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 1.28 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 size_t   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
 254         len = 0;
 255         mntfromname = mntonname = delimp = hostp = NULL;
 256
 257         /*
 258          * 1. Check if the name exists in the mounttable.
 259          */
 260         checkmntlist(name, &mntfromname, &mntonname, &type);
 261         /*
 262          * 2. Remove trailing slashes if there are any. After that
 263          * we look up the name in the mounttable again.
 264          */
 265         if (mntfromname == NULL && mntonname == NULL) {
 266                 speclen = strlen(name);
 267                 for (speclen = strlen(name);
 268                     speclen > 1 && name[speclen - 1] == '/';
 269                     speclen--)
 270                         name[speclen - 1] = '\0';
 271                 checkmntlist(name, &mntfromname, &mntonname, &type);
 272                 resolved = name;
 273                 /* Save off original name in origname */
 274                 if ((origname = strdup(name)) == NULL)
 275                         err(1, "strdup");
 276                 /*
 277                  * 3. Check if the deprecated nfs-syntax with an '@'
 278                  * has been used and translate it to the ':' syntax.
 279                  * Look up the name in the mounttable again.
 280                  */
 281                 if (mntfromname == NULL && mntonname == NULL) {
 282                         if ((delimp = strrchr(name, '@')) != NULL) {
 283                                 hostp = delimp + 1;
 284                                 if (*hostp != '\0') {
 285                                         /*
 286                                          * Make both '@' and ':'
 287                                          * notations equal
 288                                          */
 289                                         char *host = strdup(hostp);
 290                                         len = strlen(hostp);
 291                                         if (host == NULL)
 292                                                 err(1, "strdup");
 293                                         memmove(name + len + 1, name,
 294                                             (size_t)(delimp - name));
 295                                         name[len] = ':';
 296                                         memmove(name, host, len);
 297                                         free(host);
 298                                 }
 299                                 for (speclen = strlen(name);
 300                                     speclen > 1 && name[speclen - 1] == '/';
 301                                     speclen--)
 302                                         name[speclen - 1] = '\0';
 303                                 name[len + speclen + 1] = '\0';
 304                                 checkmntlist(name, &mntfromname,
 305                                     &mntonname, &type);
 306                                 resolved = name;
 307                         }
 308                         /*
 309                          * 4. Check if a relative mountpoint has been
 310                          * specified. This should happen as last check,
 311                          * the order is important. To prevent possible
 312                          * nfs-hangs, we just call realpath(3) on the
 313                          * basedir of mountpoint and add the dirname again.
 314                          * Check the name in mounttable one last time.
 315                          */
 316                         if (mntfromname == NULL && mntonname == NULL) {
 317                                 strcpy(name, origname);
 318                                 if ((getrealname(name, realname)) != NULL) {
 319                                         checkmntlist(realname,
 320                                             &mntfromname, &mntonname, &type);
 321                                         resolved = realname;
 322                                 }
 323                                 /*
 324                                  * 5. All tests failed, just hand over the
 325                                  * mountpoint to the kernel, maybe the statfs
 326                                  * structure has been truncated or is not
 327                                  * useful anymore because of a chroot(2).
 328                                  * Please note that nfs will not be able to
 329                                  * notify the nfs-server about unmounting.
 330                                  * These things can change in future when the
 331                                  * fstat structure get's more reliable,
 332                                  * but at the moment we cannot thrust it.
 333                                  */
 334                                 if (mntfromname == NULL && mntonname == NULL) {
 335                                         strcpy(name, origname);
 336                                         if (umountfs(NULL, origname,
 337                                             "none") == 0) {;
 338                                                 warnx("%s not found in "
 339                                                     "mount table, "
 340                                                     "unmounted it anyway",
 341                                                     origname);
 342                                                 free(origname);
 343                                                 return (0);
 344                                         } else
 345                                                 free(origname);
 346                                                 return (1);
 347                                 }
 348                         }
 349                 }
 350                 free(origname);
 351         } else
 352                 resolved = name;
 353
 354         if (checkvfsname(type, typelist))
 355                 return (1);
 356
 357         /*
 358          * Check if the reverse entrys of the mounttable are really the
 359          * same as the normal ones.
 360          */
 361         if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname,
 362             NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL)
 363                 err(1, "strdup");
 364         /*
 365          * Mark the uppermost mount as unmounted.
 366          */
 367         getmntname(mntfromname, mntonname, NOTHING, &type, MARK);
 368         /*
 369          * If several equal mounts are in the mounttable, check the order
 370          * and warn the user if necessary.
 371          */
 372         if (strcmp(mntfromnamerev, mntfromname ) != 0 &&
 373             strcmp(resolved, mntonname) != 0) {
 374                 warnx("cannot umount %s, %s\n        "
 375                     "is mounted there, umount it first",
 376                     mntonname, mntfromnamerev);
 377
 378                 /* call getmntname again to set mntcheck[i] to 0 */
 379                 getmntname(mntfromname, mntonname,
 380                     NOTHING, &type, UNMARK);
 381                 return (1);
 382         }
 383         free(mntfromnamerev);
 384         return (umountfs(mntfromname, mntonname, type));
 385 }
 386
 387 /*
 388  * NFS stuff and unmount(2) call
 389  */
 390 int
 391 umountfs(char *mntfromname, char *mntonname, char *type)
 392 {
 393         enum clnt_stat clnt_stat;
 394         struct timeval try;
 395         struct addrinfo *ai, hints;
 396         int do_rpc;
 397         CLIENT *clp;
 398         char *nfsdirname, *orignfsdirname;
 399         char *hostp, *delimp;
 400
 401         ai = NULL;
 402         do_rpc = 0;
 403         hostp = NULL;
 404         nfsdirname = delimp = orignfsdirname = NULL;
 405         memset(&hints, 0, sizeof hints);
 406
 407         if (strcmp(type, "nfs") == 0) {
 408                 if ((nfsdirname = strdup(mntfromname)) == NULL)
 409                         err(1, "strdup");
 410                 orignfsdirname = nfsdirname;
 411                 if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
 412                         *delimp = '\0';
 413                         hostp = nfsdirname;
 414                         getaddrinfo(hostp, NULL, &hints, &ai);
 415                         if (ai == NULL) {
 416                                 warnx("can't get net id for host");
 417                         }
 418                         nfsdirname = delimp + 1;
 419                 }
 420
 421                 /*
 422                  * Check if we have to start the rpc-call later.
 423                  * If there are still identical nfs-names mounted,
 424                  * we skip the rpc-call. Obviously this has to
 425                  * happen before unmount(2), but it should happen
 426                  * after the previous namecheck.
 427                  * A non-NULL return means that this is the last
 428                  * mount from mntfromname that is still mounted.
 429                  */
 430                 if (getmntname(mntfromname, NULL, NOTHING, &type, COUNT)
 431                      != NULL)
 432                         do_rpc = 1;
 433         }
 434
 435         if (!namematch(ai))
 436                 return (1);
 437         if (unmount(mntonname, fflag) != 0 ) {
 438                 warn("unmount of %s failed", mntonname);
 439                 return (1);
 440         }
 441         if (vflag)
 442                 printf("%s: unmount from %s\n", mntfromname, mntonname);
 443         /*
 444          * Report to mountd-server which nfsname
 445          * has been unmounted.
 446          */
 447         if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
 448                 clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
 449                 if (clp  == NULL) {
 450                         warnx("%s: %s", hostp,
 451                             clnt_spcreateerror("RPCPROG_MNT"));
 452                         return (1);
 453                 }
 454                 clp->cl_auth = authsys_create_default();
 455                 try.tv_sec = 20;
 456                 try.tv_usec = 0;
 457                 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, xdr_dir,
 458                     nfsdirname, xdr_void, (caddr_t)0, try);
 459                 if (clnt_stat != RPC_SUCCESS) {
 460                         warnx("%s: %s", hostp,
 461                             clnt_sperror(clp, "RPCMNT_UMOUNT"));
 462                         return (1);
 463                 }
 464                 /*
 465                  * Remove the unmounted entry from /var/db/mounttab.
 466                  */
 467                 if (read_mtab()) {
 468                         clean_mtab(hostp, nfsdirname, vflag);
 469                         if(!write_mtab(vflag))
 470                                 warnx("cannot remove mounttab entry %s:%s",
 471                                     hostp, nfsdirname);
 472                         free_mtab();
 473                 }
 474                 free(orignfsdirname);
 475                 auth_destroy(clp->cl_auth);
 476                 clnt_destroy(clp);
 477         }
 478         return (0);
 479 }
 480
 481 char *
 482 getmntname(const char *fromname, const char *onname,
 483     mntwhat what, char **type, dowhat mark)
 484 {
 485         static struct statfs *mntbuf;
 486         static size_t mntsize = 0;
 487         static char *mntcheck = NULL;
 488         static char *mntcount = NULL;
 489         int i, count;
 490
 491         if (mntsize <= 0) {
 492                 if ((mntsize = mntinfo(&mntbuf)) <= 0)
 493                         return (NULL);
 494         }
 495         if (mntcheck == NULL) {
 496                 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
 497                     (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
 498                         err(1, "calloc");
 499         }
 500         /*
 501          * We want to get the file systems in the reverse order
 502          * that they were mounted. Mounted and unmounted filesystems
 503          * are marked or unmarked in a table called 'mntcheck'.
 504          * Unmount(const char *dir, int flags) does only take the
 505          * mountpoint as argument, not the destination. If we don't pay
 506          * attention to the order, it can happen that a overlaying
 507          * filesystem get's unmounted instead of the one the user
 508          * has choosen.
 509          */
 510         switch (mark) {
 511         case NAME:
 512                 /* Return only the specific name */
 513                 for (i = mntsize - 1; i >= 0; i--) {
 514                         if (fromname != NULL && what == MNTON &&
 515                             !strcmp(mntbuf[i].f_mntfromname, fromname) &&
 516                             mntcheck[i] != 1) {
 517                                 if (type)
 518                                         *type = mntbuf[i].f_fstypename;
 519                                 return (mntbuf[i].f_mntonname);
 520                         }
 521                         if (fromname != NULL && what == MNTFROM &&
 522                             !strcmp(mntbuf[i].f_mntonname, fromname) &&
 523                             mntcheck[i] != 1) {
 524                                 if (type)
 525                                         *type = mntbuf[i].f_fstypename;
 526                                 return (mntbuf[i].f_mntfromname);
 527                         }
 528                 }
 529                 return (NULL);
 530         case MARK:
 531                 /* Mark current mount with '1' and return name */
 532                 for (i = mntsize - 1; i >= 0; i--) {
 533                         if (mntcheck[i] == 0 &&
 534                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 535                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 536                                 mntcheck[i] = 1;
 537                                 return (mntbuf[i].f_mntonname);
 538                         }
 539                 }
 540                 return (NULL);
 541         case UNMARK:
 542                 /* Unmark current mount with '0' and return name */
 543                 for (i = 0; i < mntsize; i++) {
 544                         if (mntcheck[i] == 1 &&
 545                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 546                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 547                                 mntcheck[i] = 0;
 548                                 return (mntbuf[i].f_mntonname);
 549                         }
 550                 }
 551                 return (NULL);
 552         case COUNT:
 553                 /* Count the equal mntfromnames */
 554                 count = 0;
 555                 for (i = mntsize - 1; i >= 0; i--) {
 556                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
 557                                 count++;
 558                 }
 559                 /* Mark the already unmounted mounts and return
 560                  * mntfromname if count <= 1. Else return NULL.
 561                  */
 562                 for (i = mntsize - 1; i >= 0; i--) {
 563                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
 564                                 if (mntcount[i] == 1)
 565                                         count--;
 566                                 else {
 567                                         mntcount[i] = 1;
 568                                         break;
 569                                 }
 570                         }
 571                 }
 572                 if (count <= 1)
 573                         return (mntbuf[i].f_mntonname);
 574                 else
 575                         return (NULL);
 576         case FREE:
 577                 free(mntbuf);
 578                 free(mntcheck);
 579                 free(mntcount);
 580                 return (NULL);
 581         default:
 582                 return (NULL);
 583         }
 584 }
 585
 586 int
 587 sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
 588 {
 589         void *p1, *p2;
 590         int len;
 591
 592         if (sa1->sa_family != sa2->sa_family)
 593                 return (1);
 594
 595         switch (sa1->sa_family) {
 596         case AF_INET:
 597                 p1 = &((struct sockaddr_in *)sa1)->sin_addr;
 598                 p2 = &((struct sockaddr_in *)sa2)->sin_addr;
 599                 len = 4;
 600                 break;
 601         case AF_INET6:
 602                 p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
 603                 p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
 604                 len = 16;
 605                 if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
 606                     ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
 607                         return (1);
 608                 break;
 609         default:
 610                 return (1);
 611         }
 612
 613         return memcmp(p1, p2, len);
 614 }
 615
 616 int
 617 namematch(struct addrinfo *ai)
 618 {
 619         struct addrinfo *aip;
 620
 621         if (nfshost == NULL || nfshost_ai == NULL)
 622                 return (1);
 623
 624         while (ai != NULL) {
 625                 aip = nfshost_ai;
 626                 while (aip != NULL) {
 627                         if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
 628                                 return (1);
 629                         aip = aip->ai_next;
 630                 }
 631                 ai = ai->ai_next;
 632         }
 633
 634         return (0);
 635 }
 636
 637 void
 638 checkmntlist(char *name, char **fromname, char **onname, char **type)
 639 {
 640
 641         *fromname = getmntname(name, NULL, MNTFROM, type, NAME);
 642         if (*fromname == NULL) {
 643                 *onname = getmntname(name, NULL, MNTON, type, NAME);
 644                 if (*onname != NULL)
 645                         *fromname = name;
 646         } else
 647                 *onname = name;
 648 }
 649
 650 size_t
 651 mntinfo(struct statfs **mntbuf)
 652 {
 653         static struct statfs *origbuf;
 654         size_t bufsize;
 655         int mntsize;
 656
 657         mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
 658         if (mntsize <= 0)
 659                 return (0);
 660         bufsize = (mntsize + 1) * sizeof(struct statfs);
 661         if ((origbuf = malloc(bufsize)) == NULL)
 662                 err(1, "malloc");
 663         mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
 664         *mntbuf = origbuf;
 665         return (mntsize);
 666 }
 667
 668 char *
 669 getrealname(char *name, char *realname)
 670 {
 671         char *dirname;
 672         int havedir;
 673         size_t baselen;
 674         size_t dirlen;
 675
 676         dirname = '\0';
 677         havedir = 0;
 678         if (*name == '/') {
 679                 if (ISDOT(name + 1) || ISDOTDOT(name + 1))
 680                         strcpy(realname, "/");
 681                 else {
 682                         if ((dirname = strrchr(name + 1, '/')) == NULL)
 683                                 snprintf(realname, MAXPATHLEN, "%s", name);
 684                         else
 685                                 havedir = 1;
 686                 }
 687         } else {
 688                 if (ISDOT(name) || ISDOTDOT(name))
 689                         realpath(name, realname);
 690                 else {
 691                         if ((dirname = strrchr(name, '/')) == NULL) {
 692                                 if ((realpath(name, realname)) == NULL)
 693                                         return (NULL);
 694                         } else
 695                                 havedir = 1;
 696                 }
 697         }
 698         if (havedir) {
 699                 *dirname++ = '\0';
 700                 if (ISDOT(dirname)) {
 701                         *dirname = '\0';
 702                         if ((realpath(name, realname)) == NULL)
 703                                 return (NULL);
 704                 } else if (ISDOTDOT(dirname)) {
 705                         *--dirname = '/';
 706                         if ((realpath(name, realname)) == NULL)
 707                                 return (NULL);
 708                 } else {
 709                         if ((realpath(name, realname)) == NULL)
 710                                 return (NULL);
 711                         baselen = strlen(realname);
 712                         dirlen = strlen(dirname);
 713                         if (baselen + dirlen + 1 > MAXPATHLEN)
 714                                 return (NULL);
 715                         if (realname[1] == '\0') {
 716                                 memmove(realname + 1, dirname, dirlen);
 717                                 realname[dirlen + 1] = '\0';
 718                         } else {
 719                                 realname[baselen] = '/';
 720                                 memmove(realname + baselen + 1,
 721                                     dirname, dirlen);
 722                                 realname[baselen + dirlen + 1] = '\0';
 723                         }
 724                 }
 725         }
 726         return (realname);
 727 }
 728
 729 /*
 730  * xdr routines for mount rpc's
 731  */
 732 int
 733 xdr_dir(XDR *xdrsp, char *dirp)
 734 {
 735
 736         return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
 737 }
 738
 739 void
 740 usage(void)
 741 {
 742
 743         fprintf(stderr, "%s\n%s\n",
 744             "usage: umount [-fv] special | node",
 745             "       umount -a | -A [-fv] [-h host] [-t type]");
 746         exit(1);
 747 }