xref: /freebsd/sys/contrib/openzfs/lib/libzutil/zutil_device_path.c (revision a27328ea392714f2bc106f138191fd465157aafb)
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 	char resolved_path[PATH_MAX];
61 
62 	if (env) {
63 		for (;;) {
64 			env += strspn(env, ":");
65 			size_t dirlen = strcspn(env, ":");
66 			if (dirlen) {
67 				(void) snprintf(path, len, "%.*s/%s",
68 				    (int)dirlen, env, name);
69 				if (access(path, F_OK) == 0)
70 					return (0);
71 
72 				env += dirlen;
73 			} else
74 				break;
75 		}
76 	} else {
77 		size_t count;
78 		const char *const *zpool_default_import_path =
79 		    zpool_default_search_paths(&count);
80 
81 		for (size_t i = 0; i < count; ++i) {
82 			(void) snprintf(path, len, "%s/%s",
83 			    zpool_default_import_path[i], name);
84 			if (access(path, F_OK) == 0)
85 				return (0);
86 		}
87 	}
88 
89 	/*
90 	 * The user can pass a relative path like ./file1 for the vdev. The path
91 	 * must contain a directory prefix like './file1' or '../file1'.  Simply
92 	 * passing 'file1' is not allowed, as it may match a block device name.
93 	 */
94 	if ((strncmp(name, "./", 2) == 0 || strncmp(name, "../", 3) == 0) &&
95 	    realpath(name, resolved_path) != NULL) {
96 		if (access(resolved_path, F_OK) == 0) {
97 			if (strlen(resolved_path) + 1 <= len) {
98 				if (strlcpy(path, resolved_path, len) < len)
99 					return (0); /* success */
100 			}
101 		}
102 	}
103 	return (errno = ENOENT);
104 }
105 
106 /*
107  * Given a shorthand device name look for a match against 'cmp_name'.  This
108  * is done by checking all prefix expansions using either the default
109  * 'zpool_default_import_paths' or the ZPOOL_IMPORT_PATH environment
110  * variable.  Proper partition suffixes will be appended if this is a
111  * whole disk.  When a match is found 0 is returned otherwise ENOENT.
112  */
113 static int
114 zfs_strcmp_shortname(const char *name, const char *cmp_name, int wholedisk)
115 {
116 	int path_len, cmp_len, i = 0, error = ENOENT;
117 	char *dir, *env, *envdup = NULL, *tmp = NULL;
118 	char path_name[MAXPATHLEN];
119 	const char *const *zpool_default_import_path = NULL;
120 	size_t count;
121 
122 	cmp_len = strlen(cmp_name);
123 	env = getenv("ZPOOL_IMPORT_PATH");
124 
125 	if (env) {
126 		envdup = strdup(env);
127 		dir = strtok_r(envdup, ":", &tmp);
128 	} else {
129 		zpool_default_import_path = zpool_default_search_paths(&count);
130 		dir = (char *)zpool_default_import_path[i];
131 	}
132 
133 	while (dir) {
134 		/* Trim trailing directory slashes from ZPOOL_IMPORT_PATH */
135 		if (env) {
136 			while (dir[strlen(dir)-1] == '/')
137 				dir[strlen(dir)-1] = '\0';
138 		}
139 
140 		path_len = snprintf(path_name, MAXPATHLEN, "%s/%s", dir, name);
141 		if (wholedisk)
142 			path_len = zfs_append_partition(path_name, MAXPATHLEN);
143 
144 		if ((path_len == cmp_len) && strcmp(path_name, cmp_name) == 0) {
145 			error = 0;
146 			break;
147 		}
148 
149 		if (env) {
150 			dir = strtok_r(NULL, ":", &tmp);
151 		} else if (++i < count) {
152 			dir = (char *)zpool_default_import_path[i];
153 		} else {
154 			dir = NULL;
155 		}
156 	}
157 
158 	if (env)
159 		free(envdup);
160 
161 	return (error);
162 }
163 
164 /*
165  * Given either a shorthand or fully qualified path name look for a match
166  * against 'cmp'.  The passed name will be expanded as needed for comparison
167  * purposes and redundant slashes stripped to ensure an accurate match.
168  */
169 int
170 zfs_strcmp_pathname(const char *name, const char *cmp, int wholedisk)
171 {
172 	int path_len, cmp_len;
173 	char path_name[MAXPATHLEN];
174 	char cmp_name[MAXPATHLEN];
175 	char *dir, *tmp = NULL;
176 
177 	/* Strip redundant slashes if they exist due to ZPOOL_IMPORT_PATH */
178 	cmp_name[0] = '\0';
179 	(void) strlcpy(path_name, cmp, sizeof (path_name));
180 	for (dir = strtok_r(path_name, "/", &tmp);
181 	    dir != NULL;
182 	    dir = strtok_r(NULL, "/", &tmp)) {
183 		strlcat(cmp_name, "/", sizeof (cmp_name));
184 		strlcat(cmp_name, dir, sizeof (cmp_name));
185 	}
186 
187 	if (name[0] != '/')
188 		return (zfs_strcmp_shortname(name, cmp_name, wholedisk));
189 
190 	(void) strlcpy(path_name, name, MAXPATHLEN);
191 	path_len = strlen(path_name);
192 	cmp_len = strlen(cmp_name);
193 
194 	if (wholedisk) {
195 		path_len = zfs_append_partition(path_name, MAXPATHLEN);
196 		if (path_len == -1)
197 			return (ENOMEM);
198 	}
199 
200 	if ((path_len != cmp_len) || strcmp(path_name, cmp_name))
201 		return (ENOENT);
202 
203 	return (0);
204 }
205