xref: /freebsd/lib/libgeom/geom_util.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*-
2  * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/disk.h>
32 #include <sys/stat.h>
33 
34 #include <stdio.h>
35 #include <fcntl.h>
36 #include <errno.h>
37 #include <stdint.h>
38 #include <unistd.h>
39 #include <string.h>
40 #include <stdlib.h>
41 #include <paths.h>
42 
43 #include <libgeom.h>
44 
45 /*
46  * Open the given provider and at least check if this is a block device.
47  */
48 int
49 g_open(const char *name, int write)
50 {
51 	char path[MAXPATHLEN];
52 	int fd;
53 
54 	if (name[0] == '/')
55 		strlcpy(path, name, sizeof(path));
56 	else
57 		snprintf(path, sizeof(path), "%s%s", _PATH_DEV, name);
58 
59 	fd = open(path, write ? O_RDWR : O_RDONLY);
60 	if (fd == -1)
61 		return (-1);
62 	/* Let try to get sectorsize, which will prove it is a GEOM provider. */
63 	if (g_sectorsize(fd) == -1) {
64 		close(fd);
65 		errno = EFTYPE;
66 		return (-1);
67 	}
68 	return (fd);
69 }
70 
71 int
72 g_close(int fd)
73 {
74 
75 	return (close(fd));
76 }
77 
78 static int
79 g_ioctl_arg(int fd, unsigned long cmd, void *arg)
80 {
81 	int ret;
82 
83 	if (arg != NULL)
84 		ret = ioctl(fd, cmd, arg);
85 	else
86 		ret = ioctl(fd, cmd);
87 	return (ret >= 0 ? 0 : -1);
88 }
89 
90 static int
91 g_ioctl(int fd, unsigned long cmd)
92 {
93 
94 	return (g_ioctl_arg(fd, cmd, NULL));
95 }
96 
97 /*
98  * Return media size of the given provider.
99  */
100 off_t
101 g_mediasize(int fd)
102 {
103 	off_t mediasize;
104 
105 	if (g_ioctl_arg(fd, DIOCGMEDIASIZE, &mediasize) == -1)
106 		mediasize = -1;
107 	return (mediasize);
108 }
109 
110 /*
111  * Return sector size of the given provider.
112  */
113 ssize_t
114 g_sectorsize(int fd)
115 {
116 	u_int sectorsize;
117 
118 	if (g_ioctl_arg(fd, DIOCGSECTORSIZE, &sectorsize) == -1)
119 		return (-1);
120 	return ((ssize_t)sectorsize);
121 }
122 
123 /*
124  * Call BIO_FLUSH for the given provider.
125  */
126 int
127 g_flush(int fd)
128 {
129 
130 	return (g_ioctl(fd, DIOCGFLUSH));
131 }
132 
133 /*
134  * Call BIO_DELETE for the given range.
135  */
136 int
137 g_delete(int fd, off_t offset, off_t length)
138 {
139 	off_t arg[2];
140 
141 	arg[0] = offset;
142 	arg[1] = length;
143 	return (g_ioctl_arg(fd, DIOCGDELETE, arg));
144 }
145 
146 /*
147  * Return ID of the given provider.
148  */
149 int
150 g_get_ident(int fd, char *ident, size_t size)
151 {
152 	char lident[DISK_IDENT_SIZE];
153 
154 	if (g_ioctl_arg(fd, DIOCGIDENT, lident) == -1)
155 		return (-1);
156 	if (lident[0] == '\0') {
157 		errno = ENOENT;
158 		return (-1);
159 	}
160 	if (strlcpy(ident, lident, size) >= size) {
161 		errno = ENAMETOOLONG;
162 		return (-1);
163 	}
164 	return (0);
165 }
166 
167 /*
168  * Return name of the provider, which has the given ID.
169  */
170 int
171 g_get_name(const char *ident, char *name, size_t size)
172 {
173 	int fd;
174 
175 	fd = g_open_by_ident(ident, 0, name, size);
176 	if (fd == -1)
177 		return (-1);
178 	g_close(fd);
179 	return (0);
180 }
181 
182 /*
183  * Find provider name by the given ID.
184  */
185 int
186 g_open_by_ident(const char *ident, int write, char *name, size_t size)
187 {
188 	char lident[DISK_IDENT_SIZE];
189 	struct gmesh mesh;
190 	struct gclass *mp;
191 	struct ggeom *gp;
192 	struct gprovider *pp;
193 	int error, fd;
194 
195 	error = geom_gettree(&mesh);
196 	if (error != 0) {
197 		errno = error;
198 		return (-1);
199 	}
200 
201 	error = ENOENT;
202 	fd = -1;
203 
204 	LIST_FOREACH(mp, &mesh.lg_class, lg_class) {
205 		LIST_FOREACH(gp, &mp->lg_geom, lg_geom) {
206 			LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
207 				fd = g_open(pp->lg_name, write);
208 				if (fd == -1)
209 					continue;
210 				if (g_get_ident(fd, lident,
211 				    sizeof(lident)) == -1) {
212 					g_close(fd);
213 					continue;
214 				}
215 				if (strcmp(ident, lident) != 0) {
216 					g_close(fd);
217 					continue;
218 				}
219 				error = 0;
220 				if (name != NULL && strlcpy(name, pp->lg_name,
221 				    size) >= size) {
222 					error = ENAMETOOLONG;
223 					g_close(fd);
224 				}
225 				goto end;
226 			}
227 		}
228 	}
229 end:
230 	geom_deletetree(&mesh);
231 	if (error != 0) {
232 		errno = error;
233 		return (-1);
234 	}
235 	return (fd);
236 }
237