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 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         /*
 263          * 2. Remove trailing slashes if there are any. After that
 264          * we look up the name in the mounttable again.
 265          */
 266         if (mntfromname == NULL && mntonname == NULL) {
 267                 speclen = strlen(name);
 268                 for (speclen = strlen(name);
 269                     speclen > 1 && name[speclen - 1] == '/';
 270                     speclen--)
 271                         name[speclen - 1] = '\0';
 272                 checkmntlist(name, &mntfromname, &mntonname, &type);
 273                 resolved = name;
 274                 /* Save off original name in origname */
 275                 if ((origname = strdup(name)) == NULL)
 276                         err(1, "strdup");
 277                 /*
 278                  * 3. Check if the deprecated nfs-syntax with an '@'
 279                  * has been used and translate it to the ':' syntax.
 280                  * Look up the name in the mounttable again.
 281                  */
 282                 if (mntfromname == NULL && mntonname == NULL) {
 283                         if ((delimp = strrchr(name, '@')) != NULL) {
 284                                 hostp = delimp + 1;
 285                                 if (*hostp != '\0') {
 286                                         /*
 287                                          * Make both '@' and ':'
 288                                          * notations equal
 289                                          */
 290                                         char *host = strdup(hostp);
 291                                         len = strlen(hostp);
 292                                         if (host == NULL)
 293                                                 err(1, "strdup");
 294                                         memmove(name + len + 1, name,
 295                                             (size_t)(delimp - name));
 296                                         name[len] = ':';
 297                                         memmove(name, host, len);
 298                                         free(host);
 299                                 }
 300                                 for (speclen = strlen(name);
 301                                     speclen > 1 && name[speclen - 1] == '/';
 302                                     speclen--)
 303                                         name[speclen - 1] = '\0';
 304                                 name[len + speclen + 1] = '\0';
 305                                 checkmntlist(name, &mntfromname,
 306                                     &mntonname, &type);
 307                                 resolved = name;
 308                         }
 309                         /*
 310                          * 4. Check if a relative mountpoint has been
 311                          * specified. This should happen as last check,
 312                          * the order is important. To prevent possible
 313                          * nfs-hangs, we just call realpath(3) on the
 314                          * basedir of mountpoint and add the dirname again.
 315                          * Check the name in mounttable one last time.
 316                          */
 317                         if (mntfromname == NULL && mntonname == NULL) {
 318                                 strcpy(name, origname);
 319                                 if ((getrealname(name, realname)) != NULL) {
 320                                         checkmntlist(realname,
 321                                             &mntfromname, &mntonname, &type);
 322                                         resolved = realname;
 323                                 }
 324                                 /*
 325                                  * 5. All tests failed, just hand over the
 326                                  * mountpoint to the kernel, maybe the statfs
 327                                  * structure has been truncated or is not
 328                                  * useful anymore because of a chroot(2).
 329                                  * Please note that nfs will not be able to
 330                                  * notify the nfs-server about unmounting.
 331                                  * These things can change in future when the
 332                                  * fstat structure get's more reliable,
 333                                  * but at the moment we cannot thrust it.
 334                                  */
 335                                 if (mntfromname == NULL && mntonname == NULL) {
 336                                         strcpy(name, origname);
 337                                         if (umountfs(NULL, origname,
 338                                             none) == 0) {;
 339                                                 warnx("%s not found in "
 340                                                     "mount table, "
 341                                                     "unmounted it anyway",
 342                                                     origname);
 343                                                 free(origname);
 344                                                 return (0);
 345                                         } else
 346                                                 free(origname);
 347                                                 return (1);
 348                                 }
 349                         }
 350                 }
 351                 free(origname);
 352         } else
 353                 resolved = name;
 354
 355         if (checkvfsname(type, typelist))
 356                 return (1);
 357
 358         /*
 359          * Check if the reverse entrys of the mounttable are really the
 360          * same as the normal ones.
 361          */
 362         if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname,
 363             NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL)
 364                 err(1, "strdup");
 365         /*
 366          * Mark the uppermost mount as unmounted.
 367          */
 368         getmntname(mntfromname, mntonname, NOTHING, &type, MARK);
 369         /*
 370          * If several equal mounts are in the mounttable, check the order
 371          * and warn the user if necessary.
 372          */
 373         if (strcmp(mntfromnamerev, mntfromname ) != 0 &&
 374             strcmp(resolved, mntonname) != 0) {
 375                 warnx("cannot umount %s, %s\n        "
 376                     "is mounted there, umount it first",
 377                     mntonname, mntfromnamerev);
 378
 379                 /* call getmntname again to set mntcheck[i] to 0 */
 380                 getmntname(mntfromname, mntonname,
 381                     NOTHING, &type, UNMARK);
 382                 return (1);
 383         }
 384         free(mntfromnamerev);
 385         return (umountfs(mntfromname, mntonname, type));
 386 }
 387
 388 /*
 389  * NFS stuff and unmount(2) call
 390  */
 391 int
 392 umountfs(char *mntfromname, char *mntonname, char *type)
 393 {
 394         enum clnt_stat clnt_stat;
 395         struct timeval try;
 396         struct addrinfo *ai, hints;
 397         int do_rpc;
 398         CLIENT *clp;
 399         char *nfsdirname, *orignfsdirname;
 400         char *hostp, *delimp;
 401
 402         ai = NULL;
 403         do_rpc = 0;
 404         hostp = NULL;
 405         nfsdirname = delimp = orignfsdirname = NULL;
 406         memset(&hints, 0, sizeof hints);
 407
 408         if (strcmp(type, "nfs") == 0) {
 409                 if ((nfsdirname = strdup(mntfromname)) == NULL)
 410                         err(1, "strdup");
 411                 orignfsdirname = nfsdirname;
 412                 if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
 413                         *delimp = '\0';
 414                         hostp = nfsdirname;
 415                         getaddrinfo(hostp, NULL, &hints, &ai);
 416                         if (ai == NULL) {
 417                                 warnx("can't get net id for host");
 418                         }
 419                         nfsdirname = delimp + 1;
 420                 }
 421
 422                 /*
 423                  * Check if we have to start the rpc-call later.
 424                  * If there are still identical nfs-names mounted,
 425                  * we skip the rpc-call. Obviously this has to
 426                  * happen before unmount(2), but it should happen
 427                  * after the previous namecheck.
 428                  * A non-NULL return means that this is the last
 429                  * mount from mntfromname that is still mounted.
 430                  */
 431                 if (getmntname(mntfromname, NULL, NOTHING, &type, COUNT)
 432                      != NULL)
 433                         do_rpc = 1;
 434         }
 435
 436         if (!namematch(ai))
 437                 return (1);
 438         if (unmount(mntonname, fflag) != 0 ) {
 439                 warn("unmount of %s failed", mntonname);
 440                 return (1);
 441         }
 442         if (vflag)
 443                 printf("%s: unmount from %s\n", mntfromname, mntonname);
 444         /*
 445          * Report to mountd-server which nfsname
 446          * has been unmounted.
 447          */
 448         if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
 449                 clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
 450                 if (clp  == NULL) {
 451                         warnx("%s: %s", hostp,
 452                             clnt_spcreateerror("RPCPROG_MNT"));
 453                         return (1);
 454                 }
 455                 clp->cl_auth = authsys_create_default();
 456                 try.tv_sec = 20;
 457                 try.tv_usec = 0;
 458                 clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir,
 459                     nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
 460                 if (clnt_stat != RPC_SUCCESS) {
 461                         warnx("%s: %s", hostp,
 462                             clnt_sperror(clp, "RPCMNT_UMOUNT"));
 463                         return (1);
 464                 }
 465                 /*
 466                  * Remove the unmounted entry from /var/db/mounttab.
 467                  */
 468                 if (read_mtab()) {
 469                         clean_mtab(hostp, nfsdirname, vflag);
 470                         if(!write_mtab(vflag))
 471                                 warnx("cannot remove mounttab entry %s:%s",
 472                                     hostp, nfsdirname);
 473                         free_mtab();
 474                 }
 475                 free(orignfsdirname);
 476                 auth_destroy(clp->cl_auth);
 477                 clnt_destroy(clp);
 478         }
 479         return (0);
 480 }
 481
 482 char *
 483 getmntname(const char *fromname, const char *onname,
 484     mntwhat what, char **type, dowhat mark)
 485 {
 486         static struct statfs *mntbuf;
 487         static int mntsize = 0;
 488         static char *mntcheck = NULL;
 489         static char *mntcount = NULL;
 490         int i, count;
 491
 492         if (mntsize <= 0) {
 493                 if ((mntsize = mntinfo(&mntbuf)) <= 0)
 494                         return (NULL);
 495         }
 496         if (mntcheck == NULL) {
 497                 if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
 498                     (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
 499                         err(1, "calloc");
 500         }
 501         /*
 502          * We want to get the file systems in the reverse order
 503          * that they were mounted. Mounted and unmounted filesystems
 504          * are marked or unmarked in a table called 'mntcheck'.
 505          * Unmount(const char *dir, int flags) does only take the
 506          * mountpoint as argument, not the destination. If we don't pay
 507          * attention to the order, it can happen that a overlaying
 508          * filesystem get's unmounted instead of the one the user
 509          * has choosen.
 510          */
 511         switch (mark) {
 512         case NAME:
 513                 /* Return only the specific name */
 514                 for (i = mntsize - 1; i >= 0; i--) {
 515                         if (fromname != NULL && what == MNTON &&
 516                             !strcmp(mntbuf[i].f_mntfromname, fromname) &&
 517                             mntcheck[i] != 1) {
 518                                 if (type)
 519                                         *type = mntbuf[i].f_fstypename;
 520                                 return (mntbuf[i].f_mntonname);
 521                         }
 522                         if (fromname != NULL && what == MNTFROM &&
 523                             !strcmp(mntbuf[i].f_mntonname, fromname) &&
 524                             mntcheck[i] != 1) {
 525                                 if (type)
 526                                         *type = mntbuf[i].f_fstypename;
 527                                 return (mntbuf[i].f_mntfromname);
 528                         }
 529                 }
 530                 return (NULL);
 531         case MARK:
 532                 /* Mark current mount with '1' and return name */
 533                 for (i = mntsize - 1; i >= 0; i--) {
 534                         if (mntcheck[i] == 0 &&
 535                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 536                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 537                                 mntcheck[i] = 1;
 538                                 return (mntbuf[i].f_mntonname);
 539                         }
 540                 }
 541                 return (NULL);
 542         case UNMARK:
 543                 /* Unmark current mount with '0' and return name */
 544                 for (i = 0; i < mntsize; i++) {
 545                         if (mntcheck[i] == 1 &&
 546                             (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
 547                             (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
 548                                 mntcheck[i] = 0;
 549                                 return (mntbuf[i].f_mntonname);
 550                         }
 551                 }
 552                 return (NULL);
 553         case COUNT:
 554                 /* Count the equal mntfromnames */
 555                 count = 0;
 556                 for (i = mntsize - 1; i >= 0; i--) {
 557                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
 558                                 count++;
 559                 }
 560                 /* Mark the already unmounted mounts and return
 561                  * mntfromname if count <= 1. Else return NULL.
 562                  */
 563                 for (i = mntsize - 1; i >= 0; i--) {
 564                         if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
 565                                 if (mntcount[i] == 1)
 566                                         count--;
 567                                 else {
 568                                         mntcount[i] = 1;
 569                                         break;
 570                                 }
 571                         }
 572                 }
 573                 if (count <= 1)
 574                         return (mntbuf[i].f_mntonname);
 575                 else
 576                         return (NULL);
 577         case FREE:
 578                 free(mntbuf);
 579                 free(mntcheck);
 580                 free(mntcount);
 581                 return (NULL);
 582         default:
 583                 return (NULL);
 584         }
 585 }
 586
 587 int
 588 sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
 589 {
 590         void *p1, *p2;
 591         int len;
 592
 593         if (sa1->sa_family != sa2->sa_family)
 594                 return (1);
 595
 596         switch (sa1->sa_family) {
 597         case AF_INET:
 598                 p1 = &((struct sockaddr_in *)sa1)->sin_addr;
 599                 p2 = &((struct sockaddr_in *)sa2)->sin_addr;
 600                 len = 4;
 601                 break;
 602         case AF_INET6:
 603                 p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
 604                 p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
 605                 len = 16;
 606                 if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
 607                     ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
 608                         return (1);
 609                 break;
 610         default:
 611                 return (1);
 612         }
 613
 614         return memcmp(p1, p2, len);
 615 }
 616
 617 int
 618 namematch(struct addrinfo *ai)
 619 {
 620         struct addrinfo *aip;
 621
 622         if (nfshost == NULL || nfshost_ai == NULL)
 623                 return (1);
 624
 625         while (ai != NULL) {
 626                 aip = nfshost_ai;
 627                 while (aip != NULL) {
 628                         if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
 629                                 return (1);
 630                         aip = aip->ai_next;
 631                 }
 632                 ai = ai->ai_next;
 633         }
 634
 635         return (0);
 636 }
 637
 638 void
 639 checkmntlist(char *name, char **fromname, char **onname, char **type)
 640 {
 641
 642         *fromname = getmntname(name, NULL, MNTFROM, type, NAME);
 643         if (*fromname == NULL) {
 644                 *onname = getmntname(name, NULL, MNTON, type, NAME);
 645                 if (*onname != NULL)
 646                         *fromname = name;
 647         } else
 648                 *onname = name;
 649 }
 650
 651 int
 652 mntinfo(struct statfs **mntbuf)
 653 {
 654         static struct statfs *origbuf;
 655         size_t bufsize;
 656         int mntsize;
 657
 658         mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
 659         if (mntsize <= 0)
 660                 return (0);
 661         bufsize = (mntsize + 1) * sizeof(struct statfs);
 662         if ((origbuf = malloc(bufsize)) == NULL)
 663                 err(1, "malloc");
 664         mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
 665         *mntbuf = origbuf;
 666         return (mntsize);
 667 }
 668
 669 char *
 670 getrealname(char *name, char *realname)
 671 {
 672         char *dirname;
 673         int havedir;
 674         size_t baselen;
 675         size_t dirlen;
 676
 677         dirname = '\0';
 678         havedir = 0;
 679         if (*name == '/') {
 680                 if (ISDOT(name + 1) || ISDOTDOT(name + 1))
 681                         strcpy(realname, "/");
 682                 else {
 683                         if ((dirname = strrchr(name + 1, '/')) == NULL)
 684                                 snprintf(realname, MAXPATHLEN, "%s", name);
 685                         else
 686                                 havedir = 1;
 687                 }
 688         } else {
 689                 if (ISDOT(name) || ISDOTDOT(name))
 690                         realpath(name, realname);
 691                 else {
 692                         if ((dirname = strrchr(name, '/')) == NULL) {
 693                                 if ((realpath(name, realname)) == NULL)
 694                                         return (NULL);
 695                         } else
 696                                 havedir = 1;
 697                 }
 698         }
 699         if (havedir) {
 700                 *dirname++ = '\0';
 701                 if (ISDOT(dirname)) {
 702                         *dirname = '\0';
 703                         if ((realpath(name, realname)) == NULL)
 704                                 return (NULL);
 705                 } else if (ISDOTDOT(dirname)) {
 706                         *--dirname = '/';
 707                         if ((realpath(name, realname)) == NULL)
 708                                 return (NULL);
 709                 } else {
 710                         if ((realpath(name, realname)) == NULL)
 711                                 return (NULL);
 712                         baselen = strlen(realname);
 713                         dirlen = strlen(dirname);
 714                         if (baselen + dirlen + 1 > MAXPATHLEN)
 715                                 return (NULL);
 716                         if (realname[1] == '\0') {
 717                                 memmove(realname + 1, dirname, dirlen);
 718                                 realname[dirlen + 1] = '\0';
 719                         } else {
 720                                 realname[baselen] = '/';
 721                                 memmove(realname + baselen + 1,
 722                                     dirname, dirlen);
 723                                 realname[baselen + dirlen + 1] = '\0';
 724                         }
 725                 }
 726         }
 727         return (realname);
 728 }
 729
 730 /*
 731  * xdr routines for mount rpc's
 732  */
 733 int
 734 xdr_dir(XDR *xdrsp, char *dirp)
 735 {
 736
 737         return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
 738 }
 739
 740 void
 741 usage(void)
 742 {
 743
 744         fprintf(stderr, "%s\n%s\n",
 745             "usage: umount [-fv] special | node",
 746             "       umount -a | -A [-fv] [-h host] [-t type]");
 747         exit(1);
 748 }