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Sourcecode: freebsd-utils version File versions

umount.c

/*-
 * Copyright (c) 1980, 1989, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1989, 1993\n\
      The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)umount.c      8.8 (Berkeley) 5/8/95";
#endif
static const char rcsid[] =
  "$FreeBSD: src/sbin/umount/umount.c,v 1.45.18.1 2008/11/25 02:59:29 kensmith Exp $";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netdb.h>
#include <rpc/rpc.h>
#include <nfs/rpcv2.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fstab.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mounttab.h"

typedef enum { FIND, REMOVE, CHECKUNIQUE } dowhat;

struct  addrinfo *nfshost_ai = NULL;
int   fflag, vflag;
char   *nfshost;

struct statfs *checkmntlist(char *);
int    checkvfsname (const char *, char **);
struct statfs *getmntentry(const char *fromname, const char *onname,
           fsid_t *fsid, dowhat what);
char   **makevfslist (const char *);
size_t       mntinfo (struct statfs **);
int    namematch (struct addrinfo *);
int    parsehexfsid(const char *hex, fsid_t *fsid);
int    sacmp (struct sockaddr *, struct sockaddr *);
int    umountall (char **);
int    checkname (char *, char **);
int    umountfs(struct statfs *sfs);
void   usage (void);
int    xdr_dir (XDR *, char *);

int
main(int argc, char *argv[])
{
      int all, errs, ch, mntsize, error;
      char **typelist = NULL;
      struct statfs *mntbuf, *sfs;
      struct addrinfo hints;

      /* Start disks transferring immediately. */
      sync();

      all = errs = 0;
      while ((ch = getopt(argc, argv, "AaF:fh:t:v")) != -1)
            switch (ch) {
            case 'A':
                  all = 2;
                  break;
            case 'a':
                  all = 1;
                  break;
            case 'F':
                  setfstab(optarg);
                  break;
            case 'f':
                  fflag = MNT_FORCE;
                  break;
            case 'h':   /* -h implies -A. */
                  all = 2;
                  nfshost = optarg;
                  break;
            case 't':
                  if (typelist != NULL)
                        err(1, "only one -t option may be specified");
                  typelist = makevfslist(optarg);
                  break;
            case 'v':
                  vflag = 1;
                  break;
            default:
                  usage();
                  /* NOTREACHED */
            }
      argc -= optind;
      argv += optind;

      if ((argc == 0 && !all) || (argc != 0 && all))
            usage();

      /* -h implies "-t nfs" if no -t flag. */
      if ((nfshost != NULL) && (typelist == NULL))
            typelist = makevfslist("nfs");

      if (nfshost != NULL) {
            memset(&hints, 0, sizeof hints);
            error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
            if (error)
                  errx(1, "%s: %s", nfshost, gai_strerror(error));
      }

      switch (all) {
      case 2:
            if ((mntsize = mntinfo(&mntbuf)) <= 0)
                  break;
            /*
             * We unmount the nfs-mounts in the reverse order
             * that they were mounted.
             */
            for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
                  sfs = &mntbuf[mntsize];
                  if (checkvfsname(sfs->f_fstypename, typelist))
                        continue;
                  if (umountfs(sfs) != 0)
                        errs = 1;
            }
            free(mntbuf);
            break;
      case 1:
            if (setfsent() == 0)
                  err(1, "%s", getfstab());
            errs = umountall(typelist);
            break;
      case 0:
            for (errs = 0; *argv != NULL; ++argv)
                  if (checkname(*argv, typelist) != 0)
                        errs = 1;
            break;
      }
      exit(errs);
}

int
umountall(char **typelist)
{
      struct xvfsconf vfc;
      struct fstab *fs;
      int rval;
      char *cp;
      static int firstcall = 1;

      if ((fs = getfsent()) != NULL)
            firstcall = 0;
      else if (firstcall)
            errx(1, "fstab reading failure");
      else
            return (0);
      do {
            /* Ignore the root. */
            if (strcmp(fs->fs_file, "/") == 0)
                  continue;
            /*
             * !!!
             * Historic practice: ignore unknown FSTAB_* fields.
             */
            if (strcmp(fs->fs_type, FSTAB_RW) &&
                strcmp(fs->fs_type, FSTAB_RO) &&
                strcmp(fs->fs_type, FSTAB_RQ))
                  continue;
            /* Ignore unknown file system types. */
            if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
                  continue;
            if (checkvfsname(fs->fs_vfstype, typelist))
                  continue;

            /*
             * We want to unmount the file systems in the reverse order
             * that they were mounted.  So, we save off the file name
             * in some allocated memory, and then call recursively.
             */
            if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
                  err(1, "malloc failed");
            (void)strcpy(cp, fs->fs_file);
            rval = umountall(typelist);
            rval = checkname(cp, typelist) || rval;
            free(cp);
            return (rval);
      } while ((fs = getfsent()) != NULL);
      return (0);
}

/*
 * Do magic checks on mountpoint/device/fsid, and then call unmount(2).
 */
int
checkname(char *name, char **typelist)
{
      char buf[MAXPATHLEN];
      struct statfs sfsbuf;
      struct stat sb;
      struct statfs *sfs;
      char *delimp;
      dev_t dev;
      int len;

      /*
       * 1. Check if the name exists in the mounttable.
       */
      sfs = checkmntlist(name);
      /*
       * 2. Remove trailing slashes if there are any. After that
       * we look up the name in the mounttable again.
       */
      if (sfs == NULL) {
            len = strlen(name);
            while (len > 1 && name[len - 1] == '/')
                  name[--len] = '\0';
            sfs = checkmntlist(name);
      }
      /*
       * 3. Check if the deprecated NFS syntax with an '@' has been used
       * and translate it to the ':' syntax. Look up the name in the
       * mount table again.
       */
      if (sfs == NULL && (delimp = strrchr(name, '@')) != NULL) {
            snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1, delimp - name,
                name);
            len = strlen(buf);
            while (len > 1 && buf[len - 1] == '/')
                  buf[--len] = '\0';
            sfs = checkmntlist(buf);
      }
      /*
       * 4. Resort to a statfs(2) call. This is the last check so that
       * hung NFS filesystems for example can be unmounted without
       * potentially blocking forever in statfs() as long as the
       * filesystem is specified unambiguously. This covers all the
       * hard cases such as symlinks and mismatches between the
       * mount list and reality.
       * We also do this if an ambiguous mount point was specified.
       */
      if (sfs == NULL || (getmntentry(NULL, name, NULL, FIND) != NULL &&
          getmntentry(NULL, name, NULL, CHECKUNIQUE) == NULL)) {
            if (statfs(name, &sfsbuf) != 0) {
                  warn("%s: statfs", name);
            } else if (stat(name, &sb) != 0) {
                  warn("%s: stat", name);
            } else if (S_ISDIR(sb.st_mode)) {
                  /* Check that `name' is the root directory. */
                  dev = sb.st_dev;
                  snprintf(buf, sizeof(buf), "%s/..", name);
                  if (stat(buf, &sb) != 0) {
                        warn("%s: stat", buf);
                  } else if (sb.st_dev == dev) {
                        warnx("%s: not a file system root directory",
                            name);
                        return (1);
                  } else
                        sfs = &sfsbuf;
            }
      }
      if (sfs == NULL) {
            warnx("%s: unknown file system", name);
            return (1);
      }
      if (checkvfsname(sfs->f_fstypename, typelist))
            return (1);
      return (umountfs(sfs));
}

/*
 * NFS stuff and unmount(2) call
 */
int
umountfs(struct statfs *sfs)
{
      char fsidbuf[64];
      enum clnt_stat clnt_stat;
      struct timeval try;
      struct addrinfo *ai, hints;
      int do_rpc;
      CLIENT *clp;
      char *nfsdirname, *orignfsdirname;
      char *hostp, *delimp;

      ai = NULL;
      do_rpc = 0;
      hostp = NULL;
      nfsdirname = delimp = orignfsdirname = NULL;
      memset(&hints, 0, sizeof hints);

      if (strcmp(sfs->f_fstypename, "nfs") == 0) {
            if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
                  err(1, "strdup");
            orignfsdirname = nfsdirname;
            if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
                  *delimp = '\0';
                  hostp = nfsdirname;
                  getaddrinfo(hostp, NULL, &hints, &ai);
                  if (ai == NULL) {
                        warnx("can't get net id for host");
                  }
                  nfsdirname = delimp + 1;
            }

            /*
             * Check if we have to start the rpc-call later.
             * If there are still identical nfs-names mounted,
             * we skip the rpc-call. Obviously this has to
             * happen before unmount(2), but it should happen
             * after the previous namecheck.
             * A non-NULL return means that this is the last
             * mount from mntfromname that is still mounted.
             */
            if (getmntentry(sfs->f_mntfromname, NULL, NULL,
                CHECKUNIQUE) != NULL)
                  do_rpc = 1;
      }

      if (!namematch(ai))
            return (1);
      /* First try to unmount using the file system ID. */
      snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
          sfs->f_fsid.val[1]);
      if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
            /* XXX, non-root users get a zero fsid, so don't warn. */
            if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
                sfs->f_fsid.val[1] != 0)
                  warn("unmount of %s failed", sfs->f_mntonname);
            if (errno != ENOENT)
                  return (1);
            /* Compatibility for old kernels. */
            if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
                  warnx("retrying using path instead of file system ID");
            if (unmount(sfs->f_mntonname, fflag) != 0) {
                  warn("unmount of %s failed", sfs->f_mntonname);
                  return (1);
            }
      }
      /* Mark this this file system as unmounted. */
      getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
      if (vflag)
            (void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
                sfs->f_mntonname);
      /*
       * Report to mountd-server which nfsname
       * has been unmounted.
       */
      if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
            clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
            if (clp  == NULL) {
                  warnx("%s: %s", hostp,
                      clnt_spcreateerror("RPCPROG_MNT"));
                  return (1);
            }
            clp->cl_auth = authsys_create_default();
            try.tv_sec = 20;
            try.tv_usec = 0;
            clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir,
                nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
            if (clnt_stat != RPC_SUCCESS) {
                  warnx("%s: %s", hostp,
                      clnt_sperror(clp, "RPCMNT_UMOUNT"));
                  return (1);
            }
            /*
             * Remove the unmounted entry from /var/db/mounttab.
             */
            if (read_mtab()) {
                  clean_mtab(hostp, nfsdirname, vflag);
                  if(!write_mtab(vflag))
                        warnx("cannot remove mounttab entry %s:%s",
                            hostp, nfsdirname);
                  free_mtab();
            }
            free(orignfsdirname);
            auth_destroy(clp->cl_auth);
            clnt_destroy(clp);
      }
      return (0);
}

struct statfs *
getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
{
      static struct statfs *mntbuf;
      static size_t mntsize = 0;
      static char *mntcheck = NULL;
      struct statfs *sfs, *foundsfs;
      int i, count;

      if (mntsize <= 0) {
            if ((mntsize = mntinfo(&mntbuf)) <= 0)
                  return (NULL);
      }
      if (mntcheck == NULL) {
            if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
                  err(1, "calloc");
      }
      /*
       * We want to get the file systems in the reverse order
       * that they were mounted. Unmounted file systems are marked
       * in a table called 'mntcheck'.
       */
      count = 0;
      foundsfs = NULL;
      for (i = mntsize - 1; i >= 0; i--) {
            if (mntcheck[i])
                  continue;
            sfs = &mntbuf[i];
            if (fromname != NULL && strcmp(sfs->f_mntfromname,
                fromname) != 0)
                  continue;
            if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
                  continue;
            if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
                sizeof(*fsid)) != 0)
                  continue;

            switch (what) {
            case CHECKUNIQUE:
                  foundsfs = sfs;
                  count++;
                  continue;
            case REMOVE:
                  mntcheck[i] = 1;
                  break;
            default:
                  break;
            }
            return (sfs);
      }

      if (what == CHECKUNIQUE && count == 1)
            return (foundsfs);
      return (NULL);
}

int
sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
{
      void *p1, *p2;
      int len;

      if (sa1->sa_family != sa2->sa_family)
            return (1);

      switch (sa1->sa_family) {
      case AF_INET:
            p1 = &((struct sockaddr_in *)sa1)->sin_addr;
            p2 = &((struct sockaddr_in *)sa2)->sin_addr;
            len = 4;
            break;
      case AF_INET6:
            p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
            p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
            len = 16;
            if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
                ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
                  return (1);
            break;
      default:
            return (1);
      }

      return memcmp(p1, p2, len);
}

int
namematch(struct addrinfo *ai)
{
      struct addrinfo *aip;

      if (nfshost == NULL || nfshost_ai == NULL)
            return (1);

      while (ai != NULL) {
            aip = nfshost_ai;
            while (aip != NULL) {
                  if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
                        return (1);
                  aip = aip->ai_next;
            }
            ai = ai->ai_next;
      }

      return (0);
}

struct statfs *
checkmntlist(char *name)
{
      struct statfs *sfs;
      fsid_t fsid;

      sfs = NULL;
      if (parsehexfsid(name, &fsid) == 0)
            sfs = getmntentry(NULL, NULL, &fsid, FIND);
      if (sfs == NULL)
            sfs = getmntentry(NULL, name, NULL, FIND);
      if (sfs == NULL)
            sfs = getmntentry(name, NULL, NULL, FIND);
      return (sfs);
}

size_t
mntinfo(struct statfs **mntbuf)
{
      static struct statfs *origbuf;
      size_t bufsize;
      int mntsize;

      mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
      if (mntsize <= 0)
            return (0);
      bufsize = (mntsize + 1) * sizeof(struct statfs);
      if ((origbuf = malloc(bufsize)) == NULL)
            err(1, "malloc");
      mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
      *mntbuf = origbuf;
      return (mntsize);
}

/*
 * Convert a hexadecimal filesystem ID to an fsid_t.
 * Returns 0 on success.
 */
int
parsehexfsid(const char *hex, fsid_t *fsid)
{
      char hexbuf[3];
      int i;

      if (strlen(hex) != sizeof(*fsid) * 2)
            return (-1);
      hexbuf[2] = '\0';
      for (i = 0; i < (int)sizeof(*fsid); i++) {
            hexbuf[0] = hex[i * 2];
            hexbuf[1] = hex[i * 2 + 1];
            if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
                  return (-1);
            ((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
      }
      return (0);
}

/*
 * xdr routines for mount rpc's
 */
int
xdr_dir(XDR *xdrsp, char *dirp)
{

      return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
}

void
usage()
{

      (void)fprintf(stderr, "%s\n%s\n",
          "usage: umount [-fv] special | node | fsid",
          "       umount -a | -A [-F fstab] [-fv] [-h host] [-t type]");
      exit(1);
}

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