xref: /freebsd/sys/contrib/openzfs/lib/libzutil/zutil_device_path.c (revision 0d66206fff44f864ea8a4b220c3a53b4caa959a0)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #include <errno.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31 
32 #include <libzutil.h>
33 
34 /* Substring from after the last slash, or the string itself if none */
35 const char *
36 zfs_basename(const char *path)
37 {
38 	const char *bn = strrchr(path, '/');
39 	return (bn ? bn + 1 : path);
40 }
41 
42 /* Return index of last slash or -1 if none */
43 ssize_t
44 zfs_dirnamelen(const char *path)
45 {
46 	const char *end = strrchr(path, '/');
47 	return (end ? end - path : -1);
48 }
49 
50 /*
51  * Given a shorthand device name check if a file by that name exists in any
52  * of the 'zpool_default_import_path' or ZPOOL_IMPORT_PATH directories.  If
53  * one is found, store its fully qualified path in the 'path' buffer passed
54  * by the caller and return 0, otherwise return an error.
55  */
56 int
57 zfs_resolve_shortname(const char *name, char *path, size_t len)
58 {
59 	const char *env = getenv("ZPOOL_IMPORT_PATH");
60 
61 	if (env) {
62 		for (;;) {
63 			env += strspn(env, ":");
64 			size_t dirlen = strcspn(env, ":");
65 			if (dirlen) {
66 				(void) snprintf(path, len, "%.*s/%s",
67 				    (int)dirlen, env, name);
68 				if (access(path, F_OK) == 0)
69 					return (0);
70 
71 				env += dirlen;
72 			} else
73 				break;
74 		}
75 	} else {
76 		size_t count;
77 		const char *const *zpool_default_import_path =
78 		    zpool_default_search_paths(&count);
79 
80 		for (size_t i = 0; i < count; ++i) {
81 			(void) snprintf(path, len, "%s/%s",
82 			    zpool_default_import_path[i], name);
83 			if (access(path, F_OK) == 0)
84 				return (0);
85 		}
86 	}
87 
88 	return (errno = ENOENT);
89 }
90 
91 /*
92  * Given a shorthand device name look for a match against 'cmp_name'.  This
93  * is done by checking all prefix expansions using either the default
94  * 'zpool_default_import_paths' or the ZPOOL_IMPORT_PATH environment
95  * variable.  Proper partition suffixes will be appended if this is a
96  * whole disk.  When a match is found 0 is returned otherwise ENOENT.
97  */
98 static int
99 zfs_strcmp_shortname(const char *name, const char *cmp_name, int wholedisk)
100 {
101 	int path_len, cmp_len, i = 0, error = ENOENT;
102 	char *dir, *env, *envdup = NULL, *tmp = NULL;
103 	char path_name[MAXPATHLEN];
104 	const char *const *zpool_default_import_path = NULL;
105 	size_t count;
106 
107 	cmp_len = strlen(cmp_name);
108 	env = getenv("ZPOOL_IMPORT_PATH");
109 
110 	if (env) {
111 		envdup = strdup(env);
112 		dir = strtok_r(envdup, ":", &tmp);
113 	} else {
114 		zpool_default_import_path = zpool_default_search_paths(&count);
115 		dir = (char *)zpool_default_import_path[i];
116 	}
117 
118 	while (dir) {
119 		/* Trim trailing directory slashes from ZPOOL_IMPORT_PATH */
120 		if (env) {
121 			while (dir[strlen(dir)-1] == '/')
122 				dir[strlen(dir)-1] = '\0';
123 		}
124 
125 		path_len = snprintf(path_name, MAXPATHLEN, "%s/%s", dir, name);
126 		if (wholedisk)
127 			path_len = zfs_append_partition(path_name, MAXPATHLEN);
128 
129 		if ((path_len == cmp_len) && strcmp(path_name, cmp_name) == 0) {
130 			error = 0;
131 			break;
132 		}
133 
134 		if (env) {
135 			dir = strtok_r(NULL, ":", &tmp);
136 		} else if (++i < count) {
137 			dir = (char *)zpool_default_import_path[i];
138 		} else {
139 			dir = NULL;
140 		}
141 	}
142 
143 	if (env)
144 		free(envdup);
145 
146 	return (error);
147 }
148 
149 /*
150  * Given either a shorthand or fully qualified path name look for a match
151  * against 'cmp'.  The passed name will be expanded as needed for comparison
152  * purposes and redundant slashes stripped to ensure an accurate match.
153  */
154 int
155 zfs_strcmp_pathname(const char *name, const char *cmp, int wholedisk)
156 {
157 	int path_len, cmp_len;
158 	char path_name[MAXPATHLEN];
159 	char cmp_name[MAXPATHLEN];
160 	char *dir, *tmp = NULL;
161 
162 	/* Strip redundant slashes if they exist due to ZPOOL_IMPORT_PATH */
163 	cmp_name[0] = '\0';
164 	(void) strlcpy(path_name, cmp, sizeof (path_name));
165 	for (dir = strtok_r(path_name, "/", &tmp);
166 	    dir != NULL;
167 	    dir = strtok_r(NULL, "/", &tmp)) {
168 		strlcat(cmp_name, "/", sizeof (cmp_name));
169 		strlcat(cmp_name, dir, sizeof (cmp_name));
170 	}
171 
172 	if (name[0] != '/')
173 		return (zfs_strcmp_shortname(name, cmp_name, wholedisk));
174 
175 	(void) strlcpy(path_name, name, MAXPATHLEN);
176 	path_len = strlen(path_name);
177 	cmp_len = strlen(cmp_name);
178 
179 	if (wholedisk) {
180 		path_len = zfs_append_partition(path_name, MAXPATHLEN);
181 		if (path_len == -1)
182 			return (ENOMEM);
183 	}
184 
185 	if ((path_len != cmp_len) || strcmp(path_name, cmp_name))
186 		return (ENOENT);
187 
188 	return (0);
189 }
190