xref: /freebsd/lib/libgeom/geom_util.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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 static char	*g_device_path_open(const char *, int *, int);
46 
47 /*
48  * Open the given provider and at least check if this is a block device.
49  */
50 int
51 g_open(const char *name, int dowrite)
52 {
53 	char *path;
54 	int fd;
55 
56 	path = g_device_path_open(name, &fd, dowrite);
57 	if (path != NULL)
58 		free(path);
59 	if (fd == -1)
60 		return (-1);
61 	return (fd);
62 }
63 
64 int
65 g_close(int fd)
66 {
67 
68 	return (close(fd));
69 }
70 
71 static int
72 g_ioctl_arg(int fd, unsigned long cmd, void *arg)
73 {
74 	int ret;
75 
76 	if (arg != NULL)
77 		ret = ioctl(fd, cmd, arg);
78 	else
79 		ret = ioctl(fd, cmd);
80 	return (ret >= 0 ? 0 : -1);
81 }
82 
83 static int
84 g_ioctl(int fd, unsigned long cmd)
85 {
86 
87 	return (g_ioctl_arg(fd, cmd, NULL));
88 }
89 
90 /*
91  * Return media size of the given provider.
92  */
93 off_t
94 g_mediasize(int fd)
95 {
96 	off_t mediasize;
97 
98 	if (g_ioctl_arg(fd, DIOCGMEDIASIZE, &mediasize) == -1)
99 		mediasize = -1;
100 	return (mediasize);
101 }
102 
103 /*
104  * Return sector size of the given provider.
105  */
106 ssize_t
107 g_sectorsize(int fd)
108 {
109 	u_int sectorsize;
110 
111 	if (g_ioctl_arg(fd, DIOCGSECTORSIZE, &sectorsize) == -1)
112 		return (-1);
113 	return ((ssize_t)sectorsize);
114 }
115 
116 /*
117  * Return stripe size of the given provider.
118  */
119 off_t
120 g_stripesize(int fd)
121 {
122 	off_t stripesize;
123 
124 	if (g_ioctl_arg(fd, DIOCGSTRIPESIZE, &stripesize) == -1)
125 		return (-1);
126 	return (stripesize);
127 }
128 
129 /*
130  * Return stripe size of the given provider.
131  */
132 off_t
133 g_stripeoffset(int fd)
134 {
135 	off_t stripeoffset;
136 
137 	if (g_ioctl_arg(fd, DIOCGSTRIPEOFFSET, &stripeoffset) == -1)
138 		return (-1);
139 	return (stripeoffset);
140 }
141 
142 /*
143  * Return the correct provider name.
144  */
145 char *
146 g_providername(int fd)
147 {
148 	char name[MAXPATHLEN];
149 
150 	if (g_ioctl_arg(fd, DIOCGPROVIDERNAME, name) == -1)
151 		return (NULL);
152 	return (strdup(name));
153 }
154 
155 /*
156  * Call BIO_FLUSH for the given provider.
157  */
158 int
159 g_flush(int fd)
160 {
161 
162 	return (g_ioctl(fd, DIOCGFLUSH));
163 }
164 
165 /*
166  * Call BIO_DELETE for the given range.
167  */
168 int
169 g_delete(int fd, off_t offset, off_t length)
170 {
171 	off_t arg[2];
172 
173 	arg[0] = offset;
174 	arg[1] = length;
175 	return (g_ioctl_arg(fd, DIOCGDELETE, arg));
176 }
177 
178 /*
179  * Return ID of the given provider.
180  */
181 int
182 g_get_ident(int fd, char *ident, size_t size)
183 {
184 	char lident[DISK_IDENT_SIZE];
185 
186 	if (g_ioctl_arg(fd, DIOCGIDENT, lident) == -1)
187 		return (-1);
188 	if (lident[0] == '\0') {
189 		errno = ENOENT;
190 		return (-1);
191 	}
192 	if (strlcpy(ident, lident, size) >= size) {
193 		errno = ENAMETOOLONG;
194 		return (-1);
195 	}
196 	return (0);
197 }
198 
199 /*
200  * Return name of the provider, which has the given ID.
201  */
202 int
203 g_get_name(const char *ident, char *name, size_t size)
204 {
205 	int fd;
206 
207 	fd = g_open_by_ident(ident, 0, name, size);
208 	if (fd == -1)
209 		return (-1);
210 	g_close(fd);
211 	return (0);
212 }
213 
214 /*
215  * Find provider name by the given ID.
216  */
217 int
218 g_open_by_ident(const char *ident, int dowrite, char *name, size_t size)
219 {
220 	char lident[DISK_IDENT_SIZE];
221 	struct gmesh mesh;
222 	struct gclass *mp;
223 	struct ggeom *gp;
224 	struct gprovider *pp;
225 	int error, fd;
226 
227 	error = geom_gettree(&mesh);
228 	if (error != 0) {
229 		errno = error;
230 		return (-1);
231 	}
232 
233 	error = ENOENT;
234 	fd = -1;
235 
236 	LIST_FOREACH(mp, &mesh.lg_class, lg_class) {
237 		LIST_FOREACH(gp, &mp->lg_geom, lg_geom) {
238 			LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
239 				fd = g_open(pp->lg_name, dowrite);
240 				if (fd == -1)
241 					continue;
242 				if (g_get_ident(fd, lident,
243 				    sizeof(lident)) == -1) {
244 					g_close(fd);
245 					continue;
246 				}
247 				if (strcmp(ident, lident) != 0) {
248 					g_close(fd);
249 					continue;
250 				}
251 				error = 0;
252 				if (name != NULL && strlcpy(name, pp->lg_name,
253 				    size) >= size) {
254 					error = ENAMETOOLONG;
255 					g_close(fd);
256 				}
257 				goto end;
258 			}
259 		}
260 	}
261 end:
262 	geom_deletetree(&mesh);
263 	if (error != 0) {
264 		errno = error;
265 		return (-1);
266 	}
267 	return (fd);
268 }
269 
270 /*
271  * Return the device path device given a partial or full path to its node.
272  * A pointer can be provided, which will be set to an opened file descriptor of
273  * not NULL.
274  */
275 static char *
276 g_device_path_open(const char *devpath, int *fdp, int dowrite)
277 {
278 	char *path;
279 	int fd;
280 
281 	/* Make sure that we can fail. */
282 	if (fdp != NULL)
283 		*fdp = -1;
284 	/* Use the device node if we're able to open it. */
285 	do {
286 		fd = open(devpath, dowrite ? O_RDWR : O_RDONLY);
287 		if (fd == -1)
288 			break;
289 		/*
290 		 * Let try to get sectorsize, which will prove it is a GEOM
291 		 * provider.
292 		 */
293 		if (g_sectorsize(fd) == -1) {
294 			close(fd);
295 			errno = EFTYPE;
296 			return (NULL);
297 		}
298 		if ((path = strdup(devpath)) == NULL) {
299 			close(fd);
300 			return (NULL);
301 		}
302 		if (fdp != NULL)
303 			*fdp = fd;
304 		else
305 			close(fd);
306 		return (path);
307 	} while (0);
308 
309 	/* If we're not given an absolute path, assume /dev/ prefix. */
310 	if (*devpath != '/') {
311 		asprintf(&path, "%s%s", _PATH_DEV, devpath);
312 		if (path == NULL)
313 			return (NULL);
314 		fd = open(path, dowrite ? O_RDWR : O_RDONLY);
315 		if (fd == -1) {
316 			free(path);
317 			return (NULL);
318 		}
319 		/*
320 		 * Let try to get sectorsize, which will prove it is a GEOM
321 		 * provider.
322 		 */
323 		if (g_sectorsize(fd) == -1) {
324 			free(path);
325 			close(fd);
326 			errno = EFTYPE;
327 			return (NULL);
328 		}
329 		if (fdp != NULL)
330 			*fdp = fd;
331 		else
332 			close(fd);
333 		return (path);
334 	}
335 	return (NULL);
336 }
337 
338 char *
339 g_device_path(const char *devpath)
340 {
341 	return (g_device_path_open(devpath, NULL, 0));
342 }
343