1/*
2 * options.c - handles option processing for PPP.
3 *
4 * Copyright (c) 1989 Carnegie Mellon University.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by Carnegie Mellon University.  The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20#define RCSID	"$Id: options.c 241182 2011-02-17 21:50:03Z $"
21
22#include <ctype.h>
23#include <stdio.h>
24#include <errno.h>
25#include <unistd.h>
26#include <fcntl.h>
27#include <stdlib.h>
28#include <syslog.h>
29#include <string.h>
30#include <pwd.h>
31#ifdef PLUGIN
32#include <dlfcn.h>
33#endif
34#ifdef PPP_FILTER
35#include <pcap.h>
36#include <pcap-int.h>
37#endif
38
39#include "pppd.h"
40#include "pathnames.h"
41
42#if defined(ultrix) || defined(NeXT)
43char *strdup __P((char *));
44#endif
45
46static const char rcsid[] = RCSID;
47
48struct option_value {
49    struct option_value *next;
50    const char *source;
51    char value[1];
52};
53
54/*
55 * Option variables and default values.
56 */
57#ifdef PPP_FILTER
58int	dflag = 0;		/* Tell libpcap we want debugging */
59#endif
60int	debug = 0;		/* Debug flag */
61int	kdebugflag = 0;		/* Tell kernel to print debug messages */
62int	default_device = 1;	/* Using /dev/tty or equivalent */
63char	devnam[MAXPATHLEN];	/* Device name */
64bool	nodetach = 0;		/* Don't detach from controlling tty */
65bool	updetach = 0;		/* Detach once link is up */
66int	maxconnect = 0;		/* Maximum connect time */
67char	user[MAXNAMELEN];	/* Username for PAP */
68char	passwd[MAXSECRETLEN];	/* Password for PAP */
69bool	persist = 0;		/* Reopen link after it goes down */
70char	our_name[MAXNAMELEN];	/* Our name for authentication purposes */
71bool	demand = 0;		/* do dial-on-demand */
72char	*ipparam = NULL;	/* Extra parameter for ip up/down scripts */
73int	idle_time_limit = 0;	/* Disconnect if idle for this many seconds */
74int	holdoff = 30;		/* # seconds to pause before reconnecting */
75bool	holdoff_specified;	/* true if a holdoff value has been given */
76int	log_to_fd = 1;		/* send log messages to this fd too */
77bool	log_default = 1;	/* log_to_fd is default (stdout) */
78int	maxfail = 10;		/* max # of unsuccessful connection attempts */
79char	linkname[MAXPATHLEN];	/* logical name for link */
80bool	tune_kernel;		/* may alter kernel settings */
81int	connect_delay = 1000;	/* wait this many ms after connect script */
82int	req_unit = -1;		/* requested interface unit */
83bool	multilink = 0;		/* Enable multilink operation */
84char	*bundle_name = NULL;	/* bundle name for multilink */
85bool	dump_options;		/* print out option values */
86bool	dryrun;			/* print out option values and exit */
87char	*domain;		/* domain name set by domain option */
88
89extern option_t auth_options[];
90extern struct stat devstat;
91
92#ifdef PPP_FILTER
93struct	bpf_program pass_filter;/* Filter program for packets to pass */
94struct	bpf_program active_filter; /* Filter program for link-active pkts */
95pcap_t  pc;			/* Fake struct pcap so we can compile expr */
96#endif
97
98char *current_option;		/* the name of the option being parsed */
99int  privileged_option;		/* set iff the current option came from root */
100char *option_source;		/* string saying where the option came from */
101int  option_priority = OPRIO_CFGFILE; /* priority of the current options */
102bool devnam_fixed;		/* can no longer change device name */
103
104static int logfile_fd = -1;	/* fd opened for log file */
105static char logfile_name[MAXPATHLEN];	/* name of log file */
106
107/*
108 * Prototypes
109 */
110static int setdomain __P((char **));
111static int readfile __P((char **));
112static int callfile __P((char **));
113static int showversion __P((char **));
114static int showhelp __P((char **));
115static void usage __P((void));
116static int setlogfile __P((char **));
117#ifdef PLUGIN
118static int loadplugin __P((char **));
119#endif
120
121#ifdef PPP_FILTER
122static int setpassfilter __P((char **));
123static int setactivefilter __P((char **));
124#endif
125
126static option_t *find_option __P((const char *name));
127static int process_option __P((option_t *, char *, char **));
128static int n_arguments __P((option_t *));
129static int number_option __P((char *, u_int32_t *, int));
130
131/*
132 * Structure to store extra lists of options.
133 */
134struct option_list {
135    option_t *options;
136    struct option_list *next;
137};
138
139static struct option_list *extra_options = NULL;
140
141/*
142 * Valid arguments.
143 */
144option_t general_options[] = {
145    { "debug", o_int, &debug,
146      "Increase debugging level", OPT_INC | OPT_NOARG | 1 },
147    { "-d", o_int, &debug,
148      "Increase debugging level",
149      OPT_ALIAS | OPT_INC | OPT_NOARG | 1 },
150
151    { "kdebug", o_int, &kdebugflag,
152      "Set kernel driver debug level", OPT_PRIO },
153
154    { "nodetach", o_bool, &nodetach,
155      "Don't detach from controlling tty", OPT_PRIO | 1 },
156    { "-detach", o_bool, &nodetach,
157      "Don't detach from controlling tty", OPT_ALIAS | OPT_PRIOSUB | 1 },
158    { "updetach", o_bool, &updetach,
159      "Detach from controlling tty once link is up",
160      OPT_PRIOSUB | OPT_A2CLR | 1, &nodetach },
161
162    { "holdoff", o_int, &holdoff,
163      "Set time in seconds before retrying connection", OPT_PRIO },
164
165    { "idle", o_int, &idle_time_limit,
166      "Set time in seconds before disconnecting idle link", OPT_PRIO },
167
168    { "maxconnect", o_int, &maxconnect,
169      "Set connection time limit",
170      OPT_PRIO | OPT_LLIMIT | OPT_NOINCR | OPT_ZEROINF },
171
172    { "domain", o_special, (void *)setdomain,
173      "Add given domain name to hostname",
174      OPT_PRIO | OPT_PRIV | OPT_A2STRVAL, &domain },
175
176    { "file", o_special, (void *)readfile,
177      "Take options from a file", OPT_NOPRINT },
178    { "call", o_special, (void *)callfile,
179      "Take options from a privileged file", OPT_NOPRINT },
180
181    { "persist", o_bool, &persist,
182      "Keep on reopening connection after close", OPT_PRIO | 1 },
183    { "nopersist", o_bool, &persist,
184      "Turn off persist option", OPT_PRIOSUB },
185
186    { "demand", o_bool, &demand,
187      "Dial on demand", OPT_INITONLY | 1, &persist },
188
189    { "--version", o_special_noarg, (void *)showversion,
190      "Show version number" },
191    { "--help", o_special_noarg, (void *)showhelp,
192      "Show brief listing of options" },
193    { "-h", o_special_noarg, (void *)showhelp,
194      "Show brief listing of options", OPT_ALIAS },
195
196    { "logfile", o_special, (void *)setlogfile,
197      "Append log messages to this file",
198      OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, &logfile_name },
199    { "logfd", o_int, &log_to_fd,
200      "Send log messages to this file descriptor",
201      OPT_PRIOSUB | OPT_A2CLR, &log_default },
202    { "nolog", o_int, &log_to_fd,
203      "Don't send log messages to any file",
204      OPT_PRIOSUB | OPT_NOARG | OPT_VAL(-1) },
205    { "nologfd", o_int, &log_to_fd,
206      "Don't send log messages to any file descriptor",
207      OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) },
208
209    { "linkname", o_string, linkname,
210      "Set logical name for link",
211      OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXPATHLEN },
212
213    { "maxfail", o_int, &maxfail,
214      "Maximum number of unsuccessful connection attempts to allow",
215      OPT_PRIO },
216
217    { "ktune", o_bool, &tune_kernel,
218      "Alter kernel settings as necessary", OPT_PRIO | 1 },
219    { "noktune", o_bool, &tune_kernel,
220      "Don't alter kernel settings", OPT_PRIOSUB },
221
222    { "connect-delay", o_int, &connect_delay,
223      "Maximum time (in ms) to wait after connect script finishes",
224      OPT_PRIO },
225
226    { "unit", o_int, &req_unit,
227      "PPP interface unit number to use if possible",
228      OPT_PRIO | OPT_LLIMIT, 0, 0 },
229
230    { "dump", o_bool, &dump_options,
231      "Print out option values after parsing all options", 1 },
232    { "dryrun", o_bool, &dryrun,
233      "Stop after parsing, printing, and checking options", 1 },
234
235#ifdef HAVE_MULTILINK
236    { "multilink", o_bool, &multilink,
237      "Enable multilink operation", OPT_PRIO | 1 },
238    { "mp", o_bool, &multilink,
239      "Enable multilink operation", OPT_PRIOSUB | OPT_ALIAS | 1 },
240    { "nomultilink", o_bool, &multilink,
241      "Disable multilink operation", OPT_PRIOSUB | 0 },
242    { "nomp", o_bool, &multilink,
243      "Disable multilink operation", OPT_PRIOSUB | OPT_ALIAS | 0 },
244
245    { "bundle", o_string, &bundle_name,
246      "Bundle name for multilink", OPT_PRIO },
247#endif /* HAVE_MULTILINK */
248
249#ifdef PLUGIN
250    { "plugin", o_special, (void *)loadplugin,
251      "Load a plug-in module into pppd", OPT_PRIV | OPT_A2LIST },
252#endif
253
254#ifdef PPP_FILTER
255    { "pdebug", o_int, &dflag,
256      "libpcap debugging", OPT_PRIO },
257
258    { "pass-filter", 1, setpassfilter,
259      "set filter for packets to pass", OPT_PRIO },
260
261    { "active-filter", 1, setactivefilter,
262      "set filter for active pkts", OPT_PRIO },
263#endif
264
265    { NULL }
266};
267
268#ifndef IMPLEMENTATION
269#define IMPLEMENTATION ""
270#endif
271
272static char *usage_string = "\
273pppd version %s\n\
274Usage: %s [ options ], where options are:\n\
275	<device>	Communicate over the named device\n\
276	<speed>		Set the baud rate to <speed>\n\
277	<loc>:<rem>	Set the local and/or remote interface IP\n\
278			addresses.  Either one may be omitted.\n\
279	asyncmap <n>	Set the desired async map to hex <n>\n\
280	auth		Require authentication from peer\n\
281        connect <p>     Invoke shell command <p> to set up the serial line\n\
282	crtscts		Use hardware RTS/CTS flow control\n\
283	defaultroute	Add default route through interface\n\
284	file <f>	Take options from file <f>\n\
285	modem		Use modem control lines\n\
286	mru <n>		Set MRU value to <n> for negotiation\n\
287See pppd(8) for more options.\n\
288";
289
290/*
291 * parse_args - parse a string of arguments from the command line.
292 */
293int
294parse_args(argc, argv)
295    int argc;
296    char **argv;
297{
298    char *arg;
299    option_t *opt;
300    int n;
301
302    privileged_option = privileged;
303    option_source = "command line";
304    option_priority = OPRIO_CMDLINE;
305    while (argc > 0) {
306	arg = *argv++;
307	--argc;
308	opt = find_option(arg);
309	if (opt == NULL) {
310	    option_error("unrecognized option '%s'", arg);
311	    usage();
312	    return 0;
313	}
314	n = n_arguments(opt);
315	if (argc < n) {
316	    option_error("too few parameters for option %s", arg);
317	    return 0;
318	}
319	if (!process_option(opt, arg, argv))
320	    return 0;
321	argc -= n;
322	argv += n;
323    }
324    return 1;
325}
326
327/*
328 * options_from_file - Read a string of options from a file,
329 * and interpret them.
330 */
331int
332options_from_file(filename, must_exist, check_prot, priv)
333    char *filename;
334    int must_exist;
335    int check_prot;
336    int priv;
337{
338    FILE *f;
339    int i, newline, ret, err;
340    option_t *opt;
341    int oldpriv, n;
342    char *oldsource;
343    char *argv[MAXARGS];
344    char args[MAXARGS][MAXWORDLEN];
345    char cmd[MAXWORDLEN];
346
347    if (check_prot)
348	seteuid(getuid());
349    f = fopen(filename, "r");
350    err = errno;
351    if (check_prot)
352	seteuid(0);
353    if (f == NULL) {
354	errno = err;
355	if (!must_exist) {
356	    if (err != ENOENT && err != ENOTDIR)
357		warn("Warning: can't open options file %s: %m", filename);
358	    return 1;
359	}
360	option_error("Can't open options file %s: %m", filename);
361	return 0;
362    }
363
364    oldpriv = privileged_option;
365    privileged_option = priv;
366    oldsource = option_source;
367    option_source = strdup(filename);
368    if (option_source == NULL)
369	option_source = "file";
370    ret = 0;
371    while (getword(f, cmd, &newline, filename)) {
372	opt = find_option(cmd);
373	if (opt == NULL) {
374	    option_error("In file %s: unrecognized option '%s'",
375			 filename, cmd);
376	    goto err;
377	}
378	n = n_arguments(opt);
379	for (i = 0; i < n; ++i) {
380	    if (!getword(f, args[i], &newline, filename)) {
381		option_error(
382			"In file %s: too few parameters for option '%s'",
383			filename, cmd);
384		goto err;
385	    }
386	    argv[i] = args[i];
387	}
388	if (!process_option(opt, cmd, argv))
389	    goto err;
390    }
391    ret = 1;
392
393err:
394    fclose(f);
395    privileged_option = oldpriv;
396    option_source = oldsource;
397    return ret;
398}
399
400/*
401 * options_from_user - See if the use has a ~/.ppprc file,
402 * and if so, interpret options from it.
403 */
404int
405options_from_user()
406{
407    char *user, *path, *file;
408    int ret;
409    struct passwd *pw;
410    size_t pl;
411
412    pw = getpwuid(getuid());
413    if (pw == NULL || (user = pw->pw_dir) == NULL || user[0] == 0)
414	return 1;
415    file = _PATH_USEROPT;
416    pl = strlen(user) + strlen(file) + 2;
417    path = malloc(pl);
418    if (path == NULL)
419	novm("init file name");
420    slprintf(path, pl, "%s/%s", user, file);
421    option_priority = OPRIO_CFGFILE;
422    ret = options_from_file(path, 0, 1, privileged);
423    free(path);
424    return ret;
425}
426
427/*
428 * options_for_tty - See if an options file exists for the serial
429 * device, and if so, interpret options from it.
430 * We only allow the per-tty options file to override anything from
431 * the command line if it is something that the user can't override
432 * once it has been set by root; this is done by giving configuration
433 * files a lower priority than the command line.
434 */
435int
436options_for_tty()
437{
438    char *dev, *path, *p;
439    int ret;
440    size_t pl;
441
442    dev = devnam;
443    if (strncmp(dev, "/dev/", 5) == 0)
444	dev += 5;
445    if (dev[0] == 0 || strcmp(dev, "tty") == 0)
446	return 1;		/* don't look for /etc/ppp/options.tty */
447    pl = strlen(_PATH_TTYOPT) + strlen(dev) + 1;
448    path = malloc(pl);
449    if (path == NULL)
450	novm("tty init file name");
451    slprintf(path, pl, "%s%s", _PATH_TTYOPT, dev);
452    /* Turn slashes into dots, for Solaris case (e.g. /dev/term/a) */
453    for (p = path + strlen(_PATH_TTYOPT); *p != 0; ++p)
454	if (*p == '/')
455	    *p = '.';
456    option_priority = OPRIO_CFGFILE;
457    ret = options_from_file(path, 0, 0, 1);
458    free(path);
459    return ret;
460}
461
462/*
463 * options_from_list - process a string of options in a wordlist.
464 */
465int
466options_from_list(w, priv)
467    struct wordlist *w;
468    int priv;
469{
470    char *argv[MAXARGS];
471    option_t *opt;
472    int i, n, ret = 0;
473    struct wordlist *w0;
474
475    privileged_option = priv;
476    option_source = "secrets file";
477    option_priority = OPRIO_SECFILE;
478
479    while (w != NULL) {
480	opt = find_option(w->word);
481	if (opt == NULL) {
482	    option_error("In secrets file: unrecognized option '%s'",
483			 w->word);
484	    goto err;
485	}
486	n = n_arguments(opt);
487	w0 = w;
488	for (i = 0; i < n; ++i) {
489	    w = w->next;
490	    if (w == NULL) {
491		option_error(
492			"In secrets file: too few parameters for option '%s'",
493			w0->word);
494		goto err;
495	    }
496	    argv[i] = w->word;
497	}
498	if (!process_option(opt, w0->word, argv))
499	    goto err;
500	w = w->next;
501    }
502    ret = 1;
503
504err:
505    return ret;
506}
507
508/*
509 * match_option - see if this option matches an option_t structure.
510 */
511static int
512match_option(name, opt, dowild)
513    char *name;
514    option_t *opt;
515    int dowild;
516{
517	int (*match) __P((char *, char **, int));
518
519	if (dowild != (opt->type == o_wild))
520		return 0;
521	if (!dowild)
522		return strcmp(name, opt->name) == 0;
523	match = (int (*) __P((char *, char **, int))) opt->addr;
524	return (*match)(name, NULL, 0);
525}
526
527/*
528 * find_option - scan the option lists for the various protocols
529 * looking for an entry with the given name.
530 * This could be optimized by using a hash table.
531 */
532static option_t *
533find_option(name)
534    const char *name;
535{
536	option_t *opt;
537	struct option_list *list;
538	int i, dowild;
539
540	for (dowild = 0; dowild <= 1; ++dowild) {
541		for (opt = general_options; opt->name != NULL; ++opt)
542			if (match_option(name, opt, dowild))
543				return opt;
544		for (opt = auth_options; opt->name != NULL; ++opt)
545			if (match_option(name, opt, dowild))
546				return opt;
547		for (list = extra_options; list != NULL; list = list->next)
548			for (opt = list->options; opt->name != NULL; ++opt)
549				if (match_option(name, opt, dowild))
550					return opt;
551		for (opt = the_channel->options; opt->name != NULL; ++opt)
552			if (match_option(name, opt, dowild))
553				return opt;
554		for (i = 0; protocols[i] != NULL; ++i)
555			if ((opt = protocols[i]->options) != NULL)
556				for (; opt->name != NULL; ++opt)
557					if (match_option(name, opt, dowild))
558						return opt;
559	}
560	return NULL;
561}
562
563/*
564 * process_option - process one new-style option.
565 */
566static int
567process_option(opt, cmd, argv)
568    option_t *opt;
569    char *cmd;
570    char **argv;
571{
572    u_int32_t v;
573    int iv, a;
574    char *sv;
575    int (*parser) __P((char **));
576    int (*wildp) __P((char *, char **, int));
577    char *optopt = (opt->type == o_wild)? "": " option";
578    int prio = option_priority;
579    option_t *mainopt = opt;
580
581    if ((opt->flags & OPT_PRIVFIX) && privileged_option)
582	prio += OPRIO_ROOT;
583    while (mainopt->flags & OPT_PRIOSUB)
584	--mainopt;
585    if (mainopt->flags & OPT_PRIO) {
586	if (prio < mainopt->priority) {
587	    /* new value doesn't override old */
588	    if (prio == OPRIO_CMDLINE && mainopt->priority > OPRIO_ROOT) {
589		option_error("%s%s set in %s cannot be overridden\n",
590			     opt->name, optopt, mainopt->source);
591		return 0;
592	    }
593	    return 1;
594	}
595	if (prio > OPRIO_ROOT && mainopt->priority == OPRIO_CMDLINE)
596	    warn("%s%s from %s overrides command line",
597		 opt->name, optopt, option_source);
598    }
599
600    if ((opt->flags & OPT_INITONLY) && phase != PHASE_INITIALIZE) {
601	option_error("%s%s cannot be changed after initialization",
602		     opt->name, optopt);
603	return 0;
604    }
605    if ((opt->flags & OPT_PRIV) && !privileged_option) {
606	option_error("using the %s%s requires root privilege",
607		     opt->name, optopt);
608	return 0;
609    }
610    if ((opt->flags & OPT_ENABLE) && *(bool *)(opt->addr2) == 0) {
611	option_error("%s%s is disabled", opt->name, optopt);
612	return 0;
613    }
614    if ((opt->flags & OPT_DEVEQUIV) && devnam_fixed) {
615	option_error("the %s%s may not be changed in %s",
616		     opt->name, optopt, option_source);
617	return 0;
618    }
619
620    switch (opt->type) {
621    case o_bool:
622	v = opt->flags & OPT_VALUE;
623	*(bool *)(opt->addr) = v;
624	if (opt->addr2 && (opt->flags & OPT_A2COPY))
625	    *(bool *)(opt->addr2) = v;
626	break;
627
628    case o_int:
629	iv = 0;
630	if ((opt->flags & OPT_NOARG) == 0) {
631	    if (!int_option(*argv, &iv))
632		return 0;
633	    if ((((opt->flags & OPT_LLIMIT) && iv < opt->lower_limit)
634		 || ((opt->flags & OPT_ULIMIT) && iv > opt->upper_limit))
635		&& !((opt->flags & OPT_ZEROOK && iv == 0))) {
636		char *zok = (opt->flags & OPT_ZEROOK)? " zero or": "";
637		switch (opt->flags & OPT_LIMITS) {
638		case OPT_LLIMIT:
639		    option_error("%s value must be%s >= %d",
640				 opt->name, zok, opt->lower_limit);
641		    break;
642		case OPT_ULIMIT:
643		    option_error("%s value must be%s <= %d",
644				 opt->name, zok, opt->upper_limit);
645		    break;
646		case OPT_LIMITS:
647		    option_error("%s value must be%s between %d and %d",
648				opt->name, opt->lower_limit, opt->upper_limit);
649		    break;
650		}
651		return 0;
652	    }
653	}
654	a = opt->flags & OPT_VALUE;
655	if (a >= 128)
656	    a -= 256;		/* sign extend */
657	iv += a;
658	if (opt->flags & OPT_INC)
659	    iv += *(int *)(opt->addr);
660	if ((opt->flags & OPT_NOINCR) && !privileged_option) {
661	    int oldv = *(int *)(opt->addr);
662	    if ((opt->flags & OPT_ZEROINF) ?
663		(oldv != 0 && (iv == 0 || iv > oldv)) : (iv > oldv)) {
664		option_error("%s value cannot be increased", opt->name);
665		return 0;
666	    }
667	}
668	*(int *)(opt->addr) = iv;
669	if (opt->addr2 && (opt->flags & OPT_A2COPY))
670	    *(int *)(opt->addr2) = iv;
671	break;
672
673    case o_uint32:
674	if (opt->flags & OPT_NOARG) {
675	    v = opt->flags & OPT_VALUE;
676	    if (v & 0x80)
677		    v |= 0xffffff00U;
678	} else if (!number_option(*argv, &v, 16))
679	    return 0;
680	if (opt->flags & OPT_OR)
681	    v |= *(u_int32_t *)(opt->addr);
682	*(u_int32_t *)(opt->addr) = v;
683	if (opt->addr2 && (opt->flags & OPT_A2COPY))
684	    *(u_int32_t *)(opt->addr2) = v;
685	break;
686
687    case o_string:
688	if (opt->flags & OPT_STATIC) {
689	    strlcpy((char *)(opt->addr), *argv, opt->upper_limit);
690	} else {
691	    sv = strdup(*argv);
692	    if (sv == NULL)
693		novm("option argument");
694	    *(char **)(opt->addr) = sv;
695	}
696	break;
697
698    case o_special_noarg:
699    case o_special:
700	parser = (int (*) __P((char **))) opt->addr;
701	if (!(*parser)(argv))
702	    return 0;
703	if (opt->flags & OPT_A2LIST) {
704	    struct option_value *ovp, **pp;
705
706	    ovp = malloc(sizeof(*ovp) + strlen(*argv));
707	    if (ovp != 0) {
708		strcpy(ovp->value, *argv);
709		ovp->source = option_source;
710		ovp->next = NULL;
711		pp = (struct option_value **) &opt->addr2;
712		while (*pp != 0)
713		    pp = &(*pp)->next;
714		*pp = ovp;
715	    }
716	}
717	break;
718
719    case o_wild:
720	wildp = (int (*) __P((char *, char **, int))) opt->addr;
721	if (!(*wildp)(cmd, argv, 1))
722	    return 0;
723	break;
724    }
725
726    if (opt->addr2 && (opt->flags & (OPT_A2COPY|OPT_ENABLE
727		|OPT_A2PRINTER|OPT_A2STRVAL|OPT_A2LIST)) == 0)
728	*(bool *)(opt->addr2) = !(opt->flags & OPT_A2CLR);
729
730    mainopt->source = option_source;
731    mainopt->priority = prio;
732    mainopt->winner = opt - mainopt;
733
734    return 1;
735}
736
737/*
738 * override_value - if the option priorities would permit us to
739 * override the value of option, return 1 and update the priority
740 * and source of the option value.  Otherwise returns 0.
741 */
742int
743override_value(option, priority, source)
744    const char *option;
745    int priority;
746    const char *source;
747{
748	option_t *opt;
749
750	opt = find_option(option);
751	if (opt == NULL)
752		return 0;
753	while (opt->flags & OPT_PRIOSUB)
754		--opt;
755	if ((opt->flags & OPT_PRIO) && priority < opt->priority)
756		return 0;
757	opt->priority = priority;
758	opt->source = source;
759	opt->winner = -1;
760	return 1;
761}
762
763/*
764 * n_arguments - tell how many arguments an option takes
765 */
766static int
767n_arguments(opt)
768    option_t *opt;
769{
770	return (opt->type == o_bool || opt->type == o_special_noarg
771		|| (opt->flags & OPT_NOARG))? 0: 1;
772}
773
774/*
775 * add_options - add a list of options to the set we grok.
776 */
777void
778add_options(opt)
779    option_t *opt;
780{
781    struct option_list *list;
782
783    list = malloc(sizeof(*list));
784    if (list == 0)
785	novm("option list entry");
786    list->options = opt;
787    list->next = extra_options;
788    extra_options = list;
789}
790
791/*
792 * remove_option - permanently remove an option from consideration...
793 * for use by modules to remove choices which no longer make sense.
794 * returns true if found an option
795 */
796int
797remove_option(name)
798    char *name;
799{
800    option_t *o;
801    o = find_option(name);
802    if (o == NULL)
803	return 0;
804    o->name = "";
805    return 1;
806}
807
808/*
809 * check_options - check that options are valid and consistent.
810 */
811void
812check_options()
813{
814	if (logfile_fd >= 0 && logfile_fd != log_to_fd)
815		close(logfile_fd);
816}
817
818/*
819 * print_option - print out an option and its value
820 */
821static void
822print_option(opt, mainopt, printer, arg)
823    option_t *opt, *mainopt;
824    void (*printer) __P((void *, char *, ...));
825    void *arg;
826{
827	int i, v;
828	char *p;
829
830	if (opt->flags & OPT_NOPRINT)
831		return;
832	switch (opt->type) {
833	case o_bool:
834		v = opt->flags & OPT_VALUE;
835		if (*(bool *)opt->addr != v)
836			/* this can happen legitimately, e.g. lock
837			   option turned off for default device */
838			break;
839		printer(arg, "%s", opt->name);
840		break;
841	case o_int:
842		v = opt->flags & OPT_VALUE;
843		if (v >= 128)
844			v -= 256;
845		i = *(int *)opt->addr;
846		if (opt->flags & OPT_NOARG) {
847			printer(arg, "%s", opt->name);
848			if (i != v) {
849				if (opt->flags & OPT_INC) {
850					for (; i > v; i -= v)
851						printer(arg, " %s", opt->name);
852				} else
853					printer(arg, " # oops: %d not %d\n",
854						i, v);
855			}
856		} else {
857			printer(arg, "%s %d", opt->name, i);
858		}
859		break;
860	case o_uint32:
861		printer(arg, "%s", opt->name);
862		if ((opt->flags & OPT_NOARG) == 0)
863			printer(arg, " %x", *(u_int32_t *)opt->addr);
864		break;
865
866	case o_string:
867		if (opt->flags & OPT_HIDE) {
868			p = "??????";
869		} else {
870			p = (char *) opt->addr;
871			if ((opt->flags & OPT_STATIC) == 0)
872				p = *(char **)p;
873		}
874		printer(arg, "%s %q", opt->name, p);
875		break;
876
877	case o_special:
878	case o_special_noarg:
879	case o_wild:
880		if (opt->type != o_wild) {
881			printer(arg, "%s", opt->name);
882			if (n_arguments(opt) == 0)
883				break;
884			printer(arg, " ");
885		}
886		if (opt->flags & OPT_A2PRINTER) {
887			void (*oprt) __P((option_t *,
888					  void ((*)__P((void *, char *, ...))),
889					  void *));
890			oprt = opt->addr2;
891			(*oprt)(opt, printer, arg);
892		} else if (opt->flags & OPT_A2STRVAL) {
893			p = (char *) opt->addr2;
894			if ((opt->flags & OPT_STATIC) == 0)
895				p = *(char **)p;
896			printer("%q", p);
897		} else if (opt->flags & OPT_A2LIST) {
898			struct option_value *ovp;
899
900			ovp = (struct option_value *) opt->addr2;
901			for (;;) {
902				printer(arg, "%q", ovp->value);
903				if ((ovp = ovp->next) == NULL)
904					break;
905				printer(arg, "\t\t# (from %s)\n%s ",
906					ovp->source, opt->name);
907			}
908		} else {
909			printer(arg, "xxx # [don't know how to print value]");
910		}
911		break;
912
913	default:
914		printer(arg, "# %s value (type %d??)", opt->name, opt->type);
915		break;
916	}
917	printer(arg, "\t\t# (from %s)\n", mainopt->source);
918}
919
920/*
921 * print_option_list - print out options in effect from an
922 * array of options.
923 */
924static void
925print_option_list(opt, printer, arg)
926    option_t *opt;
927    void (*printer) __P((void *, char *, ...));
928    void *arg;
929{
930	while (opt->name != NULL) {
931		if (opt->priority != OPRIO_DEFAULT
932		    && opt->winner != (short int) -1)
933			print_option(opt + opt->winner, opt, printer, arg);
934		do {
935			++opt;
936		} while (opt->flags & OPT_PRIOSUB);
937	}
938}
939
940/*
941 * print_options - print out what options are in effect.
942 */
943void
944print_options(printer, arg)
945    void (*printer) __P((void *, char *, ...));
946    void *arg;
947{
948	struct option_list *list;
949	int i;
950
951	printer(arg, "pppd options in effect:\n");
952	print_option_list(general_options, printer, arg);
953	print_option_list(auth_options, printer, arg);
954	for (list = extra_options; list != NULL; list = list->next)
955		print_option_list(list->options, printer, arg);
956	print_option_list(the_channel->options, printer, arg);
957	for (i = 0; protocols[i] != NULL; ++i)
958		print_option_list(protocols[i]->options, printer, arg);
959}
960
961/*
962 * usage - print out a message telling how to use the program.
963 */
964static void
965usage()
966{
967    if (phase == PHASE_INITIALIZE)
968	fprintf(stderr, usage_string, VERSION, progname);
969}
970
971/*
972 * showhelp - print out usage message and exit.
973 */
974static int
975showhelp(argv)
976    char **argv;
977{
978    if (phase == PHASE_INITIALIZE) {
979	usage();
980	exit(0);
981    }
982    return 0;
983}
984
985/*
986 * showversion - print out the version number and exit.
987 */
988static int
989showversion(argv)
990    char **argv;
991{
992    if (phase == PHASE_INITIALIZE) {
993	fprintf(stderr, "pppd version %s\n", VERSION);
994	exit(0);
995    }
996    return 0;
997}
998
999/*
1000 * option_error - print a message about an error in an option.
1001 * The message is logged, and also sent to
1002 * stderr if phase == PHASE_INITIALIZE.
1003 */
1004void
1005option_error __V((char *fmt, ...))
1006{
1007    va_list args;
1008    char buf[1024];
1009
1010#if defined(__STDC__)
1011    va_start(args, fmt);
1012#else
1013    char *fmt;
1014    va_start(args);
1015    fmt = va_arg(args, char *);
1016#endif
1017    vslprintf(buf, sizeof(buf), fmt, args);
1018    va_end(args);
1019    if (phase == PHASE_INITIALIZE)
1020	fprintf(stderr, "%s: %s\n", progname, buf);
1021    syslog(LOG_ERR, "%s", buf);
1022}
1023
1024
1025/*
1026 * Read a word from a file.
1027 * Words are delimited by white-space or by quotes (" or ').
1028 * Quotes, white-space and \ may be escaped with \.
1029 * \<newline> is ignored.
1030 */
1031int
1032getword(f, word, newlinep, filename)
1033    FILE *f;
1034    char *word;
1035    int *newlinep;
1036    char *filename;
1037{
1038    int c, len, escape;
1039    int quoted, comment;
1040    int value, digit, got, n;
1041
1042#define isoctal(c) ((c) >= '0' && (c) < '8')
1043
1044    *newlinep = 0;
1045    len = 0;
1046    escape = 0;
1047    comment = 0;
1048
1049    /*
1050     * First skip white-space and comments.
1051     */
1052    for (;;) {
1053	c = getc(f);
1054	if (c == EOF)
1055	    break;
1056
1057	/*
1058	 * A newline means the end of a comment; backslash-newline
1059	 * is ignored.  Note that we cannot have escape && comment.
1060	 */
1061	if (c == '\n') {
1062	    if (!escape) {
1063		*newlinep = 1;
1064		comment = 0;
1065	    } else
1066		escape = 0;
1067	    continue;
1068	}
1069
1070	/*
1071	 * Ignore characters other than newline in a comment.
1072	 */
1073	if (comment)
1074	    continue;
1075
1076	/*
1077	 * If this character is escaped, we have a word start.
1078	 */
1079	if (escape)
1080	    break;
1081
1082	/*
1083	 * If this is the escape character, look at the next character.
1084	 */
1085	if (c == '\\') {
1086	    escape = 1;
1087	    continue;
1088	}
1089
1090	/*
1091	 * If this is the start of a comment, ignore the rest of the line.
1092	 */
1093	if (c == '#') {
1094	    comment = 1;
1095	    continue;
1096	}
1097
1098	/*
1099	 * A non-whitespace character is the start of a word.
1100	 */
1101	if (!isspace(c))
1102	    break;
1103    }
1104
1105    /*
1106     * Save the delimiter for quoted strings.
1107     */
1108    if (!escape && (c == '"' || c == '\'')) {
1109        quoted = c;
1110	c = getc(f);
1111    } else
1112        quoted = 0;
1113
1114    /*
1115     * Process characters until the end of the word.
1116     */
1117    while (c != EOF) {
1118	if (escape) {
1119	    /*
1120	     * This character is escaped: backslash-newline is ignored,
1121	     * various other characters indicate particular values
1122	     * as for C backslash-escapes.
1123	     */
1124	    escape = 0;
1125	    if (c == '\n') {
1126	        c = getc(f);
1127		continue;
1128	    }
1129
1130	    got = 0;
1131	    switch (c) {
1132	    case 'a':
1133		value = '\a';
1134		break;
1135	    case 'b':
1136		value = '\b';
1137		break;
1138	    case 'f':
1139		value = '\f';
1140		break;
1141	    case 'n':
1142		value = '\n';
1143		break;
1144	    case 'r':
1145		value = '\r';
1146		break;
1147	    case 's':
1148		value = ' ';
1149		break;
1150	    case 't':
1151		value = '\t';
1152		break;
1153
1154	    default:
1155		if (isoctal(c)) {
1156		    /*
1157		     * \ddd octal sequence
1158		     */
1159		    value = 0;
1160		    for (n = 0; n < 3 && isoctal(c); ++n) {
1161			value = (value << 3) + (c & 07);
1162			c = getc(f);
1163		    }
1164		    got = 1;
1165		    break;
1166		}
1167
1168		if (c == 'x') {
1169		    /*
1170		     * \x<hex_string> sequence
1171		     */
1172		    value = 0;
1173		    c = getc(f);
1174		    for (n = 0; n < 2 && isxdigit(c); ++n) {
1175			digit = toupper(c) - '0';
1176			if (digit > 10)
1177			    digit += '0' + 10 - 'A';
1178			value = (value << 4) + digit;
1179			c = getc (f);
1180		    }
1181		    got = 1;
1182		    break;
1183		}
1184
1185		/*
1186		 * Otherwise the character stands for itself.
1187		 */
1188		value = c;
1189		break;
1190	    }
1191
1192	    /*
1193	     * Store the resulting character for the escape sequence.
1194	     */
1195	    if (len < MAXWORDLEN-1)
1196		word[len] = value;
1197	    ++len;
1198
1199	    if (!got)
1200		c = getc(f);
1201	    continue;
1202
1203	}
1204
1205	/*
1206	 * Not escaped: see if we've reached the end of the word.
1207	 */
1208	if (quoted) {
1209	    if (c == quoted)
1210		break;
1211	} else {
1212	    if (isspace(c) || c == '#') {
1213		ungetc (c, f);
1214		break;
1215	    }
1216	}
1217
1218	/*
1219	 * Backslash starts an escape sequence.
1220	 */
1221	if (c == '\\') {
1222	    escape = 1;
1223	    c = getc(f);
1224	    continue;
1225	}
1226
1227	/*
1228	 * An ordinary character: store it in the word and get another.
1229	 */
1230	if (len < MAXWORDLEN-1)
1231	    word[len] = c;
1232	++len;
1233
1234	c = getc(f);
1235    }
1236
1237    /*
1238     * End of the word: check for errors.
1239     */
1240    if (c == EOF) {
1241	if (ferror(f)) {
1242	    if (errno == 0)
1243		errno = EIO;
1244	    option_error("Error reading %s: %m", filename);
1245	    die(1);
1246	}
1247	/*
1248	 * If len is zero, then we didn't find a word before the
1249	 * end of the file.
1250	 */
1251	if (len == 0)
1252	    return 0;
1253    }
1254
1255    /*
1256     * Warn if the word was too long, and append a terminating null.
1257     */
1258    if (len >= MAXWORDLEN) {
1259	option_error("warning: word in file %s too long (%.20s...)",
1260		     filename, word);
1261	len = MAXWORDLEN - 1;
1262    }
1263    word[len] = 0;
1264
1265    return 1;
1266
1267#undef isoctal
1268
1269}
1270
1271/*
1272 * number_option - parse an unsigned numeric parameter for an option.
1273 */
1274static int
1275number_option(str, valp, base)
1276    char *str;
1277    u_int32_t *valp;
1278    int base;
1279{
1280    char *ptr;
1281
1282    *valp = strtoul(str, &ptr, base);
1283    if (ptr == str) {
1284	option_error("invalid numeric parameter '%s' for %s option",
1285		     str, current_option);
1286	return 0;
1287    }
1288    return 1;
1289}
1290
1291
1292/*
1293 * int_option - like number_option, but valp is int *,
1294 * the base is assumed to be 0, and *valp is not changed
1295 * if there is an error.
1296 */
1297int
1298int_option(str, valp)
1299    char *str;
1300    int *valp;
1301{
1302    u_int32_t v;
1303
1304    if (!number_option(str, &v, 0))
1305	return 0;
1306    *valp = (int) v;
1307    return 1;
1308}
1309
1310
1311/*
1312 * The following procedures parse options.
1313 */
1314
1315/*
1316 * readfile - take commands from a file.
1317 */
1318static int
1319readfile(argv)
1320    char **argv;
1321{
1322    return options_from_file(*argv, 1, 1, privileged_option);
1323}
1324
1325/*
1326 * callfile - take commands from /etc/ppp/peers/<name>.
1327 * Name may not contain /../, start with / or ../, or end in /..
1328 */
1329static int
1330callfile(argv)
1331    char **argv;
1332{
1333    char *fname, *arg, *p;
1334    int l, ok;
1335
1336    arg = *argv;
1337    ok = 1;
1338    if (arg[0] == '/' || arg[0] == 0)
1339	ok = 0;
1340    else {
1341	for (p = arg; *p != 0; ) {
1342	    if (p[0] == '.' && p[1] == '.' && (p[2] == '/' || p[2] == 0)) {
1343		ok = 0;
1344		break;
1345	    }
1346	    while (*p != '/' && *p != 0)
1347		++p;
1348	    if (*p == '/')
1349		++p;
1350	}
1351    }
1352    if (!ok) {
1353	option_error("call option value may not contain .. or start with /");
1354	return 0;
1355    }
1356
1357    l = strlen(arg) + strlen(_PATH_PEERFILES) + 1;
1358    if ((fname = (char *) malloc(l)) == NULL)
1359	novm("call file name");
1360    slprintf(fname, l, "%s%s", _PATH_PEERFILES, arg);
1361
1362    ok = options_from_file(fname, 1, 1, 1);
1363
1364    free(fname);
1365    return ok;
1366}
1367
1368#ifdef PPP_FILTER
1369/*
1370 * setpassfilter - Set the pass filter for packets
1371 */
1372static int
1373setpassfilter(argv)
1374    char **argv;
1375{
1376    pc.linktype = DLT_PPP;
1377    pc.snapshot = PPP_HDRLEN;
1378
1379    if (pcap_compile(&pc, &pass_filter, *argv, 1, netmask) == 0)
1380	return 1;
1381    option_error("error in pass-filter expression: %s\n", pcap_geterr(&pc));
1382    return 0;
1383}
1384
1385/*
1386 * setactivefilter - Set the active filter for packets
1387 */
1388static int
1389setactivefilter(argv)
1390    char **argv;
1391{
1392    pc.linktype = DLT_PPP;
1393    pc.snapshot = PPP_HDRLEN;
1394
1395    if (pcap_compile(&pc, &active_filter, *argv, 1, netmask) == 0)
1396	return 1;
1397    option_error("error in active-filter expression: %s\n", pcap_geterr(&pc));
1398    return 0;
1399}
1400#endif
1401
1402/*
1403 * setdomain - Set domain name to append to hostname
1404 */
1405static int
1406setdomain(argv)
1407    char **argv;
1408{
1409    gethostname(hostname, MAXNAMELEN);
1410    if (**argv != 0) {
1411	if (**argv != '.')
1412	    strncat(hostname, ".", MAXNAMELEN - strlen(hostname));
1413	domain = hostname + strlen(hostname);
1414	strncat(hostname, *argv, MAXNAMELEN - strlen(hostname));
1415    }
1416    hostname[MAXNAMELEN-1] = 0;
1417    return (1);
1418}
1419
1420
1421static int
1422setlogfile(argv)
1423    char **argv;
1424{
1425    int fd, err;
1426
1427    if (!privileged_option)
1428	seteuid(getuid());
1429    fd = open(*argv, O_WRONLY | O_APPEND | O_CREAT | O_EXCL, 0644);
1430    if (fd < 0 && errno == EEXIST)
1431	fd = open(*argv, O_WRONLY | O_APPEND);
1432    err = errno;
1433    if (!privileged_option)
1434	seteuid(0);
1435    if (fd < 0) {
1436	errno = err;
1437	option_error("Can't open log file %s: %m", *argv);
1438	return 0;
1439    }
1440    strlcpy(logfile_name, *argv, sizeof(logfile_name));
1441    if (logfile_fd >= 0)
1442	close(logfile_fd);
1443    logfile_fd = fd;
1444    log_to_fd = fd;
1445    log_default = 0;
1446    return 1;
1447}
1448
1449#ifdef PLUGIN
1450static int
1451loadplugin(argv)
1452    char **argv;
1453{
1454    char *arg = *argv;
1455    void *handle;
1456    const char *err;
1457    void (*init) __P((void));
1458    char *path = arg;
1459    const char *vers;
1460
1461    if (strchr(arg, '/') == 0) {
1462	const char *base = _PATH_PLUGIN;
1463	int l = strlen(base) + strlen(arg) + 2;
1464	path = malloc(l);
1465	if (path == 0)
1466	    novm("plugin file path");
1467	strlcpy(path, base, l);
1468	strlcat(path, "/", l);
1469	strlcat(path, arg, l);
1470    }
1471    handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
1472    if (handle == 0) {
1473	err = dlerror();
1474	if (err != 0)
1475	    option_error("%s", err);
1476	option_error("Couldn't load plugin %s", arg);
1477	goto err;
1478    }
1479    init = (void (*)(void))dlsym(handle, "plugin_init");
1480    if (init == 0) {
1481	option_error("%s has no initialization entry point", arg);
1482	goto errclose;
1483    }
1484    vers = (const char *) dlsym(handle, "pppd_version");
1485    if (vers == 0) {
1486	warn("Warning: plugin %s has no version information", arg);
1487    } else if (strcmp(vers, VERSION) != 0) {
1488	option_error("Plugin %s is for pppd version %s, this is %s",
1489		     vers, VERSION);
1490	goto errclose;
1491    }
1492    info("Plugin %s loaded.", arg);
1493    (*init)();
1494    return 1;
1495
1496 errclose:
1497    dlclose(handle);
1498 err:
1499    if (path != arg)
1500	free(path);
1501    return 0;
1502}
1503#endif /* PLUGIN */
1504