2 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
4 * Copyright (c) 1989 Carnegie Mellon University.
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.
20 #define RCSID "$Id: fsm.c,v 1.17 1999/08/13 06:46:12 paulus Exp $"
24 * Randomize fsm id on link/init.
25 * Deal with variable outgoing MTU.
30 #include <sys/types.h>
35 static const char rcsid[] = RCSID;
37 static void fsm_timeout __P((void *));
38 static void fsm_rconfreq __P((fsm *, int, u_char *, int));
39 static void fsm_rconfack __P((fsm *, int, u_char *, int));
40 static void fsm_rconfnakrej __P((fsm *, int, int, u_char *, int));
41 static void fsm_rtermreq __P((fsm *, int, u_char *, int));
42 static void fsm_rtermack __P((fsm *));
43 static void fsm_rcoderej __P((fsm *, u_char *, int));
44 static void fsm_sconfreq __P((fsm *, int));
46 #define PROTO_NAME(f) ((f)->callbacks->proto_name)
48 int peer_mru[NUM_PPP];
52 * fsm_init - Initialize fsm.
54 * Initialize fsm state.
62 f->id = 0; /* XXX Start with random id? */
63 f->timeouttime = DEFTIMEOUT;
64 f->maxconfreqtransmits = DEFMAXCONFREQS;
67 f->maxconfreqtransmits = ses_retries;
68 f->maxtermtransmits = DEFMAXTERMREQS;
69 f->maxnakloops = DEFMAXNAKLOOPS;
70 f->term_reason_len = 0;
75 * fsm_lowerup - The lower layer is up.
87 if( f->flags & OPT_SILENT )
90 /* Send an initial configure-request */
97 FSMDEBUG(("%s: Up event in state %d!", PROTO_NAME(f), f->state));
103 * fsm_lowerdown - The lower layer is down.
105 * Cancel all timeouts and inform upper layers.
118 if( f->callbacks->starting )
119 (*f->callbacks->starting)(f);
124 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
132 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
136 if( f->callbacks->down )
137 (*f->callbacks->down)(f);
142 FSMDEBUG(("%s: Down event in state %d!", PROTO_NAME(f), f->state));
148 * fsm_open - Link is allowed to come up.
157 if( f->callbacks->starting )
158 (*f->callbacks->starting)(f);
162 if( f->flags & OPT_SILENT )
165 /* Send an initial configure-request */
176 if( f->flags & OPT_RESTART ){
186 * fsm_close - Start closing connection.
188 * Cancel timeouts and either initiate close or possibly go directly to
196 f->term_reason = reason;
197 f->term_reason_len = (reason == NULL? 0: strlen(reason));
213 if( f->state != OPENED )
214 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
215 else if( f->callbacks->down )
216 (*f->callbacks->down)(f); /* Inform upper layers we're down */
218 /* Init restart counter, send Terminate-Request */
219 f->retransmits = f->maxtermtransmits;
220 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
221 (u_char *) f->term_reason, f->term_reason_len);
222 TIMEOUT(fsm_timeout, f, f->timeouttime);
232 * fsm_timeout - Timeout expired.
238 fsm *f = (fsm *) arg;
243 if( f->retransmits <= 0 ){
245 * We've waited for an ack long enough. Peer probably heard us.
247 f->state = (f->state == CLOSING)? CLOSED: STOPPED;
248 if( f->callbacks->finished )
249 (*f->callbacks->finished)(f);
251 /* Send Terminate-Request */
252 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
253 (u_char *) f->term_reason, f->term_reason_len);
254 TIMEOUT(fsm_timeout, f, f->timeouttime);
262 if (f->retransmits <= 0) {
263 warn("%s: timeout sending Config-Requests\n", PROTO_NAME(f));
265 if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
266 (*f->callbacks->finished)(f);
269 /* Retransmit the configure-request */
270 if (f->callbacks->retransmit)
271 (*f->callbacks->retransmit)(f);
272 fsm_sconfreq(f, 1); /* Re-send Configure-Request */
273 if( f->state == ACKRCVD )
279 FSMDEBUG(("%s: Timeout event in state %d!", PROTO_NAME(f), f->state));
285 * fsm_input - Input packet.
288 fsm_input(f, inpacket, l)
298 * Parse header (code, id and length).
299 * If packet too short, drop it.
303 FSMDEBUG(("fsm_input(%x): Rcvd short header.", f->protocol));
309 if (len < HEADERLEN) {
310 FSMDEBUG(("fsm_input(%x): Rcvd illegal length.", f->protocol));
314 FSMDEBUG(("fsm_input(%x): Rcvd short packet.", f->protocol));
317 len -= HEADERLEN; /* subtract header length */
319 if( f->state == INITIAL || f->state == STARTING ){
320 FSMDEBUG(("fsm_input(%x): Rcvd packet in state %d.",
321 f->protocol, f->state));
326 * Action depends on code.
330 fsm_rconfreq(f, id, inp, len);
334 fsm_rconfack(f, id, inp, len);
339 fsm_rconfnakrej(f, code, id, inp, len);
343 fsm_rtermreq(f, id, inp, len);
351 fsm_rcoderej(f, inp, len);
355 if( !f->callbacks->extcode
356 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
357 fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
364 * fsm_rconfreq - Receive Configure-Request.
367 fsm_rconfreq(f, id, inp, len)
373 int code, reject_if_disagree;
377 /* Go away, we're closed */
378 fsm_sdata(f, TERMACK, id, NULL, 0);
385 /* Go down and restart negotiation */
386 if( f->callbacks->down )
387 (*f->callbacks->down)(f); /* Inform upper layers */
388 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
392 /* Negotiation started by our peer */
393 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
399 * Pass the requested configuration options
400 * to protocol-specific code for checking.
402 if (f->callbacks->reqci){ /* Check CI */
403 reject_if_disagree = (f->nakloops >= f->maxnakloops);
404 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
406 code = CONFREJ; /* Reject all CI */
410 /* send the Ack, Nak or Rej to the peer */
411 fsm_sdata(f, code, id, inp, len);
413 if (code == CONFACK) {
414 if (f->state == ACKRCVD) {
415 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
417 if (f->callbacks->up)
418 (*f->callbacks->up)(f); /* Inform upper layers */
424 /* we sent CONFACK or CONFREJ */
425 if (f->state != ACKRCVD)
427 if( code == CONFNAK )
434 * fsm_rconfack - Receive Configure-Ack.
437 fsm_rconfack(f, id, inp, len)
443 if (id != f->reqid || f->seen_ack) /* Expected id? */
444 return; /* Nope, toss... */
445 if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
447 /* Ack is bad - ignore it */
448 error("Received bad configure-ack: %P", inp, len);
456 fsm_sdata(f, TERMACK, id, NULL, 0);
461 f->retransmits = f->maxconfreqtransmits;
465 /* Huh? an extra valid Ack? oh well... */
466 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
472 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
474 f->retransmits = f->maxconfreqtransmits;
475 if (f->callbacks->up)
476 (*f->callbacks->up)(f); /* Inform upper layers */
480 /* Go down and restart negotiation */
481 if (f->callbacks->down)
482 (*f->callbacks->down)(f); /* Inform upper layers */
483 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
491 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
494 fsm_rconfnakrej(f, code, id, inp, len)
500 int (*proc) __P((fsm *, u_char *, int));
503 if (id != f->reqid || f->seen_ack) /* Expected id? */
504 return; /* Nope, toss... */
505 proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
506 if (!proc || !(ret = proc(f, inp, len))) {
507 /* Nak/reject is bad - ignore it */
508 error("Received bad configure-nak/rej: %P", inp, len);
516 fsm_sdata(f, TERMACK, id, NULL, 0);
521 /* They didn't agree to what we wanted - try another request */
522 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
524 f->state = STOPPED; /* kludge for stopping CCP */
526 fsm_sconfreq(f, 0); /* Send Configure-Request */
530 /* Got a Nak/reject when we had already had an Ack?? oh well... */
531 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
537 /* Go down and restart negotiation */
538 if (f->callbacks->down)
539 (*f->callbacks->down)(f); /* Inform upper layers */
540 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
548 * fsm_rtermreq - Receive Terminate-Req.
551 fsm_rtermreq(f, id, p, len)
560 f->state = REQSENT; /* Start over but keep trying */
565 info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
567 info("%s terminated by peer", PROTO_NAME(f));
568 if (f->callbacks->down)
569 (*f->callbacks->down)(f); /* Inform upper layers */
572 TIMEOUT(fsm_timeout, f, f->timeouttime);
576 fsm_sdata(f, TERMACK, id, NULL, 0);
581 * fsm_rtermack - Receive Terminate-Ack.
589 UNTIMEOUT(fsm_timeout, f);
591 if( f->callbacks->finished )
592 (*f->callbacks->finished)(f);
595 UNTIMEOUT(fsm_timeout, f);
597 if( f->callbacks->finished )
598 (*f->callbacks->finished)(f);
606 if (f->callbacks->down)
607 (*f->callbacks->down)(f); /* Inform upper layers */
615 * fsm_rcoderej - Receive an Code-Reject.
618 fsm_rcoderej(f, inp, len)
625 if (len < HEADERLEN) {
626 FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
631 warn("%s: Rcvd Code-Reject for code %d, id %d", PROTO_NAME(f), code, id);
633 if( f->state == ACKRCVD )
639 * fsm_protreject - Peer doesn't speak this protocol.
641 * Treat this as a catastrophic error (RXJ-).
649 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
653 if( f->callbacks->finished )
654 (*f->callbacks->finished)(f);
661 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
665 if( f->callbacks->finished )
666 (*f->callbacks->finished)(f);
670 if( f->callbacks->down )
671 (*f->callbacks->down)(f);
673 /* Init restart counter, send Terminate-Request */
674 f->retransmits = f->maxtermtransmits;
675 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
676 (u_char *) f->term_reason, f->term_reason_len);
677 TIMEOUT(fsm_timeout, f, f->timeouttime);
684 FSMDEBUG(("%s: Protocol-reject event in state %d!",
685 PROTO_NAME(f), f->state));
691 * fsm_sconfreq - Send a Configure-Request.
694 fsm_sconfreq(f, retransmit)
701 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
702 /* Not currently negotiating - reset options */
703 if( f->callbacks->resetci )
704 (*f->callbacks->resetci)(f);
709 /* New request - reset retransmission counter, use new ID */
710 f->retransmits = f->maxconfreqtransmits;
717 * Make up the request packet
719 outp = outpacket_buf + PPP_HDRLEN + HEADERLEN;
720 if( f->callbacks->cilen && f->callbacks->addci ){
721 cilen = (*f->callbacks->cilen)(f);
722 if( cilen > peer_mru[f->unit] - HEADERLEN )
723 cilen = peer_mru[f->unit] - HEADERLEN;
724 if (f->callbacks->addci)
725 (*f->callbacks->addci)(f, outp, &cilen);
729 /* send the request to our peer */
730 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
732 /* start the retransmit timer */
734 TIMEOUT(fsm_timeout, f, f->timeouttime);
739 * fsm_sdata - Send some data.
741 * Used for all packets sent to our peer by this module.
744 fsm_sdata(f, code, id, data, datalen)
753 /* Adjust length to be smaller than MTU */
754 outp = outpacket_buf;
755 if (datalen > peer_mru[f->unit] - HEADERLEN)
756 datalen = peer_mru[f->unit] - HEADERLEN;
757 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
758 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
759 outlen = datalen + HEADERLEN;
760 MAKEHEADER(outp, f->protocol);
763 PUTSHORT(outlen, outp);
764 output(f->unit, outpacket_buf, outlen + PPP_HDRLEN);