1/*
2 * ipcp.c - PPP IP 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: ipcp.c,v 1.69 2004/11/13 12:03:26 paulus Exp $"
44
45/*
46 * TODO:
47 */
48
49#include <stdio.h>
50#include <string.h>
51#include <stdlib.h>
52#include <netdb.h>
53#include <sys/param.h>
54#include <sys/types.h>
55#include <sys/socket.h>
56#include <netinet/in.h>
57#include <arpa/inet.h>
58
59#include "pppd.h"
60#include "fsm.h"
61#include "ipcp.h"
62#include "pathnames.h"
63
64static const char rcsid[] = RCSID;
65
66/* global vars */
67ipcp_options ipcp_wantoptions[NUM_PPP];	/* Options that we want to request */
68ipcp_options ipcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
69ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
70ipcp_options ipcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
71
72u_int32_t netmask = 0;		/* IP netmask to set on interface */
73
74bool	disable_defaultip = 0;	/* Don't use hostname for default IP adrs */
75
76/* Hook for a plugin to know when IP protocol has come up */
77void (*ip_up_hook) __P((void)) = NULL;
78
79/* Hook for a plugin to know when IP protocol has come down */
80void (*ip_down_hook) __P((void)) = NULL;
81
82/* Hook for a plugin to choose the remote IP address */
83void (*ip_choose_hook) __P((u_int32_t *)) = NULL;
84
85/* Notifiers for when IPCP goes up and down */
86struct notifier *ip_up_notifier = NULL;
87struct notifier *ip_down_notifier = NULL;
88
89/* local vars */
90static int default_route_set[NUM_PPP];	/* Have set up a default route */
91static int proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
92static bool usepeerdns;			/* Ask peer for DNS addrs */
93static int ipcp_is_up;			/* have called np_up() */
94static int ipcp_is_open;		/* haven't called np_finished() */
95static bool ask_for_local;		/* request our address from peer */
96static char vj_value[8];		/* string form of vj option value */
97static char netmask_str[20];		/* string form of netmask value */
98
99/*
100 * Callbacks for fsm code.  (CI = Configuration Information)
101 */
102static void ipcp_resetci __P((fsm *));	/* Reset our CI */
103static int  ipcp_cilen __P((fsm *));	        /* Return length of our CI */
104static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
105static int  ipcp_ackci __P((fsm *, u_char *, int));	/* Peer ack'd our CI */
106static int  ipcp_nakci __P((fsm *, u_char *, int, int));/* Peer nak'd our CI */
107static int  ipcp_rejci __P((fsm *, u_char *, int));	/* Peer rej'd our CI */
108static int  ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
109static void ipcp_up __P((fsm *));		/* We're UP */
110static void ipcp_down __P((fsm *));		/* We're DOWN */
111static void ipcp_finished __P((fsm *));	/* Don't need lower layer */
112
113fsm ipcp_fsm[NUM_PPP];		/* IPCP fsm structure */
114
115static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
116    ipcp_resetci,		/* Reset our Configuration Information */
117    ipcp_cilen,			/* Length of our Configuration Information */
118    ipcp_addci,			/* Add our Configuration Information */
119    ipcp_ackci,			/* ACK our Configuration Information */
120    ipcp_nakci,			/* NAK our Configuration Information */
121    ipcp_rejci,			/* Reject our Configuration Information */
122    ipcp_reqci,			/* Request peer's Configuration Information */
123    ipcp_up,			/* Called when fsm reaches OPENED state */
124    ipcp_down,			/* Called when fsm leaves OPENED state */
125    NULL,			/* Called when we want the lower layer up */
126    ipcp_finished,		/* Called when we want the lower layer down */
127    NULL,			/* Called when Protocol-Reject received */
128    NULL,			/* Retransmission is necessary */
129    NULL,			/* Called to handle protocol-specific codes */
130    "IPCP"			/* String name of protocol */
131};
132
133/*
134 * Command-line options.
135 */
136static int setvjslots __P((char **));
137static int setdnsaddr __P((char **));
138static int setwinsaddr __P((char **));
139static int setnetmask __P((char **));
140int setipaddr __P((char *, char **, int));
141static void printipaddr __P((option_t *, void (*)(void *, char *,...),void *));
142
143static option_t ipcp_option_list[] = {
144    { "noip", o_bool, &ipcp_protent.enabled_flag,
145      "Disable IP and IPCP" },
146    { "-ip", o_bool, &ipcp_protent.enabled_flag,
147      "Disable IP and IPCP", OPT_ALIAS },
148
149    { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
150      "Disable VJ compression", OPT_A2CLR, &ipcp_allowoptions[0].neg_vj },
151    { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
152      "Disable VJ compression", OPT_ALIAS | OPT_A2CLR,
153      &ipcp_allowoptions[0].neg_vj },
154
155    { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
156      "Disable VJ connection-ID compression", OPT_A2CLR,
157      &ipcp_allowoptions[0].cflag },
158    { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
159      "Disable VJ connection-ID compression", OPT_ALIAS | OPT_A2CLR,
160      &ipcp_allowoptions[0].cflag },
161
162    { "vj-max-slots", o_special, (void *)setvjslots,
163      "Set maximum VJ header slots",
164      OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, vj_value },
165
166    { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
167      "Accept peer's address for us", 1 },
168    { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
169      "Accept peer's address for it", 1 },
170
171    { "ipparam", o_string, &ipparam,
172      "Set ip script parameter", OPT_PRIO },
173
174    { "noipdefault", o_bool, &disable_defaultip,
175      "Don't use name for default IP adrs", 1 },
176
177    { "ms-dns", 1, (void *)setdnsaddr,
178      "DNS address for the peer's use" },
179    { "ms-wins", 1, (void *)setwinsaddr,
180      "Nameserver for SMB over TCP/IP for peer" },
181
182    { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
183      "Set timeout for IPCP", OPT_PRIO },
184    { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
185      "Set max #xmits for term-reqs", OPT_PRIO },
186    { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
187      "Set max #xmits for conf-reqs", OPT_PRIO },
188    { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
189      "Set max #conf-naks for IPCP", OPT_PRIO },
190
191    { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
192      "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
193    { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
194      "disable defaultroute option", OPT_A2CLR,
195      &ipcp_wantoptions[0].default_route },
196    { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
197      "disable defaultroute option", OPT_ALIAS | OPT_A2CLR,
198      &ipcp_wantoptions[0].default_route },
199
200    { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
201      "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
202    { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
203      "disable proxyarp option", OPT_A2CLR,
204      &ipcp_wantoptions[0].proxy_arp },
205    { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
206      "disable proxyarp option", OPT_ALIAS | OPT_A2CLR,
207      &ipcp_wantoptions[0].proxy_arp },
208
209    { "usepeerdns", o_bool, &usepeerdns,
210      "Ask peer for DNS address(es)", 1 },
211
212    { "netmask", o_special, (void *)setnetmask,
213      "set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str },
214
215    { "ipcp-no-addresses", o_bool, &ipcp_wantoptions[0].old_addrs,
216      "Disable old-style IP-Addresses usage", OPT_A2CLR,
217      &ipcp_allowoptions[0].old_addrs },
218    { "ipcp-no-address", o_bool, &ipcp_wantoptions[0].neg_addr,
219      "Disable IP-Address usage", OPT_A2CLR,
220      &ipcp_allowoptions[0].neg_addr },
221
222    { "IP addresses", o_wild, (void *) &setipaddr,
223      "set local and remote IP addresses",
224      OPT_NOARG | OPT_A2PRINTER, (void *) &printipaddr },
225
226    { NULL }
227};
228
229/*
230 * Protocol entry points from main code.
231 */
232static void ipcp_init __P((int));
233static void ipcp_open __P((int));
234static void ipcp_close __P((int, char *));
235static void ipcp_lowerup __P((int));
236static void ipcp_lowerdown __P((int));
237static void ipcp_input __P((int, u_char *, int));
238static void ipcp_protrej __P((int));
239static int  ipcp_printpkt __P((u_char *, int,
240			       void (*) __P((void *, char *, ...)), void *));
241static void ip_check_options __P((void));
242static int  ip_demand_conf __P((int));
243static int  ip_active_pkt __P((u_char *, int));
244static void create_resolv __P((u_int32_t, u_int32_t));
245
246struct protent ipcp_protent = {
247    PPP_IPCP,
248    ipcp_init,
249    ipcp_input,
250    ipcp_protrej,
251    ipcp_lowerup,
252    ipcp_lowerdown,
253    ipcp_open,
254    ipcp_close,
255    ipcp_printpkt,
256    NULL,
257    1,
258    "IPCP",
259    "IP",
260    ipcp_option_list,
261    ip_check_options,
262    ip_demand_conf,
263    ip_active_pkt
264};
265
266static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t));
267static void ipcp_script __P((char *));		/* Run an up/down script */
268static void ipcp_script_done __P((void *));
269
270/*
271 * Lengths of configuration options.
272 */
273#define CILEN_VOID	2
274#define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
275#define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
276#define CILEN_ADDR	6	/* new-style single address option */
277#define CILEN_ADDRS	10	/* old-style dual address option */
278
279
280#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
281			 (x) == CONFNAK ? "NAK" : "REJ")
282
283/*
284 * This state variable is used to ensure that we don't
285 * run an ipcp-up/down script while one is already running.
286 */
287static enum script_state {
288    s_down,
289    s_up,
290} ipcp_script_state;
291static pid_t ipcp_script_pid;
292
293/*
294 * Make a string representation of a network IP address.
295 */
296char *
297ip_ntoa(ipaddr)
298u_int32_t ipaddr;
299{
300    static char b[64];
301
302    slprintf(b, sizeof(b), "%I", ipaddr);
303    return b;
304}
305
306/*
307 * Option parsing.
308 */
309
310/*
311 * setvjslots - set maximum number of connection slots for VJ compression
312 */
313static int
314setvjslots(argv)
315    char **argv;
316{
317    int value;
318
319    if (!int_option(*argv, &value))
320	return 0;
321    if (value < 2 || value > 16) {
322	option_error("vj-max-slots value must be between 2 and 16");
323	return 0;
324    }
325    ipcp_wantoptions [0].maxslotindex =
326        ipcp_allowoptions[0].maxslotindex = value - 1;
327    slprintf(vj_value, sizeof(vj_value), "%d", value);
328    return 1;
329}
330
331/*
332 * setdnsaddr - set the dns address(es)
333 */
334static int
335setdnsaddr(argv)
336    char **argv;
337{
338    u_int32_t dns;
339    struct hostent *hp;
340
341    dns = inet_addr(*argv);
342    if (dns == (u_int32_t) -1) {
343	if ((hp = gethostbyname(*argv)) == NULL) {
344	    option_error("invalid address parameter '%s' for ms-dns option",
345			 *argv);
346	    return 0;
347	}
348	dns = *(u_int32_t *)hp->h_addr;
349    }
350
351    /* We take the last 2 values given, the 2nd-last as the primary
352       and the last as the secondary.  If only one is given it
353       becomes both primary and secondary. */
354    if (ipcp_allowoptions[0].dnsaddr[1] == 0)
355	ipcp_allowoptions[0].dnsaddr[0] = dns;
356    else
357	ipcp_allowoptions[0].dnsaddr[0] = ipcp_allowoptions[0].dnsaddr[1];
358
359    /* always set the secondary address value. */
360    ipcp_allowoptions[0].dnsaddr[1] = dns;
361
362    return (1);
363}
364
365/*
366 * setwinsaddr - set the wins address(es)
367 * This is primrarly used with the Samba package under UNIX or for pointing
368 * the caller to the existing WINS server on a Windows NT platform.
369 */
370static int
371setwinsaddr(argv)
372    char **argv;
373{
374    u_int32_t wins;
375    struct hostent *hp;
376
377    wins = inet_addr(*argv);
378    if (wins == (u_int32_t) -1) {
379	if ((hp = gethostbyname(*argv)) == NULL) {
380	    option_error("invalid address parameter '%s' for ms-wins option",
381			 *argv);
382	    return 0;
383	}
384	wins = *(u_int32_t *)hp->h_addr;
385    }
386
387    /* We take the last 2 values given, the 2nd-last as the primary
388       and the last as the secondary.  If only one is given it
389       becomes both primary and secondary. */
390    if (ipcp_allowoptions[0].winsaddr[1] == 0)
391	ipcp_allowoptions[0].winsaddr[0] = wins;
392    else
393	ipcp_allowoptions[0].winsaddr[0] = ipcp_allowoptions[0].winsaddr[1];
394
395    /* always set the secondary address value. */
396    ipcp_allowoptions[0].winsaddr[1] = wins;
397
398    return (1);
399}
400
401/*
402 * setipaddr - Set the IP address
403 * If doit is 0, the call is to check whether this option is
404 * potentially an IP address specification.
405 * Not static so that plugins can call it to set the addresses
406 */
407int
408setipaddr(arg, argv, doit)
409    char *arg;
410    char **argv;
411    int doit;
412{
413    struct hostent *hp;
414    char *colon;
415    u_int32_t local, remote;
416    ipcp_options *wo = &ipcp_wantoptions[0];
417    static int prio_local = 0, prio_remote = 0;
418
419    /*
420     * IP address pair separated by ":".
421     */
422    if ((colon = strchr(arg, ':')) == NULL)
423	return 0;
424    if (!doit)
425	return 1;
426
427    /*
428     * If colon first character, then no local addr.
429     */
430    if (colon != arg && option_priority >= prio_local) {
431	*colon = '\0';
432	if ((local = inet_addr(arg)) == (u_int32_t) -1) {
433	    if ((hp = gethostbyname(arg)) == NULL) {
434		option_error("unknown host: %s", arg);
435		return 0;
436	    }
437	    local = *(u_int32_t *)hp->h_addr;
438	}
439	if (bad_ip_adrs(local)) {
440	    option_error("bad local IP address %s", ip_ntoa(local));
441	    return 0;
442	}
443	if (local != 0)
444	    wo->ouraddr = local;
445	*colon = ':';
446	prio_local = option_priority;
447    }
448
449    /*
450     * If colon last character, then no remote addr.
451     */
452    if (*++colon != '\0' && option_priority >= prio_remote) {
453	if ((remote = inet_addr(colon)) == (u_int32_t) -1) {
454	    if ((hp = gethostbyname(colon)) == NULL) {
455		option_error("unknown host: %s", colon);
456		return 0;
457	    }
458	    remote = *(u_int32_t *)hp->h_addr;
459	    if (remote_name[0] == 0)
460		strlcpy(remote_name, colon, sizeof(remote_name));
461	}
462	if (bad_ip_adrs(remote)) {
463	    option_error("bad remote IP address %s", ip_ntoa(remote));
464	    return 0;
465	}
466	if (remote != 0)
467	    wo->hisaddr = remote;
468	prio_remote = option_priority;
469    }
470
471    return 1;
472}
473
474static void
475printipaddr(opt, printer, arg)
476    option_t *opt;
477    void (*printer) __P((void *, char *, ...));
478    void *arg;
479{
480	ipcp_options *wo = &ipcp_wantoptions[0];
481
482	if (wo->ouraddr != 0)
483		printer(arg, "%I", wo->ouraddr);
484	printer(arg, ":");
485	if (wo->hisaddr != 0)
486		printer(arg, "%I", wo->hisaddr);
487}
488
489/*
490 * setnetmask - set the netmask to be used on the interface.
491 */
492static int
493setnetmask(argv)
494    char **argv;
495{
496    u_int32_t mask;
497    int n;
498    char *p;
499
500    /*
501     * Unfortunately, if we use inet_addr, we can't tell whether
502     * a result of all 1s is an error or a valid 255.255.255.255.
503     */
504    p = *argv;
505    n = parse_dotted_ip(p, &mask);
506
507    mask = htonl(mask);
508
509    if (n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
510	option_error("invalid netmask value '%s'", *argv);
511	return 0;
512    }
513
514    netmask = mask;
515    slprintf(netmask_str, sizeof(netmask_str), "%I", mask);
516
517    return (1);
518}
519
520int
521parse_dotted_ip(p, vp)
522    char *p;
523    u_int32_t *vp;
524{
525    int n;
526    u_int32_t v, b;
527    char *endp, *p0 = p;
528
529    v = 0;
530    for (n = 3;; --n) {
531	b = strtoul(p, &endp, 0);
532	if (endp == p)
533	    return 0;
534	if (b > 255) {
535	    if (n < 3)
536		return 0;
537	    /* accept e.g. 0xffffff00 */
538	    *vp = b;
539	    return endp - p0;
540	}
541	v |= b << (n * 8);
542	p = endp;
543	if (n == 0)
544	    break;
545	if (*p != '.')
546	    return 0;
547	++p;
548    }
549    *vp = v;
550    return p - p0;
551}
552
553
554/*
555 * ipcp_init - Initialize IPCP.
556 */
557static void
558ipcp_init(unit)
559    int unit;
560{
561    fsm *f = &ipcp_fsm[unit];
562    ipcp_options *wo = &ipcp_wantoptions[unit];
563    ipcp_options *ao = &ipcp_allowoptions[unit];
564
565    f->unit = unit;
566    f->protocol = PPP_IPCP;
567    f->callbacks = &ipcp_callbacks;
568    fsm_init(&ipcp_fsm[unit]);
569
570    memset(wo, 0, sizeof(*wo));
571    memset(ao, 0, sizeof(*ao));
572
573    wo->neg_addr = wo->old_addrs = 1;
574    wo->neg_vj = 1;
575    wo->vj_protocol = IPCP_VJ_COMP;
576    wo->maxslotindex = MAX_STATES - 1; /* really max index */
577    wo->cflag = 1;
578
579
580    /* max slots and slot-id compression are currently hardwired in */
581    /* ppp_if.c to 16 and 1, this needs to be changed (among other */
582    /* things) gmc */
583
584    ao->neg_addr = ao->old_addrs = 1;
585    ao->neg_vj = 1;
586    ao->maxslotindex = MAX_STATES - 1;
587    ao->cflag = 1;
588
589    /*
590     * XXX These control whether the user may use the proxyarp
591     * and defaultroute options.
592     */
593    ao->proxy_arp = 1;
594    ao->default_route = 1;
595}
596
597
598/*
599 * ipcp_open - IPCP is allowed to come up.
600 */
601static void
602ipcp_open(unit)
603    int unit;
604{
605    fsm_open(&ipcp_fsm[unit]);
606    ipcp_is_open = 1;
607}
608
609
610/*
611 * ipcp_close - Take IPCP down.
612 */
613static void
614ipcp_close(unit, reason)
615    int unit;
616    char *reason;
617{
618    fsm_close(&ipcp_fsm[unit], reason);
619}
620
621
622/*
623 * ipcp_lowerup - The lower layer is up.
624 */
625static void
626ipcp_lowerup(unit)
627    int unit;
628{
629    fsm_lowerup(&ipcp_fsm[unit]);
630}
631
632
633/*
634 * ipcp_lowerdown - The lower layer is down.
635 */
636static void
637ipcp_lowerdown(unit)
638    int unit;
639{
640    fsm_lowerdown(&ipcp_fsm[unit]);
641}
642
643
644/*
645 * ipcp_input - Input IPCP packet.
646 */
647static void
648ipcp_input(unit, p, len)
649    int unit;
650    u_char *p;
651    int len;
652{
653    fsm_input(&ipcp_fsm[unit], p, len);
654}
655
656
657/*
658 * ipcp_protrej - A Protocol-Reject was received for IPCP.
659 *
660 * Pretend the lower layer went down, so we shut up.
661 */
662static void
663ipcp_protrej(unit)
664    int unit;
665{
666    fsm_lowerdown(&ipcp_fsm[unit]);
667}
668
669
670/*
671 * ipcp_resetci - Reset our CI.
672 * Called by fsm_sconfreq, Send Configure Request.
673 */
674static void
675ipcp_resetci(f)
676    fsm *f;
677{
678    ipcp_options *wo = &ipcp_wantoptions[f->unit];
679    ipcp_options *go = &ipcp_gotoptions[f->unit];
680    ipcp_options *ao = &ipcp_allowoptions[f->unit];
681
682    wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
683	(ao->neg_addr || ao->old_addrs);
684    if (wo->ouraddr == 0)
685	wo->accept_local = 1;
686    if (wo->hisaddr == 0)
687	wo->accept_remote = 1;
688    wo->req_dns1 = usepeerdns;	/* Request DNS addresses from the peer */
689    wo->req_dns2 = usepeerdns;
690    *go = *wo;
691    if (!ask_for_local)
692	go->ouraddr = 0;
693    if (ip_choose_hook) {
694	ip_choose_hook(&wo->hisaddr);
695	if (wo->hisaddr) {
696	    wo->accept_remote = 0;
697	}
698    }
699    BZERO(&ipcp_hisoptions[f->unit], sizeof(ipcp_options));
700}
701
702
703/*
704 * ipcp_cilen - Return length of our CI.
705 * Called by fsm_sconfreq, Send Configure Request.
706 */
707static int
708ipcp_cilen(f)
709    fsm *f;
710{
711    ipcp_options *go = &ipcp_gotoptions[f->unit];
712    ipcp_options *wo = &ipcp_wantoptions[f->unit];
713    ipcp_options *ho = &ipcp_hisoptions[f->unit];
714
715#define LENCIADDRS(neg)		(neg ? CILEN_ADDRS : 0)
716#define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
717#define LENCIADDR(neg)		(neg ? CILEN_ADDR : 0)
718#define LENCIDNS(neg)		(neg ? (CILEN_ADDR) : 0)
719
720    /*
721     * First see if we want to change our options to the old
722     * forms because we have received old forms from the peer.
723     */
724    if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
725	go->neg_addr = 0;
726    if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
727	/* try an older style of VJ negotiation */
728	/* use the old style only if the peer did */
729	if (ho->neg_vj && ho->old_vj) {
730	    go->neg_vj = 1;
731	    go->old_vj = 1;
732	    go->vj_protocol = ho->vj_protocol;
733	}
734    }
735
736    return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
737	    LENCIVJ(go->neg_vj, go->old_vj) +
738	    LENCIADDR(go->neg_addr) +
739	    LENCIDNS(go->req_dns1) +
740	    LENCIDNS(go->req_dns2)) ;
741}
742
743
744/*
745 * ipcp_addci - Add our desired CIs to a packet.
746 * Called by fsm_sconfreq, Send Configure Request.
747 */
748static void
749ipcp_addci(f, ucp, lenp)
750    fsm *f;
751    u_char *ucp;
752    int *lenp;
753{
754    ipcp_options *go = &ipcp_gotoptions[f->unit];
755    int len = *lenp;
756
757#define ADDCIADDRS(opt, neg, val1, val2) \
758    if (neg) { \
759	if (len >= CILEN_ADDRS) { \
760	    u_int32_t l; \
761	    PUTCHAR(opt, ucp); \
762	    PUTCHAR(CILEN_ADDRS, ucp); \
763	    l = ntohl(val1); \
764	    PUTLONG(l, ucp); \
765	    l = ntohl(val2); \
766	    PUTLONG(l, ucp); \
767	    len -= CILEN_ADDRS; \
768	} else \
769	    go->old_addrs = 0; \
770    }
771
772#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
773    if (neg) { \
774	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
775	if (len >= vjlen) { \
776	    PUTCHAR(opt, ucp); \
777	    PUTCHAR(vjlen, ucp); \
778	    PUTSHORT(val, ucp); \
779	    if (!old) { \
780		PUTCHAR(maxslotindex, ucp); \
781		PUTCHAR(cflag, ucp); \
782	    } \
783	    len -= vjlen; \
784	} else \
785	    neg = 0; \
786    }
787
788#define ADDCIADDR(opt, neg, val) \
789    if (neg) { \
790	if (len >= CILEN_ADDR) { \
791	    u_int32_t l; \
792	    PUTCHAR(opt, ucp); \
793	    PUTCHAR(CILEN_ADDR, ucp); \
794	    l = ntohl(val); \
795	    PUTLONG(l, ucp); \
796	    len -= CILEN_ADDR; \
797	} else \
798	    neg = 0; \
799    }
800
801#define ADDCIDNS(opt, neg, addr) \
802    if (neg) { \
803	if (len >= CILEN_ADDR) { \
804	    u_int32_t l; \
805	    PUTCHAR(opt, ucp); \
806	    PUTCHAR(CILEN_ADDR, ucp); \
807	    l = ntohl(addr); \
808	    PUTLONG(l, ucp); \
809	    len -= CILEN_ADDR; \
810	} else \
811	    neg = 0; \
812    }
813
814    ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
815	       go->hisaddr);
816
817    ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
818	    go->maxslotindex, go->cflag);
819
820    ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
821
822    ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
823
824    ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
825
826    *lenp -= len;
827}
828
829
830/*
831 * ipcp_ackci - Ack our CIs.
832 * Called by fsm_rconfack, Receive Configure ACK.
833 *
834 * Returns:
835 *	0 - Ack was bad.
836 *	1 - Ack was good.
837 */
838static int
839ipcp_ackci(f, p, len)
840    fsm *f;
841    u_char *p;
842    int len;
843{
844    ipcp_options *go = &ipcp_gotoptions[f->unit];
845    u_short cilen, citype, cishort;
846    u_int32_t cilong;
847    u_char cimaxslotindex, cicflag;
848
849    /*
850     * CIs must be in exactly the same order that we sent...
851     * Check packet length and CI length at each step.
852     * If we find any deviations, then this packet is bad.
853     */
854
855#define ACKCIADDRS(opt, neg, val1, val2) \
856    if (neg) { \
857	u_int32_t l; \
858	if ((len -= CILEN_ADDRS) < 0) \
859	    goto bad; \
860	GETCHAR(citype, p); \
861	GETCHAR(cilen, p); \
862	if (cilen != CILEN_ADDRS || \
863	    citype != opt) \
864	    goto bad; \
865	GETLONG(l, p); \
866	cilong = htonl(l); \
867	if (val1 != cilong) \
868	    goto bad; \
869	GETLONG(l, p); \
870	cilong = htonl(l); \
871	if (val2 != cilong) \
872	    goto bad; \
873    }
874
875#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
876    if (neg) { \
877	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
878	if ((len -= vjlen) < 0) \
879	    goto bad; \
880	GETCHAR(citype, p); \
881	GETCHAR(cilen, p); \
882	if (cilen != vjlen || \
883	    citype != opt)  \
884	    goto bad; \
885	GETSHORT(cishort, p); \
886	if (cishort != val) \
887	    goto bad; \
888	if (!old) { \
889	    GETCHAR(cimaxslotindex, p); \
890	    if (cimaxslotindex != maxslotindex) \
891		goto bad; \
892	    GETCHAR(cicflag, p); \
893	    if (cicflag != cflag) \
894		goto bad; \
895	} \
896    }
897
898#define ACKCIADDR(opt, neg, val) \
899    if (neg) { \
900	u_int32_t l; \
901	if ((len -= CILEN_ADDR) < 0) \
902	    goto bad; \
903	GETCHAR(citype, p); \
904	GETCHAR(cilen, p); \
905	if (cilen != CILEN_ADDR || \
906	    citype != opt) \
907	    goto bad; \
908	GETLONG(l, p); \
909	cilong = htonl(l); \
910	if (val != cilong) \
911	    goto bad; \
912    }
913
914#define ACKCIDNS(opt, neg, addr) \
915    if (neg) { \
916	u_int32_t l; \
917	if ((len -= CILEN_ADDR) < 0) \
918	    goto bad; \
919	GETCHAR(citype, p); \
920	GETCHAR(cilen, p); \
921	if (cilen != CILEN_ADDR || citype != opt) \
922	    goto bad; \
923	GETLONG(l, p); \
924	cilong = htonl(l); \
925	if (addr != cilong) \
926	    goto bad; \
927    }
928
929    ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
930	       go->hisaddr);
931
932    ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
933	    go->maxslotindex, go->cflag);
934
935    ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
936
937    ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
938
939    ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
940
941    /*
942     * If there are any remaining CIs, then this packet is bad.
943     */
944    if (len != 0)
945	goto bad;
946    return (1);
947
948bad:
949    IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
950    return (0);
951}
952
953/*
954 * ipcp_nakci - Peer has sent a NAK for some of our CIs.
955 * This should not modify any state if the Nak is bad
956 * or if IPCP is in the OPENED state.
957 * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
958 *
959 * Returns:
960 *	0 - Nak was bad.
961 *	1 - Nak was good.
962 */
963static int
964ipcp_nakci(f, p, len, treat_as_reject)
965    fsm *f;
966    u_char *p;
967    int len;
968    int treat_as_reject;
969{
970    ipcp_options *go = &ipcp_gotoptions[f->unit];
971    u_char cimaxslotindex, cicflag;
972    u_char citype, cilen, *next;
973    u_short cishort;
974    u_int32_t ciaddr1, ciaddr2, l, cidnsaddr;
975    ipcp_options no;		/* options we've seen Naks for */
976    ipcp_options try;		/* options to request next time */
977
978    BZERO(&no, sizeof(no));
979    try = *go;
980
981    /*
982     * Any Nak'd CIs must be in exactly the same order that we sent.
983     * Check packet length and CI length at each step.
984     * If we find any deviations, then this packet is bad.
985     */
986#define NAKCIADDRS(opt, neg, code) \
987    if ((neg) && \
988	(cilen = p[1]) == CILEN_ADDRS && \
989	len >= cilen && \
990	p[0] == opt) { \
991	len -= cilen; \
992	INCPTR(2, p); \
993	GETLONG(l, p); \
994	ciaddr1 = htonl(l); \
995	GETLONG(l, p); \
996	ciaddr2 = htonl(l); \
997	no.old_addrs = 1; \
998	code \
999    }
1000
1001#define NAKCIVJ(opt, neg, code) \
1002    if (go->neg && \
1003	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
1004	len >= cilen && \
1005	p[0] == opt) { \
1006	len -= cilen; \
1007	INCPTR(2, p); \
1008	GETSHORT(cishort, p); \
1009	no.neg = 1; \
1010        code \
1011    }
1012
1013#define NAKCIADDR(opt, neg, code) \
1014    if (go->neg && \
1015	(cilen = p[1]) == CILEN_ADDR && \
1016	len >= cilen && \
1017	p[0] == opt) { \
1018	len -= cilen; \
1019	INCPTR(2, p); \
1020	GETLONG(l, p); \
1021	ciaddr1 = htonl(l); \
1022	no.neg = 1; \
1023	code \
1024    }
1025
1026#define NAKCIDNS(opt, neg, code) \
1027    if (go->neg && \
1028	((cilen = p[1]) == CILEN_ADDR) && \
1029	len >= cilen && \
1030	p[0] == opt) { \
1031	len -= cilen; \
1032	INCPTR(2, p); \
1033	GETLONG(l, p); \
1034	cidnsaddr = htonl(l); \
1035	no.neg = 1; \
1036	code \
1037    }
1038
1039    /*
1040     * Accept the peer's idea of {our,his} address, if different
1041     * from our idea, only if the accept_{local,remote} flag is set.
1042     */
1043    NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1044	       if (treat_as_reject) {
1045		   try.old_addrs = 0;
1046	       } else {
1047		   if (go->accept_local && ciaddr1) {
1048		       /* take his idea of our address */
1049		       try.ouraddr = ciaddr1;
1050		   }
1051		   if (go->accept_remote && ciaddr2) {
1052		       /* take his idea of his address */
1053		       try.hisaddr = ciaddr2;
1054		   }
1055	       }
1056	);
1057
1058    /*
1059     * Accept the peer's value of maxslotindex provided that it
1060     * is less than what we asked for.  Turn off slot-ID compression
1061     * if the peer wants.  Send old-style compress-type option if
1062     * the peer wants.
1063     */
1064    NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
1065	    if (treat_as_reject) {
1066		try.neg_vj = 0;
1067	    } else if (cilen == CILEN_VJ) {
1068		GETCHAR(cimaxslotindex, p);
1069		GETCHAR(cicflag, p);
1070		if (cishort == IPCP_VJ_COMP) {
1071		    try.old_vj = 0;
1072		    if (cimaxslotindex < go->maxslotindex)
1073			try.maxslotindex = cimaxslotindex;
1074		    if (!cicflag)
1075			try.cflag = 0;
1076		} else {
1077		    try.neg_vj = 0;
1078		}
1079	    } else {
1080		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
1081		    try.old_vj = 1;
1082		    try.vj_protocol = cishort;
1083		} else {
1084		    try.neg_vj = 0;
1085		}
1086	    }
1087	    );
1088
1089    NAKCIADDR(CI_ADDR, neg_addr,
1090	      if (treat_as_reject) {
1091		  try.neg_addr = 0;
1092		  try.old_addrs = 0;
1093	      } else if (go->accept_local && ciaddr1) {
1094		  /* take his idea of our address */
1095		  try.ouraddr = ciaddr1;
1096	      }
1097	      );
1098
1099    NAKCIDNS(CI_MS_DNS1, req_dns1,
1100	     if (treat_as_reject) {
1101		 try.req_dns1 = 0;
1102	     } else {
1103		 try.dnsaddr[0] = cidnsaddr;
1104	     }
1105	     );
1106
1107    NAKCIDNS(CI_MS_DNS2, req_dns2,
1108	     if (treat_as_reject) {
1109		 try.req_dns2 = 0;
1110	     } else {
1111		 try.dnsaddr[1] = cidnsaddr;
1112	     }
1113	     );
1114
1115    /*
1116     * There may be remaining CIs, if the peer is requesting negotiation
1117     * on an option that we didn't include in our request packet.
1118     * If they want to negotiate about IP addresses, we comply.
1119     * If they want us to ask for compression, we refuse.
1120     */
1121    while (len >= CILEN_VOID) {
1122	GETCHAR(citype, p);
1123	GETCHAR(cilen, p);
1124	if ( cilen < CILEN_VOID || (len -= cilen) < 0 )
1125	    goto bad;
1126	next = p + cilen - 2;
1127
1128	switch (citype) {
1129	case CI_COMPRESSTYPE:
1130	    if (go->neg_vj || no.neg_vj ||
1131		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
1132		goto bad;
1133	    no.neg_vj = 1;
1134	    break;
1135	case CI_ADDRS:
1136	    if ((!go->neg_addr && go->old_addrs) || no.old_addrs
1137		|| cilen != CILEN_ADDRS)
1138		goto bad;
1139	    try.neg_addr = 0;
1140	    GETLONG(l, p);
1141	    ciaddr1 = htonl(l);
1142	    if (ciaddr1 && go->accept_local)
1143		try.ouraddr = ciaddr1;
1144	    GETLONG(l, p);
1145	    ciaddr2 = htonl(l);
1146	    if (ciaddr2 && go->accept_remote)
1147		try.hisaddr = ciaddr2;
1148	    no.old_addrs = 1;
1149	    break;
1150	case CI_ADDR:
1151	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
1152		goto bad;
1153	    try.old_addrs = 0;
1154	    GETLONG(l, p);
1155	    ciaddr1 = htonl(l);
1156	    if (ciaddr1 && go->accept_local)
1157		try.ouraddr = ciaddr1;
1158	    if (try.ouraddr != 0)
1159		try.neg_addr = 1;
1160	    no.neg_addr = 1;
1161	    break;
1162	}
1163	p = next;
1164    }
1165
1166    /*
1167     * OK, the Nak is good.  Now we can update state.
1168     * If there are any remaining options, we ignore them.
1169     */
1170    if (f->state != OPENED)
1171	*go = try;
1172
1173    return 1;
1174
1175bad:
1176    IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
1177    return 0;
1178}
1179
1180
1181/*
1182 * ipcp_rejci - Reject some of our CIs.
1183 * Callback from fsm_rconfnakrej.
1184 */
1185static int
1186ipcp_rejci(f, p, len)
1187    fsm *f;
1188    u_char *p;
1189    int len;
1190{
1191    ipcp_options *go = &ipcp_gotoptions[f->unit];
1192    u_char cimaxslotindex, ciflag, cilen;
1193    u_short cishort;
1194    u_int32_t cilong;
1195    ipcp_options try;		/* options to request next time */
1196
1197    try = *go;
1198    /*
1199     * Any Rejected CIs must be in exactly the same order that we sent.
1200     * Check packet length and CI length at each step.
1201     * If we find any deviations, then this packet is bad.
1202     */
1203#define REJCIADDRS(opt, neg, val1, val2) \
1204    if ((neg) && \
1205	(cilen = p[1]) == CILEN_ADDRS && \
1206	len >= cilen && \
1207	p[0] == opt) { \
1208	u_int32_t l; \
1209	len -= cilen; \
1210	INCPTR(2, p); \
1211	GETLONG(l, p); \
1212	cilong = htonl(l); \
1213	/* Check rejected value. */ \
1214	if (cilong != val1) \
1215	    goto bad; \
1216	GETLONG(l, p); \
1217	cilong = htonl(l); \
1218	/* Check rejected value. */ \
1219	if (cilong != val2) \
1220	    goto bad; \
1221	try.old_addrs = 0; \
1222    }
1223
1224#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
1225    if (go->neg && \
1226	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
1227	len >= p[1] && \
1228	p[0] == opt) { \
1229	len -= p[1]; \
1230	INCPTR(2, p); \
1231	GETSHORT(cishort, p); \
1232	/* Check rejected value. */  \
1233	if (cishort != val) \
1234	    goto bad; \
1235	if (!old) { \
1236	   GETCHAR(cimaxslotindex, p); \
1237	   if (cimaxslotindex != maxslot) \
1238	     goto bad; \
1239	   GETCHAR(ciflag, p); \
1240	   if (ciflag != cflag) \
1241	     goto bad; \
1242        } \
1243	try.neg = 0; \
1244     }
1245
1246#define REJCIADDR(opt, neg, val) \
1247    if (go->neg && \
1248	(cilen = p[1]) == CILEN_ADDR && \
1249	len >= cilen && \
1250	p[0] == opt) { \
1251	u_int32_t l; \
1252	len -= cilen; \
1253	INCPTR(2, p); \
1254	GETLONG(l, p); \
1255	cilong = htonl(l); \
1256	/* Check rejected value. */ \
1257	if (cilong != val) \
1258	    goto bad; \
1259	try.neg = 0; \
1260    }
1261
1262#define REJCIDNS(opt, neg, dnsaddr) \
1263    if (go->neg && \
1264	((cilen = p[1]) == CILEN_ADDR) && \
1265	len >= cilen && \
1266	p[0] == opt) { \
1267	u_int32_t l; \
1268	len -= cilen; \
1269	INCPTR(2, p); \
1270	GETLONG(l, p); \
1271	cilong = htonl(l); \
1272	/* Check rejected value. */ \
1273	if (cilong != dnsaddr) \
1274	    goto bad; \
1275	try.neg = 0; \
1276    }
1277
1278
1279    REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1280	       go->ouraddr, go->hisaddr);
1281
1282    REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
1283	    go->maxslotindex, go->cflag);
1284
1285    REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
1286
1287    REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
1288
1289    REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
1290
1291    /*
1292     * If there are any remaining CIs, then this packet is bad.
1293     */
1294    if (len != 0)
1295	goto bad;
1296    /*
1297     * Now we can update state.
1298     */
1299    if (f->state != OPENED)
1300	*go = try;
1301    return 1;
1302
1303bad:
1304    IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
1305    return 0;
1306}
1307
1308
1309/*
1310 * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
1311 * Callback from fsm_rconfreq, Receive Configure Request
1312 *
1313 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
1314 * appropriately.  If reject_if_disagree is non-zero, doesn't return
1315 * CONFNAK; returns CONFREJ if it can't return CONFACK.
1316 */
1317static int
1318ipcp_reqci(f, inp, len, reject_if_disagree)
1319    fsm *f;
1320    u_char *inp;		/* Requested CIs */
1321    int *len;			/* Length of requested CIs */
1322    int reject_if_disagree;
1323{
1324    ipcp_options *wo = &ipcp_wantoptions[f->unit];
1325    ipcp_options *ho = &ipcp_hisoptions[f->unit];
1326    ipcp_options *ao = &ipcp_allowoptions[f->unit];
1327    u_char *cip, *next;		/* Pointer to current and next CIs */
1328    u_short cilen, citype;	/* Parsed len, type */
1329    u_short cishort;		/* Parsed short value */
1330    u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
1331    int rc = CONFACK;		/* Final packet return code */
1332    int orc;			/* Individual option return code */
1333    u_char *p;			/* Pointer to next char to parse */
1334    u_char *ucp = inp;		/* Pointer to current output char */
1335    int l = *len;		/* Length left */
1336    u_char maxslotindex, cflag;
1337    int d;
1338
1339    /*
1340     * Reset all his options.
1341     */
1342    BZERO(ho, sizeof(*ho));
1343
1344    /*
1345     * Process all his options.
1346     */
1347    next = inp;
1348    while (l) {
1349	orc = CONFACK;			/* Assume success */
1350	cip = p = next;			/* Remember begining of CI */
1351	if (l < 2 ||			/* Not enough data for CI header or */
1352	    p[1] < 2 ||			/*  CI length too small or */
1353	    p[1] > l) {			/*  CI length too big? */
1354	    IPCPDEBUG(("ipcp_reqci: bad CI length!"));
1355	    orc = CONFREJ;		/* Reject bad CI */
1356	    cilen = l;			/* Reject till end of packet */
1357	    l = 0;			/* Don't loop again */
1358	    goto endswitch;
1359	}
1360	GETCHAR(citype, p);		/* Parse CI type */
1361	GETCHAR(cilen, p);		/* Parse CI length */
1362	l -= cilen;			/* Adjust remaining length */
1363	next += cilen;			/* Step to next CI */
1364
1365	switch (citype) {		/* Check CI type */
1366	case CI_ADDRS:
1367	    if (!ao->old_addrs || ho->neg_addr ||
1368		cilen != CILEN_ADDRS) {	/* Check CI length */
1369		orc = CONFREJ;		/* Reject CI */
1370		break;
1371	    }
1372
1373	    /*
1374	     * If he has no address, or if we both have his address but
1375	     * disagree about it, then NAK it with our idea.
1376	     * In particular, if we don't know his address, but he does,
1377	     * then accept it.
1378	     */
1379	    GETLONG(tl, p);		/* Parse source address (his) */
1380	    ciaddr1 = htonl(tl);
1381	    if (ciaddr1 != wo->hisaddr
1382		&& (ciaddr1 == 0 || !wo->accept_remote)) {
1383		orc = CONFNAK;
1384		if (!reject_if_disagree) {
1385		    DECPTR(sizeof(u_int32_t), p);
1386		    tl = ntohl(wo->hisaddr);
1387		    PUTLONG(tl, p);
1388		}
1389	    } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1390		/*
1391		 * If neither we nor he knows his address, reject the option.
1392		 */
1393		orc = CONFREJ;
1394		wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
1395		break;
1396	    }
1397
1398	    /*
1399	     * If he doesn't know our address, or if we both have our address
1400	     * but disagree about it, then NAK it with our idea.
1401	     */
1402	    GETLONG(tl, p);		/* Parse desination address (ours) */
1403	    ciaddr2 = htonl(tl);
1404	    if (ciaddr2 != wo->ouraddr) {
1405		if (ciaddr2 == 0 || !wo->accept_local) {
1406		    orc = CONFNAK;
1407		    if (!reject_if_disagree) {
1408			DECPTR(sizeof(u_int32_t), p);
1409			tl = ntohl(wo->ouraddr);
1410			PUTLONG(tl, p);
1411		    }
1412		} else {
1413		    wo->ouraddr = ciaddr2;	/* accept peer's idea */
1414		}
1415	    }
1416
1417	    ho->old_addrs = 1;
1418	    ho->hisaddr = ciaddr1;
1419	    ho->ouraddr = ciaddr2;
1420	    break;
1421
1422	case CI_ADDR:
1423	    if (!ao->neg_addr || ho->old_addrs ||
1424		cilen != CILEN_ADDR) {	/* Check CI length */
1425		orc = CONFREJ;		/* Reject CI */
1426		break;
1427	    }
1428
1429	    /*
1430	     * If he has no address, or if we both have his address but
1431	     * disagree about it, then NAK it with our idea.
1432	     * In particular, if we don't know his address, but he does,
1433	     * then accept it.
1434	     */
1435	    GETLONG(tl, p);	/* Parse source address (his) */
1436	    ciaddr1 = htonl(tl);
1437	    if (ciaddr1 != wo->hisaddr
1438		&& (ciaddr1 == 0 || !wo->accept_remote)) {
1439		orc = CONFNAK;
1440		if (!reject_if_disagree) {
1441		    DECPTR(sizeof(u_int32_t), p);
1442		    tl = ntohl(wo->hisaddr);
1443		    PUTLONG(tl, p);
1444		}
1445	    } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1446		/*
1447		 * Don't ACK an address of 0.0.0.0 - reject it instead.
1448		 */
1449		orc = CONFREJ;
1450		wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
1451		break;
1452	    }
1453
1454	    ho->neg_addr = 1;
1455	    ho->hisaddr = ciaddr1;
1456	    break;
1457
1458	case CI_MS_DNS1:
1459	case CI_MS_DNS2:
1460	    /* Microsoft primary or secondary DNS request */
1461	    d = citype == CI_MS_DNS2;
1462
1463	    /* If we do not have a DNS address then we cannot send it */
1464	    if (ao->dnsaddr[d] == 0 ||
1465		cilen != CILEN_ADDR) {	/* Check CI length */
1466		orc = CONFREJ;		/* Reject CI */
1467		break;
1468	    }
1469	    GETLONG(tl, p);
1470	    if (htonl(tl) != ao->dnsaddr[d]) {
1471                DECPTR(sizeof(u_int32_t), p);
1472		tl = ntohl(ao->dnsaddr[d]);
1473		PUTLONG(tl, p);
1474		orc = CONFNAK;
1475            }
1476            break;
1477
1478	case CI_MS_WINS1:
1479	case CI_MS_WINS2:
1480	    /* Microsoft primary or secondary WINS request */
1481	    d = citype == CI_MS_WINS2;
1482
1483	    /* If we do not have a DNS address then we cannot send it */
1484	    if (ao->winsaddr[d] == 0 ||
1485		cilen != CILEN_ADDR) {	/* Check CI length */
1486		orc = CONFREJ;		/* Reject CI */
1487		break;
1488	    }
1489	    GETLONG(tl, p);
1490	    if (htonl(tl) != ao->winsaddr[d]) {
1491                DECPTR(sizeof(u_int32_t), p);
1492		tl = ntohl(ao->winsaddr[d]);
1493		PUTLONG(tl, p);
1494		orc = CONFNAK;
1495            }
1496            break;
1497
1498	case CI_COMPRESSTYPE:
1499	    if (!ao->neg_vj ||
1500		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
1501		orc = CONFREJ;
1502		break;
1503	    }
1504	    GETSHORT(cishort, p);
1505
1506	    if (!(cishort == IPCP_VJ_COMP ||
1507		  (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
1508		orc = CONFREJ;
1509		break;
1510	    }
1511
1512	    ho->neg_vj = 1;
1513	    ho->vj_protocol = cishort;
1514	    if (cilen == CILEN_VJ) {
1515		GETCHAR(maxslotindex, p);
1516		if (maxslotindex > ao->maxslotindex) {
1517		    orc = CONFNAK;
1518		    if (!reject_if_disagree){
1519			DECPTR(1, p);
1520			PUTCHAR(ao->maxslotindex, p);
1521		    }
1522		}
1523		GETCHAR(cflag, p);
1524		if (cflag && !ao->cflag) {
1525		    orc = CONFNAK;
1526		    if (!reject_if_disagree){
1527			DECPTR(1, p);
1528			PUTCHAR(wo->cflag, p);
1529		    }
1530		}
1531		ho->maxslotindex = maxslotindex;
1532		ho->cflag = cflag;
1533	    } else {
1534		ho->old_vj = 1;
1535		ho->maxslotindex = MAX_STATES - 1;
1536		ho->cflag = 1;
1537	    }
1538	    break;
1539
1540	default:
1541	    orc = CONFREJ;
1542	    break;
1543	}
1544endswitch:
1545	if (orc == CONFACK &&		/* Good CI */
1546	    rc != CONFACK)		/*  but prior CI wasnt? */
1547	    continue;			/* Don't send this one */
1548
1549	if (orc == CONFNAK) {		/* Nak this CI? */
1550	    if (reject_if_disagree)	/* Getting fed up with sending NAKs? */
1551		orc = CONFREJ;		/* Get tough if so */
1552	    else {
1553		if (rc == CONFREJ)	/* Rejecting prior CI? */
1554		    continue;		/* Don't send this one */
1555		if (rc == CONFACK) {	/* Ack'd all prior CIs? */
1556		    rc = CONFNAK;	/* Not anymore... */
1557		    ucp = inp;		/* Backup */
1558		}
1559	    }
1560	}
1561
1562	if (orc == CONFREJ &&		/* Reject this CI */
1563	    rc != CONFREJ) {		/*  but no prior ones? */
1564	    rc = CONFREJ;
1565	    ucp = inp;			/* Backup */
1566	}
1567
1568	/* Need to move CI? */
1569	if (ucp != cip)
1570	    BCOPY(cip, ucp, cilen);	/* Move it */
1571
1572	/* Update output pointer */
1573	INCPTR(cilen, ucp);
1574    }
1575
1576    /*
1577     * If we aren't rejecting this packet, and we want to negotiate
1578     * their address, and they didn't send their address, then we
1579     * send a NAK with a CI_ADDR option appended.  We assume the
1580     * input buffer is long enough that we can append the extra
1581     * option safely.
1582     */
1583    if (rc != CONFREJ && !ho->neg_addr && !ho->old_addrs &&
1584	wo->req_addr && !reject_if_disagree) {
1585	if (rc == CONFACK) {
1586	    rc = CONFNAK;
1587	    ucp = inp;			/* reset pointer */
1588	    wo->req_addr = 0;		/* don't ask again */
1589	}
1590	PUTCHAR(CI_ADDR, ucp);
1591	PUTCHAR(CILEN_ADDR, ucp);
1592	tl = ntohl(wo->hisaddr);
1593	PUTLONG(tl, ucp);
1594    }
1595
1596    *len = ucp - inp;			/* Compute output length */
1597    IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc)));
1598    return (rc);			/* Return final code */
1599}
1600
1601
1602/*
1603 * ip_check_options - check that any IP-related options are OK,
1604 * and assign appropriate defaults.
1605 */
1606static void
1607ip_check_options()
1608{
1609    struct hostent *hp;
1610    u_int32_t local;
1611    ipcp_options *wo = &ipcp_wantoptions[0];
1612
1613    /*
1614     * Default our local IP address based on our hostname.
1615     * If local IP address already given, don't bother.
1616     */
1617    if (wo->ouraddr == 0 && !disable_defaultip) {
1618	/*
1619	 * Look up our hostname (possibly with domain name appended)
1620	 * and take the first IP address as our local IP address.
1621	 * If there isn't an IP address for our hostname, too bad.
1622	 */
1623	wo->accept_local = 1;	/* don't insist on this default value */
1624	if ((hp = gethostbyname(hostname)) != NULL) {
1625	    local = *(u_int32_t *)hp->h_addr;
1626	    if (local != 0 && !bad_ip_adrs(local))
1627		wo->ouraddr = local;
1628	}
1629    }
1630    ask_for_local = wo->ouraddr != 0 || !disable_defaultip;
1631}
1632
1633
1634/*
1635 * ip_demand_conf - configure the interface as though
1636 * IPCP were up, for use with dial-on-demand.
1637 */
1638static int
1639ip_demand_conf(u)
1640    int u;
1641{
1642    ipcp_options *wo = &ipcp_wantoptions[u];
1643
1644    if (wo->hisaddr == 0) {
1645	/* make up an arbitrary address for the peer */
1646	wo->hisaddr = htonl(0x0a707070 + ifunit);
1647	wo->accept_remote = 1;
1648    }
1649    if (wo->ouraddr == 0) {
1650	/* make up an arbitrary address for us */
1651	wo->ouraddr = htonl(0x0a404040 + ifunit);
1652	wo->accept_local = 1;
1653	ask_for_local = 0;	/* don't tell the peer this address */
1654    }
1655    if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
1656	return 0;
1657    if (!sifup(u))
1658	return 0;
1659    if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
1660	return 0;
1661    if (wo->default_route)
1662	if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr))
1663	    default_route_set[u] = 1;
1664    if (wo->proxy_arp)
1665	if (sifproxyarp(u, wo->hisaddr))
1666	    proxy_arp_set[u] = 1;
1667
1668    notice("local  IP address %I", wo->ouraddr);
1669    notice("remote IP address %I", wo->hisaddr);
1670
1671    return 1;
1672}
1673
1674
1675/*
1676 * ipcp_up - IPCP has come UP.
1677 *
1678 * Configure the IP network interface appropriately and bring it up.
1679 */
1680static void
1681ipcp_up(f)
1682    fsm *f;
1683{
1684    u_int32_t mask;
1685    ipcp_options *ho = &ipcp_hisoptions[f->unit];
1686    ipcp_options *go = &ipcp_gotoptions[f->unit];
1687    ipcp_options *wo = &ipcp_wantoptions[f->unit];
1688
1689    IPCPDEBUG(("ipcp: up"));
1690
1691    /*
1692     * We must have a non-zero IP address for both ends of the link.
1693     */
1694    if (!ho->neg_addr && !ho->old_addrs)
1695	ho->hisaddr = wo->hisaddr;
1696
1697    if (!(go->neg_addr || go->old_addrs) && (wo->neg_addr || wo->old_addrs)
1698	&& wo->ouraddr != 0) {
1699	error("Peer refused to agree to our IP address");
1700	ipcp_close(f->unit, "Refused our IP address");
1701	return;
1702    }
1703    if (go->ouraddr == 0) {
1704	error("Could not determine local IP address");
1705	ipcp_close(f->unit, "Could not determine local IP address");
1706	return;
1707    }
1708    if (ho->hisaddr == 0) {
1709	ho->hisaddr = htonl(0x0a404040 + ifunit);
1710	warn("Could not determine remote IP address: defaulting to %I",
1711	     ho->hisaddr);
1712    }
1713    script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
1714    script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
1715
1716    if (go->dnsaddr[0])
1717	script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
1718    if (go->dnsaddr[1])
1719	script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
1720    if (usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
1721	script_setenv("USEPEERDNS", "1", 0);
1722	create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
1723    }
1724
1725    /*
1726     * Check that the peer is allowed to use the IP address it wants.
1727     */
1728    if (!auth_ip_addr(f->unit, ho->hisaddr)) {
1729	error("Peer is not authorized to use remote address %I", ho->hisaddr);
1730	ipcp_close(f->unit, "Unauthorized remote IP address");
1731	return;
1732    }
1733
1734    /* set tcp compression */
1735    sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
1736
1737    /*
1738     * If we are doing dial-on-demand, the interface is already
1739     * configured, so we put out any saved-up packets, then set the
1740     * interface to pass IP packets.
1741     */
1742    if (demand) {
1743	if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
1744	    ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr);
1745	    if (go->ouraddr != wo->ouraddr) {
1746		warn("Local IP address changed to %I", go->ouraddr);
1747		script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
1748		wo->ouraddr = go->ouraddr;
1749	    } else
1750		script_unsetenv("OLDIPLOCAL");
1751	    if (ho->hisaddr != wo->hisaddr) {
1752		warn("Remote IP address changed to %I", ho->hisaddr);
1753		script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
1754		wo->hisaddr = ho->hisaddr;
1755	    } else
1756		script_unsetenv("OLDIPREMOTE");
1757
1758	    /* Set the interface to the new addresses */
1759	    mask = GetMask(go->ouraddr);
1760	    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1761		if (debug)
1762		    warn("Interface configuration failed");
1763		ipcp_close(f->unit, "Interface configuration failed");
1764		return;
1765	    }
1766
1767	    /* assign a default route through the interface if required */
1768	    if (ipcp_wantoptions[f->unit].default_route)
1769		if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
1770		    default_route_set[f->unit] = 1;
1771
1772	    /* Make a proxy ARP entry if requested. */
1773	    if (ipcp_wantoptions[f->unit].proxy_arp)
1774		if (sifproxyarp(f->unit, ho->hisaddr))
1775		    proxy_arp_set[f->unit] = 1;
1776
1777	}
1778	demand_rexmit(PPP_IP);
1779	sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1780
1781    } else {
1782	/*
1783	 * Set IP addresses and (if specified) netmask.
1784	 */
1785	mask = GetMask(go->ouraddr);
1786
1787#if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1788	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1789	    if (debug)
1790		warn("Interface configuration failed");
1791	    ipcp_close(f->unit, "Interface configuration failed");
1792	    return;
1793	}
1794#endif
1795
1796	/* bring the interface up for IP */
1797	if (!sifup(f->unit)) {
1798	    if (debug)
1799		warn("Interface failed to come up");
1800	    ipcp_close(f->unit, "Interface configuration failed");
1801	    return;
1802	}
1803
1804#if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1805	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1806	    if (debug)
1807		warn("Interface configuration failed");
1808	    ipcp_close(f->unit, "Interface configuration failed");
1809	    return;
1810	}
1811#endif
1812	sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1813
1814	/* assign a default route through the interface if required */
1815	if (ipcp_wantoptions[f->unit].default_route)
1816	    if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
1817		default_route_set[f->unit] = 1;
1818
1819	/* Make a proxy ARP entry if requested. */
1820	if (ipcp_wantoptions[f->unit].proxy_arp)
1821	    if (sifproxyarp(f->unit, ho->hisaddr))
1822		proxy_arp_set[f->unit] = 1;
1823
1824	ipcp_wantoptions[0].ouraddr = go->ouraddr;
1825
1826	notice("local  IP address %I", go->ouraddr);
1827	notice("remote IP address %I", ho->hisaddr);
1828	if (go->dnsaddr[0])
1829	    notice("primary   DNS address %I", go->dnsaddr[0]);
1830	if (go->dnsaddr[1])
1831	    notice("secondary DNS address %I", go->dnsaddr[1]);
1832    }
1833
1834    reset_link_stats(f->unit);
1835
1836    np_up(f->unit, PPP_IP);
1837    ipcp_is_up = 1;
1838
1839    notify(ip_up_notifier, 0);
1840    if (ip_up_hook)
1841	ip_up_hook();
1842
1843    /*
1844     * Execute the ip-up script, like this:
1845     *	/etc/ppp/ip-up interface tty speed local-IP remote-IP
1846     */
1847    if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
1848	ipcp_script_state = s_up;
1849	ipcp_script(_PATH_IPUP);
1850    }
1851}
1852
1853
1854/*
1855 * ipcp_down - IPCP has gone DOWN.
1856 *
1857 * Take the IP network interface down, clear its addresses
1858 * and delete routes through it.
1859 */
1860static void
1861ipcp_down(f)
1862    fsm *f;
1863{
1864    IPCPDEBUG(("ipcp: down"));
1865    /* XXX a bit IPv4-centric here, we only need to get the stats
1866     * before the interface is marked down. */
1867    /* XXX more correct: we must get the stats before running the notifiers,
1868     * at least for the radius plugin */
1869    update_link_stats(f->unit);
1870    notify(ip_down_notifier, 0);
1871    if (ip_down_hook)
1872	ip_down_hook();
1873    if (ipcp_is_up) {
1874	ipcp_is_up = 0;
1875	np_down(f->unit, PPP_IP);
1876    }
1877    sifvjcomp(f->unit, 0, 0, 0);
1878
1879    print_link_stats(); /* _after_ running the notifiers and ip_down_hook(),
1880			 * because print_link_stats() sets link_stats_valid
1881			 * to 0 (zero) */
1882
1883    /*
1884     * If we are doing dial-on-demand, set the interface
1885     * to queue up outgoing packets (for now).
1886     */
1887    if (demand) {
1888	sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE);
1889    } else {
1890	sifnpmode(f->unit, PPP_IP, NPMODE_DROP);
1891	sifdown(f->unit);
1892	ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
1893			 ipcp_hisoptions[f->unit].hisaddr);
1894    }
1895
1896    /* Execute the ip-down script */
1897    if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
1898	ipcp_script_state = s_down;
1899	ipcp_script(_PATH_IPDOWN);
1900    }
1901}
1902
1903
1904/*
1905 * ipcp_clear_addrs() - clear the interface addresses, routes,
1906 * proxy arp entries, etc.
1907 */
1908static void
1909ipcp_clear_addrs(unit, ouraddr, hisaddr)
1910    int unit;
1911    u_int32_t ouraddr;  /* local address */
1912    u_int32_t hisaddr;  /* remote address */
1913{
1914    if (proxy_arp_set[unit]) {
1915	cifproxyarp(unit, hisaddr);
1916	proxy_arp_set[unit] = 0;
1917    }
1918    if (default_route_set[unit]) {
1919	cifdefaultroute(unit, ouraddr, hisaddr);
1920	default_route_set[unit] = 0;
1921    }
1922    cifaddr(unit, ouraddr, hisaddr);
1923}
1924
1925
1926/*
1927 * ipcp_finished - possibly shut down the lower layers.
1928 */
1929static void
1930ipcp_finished(f)
1931    fsm *f;
1932{
1933	if (ipcp_is_open) {
1934		ipcp_is_open = 0;
1935		np_finished(f->unit, PPP_IP);
1936	}
1937}
1938
1939
1940/*
1941 * ipcp_script_done - called when the ip-up or ip-down script
1942 * has finished.
1943 */
1944static void
1945ipcp_script_done(arg)
1946    void *arg;
1947{
1948    ipcp_script_pid = 0;
1949    switch (ipcp_script_state) {
1950    case s_up:
1951	if (ipcp_fsm[0].state != OPENED) {
1952	    ipcp_script_state = s_down;
1953	    ipcp_script(_PATH_IPDOWN);
1954	}
1955	break;
1956    case s_down:
1957	if (ipcp_fsm[0].state == OPENED) {
1958	    ipcp_script_state = s_up;
1959	    ipcp_script(_PATH_IPUP);
1960	}
1961	break;
1962    }
1963}
1964
1965
1966/*
1967 * ipcp_script - Execute a script with arguments
1968 * interface-name tty-name speed local-IP remote-IP.
1969 */
1970static void
1971ipcp_script(script)
1972    char *script;
1973{
1974    char strspeed[32], strlocal[32], strremote[32];
1975    char *argv[8];
1976
1977    slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
1978    slprintf(strlocal, sizeof(strlocal), "%I", ipcp_gotoptions[0].ouraddr);
1979    slprintf(strremote, sizeof(strremote), "%I", ipcp_hisoptions[0].hisaddr);
1980
1981    argv[0] = script;
1982    argv[1] = ifname;
1983    argv[2] = devnam;
1984    argv[3] = strspeed;
1985    argv[4] = strlocal;
1986    argv[5] = strremote;
1987    argv[6] = ipparam;
1988    argv[7] = NULL;
1989    ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done, NULL);
1990}
1991
1992/*
1993 * create_resolv - create the replacement resolv.conf file
1994 */
1995static void
1996create_resolv(peerdns1, peerdns2)
1997    u_int32_t peerdns1, peerdns2;
1998{
1999#ifndef ANDROID_CHANGES
2000    FILE *f;
2001
2002    f = fopen(_PATH_RESOLV, "w");
2003    if (f == NULL) {
2004	error("Failed to create %s: %m", _PATH_RESOLV);
2005	return;
2006    }
2007
2008    if (peerdns1)
2009	fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1));
2010
2011    if (peerdns2)
2012	fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2));
2013
2014    if (ferror(f))
2015	error("Write failed to %s: %m", _PATH_RESOLV);
2016
2017    fclose(f);
2018#endif
2019}
2020
2021/*
2022 * ipcp_printpkt - print the contents of an IPCP packet.
2023 */
2024static char *ipcp_codenames[] = {
2025    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
2026    "TermReq", "TermAck", "CodeRej"
2027};
2028
2029static int
2030ipcp_printpkt(p, plen, printer, arg)
2031    u_char *p;
2032    int plen;
2033    void (*printer) __P((void *, char *, ...));
2034    void *arg;
2035{
2036    int code, id, len, olen;
2037    u_char *pstart, *optend;
2038    u_short cishort;
2039    u_int32_t cilong;
2040
2041    if (plen < HEADERLEN)
2042	return 0;
2043    pstart = p;
2044    GETCHAR(code, p);
2045    GETCHAR(id, p);
2046    GETSHORT(len, p);
2047    if (len < HEADERLEN || len > plen)
2048	return 0;
2049
2050    if (code >= 1 && code <= sizeof(ipcp_codenames) / sizeof(char *))
2051	printer(arg, " %s", ipcp_codenames[code-1]);
2052    else
2053	printer(arg, " code=0x%x", code);
2054    printer(arg, " id=0x%x", id);
2055    len -= HEADERLEN;
2056    switch (code) {
2057    case CONFREQ:
2058    case CONFACK:
2059    case CONFNAK:
2060    case CONFREJ:
2061	/* print option list */
2062	while (len >= 2) {
2063	    GETCHAR(code, p);
2064	    GETCHAR(olen, p);
2065	    p -= 2;
2066	    if (olen < 2 || olen > len) {
2067		break;
2068	    }
2069	    printer(arg, " <");
2070	    len -= olen;
2071	    optend = p + olen;
2072	    switch (code) {
2073	    case CI_ADDRS:
2074		if (olen == CILEN_ADDRS) {
2075		    p += 2;
2076		    GETLONG(cilong, p);
2077		    printer(arg, "addrs %I", htonl(cilong));
2078		    GETLONG(cilong, p);
2079		    printer(arg, " %I", htonl(cilong));
2080		}
2081		break;
2082	    case CI_COMPRESSTYPE:
2083		if (olen >= CILEN_COMPRESS) {
2084		    p += 2;
2085		    GETSHORT(cishort, p);
2086		    printer(arg, "compress ");
2087		    switch (cishort) {
2088		    case IPCP_VJ_COMP:
2089			printer(arg, "VJ");
2090			break;
2091		    case IPCP_VJ_COMP_OLD:
2092			printer(arg, "old-VJ");
2093			break;
2094		    default:
2095			printer(arg, "0x%x", cishort);
2096		    }
2097		}
2098		break;
2099	    case CI_ADDR:
2100		if (olen == CILEN_ADDR) {
2101		    p += 2;
2102		    GETLONG(cilong, p);
2103		    printer(arg, "addr %I", htonl(cilong));
2104		}
2105		break;
2106	    case CI_MS_DNS1:
2107	    case CI_MS_DNS2:
2108	        p += 2;
2109		GETLONG(cilong, p);
2110		printer(arg, "ms-dns%d %I", code - CI_MS_DNS1 + 1,
2111			htonl(cilong));
2112		break;
2113	    case CI_MS_WINS1:
2114	    case CI_MS_WINS2:
2115	        p += 2;
2116		GETLONG(cilong, p);
2117		printer(arg, "ms-wins %I", htonl(cilong));
2118		break;
2119	    }
2120	    while (p < optend) {
2121		GETCHAR(code, p);
2122		printer(arg, " %.2x", code);
2123	    }
2124	    printer(arg, ">");
2125	}
2126	break;
2127
2128    case TERMACK:
2129    case TERMREQ:
2130	if (len > 0 && *p >= ' ' && *p < 0x7f) {
2131	    printer(arg, " ");
2132	    print_string((char *)p, len, printer, arg);
2133	    p += len;
2134	    len = 0;
2135	}
2136	break;
2137    }
2138
2139    /* print the rest of the bytes in the packet */
2140    for (; len > 0; --len) {
2141	GETCHAR(code, p);
2142	printer(arg, " %.2x", code);
2143    }
2144
2145    return p - pstart;
2146}
2147
2148/*
2149 * ip_active_pkt - see if this IP packet is worth bringing the link up for.
2150 * We don't bring the link up for IP fragments or for TCP FIN packets
2151 * with no data.
2152 */
2153#define IP_HDRLEN	20	/* bytes */
2154#define IP_OFFMASK	0x1fff
2155#ifndef IPPROTO_TCP
2156#define IPPROTO_TCP	6
2157#endif
2158#define TCP_HDRLEN	20
2159#define TH_FIN		0x01
2160
2161/*
2162 * We use these macros because the IP header may be at an odd address,
2163 * and some compilers might use word loads to get th_off or ip_hl.
2164 */
2165
2166#define net_short(x)	(((x)[0] << 8) + (x)[1])
2167#define get_iphl(x)	(((unsigned char *)(x))[0] & 0xF)
2168#define get_ipoff(x)	net_short((unsigned char *)(x) + 6)
2169#define get_ipproto(x)	(((unsigned char *)(x))[9])
2170#define get_tcpoff(x)	(((unsigned char *)(x))[12] >> 4)
2171#define get_tcpflags(x)	(((unsigned char *)(x))[13])
2172
2173static int
2174ip_active_pkt(pkt, len)
2175    u_char *pkt;
2176    int len;
2177{
2178    u_char *tcp;
2179    int hlen;
2180
2181    len -= PPP_HDRLEN;
2182    pkt += PPP_HDRLEN;
2183    if (len < IP_HDRLEN)
2184	return 0;
2185    if ((get_ipoff(pkt) & IP_OFFMASK) != 0)
2186	return 0;
2187    if (get_ipproto(pkt) != IPPROTO_TCP)
2188	return 1;
2189    hlen = get_iphl(pkt) * 4;
2190    if (len < hlen + TCP_HDRLEN)
2191	return 0;
2192    tcp = pkt + hlen;
2193    if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
2194	return 0;
2195    return 1;
2196}
2197