1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 *
26 * Copyright (c) 2016, Intel Corporation.
27 */
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <libudev.h>
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <fcntl.h>
38
39 /*
40 * Linux persistent device strings for vdev labels
41 *
42 * based on udev_device_get_devid() at zfs/lib/libzfs/libzfs_import.c
43 */
44
45 #define DEV_BYID_PATH "/dev/disk/by-id/"
46
47 static int
udev_device_get_devid(struct udev_device * dev,char * bufptr,size_t buflen)48 udev_device_get_devid(struct udev_device *dev, char *bufptr, size_t buflen)
49 {
50 struct udev_list_entry *entry;
51 const char *bus;
52 char devbyid[MAXPATHLEN];
53
54 /* The bus based by-id path is preferred */
55 bus = udev_device_get_property_value(dev, "ID_BUS");
56
57 if (bus == NULL) {
58 const char *dm_uuid;
59
60 /*
61 * For multipath nodes use the persistent uuid based identifier
62 *
63 * Example: 'dm-uuid-mpath-35000c5006304de3f'
64 */
65 dm_uuid = udev_device_get_property_value(dev, "DM_UUID");
66 if (dm_uuid != NULL) {
67 (void) snprintf(bufptr, buflen, "dm-uuid-%s", dm_uuid);
68 return (0);
69 }
70 return (ENODATA);
71 }
72
73 /*
74 * locate the bus specific by-id link
75 *
76 * Example: 'scsi-MG03SCA300_350000494a8cb3d67-part1'
77 */
78 (void) snprintf(devbyid, sizeof (devbyid), "%s%s-", DEV_BYID_PATH, bus);
79 entry = udev_device_get_devlinks_list_entry(dev);
80 while (entry != NULL) {
81 const char *name;
82
83 name = udev_list_entry_get_name(entry);
84 if (strncmp(name, devbyid, strlen(devbyid)) == 0) {
85 name += strlen(DEV_BYID_PATH);
86 (void) stpncpy(bufptr, name, buflen - 1);
87 bufptr[buflen - 1] = '\0';
88 return (0);
89 }
90 entry = udev_list_entry_get_next(entry);
91 }
92
93 return (ENODATA);
94 }
95
96 /*
97 * Usage: devname2devid <devicepath>
98 *
99 * Examples:
100 * # ./devname2devid /dev/sda1
101 * devid scsi-350000394a8caede4-part1
102 *
103 * # ./devname2devid /dev/dm-1
104 * devid: 'dm-uuid-mpath-35000c5006304de3f'
105 *
106 * This program accepts a disk or disk slice path and prints a
107 * device id.
108 *
109 * Exit values:
110 * 0 - means success
111 * 1 - means failure
112 *
113 */
114 int
main(int argc,char * argv[])115 main(int argc, char *argv[])
116 {
117 struct udev *udev;
118 struct udev_device *dev = NULL;
119 char devid[128], nodepath[MAXPATHLEN];
120 char *device, *sysname;
121 int ret;
122
123 if (argc == 1) {
124 (void) printf("%s <devicepath> [search path]\n", argv[0]);
125 exit(1);
126 }
127 device = argv[1];
128
129 if ((udev = udev_new()) == NULL) {
130 perror("udev_new");
131 exit(1);
132 }
133
134 /* resolve path to a runtime device node instance */
135 if (realpath(device, nodepath) == NULL) {
136 perror("realpath");
137 exit(1);
138 }
139 sysname = strrchr(nodepath, '/') + 1;
140
141 if ((dev = udev_device_new_from_subsystem_sysname(udev, "block",
142 sysname)) == NULL) {
143 perror(sysname);
144 exit(1);
145 }
146
147 if ((ret = udev_device_get_devid(dev, devid, sizeof (devid))) != 0) {
148 udev_device_unref(dev);
149 errno = ret;
150 perror(sysname);
151 exit(1);
152 }
153
154 (void) printf("devid %s\n", devid);
155
156 udev_device_unref(dev);
157 udev_unref(udev);
158
159 return (0);
160 }
161