source: vendor/3.5.0/client/umount.cifs.c@ 966

Last change on this file since 966 was 414, checked in by Herwig Bauernfeind, 16 years ago

Samba 3.5.0: Initial import
File size: 9.8 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 "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 struct stat statbuf;
150
151 /* If it is a symlink, e.g. to /proc/mounts, no need to update it. */
152 if ((lstat(MOUNTED, &statbuf) == 0) && (S_ISLNK(statbuf.st_mode)))
153 return 0;
154
155 /* Do we first need to check if it is writable? */
156
157 atexit(unlock_mtab);
158 if (lock_mtab()) {
159 printf("Mount table locked\n");
160 return -EACCES;
161 }
162
163 if(verboseflg)
164 printf("attempting to remove from mtab\n");
165
166 org_fd = setmntent(MOUNTED, "r");
167 if(org_fd == NULL) {
168 printf("Can not open %s\n",MOUNTED);
169 unlock_mtab();
170 return -EIO;
171 }
172
173 new_fd = setmntent(MOUNTED_TEMP,"w");
174 if(new_fd == NULL) {
175 printf("Can not open temp file %s", MOUNTED_TEMP);
176 endmntent(org_fd);
177 unlock_mtab();
178 return -EIO;
179 }
180
181 /* BB fix so we only remove the last entry that matches BB */
182 num_matches = 0;
183 while((mount_entry = getmntent(org_fd)) != NULL) {
184 if(strcmp(mount_entry->mnt_dir, mountpoint) == 0) {
185 num_matches++;
186 }
187 }
188 if(verboseflg)
189 printf("%d matching entries in mount table\n", num_matches);
190
191 /* Is there a better way to seek back to the first entry in mtab? */
192 endmntent(org_fd);
193 org_fd = setmntent(MOUNTED, "r");
194
195 if(org_fd == NULL) {
196 printf("Can not open %s\n",MOUNTED);
197 unlock_mtab();
198 return -EIO;
199 }
200
201 while((mount_entry = getmntent(org_fd)) != NULL) {
202 if(strcmp(mount_entry->mnt_dir, mountpoint) != 0) {
203 addmntent(new_fd, mount_entry);
204 } else {
205 if(num_matches != 1) {
206 addmntent(new_fd, mount_entry);
207 num_matches--;
208 } else if(verboseflg)
209 printf("entry not copied (ie entry is removed)\n");
210 }
211 }
212
213 if(verboseflg)
214 printf("done updating tmp file\n");
215 rc = fchmod (fileno (new_fd), S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
216 if(rc < 0) {
217 printf("error %s changing mode of %s\n", strerror(errno),
218 MOUNTED_TEMP);
219 }
220 endmntent(new_fd);
221
222 rc = rename(MOUNTED_TEMP, MOUNTED);
223
224 if(rc < 0) {
225 printf("failure %s renaming %s to %s\n",strerror(errno),
226 MOUNTED_TEMP, MOUNTED);
227 unlock_mtab();
228 return -EIO;
229 }
230
231 unlock_mtab();
232
233 return rc;
234}
235
236/* Make a canonical pathname from PATH. Returns a freshly malloced string.
237 It is up the *caller* to ensure that the PATH is sensible. i.e.
238 canonicalize ("/dev/fd0/.") returns "/dev/fd0" even though ``/dev/fd0/.''
239 is not a legal pathname for ``/dev/fd0'' Anything we cannot parse
240 we return unmodified. */
241static char *
242canonicalize(char *path)
243{
244 char *canonical;
245
246 if (path == NULL) {
247 return NULL;
248 }
249
250 if (strlen(path) > PATH_MAX) {
251 fprintf(stderr, "Mount point string too long\n");
252 return NULL;
253 }
254
255 canonical = (char *)malloc (PATH_MAX + 1);
256
257 if (!canonical) {
258 fprintf(stderr, "Error! Not enough memory!\n");
259 return NULL;
260 }
261
262 if (realpath (path, canonical))
263 return canonical;
264
265 strncpy (canonical, path, PATH_MAX);
266 canonical[PATH_MAX] = '\0';
267 return canonical;
268}
269
270int main(int argc, char ** argv)
271{
272 int c;
273 int rc;
274 int flags = 0;
275 int nomtab = 0;
276 int retry_remount = 0;
277 struct statfs statbuf;
278 char * mountpoint;
279
280 if(argc && argv) {
281 thisprogram = argv[0];
282 } else {
283 umount_cifs_usage();
284 return -EINVAL;
285 }
286
287 if(argc < 2) {
288 umount_cifs_usage();
289 return -EINVAL;
290 }
291
292 if(thisprogram == NULL)
293 thisprogram = "umount.cifs";
294
295 /* add sharename in opts string as unc= parm */
296
297 while ((c = getopt_long (argc, argv, "afhilnrvV",
298 longopts, NULL)) != -1) {
299 switch (c) {
300/* No code to do the following option yet */
301/* case 'a':
302 ++umount_all;
303 break; */
304 case '?':
305 case 'h': /* help */
306 umount_cifs_usage();
307 exit(1);
308 case 'n':
309 ++nomtab;
310 break;
311 case 'f':
312 flags |= MNT_FORCE;
313 break;
314 case 'l':
315 flags |= MNT_DETACH; /* lazy unmount */
316 break;
317 case 'e':
318 flags |= MNT_EXPIRE; /* gradually timeout */
319 break;
320 case 'r':
321 ++retry_remount;
322 break;
323 case 'v':
324 ++verboseflg;
325 break;
326 case 'V':
327 printf ("umount.cifs version: %s.%s%s\n",
328 UNMOUNT_CIFS_VERSION_MAJOR,
329 UNMOUNT_CIFS_VERSION_MINOR,
330 UNMOUNT_CIFS_VENDOR_SUFFIX);
331 exit (0);
332 default:
333 printf("unknown unmount option %c\n",c);
334 umount_cifs_usage();
335 exit(1);
336 }
337 }
338
339 /* move past the umount options */
340 argv += optind;
341 argc -= optind;
342
343 mountpoint = canonicalize(argv[0]);
344
345 if((argc < 1) || (argv[0] == NULL)) {
346 printf("\nMissing name of unmount directory\n");
347 umount_cifs_usage();
348 return -EINVAL;
349 }
350
351 if(verboseflg)
352 printf("optind %d unmount dir %s\n",optind, mountpoint);
353
354 /* check if running effectively root */
355 if(geteuid() != 0) {
356 printf("Trying to unmount when %s not installed suid\n",thisprogram);
357 if(verboseflg)
358 printf("euid = %d\n",geteuid());
359 return -EACCES;
360 }
361
362 /* fixup path if needed */
363
364 /* Trim any trailing slashes */
365 while ((strlen(mountpoint) > 1) &&
366 (mountpoint[strlen(mountpoint)-1] == '/'))
367 {
368 mountpoint[strlen(mountpoint)-1] = '\0';
369 }
370
371 /* make sure that this is a cifs filesystem */
372 rc = statfs(mountpoint, &statbuf);
373
374 if(rc || (statbuf.f_type != CIFS_MAGIC_NUMBER)) {
375 printf("This utility only unmounts cifs filesystems.\n");
376 return -EINVAL;
377 }
378
379 /* check if our uid was the one who mounted */
380 rc = umount_check_perm(mountpoint);
381 if (rc) {
382 printf("Not permitted to unmount\n");
383 return rc;
384 }
385
386 if(umount2(mountpoint, flags)) {
387 /* remember to kill daemon on error */
388 switch (errno) {
389 case 0:
390 printf("unmount failed but no error number set\n");
391 break;
392 default:
393 printf("unmount error %d = %s\n",errno,strerror(errno));
394 }
395 printf("Refer to the umount.cifs(8) manual page (man 8 umount.cifs)\n");
396 return -1;
397 } else {
398 if(verboseflg)
399 printf("umount2 succeeded\n");
400 if(nomtab == 0)
401 remove_from_mtab(mountpoint);
402 }
403
404 return 0;
405}
406
Note: See TracBrowser for help on using the repository browser.