source: branches/samba-3.0/source/client/umount.cifs.c@ 104

Last change on this file since 104 was 1, checked in by Paul Smedley, 18 years ago

Initial code import
File size: 9.0 KB
Line 
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 <sys/vfs.h>
32#include <fcntl.h>
33#include <getopt.h>
34#include <errno.h>
35#include <string.h>
36#include <mntent.h>
37
38#define UNMOUNT_CIFS_VERSION_MAJOR "0"
39#define UNMOUNT_CIFS_VERSION_MINOR "5"
40
41#ifndef UNMOUNT_CIFS_VENDOR_SUFFIX
42 #ifdef _SAMBA_BUILD_
43 #include "include/version.h"
44 #ifdef SAMBA_VERSION_VENDOR_SUFFIX
45 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING"-"SAMBA_VERSION_VENDOR_SUFFIX
46 #else
47 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING
48 #endif /* SAMBA_VERSION_OFFICIAL_STRING and SAMBA_VERSION_VENDOR_SUFFIX */
49 #else
50 #define UNMOUNT_CIFS_VENDOR_SUFFIX ""
51 #endif /* _SAMBA_BUILD_ */
52#endif /* UNMOUNT_CIFS_VENDOR_SUFFIX */
53
54#ifndef MNT_DETACH
55#define MNT_DETACH 0x02
56#endif
57
58#ifndef MNT_EXPIRE
59#define MNT_EXPIRE 0x04
60#endif
61
62#ifndef MOUNTED_LOCK
63#define MOUNTED_LOCK "/etc/mtab~"
64#endif
65#ifndef MOUNTED_TEMP
66#define MOUNTED_TEMP "/etc/mtab.tmp"
67#endif
68
69#define CIFS_IOC_CHECKUMOUNT _IO(0xCF, 2)
70#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDU */
71
72static struct option longopts[] = {
73 { "all", 0, NULL, 'a' },
74 { "help",0, NULL, 'h' },
75 { "read-only", 0, NULL, 'r' },
76 { "ro", 0, NULL, 'r' },
77 { "verbose", 0, NULL, 'v' },
78 { "version", 0, NULL, 'V' },
79 { "expire", 0, NULL, 'e' },
80 { "force", 0, 0, 'f' },
81 { "lazy", 0, 0, 'l' },
82 { "no-mtab", 0, 0, 'n' },
83 { NULL, 0, NULL, 0 }
84};
85
86const char * thisprogram;
87int verboseflg = 0;
88
89static void umount_cifs_usage(void)
90{
91 printf("\nUsage: %s <remotetarget> <dir>\n", thisprogram);
92 printf("\nUnmount the specified directory\n");
93 printf("\nLess commonly used options:");
94 printf("\n\t-r\tIf mount fails, retry with readonly remount.");
95 printf("\n\t-n\tDo not write to mtab.");
96 printf("\n\t-f\tAttempt a forced unmount, even if the fs is busy.");
97 printf("\n\t-l\tAttempt lazy unmount, Unmount now, cleanup later.");
98 printf("\n\t-v\tEnable verbose mode (may be useful for debugging).");
99 printf("\n\t-h\tDisplay this help.");
100 printf("\n\nOptions are described in more detail in the manual page");
101 printf("\n\tman 8 umount.cifs\n");
102 printf("\nTo display the version number of the cifs umount utility:");
103 printf("\n\t%s -V\n",thisprogram);
104 printf("\nInvoking the umount utility on cifs mounts, can execute");
105 printf(" /sbin/umount.cifs (if present and umount -i is not specified.\n");
106}
107
108static int umount_check_perm(char * dir)
109{
110 int fileid;
111 int rc;
112
113 /* allow root to unmount, no matter what */
114 if(getuid() == 0)
115 return 0;
116
117 /* presumably can not chdir into the target as we do on mount */
118 fileid = open(dir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0);
119 if(fileid == -1) {
120 if(verboseflg)
121 printf("error opening mountpoint %d %s",errno,strerror(errno));
122 return errno;
123 }
124
125 rc = ioctl(fileid, CIFS_IOC_CHECKUMOUNT, NULL);
126
127 if(verboseflg)
128 printf("ioctl returned %d with errno %d %s\n",rc,errno,strerror(errno));
129
130 if(rc == ENOTTY) {
131 printf("user unmounting via %s is an optional feature of",thisprogram);
132 printf(" the cifs filesystem driver (cifs.ko)");
133 printf("\n\tand requires cifs.ko version 1.32 or later\n");
134 } else if (rc > 0)
135 printf("user unmount of %s failed with %d %s\n",dir,errno,strerror(errno));
136 close(fileid);
137
138 return rc;
139}
140
141static int lock_mtab(void)
142{
143 int rc;
144
145 rc = mknod(MOUNTED_LOCK , 0600, 0);
146 if(rc == -1)
147 printf("\ngetting lock file %s failed with %s\n",MOUNTED_LOCK,
148 strerror(errno));
149
150 return rc;
151
152}
153
154static void unlock_mtab(void)
155{
156 unlink(MOUNTED_LOCK);
157}
158
159static int remove_from_mtab(char * mountpoint)
160{
161 int rc;
162 int num_matches;
163 FILE * org_fd;
164 FILE * new_fd;
165 struct mntent * mount_entry;
166
167 /* Do we need to check if it is a symlink to e.g. /proc/mounts
168 in which case we probably do not want to update it? */
169
170 /* Do we first need to check if it is writable? */
171
172 if (lock_mtab()) {
173 printf("Mount table locked\n");
174 return -EACCES;
175 }
176
177 if(verboseflg)
178 printf("attempting to remove from mtab\n");
179
180 org_fd = setmntent(MOUNTED, "r");
181
182 if(org_fd == NULL) {
183 printf("Can not open %s\n",MOUNTED);
184 unlock_mtab();
185 return -EIO;
186 }
187
188 new_fd = setmntent(MOUNTED_TEMP,"w");
189 if(new_fd == NULL) {
190 printf("Can not open temp file %s", MOUNTED_TEMP);
191 endmntent(org_fd);
192 unlock_mtab();
193 return -EIO;
194 }
195
196 /* BB fix so we only remove the last entry that matches BB */
197 num_matches = 0;
198 while((mount_entry = getmntent(org_fd)) != NULL) {
199 if(strcmp(mount_entry->mnt_dir, mountpoint) == 0) {
200 num_matches++;
201 }
202 }
203 if(verboseflg)
204 printf("%d matching entries in mount table\n", num_matches);
205
206 /* Is there a better way to seek back to the first entry in mtab? */
207 endmntent(org_fd);
208 org_fd = setmntent(MOUNTED, "r");
209
210 if(org_fd == NULL) {
211 printf("Can not open %s\n",MOUNTED);
212 unlock_mtab();
213 return -EIO;
214 }
215
216 while((mount_entry = getmntent(org_fd)) != NULL) {
217 if(strcmp(mount_entry->mnt_dir, mountpoint) != 0) {
218 addmntent(new_fd, mount_entry);
219 } else {
220 if(num_matches != 1) {
221 addmntent(new_fd, mount_entry);
222 num_matches--;
223 } else if(verboseflg)
224 printf("entry not copied (ie entry is removed)\n");
225 }
226 }
227
228 if(verboseflg)
229 printf("done updating tmp file\n");
230 rc = fchmod (fileno (new_fd), S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
231 if(rc < 0) {
232 printf("error %s changing mode of %s\n", strerror(errno),
233 MOUNTED_TEMP);
234 }
235 endmntent(new_fd);
236
237 rc = rename(MOUNTED_TEMP, MOUNTED);
238
239 if(rc < 0) {
240 printf("failure %s renaming %s to %s\n",strerror(errno),
241 MOUNTED_TEMP, MOUNTED);
242 unlock_mtab();
243 return -EIO;
244 }
245
246 unlock_mtab();
247
248 return rc;
249}
250
251int main(int argc, char ** argv)
252{
253 int c;
254 int rc;
255 int flags = 0;
256 int nomtab = 0;
257 int retry_remount = 0;
258 struct statfs statbuf;
259 char * mountpoint;
260
261 if(argc && argv) {
262 thisprogram = argv[0];
263 } else {
264 umount_cifs_usage();
265 return -EINVAL;
266 }
267
268 if(argc < 2) {
269 umount_cifs_usage();
270 return -EINVAL;
271 }
272
273 if(thisprogram == NULL)
274 thisprogram = "umount.cifs";
275
276 /* add sharename in opts string as unc= parm */
277
278 while ((c = getopt_long (argc, argv, "afhilnrvV",
279 longopts, NULL)) != -1) {
280 switch (c) {
281/* No code to do the following option yet */
282/* case 'a':
283 ++umount_all;
284 break; */
285 case '?':
286 case 'h': /* help */
287 umount_cifs_usage();
288 exit(1);
289 case 'n':
290 ++nomtab;
291 break;
292 case 'f':
293 flags |= MNT_FORCE;
294 break;
295 case 'l':
296 flags |= MNT_DETACH; /* lazy unmount */
297 break;
298 case 'e':
299 flags |= MNT_EXPIRE; /* gradually timeout */
300 break;
301 case 'r':
302 ++retry_remount;
303 break;
304 case 'v':
305 ++verboseflg;
306 break;
307 case 'V':
308 printf ("umount.cifs version: %s.%s%s\n",
309 UNMOUNT_CIFS_VERSION_MAJOR,
310 UNMOUNT_CIFS_VERSION_MINOR,
311 UNMOUNT_CIFS_VENDOR_SUFFIX);
312 exit (0);
313 default:
314 printf("unknown unmount option %c\n",c);
315 umount_cifs_usage();
316 exit(1);
317 }
318 }
319
320 /* move past the umount options */
321 argv += optind;
322 argc -= optind;
323
324 mountpoint = argv[0];
325
326 if((argc < 1) || (argv[0] == NULL)) {
327 printf("\nMissing name of unmount directory\n");
328 umount_cifs_usage();
329 return -EINVAL;
330 }
331
332 if(verboseflg)
333 printf("optind %d unmount dir %s\n",optind, mountpoint);
334
335 /* check if running effectively root */
336 if(geteuid() != 0) {
337 printf("Trying to unmount when %s not installed suid\n",thisprogram);
338 if(verboseflg)
339 printf("euid = %d\n",geteuid());
340 return -EACCES;
341 }
342
343 /* fixup path if needed */
344
345 /* make sure that this is a cifs filesystem */
346 rc = statfs(mountpoint, &statbuf);
347
348 if(rc || (statbuf.f_type != CIFS_MAGIC_NUMBER)) {
349 printf("This utility only unmounts cifs filesystems.\n");
350 return -EINVAL;
351 }
352
353 /* check if our uid was the one who mounted */
354 rc = umount_check_perm(mountpoint);
355 if (rc) {
356 printf("Not permitted to unmount\n");
357 return rc;
358 }
359
360 if(umount2(mountpoint, flags)) {
361 /* remember to kill daemon on error */
362 switch (errno) {
363 case 0:
364 printf("unmount failed but no error number set\n");
365 break;
366 default:
367 printf("unmount error %d = %s\n",errno,strerror(errno));
368 }
369 printf("Refer to the umount.cifs(8) manual page (man 8 umount.cifs)\n");
370 return -1;
371 } else {
372 if(verboseflg)
373 printf("umount2 succeeded\n");
374 if(nomtab == 0)
375 remove_from_mtab(mountpoint);
376 }
377
378 return 0;
379}
380
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