source/client/umount.cifs.c

   1 /*
   2    Unmount utility program for Linux CIFS VFS (virtual filesystem) client
   3    Copyright (C) 2005 Steve French  (sfrench@us.ibm.com)
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 #ifndef _GNU_SOURCE
  20 #define _GNU_SOURCE
  21 #endif
  22
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <unistd.h>
  26 #include <ctype.h>
  27 #include <sys/types.h>
  28 #include <sys/mount.h>
  29 #include <sys/ioctl.h>
  30 #include <sys/stat.h>
  31 #include <fcntl.h>
  32 #include <getopt.h>
  33 #include <errno.h>
  34 #include <string.h>
  35 #include <mntent.h>
  36
  37 #define UNMOUNT_CIFS_VERSION_MAJOR "0"
  38 #define UNMOUNT_CIFS_VERSION_MINOR "1"
  39
  40 #ifndef UNMOUNT_CIFS_VENDOR_SUFFIX
  41 #define UNMOUNT_CIFS_VENDOR_SUFFIX ""
  42 #endif
  43
  44 #ifndef MNT_DETACH
  45 #define MNT_DETACH 0x02
  46 #endif
  47
  48 #ifndef MNT_EXPIRE
  49 #define MNT_EXPIRE 0x04
  50 #endif
  51
  52 #define CIFS_IOC_CHECKUMOUNT _IO('c', 2)
  53
  54 static struct option longopts[] = {
  55         { "all", 0, NULL, 'a' },
  56         { "help",0, NULL, 'h' },
  57         { "read-only", 0, NULL, 'r' },
  58         { "ro", 0, NULL, 'r' },
  59         { "verbose", 0, NULL, 'v' },
  60         { "version", 0, NULL, 'V' },
  61         { "expire", 0, NULL, 'e' },
  62         { "force", 0, 0, 'f' },
  63         { "lazy", 0, 0, 'l' },
  64         { "no-mtab", 0, 0, 'n' },
  65         { NULL, 0, NULL, 0 }
  66 };
  67
  68 char * thisprogram;
  69 int verboseflg = 0;
  70
  71 static void umount_cifs_usage(void)
  72 {
  73         printf("\nUsage:  %s <remotetarget> <dir>\n", thisprogram);
  74         printf("\nUnmount the specified directory\n");
  75         printf("\nLess commonly used options:");
  76         printf("\n\t-r\tIf mount fails, retry with readonly remount.");
  77         printf("\n\t-n\tDo not write to mtab.");
  78         printf("\n\t-f\tAttempt a forced unmount, even if the fs is busy.");
  79         printf("\n\t-l\tAttempt lazy unmount, Unmount now, cleanup later.");
  80         printf("\n\t-v\tEnable verbose mode (may be useful for debugging).");
  81         printf("\n\t-h\tDisplay this help.");
  82         printf("\n\nOptions are described in more detail in the manual page");
  83         printf("\n\tman 8 umount.cifs\n");
  84         printf("\nTo display the version number of the cifs umount utility:");
  85         printf("\n\t%s -V\n",thisprogram);
  86 }
  87
  88 static int umount_check_perm(char * dir)
  89 {
  90         int fileid;
  91         int rc;
  92
  93         /* presumably can not chdir into the target as we do on mount */
  94
  95         fileid = open(dir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0);
  96         if(fileid == -1) {
  97                 if(verboseflg)
  98                         printf("error opening mountpoint %d %s",errno,strerror(errno));
  99                 return errno;
 100         }
 101
 102         rc = ioctl(fileid, CIFS_IOC_CHECKUMOUNT, NULL);
 103
 104         if(verboseflg)
 105                 printf("ioctl returned %d with errno %d %s\n",rc,errno,strerror(errno));
 106
 107         if(rc == ENOTTY)
 108                 printf("user unmounting via %s is an optional feature of the cifs filesystem driver (cifs.ko)\n\tand requires cifs.ko version 1.32 or later\n",thisprogram);
 109         else if (rc > 0)
 110                 printf("user unmount of %s failed with %d %s",dir,errno,strerror(errno));
 111         close(fileid);
 112
 113         return rc;
 114 }
 115
 116 int main(int argc, char ** argv)
 117 {
 118         int c;
 119         int rc;
 120         int flags = 0;
 121         int nomtab = 0;
 122         int retry_remount = 0;
 123         struct mntent mountent;
 124         char * mountpoint;
 125         FILE * pmntfile;
 126
 127         if(argc && argv) {
 128                 thisprogram = argv[0];
 129         } else {
 130                 umount_cifs_usage();
 131                 return -EINVAL;
 132         }
 133
 134         if(argc < 2) {
 135                 umount_cifs_usage();
 136                 return -EINVAL;
 137         }
 138
 139         if(thisprogram == NULL)
 140                 thisprogram = "umount.cifs";
 141
 142         /* add sharename in opts string as unc= parm */
 143
 144         while ((c = getopt_long (argc, argv, "afhilnrvV",
 145                          longopts, NULL)) != -1) {
 146                 switch (c) {
 147 /* No code to do the following  option yet */
 148 /*              case 'a':
 149                         ++umount_all;
 150                         break; */
 151                 case '?':
 152                 case 'h':   /* help */
 153                         umount_cifs_usage();
 154                         exit(1);
 155                 case 'n':
 156                         ++nomtab;
 157                         break;
 158                 case 'f':
 159                         flags |= MNT_FORCE;
 160                         break;
 161                 case 'l':
 162                         flags |= MNT_DETACH; /* lazy unmount */
 163                         break;
 164                 case 'e':
 165                         flags |= MNT_EXPIRE; /* gradually timeout */
 166                         break;
 167                 case 'r':
 168                         ++retry_remount;
 169                         break;
 170                 case 'v':
 171                         ++verboseflg;
 172                         break;
 173                 case 'V':
 174                         printf ("umount.cifs version: %s.%s%s\n",
 175                                 UNMOUNT_CIFS_VERSION_MAJOR,
 176                                 UNMOUNT_CIFS_VERSION_MINOR,
 177                                 UNMOUNT_CIFS_VENDOR_SUFFIX);
 178                         exit (0);
 179                 default:
 180                         printf("unknown unmount option %c\n",c);
 181                         umount_cifs_usage();
 182                         exit(1);
 183                 }
 184         }
 185
 186         /* move past the umount options */
 187         argv += optind;
 188         argc -= optind;
 189
 190         mountpoint = argv[0];
 191
 192         if((argc < 1) || (argv[0] == NULL)) {
 193                 printf("\nMissing name of unmount directory\n");
 194                 umount_cifs_usage();
 195                 return -EINVAL;
 196         }
 197
 198         if(verboseflg)
 199                 printf("optind %d unmount dir %s\n",optind, mountpoint);
 200
 201         /* check if running effectively root */
 202         if(geteuid() != 0)
 203                 printf("Trying to unmount when %s not installed suid\n",thisprogram);
 204
 205         /* fixup path if needed */
 206
 207         /* check if our uid was the one who mounted */
 208         rc = umount_check_perm(mountpoint);
 209         if (rc) {
 210                 return rc;
 211         }
 212
 213         if(umount2(mountpoint, flags)) {
 214         /* remember to kill daemon on error */
 215
 216                 switch (errno) {
 217                 case 0:
 218                         printf("mount failed but no error number set\n");
 219                         break;
 220                 default:
 221
 222                         printf("mount error %d = %s\n",errno,strerror(errno));
 223                 }
 224                 printf("Refer to the umount.cifs(8) manual page (e.g.man 8 umount.cifs)\n");
 225                 return -1;
 226         } else {
 227                 pmntfile = setmntent(MOUNTED, "a+");
 228                 if(pmntfile) {
 229 /*                      mountent.mnt_fsname = share_name;
 230                         mountent.mnt_dir = mountpoint;
 231                         mountent.mnt_type = "cifs";
 232                         mountent.mnt_opts = malloc(220);
 233                         if(mountent.mnt_opts) {
 234                                 char * mount_user = getusername();
 235                                 memset(mountent.mnt_opts,0,200);
 236                                 if(flags & MS_RDONLY)
 237                                         strcat(mountent.mnt_opts,"ro");
 238                                 else
 239                                         strcat(mountent.mnt_opts,"rw");
 240                                 if(flags & MS_MANDLOCK)
 241                                         strcat(mountent.mnt_opts,",mand");
 242                                 else
 243                                         strcat(mountent.mnt_opts,",nomand");
 244                                 if(flags & MS_NOEXEC)
 245                                         strcat(mountent.mnt_opts,",noexec");
 246                                 if(flags & MS_NOSUID)
 247                                         strcat(mountent.mnt_opts,",nosuid");
 248                                 if(flags & MS_NODEV)
 249                                         strcat(mountent.mnt_opts,",nodev");
 250                                 if(flags & MS_SYNCHRONOUS)
 251                                         strcat(mountent.mnt_opts,",synch");
 252                                 if(mount_user) {
 253                                         if(getuid() != 0) {
 254                                                 strcat(mountent.mnt_opts,",user=");
 255                                                 strcat(mountent.mnt_opts,mount_user);
 256                                         }
 257                                         free(mount_user);
 258                                 }
 259                         }
 260                         mountent.mnt_freq = 0;
 261                         mountent.mnt_passno = 0;
 262                         rc = addmntent(pmntfile,&mountent);
 263                         endmntent(pmntfile);
 264                         if(mountent.mnt_opts)
 265                                 free(mountent.mnt_opts);*/
 266                 } else {
 267                     printf("could not update mount table\n");
 268                 }
 269         }
 270
 271         return 0;
 272 }
 273