1 /* $NetBSD: ipcp.c,v 1.5 2021/01/09 16:39:28 christos Exp $ */
2
3 /*
4 * ipcp.c - PPP IP Control Protocol.
5 *
6 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. The name "Carnegie Mellon University" must not be used to
21 * endorse or promote products derived from this software without
22 * prior written permission. For permission or any legal
23 * details, please contact
24 * Office of Technology Transfer
25 * Carnegie Mellon University
26 * 5000 Forbes Avenue
27 * Pittsburgh, PA 15213-3890
28 * (412) 268-4387, fax: (412) 268-7395
29 * tech-transfer@andrew.cmu.edu
30 *
31 * 4. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by Computing Services
34 * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35 *
36 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43 */
44
45 #include <sys/cdefs.h>
46 __RCSID("$NetBSD: ipcp.c,v 1.5 2021/01/09 16:39:28 christos Exp $");
47
48 /*
49 * TODO:
50 */
51
52 #include <stdio.h>
53 #include <string.h>
54 #include <stdlib.h>
55 #include <netdb.h>
56 #include <sys/param.h>
57 #include <sys/types.h>
58 #include <sys/socket.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
61 #include <net/if.h>
62
63 #include "pppd.h"
64 #include "fsm.h"
65 #include "ipcp.h"
66 #include "pathnames.h"
67
68
69 /* global vars */
70 ipcp_options ipcp_wantoptions[NUM_PPP]; /* Options that we want to request */
71 ipcp_options ipcp_gotoptions[NUM_PPP]; /* Options that peer ack'd */
72 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
73 ipcp_options ipcp_hisoptions[NUM_PPP]; /* Options that we ack'd */
74
75 u_int32_t netmask = 0; /* IP netmask to set on interface */
76
77 bool disable_defaultip = 0; /* Don't use hostname for default IP adrs */
78 bool noremoteip = 0; /* Let him have no IP address */
79
80 /* Hook for a plugin to know when IP protocol has come up */
81 void (*ip_up_hook)(void) = NULL;
82
83 /* Hook for a plugin to know when IP protocol has come down */
84 void (*ip_down_hook)(void) = NULL;
85
86 /* Hook for a plugin to choose the remote IP address */
87 void (*ip_choose_hook)(u_int32_t *) = NULL;
88
89 /* Notifiers for when IPCP goes up and down */
90 struct notifier *ip_up_notifier = NULL;
91 struct notifier *ip_down_notifier = NULL;
92
93 /* local vars */
94 static int default_route_set[NUM_PPP]; /* Have set up a default route */
95 static int proxy_arp_set[NUM_PPP]; /* Have created proxy arp entry */
96 static bool usepeerdns; /* Ask peer for DNS addrs */
97 static int ipcp_is_up; /* have called np_up() */
98 static int ipcp_is_open; /* haven't called np_finished() */
99 static bool ask_for_local; /* request our address from peer */
100 static char vj_value[8]; /* string form of vj option value */
101 static char netmask_str[20]; /* string form of netmask value */
102
103 /*
104 * Callbacks for fsm code. (CI = Configuration Information)
105 */
106 static void ipcp_resetci (fsm *); /* Reset our CI */
107 static int ipcp_cilen (fsm *); /* Return length of our CI */
108 static void ipcp_addci (fsm *, u_char *, int *); /* Add our CI */
109 static int ipcp_ackci (fsm *, u_char *, int); /* Peer ack'd our CI */
110 static int ipcp_nakci (fsm *, u_char *, int, int);/* Peer nak'd our CI */
111 static int ipcp_rejci (fsm *, u_char *, int); /* Peer rej'd our CI */
112 static int ipcp_reqci (fsm *, u_char *, int *, int); /* Rcv CI */
113 static void ipcp_up (fsm *); /* We're UP */
114 static void ipcp_down (fsm *); /* We're DOWN */
115 static void ipcp_finished (fsm *); /* Don't need lower layer */
116
117 fsm ipcp_fsm[NUM_PPP]; /* IPCP fsm structure */
118
119 static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
120 ipcp_resetci, /* Reset our Configuration Information */
121 ipcp_cilen, /* Length of our Configuration Information */
122 ipcp_addci, /* Add our Configuration Information */
123 ipcp_ackci, /* ACK our Configuration Information */
124 ipcp_nakci, /* NAK our Configuration Information */
125 ipcp_rejci, /* Reject our Configuration Information */
126 ipcp_reqci, /* Request peer's Configuration Information */
127 ipcp_up, /* Called when fsm reaches OPENED state */
128 ipcp_down, /* Called when fsm leaves OPENED state */
129 NULL, /* Called when we want the lower layer up */
130 ipcp_finished, /* Called when we want the lower layer down */
131 NULL, /* Called when Protocol-Reject received */
132 NULL, /* Retransmission is necessary */
133 NULL, /* Called to handle protocol-specific codes */
134 "IPCP" /* String name of protocol */
135 };
136
137 /*
138 * Command-line options.
139 */
140 static int setvjslots (char **);
141 static int setdnsaddr (char **);
142 static int setwinsaddr (char **);
143 static int setnetmask (char **);
144 int setipaddr (char *, char **, int);
145 static void printipaddr (option_t *, void (*)(void *, char *,...),void *);
146
147 static option_t ipcp_option_list[] = {
148 { "noip", o_bool, &ipcp_protent.enabled_flag,
149 "Disable IP and IPCP" },
150 { "-ip", o_bool, &ipcp_protent.enabled_flag,
151 "Disable IP and IPCP", OPT_ALIAS },
152
153 { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
154 "Disable VJ compression", OPT_A2CLR, &ipcp_allowoptions[0].neg_vj },
155 { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
156 "Disable VJ compression", OPT_ALIAS | OPT_A2CLR,
157 &ipcp_allowoptions[0].neg_vj },
158
159 { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
160 "Disable VJ connection-ID compression", OPT_A2CLR,
161 &ipcp_allowoptions[0].cflag },
162 { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
163 "Disable VJ connection-ID compression", OPT_ALIAS | OPT_A2CLR,
164 &ipcp_allowoptions[0].cflag },
165
166 { "vj-max-slots", o_special, (void *)setvjslots,
167 "Set maximum VJ header slots",
168 OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, vj_value },
169
170 { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
171 "Accept peer's address for us", 1 },
172 { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
173 "Accept peer's address for it", 1 },
174
175 { "ipparam", o_string, &ipparam,
176 "Set ip script parameter", OPT_PRIO },
177
178 { "noipdefault", o_bool, &disable_defaultip,
179 "Don't use name for default IP adrs", 1 },
180
181 { "ms-dns", o_special, (void *)setdnsaddr,
182 "DNS address for the peer's use", OPT_A2LIST },
183 { "ms-wins", o_special, (void *)setwinsaddr,
184 "Nameserver for SMB over TCP/IP for peer", OPT_A2LIST },
185
186 { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
187 "Set timeout for IPCP", OPT_PRIO },
188 { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
189 "Set max #xmits for term-reqs", OPT_PRIO },
190 { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
191 "Set max #xmits for conf-reqs", OPT_PRIO },
192 { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
193 "Set max #conf-naks for IPCP", OPT_PRIO },
194
195 { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
196 "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
197 { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
198 "disable defaultroute option", OPT_A2CLR,
199 &ipcp_wantoptions[0].default_route },
200 { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
201 "disable defaultroute option", OPT_ALIAS | OPT_A2CLR,
202 &ipcp_wantoptions[0].default_route },
203
204 #ifdef __linux__
205 { "replacedefaultroute", o_bool,
206 &ipcp_wantoptions[0].replace_default_route,
207 "Replace default route", OPT_PRIV | 1
208 },
209 { "noreplacedefaultroute", o_bool,
210 &ipcp_wantoptions[0].replace_default_route,
211 "Do not replace default route", 0 },
212 #endif
213 { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
214 "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
215 { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
216 "disable proxyarp option", OPT_A2CLR,
217 &ipcp_wantoptions[0].proxy_arp },
218 { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
219 "disable proxyarp option", OPT_ALIAS | OPT_A2CLR,
220 &ipcp_wantoptions[0].proxy_arp },
221
222 { "usepeerdns", o_bool, &usepeerdns,
223 "Ask peer for DNS address(es)", 1 },
224
225 { "netmask", o_special, (void *)setnetmask,
226 "set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str },
227
228 { "ipcp-no-addresses", o_bool, &ipcp_wantoptions[0].old_addrs,
229 "Disable old-style IP-Addresses usage", OPT_A2CLR,
230 &ipcp_allowoptions[0].old_addrs },
231 { "ipcp-no-address", o_bool, &ipcp_wantoptions[0].neg_addr,
232 "Disable IP-Address usage", OPT_A2CLR,
233 &ipcp_allowoptions[0].neg_addr },
234 #ifdef __linux__
235 { "noremoteip", o_bool, &noremoteip,
236 "Allow peer to have no IP address", 1 },
237 #endif
238 { "nosendip", o_bool, &ipcp_wantoptions[0].neg_addr,
239 "Don't send our IP address to peer", OPT_A2CLR,
240 &ipcp_wantoptions[0].old_addrs},
241
242 { "IP addresses", o_wild, (void *) &setipaddr,
243 "set local and remote IP addresses",
244 OPT_NOARG | OPT_A2PRINTER, (void *) &printipaddr },
245
246 { NULL }
247 };
248
249 /*
250 * Protocol entry points from main code.
251 */
252 static void ipcp_init (int);
253 static void ipcp_open (int);
254 static void ipcp_close (int, char *);
255 static void ipcp_lowerup (int);
256 static void ipcp_lowerdown (int);
257 static void ipcp_input (int, u_char *, int);
258 static void ipcp_protrej (int);
259 static int ipcp_printpkt (u_char *, int,
260 void (*) (void *, char *, ...), void *);
261 static void ip_check_options (void);
262 static int ip_demand_conf (int);
263 static int ip_active_pkt (u_char *, int);
264 static void create_resolv (u_int32_t, u_int32_t);
265
266 struct protent ipcp_protent = {
267 PPP_IPCP,
268 ipcp_init,
269 ipcp_input,
270 ipcp_protrej,
271 ipcp_lowerup,
272 ipcp_lowerdown,
273 ipcp_open,
274 ipcp_close,
275 ipcp_printpkt,
276 NULL,
277 1,
278 "IPCP",
279 "IP",
280 ipcp_option_list,
281 ip_check_options,
282 ip_demand_conf,
283 ip_active_pkt
284 };
285
286 static void ipcp_clear_addrs (int, u_int32_t, u_int32_t, bool);
287 static void ipcp_script (char *, int); /* Run an up/down script */
288 static void ipcp_script_done (void *);
289
290 /*
291 * Lengths of configuration options.
292 */
293 #define CILEN_VOID 2
294 #define CILEN_COMPRESS 4 /* min length for compression protocol opt. */
295 #define CILEN_VJ 6 /* length for RFC1332 Van-Jacobson opt. */
296 #define CILEN_ADDR 6 /* new-style single address option */
297 #define CILEN_ADDRS 10 /* old-style dual address option */
298
299
300 #define CODENAME(x) ((x) == CONFACK ? "ACK" : \
301 (x) == CONFNAK ? "NAK" : "REJ")
302
303 /*
304 * This state variable is used to ensure that we don't
305 * run an ipcp-up/down script while one is already running.
306 */
307 static enum script_state {
308 s_down,
309 s_up,
310 } ipcp_script_state;
311 static pid_t ipcp_script_pid;
312
313 /*
314 * Make a string representation of a network IP address.
315 */
316 char *
ip_ntoa(u_int32_t ipaddr)317 ip_ntoa(u_int32_t ipaddr)
318 {
319 static char b[64];
320
321 slprintf(b, sizeof(b), "%I", ipaddr);
322 return b;
323 }
324
325 /*
326 * Option parsing.
327 */
328
329 /*
330 * setvjslots - set maximum number of connection slots for VJ compression
331 */
332 static int
setvjslots(char ** argv)333 setvjslots(char **argv)
334 {
335 int value;
336
337 if (!int_option(*argv, &value))
338 return 0;
339 if (value < 2 || value > 16) {
340 option_error("vj-max-slots value must be between 2 and 16");
341 return 0;
342 }
343 ipcp_wantoptions [0].maxslotindex =
344 ipcp_allowoptions[0].maxslotindex = value - 1;
345 slprintf(vj_value, sizeof(vj_value), "%d", value);
346 return 1;
347 }
348
349 /*
350 * setdnsaddr - set the dns address(es)
351 */
352 static int
setdnsaddr(char ** argv)353 setdnsaddr(char **argv)
354 {
355 u_int32_t dns;
356 struct hostent *hp;
357
358 dns = inet_addr(*argv);
359 if (dns == (u_int32_t) -1) {
360 if ((hp = gethostbyname(*argv)) == NULL) {
361 option_error("invalid address parameter '%s' for ms-dns option",
362 *argv);
363 return 0;
364 }
365 dns = *(u_int32_t *)hp->h_addr;
366 }
367
368 /* We take the last 2 values given, the 2nd-last as the primary
369 and the last as the secondary. If only one is given it
370 becomes both primary and secondary. */
371 if (ipcp_allowoptions[0].dnsaddr[1] == 0)
372 ipcp_allowoptions[0].dnsaddr[0] = dns;
373 else
374 ipcp_allowoptions[0].dnsaddr[0] = ipcp_allowoptions[0].dnsaddr[1];
375
376 /* always set the secondary address value. */
377 ipcp_allowoptions[0].dnsaddr[1] = dns;
378
379 return (1);
380 }
381
382 /*
383 * setwinsaddr - set the wins address(es)
384 * This is primrarly used with the Samba package under UNIX or for pointing
385 * the caller to the existing WINS server on a Windows NT platform.
386 */
387 static int
setwinsaddr(char ** argv)388 setwinsaddr(char **argv)
389 {
390 u_int32_t wins;
391 struct hostent *hp;
392
393 wins = inet_addr(*argv);
394 if (wins == (u_int32_t) -1) {
395 if ((hp = gethostbyname(*argv)) == NULL) {
396 option_error("invalid address parameter '%s' for ms-wins option",
397 *argv);
398 return 0;
399 }
400 wins = *(u_int32_t *)hp->h_addr;
401 }
402
403 /* We take the last 2 values given, the 2nd-last as the primary
404 and the last as the secondary. If only one is given it
405 becomes both primary and secondary. */
406 if (ipcp_allowoptions[0].winsaddr[1] == 0)
407 ipcp_allowoptions[0].winsaddr[0] = wins;
408 else
409 ipcp_allowoptions[0].winsaddr[0] = ipcp_allowoptions[0].winsaddr[1];
410
411 /* always set the secondary address value. */
412 ipcp_allowoptions[0].winsaddr[1] = wins;
413
414 return (1);
415 }
416
417 /*
418 * setipaddr - Set the IP address
419 * If doit is 0, the call is to check whether this option is
420 * potentially an IP address specification.
421 * Not static so that plugins can call it to set the addresses
422 */
423 int
setipaddr(char * arg,char ** argv,int doit)424 setipaddr(char *arg, char **argv, int doit)
425 {
426 struct hostent *hp;
427 char *colon;
428 u_int32_t local, remote;
429 ipcp_options *wo = &ipcp_wantoptions[0];
430 static int prio_local = 0, prio_remote = 0;
431
432 /*
433 * IP address pair separated by ":".
434 */
435 if ((colon = strchr(arg, ':')) == NULL)
436 return 0;
437 if (!doit)
438 return 1;
439
440 /*
441 * If colon first character, then no local addr.
442 */
443 if (colon != arg && option_priority >= prio_local) {
444 *colon = '\0';
445 if ((local = inet_addr(arg)) == (u_int32_t) -1) {
446 if ((hp = gethostbyname(arg)) == NULL) {
447 option_error("unknown host: %s", arg);
448 return 0;
449 }
450 local = *(u_int32_t *)hp->h_addr;
451 }
452 if (bad_ip_adrs(local)) {
453 option_error("bad local IP address %s", ip_ntoa(local));
454 return 0;
455 }
456 if (local != 0)
457 wo->ouraddr = local;
458 *colon = ':';
459 prio_local = option_priority;
460 }
461
462 /*
463 * If colon last character, then no remote addr.
464 */
465 if (*++colon != '\0' && option_priority >= prio_remote) {
466 if ((remote = inet_addr(colon)) == (u_int32_t) -1) {
467 if ((hp = gethostbyname(colon)) == NULL) {
468 option_error("unknown host: %s", colon);
469 return 0;
470 }
471 remote = *(u_int32_t *)hp->h_addr;
472 if (remote_name[0] == 0)
473 strlcpy(remote_name, colon, sizeof(remote_name));
474 }
475 if (bad_ip_adrs(remote)) {
476 option_error("bad remote IP address %s", ip_ntoa(remote));
477 return 0;
478 }
479 if (remote != 0)
480 wo->hisaddr = remote;
481 prio_remote = option_priority;
482 }
483
484 return 1;
485 }
486
487 static void
printipaddr(option_t * opt,void (* printer)(void *,char *,...),void * arg)488 printipaddr(option_t *opt, void (*printer) (void *, char *, ...), void *arg)
489 {
490 ipcp_options *wo = &ipcp_wantoptions[0];
491
492 if (wo->ouraddr != 0)
493 printer(arg, "%I", wo->ouraddr);
494 printer(arg, ":");
495 if (wo->hisaddr != 0)
496 printer(arg, "%I", wo->hisaddr);
497 }
498
499 /*
500 * setnetmask - set the netmask to be used on the interface.
501 */
502 static int
setnetmask(char ** argv)503 setnetmask(char **argv)
504 {
505 u_int32_t mask;
506 int n;
507 char *p;
508
509 /*
510 * Unfortunately, if we use inet_addr, we can't tell whether
511 * a result of all 1s is an error or a valid 255.255.255.255.
512 */
513 p = *argv;
514 n = parse_dotted_ip(p, &mask);
515
516 mask = htonl(mask);
517
518 if (n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
519 option_error("invalid netmask value '%s'", *argv);
520 return 0;
521 }
522
523 netmask = mask;
524 slprintf(netmask_str, sizeof(netmask_str), "%I", mask);
525
526 return (1);
527 }
528
529 int
parse_dotted_ip(char * p,u_int32_t * vp)530 parse_dotted_ip(char *p, u_int32_t *vp)
531 {
532 int n;
533 u_int32_t v, b;
534 char *endp, *p0 = p;
535
536 v = 0;
537 for (n = 3;; --n) {
538 b = strtoul(p, &endp, 0);
539 if (endp == p)
540 return 0;
541 if (b > 255) {
542 if (n < 3)
543 return 0;
544 /* accept e.g. 0xffffff00 */
545 *vp = b;
546 return endp - p0;
547 }
548 v |= b << (n * 8);
549 p = endp;
550 if (n == 0)
551 break;
552 if (*p != '.')
553 return 0;
554 ++p;
555 }
556 *vp = v;
557 return p - p0;
558 }
559
560
561 /*
562 * ipcp_init - Initialize IPCP.
563 */
564 static void
ipcp_init(int unit)565 ipcp_init(int unit)
566 {
567 fsm *f = &ipcp_fsm[unit];
568 ipcp_options *wo = &ipcp_wantoptions[unit];
569 ipcp_options *ao = &ipcp_allowoptions[unit];
570
571 f->unit = unit;
572 f->protocol = PPP_IPCP;
573 f->callbacks = &ipcp_callbacks;
574 fsm_init(&ipcp_fsm[unit]);
575
576 /*
577 * Some 3G modems use repeated IPCP NAKs as a way of stalling
578 * until they can contact a server on the network, so we increase
579 * the default number of NAKs we accept before we start treating
580 * them as rejects.
581 */
582 f->maxnakloops = 100;
583
584 memset(wo, 0, sizeof(*wo));
585 memset(ao, 0, sizeof(*ao));
586
587 wo->neg_addr = wo->old_addrs = 1;
588 wo->neg_vj = 1;
589 wo->vj_protocol = IPCP_VJ_COMP;
590 wo->maxslotindex = MAX_STATES - 1; /* really max index */
591 wo->cflag = 1;
592
593
594 /* max slots and slot-id compression are currently hardwired in */
595 /* ppp_if.c to 16 and 1, this needs to be changed (among other */
596 /* things) gmc */
597
598 ao->neg_addr = ao->old_addrs = 1;
599 ao->neg_vj = 1;
600 ao->maxslotindex = MAX_STATES - 1;
601 ao->cflag = 1;
602
603 /*
604 * XXX These control whether the user may use the proxyarp
605 * and defaultroute options.
606 */
607 ao->proxy_arp = 1;
608 ao->default_route = 1;
609 }
610
611
612 /*
613 * ipcp_open - IPCP is allowed to come up.
614 */
615 static void
ipcp_open(int unit)616 ipcp_open(int unit)
617 {
618 fsm_open(&ipcp_fsm[unit]);
619 ipcp_is_open = 1;
620 }
621
622
623 /*
624 * ipcp_close - Take IPCP down.
625 */
626 static void
ipcp_close(int unit,char * reason)627 ipcp_close(int unit, char *reason)
628 {
629 fsm_close(&ipcp_fsm[unit], reason);
630 }
631
632
633 /*
634 * ipcp_lowerup - The lower layer is up.
635 */
636 static void
ipcp_lowerup(int unit)637 ipcp_lowerup(int unit)
638 {
639 fsm_lowerup(&ipcp_fsm[unit]);
640 }
641
642
643 /*
644 * ipcp_lowerdown - The lower layer is down.
645 */
646 static void
ipcp_lowerdown(int unit)647 ipcp_lowerdown(int unit)
648 {
649 fsm_lowerdown(&ipcp_fsm[unit]);
650 }
651
652
653 /*
654 * ipcp_input - Input IPCP packet.
655 */
656 static void
ipcp_input(int unit,u_char * p,int len)657 ipcp_input(int unit, u_char *p, int len)
658 {
659 fsm_input(&ipcp_fsm[unit], p, len);
660 }
661
662
663 /*
664 * ipcp_protrej - A Protocol-Reject was received for IPCP.
665 *
666 * Pretend the lower layer went down, so we shut up.
667 */
668 static void
ipcp_protrej(int unit)669 ipcp_protrej(int unit)
670 {
671 fsm_lowerdown(&ipcp_fsm[unit]);
672 }
673
674
675 /*
676 * ipcp_resetci - Reset our CI.
677 * Called by fsm_sconfreq, Send Configure Request.
678 */
679 static void
ipcp_resetci(fsm * f)680 ipcp_resetci(fsm *f)
681 {
682 ipcp_options *wo = &ipcp_wantoptions[f->unit];
683 ipcp_options *go = &ipcp_gotoptions[f->unit];
684 ipcp_options *ao = &ipcp_allowoptions[f->unit];
685
686 wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
687 (ao->neg_addr || ao->old_addrs);
688 if (wo->ouraddr == 0)
689 wo->accept_local = 1;
690 if (wo->hisaddr == 0)
691 wo->accept_remote = 1;
692 wo->req_dns1 = usepeerdns; /* Request DNS addresses from the peer */
693 wo->req_dns2 = usepeerdns;
694 *go = *wo;
695 if (!ask_for_local)
696 go->ouraddr = 0;
697 if (ip_choose_hook) {
698 ip_choose_hook(&wo->hisaddr);
699 if (wo->hisaddr) {
700 wo->accept_remote = 0;
701 }
702 }
703 BZERO(&ipcp_hisoptions[f->unit], sizeof(ipcp_options));
704 }
705
706
707 /*
708 * ipcp_cilen - Return length of our CI.
709 * Called by fsm_sconfreq, Send Configure Request.
710 */
711 static int
ipcp_cilen(fsm * f)712 ipcp_cilen(fsm *f)
713 {
714 ipcp_options *go = &ipcp_gotoptions[f->unit];
715 ipcp_options *wo = &ipcp_wantoptions[f->unit];
716 ipcp_options *ho = &ipcp_hisoptions[f->unit];
717
718 #define LENCIADDRS(neg) (neg ? CILEN_ADDRS : 0)
719 #define LENCIVJ(neg, old) (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
720 #define LENCIADDR(neg) (neg ? CILEN_ADDR : 0)
721 #define LENCIDNS(neg) LENCIADDR(neg)
722 #define LENCIWINS(neg) LENCIADDR(neg)
723
724 /*
725 * First see if we want to change our options to the old
726 * forms because we have received old forms from the peer.
727 */
728 if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
729 go->neg_addr = 0;
730 if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
731 /* try an older style of VJ negotiation */
732 /* use the old style only if the peer did */
733 if (ho->neg_vj && ho->old_vj) {
734 go->neg_vj = 1;
735 go->old_vj = 1;
736 go->vj_protocol = ho->vj_protocol;
737 }
738 }
739
740 return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
741 LENCIVJ(go->neg_vj, go->old_vj) +
742 LENCIADDR(go->neg_addr) +
743 LENCIDNS(go->req_dns1) +
744 LENCIDNS(go->req_dns2) +
745 LENCIWINS(go->winsaddr[0]) +
746 LENCIWINS(go->winsaddr[1])) ;
747 }
748
749
750 /*
751 * ipcp_addci - Add our desired CIs to a packet.
752 * Called by fsm_sconfreq, Send Configure Request.
753 */
754 static void
ipcp_addci(fsm * f,u_char * ucp,int * lenp)755 ipcp_addci(fsm *f, u_char *ucp, int *lenp)
756 {
757 ipcp_options *go = &ipcp_gotoptions[f->unit];
758 int len = *lenp;
759
760 #define ADDCIADDRS(opt, neg, val1, val2) \
761 if (neg) { \
762 if (len >= CILEN_ADDRS) { \
763 u_int32_t l; \
764 PUTCHAR(opt, ucp); \
765 PUTCHAR(CILEN_ADDRS, ucp); \
766 l = ntohl(val1); \
767 PUTLONG(l, ucp); \
768 l = ntohl(val2); \
769 PUTLONG(l, ucp); \
770 len -= CILEN_ADDRS; \
771 } else \
772 go->old_addrs = 0; \
773 }
774
775 #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
776 if (neg) { \
777 int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
778 if (len >= vjlen) { \
779 PUTCHAR(opt, ucp); \
780 PUTCHAR(vjlen, ucp); \
781 PUTSHORT(val, ucp); \
782 if (!old) { \
783 PUTCHAR(maxslotindex, ucp); \
784 PUTCHAR(cflag, ucp); \
785 } \
786 len -= vjlen; \
787 } else \
788 neg = 0; \
789 }
790
791 #define ADDCIADDR(opt, neg, val) \
792 if (neg) { \
793 if (len >= CILEN_ADDR) { \
794 u_int32_t l; \
795 PUTCHAR(opt, ucp); \
796 PUTCHAR(CILEN_ADDR, ucp); \
797 l = ntohl(val); \
798 PUTLONG(l, ucp); \
799 len -= CILEN_ADDR; \
800 } else \
801 neg = 0; \
802 }
803
804 #define ADDCIDNS(opt, neg, addr) \
805 if (neg) { \
806 if (len >= CILEN_ADDR) { \
807 u_int32_t l; \
808 PUTCHAR(opt, ucp); \
809 PUTCHAR(CILEN_ADDR, ucp); \
810 l = ntohl(addr); \
811 PUTLONG(l, ucp); \
812 len -= CILEN_ADDR; \
813 } else \
814 neg = 0; \
815 }
816
817 #define ADDCIWINS(opt, addr) \
818 if (addr) { \
819 if (len >= CILEN_ADDR) { \
820 u_int32_t l; \
821 PUTCHAR(opt, ucp); \
822 PUTCHAR(CILEN_ADDR, ucp); \
823 l = ntohl(addr); \
824 PUTLONG(l, ucp); \
825 len -= CILEN_ADDR; \
826 } else \
827 addr = 0; \
828 }
829
830 ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
831 go->hisaddr);
832
833 ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
834 go->maxslotindex, go->cflag);
835
836 ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
837
838 ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
839
840 ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
841
842 ADDCIWINS(CI_MS_WINS1, go->winsaddr[0]);
843
844 ADDCIWINS(CI_MS_WINS2, go->winsaddr[1]);
845
846 *lenp -= len;
847 }
848
849
850 /*
851 * ipcp_ackci - Ack our CIs.
852 * Called by fsm_rconfack, Receive Configure ACK.
853 *
854 * Returns:
855 * 0 - Ack was bad.
856 * 1 - Ack was good.
857 */
858 static int
ipcp_ackci(fsm * f,u_char * p,int len)859 ipcp_ackci(fsm *f, u_char *p, int len)
860 {
861 ipcp_options *go = &ipcp_gotoptions[f->unit];
862 u_short cilen, citype, cishort;
863 u_int32_t cilong;
864 u_char cimaxslotindex, cicflag;
865
866 /*
867 * CIs must be in exactly the same order that we sent...
868 * Check packet length and CI length at each step.
869 * If we find any deviations, then this packet is bad.
870 */
871
872 #define ACKCIADDRS(opt, neg, val1, val2) \
873 if (neg) { \
874 u_int32_t l; \
875 if ((len -= CILEN_ADDRS) < 0) \
876 goto bad; \
877 GETCHAR(citype, p); \
878 GETCHAR(cilen, p); \
879 if (cilen != CILEN_ADDRS || \
880 citype != opt) \
881 goto bad; \
882 GETLONG(l, p); \
883 cilong = htonl(l); \
884 if (val1 != cilong) \
885 goto bad; \
886 GETLONG(l, p); \
887 cilong = htonl(l); \
888 if (val2 != cilong) \
889 goto bad; \
890 }
891
892 #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
893 if (neg) { \
894 int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
895 if ((len -= vjlen) < 0) \
896 goto bad; \
897 GETCHAR(citype, p); \
898 GETCHAR(cilen, p); \
899 if (cilen != vjlen || \
900 citype != opt) \
901 goto bad; \
902 GETSHORT(cishort, p); \
903 if (cishort != val) \
904 goto bad; \
905 if (!old) { \
906 GETCHAR(cimaxslotindex, p); \
907 if (cimaxslotindex != maxslotindex) \
908 goto bad; \
909 GETCHAR(cicflag, p); \
910 if (cicflag != cflag) \
911 goto bad; \
912 } \
913 }
914
915 #define ACKCIADDR(opt, neg, val) \
916 if (neg) { \
917 u_int32_t l; \
918 if ((len -= CILEN_ADDR) < 0) \
919 goto bad; \
920 GETCHAR(citype, p); \
921 GETCHAR(cilen, p); \
922 if (cilen != CILEN_ADDR || \
923 citype != opt) \
924 goto bad; \
925 GETLONG(l, p); \
926 cilong = htonl(l); \
927 if (val != cilong) \
928 goto bad; \
929 }
930
931 #define ACKCIDNS(opt, neg, addr) \
932 if (neg) { \
933 u_int32_t l; \
934 if ((len -= CILEN_ADDR) < 0) \
935 goto bad; \
936 GETCHAR(citype, p); \
937 GETCHAR(cilen, p); \
938 if (cilen != CILEN_ADDR || citype != opt) \
939 goto bad; \
940 GETLONG(l, p); \
941 cilong = htonl(l); \
942 if (addr != cilong) \
943 goto bad; \
944 }
945
946 #define ACKCIWINS(opt, addr) \
947 if (addr) { \
948 u_int32_t l; \
949 if ((len -= CILEN_ADDR) < 0) \
950 goto bad; \
951 GETCHAR(citype, p); \
952 GETCHAR(cilen, p); \
953 if (cilen != CILEN_ADDR || citype != opt) \
954 goto bad; \
955 GETLONG(l, p); \
956 cilong = htonl(l); \
957 if (addr != cilong) \
958 goto bad; \
959 }
960
961 ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
962 go->hisaddr);
963
964 ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
965 go->maxslotindex, go->cflag);
966
967 ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
968
969 ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
970
971 ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
972
973 ACKCIWINS(CI_MS_WINS1, go->winsaddr[0]);
974
975 ACKCIWINS(CI_MS_WINS2, go->winsaddr[1]);
976
977 /*
978 * If there are any remaining CIs, then this packet is bad.
979 */
980 if (len != 0)
981 goto bad;
982 return (1);
983
984 bad:
985 IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
986 return (0);
987 }
988
989 /*
990 * ipcp_nakci - Peer has sent a NAK for some of our CIs.
991 * This should not modify any state if the Nak is bad
992 * or if IPCP is in the OPENED state.
993 * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
994 *
995 * Returns:
996 * 0 - Nak was bad.
997 * 1 - Nak was good.
998 */
999 static int
ipcp_nakci(fsm * f,u_char * p,int len,int treat_as_reject)1000 ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
1001 {
1002 ipcp_options *go = &ipcp_gotoptions[f->unit];
1003 u_char cimaxslotindex, cicflag;
1004 u_char citype, cilen, *next;
1005 u_short cishort;
1006 u_int32_t ciaddr1, ciaddr2, l, cidnsaddr;
1007 ipcp_options no; /* options we've seen Naks for */
1008 ipcp_options try; /* options to request next time */
1009
1010 BZERO(&no, sizeof(no));
1011 try = *go;
1012
1013 /*
1014 * Any Nak'd CIs must be in exactly the same order that we sent.
1015 * Check packet length and CI length at each step.
1016 * If we find any deviations, then this packet is bad.
1017 */
1018 #define NAKCIADDRS(opt, neg, code) \
1019 if ((neg) && \
1020 (cilen = p[1]) == CILEN_ADDRS && \
1021 len >= cilen && \
1022 p[0] == opt) { \
1023 len -= cilen; \
1024 INCPTR(2, p); \
1025 GETLONG(l, p); \
1026 ciaddr1 = htonl(l); \
1027 GETLONG(l, p); \
1028 ciaddr2 = htonl(l); \
1029 no.old_addrs = 1; \
1030 code \
1031 }
1032
1033 #define NAKCIVJ(opt, neg, code) \
1034 if (go->neg && \
1035 ((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
1036 len >= cilen && \
1037 p[0] == opt) { \
1038 len -= cilen; \
1039 INCPTR(2, p); \
1040 GETSHORT(cishort, p); \
1041 no.neg = 1; \
1042 code \
1043 }
1044
1045 #define NAKCIADDR(opt, neg, code) \
1046 if (go->neg && \
1047 (cilen = p[1]) == CILEN_ADDR && \
1048 len >= cilen && \
1049 p[0] == opt) { \
1050 len -= cilen; \
1051 INCPTR(2, p); \
1052 GETLONG(l, p); \
1053 ciaddr1 = htonl(l); \
1054 no.neg = 1; \
1055 code \
1056 }
1057
1058 #define NAKCIDNS(opt, neg, code) \
1059 if (go->neg && \
1060 ((cilen = p[1]) == CILEN_ADDR) && \
1061 len >= cilen && \
1062 p[0] == opt) { \
1063 len -= cilen; \
1064 INCPTR(2, p); \
1065 GETLONG(l, p); \
1066 cidnsaddr = htonl(l); \
1067 no.neg = 1; \
1068 code \
1069 }
1070
1071 /*
1072 * Accept the peer's idea of {our,his} address, if different
1073 * from our idea, only if the accept_{local,remote} flag is set.
1074 */
1075 NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1076 if (treat_as_reject) {
1077 try.old_addrs = 0;
1078 } else {
1079 if (go->accept_local && ciaddr1) {
1080 /* take his idea of our address */
1081 try.ouraddr = ciaddr1;
1082 }
1083 if (go->accept_remote && ciaddr2) {
1084 /* take his idea of his address */
1085 try.hisaddr = ciaddr2;
1086 }
1087 }
1088 );
1089
1090 /*
1091 * Accept the peer's value of maxslotindex provided that it
1092 * is less than what we asked for. Turn off slot-ID compression
1093 * if the peer wants. Send old-style compress-type option if
1094 * the peer wants.
1095 */
1096 NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
1097 if (treat_as_reject) {
1098 try.neg_vj = 0;
1099 } else if (cilen == CILEN_VJ) {
1100 GETCHAR(cimaxslotindex, p);
1101 GETCHAR(cicflag, p);
1102 if (cishort == IPCP_VJ_COMP) {
1103 try.old_vj = 0;
1104 if (cimaxslotindex < go->maxslotindex)
1105 try.maxslotindex = cimaxslotindex;
1106 if (!cicflag)
1107 try.cflag = 0;
1108 } else {
1109 try.neg_vj = 0;
1110 }
1111 } else {
1112 if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
1113 try.old_vj = 1;
1114 try.vj_protocol = cishort;
1115 } else {
1116 try.neg_vj = 0;
1117 }
1118 }
1119 );
1120
1121 NAKCIADDR(CI_ADDR, neg_addr,
1122 if (treat_as_reject) {
1123 try.neg_addr = 0;
1124 try.old_addrs = 0;
1125 } else if (go->accept_local && ciaddr1) {
1126 /* take his idea of our address */
1127 try.ouraddr = ciaddr1;
1128 }
1129 );
1130
1131 NAKCIDNS(CI_MS_DNS1, req_dns1,
1132 if (treat_as_reject) {
1133 try.req_dns1 = 0;
1134 } else {
1135 try.dnsaddr[0] = cidnsaddr;
1136 }
1137 );
1138
1139 NAKCIDNS(CI_MS_DNS2, req_dns2,
1140 if (treat_as_reject) {
1141 try.req_dns2 = 0;
1142 } else {
1143 try.dnsaddr[1] = cidnsaddr;
1144 }
1145 );
1146
1147 /*
1148 * There may be remaining CIs, if the peer is requesting negotiation
1149 * on an option that we didn't include in our request packet.
1150 * If they want to negotiate about IP addresses, we comply.
1151 * If they want us to ask for compression, we refuse.
1152 * If they want us to ask for ms-dns, we do that, since some
1153 * peers get huffy if we don't.
1154 */
1155 while (len >= CILEN_VOID) {
1156 GETCHAR(citype, p);
1157 GETCHAR(cilen, p);
1158 if ( cilen < CILEN_VOID || (len -= cilen) < 0 )
1159 goto bad;
1160 next = p + cilen - 2;
1161
1162 switch (citype) {
1163 case CI_COMPRESSTYPE:
1164 if (go->neg_vj || no.neg_vj ||
1165 (cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
1166 goto bad;
1167 no.neg_vj = 1;
1168 break;
1169 case CI_ADDRS:
1170 if ((!go->neg_addr && go->old_addrs) || no.old_addrs
1171 || cilen != CILEN_ADDRS)
1172 goto bad;
1173 try.neg_addr = 0;
1174 GETLONG(l, p);
1175 ciaddr1 = htonl(l);
1176 if (ciaddr1 && go->accept_local)
1177 try.ouraddr = ciaddr1;
1178 GETLONG(l, p);
1179 ciaddr2 = htonl(l);
1180 if (ciaddr2 && go->accept_remote)
1181 try.hisaddr = ciaddr2;
1182 no.old_addrs = 1;
1183 break;
1184 case CI_ADDR:
1185 if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
1186 goto bad;
1187 try.old_addrs = 0;
1188 GETLONG(l, p);
1189 ciaddr1 = htonl(l);
1190 if (ciaddr1 && go->accept_local)
1191 try.ouraddr = ciaddr1;
1192 if (try.ouraddr != 0)
1193 try.neg_addr = 1;
1194 no.neg_addr = 1;
1195 break;
1196 case CI_MS_DNS1:
1197 if (go->req_dns1 || no.req_dns1 || cilen != CILEN_ADDR)
1198 goto bad;
1199 GETLONG(l, p);
1200 try.dnsaddr[0] = htonl(l);
1201 try.req_dns1 = 1;
1202 no.req_dns1 = 1;
1203 break;
1204 case CI_MS_DNS2:
1205 if (go->req_dns2 || no.req_dns2 || cilen != CILEN_ADDR)
1206 goto bad;
1207 GETLONG(l, p);
1208 try.dnsaddr[1] = htonl(l);
1209 try.req_dns2 = 1;
1210 no.req_dns2 = 1;
1211 break;
1212 case CI_MS_WINS1:
1213 case CI_MS_WINS2:
1214 if (cilen != CILEN_ADDR)
1215 goto bad;
1216 GETLONG(l, p);
1217 ciaddr1 = htonl(l);
1218 if (ciaddr1)
1219 try.winsaddr[citype == CI_MS_WINS2] = ciaddr1;
1220 break;
1221 }
1222 p = next;
1223 }
1224
1225 /*
1226 * OK, the Nak is good. Now we can update state.
1227 * If there are any remaining options, we ignore them.
1228 */
1229 if (f->state != OPENED)
1230 *go = try;
1231
1232 return 1;
1233
1234 bad:
1235 IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
1236 return 0;
1237 }
1238
1239
1240 /*
1241 * ipcp_rejci - Reject some of our CIs.
1242 * Callback from fsm_rconfnakrej.
1243 */
1244 static int
ipcp_rejci(fsm * f,u_char * p,int len)1245 ipcp_rejci(fsm *f, u_char *p, int len)
1246 {
1247 ipcp_options *go = &ipcp_gotoptions[f->unit];
1248 u_char cimaxslotindex, ciflag, cilen;
1249 u_short cishort;
1250 u_int32_t cilong;
1251 ipcp_options try; /* options to request next time */
1252
1253 try = *go;
1254 /*
1255 * Any Rejected CIs must be in exactly the same order that we sent.
1256 * Check packet length and CI length at each step.
1257 * If we find any deviations, then this packet is bad.
1258 */
1259 #define REJCIADDRS(opt, neg, val1, val2) \
1260 if ((neg) && \
1261 (cilen = p[1]) == CILEN_ADDRS && \
1262 len >= cilen && \
1263 p[0] == opt) { \
1264 u_int32_t l; \
1265 len -= cilen; \
1266 INCPTR(2, p); \
1267 GETLONG(l, p); \
1268 cilong = htonl(l); \
1269 /* Check rejected value. */ \
1270 if (cilong != val1) \
1271 goto bad; \
1272 GETLONG(l, p); \
1273 cilong = htonl(l); \
1274 /* Check rejected value. */ \
1275 if (cilong != val2) \
1276 goto bad; \
1277 try.old_addrs = 0; \
1278 }
1279
1280 #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
1281 if (go->neg && \
1282 p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
1283 len >= p[1] && \
1284 p[0] == opt) { \
1285 len -= p[1]; \
1286 INCPTR(2, p); \
1287 GETSHORT(cishort, p); \
1288 /* Check rejected value. */ \
1289 if (cishort != val) \
1290 goto bad; \
1291 if (!old) { \
1292 GETCHAR(cimaxslotindex, p); \
1293 if (cimaxslotindex != maxslot) \
1294 goto bad; \
1295 GETCHAR(ciflag, p); \
1296 if (ciflag != cflag) \
1297 goto bad; \
1298 } \
1299 try.neg = 0; \
1300 }
1301
1302 #define REJCIADDR(opt, neg, val) \
1303 if (go->neg && \
1304 (cilen = p[1]) == CILEN_ADDR && \
1305 len >= cilen && \
1306 p[0] == opt) { \
1307 u_int32_t l; \
1308 len -= cilen; \
1309 INCPTR(2, p); \
1310 GETLONG(l, p); \
1311 cilong = htonl(l); \
1312 /* Check rejected value. */ \
1313 if (cilong != val) \
1314 goto bad; \
1315 try.neg = 0; \
1316 }
1317
1318 #define REJCIDNS(opt, neg, dnsaddr) \
1319 if (go->neg && \
1320 ((cilen = p[1]) == CILEN_ADDR) && \
1321 len >= cilen && \
1322 p[0] == opt) { \
1323 u_int32_t l; \
1324 len -= cilen; \
1325 INCPTR(2, p); \
1326 GETLONG(l, p); \
1327 cilong = htonl(l); \
1328 /* Check rejected value. */ \
1329 if (cilong != dnsaddr) \
1330 goto bad; \
1331 try.neg = 0; \
1332 }
1333
1334 #define REJCIWINS(opt, addr) \
1335 if (addr && \
1336 ((cilen = p[1]) == CILEN_ADDR) && \
1337 len >= cilen && \
1338 p[0] == opt) { \
1339 u_int32_t l; \
1340 len -= cilen; \
1341 INCPTR(2, p); \
1342 GETLONG(l, p); \
1343 cilong = htonl(l); \
1344 /* Check rejected value. */ \
1345 if (cilong != addr) \
1346 goto bad; \
1347 try.winsaddr[opt == CI_MS_WINS2] = 0; \
1348 }
1349
1350 REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1351 go->ouraddr, go->hisaddr);
1352
1353 REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
1354 go->maxslotindex, go->cflag);
1355
1356 REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
1357
1358 REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
1359
1360 REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
1361
1362 REJCIWINS(CI_MS_WINS1, go->winsaddr[0]);
1363
1364 REJCIWINS(CI_MS_WINS2, go->winsaddr[1]);
1365
1366 /*
1367 * If there are any remaining CIs, then this packet is bad.
1368 */
1369 if (len != 0)
1370 goto bad;
1371 /*
1372 * Now we can update state.
1373 */
1374 if (f->state != OPENED)
1375 *go = try;
1376 return 1;
1377
1378 bad:
1379 IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
1380 return 0;
1381 }
1382
1383
1384 /*
1385 * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
1386 * Callback from fsm_rconfreq, Receive Configure Request
1387 *
1388 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
1389 * appropriately. If reject_if_disagree is non-zero, doesn't return
1390 * CONFNAK; returns CONFREJ if it can't return CONFACK.
1391 */
1392 static int
ipcp_reqci(fsm * f,u_char * inp,int * len,int reject_if_disagree)1393 ipcp_reqci(fsm *f, u_char *inp, int *len, int reject_if_disagree)
1394 {
1395 ipcp_options *wo = &ipcp_wantoptions[f->unit];
1396 ipcp_options *ho = &ipcp_hisoptions[f->unit];
1397 ipcp_options *ao = &ipcp_allowoptions[f->unit];
1398 u_char *cip, *next; /* Pointer to current and next CIs */
1399 u_short cilen, citype; /* Parsed len, type */
1400 u_short cishort; /* Parsed short value */
1401 u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
1402 int rc = CONFACK; /* Final packet return code */
1403 int orc; /* Individual option return code */
1404 u_char *p; /* Pointer to next char to parse */
1405 u_char *ucp = inp; /* Pointer to current output char */
1406 int l = *len; /* Length left */
1407 u_char maxslotindex, cflag;
1408 int d;
1409
1410 /*
1411 * Reset all his options.
1412 */
1413 BZERO(ho, sizeof(*ho));
1414
1415 /*
1416 * Process all his options.
1417 */
1418 next = inp;
1419 while (l) {
1420 orc = CONFACK; /* Assume success */
1421 cip = p = next; /* Remember begining of CI */
1422 if (l < 2 || /* Not enough data for CI header or */
1423 p[1] < 2 || /* CI length too small or */
1424 p[1] > l) { /* CI length too big? */
1425 IPCPDEBUG(("ipcp_reqci: bad CI length!"));
1426 orc = CONFREJ; /* Reject bad CI */
1427 cilen = l; /* Reject till end of packet */
1428 l = 0; /* Don't loop again */
1429 goto endswitch;
1430 }
1431 GETCHAR(citype, p); /* Parse CI type */
1432 GETCHAR(cilen, p); /* Parse CI length */
1433 l -= cilen; /* Adjust remaining length */
1434 next += cilen; /* Step to next CI */
1435
1436 switch (citype) { /* Check CI type */
1437 case CI_ADDRS:
1438 if (!ao->old_addrs || ho->neg_addr ||
1439 cilen != CILEN_ADDRS) { /* Check CI length */
1440 orc = CONFREJ; /* Reject CI */
1441 break;
1442 }
1443
1444 /*
1445 * If he has no address, or if we both have his address but
1446 * disagree about it, then NAK it with our idea.
1447 * In particular, if we don't know his address, but he does,
1448 * then accept it.
1449 */
1450 GETLONG(tl, p); /* Parse source address (his) */
1451 ciaddr1 = htonl(tl);
1452 if (ciaddr1 != wo->hisaddr
1453 && (ciaddr1 == 0 || !wo->accept_remote)) {
1454 orc = CONFNAK;
1455 if (!reject_if_disagree) {
1456 DECPTR(sizeof(u_int32_t), p);
1457 tl = ntohl(wo->hisaddr);
1458 PUTLONG(tl, p);
1459 }
1460 } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1461 /*
1462 * If neither we nor he knows his address, reject the option.
1463 */
1464 orc = CONFREJ;
1465 wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
1466 break;
1467 }
1468
1469 /*
1470 * If he doesn't know our address, or if we both have our address
1471 * but disagree about it, then NAK it with our idea.
1472 */
1473 GETLONG(tl, p); /* Parse desination address (ours) */
1474 ciaddr2 = htonl(tl);
1475 if (ciaddr2 != wo->ouraddr) {
1476 if (ciaddr2 == 0 || !wo->accept_local) {
1477 orc = CONFNAK;
1478 if (!reject_if_disagree) {
1479 DECPTR(sizeof(u_int32_t), p);
1480 tl = ntohl(wo->ouraddr);
1481 PUTLONG(tl, p);
1482 }
1483 } else {
1484 wo->ouraddr = ciaddr2; /* accept peer's idea */
1485 }
1486 }
1487
1488 ho->old_addrs = 1;
1489 ho->hisaddr = ciaddr1;
1490 ho->ouraddr = ciaddr2;
1491 break;
1492
1493 case CI_ADDR:
1494 if (!ao->neg_addr || ho->old_addrs ||
1495 cilen != CILEN_ADDR) { /* Check CI length */
1496 orc = CONFREJ; /* Reject CI */
1497 break;
1498 }
1499
1500 /*
1501 * If he has no address, or if we both have his address but
1502 * disagree about it, then NAK it with our idea.
1503 * In particular, if we don't know his address, but he does,
1504 * then accept it.
1505 */
1506 GETLONG(tl, p); /* Parse source address (his) */
1507 ciaddr1 = htonl(tl);
1508 if (ciaddr1 != wo->hisaddr
1509 && (ciaddr1 == 0 || !wo->accept_remote)) {
1510 orc = CONFNAK;
1511 if (!reject_if_disagree) {
1512 DECPTR(sizeof(u_int32_t), p);
1513 tl = ntohl(wo->hisaddr);
1514 PUTLONG(tl, p);
1515 }
1516 } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1517 /*
1518 * Don't ACK an address of 0.0.0.0 - reject it instead.
1519 */
1520 orc = CONFREJ;
1521 wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
1522 break;
1523 }
1524
1525 ho->neg_addr = 1;
1526 ho->hisaddr = ciaddr1;
1527 break;
1528
1529 case CI_MS_DNS1:
1530 case CI_MS_DNS2:
1531 /* Microsoft primary or secondary DNS request */
1532 d = citype == CI_MS_DNS2;
1533
1534 /* If we do not have a DNS address then we cannot send it */
1535 if (ao->dnsaddr[d] == 0 ||
1536 cilen != CILEN_ADDR) { /* Check CI length */
1537 orc = CONFREJ; /* Reject CI */
1538 break;
1539 }
1540 GETLONG(tl, p);
1541 if (htonl(tl) != ao->dnsaddr[d]) {
1542 DECPTR(sizeof(u_int32_t), p);
1543 tl = ntohl(ao->dnsaddr[d]);
1544 PUTLONG(tl, p);
1545 orc = CONFNAK;
1546 }
1547 break;
1548
1549 case CI_MS_WINS1:
1550 case CI_MS_WINS2:
1551 /* Microsoft primary or secondary WINS request */
1552 d = citype == CI_MS_WINS2;
1553
1554 /* If we do not have a DNS address then we cannot send it */
1555 if (ao->winsaddr[d] == 0 ||
1556 cilen != CILEN_ADDR) { /* Check CI length */
1557 orc = CONFREJ; /* Reject CI */
1558 break;
1559 }
1560 GETLONG(tl, p);
1561 if (htonl(tl) != ao->winsaddr[d]) {
1562 DECPTR(sizeof(u_int32_t), p);
1563 tl = ntohl(ao->winsaddr[d]);
1564 PUTLONG(tl, p);
1565 orc = CONFNAK;
1566 }
1567 break;
1568
1569 case CI_COMPRESSTYPE:
1570 if (!ao->neg_vj ||
1571 (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
1572 orc = CONFREJ;
1573 break;
1574 }
1575 GETSHORT(cishort, p);
1576
1577 if (!(cishort == IPCP_VJ_COMP ||
1578 (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
1579 orc = CONFREJ;
1580 break;
1581 }
1582
1583 ho->neg_vj = 1;
1584 ho->vj_protocol = cishort;
1585 if (cilen == CILEN_VJ) {
1586 GETCHAR(maxslotindex, p);
1587 if (maxslotindex > ao->maxslotindex) {
1588 orc = CONFNAK;
1589 if (!reject_if_disagree){
1590 DECPTR(1, p);
1591 PUTCHAR(ao->maxslotindex, p);
1592 }
1593 }
1594 GETCHAR(cflag, p);
1595 if (cflag && !ao->cflag) {
1596 orc = CONFNAK;
1597 if (!reject_if_disagree){
1598 DECPTR(1, p);
1599 PUTCHAR(wo->cflag, p);
1600 }
1601 }
1602 ho->maxslotindex = maxslotindex;
1603 ho->cflag = cflag;
1604 } else {
1605 ho->old_vj = 1;
1606 ho->maxslotindex = MAX_STATES - 1;
1607 ho->cflag = 1;
1608 }
1609 break;
1610
1611 default:
1612 orc = CONFREJ;
1613 break;
1614 }
1615 endswitch:
1616 if (orc == CONFACK && /* Good CI */
1617 rc != CONFACK) /* but prior CI wasnt? */
1618 continue; /* Don't send this one */
1619
1620 if (orc == CONFNAK) { /* Nak this CI? */
1621 if (reject_if_disagree) /* Getting fed up with sending NAKs? */
1622 orc = CONFREJ; /* Get tough if so */
1623 else {
1624 if (rc == CONFREJ) /* Rejecting prior CI? */
1625 continue; /* Don't send this one */
1626 if (rc == CONFACK) { /* Ack'd all prior CIs? */
1627 rc = CONFNAK; /* Not anymore... */
1628 ucp = inp; /* Backup */
1629 }
1630 }
1631 }
1632
1633 if (orc == CONFREJ && /* Reject this CI */
1634 rc != CONFREJ) { /* but no prior ones? */
1635 rc = CONFREJ;
1636 ucp = inp; /* Backup */
1637 }
1638
1639 /* Need to move CI? */
1640 if (ucp != cip)
1641 BCOPY(cip, ucp, cilen); /* Move it */
1642
1643 /* Update output pointer */
1644 INCPTR(cilen, ucp);
1645 }
1646
1647 /*
1648 * If we aren't rejecting this packet, and we want to negotiate
1649 * their address, and they didn't send their address, then we
1650 * send a NAK with a CI_ADDR option appended. We assume the
1651 * input buffer is long enough that we can append the extra
1652 * option safely.
1653 */
1654 if (rc != CONFREJ && !ho->neg_addr && !ho->old_addrs &&
1655 wo->req_addr && !reject_if_disagree && !noremoteip) {
1656 if (rc == CONFACK) {
1657 rc = CONFNAK;
1658 ucp = inp; /* reset pointer */
1659 wo->req_addr = 0; /* don't ask again */
1660 }
1661 PUTCHAR(CI_ADDR, ucp);
1662 PUTCHAR(CILEN_ADDR, ucp);
1663 tl = ntohl(wo->hisaddr);
1664 PUTLONG(tl, ucp);
1665 }
1666
1667 *len = ucp - inp; /* Compute output length */
1668 IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc)));
1669 return (rc); /* Return final code */
1670 }
1671
1672
1673 /*
1674 * ip_check_options - check that any IP-related options are OK,
1675 * and assign appropriate defaults.
1676 */
1677 static void
ip_check_options(void)1678 ip_check_options(void)
1679 {
1680 struct hostent *hp;
1681 u_int32_t local;
1682 ipcp_options *wo = &ipcp_wantoptions[0];
1683
1684 /*
1685 * Default our local IP address based on our hostname.
1686 * If local IP address already given, don't bother.
1687 */
1688 if (wo->ouraddr == 0 && !disable_defaultip) {
1689 /*
1690 * Look up our hostname (possibly with domain name appended)
1691 * and take the first IP address as our local IP address.
1692 * If there isn't an IP address for our hostname, too bad.
1693 */
1694 wo->accept_local = 1; /* don't insist on this default value */
1695 if ((hp = gethostbyname(hostname)) != NULL) {
1696 local = *(u_int32_t *)hp->h_addr;
1697 if (local != 0 && !bad_ip_adrs(local))
1698 wo->ouraddr = local;
1699 }
1700 }
1701 ask_for_local = wo->ouraddr != 0 || !disable_defaultip;
1702 }
1703
1704
1705 /*
1706 * ip_demand_conf - configure the interface as though
1707 * IPCP were up, for use with dial-on-demand.
1708 */
1709 static int
ip_demand_conf(int u)1710 ip_demand_conf(int u)
1711 {
1712 ipcp_options *wo = &ipcp_wantoptions[u];
1713
1714 if (wo->hisaddr == 0 && !noremoteip) {
1715 /* make up an arbitrary address for the peer */
1716 wo->hisaddr = htonl(0x0a707070 + ifunit);
1717 wo->accept_remote = 1;
1718 }
1719 if (wo->ouraddr == 0) {
1720 /* make up an arbitrary address for us */
1721 wo->ouraddr = htonl(0x0a404040 + ifunit);
1722 wo->accept_local = 1;
1723 ask_for_local = 0; /* don't tell the peer this address */
1724 }
1725 if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
1726 return 0;
1727 ipcp_script(_PATH_IPPREUP, 1);
1728 if (!sifup(u))
1729 return 0;
1730 if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
1731 return 0;
1732 if (wo->default_route)
1733 if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr,
1734 wo->replace_default_route))
1735 default_route_set[u] = 1;
1736 if (wo->proxy_arp)
1737 if (sifproxyarp(u, wo->hisaddr))
1738 proxy_arp_set[u] = 1;
1739
1740 notice("local IP address %I", wo->ouraddr);
1741 if (wo->hisaddr)
1742 notice("remote IP address %I", wo->hisaddr);
1743
1744 return 1;
1745 }
1746
1747
1748 /*
1749 * ipcp_up - IPCP has come UP.
1750 *
1751 * Configure the IP network interface appropriately and bring it up.
1752 */
1753 static void
ipcp_up(fsm * f)1754 ipcp_up(fsm *f)
1755 {
1756 u_int32_t mask;
1757 ipcp_options *ho = &ipcp_hisoptions[f->unit];
1758 ipcp_options *go = &ipcp_gotoptions[f->unit];
1759 ipcp_options *wo = &ipcp_wantoptions[f->unit];
1760 int ifindex;
1761
1762 IPCPDEBUG(("ipcp: up"));
1763
1764 /*
1765 * We must have a non-zero IP address for both ends of the link.
1766 */
1767 if (!ho->neg_addr && !ho->old_addrs)
1768 ho->hisaddr = wo->hisaddr;
1769
1770 if (!(go->neg_addr || go->old_addrs) && (wo->neg_addr || wo->old_addrs)
1771 && wo->ouraddr != 0) {
1772 error("Peer refused to agree to our IP address");
1773 ipcp_close(f->unit, "Refused our IP address");
1774 return;
1775 }
1776 if (go->ouraddr == 0) {
1777 error("Could not determine local IP address");
1778 ipcp_close(f->unit, "Could not determine local IP address");
1779 return;
1780 }
1781 if (ho->hisaddr == 0 && !noremoteip) {
1782 ho->hisaddr = htonl(0x0a404040 + ifunit);
1783 warn("Could not determine remote IP address: defaulting to %I",
1784 ho->hisaddr);
1785 }
1786 script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
1787 if (ho->hisaddr != 0)
1788 script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
1789
1790 if (!go->req_dns1)
1791 go->dnsaddr[0] = 0;
1792 if (!go->req_dns2)
1793 go->dnsaddr[1] = 0;
1794 if (go->dnsaddr[0])
1795 script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
1796 if (go->dnsaddr[1])
1797 script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
1798 if (usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
1799 script_setenv("USEPEERDNS", "1", 0);
1800 create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
1801 }
1802
1803 /*
1804 * Check that the peer is allowed to use the IP address it wants.
1805 */
1806 if (ho->hisaddr != 0 && !auth_ip_addr(f->unit, ho->hisaddr)) {
1807 error("Peer is not authorized to use remote address %I", ho->hisaddr);
1808 ipcp_close(f->unit, "Unauthorized remote IP address");
1809 return;
1810 }
1811
1812 /* set tcp compression */
1813 sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
1814
1815 /*
1816 * If we are doing dial-on-demand, the interface is already
1817 * configured, so we put out any saved-up packets, then set the
1818 * interface to pass IP packets.
1819 */
1820 if (demand) {
1821 if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
1822 ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr,
1823 wo->replace_default_route);
1824 if (go->ouraddr != wo->ouraddr) {
1825 warn("Local IP address changed to %I", go->ouraddr);
1826 script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
1827 wo->ouraddr = go->ouraddr;
1828 } else
1829 script_unsetenv("OLDIPLOCAL");
1830 if (ho->hisaddr != wo->hisaddr && wo->hisaddr != 0) {
1831 warn("Remote IP address changed to %I", ho->hisaddr);
1832 script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
1833 wo->hisaddr = ho->hisaddr;
1834 } else
1835 script_unsetenv("OLDIPREMOTE");
1836
1837 /* Set the interface to the new addresses */
1838 mask = GetMask(go->ouraddr);
1839 if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1840 if (debug)
1841 warn("Interface configuration failed");
1842 ipcp_close(f->unit, "Interface configuration failed");
1843 return;
1844 }
1845
1846 /* assign a default route through the interface if required */
1847 if (ipcp_wantoptions[f->unit].default_route)
1848 if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr,
1849 wo->replace_default_route))
1850 default_route_set[f->unit] = 1;
1851
1852 /* Make a proxy ARP entry if requested. */
1853 if (ho->hisaddr != 0 && ipcp_wantoptions[f->unit].proxy_arp)
1854 if (sifproxyarp(f->unit, ho->hisaddr))
1855 proxy_arp_set[f->unit] = 1;
1856
1857 }
1858 demand_rexmit(PPP_IP);
1859 sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1860
1861 } else {
1862 /*
1863 * Set IP addresses and (if specified) netmask.
1864 */
1865 mask = GetMask(go->ouraddr);
1866
1867 #if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1868 if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1869 if (debug)
1870 warn("Interface configuration failed");
1871 ipcp_close(f->unit, "Interface configuration failed");
1872 return;
1873 }
1874 #endif
1875
1876 ifindex = if_nametoindex(ifname);
1877
1878 /* run the pre-up script, if any, and wait for it to finish */
1879 ipcp_script(_PATH_IPPREUP, 1);
1880
1881 /* check if preup script renamed the interface */
1882 if (!if_indextoname(ifindex, ifname)) {
1883 error("Interface index %d failed to get renamed by a pre-up script", ifindex);
1884 ipcp_close(f->unit, "Interface configuration failed");
1885 return;
1886 }
1887
1888 /* bring the interface up for IP */
1889 if (!sifup(f->unit)) {
1890 if (debug)
1891 warn("Interface failed to come up");
1892 ipcp_close(f->unit, "Interface configuration failed");
1893 return;
1894 }
1895
1896 #if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1897 if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1898 if (debug)
1899 warn("Interface configuration failed");
1900 ipcp_close(f->unit, "Interface configuration failed");
1901 return;
1902 }
1903 #endif
1904 sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1905
1906 /* assign a default route through the interface if required */
1907 if (ipcp_wantoptions[f->unit].default_route)
1908 if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr,
1909 wo->replace_default_route))
1910 default_route_set[f->unit] = 1;
1911
1912 /* Make a proxy ARP entry if requested. */
1913 if (ho->hisaddr != 0 && ipcp_wantoptions[f->unit].proxy_arp)
1914 if (sifproxyarp(f->unit, ho->hisaddr))
1915 proxy_arp_set[f->unit] = 1;
1916
1917 ipcp_wantoptions[0].ouraddr = go->ouraddr;
1918
1919 notice("local IP address %I", go->ouraddr);
1920 if (ho->hisaddr != 0)
1921 notice("remote IP address %I", ho->hisaddr);
1922 if (go->dnsaddr[0])
1923 notice("primary DNS address %I", go->dnsaddr[0]);
1924 if (go->dnsaddr[1])
1925 notice("secondary DNS address %I", go->dnsaddr[1]);
1926 }
1927
1928 reset_link_stats(f->unit);
1929
1930 np_up(f->unit, PPP_IP);
1931 ipcp_is_up = 1;
1932
1933 notify(ip_up_notifier, 0);
1934 if (ip_up_hook)
1935 ip_up_hook();
1936
1937 /*
1938 * Execute the ip-up script, like this:
1939 * /etc/ppp/ip-up interface tty speed local-IP remote-IP
1940 */
1941 if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
1942 ipcp_script_state = s_up;
1943 ipcp_script(path_ipup, 0);
1944 }
1945 }
1946
1947
1948 /*
1949 * ipcp_down - IPCP has gone DOWN.
1950 *
1951 * Take the IP network interface down, clear its addresses
1952 * and delete routes through it.
1953 */
1954 static void
ipcp_down(fsm * f)1955 ipcp_down(fsm *f)
1956 {
1957 IPCPDEBUG(("ipcp: down"));
1958 /* XXX a bit IPv4-centric here, we only need to get the stats
1959 * before the interface is marked down. */
1960 /* XXX more correct: we must get the stats before running the notifiers,
1961 * at least for the radius plugin */
1962 update_link_stats(f->unit);
1963 notify(ip_down_notifier, 0);
1964 if (ip_down_hook)
1965 ip_down_hook();
1966 if (ipcp_is_up) {
1967 ipcp_is_up = 0;
1968 np_down(f->unit, PPP_IP);
1969 }
1970 sifvjcomp(f->unit, 0, 0, 0);
1971
1972 print_link_stats(); /* _after_ running the notifiers and ip_down_hook(),
1973 * because print_link_stats() sets link_stats_valid
1974 * to 0 (zero) */
1975
1976 /*
1977 * If we are doing dial-on-demand, set the interface
1978 * to queue up outgoing packets (for now).
1979 */
1980 if (demand) {
1981 sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE);
1982 } else {
1983 sifnpmode(f->unit, PPP_IP, NPMODE_DROP);
1984 sifdown(f->unit);
1985 ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
1986 ipcp_hisoptions[f->unit].hisaddr, 0);
1987 }
1988
1989 /* Execute the ip-down script */
1990 if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
1991 ipcp_script_state = s_down;
1992 ipcp_script(path_ipdown, 0);
1993 }
1994 }
1995
1996
1997 /*
1998 * ipcp_clear_addrs() - clear the interface addresses, routes,
1999 * proxy arp entries, etc.
2000 */
2001 static void
ipcp_clear_addrs(int unit,u_int32_t ouraddr,u_int32_t hisaddr,bool replacedefaultroute)2002 ipcp_clear_addrs(int unit, u_int32_t ouraddr, u_int32_t hisaddr, bool replacedefaultroute)
2003 {
2004 if (proxy_arp_set[unit]) {
2005 cifproxyarp(unit, hisaddr);
2006 proxy_arp_set[unit] = 0;
2007 }
2008 /* If replacedefaultroute, sifdefaultroute will be called soon
2009 * with replacedefaultroute set and that will overwrite the current
2010 * default route. This is the case only when doing demand, otherwise
2011 * during demand, this cifdefaultroute would restore the old default
2012 * route which is not what we want in this case. In the non-demand
2013 * case, we'll delete the default route and restore the old if there
2014 * is one saved by an sifdefaultroute with replacedefaultroute.
2015 */
2016 if (!replacedefaultroute && default_route_set[unit]) {
2017 cifdefaultroute(unit, ouraddr, hisaddr);
2018 default_route_set[unit] = 0;
2019 }
2020 cifaddr(unit, ouraddr, hisaddr);
2021 }
2022
2023
2024 /*
2025 * ipcp_finished - possibly shut down the lower layers.
2026 */
2027 static void
ipcp_finished(fsm * f)2028 ipcp_finished(fsm *f)
2029 {
2030 if (ipcp_is_open) {
2031 ipcp_is_open = 0;
2032 np_finished(f->unit, PPP_IP);
2033 }
2034 }
2035
2036
2037 /*
2038 * ipcp_script_done - called when the ip-up or ip-down script
2039 * has finished.
2040 */
2041 static void
ipcp_script_done(void * arg)2042 ipcp_script_done(void *arg)
2043 {
2044 ipcp_script_pid = 0;
2045 switch (ipcp_script_state) {
2046 case s_up:
2047 if (ipcp_fsm[0].state != OPENED) {
2048 ipcp_script_state = s_down;
2049 ipcp_script(path_ipdown, 0);
2050 }
2051 break;
2052 case s_down:
2053 if (ipcp_fsm[0].state == OPENED) {
2054 ipcp_script_state = s_up;
2055 ipcp_script(path_ipup, 0);
2056 }
2057 break;
2058 }
2059 }
2060
2061
2062 /*
2063 * ipcp_script - Execute a script with arguments
2064 * interface-name tty-name speed local-IP remote-IP.
2065 */
2066 static void
ipcp_script(char * script,int wait)2067 ipcp_script(char *script, int wait)
2068 {
2069 char strspeed[32], strlocal[32], strremote[32];
2070 char *argv[8];
2071
2072 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
2073 slprintf(strlocal, sizeof(strlocal), "%I", ipcp_gotoptions[0].ouraddr);
2074 slprintf(strremote, sizeof(strremote), "%I", ipcp_hisoptions[0].hisaddr);
2075
2076 argv[0] = script;
2077 argv[1] = ifname;
2078 argv[2] = devnam;
2079 argv[3] = strspeed;
2080 argv[4] = strlocal;
2081 argv[5] = strremote;
2082 argv[6] = ipparam;
2083 argv[7] = NULL;
2084 if (wait)
2085 run_program(script, argv, 0, NULL, NULL, 1);
2086 else
2087 ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done,
2088 NULL, 0);
2089 }
2090
2091 /*
2092 * create_resolv - create the replacement resolv.conf file
2093 */
2094 static void
create_resolv(u_int32_t peerdns1,u_int32_t peerdns2)2095 create_resolv(u_int32_t peerdns1, u_int32_t peerdns2)
2096 {
2097 FILE *f;
2098
2099 f = fopen(_PATH_RESOLV, "w");
2100 if (f == NULL) {
2101 error("Failed to create %s: %m", _PATH_RESOLV);
2102 return;
2103 }
2104
2105 if (peerdns1)
2106 fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1));
2107
2108 if (peerdns2)
2109 fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2));
2110
2111 if (ferror(f))
2112 error("Write failed to %s: %m", _PATH_RESOLV);
2113
2114 fclose(f);
2115 }
2116
2117 /*
2118 * ipcp_printpkt - print the contents of an IPCP packet.
2119 */
2120 static char *ipcp_codenames[] = {
2121 "ConfReq", "ConfAck", "ConfNak", "ConfRej",
2122 "TermReq", "TermAck", "CodeRej"
2123 };
2124
2125 static int
ipcp_printpkt(u_char * p,int plen,void (* printer)(void *,char *,...),void * arg)2126 ipcp_printpkt(u_char *p, int plen,
2127 void (*printer) (void *, char *, ...), void *arg)
2128 {
2129 int code, id, len, olen;
2130 u_char *pstart, *optend;
2131 u_short cishort;
2132 u_int32_t cilong;
2133
2134 if (plen < HEADERLEN)
2135 return 0;
2136 pstart = p;
2137 GETCHAR(code, p);
2138 GETCHAR(id, p);
2139 GETSHORT(len, p);
2140 if (len < HEADERLEN || len > plen)
2141 return 0;
2142
2143 if (code >= 1 && code <= sizeof(ipcp_codenames) / sizeof(char *))
2144 printer(arg, " %s", ipcp_codenames[code-1]);
2145 else
2146 printer(arg, " code=0x%x", code);
2147 printer(arg, " id=0x%x", id);
2148 len -= HEADERLEN;
2149 switch (code) {
2150 case CONFREQ:
2151 case CONFACK:
2152 case CONFNAK:
2153 case CONFREJ:
2154 /* print option list */
2155 while (len >= 2) {
2156 GETCHAR(code, p);
2157 GETCHAR(olen, p);
2158 p -= 2;
2159 if (olen < 2 || olen > len) {
2160 break;
2161 }
2162 printer(arg, " <");
2163 len -= olen;
2164 optend = p + olen;
2165 switch (code) {
2166 case CI_ADDRS:
2167 if (olen == CILEN_ADDRS) {
2168 p += 2;
2169 GETLONG(cilong, p);
2170 printer(arg, "addrs %I", htonl(cilong));
2171 GETLONG(cilong, p);
2172 printer(arg, " %I", htonl(cilong));
2173 }
2174 break;
2175 case CI_COMPRESSTYPE:
2176 if (olen >= CILEN_COMPRESS) {
2177 p += 2;
2178 GETSHORT(cishort, p);
2179 printer(arg, "compress ");
2180 switch (cishort) {
2181 case IPCP_VJ_COMP:
2182 printer(arg, "VJ");
2183 break;
2184 case IPCP_VJ_COMP_OLD:
2185 printer(arg, "old-VJ");
2186 break;
2187 default:
2188 printer(arg, "0x%x", cishort);
2189 }
2190 }
2191 break;
2192 case CI_ADDR:
2193 if (olen == CILEN_ADDR) {
2194 p += 2;
2195 GETLONG(cilong, p);
2196 printer(arg, "addr %I", htonl(cilong));
2197 }
2198 break;
2199 case CI_MS_DNS1:
2200 case CI_MS_DNS2:
2201 p += 2;
2202 GETLONG(cilong, p);
2203 printer(arg, "ms-dns%d %I", (code == CI_MS_DNS1? 1: 2),
2204 htonl(cilong));
2205 break;
2206 case CI_MS_WINS1:
2207 case CI_MS_WINS2:
2208 p += 2;
2209 GETLONG(cilong, p);
2210 printer(arg, "ms-wins %I", htonl(cilong));
2211 break;
2212 }
2213 while (p < optend) {
2214 GETCHAR(code, p);
2215 printer(arg, " %.2x", code);
2216 }
2217 printer(arg, ">");
2218 }
2219 break;
2220
2221 case TERMACK:
2222 case TERMREQ:
2223 if (len > 0 && *p >= ' ' && *p < 0x7f) {
2224 printer(arg, " ");
2225 print_string((char *)p, len, printer, arg);
2226 p += len;
2227 len = 0;
2228 }
2229 break;
2230 }
2231
2232 /* print the rest of the bytes in the packet */
2233 for (; len > 0; --len) {
2234 GETCHAR(code, p);
2235 printer(arg, " %.2x", code);
2236 }
2237
2238 return p - pstart;
2239 }
2240
2241 /*
2242 * ip_active_pkt - see if this IP packet is worth bringing the link up for.
2243 * We don't bring the link up for IP fragments or for TCP FIN packets
2244 * with no data.
2245 */
2246 #define IP_HDRLEN 20 /* bytes */
2247 #define IP_OFFMASK 0x1fff
2248 #ifndef IPPROTO_TCP
2249 #define IPPROTO_TCP 6
2250 #endif
2251 #define TCP_HDRLEN 20
2252 #define TH_FIN 0x01
2253
2254 /*
2255 * We use these macros because the IP header may be at an odd address,
2256 * and some compilers might use word loads to get th_off or ip_hl.
2257 */
2258
2259 #define net_short(x) (((x)[0] << 8) + (x)[1])
2260 #define get_iphl(x) (((unsigned char *)(x))[0] & 0xF)
2261 #define get_ipoff(x) net_short((unsigned char *)(x) + 6)
2262 #define get_ipproto(x) (((unsigned char *)(x))[9])
2263 #define get_tcpoff(x) (((unsigned char *)(x))[12] >> 4)
2264 #define get_tcpflags(x) (((unsigned char *)(x))[13])
2265
2266 static int
ip_active_pkt(u_char * pkt,int len)2267 ip_active_pkt(u_char *pkt, int len)
2268 {
2269 u_char *tcp;
2270 int hlen;
2271
2272 len -= PPP_HDRLEN;
2273 pkt += PPP_HDRLEN;
2274 if (len < IP_HDRLEN)
2275 return 0;
2276 if ((get_ipoff(pkt) & IP_OFFMASK) != 0)
2277 return 0;
2278 if (get_ipproto(pkt) != IPPROTO_TCP)
2279 return 1;
2280 hlen = get_iphl(pkt) * 4;
2281 if (len < hlen + TCP_HDRLEN)
2282 return 0;
2283 tcp = pkt + hlen;
2284 if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
2285 return 0;
2286 return 1;
2287 }
2288