1 /* $NetBSD: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 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: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 christos Exp $");
33
34 #include <sys/stat.h>
35
36 #include <stdio.h>
37 #include <string.h>
38 #include <errno.h>
39 #include <util.h>
40 #include <limits.h>
41 #include <unistd.h>
42
43 static const char *
resolve_link(char * buf,size_t bufsiz,const char * name)44 resolve_link(char *buf, size_t bufsiz, const char *name)
45 {
46 const char *dp;
47 size_t nlen;
48 ssize_t dlen;
49
50 dlen = readlink(name, buf, bufsiz - 1);
51 if (dlen == -1)
52 return name;
53
54 buf[dlen] = '\0';
55
56 if (buf[0] != '/') {
57 dp = strrchr(name, '/');
58 if (dp != NULL) {
59 nlen = dp - name + 1;
60 if (nlen + 1 > bufsiz)
61 return NULL;
62 if (nlen + dlen + 1 > bufsiz)
63 return NULL;
64
65 memmove(buf + nlen, buf, (size_t)dlen + 1);
66 memcpy(buf, name, nlen);
67 }
68 }
69
70 return buf;
71 }
72
73 const char *
getdiskrawname(char * buf,size_t bufsiz,const char * name)74 getdiskrawname(char *buf, size_t bufsiz, const char *name)
75 {
76 const char *dp;
77 struct stat st;
78 char dest[PATH_MAX];
79
80 if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) {
81 errno = EINVAL;
82 return NULL;
83 }
84
85 dp = strrchr(name, '/');
86
87 if (stat(name, &st) == -1)
88 return NULL;
89
90 if (!S_ISBLK(st.st_mode)) {
91 errno = EFTYPE;
92 return NULL;
93 }
94
95 if (dp != NULL)
96 (void)snprintf(buf, bufsiz, "%.*s/r%s", (int)(dp - name), name, dp + 1);
97 else
98 (void)snprintf(buf, bufsiz, "r%s", name);
99
100 return buf;
101 }
102
103 const char *
getdiskcookedname(char * buf,size_t bufsiz,const char * name)104 getdiskcookedname(char *buf, size_t bufsiz, const char *name)
105 {
106 const char *dp;
107 struct stat st;
108 char dest[PATH_MAX];
109
110 if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) {
111 errno = EINVAL;
112 return NULL;
113 }
114
115 dp = strrchr(name, '/');
116
117 if ((dp != NULL && dp[1] != 'r') || (dp == NULL && name[0] != 'r')) {
118 errno = EINVAL;
119 return NULL;
120 }
121
122 if (stat(name, &st) == -1)
123 return NULL;
124
125 if (!S_ISCHR(st.st_mode)) {
126 errno = EFTYPE;
127 return NULL;
128 }
129
130 if (dp != NULL)
131 (void)snprintf(buf, bufsiz, "%.*s/%s", (int)(dp - name), name, dp + 2);
132 else
133 (void)snprintf(buf, bufsiz, "%s", name + 1);
134
135 return buf;
136 }
137