1 /*
2  * options.c - handles option processing for PPP.
3  *
4  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * 3. The name "Carnegie Mellon University" must not be used to
19  *    endorse or promote products derived from this software without
20  *    prior written permission. For permission or any legal
21  *    details, please contact
22  *      Office of Technology Transfer
23  *      Carnegie Mellon University
24  *      5000 Forbes Avenue
25  *      Pittsburgh, PA  15213-3890
26  *      (412) 268-4387, fax: (412) 268-7395
27  *      tech-transfer@andrew.cmu.edu
28  *
29  * 4. Redistributions of any form whatsoever must retain the following
30  *    acknowledgment:
31  *    "This product includes software developed by Computing Services
32  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
33  *
34  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
35  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
36  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
37  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
38  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
39  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
40  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41  */
42 
43 #define RCSID	"$Id: options.c,v 1.102 2008/06/15 06:53:06 paulus Exp $"
44 
45 #include <ctype.h>
46 #include <stdio.h>
47 #include <errno.h>
48 #include <unistd.h>
49 #include <fcntl.h>
50 #include <stdlib.h>
51 #include <syslog.h>
52 #include <string.h>
53 #include <pwd.h>
54 #ifdef PLUGIN
55 #include <dlfcn.h>
56 #endif
57 
58 #ifdef PPP_FILTER
59 #include <pcap.h>
60 /*
61  * There have been 3 or 4 different names for this in libpcap CVS, but
62  * this seems to be what they have settled on...
63  * For older versions of libpcap, use DLT_PPP - but that means
64  * we lose the inbound and outbound qualifiers.
65  */
66 #ifndef DLT_PPP_PPPD
67 #ifdef DLT_PPP_WITHDIRECTION
68 #define DLT_PPP_PPPD	DLT_PPP_WITHDIRECTION
69 #else
70 #define DLT_PPP_PPPD	DLT_PPP
71 #endif
72 #endif
73 #endif /* PPP_FILTER */
74 
75 #include "pppd.h"
76 #include "pathnames.h"
77 
78 #if defined(ultrix) || defined(NeXT)
79 char *strdup __P((char *));
80 #endif
81 
82 static const char rcsid[] = RCSID;
83 
84 struct option_value {
85     struct option_value *next;
86     const char *source;
87     char value[1];
88 };
89 
90 /*
91  * Option variables and default values.
92  */
93 int	debug = 0;		/* Debug flag */
94 int	kdebugflag = 0;		/* Tell kernel to print debug messages */
95 int	default_device = 1;	/* Using /dev/tty or equivalent */
96 char	devnam[MAXPATHLEN];	/* Device name */
97 bool	nodetach = 0;		/* Don't detach from controlling tty */
98 bool	updetach = 0;		/* Detach once link is up */
99 bool	master_detach;		/* Detach when we're (only) multilink master */
100 int	maxconnect = 0;		/* Maximum connect time */
101 char	user[MAXNAMELEN];	/* Username for PAP */
102 char	passwd[MAXSECRETLEN];	/* Password for PAP */
103 bool	persist = 0;		/* Reopen link after it goes down */
104 char	our_name[MAXNAMELEN];	/* Our name for authentication purposes */
105 bool	demand = 0;		/* do dial-on-demand */
106 char	*ipparam = NULL;	/* Extra parameter for ip up/down scripts */
107 int	idle_time_limit = 0;	/* Disconnect if idle for this many seconds */
108 int	holdoff = 30;		/* # seconds to pause before reconnecting */
109 bool	holdoff_specified;	/* true if a holdoff value has been given */
110 int	log_to_fd = 1;		/* send log messages to this fd too */
111 bool	log_default = 1;	/* log_to_fd is default (stdout) */
112 int	maxfail = 10;		/* max # of unsuccessful connection attempts */
113 char	linkname[MAXPATHLEN];	/* logical name for link */
114 bool	tune_kernel;		/* may alter kernel settings */
115 int	connect_delay = 1000;	/* wait this many ms after connect script */
116 int	req_unit = -1;		/* requested interface unit */
117 bool	multilink = 0;		/* Enable multilink operation */
118 char	*bundle_name = NULL;	/* bundle name for multilink */
119 bool	dump_options;		/* print out option values */
120 bool	dryrun;			/* print out option values and exit */
121 char	*domain;		/* domain name set by domain option */
122 int	child_wait = 5;		/* # seconds to wait for children at exit */
123 struct userenv *userenv_list;	/* user environment variables */
124 
125 #ifdef MAXOCTETS
126 unsigned int  maxoctets = 0;    /* default - no limit */
127 int maxoctets_dir = 0;       /* default - sum of traffic */
128 int maxoctets_timeout = 1;   /* default 1 second */
129 #endif
130 
131 
132 extern option_t auth_options[];
133 extern struct stat devstat;
134 
135 #ifdef PPP_FILTER
136 struct	bpf_program pass_filter;/* Filter program for packets to pass */
137 struct	bpf_program active_filter; /* Filter program for link-active pkts */
138 #endif
139 
140 static option_t *curopt;	/* pointer to option being processed */
141 char *current_option;		/* the name of the option being parsed */
142 int  privileged_option;		/* set iff the current option came from root */
143 char *option_source;		/* string saying where the option came from */
144 int  option_priority = OPRIO_CFGFILE; /* priority of the current options */
145 bool devnam_fixed;		/* can no longer change device name */
146 
147 static int logfile_fd = -1;	/* fd opened for log file */
148 static char logfile_name[MAXPATHLEN];	/* name of log file */
149 
150 /*
151  * Prototypes
152  */
153 static int setdomain __P((char **));
154 static int readfile __P((char **));
155 static int callfile __P((char **));
156 static int showversion __P((char **));
157 static int showhelp __P((char **));
158 static void usage __P((void));
159 static int setlogfile __P((char **));
160 #ifdef PLUGIN
161 static int loadplugin __P((char **));
162 #endif
163 
164 #ifdef PPP_FILTER
165 static int setpassfilter __P((char **));
166 static int setactivefilter __P((char **));
167 #endif
168 
169 #ifdef MAXOCTETS
170 static int setmodir __P((char **));
171 #endif
172 
173 static int user_setenv __P((char **));
174 static void user_setprint __P((option_t *, printer_func, void *));
175 static int user_unsetenv __P((char **));
176 static void user_unsetprint __P((option_t *, printer_func, void *));
177 
178 static option_t *find_option __P((const char *name));
179 static int process_option __P((option_t *, char *, char **));
180 static int n_arguments __P((option_t *));
181 static int number_option __P((char *, u_int32_t *, int));
182 
183 /*
184  * Structure to store extra lists of options.
185  */
186 struct option_list {
187     option_t *options;
188     struct option_list *next;
189 };
190 
191 static struct option_list *extra_options = NULL;
192 
193 /*
194  * Valid arguments.
195  */
196 option_t general_options[] = {
197     { "debug", o_int, &debug,
198       "Increase debugging level", OPT_INC | OPT_NOARG | 1 },
199     { "-d", o_int, &debug,
200       "Increase debugging level",
201       OPT_ALIAS | OPT_INC | OPT_NOARG | 1 },
202 
203     { "kdebug", o_int, &kdebugflag,
204       "Set kernel driver debug level", OPT_PRIO },
205 
206     { "nodetach", o_bool, &nodetach,
207       "Don't detach from controlling tty", OPT_PRIO | 1 },
208     { "-detach", o_bool, &nodetach,
209       "Don't detach from controlling tty", OPT_ALIAS | OPT_PRIOSUB | 1 },
210     { "updetach", o_bool, &updetach,
211       "Detach from controlling tty once link is up",
212       OPT_PRIOSUB | OPT_A2CLR | 1, &nodetach },
213 
214     { "master_detach", o_bool, &master_detach,
215       "Detach when we're multilink master but have no link", 1 },
216 
217     { "holdoff", o_int, &holdoff,
218       "Set time in seconds before retrying connection",
219       OPT_PRIO, &holdoff_specified },
220 
221     { "idle", o_int, &idle_time_limit,
222       "Set time in seconds before disconnecting idle link", OPT_PRIO },
223 
224     { "maxconnect", o_int, &maxconnect,
225       "Set connection time limit",
226       OPT_PRIO | OPT_LLIMIT | OPT_NOINCR | OPT_ZEROINF },
227 
228     { "domain", o_special, (void *)setdomain,
229       "Add given domain name to hostname",
230       OPT_PRIO | OPT_PRIV | OPT_A2STRVAL, &domain },
231 
232     { "file", o_special, (void *)readfile,
233       "Take options from a file", OPT_NOPRINT },
234     { "call", o_special, (void *)callfile,
235       "Take options from a privileged file", OPT_NOPRINT },
236 
237     { "persist", o_bool, &persist,
238       "Keep on reopening connection after close", OPT_PRIO | 1 },
239     { "nopersist", o_bool, &persist,
240       "Turn off persist option", OPT_PRIOSUB },
241 
242     { "demand", o_bool, &demand,
243       "Dial on demand", OPT_INITONLY | 1, &persist },
244 
245     { "--version", o_special_noarg, (void *)showversion,
246       "Show version number" },
247     { "--help", o_special_noarg, (void *)showhelp,
248       "Show brief listing of options" },
249     { "-h", o_special_noarg, (void *)showhelp,
250       "Show brief listing of options", OPT_ALIAS },
251 
252     { "logfile", o_special, (void *)setlogfile,
253       "Append log messages to this file",
254       OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, &logfile_name },
255     { "logfd", o_int, &log_to_fd,
256       "Send log messages to this file descriptor",
257       OPT_PRIOSUB | OPT_A2CLR, &log_default },
258     { "nolog", o_int, &log_to_fd,
259       "Don't send log messages to any file",
260       OPT_PRIOSUB | OPT_NOARG | OPT_VAL(-1) },
261     { "nologfd", o_int, &log_to_fd,
262       "Don't send log messages to any file descriptor",
263       OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) },
264 
265     { "linkname", o_string, linkname,
266       "Set logical name for link",
267       OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXPATHLEN },
268 
269     { "maxfail", o_int, &maxfail,
270       "Maximum number of unsuccessful connection attempts to allow",
271       OPT_PRIO },
272 
273     { "ktune", o_bool, &tune_kernel,
274       "Alter kernel settings as necessary", OPT_PRIO | 1 },
275     { "noktune", o_bool, &tune_kernel,
276       "Don't alter kernel settings", OPT_PRIOSUB },
277 
278     { "connect-delay", o_int, &connect_delay,
279       "Maximum time (in ms) to wait after connect script finishes",
280       OPT_PRIO },
281 
282     { "unit", o_int, &req_unit,
283       "PPP interface unit number to use if possible",
284       OPT_PRIO | OPT_LLIMIT, 0, 0 },
285 
286     { "dump", o_bool, &dump_options,
287       "Print out option values after parsing all options", 1 },
288     { "dryrun", o_bool, &dryrun,
289       "Stop after parsing, printing, and checking options", 1 },
290 
291     { "child-timeout", o_int, &child_wait,
292       "Number of seconds to wait for child processes at exit",
293       OPT_PRIO },
294 
295     { "set", o_special, (void *)user_setenv,
296       "Set user environment variable",
297       OPT_A2PRINTER | OPT_NOPRINT, (void *)user_setprint },
298     { "unset", o_special, (void *)user_unsetenv,
299       "Unset user environment variable",
300       OPT_A2PRINTER | OPT_NOPRINT, (void *)user_unsetprint },
301 
302 #ifdef HAVE_MULTILINK
303     { "multilink", o_bool, &multilink,
304       "Enable multilink operation", OPT_PRIO | 1 },
305     { "mp", o_bool, &multilink,
306       "Enable multilink operation", OPT_PRIOSUB | OPT_ALIAS | 1 },
307     { "nomultilink", o_bool, &multilink,
308       "Disable multilink operation", OPT_PRIOSUB | 0 },
309     { "nomp", o_bool, &multilink,
310       "Disable multilink operation", OPT_PRIOSUB | OPT_ALIAS | 0 },
311 
312     { "bundle", o_string, &bundle_name,
313       "Bundle name for multilink", OPT_PRIO },
314 #endif /* HAVE_MULTILINK */
315 
316 #ifdef PLUGIN
317     { "plugin", o_special, (void *)loadplugin,
318       "Load a plug-in module into pppd", OPT_PRIV | OPT_A2LIST },
319 #endif
320 
321 #ifdef PPP_FILTER
322     { "pass-filter", o_special, setpassfilter,
323       "set filter for packets to pass", OPT_PRIO },
324 
325     { "active-filter", o_special, setactivefilter,
326       "set filter for active pkts", OPT_PRIO },
327 #endif
328 
329 #ifdef MAXOCTETS
330     { "maxoctets", o_int, &maxoctets,
331       "Set connection traffic limit",
332       OPT_PRIO | OPT_LLIMIT | OPT_NOINCR | OPT_ZEROINF },
333     { "mo", o_int, &maxoctets,
334       "Set connection traffic limit",
335       OPT_ALIAS | OPT_PRIO | OPT_LLIMIT | OPT_NOINCR | OPT_ZEROINF },
336     { "mo-direction", o_special, setmodir,
337       "Set direction for limit traffic (sum,in,out,max)" },
338     { "mo-timeout", o_int, &maxoctets_timeout,
339       "Check for traffic limit every N seconds", OPT_PRIO | OPT_LLIMIT | 1 },
340 #endif
341 
342     { NULL }
343 };
344 
345 #ifndef IMPLEMENTATION
346 #define IMPLEMENTATION ""
347 #endif
348 
349 static char *usage_string = "\
350 pppd version %s\n\
351 Usage: %s [ options ], where options are:\n\
352 	<device>	Communicate over the named device\n\
353 	<speed>		Set the baud rate to <speed>\n\
354 	<loc>:<rem>	Set the local and/or remote interface IP\n\
355 			addresses.  Either one may be omitted.\n\
356 	asyncmap <n>	Set the desired async map to hex <n>\n\
357 	auth		Require authentication from peer\n\
358         connect <p>     Invoke shell command <p> to set up the serial line\n\
359 	crtscts		Use hardware RTS/CTS flow control\n\
360 	defaultroute	Add default route through interface\n\
361 	file <f>	Take options from file <f>\n\
362 	modem		Use modem control lines\n\
363 	mru <n>		Set MRU value to <n> for negotiation\n\
364 See pppd(8) for more options.\n\
365 ";
366 
367 /*
368  * parse_args - parse a string of arguments from the command line.
369  */
370 int
parse_args(argc,argv)371 parse_args(argc, argv)
372     int argc;
373     char **argv;
374 {
375     char *arg;
376     option_t *opt;
377     int n;
378 
379     privileged_option = privileged;
380     option_source = "command line";
381     option_priority = OPRIO_CMDLINE;
382     while (argc > 0) {
383 	arg = *argv++;
384 	--argc;
385 	opt = find_option(arg);
386 	if (opt == NULL) {
387 	    option_error("unrecognized option '%s'", arg);
388 	    usage();
389 	    return 0;
390 	}
391 	n = n_arguments(opt);
392 	if (argc < n) {
393 	    option_error("too few parameters for option %s", arg);
394 	    return 0;
395 	}
396 	if (!process_option(opt, arg, argv))
397 	    return 0;
398 	argc -= n;
399 	argv += n;
400     }
401     return 1;
402 }
403 
404 /*
405  * options_from_file - Read a string of options from a file,
406  * and interpret them.
407  */
408 int
options_from_file(filename,must_exist,check_prot,priv)409 options_from_file(filename, must_exist, check_prot, priv)
410     char *filename;
411     int must_exist;
412     int check_prot;
413     int priv;
414 {
415     FILE *f;
416     int i, newline, ret, err;
417     option_t *opt;
418     int oldpriv, n;
419     char *oldsource;
420     uid_t euid;
421     char *argv[MAXARGS];
422     char args[MAXARGS][MAXWORDLEN];
423     char cmd[MAXWORDLEN];
424 
425     euid = geteuid();
426     if (check_prot && seteuid(getuid()) == -1) {
427 	option_error("unable to drop privileges to open %s: %m", filename);
428 	return 0;
429     }
430     f = fopen(filename, "r");
431     err = errno;
432     if (check_prot && seteuid(euid) == -1)
433 	fatal("unable to regain privileges");
434     if (f == NULL) {
435 	errno = err;
436 	if (!must_exist) {
437 	    if (err != ENOENT && err != ENOTDIR)
438 		warn("Warning: can't open options file %s: %m", filename);
439 	    return 1;
440 	}
441 	option_error("Can't open options file %s: %m", filename);
442 	return 0;
443     }
444 
445     oldpriv = privileged_option;
446     privileged_option = priv;
447     oldsource = option_source;
448     option_source = strdup(filename);
449     if (option_source == NULL)
450 	option_source = "file";
451     ret = 0;
452     while (getword(f, cmd, &newline, filename)) {
453 	opt = find_option(cmd);
454 	if (opt == NULL) {
455 	    option_error("In file %s: unrecognized option '%s'",
456 			 filename, cmd);
457 	    goto err;
458 	}
459 	n = n_arguments(opt);
460 	for (i = 0; i < n; ++i) {
461 	    if (!getword(f, args[i], &newline, filename)) {
462 		option_error(
463 			"In file %s: too few parameters for option '%s'",
464 			filename, cmd);
465 		goto err;
466 	    }
467 	    argv[i] = args[i];
468 	}
469 	if (!process_option(opt, cmd, argv))
470 	    goto err;
471     }
472     ret = 1;
473 
474 err:
475     fclose(f);
476     privileged_option = oldpriv;
477     option_source = oldsource;
478     return ret;
479 }
480 
481 /*
482  * options_from_user - See if the use has a ~/.ppprc file,
483  * and if so, interpret options from it.
484  */
485 int
options_from_user()486 options_from_user()
487 {
488     char *user, *path, *file;
489     int ret;
490     struct passwd *pw;
491     size_t pl;
492 
493     pw = getpwuid(getuid());
494     if (pw == NULL || (user = pw->pw_dir) == NULL || user[0] == 0)
495 	return 1;
496     file = _PATH_USEROPT;
497     pl = strlen(user) + strlen(file) + 2;
498     path = malloc(pl);
499     if (path == NULL)
500 	novm("init file name");
501     slprintf(path, pl, "%s/%s", user, file);
502     option_priority = OPRIO_CFGFILE;
503     ret = options_from_file(path, 0, 1, privileged);
504     free(path);
505     return ret;
506 }
507 
508 /*
509  * options_for_tty - See if an options file exists for the serial
510  * device, and if so, interpret options from it.
511  * We only allow the per-tty options file to override anything from
512  * the command line if it is something that the user can't override
513  * once it has been set by root; this is done by giving configuration
514  * files a lower priority than the command line.
515  */
516 int
options_for_tty()517 options_for_tty()
518 {
519     char *dev, *path, *p;
520     int ret;
521     size_t pl;
522 
523     dev = devnam;
524     if ((p = strstr(dev, "/dev/")) != NULL)
525 	dev = p + 5;
526     if (dev[0] == 0 || strcmp(dev, "tty") == 0)
527 	return 1;		/* don't look for /etc/ppp/options.tty */
528     pl = strlen(_PATH_TTYOPT) + strlen(dev) + 1;
529     path = malloc(pl);
530     if (path == NULL)
531 	novm("tty init file name");
532     slprintf(path, pl, "%s%s", _PATH_TTYOPT, dev);
533     /* Turn slashes into dots, for Solaris case (e.g. /dev/term/a) */
534     for (p = path + strlen(_PATH_TTYOPT); *p != 0; ++p)
535 	if (*p == '/')
536 	    *p = '.';
537     option_priority = OPRIO_CFGFILE;
538     ret = options_from_file(path, 0, 0, 1);
539     free(path);
540     return ret;
541 }
542 
543 /*
544  * options_from_list - process a string of options in a wordlist.
545  */
546 int
options_from_list(w,priv)547 options_from_list(w, priv)
548     struct wordlist *w;
549     int priv;
550 {
551     char *argv[MAXARGS];
552     option_t *opt;
553     int i, n, ret = 0;
554     struct wordlist *w0;
555 
556     privileged_option = priv;
557     option_source = "secrets file";
558     option_priority = OPRIO_SECFILE;
559 
560     while (w != NULL) {
561 	opt = find_option(w->word);
562 	if (opt == NULL) {
563 	    option_error("In secrets file: unrecognized option '%s'",
564 			 w->word);
565 	    goto err;
566 	}
567 	n = n_arguments(opt);
568 	w0 = w;
569 	for (i = 0; i < n; ++i) {
570 	    w = w->next;
571 	    if (w == NULL) {
572 		option_error(
573 			"In secrets file: too few parameters for option '%s'",
574 			w0->word);
575 		goto err;
576 	    }
577 	    argv[i] = w->word;
578 	}
579 	if (!process_option(opt, w0->word, argv))
580 	    goto err;
581 	w = w->next;
582     }
583     ret = 1;
584 
585 err:
586     return ret;
587 }
588 
589 /*
590  * match_option - see if this option matches an option_t structure.
591  */
592 static int
match_option(name,opt,dowild)593 match_option(name, opt, dowild)
594     char *name;
595     option_t *opt;
596     int dowild;
597 {
598 	int (*match) __P((char *, char **, int));
599 
600 	if (dowild != (opt->type == o_wild))
601 		return 0;
602 	if (!dowild)
603 		return strcmp(name, opt->name) == 0;
604 	match = (int (*) __P((char *, char **, int))) opt->addr;
605 	return (*match)(name, NULL, 0);
606 }
607 
608 /*
609  * find_option - scan the option lists for the various protocols
610  * looking for an entry with the given name.
611  * This could be optimized by using a hash table.
612  */
613 static option_t *
find_option(name)614 find_option(name)
615     const char *name;
616 {
617 	option_t *opt;
618 	struct option_list *list;
619 	int i, dowild;
620 
621 	for (dowild = 0; dowild <= 1; ++dowild) {
622 		for (opt = general_options; opt->name != NULL; ++opt)
623 			if (match_option(name, opt, dowild))
624 				return opt;
625 		for (opt = auth_options; opt->name != NULL; ++opt)
626 			if (match_option(name, opt, dowild))
627 				return opt;
628 		for (list = extra_options; list != NULL; list = list->next)
629 			for (opt = list->options; opt->name != NULL; ++opt)
630 				if (match_option(name, opt, dowild))
631 					return opt;
632 		for (opt = the_channel->options; opt->name != NULL; ++opt)
633 			if (match_option(name, opt, dowild))
634 				return opt;
635 		for (i = 0; protocols[i] != NULL; ++i)
636 			if ((opt = protocols[i]->options) != NULL)
637 				for (; opt->name != NULL; ++opt)
638 					if (match_option(name, opt, dowild))
639 						return opt;
640 	}
641 	return NULL;
642 }
643 
644 /*
645  * process_option - process one new-style option.
646  */
647 static int
process_option(opt,cmd,argv)648 process_option(opt, cmd, argv)
649     option_t *opt;
650     char *cmd;
651     char **argv;
652 {
653     u_int32_t v;
654     int iv, a;
655     char *sv;
656     int (*parser) __P((char **));
657     int (*wildp) __P((char *, char **, int));
658     char *optopt = (opt->type == o_wild)? "": " option";
659     int prio = option_priority;
660     option_t *mainopt = opt;
661 
662     current_option = opt->name;
663     if ((opt->flags & OPT_PRIVFIX) && privileged_option)
664 	prio += OPRIO_ROOT;
665     while (mainopt->flags & OPT_PRIOSUB)
666 	--mainopt;
667     if (mainopt->flags & OPT_PRIO) {
668 	if (prio < mainopt->priority) {
669 	    /* new value doesn't override old */
670 	    if (prio == OPRIO_CMDLINE && mainopt->priority > OPRIO_ROOT) {
671 		option_error("%s%s set in %s cannot be overridden\n",
672 			     opt->name, optopt, mainopt->source);
673 		return 0;
674 	    }
675 	    return 1;
676 	}
677 	if (prio > OPRIO_ROOT && mainopt->priority == OPRIO_CMDLINE)
678 	    warn("%s%s from %s overrides command line",
679 		 opt->name, optopt, option_source);
680     }
681 
682     if ((opt->flags & OPT_INITONLY) && phase != PHASE_INITIALIZE) {
683 	option_error("%s%s cannot be changed after initialization",
684 		     opt->name, optopt);
685 	return 0;
686     }
687     if ((opt->flags & OPT_PRIV) && !privileged_option) {
688 	option_error("using the %s%s requires root privilege",
689 		     opt->name, optopt);
690 	return 0;
691     }
692     if ((opt->flags & OPT_ENABLE) && *(bool *)(opt->addr2) == 0) {
693 	option_error("%s%s is disabled", opt->name, optopt);
694 	return 0;
695     }
696     if ((opt->flags & OPT_DEVEQUIV) && devnam_fixed) {
697 	option_error("the %s%s may not be changed in %s",
698 		     opt->name, optopt, option_source);
699 	return 0;
700     }
701 
702     switch (opt->type) {
703     case o_bool:
704 	v = opt->flags & OPT_VALUE;
705 	*(bool *)(opt->addr) = v;
706 	if (opt->addr2 && (opt->flags & OPT_A2COPY))
707 	    *(bool *)(opt->addr2) = v;
708 	else if (opt->addr2 && (opt->flags & OPT_A2CLR))
709 	    *(bool *)(opt->addr2) = 0;
710 	else if (opt->addr2 && (opt->flags & OPT_A2CLRB))
711 	    *(u_char *)(opt->addr2) &= ~v;
712 	else if (opt->addr2 && (opt->flags & OPT_A2OR))
713 	    *(u_char *)(opt->addr2) |= v;
714 	break;
715 
716     case o_int:
717 	iv = 0;
718 	if ((opt->flags & OPT_NOARG) == 0) {
719 	    if (!int_option(*argv, &iv))
720 		return 0;
721 	    if ((((opt->flags & OPT_LLIMIT) && iv < opt->lower_limit)
722 		 || ((opt->flags & OPT_ULIMIT) && iv > opt->upper_limit))
723 		&& !((opt->flags & OPT_ZEROOK && iv == 0))) {
724 		char *zok = (opt->flags & OPT_ZEROOK)? " zero or": "";
725 		switch (opt->flags & OPT_LIMITS) {
726 		case OPT_LLIMIT:
727 		    option_error("%s value must be%s >= %d",
728 				 opt->name, zok, opt->lower_limit);
729 		    break;
730 		case OPT_ULIMIT:
731 		    option_error("%s value must be%s <= %d",
732 				 opt->name, zok, opt->upper_limit);
733 		    break;
734 		case OPT_LIMITS:
735 		    option_error("%s value must be%s between %d and %d",
736 				opt->name, zok, opt->lower_limit, opt->upper_limit);
737 		    break;
738 		}
739 		return 0;
740 	    }
741 	}
742 	a = opt->flags & OPT_VALUE;
743 	if (a >= 128)
744 	    a -= 256;		/* sign extend */
745 	iv += a;
746 	if (opt->flags & OPT_INC)
747 	    iv += *(int *)(opt->addr);
748 	if ((opt->flags & OPT_NOINCR) && !privileged_option) {
749 	    int oldv = *(int *)(opt->addr);
750 	    if ((opt->flags & OPT_ZEROINF) ?
751 		(oldv != 0 && (iv == 0 || iv > oldv)) : (iv > oldv)) {
752 		option_error("%s value cannot be increased", opt->name);
753 		return 0;
754 	    }
755 	}
756 	*(int *)(opt->addr) = iv;
757 	if (opt->addr2 && (opt->flags & OPT_A2COPY))
758 	    *(int *)(opt->addr2) = iv;
759 	break;
760 
761     case o_uint32:
762 	if (opt->flags & OPT_NOARG) {
763 	    v = opt->flags & OPT_VALUE;
764 	    if (v & 0x80)
765 		    v |= 0xffffff00U;
766 	} else if (!number_option(*argv, &v, 16))
767 	    return 0;
768 	if (opt->flags & OPT_OR)
769 	    v |= *(u_int32_t *)(opt->addr);
770 	*(u_int32_t *)(opt->addr) = v;
771 	if (opt->addr2 && (opt->flags & OPT_A2COPY))
772 	    *(u_int32_t *)(opt->addr2) = v;
773 	break;
774 
775     case o_string:
776 	if (opt->flags & OPT_STATIC) {
777 	    strlcpy((char *)(opt->addr), *argv, opt->upper_limit);
778 	} else {
779 	    char **optptr = (char **)(opt->addr);
780 	    sv = strdup(*argv);
781 	    if (sv == NULL)
782 		novm("option argument");
783 	    if (*optptr)
784 		free(*optptr);
785 	    *optptr = sv;
786 	}
787 	break;
788 
789     case o_special_noarg:
790     case o_special:
791 	parser = (int (*) __P((char **))) opt->addr;
792 	curopt = opt;
793 	if (!(*parser)(argv))
794 	    return 0;
795 	if (opt->flags & OPT_A2LIST) {
796 	    struct option_value *ovp, *pp;
797 
798 	    ovp = malloc(sizeof(*ovp) + strlen(*argv));
799 	    if (ovp != 0) {
800 		strcpy(ovp->value, *argv);
801 		ovp->source = option_source;
802 		ovp->next = NULL;
803 		if (opt->addr2 == NULL) {
804 		    opt->addr2 = ovp;
805 		} else {
806 		    for (pp = opt->addr2; pp->next != NULL; pp = pp->next)
807 			;
808 		    pp->next = ovp;
809 		}
810 	    }
811 	}
812 	break;
813 
814     case o_wild:
815 	wildp = (int (*) __P((char *, char **, int))) opt->addr;
816 	if (!(*wildp)(cmd, argv, 1))
817 	    return 0;
818 	break;
819     }
820 
821     /*
822      * If addr2 wasn't used by any flag (OPT_A2COPY, etc.) but is set,
823      * treat it as a bool and set/clear it based on the OPT_A2CLR bit.
824      */
825     if (opt->addr2 && (opt->flags & (OPT_A2COPY|OPT_ENABLE
826 		|OPT_A2PRINTER|OPT_A2STRVAL|OPT_A2LIST|OPT_A2OR)) == 0)
827 	*(bool *)(opt->addr2) = !(opt->flags & OPT_A2CLR);
828 
829     mainopt->source = option_source;
830     mainopt->priority = prio;
831     mainopt->winner = opt - mainopt;
832 
833     return 1;
834 }
835 
836 /*
837  * override_value - if the option priorities would permit us to
838  * override the value of option, return 1 and update the priority
839  * and source of the option value.  Otherwise returns 0.
840  */
841 int
override_value(option,priority,source)842 override_value(option, priority, source)
843     const char *option;
844     int priority;
845     const char *source;
846 {
847 	option_t *opt;
848 
849 	opt = find_option(option);
850 	if (opt == NULL)
851 		return 0;
852 	while (opt->flags & OPT_PRIOSUB)
853 		--opt;
854 	if ((opt->flags & OPT_PRIO) && priority < opt->priority)
855 		return 0;
856 	opt->priority = priority;
857 	opt->source = source;
858 	opt->winner = -1;
859 	return 1;
860 }
861 
862 /*
863  * n_arguments - tell how many arguments an option takes
864  */
865 static int
n_arguments(opt)866 n_arguments(opt)
867     option_t *opt;
868 {
869 	return (opt->type == o_bool || opt->type == o_special_noarg
870 		|| (opt->flags & OPT_NOARG))? 0: 1;
871 }
872 
873 /*
874  * add_options - add a list of options to the set we grok.
875  */
876 void
add_options(opt)877 add_options(opt)
878     option_t *opt;
879 {
880     struct option_list *list;
881 
882     list = malloc(sizeof(*list));
883     if (list == 0)
884 	novm("option list entry");
885     list->options = opt;
886     list->next = extra_options;
887     extra_options = list;
888 }
889 
890 /*
891  * check_options - check that options are valid and consistent.
892  */
893 void
check_options()894 check_options()
895 {
896 	if (logfile_fd >= 0 && logfile_fd != log_to_fd)
897 		close(logfile_fd);
898 }
899 
900 /*
901  * print_option - print out an option and its value
902  */
903 static void
print_option(opt,mainopt,printer,arg)904 print_option(opt, mainopt, printer, arg)
905     option_t *opt, *mainopt;
906     printer_func printer;
907     void *arg;
908 {
909 	int i, v;
910 	char *p;
911 
912 	if (opt->flags & OPT_NOPRINT)
913 		return;
914 	switch (opt->type) {
915 	case o_bool:
916 		v = opt->flags & OPT_VALUE;
917 		if (*(bool *)opt->addr != v)
918 			/* this can happen legitimately, e.g. lock
919 			   option turned off for default device */
920 			break;
921 		printer(arg, "%s", opt->name);
922 		break;
923 	case o_int:
924 		v = opt->flags & OPT_VALUE;
925 		if (v >= 128)
926 			v -= 256;
927 		i = *(int *)opt->addr;
928 		if (opt->flags & OPT_NOARG) {
929 			printer(arg, "%s", opt->name);
930 			if (i != v) {
931 				if (opt->flags & OPT_INC) {
932 					for (; i > v; i -= v)
933 						printer(arg, " %s", opt->name);
934 				} else
935 					printer(arg, " # oops: %d not %d\n",
936 						i, v);
937 			}
938 		} else {
939 			printer(arg, "%s %d", opt->name, i);
940 		}
941 		break;
942 	case o_uint32:
943 		printer(arg, "%s", opt->name);
944 		if ((opt->flags & OPT_NOARG) == 0)
945 			printer(arg, " %x", *(u_int32_t *)opt->addr);
946 		break;
947 
948 	case o_string:
949 		if (opt->flags & OPT_HIDE) {
950 			p = "??????";
951 		} else {
952 			p = (char *) opt->addr;
953 			if ((opt->flags & OPT_STATIC) == 0)
954 				p = *(char **)p;
955 		}
956 		printer(arg, "%s %q", opt->name, p);
957 		break;
958 
959 	case o_special:
960 	case o_special_noarg:
961 	case o_wild:
962 		if (opt->type != o_wild) {
963 			printer(arg, "%s", opt->name);
964 			if (n_arguments(opt) == 0)
965 				break;
966 			printer(arg, " ");
967 		}
968 		if (opt->flags & OPT_A2PRINTER) {
969 			void (*oprt) __P((option_t *, printer_func, void *));
970 			oprt = (void (*) __P((option_t *, printer_func,
971 					 void *)))opt->addr2;
972 			(*oprt)(opt, printer, arg);
973 		} else if (opt->flags & OPT_A2STRVAL) {
974 			p = (char *) opt->addr2;
975 			if ((opt->flags & OPT_STATIC) == 0)
976 				p = *(char **)p;
977 			printer("%q", p);
978 		} else if (opt->flags & OPT_A2LIST) {
979 			struct option_value *ovp;
980 
981 			ovp = (struct option_value *) opt->addr2;
982 			for (;;) {
983 				printer(arg, "%q", ovp->value);
984 				if ((ovp = ovp->next) == NULL)
985 					break;
986 				printer(arg, "\t\t# (from %s)\n%s ",
987 					ovp->source, opt->name);
988 			}
989 		} else {
990 			printer(arg, "xxx # [don't know how to print value]");
991 		}
992 		break;
993 
994 	default:
995 		printer(arg, "# %s value (type %d\?\?)", opt->name, opt->type);
996 		break;
997 	}
998 	printer(arg, "\t\t# (from %s)\n", mainopt->source);
999 }
1000 
1001 /*
1002  * print_option_list - print out options in effect from an
1003  * array of options.
1004  */
1005 static void
print_option_list(opt,printer,arg)1006 print_option_list(opt, printer, arg)
1007     option_t *opt;
1008     printer_func printer;
1009     void *arg;
1010 {
1011 	while (opt->name != NULL) {
1012 		if (opt->priority != OPRIO_DEFAULT
1013 		    && opt->winner != (short int) -1)
1014 			print_option(opt + opt->winner, opt, printer, arg);
1015 		do {
1016 			++opt;
1017 		} while (opt->flags & OPT_PRIOSUB);
1018 	}
1019 }
1020 
1021 /*
1022  * print_options - print out what options are in effect.
1023  */
1024 void
print_options(printer,arg)1025 print_options(printer, arg)
1026     printer_func printer;
1027     void *arg;
1028 {
1029 	struct option_list *list;
1030 	int i;
1031 
1032 	printer(arg, "pppd options in effect:\n");
1033 	print_option_list(general_options, printer, arg);
1034 	print_option_list(auth_options, printer, arg);
1035 	for (list = extra_options; list != NULL; list = list->next)
1036 		print_option_list(list->options, printer, arg);
1037 	print_option_list(the_channel->options, printer, arg);
1038 	for (i = 0; protocols[i] != NULL; ++i)
1039 		print_option_list(protocols[i]->options, printer, arg);
1040 }
1041 
1042 /*
1043  * usage - print out a message telling how to use the program.
1044  */
1045 static void
usage()1046 usage()
1047 {
1048     if (phase == PHASE_INITIALIZE)
1049 	fprintf(stderr, usage_string, VERSION, progname);
1050 }
1051 
1052 /*
1053  * showhelp - print out usage message and exit.
1054  */
1055 static int
showhelp(argv)1056 showhelp(argv)
1057     char **argv;
1058 {
1059     if (phase == PHASE_INITIALIZE) {
1060 	usage();
1061 	exit(0);
1062     }
1063     return 0;
1064 }
1065 
1066 /*
1067  * showversion - print out the version number and exit.
1068  */
1069 static int
showversion(argv)1070 showversion(argv)
1071     char **argv;
1072 {
1073     if (phase == PHASE_INITIALIZE) {
1074 	fprintf(stderr, "pppd version %s\n", VERSION);
1075 	exit(0);
1076     }
1077     return 0;
1078 }
1079 
1080 /*
1081  * option_error - print a message about an error in an option.
1082  * The message is logged, and also sent to
1083  * stderr if phase == PHASE_INITIALIZE.
1084  */
1085 void
option_error(char * fmt,...)1086 option_error __V((char *fmt, ...))
1087 {
1088     va_list args;
1089     char buf[1024];
1090 
1091 #if defined(__STDC__)
1092     va_start(args, fmt);
1093 #else
1094     char *fmt;
1095     va_start(args);
1096     fmt = va_arg(args, char *);
1097 #endif
1098     vslprintf(buf, sizeof(buf), fmt, args);
1099     va_end(args);
1100     if (phase == PHASE_INITIALIZE)
1101 	fprintf(stderr, "%s: %s\n", progname, buf);
1102     syslog(LOG_ERR, "%s", buf);
1103 }
1104 
1105 #if 0
1106 /*
1107  * readable - check if a file is readable by the real user.
1108  */
1109 int
1110 readable(fd)
1111     int fd;
1112 {
1113     uid_t uid;
1114     int i;
1115     struct stat sbuf;
1116 
1117     uid = getuid();
1118     if (uid == 0)
1119 	return 1;
1120     if (fstat(fd, &sbuf) != 0)
1121 	return 0;
1122     if (sbuf.st_uid == uid)
1123 	return sbuf.st_mode & S_IRUSR;
1124     if (sbuf.st_gid == getgid())
1125 	return sbuf.st_mode & S_IRGRP;
1126     for (i = 0; i < ngroups; ++i)
1127 	if (sbuf.st_gid == groups[i])
1128 	    return sbuf.st_mode & S_IRGRP;
1129     return sbuf.st_mode & S_IROTH;
1130 }
1131 #endif
1132 
1133 /*
1134  * Read a word from a file.
1135  * Words are delimited by white-space or by quotes (" or ').
1136  * Quotes, white-space and \ may be escaped with \.
1137  * \<newline> is ignored.
1138  */
1139 int
getword(f,word,newlinep,filename)1140 getword(f, word, newlinep, filename)
1141     FILE *f;
1142     char *word;
1143     int *newlinep;
1144     char *filename;
1145 {
1146     int c, len, escape;
1147     int quoted, comment;
1148     int value, digit, got, n;
1149 
1150 #define isoctal(c) ((c) >= '0' && (c) < '8')
1151 
1152     *newlinep = 0;
1153     len = 0;
1154     escape = 0;
1155     comment = 0;
1156     quoted = 0;
1157 
1158     /*
1159      * First skip white-space and comments.
1160      */
1161     for (;;) {
1162 	c = getc(f);
1163 	if (c == EOF)
1164 	    break;
1165 
1166 	/*
1167 	 * A newline means the end of a comment; backslash-newline
1168 	 * is ignored.  Note that we cannot have escape && comment.
1169 	 */
1170 	if (c == '\n') {
1171 	    if (!escape) {
1172 		*newlinep = 1;
1173 		comment = 0;
1174 	    } else
1175 		escape = 0;
1176 	    continue;
1177 	}
1178 
1179 	/*
1180 	 * Ignore characters other than newline in a comment.
1181 	 */
1182 	if (comment)
1183 	    continue;
1184 
1185 	/*
1186 	 * If this character is escaped, we have a word start.
1187 	 */
1188 	if (escape)
1189 	    break;
1190 
1191 	/*
1192 	 * If this is the escape character, look at the next character.
1193 	 */
1194 	if (c == '\\') {
1195 	    escape = 1;
1196 	    continue;
1197 	}
1198 
1199 	/*
1200 	 * If this is the start of a comment, ignore the rest of the line.
1201 	 */
1202 	if (c == '#') {
1203 	    comment = 1;
1204 	    continue;
1205 	}
1206 
1207 	/*
1208 	 * A non-whitespace character is the start of a word.
1209 	 */
1210 	if (!isspace(c))
1211 	    break;
1212     }
1213 
1214     /*
1215      * Process characters until the end of the word.
1216      */
1217     while (c != EOF) {
1218 	if (escape) {
1219 	    /*
1220 	     * This character is escaped: backslash-newline is ignored,
1221 	     * various other characters indicate particular values
1222 	     * as for C backslash-escapes.
1223 	     */
1224 	    escape = 0;
1225 	    if (c == '\n') {
1226 	        c = getc(f);
1227 		continue;
1228 	    }
1229 
1230 	    got = 0;
1231 	    switch (c) {
1232 	    case 'a':
1233 		value = '\a';
1234 		break;
1235 	    case 'b':
1236 		value = '\b';
1237 		break;
1238 	    case 'f':
1239 		value = '\f';
1240 		break;
1241 	    case 'n':
1242 		value = '\n';
1243 		break;
1244 	    case 'r':
1245 		value = '\r';
1246 		break;
1247 	    case 's':
1248 		value = ' ';
1249 		break;
1250 	    case 't':
1251 		value = '\t';
1252 		break;
1253 
1254 	    default:
1255 		if (isoctal(c)) {
1256 		    /*
1257 		     * \ddd octal sequence
1258 		     */
1259 		    value = 0;
1260 		    for (n = 0; n < 3 && isoctal(c); ++n) {
1261 			value = (value << 3) + (c & 07);
1262 			c = getc(f);
1263 		    }
1264 		    got = 1;
1265 		    break;
1266 		}
1267 
1268 		if (c == 'x') {
1269 		    /*
1270 		     * \x<hex_string> sequence
1271 		     */
1272 		    value = 0;
1273 		    c = getc(f);
1274 		    for (n = 0; n < 2 && isxdigit(c); ++n) {
1275 			digit = toupper(c) - '0';
1276 			if (digit > 10)
1277 			    digit += '0' + 10 - 'A';
1278 			value = (value << 4) + digit;
1279 			c = getc (f);
1280 		    }
1281 		    got = 1;
1282 		    break;
1283 		}
1284 
1285 		/*
1286 		 * Otherwise the character stands for itself.
1287 		 */
1288 		value = c;
1289 		break;
1290 	    }
1291 
1292 	    /*
1293 	     * Store the resulting character for the escape sequence.
1294 	     */
1295 	    if (len < MAXWORDLEN) {
1296 		word[len] = value;
1297 		++len;
1298 	    }
1299 
1300 	    if (!got)
1301 		c = getc(f);
1302 	    continue;
1303 	}
1304 
1305 	/*
1306 	 * Backslash starts a new escape sequence.
1307 	 */
1308 	if (c == '\\') {
1309 	    escape = 1;
1310 	    c = getc(f);
1311 	    continue;
1312 	}
1313 
1314 	/*
1315 	 * Not escaped: check for the start or end of a quoted
1316 	 * section and see if we've reached the end of the word.
1317 	 */
1318 	if (quoted) {
1319 	    if (c == quoted) {
1320 		quoted = 0;
1321 		c = getc(f);
1322 		continue;
1323 	    }
1324 	} else if (c == '"' || c == '\'') {
1325 	    quoted = c;
1326 	    c = getc(f);
1327 	    continue;
1328 	} else if (isspace(c) || c == '#') {
1329 	    ungetc (c, f);
1330 	    break;
1331 	}
1332 
1333 	/*
1334 	 * An ordinary character: store it in the word and get another.
1335 	 */
1336 	if (len < MAXWORDLEN) {
1337 	    word[len] = c;
1338 	    ++len;
1339 	}
1340 
1341 	c = getc(f);
1342     }
1343 
1344     /*
1345      * End of the word: check for errors.
1346      */
1347     if (c == EOF) {
1348 	if (ferror(f)) {
1349 	    if (errno == 0)
1350 		errno = EIO;
1351 	    option_error("Error reading %s: %m", filename);
1352 	    die(1);
1353 	}
1354 	/*
1355 	 * If len is zero, then we didn't find a word before the
1356 	 * end of the file.
1357 	 */
1358 	if (len == 0)
1359 	    return 0;
1360 	if (quoted)
1361 	    option_error("warning: quoted word runs to end of file (%.20s...)",
1362 			 filename, word);
1363     }
1364 
1365     /*
1366      * Warn if the word was too long, and append a terminating null.
1367      */
1368     if (len >= MAXWORDLEN) {
1369 	option_error("warning: word in file %s too long (%.20s...)",
1370 		     filename, word);
1371 	len = MAXWORDLEN - 1;
1372     }
1373     word[len] = 0;
1374 
1375     return 1;
1376 
1377 #undef isoctal
1378 
1379 }
1380 
1381 /*
1382  * number_option - parse an unsigned numeric parameter for an option.
1383  */
1384 static int
number_option(str,valp,base)1385 number_option(str, valp, base)
1386     char *str;
1387     u_int32_t *valp;
1388     int base;
1389 {
1390     char *ptr;
1391 
1392     *valp = strtoul(str, &ptr, base);
1393     if (ptr == str) {
1394 	option_error("invalid numeric parameter '%s' for %s option",
1395 		     str, current_option);
1396 	return 0;
1397     }
1398     return 1;
1399 }
1400 
1401 
1402 /*
1403  * int_option - like number_option, but valp is int *,
1404  * the base is assumed to be 0, and *valp is not changed
1405  * if there is an error.
1406  */
1407 int
int_option(str,valp)1408 int_option(str, valp)
1409     char *str;
1410     int *valp;
1411 {
1412     u_int32_t v;
1413 
1414     if (!number_option(str, &v, 0))
1415 	return 0;
1416     *valp = (int) v;
1417     return 1;
1418 }
1419 
1420 
1421 /*
1422  * The following procedures parse options.
1423  */
1424 
1425 /*
1426  * readfile - take commands from a file.
1427  */
1428 static int
readfile(argv)1429 readfile(argv)
1430     char **argv;
1431 {
1432     return options_from_file(*argv, 1, 1, privileged_option);
1433 }
1434 
1435 /*
1436  * callfile - take commands from /etc/ppp/peers/<name>.
1437  * Name may not contain /../, start with / or ../, or end in /..
1438  */
1439 static int
callfile(argv)1440 callfile(argv)
1441     char **argv;
1442 {
1443     char *fname, *arg, *p;
1444     int l, ok;
1445 
1446     arg = *argv;
1447     ok = 1;
1448     if (arg[0] == '/' || arg[0] == 0)
1449 	ok = 0;
1450     else {
1451 	for (p = arg; *p != 0; ) {
1452 	    if (p[0] == '.' && p[1] == '.' && (p[2] == '/' || p[2] == 0)) {
1453 		ok = 0;
1454 		break;
1455 	    }
1456 	    while (*p != '/' && *p != 0)
1457 		++p;
1458 	    if (*p == '/')
1459 		++p;
1460 	}
1461     }
1462     if (!ok) {
1463 	option_error("call option value may not contain .. or start with /");
1464 	return 0;
1465     }
1466 
1467     l = strlen(arg) + strlen(_PATH_PEERFILES) + 1;
1468     if ((fname = (char *) malloc(l)) == NULL)
1469 	novm("call file name");
1470     slprintf(fname, l, "%s%s", _PATH_PEERFILES, arg);
1471 
1472     ok = options_from_file(fname, 1, 1, 1);
1473 
1474     free(fname);
1475     return ok;
1476 }
1477 
1478 #ifdef PPP_FILTER
1479 /*
1480  * setpassfilter - Set the pass filter for packets
1481  */
1482 static int
setpassfilter(argv)1483 setpassfilter(argv)
1484     char **argv;
1485 {
1486     pcap_t *pc;
1487     int ret = 1;
1488 
1489     pc = pcap_open_dead(DLT_PPP_PPPD, 65535);
1490     if (pcap_compile(pc, &pass_filter, *argv, 1, netmask) == -1) {
1491 	option_error("error in pass-filter expression: %s\n",
1492 		     pcap_geterr(pc));
1493 	ret = 0;
1494     }
1495     pcap_close(pc);
1496 
1497     return ret;
1498 }
1499 
1500 /*
1501  * setactivefilter - Set the active filter for packets
1502  */
1503 static int
setactivefilter(argv)1504 setactivefilter(argv)
1505     char **argv;
1506 {
1507     pcap_t *pc;
1508     int ret = 1;
1509 
1510     pc = pcap_open_dead(DLT_PPP_PPPD, 65535);
1511     if (pcap_compile(pc, &active_filter, *argv, 1, netmask) == -1) {
1512 	option_error("error in active-filter expression: %s\n",
1513 		     pcap_geterr(pc));
1514 	ret = 0;
1515     }
1516     pcap_close(pc);
1517 
1518     return ret;
1519 }
1520 #endif
1521 
1522 /*
1523  * setdomain - Set domain name to append to hostname
1524  */
1525 static int
setdomain(argv)1526 setdomain(argv)
1527     char **argv;
1528 {
1529     gethostname(hostname, MAXNAMELEN);
1530     if (**argv != 0) {
1531 	if (**argv != '.')
1532 	    strncat(hostname, ".", MAXNAMELEN - strlen(hostname));
1533 	domain = hostname + strlen(hostname);
1534 	strncat(hostname, *argv, MAXNAMELEN - strlen(hostname));
1535     }
1536     hostname[MAXNAMELEN-1] = 0;
1537     return (1);
1538 }
1539 
1540 static int
setlogfile(argv)1541 setlogfile(argv)
1542     char **argv;
1543 {
1544     int fd, err;
1545     uid_t euid;
1546 
1547     euid = geteuid();
1548     if (!privileged_option && seteuid(getuid()) == -1) {
1549 	option_error("unable to drop permissions to open %s: %m", *argv);
1550 	return 0;
1551     }
1552     fd = open(*argv, O_WRONLY | O_APPEND | O_CREAT | O_EXCL, 0644);
1553     if (fd < 0 && errno == EEXIST)
1554 	fd = open(*argv, O_WRONLY | O_APPEND);
1555     err = errno;
1556     if (!privileged_option && seteuid(euid) == -1)
1557 	fatal("unable to regain privileges: %m");
1558     if (fd < 0) {
1559 	errno = err;
1560 	option_error("Can't open log file %s: %m", *argv);
1561 	return 0;
1562     }
1563     strlcpy(logfile_name, *argv, sizeof(logfile_name));
1564     if (logfile_fd >= 0)
1565 	close(logfile_fd);
1566     logfile_fd = fd;
1567     log_to_fd = fd;
1568     log_default = 0;
1569     return 1;
1570 }
1571 
1572 #ifdef MAXOCTETS
1573 static int
setmodir(argv)1574 setmodir(argv)
1575     char **argv;
1576 {
1577     if(*argv == NULL)
1578 	return 0;
1579     if(!strcmp(*argv,"in")) {
1580         maxoctets_dir = PPP_OCTETS_DIRECTION_IN;
1581     } else if (!strcmp(*argv,"out")) {
1582         maxoctets_dir = PPP_OCTETS_DIRECTION_OUT;
1583     } else if (!strcmp(*argv,"max")) {
1584         maxoctets_dir = PPP_OCTETS_DIRECTION_MAXOVERAL;
1585     } else {
1586         maxoctets_dir = PPP_OCTETS_DIRECTION_SUM;
1587     }
1588     return 1;
1589 }
1590 #endif
1591 
1592 #ifdef PLUGIN
1593 static int
loadplugin(argv)1594 loadplugin(argv)
1595     char **argv;
1596 {
1597     char *arg = *argv;
1598     void *handle;
1599     const char *err;
1600     void (*init) __P((void));
1601     char *path = arg;
1602     const char *vers;
1603 
1604     if (strchr(arg, '/') == 0) {
1605 	const char *base = _PATH_PLUGIN;
1606 	int l = strlen(base) + strlen(arg) + 2;
1607 	path = malloc(l);
1608 	if (path == 0)
1609 	    novm("plugin file path");
1610 	strlcpy(path, base, l);
1611 	strlcat(path, "/", l);
1612 	strlcat(path, arg, l);
1613     }
1614     handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
1615     if (handle == 0) {
1616 	err = dlerror();
1617 	if (err != 0)
1618 	    option_error("%s", err);
1619 	option_error("Couldn't load plugin %s", arg);
1620 	goto err;
1621     }
1622     init = (void (*)(void))dlsym(handle, "plugin_init");
1623     if (init == 0) {
1624 	option_error("%s has no initialization entry point", arg);
1625 	goto errclose;
1626     }
1627     vers = (const char *) dlsym(handle, "pppd_version");
1628     if (vers == 0) {
1629 	warn("Warning: plugin %s has no version information", arg);
1630     } else if (strcmp(vers, VERSION) != 0) {
1631 	option_error("Plugin %s is for pppd version %s, this is %s",
1632 		     arg, vers, VERSION);
1633 	goto errclose;
1634     }
1635     info("Plugin %s loaded.", arg);
1636     (*init)();
1637     return 1;
1638 
1639  errclose:
1640     dlclose(handle);
1641  err:
1642     if (path != arg)
1643 	free(path);
1644     return 0;
1645 }
1646 #endif /* PLUGIN */
1647 
1648 /*
1649  * Set an environment variable specified by the user.
1650  */
1651 static int
user_setenv(argv)1652 user_setenv(argv)
1653     char **argv;
1654 {
1655     char *arg = argv[0];
1656     char *eqp;
1657     struct userenv *uep, **insp;
1658 
1659     if ((eqp = strchr(arg, '=')) == NULL) {
1660 	option_error("missing = in name=value: %s", arg);
1661 	return 0;
1662     }
1663     if (eqp == arg) {
1664 	option_error("missing variable name: %s", arg);
1665 	return 0;
1666     }
1667     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
1668 	int nlen = strlen(uep->ue_name);
1669 	if (nlen == (eqp - arg) &&
1670 	    strncmp(arg, uep->ue_name, nlen) == 0)
1671 	    break;
1672     }
1673     /* Ignore attempts by unprivileged users to override privileged sources */
1674     if (uep != NULL && !privileged_option && uep->ue_priv)
1675 	return 1;
1676     /* The name never changes, so allocate it with the structure */
1677     if (uep == NULL) {
1678 	uep = malloc(sizeof (*uep) + (eqp-arg));
1679 	strncpy(uep->ue_name, arg, eqp-arg);
1680 	uep->ue_name[eqp-arg] = '\0';
1681 	uep->ue_next = NULL;
1682 	insp = &userenv_list;
1683 	while (*insp != NULL)
1684 	    insp = &(*insp)->ue_next;
1685 	*insp = uep;
1686     } else {
1687 	struct userenv *uep2;
1688 	for (uep2 = userenv_list; uep2 != NULL; uep2 = uep2->ue_next) {
1689 	    if (uep2 != uep && !uep2->ue_isset)
1690 		break;
1691 	}
1692 	if (uep2 == NULL && !uep->ue_isset)
1693 	    find_option("unset")->flags |= OPT_NOPRINT;
1694 	free(uep->ue_value);
1695     }
1696     uep->ue_isset = 1;
1697     uep->ue_priv = privileged_option;
1698     uep->ue_source = option_source;
1699     uep->ue_value = strdup(eqp + 1);
1700     curopt->flags &= ~OPT_NOPRINT;
1701     return 1;
1702 }
1703 
1704 static void
user_setprint(opt,printer,arg)1705 user_setprint(opt, printer, arg)
1706     option_t *opt;
1707     printer_func printer;
1708     void *arg;
1709 {
1710     struct userenv *uep, *uepnext;
1711 
1712     uepnext = userenv_list;
1713     while (uepnext != NULL && !uepnext->ue_isset)
1714 	uepnext = uepnext->ue_next;
1715     while ((uep = uepnext) != NULL) {
1716 	uepnext = uep->ue_next;
1717 	while (uepnext != NULL && !uepnext->ue_isset)
1718 	    uepnext = uepnext->ue_next;
1719 	(*printer)(arg, "%s=%s", uep->ue_name, uep->ue_value);
1720 	if (uepnext != NULL)
1721 	    (*printer)(arg, "\t\t# (from %s)\n%s ", uep->ue_source, opt->name);
1722 	else
1723 	    opt->source = uep->ue_source;
1724     }
1725 }
1726 
1727 static int
user_unsetenv(argv)1728 user_unsetenv(argv)
1729     char **argv;
1730 {
1731     struct userenv *uep, **insp;
1732     char *arg = argv[0];
1733 
1734     if (strchr(arg, '=') != NULL) {
1735 	option_error("unexpected = in name: %s", arg);
1736 	return 0;
1737     }
1738     if (arg == '\0') {
1739 	option_error("missing variable name for unset");
1740 	return 0;
1741     }
1742     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
1743 	if (strcmp(arg, uep->ue_name) == 0)
1744 	    break;
1745     }
1746     /* Ignore attempts by unprivileged users to override privileged sources */
1747     if (uep != NULL && !privileged_option && uep->ue_priv)
1748 	return 1;
1749     /* The name never changes, so allocate it with the structure */
1750     if (uep == NULL) {
1751 	uep = malloc(sizeof (*uep) + strlen(arg));
1752 	strcpy(uep->ue_name, arg);
1753 	uep->ue_next = NULL;
1754 	insp = &userenv_list;
1755 	while (*insp != NULL)
1756 	    insp = &(*insp)->ue_next;
1757 	*insp = uep;
1758     } else {
1759 	struct userenv *uep2;
1760 	for (uep2 = userenv_list; uep2 != NULL; uep2 = uep2->ue_next) {
1761 	    if (uep2 != uep && uep2->ue_isset)
1762 		break;
1763 	}
1764 	if (uep2 == NULL && uep->ue_isset)
1765 	    find_option("set")->flags |= OPT_NOPRINT;
1766 	free(uep->ue_value);
1767     }
1768     uep->ue_isset = 0;
1769     uep->ue_priv = privileged_option;
1770     uep->ue_source = option_source;
1771     uep->ue_value = NULL;
1772     curopt->flags &= ~OPT_NOPRINT;
1773     return 1;
1774 }
1775 
1776 static void
user_unsetprint(opt,printer,arg)1777 user_unsetprint(opt, printer, arg)
1778     option_t *opt;
1779     printer_func printer;
1780     void *arg;
1781 {
1782     struct userenv *uep, *uepnext;
1783 
1784     uepnext = userenv_list;
1785     while (uepnext != NULL && uepnext->ue_isset)
1786 	uepnext = uepnext->ue_next;
1787     while ((uep = uepnext) != NULL) {
1788 	uepnext = uep->ue_next;
1789 	while (uepnext != NULL && uepnext->ue_isset)
1790 	    uepnext = uepnext->ue_next;
1791 	(*printer)(arg, "%s", uep->ue_name);
1792 	if (uepnext != NULL)
1793 	    (*printer)(arg, "\t\t# (from %s)\n%s ", uep->ue_source, opt->name);
1794 	else
1795 	    opt->source = uep->ue_source;
1796     }
1797 }
1798