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 http://www.opensolaris.org/os/licensing.
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
47static int
48udev_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 */
114int
115main(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