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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 * @(#) Copyright (c) 1980, 1989, 1993 The Regents of the University of California. All rights reserved. 30 * @(#)umount.c 8.8 (Berkeley) 5/8/95 31 * $FreeBSD: src/sbin/umount/umount.c,v 1.28 2001/10/13 02:04:54 iedowse Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/mount.h> 36 #include <sys/socket.h> 37 38 #include <netdb.h> 39 #include <rpc/rpc.h> 40 #include <nfs/rpcv2.h> 41 42 #include <err.h> 43 #include <fstab.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 49 #include "mounttab.h" 50 51 #define ISDOT(x) ((x)[0] == '.' && (x)[1] == '\0') 52 #define ISDOTDOT(x) ((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0') 53 54 typedef enum { MNTON, MNTFROM, NOTHING } mntwhat; 55 typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat; 56 57 struct addrinfo *nfshost_ai = NULL; 58 int fflag, vflag; 59 char *nfshost; 60 61 void checkmntlist (char *, char **, char **, char **); 62 int checkvfsname (const char *, char **); 63 char *getmntname (const char *, const char *, 64 mntwhat, char **, dowhat); 65 char *getrealname(char *, char *resolved_path); 66 char **makevfslist (const char *); 67 int mntinfo (struct statfs **); 68 int namematch (struct addrinfo *); 69 int sacmp (struct sockaddr *, struct sockaddr *); 70 int umountall (char **); 71 int checkname (char *, char **); 72 int umountfs (char *, char *, char *); 73 void usage (void) __dead2; 74 int xdr_dir (XDR *, char *); 75 76 int 77 main(int argc, char *argv[]) 78 { 79 int all, errs, ch, mntsize, error; 80 char **typelist = NULL, *mntonname, *mntfromname; 81 char *type, *mntfromnamerev, *mntonnamerev; 82 struct statfs *mntbuf; 83 struct addrinfo hints; 84 85 all = errs = 0; 86 while ((ch = getopt(argc, argv, "AaF:fh:t:v")) != -1) { 87 switch (ch) { 88 case 'A': 89 all = 2; 90 break; 91 case 'a': 92 all = 1; 93 break; 94 case 'F': 95 setfstab(optarg); 96 break; 97 case 'f': 98 fflag = MNT_FORCE; 99 break; 100 case 'h': /* -h implies -A. */ 101 all = 2; 102 nfshost = optarg; 103 break; 104 case 't': 105 if (typelist != NULL) 106 err(1, "only one -t option may be specified"); 107 typelist = makevfslist(optarg); 108 break; 109 case 'v': 110 vflag = 1; 111 break; 112 default: 113 usage(); 114 /* NOTREACHED */ 115 } 116 } 117 argc -= optind; 118 argv += optind; 119 120 if ((argc == 0 && !all) || (argc != 0 && all)) 121 usage(); 122 123 /* -h implies "-t nfs" if no -t flag. */ 124 if ((nfshost != NULL) && (typelist == NULL)) 125 typelist = makevfslist("nfs"); 126 127 if (nfshost != NULL) { 128 memset(&hints, 0, sizeof hints); 129 error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai); 130 if (error) 131 errx(1, "%s: %s", nfshost, gai_strerror(error)); 132 } 133 134 switch (all) { 135 case 2: 136 if ((mntsize = mntinfo(&mntbuf)) <= 0) 137 break; 138 /* 139 * We unmount the nfs-mounts in the reverse order 140 * that they were mounted. 141 */ 142 for (errs = 0, mntsize--; mntsize > 0; mntsize--) { 143 if (checkvfsname(mntbuf[mntsize].f_fstypename, 144 typelist)) 145 continue; 146 /* 147 * Check if a mountpoint is laid over by another mount. 148 * A warning will be printed to stderr if this is 149 * the case. The laid over mount remains unmounted. 150 */ 151 mntonname = mntbuf[mntsize].f_mntonname; 152 mntfromname = mntbuf[mntsize].f_mntfromname; 153 mntonnamerev = getmntname(getmntname(mntonname, 154 NULL, MNTFROM, &type, NAME), NULL, 155 MNTON, &type, NAME); 156 157 mntfromnamerev = getmntname(mntonnamerev, 158 NULL, MNTFROM, &type, NAME); 159 160 if (strcmp(mntonnamerev, mntonname) == 0 && 161 strcmp(mntfromnamerev, mntfromname ) != 0) 162 warnx("cannot umount %s, %s\n " 163 "is mounted there, umount it first", 164 mntonname, mntfromnamerev); 165 166 if (checkname(mntbuf[mntsize].f_mntonname, 167 typelist) != 0) 168 errs = 1; 169 } 170 free(mntbuf); 171 break; 172 case 1: 173 if (setfsent() == 0) 174 err(1, "%s", getfstab()); 175 errs = umountall(typelist); 176 break; 177 case 0: 178 for (errs = 0; *argv != NULL; ++argv) 179 if (checkname(*argv, typelist) != 0) 180 errs = 1; 181 break; 182 } 183 getmntname(NULL, NULL, NOTHING, NULL, FREE); 184 exit(errs); 185 } 186 187 int 188 umountall(char **typelist) 189 { 190 struct vfsconf vfc; 191 struct fstab *fs; 192 int rval; 193 char *cp; 194 static int firstcall = 1; 195 196 if ((fs = getfsent()) != NULL) 197 firstcall = 0; 198 else if (firstcall) 199 errx(1, "fstab reading failure"); 200 else 201 return (0); 202 do { 203 /* Ignore the root. */ 204 if (strcmp(fs->fs_file, "/") == 0) 205 continue; 206 /* 207 * !!! 208 * Historic practice: ignore unknown FSTAB_* fields. 209 */ 210 if (strcmp(fs->fs_type, FSTAB_RW) && 211 strcmp(fs->fs_type, FSTAB_RO) && 212 strcmp(fs->fs_type, FSTAB_RQ)) 213 continue; 214 /* Ignore unknown file system types. */ 215 if (getvfsbyname(fs->fs_vfstype, &vfc) == -1) 216 continue; 217 if (checkvfsname(fs->fs_vfstype, typelist)) 218 continue; 219 220 /* 221 * We want to unmount the file systems in the reverse order 222 * that they were mounted. So, we save off the file name 223 * in some allocated memory, and then call recursively. 224 */ 225 if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL) 226 err(1, "malloc failed"); 227 strcpy(cp, fs->fs_file); 228 rval = umountall(typelist); 229 rval = checkname(cp, typelist) || rval; 230 free(cp); 231 return (rval); 232 } while ((fs = getfsent()) != NULL); 233 return (0); 234 } 235 236 /* 237 * Do magic checks on mountpoint and device or hand over 238 * it to unmount(2) if everything fails. 239 */ 240 int 241 checkname(char *name, char **typelist) 242 { 243 size_t len; 244 int speclen; 245 char *mntonname, *mntfromname; 246 char *mntfromnamerev; 247 char *resolved, realname[MAXPATHLEN]; 248 char *type, *hostp, *delimp, *origname; 249 char none[] = "none"; 250 251 len = 0; 252 mntfromname = mntonname = delimp = hostp = NULL; 253 254 /* 255 * 1. Check if the name exists in the mounttable. 256 */ 257 checkmntlist(name, &mntfromname, &mntonname, &type); 258 if (mntfromname == NULL && mntonname == NULL) { 259 checkmntlist(getdevpath(name, 0), &mntfromname, 260 &mntonname, &type); 261 } 262 263 /* 264 * 2. Remove trailing slashes if there are any. After that 265 * we look up the name in the mounttable again. 266 */ 267 if (mntfromname == NULL && mntonname == NULL) { 268 speclen = strlen(name); 269 for (speclen = strlen(name); 270 speclen > 1 && name[speclen - 1] == '/'; 271 speclen--) 272 name[speclen - 1] = '\0'; 273 checkmntlist(name, &mntfromname, &mntonname, &type); 274 resolved = name; 275 /* Save off original name in origname */ 276 if ((origname = strdup(name)) == NULL) 277 err(1, "strdup"); 278 /* 279 * 3. Check if the deprecated nfs-syntax with an '@' 280 * has been used and translate it to the ':' syntax. 281 * Look up the name in the mounttable again. 282 */ 283 if (mntfromname == NULL && mntonname == NULL) { 284 if ((delimp = strrchr(name, '@')) != NULL) { 285 hostp = delimp + 1; 286 if (*hostp != '\0') { 287 /* 288 * Make both '@' and ':' 289 * notations equal 290 */ 291 char *host = strdup(hostp); 292 len = strlen(hostp); 293 if (host == NULL) 294 err(1, "strdup"); 295 memmove(name + len + 1, name, 296 (size_t)(delimp - name)); 297 name[len] = ':'; 298 memmove(name, host, len); 299 free(host); 300 } 301 for (speclen = strlen(name); 302 speclen > 1 && name[speclen - 1] == '/'; 303 speclen--) 304 name[speclen - 1] = '\0'; 305 name[len + speclen + 1] = '\0'; 306 checkmntlist(name, &mntfromname, 307 &mntonname, &type); 308 resolved = name; 309 } 310 /* 311 * 4. Check if a relative mountpoint has been 312 * specified. This should happen as last check, 313 * the order is important. To prevent possible 314 * nfs-hangs, we just call realpath(3) on the 315 * basedir of mountpoint and add the dirname again. 316 * Check the name in mounttable one last time. 317 */ 318 if (mntfromname == NULL && mntonname == NULL) { 319 strcpy(name, origname); 320 if ((getrealname(name, realname)) != NULL) { 321 checkmntlist(realname, 322 &mntfromname, &mntonname, &type); 323 resolved = realname; 324 } 325 /* 326 * 5. All tests failed, just hand over the 327 * mountpoint to the kernel, maybe the statfs 328 * structure has been truncated or is not 329 * useful anymore because of a chroot(2). 330 * Please note that nfs will not be able to 331 * notify the nfs-server about unmounting. 332 * These things can change in future when the 333 * fstat structure get's more reliable, 334 * but at the moment we cannot thrust it. 335 */ 336 if (mntfromname == NULL && mntonname == NULL) { 337 strcpy(name, origname); 338 if (umountfs(NULL, origname, 339 none) == 0) { 340 warnx("%s not found in " 341 "mount table, " 342 "unmounted it anyway", 343 origname); 344 free(origname); 345 return (0); 346 } else { 347 free(origname); 348 return (1); 349 } 350 } 351 } 352 } 353 free(origname); 354 } else 355 resolved = name; 356 357 if (checkvfsname(type, typelist)) 358 return (1); 359 360 /* 361 * Check if the reverse entrys of the mounttable are really the 362 * same as the normal ones. 363 */ 364 if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname, 365 NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL) 366 err(1, "strdup"); 367 /* 368 * Mark the uppermost mount as unmounted. 369 */ 370 getmntname(mntfromname, mntonname, NOTHING, &type, MARK); 371 /* 372 * If several equal mounts are in the mounttable, check the order 373 * and warn the user if necessary. 374 */ 375 if (strcmp(mntfromnamerev, mntfromname ) != 0 && 376 strcmp(resolved, mntonname) != 0) { 377 warnx("cannot umount %s, %s\n " 378 "is mounted there, umount it first", 379 mntonname, mntfromnamerev); 380 381 /* call getmntname again to set mntcheck[i] to 0 */ 382 getmntname(mntfromname, mntonname, 383 NOTHING, &type, UNMARK); 384 return (1); 385 } 386 free(mntfromnamerev); 387 return (umountfs(mntfromname, mntonname, type)); 388 } 389 390 /* 391 * NFS stuff and unmount(2) call 392 */ 393 int 394 umountfs(char *mntfromname, char *mntonname, char *type) 395 { 396 enum clnt_stat clnt_stat; 397 struct timeval try; 398 struct addrinfo *ai, hints; 399 int do_rpc; 400 CLIENT *clp; 401 char *nfsdirname, *orignfsdirname; 402 char *hostp, *delimp; 403 404 ai = NULL; 405 do_rpc = 0; 406 hostp = NULL; 407 nfsdirname = delimp = orignfsdirname = NULL; 408 memset(&hints, 0, sizeof hints); 409 410 if (strcmp(type, "nfs") == 0) { 411 if ((nfsdirname = strdup(mntfromname)) == NULL) 412 err(1, "strdup"); 413 orignfsdirname = nfsdirname; 414 if ((delimp = strrchr(nfsdirname, ':')) != NULL) { 415 *delimp = '\0'; 416 hostp = nfsdirname; 417 getaddrinfo(hostp, NULL, &hints, &ai); 418 if (ai == NULL) { 419 warnx("can't get net id for host"); 420 } 421 nfsdirname = delimp + 1; 422 } 423 424 /* 425 * Check if we have to start the rpc-call later. 426 * If there are still identical nfs-names mounted, 427 * we skip the rpc-call. Obviously this has to 428 * happen before unmount(2), but it should happen 429 * after the previous namecheck. 430 * A non-NULL return means that this is the last 431 * mount from mntfromname that is still mounted. 432 */ 433 if (getmntname(mntfromname, NULL, NOTHING, &type, COUNT) 434 != NULL) 435 do_rpc = 1; 436 } 437 438 if (!namematch(ai)) 439 return (1); 440 if (unmount(mntonname, fflag) != 0 ) { 441 warn("unmount of %s failed", mntonname); 442 return (1); 443 } 444 if (vflag) 445 printf("%s: unmount from %s\n", mntfromname, mntonname); 446 /* 447 * Report to mountd-server which nfsname 448 * has been unmounted. 449 */ 450 if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) { 451 clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp"); 452 if (clp == NULL) { 453 warnx("%s: %s", hostp, 454 clnt_spcreateerror("RPCPROG_MNT")); 455 return (1); 456 } 457 clp->cl_auth = authsys_create_default(); 458 try.tv_sec = 20; 459 try.tv_usec = 0; 460 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir, 461 nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try); 462 if (clnt_stat != RPC_SUCCESS) { 463 warnx("%s: %s", hostp, 464 clnt_sperror(clp, "RPCMNT_UMOUNT")); 465 return (1); 466 } 467 /* 468 * Remove the unmounted entry from /var/db/mounttab. 469 */ 470 if (read_mtab()) { 471 clean_mtab(hostp, nfsdirname, vflag); 472 if(!write_mtab(vflag)) 473 warnx("cannot remove mounttab entry %s:%s", 474 hostp, nfsdirname); 475 free_mtab(); 476 } 477 free(orignfsdirname); 478 auth_destroy(clp->cl_auth); 479 clnt_destroy(clp); 480 } 481 return (0); 482 } 483 484 char * 485 getmntname(const char *fromname, const char *onname, 486 mntwhat what, char **type, dowhat mark) 487 { 488 static struct statfs *mntbuf; 489 static int mntsize = 0; 490 static char *mntcheck = NULL; 491 static char *mntcount = NULL; 492 int i, count; 493 494 if (mntsize <= 0) { 495 if ((mntsize = mntinfo(&mntbuf)) <= 0) 496 return (NULL); 497 } 498 if (mntcheck == NULL) { 499 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL || 500 (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL) 501 err(1, "calloc"); 502 } 503 /* 504 * We want to get the file systems in the reverse order 505 * that they were mounted. Mounted and unmounted filesystems 506 * are marked or unmarked in a table called 'mntcheck'. 507 * Unmount(const char *dir, int flags) does only take the 508 * mountpoint as argument, not the destination. If we don't pay 509 * attention to the order, it can happen that a overlaying 510 * filesystem get's unmounted instead of the one the user 511 * has choosen. 512 */ 513 switch (mark) { 514 case NAME: 515 /* Return only the specific name */ 516 for (i = mntsize - 1; i >= 0; i--) { 517 if (fromname != NULL && what == MNTON && 518 !strcmp(mntbuf[i].f_mntfromname, fromname) && 519 mntcheck[i] != 1) { 520 if (type) 521 *type = mntbuf[i].f_fstypename; 522 return (mntbuf[i].f_mntonname); 523 } 524 if (fromname != NULL && what == MNTFROM && 525 !strcmp(mntbuf[i].f_mntonname, fromname) && 526 mntcheck[i] != 1) { 527 if (type) 528 *type = mntbuf[i].f_fstypename; 529 return (mntbuf[i].f_mntfromname); 530 } 531 } 532 return (NULL); 533 case MARK: 534 /* Mark current mount with '1' and return name */ 535 for (i = mntsize - 1; i >= 0; i--) { 536 if (mntcheck[i] == 0 && 537 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 538 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 539 mntcheck[i] = 1; 540 return (mntbuf[i].f_mntonname); 541 } 542 } 543 return (NULL); 544 case UNMARK: 545 /* Unmark current mount with '0' and return name */ 546 for (i = 0; i < mntsize; i++) { 547 if (mntcheck[i] == 1 && 548 (strcmp(mntbuf[i].f_mntonname, onname) == 0) && 549 (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) { 550 mntcheck[i] = 0; 551 return (mntbuf[i].f_mntonname); 552 } 553 } 554 return (NULL); 555 case COUNT: 556 /* Count the equal mntfromnames */ 557 count = 0; 558 for (i = mntsize - 1; i >= 0; i--) { 559 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) 560 count++; 561 } 562 /* Mark the already unmounted mounts and return 563 * mntfromname if count <= 1. Else return NULL. 564 */ 565 for (i = mntsize - 1; i >= 0; i--) { 566 if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) { 567 if (mntcount[i] == 1) 568 count--; 569 else { 570 mntcount[i] = 1; 571 break; 572 } 573 } 574 } 575 if (count <= 1) 576 return (mntbuf[i].f_mntonname); 577 else 578 return (NULL); 579 case FREE: 580 free(mntbuf); 581 free(mntcheck); 582 free(mntcount); 583 return (NULL); 584 default: 585 return (NULL); 586 } 587 } 588 589 int 590 sacmp(struct sockaddr *sa1, struct sockaddr *sa2) 591 { 592 void *p1, *p2; 593 int len; 594 595 if (sa1->sa_family != sa2->sa_family) 596 return (1); 597 598 switch (sa1->sa_family) { 599 case AF_INET: 600 p1 = &((struct sockaddr_in *)sa1)->sin_addr; 601 p2 = &((struct sockaddr_in *)sa2)->sin_addr; 602 len = 4; 603 break; 604 case AF_INET6: 605 p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr; 606 p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr; 607 len = 16; 608 if (((struct sockaddr_in6 *)sa1)->sin6_scope_id != 609 ((struct sockaddr_in6 *)sa2)->sin6_scope_id) 610 return (1); 611 break; 612 default: 613 return (1); 614 } 615 616 return memcmp(p1, p2, len); 617 } 618 619 int 620 namematch(struct addrinfo *ai) 621 { 622 struct addrinfo *aip; 623 624 if (nfshost == NULL || nfshost_ai == NULL) 625 return (1); 626 627 while (ai != NULL) { 628 aip = nfshost_ai; 629 while (aip != NULL) { 630 if (sacmp(ai->ai_addr, aip->ai_addr) == 0) 631 return (1); 632 aip = aip->ai_next; 633 } 634 ai = ai->ai_next; 635 } 636 637 return (0); 638 } 639 640 void 641 checkmntlist(char *name, char **fromname, char **onname, char **type) 642 { 643 644 *fromname = getmntname(name, NULL, MNTFROM, type, NAME); 645 if (*fromname == NULL) { 646 *onname = getmntname(name, NULL, MNTON, type, NAME); 647 if (*onname != NULL) 648 *fromname = name; 649 } else 650 *onname = name; 651 } 652 653 int 654 mntinfo(struct statfs **mntbuf) 655 { 656 static struct statfs *origbuf; 657 size_t bufsize; 658 int mntsize; 659 660 mntsize = getfsstat(NULL, 0, MNT_NOWAIT); 661 if (mntsize <= 0) 662 return (0); 663 bufsize = (mntsize + 1) * sizeof(struct statfs); 664 if ((origbuf = malloc(bufsize)) == NULL) 665 err(1, "malloc"); 666 mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT); 667 *mntbuf = origbuf; 668 return (mntsize); 669 } 670 671 char * 672 getrealname(char *name, char *realname) 673 { 674 char *dirname; 675 int havedir; 676 size_t baselen; 677 size_t dirlen; 678 679 dirname = NULL; 680 havedir = 0; 681 if (*name == '/') { 682 if (ISDOT(name + 1) || ISDOTDOT(name + 1)) 683 strcpy(realname, "/"); 684 else { 685 if ((dirname = strrchr(name + 1, '/')) == NULL) 686 snprintf(realname, MAXPATHLEN, "%s", name); 687 else 688 havedir = 1; 689 } 690 } else { 691 if (ISDOT(name) || ISDOTDOT(name)) 692 realpath(name, realname); 693 else { 694 if ((dirname = strrchr(name, '/')) == NULL) { 695 if ((realpath(name, realname)) == NULL) 696 return (NULL); 697 } else 698 havedir = 1; 699 } 700 } 701 if (havedir) { 702 *dirname++ = '\0'; 703 if (ISDOT(dirname)) { 704 *dirname = '\0'; 705 if ((realpath(name, realname)) == NULL) 706 return (NULL); 707 } else if (ISDOTDOT(dirname)) { 708 *--dirname = '/'; 709 if ((realpath(name, realname)) == NULL) 710 return (NULL); 711 } else { 712 if ((realpath(name, realname)) == NULL) 713 return (NULL); 714 baselen = strlen(realname); 715 dirlen = strlen(dirname); 716 if (baselen + dirlen + 1 > MAXPATHLEN) 717 return (NULL); 718 if (realname[1] == '\0') { 719 memmove(realname + 1, dirname, dirlen); 720 realname[dirlen + 1] = '\0'; 721 } else { 722 realname[baselen] = '/'; 723 memmove(realname + baselen + 1, 724 dirname, dirlen); 725 realname[baselen + dirlen + 1] = '\0'; 726 } 727 } 728 } 729 return (realname); 730 } 731 732 /* 733 * xdr routines for mount rpc's 734 */ 735 int 736 xdr_dir(XDR *xdrsp, char *dirp) 737 { 738 739 return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN)); 740 } 741 742 void 743 usage(void) 744 { 745 746 fprintf(stderr, "%s\n%s\n", 747 "usage: umount [-fv] special | node", 748 " umount -a | -A [-F fstab] [-fv] [-h host] [-t type]"); 749 exit(1); 750 } 751