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 * @(#) Copyright (c) 1980, 1989, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)umount.c 8.8 (Berkeley) 5/8/95 35 * $FreeBSD: src/sbin/umount/umount.c,v 1.28 2001/10/13 02:04:54 iedowse Exp $ 36 * $DragonFly: src/sbin/umount/umount.c,v 1.4 2005/11/06 12:51:01 swildner Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/mount.h> 41 #include <sys/socket.h> 42 43 #include <netdb.h> 44 #include <rpc/rpc.h> 45 #include <nfs/rpcv2.h> 46 47 #include <err.h> 48 #include <fstab.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "mounttab.h" 55 56 #define ISDOT(x) ((x)[0] == '.' && (x)[1] == '\0') 57 #define ISDOTDOT(x) ((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0') 58 59 typedef enum { MNTON, MNTFROM, NOTHING } mntwhat; 60 typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat; 61 62 struct addrinfo *nfshost_ai = NULL; 63 int fflag, vflag; 64 char *nfshost; 65 66 void checkmntlist (char *, char **, char **, char **); 67 int checkvfsname (const char *, char **); 68 char *getmntname (const char *, const char *, 69 mntwhat, char **, dowhat); 70 char *getrealname(char *, char *resolved_path); 71 char **makevfslist (const char *); 72 int mntinfo (struct statfs **); 73 int namematch (struct addrinfo *); 74 int sacmp (struct sockaddr *, struct sockaddr *); 75 int umountall (char **); 76 int checkname (char *, char **); 77 int umountfs (char *, char *, char *); 78 void usage (void); 79 int xdr_dir (XDR *, char *); 80 81 int 82 main(int argc, char *argv[]) 83 { 84 int all, errs, ch, mntsize, error; 85 char **typelist = NULL, *mntonname, *mntfromname; 86 char *type, *mntfromnamerev, *mntonnamerev; 87 struct statfs *mntbuf; 88 struct addrinfo hints; 89 90 /* Start disks transferring immediately. */ 91 sync(); 92 93 all = errs = 0; 94 while ((ch = getopt(argc, argv, "Aafh:t:v")) != -1) 95 switch (ch) { 96 case 'A': 97 all = 2; 98 break; 99 case 'a': 100 all = 1; 101 break; 102 case 'f': 103 fflag = MNT_FORCE; 104 break; 105 case 'h': /* -h implies -A. */ 106 all = 2; 107 nfshost = optarg; 108 break; 109 case 't': 110 if (typelist != NULL) 111 err(1, "only one -t option may be specified"); 112 typelist = makevfslist(optarg); 113 break; 114 case 'v': 115 vflag = 1; 116 break; 117 default: 118 usage(); 119 /* NOTREACHED */ 120 } 121 argc -= optind; 122 argv += optind; 123 124 if ((argc == 0 && !all) || (argc != 0 && all)) 125 usage(); 126 127 /* -h implies "-t nfs" if no -t flag. */ 128 if ((nfshost != NULL) && (typelist == NULL)) 129 typelist = makevfslist("nfs"); 130 131 if (nfshost != NULL) { 132 memset(&hints, 0, sizeof hints); 133 error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai); 134 if (error) 135 errx(1, "%s: %s", nfshost, gai_strerror(error)); 136 } 137 138 switch (all) { 139 case 2: 140 if ((mntsize = mntinfo(&mntbuf)) <= 0) 141 break; 142 /* 143 * We unmount the nfs-mounts in the reverse order 144 * that they were mounted. 145 */ 146 for (errs = 0, mntsize--; mntsize > 0; mntsize--) { 147 if (checkvfsname(mntbuf[mntsize].f_fstypename, 148 typelist)) 149 continue; 150 /* 151 * Check if a mountpoint is laid over by another mount. 152 * A warning will be printed to stderr if this is 153 * the case. The laid over mount remains unmounted. 154 */ 155 mntonname = mntbuf[mntsize].f_mntonname; 156 mntfromname = mntbuf[mntsize].f_mntfromname; 157 mntonnamerev = getmntname(getmntname(mntonname, 158 NULL, MNTFROM, &type, NAME), NULL, 159 MNTON, &type, NAME); 160 161 mntfromnamerev = getmntname(mntonnamerev, 162 NULL, MNTFROM, &type, NAME); 163 164 if (strcmp(mntonnamerev, mntonname) == 0 && 165 strcmp(mntfromnamerev, mntfromname ) != 0) 166 warnx("cannot umount %s, %s\n " 167 "is mounted there, umount it first", 168 mntonname, mntfromnamerev); 169 170 if (checkname(mntbuf[mntsize].f_mntonname, 171 typelist) != 0) 172 errs = 1; 173 } 174 free(mntbuf); 175 break; 176 case 1: 177 if (setfsent() == 0) 178 err(1, "%s", _PATH_FSTAB); 179 errs = umountall(typelist); 180 break; 181 case 0: 182 for (errs = 0; *argv != NULL; ++argv) 183 if (checkname(*argv, typelist) != 0) 184 errs = 1; 185 break; 186 } 187 getmntname(NULL, NULL, NOTHING, NULL, FREE); 188 exit(errs); 189 } 190 191 int 192 umountall(char **typelist) 193 { 194 struct vfsconf vfc; 195 struct fstab *fs; 196 int rval; 197 char *cp; 198 static int firstcall = 1; 199 200 if ((fs = getfsent()) != NULL) 201 firstcall = 0; 202 else if (firstcall) 203 errx(1, "fstab reading failure"); 204 else 205 return (0); 206 do { 207 /* Ignore the root. */ 208 if (strcmp(fs->fs_file, "/") == 0) 209 continue; 210 /* 211 * !!! 212 * Historic practice: ignore unknown FSTAB_* fields. 213 */ 214 if (strcmp(fs->fs_type, FSTAB_RW) && 215 strcmp(fs->fs_type, FSTAB_RO) && 216 strcmp(fs->fs_type, FSTAB_RQ)) 217 continue; 218 /* Ignore unknown file system types. */ 219 if (getvfsbyname(fs->fs_vfstype, &vfc) == -1) 220 continue; 221 if (checkvfsname(fs->fs_vfstype, typelist)) 222 continue; 223 224 /* 225 * We want to unmount the file systems in the reverse order 226 * that they were mounted. So, we save off the file name 227 * in some allocated memory, and then call recursively. 228 */ 229 if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL) 230 err(1, "malloc failed"); 231 strcpy(cp, fs->fs_file); 232 rval = umountall(typelist); 233 rval = checkname(cp, typelist) || rval; 234 free(cp); 235 return (rval); 236 } while ((fs = getfsent()) != NULL); 237 return (0); 238 } 239 240 /* 241 * Do magic checks on mountpoint and device or hand over 242 * it to unmount(2) if everything fails. 243 */ 244 int 245 checkname(char *name, char **typelist) 246 { 247 size_t len; 248 int speclen; 249 char *mntonname, *mntfromname; 250 char *mntfromnamerev; 251 char *resolved, realname[MAXPATHLEN]; 252 char *type, *hostp, *delimp, *origname; 253 char none[] = "none"; 254 255 len = 0; 256 mntfromname = mntonname = delimp = hostp = NULL; 257 258 /* 259 * 1. Check if the name exists in the mounttable. 260 */ 261 checkmntlist(name, &mntfromname, &mntonname, &type); 262 if (mntfromname == NULL && mntonname == NULL) { 263 checkmntlist(getdevpath(name, 0), &mntfromname, 264 &mntonname, &type); 265 } 266 267 /* 268 * 2. Remove trailing slashes if there are any. After that 269 * we look up the name in the mounttable again. 270 */ 271 if (mntfromname == NULL && mntonname == NULL) { 272 speclen = strlen(name); 273 for (speclen = strlen(name); 274 speclen > 1 && name[speclen - 1] == '/'; 275 speclen--) 276 name[speclen - 1] = '\0'; 277 checkmntlist(name, &mntfromname, &mntonname, &type); 278 resolved = name; 279 /* Save off original name in origname */ 280 if ((origname = strdup(name)) == NULL) 281 err(1, "strdup"); 282 /* 283 * 3. Check if the deprecated nfs-syntax with an '@' 284 * has been used and translate it to the ':' syntax. 285 * Look up the name in the mounttable again. 286 */ 287 if (mntfromname == NULL && mntonname == NULL) { 288 if ((delimp = strrchr(name, '@')) != NULL) { 289 hostp = delimp + 1; 290 if (*hostp != '\0') { 291 /* 292 * Make both '@' and ':' 293 * notations equal 294 */ 295 char *host = strdup(hostp); 296 len = strlen(hostp); 297 if (host == NULL) 298 err(1, "strdup"); 299 memmove(name + len + 1, name, 300 (size_t)(delimp - name)); 301 name[len] = ':'; 302 memmove(name, host, len); 303 free(host); 304 } 305 for (speclen = strlen(name); 306 speclen > 1 && name[speclen - 1] == '/'; 307 speclen--) 308 name[speclen - 1] = '\0'; 309 name[len + speclen + 1] = '\0'; 310 checkmntlist(name, &mntfromname, 311 &mntonname, &type); 312 resolved = name; 313 } 314 /* 315 * 4. Check if a relative mountpoint has been 316 * specified. This should happen as last check, 317 * the order is important. To prevent possible 318 * nfs-hangs, we just call realpath(3) on the 319 * basedir of mountpoint and add the dirname again. 320 * Check the name in mounttable one last time. 321 */ 322 if (mntfromname == NULL && mntonname == NULL) { 323 strcpy(name, origname); 324 if ((getrealname(name, realname)) != NULL) { 325 checkmntlist(realname, 326 &mntfromname, &mntonname, &type); 327 resolved = realname; 328 } 329 /* 330 * 5. All tests failed, just hand over the 331 * mountpoint to the kernel, maybe the statfs 332 * structure has been truncated or is not 333 * useful anymore because of a chroot(2). 334 * Please note that nfs will not be able to 335 * notify the nfs-server about unmounting. 336 * These things can change in future when the 337 * fstat structure get's more reliable, 338 * but at the moment we cannot thrust it. 339 */ 340 if (mntfromname == NULL && mntonname == NULL) { 341 strcpy(name, origname); 342 if (umountfs(NULL, origname, 343 none) == 0) {; 344 warnx("%s not found in " 345 "mount table, " 346 "unmounted it anyway", 347 origname); 348 free(origname); 349 return (0); 350 } else 351 free(origname); 352 return (1); 353 } 354 } 355 } 356 free(origname); 357 } else 358 resolved = name; 359 360 if (checkvfsname(type, typelist)) 361 return (1); 362 363 /* 364 * Check if the reverse entrys of the mounttable are really the 365 * same as the normal ones. 366 */ 367 if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname, 368 NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL) 369 err(1, "strdup"); 370 /* 371 * Mark the uppermost mount as unmounted. 372 */ 373 getmntname(mntfromname, mntonname, NOTHING, &type, MARK); 374 /* 375 * If several equal mounts are in the mounttable, check the order 376 * and warn the user if necessary. 377 */ 378 if (strcmp(mntfromnamerev, mntfromname ) != 0 && 379 strcmp(resolved, mntonname) != 0) { 380 warnx("cannot umount %s, %s\n " 381 "is mounted there, umount it first", 382 mntonname, mntfromnamerev); 383 384 /* call getmntname again to set mntcheck[i] to 0 */ 385 getmntname(mntfromname, mntonname, 386 NOTHING, &type, UNMARK); 387 return (1); 388 } 389 free(mntfromnamerev); 390 return (umountfs(mntfromname, mntonname, type)); 391 } 392 393 /* 394 * NFS stuff and unmount(2) call 395 */ 396 int 397 umountfs(char *mntfromname, char *mntonname, char *type) 398 { 399 enum clnt_stat clnt_stat; 400 struct timeval try; 401 struct addrinfo *ai, hints; 402 int do_rpc; 403 CLIENT *clp; 404 char *nfsdirname, *orignfsdirname; 405 char *hostp, *delimp; 406 407 ai = NULL; 408 do_rpc = 0; 409 hostp = NULL; 410 nfsdirname = delimp = orignfsdirname = NULL; 411 memset(&hints, 0, sizeof hints); 412 413 if (strcmp(type, "nfs") == 0) { 414 if ((nfsdirname = strdup(mntfromname)) == NULL) 415 err(1, "strdup"); 416 orignfsdirname = nfsdirname; 417 if ((delimp = strrchr(nfsdirname, ':')) != NULL) { 418 *delimp = '\0'; 419 hostp = nfsdirname; 420 getaddrinfo(hostp, NULL, &hints, &ai); 421 if (ai == NULL) { 422 warnx("can't get net id for host"); 423 } 424 nfsdirname = delimp + 1; 425 } 426 427 /* 428 * Check if we have to start the rpc-call later. 429 * If there are still identical nfs-names mounted, 430 * we skip the rpc-call. Obviously this has to 431 * happen before unmount(2), but it should happen 432 * after the previous namecheck. 433 * A non-NULL return means that this is the last 434 * mount from mntfromname that is still mounted. 435 */ 436 if (getmntname(mntfromname, NULL, NOTHING, &type, COUNT) 437 != NULL) 438 do_rpc = 1; 439 } 440 441 if (!namematch(ai)) 442 return (1); 443 if (unmount(mntonname, fflag) != 0 ) { 444 warn("unmount of %s failed", mntonname); 445 return (1); 446 } 447 if (vflag) 448 printf("%s: unmount from %s\n", mntfromname, mntonname); 449 /* 450 * Report to mountd-server which nfsname 451 * has been unmounted. 452 */ 453 if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) { 454 clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp"); 455 if (clp == NULL) { 456 warnx("%s: %s", hostp, 457 clnt_spcreateerror("RPCPROG_MNT")); 458 return (1); 459 } 460 clp->cl_auth = authsys_create_default(); 461 try.tv_sec = 20; 462 try.tv_usec = 0; 463 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir, 464 nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try); 465 if (clnt_stat != RPC_SUCCESS) { 466 warnx("%s: %s", hostp, 467 clnt_sperror(clp, "RPCMNT_UMOUNT")); 468 return (1); 469 } 470 /* 471 * Remove the unmounted entry from /var/db/mounttab. 472 */ 473 if (read_mtab()) { 474 clean_mtab(hostp, nfsdirname, vflag); 475 if(!write_mtab(vflag)) 476 warnx("cannot remove mounttab entry %s:%s", 477 hostp, nfsdirname); 478 free_mtab(); 479 } 480 free(orignfsdirname); 481 auth_destroy(clp->cl_auth); 482 clnt_destroy(clp); 483 } 484 return (0); 485 } 486 487 char * 488 getmntname(const char *fromname, const char *onname, 489 mntwhat what, char **type, dowhat mark) 490 { 491 static struct statfs *mntbuf; 492 static int mntsize = 0; 493 static char *mntcheck = NULL; 494 static char *mntcount = NULL; 495 int i, count; 496 497 if (mntsize <= 0) { 498 if ((mntsize = mntinfo(&mntbuf)) <= 0) 499 return (NULL); 500 } 501 if (mntcheck == NULL) { 502 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL || 503 (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL) 504 err(1, "calloc"); 505 } 506 /* 507 * We want to get the file systems in the reverse order 508 * that they were mounted. Mounted and unmounted filesystems 509 * are marked or unmarked in a table called 'mntcheck'. 510 * Unmount(const char *dir, int flags) does only take the 511 * mountpoint as argument, not the destination. If we don't pay 512 * attention to the order, it can happen that a overlaying 513 * filesystem get's unmounted instead of the one the user 514 * has choosen. 515 */ 516 switch (mark) { 517 case NAME: 518 /* Return only the specific name */ 519 for (i = mntsize - 1; i >= 0; i--) { 520 if (fromname != NULL && what == MNTON && 521 !strcmp(mntbuf[i].f_mntfromname, fromname) && 522 mntcheck[i] != 1) { 523 if (type) 524 *type = mntbuf[i].f_fstypename; 525 return (mntbuf[i].f_mntonname); 526 } 527 if (fromname != NULL && what == MNTFROM && 528 !strcmp(mntbuf[i].f_mntonname, fromname) && 529 mntcheck[i] != 1) { 530 if (type) 531 *type = mntbuf[i].f_fstypename; 532 return (mntbuf[i].f_mntfromname); 533 } 534 } 535 return (NULL); 536 case MARK: 537 /* Mark current mount with '1' and return name */ 538 for (i = mntsize - 1; i >= 0; i--) { 539 if (mntcheck[i] == 0 && 540 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 541 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 542 mntcheck[i] = 1; 543 return (mntbuf[i].f_mntonname); 544 } 545 } 546 return (NULL); 547 case UNMARK: 548 /* Unmark current mount with '0' and return name */ 549 for (i = 0; i < mntsize; i++) { 550 if (mntcheck[i] == 1 && 551 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 552 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 553 mntcheck[i] = 0; 554 return (mntbuf[i].f_mntonname); 555 } 556 } 557 return (NULL); 558 case COUNT: 559 /* Count the equal mntfromnames */ 560 count = 0; 561 for (i = mntsize - 1; i >= 0; i--) { 562 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) 563 count++; 564 } 565 /* Mark the already unmounted mounts and return 566 * mntfromname if count <= 1. Else return NULL. 567 */ 568 for (i = mntsize - 1; i >= 0; i--) { 569 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) { 570 if (mntcount[i] == 1) 571 count--; 572 else { 573 mntcount[i] = 1; 574 break; 575 } 576 } 577 } 578 if (count <= 1) 579 return (mntbuf[i].f_mntonname); 580 else 581 return (NULL); 582 case FREE: 583 free(mntbuf); 584 free(mntcheck); 585 free(mntcount); 586 return (NULL); 587 default: 588 return (NULL); 589 } 590 } 591 592 int 593 sacmp(struct sockaddr *sa1, struct sockaddr *sa2) 594 { 595 void *p1, *p2; 596 int len; 597 598 if (sa1->sa_family != sa2->sa_family) 599 return (1); 600 601 switch (sa1->sa_family) { 602 case AF_INET: 603 p1 = &((struct sockaddr_in *)sa1)->sin_addr; 604 p2 = &((struct sockaddr_in *)sa2)->sin_addr; 605 len = 4; 606 break; 607 case AF_INET6: 608 p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr; 609 p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr; 610 len = 16; 611 if (((struct sockaddr_in6 *)sa1)->sin6_scope_id != 612 ((struct sockaddr_in6 *)sa2)->sin6_scope_id) 613 return (1); 614 break; 615 default: 616 return (1); 617 } 618 619 return memcmp(p1, p2, len); 620 } 621 622 int 623 namematch(struct addrinfo *ai) 624 { 625 struct addrinfo *aip; 626 627 if (nfshost == NULL || nfshost_ai == NULL) 628 return (1); 629 630 while (ai != NULL) { 631 aip = nfshost_ai; 632 while (aip != NULL) { 633 if (sacmp(ai->ai_addr, aip->ai_addr) == 0) 634 return (1); 635 aip = aip->ai_next; 636 } 637 ai = ai->ai_next; 638 } 639 640 return (0); 641 } 642 643 void 644 checkmntlist(char *name, char **fromname, char **onname, char **type) 645 { 646 647 *fromname = getmntname(name, NULL, MNTFROM, type, NAME); 648 if (*fromname == NULL) { 649 *onname = getmntname(name, NULL, MNTON, type, NAME); 650 if (*onname != NULL) 651 *fromname = name; 652 } else 653 *onname = name; 654 } 655 656 int 657 mntinfo(struct statfs **mntbuf) 658 { 659 static struct statfs *origbuf; 660 size_t bufsize; 661 int mntsize; 662 663 mntsize = getfsstat(NULL, 0, MNT_NOWAIT); 664 if (mntsize <= 0) 665 return (0); 666 bufsize = (mntsize + 1) * sizeof(struct statfs); 667 if ((origbuf = malloc(bufsize)) == NULL) 668 err(1, "malloc"); 669 mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT); 670 *mntbuf = origbuf; 671 return (mntsize); 672 } 673 674 char * 675 getrealname(char *name, char *realname) 676 { 677 char *dirname; 678 int havedir; 679 size_t baselen; 680 size_t dirlen; 681 682 dirname = '\0'; 683 havedir = 0; 684 if (*name == '/') { 685 if (ISDOT(name + 1) || ISDOTDOT(name + 1)) 686 strcpy(realname, "/"); 687 else { 688 if ((dirname = strrchr(name + 1, '/')) == NULL) 689 snprintf(realname, MAXPATHLEN, "%s", name); 690 else 691 havedir = 1; 692 } 693 } else { 694 if (ISDOT(name) || ISDOTDOT(name)) 695 realpath(name, realname); 696 else { 697 if ((dirname = strrchr(name, '/')) == NULL) { 698 if ((realpath(name, realname)) == NULL) 699 return (NULL); 700 } else 701 havedir = 1; 702 } 703 } 704 if (havedir) { 705 *dirname++ = '\0'; 706 if (ISDOT(dirname)) { 707 *dirname = '\0'; 708 if ((realpath(name, realname)) == NULL) 709 return (NULL); 710 } else if (ISDOTDOT(dirname)) { 711 *--dirname = '/'; 712 if ((realpath(name, realname)) == NULL) 713 return (NULL); 714 } else { 715 if ((realpath(name, realname)) == NULL) 716 return (NULL); 717 baselen = strlen(realname); 718 dirlen = strlen(dirname); 719 if (baselen + dirlen + 1 > MAXPATHLEN) 720 return (NULL); 721 if (realname[1] == '\0') { 722 memmove(realname + 1, dirname, dirlen); 723 realname[dirlen + 1] = '\0'; 724 } else { 725 realname[baselen] = '/'; 726 memmove(realname + baselen + 1, 727 dirname, dirlen); 728 realname[baselen + dirlen + 1] = '\0'; 729 } 730 } 731 } 732 return (realname); 733 } 734 735 /* 736 * xdr routines for mount rpc's 737 */ 738 int 739 xdr_dir(XDR *xdrsp, char *dirp) 740 { 741 742 return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN)); 743 } 744 745 void 746 usage(void) 747 { 748 749 fprintf(stderr, "%s\n%s\n", 750 "usage: umount [-fv] special | node", 751 " umount -a | -A [-fv] [-h host] [-t type]"); 752 exit(1); 753 } 754