1 /*
2 * auth.c - PPP authentication and phase control.
3 *
4 * Copyright (c) 1993-2002 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
14 * endorse or promote products derived from this software without
15 * prior written permission.
16 *
17 * 3. Redistributions of any form whatsoever must retain the following
18 * acknowledgment:
19 * "This product includes software developed by Paul Mackerras
20 * <paulus@samba.org>".
21 *
22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
29 *
30 * Derived from main.c, which is:
31 *
32 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
33 *
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
36 * are met:
37 *
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 *
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in
43 * the documentation and/or other materials provided with the
44 * distribution.
45 *
46 * 3. The name "Carnegie Mellon University" must not be used to
47 * endorse or promote products derived from this software without
48 * prior written permission. For permission or any legal
49 * details, please contact
50 * Office of Technology Transfer
51 * Carnegie Mellon University
52 * 5000 Forbes Avenue
53 * Pittsburgh, PA 15213-3890
54 * (412) 268-4387, fax: (412) 268-7395
55 * tech-transfer@andrew.cmu.edu
56 *
57 * 4. Redistributions of any form whatsoever must retain the following
58 * acknowledgment:
59 * "This product includes software developed by Computing Services
60 * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
61 *
62 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
63 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
64 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
65 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
66 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
67 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
68 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
69 */
70
71 #define RCSID "$Id: auth.c,v 1.101 2004/11/12 10:30:51 paulus Exp $"
72
73 #include <stdio.h>
74 #include <stddef.h>
75 #include <stdlib.h>
76 #include <unistd.h>
77 #include <errno.h>
78 #include <pwd.h>
79 #include <grp.h>
80 #include <string.h>
81 #include <sys/types.h>
82 #include <sys/stat.h>
83 #include <sys/socket.h>
84 #include <utmp.h>
85 #include <fcntl.h>
86 #if defined(_PATH_LASTLOG) && defined(__linux__)
87 #include <lastlog.h>
88 #endif
89
90 #include <netdb.h>
91 #include <netinet/in.h>
92 #include <arpa/inet.h>
93
94 #ifdef USE_PAM
95 #include <security/pam_appl.h>
96 #endif
97
98 #ifdef HAS_SHADOW
99 #include <shadow.h>
100 #ifndef PW_PPP
101 #define PW_PPP PW_LOGIN
102 #endif
103 #endif
104 #include <time.h>
105
106 #include "pppd.h"
107 #include "fsm.h"
108 #include "lcp.h"
109 #include "ccp.h"
110 #include "ecp.h"
111 #include "ipcp.h"
112 #include "upap.h"
113 #include "chap-new.h"
114 #include "eap.h"
115 #ifdef CBCP_SUPPORT
116 #include "cbcp.h"
117 #endif
118 #include "pathnames.h"
119
120 static const char rcsid[] = RCSID;
121
122 /* Bits in scan_authfile return value */
123 #define NONWILD_SERVER 1
124 #define NONWILD_CLIENT 2
125
126 #define ISWILD(word) (word[0] == '*' && word[1] == 0)
127
128 /* The name by which the peer authenticated itself to us. */
129 char peer_authname[MAXNAMELEN];
130
131 /* Records which authentication operations haven't completed yet. */
132 static int auth_pending[NUM_PPP];
133
134 /* Records which authentication operations have been completed. */
135 int auth_done[NUM_PPP];
136
137 /* Set if we have successfully called plogin() */
138 static int logged_in;
139
140 /* List of addresses which the peer may use. */
141 static struct permitted_ip *addresses[NUM_PPP];
142
143 /* Wordlist giving addresses which the peer may use
144 without authenticating itself. */
145 static struct wordlist *noauth_addrs;
146
147 /* Remote telephone number, if available */
148 char remote_number[MAXNAMELEN];
149
150 /* Wordlist giving remote telephone numbers which may connect. */
151 static struct wordlist *permitted_numbers;
152
153 /* Extra options to apply, from the secrets file entry for the peer. */
154 static struct wordlist *extra_options;
155
156 /* Number of network protocols which we have opened. */
157 static int num_np_open;
158
159 /* Number of network protocols which have come up. */
160 static int num_np_up;
161
162 /* Set if we got the contents of passwd[] from the pap-secrets file. */
163 static int passwd_from_file;
164
165 /* Set if we require authentication only because we have a default route. */
166 static bool default_auth;
167
168 /* Hook to enable a plugin to control the idle time limit */
169 int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
170
171 /* Hook for a plugin to say whether we can possibly authenticate any peer */
172 int (*pap_check_hook) __P((void)) = NULL;
173
174 /* Hook for a plugin to check the PAP user and password */
175 int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
176 struct wordlist **paddrs,
177 struct wordlist **popts)) = NULL;
178
179 /* Hook for a plugin to know about the PAP user logout */
180 void (*pap_logout_hook) __P((void)) = NULL;
181
182 /* Hook for a plugin to get the PAP password for authenticating us */
183 int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
184
185 /* Hook for a plugin to say if we can possibly authenticate a peer using CHAP */
186 int (*chap_check_hook) __P((void)) = NULL;
187
188 /* Hook for a plugin to get the CHAP password for authenticating us */
189 int (*chap_passwd_hook) __P((char *user, char *passwd)) = NULL;
190
191 /* Hook for a plugin to say whether it is OK if the peer
192 refuses to authenticate. */
193 int (*null_auth_hook) __P((struct wordlist **paddrs,
194 struct wordlist **popts)) = NULL;
195
196 int (*allowed_address_hook) __P((u_int32_t addr)) = NULL;
197
198 /* A notifier for when the peer has authenticated itself,
199 and we are proceeding to the network phase. */
200 struct notifier *auth_up_notifier = NULL;
201
202 /* A notifier for when the link goes down. */
203 struct notifier *link_down_notifier = NULL;
204
205 /*
206 * This is used to ensure that we don't start an auth-up/down
207 * script while one is already running.
208 */
209 enum script_state {
210 s_down,
211 s_up
212 };
213
214 static enum script_state auth_state = s_down;
215 static enum script_state auth_script_state = s_down;
216 static pid_t auth_script_pid = 0;
217
218 static int used_login; /* peer authenticated against login database */
219
220 /*
221 * Option variables.
222 */
223 bool uselogin = 0; /* Use /etc/passwd for checking PAP */
224 bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
225 bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
226 bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
227 bool refuse_eap = 0; /* Don't wanna auth. ourselves with EAP */
228 #ifdef CHAPMS
229 bool refuse_mschap = 0; /* Don't wanna auth. ourselves with MS-CHAP */
230 bool refuse_mschap_v2 = 0; /* Don't wanna auth. ourselves with MS-CHAPv2 */
231 #else
232 bool refuse_mschap = 1; /* Don't wanna auth. ourselves with MS-CHAP */
233 bool refuse_mschap_v2 = 1; /* Don't wanna auth. ourselves with MS-CHAPv2 */
234 #endif
235 bool usehostname = 0; /* Use hostname for our_name */
236 bool auth_required = 0; /* Always require authentication from peer */
237 bool allow_any_ip = 0; /* Allow peer to use any IP address */
238 bool explicit_remote = 0; /* User specified explicit remote name */
239 char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
240
241 static char *uafname; /* name of most recent +ua file */
242
243 extern char *crypt __P((const char *, const char *));
244
245 /* Prototypes for procedures local to this file. */
246
247 static void network_phase __P((int));
248 static void check_idle __P((void *));
249 static void connect_time_expired __P((void *));
250 static int plogin __P((char *, char *, char **));
251 static void plogout __P((void));
252 static int null_login __P((int));
253 static int get_pap_passwd __P((char *));
254 static int have_pap_secret __P((int *));
255 static int have_chap_secret __P((char *, char *, int, int *));
256 static int have_srp_secret __P((char *client, char *server, int need_ip,
257 int *lacks_ipp));
258 static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
259 static int scan_authfile __P((FILE *, char *, char *, char *,
260 struct wordlist **, struct wordlist **,
261 char *, int));
262 static void free_wordlist __P((struct wordlist *));
263 static void auth_script __P((char *));
264 static void auth_script_done __P((void *));
265 static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
266 static int some_ip_ok __P((struct wordlist *));
267 static int setupapfile __P((char **));
268 static int privgroup __P((char **));
269 static int set_noauth_addr __P((char **));
270 static int set_permitted_number __P((char **));
271 static void check_access __P((FILE *, char *));
272 static int wordlist_count __P((struct wordlist *));
273
274 #ifdef MAXOCTETS
275 static void check_maxoctets __P((void *));
276 #endif
277
278 /*
279 * Authentication-related options.
280 */
281 option_t auth_options[] = {
282 { "auth", o_bool, &auth_required,
283 "Require authentication from peer", OPT_PRIO | 1 },
284 { "noauth", o_bool, &auth_required,
285 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
286 &allow_any_ip },
287 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
288 "Require PAP authentication from peer",
289 OPT_PRIOSUB | 1, &auth_required },
290 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
291 "Require PAP authentication from peer",
292 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
293 { "require-chap", o_bool, &auth_required,
294 "Require CHAP authentication from peer",
295 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
296 &lcp_wantoptions[0].chap_mdtype },
297 { "+chap", o_bool, &auth_required,
298 "Require CHAP authentication from peer",
299 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
300 &lcp_wantoptions[0].chap_mdtype },
301 #ifdef CHAPMS
302 { "require-mschap", o_bool, &auth_required,
303 "Require MS-CHAP authentication from peer",
304 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
305 &lcp_wantoptions[0].chap_mdtype },
306 { "+mschap", o_bool, &auth_required,
307 "Require MS-CHAP authentication from peer",
308 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
309 &lcp_wantoptions[0].chap_mdtype },
310 { "require-mschap-v2", o_bool, &auth_required,
311 "Require MS-CHAPv2 authentication from peer",
312 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
313 &lcp_wantoptions[0].chap_mdtype },
314 { "+mschap-v2", o_bool, &auth_required,
315 "Require MS-CHAPv2 authentication from peer",
316 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
317 &lcp_wantoptions[0].chap_mdtype },
318 #endif
319
320 { "refuse-pap", o_bool, &refuse_pap,
321 "Don't agree to auth to peer with PAP", 1 },
322 { "-pap", o_bool, &refuse_pap,
323 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
324 { "refuse-chap", o_bool, &refuse_chap,
325 "Don't agree to auth to peer with CHAP",
326 OPT_A2CLRB | MDTYPE_MD5,
327 &lcp_allowoptions[0].chap_mdtype },
328 { "-chap", o_bool, &refuse_chap,
329 "Don't allow CHAP authentication with peer",
330 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5,
331 &lcp_allowoptions[0].chap_mdtype },
332 #ifdef CHAPMS
333 { "refuse-mschap", o_bool, &refuse_mschap,
334 "Don't agree to auth to peer with MS-CHAP",
335 OPT_A2CLRB | MDTYPE_MICROSOFT,
336 &lcp_allowoptions[0].chap_mdtype },
337 { "-mschap", o_bool, &refuse_mschap,
338 "Don't allow MS-CHAP authentication with peer",
339 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT,
340 &lcp_allowoptions[0].chap_mdtype },
341 { "refuse-mschap-v2", o_bool, &refuse_mschap_v2,
342 "Don't agree to auth to peer with MS-CHAPv2",
343 OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
344 &lcp_allowoptions[0].chap_mdtype },
345 { "-mschap-v2", o_bool, &refuse_mschap_v2,
346 "Don't allow MS-CHAPv2 authentication with peer",
347 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
348 &lcp_allowoptions[0].chap_mdtype },
349 #endif
350
351 { "require-eap", o_bool, &lcp_wantoptions[0].neg_eap,
352 "Require EAP authentication from peer", OPT_PRIOSUB | 1,
353 &auth_required },
354 { "refuse-eap", o_bool, &refuse_eap,
355 "Don't agree to authenticate to peer with EAP", 1 },
356
357 { "name", o_string, our_name,
358 "Set local name for authentication",
359 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
360
361 { "+ua", o_special, (void *)setupapfile,
362 "Get PAP user and password from file",
363 OPT_PRIO | OPT_A2STRVAL, &uafname },
364
365 { "user", o_string, user,
366 "Set name for auth with peer", OPT_PRIO | OPT_STATIC, NULL, MAXNAMELEN },
367
368 { "password", o_string, passwd,
369 "Password for authenticating us to the peer",
370 OPT_PRIO | OPT_STATIC | OPT_HIDE, NULL, MAXSECRETLEN },
371
372 { "usehostname", o_bool, &usehostname,
373 "Must use hostname for authentication", 1 },
374
375 { "remotename", o_string, remote_name,
376 "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
377 &explicit_remote, MAXNAMELEN },
378
379 { "login", o_bool, &uselogin,
380 "Use system password database for PAP", 1 },
381
382 { "papcrypt", o_bool, &cryptpap,
383 "PAP passwords are encrypted", 1 },
384
385 { "privgroup", o_special, (void *)privgroup,
386 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
387
388 { "allow-ip", o_special, (void *)set_noauth_addr,
389 "Set IP address(es) which can be used without authentication",
390 OPT_PRIV | OPT_A2LIST },
391
392 { "remotenumber", o_string, remote_number,
393 "Set remote telephone number for authentication", OPT_PRIO | OPT_STATIC,
394 NULL, MAXNAMELEN },
395
396 { "allow-number", o_special, (void *)set_permitted_number,
397 "Set telephone number(s) which are allowed to connect",
398 OPT_PRIV | OPT_A2LIST },
399
400 { NULL }
401 };
402
403 /*
404 * setupapfile - specifies UPAP info for authenticating with peer.
405 */
406 static int
setupapfile(argv)407 setupapfile(argv)
408 char **argv;
409 {
410 FILE *ufile;
411 int l;
412 char u[MAXNAMELEN], p[MAXSECRETLEN];
413 char *fname;
414
415 lcp_allowoptions[0].neg_upap = 1;
416
417 /* open user info file */
418 fname = strdup(*argv);
419 if (fname == NULL)
420 novm("+ua file name");
421 seteuid(getuid());
422 ufile = fopen(fname, "r");
423 seteuid(0);
424 if (ufile == NULL) {
425 option_error("unable to open user login data file %s", fname);
426 return 0;
427 }
428 check_access(ufile, fname);
429 uafname = fname;
430
431 /* get username */
432 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
433 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL) {
434 fclose(ufile);
435 option_error("unable to read user login data file %s", fname);
436 return 0;
437 }
438 fclose(ufile);
439
440 /* get rid of newlines */
441 l = strlen(u);
442 if (l > 0 && u[l-1] == '\n')
443 u[l-1] = 0;
444 l = strlen(p);
445 if (l > 0 && p[l-1] == '\n')
446 p[l-1] = 0;
447
448 if (override_value("user", option_priority, fname))
449 strlcpy(user, u, sizeof(user));
450 if (override_value("passwd", option_priority, fname))
451 strlcpy(passwd, p, sizeof(passwd));
452
453 return (1);
454 }
455
456
457 /*
458 * privgroup - allow members of the group to have privileged access.
459 */
460 static int
privgroup(argv)461 privgroup(argv)
462 char **argv;
463 {
464 struct group *g;
465 int i;
466
467 g = getgrnam(*argv);
468 if (g == 0) {
469 option_error("group %s is unknown", *argv);
470 return 0;
471 }
472 for (i = 0; i < ngroups; ++i) {
473 if (groups[i] == g->gr_gid) {
474 privileged = 1;
475 break;
476 }
477 }
478 return 1;
479 }
480
481
482 /*
483 * set_noauth_addr - set address(es) that can be used without authentication.
484 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
485 */
486 static int
set_noauth_addr(argv)487 set_noauth_addr(argv)
488 char **argv;
489 {
490 char *addr = *argv;
491 int l = strlen(addr) + 1;
492 struct wordlist *wp;
493
494 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
495 if (wp == NULL)
496 novm("allow-ip argument");
497 wp->word = (char *) (wp + 1);
498 wp->next = noauth_addrs;
499 BCOPY(addr, wp->word, l);
500 noauth_addrs = wp;
501 return 1;
502 }
503
504
505 /*
506 * set_permitted_number - set remote telephone number(s) that may connect.
507 */
508 static int
set_permitted_number(argv)509 set_permitted_number(argv)
510 char **argv;
511 {
512 char *number = *argv;
513 int l = strlen(number) + 1;
514 struct wordlist *wp;
515
516 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
517 if (wp == NULL)
518 novm("allow-number argument");
519 wp->word = (char *) (wp + 1);
520 wp->next = permitted_numbers;
521 BCOPY(number, wp->word, l);
522 permitted_numbers = wp;
523 return 1;
524 }
525
526
527 /*
528 * An Open on LCP has requested a change from Dead to Establish phase.
529 * Do what's necessary to bring the physical layer up.
530 */
531 void
link_required(unit)532 link_required(unit)
533 int unit;
534 {
535 new_phase(PHASE_SERIALCONN);
536
537 devfd = the_channel->connect();
538 if (devfd < 0)
539 goto fail;
540
541 /* set up the serial device as a ppp interface */
542 /*
543 * N.B. we used to do tdb_writelock/tdb_writeunlock around this
544 * (from establish_ppp to set_ifunit). However, we won't be
545 * doing the set_ifunit in multilink mode, which is the only time
546 * we need the atomicity that the tdb_writelock/tdb_writeunlock
547 * gives us. Thus we don't need the tdb_writelock/tdb_writeunlock.
548 */
549 fd_ppp = the_channel->establish_ppp(devfd);
550 if (fd_ppp < 0) {
551 status = EXIT_FATAL_ERROR;
552 goto disconnect;
553 }
554
555 if (!demand && ifunit >= 0)
556 set_ifunit(1);
557
558 /*
559 * Start opening the connection and wait for
560 * incoming events (reply, timeout, etc.).
561 */
562 if (ifunit >= 0)
563 notice("Connect: %s <--> %s", ifname, ppp_devnam);
564 else
565 notice("Starting negotiation on %s", ppp_devnam);
566 add_fd(fd_ppp);
567
568 status = EXIT_NEGOTIATION_FAILED;
569 new_phase(PHASE_ESTABLISH);
570
571 lcp_lowerup(0);
572 return;
573
574 disconnect:
575 new_phase(PHASE_DISCONNECT);
576 if (the_channel->disconnect)
577 the_channel->disconnect();
578
579 fail:
580 new_phase(PHASE_DEAD);
581 if (the_channel->cleanup)
582 (*the_channel->cleanup)();
583
584 }
585
586 /*
587 * LCP has terminated the link; go to the Dead phase and take the
588 * physical layer down.
589 */
590 void
link_terminated(unit)591 link_terminated(unit)
592 int unit;
593 {
594 if (phase == PHASE_DEAD || phase == PHASE_MASTER)
595 return;
596 new_phase(PHASE_DISCONNECT);
597
598 if (pap_logout_hook) {
599 pap_logout_hook();
600 } else {
601 if (logged_in)
602 plogout();
603 }
604
605 if (!doing_multilink) {
606 notice("Connection terminated.");
607 print_link_stats();
608 } else
609 notice("Link terminated.");
610
611 /*
612 * Delete pid files before disestablishing ppp. Otherwise it
613 * can happen that another pppd gets the same unit and then
614 * we delete its pid file.
615 */
616 if (!doing_multilink && !demand)
617 remove_pidfiles();
618
619 /*
620 * If we may want to bring the link up again, transfer
621 * the ppp unit back to the loopback. Set the
622 * real serial device back to its normal mode of operation.
623 */
624 if (fd_ppp >= 0) {
625 remove_fd(fd_ppp);
626 clean_check();
627 the_channel->disestablish_ppp(devfd);
628 if (doing_multilink)
629 mp_exit_bundle();
630 fd_ppp = -1;
631 }
632 if (!hungup)
633 lcp_lowerdown(0);
634 if (!doing_multilink && !demand)
635 script_unsetenv("IFNAME");
636
637 /*
638 * Run disconnector script, if requested.
639 * XXX we may not be able to do this if the line has hung up!
640 */
641 if (devfd >= 0 && the_channel->disconnect) {
642 the_channel->disconnect();
643 devfd = -1;
644 }
645
646 if (doing_multilink && multilink_master) {
647 if (!bundle_terminating)
648 new_phase(PHASE_MASTER);
649 else
650 mp_bundle_terminated();
651 } else
652 new_phase(PHASE_DEAD);
653 }
654
655 /*
656 * LCP has gone down; it will either die or try to re-establish.
657 */
658 void
link_down(unit)659 link_down(unit)
660 int unit;
661 {
662 if (auth_state != s_down) {
663 notify(link_down_notifier, 0);
664 auth_state = s_down;
665 if (auth_script_state == s_up && auth_script_pid == 0) {
666 update_link_stats(unit);
667 auth_script_state = s_down;
668 auth_script(_PATH_AUTHDOWN);
669 }
670 }
671 if (!doing_multilink) {
672 upper_layers_down(unit);
673 if (phase != PHASE_DEAD && phase != PHASE_MASTER)
674 new_phase(PHASE_ESTABLISH);
675 }
676 /* XXX if doing_multilink, should do something to stop
677 network-layer traffic on the link */
678 }
679
upper_layers_down(int unit)680 void upper_layers_down(int unit)
681 {
682 int i;
683 struct protent *protp;
684
685 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
686 if (!protp->enabled_flag)
687 continue;
688 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
689 (*protp->lowerdown)(unit);
690 if (protp->protocol < 0xC000 && protp->close != NULL)
691 (*protp->close)(unit, "LCP down");
692 }
693 num_np_open = 0;
694 num_np_up = 0;
695 }
696
697 /*
698 * The link is established.
699 * Proceed to the Dead, Authenticate or Network phase as appropriate.
700 */
701 void
link_established(unit)702 link_established(unit)
703 int unit;
704 {
705 int auth;
706 lcp_options *wo = &lcp_wantoptions[unit];
707 lcp_options *go = &lcp_gotoptions[unit];
708 lcp_options *ho = &lcp_hisoptions[unit];
709 int i;
710 struct protent *protp;
711
712 /*
713 * Tell higher-level protocols that LCP is up.
714 */
715 if (!doing_multilink) {
716 for (i = 0; (protp = protocols[i]) != NULL; ++i)
717 if (protp->protocol != PPP_LCP && protp->enabled_flag
718 && protp->lowerup != NULL)
719 (*protp->lowerup)(unit);
720 }
721
722 if (!auth_required && noauth_addrs != NULL)
723 set_allowed_addrs(unit, NULL, NULL);
724
725 if (auth_required && !(go->neg_upap || go->neg_chap || go->neg_eap)) {
726 /*
727 * We wanted the peer to authenticate itself, and it refused:
728 * if we have some address(es) it can use without auth, fine,
729 * otherwise treat it as though it authenticated with PAP using
730 * a username of "" and a password of "". If that's not OK,
731 * boot it out.
732 */
733 if (noauth_addrs != NULL) {
734 set_allowed_addrs(unit, NULL, NULL);
735 } else if (!wo->neg_upap || uselogin || !null_login(unit)) {
736 warn("peer refused to authenticate: terminating link");
737 lcp_close(unit, "peer refused to authenticate");
738 status = EXIT_PEER_AUTH_FAILED;
739 return;
740 }
741 }
742
743 new_phase(PHASE_AUTHENTICATE);
744 used_login = 0;
745 auth = 0;
746 if (go->neg_eap) {
747 eap_authpeer(unit, our_name);
748 auth |= EAP_PEER;
749 } else if (go->neg_chap) {
750 chap_auth_peer(unit, our_name, CHAP_DIGEST(go->chap_mdtype));
751 auth |= CHAP_PEER;
752 } else if (go->neg_upap) {
753 upap_authpeer(unit);
754 auth |= PAP_PEER;
755 }
756 if (ho->neg_eap) {
757 eap_authwithpeer(unit, user);
758 auth |= EAP_WITHPEER;
759 } else if (ho->neg_chap) {
760 chap_auth_with_peer(unit, user, CHAP_DIGEST(ho->chap_mdtype));
761 auth |= CHAP_WITHPEER;
762 } else if (ho->neg_upap) {
763 if (passwd[0] == 0) {
764 passwd_from_file = 1;
765 if (!get_pap_passwd(passwd))
766 error("No secret found for PAP login");
767 }
768 upap_authwithpeer(unit, user, passwd);
769 auth |= PAP_WITHPEER;
770 }
771 auth_pending[unit] = auth;
772 auth_done[unit] = 0;
773
774 if (!auth)
775 network_phase(unit);
776 }
777
778 /*
779 * Proceed to the network phase.
780 */
781 static void
network_phase(unit)782 network_phase(unit)
783 int unit;
784 {
785 lcp_options *go = &lcp_gotoptions[unit];
786
787 /* Log calling number. */
788 if (*remote_number)
789 notice("peer from calling number %q authorized", remote_number);
790
791 /*
792 * If the peer had to authenticate, run the auth-up script now.
793 */
794 if (go->neg_chap || go->neg_upap || go->neg_eap) {
795 notify(auth_up_notifier, 0);
796 auth_state = s_up;
797 if (auth_script_state == s_down && auth_script_pid == 0) {
798 auth_script_state = s_up;
799 auth_script(_PATH_AUTHUP);
800 }
801 }
802
803 #ifdef CBCP_SUPPORT
804 /*
805 * If we negotiated callback, do it now.
806 */
807 if (go->neg_cbcp) {
808 new_phase(PHASE_CALLBACK);
809 (*cbcp_protent.open)(unit);
810 return;
811 }
812 #endif
813
814 /*
815 * Process extra options from the secrets file
816 */
817 if (extra_options) {
818 options_from_list(extra_options, 1);
819 free_wordlist(extra_options);
820 extra_options = 0;
821 }
822 start_networks(unit);
823 }
824
825 void
start_networks(unit)826 start_networks(unit)
827 int unit;
828 {
829 int i;
830 struct protent *protp;
831 int ecp_required, mppe_required;
832
833 new_phase(PHASE_NETWORK);
834
835 #ifdef HAVE_MULTILINK
836 if (multilink) {
837 if (mp_join_bundle()) {
838 if (updetach && !nodetach)
839 detach();
840 return;
841 }
842 }
843 #endif /* HAVE_MULTILINK */
844
845 #ifdef PPP_FILTER
846 if (!demand)
847 set_filters(&pass_filter, &active_filter);
848 #endif
849 /* Start CCP and ECP */
850 for (i = 0; (protp = protocols[i]) != NULL; ++i)
851 if ((protp->protocol == PPP_ECP || protp->protocol == PPP_CCP)
852 && protp->enabled_flag && protp->open != NULL)
853 (*protp->open)(0);
854
855 /*
856 * Bring up other network protocols iff encryption is not required.
857 */
858 ecp_required = ecp_gotoptions[unit].required;
859 mppe_required = ccp_gotoptions[unit].mppe;
860 if (!ecp_required && !mppe_required)
861 continue_networks(unit);
862 }
863
864 void
continue_networks(unit)865 continue_networks(unit)
866 int unit;
867 {
868 int i;
869 struct protent *protp;
870
871 /*
872 * Start the "real" network protocols.
873 */
874 for (i = 0; (protp = protocols[i]) != NULL; ++i)
875 if (protp->protocol < 0xC000
876 && protp->protocol != PPP_CCP && protp->protocol != PPP_ECP
877 && protp->enabled_flag && protp->open != NULL) {
878 (*protp->open)(0);
879 ++num_np_open;
880 }
881
882 if (num_np_open == 0)
883 /* nothing to do */
884 lcp_close(0, "No network protocols running");
885 }
886
887 /*
888 * The peer has failed to authenticate himself using `protocol'.
889 */
890 void
auth_peer_fail(unit,protocol)891 auth_peer_fail(unit, protocol)
892 int unit, protocol;
893 {
894 /*
895 * Authentication failure: take the link down
896 */
897 lcp_close(unit, "Authentication failed");
898 status = EXIT_PEER_AUTH_FAILED;
899 }
900
901 /*
902 * The peer has been successfully authenticated using `protocol'.
903 */
904 void
auth_peer_success(unit,protocol,prot_flavor,name,namelen)905 auth_peer_success(unit, protocol, prot_flavor, name, namelen)
906 int unit, protocol, prot_flavor;
907 char *name;
908 int namelen;
909 {
910 int bit;
911
912 switch (protocol) {
913 case PPP_CHAP:
914 bit = CHAP_PEER;
915 switch (prot_flavor) {
916 case CHAP_MD5:
917 bit |= CHAP_MD5_PEER;
918 break;
919 #ifdef CHAPMS
920 case CHAP_MICROSOFT:
921 bit |= CHAP_MS_PEER;
922 break;
923 case CHAP_MICROSOFT_V2:
924 bit |= CHAP_MS2_PEER;
925 break;
926 #endif
927 }
928 break;
929 case PPP_PAP:
930 bit = PAP_PEER;
931 break;
932 case PPP_EAP:
933 bit = EAP_PEER;
934 break;
935 default:
936 warn("auth_peer_success: unknown protocol %x", protocol);
937 return;
938 }
939
940 /*
941 * Save the authenticated name of the peer for later.
942 */
943 if (namelen > sizeof(peer_authname) - 1)
944 namelen = sizeof(peer_authname) - 1;
945 BCOPY(name, peer_authname, namelen);
946 peer_authname[namelen] = 0;
947 script_setenv("PEERNAME", peer_authname, 0);
948
949 /* Save the authentication method for later. */
950 auth_done[unit] |= bit;
951
952 /*
953 * If there is no more authentication still to be done,
954 * proceed to the network (or callback) phase.
955 */
956 if ((auth_pending[unit] &= ~bit) == 0)
957 network_phase(unit);
958 }
959
960 /*
961 * We have failed to authenticate ourselves to the peer using `protocol'.
962 */
963 void
auth_withpeer_fail(unit,protocol)964 auth_withpeer_fail(unit, protocol)
965 int unit, protocol;
966 {
967 if (passwd_from_file)
968 BZERO(passwd, MAXSECRETLEN);
969 /*
970 * We've failed to authenticate ourselves to our peer.
971 * Some servers keep sending CHAP challenges, but there
972 * is no point in persisting without any way to get updated
973 * authentication secrets.
974 */
975 lcp_close(unit, "Failed to authenticate ourselves to peer");
976 status = EXIT_AUTH_TOPEER_FAILED;
977 }
978
979 /*
980 * We have successfully authenticated ourselves with the peer using `protocol'.
981 */
982 void
auth_withpeer_success(unit,protocol,prot_flavor)983 auth_withpeer_success(unit, protocol, prot_flavor)
984 int unit, protocol, prot_flavor;
985 {
986 int bit;
987
988 switch (protocol) {
989 case PPP_CHAP:
990 bit = CHAP_WITHPEER;
991 switch (prot_flavor) {
992 case CHAP_MD5:
993 bit |= CHAP_MD5_WITHPEER;
994 break;
995 #ifdef CHAPMS
996 case CHAP_MICROSOFT:
997 bit |= CHAP_MS_WITHPEER;
998 break;
999 case CHAP_MICROSOFT_V2:
1000 bit |= CHAP_MS2_WITHPEER;
1001 break;
1002 #endif
1003 }
1004 break;
1005 case PPP_PAP:
1006 if (passwd_from_file)
1007 BZERO(passwd, MAXSECRETLEN);
1008 bit = PAP_WITHPEER;
1009 break;
1010 case PPP_EAP:
1011 bit = EAP_WITHPEER;
1012 break;
1013 default:
1014 warn("auth_withpeer_success: unknown protocol %x", protocol);
1015 bit = 0;
1016 }
1017
1018 /* Save the authentication method for later. */
1019 auth_done[unit] |= bit;
1020
1021 /*
1022 * If there is no more authentication still being done,
1023 * proceed to the network (or callback) phase.
1024 */
1025 if ((auth_pending[unit] &= ~bit) == 0)
1026 network_phase(unit);
1027 }
1028
1029
1030 /*
1031 * np_up - a network protocol has come up.
1032 */
1033 void
np_up(unit,proto)1034 np_up(unit, proto)
1035 int unit, proto;
1036 {
1037 int tlim;
1038
1039 if (num_np_up == 0) {
1040 /*
1041 * At this point we consider that the link has come up successfully.
1042 */
1043 status = EXIT_OK;
1044 unsuccess = 0;
1045 new_phase(PHASE_RUNNING);
1046
1047 if (idle_time_hook != 0)
1048 tlim = (*idle_time_hook)(NULL);
1049 else
1050 tlim = idle_time_limit;
1051 if (tlim > 0)
1052 TIMEOUT(check_idle, NULL, tlim);
1053
1054 /*
1055 * Set a timeout to close the connection once the maximum
1056 * connect time has expired.
1057 */
1058 if (maxconnect > 0)
1059 TIMEOUT(connect_time_expired, 0, maxconnect);
1060
1061 #ifdef MAXOCTETS
1062 if (maxoctets > 0)
1063 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1064 #endif
1065
1066 /*
1067 * Detach now, if the updetach option was given.
1068 */
1069 if (updetach && !nodetach)
1070 detach();
1071 }
1072 ++num_np_up;
1073 }
1074
1075 /*
1076 * np_down - a network protocol has gone down.
1077 */
1078 void
np_down(unit,proto)1079 np_down(unit, proto)
1080 int unit, proto;
1081 {
1082 if (--num_np_up == 0) {
1083 UNTIMEOUT(check_idle, NULL);
1084 UNTIMEOUT(connect_time_expired, NULL);
1085 #ifdef MAXOCTETS
1086 UNTIMEOUT(check_maxoctets, NULL);
1087 #endif
1088 new_phase(PHASE_NETWORK);
1089 }
1090 }
1091
1092 /*
1093 * np_finished - a network protocol has finished using the link.
1094 */
1095 void
np_finished(unit,proto)1096 np_finished(unit, proto)
1097 int unit, proto;
1098 {
1099 if (--num_np_open <= 0) {
1100 /* no further use for the link: shut up shop. */
1101 lcp_close(0, "No network protocols running");
1102 }
1103 }
1104
1105 #ifdef MAXOCTETS
1106 static void
check_maxoctets(arg)1107 check_maxoctets(arg)
1108 void *arg;
1109 {
1110 int diff;
1111 unsigned int used;
1112
1113 update_link_stats(ifunit);
1114 link_stats_valid=0;
1115
1116 switch(maxoctets_dir) {
1117 case PPP_OCTETS_DIRECTION_IN:
1118 used = link_stats.bytes_in;
1119 break;
1120 case PPP_OCTETS_DIRECTION_OUT:
1121 used = link_stats.bytes_out;
1122 break;
1123 case PPP_OCTETS_DIRECTION_MAXOVERAL:
1124 case PPP_OCTETS_DIRECTION_MAXSESSION:
1125 used = (link_stats.bytes_in > link_stats.bytes_out) ? link_stats.bytes_in : link_stats.bytes_out;
1126 break;
1127 default:
1128 used = link_stats.bytes_in+link_stats.bytes_out;
1129 break;
1130 }
1131 diff = maxoctets - used;
1132 if(diff < 0) {
1133 notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used);
1134 lcp_close(0, "Traffic limit");
1135 need_holdoff = 0;
1136 status = EXIT_TRAFFIC_LIMIT;
1137 } else {
1138 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1139 }
1140 }
1141 #endif
1142
1143 /*
1144 * check_idle - check whether the link has been idle for long
1145 * enough that we can shut it down.
1146 */
1147 static void
check_idle(arg)1148 check_idle(arg)
1149 void *arg;
1150 {
1151 struct ppp_idle idle;
1152 time_t itime;
1153 int tlim;
1154
1155 if (!get_idle_time(0, &idle))
1156 return;
1157 if (idle_time_hook != 0) {
1158 tlim = idle_time_hook(&idle);
1159 } else {
1160 itime = MIN(idle.xmit_idle, idle.recv_idle);
1161 tlim = idle_time_limit - itime;
1162 }
1163 if (tlim <= 0) {
1164 /* link is idle: shut it down. */
1165 notice("Terminating connection due to lack of activity.");
1166 lcp_close(0, "Link inactive");
1167 need_holdoff = 0;
1168 status = EXIT_IDLE_TIMEOUT;
1169 } else {
1170 TIMEOUT(check_idle, NULL, tlim);
1171 }
1172 }
1173
1174 /*
1175 * connect_time_expired - log a message and close the connection.
1176 */
1177 static void
connect_time_expired(arg)1178 connect_time_expired(arg)
1179 void *arg;
1180 {
1181 info("Connect time expired");
1182 status = EXIT_CONNECT_TIME;
1183 lcp_close(0, "Connect time expired"); /* Close connection */
1184 }
1185
1186 /*
1187 * auth_check_options - called to check authentication options.
1188 */
1189 void
auth_check_options()1190 auth_check_options()
1191 {
1192 lcp_options *wo = &lcp_wantoptions[0];
1193 int can_auth;
1194 int lacks_ip;
1195
1196 /* Default our_name to hostname, and user to our_name */
1197 if (our_name[0] == 0 || usehostname)
1198 strlcpy(our_name, hostname, sizeof(our_name));
1199 if (user[0] == 0)
1200 strlcpy(user, our_name, sizeof(user));
1201
1202 /*
1203 * If we have a default route, require the peer to authenticate
1204 * unless the noauth option was given or the real user is root.
1205 */
1206 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
1207 auth_required = 1;
1208 default_auth = 1;
1209 }
1210
1211 /* If we selected any CHAP flavors, we should probably negotiate it. :-) */
1212 if (wo->chap_mdtype)
1213 wo->neg_chap = 1;
1214
1215 /* If authentication is required, ask peer for CHAP, PAP, or EAP. */
1216 if (auth_required) {
1217 allow_any_ip = 0;
1218 if (!wo->neg_chap && !wo->neg_upap && !wo->neg_eap) {
1219 wo->neg_chap = chap_mdtype_all != MDTYPE_NONE;
1220 wo->chap_mdtype = chap_mdtype_all;
1221 wo->neg_upap = 1;
1222 wo->neg_eap = 1;
1223 }
1224 } else {
1225 wo->neg_chap = 0;
1226 wo->chap_mdtype = MDTYPE_NONE;
1227 wo->neg_upap = 0;
1228 wo->neg_eap = 0;
1229 }
1230
1231 /*
1232 * Check whether we have appropriate secrets to use
1233 * to authenticate the peer. Note that EAP can authenticate by way
1234 * of a CHAP-like exchanges as well as SRP.
1235 */
1236 lacks_ip = 0;
1237 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
1238 if (!can_auth && (wo->neg_chap || wo->neg_eap)) {
1239 can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
1240 our_name, 1, &lacks_ip);
1241 }
1242 if (!can_auth && wo->neg_eap) {
1243 can_auth = have_srp_secret((explicit_remote? remote_name: NULL),
1244 our_name, 1, &lacks_ip);
1245 }
1246
1247 if (auth_required && !can_auth && noauth_addrs == NULL) {
1248 if (default_auth) {
1249 option_error(
1250 "By default the remote system is required to authenticate itself");
1251 option_error(
1252 "(because this system has a default route to the internet)");
1253 } else if (explicit_remote)
1254 option_error(
1255 "The remote system (%s) is required to authenticate itself",
1256 remote_name);
1257 else
1258 option_error(
1259 "The remote system is required to authenticate itself");
1260 option_error(
1261 "but I couldn't find any suitable secret (password) for it to use to do so.");
1262 if (lacks_ip)
1263 option_error(
1264 "(None of the available passwords would let it use an IP address.)");
1265
1266 exit(1);
1267 }
1268
1269 /*
1270 * Early check for remote number authorization.
1271 */
1272 if (!auth_number()) {
1273 warn("calling number %q is not authorized", remote_number);
1274 exit(EXIT_CNID_AUTH_FAILED);
1275 }
1276 }
1277
1278 /*
1279 * auth_reset - called when LCP is starting negotiations to recheck
1280 * authentication options, i.e. whether we have appropriate secrets
1281 * to use for authenticating ourselves and/or the peer.
1282 */
1283 void
auth_reset(unit)1284 auth_reset(unit)
1285 int unit;
1286 {
1287 lcp_options *go = &lcp_gotoptions[unit];
1288 lcp_options *ao = &lcp_allowoptions[unit];
1289 int hadchap;
1290
1291 hadchap = -1;
1292 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
1293 ao->neg_chap = (!refuse_chap || !refuse_mschap || !refuse_mschap_v2)
1294 && (passwd[0] != 0 ||
1295 (hadchap = have_chap_secret(user, (explicit_remote? remote_name:
1296 NULL), 0, NULL)));
1297 ao->neg_eap = !refuse_eap && (
1298 passwd[0] != 0 ||
1299 (hadchap == 1 || (hadchap == -1 && have_chap_secret(user,
1300 (explicit_remote? remote_name: NULL), 0, NULL))) ||
1301 have_srp_secret(user, (explicit_remote? remote_name: NULL), 0, NULL));
1302
1303 hadchap = -1;
1304 if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
1305 go->neg_upap = 0;
1306 if (go->neg_chap) {
1307 if (!(hadchap = have_chap_secret((explicit_remote? remote_name: NULL),
1308 our_name, 1, NULL)))
1309 go->neg_chap = 0;
1310 }
1311 if (go->neg_eap &&
1312 (hadchap == 0 || (hadchap == -1 &&
1313 !have_chap_secret((explicit_remote? remote_name: NULL), our_name,
1314 1, NULL))) &&
1315 !have_srp_secret((explicit_remote? remote_name: NULL), our_name, 1,
1316 NULL))
1317 go->neg_eap = 0;
1318 }
1319
1320
1321 /*
1322 * check_passwd - Check the user name and passwd against the PAP secrets
1323 * file. If requested, also check against the system password database,
1324 * and login the user if OK.
1325 *
1326 * returns:
1327 * UPAP_AUTHNAK: Authentication failed.
1328 * UPAP_AUTHACK: Authentication succeeded.
1329 * In either case, msg points to an appropriate message.
1330 */
1331 int
check_passwd(unit,auser,userlen,apasswd,passwdlen,msg)1332 check_passwd(unit, auser, userlen, apasswd, passwdlen, msg)
1333 int unit;
1334 char *auser;
1335 int userlen;
1336 char *apasswd;
1337 int passwdlen;
1338 char **msg;
1339 {
1340 #if 1
1341 return UPAP_AUTHNAK;
1342 #else
1343 int ret;
1344 char *filename;
1345 FILE *f;
1346 struct wordlist *addrs = NULL, *opts = NULL;
1347 char passwd[256], user[256];
1348 char secret[MAXWORDLEN];
1349 static int attempts = 0;
1350
1351 /*
1352 * Make copies of apasswd and auser, then null-terminate them.
1353 * If there are unprintable characters in the password, make
1354 * them visible.
1355 */
1356 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
1357 slprintf(user, sizeof(user), "%.*v", userlen, auser);
1358 *msg = "";
1359
1360 /*
1361 * Check if a plugin wants to handle this.
1362 */
1363 if (pap_auth_hook) {
1364 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
1365 if (ret >= 0) {
1366 /* note: set_allowed_addrs() saves opts (but not addrs):
1367 don't free it! */
1368 if (ret)
1369 set_allowed_addrs(unit, addrs, opts);
1370 else if (opts != 0)
1371 free_wordlist(opts);
1372 if (addrs != 0)
1373 free_wordlist(addrs);
1374 BZERO(passwd, sizeof(passwd));
1375 return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
1376 }
1377 }
1378
1379 /*
1380 * Open the file of pap secrets and scan for a suitable secret
1381 * for authenticating this user.
1382 */
1383 filename = _PATH_UPAPFILE;
1384 addrs = opts = NULL;
1385 ret = UPAP_AUTHNAK;
1386 f = fopen(filename, "r");
1387 if (f == NULL) {
1388 error("Can't open PAP password file %s: %m", filename);
1389
1390 } else {
1391 check_access(f, filename);
1392 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename, 0) < 0) {
1393 warn("no PAP secret found for %s", user);
1394 } else {
1395 /*
1396 * If the secret is "@login", it means to check
1397 * the password against the login database.
1398 */
1399 int login_secret = strcmp(secret, "@login") == 0;
1400 ret = UPAP_AUTHACK;
1401 if (uselogin || login_secret) {
1402 /* login option or secret is @login */
1403 if ((ret = plogin(user, passwd, msg)) == UPAP_AUTHACK)
1404 used_login = 1;
1405 }
1406 if (secret[0] != 0 && !login_secret) {
1407 /* password given in pap-secrets - must match */
1408 if ((cryptpap || strcmp(passwd, secret) != 0)
1409 && strcmp(crypt(passwd, secret), secret) != 0)
1410 ret = UPAP_AUTHNAK;
1411 }
1412 }
1413 fclose(f);
1414 }
1415
1416 if (ret == UPAP_AUTHNAK) {
1417 if (**msg == 0)
1418 *msg = "Login incorrect";
1419 /*
1420 * XXX can we ever get here more than once??
1421 * Frustrate passwd stealer programs.
1422 * Allow 10 tries, but start backing off after 3 (stolen from login).
1423 * On 10'th, drop the connection.
1424 */
1425 if (attempts++ >= 10) {
1426 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
1427 lcp_close(unit, "login failed");
1428 }
1429 if (attempts > 3)
1430 sleep((u_int) (attempts - 3) * 5);
1431 if (opts != NULL)
1432 free_wordlist(opts);
1433
1434 } else {
1435 attempts = 0; /* Reset count */
1436 if (**msg == 0)
1437 *msg = "Login ok";
1438 set_allowed_addrs(unit, addrs, opts);
1439 }
1440
1441 if (addrs != NULL)
1442 free_wordlist(addrs);
1443 BZERO(passwd, sizeof(passwd));
1444 BZERO(secret, sizeof(secret));
1445
1446 return ret;
1447 #endif
1448 }
1449
1450 /*
1451 * This function is needed for PAM.
1452 */
1453
1454 #ifdef USE_PAM
1455 /* Static variables used to communicate between the conversation function
1456 * and the server_login function
1457 */
1458 static char *PAM_username;
1459 static char *PAM_password;
1460 static int PAM_error = 0;
1461 static pam_handle_t *pamh = NULL;
1462
1463 /* PAM conversation function
1464 * Here we assume (for now, at least) that echo on means login name, and
1465 * echo off means password.
1466 */
1467
PAM_conv(int num_msg,const struct pam_message ** msg,struct pam_response ** resp,void * appdata_ptr)1468 static int PAM_conv (int num_msg,
1469 #ifndef SOL2
1470 const
1471 #endif
1472 struct pam_message **msg,
1473 struct pam_response **resp, void *appdata_ptr)
1474 {
1475 int replies = 0;
1476 struct pam_response *reply = NULL;
1477
1478 #define COPY_STRING(s) (s) ? strdup(s) : NULL
1479
1480 reply = malloc(sizeof(struct pam_response) * num_msg);
1481 if (!reply) return PAM_CONV_ERR;
1482
1483 for (replies = 0; replies < num_msg; replies++) {
1484 switch (msg[replies]->msg_style) {
1485 case PAM_PROMPT_ECHO_ON:
1486 reply[replies].resp_retcode = PAM_SUCCESS;
1487 reply[replies].resp = COPY_STRING(PAM_username);
1488 /* PAM frees resp */
1489 break;
1490 case PAM_PROMPT_ECHO_OFF:
1491 reply[replies].resp_retcode = PAM_SUCCESS;
1492 reply[replies].resp = COPY_STRING(PAM_password);
1493 /* PAM frees resp */
1494 break;
1495 case PAM_TEXT_INFO:
1496 /* fall through */
1497 case PAM_ERROR_MSG:
1498 /* ignore it, but pam still wants a NULL response... */
1499 reply[replies].resp_retcode = PAM_SUCCESS;
1500 reply[replies].resp = NULL;
1501 break;
1502 default:
1503 /* Must be an error of some sort... */
1504 free (reply);
1505 PAM_error = 1;
1506 return PAM_CONV_ERR;
1507 }
1508 }
1509 *resp = reply;
1510 return PAM_SUCCESS;
1511 }
1512
1513 static struct pam_conv PAM_conversation = {
1514 &PAM_conv,
1515 NULL
1516 };
1517 #endif /* USE_PAM */
1518
1519 /*
1520 * plogin - Check the user name and password against the system
1521 * password database, and login the user if OK.
1522 *
1523 * returns:
1524 * UPAP_AUTHNAK: Login failed.
1525 * UPAP_AUTHACK: Login succeeded.
1526 * In either case, msg points to an appropriate message.
1527 */
1528
1529 static int
plogin(user,passwd,msg)1530 plogin(user, passwd, msg)
1531 char *user;
1532 char *passwd;
1533 char **msg;
1534 {
1535 char *tty;
1536
1537 #if 1
1538 return UPAP_AUTHNAK;
1539 #else
1540 #ifdef USE_PAM
1541 int pam_error;
1542
1543 pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh);
1544 if (pam_error != PAM_SUCCESS) {
1545 *msg = (char *) pam_strerror (pamh, pam_error);
1546 reopen_log();
1547 return UPAP_AUTHNAK;
1548 }
1549 /*
1550 * Define the fields for the credential validation
1551 */
1552
1553 PAM_username = user;
1554 PAM_password = passwd;
1555 PAM_error = 0;
1556 pam_set_item (pamh, PAM_TTY, devnam); /* this might be useful to some modules */
1557
1558 /*
1559 * Validate the user
1560 */
1561 pam_error = pam_authenticate (pamh, PAM_SILENT);
1562 if (pam_error == PAM_SUCCESS && !PAM_error) {
1563 pam_error = pam_acct_mgmt (pamh, PAM_SILENT);
1564 if (pam_error == PAM_SUCCESS)
1565 pam_error = pam_open_session (pamh, PAM_SILENT);
1566 }
1567
1568 *msg = (char *) pam_strerror (pamh, pam_error);
1569
1570 /*
1571 * Clean up the mess
1572 */
1573 reopen_log(); /* apparently the PAM stuff does closelog() */
1574 PAM_username = NULL;
1575 PAM_password = NULL;
1576 if (pam_error != PAM_SUCCESS)
1577 return UPAP_AUTHNAK;
1578 #else /* #ifdef USE_PAM */
1579
1580 /*
1581 * Use the non-PAM methods directly
1582 */
1583
1584 #ifdef HAS_SHADOW
1585 struct spwd *spwd;
1586 struct spwd *getspnam();
1587 #endif
1588 struct passwd *pw = getpwnam(user);
1589
1590 endpwent();
1591 if (pw == NULL)
1592 return (UPAP_AUTHNAK);
1593
1594 #ifdef HAS_SHADOW
1595 spwd = getspnam(user);
1596 endspent();
1597 if (spwd) {
1598 /* check the age of the password entry */
1599 long now = time(NULL) / 86400L;
1600
1601 if ((spwd->sp_expire > 0 && now >= spwd->sp_expire)
1602 || ((spwd->sp_max >= 0 && spwd->sp_max < 10000)
1603 && spwd->sp_lstchg >= 0
1604 && now >= spwd->sp_lstchg + spwd->sp_max)) {
1605 warn("Password for %s has expired", user);
1606 return (UPAP_AUTHNAK);
1607 }
1608 pw->pw_passwd = spwd->sp_pwdp;
1609 }
1610 #endif
1611
1612 /*
1613 * If no passwd, don't let them login.
1614 */
1615 if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2
1616 || strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0)
1617 return (UPAP_AUTHNAK);
1618
1619 #endif /* #ifdef USE_PAM */
1620
1621 /*
1622 * Write a wtmp entry for this user.
1623 */
1624
1625 tty = devnam;
1626 if (strncmp(tty, "/dev/", 5) == 0)
1627 tty += 5;
1628 logwtmp(tty, user, ifname); /* Add wtmp login entry */
1629
1630 #if defined(_PATH_LASTLOG) && !defined(USE_PAM)
1631 if (pw != (struct passwd *)NULL) {
1632 struct lastlog ll;
1633 int fd;
1634
1635 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
1636 (void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET);
1637 memset((void *)&ll, 0, sizeof(ll));
1638 (void)time(&ll.ll_time);
1639 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
1640 (void)write(fd, (char *)&ll, sizeof(ll));
1641 (void)close(fd);
1642 }
1643 }
1644 #endif /* _PATH_LASTLOG and not USE_PAM */
1645
1646 info("user %s logged in", user);
1647 logged_in = 1;
1648
1649 return (UPAP_AUTHACK);
1650 #endif
1651 }
1652
1653 /*
1654 * plogout - Logout the user.
1655 */
1656 static void
plogout()1657 plogout()
1658 {
1659 #ifdef USE_PAM
1660 int pam_error;
1661
1662 if (pamh != NULL) {
1663 pam_error = pam_close_session (pamh, PAM_SILENT);
1664 pam_end (pamh, pam_error);
1665 pamh = NULL;
1666 }
1667 /* Apparently the pam stuff does closelog(). */
1668 reopen_log();
1669 #else /* ! USE_PAM */
1670 char *tty;
1671
1672 tty = devnam;
1673 if (strncmp(tty, "/dev/", 5) == 0)
1674 tty += 5;
1675 logwtmp(tty, "", ""); /* Wipe out utmp logout entry */
1676 #endif /* ! USE_PAM */
1677 logged_in = 0;
1678 }
1679
1680
1681 /*
1682 * null_login - Check if a username of "" and a password of "" are
1683 * acceptable, and iff so, set the list of acceptable IP addresses
1684 * and return 1.
1685 */
1686 static int
null_login(unit)1687 null_login(unit)
1688 int unit;
1689 {
1690 char *filename;
1691 FILE *f;
1692 int i, ret;
1693 struct wordlist *addrs, *opts;
1694 char secret[MAXWORDLEN];
1695
1696 /*
1697 * Check if a plugin wants to handle this.
1698 */
1699 ret = -1;
1700 if (null_auth_hook)
1701 ret = (*null_auth_hook)(&addrs, &opts);
1702
1703 /*
1704 * Open the file of pap secrets and scan for a suitable secret.
1705 */
1706 if (ret <= 0) {
1707 filename = _PATH_UPAPFILE;
1708 addrs = NULL;
1709 f = fopen(filename, "r");
1710 if (f == NULL)
1711 return 0;
1712 check_access(f, filename);
1713
1714 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename, 0);
1715 ret = i >= 0 && secret[0] == 0;
1716 BZERO(secret, sizeof(secret));
1717 fclose(f);
1718 }
1719
1720 if (ret)
1721 set_allowed_addrs(unit, addrs, opts);
1722 else if (opts != 0)
1723 free_wordlist(opts);
1724 if (addrs != 0)
1725 free_wordlist(addrs);
1726
1727 return ret;
1728 }
1729
1730
1731 /*
1732 * get_pap_passwd - get a password for authenticating ourselves with
1733 * our peer using PAP. Returns 1 on success, 0 if no suitable password
1734 * could be found.
1735 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1736 */
1737 static int
get_pap_passwd(passwd)1738 get_pap_passwd(passwd)
1739 char *passwd;
1740 {
1741 char *filename;
1742 FILE *f;
1743 int ret;
1744 char secret[MAXWORDLEN];
1745
1746 /*
1747 * Check whether a plugin wants to supply this.
1748 */
1749 if (pap_passwd_hook) {
1750 ret = (*pap_passwd_hook)(user, passwd);
1751 if (ret >= 0)
1752 return ret;
1753 }
1754
1755 filename = _PATH_UPAPFILE;
1756 f = fopen(filename, "r");
1757 if (f == NULL)
1758 return 0;
1759 check_access(f, filename);
1760 ret = scan_authfile(f, user,
1761 (remote_name[0]? remote_name: NULL),
1762 secret, NULL, NULL, filename, 0);
1763 fclose(f);
1764 if (ret < 0)
1765 return 0;
1766 if (passwd != NULL)
1767 strlcpy(passwd, secret, MAXSECRETLEN);
1768 BZERO(secret, sizeof(secret));
1769 return 1;
1770 }
1771
1772
1773 /*
1774 * have_pap_secret - check whether we have a PAP file with any
1775 * secrets that we could possibly use for authenticating the peer.
1776 */
1777 static int
have_pap_secret(lacks_ipp)1778 have_pap_secret(lacks_ipp)
1779 int *lacks_ipp;
1780 {
1781 FILE *f;
1782 int ret;
1783 char *filename;
1784 struct wordlist *addrs;
1785
1786 /* let the plugin decide, if there is one */
1787 if (pap_check_hook) {
1788 ret = (*pap_check_hook)();
1789 if (ret >= 0)
1790 return ret;
1791 }
1792
1793 filename = _PATH_UPAPFILE;
1794 f = fopen(filename, "r");
1795 if (f == NULL)
1796 return 0;
1797
1798 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1799 NULL, &addrs, NULL, filename, 0);
1800 fclose(f);
1801 if (ret >= 0 && !some_ip_ok(addrs)) {
1802 if (lacks_ipp != 0)
1803 *lacks_ipp = 1;
1804 ret = -1;
1805 }
1806 if (addrs != 0)
1807 free_wordlist(addrs);
1808
1809 return ret >= 0;
1810 }
1811
1812
1813 /*
1814 * have_chap_secret - check whether we have a CHAP file with a
1815 * secret that we could possibly use for authenticating `client'
1816 * on `server'. Either can be the null string, meaning we don't
1817 * know the identity yet.
1818 */
1819 static int
have_chap_secret(client,server,need_ip,lacks_ipp)1820 have_chap_secret(client, server, need_ip, lacks_ipp)
1821 char *client;
1822 char *server;
1823 int need_ip;
1824 int *lacks_ipp;
1825 {
1826 FILE *f;
1827 int ret;
1828 char *filename;
1829 struct wordlist *addrs;
1830
1831 if (chap_check_hook) {
1832 ret = (*chap_check_hook)();
1833 if (ret >= 0) {
1834 return ret;
1835 }
1836 }
1837
1838 filename = _PATH_CHAPFILE;
1839 f = fopen(filename, "r");
1840 if (f == NULL)
1841 return 0;
1842
1843 if (client != NULL && client[0] == 0)
1844 client = NULL;
1845 else if (server != NULL && server[0] == 0)
1846 server = NULL;
1847
1848 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1849 fclose(f);
1850 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1851 if (lacks_ipp != 0)
1852 *lacks_ipp = 1;
1853 ret = -1;
1854 }
1855 if (addrs != 0)
1856 free_wordlist(addrs);
1857
1858 return ret >= 0;
1859 }
1860
1861
1862 /*
1863 * have_srp_secret - check whether we have a SRP file with a
1864 * secret that we could possibly use for authenticating `client'
1865 * on `server'. Either can be the null string, meaning we don't
1866 * know the identity yet.
1867 */
1868 static int
have_srp_secret(client,server,need_ip,lacks_ipp)1869 have_srp_secret(client, server, need_ip, lacks_ipp)
1870 char *client;
1871 char *server;
1872 int need_ip;
1873 int *lacks_ipp;
1874 {
1875 FILE *f;
1876 int ret;
1877 char *filename;
1878 struct wordlist *addrs;
1879
1880 filename = _PATH_SRPFILE;
1881 f = fopen(filename, "r");
1882 if (f == NULL)
1883 return 0;
1884
1885 if (client != NULL && client[0] == 0)
1886 client = NULL;
1887 else if (server != NULL && server[0] == 0)
1888 server = NULL;
1889
1890 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1891 fclose(f);
1892 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1893 if (lacks_ipp != 0)
1894 *lacks_ipp = 1;
1895 ret = -1;
1896 }
1897 if (addrs != 0)
1898 free_wordlist(addrs);
1899
1900 return ret >= 0;
1901 }
1902
1903
1904 /*
1905 * get_secret - open the CHAP secret file and return the secret
1906 * for authenticating the given client on the given server.
1907 * (We could be either client or server).
1908 */
1909 int
get_secret(unit,client,server,secret,secret_len,am_server)1910 get_secret(unit, client, server, secret, secret_len, am_server)
1911 int unit;
1912 char *client;
1913 char *server;
1914 char *secret;
1915 int *secret_len;
1916 int am_server;
1917 {
1918 FILE *f;
1919 int ret, len;
1920 char *filename;
1921 struct wordlist *addrs, *opts;
1922 char secbuf[MAXWORDLEN];
1923
1924 if (!am_server && passwd[0] != 0) {
1925 strlcpy(secbuf, passwd, sizeof(secbuf));
1926 } else if (!am_server && chap_passwd_hook) {
1927 if ( (*chap_passwd_hook)(client, secbuf) < 0) {
1928 error("Unable to obtain CHAP password for %s on %s from plugin",
1929 client, server);
1930 return 0;
1931 }
1932 } else {
1933 filename = _PATH_CHAPFILE;
1934 addrs = NULL;
1935 secbuf[0] = 0;
1936
1937 f = fopen(filename, "r");
1938 if (f == NULL) {
1939 error("Can't open chap secret file %s: %m", filename);
1940 return 0;
1941 }
1942 check_access(f, filename);
1943
1944 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename, 0);
1945 fclose(f);
1946 if (ret < 0)
1947 return 0;
1948
1949 if (am_server)
1950 set_allowed_addrs(unit, addrs, opts);
1951 else if (opts != 0)
1952 free_wordlist(opts);
1953 if (addrs != 0)
1954 free_wordlist(addrs);
1955 }
1956
1957 len = strlen(secbuf);
1958 if (len > MAXSECRETLEN) {
1959 error("Secret for %s on %s is too long", client, server);
1960 len = MAXSECRETLEN;
1961 }
1962 BCOPY(secbuf, secret, len);
1963 BZERO(secbuf, sizeof(secbuf));
1964 *secret_len = len;
1965
1966 return 1;
1967 }
1968
1969
1970 /*
1971 * get_srp_secret - open the SRP secret file and return the secret
1972 * for authenticating the given client on the given server.
1973 * (We could be either client or server).
1974 */
1975 int
get_srp_secret(unit,client,server,secret,am_server)1976 get_srp_secret(unit, client, server, secret, am_server)
1977 int unit;
1978 char *client;
1979 char *server;
1980 char *secret;
1981 int am_server;
1982 {
1983 FILE *fp;
1984 int ret;
1985 char *filename;
1986 struct wordlist *addrs, *opts;
1987
1988 if (!am_server && passwd[0] != '\0') {
1989 strlcpy(secret, passwd, MAXWORDLEN);
1990 } else {
1991 filename = _PATH_SRPFILE;
1992 addrs = NULL;
1993
1994 fp = fopen(filename, "r");
1995 if (fp == NULL) {
1996 error("Can't open srp secret file %s: %m", filename);
1997 return 0;
1998 }
1999 check_access(fp, filename);
2000
2001 secret[0] = '\0';
2002 ret = scan_authfile(fp, client, server, secret, &addrs, &opts,
2003 filename, am_server);
2004 fclose(fp);
2005 if (ret < 0)
2006 return 0;
2007
2008 if (am_server)
2009 set_allowed_addrs(unit, addrs, opts);
2010 else if (opts != NULL)
2011 free_wordlist(opts);
2012 if (addrs != NULL)
2013 free_wordlist(addrs);
2014 }
2015
2016 return 1;
2017 }
2018
2019 /*
2020 * set_allowed_addrs() - set the list of allowed addresses.
2021 * Also looks for `--' indicating options to apply for this peer
2022 * and leaves the following words in extra_options.
2023 */
2024 static void
set_allowed_addrs(unit,addrs,opts)2025 set_allowed_addrs(unit, addrs, opts)
2026 int unit;
2027 struct wordlist *addrs;
2028 struct wordlist *opts;
2029 {
2030 int n;
2031 struct wordlist *ap, **plink;
2032 struct permitted_ip *ip;
2033 char *ptr_word, *ptr_mask;
2034 struct hostent *hp;
2035 struct netent *np;
2036 u_int32_t a, mask, ah, offset;
2037 struct ipcp_options *wo = &ipcp_wantoptions[unit];
2038 u_int32_t suggested_ip = 0;
2039
2040 if (addresses[unit] != NULL)
2041 free(addresses[unit]);
2042 addresses[unit] = NULL;
2043 if (extra_options != NULL)
2044 free_wordlist(extra_options);
2045 extra_options = opts;
2046
2047 /*
2048 * Count the number of IP addresses given.
2049 */
2050 n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
2051 if (n == 0)
2052 return;
2053 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
2054 if (ip == 0)
2055 return;
2056
2057 /* temporarily append the noauth_addrs list to addrs */
2058 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
2059 ;
2060 *plink = noauth_addrs;
2061
2062 n = 0;
2063 for (ap = addrs; ap != NULL; ap = ap->next) {
2064 /* "-" means no addresses authorized, "*" means any address allowed */
2065 ptr_word = ap->word;
2066 if (strcmp(ptr_word, "-") == 0)
2067 break;
2068 if (strcmp(ptr_word, "*") == 0) {
2069 ip[n].permit = 1;
2070 ip[n].base = ip[n].mask = 0;
2071 ++n;
2072 break;
2073 }
2074
2075 ip[n].permit = 1;
2076 if (*ptr_word == '!') {
2077 ip[n].permit = 0;
2078 ++ptr_word;
2079 }
2080
2081 mask = ~ (u_int32_t) 0;
2082 offset = 0;
2083 ptr_mask = strchr (ptr_word, '/');
2084 if (ptr_mask != NULL) {
2085 int bit_count;
2086 char *endp;
2087
2088 bit_count = (int) strtol (ptr_mask+1, &endp, 10);
2089 if (bit_count <= 0 || bit_count > 32) {
2090 warn("invalid address length %v in auth. address list",
2091 ptr_mask+1);
2092 continue;
2093 }
2094 bit_count = 32 - bit_count; /* # bits in host part */
2095 if (*endp == '+') {
2096 offset = ifunit + 1;
2097 ++endp;
2098 }
2099 if (*endp != 0) {
2100 warn("invalid address length syntax: %v", ptr_mask+1);
2101 continue;
2102 }
2103 *ptr_mask = '\0';
2104 mask <<= bit_count;
2105 }
2106
2107 hp = gethostbyname(ptr_word);
2108 if (hp != NULL && hp->h_addrtype == AF_INET) {
2109 a = *(u_int32_t *)hp->h_addr;
2110 } else {
2111 np = getnetbyname (ptr_word);
2112 if (np != NULL && np->n_addrtype == AF_INET) {
2113 a = htonl ((u_int32_t)np->n_net);
2114 if (ptr_mask == NULL) {
2115 /* calculate appropriate mask for net */
2116 ah = ntohl(a);
2117 if (IN_CLASSA(ah))
2118 mask = IN_CLASSA_NET;
2119 else if (IN_CLASSB(ah))
2120 mask = IN_CLASSB_NET;
2121 else if (IN_CLASSC(ah))
2122 mask = IN_CLASSC_NET;
2123 }
2124 } else {
2125 a = inet_addr (ptr_word);
2126 }
2127 }
2128
2129 if (ptr_mask != NULL)
2130 *ptr_mask = '/';
2131
2132 if (a == (u_int32_t)-1L) {
2133 warn("unknown host %s in auth. address list", ap->word);
2134 continue;
2135 }
2136 if (offset != 0) {
2137 if (offset >= ~mask) {
2138 warn("interface unit %d too large for subnet %v",
2139 ifunit, ptr_word);
2140 continue;
2141 }
2142 a = htonl((ntohl(a) & mask) + offset);
2143 mask = ~(u_int32_t)0;
2144 }
2145 ip[n].mask = htonl(mask);
2146 ip[n].base = a & ip[n].mask;
2147 ++n;
2148 if (~mask == 0 && suggested_ip == 0)
2149 suggested_ip = a;
2150 }
2151 *plink = NULL;
2152
2153 ip[n].permit = 0; /* make the last entry forbid all addresses */
2154 ip[n].base = 0; /* to terminate the list */
2155 ip[n].mask = 0;
2156
2157 addresses[unit] = ip;
2158
2159 /*
2160 * If the address given for the peer isn't authorized, or if
2161 * the user hasn't given one, AND there is an authorized address
2162 * which is a single host, then use that if we find one.
2163 */
2164 if (suggested_ip != 0
2165 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
2166 wo->hisaddr = suggested_ip;
2167 /*
2168 * Do we insist on this address? No, if there are other
2169 * addresses authorized than the suggested one.
2170 */
2171 if (n > 1)
2172 wo->accept_remote = 1;
2173 }
2174 }
2175
2176 /*
2177 * auth_ip_addr - check whether the peer is authorized to use
2178 * a given IP address. Returns 1 if authorized, 0 otherwise.
2179 */
2180 int
auth_ip_addr(unit,addr)2181 auth_ip_addr(unit, addr)
2182 int unit;
2183 u_int32_t addr;
2184 {
2185 int ok;
2186
2187 /* don't allow loopback or multicast address */
2188 if (bad_ip_adrs(addr))
2189 return 0;
2190
2191 if (allowed_address_hook) {
2192 ok = allowed_address_hook(addr);
2193 if (ok >= 0) return ok;
2194 }
2195
2196 if (addresses[unit] != NULL) {
2197 ok = ip_addr_check(addr, addresses[unit]);
2198 if (ok >= 0)
2199 return ok;
2200 }
2201
2202 if (auth_required)
2203 return 0; /* no addresses authorized */
2204 return allow_any_ip || privileged || !have_route_to(addr);
2205 }
2206
2207 static int
ip_addr_check(addr,addrs)2208 ip_addr_check(addr, addrs)
2209 u_int32_t addr;
2210 struct permitted_ip *addrs;
2211 {
2212 for (; ; ++addrs)
2213 if ((addr & addrs->mask) == addrs->base)
2214 return addrs->permit;
2215 }
2216
2217 /*
2218 * bad_ip_adrs - return 1 if the IP address is one we don't want
2219 * to use, such as an address in the loopback net or a multicast address.
2220 * addr is in network byte order.
2221 */
2222 int
bad_ip_adrs(addr)2223 bad_ip_adrs(addr)
2224 u_int32_t addr;
2225 {
2226 addr = ntohl(addr);
2227 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
2228 || IN_MULTICAST(addr) || IN_BADCLASS(addr);
2229 }
2230
2231 /*
2232 * some_ip_ok - check a wordlist to see if it authorizes any
2233 * IP address(es).
2234 */
2235 static int
some_ip_ok(addrs)2236 some_ip_ok(addrs)
2237 struct wordlist *addrs;
2238 {
2239 for (; addrs != 0; addrs = addrs->next) {
2240 if (addrs->word[0] == '-')
2241 break;
2242 if (addrs->word[0] != '!')
2243 return 1; /* some IP address is allowed */
2244 }
2245 return 0;
2246 }
2247
2248 /*
2249 * auth_number - check whether the remote number is allowed to connect.
2250 * Returns 1 if authorized, 0 otherwise.
2251 */
2252 int
auth_number()2253 auth_number()
2254 {
2255 struct wordlist *wp = permitted_numbers;
2256 int l;
2257
2258 /* Allow all if no authorization list. */
2259 if (!wp)
2260 return 1;
2261
2262 /* Allow if we have a match in the authorization list. */
2263 while (wp) {
2264 /* trailing '*' wildcard */
2265 l = strlen(wp->word);
2266 if ((wp->word)[l - 1] == '*')
2267 l--;
2268 if (!strncasecmp(wp->word, remote_number, l))
2269 return 1;
2270 wp = wp->next;
2271 }
2272
2273 return 0;
2274 }
2275
2276 /*
2277 * check_access - complain if a secret file has too-liberal permissions.
2278 */
2279 static void
check_access(f,filename)2280 check_access(f, filename)
2281 FILE *f;
2282 char *filename;
2283 {
2284 struct stat sbuf;
2285
2286 if (fstat(fileno(f), &sbuf) < 0) {
2287 warn("cannot stat secret file %s: %m", filename);
2288 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
2289 warn("Warning - secret file %s has world and/or group access",
2290 filename);
2291 }
2292 }
2293
2294
2295 /*
2296 * scan_authfile - Scan an authorization file for a secret suitable
2297 * for authenticating `client' on `server'. The return value is -1
2298 * if no secret is found, otherwise >= 0. The return value has
2299 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
2300 * NONWILD_SERVER set if the secret didn't have "*" for the server.
2301 * Any following words on the line up to a "--" (i.e. address authorization
2302 * info) are placed in a wordlist and returned in *addrs. Any
2303 * following words (extra options) are placed in a wordlist and
2304 * returned in *opts.
2305 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
2306 * Flags are non-zero if we need two colons in the secret in order to
2307 * match.
2308 */
2309 static int
scan_authfile(f,client,server,secret,addrs,opts,filename,flags)2310 scan_authfile(f, client, server, secret, addrs, opts, filename, flags)
2311 FILE *f;
2312 char *client;
2313 char *server;
2314 char *secret;
2315 struct wordlist **addrs;
2316 struct wordlist **opts;
2317 char *filename;
2318 int flags;
2319 {
2320 int newline, xxx;
2321 int got_flag, best_flag;
2322 FILE *sf;
2323 struct wordlist *ap, *addr_list, *alist, **app;
2324 char word[MAXWORDLEN];
2325 char atfile[MAXWORDLEN];
2326 char lsecret[MAXWORDLEN];
2327 char *cp;
2328
2329 if (addrs != NULL)
2330 *addrs = NULL;
2331 if (opts != NULL)
2332 *opts = NULL;
2333 addr_list = NULL;
2334 if (!getword(f, word, &newline, filename))
2335 return -1; /* file is empty??? */
2336 newline = 1;
2337 best_flag = -1;
2338 for (;;) {
2339 /*
2340 * Skip until we find a word at the start of a line.
2341 */
2342 while (!newline && getword(f, word, &newline, filename))
2343 ;
2344 if (!newline)
2345 break; /* got to end of file */
2346
2347 /*
2348 * Got a client - check if it's a match or a wildcard.
2349 */
2350 got_flag = 0;
2351 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
2352 newline = 0;
2353 continue;
2354 }
2355 if (!ISWILD(word))
2356 got_flag = NONWILD_CLIENT;
2357
2358 /*
2359 * Now get a server and check if it matches.
2360 */
2361 if (!getword(f, word, &newline, filename))
2362 break;
2363 if (newline)
2364 continue;
2365 if (!ISWILD(word)) {
2366 if (server != NULL && strcmp(word, server) != 0)
2367 continue;
2368 got_flag |= NONWILD_SERVER;
2369 }
2370
2371 /*
2372 * Got some sort of a match - see if it's better than what
2373 * we have already.
2374 */
2375 if (got_flag <= best_flag)
2376 continue;
2377
2378 /*
2379 * Get the secret.
2380 */
2381 if (!getword(f, word, &newline, filename))
2382 break;
2383 if (newline)
2384 continue;
2385
2386 /*
2387 * SRP-SHA1 authenticator should never be reading secrets from
2388 * a file. (Authenticatee may, though.)
2389 */
2390 if (flags && ((cp = strchr(word, ':')) == NULL ||
2391 strchr(cp + 1, ':') == NULL))
2392 continue;
2393
2394 if (secret != NULL) {
2395 /*
2396 * Special syntax: @/pathname means read secret from file.
2397 */
2398 if (word[0] == '@' && word[1] == '/') {
2399 strlcpy(atfile, word+1, sizeof(atfile));
2400 if ((sf = fopen(atfile, "r")) == NULL) {
2401 warn("can't open indirect secret file %s", atfile);
2402 continue;
2403 }
2404 check_access(sf, atfile);
2405 if (!getword(sf, word, &xxx, atfile)) {
2406 warn("no secret in indirect secret file %s", atfile);
2407 fclose(sf);
2408 continue;
2409 }
2410 fclose(sf);
2411 }
2412 strlcpy(lsecret, word, sizeof(lsecret));
2413 }
2414
2415 /*
2416 * Now read address authorization info and make a wordlist.
2417 */
2418 app = &alist;
2419 for (;;) {
2420 if (!getword(f, word, &newline, filename) || newline)
2421 break;
2422 ap = (struct wordlist *)
2423 malloc(sizeof(struct wordlist) + strlen(word) + 1);
2424 if (ap == NULL)
2425 novm("authorized addresses");
2426 ap->word = (char *) (ap + 1);
2427 strcpy(ap->word, word);
2428 *app = ap;
2429 app = &ap->next;
2430 }
2431 *app = NULL;
2432
2433 /*
2434 * This is the best so far; remember it.
2435 */
2436 best_flag = got_flag;
2437 if (addr_list)
2438 free_wordlist(addr_list);
2439 addr_list = alist;
2440 if (secret != NULL)
2441 strlcpy(secret, lsecret, MAXWORDLEN);
2442
2443 if (!newline)
2444 break;
2445 }
2446
2447 /* scan for a -- word indicating the start of options */
2448 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
2449 if (strcmp(ap->word, "--") == 0)
2450 break;
2451 /* ap = start of options */
2452 if (ap != NULL) {
2453 ap = ap->next; /* first option */
2454 free(*app); /* free the "--" word */
2455 *app = NULL; /* terminate addr list */
2456 }
2457 if (opts != NULL)
2458 *opts = ap;
2459 else if (ap != NULL)
2460 free_wordlist(ap);
2461 if (addrs != NULL)
2462 *addrs = addr_list;
2463 else if (addr_list != NULL)
2464 free_wordlist(addr_list);
2465
2466 return best_flag;
2467 }
2468
2469 /*
2470 * wordlist_count - return the number of items in a wordlist
2471 */
2472 static int
wordlist_count(wp)2473 wordlist_count(wp)
2474 struct wordlist *wp;
2475 {
2476 int n;
2477
2478 for (n = 0; wp != NULL; wp = wp->next)
2479 ++n;
2480 return n;
2481 }
2482
2483 /*
2484 * free_wordlist - release memory allocated for a wordlist.
2485 */
2486 static void
free_wordlist(wp)2487 free_wordlist(wp)
2488 struct wordlist *wp;
2489 {
2490 struct wordlist *next;
2491
2492 while (wp != NULL) {
2493 next = wp->next;
2494 free(wp);
2495 wp = next;
2496 }
2497 }
2498
2499 /*
2500 * auth_script_done - called when the auth-up or auth-down script
2501 * has finished.
2502 */
2503 static void
auth_script_done(arg)2504 auth_script_done(arg)
2505 void *arg;
2506 {
2507 auth_script_pid = 0;
2508 switch (auth_script_state) {
2509 case s_up:
2510 if (auth_state == s_down) {
2511 auth_script_state = s_down;
2512 auth_script(_PATH_AUTHDOWN);
2513 }
2514 break;
2515 case s_down:
2516 if (auth_state == s_up) {
2517 auth_script_state = s_up;
2518 auth_script(_PATH_AUTHUP);
2519 }
2520 break;
2521 }
2522 }
2523
2524 /*
2525 * auth_script - execute a script with arguments
2526 * interface-name peer-name real-user tty speed
2527 */
2528 static void
auth_script(script)2529 auth_script(script)
2530 char *script;
2531 {
2532 char strspeed[32];
2533 struct passwd *pw;
2534 char struid[32];
2535 char *user_name;
2536 char *argv[8];
2537
2538 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
2539 user_name = pw->pw_name;
2540 else {
2541 slprintf(struid, sizeof(struid), "%d", getuid());
2542 user_name = struid;
2543 }
2544 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
2545
2546 argv[0] = script;
2547 argv[1] = ifname;
2548 argv[2] = peer_authname;
2549 argv[3] = user_name;
2550 argv[4] = devnam;
2551 argv[5] = strspeed;
2552 argv[6] = NULL;
2553
2554 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);
2555 }
2556