xref: /freebsd/contrib/openpam/include/security/openpam.h (revision 31c521e9ea84e8e213bb9298fe5961b65d79654a)
15c1eca55SDag-Erling Smørgrav /*-
231c521e9SDag-Erling Smørgrav  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
35c1eca55SDag-Erling Smørgrav  * All rights reserved.
45c1eca55SDag-Erling Smørgrav  *
55c1eca55SDag-Erling Smørgrav  * This software was developed for the FreeBSD Project by ThinkSec AS and
6ee02aaa9SDag-Erling Smørgrav  * Network Associates Laboratories, the Security Research Division of
7ee02aaa9SDag-Erling Smørgrav  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
8ee02aaa9SDag-Erling Smørgrav  * ("CBOSS"), as part of the DARPA CHATS research program.
95c1eca55SDag-Erling Smørgrav  *
105c1eca55SDag-Erling Smørgrav  * Redistribution and use in source and binary forms, with or without
115c1eca55SDag-Erling Smørgrav  * modification, are permitted provided that the following conditions
125c1eca55SDag-Erling Smørgrav  * are met:
135c1eca55SDag-Erling Smørgrav  * 1. Redistributions of source code must retain the above copyright
145c1eca55SDag-Erling Smørgrav  *    notice, this list of conditions and the following disclaimer.
155c1eca55SDag-Erling Smørgrav  * 2. Redistributions in binary form must reproduce the above copyright
165c1eca55SDag-Erling Smørgrav  *    notice, this list of conditions and the following disclaimer in the
175c1eca55SDag-Erling Smørgrav  *    documentation and/or other materials provided with the distribution.
185c1eca55SDag-Erling Smørgrav  * 3. The name of the author may not be used to endorse or promote
195c1eca55SDag-Erling Smørgrav  *    products derived from this software without specific prior written
205c1eca55SDag-Erling Smørgrav  *    permission.
215c1eca55SDag-Erling Smørgrav  *
225c1eca55SDag-Erling Smørgrav  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
235c1eca55SDag-Erling Smørgrav  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
245c1eca55SDag-Erling Smørgrav  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
255c1eca55SDag-Erling Smørgrav  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
265c1eca55SDag-Erling Smørgrav  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
275c1eca55SDag-Erling Smørgrav  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
285c1eca55SDag-Erling Smørgrav  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
295c1eca55SDag-Erling Smørgrav  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
305c1eca55SDag-Erling Smørgrav  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
315c1eca55SDag-Erling Smørgrav  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
325c1eca55SDag-Erling Smørgrav  * SUCH DAMAGE.
335c1eca55SDag-Erling Smørgrav  *
3431c521e9SDag-Erling Smørgrav  * $P4: //depot/projects/openpam/include/security/openpam.h#24 $
355c1eca55SDag-Erling Smørgrav  */
365c1eca55SDag-Erling Smørgrav 
375c1eca55SDag-Erling Smørgrav #ifndef _SECURITY_OPENPAM_H_INCLUDED
385c1eca55SDag-Erling Smørgrav #define _SECURITY_OPENPAM_H_INCLUDED
395c1eca55SDag-Erling Smørgrav 
405c1eca55SDag-Erling Smørgrav /*
415c1eca55SDag-Erling Smørgrav  * Annoying but necessary header pollution
425c1eca55SDag-Erling Smørgrav  */
435c1eca55SDag-Erling Smørgrav #include <stdarg.h>
445c1eca55SDag-Erling Smørgrav 
455c1eca55SDag-Erling Smørgrav #ifdef __cplusplus
465c1eca55SDag-Erling Smørgrav extern "C" {
475c1eca55SDag-Erling Smørgrav #endif
485c1eca55SDag-Erling Smørgrav 
4993889be5SDag-Erling Smørgrav struct passwd;
5093889be5SDag-Erling Smørgrav 
515c1eca55SDag-Erling Smørgrav /*
525c1eca55SDag-Erling Smørgrav  * API extensions
535c1eca55SDag-Erling Smørgrav  */
5493889be5SDag-Erling Smørgrav int
5593889be5SDag-Erling Smørgrav openpam_borrow_cred(pam_handle_t *_pamh,
5693889be5SDag-Erling Smørgrav 	const struct passwd *_pwd);
5793889be5SDag-Erling Smørgrav 
5893889be5SDag-Erling Smørgrav void
5993889be5SDag-Erling Smørgrav openpam_free_data(pam_handle_t *_pamh,
6093889be5SDag-Erling Smørgrav 	void *_data,
6193889be5SDag-Erling Smørgrav 	int _status);
6293889be5SDag-Erling Smørgrav 
6346acc370SDag-Erling Smørgrav const char *
6446acc370SDag-Erling Smørgrav openpam_get_option(pam_handle_t *_pamh,
6546acc370SDag-Erling Smørgrav 	const char *_option);
6646acc370SDag-Erling Smørgrav 
6746acc370SDag-Erling Smørgrav int
6893889be5SDag-Erling Smørgrav openpam_restore_cred(pam_handle_t *_pamh);
6993889be5SDag-Erling Smørgrav 
7093889be5SDag-Erling Smørgrav int
7146acc370SDag-Erling Smørgrav openpam_set_option(pam_handle_t *_pamh,
7246acc370SDag-Erling Smørgrav 	const char *_option,
7346acc370SDag-Erling Smørgrav 	const char *_value);
7446acc370SDag-Erling Smørgrav 
755c1eca55SDag-Erling Smørgrav int
765c1eca55SDag-Erling Smørgrav pam_error(pam_handle_t *_pamh,
775c1eca55SDag-Erling Smørgrav 	const char *_fmt,
785c1eca55SDag-Erling Smørgrav 	...);
795c1eca55SDag-Erling Smørgrav 
805c1eca55SDag-Erling Smørgrav int
815c1eca55SDag-Erling Smørgrav pam_get_authtok(pam_handle_t *_pamh,
8211d144d3SDag-Erling Smørgrav 	int _item,
835c1eca55SDag-Erling Smørgrav 	const char **_authtok,
845c1eca55SDag-Erling Smørgrav 	const char *_prompt);
855c1eca55SDag-Erling Smørgrav 
865c1eca55SDag-Erling Smørgrav int
875c1eca55SDag-Erling Smørgrav pam_info(pam_handle_t *_pamh,
885c1eca55SDag-Erling Smørgrav 	const char *_fmt,
895c1eca55SDag-Erling Smørgrav 	...);
905c1eca55SDag-Erling Smørgrav 
915c1eca55SDag-Erling Smørgrav int
925c1eca55SDag-Erling Smørgrav pam_prompt(pam_handle_t *_pamh,
935c1eca55SDag-Erling Smørgrav 	int _style,
945c1eca55SDag-Erling Smørgrav 	char **_resp,
955c1eca55SDag-Erling Smørgrav 	const char *_fmt,
965c1eca55SDag-Erling Smørgrav 	...);
975c1eca55SDag-Erling Smørgrav 
985c1eca55SDag-Erling Smørgrav int
995c1eca55SDag-Erling Smørgrav pam_setenv(pam_handle_t *_pamh,
1005c1eca55SDag-Erling Smørgrav 	const char *_name,
1015c1eca55SDag-Erling Smørgrav 	const char *_value,
1025c1eca55SDag-Erling Smørgrav 	int _overwrite);
1035c1eca55SDag-Erling Smørgrav 
1045c1eca55SDag-Erling Smørgrav int
1055c1eca55SDag-Erling Smørgrav pam_vinfo(pam_handle_t *_pamh,
1065c1eca55SDag-Erling Smørgrav 	const char *_fmt,
1075c1eca55SDag-Erling Smørgrav 	va_list _ap);
1085c1eca55SDag-Erling Smørgrav 
1095c1eca55SDag-Erling Smørgrav int
1105c1eca55SDag-Erling Smørgrav pam_verror(pam_handle_t *_pamh,
1115c1eca55SDag-Erling Smørgrav 	const char *_fmt,
1125c1eca55SDag-Erling Smørgrav 	va_list _ap);
1135c1eca55SDag-Erling Smørgrav 
1145c1eca55SDag-Erling Smørgrav int
1155c1eca55SDag-Erling Smørgrav pam_vprompt(pam_handle_t *_pamh,
1165c1eca55SDag-Erling Smørgrav 	int _style,
1175c1eca55SDag-Erling Smørgrav 	char **_resp,
1185c1eca55SDag-Erling Smørgrav 	const char *_fmt,
1195c1eca55SDag-Erling Smørgrav 	va_list _ap);
1205c1eca55SDag-Erling Smørgrav 
1215c1eca55SDag-Erling Smørgrav /*
12231c521e9SDag-Erling Smørgrav  * Read cooked lines.
12331c521e9SDag-Erling Smørgrav  * Checking for FOPEN_MAX is a fairly reliable way to detect the presence
12431c521e9SDag-Erling Smørgrav  * of <stdio.h>
12531c521e9SDag-Erling Smørgrav  */
12631c521e9SDag-Erling Smørgrav #ifdef FOPEN_MAX
12731c521e9SDag-Erling Smørgrav char *
12831c521e9SDag-Erling Smørgrav openpam_readline(FILE *_f,
12931c521e9SDag-Erling Smørgrav 	int *_lineno,
13031c521e9SDag-Erling Smørgrav 	size_t *_lenp);
13131c521e9SDag-Erling Smørgrav #endif
13231c521e9SDag-Erling Smørgrav 
13331c521e9SDag-Erling Smørgrav /*
1345c1eca55SDag-Erling Smørgrav  * Log levels
1355c1eca55SDag-Erling Smørgrav  */
1365c1eca55SDag-Erling Smørgrav enum {
1375c1eca55SDag-Erling Smørgrav 	PAM_LOG_DEBUG,
1385c1eca55SDag-Erling Smørgrav 	PAM_LOG_VERBOSE,
1395c1eca55SDag-Erling Smørgrav 	PAM_LOG_NOTICE,
1405c1eca55SDag-Erling Smørgrav 	PAM_LOG_ERROR
1415c1eca55SDag-Erling Smørgrav };
1425c1eca55SDag-Erling Smørgrav 
1435c1eca55SDag-Erling Smørgrav /*
1445c1eca55SDag-Erling Smørgrav  * Log to syslog
1455c1eca55SDag-Erling Smørgrav  */
14611d144d3SDag-Erling Smørgrav void
14711d144d3SDag-Erling Smørgrav _openpam_log(int _level,
1485c1eca55SDag-Erling Smørgrav 	const char *_func,
1495c1eca55SDag-Erling Smørgrav 	const char *_fmt,
1505c1eca55SDag-Erling Smørgrav 	...);
1515c1eca55SDag-Erling Smørgrav 
15255e3fbc9SDag-Erling Smørgrav #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
15355e3fbc9SDag-Erling Smørgrav #define openpam_log(lvl, ...) \
15455e3fbc9SDag-Erling Smørgrav 	_openpam_log((lvl), __func__, __VA_ARGS__)
15555e3fbc9SDag-Erling Smørgrav #elif defined(__GNUC__) && (__GNUC__ >= 3)
15655e3fbc9SDag-Erling Smørgrav #define openpam_log(lvl, ...) \
15755e3fbc9SDag-Erling Smørgrav 	_openpam_log((lvl), __func__, __VA_ARGS__)
15811d144d3SDag-Erling Smørgrav #elif defined(__GNUC__) && (__GNUC__ >= 2) && (__GNUC_MINOR__ >= 95)
1598d38dc9dSDag-Erling Smørgrav #define openpam_log(lvl, fmt...) \
160bdcb69e2SDag-Erling Smørgrav 	_openpam_log((lvl), __func__, ##fmt)
16111d144d3SDag-Erling Smørgrav #elif defined(__GNUC__) && defined(__FUNCTION__)
1625c1eca55SDag-Erling Smørgrav #define openpam_log(lvl, fmt...) \
16311d144d3SDag-Erling Smørgrav 	_openpam_log((lvl), __FUNCTION__, ##fmt)
1645c1eca55SDag-Erling Smørgrav #else
16511d144d3SDag-Erling Smørgrav void
16611d144d3SDag-Erling Smørgrav openpam_log(int _level,
16711d144d3SDag-Erling Smørgrav 	const char *_format,
16811d144d3SDag-Erling Smørgrav 	...);
1695c1eca55SDag-Erling Smørgrav #endif
1705c1eca55SDag-Erling Smørgrav 
1715c1eca55SDag-Erling Smørgrav /*
1725c1eca55SDag-Erling Smørgrav  * Generic conversation function
1735c1eca55SDag-Erling Smørgrav  */
1745c1eca55SDag-Erling Smørgrav struct pam_message;
1755c1eca55SDag-Erling Smørgrav struct pam_response;
1765c1eca55SDag-Erling Smørgrav int openpam_ttyconv(int _n,
1775c1eca55SDag-Erling Smørgrav 	const struct pam_message **_msg,
1785c1eca55SDag-Erling Smørgrav 	struct pam_response **_resp,
1795c1eca55SDag-Erling Smørgrav 	void *_data);
1805c1eca55SDag-Erling Smørgrav 
1815c1eca55SDag-Erling Smørgrav /*
182ac7e3b9dSDag-Erling Smørgrav  * Null conversation function
183ac7e3b9dSDag-Erling Smørgrav  */
184ac7e3b9dSDag-Erling Smørgrav int openpam_nullconv(int _n,
185ac7e3b9dSDag-Erling Smørgrav 	const struct pam_message **_msg,
186ac7e3b9dSDag-Erling Smørgrav 	struct pam_response **_resp,
187ac7e3b9dSDag-Erling Smørgrav 	void *_data);
188ac7e3b9dSDag-Erling Smørgrav 
189ac7e3b9dSDag-Erling Smørgrav /*
1905c1eca55SDag-Erling Smørgrav  * PAM primitives
1915c1eca55SDag-Erling Smørgrav  */
1925c1eca55SDag-Erling Smørgrav enum {
1935c1eca55SDag-Erling Smørgrav 	PAM_SM_AUTHENTICATE,
1945c1eca55SDag-Erling Smørgrav 	PAM_SM_SETCRED,
1955c1eca55SDag-Erling Smørgrav 	PAM_SM_ACCT_MGMT,
1965c1eca55SDag-Erling Smørgrav 	PAM_SM_OPEN_SESSION,
1975c1eca55SDag-Erling Smørgrav 	PAM_SM_CLOSE_SESSION,
1985c1eca55SDag-Erling Smørgrav 	PAM_SM_CHAUTHTOK,
1995c1eca55SDag-Erling Smørgrav 	/* keep this last */
2005c1eca55SDag-Erling Smørgrav 	PAM_NUM_PRIMITIVES
2015c1eca55SDag-Erling Smørgrav };
2025c1eca55SDag-Erling Smørgrav 
2035c1eca55SDag-Erling Smørgrav /*
2045c1eca55SDag-Erling Smørgrav  * Dummy service module function
2055c1eca55SDag-Erling Smørgrav  */
2065c1eca55SDag-Erling Smørgrav #define PAM_SM_DUMMY(type)						\
2075c1eca55SDag-Erling Smørgrav PAM_EXTERN int								\
2085c1eca55SDag-Erling Smørgrav pam_sm_##type(pam_handle_t *pamh, int flags,				\
2095c1eca55SDag-Erling Smørgrav     int argc, const char *argv[])					\
2105c1eca55SDag-Erling Smørgrav {									\
2115c1eca55SDag-Erling Smørgrav 	return (PAM_IGNORE);						\
2125c1eca55SDag-Erling Smørgrav }
2135c1eca55SDag-Erling Smørgrav 
2145c1eca55SDag-Erling Smørgrav /*
2155c1eca55SDag-Erling Smørgrav  * PAM service module functions match this typedef
2165c1eca55SDag-Erling Smørgrav  */
2175c1eca55SDag-Erling Smørgrav struct pam_handle;
2185c1eca55SDag-Erling Smørgrav typedef int (*pam_func_t)(struct pam_handle *, int, int, const char **);
2195c1eca55SDag-Erling Smørgrav 
2205c1eca55SDag-Erling Smørgrav /*
2215c1eca55SDag-Erling Smørgrav  * A struct that describes a module.
2225c1eca55SDag-Erling Smørgrav  */
2235c1eca55SDag-Erling Smørgrav typedef struct pam_module pam_module_t;
2245c1eca55SDag-Erling Smørgrav struct pam_module {
2254579d22cSDag-Erling Smørgrav 	char		*path;
2265c1eca55SDag-Erling Smørgrav 	pam_func_t	 func[PAM_NUM_PRIMITIVES];
2275c1eca55SDag-Erling Smørgrav 	void		*dlh;
2285c1eca55SDag-Erling Smørgrav 	int		 refcount;
2295c1eca55SDag-Erling Smørgrav 	pam_module_t	*prev;
2305c1eca55SDag-Erling Smørgrav 	pam_module_t	*next;
2315c1eca55SDag-Erling Smørgrav };
2325c1eca55SDag-Erling Smørgrav 
2335c1eca55SDag-Erling Smørgrav /*
234b825a3acSDag-Erling Smørgrav  * Source-code compatibility with Linux-PAM modules
235b825a3acSDag-Erling Smørgrav  */
236b825a3acSDag-Erling Smørgrav #if defined(PAM_SM_AUTH) || defined(PAM_SM_ACCOUNT) || \
237b825a3acSDag-Erling Smørgrav 	defined(PAM_SM_SESSION) || defined(PAM_SM_PASSWORD)
238b825a3acSDag-Erling Smørgrav #define LINUX_PAM_MODULE
239b825a3acSDag-Erling Smørgrav #endif
240b825a3acSDag-Erling Smørgrav #if defined(LINUX_PAM_MODULE) && !defined(PAM_SM_AUTH)
241b825a3acSDag-Erling Smørgrav #define _PAM_SM_AUTHENTICATE	0
242b825a3acSDag-Erling Smørgrav #define _PAM_SM_SETCRED		0
243b825a3acSDag-Erling Smørgrav #else
244b825a3acSDag-Erling Smørgrav #undef PAM_SM_AUTH
245b825a3acSDag-Erling Smørgrav #define PAM_SM_AUTH
246b825a3acSDag-Erling Smørgrav #define _PAM_SM_AUTHENTICATE	pam_sm_authenticate
247b825a3acSDag-Erling Smørgrav #define _PAM_SM_SETCRED		pam_sm_setcred
248b825a3acSDag-Erling Smørgrav #endif
249b825a3acSDag-Erling Smørgrav #if defined(LINUX_PAM_MODULE) && !defined(PAM_SM_ACCOUNT)
250b825a3acSDag-Erling Smørgrav #define _PAM_SM_ACCT_MGMT	0
251b825a3acSDag-Erling Smørgrav #else
252b825a3acSDag-Erling Smørgrav #undef PAM_SM_ACCOUNT
253b825a3acSDag-Erling Smørgrav #define PAM_SM_ACCOUNT
254b825a3acSDag-Erling Smørgrav #define _PAM_SM_ACCT_MGMT	pam_sm_acct_mgmt
255b825a3acSDag-Erling Smørgrav #endif
256b825a3acSDag-Erling Smørgrav #if defined(LINUX_PAM_MODULE) && !defined(PAM_SM_SESSION)
257b825a3acSDag-Erling Smørgrav #define _PAM_SM_OPEN_SESSION	0
258b825a3acSDag-Erling Smørgrav #define _PAM_SM_CLOSE_SESSION	0
259b825a3acSDag-Erling Smørgrav #else
260b825a3acSDag-Erling Smørgrav #undef PAM_SM_SESSION
261b825a3acSDag-Erling Smørgrav #define PAM_SM_SESSION
262b825a3acSDag-Erling Smørgrav #define _PAM_SM_OPEN_SESSION	pam_sm_open_session
263b825a3acSDag-Erling Smørgrav #define _PAM_SM_CLOSE_SESSION	pam_sm_close_session
264b825a3acSDag-Erling Smørgrav #endif
265b825a3acSDag-Erling Smørgrav #if defined(LINUX_PAM_MODULE) && !defined(PAM_SM_PASSWORD)
266b825a3acSDag-Erling Smørgrav #define _PAM_SM_CHAUTHTOK	0
267b825a3acSDag-Erling Smørgrav #else
268b825a3acSDag-Erling Smørgrav #undef PAM_SM_PASSWORD
269b825a3acSDag-Erling Smørgrav #define PAM_SM_PASSWORD
270b825a3acSDag-Erling Smørgrav #define _PAM_SM_CHAUTHTOK	pam_sm_chauthtok
271b825a3acSDag-Erling Smørgrav #endif
272b825a3acSDag-Erling Smørgrav 
273b825a3acSDag-Erling Smørgrav /*
2745c1eca55SDag-Erling Smørgrav  * Infrastructure for static modules using GCC linker sets.
2755c1eca55SDag-Erling Smørgrav  * You are not expected to understand this.
2765c1eca55SDag-Erling Smørgrav  */
2775c1eca55SDag-Erling Smørgrav #if defined(__FreeBSD__)
2785c1eca55SDag-Erling Smørgrav #define PAM_SOEXT ".so"
2795c1eca55SDag-Erling Smørgrav #else
28011d144d3SDag-Erling Smørgrav #ifndef NO_STATIC_MODULES
28111d144d3SDag-Erling Smørgrav #define NO_STATIC_MODULES
2825c1eca55SDag-Erling Smørgrav #endif
28311d144d3SDag-Erling Smørgrav #endif
28411d144d3SDag-Erling Smørgrav #if defined(__GNUC__) && !defined(__PIC__) && !defined(NO_STATIC_MODULES)
2855c1eca55SDag-Erling Smørgrav /* gcc, static linking */
2865c1eca55SDag-Erling Smørgrav #include <sys/cdefs.h>
2875c1eca55SDag-Erling Smørgrav #include <linker_set.h>
2885c1eca55SDag-Erling Smørgrav #define OPENPAM_STATIC_MODULES
2895c1eca55SDag-Erling Smørgrav #define PAM_EXTERN static
2905c1eca55SDag-Erling Smørgrav #define PAM_MODULE_ENTRY(name)						\
2914579d22cSDag-Erling Smørgrav static char _pam_name[] = name PAM_SOEXT;				\
2924579d22cSDag-Erling Smørgrav static struct pam_module _pam_module = { _pam_name, {			\
293b825a3acSDag-Erling Smørgrav     _PAM_SM_AUTHENTICATE, _PAM_SM_SETCRED, _PAM_SM_ACCT_MGMT,		\
294b825a3acSDag-Erling Smørgrav     _PAM_SM_OPEN_SESSION, _PAM_SM_CLOSE_SESSION, _PAM_SM_CHAUTHTOK },	\
2955c1eca55SDag-Erling Smørgrav     NULL, 0, NULL, NULL };						\
29646acc370SDag-Erling Smørgrav DATA_SET(_openpam_static_modules, _pam_module)
2975c1eca55SDag-Erling Smørgrav #else
2985c1eca55SDag-Erling Smørgrav /* normal case */
2995c1eca55SDag-Erling Smørgrav #define PAM_EXTERN
3005c1eca55SDag-Erling Smørgrav #define PAM_MODULE_ENTRY(name)
3015c1eca55SDag-Erling Smørgrav #endif
3025c1eca55SDag-Erling Smørgrav 
3035c1eca55SDag-Erling Smørgrav #ifdef __cplusplus
3045c1eca55SDag-Erling Smørgrav }
3055c1eca55SDag-Erling Smørgrav #endif
3065c1eca55SDag-Erling Smørgrav 
3075c1eca55SDag-Erling Smørgrav #endif
308