2 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
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43 #define RCSID "$Id: fsm.c,v 1.22 2004/02/02 03:57:19 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.
211 terminate_layer(f, nextstate)
215 if( f->state != OPENED )
216 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
217 else if( f->callbacks->down )
218 (*f->callbacks->down)(f); /* Inform upper layers we're down */
220 /* Init restart counter and send Terminate-Request */
221 f->retransmits = f->maxtermtransmits;
222 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
223 (u_char *) f->term_reason, f->term_reason_len);
225 if (f->retransmits == 0) {
227 * User asked for no terminate requests at all; just close it.
228 * We've already fired off one Terminate-Request just to be nice
229 * to the peer, but we're not going to wait for a reply.
231 f->state = nextstate == CLOSING ? CLOSED : STOPPED;
232 if( f->callbacks->finished )
233 (*f->callbacks->finished)(f);
237 TIMEOUT(fsm_timeout, f, f->timeouttime);
240 f->state = nextstate;
244 * fsm_close - Start closing connection.
246 * Cancel timeouts and either initiate close or possibly go directly to
254 f->term_reason = reason;
255 f->term_reason_len = (reason == NULL? 0: strlen(reason));
271 terminate_layer(f, CLOSING);
278 * fsm_timeout - Timeout expired.
284 fsm *f = (fsm *) arg;
289 if( f->retransmits <= 0 ){
291 * We've waited for an ack long enough. Peer probably heard us.
293 f->state = (f->state == CLOSING)? CLOSED: STOPPED;
294 if( f->callbacks->finished )
295 (*f->callbacks->finished)(f);
297 /* Send Terminate-Request */
298 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
299 (u_char *) f->term_reason, f->term_reason_len);
300 TIMEOUT(fsm_timeout, f, f->timeouttime);
308 if (f->retransmits <= 0) {
309 warn("%s: timeout sending Config-Requests\n", PROTO_NAME(f));
311 if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
312 (*f->callbacks->finished)(f);
315 /* Retransmit the configure-request */
316 if (f->callbacks->retransmit)
317 (*f->callbacks->retransmit)(f);
318 fsm_sconfreq(f, 1); /* Re-send Configure-Request */
319 if( f->state == ACKRCVD )
325 FSMDEBUG(("%s: Timeout event in state %d!", PROTO_NAME(f), f->state));
331 * fsm_input - Input packet.
334 fsm_input(f, inpacket, l)
344 * Parse header (code, id and length).
345 * If packet too short, drop it.
349 FSMDEBUG(("fsm_input(%x): Rcvd short header.", f->protocol));
355 if (len < HEADERLEN) {
356 FSMDEBUG(("fsm_input(%x): Rcvd illegal length.", f->protocol));
360 FSMDEBUG(("fsm_input(%x): Rcvd short packet.", f->protocol));
363 len -= HEADERLEN; /* subtract header length */
365 if( f->state == INITIAL || f->state == STARTING ){
366 FSMDEBUG(("fsm_input(%x): Rcvd packet in state %d.",
367 f->protocol, f->state));
372 * Action depends on code.
376 fsm_rconfreq(f, id, inp, len);
380 fsm_rconfack(f, id, inp, len);
385 fsm_rconfnakrej(f, code, id, inp, len);
389 fsm_rtermreq(f, id, inp, len);
397 fsm_rcoderej(f, inp, len);
401 if( !f->callbacks->extcode
402 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
403 fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
410 * fsm_rconfreq - Receive Configure-Request.
413 fsm_rconfreq(f, id, inp, len)
419 int code, reject_if_disagree;
423 /* Go away, we're closed */
424 fsm_sdata(f, TERMACK, id, NULL, 0);
431 /* Go down and restart negotiation */
432 if( f->callbacks->down )
433 (*f->callbacks->down)(f); /* Inform upper layers */
434 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
439 /* Negotiation started by our peer */
440 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
446 * Pass the requested configuration options
447 * to protocol-specific code for checking.
449 if (f->callbacks->reqci){ /* Check CI */
450 reject_if_disagree = (f->nakloops >= f->maxnakloops);
451 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
453 code = CONFREJ; /* Reject all CI */
457 /* send the Ack, Nak or Rej to the peer */
458 fsm_sdata(f, code, id, inp, len);
460 if (code == CONFACK) {
461 if (f->state == ACKRCVD) {
462 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
464 if (f->callbacks->up)
465 (*f->callbacks->up)(f); /* Inform upper layers */
471 /* we sent CONFACK or CONFREJ */
472 if (f->state != ACKRCVD)
474 if( code == CONFNAK )
481 * fsm_rconfack - Receive Configure-Ack.
484 fsm_rconfack(f, id, inp, len)
490 if (id != f->reqid || f->seen_ack) /* Expected id? */
491 return; /* Nope, toss... */
492 if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
494 /* Ack is bad - ignore it */
495 error("Received bad configure-ack: %P", inp, len);
503 fsm_sdata(f, TERMACK, id, NULL, 0);
508 f->retransmits = f->maxconfreqtransmits;
512 /* Huh? an extra valid Ack? oh well... */
513 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
519 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
521 f->retransmits = f->maxconfreqtransmits;
522 if (f->callbacks->up)
523 (*f->callbacks->up)(f); /* Inform upper layers */
527 /* Go down and restart negotiation */
528 if (f->callbacks->down)
529 (*f->callbacks->down)(f); /* Inform upper layers */
530 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
538 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
541 fsm_rconfnakrej(f, code, id, inp, len)
547 int (*proc) __P((fsm *, u_char *, int));
550 if (id != f->reqid || f->seen_ack) /* Expected id? */
551 return; /* Nope, toss... */
552 proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
553 if (!proc || !(ret = proc(f, inp, len))) {
554 /* Nak/reject is bad - ignore it */
555 error("Received bad configure-nak/rej: %P", inp, len);
563 fsm_sdata(f, TERMACK, id, NULL, 0);
568 /* They didn't agree to what we wanted - try another request */
569 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
571 f->state = STOPPED; /* kludge for stopping CCP */
573 fsm_sconfreq(f, 0); /* Send Configure-Request */
577 /* Got a Nak/reject when we had already had an Ack?? oh well... */
578 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
584 /* Go down and restart negotiation */
585 if (f->callbacks->down)
586 (*f->callbacks->down)(f); /* Inform upper layers */
587 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
595 * fsm_rtermreq - Receive Terminate-Req.
598 fsm_rtermreq(f, id, p, len)
607 f->state = REQSENT; /* Start over but keep trying */
612 info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
614 info("%s terminated by peer", PROTO_NAME(f));
617 if (f->callbacks->down)
618 (*f->callbacks->down)(f); /* Inform upper layers */
619 TIMEOUT(fsm_timeout, f, f->timeouttime);
623 fsm_sdata(f, TERMACK, id, NULL, 0);
628 * fsm_rtermack - Receive Terminate-Ack.
636 UNTIMEOUT(fsm_timeout, f);
638 if( f->callbacks->finished )
639 (*f->callbacks->finished)(f);
642 UNTIMEOUT(fsm_timeout, f);
644 if( f->callbacks->finished )
645 (*f->callbacks->finished)(f);
653 if (f->callbacks->down)
654 (*f->callbacks->down)(f); /* Inform upper layers */
663 * fsm_rcoderej - Receive an Code-Reject.
666 fsm_rcoderej(f, inp, len)
673 if (len < HEADERLEN) {
674 FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
679 warn("%s: Rcvd Code-Reject for code %d, id %d", PROTO_NAME(f), code, id);
681 if( f->state == ACKRCVD )
687 * fsm_protreject - Peer doesn't speak this protocol.
689 * Treat this as a catastrophic error (RXJ-).
697 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
701 if( f->callbacks->finished )
702 (*f->callbacks->finished)(f);
709 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
713 if( f->callbacks->finished )
714 (*f->callbacks->finished)(f);
718 terminate_layer(f, STOPPING);
722 FSMDEBUG(("%s: Protocol-reject event in state %d!",
723 PROTO_NAME(f), f->state));
729 * fsm_sconfreq - Send a Configure-Request.
732 fsm_sconfreq(f, retransmit)
739 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
740 /* Not currently negotiating - reset options */
741 if( f->callbacks->resetci )
742 (*f->callbacks->resetci)(f);
747 /* New request - reset retransmission counter, use new ID */
748 f->retransmits = f->maxconfreqtransmits;
755 * Make up the request packet
757 outp = outpacket_buf + PPP_HDRLEN + HEADERLEN;
758 if( f->callbacks->cilen && f->callbacks->addci ){
759 cilen = (*f->callbacks->cilen)(f);
760 if( cilen > peer_mru[f->unit] - HEADERLEN )
761 cilen = peer_mru[f->unit] - HEADERLEN;
762 if (f->callbacks->addci)
763 (*f->callbacks->addci)(f, outp, &cilen);
767 /* send the request to our peer */
768 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
770 /* start the retransmit timer */
772 TIMEOUT(fsm_timeout, f, f->timeouttime);
777 * fsm_sdata - Send some data.
779 * Used for all packets sent to our peer by this module.
782 fsm_sdata(f, code, id, data, datalen)
791 /* Adjust length to be smaller than MTU */
792 outp = outpacket_buf;
793 if (datalen > peer_mru[f->unit] - HEADERLEN)
794 datalen = peer_mru[f->unit] - HEADERLEN;
795 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
796 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
797 outlen = datalen + HEADERLEN;
798 MAKEHEADER(outp, f->protocol);
801 PUTSHORT(outlen, outp);
802 output(f->unit, outpacket_buf, outlen + PPP_HDRLEN);