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
62static void fsm_timeout (void *);
63static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len);
64static void fsm_rconfack(fsm *f, int id, u_char *inp, int len);
65static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len);
66static void fsm_rtermreq(fsm *f, int id, u_char *p, int len);
67static void fsm_rtermack(fsm *f);
68static void fsm_rcoderej(fsm *f, u_char *inp, int len);
69static 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 */
78void 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 */
91void 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 */
119void 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 */
160void 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 */
200static 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 */
237void 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 */
266static 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 */
318void 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 */
392static 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 */
459static 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 */
515static 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 */
580static 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 */
611static 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 */
645static 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 */
666void 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 */
706static 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 */
770void 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