1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2005 Jean-Sebastien Pedron
5 * Copyright (c) 2005 Csaba Henk
6 * All rights reserved.
7 *
8 * Copyright (c) 2019 The FreeBSD Foundation
9 *
10 * Portions of this software were developed by BFF Storage Systems under
11 * sponsorship from the FreeBSD Foundation.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 */
35
36 #include <sys/param.h>
37 #include <sys/mount.h>
38 #include <sys/uio.h>
39 #include <sys/stat.h>
40 #include <sys/sysctl.h>
41
42 #include <err.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <sysexits.h>
47 #include <unistd.h>
48 #include <fcntl.h>
49 #include <signal.h>
50 #include <getopt.h>
51 #include <limits.h>
52 #include <mntopts.h>
53 #include <osreldate.h>
54 #include <paths.h>
55
56 #ifndef FUSE4BSD_VERSION
57 #define FUSE4BSD_VERSION "0.3.9-pre1"
58 #endif
59
60 void __usage_short(void);
61 void usage(void);
62 void helpmsg(void);
63 void showversion(void);
64
65 static struct mntopt mopts[] = {
66 #define ALTF_PRIVATE 0x01
67 { "private", 0, ALTF_PRIVATE, 1 },
68 { "neglect_shares", 0, 0x02, 1 },
69 { "push_symlinks_in", 0, 0x04, 1 },
70 { "allow_other", 0, 0x08, 1 },
71 { "default_permissions", 0, 0x10, 1 },
72 #define ALTF_MAXREAD 0x20
73 { "max_read=", 0, ALTF_MAXREAD, 1 },
74 #define ALTF_SUBTYPE 0x40
75 { "subtype=", 0, ALTF_SUBTYPE, 1 },
76 #define ALTF_FSNAME 0x80
77 { "fsname=", 0, ALTF_FSNAME, 1 },
78 /*
79 * MOPT_AUTOMOUNTED, included by MOPT_STDOPTS, does not fit into
80 * the 'flags' argument to nmount(2). We have to abuse altflags
81 * to pass it, as string, via iovec.
82 */
83 #define ALTF_AUTOMOUNTED 0x100
84 { "automounted", 0, ALTF_AUTOMOUNTED, 1 },
85 #define ALTF_INTR 0x200
86 { "intr", 0, ALTF_INTR, 1 },
87 #define ALTF_AUTOUNMOUNT 0x400
88 { "auto_unmount", 0, ALTF_AUTOUNMOUNT, 1 },
89 /* Linux specific options, we silently ignore them */
90 { "fd=", 0, 0x00, 1 },
91 { "rootmode=", 0, 0x00, 1 },
92 { "user_id=", 0, 0x00, 1 },
93 { "group_id=", 0, 0x00, 1 },
94 { "large_read", 0, 0x00, 1 },
95 /* "nonempty", just the first two chars are stripped off during parsing */
96 { "nempty", 0, 0x00, 1 },
97 { "async", 0, MNT_ASYNC, 0},
98 { "noasync", 1, MNT_ASYNC, 0},
99 MOPT_STDOPTS,
100 MOPT_END
101 };
102
103 struct mntval {
104 int mv_flag;
105 void *mv_value;
106 int mv_len;
107 };
108
109 static struct mntval mvals[] = {
110 { ALTF_MAXREAD, NULL, 0 },
111 { ALTF_SUBTYPE, NULL, 0 },
112 { ALTF_FSNAME, NULL, 0 },
113 { 0, NULL, 0 }
114 };
115
116 #define DEFAULT_MOUNT_FLAGS ALTF_PRIVATE
117
118 int
main(int argc,char * argv[])119 main(int argc, char *argv[])
120 {
121 struct iovec *iov;
122 int mntflags, iovlen, verbose = 0;
123 char *dev = NULL, *dir = NULL, mntpath[MAXPATHLEN];
124 char *devo = NULL, *diro = NULL;
125 char ndev[128], fdstr[15];
126 int i, done = 0, reject_allow_other = 0, safe_level = 0;
127 int altflags = DEFAULT_MOUNT_FLAGS;
128 int __altflags = DEFAULT_MOUNT_FLAGS;
129 int ch = 0;
130 struct mntopt *mo;
131 struct mntval *mv;
132 static struct option longopts[] = {
133 {"reject-allow_other", no_argument, NULL, 'A'},
134 {"safe", no_argument, NULL, 'S'},
135 {"daemon", required_argument, NULL, 'D'},
136 {"daemon_opts", required_argument, NULL, 'O'},
137 {"special", required_argument, NULL, 's'},
138 {"mountpath", required_argument, NULL, 'm'},
139 {"version", no_argument, NULL, 'V'},
140 {"help", no_argument, NULL, 'h'},
141 {0,0,0,0}
142 };
143 int pid = 0;
144 int fd = -1, fdx;
145 char *ep;
146 char *daemon_str = NULL, *daemon_opts = NULL;
147
148 /*
149 * We want a parsing routine which is not sensitive to
150 * the position of args/opts; it should extract the
151 * first two args and stop at the beginning of the rest.
152 * (This makes it easier to call mount_fusefs from external
153 * utils than it is with a strict "util flags args" syntax.)
154 */
155
156 iov = NULL;
157 iovlen = 0;
158 mntflags = 0;
159 /* All in all, I feel it more robust this way... */
160 unsetenv("POSIXLY_CORRECT");
161 if (getenv("MOUNT_FUSEFS_IGNORE_UNKNOWN"))
162 getmnt_silent = 1;
163 if (getenv("MOUNT_FUSEFS_VERBOSE"))
164 verbose = 1;
165
166 do {
167 for (i = 0; i < 3; i++) {
168 if (optind < argc && argv[optind][0] != '-') {
169 if (dir) {
170 done = 1;
171 break;
172 }
173 if (dev)
174 dir = argv[optind];
175 else
176 dev = argv[optind];
177 optind++;
178 }
179 }
180 switch(ch) {
181 case 'A':
182 reject_allow_other = 1;
183 break;
184 case 'S':
185 safe_level = 1;
186 break;
187 case 'D':
188 if (daemon_str)
189 errx(1, "daemon specified inconsistently");
190 daemon_str = optarg;
191 break;
192 case 'O':
193 if (daemon_opts)
194 errx(1, "daemon opts specified inconsistently");
195 daemon_opts = optarg;
196 break;
197 case 'o':
198 getmntopts(optarg, mopts, &mntflags, &altflags);
199 for (mv = mvals; mv->mv_flag; ++mv) {
200 if (! (altflags & mv->mv_flag))
201 continue;
202 for (mo = mopts; mo->m_flag; ++mo) {
203 char *p, *q;
204
205 if (mo->m_flag != mv->mv_flag)
206 continue;
207 p = strstr(optarg, mo->m_option);
208 if (p) {
209 p += strlen(mo->m_option);
210 q = p;
211 while (*q != '\0' && *q != ',')
212 q++;
213 mv->mv_len = q - p + 1;
214 mv->mv_value = malloc(mv->mv_len);
215 if (mv->mv_value == NULL)
216 err(1, "malloc");
217 memcpy(mv->mv_value, p, mv->mv_len - 1);
218 ((char *)mv->mv_value)[mv->mv_len - 1] = '\0';
219 break;
220 }
221 }
222 }
223 break;
224 case 's':
225 if (devo)
226 errx(1, "special specified inconsistently");
227 devo = optarg;
228 break;
229 case 'm':
230 if (diro)
231 errx(1, "mount path specified inconsistently");
232 diro = optarg;
233 break;
234 case 'v':
235 verbose = 1;
236 break;
237 case 'h':
238 helpmsg();
239 break;
240 case 'V':
241 showversion();
242 break;
243 case '\0':
244 break;
245 case '?':
246 default:
247 usage();
248 }
249 if (done)
250 break;
251 } while ((ch = getopt_long(argc, argv, "AvVho:SD:O:s:m:", longopts, NULL)) != -1);
252
253 argc -= optind;
254 argv += optind;
255
256 if (devo) {
257 if (dev)
258 errx(1, "special specified inconsistently");
259 dev = devo;
260 } else if (diro)
261 errx(1, "if mountpoint is given via an option, special should also be given via an option");
262
263 if (diro) {
264 if (dir)
265 errx(1, "mount path specified inconsistently");
266 dir = diro;
267 }
268
269 if ((! dev) && argc > 0) {
270 dev = *argv++;
271 argc--;
272 }
273
274 if ((! dir) && argc > 0) {
275 dir = *argv++;
276 argc--;
277 }
278
279 if (! (dev && dir))
280 errx(1, "missing special and/or mountpoint");
281
282 for (mo = mopts; mo->m_flag; ++mo) {
283 if (altflags & mo->m_flag) {
284 int iov_done = 0;
285
286 if (reject_allow_other &&
287 strcmp(mo->m_option, "allow_other") == 0)
288 /*
289 * reject_allow_other is stronger than a
290 * negative of allow_other: if this is set,
291 * allow_other is blocked, period.
292 */
293 errx(1, "\"allow_other\" usage is banned by respective option");
294
295 for (mv = mvals; mv->mv_flag; ++mv) {
296 if (mo->m_flag != mv->mv_flag)
297 continue;
298 if (mv->mv_value) {
299 build_iovec(&iov, &iovlen, mo->m_option, mv->mv_value, mv->mv_len);
300 iov_done = 1;
301 break;
302 }
303 }
304 if (! iov_done)
305 build_iovec(&iov, &iovlen, mo->m_option,
306 __DECONST(void *, ""), -1);
307 }
308 if (__altflags & mo->m_flag) {
309 char *uscore_opt;
310
311 if (asprintf(&uscore_opt, "__%s", mo->m_option) == -1)
312 err(1, "failed to allocate memory");
313 build_iovec(&iov, &iovlen, uscore_opt,
314 __DECONST(void *, ""), -1);
315 free(uscore_opt);
316 }
317 }
318
319 if (getenv("MOUNT_FUSEFS_SAFE"))
320 safe_level = 1;
321
322 if (safe_level > 0 && (argc > 0 || daemon_str || daemon_opts))
323 errx(1, "safe mode, spawning daemon not allowed");
324
325 if ((argc > 0 && (daemon_str || daemon_opts)) ||
326 (daemon_opts && ! daemon_str))
327 errx(1, "daemon specified inconsistently");
328
329 /*
330 * Resolve the mountpoint with realpath(3) and remove unnecessary
331 * slashes from the devicename if there are any.
332 */
333 if (checkpath(dir, mntpath) != 0)
334 err(1, "%s", mntpath);
335 (void)rmslashes(dev, dev);
336
337 if (strcmp(dev, "auto") == 0)
338 dev = __DECONST(char *, "/dev/fuse");
339
340 if (strcmp(dev, "/dev/fuse") == 0) {
341 if (! (argc > 0 || daemon_str)) {
342 fprintf(stderr, "Please also specify the fuse daemon to run when mounting via the multiplexer!\n");
343 usage();
344 }
345 if ((fd = open(dev, O_RDWR)) < 0)
346 err(1, "failed to open fuse device");
347 } else {
348 fdx = strtol(dev, &ep, 10);
349 if (*ep == '\0')
350 fd = fdx;
351 }
352
353 /* Identifying device */
354 if (fd >= 0) {
355 struct stat sbuf;
356 char *ndevbas, *lep;
357
358 if (fstat(fd, &sbuf) == -1)
359 err(1, "cannot stat device file descriptor");
360
361 strcpy(ndev, _PATH_DEV);
362 ndevbas = ndev + strlen(_PATH_DEV);
363 devname_r(sbuf.st_rdev, S_IFCHR, ndevbas,
364 sizeof(ndev) - strlen(_PATH_DEV));
365
366 if (strncmp(ndevbas, "fuse", 4))
367 errx(1, "mounting inappropriate device");
368
369 strtol(ndevbas + 4, &lep, 10);
370 if (*lep != '\0')
371 errx(1, "mounting inappropriate device");
372
373 dev = ndev;
374 }
375
376 if (argc > 0 || daemon_str) {
377 char *fds;
378
379 if (fd < 0 && (fd = open(dev, O_RDWR)) < 0)
380 err(1, "failed to open fuse device");
381
382 if (asprintf(&fds, "%d", fd) == -1)
383 err(1, "failed to allocate memory");
384 setenv("FUSE_DEV_FD", fds, 1);
385 free(fds);
386 setenv("FUSE_NO_MOUNT", "1", 1);
387
388 if (daemon_str) {
389 char *bgdaemon;
390 int len;
391
392 if (! daemon_opts)
393 daemon_opts = __DECONST(char *, "");
394
395 len = strlen(daemon_str) + 1 + strlen(daemon_opts) +
396 2 + 1;
397 bgdaemon = calloc(1, len);
398
399 if (! bgdaemon)
400 err(1, "failed to allocate memory");
401
402 strlcpy(bgdaemon, daemon_str, len);
403 strlcat(bgdaemon, " ", len);
404 strlcat(bgdaemon, daemon_opts, len);
405 strlcat(bgdaemon, " &", len);
406
407 if (system(bgdaemon))
408 err(1, "failed to call fuse daemon");
409 } else {
410 if ((pid = fork()) < 0)
411 err(1, "failed to fork for fuse daemon");
412
413 if (pid == 0) {
414 execvp(argv[0], argv);
415 err(1, "failed to exec fuse daemon");
416 }
417 }
418 }
419
420 /* Prepare the options vector for nmount(). build_iovec() is declared
421 * in mntopts.h. */
422 sprintf(fdstr, "%d", fd);
423 build_iovec(&iov, &iovlen, "fstype", __DECONST(void *, "fusefs"), -1);
424 build_iovec(&iov, &iovlen, "fspath", mntpath, -1);
425 build_iovec(&iov, &iovlen, "from", dev, -1);
426 build_iovec(&iov, &iovlen, "fd", fdstr, -1);
427
428 if (verbose)
429 fprintf(stderr, "mounting fuse daemon on device %s\n", dev);
430
431 if (nmount(iov, iovlen, mntflags) < 0)
432 err(EX_OSERR, "%s on %s", dev, mntpath);
433
434 exit(0);
435 }
436
437 void
__usage_short(void)438 __usage_short(void) {
439 fprintf(stderr,
440 "usage:\n%s [-A|-S|-v|-V|-h|-D daemon|-O args|-s special|-m node|-o option...] special node [daemon args...]\n\n",
441 getprogname());
442 }
443
444 void
usage(void)445 usage(void)
446 {
447 struct mntopt *mo;
448
449 __usage_short();
450
451 fprintf(stderr, "known options:\n");
452 for (mo = mopts; mo->m_flag; ++mo)
453 fprintf(stderr, "\t%s\n", mo->m_option);
454
455 fprintf(stderr, "\n(use -h for a detailed description of these options)\n");
456 exit(EX_USAGE);
457 }
458
459 void
helpmsg(void)460 helpmsg(void)
461 {
462 if (! getenv("MOUNT_FUSEFS_CALL_BY_LIB")) {
463 __usage_short();
464 fprintf(stderr, "description of options:\n");
465 }
466
467 /*
468 * The main use case of this function is giving info embedded in general
469 * FUSE lib help output. Therefore the style and the content of the output
470 * tries to fit there as much as possible.
471 */
472 fprintf(stderr,
473 " -o allow_other allow access to other users\n"
474 /* " -o nonempty allow mounts over non-empty file/dir\n" */
475 " -o default_permissions enable permission checking by kernel\n"
476 " -o intr interruptible mount\n"
477 " -o fsname=NAME set filesystem name\n"
478 /*
479 " -o large_read issue large read requests (2.4 only)\n"
480 */
481 " -o subtype=NAME set filesystem type\n"
482 " -o max_read=N set maximum size of read requests\n"
483 " -o noprivate allow secondary mounting of the filesystem\n"
484 " -o neglect_shares don't report EBUSY when unmount attempted\n"
485 " in presence of secondary mounts\n"
486 " -o push_symlinks_in prefix absolute symlinks with mountpoint\n"
487 );
488 exit(EX_USAGE);
489 }
490
491 void
showversion(void)492 showversion(void)
493 {
494 puts("mount_fusefs [fuse4bsd] version: " FUSE4BSD_VERSION);
495 exit(EX_USAGE);
496 }
497