1 /*****************************************************************************
2 * fsm.c - Network Control Protocol Finite State Machine program file.
4 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
5 * portions Copyright (c) 1997 by Global Election Systems Inc.
7 * The authors hereby grant permission to use, copy, modify, distribute,
8 * and license this software and its documentation for any purpose, provided
9 * that existing copyright notices are retained in all copies and that this
10 * notice and the following disclaimer are included verbatim in any
11 * distributions. No written agreement, license, or royalty fee is required
12 * for any of the authorized uses.
14 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 ******************************************************************************
28 * 03-01-01 Marc Boucher <marc@mbsi.ca>
30 * 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
31 * Original based on BSD fsm.c.
32 *****************************************************************************/
34 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
36 * Copyright (c) 1989 Carnegie Mellon University.
37 * All rights reserved.
39 * Redistribution and use in source and binary forms are permitted
40 * provided that the above copyright notice and this paragraph are
41 * duplicated in all such forms and that any documentation,
42 * advertising materials, and other materials related to such
43 * distribution and use acknowledge that the software was developed
44 * by Carnegie Mellon University. The name of the
45 * University may not be used to endorse or promote products derived
46 * from this software without specific prior written permission.
47 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
48 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
49 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
55 * Randomize fsm id on link/init.
56 * Deal with variable outgoing MTU.
65 /*************************/
66 /*** LOCAL DEFINITIONS ***/
67 /*************************/
70 /************************/
71 /*** LOCAL DATA TYPES ***/
72 /************************/
75 /***********************************/
76 /*** LOCAL FUNCTION DECLARATIONS ***/
77 /***********************************/
78 static void fsm_timeout (void *);
79 static void fsm_rconfreq (fsm *, u_char, u_char *, int);
80 static void fsm_rconfack (fsm *, int, u_char *, int);
81 static void fsm_rconfnakrej (fsm *, int, int, u_char *, int);
82 static void fsm_rtermreq (fsm *, int, u_char *, int);
83 static void fsm_rtermack (fsm *);
84 static void fsm_rcoderej (fsm *, u_char *, int);
85 static void fsm_sconfreq (fsm *, int);
87 #define PROTO_NAME(f) ((f)->callbacks->proto_name)
90 /******************************/
91 /*** PUBLIC DATA STRUCTURES ***/
92 /******************************/
95 /*****************************/
96 /*** LOCAL DATA STRUCTURES ***/
97 /*****************************/
98 int peer_mru[NUM_PPP];
101 /***********************************/
102 /*** PUBLIC FUNCTION DEFINITIONS ***/
103 /***********************************/
106 * fsm_init - Initialize fsm.
108 * Initialize fsm state.
110 void fsm_init(fsm *f)
114 f->id = 0; /* XXX Start with random id? */
115 f->timeouttime = FSM_DEFTIMEOUT;
116 f->maxconfreqtransmits = FSM_DEFMAXCONFREQS;
117 f->maxtermtransmits = FSM_DEFMAXTERMREQS;
118 f->maxnakloops = FSM_DEFMAXNAKLOOPS;
119 f->term_reason_len = 0;
124 * fsm_lowerup - The lower layer is up.
126 void fsm_lowerup(fsm *f)
128 int oldState = f->state;
136 if( f->flags & OPT_SILENT )
139 /* Send an initial configure-request */
146 FSMDEBUG((LOG_INFO, "%s: Up event in state %d!\n",
147 PROTO_NAME(f), f->state));
150 FSMDEBUG((LOG_INFO, "%s: lowerup state %d -> %d\n",
151 PROTO_NAME(f), oldState, f->state));
156 * fsm_lowerdown - The lower layer is down.
158 * Cancel all timeouts and inform upper layers.
160 void fsm_lowerdown(fsm *f)
162 int oldState = f->state;
171 if( f->callbacks->starting )
172 (*f->callbacks->starting)(f);
177 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
185 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
189 if( f->callbacks->down )
190 (*f->callbacks->down)(f);
195 FSMDEBUG((LOG_INFO, "%s: Down event in state %d!\n",
196 PROTO_NAME(f), f->state));
199 FSMDEBUG((LOG_INFO, "%s: lowerdown state %d -> %d\n",
200 PROTO_NAME(f), oldState, f->state));
205 * fsm_open - Link is allowed to come up.
207 void fsm_open(fsm *f)
209 int oldState = f->state;
214 if( f->callbacks->starting )
215 (*f->callbacks->starting)(f);
219 if( f->flags & OPT_SILENT )
222 /* Send an initial configure-request */
233 if( f->flags & OPT_RESTART ){
240 FSMDEBUG((LOG_INFO, "%s: open state %d -> %d\n",
241 PROTO_NAME(f), oldState, f->state));
246 * fsm_close - Start closing connection.
248 * Cancel timeouts and either initiate close or possibly go directly to
251 void fsm_close(fsm *f, char *reason)
253 int oldState = f->state;
255 f->term_reason = reason;
256 f->term_reason_len = (reason == NULL? 0: strlen(reason));
272 if( f->state != OPENED )
273 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
274 else if( f->callbacks->down )
275 (*f->callbacks->down)(f); /* Inform upper layers we're down */
277 /* Init restart counter, send Terminate-Request */
278 f->retransmits = f->maxtermtransmits;
279 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
280 (u_char *) f->term_reason, f->term_reason_len);
281 TIMEOUT(fsm_timeout, f, f->timeouttime);
288 FSMDEBUG((LOG_INFO, "%s: close reason=%s state %d -> %d\n",
289 PROTO_NAME(f), reason, oldState, f->state));
294 * fsm_sdata - Send some data.
296 * Used for all packets sent to our peer by this module.
309 /* Adjust length to be smaller than MTU */
310 outp = outpacket_buf[f->unit];
311 if (datalen > peer_mru[f->unit] - (int)HEADERLEN)
312 datalen = peer_mru[f->unit] - HEADERLEN;
313 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
314 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
315 outlen = datalen + HEADERLEN;
316 MAKEHEADER(outp, f->protocol);
319 PUTSHORT(outlen, outp);
320 pppWrite(f->unit, outpacket_buf[f->unit], outlen + PPP_HDRLEN);
321 FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d,%d,%d.\n",
322 PROTO_NAME(f), code, id, outlen));
327 * fsm_input - Input packet.
329 void fsm_input(fsm *f, u_char *inpacket, int l)
331 u_char *inp = inpacket;
336 * Parse header (code, id and length).
337 * If packet too short, drop it.
340 FSMDEBUG((LOG_WARNING, "fsm_input(%x): Rcvd short header.\n",
347 if (len < HEADERLEN) {
348 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd illegal length.\n",
353 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd short packet.\n",
357 len -= HEADERLEN; /* subtract header length */
359 if( f->state == INITIAL || f->state == STARTING ){
360 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd packet in state %d.\n",
361 f->protocol, f->state));
364 FSMDEBUG((LOG_INFO, "fsm_input(%s):%d,%d,%d\n", PROTO_NAME(f), code, id, l));
366 * Action depends on code.
370 fsm_rconfreq(f, id, inp, len);
374 fsm_rconfack(f, id, inp, len);
379 fsm_rconfnakrej(f, code, id, inp, len);
383 fsm_rtermreq(f, id, inp, len);
391 fsm_rcoderej(f, inp, len);
395 if( !f->callbacks->extcode
396 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
397 fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
404 * fsm_protreject - Peer doesn't speak this protocol.
406 * Treat this as a catastrophic error (RXJ-).
408 void fsm_protreject(fsm *f)
412 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
416 if( f->callbacks->finished )
417 (*f->callbacks->finished)(f);
424 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
428 if( f->callbacks->finished )
429 (*f->callbacks->finished)(f);
433 if( f->callbacks->down )
434 (*f->callbacks->down)(f);
436 /* Init restart counter, send Terminate-Request */
437 f->retransmits = f->maxtermtransmits;
438 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
439 (u_char *) f->term_reason, f->term_reason_len);
440 TIMEOUT(fsm_timeout, f, f->timeouttime);
447 FSMDEBUG((LOG_INFO, "%s: Protocol-reject event in state %d!\n",
448 PROTO_NAME(f), f->state));
456 /**********************************/
457 /*** LOCAL FUNCTION DEFINITIONS ***/
458 /**********************************/
461 * fsm_timeout - Timeout expired.
463 static void fsm_timeout(void *arg)
465 fsm *f = (fsm *) arg;
470 if( f->retransmits <= 0 ){
471 FSMDEBUG((LOG_WARNING, "%s: timeout sending Terminate-Request state=%d\n",
472 PROTO_NAME(f), f->state));
474 * We've waited for an ack long enough. Peer probably heard us.
476 f->state = (f->state == CLOSING)? CLOSED: STOPPED;
477 if( f->callbacks->finished )
478 (*f->callbacks->finished)(f);
480 FSMDEBUG((LOG_WARNING, "%s: timeout resending Terminate-Requests state=%d\n",
481 PROTO_NAME(f), f->state));
482 /* Send Terminate-Request */
483 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
484 (u_char *) f->term_reason, f->term_reason_len);
485 TIMEOUT(fsm_timeout, f, f->timeouttime);
493 if (f->retransmits <= 0) {
494 FSMDEBUG((LOG_WARNING, "%s: timeout sending Config-Requests state=%d\n",
495 PROTO_NAME(f), f->state));
497 if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
498 (*f->callbacks->finished)(f);
501 FSMDEBUG((LOG_WARNING, "%s: timeout resending Config-Request state=%d\n",
502 PROTO_NAME(f), f->state));
503 /* Retransmit the configure-request */
504 if (f->callbacks->retransmit)
505 (*f->callbacks->retransmit)(f);
506 fsm_sconfreq(f, 1); /* Re-send Configure-Request */
507 if( f->state == ACKRCVD )
513 FSMDEBUG((LOG_INFO, "%s: Timeout event in state %d!\n",
514 PROTO_NAME(f), f->state));
520 * fsm_rconfreq - Receive Configure-Request.
522 static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len)
524 int code, reject_if_disagree;
526 FSMDEBUG((LOG_INFO, "fsm_rconfreq(%s): Rcvd id %d state=%d\n",
527 PROTO_NAME(f), id, f->state));
530 /* Go away, we're closed */
531 fsm_sdata(f, TERMACK, id, NULL, 0);
538 /* Go down and restart negotiation */
539 if( f->callbacks->down )
540 (*f->callbacks->down)(f); /* Inform upper layers */
541 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
545 /* Negotiation started by our peer */
546 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
552 * Pass the requested configuration options
553 * to protocol-specific code for checking.
555 if (f->callbacks->reqci){ /* Check CI */
556 reject_if_disagree = (f->nakloops >= f->maxnakloops);
557 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
560 code = CONFREJ; /* Reject all CI */
564 /* send the Ack, Nak or Rej to the peer */
565 fsm_sdata(f, (u_char)code, id, inp, len);
567 if (code == CONFACK) {
568 if (f->state == ACKRCVD) {
569 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
571 if (f->callbacks->up)
572 (*f->callbacks->up)(f); /* Inform upper layers */
579 /* we sent CONFACK or CONFREJ */
580 if (f->state != ACKRCVD)
582 if( code == CONFNAK )
589 * fsm_rconfack - Receive Configure-Ack.
591 static void fsm_rconfack(fsm *f, int id, u_char *inp, int len)
593 FSMDEBUG((LOG_INFO, "fsm_rconfack(%s): Rcvd id %d state=%d\n",
594 PROTO_NAME(f), id, f->state));
596 if (id != f->reqid || f->seen_ack) /* Expected id? */
597 return; /* Nope, toss... */
598 if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
600 /* Ack is bad - ignore it */
601 FSMDEBUG((LOG_INFO, "%s: received bad Ack (length %d)\n",
602 PROTO_NAME(f), len));
610 fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
615 f->retransmits = f->maxconfreqtransmits;
619 /* Huh? an extra valid Ack? oh well... */
620 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
626 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
628 f->retransmits = f->maxconfreqtransmits;
629 if (f->callbacks->up)
630 (*f->callbacks->up)(f); /* Inform upper layers */
634 /* Go down and restart negotiation */
635 if (f->callbacks->down)
636 (*f->callbacks->down)(f); /* Inform upper layers */
637 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
645 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
647 static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len)
649 int (*proc) (fsm *, u_char *, int);
652 FSMDEBUG((LOG_INFO, "fsm_rconfnakrej(%s): Rcvd id %d state=%d\n",
653 PROTO_NAME(f), id, f->state));
655 if (id != f->reqid || f->seen_ack) /* Expected id? */
656 return; /* Nope, toss... */
657 proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
658 if (!proc || !(ret = proc(f, inp, len))) {
659 /* Nak/reject is bad - ignore it */
660 FSMDEBUG((LOG_INFO, "%s: received bad %s (length %d)\n",
661 PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len));
669 fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
674 /* They didn't agree to what we wanted - try another request */
675 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
677 f->state = STOPPED; /* kludge for stopping CCP */
679 fsm_sconfreq(f, 0); /* Send Configure-Request */
683 /* Got a Nak/reject when we had already had an Ack?? oh well... */
684 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
690 /* Go down and restart negotiation */
691 if (f->callbacks->down)
692 (*f->callbacks->down)(f); /* Inform upper layers */
693 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
701 * fsm_rtermreq - Receive Terminate-Req.
703 static void fsm_rtermreq(fsm *f, int id, u_char *p, int len)
705 FSMDEBUG((LOG_INFO, "fsm_rtermreq(%s): Rcvd id %d state=%d\n",
706 PROTO_NAME(f), id, f->state));
711 f->state = REQSENT; /* Start over but keep trying */
716 FSMDEBUG((LOG_INFO, "%s terminated by peer (%x)\n", PROTO_NAME(f), p));
718 FSMDEBUG((LOG_INFO, "%s terminated by peer\n", PROTO_NAME(f)));
720 if (f->callbacks->down)
721 (*f->callbacks->down)(f); /* Inform upper layers */
724 TIMEOUT(fsm_timeout, f, f->timeouttime);
728 fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
733 * fsm_rtermack - Receive Terminate-Ack.
735 static void fsm_rtermack(fsm *f)
737 FSMDEBUG((LOG_INFO, "fsm_rtermack(%s): state=%d\n",
738 PROTO_NAME(f), f->state));
742 UNTIMEOUT(fsm_timeout, f);
744 if( f->callbacks->finished )
745 (*f->callbacks->finished)(f);
748 UNTIMEOUT(fsm_timeout, f);
750 if( f->callbacks->finished )
751 (*f->callbacks->finished)(f);
759 if (f->callbacks->down)
760 (*f->callbacks->down)(f); /* Inform upper layers */
768 * fsm_rcoderej - Receive an Code-Reject.
770 static void fsm_rcoderej(fsm *f, u_char *inp, int len)
774 FSMDEBUG((LOG_INFO, "fsm_rcoderej(%s): state=%d\n",
775 PROTO_NAME(f), f->state));
777 if (len < HEADERLEN) {
778 FSMDEBUG((LOG_INFO, "fsm_rcoderej: Rcvd short Code-Reject packet!\n"));
783 FSMDEBUG((LOG_WARNING, "%s: Rcvd Code-Reject for code %d, id %d\n",
784 PROTO_NAME(f), code, id));
786 if( f->state == ACKRCVD )
792 * fsm_sconfreq - Send a Configure-Request.
794 static void fsm_sconfreq(fsm *f, int retransmit)
799 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
800 /* Not currently negotiating - reset options */
801 if( f->callbacks->resetci )
802 (*f->callbacks->resetci)(f);
807 /* New request - reset retransmission counter, use new ID */
808 f->retransmits = f->maxconfreqtransmits;
815 * Make up the request packet
817 outp = outpacket_buf[f->unit] + PPP_HDRLEN + HEADERLEN;
818 if( f->callbacks->cilen && f->callbacks->addci ){
819 cilen = (*f->callbacks->cilen)(f);
820 if( cilen > peer_mru[f->unit] - (int)HEADERLEN )
821 cilen = peer_mru[f->unit] - HEADERLEN;
822 if (f->callbacks->addci)
823 (*f->callbacks->addci)(f, outp, &cilen);
827 /* send the request to our peer */
828 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
830 /* start the retransmit timer */
832 TIMEOUT(fsm_timeout, f, f->timeouttime);
834 FSMDEBUG((LOG_INFO, "%s: sending Configure-Request, id %d\n",
835 PROTO_NAME(f), f->reqid));
838 #endif /* PPP_SUPPORT */