xref: /src/lib/libutil/opendisk.c

/*	$NetBSD: opendisk.c,v 1.8 2001/11/01 06:53:25 lukem Exp $	*/

/*-
 * Copyright (c) 1997 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Luke Mewburn.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: opendisk.c,v 1.8 2001/11/01 06:53:25 lukem Exp $");
#endif

#include <sys/param.h>

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

int
opendisk(const char *path, int flags, char *buf, size_t buflen, int iscooked)
{
	struct stat sb;
	int	f, pass, rawpart, serrno;

	if (buf == NULL) {
		errno = EFAULT;
		return (-1);
	}
	if ((flags & O_CREAT) != 0) {
		errno = EINVAL;
		return (-1);
	}

	rawpart = getrawpartition();
	if (rawpart < 0)
		return (-1);	/* sysctl(3) in getrawpartition sets errno */

	for (pass = 0; pass < 4; pass++) {
		switch (pass) {
		case 0:
			snprintf(buf, buflen, "%s", path);
			break;
		case 1:
			snprintf(buf, buflen, "%s%c", path, 'a' + rawpart);
			break;
		case 2:
			if (strchr(path, '/') != NULL)
				return (-1);
			snprintf(buf, buflen, "%s%s%s", _PATH_DEV,
			    iscooked ? "" : "r", path);
			break;
		case 3:
			snprintf(buf, buflen, "%s%s%s%c", _PATH_DEV,
			    iscooked ? "" : "r", path, 'a' + rawpart);
			break;
		}
		f = open(buf, flags);
		if (f == -1 && errno != ENOENT)
			return (-1);
		if (f != -1) {
			if (fstat(f, &sb) == -1) {
				serrno = errno;
				close (f);
				errno = serrno;
				f = -1;
			} else if ((!iscooked && !S_ISCHR(sb.st_mode)) ||
			    	   ( iscooked && !S_ISBLK(sb.st_mode)) ) {
				close (f);
				errno = ENODEV;
				f = -1;
			}
			return (f);
		}
	}
	return (f);
}