1 /*- 2 * Copyright (c) 1980, 1989, 1993 3 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static const char copyright[] = 36 "@(#) Copyright (c) 1980, 1989, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)umount.c 8.8 (Berkeley) 5/8/95"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD$"; 46 #endif /* not lint */ 47 48 #include <sys/param.h> 49 #include <sys/mount.h> 50 #include <sys/socket.h> 51 52 #include <netdb.h> 53 #include <rpc/rpc.h> 54 #include <nfs/rpcv2.h> 55 56 #include <err.h> 57 #include <fstab.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "mounttab.h" 64 65 #define ISDOT(x) ((x)[0] == '.' && (x)[1] == '\0') 66 #define ISDOTDOT(x) ((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0') 67 68 typedef enum { MNTON, MNTFROM, NOTHING } mntwhat; 69 typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat; 70 71 struct mtablist *mtabhead; 72 struct addrinfo *nfshost_ai = NULL; 73 int fflag, vflag; 74 char *nfshost; 75 76 void checkmntlist (char *, char **, char **, char **); 77 int checkvfsname (const char *, char **); 78 char *getmntname (const char *, const char *, 79 mntwhat, char **, dowhat); 80 char *getrealname(char *, char *resolved_path); 81 char **makevfslist (const char *); 82 size_t mntinfo (struct statfs **); 83 int namematch (struct addrinfo *); 84 int sacmp (struct sockaddr *, struct sockaddr *); 85 int umountall (char **); 86 int checkname (char *, char **); 87 int umountfs (char *, char *, char *); 88 void usage (void); 89 int xdr_dir (XDR *, char *); 90 91 int 92 main(int argc, char *argv[]) 93 { 94 int all, errs, ch, mntsize, error; 95 char **typelist = NULL, *mntonname, *mntfromname; 96 char *type, *mntfromnamerev, *mntonnamerev; 97 struct statfs *mntbuf; 98 struct addrinfo hints; 99 100 /* Start disks transferring immediately. */ 101 sync(); 102 103 all = errs = 0; 104 while ((ch = getopt(argc, argv, "Aafh:t:v")) != -1) 105 switch (ch) { 106 case 'A': 107 all = 2; 108 break; 109 case 'a': 110 all = 1; 111 break; 112 case 'f': 113 fflag = MNT_FORCE; 114 break; 115 case 'h': /* -h implies -A. */ 116 all = 2; 117 nfshost = optarg; 118 break; 119 case 't': 120 if (typelist != NULL) 121 err(1, "only one -t option may be specified"); 122 typelist = makevfslist(optarg); 123 break; 124 case 'v': 125 vflag = 1; 126 break; 127 default: 128 usage(); 129 /* NOTREACHED */ 130 } 131 argc -= optind; 132 argv += optind; 133 134 if ((argc == 0 && !all) || (argc != 0 && all)) 135 usage(); 136 137 /* -h implies "-t nfs" if no -t flag. */ 138 if ((nfshost != NULL) && (typelist == NULL)) 139 typelist = makevfslist("nfs"); 140 141 if (nfshost != NULL) { 142 memset(&hints, 0, sizeof hints); 143 error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai); 144 if (error) { 145 fprintf(stderr, "ndp: %s: %s\n", nfshost, 146 gai_strerror(error)); 147 } 148 } 149 150 switch (all) { 151 case 2: 152 if ((mntsize = mntinfo(&mntbuf)) <= 0) 153 break; 154 /* 155 * We unmount the nfs-mounts in the reverse order 156 * that they were mounted. 157 */ 158 for (errs = 0, mntsize--; mntsize > 0; mntsize--) { 159 if (checkvfsname(mntbuf[mntsize].f_fstypename, 160 typelist)) 161 continue; 162 /* 163 * Check if a mountpoint is laid over by another mount. 164 * A warning will be printed to stderr if this is 165 * the case. The laid over mount remains unmounted. 166 */ 167 mntonname = mntbuf[mntsize].f_mntonname; 168 mntfromname = mntbuf[mntsize].f_mntfromname; 169 mntonnamerev = getmntname(getmntname(mntonname, 170 NULL, MNTFROM, &type, NAME), NULL, 171 MNTON, &type, NAME); 172 173 mntfromnamerev = getmntname(mntonnamerev, 174 NULL, MNTFROM, &type, NAME); 175 176 if (strcmp(mntonnamerev, mntonname) == 0 && 177 strcmp(mntfromnamerev, mntfromname ) != 0) 178 warnx("cannot umount %s, %s\n " 179 "is mounted there, umount it first", 180 mntonname, mntfromnamerev); 181 182 if (checkname(mntbuf[mntsize].f_mntonname, 183 typelist) != 0) 184 errs = 1; 185 } 186 free(mntbuf); 187 break; 188 case 1: 189 if (setfsent() == 0) 190 err(1, "%s", _PATH_FSTAB); 191 errs = umountall(typelist); 192 break; 193 case 0: 194 for (errs = 0; *argv != NULL; ++argv) 195 if (checkname(*argv, typelist) != 0) 196 errs = 1; 197 break; 198 } 199 (void)getmntname(NULL, NULL, NOTHING, NULL, FREE); 200 exit(errs); 201 } 202 203 int 204 umountall(char **typelist) 205 { 206 struct vfsconf vfc; 207 struct fstab *fs; 208 int rval; 209 char *cp; 210 static int firstcall = 1; 211 212 if ((fs = getfsent()) != NULL) 213 firstcall = 0; 214 else if (firstcall) 215 errx(1, "fstab reading failure"); 216 else 217 return (0); 218 do { 219 /* Ignore the root. */ 220 if (strcmp(fs->fs_file, "/") == 0) 221 continue; 222 /* 223 * !!! 224 * Historic practice: ignore unknown FSTAB_* fields. 225 */ 226 if (strcmp(fs->fs_type, FSTAB_RW) && 227 strcmp(fs->fs_type, FSTAB_RO) && 228 strcmp(fs->fs_type, FSTAB_RQ)) 229 continue; 230 /* Ignore unknown file system types. */ 231 if (getvfsbyname(fs->fs_vfstype, &vfc) == -1) 232 continue; 233 if (checkvfsname(fs->fs_vfstype, typelist)) 234 continue; 235 236 /* 237 * We want to unmount the file systems in the reverse order 238 * that they were mounted. So, we save off the file name 239 * in some allocated memory, and then call recursively. 240 */ 241 if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL) 242 err(1, "malloc failed"); 243 (void)strcpy(cp, fs->fs_file); 244 rval = umountall(typelist); 245 rval = checkname(cp, typelist) || rval; 246 free(cp); 247 return (rval); 248 } while ((fs = getfsent()) != NULL); 249 return (0); 250 } 251 252 /* 253 * Do magic checks on mountpoint and device or hand over 254 * it to unmount(2) if everything fails. 255 */ 256 int 257 checkname(char *name, char **typelist) 258 { 259 size_t len; 260 int speclen; 261 char *mntonname, *mntfromname; 262 char *mntfromnamerev; 263 char *resolved, realname[MAXPATHLEN]; 264 char *type, *hostp, *delimp, *origname; 265 266 len = 0; 267 mntfromname = mntonname = delimp = hostp = NULL; 268 269 /* 270 * 1. Check if the name exists in the mounttable. 271 */ 272 (void)checkmntlist(name, &mntfromname, &mntonname, &type); 273 /* 274 * 2. Remove trailing slashes if there are any. After that 275 * we look up the name in the mounttable again. 276 */ 277 if (mntfromname == NULL && mntonname == NULL) { 278 speclen = strlen(name); 279 for (speclen = strlen(name); 280 speclen > 1 && name[speclen - 1] == '/'; 281 speclen--) 282 name[speclen - 1] = '\0'; 283 (void)checkmntlist(name, &mntfromname, &mntonname, &type); 284 resolved = name; 285 /* Save off original name in origname */ 286 if ((origname = strdup(name)) == NULL) 287 err(1, "strdup"); 288 /* 289 * 3. Check if the deprecated nfs-syntax with an '@' 290 * has been used and translate it to the ':' syntax. 291 * Look up the name in the mounttable again. 292 */ 293 if (mntfromname == NULL && mntonname == NULL) { 294 if ((delimp = strrchr(name, '@')) != NULL) { 295 hostp = delimp + 1; 296 if (*hostp != '\0') { 297 /* 298 * Make both '@' and ':' 299 * notations equal 300 */ 301 char *host = strdup(hostp); 302 len = strlen(hostp); 303 if (host == NULL) 304 err(1, "strdup"); 305 memmove(name + len + 1, name, 306 (size_t)(delimp - name)); 307 name[len] = ':'; 308 memmove(name, host, len); 309 free(host); 310 } 311 for (speclen = strlen(name); 312 speclen > 1 && name[speclen - 1] == '/'; 313 speclen--) 314 name[speclen - 1] = '\0'; 315 name[len + speclen + 1] = '\0'; 316 (void)checkmntlist(name, &mntfromname, 317 &mntonname, &type); 318 resolved = name; 319 } 320 /* 321 * 4. Check if a relative mountpoint has been 322 * specified. This should happen as last check, 323 * the order is important. To prevent possible 324 * nfs-hangs, we just call realpath(3) on the 325 * basedir of mountpoint and add the dirname again. 326 * Check the name in mounttable one last time. 327 */ 328 if (mntfromname == NULL && mntonname == NULL) { 329 (void)strcpy(name, origname); 330 if ((getrealname(name, realname)) != NULL) { 331 (void)checkmntlist(realname, 332 &mntfromname, &mntonname, &type); 333 resolved = realname; 334 } 335 /* 336 * 5. All tests failed, just hand over the 337 * mountpoint to the kernel, maybe the statfs 338 * structure has been truncated or is not 339 * useful anymore because of a chroot(2). 340 * Please note that nfs will not be able to 341 * notify the nfs-server about unmounting. 342 * These things can change in future when the 343 * fstat structure get's more reliable, 344 * but at the moment we cannot thrust it. 345 */ 346 if (mntfromname == NULL && mntonname == NULL) { 347 (void)strcpy(name, origname); 348 if (umountfs(NULL, origname, 349 "none") == 0) {; 350 warnx("%s not found in " 351 "mount table, " 352 "unmounted it anyway", 353 origname); 354 free(origname); 355 return (0); 356 } else 357 free(origname); 358 return (1); 359 } 360 } 361 } 362 free(origname); 363 } else 364 resolved = name; 365 366 if (checkvfsname(type, typelist)) 367 return (1); 368 369 /* 370 * Check if the reverse entrys of the mounttable are really the 371 * same as the normal ones. 372 */ 373 if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname, 374 NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL) 375 err(1, "strdup"); 376 /* 377 * Mark the uppermost mount as unmounted. 378 */ 379 (void)getmntname(mntfromname, mntonname, NOTHING, &type, MARK); 380 /* 381 * If several equal mounts are in the mounttable, check the order 382 * and warn the user if necessary. 383 */ 384 if (strcmp(mntfromnamerev, mntfromname ) != 0 && 385 strcmp(resolved, mntonname) != 0) { 386 warnx("cannot umount %s, %s\n " 387 "is mounted there, umount it first", 388 mntonname, mntfromnamerev); 389 390 /* call getmntname again to set mntcheck[i] to 0 */ 391 (void)getmntname(mntfromname, mntonname, 392 NOTHING, &type, UNMARK); 393 return (1); 394 } 395 free(mntfromnamerev); 396 umountfs(mntfromname, mntonname, type); 397 } 398 399 /* 400 * NFS stuff and unmount(2) call 401 */ 402 int 403 umountfs(char *mntfromname, char *mntonname, char *type) 404 { 405 enum clnt_stat clnt_stat; 406 struct timeval try; 407 struct mtablist *mtab; 408 struct addrinfo *ai, hints; 409 int do_rpc; 410 CLIENT *clp; 411 char *nfsdirname, *orignfsdirname; 412 char *hostp, *delimp; 413 414 mtab = NULL; 415 ai = NULL; 416 nfsdirname = delimp = orignfsdirname = NULL; 417 memset(&hints, 0, sizeof hints); 418 419 if (!strcmp(type, "nfs")) { 420 if ((nfsdirname = strdup(mntfromname)) == NULL) 421 err(1, "strdup"); 422 orignfsdirname = nfsdirname; 423 if ((delimp = strrchr(nfsdirname, ':')) != NULL) { 424 *delimp = '\0'; 425 hostp = nfsdirname; 426 getaddrinfo(hostp, NULL, &hints, &ai); 427 if (ai == NULL) { 428 warnx("can't get net id for host"); 429 } 430 nfsdirname = delimp + 1; 431 } 432 } 433 /* 434 * Check if we have to start the rpc-call later. 435 * If there are still identical nfs-names mounted, 436 * we skip the rpc-call. Obviously this has to 437 * happen before unmount(2), but it should happen 438 * after the previous namecheck. 439 */ 440 if (strcmp(type, "nfs") == 0 && getmntname(mntfromname, NULL, NOTHING, 441 &type, COUNT) != NULL) 442 do_rpc = 1; 443 else 444 do_rpc = 0; 445 446 if (!namematch(ai)) 447 return (1); 448 if (unmount(mntonname, fflag) != 0 ) { 449 warn("unmount of %s failed", mntonname); 450 return (1); 451 } 452 if (vflag) 453 (void)printf("%s: unmount from %s\n", mntfromname, mntonname); 454 /* 455 * Report to mountd-server which nfsname 456 * has been unmounted. 457 */ 458 if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) { 459 clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp"); 460 if (clp == NULL) { 461 clnt_pcreateerror("Cannot MNT PRC"); 462 return (1); 463 } 464 clp->cl_auth = authsys_create_default(); 465 try.tv_sec = 20; 466 try.tv_usec = 0; 467 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, xdr_dir, 468 nfsdirname, xdr_void, (caddr_t)0, try); 469 if (clnt_stat != RPC_SUCCESS) { 470 clnt_perror(clp, "Bad MNT RPC"); 471 return (1); 472 } 473 /* 474 * Remove the unmounted entry from /var/db/mounttab. 475 */ 476 if (read_mtab(mtab)) { 477 mtab = mtabhead; 478 clean_mtab(hostp, nfsdirname); 479 if(!write_mtab()) 480 warnx("cannot remove entry %s:%s", 481 hostp, nfsdirname); 482 free_mtab(); 483 } 484 free(orignfsdirname); 485 auth_destroy(clp->cl_auth); 486 clnt_destroy(clp); 487 } 488 return (0); 489 } 490 491 char * 492 getmntname(const char *fromname, const char *onname, 493 mntwhat what, char **type, dowhat mark) 494 { 495 static struct statfs *mntbuf; 496 static size_t mntsize = 0; 497 static char *mntcheck = NULL; 498 static char *mntcount = NULL; 499 int i, count; 500 501 if (mntsize <= 0) { 502 if ((mntsize = mntinfo(&mntbuf)) <= 0) 503 return (NULL); 504 } 505 if (mntcheck == NULL) { 506 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL || 507 (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL) 508 err(1, "calloc"); 509 } 510 /* 511 * We want to get the file systems in the reverse order 512 * that they were mounted. Mounted and unmounted filesystems 513 * are marked or unmarked in a table called 'mntcheck'. 514 * Unmount(const char *dir, int flags) does only take the 515 * mountpoint as argument, not the destination. If we don't pay 516 * attention to the order, it can happen that a overlaying 517 * filesystem get's unmounted instead of the one the user 518 * has choosen. 519 */ 520 switch (mark) { 521 case NAME: 522 /* Return only the specific name */ 523 for (i = mntsize - 1; i >= 0; i--) { 524 if (fromname != NULL && what == MNTON && 525 !strcmp(mntbuf[i].f_mntfromname, fromname) && 526 mntcheck[i] != 1) { 527 if (type) 528 *type = mntbuf[i].f_fstypename; 529 return (mntbuf[i].f_mntonname); 530 } 531 if (fromname != NULL && what == MNTFROM && 532 !strcmp(mntbuf[i].f_mntonname, fromname) && 533 mntcheck[i] != 1) { 534 if (type) 535 *type = mntbuf[i].f_fstypename; 536 return (mntbuf[i].f_mntfromname); 537 } 538 } 539 return (NULL); 540 case MARK: 541 /* Mark current mount with '1' and return name */ 542 for (i = mntsize - 1; i >= 0; i--) { 543 if (mntcheck[i] == 0 && 544 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 545 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 546 mntcheck[i] = 1; 547 return (mntbuf[i].f_mntonname); 548 } 549 } 550 return (NULL); 551 case UNMARK: 552 /* Unmark current mount with '0' and return name */ 553 for (i = 0; i < mntsize; i++) { 554 if (mntcheck[i] == 1 && 555 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 556 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 557 mntcheck[i] = 0; 558 return (mntbuf[i].f_mntonname); 559 } 560 } 561 return (NULL); 562 case COUNT: 563 /* Count the equal mntfromnames */ 564 count = 0; 565 for (i = mntsize - 1; i >= 0; i--) { 566 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) 567 count++; 568 } 569 /* Mark the already unmounted mounts and return 570 * mntfromname if count <= 1. Else return NULL. 571 */ 572 for (i = mntsize - 1; i >= 0; i--) { 573 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) { 574 if (mntcount[i] == 1) 575 count--; 576 else { 577 mntcount[i] = 1; 578 break; 579 } 580 } 581 } 582 if (count <= 1) 583 return (mntbuf[i].f_mntonname); 584 else 585 return (NULL); 586 case FREE: 587 free(mntbuf); 588 free(mntcheck); 589 free(mntcount); 590 return (NULL); 591 default: 592 return (NULL); 593 } 594 } 595 596 int 597 sacmp(struct sockaddr *sa1, struct sockaddr *sa2) 598 { 599 void *p1, *p2; 600 int len; 601 602 if (sa1->sa_family != sa2->sa_family) 603 return (1); 604 605 switch (sa1->sa_family) { 606 case AF_INET: 607 p1 = &((struct sockaddr_in *)sa1)->sin_addr; 608 p2 = &((struct sockaddr_in *)sa2)->sin_addr; 609 len = 4; 610 break; 611 case AF_INET6: 612 p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr; 613 p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr; 614 len = 16; 615 if (((struct sockaddr_in6 *)sa1)->sin6_scope_id != 616 ((struct sockaddr_in6 *)sa2)->sin6_scope_id) 617 return (1); 618 break; 619 default: 620 return (1); 621 } 622 623 return memcmp(p1, p2, len); 624 } 625 626 int 627 namematch(struct addrinfo *ai) 628 { 629 struct addrinfo *aip; 630 631 if (nfshost == NULL || nfshost_ai == NULL) 632 return (1); 633 634 while (ai != NULL) { 635 aip = nfshost_ai; 636 while (aip != NULL) { 637 if (sacmp(ai->ai_addr, aip->ai_addr) == 0) 638 return (1); 639 aip = aip->ai_next; 640 } 641 ai = ai->ai_next; 642 } 643 644 return (0); 645 } 646 647 void 648 checkmntlist(char *name, char **fromname, char **onname, char **type) 649 { 650 651 *fromname = getmntname(name, NULL, MNTFROM, type, NAME); 652 if (*fromname == NULL) { 653 *onname = getmntname(name, NULL, MNTON, type, NAME); 654 if (*onname != NULL) 655 *fromname = name; 656 } else 657 *onname = name; 658 } 659 660 size_t 661 mntinfo(struct statfs **mntbuf) 662 { 663 static struct statfs *origbuf; 664 size_t bufsize; 665 int mntsize; 666 667 mntsize = getfsstat(NULL, 0, MNT_NOWAIT); 668 if (mntsize <= 0) 669 return (0); 670 bufsize = (mntsize + 1) * sizeof(struct statfs); 671 if ((origbuf = malloc(bufsize)) == NULL) 672 err(1, "malloc"); 673 mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT); 674 *mntbuf = origbuf; 675 return (mntsize); 676 } 677 678 char * 679 getrealname(char *name, char *realname) 680 { 681 char *dirname; 682 int havedir; 683 size_t baselen; 684 size_t dirlen; 685 686 dirname = '\0'; 687 havedir = 0; 688 if (*name == '/') { 689 if (ISDOT(name + 1) || ISDOTDOT(name + 1)) 690 strcpy(realname, "/"); 691 else { 692 if ((dirname = strrchr(name + 1, '/')) == NULL) 693 snprintf(realname, MAXPATHLEN, "%s", name); 694 else 695 havedir = 1; 696 } 697 } else { 698 if (ISDOT(name) || ISDOTDOT(name)) 699 (void)realpath(name, realname); 700 else { 701 if ((dirname = strrchr(name, '/')) == NULL) { 702 if ((realpath(name, realname)) == NULL) 703 return (NULL); 704 } else 705 havedir = 1; 706 } 707 } 708 if (havedir) { 709 *dirname++ = '\0'; 710 if (ISDOT(dirname)) { 711 *dirname = '\0'; 712 if ((realpath(name, realname)) == NULL) 713 return (NULL); 714 } else if (ISDOTDOT(dirname)) { 715 *--dirname = '/'; 716 if ((realpath(name, realname)) == NULL) 717 return (NULL); 718 } else { 719 if ((realpath(name, realname)) == NULL) 720 return (NULL); 721 baselen = strlen(realname); 722 dirlen = strlen(dirname); 723 if (baselen + dirlen + 1 > MAXPATHLEN) 724 return (NULL); 725 if (realname[1] == '\0') { 726 memmove(realname + 1, dirname, dirlen); 727 realname[dirlen + 1] = '\0'; 728 } else { 729 realname[baselen] = '/'; 730 memmove(realname + baselen + 1, 731 dirname, dirlen); 732 realname[baselen + dirlen + 1] = '\0'; 733 } 734 } 735 } 736 return (realname); 737 } 738 739 /* 740 * xdr routines for mount rpc's 741 */ 742 int 743 xdr_dir(XDR *xdrsp, char *dirp) 744 { 745 746 return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN)); 747 } 748 749 void 750 usage() 751 { 752 753 (void)fprintf(stderr, "%s\n%s\n", 754 "usage: umount [-fv] special | node", 755 " umount -a | -A [-fv] [-h host] [-t type]"); 756 exit(1); 757 } 758