shadow/lib/getdef.c
Serge Hallyn 2b22a6909d libsubid: don't print error messages on stderr by default
Closes #325

Add a new subid_init() function which can be used to specify the
stream on which error messages should be printed.  (If you want to
get fancy you can redirect that to memory :)  If subid_init() is
not called, use stderr.  If NULL is passed, then /dev/null will
be used.

This patch also fixes up the 'Prog', which previously had to be
defined by any program linking against libsubid.  Now, by default
in libsubid it will show (subid).  Once subid_init() is called,
it will use the first variable passed to subid_init().

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-15 12:38:55 -05:00

649 lines
14 KiB
C

/*
* Copyright (c) 1991 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2002 - 2006, Tomasz Kłoczko
* Copyright (c) 2007 - 2008, Nicolas François
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT
* HOLDERS 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>
#ident "$Id$"
#include "prototypes.h"
#include "defines.h"
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#ifdef USE_ECONF
#include <libeconf.h>
#endif
#include "getdef.h"
/*
* A configuration item definition.
*/
struct itemdef {
/*@null@*/const char *name; /* name of the item */
/*@null@*/char *value; /* value given, or NULL if no value */
};
#define PAMDEFS \
{"CHFN_AUTH", NULL}, \
{"CHSH_AUTH", NULL}, \
{"CRACKLIB_DICTPATH", NULL}, \
{"ENV_HZ", NULL}, \
{"ENVIRON_FILE", NULL}, \
{"ENV_TZ", NULL}, \
{"FAILLOG_ENAB", NULL}, \
{"FTMP_FILE", NULL}, \
{"ISSUE_FILE", NULL}, \
{"LASTLOG_ENAB", NULL}, \
{"LOGIN_STRING", NULL}, \
{"MAIL_CHECK_ENAB", NULL}, \
{"MOTD_FILE", NULL}, \
{"NOLOGINS_FILE", NULL}, \
{"OBSCURE_CHECKS_ENAB", NULL}, \
{"PASS_ALWAYS_WARN", NULL}, \
{"PASS_CHANGE_TRIES", NULL}, \
{"PASS_MAX_LEN", NULL}, \
{"PASS_MIN_LEN", NULL}, \
{"PORTTIME_CHECKS_ENAB", NULL}, \
{"QUOTAS_ENAB", NULL}, \
{"SU_WHEEL_ONLY", NULL}, \
{"ULIMIT", NULL},
/*
* Items used in other tools (util-linux, etc.)
*/
#define FOREIGNDEFS \
{"ALWAYS_SET_PATH", NULL}, \
{"ENV_ROOTPATH", NULL}, \
{"LOGIN_KEEP_USERNAME", NULL}, \
{"LOGIN_PLAIN_PROMPT", NULL}, \
{"MOTD_FIRSTONLY", NULL}, \
#define NUMDEFS (sizeof(def_table)/sizeof(def_table[0]))
static struct itemdef def_table[] = {
{"CHFN_RESTRICT", NULL},
{"CONSOLE_GROUPS", NULL},
{"CONSOLE", NULL},
{"CREATE_HOME", NULL},
{"DEFAULT_HOME", NULL},
{"ENCRYPT_METHOD", NULL},
{"ENV_PATH", NULL},
{"ENV_SUPATH", NULL},
{"ERASECHAR", NULL},
{"FAIL_DELAY", NULL},
{"FAKE_SHELL", NULL},
{"GID_MAX", NULL},
{"GID_MIN", NULL},
{"HOME_MODE", NULL},
{"HUSHLOGIN_FILE", NULL},
{"KILLCHAR", NULL},
{"LASTLOG_UID_MAX", NULL},
{"LOGIN_RETRIES", NULL},
{"LOGIN_TIMEOUT", NULL},
{"LOG_OK_LOGINS", NULL},
{"LOG_UNKFAIL_ENAB", NULL},
{"MAIL_DIR", NULL},
{"MAIL_FILE", NULL},
{"MAX_MEMBERS_PER_GROUP", NULL},
{"MD5_CRYPT_ENAB", NULL},
{"NONEXISTENT", NULL},
{"PASS_MAX_DAYS", NULL},
{"PASS_MIN_DAYS", NULL},
{"PASS_WARN_AGE", NULL},
#ifdef USE_SHA_CRYPT
{"SHA_CRYPT_MAX_ROUNDS", NULL},
{"SHA_CRYPT_MIN_ROUNDS", NULL},
#endif
#ifdef USE_BCRYPT
{"BCRYPT_MAX_ROUNDS", NULL},
{"BCRYPT_MIN_ROUNDS", NULL},
#endif
#ifdef USE_YESCRYPT
{"YESCRYPT_COST_FACTOR", NULL},
#endif
{"SUB_GID_COUNT", NULL},
{"SUB_GID_MAX", NULL},
{"SUB_GID_MIN", NULL},
{"SUB_UID_COUNT", NULL},
{"SUB_UID_MAX", NULL},
{"SUB_UID_MIN", NULL},
{"SULOG_FILE", NULL},
{"SU_NAME", NULL},
{"SYS_GID_MAX", NULL},
{"SYS_GID_MIN", NULL},
{"SYS_UID_MAX", NULL},
{"SYS_UID_MIN", NULL},
{"TTYGROUP", NULL},
{"TTYPERM", NULL},
{"TTYTYPE_FILE", NULL},
{"UID_MAX", NULL},
{"UID_MIN", NULL},
{"UMASK", NULL},
{"USERDEL_CMD", NULL},
{"USERGROUPS_ENAB", NULL},
#ifndef USE_PAM
PAMDEFS
#endif
#ifdef USE_SYSLOG
{"SYSLOG_SG_ENAB", NULL},
{"SYSLOG_SU_ENAB", NULL},
#endif
#ifdef WITH_TCB
{"TCB_AUTH_GROUP", NULL},
{"TCB_SYMLINKS", NULL},
{"USE_TCB", NULL},
#endif
{"FORCE_SHADOW", NULL},
{"GRANT_AUX_GROUP_SUBIDS", NULL},
{"PREVENT_NO_AUTH", NULL},
{NULL, NULL}
};
#define NUMKNOWNDEFS (sizeof(knowndef_table)/sizeof(knowndef_table[0]))
static struct itemdef knowndef_table[] = {
#ifdef USE_PAM
PAMDEFS
#endif
FOREIGNDEFS
{NULL, NULL}
};
#ifdef USE_ECONF
#ifdef VENDORDIR
static const char* vendordir = VENDORDIR;
#else
static const char* vendordir = NULL;
#endif
static const char* sysconfdir = "/etc";
#else
#ifndef LOGINDEFS
#define LOGINDEFS "/etc/login.defs"
#endif
static const char* def_fname = LOGINDEFS; /* login config defs file */
#endif
static bool def_loaded = false; /* are defs already loaded? */
/* local function prototypes */
static /*@observer@*/ /*@null@*/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.
*/
/*@observer@*/ /*@null@*/const char *getdef_str (const char *item)
{
struct itemdef *d;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
return ((NULL == d)? (const char *) NULL : d->value);
}
/*
* getdef_bool - get boolean value from table of definitions.
*
* Return TRUE if specified item is defined as "yes", else FALSE.
*/
bool getdef_bool (const char *item)
{
struct itemdef *d;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
if ((NULL == d) || (NULL == d->value)) {
return false;
}
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;
long val;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
if ((NULL == d) || (NULL == d->value)) {
return dflt;
}
if ( (getlong (d->value, &val) == 0)
|| (val > INT_MAX)
|| (val < INT_MIN)) {
fprintf (shadow_logfd,
_("configuration error - cannot parse %s value: '%s'"),
item, d->value);
return dflt;
}
return (int) val;
}
/*
* 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;
long val;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
if ((NULL == d) || (NULL == d->value)) {
return dflt;
}
if ( (getlong (d->value, &val) == 0)
|| (val < 0)
|| (val > INT_MAX)) {
fprintf (shadow_logfd,
_("configuration error - cannot parse %s value: '%s'"),
item, d->value);
return dflt;
}
return (unsigned int) val;
}
/*
* 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;
long val;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
if ((NULL == d) || (NULL == d->value)) {
return dflt;
}
if (getlong (d->value, &val) == 0) {
fprintf (shadow_logfd,
_("configuration error - cannot parse %s value: '%s'"),
item, d->value);
return dflt;
}
return val;
}
/*
* getdef_ulong - get unsigned long 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 long getdef_ulong (const char *item, unsigned long dflt)
{
struct itemdef *d;
unsigned long val;
if (!def_loaded) {
def_load ();
}
d = def_find (item);
if ((NULL == d) || (NULL == d->value)) {
return dflt;
}
if (getulong (d->value, &val) == 0) {
/* FIXME: we should have a getulong */
fprintf (shadow_logfd,
_("configuration error - cannot parse %s value: '%s'"),
item, d->value);
return dflt;
}
return val;
}
/*
* 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.
*/
d = def_find (name);
if (NULL == d) {
return -1;
}
/*
* Save off the value.
*/
cp = strdup (value);
if (NULL == cp) {
(void) fputs (_("Could not allocate space for config info.\n"),
shadow_logfd);
SYSLOG ((LOG_ERR, "could not allocate space for config info"));
return -1;
}
if (NULL != d->value) {
free (d->value);
}
d->value = cp;
return 0;
}
/*
* def_find - locate named item in table
*
* Search through a table of configurable items to locate the
* specified configuration option.
*/
static /*@observer@*/ /*@null@*/struct itemdef *def_find (const char *name)
{
struct itemdef *ptr;
/*
* Search into the table.
*/
for (ptr = def_table; NULL != ptr->name; ptr++) {
if (strcmp (ptr->name, name) == 0) {
return ptr;
}
}
/*
* Item was never found.
*/
for (ptr = knowndef_table; NULL != ptr->name; ptr++) {
if (strcmp (ptr->name, name) == 0) {
goto out;
}
}
fprintf (shadow_logfd,
_("configuration error - unknown item '%s' (notify administrator)\n"),
name);
SYSLOG ((LOG_CRIT, "unknown configuration item `%s'", name));
out:
return (struct itemdef *) NULL;
}
/*
* setdef_config_file - set the default configuration file path
*
* must be called prior to any def* calls.
*/
void setdef_config_file (const char* file)
{
#ifdef USE_ECONF
size_t len;
char* cp;
len = strlen(file) + strlen(sysconfdir) + 2;
cp = malloc(len);
if (cp == NULL)
exit (13);
snprintf(cp, len, "%s/%s", file, sysconfdir);
sysconfdir = cp;
#ifdef VENDORDIR
len = strlen(file) + strlen(vendordir) + 2;
cp = malloc(len);
if (cp == NULL)
exit (13);
snprintf(cp, len, "%s/%s", file, vendordir);
vendordir = cp;
#endif
#else
def_fname = file;
#endif
}
/*
* def_load - load configuration table
*
* Loads the user-configured options from the default configuration file
*/
static void def_load (void)
{
#ifdef USE_ECONF
econf_file *defs_file = NULL;
econf_err error;
char **keys;
size_t key_number;
#else
int i;
FILE *fp;
char buf[1024], *name, *value, *s;
#endif
/*
* Set the initialized flag.
* (do it early to prevent recursion in putdef_str())
*/
def_loaded = true;
#ifdef USE_ECONF
error = econf_readDirs (&defs_file, vendordir, sysconfdir, "login", "defs", " \t", "#");
if (error) {
if (error == ECONF_NOFILE)
return;
SYSLOG ((LOG_CRIT, "cannot open login definitions [%s]",
econf_errString(error)));
exit (EXIT_FAILURE);
}
if ((error = econf_getKeys(defs_file, NULL, &key_number, &keys))) {
SYSLOG ((LOG_CRIT, "cannot read login definitions [%s]",
econf_errString(error)));
exit (EXIT_FAILURE);
}
for (size_t i = 0; i < key_number; i++) {
char *value;
econf_getStringValue(defs_file, NULL, keys[i], &value);
/*
* Store the value in def_table.
*
* Ignore failures to load the login.defs file.
* The error was already reported to the user and to
* syslog. The tools will just use their default values.
*/
(void)putdef_str (keys[i], value);
}
econf_free (keys);
econf_free (defs_file);
#else
/*
* Open the configuration definitions file.
*/
fp = fopen (def_fname, "r");
if (NULL == fp) {
if (errno == ENOENT)
return;
int err = errno;
SYSLOG ((LOG_CRIT, "cannot open login definitions %s [%s]",
def_fname, strerror (err)));
exit (EXIT_FAILURE);
}
/*
* Go through all of the lines in the file.
*/
while (fgets (buf, (int) sizeof (buf), fp) != NULL) {
/*
* Trim trailing whitespace.
*/
for (i = (int) strlen (buf) - 1; i >= 0; --i) {
if (!isspace (buf[i])) {
break;
}
}
i++;
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.
*
* Ignore failures to load the login.defs file.
* The error was already reported to the user and to
* syslog. The tools will just use their default values.
*/
(void)putdef_str (name, value);
}
if (ferror (fp) != 0) {
int err = errno;
SYSLOG ((LOG_CRIT, "cannot read login definitions %s [%s]",
def_fname, strerror (err)));
exit (EXIT_FAILURE);
}
(void) fclose (fp);
#endif
}
#ifdef CKDEFS
int main (int argc, char **argv)
{
int i;
char *cp;
struct itemdef *d;
def_load ();
for (i = 0; i < NUMDEFS; ++i) {
d = def_find (def_table[i].name);
if (NULL == d) {
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++) {
cp = getdef_str (argv[1]);
if (NULL != cp) {
printf ("%s `%s'\n", argv[1], cp);
} else {
printf ("%s not found\n", argv[1]);
}
}
exit (EXIT_SUCCESS);
}
#endif