shadow/lib/getdef.c
Alejandro Colomar efbbcade43 Use safer allocation macros
Use of these macros, apart from the benefits mentioned in the commit
that adds the macros, has some other good side effects:

-  Consistency in getting the size of the object from sizeof(type),
   instead of a mix of sizeof(type) sometimes and sizeof(*p) other
   times.

-  More readable code: no casts, and no sizeof(), so also shorter lines
   that we don't need to cut.

-  Consistency in using array allocation calls for allocations of arrays
   of objects, even when the object size is 1.

Cc: Valentin V. Bartenev <vbartenev@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-02-23 20:28:43 -06:00

626 lines
13 KiB
C

/*
* SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2002 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2008, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include "prototypes.h"
#include "defines.h"
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#ifdef USE_ECONF
#include <libeconf.h>
#endif
#include "alloc.h"
#include "getdef.h"
#include "shadowlog_internal.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}, \
{"HMAC_CRYPTO_ALGO", 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
{"SYSLOG_SG_ENAB", NULL},
{"SYSLOG_SU_ENAB", NULL},
#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) ? 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 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 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) {
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;
}
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 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 = MALLOCARRAY(len, char);
if (cp == NULL)
exit (13);
snprintf(cp, len, "%s/%s", file, sysconfdir);
sysconfdir = cp;
#ifdef VENDORDIR
len = strlen(file) + strlen(vendordir) + 2;
cp = MALLOCARRAY(len, char);
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, sizeof (buf), fp) != NULL) {
/*
* Trim trailing whitespace.
*/
for (i = (ptrdiff_t) 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