1 /* $OpenBSD: readlabel.c,v 1.15 2019/06/28 13:32:43 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/types.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 <limits.h> 39 #include <fcntl.h> 40 #include <paths.h> 41 #include <string.h> 42 #include <unistd.h> 43 44 #include "util.h" 45 46 /* 47 * Try to get a disklabel for the specified device, and return mount_xxx 48 * style filesystem type name for the specified partition. 49 */ 50 char * 51 readlabelfs(char *device, int verbose) 52 { 53 char rpath[PATH_MAX]; 54 struct dk_diskmap dm; 55 struct disklabel dk; 56 char part, *type; 57 struct stat sbuf; 58 int fd = -1; 59 60 /* Perform disk mapping if device is given as a DUID. */ 61 if (isduid(device, 0)) { 62 if ((fd = open("/dev/diskmap", O_RDONLY|O_CLOEXEC)) != -1) { 63 bzero(&dm, sizeof(struct dk_diskmap)); 64 strlcpy(rpath, device, sizeof(rpath)); 65 part = rpath[strlen(rpath) - 1]; 66 dm.device = rpath; 67 dm.fd = fd; 68 dm.flags = DM_OPENPART; 69 if (ioctl(fd, DIOCMAP, &dm) == -1) 70 close(fd); 71 else 72 goto disklabel; 73 } 74 } 75 76 /* Assuming device is of the form /dev/??p, build a raw partition. */ 77 if (stat(device, &sbuf) == -1) { 78 if (verbose) 79 warn("%s", device); 80 return (NULL); 81 } 82 switch (sbuf.st_mode & S_IFMT) { 83 case S_IFCHR: 84 /* Ok... already a raw device. Hmm. */ 85 strlcpy(rpath, device, sizeof(rpath)); 86 87 /* Change partition name. */ 88 part = rpath[strlen(rpath) - 1]; 89 rpath[strlen(rpath) - 1] = 'a' + getrawpartition(); 90 break; 91 case S_IFBLK: 92 if (strlen(device) > sizeof(_PATH_DEV) - 1) { 93 snprintf(rpath, sizeof(rpath), "%sr%s", _PATH_DEV, 94 &device[sizeof(_PATH_DEV) - 1]); 95 /* Change partition name. */ 96 part = rpath[strlen(rpath) - 1]; 97 rpath[strlen(rpath) - 1] = 'a' + getrawpartition(); 98 break; 99 } 100 /* FALLTHROUGH */ 101 default: 102 if (verbose) 103 warnx("%s: not a device node", device); 104 return (NULL); 105 } 106 107 /* If rpath doesn't exist, change that partition back. */ 108 fd = open(rpath, O_RDONLY|O_CLOEXEC); 109 if (fd == -1) { 110 if (errno == ENOENT) { 111 rpath[strlen(rpath) - 1] = part; 112 113 fd = open(rpath, O_RDONLY|O_CLOEXEC); 114 if (fd == -1) { 115 if (verbose) 116 warn("%s", rpath); 117 return (NULL); 118 } 119 } else { 120 if (verbose) 121 warn("%s", rpath); 122 return (NULL); 123 } 124 } 125 126 disklabel: 127 128 if (ioctl(fd, DIOCGDINFO, &dk) == -1) { 129 if (verbose) 130 warn("%s: couldn't read disklabel", rpath); 131 close(fd); 132 return (NULL); 133 } 134 close(fd); 135 136 if (dk.d_partitions[part - 'a'].p_fstype >= FSMAXTYPES) { 137 if (verbose) 138 warnx("%s: bad filesystem type in label", rpath); 139 return (NULL); 140 } 141 142 type = fstypesnames[dk.d_partitions[part - 'a'].p_fstype]; 143 return ((type[0] == '\0') ? NULL : type); 144 } 145