1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2005 Jean-Sebastien Pedron 5 * Copyright (c) 2005 Csaba Henk 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/mount.h> 36 #include <sys/uio.h> 37 #include <sys/stat.h> 38 #include <sys/sysctl.h> 39 40 #include <err.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <sysexits.h> 45 #include <unistd.h> 46 #include <fcntl.h> 47 #include <signal.h> 48 #include <getopt.h> 49 #include <limits.h> 50 #include <osreldate.h> 51 #include <paths.h> 52 53 #include "mntopts.h" 54 55 #ifndef FUSE4BSD_VERSION 56 #define FUSE4BSD_VERSION "0.3.9-pre1" 57 #endif 58 59 void __usage_short(void); 60 void usage(void); 61 void helpmsg(void); 62 void showversion(void); 63 int init_backgrounded(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_SYNC_UNMOUNT 0x80 77 { "sync_unmount", 0, ALTF_SYNC_UNMOUNT, 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 /* Linux specific options, we silently ignore them */ 86 { "fsname=", 0, 0x00, 1 }, 87 { "fd=", 0, 0x00, 1 }, 88 { "rootmode=", 0, 0x00, 1 }, 89 { "user_id=", 0, 0x00, 1 }, 90 { "group_id=", 0, 0x00, 1 }, 91 { "large_read", 0, 0x00, 1 }, 92 /* "nonempty", just the first two chars are stripped off during parsing */ 93 { "nempty", 0, 0x00, 1 }, 94 MOPT_STDOPTS, 95 MOPT_END 96 }; 97 98 struct mntval { 99 int mv_flag; 100 void *mv_value; 101 int mv_len; 102 }; 103 104 static struct mntval mvals[] = { 105 { ALTF_MAXREAD, NULL, 0 }, 106 { ALTF_SUBTYPE, NULL, 0 }, 107 { 0, NULL, 0 } 108 }; 109 110 #define DEFAULT_MOUNT_FLAGS ALTF_PRIVATE | ALTF_SYNC_UNMOUNT 111 112 int 113 main(int argc, char *argv[]) 114 { 115 struct iovec *iov; 116 int mntflags, iovlen, verbose = 0; 117 char *dev = NULL, *dir = NULL, mntpath[MAXPATHLEN]; 118 char *devo = NULL, *diro = NULL; 119 char ndev[128], fdstr[15]; 120 int i, done = 0, reject_allow_other = 0, safe_level = 0; 121 int altflags = DEFAULT_MOUNT_FLAGS; 122 int __altflags = DEFAULT_MOUNT_FLAGS; 123 int ch = 0; 124 struct mntopt *mo; 125 struct mntval *mv; 126 static struct option longopts[] = { 127 {"reject-allow_other", no_argument, NULL, 'A'}, 128 {"safe", no_argument, NULL, 'S'}, 129 {"daemon", required_argument, NULL, 'D'}, 130 {"daemon_opts", required_argument, NULL, 'O'}, 131 {"special", required_argument, NULL, 's'}, 132 {"mountpath", required_argument, NULL, 'm'}, 133 {"version", no_argument, NULL, 'V'}, 134 {"help", no_argument, NULL, 'h'}, 135 {0,0,0,0} 136 }; 137 int pid = 0; 138 int fd = -1, fdx; 139 char *ep; 140 char *daemon_str = NULL, *daemon_opts = NULL; 141 142 /* 143 * We want a parsing routine which is not sensitive to 144 * the position of args/opts; it should extract the 145 * first two args and stop at the beginning of the rest. 146 * (This makes it easier to call mount_fusefs from external 147 * utils than it is with a strict "util flags args" syntax.) 148 */ 149 150 iov = NULL; 151 iovlen = 0; 152 mntflags = 0; 153 /* All in all, I feel it more robust this way... */ 154 unsetenv("POSIXLY_CORRECT"); 155 if (getenv("MOUNT_FUSEFS_IGNORE_UNKNOWN")) 156 getmnt_silent = 1; 157 if (getenv("MOUNT_FUSEFS_VERBOSE")) 158 verbose = 1; 159 160 do { 161 for (i = 0; i < 3; i++) { 162 if (optind < argc && argv[optind][0] != '-') { 163 if (dir) { 164 done = 1; 165 break; 166 } 167 if (dev) 168 dir = argv[optind]; 169 else 170 dev = argv[optind]; 171 optind++; 172 } 173 } 174 switch(ch) { 175 case 'A': 176 reject_allow_other = 1; 177 break; 178 case 'S': 179 safe_level = 1; 180 break; 181 case 'D': 182 if (daemon_str) 183 errx(1, "daemon specified inconsistently"); 184 daemon_str = optarg; 185 break; 186 case 'O': 187 if (daemon_opts) 188 errx(1, "daemon opts specified inconsistently"); 189 daemon_opts = optarg; 190 break; 191 case 'o': 192 getmntopts(optarg, mopts, &mntflags, &altflags); 193 for (mv = mvals; mv->mv_flag; ++mv) { 194 if (! (altflags & mv->mv_flag)) 195 continue; 196 for (mo = mopts; mo->m_flag; ++mo) { 197 char *p, *q; 198 199 if (mo->m_flag != mv->mv_flag) 200 continue; 201 p = strstr(optarg, mo->m_option); 202 if (p) { 203 p += strlen(mo->m_option); 204 q = p; 205 while (*q != '\0' && *q != ',') 206 q++; 207 mv->mv_len = q - p + 1; 208 mv->mv_value = malloc(mv->mv_len); 209 memcpy(mv->mv_value, p, mv->mv_len - 1); 210 ((char *)mv->mv_value)[mv->mv_len - 1] = '\0'; 211 break; 212 } 213 } 214 } 215 break; 216 case 's': 217 if (devo) 218 errx(1, "special specified inconsistently"); 219 devo = optarg; 220 break; 221 case 'm': 222 if (diro) 223 errx(1, "mount path specified inconsistently"); 224 diro = optarg; 225 break; 226 case 'v': 227 verbose = 1; 228 break; 229 case 'h': 230 helpmsg(); 231 break; 232 case 'V': 233 showversion(); 234 break; 235 case '\0': 236 break; 237 case '?': 238 default: 239 usage(); 240 } 241 if (done) 242 break; 243 } while ((ch = getopt_long(argc, argv, "AvVho:SD:O:s:m:", longopts, NULL)) != -1); 244 245 argc -= optind; 246 argv += optind; 247 248 if (devo) { 249 if (dev) 250 errx(1, "special specified inconsistently"); 251 dev = devo; 252 } else if (diro) 253 errx(1, "if mountpoint is given via an option, special should also be given via an option"); 254 255 if (diro) { 256 if (dir) 257 errx(1, "mount path specified inconsistently"); 258 dir = diro; 259 } 260 261 if ((! dev) && argc > 0) { 262 dev = *argv++; 263 argc--; 264 } 265 266 if ((! dir) && argc > 0) { 267 dir = *argv++; 268 argc--; 269 } 270 271 if (! (dev && dir)) 272 errx(1, "missing special and/or mountpoint"); 273 274 for (mo = mopts; mo->m_flag; ++mo) { 275 if (altflags & mo->m_flag) { 276 int iov_done = 0; 277 278 if (reject_allow_other && 279 strcmp(mo->m_option, "allow_other") == 0) 280 /* 281 * reject_allow_other is stronger than a 282 * negative of allow_other: if this is set, 283 * allow_other is blocked, period. 284 */ 285 errx(1, "\"allow_other\" usage is banned by respective option"); 286 287 for (mv = mvals; mv->mv_flag; ++mv) { 288 if (mo->m_flag != mv->mv_flag) 289 continue; 290 if (mv->mv_value) { 291 build_iovec(&iov, &iovlen, mo->m_option, mv->mv_value, mv->mv_len); 292 iov_done = 1; 293 break; 294 } 295 } 296 if (! iov_done) 297 build_iovec(&iov, &iovlen, mo->m_option, 298 __DECONST(void *, ""), -1); 299 } 300 if (__altflags & mo->m_flag) { 301 char *uscore_opt; 302 303 if (asprintf(&uscore_opt, "__%s", mo->m_option) == -1) 304 err(1, "failed to allocate memory"); 305 build_iovec(&iov, &iovlen, uscore_opt, 306 __DECONST(void *, ""), -1); 307 free(uscore_opt); 308 } 309 } 310 311 if (getenv("MOUNT_FUSEFS_SAFE")) 312 safe_level = 1; 313 314 if (safe_level > 0 && (argc > 0 || daemon_str || daemon_opts)) 315 errx(1, "safe mode, spawning daemon not allowed"); 316 317 if ((argc > 0 && (daemon_str || daemon_opts)) || 318 (daemon_opts && ! daemon_str)) 319 errx(1, "daemon specified inconsistently"); 320 321 /* 322 * Resolve the mountpoint with realpath(3) and remove unnecessary 323 * slashes from the devicename if there are any. 324 */ 325 if (checkpath(dir, mntpath) != 0) 326 err(1, "%s", mntpath); 327 (void)rmslashes(dev, dev); 328 329 if (strcmp(dev, "auto") == 0) 330 dev = __DECONST(char *, "/dev/fuse"); 331 332 if (strcmp(dev, "/dev/fuse") == 0) { 333 if (! (argc > 0 || daemon_str)) { 334 fprintf(stderr, "Please also specify the fuse daemon to run when mounting via the multiplexer!\n"); 335 usage(); 336 } 337 if ((fd = open(dev, O_RDWR)) < 0) 338 err(1, "failed to open fuse device"); 339 } else { 340 fdx = strtol(dev, &ep, 10); 341 if (*ep == '\0') 342 fd = fdx; 343 } 344 345 /* Identifying device */ 346 if (fd >= 0) { 347 struct stat sbuf; 348 char *ndevbas, *lep; 349 350 if (fstat(fd, &sbuf) == -1) 351 err(1, "cannot stat device file descriptor"); 352 353 strcpy(ndev, _PATH_DEV); 354 ndevbas = ndev + strlen(_PATH_DEV); 355 devname_r(sbuf.st_rdev, S_IFCHR, ndevbas, 356 sizeof(ndev) - strlen(_PATH_DEV)); 357 358 if (strncmp(ndevbas, "fuse", 4)) 359 errx(1, "mounting inappropriate device"); 360 361 strtol(ndevbas + 4, &lep, 10); 362 if (*lep != '\0') 363 errx(1, "mounting inappropriate device"); 364 365 dev = ndev; 366 } 367 368 if (argc > 0 || daemon_str) { 369 char *fds; 370 371 if (fd < 0 && (fd = open(dev, O_RDWR)) < 0) 372 err(1, "failed to open fuse device"); 373 374 if (asprintf(&fds, "%d", fd) == -1) 375 err(1, "failed to allocate memory"); 376 setenv("FUSE_DEV_FD", fds, 1); 377 free(fds); 378 setenv("FUSE_NO_MOUNT", "1", 1); 379 380 if (daemon_str) { 381 char *bgdaemon; 382 int len; 383 384 if (! daemon_opts) 385 daemon_opts = __DECONST(char *, ""); 386 387 len = strlen(daemon_str) + 1 + strlen(daemon_opts) + 388 2 + 1; 389 bgdaemon = calloc(1, len); 390 391 if (! bgdaemon) 392 err(1, "failed to allocate memory"); 393 394 strlcpy(bgdaemon, daemon_str, len); 395 strlcat(bgdaemon, " ", len); 396 strlcat(bgdaemon, daemon_opts, len); 397 strlcat(bgdaemon, " &", len); 398 399 if (system(bgdaemon)) 400 err(1, "failed to call fuse daemon"); 401 } else { 402 if ((pid = fork()) < 0) 403 err(1, "failed to fork for fuse daemon"); 404 405 if (pid == 0) { 406 execvp(argv[0], argv); 407 err(1, "failed to exec fuse daemon"); 408 } 409 } 410 } 411 412 if (fd >= 0 && ! init_backgrounded() && close(fd) < 0) { 413 if (pid) 414 kill(pid, SIGKILL); 415 err(1, "failed to close fuse device"); 416 } 417 418 /* Prepare the options vector for nmount(). build_iovec() is declared 419 * in mntopts.h. */ 420 sprintf(fdstr, "%d", fd); 421 build_iovec(&iov, &iovlen, "fstype", __DECONST(void *, "fusefs"), -1); 422 build_iovec(&iov, &iovlen, "fspath", mntpath, -1); 423 build_iovec(&iov, &iovlen, "from", dev, -1); 424 build_iovec(&iov, &iovlen, "fd", fdstr, -1); 425 426 if (verbose) 427 fprintf(stderr, "mounting fuse daemon on device %s\n", dev); 428 429 if (nmount(iov, iovlen, mntflags) < 0) 430 err(EX_OSERR, "%s on %s", dev, mntpath); 431 432 exit(0); 433 } 434 435 void 436 __usage_short(void) { 437 fprintf(stderr, 438 "usage:\n%s [-A|-S|-v|-V|-h|-D daemon|-O args|-s special|-m node|-o option...] special node [daemon args...]\n\n", 439 getprogname()); 440 } 441 442 void 443 usage(void) 444 { 445 struct mntopt *mo; 446 447 __usage_short(); 448 449 fprintf(stderr, "known options:\n"); 450 for (mo = mopts; mo->m_flag; ++mo) 451 fprintf(stderr, "\t%s\n", mo->m_option); 452 453 fprintf(stderr, "\n(use -h for a detailed description of these options)\n"); 454 exit(EX_USAGE); 455 } 456 457 void 458 helpmsg(void) 459 { 460 if (! getenv("MOUNT_FUSEFS_CALL_BY_LIB")) { 461 __usage_short(); 462 fprintf(stderr, "description of options:\n"); 463 } 464 465 /* 466 * The main use case of this function is giving info embedded in general 467 * FUSE lib help output. Therefore the style and the content of the output 468 * tries to fit there as much as possible. 469 */ 470 fprintf(stderr, 471 " -o allow_other allow access to other users\n" 472 /* " -o nonempty allow mounts over non-empty file/dir\n" */ 473 " -o default_permissions enable permission checking by kernel\n" 474 /* 475 " -o fsname=NAME set filesystem name\n" 476 " -o large_read issue large read requests (2.4 only)\n" 477 */ 478 " -o subtype=NAME set filesystem type\n" 479 " -o max_read=N set maximum size of read requests\n" 480 " -o noprivate allow secondary mounting of the filesystem\n" 481 " -o neglect_shares don't report EBUSY when unmount attempted\n" 482 " in presence of secondary mounts\n" 483 " -o push_symlinks_in prefix absolute symlinks with mountpoint\n" 484 " -o sync_unmount do unmount synchronously\n" 485 ); 486 exit(EX_USAGE); 487 } 488 489 void 490 showversion(void) 491 { 492 puts("mount_fusefs [fuse4bsd] version: " FUSE4BSD_VERSION); 493 exit(EX_USAGE); 494 } 495 496 int 497 init_backgrounded(void) 498 { 499 int ibg; 500 size_t len; 501 502 len = sizeof(ibg); 503 504 if (sysctlbyname("vfs.fuse.init_backgrounded", &ibg, &len, NULL, 0)) 505 return (0); 506 507 return (ibg); 508 } 509