xref: /freebsd/usr.sbin/ppp/fsm.h (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
4  *                           Internet Initiative Japan, Inc (IIJ)
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /*
32  *  State of machine
33  */
34 #define	ST_INITIAL	0
35 #define	ST_STARTING	1
36 #define	ST_CLOSED	2
37 #define	ST_STOPPED	3
38 #define	ST_CLOSING	4
39 #define	ST_STOPPING	5
40 #define	ST_REQSENT	6
41 #define	ST_ACKRCVD	7
42 #define	ST_ACKSENT	8
43 #define	ST_OPENED	9
44 
45 #define	ST_MAX		10
46 #define	ST_UNDEF	-1
47 
48 #define	MODE_REQ	0
49 #define	MODE_NAK	1
50 #define	MODE_REJ	2
51 #define	MODE_NOP	3
52 #define	MODE_ACK	4	/* pseudo mode for ccp negotiations */
53 
54 #define	OPEN_PASSIVE	-1
55 
56 #define FSM_REQ_TIMER	1
57 #define FSM_TRM_TIMER	2
58 
59 #define FSM_OPTLEN	100
60 
61 struct fsm;
62 
63 struct fsm_retry {
64   u_int timeout;                             /* FSM retry frequency */
65   u_int maxreq;                              /* Max Config REQ retries */
66   u_int maxtrm;                              /* Max Term REQ retries */
67 };
68 
69 struct fsm_decode {
70   u_char ack[FSM_OPTLEN], *ackend;
71   u_char nak[FSM_OPTLEN], *nakend;
72   u_char rej[FSM_OPTLEN], *rejend;
73 };
74 
75 struct fsm_callbacks {
76   int (*LayerUp)(struct fsm *);                 /* Layer is now up (tlu) */
77   void (*LayerDown)(struct fsm *);              /* About to come down (tld) */
78   void (*LayerStart)(struct fsm *);             /* Layer about to start (tls) */
79   void (*LayerFinish)(struct fsm *);            /* Layer now down (tlf) */
80   void (*InitRestartCounter)(struct fsm *, int);/* Set fsm timer load */
81   void (*SendConfigReq)(struct fsm *);          /* Send REQ please */
82   void (*SentTerminateReq)(struct fsm *);       /* Term REQ just sent */
83   void (*SendTerminateAck)(struct fsm *, u_char); /* Send Term ACK please */
84   void (*DecodeConfig)(struct fsm *, u_char *, u_char *, int,
85                        struct fsm_decode *);    /* Deal with incoming data */
86   int (*RecvResetReq)(struct fsm *fp);          /* Reset output */
87   void (*RecvResetAck)(struct fsm *fp, u_char); /* Reset input */
88 };
89 
90 struct fsm_parent {
91   void (*LayerStart) (void *, struct fsm *);         /* tls */
92   void (*LayerUp) (void *, struct fsm *);            /* tlu */
93   void (*LayerDown) (void *, struct fsm *);          /* tld */
94   void (*LayerFinish) (void *, struct fsm *);        /* tlf */
95   void *object;
96 };
97 
98 struct link;
99 struct bundle;
100 
101 struct fsm {
102   const char *name;		/* Name of protocol */
103   u_short proto;		/* Protocol number */
104   u_short min_code;
105   u_short max_code;
106   int open_mode;		/* Delay before config REQ (-1 forever) */
107   unsigned state;		/* State of the machine */
108   u_char reqid;			/* Next request id */
109   int restart;			/* Restart counter value */
110 
111   struct {
112     int reqs;			/* Max config REQs before a close() */
113     int naks;			/* Max config NAKs before a close() */
114     int rejs;			/* Max config REJs before a close() */
115   } more;
116 
117   struct pppTimer FsmTimer;	/* Restart Timer */
118   struct pppTimer OpenTimer;	/* Delay before opening */
119 
120   /*
121    * This timer times the ST_STOPPED state out after the given value
122    * (specified via "set stopped ...").  Although this isn't specified in the
123    * rfc, the rfc *does* say that "the application may use higher level
124    * timers to avoid deadlock". The StoppedTimer takes effect when the other
125    * side ABENDs rather than going into ST_ACKSENT (and sending the ACK),
126    * causing ppp to time out and drop into ST_STOPPED.  At this point,
127    * nothing will change this state :-(
128    */
129   struct pppTimer StoppedTimer;
130   int LogLevel;
131 
132   /* The link layer active with this FSM (may be our bundle below) */
133   struct link *link;
134 
135   /* Our high-level link */
136   struct bundle *bundle;
137 
138   const struct fsm_parent *parent;
139   const struct fsm_callbacks *fn;
140 };
141 
142 struct fsmheader {
143   u_char code;			/* Request code */
144   u_char id;			/* Identification */
145   u_short length;		/* Length of packet */
146 };
147 
148 #define	CODE_CONFIGREQ	1
149 #define	CODE_CONFIGACK	2
150 #define	CODE_CONFIGNAK	3
151 #define	CODE_CONFIGREJ	4
152 #define	CODE_TERMREQ	5
153 #define	CODE_TERMACK	6
154 #define	CODE_CODEREJ	7
155 #define	CODE_PROTOREJ	8
156 #define	CODE_ECHOREQ	9	/* Used in LCP */
157 #define	CODE_ECHOREP	10	/* Used in LCP */
158 #define	CODE_DISCREQ	11
159 #define	CODE_IDENT	12	/* Used in LCP Extension */
160 #define	CODE_TIMEREM	13	/* Used in LCP Extension */
161 #define	CODE_RESETREQ	14	/* Used in CCP */
162 #define	CODE_RESETACK	15	/* Used in CCP */
163 
164 struct fsm_opt_hdr {
165   u_char id;
166   u_char len;
167 } __packed;
168 
169 #define MAX_FSM_OPT_LEN 52
170 struct fsm_opt {
171   struct fsm_opt_hdr hdr;
172   u_char data[MAX_FSM_OPT_LEN-2];
173 };
174 
175 #define INC_FSM_OPT(ty, length, o)                      \
176   do {                                                  \
177     (o)->hdr.id = (ty);                                 \
178     (o)->hdr.len = (length);                            \
179     (o) = (struct fsm_opt *)((u_char *)(o) + (length)); \
180   } while (0)
181 
182 
183 extern void fsm_Init(struct fsm *, const char *, u_short, int, int, int,
184                      struct bundle *, struct link *, const  struct fsm_parent *,
185                      struct fsm_callbacks *, const char * const [3]);
186 extern void fsm_Output(struct fsm *, u_int, u_int, u_char *, unsigned, int);
187 extern void fsm_Open(struct fsm *);
188 extern void fsm_Up(struct fsm *);
189 extern void fsm_Down(struct fsm *);
190 extern void fsm_Input(struct fsm *, struct mbuf *);
191 extern void fsm_Close(struct fsm *);
192 extern int fsm_NullRecvResetReq(struct fsm *);
193 extern void fsm_NullRecvResetAck(struct fsm *, u_char);
194 extern void fsm_Reopen(struct fsm *);
195 extern void fsm2initial(struct fsm *);
196 extern const char *State2Nam(u_int);
197 extern struct fsm_opt *fsm_readopt(u_char **);
198 extern void fsm_rej(struct fsm_decode *, const struct fsm_opt *);
199 extern void fsm_ack(struct fsm_decode *, const struct fsm_opt *);
200 extern void fsm_nak(struct fsm_decode *, const struct fsm_opt *);
201 extern void fsm_opt_normalise(struct fsm_decode *);
202