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1 /*
2  * fsm.c - {Link, IP} Control Protocol Finite State Machine.
3  *
4  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * 3. The name "Carnegie Mellon University" must not be used to
19  *    endorse or promote products derived from this software without
20  *    prior written permission. For permission or any legal
21  *    details, please contact
22  *      Office of Technology Transfer
23  *      Carnegie Mellon University
24  *      5000 Forbes Avenue
25  *      Pittsburgh, PA  15213-3890
26  *      (412) 268-4387, fax: (412) 268-7395
27  *      tech-transfer@andrew.cmu.edu
28  *
29  * 4. Redistributions of any form whatsoever must retain the following
30  *    acknowledgment:
31  *    "This product includes software developed by Computing Services
32  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
33  *
34  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
35  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
36  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
37  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
38  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
39  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
40  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41  */
42 
43 #include "netif/ppp/ppp_opts.h"
44 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
45 
46 /*
47  * @todo:
48  * Randomize fsm id on link/init.
49  * Deal with variable outgoing MTU.
50  */
51 
52 #if 0 /* UNUSED */
53 #include <stdio.h>
54 #include <string.h>
55 #include <sys/types.h>
56 #endif /* UNUSED */
57 
58 #include "netif/ppp/ppp_impl.h"
59 
60 #include "netif/ppp/fsm.h"
61 
62 static void fsm_timeout (void *);
63 static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len);
64 static void fsm_rconfack(fsm *f, int id, u_char *inp, int len);
65 static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len);
66 static void fsm_rtermreq(fsm *f, int id, u_char *p, int len);
67 static void fsm_rtermack(fsm *f);
68 static void fsm_rcoderej(fsm *f, u_char *inp, int len);
69 static void fsm_sconfreq(fsm *f, int retransmit);
70 
71 #define PROTO_NAME(f)	((f)->callbacks->proto_name)
72 
73 /*
74  * fsm_init - Initialize fsm.
75  *
76  * Initialize fsm state.
77  */
fsm_init(fsm * f)78 void fsm_init(fsm *f) {
79     ppp_pcb *pcb = f->pcb;
80     f->state = PPP_FSM_INITIAL;
81     f->flags = 0;
82     f->id = 0;				/* XXX Start with random id? */
83     f->maxnakloops = pcb->settings.fsm_max_nak_loops;
84     f->term_reason_len = 0;
85 }
86 
87 
88 /*
89  * fsm_lowerup - The lower layer is up.
90  */
fsm_lowerup(fsm * f)91 void fsm_lowerup(fsm *f) {
92     switch( f->state ){
93     case PPP_FSM_INITIAL:
94 	f->state = PPP_FSM_CLOSED;
95 	break;
96 
97     case PPP_FSM_STARTING:
98 	if( f->flags & OPT_SILENT )
99 	    f->state = PPP_FSM_STOPPED;
100 	else {
101 	    /* Send an initial configure-request */
102 	    fsm_sconfreq(f, 0);
103 	    f->state = PPP_FSM_REQSENT;
104 	}
105 	break;
106 
107     default:
108 	FSMDEBUG(("%s: Up event in state %d!", PROTO_NAME(f), f->state));
109 	/* no break */
110     }
111 }
112 
113 
114 /*
115  * fsm_lowerdown - The lower layer is down.
116  *
117  * Cancel all timeouts and inform upper layers.
118  */
fsm_lowerdown(fsm * f)119 void fsm_lowerdown(fsm *f) {
120     switch( f->state ){
121     case PPP_FSM_CLOSED:
122 	f->state = PPP_FSM_INITIAL;
123 	break;
124 
125     case PPP_FSM_STOPPED:
126 	f->state = PPP_FSM_STARTING;
127 	if( f->callbacks->starting )
128 	    (*f->callbacks->starting)(f);
129 	break;
130 
131     case PPP_FSM_CLOSING:
132 	f->state = PPP_FSM_INITIAL;
133 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
134 	break;
135 
136     case PPP_FSM_STOPPING:
137     case PPP_FSM_REQSENT:
138     case PPP_FSM_ACKRCVD:
139     case PPP_FSM_ACKSENT:
140 	f->state = PPP_FSM_STARTING;
141 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
142 	break;
143 
144     case PPP_FSM_OPENED:
145 	if( f->callbacks->down )
146 	    (*f->callbacks->down)(f);
147 	f->state = PPP_FSM_STARTING;
148 	break;
149 
150     default:
151 	FSMDEBUG(("%s: Down event in state %d!", PROTO_NAME(f), f->state));
152 	/* no break */
153     }
154 }
155 
156 
157 /*
158  * fsm_open - Link is allowed to come up.
159  */
fsm_open(fsm * f)160 void fsm_open(fsm *f) {
161     switch( f->state ){
162     case PPP_FSM_INITIAL:
163 	f->state = PPP_FSM_STARTING;
164 	if( f->callbacks->starting )
165 	    (*f->callbacks->starting)(f);
166 	break;
167 
168     case PPP_FSM_CLOSED:
169 	if( f->flags & OPT_SILENT )
170 	    f->state = PPP_FSM_STOPPED;
171 	else {
172 	    /* Send an initial configure-request */
173 	    fsm_sconfreq(f, 0);
174 	    f->state = PPP_FSM_REQSENT;
175 	}
176 	break;
177 
178     case PPP_FSM_CLOSING:
179 	f->state = PPP_FSM_STOPPING;
180 	/* fall through */
181 	/* no break */
182     case PPP_FSM_STOPPED:
183     case PPP_FSM_OPENED:
184 	if( f->flags & OPT_RESTART ){
185 	    fsm_lowerdown(f);
186 	    fsm_lowerup(f);
187 	}
188 	break;
189     default:
190 	break;
191     }
192 }
193 
194 /*
195  * terminate_layer - Start process of shutting down the FSM
196  *
197  * Cancel any timeout running, notify upper layers we're done, and
198  * send a terminate-request message as configured.
199  */
terminate_layer(fsm * f,int nextstate)200 static void terminate_layer(fsm *f, int nextstate) {
201     ppp_pcb *pcb = f->pcb;
202 
203     if( f->state != PPP_FSM_OPENED )
204 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
205     else if( f->callbacks->down )
206 	(*f->callbacks->down)(f);	/* Inform upper layers we're down */
207 
208     /* Init restart counter and send Terminate-Request */
209     f->retransmits = pcb->settings.fsm_max_term_transmits;
210     fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
211 	      (const u_char *) f->term_reason, f->term_reason_len);
212 
213     if (f->retransmits == 0) {
214 	/*
215 	 * User asked for no terminate requests at all; just close it.
216 	 * We've already fired off one Terminate-Request just to be nice
217 	 * to the peer, but we're not going to wait for a reply.
218 	 */
219 	f->state = nextstate == PPP_FSM_CLOSING ? PPP_FSM_CLOSED : PPP_FSM_STOPPED;
220 	if( f->callbacks->finished )
221 	    (*f->callbacks->finished)(f);
222 	return;
223     }
224 
225     TIMEOUT(fsm_timeout, f, pcb->settings.fsm_timeout_time);
226     --f->retransmits;
227 
228     f->state = nextstate;
229 }
230 
231 /*
232  * fsm_close - Start closing connection.
233  *
234  * Cancel timeouts and either initiate close or possibly go directly to
235  * the PPP_FSM_CLOSED state.
236  */
fsm_close(fsm * f,const char * reason)237 void fsm_close(fsm *f, const char *reason) {
238     f->term_reason = reason;
239     f->term_reason_len = (reason == NULL? 0: (u8_t)LWIP_MIN(strlen(reason), 0xFF) );
240     switch( f->state ){
241     case PPP_FSM_STARTING:
242 	f->state = PPP_FSM_INITIAL;
243 	break;
244     case PPP_FSM_STOPPED:
245 	f->state = PPP_FSM_CLOSED;
246 	break;
247     case PPP_FSM_STOPPING:
248 	f->state = PPP_FSM_CLOSING;
249 	break;
250 
251     case PPP_FSM_REQSENT:
252     case PPP_FSM_ACKRCVD:
253     case PPP_FSM_ACKSENT:
254     case PPP_FSM_OPENED:
255 	terminate_layer(f, PPP_FSM_CLOSING);
256 	break;
257     default:
258 	break;
259     }
260 }
261 
262 
263 /*
264  * fsm_timeout - Timeout expired.
265  */
fsm_timeout(void * arg)266 static void fsm_timeout(void *arg) {
267     fsm *f = (fsm *) arg;
268     ppp_pcb *pcb = f->pcb;
269 
270     switch (f->state) {
271     case PPP_FSM_CLOSING:
272     case PPP_FSM_STOPPING:
273 	if( f->retransmits <= 0 ){
274 	    /*
275 	     * We've waited for an ack long enough.  Peer probably heard us.
276 	     */
277 	    f->state = (f->state == PPP_FSM_CLOSING)? PPP_FSM_CLOSED: PPP_FSM_STOPPED;
278 	    if( f->callbacks->finished )
279 		(*f->callbacks->finished)(f);
280 	} else {
281 	    /* Send Terminate-Request */
282 	    fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
283 		      (const u_char *) f->term_reason, f->term_reason_len);
284 	    TIMEOUT(fsm_timeout, f, pcb->settings.fsm_timeout_time);
285 	    --f->retransmits;
286 	}
287 	break;
288 
289     case PPP_FSM_REQSENT:
290     case PPP_FSM_ACKRCVD:
291     case PPP_FSM_ACKSENT:
292 	if (f->retransmits <= 0) {
293 	    ppp_warn("%s: timeout sending Config-Requests", PROTO_NAME(f));
294 	    f->state = PPP_FSM_STOPPED;
295 	    if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
296 		(*f->callbacks->finished)(f);
297 
298 	} else {
299 	    /* Retransmit the configure-request */
300 	    if (f->callbacks->retransmit)
301 		(*f->callbacks->retransmit)(f);
302 	    fsm_sconfreq(f, 1);		/* Re-send Configure-Request */
303 	    if( f->state == PPP_FSM_ACKRCVD )
304 		f->state = PPP_FSM_REQSENT;
305 	}
306 	break;
307 
308     default:
309 	FSMDEBUG(("%s: Timeout event in state %d!", PROTO_NAME(f), f->state));
310 	/* no break */
311     }
312 }
313 
314 
315 /*
316  * fsm_input - Input packet.
317  */
fsm_input(fsm * f,u_char * inpacket,int l)318 void fsm_input(fsm *f, u_char *inpacket, int l) {
319     u_char *inp;
320     u_char code, id;
321     int len;
322 
323     /*
324      * Parse header (code, id and length).
325      * If packet too short, drop it.
326      */
327     inp = inpacket;
328     if (l < HEADERLEN) {
329 	FSMDEBUG(("fsm_input(%x): Rcvd short header.", f->protocol));
330 	return;
331     }
332     GETCHAR(code, inp);
333     GETCHAR(id, inp);
334     GETSHORT(len, inp);
335     if (len < HEADERLEN) {
336 	FSMDEBUG(("fsm_input(%x): Rcvd illegal length.", f->protocol));
337 	return;
338     }
339     if (len > l) {
340 	FSMDEBUG(("fsm_input(%x): Rcvd short packet.", f->protocol));
341 	return;
342     }
343     len -= HEADERLEN;		/* subtract header length */
344 
345     if( f->state == PPP_FSM_INITIAL || f->state == PPP_FSM_STARTING ){
346 	FSMDEBUG(("fsm_input(%x): Rcvd packet in state %d.",
347 		  f->protocol, f->state));
348 	return;
349     }
350 
351     /*
352      * Action depends on code.
353      */
354     switch (code) {
355     case CONFREQ:
356 	fsm_rconfreq(f, id, inp, len);
357 	break;
358 
359     case CONFACK:
360 	fsm_rconfack(f, id, inp, len);
361 	break;
362 
363     case CONFNAK:
364     case CONFREJ:
365 	fsm_rconfnakrej(f, code, id, inp, len);
366 	break;
367 
368     case TERMREQ:
369 	fsm_rtermreq(f, id, inp, len);
370 	break;
371 
372     case TERMACK:
373 	fsm_rtermack(f);
374 	break;
375 
376     case CODEREJ:
377 	fsm_rcoderej(f, inp, len);
378 	break;
379 
380     default:
381 	if( !f->callbacks->extcode
382 	   || !(*f->callbacks->extcode)(f, code, id, inp, len) )
383 	    fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
384 	break;
385     }
386 }
387 
388 
389 /*
390  * fsm_rconfreq - Receive Configure-Request.
391  */
fsm_rconfreq(fsm * f,u_char id,u_char * inp,int len)392 static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len) {
393     int code, reject_if_disagree;
394 
395     switch( f->state ){
396     case PPP_FSM_CLOSED:
397 	/* Go away, we're closed */
398 	fsm_sdata(f, TERMACK, id, NULL, 0);
399 	return;
400     case PPP_FSM_CLOSING:
401     case PPP_FSM_STOPPING:
402 	return;
403 
404     case PPP_FSM_OPENED:
405 	/* Go down and restart negotiation */
406 	if( f->callbacks->down )
407 	    (*f->callbacks->down)(f);	/* Inform upper layers */
408 	fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
409 	f->state = PPP_FSM_REQSENT;
410 	break;
411 
412     case PPP_FSM_STOPPED:
413 	/* Negotiation started by our peer */
414 	fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
415 	f->state = PPP_FSM_REQSENT;
416 	break;
417     default:
418 	break;
419     }
420 
421     /*
422      * Pass the requested configuration options
423      * to protocol-specific code for checking.
424      */
425     if (f->callbacks->reqci){		/* Check CI */
426 	reject_if_disagree = (f->nakloops >= f->maxnakloops);
427 	code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
428     } else if (len)
429 	code = CONFREJ;			/* Reject all CI */
430     else
431 	code = CONFACK;
432 
433     /* send the Ack, Nak or Rej to the peer */
434     fsm_sdata(f, code, id, inp, len);
435 
436     if (code == CONFACK) {
437 	if (f->state == PPP_FSM_ACKRCVD) {
438 	    UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
439 	    f->state = PPP_FSM_OPENED;
440 	    if (f->callbacks->up)
441 		(*f->callbacks->up)(f);	/* Inform upper layers */
442 	} else
443 	    f->state = PPP_FSM_ACKSENT;
444 	f->nakloops = 0;
445 
446     } else {
447 	/* we sent CONFACK or CONFREJ */
448 	if (f->state != PPP_FSM_ACKRCVD)
449 	    f->state = PPP_FSM_REQSENT;
450 	if( code == CONFNAK )
451 	    ++f->nakloops;
452     }
453 }
454 
455 
456 /*
457  * fsm_rconfack - Receive Configure-Ack.
458  */
fsm_rconfack(fsm * f,int id,u_char * inp,int len)459 static void fsm_rconfack(fsm *f, int id, u_char *inp, int len) {
460     ppp_pcb *pcb = f->pcb;
461 
462     if (id != f->reqid || f->seen_ack)		/* Expected id? */
463 	return;					/* Nope, toss... */
464     if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
465 	  (len == 0)) ){
466 	/* Ack is bad - ignore it */
467 	ppp_error("Received bad configure-ack: %P", inp, len);
468 	return;
469     }
470     f->seen_ack = 1;
471     f->rnakloops = 0;
472 
473     switch (f->state) {
474     case PPP_FSM_CLOSED:
475     case PPP_FSM_STOPPED:
476 	fsm_sdata(f, TERMACK, id, NULL, 0);
477 	break;
478 
479     case PPP_FSM_REQSENT:
480 	f->state = PPP_FSM_ACKRCVD;
481 	f->retransmits = pcb->settings.fsm_max_conf_req_transmits;
482 	break;
483 
484     case PPP_FSM_ACKRCVD:
485 	/* Huh? an extra valid Ack? oh well... */
486 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
487 	fsm_sconfreq(f, 0);
488 	f->state = PPP_FSM_REQSENT;
489 	break;
490 
491     case PPP_FSM_ACKSENT:
492 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
493 	f->state = PPP_FSM_OPENED;
494 	f->retransmits = pcb->settings.fsm_max_conf_req_transmits;
495 	if (f->callbacks->up)
496 	    (*f->callbacks->up)(f);	/* Inform upper layers */
497 	break;
498 
499     case PPP_FSM_OPENED:
500 	/* Go down and restart negotiation */
501 	if (f->callbacks->down)
502 	    (*f->callbacks->down)(f);	/* Inform upper layers */
503 	fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
504 	f->state = PPP_FSM_REQSENT;
505 	break;
506     default:
507 	break;
508     }
509 }
510 
511 
512 /*
513  * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
514  */
fsm_rconfnakrej(fsm * f,int code,int id,u_char * inp,int len)515 static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len) {
516     int ret;
517     int treat_as_reject;
518 
519     if (id != f->reqid || f->seen_ack)	/* Expected id? */
520 	return;				/* Nope, toss... */
521 
522     if (code == CONFNAK) {
523 	++f->rnakloops;
524 	treat_as_reject = (f->rnakloops >= f->maxnakloops);
525 	if (f->callbacks->nakci == NULL
526 	    || !(ret = f->callbacks->nakci(f, inp, len, treat_as_reject))) {
527 	    ppp_error("Received bad configure-nak: %P", inp, len);
528 	    return;
529 	}
530     } else {
531 	f->rnakloops = 0;
532 	if (f->callbacks->rejci == NULL
533 	    || !(ret = f->callbacks->rejci(f, inp, len))) {
534 	    ppp_error("Received bad configure-rej: %P", inp, len);
535 	    return;
536 	}
537     }
538 
539     f->seen_ack = 1;
540 
541     switch (f->state) {
542     case PPP_FSM_CLOSED:
543     case PPP_FSM_STOPPED:
544 	fsm_sdata(f, TERMACK, id, NULL, 0);
545 	break;
546 
547     case PPP_FSM_REQSENT:
548     case PPP_FSM_ACKSENT:
549 	/* They didn't agree to what we wanted - try another request */
550 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
551 	if (ret < 0)
552 	    f->state = PPP_FSM_STOPPED;		/* kludge for stopping CCP */
553 	else
554 	    fsm_sconfreq(f, 0);		/* Send Configure-Request */
555 	break;
556 
557     case PPP_FSM_ACKRCVD:
558 	/* Got a Nak/reject when we had already had an Ack?? oh well... */
559 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
560 	fsm_sconfreq(f, 0);
561 	f->state = PPP_FSM_REQSENT;
562 	break;
563 
564     case PPP_FSM_OPENED:
565 	/* Go down and restart negotiation */
566 	if (f->callbacks->down)
567 	    (*f->callbacks->down)(f);	/* Inform upper layers */
568 	fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
569 	f->state = PPP_FSM_REQSENT;
570 	break;
571     default:
572 	break;
573     }
574 }
575 
576 
577 /*
578  * fsm_rtermreq - Receive Terminate-Req.
579  */
fsm_rtermreq(fsm * f,int id,u_char * p,int len)580 static void fsm_rtermreq(fsm *f, int id, u_char *p, int len) {
581     ppp_pcb *pcb = f->pcb;
582 
583     switch (f->state) {
584     case PPP_FSM_ACKRCVD:
585     case PPP_FSM_ACKSENT:
586 	f->state = PPP_FSM_REQSENT;		/* Start over but keep trying */
587 	break;
588 
589     case PPP_FSM_OPENED:
590 	if (len > 0) {
591 	    ppp_info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
592 	} else
593 	    ppp_info("%s terminated by peer", PROTO_NAME(f));
594 	f->retransmits = 0;
595 	f->state = PPP_FSM_STOPPING;
596 	if (f->callbacks->down)
597 	    (*f->callbacks->down)(f);	/* Inform upper layers */
598 	TIMEOUT(fsm_timeout, f, pcb->settings.fsm_timeout_time);
599 	break;
600     default:
601 	break;
602     }
603 
604     fsm_sdata(f, TERMACK, id, NULL, 0);
605 }
606 
607 
608 /*
609  * fsm_rtermack - Receive Terminate-Ack.
610  */
fsm_rtermack(fsm * f)611 static void fsm_rtermack(fsm *f) {
612     switch (f->state) {
613     case PPP_FSM_CLOSING:
614 	UNTIMEOUT(fsm_timeout, f);
615 	f->state = PPP_FSM_CLOSED;
616 	if( f->callbacks->finished )
617 	    (*f->callbacks->finished)(f);
618 	break;
619     case PPP_FSM_STOPPING:
620 	UNTIMEOUT(fsm_timeout, f);
621 	f->state = PPP_FSM_STOPPED;
622 	if( f->callbacks->finished )
623 	    (*f->callbacks->finished)(f);
624 	break;
625 
626     case PPP_FSM_ACKRCVD:
627 	f->state = PPP_FSM_REQSENT;
628 	break;
629 
630     case PPP_FSM_OPENED:
631 	if (f->callbacks->down)
632 	    (*f->callbacks->down)(f);	/* Inform upper layers */
633 	fsm_sconfreq(f, 0);
634 	f->state = PPP_FSM_REQSENT;
635 	break;
636     default:
637 	break;
638     }
639 }
640 
641 
642 /*
643  * fsm_rcoderej - Receive an Code-Reject.
644  */
fsm_rcoderej(fsm * f,u_char * inp,int len)645 static void fsm_rcoderej(fsm *f, u_char *inp, int len) {
646     u_char code, id;
647 
648     if (len < HEADERLEN) {
649 	FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
650 	return;
651     }
652     GETCHAR(code, inp);
653     GETCHAR(id, inp);
654     ppp_warn("%s: Rcvd Code-Reject for code %d, id %d", PROTO_NAME(f), code, id);
655 
656     if( f->state == PPP_FSM_ACKRCVD )
657 	f->state = PPP_FSM_REQSENT;
658 }
659 
660 
661 /*
662  * fsm_protreject - Peer doesn't speak this protocol.
663  *
664  * Treat this as a catastrophic error (RXJ-).
665  */
fsm_protreject(fsm * f)666 void fsm_protreject(fsm *f) {
667     switch( f->state ){
668     case PPP_FSM_CLOSING:
669 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
670 	/* fall through */
671 	/* no break */
672     case PPP_FSM_CLOSED:
673 	f->state = PPP_FSM_CLOSED;
674 	if( f->callbacks->finished )
675 	    (*f->callbacks->finished)(f);
676 	break;
677 
678     case PPP_FSM_STOPPING:
679     case PPP_FSM_REQSENT:
680     case PPP_FSM_ACKRCVD:
681     case PPP_FSM_ACKSENT:
682 	UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
683 	/* fall through */
684 	/* no break */
685     case PPP_FSM_STOPPED:
686 	f->state = PPP_FSM_STOPPED;
687 	if( f->callbacks->finished )
688 	    (*f->callbacks->finished)(f);
689 	break;
690 
691     case PPP_FSM_OPENED:
692 	terminate_layer(f, PPP_FSM_STOPPING);
693 	break;
694 
695     default:
696 	FSMDEBUG(("%s: Protocol-reject event in state %d!",
697 		  PROTO_NAME(f), f->state));
698 	/* no break */
699     }
700 }
701 
702 
703 /*
704  * fsm_sconfreq - Send a Configure-Request.
705  */
fsm_sconfreq(fsm * f,int retransmit)706 static void fsm_sconfreq(fsm *f, int retransmit) {
707     ppp_pcb *pcb = f->pcb;
708     struct pbuf *p;
709     u_char *outp;
710     int cilen;
711 
712     if( f->state != PPP_FSM_REQSENT && f->state != PPP_FSM_ACKRCVD && f->state != PPP_FSM_ACKSENT ){
713 	/* Not currently negotiating - reset options */
714 	if( f->callbacks->resetci )
715 	    (*f->callbacks->resetci)(f);
716 	f->nakloops = 0;
717 	f->rnakloops = 0;
718     }
719 
720     if( !retransmit ){
721 	/* New request - reset retransmission counter, use new ID */
722 	f->retransmits = pcb->settings.fsm_max_conf_req_transmits;
723 	f->reqid = ++f->id;
724     }
725 
726     f->seen_ack = 0;
727 
728     /*
729      * Make up the request packet
730      */
731     if( f->callbacks->cilen && f->callbacks->addci ){
732 	cilen = (*f->callbacks->cilen)(f);
733 	if( cilen > pcb->peer_mru - HEADERLEN )
734 	    cilen = pcb->peer_mru - HEADERLEN;
735     } else
736 	cilen = 0;
737 
738     p = pbuf_alloc(PBUF_RAW, (u16_t)(cilen + HEADERLEN + PPP_HDRLEN), PPP_CTRL_PBUF_TYPE);
739     if(NULL == p)
740         return;
741     if(p->tot_len != p->len) {
742         pbuf_free(p);
743         return;
744     }
745 
746     /* send the request to our peer */
747     outp = (u_char*)p->payload;
748     MAKEHEADER(outp, f->protocol);
749     PUTCHAR(CONFREQ, outp);
750     PUTCHAR(f->reqid, outp);
751     PUTSHORT(cilen + HEADERLEN, outp);
752     if (cilen != 0) {
753 	(*f->callbacks->addci)(f, outp, &cilen);
754 	LWIP_ASSERT("cilen == p->len - HEADERLEN - PPP_HDRLEN", cilen == p->len - HEADERLEN - PPP_HDRLEN);
755     }
756 
757     ppp_write(pcb, p);
758 
759     /* start the retransmit timer */
760     --f->retransmits;
761     TIMEOUT(fsm_timeout, f, pcb->settings.fsm_timeout_time);
762 }
763 
764 
765 /*
766  * fsm_sdata - Send some data.
767  *
768  * Used for all packets sent to our peer by this module.
769  */
fsm_sdata(fsm * f,u_char code,u_char id,const u_char * data,int datalen)770 void fsm_sdata(fsm *f, u_char code, u_char id, const u_char *data, int datalen) {
771     ppp_pcb *pcb = f->pcb;
772     struct pbuf *p;
773     u_char *outp;
774     int outlen;
775 
776     /* Adjust length to be smaller than MTU */
777     if (datalen > pcb->peer_mru - HEADERLEN)
778 	datalen = pcb->peer_mru - HEADERLEN;
779     outlen = datalen + HEADERLEN;
780 
781     p = pbuf_alloc(PBUF_RAW, (u16_t)(outlen + PPP_HDRLEN), PPP_CTRL_PBUF_TYPE);
782     if(NULL == p)
783         return;
784     if(p->tot_len != p->len) {
785         pbuf_free(p);
786         return;
787     }
788 
789     outp = (u_char*)p->payload;
790     if (datalen) /* && data != outp + PPP_HDRLEN + HEADERLEN)  -- was only for fsm_sconfreq() */
791 	MEMCPY(outp + PPP_HDRLEN + HEADERLEN, data, datalen);
792     MAKEHEADER(outp, f->protocol);
793     PUTCHAR(code, outp);
794     PUTCHAR(id, outp);
795     PUTSHORT(outlen, outp);
796     ppp_write(pcb, p);
797 }
798 
799 #endif /* PPP_SUPPORT */
800