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 #include "netif/ppp/ppp_opts.h"
46 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
47 
48 #ifndef FSM_H
49 #define	FSM_H
50 
51 #include "ppp.h"
52 
53 /*
54  * Packet header = Code, id, length.
55  */
56 #define HEADERLEN	4
57 
58 
59 /*
60  *  CP (LCP, IPCP, etc.) codes.
61  */
62 #define CONFREQ		1	/* Configuration Request */
63 #define CONFACK		2	/* Configuration Ack */
64 #define CONFNAK		3	/* Configuration Nak */
65 #define CONFREJ		4	/* Configuration Reject */
66 #define TERMREQ		5	/* Termination Request */
67 #define TERMACK		6	/* Termination Ack */
68 #define CODEREJ		7	/* Code Reject */
69 
70 
71 /*
72  * Each FSM is described by an fsm structure and fsm callbacks.
73  */
74 typedef struct fsm {
75     ppp_pcb *pcb;		/* PPP Interface */
76     const struct fsm_callbacks *callbacks;	/* Callback routines */
77     const char *term_reason;	/* Reason for closing protocol */
78     u8_t seen_ack;		/* Have received valid Ack/Nak/Rej to Req */
79 				  /* -- This is our only flag, we might use u_int :1 if we have more flags */
80     u16_t protocol;		/* Data Link Layer Protocol field value */
81     u8_t state;			/* State */
82     u8_t flags;			/* Contains option bits */
83     u8_t id;			/* Current id */
84     u8_t reqid;			/* Current request id */
85     u8_t retransmits;		/* Number of retransmissions left */
86     u8_t nakloops;		/* Number of nak loops since last ack */
87     u8_t rnakloops;		/* Number of naks received */
88     u8_t maxnakloops;		/* Maximum number of nak loops tolerated
89 				   (necessary because IPCP require a custom large max nak loops value) */
90     u8_t term_reason_len;	/* Length of term_reason */
91 } fsm;
92 
93 
94 typedef struct fsm_callbacks {
95     void (*resetci)		/* Reset our Configuration Information */
96 		(fsm *);
97     int  (*cilen)		/* Length of our Configuration Information */
98 		(fsm *);
99     void (*addci) 		/* Add our Configuration Information */
100 		(fsm *, u_char *, int *);
101     int  (*ackci)		/* ACK our Configuration Information */
102 		(fsm *, u_char *, int);
103     int  (*nakci)		/* NAK our Configuration Information */
104 		(fsm *, u_char *, int, int);
105     int  (*rejci)		/* Reject our Configuration Information */
106 		(fsm *, u_char *, int);
107     int  (*reqci)		/* Request peer's Configuration Information */
108 		(fsm *, u_char *, int *, int);
109     void (*up)			/* Called when fsm reaches PPP_FSM_OPENED state */
110 		(fsm *);
111     void (*down)		/* Called when fsm leaves PPP_FSM_OPENED state */
112 		(fsm *);
113     void (*starting)		/* Called when we want the lower layer */
114 		(fsm *);
115     void (*finished)		/* Called when we don't want the lower layer */
116 		(fsm *);
117     void (*protreject)		/* Called when Protocol-Reject received */
118 		(int);
119     void (*retransmit)		/* Retransmission is necessary */
120 		(fsm *);
121     int  (*extcode)		/* Called when unknown code received */
122 		(fsm *, int, int, u_char *, int);
123     const char *proto_name;	/* String name for protocol (for messages) */
124 } fsm_callbacks;
125 
126 
127 /*
128  * Link states.
129  */
130 #define PPP_FSM_INITIAL		0	/* Down, hasn't been opened */
131 #define PPP_FSM_STARTING	1	/* Down, been opened */
132 #define PPP_FSM_CLOSED		2	/* Up, hasn't been opened */
133 #define PPP_FSM_STOPPED		3	/* Open, waiting for down event */
134 #define PPP_FSM_CLOSING		4	/* Terminating the connection, not open */
135 #define PPP_FSM_STOPPING	5	/* Terminating, but open */
136 #define PPP_FSM_REQSENT		6	/* We've sent a Config Request */
137 #define PPP_FSM_ACKRCVD		7	/* We've received a Config Ack */
138 #define PPP_FSM_ACKSENT		8	/* We've sent a Config Ack */
139 #define PPP_FSM_OPENED		9	/* Connection available */
140 
141 
142 /*
143  * Flags - indicate options controlling FSM operation
144  */
145 #define OPT_PASSIVE	1	/* Don't die if we don't get a response */
146 #define OPT_RESTART	2	/* Treat 2nd OPEN as DOWN, UP */
147 #define OPT_SILENT	4	/* Wait for peer to speak first */
148 
149 
150 /*
151  * Timeouts.
152  */
153 #if 0 /* moved to ppp_opts.h */
154 #define DEFTIMEOUT	3	/* Timeout time in seconds */
155 #define DEFMAXTERMREQS	2	/* Maximum Terminate-Request transmissions */
156 #define DEFMAXCONFREQS	10	/* Maximum Configure-Request transmissions */
157 #define DEFMAXNAKLOOPS	5	/* Maximum number of nak loops */
158 #endif /* moved to ppp_opts.h */
159 
160 
161 /*
162  * Prototypes
163  */
164 void fsm_init(fsm *f);
165 void fsm_lowerup(fsm *f);
166 void fsm_lowerdown(fsm *f);
167 void fsm_open(fsm *f);
168 void fsm_close(fsm *f, const char *reason);
169 void fsm_input(fsm *f, u_char *inpacket, int l);
170 void fsm_protreject(fsm *f);
171 void fsm_sdata(fsm *f, u_char code, u_char id, const u_char *data, int datalen);
172 
173 
174 #endif /* FSM_H */
175 #endif /* PPP_SUPPORT */
176