     int retransmits;		/* Number of retransmissions left */
79     int maxtermtransmits;	/* Maximum Terminate-Request transmissions */
80     int nakloops;		/* Number of nak loops since last ack */
81     int rnakloops;		/* Number of naks received */
82     int maxnakloops;		/* Maximum number of nak loops tolerated */
83     struct fsm_callbacks *callbacks;	/* Callback routines */
84     char *term_reason;		/* Reason for closing protocol */
85     int term_reason_len;	/* Length of term_reason */
86 } fsm;
87 
88 
89 typedef struct fsm_callbacks {
90     void (*resetci)(fsm *);	/* Reset our Configuration Information */
91     int  (*cilen)(fsm *);	/* Length of our Configuration Information */
92     void (*addci) 		/* Add our Configuration Information */
93 		(fsm *, u_char *, int *);
94     int  (*ackci)		/* ACK our Configuration Information */
95 		(fsm *, u_char *, int);
96     int  (*nakci)		/* NAK our Configuration Information */
97 		(fsm *, u_char *, int, int);
98     int  (*rejci)		/* Reject our Configuration Information */
99 		(fsm *, u_char *, int);
100     int  (*reqci)		/* Request peer's Configuration Information */
101 		(fsm *, u_char *, int *, int);
102     void (*up)(fsm *);		/* Called when fsm reaches OPENED state */
103     void (*down)(fsm *);	/* Called when fsm leaves OPENED state */
104     void (*starting)(fsm *);	/* Called when we want the lower layer */
105     void (*finished)(fsm *);	/* Called when we don't want the lower layer */
106     void (*protreject)(int);	/* Called when Protocol-Reject received */
107     void (*retransmit)(fsm *);	/* Retransmission is necessary */
108     int  (*extcode)		/* Called when unknown code received */
109 		(fsm *, int, int, u_char *, int);
110     char *proto_name;		/* String name for protocol (for messages) */
111 } fsm_callbacks;
112 
113 
114 /*
115  * Link states.
116  */
117 #define INITIAL		0	/* Down, hasn't been opened */
118 #define STARTING	1	/* Down, been opened */
119 #define CLOSED		2	/* Up, hasn't been opened */
120 #define STOPPED		3	/* Open, waiting for down event */
121 #define CLOSING		4	/* Terminating the connection, not open */
122 #define STOPPING	5	/* Terminating, but open */
123 #define REQSENT		6	/* We've sent a Config Request */
124 #define ACKRCVD		7	/* We've received a Config Ack */
125 #define ACKSENT		8	/* We've sent a Config Ack */
126 #define OPENED		9	/* Connection available */
127 
128 
129 /*
130  * Flags - indicate options controlling FSM operation
131  */
132 #define OPT_PASSIVE	1	/* Don't die if we don't get a response */
133 #define OPT_RESTART	2	/* Treat 2nd OPEN as DOWN, UP */
134 #define OPT_SILENT	4	/* Wait for peer to speak first */
135 
136 
137 /*
138  * Timeouts.
139  */
140 #define DEFTIMEOUT	3	/* Timeout time in seconds */
141 #define DEFMAXTERMREQS	2	/* Maximum Terminate-Request transmissions */
142 #define DEFMAXCONFREQS	10	/* Maximum Configure-Request transmissions */
143 #define DEFMAXNAKLOOPS	5	/* Maximum number of nak loops */
144 
145 
146 /*
147  * Prototypes
148  */
149 void fsm_init (fsm *);
150 void fsm_lowerup (fsm *);
151 void fsm_lowerdown (fsm *);
152 void fsm_open (fsm *);
153 void fsm_close (fsm *, char *);
154 void fsm_input (fsm *, u_char *, int);
155 void fsm_protreject (fsm *);
156 void fsm_sdata (fsm *, int, int, u_char *, int);
157 
158 
159 /*
160  * Variables
161  */
162 extern int peer_mru[];		/* currently negotiated peer MRU (per unit) */
163