shadow/lib/getdef.c

/*
 * Copyright 1991 - 1994, Julianne Frances Haugh and Chip Rosenthal
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#include "rcsid.h"
RCSID("$Id: getdef.c,v 1.18 2003/05/12 02:40:08 kloczek Exp $")

#include "prototypes.h"
#include "defines.h"
#include <stdio.h>
#include <ctype.h>
#include "getdef.h"

/*
 * A configuration item definition.
 */

struct itemdef {
	const char *name;	/* name of the item			*/
	char *value;		/* value given, or NULL if no value	*/
};

/*
 * This list *must* be sorted by the "name" member.
 */

#define NUMDEFS	(sizeof(def_table)/sizeof(def_table[0]))
static struct itemdef def_table[] = {
	{ "CHFN_AUTH",			NULL },
	{ "CHFN_RESTRICT",		NULL },
#ifdef USE_PAM
	{ "CLOSE_SESSIONS",		NULL },
#endif
	{ "CONSOLE",			NULL },
	{ "CONSOLE_GROUPS",		NULL },
	{ "CRACKLIB_DICTPATH",		NULL },
	{ "CREATE_HOME",		NULL },
	{ "DEFAULT_HOME",		NULL },
	{ "ENVIRON_FILE",		NULL },
	{ "ENV_HZ",			NULL },
	{ "ENV_PATH",			NULL },
	{ "ENV_ROOTPATH",		NULL },  /* SuSE compatibility? */
	{ "ENV_SUPATH",			NULL },
	{ "ENV_TZ",			NULL },
	{ "ERASECHAR",			NULL },
	{ "FAILLOG_ENAB",		NULL },
	{ "FAIL_DELAY",			NULL },
	{ "FAKE_SHELL",			NULL },
	{ "FTMP_FILE",			NULL },
	{ "GETPASS_ASTERISKS",		NULL },
	{ "GID_MAX",			NULL },
	{ "GID_MIN",			NULL },
	{ "HUSHLOGIN_FILE",		NULL },
	{ "ISSUE_FILE",			NULL },
	{ "KILLCHAR",			NULL },
	{ "LASTLOG_ENAB",		NULL },
	{ "LOGIN_RETRIES",		NULL },
	{ "LOGIN_STRING",		NULL },
	{ "LOGIN_TIMEOUT",		NULL },
	{ "LOG_OK_LOGINS",		NULL },
	{ "LOG_UNKFAIL_ENAB",		NULL },
	{ "MAIL_CHECK_ENAB",		NULL },
	{ "MAIL_DIR",			NULL },
	{ "MAIL_FILE",			NULL },
	{ "MD5_CRYPT_ENAB",		NULL },
	{ "MOTD_FILE",			NULL },
	{ "NOLOGINS_FILE",		NULL },
	{ "NOLOGIN_STR",		NULL },
	{ "OBSCURE_CHECKS_ENAB",	NULL },
	{ "PASS_ALWAYS_WARN",		NULL },
	{ "PASS_CHANGE_TRIES",		NULL },
	{ "PASS_MAX_DAYS",		NULL },
	{ "PASS_MAX_LEN",		NULL },
	{ "PASS_MIN_DAYS",		NULL },
	{ "PASS_MIN_LEN",		NULL },
	{ "PASS_WARN_AGE",		NULL },
	{ "PORTTIME_CHECKS_ENAB",	NULL },
	{ "QMAIL_DIR",			NULL },
	{ "QUOTAS_ENAB",		NULL },
	{ "SULOG_FILE",			NULL },
	{ "SU_NAME",			NULL },
	{ "SU_WHEEL_ONLY",		NULL },
#ifdef USE_SYSLOG
	{ "SYSLOG_SG_ENAB",		NULL },
	{ "SYSLOG_SU_ENAB",		NULL },
#endif
	{ "TTYGROUP",			NULL },
	{ "TTYPERM",			NULL },
	{ "TTYTYPE_FILE",		NULL },
	{ "UID_MAX",			NULL },
	{ "UID_MIN",			NULL },
	{ "ULIMIT",			NULL },
	{ "UMASK",			NULL },
	{ "USERDEL_CMD",		NULL },
	{ "USERGROUPS_ENAB",		NULL }
};

#ifndef LOGINDEFS
#define LOGINDEFS "/etc/login.defs"
#endif

static char def_fname[] = LOGINDEFS;	/* login config defs file	*/
static int def_loaded = 0;		/* are defs already loaded?	*/

extern long strtol();

/* local function prototypes */
static struct itemdef *def_find(const char *);
static void def_load(void);


/*
 * getdef_str - get string value from table of definitions.
 *
 * Return point to static data for specified item, or NULL if item is not
 * defined.  First time invoked, will load definitions from the file.
 */

char *
getdef_str(const char *item)
{
	struct itemdef *d;

	if (!def_loaded)
		def_load();

	return ((d = def_find(item)) == NULL ? (char *)NULL : d->value);
}


/*
 * getdef_bool - get boolean value from table of definitions.
 *
 * Return TRUE if specified item is defined as "yes", else FALSE.
 */

int
getdef_bool(const char *item)
{
	struct itemdef *d;

	if (!def_loaded)
		def_load();

	if ((d = def_find(item)) == NULL || d->value == NULL)
		return 0;

	return (strcasecmp(d->value, "yes") == 0);
}


/*
 * getdef_num - get numerical value from table of definitions
 *
 * Returns numeric value of specified item, else the "dflt" value if
 * the item is not defined.  Octal (leading "0") and hex (leading "0x")
 * values are handled.
 */

int
getdef_num(const char *item, int dflt)
{
	struct itemdef *d;

	if (!def_loaded)
		def_load();

	if ((d = def_find(item)) == NULL || d->value == NULL)
		return dflt;

	return (int) strtol(d->value, (char **)NULL, 0);
}


/*
 * getdef_unum - get unsigned numerical value from table of definitions
 *
 * Returns numeric value of specified item, else the "dflt" value if
 * the item is not defined.  Octal (leading "0") and hex (leading "0x")
 * values are handled.
 */

unsigned int
getdef_unum(const char *item, unsigned int dflt)
{
	struct itemdef *d;

	if (!def_loaded)
		def_load();

	if ((d = def_find(item)) == NULL || d->value == NULL)
		return dflt;

	return (unsigned int) strtoul(d->value, (char **)NULL, 0);
}


/*
 * getdef_long - get long integer value from table of definitions
 *
 * Returns numeric value of specified item, else the "dflt" value if
 * the item is not defined.  Octal (leading "0") and hex (leading "0x")
 * values are handled.
 */

long
getdef_long(const char *item, long dflt)
{
	struct itemdef *d;

	if (!def_loaded)
		def_load();

	if ((d = def_find(item)) == NULL || d->value == NULL)
		return dflt;

	return strtol(d->value, (char **)NULL, 0);
}


/*
 * putdef_str - override the value read from /etc/login.defs
 * (also used when loading the initial defaults)
 */

int
putdef_str(const char *name, const char *value)
{
	struct itemdef *d;
	char *cp;

	if (!def_loaded)
		def_load();

	/*
	 * Locate the slot to save the value.  If this parameter
	 * is unknown then "def_find" will print an err message.
	 */
	if ((d = def_find(name)) == NULL)
		return -1;

	/*
	 * Save off the value.
	 */
	if ((cp = strdup(value)) == NULL) {
		fprintf(stderr,
			_("Could not allocate space for config info.\n"));
		SYSLOG((LOG_ERR,
			"could not allocate space for config info"));
		return -1;
	}

	if (d->value)
		free(d->value);

	d->value = cp;
	return 0;
}


/*
 * def_find - locate named item in table
 *
 * Search through a sorted table of configurable items to locate the
 * specified configuration option.
 */

static struct itemdef *
def_find(const char *name)
{
	int min, max, curr, n;

	/*
	 * Invariant - desired item in range [min:max].
	 */

	min = 0;
	max = NUMDEFS-1;

	/*
	 * Binary search into the table.  Relies on the items being
	 * sorted by name.
	 */

	while (min <= max) {
		curr = (min+max)/2;

		if (! (n = strcmp(def_table[curr].name, name)))
			return &def_table[curr];

		if (n < 0)
			min = curr+1;
		else
			max = curr-1;
	}

	/*
	 * Item was never found.
	 */

	fprintf(stderr, _("configuration error - unknown item '%s' (notify administrator)\n"), name);
	SYSLOG((LOG_CRIT, "unknown configuration item `%s'", name));
	return (struct itemdef *) NULL;
}

/*
 * def_load - load configuration table
 *
 * Loads the user-configured options from the default configuration file
 */

static void
def_load(void)
{
	int i;
	FILE *fp;
	char buf[1024], *name, *value, *s;

	/*
	 * Open the configuration definitions file.
	 */
	if ((fp = fopen(def_fname, "r")) == NULL) {
		SYSLOG((LOG_CRIT, "cannot open login definitions %s [%m]",
			def_fname));
		return;
	}

	/*
	 * Set the initialized flag.
	 * (do it early to prevent recursion in putdef_str())
	 */
	++def_loaded;

	/*
	 * Go through all of the lines in the file.
	 */
	while (fgets(buf, sizeof(buf), fp) != NULL) {

		/*
		 * Trim trailing whitespace.
		 */
		for (i = strlen(buf)-1 ; i >= 0 ; --i) {
			if (!isspace(buf[i]))
				break;
		}
		buf[++i] = '\0';

		/*
		 * Break the line into two fields.
		 */
		name = buf + strspn(buf, " \t");	/* first nonwhite */
		if (*name == '\0' || *name == '#')
			continue;			/* comment or empty */

		s = name + strcspn(name, " \t");	/* end of field */
		if (*s == '\0')
			continue;			/* only 1 field?? */

		*s++ = '\0';
		value = s + strspn(s, " \"\t");		/* next nonwhite */
		*(value + strcspn(value, "\"")) = '\0';

		/*
		 * Store the value in def_table.
		 */
		putdef_str(name, value);
	}
	(void) fclose(fp);
}


#ifdef CKDEFS
int
main(int argc, char **argv)
{
	int i;
	char *cp;
	struct itemdef *d;

	def_load ();

	for (i = 0 ; i < NUMDEFS ; ++i) {
		if ((d = def_find(def_table[i].name)) == NULL)
			printf("error - lookup '%s' failed\n", def_table[i].name);
		else
			printf("%4d %-24s %s\n", i+1, d->name, d->value);
	}
	for (i = 1;i < argc;i++) {
		if ((cp = getdef_str (argv[1])) != NULL)
			printf ("%s `%s'\n", argv[1], cp);
		else
			printf ("%s not found\n", argv[1]);
	}
	exit(0);
}
#endif