2 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
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43 #define RCSID "$Id: fsm.c,v 1.23 2004/11/13 02:28:15 paulus Exp $"
47 * Randomize fsm id on link/init.
48 * Deal with variable outgoing MTU.
53 #include <sys/types.h>
59 static void fsm_timeout __P((void *));
60 static void fsm_rconfreq __P((fsm *, int, u_char *, int));
61 static void fsm_rconfack __P((fsm *, int, u_char *, int));
62 static void fsm_rconfnakrej __P((fsm *, int, int, u_char *, int));
63 static void fsm_rtermreq __P((fsm *, int, u_char *, int));
64 static void fsm_rtermack __P((fsm *));
65 static void fsm_rcoderej __P((fsm *, u_char *, int));
66 static void fsm_sconfreq __P((fsm *, int));
68 #define PROTO_NAME(f) ((f)->callbacks->proto_name)
70 int peer_mru[NUM_PPP];
74 * fsm_init - Initialize fsm.
76 * Initialize fsm state.
84 f->id = 0; /* XXX Start with random id? */
85 f->timeouttime = DEFTIMEOUT;
86 f->maxconfreqtransmits = DEFMAXCONFREQS;
87 f->maxtermtransmits = DEFMAXTERMREQS;
88 f->maxnakloops = DEFMAXNAKLOOPS;
89 f->term_reason_len = 0;
94 * fsm_lowerup - The lower layer is up.
106 if( f->flags & OPT_SILENT )
109 /* Send an initial configure-request */
116 FSMDEBUG(("%s: Up event in state %d!", PROTO_NAME(f), f->state));
122 * fsm_lowerdown - The lower layer is down.
124 * Cancel all timeouts and inform upper layers.
137 if( f->callbacks->starting )
138 (*f->callbacks->starting)(f);
143 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
151 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
155 if( f->callbacks->down )
156 (*f->callbacks->down)(f);
161 FSMDEBUG(("%s: Down event in state %d!", PROTO_NAME(f), f->state));
167 * fsm_open - Link is allowed to come up.
176 if( f->callbacks->starting )
177 (*f->callbacks->starting)(f);
181 if( f->flags & OPT_SILENT )
184 /* Send an initial configure-request */
195 if( f->flags & OPT_RESTART ){
204 * terminate_layer - Start process of shutting down the FSM
206 * Cancel any timeout running, notify upper layers we're done, and
207 * send a terminate-request message as configured.
210 terminate_layer(f, nextstate)
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.
230 f->state = nextstate == CLOSING ? CLOSED : STOPPED;
231 if( f->callbacks->finished )
232 (*f->callbacks->finished)(f);
236 TIMEOUT(fsm_timeout, f, f->timeouttime);
239 f->state = nextstate;
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));
270 terminate_layer(f, CLOSING);
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 CONFNAK 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);
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)
550 if (id != f->reqid || f->seen_ack) /* Expected id? */
551 return; /* Nope, toss... */
553 if (code == CONFNAK) {
555 treat_as_reject = (f->rnakloops >= f->maxnakloops);
556 if (f->callbacks->nakci == NULL
557 || !(ret = f->callbacks->nakci(f, inp, len, treat_as_reject))) {
558 error("Received bad configure-nak: %P", inp, len);
563 if (f->callbacks->rejci == NULL
564 || !(ret = f->callbacks->rejci(f, inp, len))) {
565 error("Received bad configure-rej: %P", inp, len);
575 fsm_sdata(f, TERMACK, id, NULL, 0);
580 /* They didn't agree to what we wanted - try another request */
581 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
583 f->state = STOPPED; /* kludge for stopping CCP */
585 fsm_sconfreq(f, 0); /* Send Configure-Request */
589 /* Got a Nak/reject when we had already had an Ack?? oh well... */
590 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
596 /* Go down and restart negotiation */
597 if (f->callbacks->down)
598 (*f->callbacks->down)(f); /* Inform upper layers */
599 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
607 * fsm_rtermreq - Receive Terminate-Req.
610 fsm_rtermreq(f, id, p, len)
619 f->state = REQSENT; /* Start over but keep trying */
624 info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
626 info("%s terminated by peer", PROTO_NAME(f));
629 if (f->callbacks->down)
630 (*f->callbacks->down)(f); /* Inform upper layers */
631 TIMEOUT(fsm_timeout, f, f->timeouttime);
635 fsm_sdata(f, TERMACK, id, NULL, 0);
640 * fsm_rtermack - Receive Terminate-Ack.
648 UNTIMEOUT(fsm_timeout, f);
650 if( f->callbacks->finished )
651 (*f->callbacks->finished)(f);
654 UNTIMEOUT(fsm_timeout, f);
656 if( f->callbacks->finished )
657 (*f->callbacks->finished)(f);
665 if (f->callbacks->down)
666 (*f->callbacks->down)(f); /* Inform upper layers */
675 * fsm_rcoderej - Receive an Code-Reject.
678 fsm_rcoderej(f, inp, len)
685 if (len < HEADERLEN) {
686 FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
691 warn("%s: Rcvd Code-Reject for code %d, id %d", PROTO_NAME(f), code, id);
693 if( f->state == ACKRCVD )
699 * fsm_protreject - Peer doesn't speak this protocol.
701 * Treat this as a catastrophic error (RXJ-).
709 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
713 if( f->callbacks->finished )
714 (*f->callbacks->finished)(f);
721 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
725 if( f->callbacks->finished )
726 (*f->callbacks->finished)(f);
730 terminate_layer(f, STOPPING);
734 FSMDEBUG(("%s: Protocol-reject event in state %d!",
735 PROTO_NAME(f), f->state));
741 * fsm_sconfreq - Send a Configure-Request.
744 fsm_sconfreq(f, retransmit)
751 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
752 /* Not currently negotiating - reset options */
753 if( f->callbacks->resetci )
754 (*f->callbacks->resetci)(f);
760 /* New request - reset retransmission counter, use new ID */
761 f->retransmits = f->maxconfreqtransmits;
768 * Make up the request packet
770 outp = outpacket_buf + PPP_HDRLEN + HEADERLEN;
771 if( f->callbacks->cilen && f->callbacks->addci ){
772 cilen = (*f->callbacks->cilen)(f);
773 if( cilen > peer_mru[f->unit] - HEADERLEN )
774 cilen = peer_mru[f->unit] - HEADERLEN;
775 if (f->callbacks->addci)
776 (*f->callbacks->addci)(f, outp, &cilen);
780 /* send the request to our peer */
781 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
783 /* start the retransmit timer */
785 TIMEOUT(fsm_timeout, f, f->timeouttime);
790 * fsm_sdata - Send some data.
792 * Used for all packets sent to our peer by this module.
795 fsm_sdata(f, code, id, data, datalen)
804 /* Adjust length to be smaller than MTU */
805 outp = outpacket_buf;
806 if (datalen > peer_mru[f->unit] - HEADERLEN)
807 datalen = peer_mru[f->unit] - HEADERLEN;
808 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
809 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
810 outlen = datalen + HEADERLEN;
811 MAKEHEADER(outp, f->protocol);
814 PUTSHORT(outlen, outp);
815 output(f->unit, outpacket_buf, outlen + PPP_HDRLEN);