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.
19 * $FreeBSD: src/usr.sbin/pppd/fsm.c,v 1.8 1999/08/28 01:19:02 peter Exp $
20 * $DragonFly: src/usr.sbin/pppd/fsm.c,v 1.3 2003/11/03 19:31:40 eirikn Exp $
25 * Randomize fsm id on link/init.
26 * Deal with variable outgoing MTU.
31 #include <sys/types.h>
37 static void fsm_timeout(void *);
38 static void fsm_rconfreq(fsm *, int, u_char *, int);
39 static void fsm_rconfack(fsm *, int, u_char *, int);
40 static void fsm_rconfnakrej(fsm *, int, int, u_char *, int);
41 static void fsm_rtermreq(fsm *, int, u_char *, int);
42 static void fsm_rtermack(fsm *);
43 static void fsm_rcoderej(fsm *, u_char *, int);
44 static void fsm_sconfreq(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;
65 f->maxtermtransmits = DEFMAXTERMREQS;
66 f->maxnakloops = DEFMAXNAKLOOPS;
67 f->term_reason_len = 0;
72 * fsm_lowerup - The lower layer is up.
84 if( f->flags & OPT_SILENT )
87 /* Send an initial configure-request */
94 FSMDEBUG((LOG_INFO, "%s: Up event in state %d!",
95 PROTO_NAME(f), f->state));
101 * fsm_lowerdown - The lower layer is down.
103 * Cancel all timeouts and inform upper layers.
116 if( f->callbacks->starting )
117 (*f->callbacks->starting)(f);
122 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
130 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
134 if( f->callbacks->down )
135 (*f->callbacks->down)(f);
140 FSMDEBUG((LOG_INFO, "%s: Down event in state %d!",
141 PROTO_NAME(f), f->state));
147 * fsm_open - Link is allowed to come up.
156 if( f->callbacks->starting )
157 (*f->callbacks->starting)(f);
161 if( f->flags & OPT_SILENT )
164 /* Send an initial configure-request */
175 if( f->flags & OPT_RESTART ){
185 * fsm_close - Start closing connection.
187 * Cancel timeouts and either initiate close or possibly go directly to
195 f->term_reason = reason;
196 f->term_reason_len = (reason == NULL? 0: strlen(reason));
212 if( f->state != OPENED )
213 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
214 else if( f->callbacks->down )
215 (*f->callbacks->down)(f); /* Inform upper layers we're down */
217 /* Init restart counter, send Terminate-Request */
218 f->retransmits = f->maxtermtransmits;
219 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
220 (u_char *) f->term_reason, f->term_reason_len);
221 TIMEOUT(fsm_timeout, f, f->timeouttime);
231 * fsm_timeout - Timeout expired.
237 fsm *f = (fsm *) arg;
242 if( f->retransmits <= 0 ){
244 * We've waited for an ack long enough. Peer probably heard us.
246 f->state = (f->state == CLOSING)? CLOSED: STOPPED;
247 if( f->callbacks->finished )
248 (*f->callbacks->finished)(f);
250 /* Send Terminate-Request */
251 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
252 (u_char *) f->term_reason, f->term_reason_len);
253 TIMEOUT(fsm_timeout, f, f->timeouttime);
261 if (f->retransmits <= 0) {
262 syslog(LOG_WARNING, "%s: timeout sending Config-Requests",
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((LOG_INFO, "%s: Timeout event in state %d!",
280 PROTO_NAME(f), f->state));
286 * fsm_input - Input packet.
289 fsm_input(f, inpacket, l)
299 * Parse header (code, id and length).
300 * If packet too short, drop it.
304 FSMDEBUG((LOG_WARNING, "fsm_input(%x): Rcvd short header.",
311 if (len < HEADERLEN) {
312 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd illegal length.",
317 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd short packet.",
321 len -= HEADERLEN; /* subtract header length */
323 if( f->state == INITIAL || f->state == STARTING ){
324 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd packet in state %d.",
325 f->protocol, f->state));
330 * Action depends on code.
334 fsm_rconfreq(f, id, inp, len);
338 fsm_rconfack(f, id, inp, len);
343 fsm_rconfnakrej(f, code, id, inp, len);
347 fsm_rtermreq(f, id, inp, len);
355 fsm_rcoderej(f, inp, len);
359 if( !f->callbacks->extcode
360 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
361 fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
368 * fsm_rconfreq - Receive Configure-Request.
371 fsm_rconfreq(f, id, inp, len)
377 int code, reject_if_disagree;
379 FSMDEBUG((LOG_INFO, "fsm_rconfreq(%s): Rcvd id %d.", PROTO_NAME(f), id));
382 /* Go away, we're closed */
383 fsm_sdata(f, TERMACK, id, NULL, 0);
390 /* Go down and restart negotiation */
391 if( f->callbacks->down )
392 (*f->callbacks->down)(f); /* Inform upper layers */
393 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
397 /* Negotiation started by our peer */
398 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
404 * Pass the requested configuration options
405 * to protocol-specific code for checking.
407 if (f->callbacks->reqci){ /* Check CI */
408 reject_if_disagree = (f->nakloops >= f->maxnakloops);
409 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
411 code = CONFREJ; /* Reject all CI */
415 /* send the Ack, Nak or Rej to the peer */
416 fsm_sdata(f, code, id, inp, len);
418 if (code == CONFACK) {
419 if (f->state == ACKRCVD) {
420 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
422 if (f->callbacks->up)
423 (*f->callbacks->up)(f); /* Inform upper layers */
429 /* we sent CONFACK or CONFREJ */
430 if (f->state != ACKRCVD)
432 if( code == CONFNAK )
439 * fsm_rconfack - Receive Configure-Ack.
442 fsm_rconfack(f, id, inp, len)
448 FSMDEBUG((LOG_INFO, "fsm_rconfack(%s): Rcvd id %d.",
451 if (id != f->reqid || f->seen_ack) /* Expected id? */
452 return; /* Nope, toss... */
453 if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
455 /* Ack is bad - ignore it */
456 log_packet(inp, len, "Received bad configure-ack: ", LOG_ERR);
457 FSMDEBUG((LOG_INFO, "%s: received bad Ack (length %d)",
458 PROTO_NAME(f), len));
466 fsm_sdata(f, TERMACK, id, NULL, 0);
471 f->retransmits = f->maxconfreqtransmits;
475 /* Huh? an extra valid Ack? oh well... */
476 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
482 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
484 f->retransmits = f->maxconfreqtransmits;
485 if (f->callbacks->up)
486 (*f->callbacks->up)(f); /* Inform upper layers */
490 /* Go down and restart negotiation */
491 if (f->callbacks->down)
492 (*f->callbacks->down)(f); /* Inform upper layers */
493 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
501 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
504 fsm_rconfnakrej(f, code, id, inp, len)
510 int (*proc)(fsm *, u_char *, int);
513 FSMDEBUG((LOG_INFO, "fsm_rconfnakrej(%s): Rcvd id %d.",
516 if (id != f->reqid || f->seen_ack) /* Expected id? */
517 return; /* Nope, toss... */
518 proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
519 if (!proc || !(ret = proc(f, inp, len))) {
520 /* Nak/reject is bad - ignore it */
521 log_packet(inp, len, "Received bad configure-nak/rej: ", LOG_ERR);
522 FSMDEBUG((LOG_INFO, "%s: received bad %s (length %d)",
523 PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len));
531 fsm_sdata(f, TERMACK, id, NULL, 0);
536 /* They didn't agree to what we wanted - try another request */
537 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
539 f->state = STOPPED; /* kludge for stopping CCP */
541 fsm_sconfreq(f, 0); /* Send Configure-Request */
545 /* Got a Nak/reject when we had already had an Ack?? oh well... */
546 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
552 /* Go down and restart negotiation */
553 if (f->callbacks->down)
554 (*f->callbacks->down)(f); /* Inform upper layers */
555 fsm_sconfreq(f, 0); /* Send initial Configure-Request */
563 * fsm_rtermreq - Receive Terminate-Req.
566 fsm_rtermreq(f, id, p, len)
574 FSMDEBUG((LOG_INFO, "fsm_rtermreq(%s): Rcvd id %d.",
580 f->state = REQSENT; /* Start over but keep trying */
585 fmtmsg(str, sizeof(str), "%0.*v", len, p);
586 syslog(LOG_INFO, "%s terminated by peer (%s)", PROTO_NAME(f), str);
588 syslog(LOG_INFO, "%s terminated by peer", PROTO_NAME(f));
589 if (f->callbacks->down)
590 (*f->callbacks->down)(f); /* Inform upper layers */
593 TIMEOUT(fsm_timeout, f, f->timeouttime);
597 fsm_sdata(f, TERMACK, id, NULL, 0);
602 * fsm_rtermack - Receive Terminate-Ack.
608 FSMDEBUG((LOG_INFO, "fsm_rtermack(%s).", PROTO_NAME(f)));
612 UNTIMEOUT(fsm_timeout, f);
614 if( f->callbacks->finished )
615 (*f->callbacks->finished)(f);
618 UNTIMEOUT(fsm_timeout, f);
620 if( f->callbacks->finished )
621 (*f->callbacks->finished)(f);
629 if (f->callbacks->down)
630 (*f->callbacks->down)(f); /* Inform upper layers */
638 * fsm_rcoderej - Receive an Code-Reject.
641 fsm_rcoderej(f, inp, len)
648 FSMDEBUG((LOG_INFO, "fsm_rcoderej(%s).", PROTO_NAME(f)));
650 if (len < HEADERLEN) {
651 FSMDEBUG((LOG_INFO, "fsm_rcoderej: Rcvd short Code-Reject packet!"));
656 syslog(LOG_WARNING, "%s: Rcvd Code-Reject for code %d, id %d",
657 PROTO_NAME(f), code, id);
659 if( f->state == ACKRCVD )
665 * fsm_protreject - Peer doesn't speak this protocol.
667 * Treat this as a catastrophic error (RXJ-).
675 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
679 if( f->callbacks->finished )
680 (*f->callbacks->finished)(f);
687 UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
691 if( f->callbacks->finished )
692 (*f->callbacks->finished)(f);
696 if( f->callbacks->down )
697 (*f->callbacks->down)(f);
699 /* Init restart counter, send Terminate-Request */
700 f->retransmits = f->maxtermtransmits;
701 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
702 (u_char *) f->term_reason, f->term_reason_len);
703 TIMEOUT(fsm_timeout, f, f->timeouttime);
710 FSMDEBUG((LOG_INFO, "%s: Protocol-reject event in state %d!",
711 PROTO_NAME(f), f->state));
717 * fsm_sconfreq - Send a Configure-Request.
720 fsm_sconfreq(f, retransmit)
727 if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
728 /* Not currently negotiating - reset options */
729 if( f->callbacks->resetci )
730 (*f->callbacks->resetci)(f);
735 /* New request - reset retransmission counter, use new ID */
736 f->retransmits = f->maxconfreqtransmits;
743 * Make up the request packet
745 outp = outpacket_buf + PPP_HDRLEN + HEADERLEN;
746 if( f->callbacks->cilen && f->callbacks->addci ){
747 cilen = (*f->callbacks->cilen)(f);
748 if( cilen > peer_mru[f->unit] - HEADERLEN )
749 cilen = peer_mru[f->unit] - HEADERLEN;
750 if (f->callbacks->addci)
751 (*f->callbacks->addci)(f, outp, &cilen);
755 /* send the request to our peer */
756 fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
758 /* start the retransmit timer */
760 TIMEOUT(fsm_timeout, f, f->timeouttime);
762 FSMDEBUG((LOG_INFO, "%s: sending Configure-Request, id %d",
763 PROTO_NAME(f), f->reqid));
768 * fsm_sdata - Send some data.
770 * Used for all packets sent to our peer by this module.
773 fsm_sdata(f, code, id, data, datalen)
782 /* Adjust length to be smaller than MTU */
783 outp = outpacket_buf;
784 if (datalen > peer_mru[f->unit] - HEADERLEN)
785 datalen = peer_mru[f->unit] - HEADERLEN;
786 if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
787 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
788 outlen = datalen + HEADERLEN;
789 MAKEHEADER(outp, f->protocol);
792 PUTSHORT(outlen, outp);
793 output(f->unit, outpacket_buf, outlen + PPP_HDRLEN);
795 FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d, id %d.",
796 PROTO_NAME(f), code, id));