xref: /netbsd-src/lib/libutil/getfsspecname.c (revision 3feacbccbd4c8b6fd5f19c8e34474c4c3f8923d7)
1 /*	$NetBSD: getfsspecname.c,v 1.5 2014/05/25 13:46:07 christos 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 1.5 2014/05/25 13:46:07 christos 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 
51 const char *
52 getfsspecname(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 	if (strncasecmp(name, "NAME=", 5) != 0) {
63 #ifdef COMPAT_DKWEDGE
64 		/*
65 		 * We try to open the disk name, and if we fail with EBUSY
66 		 * we use the name as the label to find the wedge.
67 		 */
68 		char rbuf[MAXPATHLEN];
69 		if (name[0] == '/') {
70 			if (getdiskrawname(rbuf, sizeof(rbuf), name) != NULL) {
71 				if ((fd = open(rbuf, O_RDONLY)) == -1) {
72 					if (errno == EBUSY) {
73 						name = strrchr(name, '/') + 1;
74 						goto search;
75 					}
76 				} else
77 					close(fd);
78 			}
79 		}
80 #endif
81 		strlcpy(buf, name, bufsiz);
82 		return buf;
83 	} else
84 		name += 5;
85 
86 #ifdef COMPAT_DKWEDGE
87 search:
88 #endif
89 	vname = malloc(strlen(name) * 4 + 1);
90 	if (vname == NULL) {
91 		savee = errno;
92 		strlcpy(buf, "malloc failed", bufsiz);
93 		goto out;
94 	}
95 
96 	strunvis(vname, name);
97 
98 	if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) {
99 		savee = errno;
100 		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
101 		goto out;
102 	}
103 
104 	drives = malloc(len);
105 	if (drives == NULL) {
106 		savee = errno;
107 		strlcpy(buf, "malloc failed", bufsiz);
108 		goto out;
109 	}
110 	if (sysctl(mib, miblen, drives, &len, NULL, 0) == -1) {
111 		savee = errno;
112 		strlcpy(buf, "sysctl hw.disknames failed", bufsiz);
113 		goto out;
114 	}
115 
116 	for (dk = strtok(drives, " "); dk != NULL; dk = strtok(NULL, " ")) {
117 		struct dkwedge_info dkw;
118 		if (strncmp(dk, "dk", 2) != 0)
119 			continue;
120 		fd = opendisk(dk, O_RDONLY, buf, bufsiz, 0);
121 		if (fd == -1)
122 			continue;
123 		if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == -1) {
124 			savee = errno;
125 			snprintf(buf, bufsiz, "%s: getwedgeinfo", dk);
126 			(void)close(fd);
127 			goto out;
128 		}
129 		(void)close(fd);
130 		if (strcmp(vname, (char *)dkw.dkw_wname) == 0) {
131 			p = strstr(buf, "/rdk");
132 			goto good;
133 		}
134 	}
135 #ifdef COMPAT_DKWEDGE
136 	/* Last ditch effort assuming NAME=label, and label is a disk name */
137 	fd = opendisk(name, O_RDONLY, buf, bufsiz, 0);
138 	if (fd != -1) {
139 		close(fd);
140 		p = strstr(buf, "/r");
141 		goto good;
142 	}
143 #endif
144 	savee = ESRCH;
145 	snprintf(buf, bufsiz, "no match for `%s'", vname);
146 out:
147 	buf = NULL;
148 good:
149 	if (p++ != NULL)
150 		strcpy(p, p + 1);
151 	free(drives);
152 	free(vname);
153 	errno = savee;
154 	return buf;
155 }
156