lib/libutil/getfsspecname.c

   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 }