lib/libutil/getfsspecname.c

   1 /*      $NetBSD: getfsspecname.c,v 1.5 2014/05/25 13:46:07 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 1.5 2014/05/25 13:46:07 christos Exp $");
  33
  34 #include <sys/types.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/sysctl.h>
  37 #include <sys/disk.h>
  38
  39 #include <stdio.h>
  40 #include <vis.h>
  41 #include <string.h>
  42 #include <fstab.h>
  43 #include <fcntl.h>
  44 #include <stdlib.h>
  45 #include <errno.h>
  46 #include <unistd.h>
  47 #include <util.h>
  48
  49 #if !defined(__minix)
  50 #define COMPAT_DKWEDGE  /* To be removed */
  51 #endif /* !defined(__minix) */
  52
  53 const char *
  54 getfsspecname(char *buf, size_t bufsiz, const char *name)
  55 {
  56         static const int mib[] = { CTL_HW, HW_DISKNAMES };
  57         static const unsigned int miblen = __arraycount(mib);
  58         char *drives, *dk, *p;
  59         size_t len;
  60         int fd, savee = errno;
  61         char *vname;
  62
  63         p = drives = vname = NULL;
  64         if (strncasecmp(name, "NAME=", 5) != 0) {
  65 #ifdef COMPAT_DKWEDGE
  66                 /*
  67                  * We try to open the disk name, and if we fail with EBUSY
  68                  * we use the name as the label to find the wedge.
  69                  */
  70                 char rbuf[MAXPATHLEN];
  71                 if (name[0] == '/') {
  72                         if (getdiskrawname(rbuf, sizeof(rbuf), name) != NULL) {
  73                                 if ((fd = open(rbuf, O_RDONLY)) == -1) {
  74                                         if (errno == EBUSY) {
  75                                                 name = strrchr(name, '/') + 1;
  76                                                 goto search;
  77                                         }
  78                                 } else
  79                                         close(fd);
  80                         }
  81                 }
  82 #endif
  83                 strlcpy(buf, name, bufsiz);
  84                 return buf;
  85         } else
  86                 name += 5;
  87
  88 #ifdef COMPAT_DKWEDGE
  89 search:
  90 #endif
  91         vname = malloc(strlen(name) * 4 + 1);
  92         if (vname == NULL) {
  93                 savee = errno;
  94                 strlcpy(buf, "malloc failed", bufsiz);
  95                 goto out;
  96         }
  97
  98         strunvis(vname, name);
  99
 100         if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) {
 101                 savee = errno;
 102                 strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
 103                 goto out;
 104         }
 105
 106         drives = malloc(len);
 107         if (drives == NULL) {
 108                 savee = errno;
 109                 strlcpy(buf, "malloc failed", bufsiz);
 110                 goto out;
 111         }
 112         if (sysctl(mib, miblen, drives, &len, NULL, 0) == -1) {
 113                 savee = errno;
 114                 strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
 115                 goto out;
 116         }
 117
 118         for (dk = strtok(drives, " "); dk != NULL; dk = strtok(NULL, " ")) {
 119                 struct dkwedge_info dkw;
 120                 if (strncmp(dk, "dk", 2) != 0)
 121                         continue;
 122                 fd = opendisk(dk, O_RDONLY, buf, bufsiz, 0);
 123                 if (fd == -1)
 124                         continue;
 125                 if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == -1) {
 126                         savee = errno;
 127                         snprintf(buf, bufsiz, "%s: getwedgeinfo", dk);
 128                         (void)close(fd);
 129                         goto out;
 130                 }
 131                 (void)close(fd);
 132                 if (strcmp(vname, (char *)dkw.dkw_wname) == 0) {
 133                         p = strstr(buf, "/rdk");
 134                         goto good;
 135                 }
 136         }
 137 #ifdef COMPAT_DKWEDGE
 138         /* Last ditch effort assuming NAME=label, and label is a disk name */
 139         fd = opendisk(name, O_RDONLY, buf, bufsiz, 0);
 140         if (fd != -1) {
 141                 close(fd);
 142                 p = strstr(buf, "/r");
 143                 goto good;
 144         }
 145 #endif
 146         savee = ESRCH;
 147         snprintf(buf, bufsiz, "no match for `%s'", vname);
 148 out:
 149         buf = NULL;
 150 good:
 151         if (p++ != NULL)
 152                 strcpy(p, p + 1);
 153         free(drives);
 154         free(vname);
 155         errno = savee;
 156         return buf;
 157 }