1/*
2 * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
3 *
4 * Copyright (c) 1989 Carnegie Mellon University.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by Carnegie Mellon University.  The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 *
19 * $Id$
20 */
21
22/*
23 * Packet header = Code, id, length.
24 */
25#define HEADERLEN	4
26
27
28/*
29 *  CP (LCP, IPCP, etc.) codes.
30 */
31#define CONFREQ		1	/* Configuration Request */
32#define CONFACK		2	/* Configuration Ack */
33#define CONFNAK		3	/* Configuration Nak */
34#define CONFREJ		4	/* Configuration Reject */
35#define TERMREQ		5	/* Termination Request */
36#define TERMACK		6	/* Termination Ack */
37#define CODEREJ		7	/* Code Reject */
38
39
40/*
41 * Each FSM is described by an fsm structure and fsm callbacks.
42 */
43typedef struct fsm {
44    int unit;			/* Interface unit number */
45    int protocol;		/* Data Link Layer Protocol field value */
46    int state;			/* State */
47    int flags;			/* Contains option bits */
48    u_char id;			/* Current id */
49    u_char reqid;		/* Current request id */
50    u_char seen_ack;		/* Have received valid Ack/Nak/Rej to Req */
51    int timeouttime;		/* Timeout time in milliseconds */
52    int maxconfreqtransmits;	/* Maximum Configure-Request transmissions */
53    int retransmits;		/* Number of retransmissions left */
54    int maxtermtransmits;	/* Maximum Terminate-Request transmissions */
55    int nakloops;		/* Number of nak loops since last ack */
56    int maxnakloops;		/* Maximum number of nak loops tolerated */
57    struct fsm_callbacks *callbacks;	/* Callback routines */
58    char *term_reason;		/* Reason for closing protocol */
59    int term_reason_len;	/* Length of term_reason */
60} fsm;
61
62
63typedef struct fsm_callbacks {
64    void (*resetci)		/* Reset our Configuration Information */
65		__P((fsm *));
66    int  (*cilen)		/* Length of our Configuration Information */
67		__P((fsm *));
68    void (*addci) 		/* Add our Configuration Information */
69		__P((fsm *, u_char *, int *));
70    int  (*ackci)		/* ACK our Configuration Information */
71		__P((fsm *, u_char *, int));
72    int  (*nakci)		/* NAK our Configuration Information */
73		__P((fsm *, u_char *, int));
74    int  (*rejci)		/* Reject our Configuration Information */
75		__P((fsm *, u_char *, int));
76    int  (*reqci)		/* Request peer's Configuration Information */
77		__P((fsm *, u_char *, int *, int));
78    void (*up)			/* Called when fsm reaches OPENED state */
79		__P((fsm *));
80    void (*down)		/* Called when fsm leaves OPENED state */
81		__P((fsm *));
82    void (*starting)		/* Called when we want the lower layer */
83		__P((fsm *));
84    void (*finished)		/* Called when we don't want the lower layer */
85		__P((fsm *));
86    void (*protreject)		/* Called when Protocol-Reject received */
87		__P((int));
88    void (*retransmit)		/* Retransmission is necessary */
89		__P((fsm *));
90    int  (*extcode)		/* Called when unknown code received */
91		__P((fsm *, int, int, u_char *, int));
92    char *proto_name;		/* String name for protocol (for messages) */
93} fsm_callbacks;
94
95
96/*
97 * Link states.
98 */
99#define INITIAL		0	/* Down, hasn't been opened */
100#define STARTING	1	/* Down, been opened */
101#define CLOSED		2	/* Up, hasn't been opened */
102#define STOPPED		3	/* Open, waiting for down event */
103#define CLOSING		4	/* Terminating the connection, not open */
104#define STOPPING	5	/* Terminating, but open */
105#define REQSENT		6	/* We've sent a Config Request */
106#define ACKRCVD		7	/* We've received a Config Ack */
107#define ACKSENT		8	/* We've sent a Config Ack */
108#define OPENED		9	/* Connection available */
109
110
111/*
112 * Flags - indicate options controlling FSM operation
113 */
114#define OPT_PASSIVE	1	/* Don't die if we don't get a response */
115#define OPT_RESTART	2	/* Treat 2nd OPEN as DOWN, UP */
116#define OPT_SILENT	4	/* Wait for peer to speak first */
117
118
119/*
120 * Timeouts.
121 */
122#define DEFTIMEOUT	3	/* Timeout time in seconds */
123#define DEFMAXTERMREQS	2	/* Maximum Terminate-Request transmissions */
124#define DEFMAXCONFREQS	10	/* Maximum Configure-Request transmissions */
125#define DEFMAXNAKLOOPS	5	/* Maximum number of nak loops */
126
127
128/*
129 * Prototypes
130 */
131void fsm_init __P((fsm *));
132void fsm_lowerup __P((fsm *));
133void fsm_lowerdown __P((fsm *));
134void fsm_open __P((fsm *));
135void fsm_close __P((fsm *, char *));
136void fsm_input __P((fsm *, u_char *, int));
137void fsm_protreject __P((fsm *));
138void fsm_sdata __P((fsm *, int, int, u_char *, int));
139
140
141/*
142 * Variables
143 */
144extern int peer_mru[];		/* currently negotiated peer MRU (per unit) */
145