2 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
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43 #define RCSID "$Id: fsm.c,v 1.21 2004/02/02 02:52:51 carlsonj Exp $"
47 * Randomize fsm id on link/init.
48 * Deal with variable outgoing MTU.
53 #include <sys/types.h>
58 static const char rcsid[] = RCSID;
60 static void fsm_timeout __P((void *));
61 static void fsm_rconfreq __P((fsm *, int, u_char *, int));
62 static void fsm_rconfack __P((fsm *, int, u_char *, int));
63 static void fsm_rconfnakrej __P((fsm *, int, int, u_char *, int));
64 static void fsm_rtermreq __P((fsm *, int, u_char *, int));
65 static void fsm_rtermack __P((fsm *));
66 static void fsm_rcoderej __P((fsm *, u_char *, int));
67 static void fsm_sconfreq __P((fsm *, int));
69 #define PROTO_NAME(f) ((f)->callbacks->proto_name)
71 int peer_mru[NUM_PPP];
75 * fsm_init - Initialize fsm.
77 * Initialize fsm state.
85 f->id = 0; /* XXX Start with random id? */
86 f->timeouttime = DEFTIMEOUT;
87 f->maxconfreqtransmits = DEFMAXCONFREQS;
88 f->maxtermtransmits = DEFMAXTERMREQS;
89 f->maxnakloops = DEFMAXNAKLOOPS;
90 f->term_reason_len = 0;
95 * fsm_lowerup - The lower layer is up.
107 if( f->flags & OPT_SILENT )
110 /* Send an initial configure-request */
117 FSMDEBUG(("%s: Up event in state %d!", PROTO_NAME(f), f->state));
123 * fsm_lowerdown - The lower layer is down.
125 * Cancel all timeouts and inform upper layers.
138 if( f->callbacks->starting )
139 (*f->callbacks->starting)(f);
144 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
152 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
156 if( f->callbacks->down )
157 (*f->callbacks->down)(f);
162 FSMDEBUG(("%s: Down event in state %d!", PROTO_NAME(f), f->state));
168 * fsm_open - Link is allowed to come up.
177 if( f->callbacks->starting )
178 (*f->callbacks->starting)(f);
182 if( f->flags & OPT_SILENT )
185 /* Send an initial configure-request */
196 if( f->flags & OPT_RESTART ){
205 * terminate_layer - Start process of shutting down the FSM
207 * Cancel any timeout running, notify upper layers we're done, and
208 * send a terminate-request message as configured.
214 if( f->state != OPENED )
215 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
216 else if( f->callbacks->down )
217 (*f->callbacks->down)(f); /* Inform upper layers we're down */
219 /* Init restart counter and send Terminate-Request */
220 f->retransmits = f->maxtermtransmits;
221 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
222 (u_char *) f->term_reason, f->term_reason_len);
224 if (f->retransmits == 0) {
226 * User asked for no terminate requests at all; just close it.
227 * We've already fired off one Terminate-Request just to be nice
228 * to the peer, but we're not going to wait for a reply.
231 if( f->callbacks->finished )
232 (*f->callbacks->finished)(f);
236 TIMEOUT(fsm_timeout, f, f->timeouttime);
243 * fsm_close - Start closing connection.
245 * Cancel timeouts and either initiate close or possibly go directly to
253 f->term_reason = reason;
254 f->term_reason_len = (reason == NULL? 0: strlen(reason));
277 * fsm_timeout - Timeout expired.
283 fsm *f = (fsm *) arg;
288 if( f->retransmits <= 0 ){
290 * We've waited for an ack long enough. Peer probably heard us.
292 f->state = (f->state == CLOSING)? CLOSED: STOPPED;
293 if( f->callbacks->finished )
294 (*f->callbacks->finished)(f);
296 /* Send Terminate-Request */
297 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
298 (u_char *) f->term_reason, f->term_reason_len);
299 TIMEOUT(fsm_timeout, f, f->timeouttime);
307 if (f->retransmits <= 0) {
308 warn("%s: timeout sending Config-Requests\n", PROTO_NAME(f));
310 if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
311 (*f->callbacks->finished)(f);
314 /* Retransmit the configure-request */
315 if (f->callbacks->retransmit)
316 (*f->callbacks->retransmit)(f);
317 fsm_sconfreq(f, 1); /* Re-send Configure-Request */
318 if( f->state == ACKRCVD )
324 FSMDEBUG(("%s: Timeout event in state %d!", PROTO_NAME(f), f->state));
330 * fsm_input - Input packet.
333 fsm_input(f, inpacket, l)
343 * Parse header (code, id and length).
344 * If packet too short, drop it.
348 FSMDEBUG(("fsm_input(%x): Rcvd short header.", f->protocol));
354 if (len < HEADERLEN) {
355 FSMDEBUG(("fsm_input(%x): Rcvd illegal length.", f->protocol));
359 FSMDEBUG(("fsm_input(%x): Rcvd short packet.", f->protocol));
362 len -= HEADERLEN; /* subtract header length */
364 if( f->state == INITIAL || f->state == STARTING ){
365 FSMDEBUG(("fsm_input(%x): Rcvd packet in state %d.",
366 f->protocol, f->state));
371 * Action depends on code.
375 fsm_rconfreq(f, id, inp, len);
379 fsm_rconfack(f, id, inp, len);
384 fsm_rconfnakrej(f, code, id, inp, len);
388 fsm_rtermreq(f, id, inp, len);
396 fsm_rcoderej(f, inp, len);
400 if( !f->callbacks->extcode
401 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
402 fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
409 * fsm_rconfreq - Receive Configure-Request.
412 fsm_rconfreq(f, id, inp, len)
418 int code, reject_if_disagree;
422 /* Go away, we're closed */
423 fsm_sdata(f, TERMACK, id, NULL, 0);
430 /* Go down and restart negotiation */
431 if( f->callbacks->down )
432 (*f->callbacks->down)(f); /* Inform upper layers */
433 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
438 /* Negotiation started by our peer */
439 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
445 * Pass the requested configuration options
446 * to protocol-specific code for checking.
448 if (f->callbacks->reqci){ /* Check CI */
449 reject_if_disagree = (f->nakloops >= f->maxnakloops);
450 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
452 code = CONFREJ; /* Reject all CI */
456 /* send the Ack, Nak or Rej to the peer */
457 fsm_sdata(f, code, id, inp, len);
459 if (code == CONFACK) {
460 if (f->state == ACKRCVD) {
461 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
463 if (f->callbacks->up)
464 (*f->callbacks->up)(f); /* Inform upper layers */
470 /* we sent CONFACK or CONFREJ */
471 if (f->state != ACKRCVD)
473 if( code == CONFNAK )
480 * fsm_rconfack - Receive Configure-Ack.
483 fsm_rconfack(f, id, inp, len)
489 if (id != f->reqid || f->seen_ack) /* Expected id? */
490 return; /* Nope, toss... */
491 if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
493 /* Ack is bad - ignore it */
494 error("Received bad configure-ack: %P", inp, len);
502 fsm_sdata(f, TERMACK, id, NULL, 0);
507 f->retransmits = f->maxconfreqtransmits;
511 /* Huh? an extra valid Ack? oh well... */
512 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
518 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
520 f->retransmits = f->maxconfreqtransmits;
521 if (f->callbacks->up)
522 (*f->callbacks->up)(f); /* Inform upper layers */
526 /* Go down and restart negotiation */
527 if (f->callbacks->down)
528 (*f->callbacks->down)(f); /* Inform upper layers */
529 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
537 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
540 fsm_rconfnakrej(f, code, id, inp, len)
546 int (*proc) __P((fsm *, u_char *, int));
549 if (id != f->reqid || f->seen_ack) /* Expected id? */
550 return; /* Nope, toss... */
551 proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
552 if (!proc || !(ret = proc(f, inp, len))) {
553 /* Nak/reject is bad - ignore it */
554 error("Received bad configure-nak/rej: %P", inp, len);
562 fsm_sdata(f, TERMACK, id, NULL, 0);
567 /* They didn't agree to what we wanted - try another request */
568 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
570 f->state = STOPPED; /* kludge for stopping CCP */
572 fsm_sconfreq(f, 0); /* Send Configure-Request */
576 /* Got a Nak/reject when we had already had an Ack?? oh well... */
577 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
583 /* Go down and restart negotiation */
584 if (f->callbacks->down)
585 (*f->callbacks->down)(f); /* Inform upper layers */
586 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
594 * fsm_rtermreq - Receive Terminate-Req.
597 fsm_rtermreq(f, id, p, len)
606 f->state = REQSENT; /* Start over but keep trying */
611 info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
613 info("%s terminated by peer", PROTO_NAME(f));
616 if (f->callbacks->down)
617 (*f->callbacks->down)(f); /* Inform upper layers */
618 TIMEOUT(fsm_timeout, f, f->timeouttime);
622 fsm_sdata(f, TERMACK, id, NULL, 0);
627 * fsm_rtermack - Receive Terminate-Ack.
635 UNTIMEOUT(fsm_timeout, f);
637 if( f->callbacks->finished )
638 (*f->callbacks->finished)(f);
641 UNTIMEOUT(fsm_timeout, f);
643 if( f->callbacks->finished )
644 (*f->callbacks->finished)(f);
652 if (f->callbacks->down)
653 (*f->callbacks->down)(f); /* Inform upper layers */
662 * fsm_rcoderej - Receive an Code-Reject.
665 fsm_rcoderej(f, inp, len)
672 if (len < HEADERLEN) {
673 FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
678 warn("%s: Rcvd Code-Reject for code %d, id %d", PROTO_NAME(f), code, id);
680 if( f->state == ACKRCVD )
686 * fsm_protreject - Peer doesn't speak this protocol.
688 * Treat this as a catastrophic error (RXJ-).
696 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
700 if( f->callbacks->finished )
701 (*f->callbacks->finished)(f);
708 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
712 if( f->callbacks->finished )
713 (*f->callbacks->finished)(f);
721 FSMDEBUG(("%s: Protocol-reject event in state %d!",
722 PROTO_NAME(f), f->state));
728 * fsm_sconfreq - Send a Configure-Request.
731 fsm_sconfreq(f, retransmit)
738 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
739 /* Not currently negotiating - reset options */
740 if( f->callbacks->resetci )
741 (*f->callbacks->resetci)(f);
746 /* New request - reset retransmission counter, use new ID */
747 f->retransmits = f->maxconfreqtransmits;
754 * Make up the request packet
756 outp = outpacket_buf + PPP_HDRLEN + HEADERLEN;
757 if( f->callbacks->cilen && f->callbacks->addci ){
758 cilen = (*f->callbacks->cilen)(f);
759 if( cilen > peer_mru[f->unit] - HEADERLEN )
760 cilen = peer_mru[f->unit] - HEADERLEN;
761 if (f->callbacks->addci)
762 (*f->callbacks->addci)(f, outp, &cilen);
766 /* send the request to our peer */
767 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
769 /* start the retransmit timer */
771 TIMEOUT(fsm_timeout, f, f->timeouttime);
776 * fsm_sdata - Send some data.
778 * Used for all packets sent to our peer by this module.
781 fsm_sdata(f, code, id, data, datalen)
790 /* Adjust length to be smaller than MTU */
791 outp = outpacket_buf;
792 if (datalen > peer_mru[f->unit] - HEADERLEN)
793 datalen = peer_mru[f->unit] - HEADERLEN;
794 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
795 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
796 outlen = datalen + HEADERLEN;
797 MAKEHEADER(outp, f->protocol);
800 PUTSHORT(outlen, outp);
801 output(f->unit, outpacket_buf, outlen + PPP_HDRLEN);