コード例 #1
0
ファイル: amfs_toplvl.c プロジェクト: randy1/DragonFlyBSD
/*
 * Mount an automounter directory.
 * The automounter is connected into the system
 * as a user-level NFS server.  mount_amfs_toplvl constructs
 * the necessary NFS parameters to be given to the
 * kernel so that it will talk back to us.
 *
 * NOTE: automounter mounts in themselves are using NFS Version 2.
 */
static int
mount_amfs_toplvl(char *dir, char *opts)
{
    char fs_hostname[MAXHOSTNAMELEN + MAXPATHLEN + 1];
    int retry, error, genflags;
    mntent_t mnt;
    nfs_args_t nfs_args;
    am_nfs_fh *fhp;
    am_nfs_handle_t anh;
    MTYPE_TYPE type = MOUNT_TYPE_NFS;
#ifndef HAVE_TRANSPORT_TYPE_TLI
    u_short port;
    struct sockaddr_in sin;
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    memset((voidp) &mnt, 0, sizeof(mnt));
    mnt.mnt_dir = dir;
    mnt.mnt_fsname = pid_fsname;
    mnt.mnt_opts = opts;

    /*
     * Make sure that amd's top-level NFS mounts are hidden by default
     * from df.
     * If they don't appear to support the either the "ignore" mnttab
     * option entry, or the "auto" one, set the mount type to "nfs".
     */
    mnt.mnt_type = HIDE_MOUNT_TYPE;

    retry = hasmntval(&mnt, MNTTAB_OPT_RETRY);
    if (retry <= 0)
        retry = 2;			/* XXX */

    /*
     * SET MOUNT ARGS
     */
    /*
     * get fhandle of remote path for automount point
     */
    fhp = root_fh(dir);
    if (!fhp) {
        plog(XLOG_FATAL, "Can't find root file handle for %s", dir);
        return EINVAL;
    }

#ifndef HAVE_TRANSPORT_TYPE_TLI
    /*
     * Create sockaddr to point to the local machine.  127.0.0.1
     * is not used since that will not work in HP-UX clusters and
     * this is no more expensive.
     */
    memset((voidp) &sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_addr = myipaddr;
    port = hasmntval(&mnt, MNTTAB_OPT_PORT);
    if (port) {
        sin.sin_port = htons(port);
    } else {
        plog(XLOG_ERROR, "no port number specified for %s", dir);
        return EINVAL;
    }
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    /*
     * Make a ``hostname'' string for the kernel
     */
    sprintf(fs_hostname, "pid%ld@%s:%s",
            (long) (foreground ? am_mypid : getppid()),
            am_get_hostname(),
            dir);
    /*
     * Most kernels have a name length restriction (64 bytes)...
     */
    if (strlen(fs_hostname) >= MAXHOSTNAMELEN)
        strcpy(fs_hostname + MAXHOSTNAMELEN - 3, "..");
#ifdef HOSTNAMESZ
    /*
     * ... and some of these restrictions are 32 bytes (HOSTNAMESZ)
     * If you need to get the definition for HOSTNAMESZ found, you may
     * add the proper header file to the conf/nfs_prot/nfs_prot_*.h file.
     */
    if (strlen(fs_hostname) >= HOSTNAMESZ)
        strcpy(fs_hostname + HOSTNAMESZ - 3, "..");
#endif /* HOSTNAMESZ */

    /*
     * Finally we can compute the mount genflags set above,
     * and add any automounter specific flags.
     */
    genflags = compute_mount_flags(&mnt);
    genflags |= compute_automounter_mount_flags(&mnt);

    /* setup the many fields and flags within nfs_args */
    memmove(&anh.v2.fhs_fh, fhp, sizeof(*fhp));
#ifdef HAVE_TRANSPORT_TYPE_TLI
    compute_nfs_args(&nfs_args,
                     &mnt,
                     genflags,
                     nfsncp,
                     NULL,	/* remote host IP addr is set below */
                     NFS_VERSION,	/* version 2 */
                     "udp",
                     &anh,
                     fs_hostname,
                     pid_fsname);
    /*
     * IMPORTANT: set the correct IP address AFTERWARDS.  It cannot
     * be done using the normal mechanism of compute_nfs_args(), because
     * that one will allocate a new address and use NFS_SA_DREF() to copy
     * parts to it, while assuming that the ip_addr passed is always
     * a "struct sockaddr_in".  That assumption is incorrect on TLI systems,
     * because they define a special macro HOST_SELF which is DIFFERENT
     * than localhost (127.0.0.1)!
     */
    nfs_args.addr = &nfsxprt->xp_ltaddr;
#else /* not HAVE_TRANSPORT_TYPE_TLI */
    compute_nfs_args(&nfs_args,
                     &mnt,
                     genflags,
                     &sin,
                     NFS_VERSION,	/* version 2 */
                     "udp",
                     &anh,
                     fs_hostname,
                     pid_fsname);
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    /*************************************************************************
     * NOTE: while compute_nfs_args() works ok for regular NFS mounts	   *
     * the toplvl one is not, and so some options must be corrected by hand  *
     * more carefully, *after* compute_nfs_args() runs.			   *
     *************************************************************************/
    compute_automounter_nfs_args(&nfs_args, &mnt);

    /* This is it!  Here we try to mount amd on its mount points */
#ifdef DEBUG
    amuDebug(D_TRACE) {
        print_nfs_args(&nfs_args, 0);
        plog(XLOG_DEBUG, "Generic mount flags 0x%x", genflags);
    }
#endif /* DEBUG */
    error = mount_fs(&mnt, genflags, (caddr_t) &nfs_args, retry, type,
                     0, NULL, mnttab_file_name);

#ifdef HAVE_TRANSPORT_TYPE_TLI
    free_knetconfig(nfs_args.knconf);
    /*
     * local automounter mounts do not allocate a special address, so
     * no need to XFREE(nfs_args.addr) under TLI.
     */
#endif /* HAVE_TRANSPORT_TYPE_TLI */

    return error;
}
コード例 #2
0
ファイル: hlfsd.c プロジェクト: AzerTyQsdF/osx
int
main(int argc, char *argv[])
{
  char *dot;
  char *mntopts = (char *) NULL;
  char hostpid_fs[MAXHOSTNAMELEN + 1 + 16];	/* room for ":(pid###)" */
  char progpid_fs[PROGNAMESZ + 1 + 11];		/* room for ":pid" */
  char preopts[128];
  char *progname;
  int forcecache = 0;
  int forcefast = 0;
  int genflags = 0;
  int opt, ret;
  int opterrs = 0;
  int retry;
  int soNFS;			/* NFS socket */
  int s = -99;
  mntent_t mnt;
  nfs_args_t nfs_args;
  am_nfs_handle_t anh;
  struct dirent *direntry;
  struct group *grp;
  struct stat stmodes;
  DIR *mountdir;
  MTYPE_TYPE type = MOUNT_TYPE_NFS;

#ifdef HAVE_SIGACTION
  struct sigaction sa;
#endif /* not HAVE_SIGACTION */

#ifndef HAVE_TRANSPORT_TYPE_TLI
  struct sockaddr_in localsocket;
#endif /* not HAVE_TRANSPORT_TYPE_TLI */


  /* get program name and truncate so we don't overflow progpid_fs */

  if ((progname = strrchr(argv[0], '/')) != NULL)
    progname++;
  else
    progname = argv[0];
  if ((int) strlen(progname) > PROGNAMESZ) /* truncate to reasonable size */
    progname[PROGNAMESZ] = '\0';
  am_set_progname(progname);

  while ((opt = getopt(argc, argv, "a:c:CD:fg:hi:l:no:pP:x:v")) != -1)
    switch (opt) {

    case 'a':
      if (!optarg || optarg[0] != '/') {
	printf("%s: invalid directory for -a: %s\n",
	       am_get_progname(), optarg);
	exit(3);
      }
      alt_spooldir = optarg;
      break;

    case 'c':
      if (!atoi(optarg)) {
	printf("%s: invalid interval for -c: %s\n",
	       am_get_progname(), optarg);
	exit(3);
      }
      cache_interval = atoi(optarg);
      break;

    case 'C':
      forcecache++;
      break;

    case 'f':
      forcefast++;
      break;

    case 'g':
      hlfs_group = optarg;
      break;

    case 'i':
      if (!atoi(optarg)) {
	printf("%s: invalid interval for -i: %s\n",
	       am_get_progname(), optarg);
	exit(3);
      }
      reloadinterval.it_interval.tv_sec = atoi(optarg);
      reloadinterval.it_value.tv_sec = atoi(optarg);
      break;

    case 'l':
      logfile = optarg;
      break;

    case 'n':
      noverify++;
      break;

    case 'o':
      mntopts = optarg;
      break;

    case 'p':
      printpid++;
      break;

    case 'P':
      passwdfile = optarg;
      break;

    case 'v':
      fprintf(stderr, "%s\n", HLFSD_VERSION);
      exit(0);

    case 'x':
      opterrs += switch_option(optarg);
      break;

    case 'D':
#ifdef DEBUG
      opterrs += debug_option(optarg);
#else /* not DEBUG */
      fprintf(stderr, "%s: not compiled with DEBUG -- sorry.\n", am_get_progname());
#endif /* not DEBUG */
      break;

    case 'h':
    case '?':
      opterrs++;
    }

  /* set some default debugging options */
  if (xlog_level_init == ~0)
    switch_option("");
  /* need my pid before any dlog/plog */
  am_set_mypid();
#ifdef DEBUG
  switch_option("debug");
#endif /* DEBUG */

/*
 * Terminate if did not ask to forcecache (-C) and hlfsd would not be able
 * to set the minimum cache intervals.
 */
#if !defined(MNT2_NFS_OPT_ACREGMIN) && !defined(MNT2_NFS_OPT_NOAC) && !defined(HAVE_NFS_ARGS_T_ACREGMIN)
  if (!forcecache) {
    fprintf(stderr, "%s: will not be able to turn off attribute caches.\n", am_get_progname());
    exit(1);
  }
#endif /* !defined(MNT2_NFS_OPT_ACREGMIN) && !defined(MNT2_NFS_OPT_NOAC) && !defined(HAVE_NFS_ARGS_T_ACREGMIN) */


  switch (argc - optind) {
  case 2:
    home_subdir = argv[optind + 1];
  case 1:
    dir_name = argv[optind];
  case 0:
    break;
  default:
    opterrs++;
  }

  if (opterrs)
    usage();

  /* ensure that only root can run hlfsd */
  if (geteuid()) {
    fprintf(stderr, "hlfsd can only be run as root\n");
    exit(1);
  }
  setbuf(stdout, (char *) NULL);
  umask(0);

  /* find gid for hlfs_group */
  if ((grp = getgrnam(hlfs_group)) == (struct group *) NULL) {
    fprintf(stderr, "%s: cannot get gid for group \"%s\".\n",
	    am_get_progname(), hlfs_group);
  } else {
    hlfs_gid = grp->gr_gid;
  }

  /* get hostname for logging and open log before we reset umask */
  gethostname(hostname, sizeof(hostname));
  hostname[sizeof(hostname) - 1] = '\0';
  if ((dot = strchr(hostname, '.')) != NULL)
    *dot = '\0';
  orig_umask = umask(0);
  if (logfile)
    switch_to_logfile(logfile, orig_umask);

#if defined(DEBUG) && !defined(MOUNT_TABLE_ON_FILE)
  if (debug_flags & D_MTAB)
    dlog("-D mtab option ignored");
#endif /* defined(DEBUG) && !defined(MOUNT_TABLE_ON_FILE) */

  /* avoid hanging on other NFS servers if started elsewhere */
  if (chdir("/") < 0)
    fatal("cannot chdir to /: %m");

  if (geteuid() != 0)
    fatal("must be root to mount filesystems");

  /*
   * dir_name must match "^(/.*)/([^/]+)$", and is split at last '/' with
   * slinkname = `basename $dir_name` - requires dir_name be writable
   */

  if (dir_name[0] != '/'
      || ((slinkname = strrchr(dir_name, '/')), *slinkname++ = '\0',
	  (dir_name[0] == '\0' || slinkname[0] == '\0'))) {
    if (slinkname)
      *--slinkname = '/';
    printf("%s: invalid mount directory/link %s\n",
	   am_get_progname(), dir_name);
    exit(3);
  }

  clock_valid = 0;		/* invalidate logging clock */

  if (!forcefast) {
    /* make sure mount point exists and is at least mode 555 */
    if (stat(dir_name, &stmodes) < 0)
      if (errno != ENOENT || mkdirs(dir_name, 0555) < 0
	  || stat(dir_name, &stmodes) < 0)
	fatalerror(dir_name);

    if ((stmodes.st_mode & 0555) != 0555) {
      fprintf(stderr, "%s: directory %s not read/executable\n",
	      am_get_progname(), dir_name);
      plog(XLOG_WARNING, "directory %s not read/executable",
	   dir_name);
    }

    /* warn if extraneous stuff will be hidden by mount */
    if ((mountdir = opendir(dir_name)) == NULL)
      fatalerror(dir_name);

    while ((direntry = readdir(mountdir)) != NULL) {
      if (!NSTREQ(".", direntry->d_name, NAMLEN(direntry)) &&
	  !NSTREQ("..", direntry->d_name, NAMLEN(direntry)) &&
	  !NSTREQ(slinkname, direntry->d_name, NAMLEN(direntry)))
	break;
    }

    if (direntry != NULL) {
      fprintf(stderr, "%s: %s/%s will be hidden by mount\n",
	      am_get_progname(), dir_name, direntry->d_name);
      plog(XLOG_WARNING, "%s/%s will be hidden by mount\n",
	   dir_name, direntry->d_name);
    }
    closedir(mountdir);

    /* make sure alternate spool dir exists */
    if ((errno = mkdirs(alt_spooldir, OPEN_SPOOLMODE))) {
      fprintf(stderr, "%s: cannot create alternate dir ",
	      am_get_progname());
      perror(alt_spooldir);
      plog(XLOG_ERROR, "cannot create alternate dir %s: %m",
	   alt_spooldir);
    }
    chmod(alt_spooldir, OPEN_SPOOLMODE);

    /* create failsafe link to alternate spool directory */
    slinkname[-1] = '/';	/* unsplit dir_name to include link */
    if (lstat(dir_name, &stmodes) == 0 &&
	(stmodes.st_mode & S_IFMT) != S_IFLNK) {
      fprintf(stderr, "%s: failsafe %s not a symlink\n",
	      am_get_progname(), dir_name);
      plog(XLOG_WARNING, "failsafe %s not a symlink\n",
	   dir_name);
    } else {
      unlink(dir_name);

      if (symlink(alt_spooldir, dir_name) < 0) {
	fprintf(stderr,
		"%s: cannot create failsafe symlink %s -> ",
		am_get_progname(), dir_name);
	perror(alt_spooldir);
	plog(XLOG_WARNING,
	     "cannot create failsafe symlink %s -> %s: %m",
	     dir_name, alt_spooldir);
      }
    }

    slinkname[-1] = '\0';	/* resplit dir_name */
  } /* end of "if (!forcefast) {" */

  /*
   * Register hlfsd as an nfs service with the portmapper.
   */
#ifdef HAVE_TRANSPORT_TYPE_TLI
  ret = create_nfs_service(&soNFS, &nfs_port, &nfsxprt, nfs_program_2);
#else /* not HAVE_TRANSPORT_TYPE_TLI */
  ret = create_nfs_service(&soNFS, &nfs_port, &nfsxprt, nfs_program_2);
#endif /* not HAVE_TRANSPORT_TYPE_TLI */
  if (ret != 0)
    fatal("cannot create NFS service");

#ifdef HAVE_SIGACTION
  sa.sa_handler = proceed;
  sa.sa_flags = 0;
  sigemptyset(&(sa.sa_mask));
  sigaddset(&(sa.sa_mask), SIGUSR2);
  sigaction(SIGUSR2, &sa, NULL);
#else /* not HAVE_SIGACTION */
  signal(SIGUSR2, proceed);
#endif /* not HAVE_SIGACTION */

  plog(XLOG_INFO, "Initializing hlfsd...");
  hlfsd_init();			/* start up child (forking) to run svc_run */

#ifdef HAVE_SIGACTION
  sa.sa_handler = reaper;
  sa.sa_flags = 0;
  sigemptyset(&(sa.sa_mask));
  sigaddset(&(sa.sa_mask), SIGCHLD);
  sigaction(SIGCHLD, &sa, NULL);
#else /* not HAVE_SIGACTION */
  signal(SIGCHLD, reaper);
#endif /* not HAVE_SIGACTION */

#ifdef DEBUG
  /*
   * In the parent, if -D nodaemon (or -D daemon) , we don't need to
   * set this signal handler.
   */
  amuDebug(D_DAEMON) {
#endif /* DEBUG */
    /* XXX: port to use pure svr4 signals */
    s = -99;
    while (stoplight != SIGUSR2) {
      plog(XLOG_INFO, "parent waits for child to setup (stoplight=%d)", stoplight);
      s = sigpause(0);		/* wait for child to set up */
      sleep(1);
    }
#ifdef DEBUG
  }
#endif /* DEBUG */

  /*
   * setup options to mount table (/etc/{mtab,mnttab}) entry
   */
  sprintf(hostpid_fs, "%s:(pid%d)", hostname, masterpid);
  memset((char *) &mnt, 0, sizeof(mnt));
  mnt.mnt_dir = dir_name;	/* i.e., "/mail" */
  mnt.mnt_fsname = hostpid_fs;
  if (mntopts) {
    mnt.mnt_opts = mntopts;
  } else {
    strcpy(preopts, default_mntopts);
    /*
     * Turn off all kinds of attribute and symlink caches as
     * much as possible.  Also make sure that mount does not
     * show up to df.
     */
#ifdef MNTTAB_OPT_INTR
    strcat(preopts, ",");
    strcat(preopts, MNTTAB_OPT_INTR);
#endif /* MNTTAB_OPT_INTR */
#ifdef MNTTAB_OPT_IGNORE
    strcat(preopts, ",");
    strcat(preopts, MNTTAB_OPT_IGNORE);
#endif /* MNTTAB_OPT_IGNORE */
#ifdef MNT2_GEN_OPT_CACHE
    strcat(preopts, ",nocache");
#endif /* MNT2_GEN_OPT_CACHE */
#ifdef MNT2_NFS_OPT_SYMTTL
    strcat(preopts, ",symttl=0");
#endif /* MNT2_NFS_OPT_SYMTTL */
    mnt.mnt_opts = preopts;
  }

  /*
   * Make sure that amd's top-level NFS mounts are hidden by default
   * from df.
   * If they don't appear to support the either the "ignore" mnttab
   * option entry, or the "auto" one, set the mount type to "nfs".
   */
#ifdef HIDE_MOUNT_TYPE
  mnt.mnt_type = HIDE_MOUNT_TYPE;
#else /* not HIDE_MOUNT_TYPE */
  mnt.mnt_type = "nfs";
#endif /* not HIDE_MOUNT_TYPE */
  /* some systems don't have a mount type, but a mount flag */

#ifndef HAVE_TRANSPORT_TYPE_TLI
  amu_get_myaddress(&localsocket.sin_addr);
  localsocket.sin_family = AF_INET;
  localsocket.sin_port = htons(nfsxprt->xp_port);
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

  /*
   * Update hostname field.
   * Make some name prog:pid (i.e., hlfsd:174) for hostname
   */
  sprintf(progpid_fs, "%s:%d", am_get_progname(), masterpid);

  /* Most kernels have a name length restriction. */
  if ((int) strlen(progpid_fs) >= (int) MAXHOSTNAMELEN)
    strcpy(progpid_fs + MAXHOSTNAMELEN - 3, "..");

  genflags = compute_mount_flags(&mnt);

  retry = hasmntval(&mnt, MNTTAB_OPT_RETRY);
  if (retry <= 0)
    retry = 1;			/* XXX */

  memmove(&anh.v2.fhs_fh, root_fhp, sizeof(*root_fhp));
#ifdef HAVE_TRANSPORT_TYPE_TLI
  compute_nfs_args(&nfs_args,
		   &mnt,
		   genflags,
		   nfsncp,
		   NULL,	/* remote host IP addr is set below */
		   NFS_VERSION,	/* version 2 */
		   "udp",	/* XXX: shouldn't this be "udp"? */
		   &anh,
		   progpid_fs,	/* host name for kernel */
		   hostpid_fs); /* filesystem name for kernel */
  /*
   * IMPORTANT: set the correct IP address AFTERWARDS.  It cannot
   * be done using the normal mechanism of compute_nfs_args(), because
   * that one will allocate a new address and use NFS_SA_DREF() to copy
   * parts to it, while assuming that the ip_addr passed is always
   * a "struct sockaddr_in".  That assumption is incorrect on TLI systems,
   * because they define a special macro HOST_SELF which is DIFFERENT
   * than localhost (127.0.0.1)!
   */
  nfs_args.addr = &nfsxprt->xp_ltaddr;
#else /* not HAVE_TRANSPORT_TYPE_TLI */
  compute_nfs_args(&nfs_args,
		   &mnt,
		   genflags,
		   NULL,
		   &localsocket,
		   NFS_VERSION, /* version 2 */
		   "udp",	/* XXX: shouldn't this be "udp"? */
		   &anh,
		   progpid_fs,	/* host name for kernel */
		   hostpid_fs); /* filesystem name for kernel */
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

  /*************************************************************************
   * NOTE: while compute_nfs_args() works ok for regular NFS mounts	   *
   * the toplvl one is not, and so some options must be corrected by hand  *
   * more carefully, *after* compute_nfs_args() runs.			   *
   *************************************************************************/
  compute_automounter_nfs_args(&nfs_args, &mnt);

  clock_valid = 0;		/* invalidate logging clock */

/*
 * The following code could be cleverly ifdef-ed, but I duplicated the
 * mount_fs call three times for simplicity and readability.
 */
#ifdef DEBUG
/*
 * For some reason, this mount may have to be done in the background, if I am
 * using -D nodebug.  I suspect that the actual act of mounting requires
 * calling to hlfsd itself to invoke one or more of its nfs calls, to stat
 * /mail.  That means that even if you say -D nodaemon, at least the mount
 * of hlfsd itself on top of /mail will be done in the background.
 * The other alternative I have is to run svc_run, but set a special
 * signal handler to perform the mount in N seconds via some alarm.
 *      -Erez Zadok.
 */
  amuDebug(D_DAEMON) {	/* asked for -D daemon */
    plog(XLOG_INFO, "parent NFS mounting hlfsd service points");
    if (mount_fs2(&mnt, dir_name, genflags, (caddr_t) &nfs_args, retry, type, 0, NULL, mnttab_file_name) < 0)
      fatal("nfsmount: %m");
  } else {			/* asked for -D nodaemon */
    if (fork() == 0) {		/* child runs mount */
コード例 #3
0
ファイル: autil.c プロジェクト: 0mp/freebsd
/*
 * Mount an automounter directory.
 * The automounter is connected into the system
 * as a user-level NFS server.  amfs_mount constructs
 * the necessary NFS parameters to be given to the
 * kernel so that it will talk back to us.
 *
 * NOTE: automounter mounts in themselves are using NFS Version 2 (UDP).
 *
 * NEW: on certain systems, mounting can be done using the
 * kernel-level automount (autofs) support. In that case,
 * we don't need NFS at all here.
 */
int
amfs_mount(am_node *mp, mntfs *mf, char *opts)
{
  char fs_hostname[MAXHOSTNAMELEN + MAXPATHLEN + 1];
  int retry, error = 0, genflags;
  int on_autofs = mf->mf_flags & MFF_ON_AUTOFS;
  char *dir = mf->mf_mount;
  mntent_t mnt;
  MTYPE_TYPE type;
  int forced_unmount = 0;	/* are we using forced unmounts? */
  u_long nfs_version = get_nfs_dispatcher_version(nfs_dispatcher);

  memset(&mnt, 0, sizeof(mnt));
  mnt.mnt_dir = dir;
  mnt.mnt_fsname = pid_fsname;
  mnt.mnt_opts = opts;

#ifdef HAVE_FS_AUTOFS
  if (mf->mf_flags & MFF_IS_AUTOFS) {
    type = MOUNT_TYPE_AUTOFS;
    /*
     * Make sure that amd's top-level autofs mounts are hidden by default
     * from df.
     * XXX: It works ok on Linux, might not work on other systems.
     */
    mnt.mnt_type = "autofs";
  } else
#endif /* HAVE_FS_AUTOFS */
  {
    type = MOUNT_TYPE_NFS;
    /*
     * Make sure that amd's top-level NFS mounts are hidden by default
     * from df.
     * If they don't appear to support the either the "ignore" mnttab
     * option entry, or the "auto" one, set the mount type to "nfs".
     */
    mnt.mnt_type = HIDE_MOUNT_TYPE;
  }

  retry = hasmntval(&mnt, MNTTAB_OPT_RETRY);
  if (retry <= 0)
    retry = 2;			/* XXX: default to 2 retries */

  /*
   * SET MOUNT ARGS
   */

  /*
   * Make a ``hostname'' string for the kernel
   */
  xsnprintf(fs_hostname, sizeof(fs_hostname), "pid%ld@%s:%s",
	    get_server_pid(), am_get_hostname(), dir);
  /*
   * Most kernels have a name length restriction (64 bytes)...
   */
  if (strlen(fs_hostname) >= MAXHOSTNAMELEN)
    xstrlcpy(fs_hostname + MAXHOSTNAMELEN - 3, "..",
	     sizeof(fs_hostname) - MAXHOSTNAMELEN + 3);
#ifdef HOSTNAMESZ
  /*
   * ... and some of these restrictions are 32 bytes (HOSTNAMESZ)
   * If you need to get the definition for HOSTNAMESZ found, you may
   * add the proper header file to the conf/nfs_prot/nfs_prot_*.h file.
   */
  if (strlen(fs_hostname) >= HOSTNAMESZ)
    xstrlcpy(fs_hostname + HOSTNAMESZ - 3, "..",
	     sizeof(fs_hostname) - HOSTNAMESZ + 3);
#endif /* HOSTNAMESZ */

  /*
   * Finally we can compute the mount genflags set above,
   * and add any automounter specific flags.
   */
  genflags = compute_mount_flags(&mnt);
#ifdef HAVE_FS_AUTOFS
  if (on_autofs)
    genflags |= autofs_compute_mount_flags(&mnt);
#endif /* HAVE_FS_AUTOFS */
  genflags |= compute_automounter_mount_flags(&mnt);

again:
  if (!(mf->mf_flags & MFF_IS_AUTOFS)) {
    nfs_args_t nfs_args;
    am_nfs_handle_t *fhp, anh;
#ifndef HAVE_TRANSPORT_TYPE_TLI
    u_short port;
    struct sockaddr_in sin;
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    /*
     * get fhandle of remote path for automount point
     */
    fhp = get_root_nfs_fh(dir, &anh);
    if (!fhp) {
      plog(XLOG_FATAL, "Can't find root file handle for %s", dir);
      return EINVAL;
    }

#ifndef HAVE_TRANSPORT_TYPE_TLI
    /*
     * Create sockaddr to point to the local machine.
     */
    memset(&sin, 0, sizeof(sin));
    /* as per POSIX, sin_len need not be set (used internally by kernel) */
    sin.sin_family = AF_INET;
    sin.sin_addr = myipaddr;
    port = hasmntval(&mnt, MNTTAB_OPT_PORT);
    if (port) {
      sin.sin_port = htons(port);
    } else {
      plog(XLOG_ERROR, "no port number specified for %s", dir);
      return EINVAL;
    }
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    /* setup the many fields and flags within nfs_args */
#ifdef HAVE_TRANSPORT_TYPE_TLI
    compute_nfs_args(&nfs_args,
		     &mnt,
		     genflags,
		     nfsncp,
		     NULL,	/* remote host IP addr is set below */
		     nfs_version,
		     "udp",
		     fhp,
		     fs_hostname,
		     pid_fsname);
    /*
     * IMPORTANT: set the correct IP address AFTERWARDS.  It cannot
     * be done using the normal mechanism of compute_nfs_args(), because
     * that one will allocate a new address and use NFS_SA_DREF() to copy
     * parts to it, while assuming that the ip_addr passed is always
     * a "struct sockaddr_in".  That assumption is incorrect on TLI systems,
     * because they define a special macro HOST_SELF which is DIFFERENT
     * than localhost (127.0.0.1)!
     */
    nfs_args.addr = &nfsxprt->xp_ltaddr;
#else /* not HAVE_TRANSPORT_TYPE_TLI */
    compute_nfs_args(&nfs_args,
		     &mnt,
		     genflags,
		     NULL,
		     &sin,
		     nfs_version,
		     "udp",
		     fhp,
		     fs_hostname,
		     pid_fsname);
#endif /* not HAVE_TRANSPORT_TYPE_TLI */

    /*************************************************************************
     * NOTE: while compute_nfs_args() works ok for regular NFS mounts	     *
     * the toplvl one is not quite regular, and so some options must be      *
     * corrected by hand more carefully, *after* compute_nfs_args() runs.    *
     *************************************************************************/
    compute_automounter_nfs_args(&nfs_args, &mnt);

    if (amuDebug(D_TRACE)) {
      print_nfs_args(&nfs_args, 0);
      plog(XLOG_DEBUG, "Generic mount flags 0x%x", genflags);
    }

    /* This is it!  Here we try to mount amd on its mount points */
    error = mount_fs(&mnt, genflags, (caddr_t) &nfs_args,
		     retry, type, 0, NULL, mnttab_file_name, on_autofs);

#ifdef HAVE_TRANSPORT_TYPE_TLI
    free_knetconfig(nfs_args.knconf);
    /*
     * local automounter mounts do not allocate a special address, so
     * no need to XFREE(nfs_args.addr) under TLI.
     */
#endif /* HAVE_TRANSPORT_TYPE_TLI */

#ifdef HAVE_FS_AUTOFS
  } else {
    /* This is it!  Here we try to mount amd on its mount points */
    error = mount_fs(&mnt, genflags, (caddr_t) mp->am_autofs_fh,
		     retry, type, 0, NULL, mnttab_file_name, on_autofs);
#endif /* HAVE_FS_AUTOFS */
  }
  if (error == 0 || forced_unmount)
     return error;

  /*
   * If user wants forced/lazy unmount semantics, then try it iff the
   * current mount failed with EIO or ESTALE.
   */
  if (gopt.flags & CFM_FORCED_UNMOUNTS) {
    switch (errno) {
    case ESTALE:
    case EIO:
      forced_unmount = errno;
      plog(XLOG_WARNING, "Mount %s failed (%m); force unmount.", mp->am_path);
      if ((error = UMOUNT_FS(mp->am_path, mnttab_file_name,
			     AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH)) < 0) {
	plog(XLOG_WARNING, "Forced umount %s failed: %m.", mp->am_path);
	errno = forced_unmount;
      } else
	goto again;
    default:
      break;
    }
  }

  return error;
}