xref: /illumos-gate/usr/src/cmd/lofiadm/main.c (revision f48205be)
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 http://www.opensolaris.org/os/licensing.
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * lofiadm - administer lofi(7d). Very simple, add and remove file<->device
26  * associations, and display status. All the ioctls are private between
27  * lofi and lofiadm, and so are very simple - device information is
28  * communicated via a minor number.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/lofi.h>
36 #include <sys/stat.h>
37 #include <stdio.h>
38 #include <fcntl.h>
39 #include <locale.h>
40 #include <string.h>
41 #include <errno.h>
42 #include <stdlib.h>
43 #include <unistd.h>
44 #include <stropts.h>
45 #include <libdevinfo.h>
46 #include "utils.h"
47 
48 static const char USAGE[] =
49 	"Usage: %s -a file [ device ]\n"
50 	"       %s -d file | device \n"
51 	"       %s [ device | file ]\n";
52 
53 static const char *pname;
54 static int	addflag = 0;
55 static int	deleteflag = 0;
56 static int	errflag = 0;
57 
58 #define	FORMAT "%-20s     %s\n"
59 
60 /*
61  * Print the list of all the mappings. Including a header.
62  */
63 static void
64 print_mappings(int fd)
65 {
66 	struct lofi_ioctl li;
67 	int	minor;
68 	int	maxminor;
69 	char	path[MAXPATHLEN + 1];
70 
71 	li.li_minor = 0;
72 	if (ioctl(fd, LOFI_GET_MAXMINOR, &li) == -1) {
73 		perror("ioctl");
74 		exit(E_ERROR);
75 	}
76 
77 	maxminor = li.li_minor;
78 
79 	(void) printf(FORMAT, "Block Device", "File");
80 	for (minor = 1; minor <= maxminor; minor++) {
81 		li.li_minor = minor;
82 		if (ioctl(fd, LOFI_GET_FILENAME, &li) == -1) {
83 			if (errno == ENXIO)
84 				continue;
85 			perror("ioctl");
86 			break;
87 		}
88 		(void) snprintf(path, sizeof (path), "/dev/%s/%d",
89 		    LOFI_BLOCK_NAME, minor);
90 		(void) printf(FORMAT, path, li.li_filename);
91 	}
92 }
93 
94 static void
95 usage(void)
96 {
97 	(void) fprintf(stderr, gettext(USAGE), pname, pname, pname);
98 	exit(E_USAGE);
99 }
100 
101 /*
102  * Translate a lofi device name to a minor number. We might be asked
103  * to do this when there is no association (such as when the user specifies
104  * a particular device), so we can only look at the string.
105  */
106 static int
107 name_to_minor(const char *devicename)
108 {
109 	int	minor;
110 
111 	if (sscanf(devicename, "/dev/" LOFI_BLOCK_NAME "/%d", &minor) == 1) {
112 		return (minor);
113 	}
114 	if (sscanf(devicename, "/dev/" LOFI_CHAR_NAME "/%d", &minor) == 1) {
115 		return (minor);
116 	}
117 	return (0);
118 }
119 
120 /*
121  * This might be the first time we've used this minor number. If so,
122  * it might also be that the /dev links are in the process of being created
123  * by devfsadmd (or that they'll be created "soon"). We cannot return
124  * until they're there or the invoker of lofiadm might try to use them
125  * and not find them. This can happen if a shell script is running on
126  * an MP.
127  */
128 static int sleeptime = 2;	/* number of seconds to sleep between stat's */
129 static int maxsleep = 120;	/* maximum number of seconds to sleep */
130 
131 static void
132 wait_until_dev_complete(int minor)
133 {
134 	struct stat64 buf;
135 	int	cursleep;
136 	char	blkpath[MAXPATHLEN + 1];
137 	char	charpath[MAXPATHLEN + 1];
138 	di_devlink_handle_t hdl;
139 
140 
141 	(void) snprintf(blkpath, sizeof (blkpath), "/dev/%s/%d",
142 	    LOFI_BLOCK_NAME, minor);
143 	(void) snprintf(charpath, sizeof (charpath), "/dev/%s/%d",
144 	    LOFI_CHAR_NAME, minor);
145 
146 	/* Check if links already present */
147 	if (stat64(blkpath, &buf) == 0 && stat64(charpath, &buf) == 0)
148 		return;
149 
150 	/* First use di_devlink_init() */
151 	if (hdl = di_devlink_init("lofi", DI_MAKE_LINK)) {
152 		(void) di_devlink_fini(&hdl);
153 		goto out;
154 	}
155 
156 	/*
157 	 * Under normal conditions, di_devlink_init(DI_MAKE_LINK) above will
158 	 * only fail if the caller is non-root. In that case, wait for
159 	 * link creation via sysevents.
160 	 */
161 	cursleep = 0;
162 	while (cursleep < maxsleep) {
163 		if ((stat64(blkpath, &buf) == -1) ||
164 		    (stat64(charpath, &buf) == -1)) {
165 			(void) sleep(sleeptime);
166 			cursleep += sleeptime;
167 			continue;
168 		}
169 		return;
170 	}
171 
172 	/* one last try */
173 
174 out:
175 	if (stat64(blkpath, &buf) == -1) {
176 		die(gettext("%s was not created"), blkpath);
177 	}
178 	if (stat64(charpath, &buf) == -1) {
179 		die(gettext("%s was not created"), charpath);
180 	}
181 }
182 
183 /*
184  * Add a device association. If devicename is NULL, let the driver
185  * pick a device.
186  */
187 static void
188 add_mapping(int lfd, const char *devicename, const char *filename)
189 {
190 	struct lofi_ioctl li;
191 	int	minor;
192 
193 	if (devicename == NULL) {
194 		/* pick one */
195 		li.li_minor = 0;
196 		(void) strcpy(li.li_filename, filename);
197 		minor = ioctl(lfd, LOFI_MAP_FILE, &li);
198 		if (minor == -1) {
199 			die(gettext("could not map file %s"), filename);
200 		}
201 		wait_until_dev_complete(minor);
202 		/* print one picked */
203 		(void) printf("/dev/%s/%d\n", LOFI_BLOCK_NAME, minor);
204 		return;
205 	}
206 	/* use device we were given */
207 	minor = name_to_minor(devicename);
208 	if (minor == 0) {
209 		die(gettext("malformed device name %s\n"), devicename);
210 	}
211 	(void) strcpy(li.li_filename, filename);
212 	li.li_minor = minor;
213 	if (ioctl(lfd, LOFI_MAP_FILE_MINOR, &li) == -1) {
214 		die(gettext("could not map file %s to %s"), filename,
215 		    devicename);
216 	}
217 	wait_until_dev_complete(minor);
218 }
219 
220 /*
221  * Remove an association. Delete by device name if non-NULL, or by
222  * filename otherwise.
223  */
224 static void
225 delete_mapping(int lfd, const char *devicename, const char *filename)
226 {
227 	struct lofi_ioctl li;
228 
229 	if (devicename == NULL) {
230 		/* delete by filename */
231 		(void) strcpy(li.li_filename, filename);
232 		li.li_minor = 0;
233 		if (ioctl(lfd, LOFI_UNMAP_FILE, &li) == -1) {
234 			die(gettext("could not unmap file %s"), filename);
235 		}
236 		return;
237 	}
238 	/* delete by device */
239 
240 	li.li_minor = name_to_minor(devicename);
241 	if (li.li_minor == 0) {
242 		die(gettext("malformed device name %s\n"), devicename);
243 	}
244 	if (ioctl(lfd, LOFI_UNMAP_FILE_MINOR, &li) == -1) {
245 		die(gettext("could not unmap device %s"), devicename);
246 	}
247 }
248 
249 static void
250 print_one_mapping(int lfd, const char *devicename, const char *filename)
251 {
252 	struct lofi_ioctl li;
253 
254 	if (devicename == NULL) {
255 		/* given filename, print devicename */
256 		li.li_minor = 0;
257 		(void) strcpy(li.li_filename, filename);
258 		if (ioctl(lfd, LOFI_GET_MINOR, &li) == -1) {
259 			die(gettext("could not find device for %s"), filename);
260 		}
261 		(void) printf("/dev/%s/%d\n", LOFI_BLOCK_NAME, li.li_minor);
262 		return;
263 	}
264 
265 	/* given devicename, print filename */
266 	li.li_minor = name_to_minor(devicename);
267 	if (li.li_minor == 0) {
268 		die(gettext("malformed device name %s\n"), devicename);
269 	}
270 	if (ioctl(lfd, LOFI_GET_FILENAME, &li) == -1) {
271 		die(gettext("could not find filename for %s"), devicename);
272 	}
273 	(void) printf("%s\n", li.li_filename);
274 }
275 
276 int
277 main(int argc, char *argv[])
278 {
279 	int	lfd;
280 	int	c;
281 	int	error;
282 	struct stat64 buf;
283 	const char *devicename = NULL;
284 	const char *filename = NULL;
285 	int	openflag;
286 	int	minor;
287 	int	fd = -1;
288 	static char *lofictl = "/dev/" LOFI_CTL_NAME;
289 
290 	pname = getpname(argv[0]);
291 
292 	(void) setlocale(LC_ALL, "");
293 	(void) textdomain(TEXT_DOMAIN);
294 
295 	while ((c = getopt(argc, argv, "a:d:")) != EOF) {
296 		switch (c) {
297 		case 'a':
298 			addflag = 1;
299 			filename = optarg;
300 			fd = open64(filename, O_RDONLY);
301 			if (fd == -1) {
302 				die(gettext("open: %s"), filename);
303 			}
304 			error = fstat64(fd, &buf);
305 			if (error == -1) {
306 				die(gettext("fstat: %s"), filename);
307 			} else if (!S_ISLOFIABLE(buf.st_mode)) {
308 				die(gettext("%s is not a regular file, "
309 				    "block, or character device\n"),
310 				    filename);
311 			} else if ((buf.st_size % DEV_BSIZE) != 0) {
312 				die(gettext("size of %s is not a multiple "
313 				    "of %d\n"),
314 				    filename, DEV_BSIZE);
315 			}
316 			(void) close(fd);
317 			minor = name_to_minor(filename);
318 			if (minor != 0) {
319 				die(gettext("cannot use " LOFI_DRIVER_NAME
320 				    " on itself\n"), devicename);
321 			}
322 			if (((argc - optind) > 0) && (*argv[optind] != '-')) {
323 				/* optional device */
324 				devicename = argv[optind];
325 				optind++;
326 			}
327 			break;
328 		case 'd':
329 			deleteflag = 1;
330 
331 			minor = name_to_minor(optarg);
332 			if (minor != 0)
333 				devicename = optarg;
334 			else
335 				filename = optarg;
336 			break;
337 		case '?':
338 		default:
339 			errflag = 1;
340 			break;
341 		}
342 	}
343 	if (errflag || (addflag && deleteflag))
344 		usage();
345 
346 	switch (argc - optind) {
347 	case 0: /* no more args */
348 		break;
349 	case 1: /* one arg without options means print the association */
350 		if (addflag || deleteflag)
351 			usage();
352 		minor = name_to_minor(argv[optind]);
353 		if (minor != 0)
354 			devicename = argv[optind];
355 		else
356 			filename = argv[optind];
357 		break;
358 	default:
359 		usage();
360 		break;
361 	}
362 
363 	if (filename && !valid_abspath(filename))
364 		exit(E_ERROR);
365 
366 	/*
367 	 * Here, we know the arguments are correct, the filename is an
368 	 * absolute path, it exists and is a regular file. We don't yet
369 	 * know that the device name is ok or not.
370 	 */
371 	/*
372 	 * Now to the real work.
373 	 */
374 	openflag = O_EXCL;
375 	if (addflag || deleteflag)
376 		openflag |= O_RDWR;
377 	else
378 		openflag |= O_RDONLY;
379 	lfd = open(lofictl, openflag);
380 	if (lfd == -1) {
381 		if ((errno == EPERM) || (errno == EACCES)) {
382 			die("you do not have permission to perform "
383 			    "that operation.\n");
384 		} else {
385 			die("%s", lofictl);
386 		}
387 		/*NOTREACHED*/
388 	}
389 	if (addflag)
390 		add_mapping(lfd, devicename, filename);
391 	else if (deleteflag)
392 		delete_mapping(lfd, devicename, filename);
393 	else if (filename || devicename)
394 		print_one_mapping(lfd, devicename, filename);
395 	else
396 		print_mappings(lfd);
397 	(void) close(lfd);
398 	return (E_SUCCESS);
399 }
400