xref: /freebsd/sys/contrib/openzfs/lib/libzutil/zutil_device_path.c (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
25  */
26 
27 #include <errno.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 
33 #include <libzutil.h>
34 
35 /* Substring from after the last slash, or the string itself if none */
36 const char *
zfs_basename(const char * path)37 zfs_basename(const char *path)
38 {
39 	const char *bn = strrchr(path, '/');
40 	return (bn ? bn + 1 : path);
41 }
42 
43 /* Return index of last slash or -1 if none */
44 ssize_t
zfs_dirnamelen(const char * path)45 zfs_dirnamelen(const char *path)
46 {
47 	const char *end = strrchr(path, '/');
48 	return (end ? end - path : -1);
49 }
50 
51 /*
52  * Given a shorthand device name check if a file by that name exists in any
53  * of the 'zpool_default_import_path' or ZPOOL_IMPORT_PATH directories.  If
54  * one is found, store its fully qualified path in the 'path' buffer passed
55  * by the caller and return 0, otherwise return an error.
56  */
57 int
zfs_resolve_shortname(const char * name,char * path,size_t len)58 zfs_resolve_shortname(const char *name, char *path, size_t len)
59 {
60 	const char *env = getenv("ZPOOL_IMPORT_PATH");
61 	char resolved_path[PATH_MAX];
62 
63 	if (env) {
64 		for (;;) {
65 			env += strspn(env, ":");
66 			size_t dirlen = strcspn(env, ":");
67 			if (dirlen) {
68 				(void) snprintf(path, len, "%.*s/%s",
69 				    (int)dirlen, env, name);
70 				if (access(path, F_OK) == 0)
71 					return (0);
72 
73 				env += dirlen;
74 			} else
75 				break;
76 		}
77 	} else {
78 		size_t count;
79 		const char *const *zpool_default_import_path =
80 		    zpool_default_search_paths(&count);
81 
82 		for (size_t i = 0; i < count; ++i) {
83 			(void) snprintf(path, len, "%s/%s",
84 			    zpool_default_import_path[i], name);
85 			if (access(path, F_OK) == 0)
86 				return (0);
87 		}
88 	}
89 
90 	/*
91 	 * The user can pass a relative path like ./file1 for the vdev. The path
92 	 * must contain a directory prefix like './file1' or '../file1'.  Simply
93 	 * passing 'file1' is not allowed, as it may match a block device name.
94 	 */
95 	if ((strncmp(name, "./", 2) == 0 || strncmp(name, "../", 3) == 0) &&
96 	    realpath(name, resolved_path) != NULL) {
97 		if (access(resolved_path, F_OK) == 0) {
98 			if (strlen(resolved_path) + 1 <= len) {
99 				if (strlcpy(path, resolved_path, len) < len)
100 					return (0); /* success */
101 			}
102 		}
103 	}
104 	return (errno = ENOENT);
105 }
106 
107 /*
108  * Given a shorthand device name look for a match against 'cmp_name'.  This
109  * is done by checking all prefix expansions using either the default
110  * 'zpool_default_import_paths' or the ZPOOL_IMPORT_PATH environment
111  * variable.  Proper partition suffixes will be appended if this is a
112  * whole disk.  When a match is found 0 is returned otherwise ENOENT.
113  */
114 static int
zfs_strcmp_shortname(const char * name,const char * cmp_name,int wholedisk)115 zfs_strcmp_shortname(const char *name, const char *cmp_name, int wholedisk)
116 {
117 	int path_len, cmp_len, i = 0, error = ENOENT;
118 	char *dir, *env, *envdup = NULL, *tmp = NULL;
119 	char path_name[MAXPATHLEN];
120 	const char *const *zpool_default_import_path = NULL;
121 	size_t count;
122 
123 	cmp_len = strlen(cmp_name);
124 	env = getenv("ZPOOL_IMPORT_PATH");
125 
126 	if (env) {
127 		envdup = strdup(env);
128 		dir = strtok_r(envdup, ":", &tmp);
129 	} else {
130 		zpool_default_import_path = zpool_default_search_paths(&count);
131 		dir = (char *)zpool_default_import_path[i];
132 	}
133 
134 	while (dir) {
135 		/* Trim trailing directory slashes from ZPOOL_IMPORT_PATH */
136 		if (env) {
137 			while (dir[strlen(dir)-1] == '/')
138 				dir[strlen(dir)-1] = '\0';
139 		}
140 
141 		path_len = snprintf(path_name, MAXPATHLEN, "%s/%s", dir, name);
142 		if (wholedisk)
143 			path_len = zfs_append_partition(path_name, MAXPATHLEN);
144 
145 		if ((path_len == cmp_len) && strcmp(path_name, cmp_name) == 0) {
146 			error = 0;
147 			break;
148 		}
149 
150 		if (env) {
151 			dir = strtok_r(NULL, ":", &tmp);
152 		} else if (++i < count) {
153 			dir = (char *)zpool_default_import_path[i];
154 		} else {
155 			dir = NULL;
156 		}
157 	}
158 
159 	if (env)
160 		free(envdup);
161 
162 	return (error);
163 }
164 
165 /*
166  * Given either a shorthand or fully qualified path name look for a match
167  * against 'cmp'.  The passed name will be expanded as needed for comparison
168  * purposes and redundant slashes stripped to ensure an accurate match.
169  */
170 int
zfs_strcmp_pathname(const char * name,const char * cmp,int wholedisk)171 zfs_strcmp_pathname(const char *name, const char *cmp, int wholedisk)
172 {
173 	int path_len, cmp_len;
174 	char path_name[MAXPATHLEN];
175 	char cmp_name[MAXPATHLEN];
176 	char *dir, *tmp = NULL;
177 
178 	/* Strip redundant slashes if they exist due to ZPOOL_IMPORT_PATH */
179 	cmp_name[0] = '\0';
180 	(void) strlcpy(path_name, cmp, sizeof (path_name));
181 	for (dir = strtok_r(path_name, "/", &tmp);
182 	    dir != NULL;
183 	    dir = strtok_r(NULL, "/", &tmp)) {
184 		strlcat(cmp_name, "/", sizeof (cmp_name));
185 		strlcat(cmp_name, dir, sizeof (cmp_name));
186 	}
187 
188 	if (name[0] != '/')
189 		return (zfs_strcmp_shortname(name, cmp_name, wholedisk));
190 
191 	(void) strlcpy(path_name, name, MAXPATHLEN);
192 	path_len = strlen(path_name);
193 	cmp_len = strlen(cmp_name);
194 
195 	if (wholedisk) {
196 		path_len = zfs_append_partition(path_name, MAXPATHLEN);
197 		if (path_len == -1)
198 			return (ENOMEM);
199 	}
200 
201 	if ((path_len != cmp_len) || strcmp(path_name, cmp_name))
202 		return (ENOENT);
203 
204 	return (0);
205 }
206