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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 
64 static const char rcsid[] = RCSID;
65 
66 /* global vars */
67 ipcp_options ipcp_wantoptions[NUM_PPP];	/* Options that we want to request */
68 ipcp_options ipcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
69 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
70 ipcp_options ipcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
71 
72 u_int32_t netmask = 0;		/* IP netmask to set on interface */
73 
74 bool	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 */
77 void (*ip_up_hook) __P((void)) = NULL;
78 
79 /* Hook for a plugin to know when IP protocol has come down */
80 void (*ip_down_hook) __P((void)) = NULL;
81 
82 /* Hook for a plugin to choose the remote IP address */
83 void (*ip_choose_hook) __P((u_int32_t *)) = NULL;
84 
85 /* Notifiers for when IPCP goes up and down */
86 struct notifier *ip_up_notifier = NULL;
87 struct notifier *ip_down_notifier = NULL;
88 
89 /* local vars */
90 static int default_route_set[NUM_PPP];	/* Have set up a default route */
91 static int proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
92 static bool usepeerdns;			/* Ask peer for DNS addrs */
93 static int ipcp_is_up;			/* have called np_up() */
94 static int ipcp_is_open;		/* haven't called np_finished() */
95 static bool ask_for_local;		/* request our address from peer */
96 static char vj_value[8];		/* string form of vj option value */
97 static char netmask_str[20];		/* string form of netmask value */
98 
99 /*
100  * Callbacks for fsm code.  (CI = Configuration Information)
101  */
102 static void ipcp_resetci __P((fsm *));	/* Reset our CI */
103 static int  ipcp_cilen __P((fsm *));	        /* Return length of our CI */
104 static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
105 static int  ipcp_ackci __P((fsm *, u_char *, int));	/* Peer ack'd our CI */
106 static int  ipcp_nakci __P((fsm *, u_char *, int, int));/* Peer nak'd our CI */
107 static int  ipcp_rejci __P((fsm *, u_char *, int));	/* Peer rej'd our CI */
108 static int  ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
109 static void ipcp_up __P((fsm *));		/* We're UP */
110 static void ipcp_down __P((fsm *));		/* We're DOWN */
111 static void ipcp_finished __P((fsm *));	/* Don't need lower layer */
112 
113 fsm ipcp_fsm[NUM_PPP];		/* IPCP fsm structure */
114 
115 static 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  */
136 static int setvjslots __P((char **));
137 static int setdnsaddr __P((char **));
138 static int setwinsaddr __P((char **));
139 static int setnetmask __P((char **));
140 int setipaddr __P((char *, char **, int));
141 static void printipaddr __P((option_t *, void (*)(void *, char *,...),void *));
142 
143 static 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  */
232 static void ipcp_init __P((int));
233 static void ipcp_open __P((int));
234 static void ipcp_close __P((int, char *));
235 static void ipcp_lowerup __P((int));
236 static void ipcp_lowerdown __P((int));
237 static void ipcp_input __P((int, u_char *, int));
238 static void ipcp_protrej __P((int));
239 static int  ipcp_printpkt __P((u_char *, int,
240 			       void (*) __P((void *, char *, ...)), void *));
241 static void ip_check_options __P((void));
242 static int  ip_demand_conf __P((int));
243 static int  ip_active_pkt __P((u_char *, int));
244 static void create_resolv __P((u_int32_t, u_int32_t));
245 
246 struct 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 
266 static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t));
267 static void ipcp_script __P((char *));		/* Run an up/down script */
268 static 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  */
287 static enum script_state {
288     s_down,
289     s_up,
290 } ipcp_script_state;
291 static pid_t ipcp_script_pid;
292 
293 /*
294  * Make a string representation of a network IP address.
295  */
296 char *
ip_ntoa(ipaddr)297 ip_ntoa(ipaddr)
298 u_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  */
313 static int
setvjslots(argv)314 setvjslots(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  */
334 static int
setdnsaddr(argv)335 setdnsaddr(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  */
370 static int
setwinsaddr(argv)371 setwinsaddr(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  */
407 int
setipaddr(arg,argv,doit)408 setipaddr(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 
474 static void
printipaddr(opt,printer,arg)475 printipaddr(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  */
492 static int
setnetmask(argv)493 setnetmask(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 
520 int
parse_dotted_ip(p,vp)521 parse_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  */
557 static void
ipcp_init(unit)558 ipcp_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  */
601 static void
ipcp_open(unit)602 ipcp_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  */
613 static void
ipcp_close(unit,reason)614 ipcp_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  */
625 static void
ipcp_lowerup(unit)626 ipcp_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  */
636 static void
ipcp_lowerdown(unit)637 ipcp_lowerdown(unit)
638     int unit;
639 {
640     fsm_lowerdown(&ipcp_fsm[unit]);
641 }
642 
643 
644 /*
645  * ipcp_input - Input IPCP packet.
646  */
647 static void
ipcp_input(unit,p,len)648 ipcp_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  */
662 static void
ipcp_protrej(unit)663 ipcp_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  */
674 static void
ipcp_resetci(f)675 ipcp_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  */
707 static int
ipcp_cilen(f)708 ipcp_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  */
748 static void
ipcp_addci(f,ucp,lenp)749 ipcp_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  */
838 static int
ipcp_ackci(f,p,len)839 ipcp_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 
948 bad:
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  */
963 static int
ipcp_nakci(f,p,len,treat_as_reject)964 ipcp_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 
1175 bad:
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  */
1185 static int
ipcp_rejci(f,p,len)1186 ipcp_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 
1303 bad:
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  */
1317 static int
ipcp_reqci(f,inp,len,reject_if_disagree)1318 ipcp_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 	}
1544 endswitch:
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  */
1606 static void
ip_check_options()1607 ip_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  */
1638 static int
ip_demand_conf(u)1639 ip_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  */
1680 static void
ipcp_up(f)1681 ipcp_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  */
1860 static void
ipcp_down(f)1861 ipcp_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  */
1908 static void
ipcp_clear_addrs(unit,ouraddr,hisaddr)1909 ipcp_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  */
1929 static void
ipcp_finished(f)1930 ipcp_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  */
1944 static void
ipcp_script_done(arg)1945 ipcp_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  */
1970 static void
ipcp_script(script)1971 ipcp_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  */
1995 static void
create_resolv(peerdns1,peerdns2)1996 create_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  */
2024 static char *ipcp_codenames[] = {
2025     "ConfReq", "ConfAck", "ConfNak", "ConfRej",
2026     "TermReq", "TermAck", "CodeRej"
2027 };
2028 
2029 static int
ipcp_printpkt(p,plen,printer,arg)2030 ipcp_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 
2173 static int
ip_active_pkt(pkt,len)2174 ip_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