1 /*
2  * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
3  *
4  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * 3. The name "Carnegie Mellon University" must not be used to
19  *    endorse or promote products derived from this software without
20  *    prior written permission. For permission or any legal
21  *    details, please contact
22  *      Office of Technology Transfer
23  *      Carnegie Mellon University
24  *      5000 Forbes Avenue
25  *      Pittsburgh, PA  15213-3890
26  *      (412) 268-4387, fax: (412) 268-7395
27  *      tech-transfer@andrew.cmu.edu
28  *
29  * 4. Redistributions of any form whatsoever must retain the following
30  *    acknowledgment:
31  *    "This product includes software developed by Computing Services
32  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
33  *
34  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
35  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
36  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
37  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
38  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
39  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
40  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41  *
42  * $Id: fsm.h,v 1.10 2004/11/13 02:28:15 paulus Exp $
43  */
44 
45 /*
46  * Packet header = Code, id, length.
47  */
48 #define HEADERLEN	4
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  */
66 typedef 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 rnakloops;		/* Number of naks received */
80     int maxnakloops;		/* Maximum number of nak loops tolerated */
81     struct fsm_callbacks *callbacks;	/* Callback routines */
82     char *term_reason;		/* Reason for closing protocol */
83     int term_reason_len;	/* Length of term_reason */
84 } fsm;
85 
86 
87 typedef struct fsm_callbacks {
88     void (*resetci)		/* Reset our Configuration Information */
89 		__P((fsm *));
90     int  (*cilen)		/* Length of our Configuration Information */
91 		__P((fsm *));
92     void (*addci) 		/* Add our Configuration Information */
93 		__P((fsm *, u_char *, int *));
94     int  (*ackci)		/* ACK our Configuration Information */
95 		__P((fsm *, u_char *, int));
96     int  (*nakci)		/* NAK our Configuration Information */
97 		__P((fsm *, u_char *, int, int));
98     int  (*rejci)		/* Reject our Configuration Information */
99 		__P((fsm *, u_char *, int));
100     int  (*reqci)		/* Request peer's Configuration Information */
101 		__P((fsm *, u_char *, int *, int));
102     void (*up)			/* Called when fsm reaches OPENED state */
103 		__P((fsm *));
104     void (*down)		/* Called when fsm leaves OPENED state */
105 		__P((fsm *));
106     void (*starting)		/* Called when we want the lower layer */
107 		__P((fsm *));
108     void (*finished)		/* Called when we don't want the lower layer */
109 		__P((fsm *));
110     void (*protreject)		/* Called when Protocol-Reject received */
111 		__P((int));
112     void (*retransmit)		/* Retransmission is necessary */
113 		__P((fsm *));
114     int  (*extcode)		/* Called when unknown code received */
115 		__P((fsm *, int, int, u_char *, int));
116     char *proto_name;		/* String name for protocol (for messages) */
117 } fsm_callbacks;
118 
119 
120 /*
121  * Link states.
122  */
123 #define INITIAL		0	/* Down, hasn't been opened */
124 #define STARTING	1	/* Down, been opened */
125 #define CLOSED		2	/* Up, hasn't been opened */
126 #define STOPPED		3	/* Open, waiting for down event */
127 #define CLOSING		4	/* Terminating the connection, not open */
128 #define STOPPING	5	/* Terminating, but open */
129 #define REQSENT		6	/* We've sent a Config Request */
130 #define ACKRCVD		7	/* We've received a Config Ack */
131 #define ACKSENT		8	/* We've sent a Config Ack */
132 #define OPENED		9	/* Connection available */
133 
134 
135 /*
136  * Flags - indicate options controlling FSM operation
137  */
138 #define OPT_PASSIVE	1	/* Don't die if we don't get a response */
139 #define OPT_RESTART	2	/* Treat 2nd OPEN as DOWN, UP */
140 #define OPT_SILENT	4	/* Wait for peer to speak first */
141 
142 
143 /*
144  * Timeouts.
145  */
146 #define DEFTIMEOUT	3	/* Timeout time in seconds */
147 #define DEFMAXTERMREQS	2	/* Maximum Terminate-Request transmissions */
148 #define DEFMAXCONFREQS	10	/* Maximum Configure-Request transmissions */
149 #define DEFMAXNAKLOOPS	5	/* Maximum number of nak loops */
150 
151 
152 /*
153  * Prototypes
154  */
155 void fsm_init __P((fsm *));
156 void fsm_lowerup __P((fsm *));
157 void fsm_lowerdown __P((fsm *));
158 void fsm_open __P((fsm *));
159 void fsm_close __P((fsm *, char *));
160 void fsm_input __P((fsm *, u_char *, int));
161 void fsm_protreject __P((fsm *));
162 void fsm_sdata __P((fsm *, int, int, u_char *, int));
163 
164 
165 /*
166  * Variables
167  */
168 extern int peer_mru[];		/* currently negotiated peer MRU (per unit) */
169