sbin/umount/umount.c

   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 1.22.2.1 2001/12/13 01:27:15 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
  42 #include <netdb.h>
  43 #include <rpc/rpc.h>
  44 #include <nfs/rpcv2.h>
  45
  46 #include <err.h>
  47 #include <fstab.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52
  53 #include "mounttab.h"
  54
  55 #define ISDOT(x)        ((x)[0] == '.' && (x)[1] == '\0')
  56 #define ISDOTDOT(x)     ((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0')
  57
  58 typedef enum { MNTON, MNTFROM, NOTHING } mntwhat;
  59 typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat;
  60
  61 int     fflag, vflag;
  62 char   *nfshost;
  63
  64 void     checkmntlist (char *, char **, char **, char **);
  65 int      checkvfsname (const char *, char **);
  66 char    *getmntname (const char *, const char *,
  67          mntwhat, char **, dowhat);
  68 char    *getrealname(char *, char *resolved_path);
  69 char   **makevfslist (const char *);
  70 size_t   mntinfo (struct statfs **);
  71 int      namematch (struct hostent *);
  72 int      umountall (char **);
  73 int      umountfs (char *, char **);
  74 void     usage (void);
  75 int      xdr_dir (XDR *, char *);
  76
  77 int
  78 main(int argc, char *argv[])
  79 {
  80         int all, errs, ch, mntsize;
  81         char **typelist = NULL, *mntonname, *mntfromname;
  82         char *type, *mntfromnamerev, *mntonnamerev;
  83         struct statfs *mntbuf;
  84
  85         /* Start disks transferring immediately. */
  86         sync();
  87
  88         all = errs = 0;
  89         while ((ch = getopt(argc, argv, "Aafh:t:v")) != -1)
  90                 switch (ch) {
  91                 case 'A':
  92                         all = 2;
  93                         break;
  94                 case 'a':
  95                         all = 1;
  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         argc -= optind;
 117         argv += optind;
 118
 119         if ((argc == 0 && !all) || (argc != 0 && all))
 120                 usage();
 121
 122         /* -h implies "-t nfs" if no -t flag. */
 123         if ((nfshost != NULL) && (typelist == NULL))
 124                 typelist = makevfslist("nfs");
 125
 126         switch (all) {
 127         case 2:
 128                 if ((mntsize = mntinfo(&mntbuf)) <= 0)
 129                         break;
 130                 /*
 131                  * We unmount the nfs-mounts in the reverse order
 132                  * that they were mounted.
 133                  */
 134                 for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
 135                         if (checkvfsname(mntbuf[mntsize].f_fstypename,
 136                             typelist))
 137                                 continue;
 138                         /*
 139                          * Check if a mountpoint is laid over by another mount.
 140                          * A warning will be printed to stderr if this is
 141                          * the case. The laid over mount remains unmounted.
 142                          */
 143                         mntonname = mntbuf[mntsize].f_mntonname;
 144                         mntfromname = mntbuf[mntsize].f_mntfromname;
 145                         mntonnamerev = getmntname(getmntname(mntonname,
 146                             NULL, MNTFROM, &type, NAME), NULL,
 147                             MNTON, &type, NAME);
 148
 149                         mntfromnamerev = getmntname(mntonnamerev,
 150                             NULL, MNTFROM, &type, NAME);
 151
 152                         if (strcmp(mntonnamerev, mntonname) == 0 &&
 153                             strcmp(mntfromnamerev, mntfromname ) != 0)
 154                                 warnx("cannot umount %s, %s\n        "
 155                                     "is mounted there, umount it first",
 156                                     mntonname, mntfromnamerev);
 157
 158                         if (umountfs(mntbuf[mntsize].f_mntonname,
 159                             typelist) != 0)
 160                                 errs = 1;
 161                 }
 162                 free(mntbuf);
 163                 break;
 164         case 1:
 165                 if (setfsent() == 0)
 166                         err(1, "%s", _PATH_FSTAB);
 167                 errs = umountall(typelist);
 168                 break;
 169         case 0:
 170                 for (errs = 0; *argv != NULL; ++argv)
 171                         if (umountfs(*argv, typelist) != 0)
 172                                 errs = 1;
 173                 break;
 174         }
 175         getmntname(NULL, NULL, NOTHING, NULL, FREE);
 176         exit(errs);
 177 }
 178
 179 int
 180 umountall(char **typelist)
 181 {
 182         struct vfsconf vfc;
 183         struct fstab *fs;
 184         int rval;
 185         char *cp;
 186         static int firstcall = 1;
 187
 188         if ((fs = getfsent()) != NULL)
 189                 firstcall = 0;
 190         else if (firstcall)
 191                 errx(1, "fstab reading failure");
 192         else
 193                 return (0);
 194         do {
 195                 /* Ignore the root. */
 196                 if (strcmp(fs->fs_file, "/") == 0)
 197                         continue;
 198                 /*
 199                  * !!!
 200                  * Historic practice: ignore unknown FSTAB_* fields.
 201                  */
 202                 if (strcmp(fs->fs_type, FSTAB_RW) &&
 203                     strcmp(fs->fs_type, FSTAB_RO) &&
 204                     strcmp(fs->fs_type, FSTAB_RQ))
 205                         continue;
 206                 /* If an unknown file system type, complain. */
 207                 if (getvfsbyname(fs->fs_vfstype, &vfc) == -1) {
 208                         warnx("%s: unknown mount type", fs->fs_vfstype);
 209                         continue;
 210                 }
 211                 if (checkvfsname(fs->fs_vfstype, typelist))
 212                         continue;
 213
 214                 /*
 215                  * We want to unmount the file systems in the reverse order
 216                  * that they were mounted.  So, we save off the file name
 217                  * in some allocated memory, and then call recursively.
 218                  */
 219                 if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
 220                         err(1, "malloc failed");
 221                 strcpy(cp, fs->fs_file);
 222                 rval = umountall(typelist);
 223                 rval = umountfs(cp, typelist) || rval;
 224                 free(cp);
 225                 return (rval);
 226         } while ((fs = getfsent()) != NULL);
 227         return (0);
 228 }
 229
 230 int
 231 umountfs(char *name, char **typelist)
 232 {
 233         enum clnt_stat clnt_stat;
 234         struct hostent *hp;
 235         struct mtablist *mtab;
 236         struct sockaddr_in saddr;
 237         struct timeval pertry, try;
 238         CLIENT *clp;
 239         size_t len;
 240         int so, speclen, do_rpc;
 241         char *mntonname, *mntfromname;
 242         char *mntfromnamerev;
 243         char *nfsdirname, *orignfsdirname;
 244         char *resolved, realname[MAXPATHLEN];
 245         char *type, *delimp, *hostp, *origname;
 246
 247         len = 0;
 248         mtab = NULL;
 249         mntfromname = mntonname = delimp = hostp = orignfsdirname = NULL;
 250
 251         /*
 252          * 1. Check if the name exists in the mounttable.
 253          */
 254         checkmntlist(name, &mntfromname, &mntonname, &type);
 255         /*
 256          * 2. Remove trailing slashes if there are any. After that
 257          * we look up the name in the mounttable again.
 258          */
 259         if (mntfromname == NULL && mntonname == NULL) {
 260                 speclen = strlen(name);
 261                 for (speclen = strlen(name);
 262                     speclen > 1 && name[speclen - 1] == '/';
 263                     speclen--)
 264                         name[speclen - 1] = '\0';
 265                 checkmntlist(name, &mntfromname, &mntonname, &type);
 266                 resolved = name;
 267                 /* Save off original name in origname */
 268                 if ((origname = strdup(name)) == NULL)
 269                         err(1, "strdup");
 270                 /*
 271                  * 3. Check if the deprecated nfs-syntax with an '@'
 272                  * has been used and translate it to the ':' syntax.
 273                  * Look up the name in the mounttable again.
 274                  */
 275                 if (mntfromname == NULL && mntonname == NULL) {
 276                         if ((delimp = strrchr(name, '@')) != NULL) {
 277                                 hostp = delimp + 1;
 278                                 if (*hostp != '\0') {
 279                                         /*
 280                                          * Make both '@' and ':'
 281                                          * notations equal
 282                                          */
 283                                         char *host = strdup(hostp);
 284                                         len = strlen(hostp);
 285                                         if (host == NULL)
 286                                                 err(1, "strdup");
 287                                         memmove(name + len + 1, name,
 288                                             (size_t)(delimp - name));
 289                                         name[len] = ':';
 290                                         memmove(name, host, len);
 291                                         free(host);
 292                                 }
 293                                 for (speclen = strlen(name);
 294                                     speclen > 1 && name[speclen - 1] == '/';
 295                                     speclen--)
 296                                         name[speclen - 1] = '\0';
 297                                 name[len + speclen + 1] = '\0';
 298                                 checkmntlist(name, &mntfromname,
 299                                     &mntonname, &type);
 300                                 resolved = name;
 301                         }
 302                         /*
 303                          * 4. Check if a relative mountpoint has been
 304                          * specified. This should happen as last check,
 305                          * the order is important. To prevent possible
 306                          * nfs-hangs, we just call realpath(3) on the
 307                          * basedir of mountpoint and add the dirname again.
 308                          * Check the name in mounttable one last time.
 309                          */
 310                         if (mntfromname == NULL && mntonname == NULL) {
 311                                 strcpy(name, origname);
 312                                 if ((getrealname(name, realname)) != NULL) {
 313                                         checkmntlist(realname,
 314                                             &mntfromname, &mntonname, &type);
 315                                         resolved = realname;
 316                                 }
 317                                 /*
 318                                  * All tests failed, return to main()
 319                                  */
 320                                 if (mntfromname == NULL && mntonname == NULL) {
 321                                         strcpy(name, origname);
 322                                         warnx("%s: not currently mounted",
 323                                             origname);
 324                                         free(origname);
 325                                         return (1);
 326                                 }
 327                         }
 328                 }
 329                 free(origname);
 330         } else
 331                 resolved = name;
 332
 333         if (checkvfsname(type, typelist))
 334                 return (1);
 335
 336         hp = NULL;
 337         nfsdirname = NULL;
 338         if (!strcmp(type, "nfs")) {
 339                 if ((nfsdirname = strdup(mntfromname)) == NULL)
 340                         err(1, "strdup");
 341                 orignfsdirname = nfsdirname;
 342                 if ((delimp = strchr(nfsdirname, ':')) != NULL) {
 343                         *delimp = '\0';
 344                         hostp = nfsdirname;
 345                         if ((hp = gethostbyname(hostp)) == NULL) {
 346                                 warnx("can't get net id for host");
 347                         }
 348                         nfsdirname = delimp + 1;
 349                 }
 350         }
 351         /*
 352          * Check if the reverse entrys of the mounttable are really the
 353          * same as the normal ones.
 354          */
 355         if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname,
 356             NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL)
 357                 err(1, "strdup");
 358         /*
 359          * Mark the uppermost mount as unmounted.
 360          */
 361         getmntname(mntfromname, mntonname, NOTHING, &type, MARK);
 362         /*
 363          * If several equal mounts are in the mounttable, check the order
 364          * and warn the user if necessary.
 365          */
 366         if (strcmp(mntfromnamerev, mntfromname ) != 0 &&
 367             strcmp(resolved, mntonname) != 0) {
 368                 warnx("cannot umount %s, %s\n        "
 369                     "is mounted there, umount it first",
 370                     mntonname, mntfromnamerev);
 371
 372                 /* call getmntname again to set mntcheck[i] to 0 */
 373                 getmntname(mntfromname, mntonname,
 374                     NOTHING, &type, UNMARK);
 375                 return (1);
 376         }
 377         free(mntfromnamerev);
 378         /*
 379          * Check if we have to start the rpc-call later.
 380          * If there are still identical nfs-names mounted,
 381          * we skip the rpc-call. Obviously this has to
 382          * happen before unmount(2), but it should happen
 383          * after the previous namecheck.
 384          */
 385         if (strcmp(type, "nfs") == 0 && getmntname(mntfromname, NULL, NOTHING,
 386             &type, COUNT) != NULL)
 387                 do_rpc = 1;
 388         else
 389                 do_rpc = 0;
 390         if (!namematch(hp))
 391                 return (1);
 392         if (unmount(mntonname, fflag) != 0 ) {
 393                 warn("unmount of %s failed", mntonname);
 394                 return (1);
 395         }
 396         if (vflag)
 397                 printf("%s: unmount from %s\n", mntfromname, mntonname);
 398         /*
 399          * Report to mountd-server which nfsname
 400          * has been unmounted.
 401          */
 402         if (hp != NULL && !(fflag & MNT_FORCE) && do_rpc) {
 403                 memset(&saddr, 0, sizeof(saddr));
 404                 saddr.sin_family = AF_INET;
 405                 saddr.sin_port = 0;
 406                 memmove(&saddr.sin_addr, hp->h_addr,
 407                     MIN(hp->h_length, sizeof(saddr.sin_addr)));
 408                 pertry.tv_sec = 3;
 409                 pertry.tv_usec = 0;
 410                 so = RPC_ANYSOCK;
 411                 if ((clp = clntudp_create(&saddr,
 412                     RPCPROG_MNT, RPCMNT_VER1, pertry, &so)) == NULL) {
 413                         clnt_pcreateerror("Cannot MNT PRC");
 414                         return (1);
 415                 }
 416                 clp->cl_auth = authunix_create_default();
 417                 try.tv_sec = 20;
 418                 try.tv_usec = 0;
 419                 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, xdr_dir,
 420                     nfsdirname, xdr_void, (caddr_t)0, try);
 421                 if (clnt_stat != RPC_SUCCESS) {
 422                         clnt_perror(clp, "Bad MNT RPC");
 423                         return (1);
 424                 }
 425                 /*
 426                  * Remove the unmounted entry from /var/db/mounttab.
 427                  */
 428                 if (read_mtab()) {
 429                         clean_mtab(hostp, nfsdirname, vflag);
 430                         if(!write_mtab(vflag))
 431                                 warnx("cannot remove mounttab entry %s:%s",
 432                                     hostp, nfsdirname);
 433                         free_mtab();
 434                 }
 435                 free(orignfsdirname);
 436                 auth_destroy(clp->cl_auth);
 437                 clnt_destroy(clp);
 438         }
 439         return (0);
 440 }
 441
 442 char *
 443 getmntname(const char *fromname, const char *onname,
 444     mntwhat what, char **type, dowhat mark)
 445 {
 446         static struct statfs *mntbuf;
 447         static size_t mntsize = 0;
 448         static char *mntcheck = NULL;
 449         static char *mntcount = NULL;
 450         int i, count;
 451
 452         if (mntsize <= 0) {
 453                 if ((mntsize = mntinfo(&mntbuf)) <= 0)
 454                         return (NULL);
 455         }
 456         if (mntcheck == NULL) {
 457                 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
 458                     (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
 459                         err(1, "calloc");
 460         }
 461         /*
 462          * We want to get the file systems in the reverse order
 463          * that they were mounted. Mounted and unmounted filesystems
 464          * are marked or unmarked in a table called 'mntcheck'.
 465          * Unmount(const char *dir, int flags) does only take the
 466          * mountpoint as argument, not the destination. If we don't pay
 467          * attention to the order, it can happen that a overlaying
 468          * filesystem get's unmounted instead of the one the user
 469          * has choosen.
 470          */
 471         switch (mark) {
 472         case NAME:
 473                 /* Return only the specific name */
 474                 for (i = mntsize - 1; i >= 0; i--) {
 475                         if (fromname != NULL && what == MNTON &&
 476                             !strcmp(mntbuf[i].f_mntfromname, fromname) &&
 477                             mntcheck[i] != 1) {
 478                                 if (type)
 479                                         *type = mntbuf[i].f_fstypename;
 480                                 return (mntbuf[i].f_mntonname);
 481                         }
 482                         if (fromname != NULL && what == MNTFROM &&
 483                             !strcmp(mntbuf[i].f_mntonname, fromname) &&
 484                             mntcheck[i] != 1) {
 485                                 if (type)
 486                                         *type = mntbuf[i].f_fstypename;
 487                                 return (mntbuf[i].f_mntfromname);
 488                         }
 489                 }
 490                 return (NULL);
 491         case MARK:
 492                 /* Mark current mount with '1' and return name */
 493                 for (i = mntsize - 1; i >= 0; i--) {
 494                         if (mntcheck[i] == 0 &&
 495                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 496                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 497                                 mntcheck[i] = 1;
 498                                 return (mntbuf[i].f_mntonname);
 499                         }
 500                 }
 501                 return (NULL);
 502         case UNMARK:
 503                 /* Unmark current mount with '0' and return name */
 504                 for (i = 0; i < mntsize; i++) {
 505                         if (mntcheck[i] == 1 &&
 506                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 507                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 508                                 mntcheck[i] = 0;
 509                                 return (mntbuf[i].f_mntonname);
 510                         }
 511                 }
 512                 return (NULL);
 513         case COUNT:
 514                 /* Count the equal mntfromnames */
 515                 count = 0;
 516                 for (i = mntsize - 1; i >= 0; i--) {
 517                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
 518                                 count++;
 519                 }
 520                 /* Mark the already unmounted mounts and return
 521                  * mntfromname if count <= 1. Else return NULL.
 522                  */
 523                 for (i = mntsize - 1; i >= 0; i--) {
 524                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
 525                                 if (mntcount[i] == 1)
 526                                         count--;
 527                                 else {
 528                                         mntcount[i] = 1;
 529                                         break;
 530                                 }
 531                         }
 532                 }
 533                 if (count <= 1)
 534                         return (mntbuf[i].f_mntonname);
 535                 else
 536                         return (NULL);
 537         case FREE:
 538                 free(mntbuf);
 539                 free(mntcheck);
 540                 free(mntcount);
 541                 return (NULL);
 542         default:
 543                 return (NULL);
 544         }
 545 }
 546
 547 int
 548 namematch(struct hostent *hp)
 549 {
 550         char *cp, **np;
 551
 552         if ((hp == NULL) || (nfshost == NULL))
 553                 return (1);
 554
 555         if (strcasecmp(nfshost, hp->h_name) == 0)
 556                 return (1);
 557
 558         if ((cp = strchr(hp->h_name, '.')) != NULL) {
 559                 *cp = '\0';
 560                 if (strcasecmp(nfshost, hp->h_name) == 0)
 561                         return (1);
 562         }
 563         for (np = hp->h_aliases; *np; np++) {
 564                 if (strcasecmp(nfshost, *np) == 0)
 565                         return (1);
 566                 if ((cp = strchr(*np, '.')) != NULL) {
 567                         *cp = '\0';
 568                         if (strcasecmp(nfshost, *np) == 0)
 569                                 return (1);
 570                 }
 571         }
 572         return (0);
 573 }
 574
 575 void
 576 checkmntlist(char *name, char **fromname, char **onname, char **type)
 577 {
 578
 579         *fromname = getmntname(name, NULL, MNTFROM, type, NAME);
 580         if (*fromname == NULL) {
 581                 *onname = getmntname(name, NULL, MNTON, type, NAME);
 582                 if (*onname != NULL)
 583                         *fromname = name;
 584         } else
 585                 *onname = name;
 586 }
 587
 588 size_t
 589 mntinfo(struct statfs **mntbuf)
 590 {
 591         static struct statfs *origbuf;
 592         size_t bufsize;
 593         int mntsize;
 594
 595         mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
 596         if (mntsize <= 0)
 597                 return (0);
 598         bufsize = (mntsize + 1) * sizeof(struct statfs);
 599         if ((origbuf = malloc(bufsize)) == NULL)
 600                 err(1, "malloc");
 601         mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
 602         *mntbuf = origbuf;
 603         return (mntsize);
 604 }
 605
 606 char *
 607 getrealname(char *name, char *realname)
 608 {
 609         char *dirname;
 610         int havedir;
 611         size_t baselen;
 612         size_t dirlen;
 613
 614         dirname = '\0';
 615         havedir = 0;
 616         if (*name == '/') {
 617                 if (ISDOT(name + 1) || ISDOTDOT(name + 1))
 618                         strcpy(realname, "/");
 619                 else {
 620                         if ((dirname = strrchr(name + 1, '/')) == NULL)
 621                                 snprintf(realname, MAXPATHLEN, "%s", name);
 622                         else
 623                                 havedir = 1;
 624                 }
 625         } else {
 626                 if (ISDOT(name) || ISDOTDOT(name))
 627                         realpath(name, realname);
 628                 else {
 629                         if ((dirname = strrchr(name, '/')) == NULL) {
 630                                 if ((realpath(name, realname)) == NULL)
 631                                         return (NULL);
 632                         } else
 633                                 havedir = 1;
 634                 }
 635         }
 636         if (havedir) {
 637                 *dirname++ = '\0';
 638                 if (ISDOT(dirname)) {
 639                         *dirname = '\0';
 640                         if ((realpath(name, realname)) == NULL)
 641                                 return (NULL);
 642                 } else if (ISDOTDOT(dirname)) {
 643                         *--dirname = '/';
 644                         if ((realpath(name, realname)) == NULL)
 645                                 return (NULL);
 646                 } else {
 647                         if ((realpath(name, realname)) == NULL)
 648                                 return (NULL);
 649                         baselen = strlen(realname);
 650                         dirlen = strlen(dirname);
 651                         if (baselen + dirlen + 1 > MAXPATHLEN)
 652                                 return (NULL);
 653                         if (realname[1] == '\0') {
 654                                 memmove(realname + 1, dirname, dirlen);
 655                                 realname[dirlen + 1] = '\0';
 656                         } else {
 657                                 realname[baselen] = '/';
 658                                 memmove(realname + baselen + 1,
 659                                     dirname, dirlen);
 660                                 realname[baselen + dirlen + 1] = '\0';
 661                         }
 662                 }
 663         }
 664         return (realname);
 665 }
 666
 667 /*
 668  * xdr routines for mount rpc's
 669  */
 670 int
 671 xdr_dir(XDR *xdrsp, char *dirp)
 672 {
 673
 674         return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
 675 }
 676
 677 void
 678 usage(void)
 679 {
 680
 681         fprintf(stderr, "%s\n%s\n",
 682             "usage: umount [-fv] special | node",
 683             "       umount -a | -A [-fv] [-h host] [-t type]");
 684         exit(1);
 685 }