1 /* $OpenBSD: readlabel.c,v 1.12 2014/06/30 00:25:37 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1996, Jason Downs. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, 19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/param.h> 29 #include <sys/disk.h> 30 #include <sys/dkio.h> 31 #define DKTYPENAMES 32 #include <sys/disklabel.h> 33 #include <sys/ioctl.h> 34 #include <sys/stat.h> 35 #include <stdio.h> 36 #include <err.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <paths.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #include "util.h" 44 45 /* 46 * Try to get a disklabel for the specified device, and return mount_xxx 47 * style filesystem type name for the specified partition. 48 */ 49 char * 50 readlabelfs(char *device, int verbose) 51 { 52 char rpath[MAXPATHLEN]; 53 struct dk_diskmap dm; 54 struct disklabel dk; 55 char part, *type; 56 struct stat sbuf; 57 int fd = -1; 58 59 /* Perform disk mapping if device is given as a DUID. */ 60 if (isduid(device, 0)) { 61 if ((fd = open("/dev/diskmap", O_RDONLY)) != -1) { 62 bzero(&dm, sizeof(struct dk_diskmap)); 63 strlcpy(rpath, device, sizeof(rpath)); 64 part = rpath[strlen(rpath) - 1]; 65 dm.device = rpath; 66 dm.fd = fd; 67 dm.flags = DM_OPENPART; 68 if (ioctl(fd, DIOCMAP, &dm) == -1) 69 close(fd); 70 else 71 goto disklabel; 72 } 73 } 74 75 /* Assuming device is of the form /dev/??p, build a raw partition. */ 76 if (stat(device, &sbuf) < 0) { 77 if (verbose) 78 warn("%s", device); 79 return (NULL); 80 } 81 switch (sbuf.st_mode & S_IFMT) { 82 case S_IFCHR: 83 /* Ok... already a raw device. Hmm. */ 84 strlcpy(rpath, device, sizeof(rpath)); 85 86 /* Change partition name. */ 87 part = rpath[strlen(rpath) - 1]; 88 rpath[strlen(rpath) - 1] = 'a' + getrawpartition(); 89 break; 90 case S_IFBLK: 91 if (strlen(device) > sizeof(_PATH_DEV) - 1) { 92 snprintf(rpath, sizeof(rpath), "%sr%s", _PATH_DEV, 93 &device[sizeof(_PATH_DEV) - 1]); 94 /* Change partition name. */ 95 part = rpath[strlen(rpath) - 1]; 96 rpath[strlen(rpath) - 1] = 'a' + getrawpartition(); 97 break; 98 } 99 /* FALLTHROUGH */ 100 default: 101 if (verbose) 102 warnx("%s: not a device node", device); 103 return (NULL); 104 } 105 106 /* If rpath doesn't exist, change that partition back. */ 107 fd = open(rpath, O_RDONLY); 108 if (fd < 0) { 109 if (errno == ENOENT) { 110 rpath[strlen(rpath) - 1] = part; 111 112 fd = open(rpath, O_RDONLY); 113 if (fd < 0) { 114 if (verbose) 115 warn("%s", rpath); 116 return (NULL); 117 } 118 } else { 119 if (verbose) 120 warn("%s", rpath); 121 return (NULL); 122 } 123 } 124 125 disklabel: 126 127 if (ioctl(fd, DIOCGDINFO, &dk) < 0) { 128 if (verbose) 129 warn("%s: couldn't read disklabel", rpath); 130 close(fd); 131 return (NULL); 132 } 133 close(fd); 134 135 if (dk.d_partitions[part - 'a'].p_fstype >= FSMAXTYPES) { 136 if (verbose) 137 warnx("%s: bad filesystem type in label", rpath); 138 return (NULL); 139 } 140 141 type = fstypesnames[dk.d_partitions[part - 'a'].p_fstype]; 142 return ((type[0] == '\0') ? NULL : type); 143 } 144