source: branches/samba-3.3.x/source/client/umount.cifs.c@ 425

Last change on this file since 425 was 221, checked in by Herwig Bauernfeind, 16 years ago

Update Samba 3.3 to 3.3.1
File size: 10.1 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#include <limits.h>
37#include "mount.h"
38
39#define UNMOUNT_CIFS_VERSION_MAJOR "0"
40#define UNMOUNT_CIFS_VERSION_MINOR "6"
41
42#ifndef UNMOUNT_CIFS_VENDOR_SUFFIX
43 #ifdef _SAMBA_BUILD_
44 #include "include/version.h"
45 #ifdef SAMBA_VERSION_VENDOR_SUFFIX
46 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING"-"SAMBA_VERSION_VENDOR_SUFFIX
47 #else
48 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING
49 #endif /* SAMBA_VERSION_OFFICIAL_STRING and SAMBA_VERSION_VENDOR_SUFFIX */
50 #else
51 #define UNMOUNT_CIFS_VENDOR_SUFFIX ""
52 #endif /* _SAMBA_BUILD_ */
53#endif /* UNMOUNT_CIFS_VENDOR_SUFFIX */
54
55#ifndef MNT_DETACH
56#define MNT_DETACH 0x02
57#endif
58
59#ifndef MNT_EXPIRE
60#define MNT_EXPIRE 0x04
61#endif
62
63#ifndef MOUNTED_LOCK
64#define MOUNTED_LOCK "/etc/mtab~"
65#endif
66#ifndef MOUNTED_TEMP
67#define MOUNTED_TEMP "/etc/mtab.tmp"
68#endif
69
70#define CIFS_IOC_CHECKUMOUNT _IO(0xCF, 2)
71#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDU */
72
73static struct option longopts[] = {
74 { "all", 0, NULL, 'a' },
75 { "help",0, NULL, 'h' },
76 { "read-only", 0, NULL, 'r' },
77 { "ro", 0, NULL, 'r' },
78 { "verbose", 0, NULL, 'v' },
79 { "version", 0, NULL, 'V' },
80 { "expire", 0, NULL, 'e' },
81 { "force", 0, 0, 'f' },
82 { "lazy", 0, 0, 'l' },
83 { "no-mtab", 0, 0, 'n' },
84 { NULL, 0, NULL, 0 }
85};
86
87const char * thisprogram;
88int verboseflg = 0;
89
90static void umount_cifs_usage(void)
91{
92 printf("\nUsage: %s <remotetarget> <dir>\n", thisprogram);
93 printf("\nUnmount the specified directory\n");
94 printf("\nLess commonly used options:");
95 printf("\n\t-r\tIf mount fails, retry with readonly remount.");
96 printf("\n\t-n\tDo not write to mtab.");
97 printf("\n\t-f\tAttempt a forced unmount, even if the fs is busy.");
98 printf("\n\t-l\tAttempt lazy unmount, Unmount now, cleanup later.");
99 printf("\n\t-v\tEnable verbose mode (may be useful for debugging).");
100 printf("\n\t-h\tDisplay this help.");
101 printf("\n\nOptions are described in more detail in the manual page");
102 printf("\n\tman 8 umount.cifs\n");
103 printf("\nTo display the version number of the cifs umount utility:");
104 printf("\n\t%s -V\n",thisprogram);
105 printf("\nInvoking the umount utility on cifs mounts, can execute");
106 printf(" /sbin/umount.cifs (if present and umount -i is not specified.\n");
107}
108
109static int umount_check_perm(char * dir)
110{
111 int fileid;
112 int rc;
113
114 /* allow root to unmount, no matter what */
115 if(getuid() == 0)
116 return 0;
117
118 /* presumably can not chdir into the target as we do on mount */
119 fileid = open(dir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0);
120 if(fileid == -1) {
121 if(verboseflg)
122 printf("error opening mountpoint %d %s",errno,strerror(errno));
123 return errno;
124 }
125
126 rc = ioctl(fileid, CIFS_IOC_CHECKUMOUNT, NULL);
127
128 if(verboseflg)
129 printf("ioctl returned %d with errno %d %s\n",rc,errno,strerror(errno));
130
131 if(rc == ENOTTY) {
132 printf("user unmounting via %s is an optional feature of",thisprogram);
133 printf(" the cifs filesystem driver (cifs.ko)");
134 printf("\n\tand requires cifs.ko version 1.32 or later\n");
135 } else if (rc != 0)
136 printf("user unmount of %s failed with %d %s\n",dir,errno,strerror(errno));
137 close(fileid);
138
139 return rc;
140}
141
142static int remove_from_mtab(char * mountpoint)
143{
144 int rc;
145 int num_matches;
146 FILE * org_fd;
147 FILE * new_fd;
148 struct mntent * mount_entry;
149
150 /* Do we need to check if it is a symlink to e.g. /proc/mounts
151 in which case we probably do not want to update it? */
152
153 /* Do we first need to check if it is writable? */
154
155 atexit(unlock_mtab);
156 if (lock_mtab()) {
157 printf("Mount table locked\n");
158 return -EACCES;
159 }
160
161 if(verboseflg)
162 printf("attempting to remove from mtab\n");
163
164 org_fd = setmntent(MOUNTED, "r");
165
166 if(org_fd == NULL) {
167 printf("Can not open %s\n",MOUNTED);
168 unlock_mtab();
169 return -EIO;
170 }
171
172 new_fd = setmntent(MOUNTED_TEMP,"w");
173 if(new_fd == NULL) {
174 printf("Can not open temp file %s", MOUNTED_TEMP);
175 endmntent(org_fd);
176 unlock_mtab();
177 return -EIO;
178 }
179
180 /* BB fix so we only remove the last entry that matches BB */
181 num_matches = 0;
182 while((mount_entry = getmntent(org_fd)) != NULL) {
183 if(strcmp(mount_entry->mnt_dir, mountpoint) == 0) {
184 num_matches++;
185 }
186 }
187 if(verboseflg)
188 printf("%d matching entries in mount table\n", num_matches);
189
190 /* Is there a better way to seek back to the first entry in mtab? */
191 endmntent(org_fd);
192 org_fd = setmntent(MOUNTED, "r");
193
194 if(org_fd == NULL) {
195 printf("Can not open %s\n",MOUNTED);
196 unlock_mtab();
197 return -EIO;
198 }
199
200 while((mount_entry = getmntent(org_fd)) != NULL) {
201 if(strcmp(mount_entry->mnt_dir, mountpoint) != 0) {
202 addmntent(new_fd, mount_entry);
203 } else {
204 if(num_matches != 1) {
205 addmntent(new_fd, mount_entry);
206 num_matches--;
207 } else if(verboseflg)
208 printf("entry not copied (ie entry is removed)\n");
209 }
210 }
211
212 if(verboseflg)
213 printf("done updating tmp file\n");
214 rc = fchmod (fileno (new_fd), S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
215 if(rc < 0) {
216 printf("error %s changing mode of %s\n", strerror(errno),
217 MOUNTED_TEMP);
218 }
219 endmntent(new_fd);
220
221 rc = rename(MOUNTED_TEMP, MOUNTED);
222
223 if(rc < 0) {
224 printf("failure %s renaming %s to %s\n",strerror(errno),
225 MOUNTED_TEMP, MOUNTED);
226 unlock_mtab();
227 return -EIO;
228 }
229
230 unlock_mtab();
231
232 return rc;
233}
234
235/* Make a canonical pathname from PATH. Returns a freshly malloced string.
236 It is up the *caller* to ensure that the PATH is sensible. i.e.
237 canonicalize ("/dev/fd0/.") returns "/dev/fd0" even though ``/dev/fd0/.''
238 is not a legal pathname for ``/dev/fd0'' Anything we cannot parse
239 we return unmodified. */
240static char *
241canonicalize(char *path)
242{
243 char *canonical;
244
245 if (path == NULL) {
246 return NULL;
247 }
248
249 if (strlen(path) > PATH_MAX) {
250 fprintf(stderr, "Mount point string too long\n");
251 return NULL;
252 }
253
254 canonical = (char *)malloc (PATH_MAX + 1);
255
256 if (!canonical) {
257 fprintf(stderr, "Error! Not enough memory!\n");
258 return NULL;
259 }
260
261 if (realpath (path, canonical))
262 return canonical;
263
264 strncpy (canonical, path, PATH_MAX);
265 canonical[PATH_MAX] = '\0';
266 return canonical;
267}
268
269int main(int argc, char ** argv)
270{
271 int c;
272 int rc;
273 int flags = 0;
274 int nomtab = 0;
275 int retry_remount = 0;
276 struct statfs statbuf;
277 char * mountpoint;
278
279 if(argc && argv) {
280 thisprogram = argv[0];
281 } else {
282 umount_cifs_usage();
283 return -EINVAL;
284 }
285
286 if(argc < 2) {
287 umount_cifs_usage();
288 return -EINVAL;
289 }
290
291 if(thisprogram == NULL)
292 thisprogram = "umount.cifs";
293
294 /* add sharename in opts string as unc= parm */
295
296 while ((c = getopt_long (argc, argv, "afhilnrvV",
297 longopts, NULL)) != -1) {
298 switch (c) {
299/* No code to do the following option yet */
300/* case 'a':
301 ++umount_all;
302 break; */
303 case '?':
304 case 'h': /* help */
305 umount_cifs_usage();
306 exit(1);
307 case 'n':
308 ++nomtab;
309 break;
310 case 'f':
311 flags |= MNT_FORCE;
312 break;
313 case 'l':
314 flags |= MNT_DETACH; /* lazy unmount */
315 break;
316 case 'e':
317 flags |= MNT_EXPIRE; /* gradually timeout */
318 break;
319 case 'r':
320 ++retry_remount;
321 break;
322 case 'v':
323 ++verboseflg;
324 break;
325 case 'V':
326 printf ("umount.cifs version: %s.%s%s\n",
327 UNMOUNT_CIFS_VERSION_MAJOR,
328 UNMOUNT_CIFS_VERSION_MINOR,
329 UNMOUNT_CIFS_VENDOR_SUFFIX);
330 exit (0);
331 default:
332 printf("unknown unmount option %c\n",c);
333 umount_cifs_usage();
334 exit(1);
335 }
336 }
337
338 /* move past the umount options */
339 argv += optind;
340 argc -= optind;
341
342 mountpoint = canonicalize(argv[0]);
343
344 if((argc < 1) || (argv[0] == NULL)) {
345 printf("\nMissing name of unmount directory\n");
346 umount_cifs_usage();
347 return -EINVAL;
348 }
349
350 if(verboseflg)
351 printf("optind %d unmount dir %s\n",optind, mountpoint);
352
353 /* check if running effectively root */
354 if(geteuid() != 0) {
355 printf("Trying to unmount when %s not installed suid\n",thisprogram);
356 if(verboseflg)
357 printf("euid = %d\n",geteuid());
358 return -EACCES;
359 }
360
361 /* fixup path if needed */
362
363 /* Trim any trailing slashes */
364 while ((strlen(mountpoint) > 1) &&
365 (mountpoint[strlen(mountpoint)-1] == '/'))
366 {
367 mountpoint[strlen(mountpoint)-1] = '\0';
368 }
369
370 /* make sure that this is a cifs filesystem */
371 rc = statfs(mountpoint, &statbuf);
372
373 if(rc || (statbuf.f_type != CIFS_MAGIC_NUMBER)) {
374 printf("This utility only unmounts cifs filesystems.\n");
375 return -EINVAL;
376 }
377
378 /* check if our uid was the one who mounted */
379 rc = umount_check_perm(mountpoint);
380 if (rc) {
381 printf("Not permitted to unmount\n");
382 return rc;
383 }
384
385 if(umount2(mountpoint, flags)) {
386 /* remember to kill daemon on error */
387 switch (errno) {
388 case 0:
389 printf("unmount failed but no error number set\n");
390 break;
391 default:
392 printf("unmount error %d = %s\n",errno,strerror(errno));
393 }
394 printf("Refer to the umount.cifs(8) manual page (man 8 umount.cifs)\n");
395 return -1;
396 } else {
397 if(verboseflg)
398 printf("umount2 succeeded\n");
399 if(nomtab == 0)
400 remove_from_mtab(mountpoint);
401 }
402
403 return 0;
404}
405
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