[apple/libc.git] / util / opendev.c

/*
 * Copyright (c) 2000, Todd C. Miller.  All rights reserved.
 * Copyright (c) 1996, Jason Downs.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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 <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <pthread.h>

#include "util.h"

/*
 * opendev(3) is an inherently non-thread-safe API, since
 * it returns a buffer to global storage. However we can
 * at least make sure the storage allocation is thread safe
 * and does not leak memory in case of simultaneous
 * initialization
 */
static pthread_once_t opendev_namebuf_once = PTHREAD_ONCE_INIT;
static char *namebuf = NULL;

static void opendev_namebuf_init(void);

int
opendev(path, oflags, dflags, realpath)
	char *path;
	int oflags;
	int dflags;
	char **realpath;
{
	int fd;
	char *slash, *prefix;

	/* Initial state */
	if (realpath)
		*realpath = path;
	fd = -1;
	errno = ENOENT;

	if (pthread_once(&opendev_namebuf_once,
					 opendev_namebuf_init)
		|| !namebuf) {
		errno = ENOMEM;
		return -1;
	}

	if (dflags & OPENDEV_BLCK)
		prefix = "";			/* block device */
	else
		prefix = "r";			/* character device */

	if ((slash = strchr(path, '/')))
		fd = open(path, oflags);
	else if (dflags & OPENDEV_PART) {
		if (snprintf(namebuf, PATH_MAX, "%s%s%s",
		    _PATH_DEV, prefix, path) < PATH_MAX) {
			char *slice;
			while ((slice = strrchr(namebuf, 's')) &&
			    isdigit(*(slice-1))) *slice = '\0';
			fd = open(namebuf, oflags);
			if (realpath)
				*realpath = namebuf;
		} else
			errno = ENAMETOOLONG;
	}
	if (!slash && fd == -1 && errno == ENOENT) {
		if (snprintf(namebuf, PATH_MAX, "%s%s%s",
		    _PATH_DEV, prefix, path) < PATH_MAX) {
			fd = open(namebuf, oflags);
			if (realpath)
				*realpath = namebuf;
		} else
			errno = ENAMETOOLONG;
	}
	return (fd);
}

static void opendev_namebuf_init(void)
{
	namebuf = malloc(PATH_MAX);
}
Commit	Line	Data
9385eb3d A	1	/*
	2	* Copyright (c) 2000, Todd C. Miller. All rights reserved.
	3	* Copyright (c) 1996, Jason Downs. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
	15	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	16	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	17	* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
	18	* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	19	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	20	* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	21	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	24	* SUCH DAMAGE.
	25	*/
	26
	27	#include <ctype.h>
	28	#include <errno.h>
	29	#include <fcntl.h>
	30	#include <limits.h>
	31	#include <paths.h>
	32	#include <stdio.h>
	33	#include <string.h>
1f2f436a	34	#include <pthread.h>
9385eb3d A	35
	36	#include "util.h"
	37
1f2f436a A	38	/*
	39	* opendev(3) is an inherently non-thread-safe API, since
	40	* it returns a buffer to global storage. However we can
	41	* at least make sure the storage allocation is thread safe
	42	* and does not leak memory in case of simultaneous
	43	* initialization
	44	*/
	45	static pthread_once_t opendev_namebuf_once = PTHREAD_ONCE_INIT;
	46	static char *namebuf = NULL;
	47
	48	static void opendev_namebuf_init(void);
	49
9385eb3d A	50	int
	51	opendev(path, oflags, dflags, realpath)
	52	char *path;
	53	int oflags;
	54	int dflags;
	55	char **realpath;
	56	{
	57	int fd;
	58	char slash, prefix;
9385eb3d A	59
	60	/* Initial state */
	61	if (realpath)
	62	*realpath = path;
	63	fd = -1;
	64	errno = ENOENT;
	65
1f2f436a A	66	if (pthread_once(&opendev_namebuf_once,
	67	opendev_namebuf_init)
	68	\|\| !namebuf) {
	69	errno = ENOMEM;
	70	return -1;
	71	}
	72
9385eb3d A	73	if (dflags & OPENDEV_BLCK)
	74	prefix = ""; /* block device */
	75	else
	76	prefix = "r"; /* character device */
	77
	78	if ((slash = strchr(path, '/')))
	79	fd = open(path, oflags);
	80	else if (dflags & OPENDEV_PART) {
1f2f436a A	81	if (snprintf(namebuf, PATH_MAX, "%s%s%s",
1f2f436a A	82	_PATH_DEV, prefix, path) < PATH_MAX) {
9385eb3d A	83	char *slice;
	84	while ((slice = strrchr(namebuf, 's')) &&
	85	isdigit((slice-1))) slice = '\0';
	86	fd = open(namebuf, oflags);
	87	if (realpath)
	88	*realpath = namebuf;
	89	} else
	90	errno = ENAMETOOLONG;
	91	}
	92	if (!slash && fd == -1 && errno == ENOENT) {
1f2f436a A	93	if (snprintf(namebuf, PATH_MAX, "%s%s%s",
1f2f436a A	94	_PATH_DEV, prefix, path) < PATH_MAX) {
9385eb3d A	95	fd = open(namebuf, oflags);
	96	if (realpath)
	97	*realpath = namebuf;
	98	} else
	99	errno = ENAMETOOLONG;
	100	}
	101	return (fd);
	102	}
1f2f436a A	103
	104	static void opendev_namebuf_init(void)
	105	{
	106	namebuf = malloc(PATH_MAX);
	107	}