1/*
2 * lcp.c - PPP Link Control Protocol.
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#define RCSID	"$Id: lcp.c,v 1.76 2006/05/22 00:04:07 paulus Exp $"
44
45/*
46 * TODO:
47 */
48
49#include <stdio.h>
50#include <string.h>
51#include <stdlib.h>
52
53#include "pppd.h"
54#include "fsm.h"
55#include "lcp.h"
56#include "chap-new.h"
57#include "magic.h"
58
59static const char rcsid[] = RCSID;
60
61/*
62 * When the link comes up we want to be able to wait for a short while,
63 * or until seeing some input from the peer, before starting to send
64 * configure-requests.  We do this by delaying the fsm_lowerup call.
65 */
66/* steal a bit in fsm flags word */
67#define DELAYED_UP	0x100
68
69static void lcp_delayed_up __P((void *));
70
71/*
72 * LCP-related command-line options.
73 */
74int	lcp_echo_interval = 0; 	/* Interval between LCP echo-requests */
75int	lcp_echo_fails = 0;	/* Tolerance to unanswered echo-requests */
76bool	lax_recv = 0;		/* accept control chars in asyncmap */
77bool	noendpoint = 0;		/* don't send/accept endpoint discriminator */
78
79static int noopt __P((char **));
80
81#ifdef HAVE_MULTILINK
82static int setendpoint __P((char **));
83static void printendpoint __P((option_t *, void (*)(void *, char *, ...),
84			       void *));
85#endif /* HAVE_MULTILINK */
86
87static option_t lcp_option_list[] = {
88    /* LCP options */
89    { "-all", o_special_noarg, (void *)noopt,
90      "Don't request/allow any LCP options" },
91
92    { "noaccomp", o_bool, &lcp_wantoptions[0].neg_accompression,
93      "Disable address/control compression",
94      OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
95    { "-ac", o_bool, &lcp_wantoptions[0].neg_accompression,
96      "Disable address/control compression",
97      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
98
99    { "asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
100      "Set asyncmap (for received packets)",
101      OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
102    { "-as", o_uint32, &lcp_wantoptions[0].asyncmap,
103      "Set asyncmap (for received packets)",
104      OPT_ALIAS | OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
105    { "default-asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
106      "Disable asyncmap negotiation",
107      OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
108      &lcp_allowoptions[0].neg_asyncmap },
109    { "-am", o_uint32, &lcp_wantoptions[0].asyncmap,
110      "Disable asyncmap negotiation",
111      OPT_ALIAS | OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
112      &lcp_allowoptions[0].neg_asyncmap },
113
114    { "nomagic", o_bool, &lcp_wantoptions[0].neg_magicnumber,
115      "Disable magic number negotiation (looped-back line detection)",
116      OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
117    { "-mn", o_bool, &lcp_wantoptions[0].neg_magicnumber,
118      "Disable magic number negotiation (looped-back line detection)",
119      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
120
121    { "mru", o_int, &lcp_wantoptions[0].mru,
122      "Set MRU (maximum received packet size) for negotiation",
123      OPT_PRIO, &lcp_wantoptions[0].neg_mru },
124    { "default-mru", o_bool, &lcp_wantoptions[0].neg_mru,
125      "Disable MRU negotiation (use default 1500)",
126      OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
127    { "-mru", o_bool, &lcp_wantoptions[0].neg_mru,
128      "Disable MRU negotiation (use default 1500)",
129      OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
130
131    { "mtu", o_int, &lcp_allowoptions[0].mru,
132      "Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU },
133
134    { "nopcomp", o_bool, &lcp_wantoptions[0].neg_pcompression,
135      "Disable protocol field compression",
136      OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
137    { "-pc", o_bool, &lcp_wantoptions[0].neg_pcompression,
138      "Disable protocol field compression",
139      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
140
141    { "passive", o_bool, &lcp_wantoptions[0].passive,
142      "Set passive mode", 1 },
143    { "-p", o_bool, &lcp_wantoptions[0].passive,
144      "Set passive mode", OPT_ALIAS | 1 },
145
146    { "silent", o_bool, &lcp_wantoptions[0].silent,
147      "Set silent mode", 1 },
148
149    { "lcp-echo-failure", o_int, &lcp_echo_fails,
150      "Set number of consecutive echo failures to indicate link failure",
151      OPT_PRIO },
152    { "lcp-echo-interval", o_int, &lcp_echo_interval,
153      "Set time in seconds between LCP echo requests", OPT_PRIO },
154    { "lcp-restart", o_int, &lcp_fsm[0].timeouttime,
155      "Set time in seconds between LCP retransmissions", OPT_PRIO },
156    { "lcp-max-terminate", o_int, &lcp_fsm[0].maxtermtransmits,
157      "Set maximum number of LCP terminate-request transmissions", OPT_PRIO },
158    { "lcp-max-configure", o_int, &lcp_fsm[0].maxconfreqtransmits,
159      "Set maximum number of LCP configure-request transmissions", OPT_PRIO },
160    { "lcp-max-failure", o_int, &lcp_fsm[0].maxnakloops,
161      "Set limit on number of LCP configure-naks", OPT_PRIO },
162
163    { "receive-all", o_bool, &lax_recv,
164      "Accept all received control characters", 1 },
165
166#ifdef HAVE_MULTILINK
167    { "mrru", o_int, &lcp_wantoptions[0].mrru,
168      "Maximum received packet size for multilink bundle",
169      OPT_PRIO, &lcp_wantoptions[0].neg_mrru },
170
171    { "mpshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
172      "Use short sequence numbers in multilink headers",
173      OPT_PRIO | 1, &lcp_allowoptions[0].neg_ssnhf },
174    { "nompshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
175      "Don't use short sequence numbers in multilink headers",
176      OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_ssnhf },
177
178    { "endpoint", o_special, (void *) setendpoint,
179      "Endpoint discriminator for multilink",
180      OPT_PRIO | OPT_A2PRINTER, (void *) printendpoint },
181#endif /* HAVE_MULTILINK */
182
183    { "noendpoint", o_bool, &noendpoint,
184      "Don't send or accept multilink endpoint discriminator", 1 },
185
186    {NULL}
187};
188
189/* global vars */
190fsm lcp_fsm[NUM_PPP];			/* LCP fsm structure (global)*/
191lcp_options lcp_wantoptions[NUM_PPP];	/* Options that we want to request */
192lcp_options lcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
193lcp_options lcp_allowoptions[NUM_PPP];	/* Options we allow peer to request */
194lcp_options lcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
195
196static int lcp_echos_pending = 0;	/* Number of outstanding echo msgs */
197static int lcp_echo_number   = 0;	/* ID number of next echo frame */
198static int lcp_echo_timer_running = 0;  /* set if a timer is running */
199
200static u_char nak_buffer[PPP_MRU];	/* where we construct a nak packet */
201
202/*
203 * Callbacks for fsm code.  (CI = Configuration Information)
204 */
205static void lcp_resetci __P((fsm *));	/* Reset our CI */
206static int  lcp_cilen __P((fsm *));		/* Return length of our CI */
207static void lcp_addci __P((fsm *, u_char *, int *)); /* Add our CI to pkt */
208static int  lcp_ackci __P((fsm *, u_char *, int)); /* Peer ack'd our CI */
209static int  lcp_nakci __P((fsm *, u_char *, int, int)); /* Peer nak'd our CI */
210static int  lcp_rejci __P((fsm *, u_char *, int)); /* Peer rej'd our CI */
211static int  lcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv peer CI */
212static void lcp_up __P((fsm *));		/* We're UP */
213static void lcp_down __P((fsm *));		/* We're DOWN */
214static void lcp_starting __P((fsm *));	/* We need lower layer up */
215static void lcp_finished __P((fsm *));	/* We need lower layer down */
216static int  lcp_extcode __P((fsm *, int, int, u_char *, int));
217static void lcp_rprotrej __P((fsm *, u_char *, int));
218
219/*
220 * routines to send LCP echos to peer
221 */
222
223static void lcp_echo_lowerup __P((int));
224static void lcp_echo_lowerdown __P((int));
225static void LcpEchoTimeout __P((void *));
226static void lcp_received_echo_reply __P((fsm *, int, u_char *, int));
227static void LcpSendEchoRequest __P((fsm *));
228static void LcpLinkFailure __P((fsm *));
229static void LcpEchoCheck __P((fsm *));
230
231static fsm_callbacks lcp_callbacks = {	/* LCP callback routines */
232    lcp_resetci,		/* Reset our Configuration Information */
233    lcp_cilen,			/* Length of our Configuration Information */
234    lcp_addci,			/* Add our Configuration Information */
235    lcp_ackci,			/* ACK our Configuration Information */
236    lcp_nakci,			/* NAK our Configuration Information */
237    lcp_rejci,			/* Reject our Configuration Information */
238    lcp_reqci,			/* Request peer's Configuration Information */
239    lcp_up,			/* Called when fsm reaches OPENED state */
240    lcp_down,			/* Called when fsm leaves OPENED state */
241    lcp_starting,		/* Called when we want the lower layer up */
242    lcp_finished,		/* Called when we want the lower layer down */
243    NULL,			/* Called when Protocol-Reject received */
244    NULL,			/* Retransmission is necessary */
245    lcp_extcode,		/* Called to handle LCP-specific codes */
246    "LCP"			/* String name of protocol */
247};
248
249/*
250 * Protocol entry points.
251 * Some of these are called directly.
252 */
253
254static void lcp_init __P((int));
255static void lcp_input __P((int, u_char *, int));
256static void lcp_protrej __P((int));
257static int  lcp_printpkt __P((u_char *, int,
258			      void (*) __P((void *, char *, ...)), void *));
259
260struct protent lcp_protent = {
261    PPP_LCP,
262    lcp_init,
263    lcp_input,
264    lcp_protrej,
265    lcp_lowerup,
266    lcp_lowerdown,
267    lcp_open,
268    lcp_close,
269    lcp_printpkt,
270    NULL,
271    1,
272    "LCP",
273    NULL,
274    lcp_option_list,
275    NULL,
276    NULL,
277    NULL
278};
279
280int lcp_loopbackfail = DEFLOOPBACKFAIL;
281
282/*
283 * Length of each type of configuration option (in octets)
284 */
285#define CILEN_VOID	2
286#define CILEN_CHAR	3
287#define CILEN_SHORT	4	/* CILEN_VOID + 2 */
288#define CILEN_CHAP	5	/* CILEN_VOID + 2 + 1 */
289#define CILEN_LONG	6	/* CILEN_VOID + 4 */
290#define CILEN_LQR	8	/* CILEN_VOID + 2 + 4 */
291#define CILEN_CBCP	3
292
293#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
294			 (x) == CONFNAK ? "NAK" : "REJ")
295
296/*
297 * noopt - Disable all options (why?).
298 */
299static int
300noopt(argv)
301    char **argv;
302{
303    BZERO((char *) &lcp_wantoptions[0], sizeof (struct lcp_options));
304    BZERO((char *) &lcp_allowoptions[0], sizeof (struct lcp_options));
305
306    return (1);
307}
308
309#ifdef HAVE_MULTILINK
310static int
311setendpoint(argv)
312    char **argv;
313{
314    if (str_to_epdisc(&lcp_wantoptions[0].endpoint, *argv)) {
315	lcp_wantoptions[0].neg_endpoint = 1;
316	return 1;
317    }
318    option_error("Can't parse '%s' as an endpoint discriminator", *argv);
319    return 0;
320}
321
322static void
323printendpoint(opt, printer, arg)
324    option_t *opt;
325    void (*printer) __P((void *, char *, ...));
326    void *arg;
327{
328	printer(arg, "%s", epdisc_to_str(&lcp_wantoptions[0].endpoint));
329}
330#endif /* HAVE_MULTILINK */
331
332/*
333 * lcp_init - Initialize LCP.
334 */
335static void
336lcp_init(unit)
337    int unit;
338{
339    fsm *f = &lcp_fsm[unit];
340    lcp_options *wo = &lcp_wantoptions[unit];
341    lcp_options *ao = &lcp_allowoptions[unit];
342
343    f->unit = unit;
344    f->protocol = PPP_LCP;
345    f->callbacks = &lcp_callbacks;
346
347    fsm_init(f);
348
349    BZERO(wo, sizeof(*wo));
350    wo->neg_mru = 1;
351    wo->mru = DEFMRU;
352    wo->neg_asyncmap = 1;
353    wo->neg_magicnumber = 1;
354    wo->neg_pcompression = 1;
355    wo->neg_accompression = 1;
356
357    BZERO(ao, sizeof(*ao));
358    ao->neg_mru = 1;
359    ao->mru = MAXMRU;
360    ao->neg_asyncmap = 1;
361    ao->neg_chap = 1;
362    ao->chap_mdtype = chap_mdtype_all;
363    ao->neg_upap = 1;
364    ao->neg_eap = 1;
365    ao->neg_magicnumber = 1;
366    ao->neg_pcompression = 1;
367    ao->neg_accompression = 1;
368    ao->neg_endpoint = 1;
369}
370
371
372/*
373 * lcp_open - LCP is allowed to come up.
374 */
375void
376lcp_open(unit)
377    int unit;
378{
379    fsm *f = &lcp_fsm[unit];
380    lcp_options *wo = &lcp_wantoptions[unit];
381
382    f->flags &= ~(OPT_PASSIVE | OPT_SILENT);
383    if (wo->passive)
384	f->flags |= OPT_PASSIVE;
385    if (wo->silent)
386	f->flags |= OPT_SILENT;
387    fsm_open(f);
388}
389
390
391/*
392 * lcp_close - Take LCP down.
393 */
394void
395lcp_close(unit, reason)
396    int unit;
397    char *reason;
398{
399    fsm *f = &lcp_fsm[unit];
400    int oldstate;
401
402    if (phase != PHASE_DEAD && phase != PHASE_MASTER)
403	new_phase(PHASE_TERMINATE);
404
405    if (f->flags & DELAYED_UP) {
406	untimeout(lcp_delayed_up, f);
407	f->state = STOPPED;
408    }
409    oldstate = f->state;
410
411    fsm_close(f, reason);
412    if (oldstate == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT|DELAYED_UP)) {
413	/*
414	 * This action is not strictly according to the FSM in RFC1548,
415	 * but it does mean that the program terminates if you do a
416	 * lcp_close() when a connection hasn't been established
417	 * because we are in passive/silent mode or because we have
418	 * delayed the fsm_lowerup() call and it hasn't happened yet.
419	 */
420	f->flags &= ~DELAYED_UP;
421	lcp_finished(f);
422    }
423}
424
425
426/*
427 * lcp_lowerup - The lower layer is up.
428 */
429void
430lcp_lowerup(unit)
431    int unit;
432{
433    lcp_options *wo = &lcp_wantoptions[unit];
434    fsm *f = &lcp_fsm[unit];
435
436    /*
437     * Don't use A/C or protocol compression on transmission,
438     * but accept A/C and protocol compressed packets
439     * if we are going to ask for A/C and protocol compression.
440     */
441    if (ppp_send_config(unit, PPP_MRU, 0xffffffff, 0, 0) < 0
442	|| ppp_recv_config(unit, PPP_MRU, (lax_recv? 0: 0xffffffff),
443			   wo->neg_pcompression, wo->neg_accompression) < 0)
444	    return;
445    peer_mru[unit] = PPP_MRU;
446
447    if (listen_time != 0) {
448	f->flags |= DELAYED_UP;
449	timeout(lcp_delayed_up, f, 0, listen_time * 1000);
450    } else
451	fsm_lowerup(f);
452}
453
454
455/*
456 * lcp_lowerdown - The lower layer is down.
457 */
458void
459lcp_lowerdown(unit)
460    int unit;
461{
462    fsm *f = &lcp_fsm[unit];
463
464    if (f->flags & DELAYED_UP) {
465	f->flags &= ~DELAYED_UP;
466	untimeout(lcp_delayed_up, f);
467    } else
468	fsm_lowerdown(&lcp_fsm[unit]);
469}
470
471
472/*
473 * lcp_delayed_up - Bring the lower layer up now.
474 */
475static void
476lcp_delayed_up(arg)
477    void *arg;
478{
479    fsm *f = arg;
480
481    if (f->flags & DELAYED_UP) {
482	f->flags &= ~DELAYED_UP;
483	fsm_lowerup(f);
484    }
485}
486
487
488/*
489 * lcp_input - Input LCP packet.
490 */
491static void
492lcp_input(unit, p, len)
493    int unit;
494    u_char *p;
495    int len;
496{
497    fsm *f = &lcp_fsm[unit];
498
499    if (f->flags & DELAYED_UP) {
500	f->flags &= ~DELAYED_UP;
501	untimeout(lcp_delayed_up, f);
502	fsm_lowerup(f);
503    }
504    fsm_input(f, p, len);
505}
506
507/*
508 * lcp_extcode - Handle a LCP-specific code.
509 */
510static int
511lcp_extcode(f, code, id, inp, len)
512    fsm *f;
513    int code, id;
514    u_char *inp;
515    int len;
516{
517    u_char *magp;
518
519    switch( code ){
520    case PROTREJ:
521	lcp_rprotrej(f, inp, len);
522	break;
523
524    case ECHOREQ:
525	if (f->state != OPENED)
526	    break;
527	magp = inp;
528	PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);
529	fsm_sdata(f, ECHOREP, id, inp, len);
530	break;
531
532    case ECHOREP:
533	lcp_received_echo_reply(f, id, inp, len);
534	break;
535
536    case DISCREQ:
537    case IDENTIF:
538    case TIMEREM:
539	break;
540
541    default:
542	return 0;
543    }
544    return 1;
545}
546
547
548/*
549 * lcp_rprotrej - Receive an Protocol-Reject.
550 *
551 * Figure out which protocol is rejected and inform it.
552 */
553static void
554lcp_rprotrej(f, inp, len)
555    fsm *f;
556    u_char *inp;
557    int len;
558{
559    int i;
560    struct protent *protp;
561    u_short prot;
562    const char *pname;
563
564    if (len < 2) {
565	LCPDEBUG(("lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
566	return;
567    }
568
569    GETSHORT(prot, inp);
570
571    /*
572     * Protocol-Reject packets received in any state other than the LCP
573     * OPENED state SHOULD be silently discarded.
574     */
575    if( f->state != OPENED ){
576	LCPDEBUG(("Protocol-Reject discarded: LCP in state %d", f->state));
577	return;
578    }
579
580    pname = protocol_name(prot);
581
582    /*
583     * Upcall the proper Protocol-Reject routine.
584     */
585    for (i = 0; (protp = protocols[i]) != NULL; ++i)
586	if (protp->protocol == prot && protp->enabled_flag) {
587	    if (pname == NULL)
588		dbglog("Protocol-Reject for 0x%x received", prot);
589	    else
590		dbglog("Protocol-Reject for '%s' (0x%x) received", pname,
591		       prot);
592	    (*protp->protrej)(f->unit);
593	    return;
594	}
595
596    if (pname == NULL)
597	warn("Protocol-Reject for unsupported protocol 0x%x", prot);
598    else
599	warn("Protocol-Reject for unsupported protocol '%s' (0x%x)", pname,
600	     prot);
601}
602
603
604/*
605 * lcp_protrej - A Protocol-Reject was received.
606 */
607/*ARGSUSED*/
608static void
609lcp_protrej(unit)
610    int unit;
611{
612    /*
613     * Can't reject LCP!
614     */
615    error("Received Protocol-Reject for LCP!");
616    fsm_protreject(&lcp_fsm[unit]);
617}
618
619
620/*
621 * lcp_sprotrej - Send a Protocol-Reject for some protocol.
622 */
623void
624lcp_sprotrej(unit, p, len)
625    int unit;
626    u_char *p;
627    int len;
628{
629    /*
630     * Send back the protocol and the information field of the
631     * rejected packet.  We only get here if LCP is in the OPENED state.
632     */
633    p += 2;
634    len -= 2;
635
636    fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
637	      p, len);
638}
639
640
641/*
642 * lcp_resetci - Reset our CI.
643 */
644static void
645lcp_resetci(f)
646    fsm *f;
647{
648    lcp_options *wo = &lcp_wantoptions[f->unit];
649    lcp_options *go = &lcp_gotoptions[f->unit];
650    lcp_options *ao = &lcp_allowoptions[f->unit];
651
652    wo->magicnumber = magic();
653    wo->numloops = 0;
654    *go = *wo;
655    if (!multilink) {
656	go->neg_mrru = 0;
657	go->neg_ssnhf = 0;
658	go->neg_endpoint = 0;
659    }
660    if (noendpoint)
661	ao->neg_endpoint = 0;
662    peer_mru[f->unit] = PPP_MRU;
663    auth_reset(f->unit);
664}
665
666
667/*
668 * lcp_cilen - Return length of our CI.
669 */
670static int
671lcp_cilen(f)
672    fsm *f;
673{
674    lcp_options *go = &lcp_gotoptions[f->unit];
675
676#define LENCIVOID(neg)	((neg) ? CILEN_VOID : 0)
677#define LENCICHAP(neg)	((neg) ? CILEN_CHAP : 0)
678#define LENCISHORT(neg)	((neg) ? CILEN_SHORT : 0)
679#define LENCILONG(neg)	((neg) ? CILEN_LONG : 0)
680#define LENCILQR(neg)	((neg) ? CILEN_LQR: 0)
681#define LENCICBCP(neg)	((neg) ? CILEN_CBCP: 0)
682    /*
683     * NB: we only ask for one of CHAP, UPAP, or EAP, even if we will
684     * accept more than one.  We prefer EAP first, then CHAP, then
685     * PAP.
686     */
687    return (LENCISHORT(go->neg_mru && go->mru != DEFMRU) +
688	    LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) +
689	    LENCISHORT(go->neg_eap) +
690	    LENCICHAP(!go->neg_eap && go->neg_chap) +
691	    LENCISHORT(!go->neg_eap && !go->neg_chap && go->neg_upap) +
692	    LENCILQR(go->neg_lqr) +
693	    LENCICBCP(go->neg_cbcp) +
694	    LENCILONG(go->neg_magicnumber) +
695	    LENCIVOID(go->neg_pcompression) +
696	    LENCIVOID(go->neg_accompression) +
697	    LENCISHORT(go->neg_mrru) +
698	    LENCIVOID(go->neg_ssnhf) +
699	    (go->neg_endpoint? CILEN_CHAR + go->endpoint.length: 0));
700}
701
702
703/*
704 * lcp_addci - Add our desired CIs to a packet.
705 */
706static void
707lcp_addci(f, ucp, lenp)
708    fsm *f;
709    u_char *ucp;
710    int *lenp;
711{
712    lcp_options *go = &lcp_gotoptions[f->unit];
713    u_char *start_ucp = ucp;
714
715#define ADDCIVOID(opt, neg) \
716    if (neg) { \
717	PUTCHAR(opt, ucp); \
718	PUTCHAR(CILEN_VOID, ucp); \
719    }
720#define ADDCISHORT(opt, neg, val) \
721    if (neg) { \
722	PUTCHAR(opt, ucp); \
723	PUTCHAR(CILEN_SHORT, ucp); \
724	PUTSHORT(val, ucp); \
725    }
726#define ADDCICHAP(opt, neg, val) \
727    if (neg) { \
728	PUTCHAR((opt), ucp); \
729	PUTCHAR(CILEN_CHAP, ucp); \
730	PUTSHORT(PPP_CHAP, ucp); \
731	PUTCHAR((CHAP_DIGEST(val)), ucp); \
732    }
733#define ADDCILONG(opt, neg, val) \
734    if (neg) { \
735	PUTCHAR(opt, ucp); \
736	PUTCHAR(CILEN_LONG, ucp); \
737	PUTLONG(val, ucp); \
738    }
739#define ADDCILQR(opt, neg, val) \
740    if (neg) { \
741	PUTCHAR(opt, ucp); \
742	PUTCHAR(CILEN_LQR, ucp); \
743	PUTSHORT(PPP_LQR, ucp); \
744	PUTLONG(val, ucp); \
745    }
746#define ADDCICHAR(opt, neg, val) \
747    if (neg) { \
748	PUTCHAR(opt, ucp); \
749	PUTCHAR(CILEN_CHAR, ucp); \
750	PUTCHAR(val, ucp); \
751    }
752#define ADDCIENDP(opt, neg, class, val, len) \
753    if (neg) { \
754	int i; \
755	PUTCHAR(opt, ucp); \
756	PUTCHAR(CILEN_CHAR + len, ucp); \
757	PUTCHAR(class, ucp); \
758	for (i = 0; i < len; ++i) \
759	    PUTCHAR(val[i], ucp); \
760    }
761
762    ADDCISHORT(CI_MRU, go->neg_mru && go->mru != DEFMRU, go->mru);
763    ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
764	      go->asyncmap);
765    ADDCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
766    ADDCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
767    ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap,
768	       PPP_PAP);
769    ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
770    ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
771    ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
772    ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
773    ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
774    ADDCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
775    ADDCIVOID(CI_SSNHF, go->neg_ssnhf);
776    ADDCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class,
777	      go->endpoint.value, go->endpoint.length);
778
779    if (ucp - start_ucp != *lenp) {
780	/* this should never happen, because peer_mtu should be 1500 */
781	error("Bug in lcp_addci: wrong length");
782    }
783}
784
785
786/*
787 * lcp_ackci - Ack our CIs.
788 * This should not modify any state if the Ack is bad.
789 *
790 * Returns:
791 *	0 - Ack was bad.
792 *	1 - Ack was good.
793 */
794static int
795lcp_ackci(f, p, len)
796    fsm *f;
797    u_char *p;
798    int len;
799{
800    lcp_options *go = &lcp_gotoptions[f->unit];
801    u_char cilen, citype, cichar;
802    u_short cishort;
803    u_int32_t cilong;
804
805    /*
806     * CIs must be in exactly the same order that we sent.
807     * Check packet length and CI length at each step.
808     * If we find any deviations, then this packet is bad.
809     */
810#define ACKCIVOID(opt, neg) \
811    if (neg) { \
812	if ((len -= CILEN_VOID) < 0) \
813	    goto bad; \
814	GETCHAR(citype, p); \
815	GETCHAR(cilen, p); \
816	if (cilen != CILEN_VOID || \
817	    citype != opt) \
818	    goto bad; \
819    }
820#define ACKCISHORT(opt, neg, val) \
821    if (neg) { \
822	if ((len -= CILEN_SHORT) < 0) \
823	    goto bad; \
824	GETCHAR(citype, p); \
825	GETCHAR(cilen, p); \
826	if (cilen != CILEN_SHORT || \
827	    citype != opt) \
828	    goto bad; \
829	GETSHORT(cishort, p); \
830	if (cishort != val) \
831	    goto bad; \
832    }
833#define ACKCICHAR(opt, neg, val) \
834    if (neg) { \
835	if ((len -= CILEN_CHAR) < 0) \
836	    goto bad; \
837	GETCHAR(citype, p); \
838	GETCHAR(cilen, p); \
839	if (cilen != CILEN_CHAR || \
840	    citype != opt) \
841	    goto bad; \
842	GETCHAR(cichar, p); \
843	if (cichar != val) \
844	    goto bad; \
845    }
846#define ACKCICHAP(opt, neg, val) \
847    if (neg) { \
848	if ((len -= CILEN_CHAP) < 0) \
849	    goto bad; \
850	GETCHAR(citype, p); \
851	GETCHAR(cilen, p); \
852	if (cilen != CILEN_CHAP || \
853	    citype != (opt)) \
854	    goto bad; \
855	GETSHORT(cishort, p); \
856	if (cishort != PPP_CHAP) \
857	    goto bad; \
858	GETCHAR(cichar, p); \
859	if (cichar != (CHAP_DIGEST(val))) \
860	  goto bad; \
861    }
862#define ACKCILONG(opt, neg, val) \
863    if (neg) { \
864	if ((len -= CILEN_LONG) < 0) \
865	    goto bad; \
866	GETCHAR(citype, p); \
867	GETCHAR(cilen, p); \
868	if (cilen != CILEN_LONG || \
869	    citype != opt) \
870	    goto bad; \
871	GETLONG(cilong, p); \
872	if (cilong != val) \
873	    goto bad; \
874    }
875#define ACKCILQR(opt, neg, val) \
876    if (neg) { \
877	if ((len -= CILEN_LQR) < 0) \
878	    goto bad; \
879	GETCHAR(citype, p); \
880	GETCHAR(cilen, p); \
881	if (cilen != CILEN_LQR || \
882	    citype != opt) \
883	    goto bad; \
884	GETSHORT(cishort, p); \
885	if (cishort != PPP_LQR) \
886	    goto bad; \
887	GETLONG(cilong, p); \
888	if (cilong != val) \
889	  goto bad; \
890    }
891#define ACKCIENDP(opt, neg, class, val, vlen) \
892    if (neg) { \
893	int i; \
894	if ((len -= CILEN_CHAR + vlen) < 0) \
895	    goto bad; \
896	GETCHAR(citype, p); \
897	GETCHAR(cilen, p); \
898	if (cilen != CILEN_CHAR + vlen || \
899	    citype != opt) \
900	    goto bad; \
901	GETCHAR(cichar, p); \
902	if (cichar != class) \
903	    goto bad; \
904	for (i = 0; i < vlen; ++i) { \
905	    GETCHAR(cichar, p); \
906	    if (cichar != val[i]) \
907		goto bad; \
908	} \
909    }
910
911    ACKCISHORT(CI_MRU, go->neg_mru && go->mru != DEFMRU, go->mru);
912    ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
913	      go->asyncmap);
914    ACKCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
915    ACKCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
916    ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap,
917	       PPP_PAP);
918    ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
919    ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
920    ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
921    ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
922    ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
923    ACKCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
924    ACKCIVOID(CI_SSNHF, go->neg_ssnhf);
925    ACKCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class,
926	      go->endpoint.value, go->endpoint.length);
927
928    /*
929     * If there are any remaining CIs, then this packet is bad.
930     */
931    if (len != 0)
932	goto bad;
933    return (1);
934bad:
935    LCPDEBUG(("lcp_acki: received bad Ack!"));
936    return (0);
937}
938
939
940/*
941 * lcp_nakci - Peer has sent a NAK for some of our CIs.
942 * This should not modify any state if the Nak is bad
943 * or if LCP is in the OPENED state.
944 *
945 * Returns:
946 *	0 - Nak was bad.
947 *	1 - Nak was good.
948 */
949static int
950lcp_nakci(f, p, len, treat_as_reject)
951    fsm *f;
952    u_char *p;
953    int len;
954    int treat_as_reject;
955{
956    lcp_options *go = &lcp_gotoptions[f->unit];
957    lcp_options *wo = &lcp_wantoptions[f->unit];
958    u_char citype, cichar, *next;
959    u_short cishort;
960    u_int32_t cilong;
961    lcp_options no;		/* options we've seen Naks for */
962    lcp_options try;		/* options to request next time */
963    int looped_back = 0;
964    int cilen;
965
966    BZERO(&no, sizeof(no));
967    try = *go;
968
969    /*
970     * Any Nak'd CIs must be in exactly the same order that we sent.
971     * Check packet length and CI length at each step.
972     * If we find any deviations, then this packet is bad.
973     */
974#define NAKCIVOID(opt, neg) \
975    if (go->neg && \
976	len >= CILEN_VOID && \
977	p[1] == CILEN_VOID && \
978	p[0] == opt) { \
979	len -= CILEN_VOID; \
980	INCPTR(CILEN_VOID, p); \
981	no.neg = 1; \
982	try.neg = 0; \
983    }
984#define NAKCICHAP(opt, neg, code) \
985    if (go->neg && \
986	len >= CILEN_CHAP && \
987	p[1] == CILEN_CHAP && \
988	p[0] == opt) { \
989	len -= CILEN_CHAP; \
990	INCPTR(2, p); \
991	GETSHORT(cishort, p); \
992	GETCHAR(cichar, p); \
993	no.neg = 1; \
994	code \
995    }
996#define NAKCICHAR(opt, neg, code) \
997    if (go->neg && \
998	len >= CILEN_CHAR && \
999	p[1] == CILEN_CHAR && \
1000	p[0] == opt) { \
1001	len -= CILEN_CHAR; \
1002	INCPTR(2, p); \
1003	GETCHAR(cichar, p); \
1004	no.neg = 1; \
1005	code \
1006    }
1007#define NAKCISHORT(opt, neg, code) \
1008    if (go->neg && \
1009	len >= CILEN_SHORT && \
1010	p[1] == CILEN_SHORT && \
1011	p[0] == opt) { \
1012	len -= CILEN_SHORT; \
1013	INCPTR(2, p); \
1014	GETSHORT(cishort, p); \
1015	no.neg = 1; \
1016	code \
1017    }
1018#define NAKCILONG(opt, neg, code) \
1019    if (go->neg && \
1020	len >= CILEN_LONG && \
1021	p[1] == CILEN_LONG && \
1022	p[0] == opt) { \
1023	len -= CILEN_LONG; \
1024	INCPTR(2, p); \
1025	GETLONG(cilong, p); \
1026	no.neg = 1; \
1027	code \
1028    }
1029#define NAKCILQR(opt, neg, code) \
1030    if (go->neg && \
1031	len >= CILEN_LQR && \
1032	p[1] == CILEN_LQR && \
1033	p[0] == opt) { \
1034	len -= CILEN_LQR; \
1035	INCPTR(2, p); \
1036	GETSHORT(cishort, p); \
1037	GETLONG(cilong, p); \
1038	no.neg = 1; \
1039	code \
1040    }
1041#define NAKCIENDP(opt, neg) \
1042    if (go->neg && \
1043	len >= CILEN_CHAR && \
1044	p[0] == opt && \
1045	p[1] >= CILEN_CHAR && \
1046	p[1] <= len) { \
1047	len -= p[1]; \
1048	INCPTR(p[1], p); \
1049	no.neg = 1; \
1050	try.neg = 0; \
1051    }
1052
1053    /*
1054     * NOTE!  There must be no assignments to individual fields of *go in
1055     * the code below.  Any such assignment is a BUG!
1056     */
1057    /*
1058     * We don't care if they want to send us smaller packets than
1059     * we want.  Therefore, accept any MRU less than what we asked for,
1060     * but then ignore the new value when setting the MRU in the kernel.
1061     * If they send us a bigger MRU than what we asked, accept it, up to
1062     * the limit of the default MRU we'd get if we didn't negotiate.
1063     */
1064    if (go->neg_mru && go->mru != DEFMRU) {
1065	NAKCISHORT(CI_MRU, neg_mru,
1066		   if (cishort <= wo->mru || cishort <= DEFMRU)
1067		       try.mru = cishort;
1068		   );
1069    }
1070
1071    /*
1072     * Add any characters they want to our (receive-side) asyncmap.
1073     */
1074    if (go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) {
1075	NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
1076		  try.asyncmap = go->asyncmap | cilong;
1077		  );
1078    }
1079
1080    /*
1081     * If they've nak'd our authentication-protocol, check whether
1082     * they are proposing a different protocol, or a different
1083     * hash algorithm for CHAP.
1084     */
1085    if ((go->neg_chap || go->neg_upap || go->neg_eap)
1086	&& len >= CILEN_SHORT
1087	&& p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
1088	cilen = p[1];
1089	len -= cilen;
1090	no.neg_chap = go->neg_chap;
1091	no.neg_upap = go->neg_upap;
1092	no.neg_eap = go->neg_eap;
1093	INCPTR(2, p);
1094	GETSHORT(cishort, p);
1095	if (cishort == PPP_PAP && cilen == CILEN_SHORT) {
1096	    /* If we were asking for EAP, then we need to stop that. */
1097	    if (go->neg_eap)
1098		try.neg_eap = 0;
1099
1100	    /* If we were asking for CHAP, then we need to stop that. */
1101	    else if (go->neg_chap)
1102		try.neg_chap = 0;
1103	    /*
1104	     * If we weren't asking for CHAP or EAP, then we were asking for
1105	     * PAP, in which case this Nak is bad.
1106	     */
1107	    else
1108		goto bad;
1109
1110	} else if (cishort == PPP_CHAP && cilen == CILEN_CHAP) {
1111	    GETCHAR(cichar, p);
1112	    /* Stop asking for EAP, if we were. */
1113	    if (go->neg_eap) {
1114		try.neg_eap = 0;
1115		/* Try to set up to use their suggestion, if possible */
1116		if (CHAP_CANDIGEST(go->chap_mdtype, cichar))
1117		    try.chap_mdtype = CHAP_MDTYPE_D(cichar);
1118	    } else if (go->neg_chap) {
1119		/*
1120		 * We were asking for our preferred algorithm, they must
1121		 * want something different.
1122		 */
1123		if (cichar != CHAP_DIGEST(go->chap_mdtype)) {
1124		    if (CHAP_CANDIGEST(go->chap_mdtype, cichar)) {
1125			/* Use their suggestion if we support it ... */
1126			try.chap_mdtype = CHAP_MDTYPE_D(cichar);
1127		    } else {
1128			/* ... otherwise, try our next-preferred algorithm. */
1129			try.chap_mdtype &= ~(CHAP_MDTYPE(try.chap_mdtype));
1130			if (try.chap_mdtype == MDTYPE_NONE) /* out of algos */
1131			    try.neg_chap = 0;
1132		    }
1133		} else {
1134		    /*
1135		     * Whoops, they Nak'd our algorithm of choice
1136		     * but then suggested it back to us.
1137		     */
1138		    goto bad;
1139		}
1140	    } else {
1141		/*
1142		 * Stop asking for PAP if we were asking for it.
1143		 */
1144		try.neg_upap = 0;
1145	    }
1146
1147	} else {
1148
1149	    /*
1150	     * If we were asking for EAP, and they're Conf-Naking EAP,
1151	     * well, that's just strange.  Nobody should do that.
1152	     */
1153	    if (cishort == PPP_EAP && cilen == CILEN_SHORT && go->neg_eap)
1154		dbglog("Unexpected Conf-Nak for EAP");
1155
1156	    /*
1157	     * We don't recognize what they're suggesting.
1158	     * Stop asking for what we were asking for.
1159	     */
1160	    if (go->neg_eap)
1161		try.neg_eap = 0;
1162	    else if (go->neg_chap)
1163		try.neg_chap = 0;
1164	    else
1165		try.neg_upap = 0;
1166	    p += cilen - CILEN_SHORT;
1167	}
1168    }
1169
1170    /*
1171     * If they can't cope with our link quality protocol, we'll have
1172     * to stop asking for LQR.  We haven't got any other protocol.
1173     * If they Nak the reporting period, take their value XXX ?
1174     */
1175    NAKCILQR(CI_QUALITY, neg_lqr,
1176	     if (cishort != PPP_LQR)
1177		 try.neg_lqr = 0;
1178	     else
1179		 try.lqr_period = cilong;
1180	     );
1181
1182    /*
1183     * Only implementing CBCP...not the rest of the callback options
1184     */
1185    NAKCICHAR(CI_CALLBACK, neg_cbcp,
1186              try.neg_cbcp = 0;
1187              );
1188
1189    /*
1190     * Check for a looped-back line.
1191     */
1192    NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
1193	      try.magicnumber = magic();
1194	      looped_back = 1;
1195	      );
1196
1197    /*
1198     * Peer shouldn't send Nak for protocol compression or
1199     * address/control compression requests; they should send
1200     * a Reject instead.  If they send a Nak, treat it as a Reject.
1201     */
1202    NAKCIVOID(CI_PCOMPRESSION, neg_pcompression);
1203    NAKCIVOID(CI_ACCOMPRESSION, neg_accompression);
1204
1205    /*
1206     * Nak for MRRU option - accept their value if it is smaller
1207     * than the one we want.
1208     */
1209    if (go->neg_mrru) {
1210	NAKCISHORT(CI_MRRU, neg_mrru,
1211		   if (treat_as_reject)
1212		       try.neg_mrru = 0;
1213		   else if (cishort <= wo->mrru)
1214		       try.mrru = cishort;
1215		   );
1216    }
1217
1218    /*
1219     * Nak for short sequence numbers shouldn't be sent, treat it
1220     * like a reject.
1221     */
1222    NAKCIVOID(CI_SSNHF, neg_ssnhf);
1223
1224    /*
1225     * Nak of the endpoint discriminator option is not permitted,
1226     * treat it like a reject.
1227     */
1228    NAKCIENDP(CI_EPDISC, neg_endpoint);
1229
1230    /*
1231     * There may be remaining CIs, if the peer is requesting negotiation
1232     * on an option that we didn't include in our request packet.
1233     * If we see an option that we requested, or one we've already seen
1234     * in this packet, then this packet is bad.
1235     * If we wanted to respond by starting to negotiate on the requested
1236     * option(s), we could, but we don't, because except for the
1237     * authentication type and quality protocol, if we are not negotiating
1238     * an option, it is because we were told not to.
1239     * For the authentication type, the Nak from the peer means
1240     * `let me authenticate myself with you' which is a bit pointless.
1241     * For the quality protocol, the Nak means `ask me to send you quality
1242     * reports', but if we didn't ask for them, we don't want them.
1243     * An option we don't recognize represents the peer asking to
1244     * negotiate some option we don't support, so ignore it.
1245     */
1246    while (len >= CILEN_VOID) {
1247	GETCHAR(citype, p);
1248	GETCHAR(cilen, p);
1249	if (cilen < CILEN_VOID || (len -= cilen) < 0)
1250	    goto bad;
1251	next = p + cilen - 2;
1252
1253	switch (citype) {
1254	case CI_MRU:
1255	    if ((go->neg_mru && go->mru != DEFMRU)
1256		|| no.neg_mru || cilen != CILEN_SHORT)
1257		goto bad;
1258	    GETSHORT(cishort, p);
1259	    if (cishort < DEFMRU) {
1260		try.neg_mru = 1;
1261		try.mru = cishort;
1262	    }
1263	    break;
1264	case CI_ASYNCMAP:
1265	    if ((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF)
1266		|| no.neg_asyncmap || cilen != CILEN_LONG)
1267		goto bad;
1268	    break;
1269	case CI_AUTHTYPE:
1270	    if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap ||
1271		go->neg_eap || no.neg_eap)
1272		goto bad;
1273	    break;
1274	case CI_MAGICNUMBER:
1275	    if (go->neg_magicnumber || no.neg_magicnumber ||
1276		cilen != CILEN_LONG)
1277		goto bad;
1278	    break;
1279	case CI_PCOMPRESSION:
1280	    if (go->neg_pcompression || no.neg_pcompression
1281		|| cilen != CILEN_VOID)
1282		goto bad;
1283	    break;
1284	case CI_ACCOMPRESSION:
1285	    if (go->neg_accompression || no.neg_accompression
1286		|| cilen != CILEN_VOID)
1287		goto bad;
1288	    break;
1289	case CI_QUALITY:
1290	    if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
1291		goto bad;
1292	    break;
1293	case CI_MRRU:
1294	    if (go->neg_mrru || no.neg_mrru || cilen != CILEN_SHORT)
1295		goto bad;
1296	    break;
1297	case CI_SSNHF:
1298	    if (go->neg_ssnhf || no.neg_ssnhf || cilen != CILEN_VOID)
1299		goto bad;
1300	    try.neg_ssnhf = 1;
1301	    break;
1302	case CI_EPDISC:
1303	    if (go->neg_endpoint || no.neg_endpoint || cilen < CILEN_CHAR)
1304		goto bad;
1305	    break;
1306	}
1307	p = next;
1308    }
1309
1310    /*
1311     * OK, the Nak is good.  Now we can update state.
1312     * If there are any options left we ignore them.
1313     */
1314    if (f->state != OPENED) {
1315	if (looped_back) {
1316	    if (++try.numloops >= lcp_loopbackfail) {
1317		notice("Serial line is looped back.");
1318		status = EXIT_LOOPBACK;
1319		lcp_close(f->unit, "Loopback detected");
1320	    }
1321	} else
1322	    try.numloops = 0;
1323	*go = try;
1324    }
1325
1326    return 1;
1327
1328bad:
1329    LCPDEBUG(("lcp_nakci: received bad Nak!"));
1330    return 0;
1331}
1332
1333
1334/*
1335 * lcp_rejci - Peer has Rejected some of our CIs.
1336 * This should not modify any state if the Reject is bad
1337 * or if LCP is in the OPENED state.
1338 *
1339 * Returns:
1340 *	0 - Reject was bad.
1341 *	1 - Reject was good.
1342 */
1343static int
1344lcp_rejci(f, p, len)
1345    fsm *f;
1346    u_char *p;
1347    int len;
1348{
1349    lcp_options *go = &lcp_gotoptions[f->unit];
1350    u_char cichar;
1351    u_short cishort;
1352    u_int32_t cilong;
1353    lcp_options try;		/* options to request next time */
1354
1355    try = *go;
1356
1357    /*
1358     * Any Rejected CIs must be in exactly the same order that we sent.
1359     * Check packet length and CI length at each step.
1360     * If we find any deviations, then this packet is bad.
1361     */
1362#define REJCIVOID(opt, neg) \
1363    if (go->neg && \
1364	len >= CILEN_VOID && \
1365	p[1] == CILEN_VOID && \
1366	p[0] == opt) { \
1367	len -= CILEN_VOID; \
1368	INCPTR(CILEN_VOID, p); \
1369	try.neg = 0; \
1370    }
1371#define REJCISHORT(opt, neg, val) \
1372    if (go->neg && \
1373	len >= CILEN_SHORT && \
1374	p[1] == CILEN_SHORT && \
1375	p[0] == opt) { \
1376	len -= CILEN_SHORT; \
1377	INCPTR(2, p); \
1378	GETSHORT(cishort, p); \
1379	/* Check rejected value. */ \
1380	if (cishort != val) \
1381	    goto bad; \
1382	try.neg = 0; \
1383    }
1384#define REJCICHAP(opt, neg, val) \
1385    if (go->neg && \
1386	len >= CILEN_CHAP && \
1387	p[1] == CILEN_CHAP && \
1388	p[0] == opt) { \
1389	len -= CILEN_CHAP; \
1390	INCPTR(2, p); \
1391	GETSHORT(cishort, p); \
1392	GETCHAR(cichar, p); \
1393	/* Check rejected value. */ \
1394	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
1395	    goto bad; \
1396	try.neg = 0; \
1397	try.neg_eap = try.neg_upap = 0; \
1398    }
1399#define REJCILONG(opt, neg, val) \
1400    if (go->neg && \
1401	len >= CILEN_LONG && \
1402	p[1] == CILEN_LONG && \
1403	p[0] == opt) { \
1404	len -= CILEN_LONG; \
1405	INCPTR(2, p); \
1406	GETLONG(cilong, p); \
1407	/* Check rejected value. */ \
1408	if (cilong != val) \
1409	    goto bad; \
1410	try.neg = 0; \
1411    }
1412#define REJCILQR(opt, neg, val) \
1413    if (go->neg && \
1414	len >= CILEN_LQR && \
1415	p[1] == CILEN_LQR && \
1416	p[0] == opt) { \
1417	len -= CILEN_LQR; \
1418	INCPTR(2, p); \
1419	GETSHORT(cishort, p); \
1420	GETLONG(cilong, p); \
1421	/* Check rejected value. */ \
1422	if (cishort != PPP_LQR || cilong != val) \
1423	    goto bad; \
1424	try.neg = 0; \
1425    }
1426#define REJCICBCP(opt, neg, val) \
1427    if (go->neg && \
1428	len >= CILEN_CBCP && \
1429	p[1] == CILEN_CBCP && \
1430	p[0] == opt) { \
1431	len -= CILEN_CBCP; \
1432	INCPTR(2, p); \
1433	GETCHAR(cichar, p); \
1434	/* Check rejected value. */ \
1435	if (cichar != val) \
1436	    goto bad; \
1437	try.neg = 0; \
1438    }
1439#define REJCIENDP(opt, neg, class, val, vlen) \
1440    if (go->neg && \
1441	len >= CILEN_CHAR + vlen && \
1442	p[0] == opt && \
1443	p[1] == CILEN_CHAR + vlen) { \
1444	int i; \
1445	len -= CILEN_CHAR + vlen; \
1446	INCPTR(2, p); \
1447	GETCHAR(cichar, p); \
1448	if (cichar != class) \
1449	    goto bad; \
1450	for (i = 0; i < vlen; ++i) { \
1451	    GETCHAR(cichar, p); \
1452	    if (cichar != val[i]) \
1453		goto bad; \
1454	} \
1455	try.neg = 0; \
1456    }
1457
1458    REJCISHORT(CI_MRU, neg_mru, go->mru);
1459    REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
1460    REJCISHORT(CI_AUTHTYPE, neg_eap, PPP_EAP);
1461    if (!go->neg_eap) {
1462	REJCICHAP(CI_AUTHTYPE, neg_chap, go->chap_mdtype);
1463	if (!go->neg_chap) {
1464	    REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
1465	}
1466    }
1467    REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
1468    REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
1469    REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
1470    REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
1471    REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
1472    REJCISHORT(CI_MRRU, neg_mrru, go->mrru);
1473    REJCIVOID(CI_SSNHF, neg_ssnhf);
1474    REJCIENDP(CI_EPDISC, neg_endpoint, go->endpoint.class,
1475	      go->endpoint.value, go->endpoint.length);
1476
1477    /*
1478     * If there are any remaining CIs, then this packet is bad.
1479     */
1480    if (len != 0)
1481	goto bad;
1482    /*
1483     * Now we can update state.
1484     */
1485    if (f->state != OPENED)
1486	*go = try;
1487    return 1;
1488
1489bad:
1490    LCPDEBUG(("lcp_rejci: received bad Reject!"));
1491    return 0;
1492}
1493
1494
1495/*
1496 * lcp_reqci - Check the peer's requested CIs and send appropriate response.
1497 *
1498 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
1499 * appropriately.  If reject_if_disagree is non-zero, doesn't return
1500 * CONFNAK; returns CONFREJ if it can't return CONFACK.
1501 */
1502static int
1503lcp_reqci(f, inp, lenp, reject_if_disagree)
1504    fsm *f;
1505    u_char *inp;		/* Requested CIs */
1506    int *lenp;			/* Length of requested CIs */
1507    int reject_if_disagree;
1508{
1509    lcp_options *go = &lcp_gotoptions[f->unit];
1510    lcp_options *ho = &lcp_hisoptions[f->unit];
1511    lcp_options *ao = &lcp_allowoptions[f->unit];
1512    u_char *cip, *next;		/* Pointer to current and next CIs */
1513    int cilen, citype, cichar;	/* Parsed len, type, char value */
1514    u_short cishort;		/* Parsed short value */
1515    u_int32_t cilong;		/* Parse long value */
1516    int rc = CONFACK;		/* Final packet return code */
1517    int orc;			/* Individual option return code */
1518    u_char *p;			/* Pointer to next char to parse */
1519    u_char *rejp;		/* Pointer to next char in reject frame */
1520    u_char *nakp;		/* Pointer to next char in Nak frame */
1521    int l = *lenp;		/* Length left */
1522
1523    /*
1524     * Reset all his options.
1525     */
1526    BZERO(ho, sizeof(*ho));
1527
1528    /*
1529     * Process all his options.
1530     */
1531    next = inp;
1532    nakp = nak_buffer;
1533    rejp = inp;
1534    while (l) {
1535	orc = CONFACK;			/* Assume success */
1536	cip = p = next;			/* Remember begining of CI */
1537	if (l < 2 ||			/* Not enough data for CI header or */
1538	    p[1] < 2 ||			/*  CI length too small or */
1539	    p[1] > l) {			/*  CI length too big? */
1540	    LCPDEBUG(("lcp_reqci: bad CI length!"));
1541	    orc = CONFREJ;		/* Reject bad CI */
1542	    cilen = l;			/* Reject till end of packet */
1543	    l = 0;			/* Don't loop again */
1544	    citype = 0;
1545	    goto endswitch;
1546	}
1547	GETCHAR(citype, p);		/* Parse CI type */
1548	GETCHAR(cilen, p);		/* Parse CI length */
1549	l -= cilen;			/* Adjust remaining length */
1550	next += cilen;			/* Step to next CI */
1551
1552	switch (citype) {		/* Check CI type */
1553	case CI_MRU:
1554	    if (!ao->neg_mru ||		/* Allow option? */
1555		cilen != CILEN_SHORT) {	/* Check CI length */
1556		orc = CONFREJ;		/* Reject CI */
1557		break;
1558	    }
1559	    GETSHORT(cishort, p);	/* Parse MRU */
1560
1561	    /*
1562	     * He must be able to receive at least our minimum.
1563	     * No need to check a maximum.  If he sends a large number,
1564	     * we'll just ignore it.
1565	     */
1566	    if (cishort < MINMRU) {
1567		orc = CONFNAK;		/* Nak CI */
1568		PUTCHAR(CI_MRU, nakp);
1569		PUTCHAR(CILEN_SHORT, nakp);
1570		PUTSHORT(MINMRU, nakp);	/* Give him a hint */
1571		break;
1572	    }
1573	    ho->neg_mru = 1;		/* Remember he sent MRU */
1574	    ho->mru = cishort;		/* And remember value */
1575	    break;
1576
1577	case CI_ASYNCMAP:
1578	    if (!ao->neg_asyncmap ||
1579		cilen != CILEN_LONG) {
1580		orc = CONFREJ;
1581		break;
1582	    }
1583	    GETLONG(cilong, p);
1584
1585	    /*
1586	     * Asyncmap must have set at least the bits
1587	     * which are set in lcp_allowoptions[unit].asyncmap.
1588	     */
1589	    if ((ao->asyncmap & ~cilong) != 0) {
1590		orc = CONFNAK;
1591		PUTCHAR(CI_ASYNCMAP, nakp);
1592		PUTCHAR(CILEN_LONG, nakp);
1593		PUTLONG(ao->asyncmap | cilong, nakp);
1594		break;
1595	    }
1596	    ho->neg_asyncmap = 1;
1597	    ho->asyncmap = cilong;
1598	    break;
1599
1600	case CI_AUTHTYPE:
1601	    if (cilen < CILEN_SHORT ||
1602		!(ao->neg_upap || ao->neg_chap || ao->neg_eap)) {
1603		/*
1604		 * Reject the option if we're not willing to authenticate.
1605		 */
1606		dbglog("No auth is possible");
1607		orc = CONFREJ;
1608		break;
1609	    }
1610	    GETSHORT(cishort, p);
1611
1612	    /*
1613	     * Authtype must be PAP, CHAP, or EAP.
1614	     *
1615	     * Note: if more than one of ao->neg_upap, ao->neg_chap, and
1616	     * ao->neg_eap are set, and the peer sends a Configure-Request
1617	     * with two or more authenticate-protocol requests, then we will
1618	     * reject the second request.
1619	     * Whether we end up doing CHAP, UPAP, or EAP depends then on
1620	     * the ordering of the CIs in the peer's Configure-Request.
1621             */
1622
1623	    if (cishort == PPP_PAP) {
1624		/* we've already accepted CHAP or EAP */
1625		if (ho->neg_chap || ho->neg_eap ||
1626		    cilen != CILEN_SHORT) {
1627		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
1628		    orc = CONFREJ;
1629		    break;
1630		}
1631		if (!ao->neg_upap) {	/* we don't want to do PAP */
1632		    orc = CONFNAK;	/* NAK it and suggest CHAP or EAP */
1633		    PUTCHAR(CI_AUTHTYPE, nakp);
1634		    if (ao->neg_eap) {
1635			PUTCHAR(CILEN_SHORT, nakp);
1636			PUTSHORT(PPP_EAP, nakp);
1637		    } else {
1638			PUTCHAR(CILEN_CHAP, nakp);
1639			PUTSHORT(PPP_CHAP, nakp);
1640			PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
1641		    }
1642		    break;
1643		}
1644		ho->neg_upap = 1;
1645		break;
1646	    }
1647	    if (cishort == PPP_CHAP) {
1648		/* we've already accepted PAP or EAP */
1649		if (ho->neg_upap || ho->neg_eap ||
1650		    cilen != CILEN_CHAP) {
1651		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
1652		    orc = CONFREJ;
1653		    break;
1654		}
1655		if (!ao->neg_chap) {	/* we don't want to do CHAP */
1656		    orc = CONFNAK;	/* NAK it and suggest EAP or PAP */
1657		    PUTCHAR(CI_AUTHTYPE, nakp);
1658		    PUTCHAR(CILEN_SHORT, nakp);
1659		    if (ao->neg_eap) {
1660			PUTSHORT(PPP_EAP, nakp);
1661		    } else {
1662			PUTSHORT(PPP_PAP, nakp);
1663		    }
1664		    break;
1665		}
1666		GETCHAR(cichar, p);	/* get digest type */
1667		if (!(CHAP_CANDIGEST(ao->chap_mdtype, cichar))) {
1668		    /*
1669		     * We can't/won't do the requested type,
1670		     * suggest something else.
1671		     */
1672		    orc = CONFNAK;
1673		    PUTCHAR(CI_AUTHTYPE, nakp);
1674		    PUTCHAR(CILEN_CHAP, nakp);
1675		    PUTSHORT(PPP_CHAP, nakp);
1676		    PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
1677		    break;
1678		}
1679		ho->chap_mdtype = CHAP_MDTYPE_D(cichar); /* save md type */
1680		ho->neg_chap = 1;
1681		break;
1682	    }
1683	    if (cishort == PPP_EAP) {
1684		/* we've already accepted CHAP or PAP */
1685		if (ho->neg_chap || ho->neg_upap || cilen != CILEN_SHORT) {
1686		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE EAP, rejecting..."));
1687		    orc = CONFREJ;
1688		    break;
1689		}
1690		if (!ao->neg_eap) {	/* we don't want to do EAP */
1691		    orc = CONFNAK;	/* NAK it and suggest CHAP or PAP */
1692		    PUTCHAR(CI_AUTHTYPE, nakp);
1693		    if (ao->neg_chap) {
1694			PUTCHAR(CILEN_CHAP, nakp);
1695			PUTSHORT(PPP_CHAP, nakp);
1696			PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
1697		    } else {
1698			PUTCHAR(CILEN_SHORT, nakp);
1699			PUTSHORT(PPP_PAP, nakp);
1700		    }
1701		    break;
1702		}
1703		ho->neg_eap = 1;
1704		break;
1705	    }
1706
1707	    /*
1708	     * We don't recognize the protocol they're asking for.
1709	     * Nak it with something we're willing to do.
1710	     * (At this point we know ao->neg_upap || ao->neg_chap ||
1711	     * ao->neg_eap.)
1712	     */
1713	    orc = CONFNAK;
1714	    PUTCHAR(CI_AUTHTYPE, nakp);
1715	    if (ao->neg_eap) {
1716		PUTCHAR(CILEN_SHORT, nakp);
1717		PUTSHORT(PPP_EAP, nakp);
1718	    } else if (ao->neg_chap) {
1719		PUTCHAR(CILEN_CHAP, nakp);
1720		PUTSHORT(PPP_CHAP, nakp);
1721		PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakp);
1722	    } else {
1723		PUTCHAR(CILEN_SHORT, nakp);
1724		PUTSHORT(PPP_PAP, nakp);
1725	    }
1726	    break;
1727
1728	case CI_QUALITY:
1729	    if (!ao->neg_lqr ||
1730		cilen != CILEN_LQR) {
1731		orc = CONFREJ;
1732		break;
1733	    }
1734
1735	    GETSHORT(cishort, p);
1736	    GETLONG(cilong, p);
1737
1738	    /*
1739	     * Check the protocol and the reporting period.
1740	     * XXX When should we Nak this, and what with?
1741	     */
1742	    if (cishort != PPP_LQR) {
1743		orc = CONFNAK;
1744		PUTCHAR(CI_QUALITY, nakp);
1745		PUTCHAR(CILEN_LQR, nakp);
1746		PUTSHORT(PPP_LQR, nakp);
1747		PUTLONG(ao->lqr_period, nakp);
1748		break;
1749	    }
1750	    break;
1751
1752	case CI_MAGICNUMBER:
1753	    if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
1754		cilen != CILEN_LONG) {
1755		orc = CONFREJ;
1756		break;
1757	    }
1758	    GETLONG(cilong, p);
1759
1760	    /*
1761	     * He must have a different magic number.
1762	     */
1763	    if (go->neg_magicnumber &&
1764		cilong == go->magicnumber) {
1765		cilong = magic();	/* Don't put magic() inside macro! */
1766		orc = CONFNAK;
1767		PUTCHAR(CI_MAGICNUMBER, nakp);
1768		PUTCHAR(CILEN_LONG, nakp);
1769		PUTLONG(cilong, nakp);
1770		break;
1771	    }
1772	    ho->neg_magicnumber = 1;
1773	    ho->magicnumber = cilong;
1774	    break;
1775
1776
1777	case CI_PCOMPRESSION:
1778	    if (!ao->neg_pcompression ||
1779		cilen != CILEN_VOID) {
1780		orc = CONFREJ;
1781		break;
1782	    }
1783	    ho->neg_pcompression = 1;
1784	    break;
1785
1786	case CI_ACCOMPRESSION:
1787	    if (!ao->neg_accompression ||
1788		cilen != CILEN_VOID) {
1789		orc = CONFREJ;
1790		break;
1791	    }
1792	    ho->neg_accompression = 1;
1793	    break;
1794
1795	case CI_MRRU:
1796	    if (!ao->neg_mrru || !multilink ||
1797		cilen != CILEN_SHORT) {
1798		orc = CONFREJ;
1799		break;
1800	    }
1801
1802	    GETSHORT(cishort, p);
1803	    /* possibly should insist on a minimum/maximum MRRU here */
1804	    ho->neg_mrru = 1;
1805	    ho->mrru = cishort;
1806	    break;
1807
1808	case CI_SSNHF:
1809	    if (!ao->neg_ssnhf || !multilink ||
1810		cilen != CILEN_VOID) {
1811		orc = CONFREJ;
1812		break;
1813	    }
1814	    ho->neg_ssnhf = 1;
1815	    break;
1816
1817	case CI_EPDISC:
1818	    if (!ao->neg_endpoint ||
1819		cilen < CILEN_CHAR ||
1820		cilen > CILEN_CHAR + MAX_ENDP_LEN) {
1821		orc = CONFREJ;
1822		break;
1823	    }
1824	    GETCHAR(cichar, p);
1825	    cilen -= CILEN_CHAR;
1826	    ho->neg_endpoint = 1;
1827	    ho->endpoint.class = cichar;
1828	    ho->endpoint.length = cilen;
1829	    BCOPY(p, ho->endpoint.value, cilen);
1830	    INCPTR(cilen, p);
1831	    break;
1832
1833	default:
1834	    LCPDEBUG(("lcp_reqci: rcvd unknown option %d", citype));
1835	    orc = CONFREJ;
1836	    break;
1837	}
1838
1839endswitch:
1840	if (orc == CONFACK &&		/* Good CI */
1841	    rc != CONFACK)		/*  but prior CI wasnt? */
1842	    continue;			/* Don't send this one */
1843
1844	if (orc == CONFNAK) {		/* Nak this CI? */
1845	    if (reject_if_disagree	/* Getting fed up with sending NAKs? */
1846		&& citype != CI_MAGICNUMBER) {
1847		orc = CONFREJ;		/* Get tough if so */
1848	    } else {
1849		if (rc == CONFREJ)	/* Rejecting prior CI? */
1850		    continue;		/* Don't send this one */
1851		rc = CONFNAK;
1852	    }
1853	}
1854	if (orc == CONFREJ) {		/* Reject this CI */
1855	    rc = CONFREJ;
1856	    if (cip != rejp)		/* Need to move rejected CI? */
1857		BCOPY(cip, rejp, cilen); /* Move it */
1858	    INCPTR(cilen, rejp);	/* Update output pointer */
1859	}
1860    }
1861
1862    /*
1863     * If we wanted to send additional NAKs (for unsent CIs), the
1864     * code would go here.  The extra NAKs would go at *nakp.
1865     * At present there are no cases where we want to ask the
1866     * peer to negotiate an option.
1867     */
1868
1869    switch (rc) {
1870    case CONFACK:
1871	*lenp = next - inp;
1872	break;
1873    case CONFNAK:
1874	/*
1875	 * Copy the Nak'd options from the nak_buffer to the caller's buffer.
1876	 */
1877	*lenp = nakp - nak_buffer;
1878	BCOPY(nak_buffer, inp, *lenp);
1879	break;
1880    case CONFREJ:
1881	*lenp = rejp - inp;
1882	break;
1883    }
1884
1885    LCPDEBUG(("lcp_reqci: returning CONF%s.", CODENAME(rc)));
1886    return (rc);			/* Return final code */
1887}
1888
1889
1890/*
1891 * lcp_up - LCP has come UP.
1892 */
1893static void
1894lcp_up(f)
1895    fsm *f;
1896{
1897    lcp_options *wo = &lcp_wantoptions[f->unit];
1898    lcp_options *ho = &lcp_hisoptions[f->unit];
1899    lcp_options *go = &lcp_gotoptions[f->unit];
1900    lcp_options *ao = &lcp_allowoptions[f->unit];
1901    int mtu, mru;
1902
1903    if (!go->neg_magicnumber)
1904	go->magicnumber = 0;
1905    if (!ho->neg_magicnumber)
1906	ho->magicnumber = 0;
1907
1908    /*
1909     * Set our MTU to the smaller of the MTU we wanted and
1910     * the MRU our peer wanted.  If we negotiated an MRU,
1911     * set our MRU to the larger of value we wanted and
1912     * the value we got in the negotiation.
1913     * Note on the MTU: the link MTU can be the MRU the peer wanted,
1914     * the interface MTU is set to the lowest of that, the
1915     * MTU we want to use, and our link MRU.
1916     */
1917    mtu = ho->neg_mru? ho->mru: PPP_MRU;
1918    mru = go->neg_mru? MAX(wo->mru, go->mru): PPP_MRU;
1919#ifdef HAVE_MULTILINK
1920    if (!(multilink && go->neg_mrru && ho->neg_mrru))
1921#endif /* HAVE_MULTILINK */
1922	netif_set_mtu(f->unit, MIN(MIN(mtu, mru), ao->mru));
1923    ppp_send_config(f->unit, mtu,
1924		    (ho->neg_asyncmap? ho->asyncmap: 0xffffffff),
1925		    ho->neg_pcompression, ho->neg_accompression);
1926    ppp_recv_config(f->unit, mru,
1927		    (lax_recv? 0: go->neg_asyncmap? go->asyncmap: 0xffffffff),
1928		    go->neg_pcompression, go->neg_accompression);
1929
1930    if (ho->neg_mru)
1931	peer_mru[f->unit] = ho->mru;
1932
1933    lcp_echo_lowerup(f->unit);  /* Enable echo messages */
1934
1935    link_established(f->unit);
1936}
1937
1938
1939/*
1940 * lcp_down - LCP has gone DOWN.
1941 *
1942 * Alert other protocols.
1943 */
1944static void
1945lcp_down(f)
1946    fsm *f;
1947{
1948    lcp_options *go = &lcp_gotoptions[f->unit];
1949
1950    lcp_echo_lowerdown(f->unit);
1951
1952    link_down(f->unit);
1953
1954    ppp_send_config(f->unit, PPP_MRU, 0xffffffff, 0, 0);
1955    ppp_recv_config(f->unit, PPP_MRU,
1956		    (go->neg_asyncmap? go->asyncmap: 0xffffffff),
1957		    go->neg_pcompression, go->neg_accompression);
1958    peer_mru[f->unit] = PPP_MRU;
1959}
1960
1961
1962/*
1963 * lcp_starting - LCP needs the lower layer up.
1964 */
1965static void
1966lcp_starting(f)
1967    fsm *f;
1968{
1969    link_required(f->unit);
1970}
1971
1972
1973/*
1974 * lcp_finished - LCP has finished with the lower layer.
1975 */
1976static void
1977lcp_finished(f)
1978    fsm *f;
1979{
1980    link_terminated(f->unit);
1981}
1982
1983
1984/*
1985 * lcp_printpkt - print the contents of an LCP packet.
1986 */
1987static char *lcp_codenames[] = {
1988    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
1989    "TermReq", "TermAck", "CodeRej", "ProtRej",
1990    "EchoReq", "EchoRep", "DiscReq", "Ident",
1991    "TimeRem"
1992};
1993
1994static int
1995lcp_printpkt(p, plen, printer, arg)
1996    u_char *p;
1997    int plen;
1998    void (*printer) __P((void *, char *, ...));
1999    void *arg;
2000{
2001    int code, id, len, olen, i;
2002    u_char *pstart, *optend;
2003    u_short cishort;
2004    u_int32_t cilong;
2005
2006    if (plen < HEADERLEN)
2007	return 0;
2008    pstart = p;
2009    GETCHAR(code, p);
2010    GETCHAR(id, p);
2011    GETSHORT(len, p);
2012    if (len < HEADERLEN || len > plen)
2013	return 0;
2014
2015    if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *))
2016	printer(arg, " %s", lcp_codenames[code-1]);
2017    else
2018	printer(arg, " code=0x%x", code);
2019    printer(arg, " id=0x%x", id);
2020    len -= HEADERLEN;
2021    switch (code) {
2022    case CONFREQ:
2023    case CONFACK:
2024    case CONFNAK:
2025    case CONFREJ:
2026	/* print option list */
2027	while (len >= 2) {
2028	    GETCHAR(code, p);
2029	    GETCHAR(olen, p);
2030	    p -= 2;
2031	    if (olen < 2 || olen > len) {
2032		break;
2033	    }
2034	    printer(arg, " <");
2035	    len -= olen;
2036	    optend = p + olen;
2037	    switch (code) {
2038	    case CI_MRU:
2039		if (olen == CILEN_SHORT) {
2040		    p += 2;
2041		    GETSHORT(cishort, p);
2042		    printer(arg, "mru %d", cishort);
2043		}
2044		break;
2045	    case CI_ASYNCMAP:
2046		if (olen == CILEN_LONG) {
2047		    p += 2;
2048		    GETLONG(cilong, p);
2049		    printer(arg, "asyncmap 0x%x", cilong);
2050		}
2051		break;
2052	    case CI_AUTHTYPE:
2053		if (olen >= CILEN_SHORT) {
2054		    p += 2;
2055		    printer(arg, "auth ");
2056		    GETSHORT(cishort, p);
2057		    switch (cishort) {
2058		    case PPP_PAP:
2059			printer(arg, "pap");
2060			break;
2061		    case PPP_CHAP:
2062			printer(arg, "chap");
2063			if (p < optend) {
2064			    switch (*p) {
2065			    case CHAP_MD5:
2066				printer(arg, " MD5");
2067				++p;
2068				break;
2069			    case CHAP_MICROSOFT:
2070				printer(arg, " MS");
2071				++p;
2072				break;
2073
2074			    case CHAP_MICROSOFT_V2:
2075				printer(arg, " MS-v2");
2076				++p;
2077				break;
2078			    }
2079			}
2080			break;
2081		    case PPP_EAP:
2082			printer(arg, "eap");
2083			break;
2084		    default:
2085			printer(arg, "0x%x", cishort);
2086		    }
2087		}
2088		break;
2089	    case CI_QUALITY:
2090		if (olen >= CILEN_SHORT) {
2091		    p += 2;
2092		    printer(arg, "quality ");
2093		    GETSHORT(cishort, p);
2094		    switch (cishort) {
2095		    case PPP_LQR:
2096			printer(arg, "lqr");
2097			break;
2098		    default:
2099			printer(arg, "0x%x", cishort);
2100		    }
2101		}
2102		break;
2103	    case CI_CALLBACK:
2104		if (olen >= CILEN_CHAR) {
2105		    p += 2;
2106		    printer(arg, "callback ");
2107		    GETCHAR(cishort, p);
2108		    switch (cishort) {
2109		    case CBCP_OPT:
2110			printer(arg, "CBCP");
2111			break;
2112		    default:
2113			printer(arg, "0x%x", cishort);
2114		    }
2115		}
2116		break;
2117	    case CI_MAGICNUMBER:
2118		if (olen == CILEN_LONG) {
2119		    p += 2;
2120		    GETLONG(cilong, p);
2121		    printer(arg, "magic 0x%x", cilong);
2122		}
2123		break;
2124	    case CI_PCOMPRESSION:
2125		if (olen == CILEN_VOID) {
2126		    p += 2;
2127		    printer(arg, "pcomp");
2128		}
2129		break;
2130	    case CI_ACCOMPRESSION:
2131		if (olen == CILEN_VOID) {
2132		    p += 2;
2133		    printer(arg, "accomp");
2134		}
2135		break;
2136	    case CI_MRRU:
2137		if (olen == CILEN_SHORT) {
2138		    p += 2;
2139		    GETSHORT(cishort, p);
2140		    printer(arg, "mrru %d", cishort);
2141		}
2142		break;
2143	    case CI_SSNHF:
2144		if (olen == CILEN_VOID) {
2145		    p += 2;
2146		    printer(arg, "ssnhf");
2147		}
2148		break;
2149	    case CI_EPDISC:
2150#ifdef HAVE_MULTILINK
2151		if (olen >= CILEN_CHAR) {
2152		    struct epdisc epd;
2153		    p += 2;
2154		    GETCHAR(epd.class, p);
2155		    epd.length = olen - CILEN_CHAR;
2156		    if (epd.length > MAX_ENDP_LEN)
2157			epd.length = MAX_ENDP_LEN;
2158		    if (epd.length > 0) {
2159			BCOPY(p, epd.value, epd.length);
2160			p += epd.length;
2161		    }
2162		    printer(arg, "endpoint [%s]", epdisc_to_str(&epd));
2163		}
2164#else
2165		printer(arg, "endpoint");
2166#endif
2167		break;
2168	    }
2169	    while (p < optend) {
2170		GETCHAR(code, p);
2171		printer(arg, " %.2x", code);
2172	    }
2173	    printer(arg, ">");
2174	}
2175	break;
2176
2177    case TERMACK:
2178    case TERMREQ:
2179	if (len > 0 && *p >= ' ' && *p < 0x7f) {
2180	    printer(arg, " ");
2181	    print_string((char *)p, len, printer, arg);
2182	    p += len;
2183	    len = 0;
2184	}
2185	break;
2186
2187    case ECHOREQ:
2188    case ECHOREP:
2189    case DISCREQ:
2190	if (len >= 4) {
2191	    GETLONG(cilong, p);
2192	    printer(arg, " magic=0x%x", cilong);
2193	    len -= 4;
2194	}
2195	break;
2196
2197    case IDENTIF:
2198    case TIMEREM:
2199	if (len >= 4) {
2200	    GETLONG(cilong, p);
2201	    printer(arg, " magic=0x%x", cilong);
2202	    len -= 4;
2203	}
2204	if (code == TIMEREM) {
2205	    if (len < 4)
2206		break;
2207	    GETLONG(cilong, p);
2208	    printer(arg, " seconds=%u", cilong);
2209	    len -= 4;
2210	}
2211	if (len > 0) {
2212	    printer(arg, " ");
2213	    print_string((char *)p, len, printer, arg);
2214	    p += len;
2215	    len = 0;
2216	}
2217	break;
2218    }
2219
2220    /* print the rest of the bytes in the packet */
2221    for (i = 0; i < len && i < 32; ++i) {
2222	GETCHAR(code, p);
2223	printer(arg, " %.2x", code);
2224    }
2225    if (i < len) {
2226	printer(arg, " ...");
2227	p += len - i;
2228    }
2229
2230    return p - pstart;
2231}
2232
2233/*
2234 * Time to shut down the link because there is nothing out there.
2235 */
2236
2237static
2238void LcpLinkFailure (f)
2239    fsm *f;
2240{
2241    if (f->state == OPENED) {
2242	info("No response to %d echo-requests", lcp_echos_pending);
2243        notice("Serial link appears to be disconnected.");
2244	status = EXIT_PEER_DEAD;
2245	lcp_close(f->unit, "Peer not responding");
2246    }
2247}
2248
2249/*
2250 * Timer expired for the LCP echo requests from this process.
2251 */
2252
2253static void
2254LcpEchoCheck (f)
2255    fsm *f;
2256{
2257    LcpSendEchoRequest (f);
2258    if (f->state != OPENED)
2259	return;
2260
2261    /*
2262     * Start the timer for the next interval.
2263     */
2264    if (lcp_echo_timer_running)
2265	warn("assertion lcp_echo_timer_running==0 failed");
2266    TIMEOUT (LcpEchoTimeout, f, lcp_echo_interval);
2267    lcp_echo_timer_running = 1;
2268}
2269
2270/*
2271 * LcpEchoTimeout - Timer expired on the LCP echo
2272 */
2273
2274static void
2275LcpEchoTimeout (arg)
2276    void *arg;
2277{
2278    if (lcp_echo_timer_running != 0) {
2279        lcp_echo_timer_running = 0;
2280        LcpEchoCheck ((fsm *) arg);
2281    }
2282}
2283
2284/*
2285 * LcpEchoReply - LCP has received a reply to the echo
2286 */
2287
2288static void
2289lcp_received_echo_reply (f, id, inp, len)
2290    fsm *f;
2291    int id;
2292    u_char *inp;
2293    int len;
2294{
2295    u_int32_t magic;
2296
2297    /* Check the magic number - don't count replies from ourselves. */
2298    if (len < 4) {
2299	dbglog("lcp: received short Echo-Reply, length %d", len);
2300	return;
2301    }
2302    GETLONG(magic, inp);
2303    if (lcp_gotoptions[f->unit].neg_magicnumber
2304	&& magic == lcp_gotoptions[f->unit].magicnumber) {
2305	warn("appear to have received our own echo-reply!");
2306	return;
2307    }
2308
2309    /* Reset the number of outstanding echo frames */
2310    lcp_echos_pending = 0;
2311}
2312
2313/*
2314 * LcpSendEchoRequest - Send an echo request frame to the peer
2315 */
2316
2317static void
2318LcpSendEchoRequest (f)
2319    fsm *f;
2320{
2321    u_int32_t lcp_magic;
2322    u_char pkt[4], *pktp;
2323
2324    /*
2325     * Detect the failure of the peer at this point.
2326     */
2327    if (lcp_echo_fails != 0) {
2328        if (lcp_echos_pending >= lcp_echo_fails) {
2329            LcpLinkFailure(f);
2330	    lcp_echos_pending = 0;
2331	}
2332    }
2333
2334    /*
2335     * Make and send the echo request frame.
2336     */
2337    if (f->state == OPENED) {
2338        lcp_magic = lcp_gotoptions[f->unit].magicnumber;
2339	pktp = pkt;
2340	PUTLONG(lcp_magic, pktp);
2341        fsm_sdata(f, ECHOREQ, lcp_echo_number++ & 0xFF, pkt, pktp - pkt);
2342	++lcp_echos_pending;
2343    }
2344}
2345
2346/*
2347 * lcp_echo_lowerup - Start the timer for the LCP frame
2348 */
2349
2350static void
2351lcp_echo_lowerup (unit)
2352    int unit;
2353{
2354    fsm *f = &lcp_fsm[unit];
2355
2356    /* Clear the parameters for generating echo frames */
2357    lcp_echos_pending      = 0;
2358    lcp_echo_number        = 0;
2359    lcp_echo_timer_running = 0;
2360
2361    /* If a timeout interval is specified then start the timer */
2362    if (lcp_echo_interval != 0)
2363        LcpEchoCheck (f);
2364}
2365
2366/*
2367 * lcp_echo_lowerdown - Stop the timer for the LCP frame
2368 */
2369
2370static void
2371lcp_echo_lowerdown (unit)
2372    int unit;
2373{
2374    fsm *f = &lcp_fsm[unit];
2375
2376    if (lcp_echo_timer_running != 0) {
2377        UNTIMEOUT (LcpEchoTimeout, f);
2378        lcp_echo_timer_running = 0;
2379    }
2380}
2381