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 1.117 2008/07/01 12:27:56 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 
95 #ifdef HAS_SHADOW
96 #include <shadow.h>
97 #ifndef PW_PPP
98 #define PW_PPP PW_LOGIN
99 #endif
100 #endif
101 #include <time.h>
102 
103 #include "pppd.h"
104 #include "fsm.h"
105 #include "lcp.h"
106 #include "ccp.h"
107 #include "ecp.h"
108 #include "ipcp.h"
109 #include "upap.h"
110 #include "chap-new.h"
111 #include "eap.h"
112 #ifdef CBCP_SUPPORT
113 #include "cbcp.h"
114 #endif
115 #include "pathnames.h"
116 #include "session.h"
117 
118 static const char rcsid[] = RCSID;
119 
120 /* Bits in scan_authfile return value */
121 #define NONWILD_SERVER	1
122 #define NONWILD_CLIENT	2
123 
124 #define ISWILD(word)	(word[0] == '*' && word[1] == 0)
125 
126 /* The name by which the peer authenticated itself to us. */
127 char peer_authname[MAXNAMELEN];
128 
129 /* Records which authentication operations haven't completed yet. */
130 static int auth_pending[NUM_PPP];
131 
132 /* Records which authentication operations have been completed. */
133 int auth_done[NUM_PPP];
134 
135 /* List of addresses which the peer may use. */
136 static struct permitted_ip *addresses[NUM_PPP];
137 
138 /* Wordlist giving addresses which the peer may use
139    without authenticating itself. */
140 static struct wordlist *noauth_addrs;
141 
142 /* Remote telephone number, if available */
143 char remote_number[MAXNAMELEN];
144 
145 /* Wordlist giving remote telephone numbers which may connect. */
146 static struct wordlist *permitted_numbers;
147 
148 /* Extra options to apply, from the secrets file entry for the peer. */
149 static struct wordlist *extra_options;
150 
151 /* Number of network protocols which we have opened. */
152 static int num_np_open;
153 
154 /* Number of network protocols which have come up. */
155 static int num_np_up;
156 
157 /* Set if we got the contents of passwd[] from the pap-secrets file. */
158 static int passwd_from_file;
159 
160 /* Set if we require authentication only because we have a default route. */
161 static bool default_auth;
162 
163 /* Hook to enable a plugin to control the idle time limit */
164 int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
165 
166 /* Hook for a plugin to say whether we can possibly authenticate any peer */
167 int (*pap_check_hook) __P((void)) = NULL;
168 
169 /* Hook for a plugin to check the PAP user and password */
170 int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
171 			  struct wordlist **paddrs,
172 			  struct wordlist **popts)) = NULL;
173 
174 /* Hook for a plugin to know about the PAP user logout */
175 void (*pap_logout_hook) __P((void)) = NULL;
176 
177 /* Hook for a plugin to get the PAP password for authenticating us */
178 int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
179 
180 /* Hook for a plugin to say if we can possibly authenticate a peer using CHAP */
181 int (*chap_check_hook) __P((void)) = NULL;
182 
183 /* Hook for a plugin to get the CHAP password for authenticating us */
184 int (*chap_passwd_hook) __P((char *user, char *passwd)) = NULL;
185 
186 /* Hook for a plugin to say whether it is OK if the peer
187    refuses to authenticate. */
188 int (*null_auth_hook) __P((struct wordlist **paddrs,
189 			   struct wordlist **popts)) = NULL;
190 
191 int (*allowed_address_hook) __P((u_int32_t addr)) = NULL;
192 
193 #ifdef HAVE_MULTILINK
194 /* Hook for plugin to hear when an interface joins a multilink bundle */
195 void (*multilink_join_hook) __P((void)) = NULL;
196 #endif
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 /*
219  * Option variables.
220  */
221 bool uselogin = 0;		/* Use /etc/passwd for checking PAP */
222 bool session_mgmt = 0;		/* Do session management (login records) */
223 bool cryptpap = 0;		/* Passwords in pap-secrets are encrypted */
224 bool refuse_pap = 0;		/* Don't wanna auth. ourselves with PAP */
225 bool refuse_chap = 0;		/* Don't wanna auth. ourselves with CHAP */
226 bool refuse_eap = 0;		/* Don't wanna auth. ourselves with EAP */
227 #ifdef CHAPMS
228 bool refuse_mschap = 0;		/* Don't wanna auth. ourselves with MS-CHAP */
229 bool refuse_mschap_v2 = 0;	/* Don't wanna auth. ourselves with MS-CHAPv2 */
230 #else
231 bool refuse_mschap = 1;		/* Don't wanna auth. ourselves with MS-CHAP */
232 bool refuse_mschap_v2 = 1;	/* Don't wanna auth. ourselves with MS-CHAPv2 */
233 #endif
234 bool usehostname = 0;		/* Use hostname for our_name */
235 bool auth_required = 0;		/* Always require authentication from peer */
236 bool allow_any_ip = 0;		/* Allow peer to use any IP address */
237 bool explicit_remote = 0;	/* User specified explicit remote name */
238 bool explicit_user = 0;		/* Set if "user" option supplied */
239 bool explicit_passwd = 0;	/* Set if "password" option supplied */
240 char remote_name[MAXNAMELEN];	/* Peer's name for authentication */
241 
242 static char *uafname;		/* name of most recent +ua file */
243 
244 extern char *crypt __P((const char *, const char *));
245 
246 /* Prototypes for procedures local to this file. */
247 
248 static void network_phase __P((int));
249 static void check_idle __P((void *));
250 static void connect_time_expired __P((void *));
251 static int  null_login __P((int));
252 static int  get_pap_passwd __P((char *));
253 static int  have_pap_secret __P((int *));
254 static int  have_chap_secret __P((char *, char *, int, int *));
255 static int  have_srp_secret __P((char *client, char *server, int need_ip,
256     int *lacks_ipp));
257 static int  ip_addr_check __P((u_int32_t, struct permitted_ip *));
258 static int  scan_authfile __P((FILE *, char *, char *, char *,
259 			       struct wordlist **, struct wordlist **,
260 			       char *, int));
261 static void free_wordlist __P((struct wordlist *));
262 static void auth_script __P((char *));
263 static void auth_script_done __P((void *));
264 static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
265 static int  some_ip_ok __P((struct wordlist *));
266 static int  setupapfile __P((char **));
267 static int  privgroup __P((char **));
268 static int  set_noauth_addr __P((char **));
269 static int  set_permitted_number __P((char **));
270 static void check_access __P((FILE *, char *));
271 static int  wordlist_count __P((struct wordlist *));
272 
273 #ifdef MAXOCTETS
274 static void check_maxoctets __P((void *));
275 #endif
276 
277 /*
278  * Authentication-related options.
279  */
280 option_t auth_options[] = {
281     { "auth", o_bool, &auth_required,
282       "Require authentication from peer", OPT_PRIO | 1 },
283     { "noauth", o_bool, &auth_required,
284       "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
285       &allow_any_ip },
286     { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
287       "Require PAP authentication from peer",
288       OPT_PRIOSUB | 1, &auth_required },
289     { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
290       "Require PAP authentication from peer",
291       OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
292     { "require-chap", o_bool, &auth_required,
293       "Require CHAP authentication from peer",
294       OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
295       &lcp_wantoptions[0].chap_mdtype },
296     { "+chap", o_bool, &auth_required,
297       "Require CHAP authentication from peer",
298       OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
299       &lcp_wantoptions[0].chap_mdtype },
300 #ifdef CHAPMS
301     { "require-mschap", o_bool, &auth_required,
302       "Require MS-CHAP authentication from peer",
303       OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
304       &lcp_wantoptions[0].chap_mdtype },
305     { "+mschap", o_bool, &auth_required,
306       "Require MS-CHAP authentication from peer",
307       OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
308       &lcp_wantoptions[0].chap_mdtype },
309     { "require-mschap-v2", o_bool, &auth_required,
310       "Require MS-CHAPv2 authentication from peer",
311       OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
312       &lcp_wantoptions[0].chap_mdtype },
313     { "+mschap-v2", o_bool, &auth_required,
314       "Require MS-CHAPv2 authentication from peer",
315       OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
316       &lcp_wantoptions[0].chap_mdtype },
317 #endif
318 
319     { "refuse-pap", o_bool, &refuse_pap,
320       "Don't agree to auth to peer with PAP", 1 },
321     { "-pap", o_bool, &refuse_pap,
322       "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
323     { "refuse-chap", o_bool, &refuse_chap,
324       "Don't agree to auth to peer with CHAP",
325       OPT_A2CLRB | MDTYPE_MD5,
326       &lcp_allowoptions[0].chap_mdtype },
327     { "-chap", o_bool, &refuse_chap,
328       "Don't allow CHAP authentication with peer",
329       OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5,
330       &lcp_allowoptions[0].chap_mdtype },
331 #ifdef CHAPMS
332     { "refuse-mschap", o_bool, &refuse_mschap,
333       "Don't agree to auth to peer with MS-CHAP",
334       OPT_A2CLRB | MDTYPE_MICROSOFT,
335       &lcp_allowoptions[0].chap_mdtype },
336     { "-mschap", o_bool, &refuse_mschap,
337       "Don't allow MS-CHAP authentication with peer",
338       OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT,
339       &lcp_allowoptions[0].chap_mdtype },
340     { "refuse-mschap-v2", o_bool, &refuse_mschap_v2,
341       "Don't agree to auth to peer with MS-CHAPv2",
342       OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
343       &lcp_allowoptions[0].chap_mdtype },
344     { "-mschap-v2", o_bool, &refuse_mschap_v2,
345       "Don't allow MS-CHAPv2 authentication with peer",
346       OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
347       &lcp_allowoptions[0].chap_mdtype },
348 #endif
349 
350     { "require-eap", o_bool, &lcp_wantoptions[0].neg_eap,
351       "Require EAP authentication from peer", OPT_PRIOSUB | 1,
352       &auth_required },
353     { "refuse-eap", o_bool, &refuse_eap,
354       "Don't agree to authenticate to peer with EAP", 1 },
355 
356     { "name", o_string, our_name,
357       "Set local name for authentication",
358       OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
359 
360     { "+ua", o_special, (void *)setupapfile,
361       "Get PAP user and password from file",
362       OPT_PRIO | OPT_A2STRVAL, &uafname },
363 
364     { "user", o_string, user,
365       "Set name for auth with peer", OPT_PRIO | OPT_STATIC,
366       &explicit_user, MAXNAMELEN },
367 
368     { "password", o_string, passwd,
369       "Password for authenticating us to the peer",
370       OPT_PRIO | OPT_STATIC | OPT_HIDE,
371       &explicit_passwd, MAXSECRETLEN },
372 
373     { "usehostname", o_bool, &usehostname,
374       "Must use hostname for authentication", 1 },
375 
376     { "remotename", o_string, remote_name,
377       "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
378       &explicit_remote, MAXNAMELEN },
379 
380     { "login", o_bool, &uselogin,
381       "Use system password database for PAP", OPT_A2COPY | 1 ,
382       &session_mgmt },
383     { "enable-session", o_bool, &session_mgmt,
384       "Enable session accounting for remote peers", OPT_PRIV | 1 },
385 
386     { "papcrypt", o_bool, &cryptpap,
387       "PAP passwords are encrypted", 1 },
388 
389     { "privgroup", o_special, (void *)privgroup,
390       "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
391 
392     { "allow-ip", o_special, (void *)set_noauth_addr,
393       "Set IP address(es) which can be used without authentication",
394       OPT_PRIV | OPT_A2LIST },
395 
396     { "remotenumber", o_string, remote_number,
397       "Set remote telephone number for authentication", OPT_PRIO | OPT_STATIC,
398       NULL, MAXNAMELEN },
399 
400     { "allow-number", o_special, (void *)set_permitted_number,
401       "Set telephone number(s) which are allowed to connect",
402       OPT_PRIV | OPT_A2LIST },
403 
404     { NULL }
405 };
406 
407 /*
408  * setupapfile - specifies UPAP info for authenticating with peer.
409  */
410 static int
setupapfile(argv)411 setupapfile(argv)
412     char **argv;
413 {
414     FILE *ufile;
415     int l;
416     uid_t euid;
417     char u[MAXNAMELEN], p[MAXSECRETLEN];
418     char *fname;
419 
420     lcp_allowoptions[0].neg_upap = 1;
421 
422     /* open user info file */
423     fname = strdup(*argv);
424     if (fname == NULL)
425 	novm("+ua file name");
426     euid = geteuid();
427     if (seteuid(getuid()) == -1) {
428 	option_error("unable to reset uid before opening %s: %m", fname);
429 	return 0;
430     }
431     ufile = fopen(fname, "r");
432     if (seteuid(euid) == -1)
433 	fatal("unable to regain privileges: %m");
434     if (ufile == NULL) {
435 	option_error("unable to open user login data file %s", fname);
436 	return 0;
437     }
438     check_access(ufile, fname);
439     uafname = fname;
440 
441     /* get username */
442     if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
443 	|| fgets(p, MAXSECRETLEN - 1, ufile) == NULL) {
444 	fclose(ufile);
445 	option_error("unable to read user login data file %s", fname);
446 	return 0;
447     }
448     fclose(ufile);
449 
450     /* get rid of newlines */
451     l = strlen(u);
452     if (l > 0 && u[l-1] == '\n')
453 	u[l-1] = 0;
454     l = strlen(p);
455     if (l > 0 && p[l-1] == '\n')
456 	p[l-1] = 0;
457 
458     if (override_value("user", option_priority, fname)) {
459 	strlcpy(user, u, sizeof(user));
460 	explicit_user = 1;
461     }
462     if (override_value("passwd", option_priority, fname)) {
463 	strlcpy(passwd, p, sizeof(passwd));
464 	explicit_passwd = 1;
465     }
466 
467     return (1);
468 }
469 
470 
471 /*
472  * privgroup - allow members of the group to have privileged access.
473  */
474 static int
privgroup(argv)475 privgroup(argv)
476     char **argv;
477 {
478     struct group *g;
479     int i;
480 
481     g = getgrnam(*argv);
482     if (g == 0) {
483 	option_error("group %s is unknown", *argv);
484 	return 0;
485     }
486     for (i = 0; i < ngroups; ++i) {
487 	if (groups[i] == g->gr_gid) {
488 	    privileged = 1;
489 	    break;
490 	}
491     }
492     return 1;
493 }
494 
495 
496 /*
497  * set_noauth_addr - set address(es) that can be used without authentication.
498  * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
499  */
500 static int
set_noauth_addr(argv)501 set_noauth_addr(argv)
502     char **argv;
503 {
504     char *addr = *argv;
505     int l = strlen(addr) + 1;
506     struct wordlist *wp;
507 
508     wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
509     if (wp == NULL)
510 	novm("allow-ip argument");
511     wp->word = (char *) (wp + 1);
512     wp->next = noauth_addrs;
513     BCOPY(addr, wp->word, l);
514     noauth_addrs = wp;
515     return 1;
516 }
517 
518 
519 /*
520  * set_permitted_number - set remote telephone number(s) that may connect.
521  */
522 static int
set_permitted_number(argv)523 set_permitted_number(argv)
524     char **argv;
525 {
526     char *number = *argv;
527     int l = strlen(number) + 1;
528     struct wordlist *wp;
529 
530     wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
531     if (wp == NULL)
532 	novm("allow-number argument");
533     wp->word = (char *) (wp + 1);
534     wp->next = permitted_numbers;
535     BCOPY(number, wp->word, l);
536     permitted_numbers = wp;
537     return 1;
538 }
539 
540 
541 /*
542  * An Open on LCP has requested a change from Dead to Establish phase.
543  */
544 void
link_required(unit)545 link_required(unit)
546     int unit;
547 {
548 }
549 
550 /*
551  * Bring the link up to the point of being able to do ppp.
552  */
start_link(unit)553 void start_link(unit)
554     int unit;
555 {
556     status = EXIT_CONNECT_FAILED;
557     new_phase(PHASE_SERIALCONN);
558 
559     hungup = 0;
560     devfd = the_channel->connect();
561     if (devfd < 0)
562 	goto fail;
563 
564     /* set up the serial device as a ppp interface */
565     /*
566      * N.B. we used to do tdb_writelock/tdb_writeunlock around this
567      * (from establish_ppp to set_ifunit).  However, we won't be
568      * doing the set_ifunit in multilink mode, which is the only time
569      * we need the atomicity that the tdb_writelock/tdb_writeunlock
570      * gives us.  Thus we don't need the tdb_writelock/tdb_writeunlock.
571      */
572     fd_ppp = the_channel->establish_ppp(devfd);
573     if (fd_ppp < 0) {
574 	status = EXIT_FATAL_ERROR;
575 	goto disconnect;
576     }
577 
578     if (!demand && ifunit >= 0)
579 	set_ifunit(1);
580 
581     /*
582      * Start opening the connection and wait for
583      * incoming events (reply, timeout, etc.).
584      */
585     if (ifunit >= 0)
586 	notice("Connect: %s <--> %s", ifname, ppp_devnam);
587     else
588 	notice("Starting negotiation on %s", ppp_devnam);
589     add_fd(fd_ppp);
590 
591     status = EXIT_NEGOTIATION_FAILED;
592     new_phase(PHASE_ESTABLISH);
593 
594     lcp_lowerup(0);
595     return;
596 
597  disconnect:
598     new_phase(PHASE_DISCONNECT);
599     if (the_channel->disconnect)
600 	the_channel->disconnect();
601 
602  fail:
603     new_phase(PHASE_DEAD);
604     if (the_channel->cleanup)
605 	(*the_channel->cleanup)();
606 }
607 
608 /*
609  * LCP has terminated the link; go to the Dead phase and take the
610  * physical layer down.
611  */
612 void
link_terminated(unit)613 link_terminated(unit)
614     int unit;
615 {
616     if (phase == PHASE_DEAD || phase == PHASE_MASTER)
617 	return;
618     new_phase(PHASE_DISCONNECT);
619 
620     if (pap_logout_hook) {
621 	pap_logout_hook();
622     }
623     session_end(devnam);
624 
625     if (!doing_multilink) {
626 	notice("Connection terminated.");
627 	print_link_stats();
628     } else
629 	notice("Link terminated.");
630 
631     /*
632      * Delete pid files before disestablishing ppp.  Otherwise it
633      * can happen that another pppd gets the same unit and then
634      * we delete its pid file.
635      */
636     if (!doing_multilink && !demand)
637 	remove_pidfiles();
638 
639     /*
640      * If we may want to bring the link up again, transfer
641      * the ppp unit back to the loopback.  Set the
642      * real serial device back to its normal mode of operation.
643      */
644     if (fd_ppp >= 0) {
645 	remove_fd(fd_ppp);
646 	clean_check();
647 	the_channel->disestablish_ppp(devfd);
648 	if (doing_multilink)
649 	    mp_exit_bundle();
650 	fd_ppp = -1;
651     }
652     if (!hungup)
653 	lcp_lowerdown(0);
654     if (!doing_multilink && !demand)
655 	script_unsetenv("IFNAME");
656 
657     /*
658      * Run disconnector script, if requested.
659      * XXX we may not be able to do this if the line has hung up!
660      */
661     if (devfd >= 0 && the_channel->disconnect) {
662 	the_channel->disconnect();
663 	devfd = -1;
664     }
665     if (the_channel->cleanup)
666 	(*the_channel->cleanup)();
667 
668     if (doing_multilink && multilink_master) {
669 	if (!bundle_terminating) {
670 	    new_phase(PHASE_MASTER);
671 	    if (master_detach && !detached)
672 		detach();
673 	} else
674 	    mp_bundle_terminated();
675     } else
676 	new_phase(PHASE_DEAD);
677 }
678 
679 /*
680  * LCP has gone down; it will either die or try to re-establish.
681  */
682 void
link_down(unit)683 link_down(unit)
684     int unit;
685 {
686     if (auth_state != s_down) {
687 	notify(link_down_notifier, 0);
688 	auth_state = s_down;
689 	if (auth_script_state == s_up && auth_script_pid == 0) {
690 	    update_link_stats(unit);
691 	    auth_script_state = s_down;
692 	    auth_script(_PATH_AUTHDOWN);
693 	}
694     }
695     if (!doing_multilink) {
696 	upper_layers_down(unit);
697 	if (phase != PHASE_DEAD && phase != PHASE_MASTER)
698 	    new_phase(PHASE_ESTABLISH);
699     }
700     /* XXX if doing_multilink, should do something to stop
701        network-layer traffic on the link */
702 }
703 
upper_layers_down(int unit)704 void upper_layers_down(int unit)
705 {
706     int i;
707     struct protent *protp;
708 
709     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
710 	if (!protp->enabled_flag)
711 	    continue;
712         if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
713 	    (*protp->lowerdown)(unit);
714         if (protp->protocol < 0xC000 && protp->close != NULL)
715 	    (*protp->close)(unit, "LCP down");
716     }
717     num_np_open = 0;
718     num_np_up = 0;
719 }
720 
721 /*
722  * The link is established.
723  * Proceed to the Dead, Authenticate or Network phase as appropriate.
724  */
725 void
link_established(unit)726 link_established(unit)
727     int unit;
728 {
729     int auth;
730     lcp_options *wo = &lcp_wantoptions[unit];
731     lcp_options *go = &lcp_gotoptions[unit];
732     lcp_options *ho = &lcp_hisoptions[unit];
733     int i;
734     struct protent *protp;
735 
736     /*
737      * Tell higher-level protocols that LCP is up.
738      */
739     if (!doing_multilink) {
740 	for (i = 0; (protp = protocols[i]) != NULL; ++i)
741 	    if (protp->protocol != PPP_LCP && protp->enabled_flag
742 		&& protp->lowerup != NULL)
743 		(*protp->lowerup)(unit);
744     }
745 
746     if (!auth_required && noauth_addrs != NULL)
747 	set_allowed_addrs(unit, NULL, NULL);
748 
749     if (auth_required && !(go->neg_upap || go->neg_chap || go->neg_eap)) {
750 	/*
751 	 * We wanted the peer to authenticate itself, and it refused:
752 	 * if we have some address(es) it can use without auth, fine,
753 	 * otherwise treat it as though it authenticated with PAP using
754 	 * a username of "" and a password of "".  If that's not OK,
755 	 * boot it out.
756 	 */
757 	if (noauth_addrs != NULL) {
758 	    set_allowed_addrs(unit, NULL, NULL);
759 	} else if (!wo->neg_upap || uselogin || !null_login(unit)) {
760 	    warn("peer refused to authenticate: terminating link");
761 	    status = EXIT_PEER_AUTH_FAILED;
762 	    lcp_close(unit, "peer refused to authenticate");
763 	    return;
764 	}
765     }
766 
767     new_phase(PHASE_AUTHENTICATE);
768     auth = 0;
769     if (go->neg_eap) {
770 	eap_authpeer(unit, our_name);
771 	auth |= EAP_PEER;
772     } else if (go->neg_chap) {
773 	chap_auth_peer(unit, our_name, CHAP_DIGEST(go->chap_mdtype));
774 	auth |= CHAP_PEER;
775     } else if (go->neg_upap) {
776 	upap_authpeer(unit);
777 	auth |= PAP_PEER;
778     }
779     if (ho->neg_eap) {
780 	eap_authwithpeer(unit, user);
781 	auth |= EAP_WITHPEER;
782     } else if (ho->neg_chap) {
783 	chap_auth_with_peer(unit, user, CHAP_DIGEST(ho->chap_mdtype));
784 	auth |= CHAP_WITHPEER;
785     } else if (ho->neg_upap) {
786 	/* If a blank password was explicitly given as an option, trust
787 	   the user and don't try to look up one. */
788 	if (passwd[0] == 0 && !explicit_passwd) {
789 	    passwd_from_file = 1;
790 	    if (!get_pap_passwd(passwd))
791 		error("No secret found for PAP login");
792 	}
793 	upap_authwithpeer(unit, user, passwd);
794 	auth |= PAP_WITHPEER;
795     }
796     auth_pending[unit] = auth;
797     auth_done[unit] = 0;
798 
799     if (!auth)
800 	network_phase(unit);
801 }
802 
803 /*
804  * Proceed to the network phase.
805  */
806 static void
network_phase(unit)807 network_phase(unit)
808     int unit;
809 {
810     lcp_options *go = &lcp_gotoptions[unit];
811 
812     /* Log calling number. */
813     if (*remote_number)
814 	notice("peer from calling number %q authorized", remote_number);
815 
816     /*
817      * If the peer had to authenticate, run the auth-up script now.
818      */
819     if (go->neg_chap || go->neg_upap || go->neg_eap) {
820 	notify(auth_up_notifier, 0);
821 	auth_state = s_up;
822 	if (auth_script_state == s_down && auth_script_pid == 0) {
823 	    auth_script_state = s_up;
824 	    auth_script(_PATH_AUTHUP);
825 	}
826     }
827 
828 #ifdef CBCP_SUPPORT
829     /*
830      * If we negotiated callback, do it now.
831      */
832     if (go->neg_cbcp) {
833 	new_phase(PHASE_CALLBACK);
834 	(*cbcp_protent.open)(unit);
835 	return;
836     }
837 #endif
838 
839     /*
840      * Process extra options from the secrets file
841      */
842     if (extra_options) {
843 	options_from_list(extra_options, 1);
844 	free_wordlist(extra_options);
845 	extra_options = 0;
846     }
847     start_networks(unit);
848 }
849 
850 void
start_networks(unit)851 start_networks(unit)
852     int unit;
853 {
854     int i;
855     struct protent *protp;
856     int ecp_required, mppe_required;
857 
858     new_phase(PHASE_NETWORK);
859 
860 #ifdef HAVE_MULTILINK
861     if (multilink) {
862 	if (mp_join_bundle()) {
863 	    if (multilink_join_hook)
864 		(*multilink_join_hook)();
865 	    if (updetach && !nodetach)
866 		detach();
867 	    return;
868 	}
869     }
870 #endif /* HAVE_MULTILINK */
871 
872 #ifdef PPP_FILTER
873     if (!demand)
874 	set_filters(&pass_filter, &active_filter);
875 #endif
876     /* Start CCP and ECP */
877     for (i = 0; (protp = protocols[i]) != NULL; ++i)
878 	if ((protp->protocol == PPP_ECP || protp->protocol == PPP_CCP)
879 	    && protp->enabled_flag && protp->open != NULL)
880 	    (*protp->open)(0);
881 
882     /*
883      * Bring up other network protocols iff encryption is not required.
884      */
885     ecp_required = ecp_gotoptions[unit].required;
886     mppe_required = ccp_gotoptions[unit].mppe;
887     if (!ecp_required && !mppe_required)
888 	continue_networks(unit);
889 }
890 
891 void
continue_networks(unit)892 continue_networks(unit)
893     int unit;
894 {
895     int i;
896     struct protent *protp;
897 
898     /*
899      * Start the "real" network protocols.
900      */
901     for (i = 0; (protp = protocols[i]) != NULL; ++i)
902 	if (protp->protocol < 0xC000
903 	    && protp->protocol != PPP_CCP && protp->protocol != PPP_ECP
904 	    && protp->enabled_flag && protp->open != NULL) {
905 	    (*protp->open)(0);
906 	    ++num_np_open;
907 	}
908 
909     if (num_np_open == 0)
910 	/* nothing to do */
911 	lcp_close(0, "No network protocols running");
912 }
913 
914 /*
915  * The peer has failed to authenticate himself using `protocol'.
916  */
917 void
auth_peer_fail(unit,protocol)918 auth_peer_fail(unit, protocol)
919     int unit, protocol;
920 {
921     /*
922      * Authentication failure: take the link down
923      */
924     status = EXIT_PEER_AUTH_FAILED;
925     lcp_close(unit, "Authentication failed");
926 }
927 
928 /*
929  * The peer has been successfully authenticated using `protocol'.
930  */
931 void
auth_peer_success(unit,protocol,prot_flavor,name,namelen)932 auth_peer_success(unit, protocol, prot_flavor, name, namelen)
933     int unit, protocol, prot_flavor;
934     char *name;
935     int namelen;
936 {
937     int bit;
938 
939     switch (protocol) {
940     case PPP_CHAP:
941 	bit = CHAP_PEER;
942 	switch (prot_flavor) {
943 	case CHAP_MD5:
944 	    bit |= CHAP_MD5_PEER;
945 	    break;
946 #ifdef CHAPMS
947 	case CHAP_MICROSOFT:
948 	    bit |= CHAP_MS_PEER;
949 	    break;
950 	case CHAP_MICROSOFT_V2:
951 	    bit |= CHAP_MS2_PEER;
952 	    break;
953 #endif
954 	}
955 	break;
956     case PPP_PAP:
957 	bit = PAP_PEER;
958 	break;
959     case PPP_EAP:
960 	bit = EAP_PEER;
961 	break;
962     default:
963 	warn("auth_peer_success: unknown protocol %x", protocol);
964 	return;
965     }
966 
967     /*
968      * Save the authenticated name of the peer for later.
969      */
970     if (namelen > sizeof(peer_authname) - 1)
971 	namelen = sizeof(peer_authname) - 1;
972     BCOPY(name, peer_authname, namelen);
973     peer_authname[namelen] = 0;
974     script_setenv("PEERNAME", peer_authname, 0);
975 
976     /* Save the authentication method for later. */
977     auth_done[unit] |= bit;
978 
979     /*
980      * If there is no more authentication still to be done,
981      * proceed to the network (or callback) phase.
982      */
983     if ((auth_pending[unit] &= ~bit) == 0)
984         network_phase(unit);
985 }
986 
987 /*
988  * We have failed to authenticate ourselves to the peer using `protocol'.
989  */
990 void
auth_withpeer_fail(unit,protocol)991 auth_withpeer_fail(unit, protocol)
992     int unit, protocol;
993 {
994     if (passwd_from_file)
995 	BZERO(passwd, MAXSECRETLEN);
996     /*
997      * We've failed to authenticate ourselves to our peer.
998      * Some servers keep sending CHAP challenges, but there
999      * is no point in persisting without any way to get updated
1000      * authentication secrets.
1001      */
1002     status = EXIT_AUTH_TOPEER_FAILED;
1003     lcp_close(unit, "Failed to authenticate ourselves to peer");
1004 }
1005 
1006 /*
1007  * We have successfully authenticated ourselves with the peer using `protocol'.
1008  */
1009 void
auth_withpeer_success(unit,protocol,prot_flavor)1010 auth_withpeer_success(unit, protocol, prot_flavor)
1011     int unit, protocol, prot_flavor;
1012 {
1013     int bit;
1014     const char *prot = "";
1015 
1016     switch (protocol) {
1017     case PPP_CHAP:
1018 	bit = CHAP_WITHPEER;
1019 	prot = "CHAP";
1020 	switch (prot_flavor) {
1021 	case CHAP_MD5:
1022 	    bit |= CHAP_MD5_WITHPEER;
1023 	    break;
1024 #ifdef CHAPMS
1025 	case CHAP_MICROSOFT:
1026 	    bit |= CHAP_MS_WITHPEER;
1027 	    break;
1028 	case CHAP_MICROSOFT_V2:
1029 	    bit |= CHAP_MS2_WITHPEER;
1030 	    break;
1031 #endif
1032 	}
1033 	break;
1034     case PPP_PAP:
1035 	if (passwd_from_file)
1036 	    BZERO(passwd, MAXSECRETLEN);
1037 	bit = PAP_WITHPEER;
1038 	prot = "PAP";
1039 	break;
1040     case PPP_EAP:
1041 	bit = EAP_WITHPEER;
1042 	prot = "EAP";
1043 	break;
1044     default:
1045 	warn("auth_withpeer_success: unknown protocol %x", protocol);
1046 	bit = 0;
1047     }
1048 
1049     notice("%s authentication succeeded", prot);
1050 
1051     /* Save the authentication method for later. */
1052     auth_done[unit] |= bit;
1053 
1054     /*
1055      * If there is no more authentication still being done,
1056      * proceed to the network (or callback) phase.
1057      */
1058     if ((auth_pending[unit] &= ~bit) == 0)
1059 	network_phase(unit);
1060 }
1061 
1062 
1063 /*
1064  * np_up - a network protocol has come up.
1065  */
1066 void
np_up(unit,proto)1067 np_up(unit, proto)
1068     int unit, proto;
1069 {
1070     int tlim;
1071 
1072     if (num_np_up == 0) {
1073 	/*
1074 	 * At this point we consider that the link has come up successfully.
1075 	 */
1076 	status = EXIT_OK;
1077 	unsuccess = 0;
1078 	new_phase(PHASE_RUNNING);
1079 
1080 	if (idle_time_hook != 0)
1081 	    tlim = (*idle_time_hook)(NULL);
1082 	else
1083 	    tlim = idle_time_limit;
1084 	if (tlim > 0)
1085 	    TIMEOUT(check_idle, NULL, tlim);
1086 
1087 	/*
1088 	 * Set a timeout to close the connection once the maximum
1089 	 * connect time has expired.
1090 	 */
1091 	if (maxconnect > 0)
1092 	    TIMEOUT(connect_time_expired, 0, maxconnect);
1093 
1094 #ifdef MAXOCTETS
1095 	if (maxoctets > 0)
1096 	    TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1097 #endif
1098 
1099 	/*
1100 	 * Detach now, if the updetach option was given.
1101 	 */
1102 	if (updetach && !nodetach)
1103 	    detach();
1104     }
1105     ++num_np_up;
1106 }
1107 
1108 /*
1109  * np_down - a network protocol has gone down.
1110  */
1111 void
np_down(unit,proto)1112 np_down(unit, proto)
1113     int unit, proto;
1114 {
1115     if (--num_np_up == 0) {
1116 	UNTIMEOUT(check_idle, NULL);
1117 	UNTIMEOUT(connect_time_expired, NULL);
1118 #ifdef MAXOCTETS
1119 	UNTIMEOUT(check_maxoctets, NULL);
1120 #endif
1121 	new_phase(PHASE_NETWORK);
1122     }
1123 }
1124 
1125 /*
1126  * np_finished - a network protocol has finished using the link.
1127  */
1128 void
np_finished(unit,proto)1129 np_finished(unit, proto)
1130     int unit, proto;
1131 {
1132     if (--num_np_open <= 0) {
1133 	/* no further use for the link: shut up shop. */
1134 	lcp_close(0, "No network protocols running");
1135     }
1136 }
1137 
1138 #ifdef MAXOCTETS
1139 static void
check_maxoctets(arg)1140 check_maxoctets(arg)
1141     void *arg;
1142 {
1143     unsigned int used;
1144 
1145     update_link_stats(ifunit);
1146     link_stats_valid=0;
1147 
1148     switch(maxoctets_dir) {
1149 	case PPP_OCTETS_DIRECTION_IN:
1150 	    used = link_stats.bytes_in;
1151 	    break;
1152 	case PPP_OCTETS_DIRECTION_OUT:
1153 	    used = link_stats.bytes_out;
1154 	    break;
1155 	case PPP_OCTETS_DIRECTION_MAXOVERAL:
1156 	case PPP_OCTETS_DIRECTION_MAXSESSION:
1157 	    used = (link_stats.bytes_in > link_stats.bytes_out) ? link_stats.bytes_in : link_stats.bytes_out;
1158 	    break;
1159 	default:
1160 	    used = link_stats.bytes_in+link_stats.bytes_out;
1161 	    break;
1162     }
1163     if (used > maxoctets) {
1164 	notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used);
1165 	status = EXIT_TRAFFIC_LIMIT;
1166 	lcp_close(0, "Traffic limit");
1167 	need_holdoff = 0;
1168     } else {
1169         TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1170     }
1171 }
1172 #endif
1173 
1174 /*
1175  * check_idle - check whether the link has been idle for long
1176  * enough that we can shut it down.
1177  */
1178 static void
check_idle(arg)1179 check_idle(arg)
1180     void *arg;
1181 {
1182     struct ppp_idle idle;
1183     time_t itime;
1184     int tlim;
1185 
1186     if (!get_idle_time(0, &idle))
1187 	return;
1188     if (idle_time_hook != 0) {
1189 	tlim = idle_time_hook(&idle);
1190     } else {
1191 	itime = MIN(idle.xmit_idle, idle.recv_idle);
1192 	tlim = idle_time_limit - itime;
1193     }
1194     if (tlim <= 0) {
1195 	/* link is idle: shut it down. */
1196 	notice("Terminating connection due to lack of activity.");
1197 	status = EXIT_IDLE_TIMEOUT;
1198 	lcp_close(0, "Link inactive");
1199 	need_holdoff = 0;
1200     } else {
1201 	TIMEOUT(check_idle, NULL, tlim);
1202     }
1203 }
1204 
1205 /*
1206  * connect_time_expired - log a message and close the connection.
1207  */
1208 static void
connect_time_expired(arg)1209 connect_time_expired(arg)
1210     void *arg;
1211 {
1212     info("Connect time expired");
1213     status = EXIT_CONNECT_TIME;
1214     lcp_close(0, "Connect time expired");	/* Close connection */
1215 }
1216 
1217 /*
1218  * auth_check_options - called to check authentication options.
1219  */
1220 void
auth_check_options()1221 auth_check_options()
1222 {
1223     lcp_options *wo = &lcp_wantoptions[0];
1224     int can_auth;
1225     int lacks_ip;
1226 
1227     /* Default our_name to hostname, and user to our_name */
1228     if (our_name[0] == 0 || usehostname)
1229 	strlcpy(our_name, hostname, sizeof(our_name));
1230     /* If a blank username was explicitly given as an option, trust
1231        the user and don't use our_name */
1232     if (user[0] == 0 && !explicit_user)
1233 	strlcpy(user, our_name, sizeof(user));
1234 
1235     /*
1236      * If we have a default route, require the peer to authenticate
1237      * unless the noauth option was given or the real user is root.
1238      */
1239     if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
1240 	auth_required = 1;
1241 	default_auth = 1;
1242     }
1243 
1244     /* If we selected any CHAP flavors, we should probably negotiate it. :-) */
1245     if (wo->chap_mdtype)
1246 	wo->neg_chap = 1;
1247 
1248     /* If authentication is required, ask peer for CHAP, PAP, or EAP. */
1249     if (auth_required) {
1250 	allow_any_ip = 0;
1251 	if (!wo->neg_chap && !wo->neg_upap && !wo->neg_eap) {
1252 	    wo->neg_chap = chap_mdtype_all != MDTYPE_NONE;
1253 	    wo->chap_mdtype = chap_mdtype_all;
1254 	    wo->neg_upap = 1;
1255 	    wo->neg_eap = 1;
1256 	}
1257     } else {
1258 	wo->neg_chap = 0;
1259 	wo->chap_mdtype = MDTYPE_NONE;
1260 	wo->neg_upap = 0;
1261 	wo->neg_eap = 0;
1262     }
1263 
1264     /*
1265      * Check whether we have appropriate secrets to use
1266      * to authenticate the peer.  Note that EAP can authenticate by way
1267      * of a CHAP-like exchanges as well as SRP.
1268      */
1269     lacks_ip = 0;
1270     can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
1271     if (!can_auth && (wo->neg_chap || wo->neg_eap)) {
1272 	can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
1273 				    our_name, 1, &lacks_ip);
1274     }
1275     if (!can_auth && wo->neg_eap) {
1276 	can_auth = have_srp_secret((explicit_remote? remote_name: NULL),
1277 				    our_name, 1, &lacks_ip);
1278     }
1279 
1280     if (auth_required && !can_auth && noauth_addrs == NULL) {
1281 	if (default_auth) {
1282 	    option_error(
1283 "By default the remote system is required to authenticate itself");
1284 	    option_error(
1285 "(because this system has a default route to the internet)");
1286 	} else if (explicit_remote)
1287 	    option_error(
1288 "The remote system (%s) is required to authenticate itself",
1289 			 remote_name);
1290 	else
1291 	    option_error(
1292 "The remote system is required to authenticate itself");
1293 	option_error(
1294 "but I couldn't find any suitable secret (password) for it to use to do so.");
1295 	if (lacks_ip)
1296 	    option_error(
1297 "(None of the available passwords would let it use an IP address.)");
1298 
1299 	exit(1);
1300     }
1301 
1302     /*
1303      * Early check for remote number authorization.
1304      */
1305     if (!auth_number()) {
1306 	warn("calling number %q is not authorized", remote_number);
1307 	exit(EXIT_CNID_AUTH_FAILED);
1308     }
1309 }
1310 
1311 /*
1312  * auth_reset - called when LCP is starting negotiations to recheck
1313  * authentication options, i.e. whether we have appropriate secrets
1314  * to use for authenticating ourselves and/or the peer.
1315  */
1316 void
auth_reset(unit)1317 auth_reset(unit)
1318     int unit;
1319 {
1320     lcp_options *go = &lcp_gotoptions[unit];
1321     lcp_options *ao = &lcp_allowoptions[unit];
1322     int hadchap;
1323 
1324     hadchap = -1;
1325     ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
1326     ao->neg_chap = (!refuse_chap || !refuse_mschap || !refuse_mschap_v2)
1327 	&& (passwd[0] != 0 ||
1328 	    (hadchap = have_chap_secret(user, (explicit_remote? remote_name:
1329 					       NULL), 0, NULL)));
1330     ao->neg_eap = !refuse_eap && (
1331 	passwd[0] != 0 ||
1332 	(hadchap == 1 || (hadchap == -1 && have_chap_secret(user,
1333 	    (explicit_remote? remote_name: NULL), 0, NULL))) ||
1334 	have_srp_secret(user, (explicit_remote? remote_name: NULL), 0, NULL));
1335 
1336     hadchap = -1;
1337     if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
1338 	go->neg_upap = 0;
1339     if (go->neg_chap) {
1340 	if (!(hadchap = have_chap_secret((explicit_remote? remote_name: NULL),
1341 			      our_name, 1, NULL)))
1342 	    go->neg_chap = 0;
1343     }
1344     if (go->neg_eap &&
1345 	(hadchap == 0 || (hadchap == -1 &&
1346 	    !have_chap_secret((explicit_remote? remote_name: NULL), our_name,
1347 		1, NULL))) &&
1348 	!have_srp_secret((explicit_remote? remote_name: NULL), our_name, 1,
1349 	    NULL))
1350 	go->neg_eap = 0;
1351 }
1352 
1353 
1354 /*
1355  * check_passwd - Check the user name and passwd against the PAP secrets
1356  * file.  If requested, also check against the system password database,
1357  * and login the user if OK.
1358  *
1359  * returns:
1360  *	UPAP_AUTHNAK: Authentication failed.
1361  *	UPAP_AUTHACK: Authentication succeeded.
1362  * In either case, msg points to an appropriate message.
1363  */
1364 int
check_passwd(unit,auser,userlen,apasswd,passwdlen,msg)1365 check_passwd(unit, auser, userlen, apasswd, passwdlen, msg)
1366     int unit;
1367     char *auser;
1368     int userlen;
1369     char *apasswd;
1370     int passwdlen;
1371     char **msg;
1372 {
1373 #if defined(__ANDROID__)
1374     return UPAP_AUTHNAK;
1375 #else
1376     int ret;
1377     char *filename;
1378     FILE *f;
1379     struct wordlist *addrs = NULL, *opts = NULL;
1380     char passwd[256], user[256];
1381     char secret[MAXWORDLEN];
1382     static int attempts = 0;
1383 
1384     /*
1385      * Make copies of apasswd and auser, then null-terminate them.
1386      * If there are unprintable characters in the password, make
1387      * them visible.
1388      */
1389     slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
1390     slprintf(user, sizeof(user), "%.*v", userlen, auser);
1391     *msg = "";
1392 
1393     /*
1394      * Check if a plugin wants to handle this.
1395      */
1396     if (pap_auth_hook) {
1397 	ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
1398 	if (ret >= 0) {
1399 	    /* note: set_allowed_addrs() saves opts (but not addrs):
1400 	       don't free it! */
1401 	    if (ret)
1402 		set_allowed_addrs(unit, addrs, opts);
1403 	    else if (opts != 0)
1404 		free_wordlist(opts);
1405 	    if (addrs != 0)
1406 		free_wordlist(addrs);
1407 	    BZERO(passwd, sizeof(passwd));
1408 	    return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
1409 	}
1410     }
1411 
1412     /*
1413      * Open the file of pap secrets and scan for a suitable secret
1414      * for authenticating this user.
1415      */
1416     filename = _PATH_UPAPFILE;
1417     addrs = opts = NULL;
1418     ret = UPAP_AUTHNAK;
1419     f = fopen(filename, "r");
1420     if (f == NULL) {
1421 	error("Can't open PAP password file %s: %m", filename);
1422 
1423     } else {
1424 	check_access(f, filename);
1425 	if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename, 0) < 0) {
1426 	    warn("no PAP secret found for %s", user);
1427 	} else {
1428 	    /*
1429 	     * If the secret is "@login", it means to check
1430 	     * the password against the login database.
1431 	     */
1432 	    int login_secret = strcmp(secret, "@login") == 0;
1433 	    ret = UPAP_AUTHACK;
1434 	    if (uselogin || login_secret) {
1435 		/* login option or secret is @login */
1436 		if (session_full(user, passwd, devnam, msg) == 0) {
1437 		    ret = UPAP_AUTHNAK;
1438 		}
1439 	    } else if (session_mgmt) {
1440 		if (session_check(user, NULL, devnam, NULL) == 0) {
1441 		    warn("Peer %q failed PAP Session verification", user);
1442 		    ret = UPAP_AUTHNAK;
1443 		}
1444 	    }
1445 	    if (secret[0] != 0 && !login_secret) {
1446 		/* password given in pap-secrets - must match */
1447 		if (cryptpap || strcmp(passwd, secret) != 0) {
1448 		    char *cbuf = crypt(passwd, secret);
1449 		    if (!cbuf || strcmp(cbuf, secret) != 0)
1450 			ret = UPAP_AUTHNAK;
1451 		}
1452 	    }
1453 	}
1454 	fclose(f);
1455     }
1456 
1457     if (ret == UPAP_AUTHNAK) {
1458         if (**msg == 0)
1459 	    *msg = "Login incorrect";
1460 	/*
1461 	 * XXX can we ever get here more than once??
1462 	 * Frustrate passwd stealer programs.
1463 	 * Allow 10 tries, but start backing off after 3 (stolen from login).
1464 	 * On 10'th, drop the connection.
1465 	 */
1466 	if (attempts++ >= 10) {
1467 	    warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
1468 	    lcp_close(unit, "login failed");
1469 	}
1470 	if (attempts > 3)
1471 	    sleep((u_int) (attempts - 3) * 5);
1472 	if (opts != NULL)
1473 	    free_wordlist(opts);
1474 
1475     } else {
1476 	attempts = 0;			/* Reset count */
1477 	if (**msg == 0)
1478 	    *msg = "Login ok";
1479 	set_allowed_addrs(unit, addrs, opts);
1480     }
1481 
1482     if (addrs != NULL)
1483 	free_wordlist(addrs);
1484     BZERO(passwd, sizeof(passwd));
1485     BZERO(secret, sizeof(secret));
1486 
1487     return ret;
1488 #endif
1489 }
1490 
1491 /*
1492  * null_login - Check if a username of "" and a password of "" are
1493  * acceptable, and iff so, set the list of acceptable IP addresses
1494  * and return 1.
1495  */
1496 static int
null_login(unit)1497 null_login(unit)
1498     int unit;
1499 {
1500     char *filename;
1501     FILE *f;
1502     int i, ret;
1503     struct wordlist *addrs, *opts;
1504     char secret[MAXWORDLEN];
1505 
1506     /*
1507      * Check if a plugin wants to handle this.
1508      */
1509     ret = -1;
1510     if (null_auth_hook)
1511 	ret = (*null_auth_hook)(&addrs, &opts);
1512 
1513     /*
1514      * Open the file of pap secrets and scan for a suitable secret.
1515      */
1516     if (ret <= 0) {
1517 	filename = _PATH_UPAPFILE;
1518 	addrs = NULL;
1519 	f = fopen(filename, "r");
1520 	if (f == NULL)
1521 	    return 0;
1522 	check_access(f, filename);
1523 
1524 	i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename, 0);
1525 	ret = i >= 0 && secret[0] == 0;
1526 	BZERO(secret, sizeof(secret));
1527 	fclose(f);
1528     }
1529 
1530     if (ret)
1531 	set_allowed_addrs(unit, addrs, opts);
1532     else if (opts != 0)
1533 	free_wordlist(opts);
1534     if (addrs != 0)
1535 	free_wordlist(addrs);
1536 
1537     return ret;
1538 }
1539 
1540 
1541 /*
1542  * get_pap_passwd - get a password for authenticating ourselves with
1543  * our peer using PAP.  Returns 1 on success, 0 if no suitable password
1544  * could be found.
1545  * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1546  */
1547 static int
get_pap_passwd(passwd)1548 get_pap_passwd(passwd)
1549     char *passwd;
1550 {
1551     char *filename;
1552     FILE *f;
1553     int ret;
1554     char secret[MAXWORDLEN];
1555 
1556     /*
1557      * Check whether a plugin wants to supply this.
1558      */
1559     if (pap_passwd_hook) {
1560 	ret = (*pap_passwd_hook)(user, passwd);
1561 	if (ret >= 0)
1562 	    return ret;
1563     }
1564 
1565     filename = _PATH_UPAPFILE;
1566     f = fopen(filename, "r");
1567     if (f == NULL)
1568 	return 0;
1569     check_access(f, filename);
1570     ret = scan_authfile(f, user,
1571 			(remote_name[0]? remote_name: NULL),
1572 			secret, NULL, NULL, filename, 0);
1573     fclose(f);
1574     if (ret < 0)
1575 	return 0;
1576     if (passwd != NULL)
1577 	strlcpy(passwd, secret, MAXSECRETLEN);
1578     BZERO(secret, sizeof(secret));
1579     return 1;
1580 }
1581 
1582 
1583 /*
1584  * have_pap_secret - check whether we have a PAP file with any
1585  * secrets that we could possibly use for authenticating the peer.
1586  */
1587 static int
have_pap_secret(lacks_ipp)1588 have_pap_secret(lacks_ipp)
1589     int *lacks_ipp;
1590 {
1591     FILE *f;
1592     int ret;
1593     char *filename;
1594     struct wordlist *addrs;
1595 
1596     /* let the plugin decide, if there is one */
1597     if (pap_check_hook) {
1598 	ret = (*pap_check_hook)();
1599 	if (ret >= 0)
1600 	    return ret;
1601     }
1602 
1603     filename = _PATH_UPAPFILE;
1604     f = fopen(filename, "r");
1605     if (f == NULL)
1606 	return 0;
1607 
1608     ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1609 			NULL, &addrs, NULL, filename, 0);
1610     fclose(f);
1611     if (ret >= 0 && !some_ip_ok(addrs)) {
1612 	if (lacks_ipp != 0)
1613 	    *lacks_ipp = 1;
1614 	ret = -1;
1615     }
1616     if (addrs != 0)
1617 	free_wordlist(addrs);
1618 
1619     return ret >= 0;
1620 }
1621 
1622 
1623 /*
1624  * have_chap_secret - check whether we have a CHAP file with a
1625  * secret that we could possibly use for authenticating `client'
1626  * on `server'.  Either can be the null string, meaning we don't
1627  * know the identity yet.
1628  */
1629 static int
have_chap_secret(client,server,need_ip,lacks_ipp)1630 have_chap_secret(client, server, need_ip, lacks_ipp)
1631     char *client;
1632     char *server;
1633     int need_ip;
1634     int *lacks_ipp;
1635 {
1636     FILE *f;
1637     int ret;
1638     char *filename;
1639     struct wordlist *addrs;
1640 
1641     if (chap_check_hook) {
1642 	ret = (*chap_check_hook)();
1643 	if (ret >= 0) {
1644 	    return ret;
1645 	}
1646     }
1647 
1648     filename = _PATH_CHAPFILE;
1649     f = fopen(filename, "r");
1650     if (f == NULL)
1651 	return 0;
1652 
1653     if (client != NULL && client[0] == 0)
1654 	client = NULL;
1655     else if (server != NULL && server[0] == 0)
1656 	server = NULL;
1657 
1658     ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1659     fclose(f);
1660     if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1661 	if (lacks_ipp != 0)
1662 	    *lacks_ipp = 1;
1663 	ret = -1;
1664     }
1665     if (addrs != 0)
1666 	free_wordlist(addrs);
1667 
1668     return ret >= 0;
1669 }
1670 
1671 
1672 /*
1673  * have_srp_secret - check whether we have a SRP file with a
1674  * secret that we could possibly use for authenticating `client'
1675  * on `server'.  Either can be the null string, meaning we don't
1676  * know the identity yet.
1677  */
1678 static int
have_srp_secret(client,server,need_ip,lacks_ipp)1679 have_srp_secret(client, server, need_ip, lacks_ipp)
1680     char *client;
1681     char *server;
1682     int need_ip;
1683     int *lacks_ipp;
1684 {
1685     FILE *f;
1686     int ret;
1687     char *filename;
1688     struct wordlist *addrs;
1689 
1690     filename = _PATH_SRPFILE;
1691     f = fopen(filename, "r");
1692     if (f == NULL)
1693 	return 0;
1694 
1695     if (client != NULL && client[0] == 0)
1696 	client = NULL;
1697     else if (server != NULL && server[0] == 0)
1698 	server = NULL;
1699 
1700     ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1701     fclose(f);
1702     if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1703 	if (lacks_ipp != 0)
1704 	    *lacks_ipp = 1;
1705 	ret = -1;
1706     }
1707     if (addrs != 0)
1708 	free_wordlist(addrs);
1709 
1710     return ret >= 0;
1711 }
1712 
1713 
1714 /*
1715  * get_secret - open the CHAP secret file and return the secret
1716  * for authenticating the given client on the given server.
1717  * (We could be either client or server).
1718  */
1719 int
get_secret(unit,client,server,secret,secret_len,am_server)1720 get_secret(unit, client, server, secret, secret_len, am_server)
1721     int unit;
1722     char *client;
1723     char *server;
1724     char *secret;
1725     int *secret_len;
1726     int am_server;
1727 {
1728     FILE *f;
1729     int ret, len;
1730     char *filename;
1731     struct wordlist *addrs, *opts;
1732     char secbuf[MAXWORDLEN];
1733 
1734     if (!am_server && passwd[0] != 0) {
1735 	strlcpy(secbuf, passwd, sizeof(secbuf));
1736     } else if (!am_server && chap_passwd_hook) {
1737 	if ( (*chap_passwd_hook)(client, secbuf) < 0) {
1738 	    error("Unable to obtain CHAP password for %s on %s from plugin",
1739 		  client, server);
1740 	    return 0;
1741 	}
1742     } else {
1743 	filename = _PATH_CHAPFILE;
1744 	addrs = NULL;
1745 	secbuf[0] = 0;
1746 
1747 	f = fopen(filename, "r");
1748 	if (f == NULL) {
1749 	    error("Can't open chap secret file %s: %m", filename);
1750 	    return 0;
1751 	}
1752 	check_access(f, filename);
1753 
1754 	ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename, 0);
1755 	fclose(f);
1756 	if (ret < 0)
1757 	    return 0;
1758 
1759 	if (am_server)
1760 	    set_allowed_addrs(unit, addrs, opts);
1761 	else if (opts != 0)
1762 	    free_wordlist(opts);
1763 	if (addrs != 0)
1764 	    free_wordlist(addrs);
1765     }
1766 
1767     len = strlen(secbuf);
1768     if (len > MAXSECRETLEN) {
1769 	error("Secret for %s on %s is too long", client, server);
1770 	len = MAXSECRETLEN;
1771     }
1772     BCOPY(secbuf, secret, len);
1773     BZERO(secbuf, sizeof(secbuf));
1774     *secret_len = len;
1775 
1776     return 1;
1777 }
1778 
1779 
1780 /*
1781  * get_srp_secret - open the SRP secret file and return the secret
1782  * for authenticating the given client on the given server.
1783  * (We could be either client or server).
1784  */
1785 int
get_srp_secret(unit,client,server,secret,am_server)1786 get_srp_secret(unit, client, server, secret, am_server)
1787     int unit;
1788     char *client;
1789     char *server;
1790     char *secret;
1791     int am_server;
1792 {
1793     FILE *fp;
1794     int ret;
1795     char *filename;
1796     struct wordlist *addrs, *opts;
1797 
1798     if (!am_server && passwd[0] != '\0') {
1799 	strlcpy(secret, passwd, MAXWORDLEN);
1800     } else {
1801 	filename = _PATH_SRPFILE;
1802 	addrs = NULL;
1803 
1804 	fp = fopen(filename, "r");
1805 	if (fp == NULL) {
1806 	    error("Can't open srp secret file %s: %m", filename);
1807 	    return 0;
1808 	}
1809 	check_access(fp, filename);
1810 
1811 	secret[0] = '\0';
1812 	ret = scan_authfile(fp, client, server, secret, &addrs, &opts,
1813 	    filename, am_server);
1814 	fclose(fp);
1815 	if (ret < 0)
1816 	    return 0;
1817 
1818 	if (am_server)
1819 	    set_allowed_addrs(unit, addrs, opts);
1820 	else if (opts != NULL)
1821 	    free_wordlist(opts);
1822 	if (addrs != NULL)
1823 	    free_wordlist(addrs);
1824     }
1825 
1826     return 1;
1827 }
1828 
1829 /*
1830  * set_allowed_addrs() - set the list of allowed addresses.
1831  * Also looks for `--' indicating options to apply for this peer
1832  * and leaves the following words in extra_options.
1833  */
1834 static void
set_allowed_addrs(unit,addrs,opts)1835 set_allowed_addrs(unit, addrs, opts)
1836     int unit;
1837     struct wordlist *addrs;
1838     struct wordlist *opts;
1839 {
1840     int n;
1841     struct wordlist *ap, **plink;
1842     struct permitted_ip *ip;
1843     char *ptr_word, *ptr_mask;
1844     struct hostent *hp;
1845     struct netent *np;
1846     u_int32_t a, mask, ah, offset;
1847     struct ipcp_options *wo = &ipcp_wantoptions[unit];
1848     u_int32_t suggested_ip = 0;
1849 
1850     if (addresses[unit] != NULL)
1851 	free(addresses[unit]);
1852     addresses[unit] = NULL;
1853     if (extra_options != NULL)
1854 	free_wordlist(extra_options);
1855     extra_options = opts;
1856 
1857     /*
1858      * Count the number of IP addresses given.
1859      */
1860     n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
1861     if (n == 0)
1862 	return;
1863     ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
1864     if (ip == 0)
1865 	return;
1866 
1867     /* temporarily append the noauth_addrs list to addrs */
1868     for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
1869 	;
1870     *plink = noauth_addrs;
1871 
1872     n = 0;
1873     for (ap = addrs; ap != NULL; ap = ap->next) {
1874 	/* "-" means no addresses authorized, "*" means any address allowed */
1875 	ptr_word = ap->word;
1876 	if (strcmp(ptr_word, "-") == 0)
1877 	    break;
1878 	if (strcmp(ptr_word, "*") == 0) {
1879 	    ip[n].permit = 1;
1880 	    ip[n].base = ip[n].mask = 0;
1881 	    ++n;
1882 	    break;
1883 	}
1884 
1885 	ip[n].permit = 1;
1886 	if (*ptr_word == '!') {
1887 	    ip[n].permit = 0;
1888 	    ++ptr_word;
1889 	}
1890 
1891 	mask = ~ (u_int32_t) 0;
1892 	offset = 0;
1893 	ptr_mask = strchr (ptr_word, '/');
1894 	if (ptr_mask != NULL) {
1895 	    int bit_count;
1896 	    char *endp;
1897 
1898 	    bit_count = (int) strtol (ptr_mask+1, &endp, 10);
1899 	    if (bit_count <= 0 || bit_count > 32) {
1900 		warn("invalid address length %v in auth. address list",
1901 		     ptr_mask+1);
1902 		continue;
1903 	    }
1904 	    bit_count = 32 - bit_count;	/* # bits in host part */
1905 	    if (*endp == '+') {
1906 		offset = ifunit + 1;
1907 		++endp;
1908 	    }
1909 	    if (*endp != 0) {
1910 		warn("invalid address length syntax: %v", ptr_mask+1);
1911 		continue;
1912 	    }
1913 	    *ptr_mask = '\0';
1914 	    mask <<= bit_count;
1915 	}
1916 
1917 	hp = gethostbyname(ptr_word);
1918 	if (hp != NULL && hp->h_addrtype == AF_INET) {
1919 	    a = *(u_int32_t *)hp->h_addr;
1920 	} else {
1921 	    np = getnetbyname (ptr_word);
1922 	    if (np != NULL && np->n_addrtype == AF_INET) {
1923 		a = htonl ((u_int32_t)np->n_net);
1924 		if (ptr_mask == NULL) {
1925 		    /* calculate appropriate mask for net */
1926 		    ah = ntohl(a);
1927 		    if (IN_CLASSA(ah))
1928 			mask = IN_CLASSA_NET;
1929 		    else if (IN_CLASSB(ah))
1930 			mask = IN_CLASSB_NET;
1931 		    else if (IN_CLASSC(ah))
1932 			mask = IN_CLASSC_NET;
1933 		}
1934 	    } else {
1935 		a = inet_addr (ptr_word);
1936 	    }
1937 	}
1938 
1939 	if (ptr_mask != NULL)
1940 	    *ptr_mask = '/';
1941 
1942 	if (a == (u_int32_t)-1L) {
1943 	    warn("unknown host %s in auth. address list", ap->word);
1944 	    continue;
1945 	}
1946 	if (offset != 0) {
1947 	    if (offset >= ~mask) {
1948 		warn("interface unit %d too large for subnet %v",
1949 		     ifunit, ptr_word);
1950 		continue;
1951 	    }
1952 	    a = htonl((ntohl(a) & mask) + offset);
1953 	    mask = ~(u_int32_t)0;
1954 	}
1955 	ip[n].mask = htonl(mask);
1956 	ip[n].base = a & ip[n].mask;
1957 	++n;
1958 	if (~mask == 0 && suggested_ip == 0)
1959 	    suggested_ip = a;
1960     }
1961     *plink = NULL;
1962 
1963     ip[n].permit = 0;		/* make the last entry forbid all addresses */
1964     ip[n].base = 0;		/* to terminate the list */
1965     ip[n].mask = 0;
1966 
1967     addresses[unit] = ip;
1968 
1969     /*
1970      * If the address given for the peer isn't authorized, or if
1971      * the user hasn't given one, AND there is an authorized address
1972      * which is a single host, then use that if we find one.
1973      */
1974     if (suggested_ip != 0
1975 	&& (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
1976 	wo->hisaddr = suggested_ip;
1977 	/*
1978 	 * Do we insist on this address?  No, if there are other
1979 	 * addresses authorized than the suggested one.
1980 	 */
1981 	if (n > 1)
1982 	    wo->accept_remote = 1;
1983     }
1984 }
1985 
1986 /*
1987  * auth_ip_addr - check whether the peer is authorized to use
1988  * a given IP address.  Returns 1 if authorized, 0 otherwise.
1989  */
1990 int
auth_ip_addr(unit,addr)1991 auth_ip_addr(unit, addr)
1992     int unit;
1993     u_int32_t addr;
1994 {
1995     int ok;
1996 
1997     /* don't allow loopback or multicast address */
1998     if (bad_ip_adrs(addr))
1999 	return 0;
2000 
2001     if (allowed_address_hook) {
2002 	ok = allowed_address_hook(addr);
2003 	if (ok >= 0) return ok;
2004     }
2005 
2006     if (addresses[unit] != NULL) {
2007 	ok = ip_addr_check(addr, addresses[unit]);
2008 	if (ok >= 0)
2009 	    return ok;
2010     }
2011 
2012     if (auth_required)
2013 	return 0;		/* no addresses authorized */
2014     return allow_any_ip || privileged || !have_route_to(addr);
2015 }
2016 
2017 static int
ip_addr_check(addr,addrs)2018 ip_addr_check(addr, addrs)
2019     u_int32_t addr;
2020     struct permitted_ip *addrs;
2021 {
2022     for (; ; ++addrs)
2023 	if ((addr & addrs->mask) == addrs->base)
2024 	    return addrs->permit;
2025 }
2026 
2027 /*
2028  * bad_ip_adrs - return 1 if the IP address is one we don't want
2029  * to use, such as an address in the loopback net or a multicast address.
2030  * addr is in network byte order.
2031  */
2032 int
bad_ip_adrs(addr)2033 bad_ip_adrs(addr)
2034     u_int32_t addr;
2035 {
2036     addr = ntohl(addr);
2037     return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
2038 	|| IN_MULTICAST(addr) || IN_BADCLASS(addr);
2039 }
2040 
2041 /*
2042  * some_ip_ok - check a wordlist to see if it authorizes any
2043  * IP address(es).
2044  */
2045 static int
some_ip_ok(addrs)2046 some_ip_ok(addrs)
2047     struct wordlist *addrs;
2048 {
2049     for (; addrs != 0; addrs = addrs->next) {
2050 	if (addrs->word[0] == '-')
2051 	    break;
2052 	if (addrs->word[0] != '!')
2053 	    return 1;		/* some IP address is allowed */
2054     }
2055     return 0;
2056 }
2057 
2058 /*
2059  * auth_number - check whether the remote number is allowed to connect.
2060  * Returns 1 if authorized, 0 otherwise.
2061  */
2062 int
auth_number()2063 auth_number()
2064 {
2065     struct wordlist *wp = permitted_numbers;
2066     int l;
2067 
2068     /* Allow all if no authorization list. */
2069     if (!wp)
2070 	return 1;
2071 
2072     /* Allow if we have a match in the authorization list. */
2073     while (wp) {
2074 	/* trailing '*' wildcard */
2075 	l = strlen(wp->word);
2076 	if ((wp->word)[l - 1] == '*')
2077 	    l--;
2078 	if (!strncasecmp(wp->word, remote_number, l))
2079 	    return 1;
2080 	wp = wp->next;
2081     }
2082 
2083     return 0;
2084 }
2085 
2086 /*
2087  * check_access - complain if a secret file has too-liberal permissions.
2088  */
2089 static void
check_access(f,filename)2090 check_access(f, filename)
2091     FILE *f;
2092     char *filename;
2093 {
2094     struct stat sbuf;
2095 
2096     if (fstat(fileno(f), &sbuf) < 0) {
2097 	warn("cannot stat secret file %s: %m", filename);
2098     } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
2099 	warn("Warning - secret file %s has world and/or group access",
2100 	     filename);
2101     }
2102 }
2103 
2104 
2105 /*
2106  * scan_authfile - Scan an authorization file for a secret suitable
2107  * for authenticating `client' on `server'.  The return value is -1
2108  * if no secret is found, otherwise >= 0.  The return value has
2109  * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
2110  * NONWILD_SERVER set if the secret didn't have "*" for the server.
2111  * Any following words on the line up to a "--" (i.e. address authorization
2112  * info) are placed in a wordlist and returned in *addrs.  Any
2113  * following words (extra options) are placed in a wordlist and
2114  * returned in *opts.
2115  * We assume secret is NULL or points to MAXWORDLEN bytes of space.
2116  * Flags are non-zero if we need two colons in the secret in order to
2117  * match.
2118  */
2119 static int
scan_authfile(f,client,server,secret,addrs,opts,filename,flags)2120 scan_authfile(f, client, server, secret, addrs, opts, filename, flags)
2121     FILE *f;
2122     char *client;
2123     char *server;
2124     char *secret;
2125     struct wordlist **addrs;
2126     struct wordlist **opts;
2127     char *filename;
2128     int flags;
2129 {
2130     int newline, xxx;
2131     int got_flag, best_flag;
2132     FILE *sf;
2133     struct wordlist *ap, *addr_list, *alist, **app;
2134     char word[MAXWORDLEN];
2135     char atfile[MAXWORDLEN];
2136     char lsecret[MAXWORDLEN];
2137     char *cp;
2138 
2139     if (addrs != NULL)
2140 	*addrs = NULL;
2141     if (opts != NULL)
2142 	*opts = NULL;
2143     addr_list = NULL;
2144     if (!getword(f, word, &newline, filename))
2145 	return -1;		/* file is empty??? */
2146     newline = 1;
2147     best_flag = -1;
2148     for (;;) {
2149 	/*
2150 	 * Skip until we find a word at the start of a line.
2151 	 */
2152 	while (!newline && getword(f, word, &newline, filename))
2153 	    ;
2154 	if (!newline)
2155 	    break;		/* got to end of file */
2156 
2157 	/*
2158 	 * Got a client - check if it's a match or a wildcard.
2159 	 */
2160 	got_flag = 0;
2161 	if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
2162 	    newline = 0;
2163 	    continue;
2164 	}
2165 	if (!ISWILD(word))
2166 	    got_flag = NONWILD_CLIENT;
2167 
2168 	/*
2169 	 * Now get a server and check if it matches.
2170 	 */
2171 	if (!getword(f, word, &newline, filename))
2172 	    break;
2173 	if (newline)
2174 	    continue;
2175 	if (!ISWILD(word)) {
2176 	    if (server != NULL && strcmp(word, server) != 0)
2177 		continue;
2178 	    got_flag |= NONWILD_SERVER;
2179 	}
2180 
2181 	/*
2182 	 * Got some sort of a match - see if it's better than what
2183 	 * we have already.
2184 	 */
2185 	if (got_flag <= best_flag)
2186 	    continue;
2187 
2188 	/*
2189 	 * Get the secret.
2190 	 */
2191 	if (!getword(f, word, &newline, filename))
2192 	    break;
2193 	if (newline)
2194 	    continue;
2195 
2196 	/*
2197 	 * SRP-SHA1 authenticator should never be reading secrets from
2198 	 * a file.  (Authenticatee may, though.)
2199 	 */
2200 	if (flags && ((cp = strchr(word, ':')) == NULL ||
2201 	    strchr(cp + 1, ':') == NULL))
2202 	    continue;
2203 
2204 	if (secret != NULL) {
2205 	    /*
2206 	     * Special syntax: @/pathname means read secret from file.
2207 	     */
2208 	    if (word[0] == '@' && word[1] == '/') {
2209 		strlcpy(atfile, word+1, sizeof(atfile));
2210 		if ((sf = fopen(atfile, "r")) == NULL) {
2211 		    warn("can't open indirect secret file %s", atfile);
2212 		    continue;
2213 		}
2214 		check_access(sf, atfile);
2215 		if (!getword(sf, word, &xxx, atfile)) {
2216 		    warn("no secret in indirect secret file %s", atfile);
2217 		    fclose(sf);
2218 		    continue;
2219 		}
2220 		fclose(sf);
2221 	    }
2222 	    strlcpy(lsecret, word, sizeof(lsecret));
2223 	}
2224 
2225 	/*
2226 	 * Now read address authorization info and make a wordlist.
2227 	 */
2228 	app = &alist;
2229 	for (;;) {
2230 	    if (!getword(f, word, &newline, filename) || newline)
2231 		break;
2232 	    ap = (struct wordlist *)
2233 		    malloc(sizeof(struct wordlist) + strlen(word) + 1);
2234 	    if (ap == NULL)
2235 		novm("authorized addresses");
2236 	    ap->word = (char *) (ap + 1);
2237 	    strcpy(ap->word, word);
2238 	    *app = ap;
2239 	    app = &ap->next;
2240 	}
2241 	*app = NULL;
2242 
2243 	/*
2244 	 * This is the best so far; remember it.
2245 	 */
2246 	best_flag = got_flag;
2247 	if (addr_list)
2248 	    free_wordlist(addr_list);
2249 	addr_list = alist;
2250 	if (secret != NULL)
2251 	    strlcpy(secret, lsecret, MAXWORDLEN);
2252 
2253 	if (!newline)
2254 	    break;
2255     }
2256 
2257     /* scan for a -- word indicating the start of options */
2258     for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
2259 	if (strcmp(ap->word, "--") == 0)
2260 	    break;
2261     /* ap = start of options */
2262     if (ap != NULL) {
2263 	ap = ap->next;		/* first option */
2264 	free(*app);			/* free the "--" word */
2265 	*app = NULL;		/* terminate addr list */
2266     }
2267     if (opts != NULL)
2268 	*opts = ap;
2269     else if (ap != NULL)
2270 	free_wordlist(ap);
2271     if (addrs != NULL)
2272 	*addrs = addr_list;
2273     else if (addr_list != NULL)
2274 	free_wordlist(addr_list);
2275 
2276     return best_flag;
2277 }
2278 
2279 /*
2280  * wordlist_count - return the number of items in a wordlist
2281  */
2282 static int
wordlist_count(wp)2283 wordlist_count(wp)
2284     struct wordlist *wp;
2285 {
2286     int n;
2287 
2288     for (n = 0; wp != NULL; wp = wp->next)
2289 	++n;
2290     return n;
2291 }
2292 
2293 /*
2294  * free_wordlist - release memory allocated for a wordlist.
2295  */
2296 static void
free_wordlist(wp)2297 free_wordlist(wp)
2298     struct wordlist *wp;
2299 {
2300     struct wordlist *next;
2301 
2302     while (wp != NULL) {
2303 	next = wp->next;
2304 	free(wp);
2305 	wp = next;
2306     }
2307 }
2308 
2309 /*
2310  * auth_script_done - called when the auth-up or auth-down script
2311  * has finished.
2312  */
2313 static void
auth_script_done(arg)2314 auth_script_done(arg)
2315     void *arg;
2316 {
2317     auth_script_pid = 0;
2318     switch (auth_script_state) {
2319     case s_up:
2320 	if (auth_state == s_down) {
2321 	    auth_script_state = s_down;
2322 	    auth_script(_PATH_AUTHDOWN);
2323 	}
2324 	break;
2325     case s_down:
2326 	if (auth_state == s_up) {
2327 	    auth_script_state = s_up;
2328 	    auth_script(_PATH_AUTHUP);
2329 	}
2330 	break;
2331     }
2332 }
2333 
2334 /*
2335  * auth_script - execute a script with arguments
2336  * interface-name peer-name real-user tty speed
2337  */
2338 static void
auth_script(script)2339 auth_script(script)
2340     char *script;
2341 {
2342     char strspeed[32];
2343     struct passwd *pw;
2344     char struid[32];
2345     char *user_name;
2346     char *argv[8];
2347 
2348     if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
2349 	user_name = pw->pw_name;
2350     else {
2351 	slprintf(struid, sizeof(struid), "%d", getuid());
2352 	user_name = struid;
2353     }
2354     slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
2355 
2356     argv[0] = script;
2357     argv[1] = ifname;
2358     argv[2] = peer_authname;
2359     argv[3] = user_name;
2360     argv[4] = devnam;
2361     argv[5] = strspeed;
2362     argv[6] = NULL;
2363 
2364     auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL, 0);
2365 }
2366