source: branches/samba-3.2.x/source/client/umount.cifs.c@ 206

Last change on this file since 206 was 133, checked in by Paul Smedley, 17 years ago

Update trunk to 3.2.0pre3
File size: 9.1 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 3 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, see <http://www.gnu.org/licenses/>. */
17
18#ifndef _GNU_SOURCE
19#define _GNU_SOURCE
20#endif
21
22#include <stdlib.h>
23#include <stdio.h>
24#include <unistd.h>
25#include <ctype.h>
26#include <sys/types.h>
27#include <sys/mount.h>
28#include <sys/ioctl.h>
29#include <sys/stat.h>
30#include <sys/vfs.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 "5"
39
40#ifndef UNMOUNT_CIFS_VENDOR_SUFFIX
41 #ifdef _SAMBA_BUILD_
42 #include "include/version.h"
43 #ifdef SAMBA_VERSION_VENDOR_SUFFIX
44 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING"-"SAMBA_VERSION_VENDOR_SUFFIX
45 #else
46 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING
47 #endif /* SAMBA_VERSION_OFFICIAL_STRING and SAMBA_VERSION_VENDOR_SUFFIX */
48 #else
49 #define UNMOUNT_CIFS_VENDOR_SUFFIX ""
50 #endif /* _SAMBA_BUILD_ */
51#endif /* UNMOUNT_CIFS_VENDOR_SUFFIX */
52
53#ifndef MNT_DETACH
54#define MNT_DETACH 0x02
55#endif
56
57#ifndef MNT_EXPIRE
58#define MNT_EXPIRE 0x04
59#endif
60
61#ifndef MOUNTED_LOCK
62#define MOUNTED_LOCK "/etc/mtab~"
63#endif
64#ifndef MOUNTED_TEMP
65#define MOUNTED_TEMP "/etc/mtab.tmp"
66#endif
67
68#define CIFS_IOC_CHECKUMOUNT _IO(0xCF, 2)
69#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDU */
70
71static struct option longopts[] = {
72 { "all", 0, NULL, 'a' },
73 { "help",0, NULL, 'h' },
74 { "read-only", 0, NULL, 'r' },
75 { "ro", 0, NULL, 'r' },
76 { "verbose", 0, NULL, 'v' },
77 { "version", 0, NULL, 'V' },
78 { "expire", 0, NULL, 'e' },
79 { "force", 0, 0, 'f' },
80 { "lazy", 0, 0, 'l' },
81 { "no-mtab", 0, 0, 'n' },
82 { NULL, 0, NULL, 0 }
83};
84
85const char * thisprogram;
86int verboseflg = 0;
87
88static void umount_cifs_usage(void)
89{
90 printf("\nUsage: %s <remotetarget> <dir>\n", thisprogram);
91 printf("\nUnmount the specified directory\n");
92 printf("\nLess commonly used options:");
93 printf("\n\t-r\tIf mount fails, retry with readonly remount.");
94 printf("\n\t-n\tDo not write to mtab.");
95 printf("\n\t-f\tAttempt a forced unmount, even if the fs is busy.");
96 printf("\n\t-l\tAttempt lazy unmount, Unmount now, cleanup later.");
97 printf("\n\t-v\tEnable verbose mode (may be useful for debugging).");
98 printf("\n\t-h\tDisplay this help.");
99 printf("\n\nOptions are described in more detail in the manual page");
100 printf("\n\tman 8 umount.cifs\n");
101 printf("\nTo display the version number of the cifs umount utility:");
102 printf("\n\t%s -V\n",thisprogram);
103 printf("\nInvoking the umount utility on cifs mounts, can execute");
104 printf(" /sbin/umount.cifs (if present and umount -i is not specified.\n");
105}
106
107static int umount_check_perm(char * dir)
108{
109 int fileid;
110 int rc;
111
112 /* allow root to unmount, no matter what */
113 if(getuid() == 0)
114 return 0;
115
116 /* presumably can not chdir into the target as we do on mount */
117 fileid = open(dir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0);
118 if(fileid == -1) {
119 if(verboseflg)
120 printf("error opening mountpoint %d %s",errno,strerror(errno));
121 return errno;
122 }
123
124 rc = ioctl(fileid, CIFS_IOC_CHECKUMOUNT, NULL);
125
126 if(verboseflg)
127 printf("ioctl returned %d with errno %d %s\n",rc,errno,strerror(errno));
128
129 if(rc == ENOTTY) {
130 printf("user unmounting via %s is an optional feature of",thisprogram);
131 printf(" the cifs filesystem driver (cifs.ko)");
132 printf("\n\tand requires cifs.ko version 1.32 or later\n");
133 } else if (rc != 0)
134 printf("user unmount of %s failed with %d %s\n",dir,errno,strerror(errno));
135 close(fileid);
136
137 return rc;
138}
139
140static int lock_mtab(void)
141{
142 int rc;
143
144 rc = mknod(MOUNTED_LOCK , 0600, 0);
145 if(rc == -1)
146 printf("\ngetting lock file %s failed with %s\n",MOUNTED_LOCK,
147 strerror(errno));
148
149 return rc;
150
151}
152
153static void unlock_mtab(void)
154{
155 unlink(MOUNTED_LOCK);
156}
157
158static int remove_from_mtab(char * mountpoint)
159{
160 int rc;
161 int num_matches;
162 FILE * org_fd;
163 FILE * new_fd;
164 struct mntent * mount_entry;
165
166 /* Do we need to check if it is a symlink to e.g. /proc/mounts
167 in which case we probably do not want to update it? */
168
169 /* Do we first need to check if it is writable? */
170
171 if (lock_mtab()) {
172 printf("Mount table locked\n");
173 return -EACCES;
174 }
175
176 if(verboseflg)
177 printf("attempting to remove from mtab\n");
178
179 org_fd = setmntent(MOUNTED, "r");
180
181 if(org_fd == NULL) {
182 printf("Can not open %s\n",MOUNTED);
183 unlock_mtab();
184 return -EIO;
185 }
186
187 new_fd = setmntent(MOUNTED_TEMP,"w");
188 if(new_fd == NULL) {
189 printf("Can not open temp file %s", MOUNTED_TEMP);
190 endmntent(org_fd);
191 unlock_mtab();
192 return -EIO;
193 }
194
195 /* BB fix so we only remove the last entry that matches BB */
196 num_matches = 0;
197 while((mount_entry = getmntent(org_fd)) != NULL) {
198 if(strcmp(mount_entry->mnt_dir, mountpoint) == 0) {
199 num_matches++;
200 }
201 }
202 if(verboseflg)
203 printf("%d matching entries in mount table\n", num_matches);
204
205 /* Is there a better way to seek back to the first entry in mtab? */
206 endmntent(org_fd);
207 org_fd = setmntent(MOUNTED, "r");
208
209 if(org_fd == NULL) {
210 printf("Can not open %s\n",MOUNTED);
211 unlock_mtab();
212 return -EIO;
213 }
214
215 while((mount_entry = getmntent(org_fd)) != NULL) {
216 if(strcmp(mount_entry->mnt_dir, mountpoint) != 0) {
217 addmntent(new_fd, mount_entry);
218 } else {
219 if(num_matches != 1) {
220 addmntent(new_fd, mount_entry);
221 num_matches--;
222 } else if(verboseflg)
223 printf("entry not copied (ie entry is removed)\n");
224 }
225 }
226
227 if(verboseflg)
228 printf("done updating tmp file\n");
229 rc = fchmod (fileno (new_fd), S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
230 if(rc < 0) {
231 printf("error %s changing mode of %s\n", strerror(errno),
232 MOUNTED_TEMP);
233 }
234 endmntent(new_fd);
235
236 rc = rename(MOUNTED_TEMP, MOUNTED);
237
238 if(rc < 0) {
239 printf("failure %s renaming %s to %s\n",strerror(errno),
240 MOUNTED_TEMP, MOUNTED);
241 unlock_mtab();
242 return -EIO;
243 }
244
245 unlock_mtab();
246
247 return rc;
248}
249
250int main(int argc, char ** argv)
251{
252 int c;
253 int rc;
254 int flags = 0;
255 int nomtab = 0;
256 int retry_remount = 0;
257 struct statfs statbuf;
258 char * mountpoint;
259
260 if(argc && argv) {
261 thisprogram = argv[0];
262 } else {
263 umount_cifs_usage();
264 return -EINVAL;
265 }
266
267 if(argc < 2) {
268 umount_cifs_usage();
269 return -EINVAL;
270 }
271
272 if(thisprogram == NULL)
273 thisprogram = "umount.cifs";
274
275 /* add sharename in opts string as unc= parm */
276
277 while ((c = getopt_long (argc, argv, "afhilnrvV",
278 longopts, NULL)) != -1) {
279 switch (c) {
280/* No code to do the following option yet */
281/* case 'a':
282 ++umount_all;
283 break; */
284 case '?':
285 case 'h': /* help */
286 umount_cifs_usage();
287 exit(1);
288 case 'n':
289 ++nomtab;
290 break;
291 case 'f':
292 flags |= MNT_FORCE;
293 break;
294 case 'l':
295 flags |= MNT_DETACH; /* lazy unmount */
296 break;
297 case 'e':
298 flags |= MNT_EXPIRE; /* gradually timeout */
299 break;
300 case 'r':
301 ++retry_remount;
302 break;
303 case 'v':
304 ++verboseflg;
305 break;
306 case 'V':
307 printf ("umount.cifs version: %s.%s%s\n",
308 UNMOUNT_CIFS_VERSION_MAJOR,
309 UNMOUNT_CIFS_VERSION_MINOR,
310 UNMOUNT_CIFS_VENDOR_SUFFIX);
311 exit (0);
312 default:
313 printf("unknown unmount option %c\n",c);
314 umount_cifs_usage();
315 exit(1);
316 }
317 }
318
319 /* move past the umount options */
320 argv += optind;
321 argc -= optind;
322
323 mountpoint = argv[0];
324
325 if((argc < 1) || (argv[0] == NULL)) {
326 printf("\nMissing name of unmount directory\n");
327 umount_cifs_usage();
328 return -EINVAL;
329 }
330
331 if(verboseflg)
332 printf("optind %d unmount dir %s\n",optind, mountpoint);
333
334 /* check if running effectively root */
335 if(geteuid() != 0) {
336 printf("Trying to unmount when %s not installed suid\n",thisprogram);
337 if(verboseflg)
338 printf("euid = %d\n",geteuid());
339 return -EACCES;
340 }
341
342 /* fixup path if needed */
343
344 /* Trim any trailing slashes */
345 while ((strlen(mountpoint) > 1) &&
346 (mountpoint[strlen(mountpoint)-1] == '/'))
347 {
348 mountpoint[strlen(mountpoint)-1] = '\0';
349 }
350
351 /* make sure that this is a cifs filesystem */
352 rc = statfs(mountpoint, &statbuf);
353
354 if(rc || (statbuf.f_type != CIFS_MAGIC_NUMBER)) {
355 printf("This utility only unmounts cifs filesystems.\n");
356 return -EINVAL;
357 }
358
359 /* check if our uid was the one who mounted */
360 rc = umount_check_perm(mountpoint);
361 if (rc) {
362 printf("Not permitted to unmount\n");
363 return rc;
364 }
365
366 if(umount2(mountpoint, flags)) {
367 /* remember to kill daemon on error */
368 switch (errno) {
369 case 0:
370 printf("unmount failed but no error number set\n");
371 break;
372 default:
373 printf("unmount error %d = %s\n",errno,strerror(errno));
374 }
375 printf("Refer to the umount.cifs(8) manual page (man 8 umount.cifs)\n");
376 return -1;
377 } else {
378 if(verboseflg)
379 printf("umount2 succeeded\n");
380 if(nomtab == 0)
381 remove_from_mtab(mountpoint);
382 }
383
384 return 0;
385}
386
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