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getfsspecname.c revision 1.3 
      1 /*	$NetBSD: getfsspecname.c,v 1.3 2012/04/08 20:56:12 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2012 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 #include <sys/cdefs.h>
     32 __RCSID("$NetBSD: getfsspecname.c,v 1.3 2012/04/08 20:56:12 christos Exp $");
     33 
     34 #include <sys/types.h>
     35 #include <sys/sysctl.h>
     36 #include <sys/disk.h>
     37 
     38 #include <stdio.h>
     39 #include <vis.h>
     40 #include <string.h>
     41 #include <fstab.h>
     42 #include <fcntl.h>
     43 #include <stdlib.h>
     44 #include <errno.h>
     45 #include <unistd.h>
     46 #include <util.h>
     47 
     48 #define COMPAT_DKWEDGE	/* To be removed */
     49 
     50 const char *
     51 getfsspecname(char *buf, size_t bufsiz, const char *name)
     52 {
     53 	static const int mib[] = { CTL_HW, HW_DISKNAMES };
     54 	static const unsigned int miblen = __arraycount(mib);
     55 	char *drives, *dk;
     56 	size_t len;
     57 	int fd, savee;
     58 	char *vname;
     59 
     60 	drives = NULL;
     61 	vname = NULL;
     62 	if (strncasecmp(name, "NAME=", 5) != 0) {
     63 #ifdef COMPAT_DKWEDGE
     64 		/*
     65 		 * We try to open the disk name, and if we fail with EBUSY
     66 		 * we use the name as the label to find the wedge.
     67 		 */
     68 		char rbuf[MAXPATHLEN];
     69 		if (name[0] == '/') {
     70 			if (getdiskrawname(rbuf, sizeof(rbuf), name) != NULL) {
     71 				if ((fd = open(rbuf, O_RDONLY)) == -1) {
     72 					if (errno == EBUSY) {
     73 						name = strrchr(name, '/') + 1;
     74 						goto search;
     75 					}
     76 				} else
     77 					close(fd);
     78 			}
     79 		}
     80 #endif
     81 		strlcpy(buf, name, bufsiz);
     82 		return buf;
     83 	} else
     84 		name += 5;
     85 
     86 #ifdef COMPAT_DKWEDGE
     87 search:
     88 #endif
     89 	vname = malloc(strlen(name) * 4 + 1);
     90 	if (vname == NULL) {
     91 		savee = errno;
     92 		strlcpy(buf, "malloc failed", bufsiz);
     93 		goto out;
     94 	}
     95 
     96 	strunvis(vname, name);
     97 
     98 	if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) {
     99 		savee = errno;
    100 		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
    101 		goto out;
    102 	}
    103 
    104 	drives = malloc(len);
    105 	if (drives == NULL) {
    106 		savee = errno;
    107 		strlcpy(buf, "malloc failed", bufsiz);
    108 		goto out;
    109 	}
    110 	if (sysctl(mib, miblen, drives, &len, NULL, 0) == -1) {
    111 		savee = errno;
    112 		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
    113 		goto out;
    114 	}
    115 
    116 	for (dk = strtok(drives, " "); dk != NULL; dk = strtok(NULL, " ")) {
    117 		struct dkwedge_info dkw;
    118 		if (strncmp(dk, "dk", 2) != 0)
    119 			continue;
    120 		fd = opendisk(dk, O_RDONLY, buf, bufsiz, 0);
    121 		if (fd == -1)
    122 			continue;
    123 		if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == -1) {
    124 			savee = errno;
    125 			snprintf(buf, bufsiz, "%s: getwedgeinfo", dk);
    126 			(void)close(fd);
    127 			goto out;
    128 		}
    129 		(void)close(fd);
    130 		if (strcmp(vname, (char *)dkw.dkw_wname) == 0) {
    131 			char *p = strstr(buf, "/rdk");
    132 			if (p++ == NULL)
    133 				return buf;
    134 			strcpy(p, p + 1);
    135 			free(drives);
    136 			free(vname);
    137 			return buf;
    138 		}
    139 	}
    140 	savee = ESRCH;
    141 	snprintf(buf, bufsiz, "no match for `%s'", vname);
    142 out:
    143 	free(drives);
    144 	free(vname);
    145 	errno = savee;
    146 	return NULL;
    147 }
    148