1/*	$NetBSD: getfsspecname.c,v 1.8 2018/12/27 21:35:48 alnsn 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 1.8 2018/12/27 21:35:48 alnsn 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#define COMPAT_DKWEDGE	/* To be removed */
50
51const char *
52getfsspecname(char *buf, size_t bufsiz, const char *name)
53{
54	static const int mib[] = { CTL_HW, HW_DISKNAMES };
55	static const unsigned int miblen = __arraycount(mib);
56	char *drives, *dk, *p;
57	size_t len;
58	int fd, savee = errno;
59	char *vname;
60
61	p = drives = vname = NULL;
62
63	/*
64	 * If the name starts with "ROOT.", replace it with "/dev/<root_device>",
65	 * where <root_device> is the value of the kern.root_device sysctl. Any
66	 * characters after the special "ROOT." token are appended to the end
67	 * of this path.
68	 */
69	if (strncasecmp(name, "ROOT.", 5) == 0 && strchr(name, ':') == NULL) {
70		static const int mib_root[] = { CTL_KERN, KERN_ROOT_DEVICE };
71		static const unsigned int mib_rootlen = __arraycount(mib_root);
72
73		strlcpy(buf, "/dev/", bufsiz);
74		len = bufsiz - 5;
75		if (sysctl(mib_root, mib_rootlen, buf + 5, &len, NULL, 0) == -1) {
76			savee = errno;
77			strlcpy(buf, "sysctl kern.root_device failed", bufsiz);
78			goto out;
79		}
80		strlcat(buf, name + 5, bufsiz);
81		return buf;
82	}
83
84	if (strncasecmp(name, "NAME=", 5) != 0) {
85#ifdef COMPAT_DKWEDGE
86		/*
87		 * We try to open the disk name, and if we fail with EBUSY
88		 * we use the name as the label to find the wedge.
89		 */
90		char rbuf[MAXPATHLEN];
91		if (name[0] == '/') {
92			if (getdiskrawname(rbuf, sizeof(rbuf), name) != NULL) {
93				if ((fd = open(rbuf, O_RDONLY)) == -1) {
94					if (errno == EBUSY) {
95						name = strrchr(name, '/') + 1;
96						goto search;
97					}
98				} else
99					close(fd);
100			}
101		}
102#endif
103		strlcpy(buf, name, bufsiz);
104		return buf;
105	} else
106		name += 5;
107
108#ifdef COMPAT_DKWEDGE
109search:
110#endif
111	vname = malloc(strlen(name) + 1);
112	if (vname == NULL) {
113		savee = errno;
114		strlcpy(buf, "malloc failed", bufsiz);
115		goto out;
116	}
117
118	strunvis(vname, name);
119
120	if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) {
121		savee = errno;
122		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
123		goto out;
124	}
125
126	drives = malloc(len);
127	if (drives == NULL) {
128		savee = errno;
129		strlcpy(buf, "malloc failed", bufsiz);
130		goto out;
131	}
132	if (sysctl(mib, miblen, drives, &len, NULL, 0) == -1) {
133		savee = errno;
134		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
135		goto out;
136	}
137
138	for (dk = strtok(drives, " "); dk != NULL; dk = strtok(NULL, " ")) {
139		struct dkwedge_info dkw;
140		if (strncmp(dk, "dk", 2) != 0)
141			continue;
142		fd = opendisk(dk, O_RDONLY, buf, bufsiz, 0);
143		if (fd == -1)
144			continue;
145		if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == -1) {
146			savee = errno;
147			snprintf(buf, bufsiz, "%s: getwedgeinfo", dk);
148			(void)close(fd);
149			goto out;
150		}
151		(void)close(fd);
152		if (strcmp(vname, (char *)dkw.dkw_wname) == 0) {
153			p = strstr(buf, "/rdk");
154			goto good;
155		}
156	}
157#ifdef COMPAT_DKWEDGE
158	/* Last ditch effort assuming NAME=label, and label is a disk name */
159	fd = opendisk(name, O_RDONLY, buf, bufsiz, 0);
160	if (fd != -1) {
161		close(fd);
162		p = strstr(buf, "/r");
163		goto good;
164	}
165#endif
166	savee = ESRCH;
167	snprintf(buf, bufsiz, "no match for `%s'", vname);
168out:
169	buf = NULL;
170good:
171	if (p++ != NULL)
172		strcpy(p, p + 1);
173	free(drives);
174	free(vname);
175	errno = savee;
176	return buf;
177}
178