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

Last change on this file was 312, checked in by Herwig Bauernfeind, 16 years ago

Update 3.0 to final 3.0.36 (source)
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 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#include <limits.h>
38#include "mount.h"
39
40#define UNMOUNT_CIFS_VERSION_MAJOR "0"
41#define UNMOUNT_CIFS_VERSION_MINOR "6"
42
43#ifndef UNMOUNT_CIFS_VENDOR_SUFFIX
44 #ifdef _SAMBA_BUILD_
45 #include "include/version.h"
46 #ifdef SAMBA_VERSION_VENDOR_SUFFIX
47 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING"-"SAMBA_VERSION_VENDOR_SUFFIX
48 #else
49 #define UNMOUNT_CIFS_VENDOR_SUFFIX "-"SAMBA_VERSION_OFFICIAL_STRING
50 #endif /* SAMBA_VERSION_OFFICIAL_STRING and SAMBA_VERSION_VENDOR_SUFFIX */
51 #else
52 #define UNMOUNT_CIFS_VENDOR_SUFFIX ""
53 #endif /* _SAMBA_BUILD_ */
54#endif /* UNMOUNT_CIFS_VENDOR_SUFFIX */
55
56#ifndef MNT_DETACH
57#define MNT_DETACH 0x02
58#endif
59
60#ifndef MNT_EXPIRE
61#define MNT_EXPIRE 0x04
62#endif
63
64#ifndef MOUNTED_LOCK
65#define MOUNTED_LOCK "/etc/mtab~"
66#endif
67#ifndef MOUNTED_TEMP
68#define MOUNTED_TEMP "/etc/mtab.tmp"
69#endif
70
71#define CIFS_IOC_CHECKUMOUNT _IO(0xCF, 2)
72#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDU */
73
74static struct option longopts[] = {
75 { "all", 0, NULL, 'a' },
76 { "help",0, NULL, 'h' },
77 { "read-only", 0, NULL, 'r' },
78 { "ro", 0, NULL, 'r' },
79 { "verbose", 0, NULL, 'v' },
80 { "version", 0, NULL, 'V' },
81 { "expire", 0, NULL, 'e' },
82 { "force", 0, 0, 'f' },
83 { "lazy", 0, 0, 'l' },
84 { "no-mtab", 0, 0, 'n' },
85 { NULL, 0, NULL, 0 }
86};
87
88const char * thisprogram;
89int verboseflg = 0;
90
91static void umount_cifs_usage(void)
92{
93 printf("\nUsage: %s <remotetarget> <dir>\n", thisprogram);
94 printf("\nUnmount the specified directory\n");
95 printf("\nLess commonly used options:");
96 printf("\n\t-r\tIf mount fails, retry with readonly remount.");
97 printf("\n\t-n\tDo not write to mtab.");
98 printf("\n\t-f\tAttempt a forced unmount, even if the fs is busy.");
99 printf("\n\t-l\tAttempt lazy unmount, Unmount now, cleanup later.");
100 printf("\n\t-v\tEnable verbose mode (may be useful for debugging).");
101 printf("\n\t-h\tDisplay this help.");
102 printf("\n\nOptions are described in more detail in the manual page");
103 printf("\n\tman 8 umount.cifs\n");
104 printf("\nTo display the version number of the cifs umount utility:");
105 printf("\n\t%s -V\n",thisprogram);
106 printf("\nInvoking the umount utility on cifs mounts, can execute");
107 printf(" /sbin/umount.cifs (if present and umount -i is not specified.\n");
108}
109
110static int umount_check_perm(char * dir)
111{
112 int fileid;
113 int rc;
114
115 /* allow root to unmount, no matter what */
116 if(getuid() == 0)
117 return 0;
118
119 /* presumably can not chdir into the target as we do on mount */
120 fileid = open(dir, O_RDONLY | O_DIRECTORY | O_NOFOLLOW, 0);
121 if(fileid == -1) {
122 if(verboseflg)
123 printf("error opening mountpoint %d %s",errno,strerror(errno));
124 return errno;
125 }
126
127 rc = ioctl(fileid, CIFS_IOC_CHECKUMOUNT, NULL);
128
129 if(verboseflg)
130 printf("ioctl returned %d with errno %d %s\n",rc,errno,strerror(errno));
131
132 if(rc == ENOTTY) {
133 printf("user unmounting via %s is an optional feature of",thisprogram);
134 printf(" the cifs filesystem driver (cifs.ko)");
135 printf("\n\tand requires cifs.ko version 1.32 or later\n");
136 } else if (rc != 0)
137 printf("user unmount of %s failed with %d %s\n",dir,errno,strerror(errno));
138 close(fileid);
139
140 return rc;
141}
142
143static int remove_from_mtab(char * mountpoint)
144{
145 int rc;
146 int num_matches;
147 FILE * org_fd;
148 FILE * new_fd;
149 struct mntent * mount_entry;
150
151 /* Do we need to check if it is a symlink to e.g. /proc/mounts
152 in which case we probably do not want to update it? */
153
154 /* Do we first need to check if it is writable? */
155
156 atexit(unlock_mtab);
157 if (lock_mtab()) {
158 printf("Mount table locked\n");
159 return -EACCES;
160 }
161
162 if(verboseflg)
163 printf("attempting to remove from mtab\n");
164
165 org_fd = setmntent(MOUNTED, "r");
166
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 = malloc (PATH_MAX + 1);
245
246 if (!canonical) {
247 fprintf(stderr, "Error! Not enough memory!\n");
248 return NULL;
249 }
250
251 if (strlen(path) > PATH_MAX) {
252 fprintf(stderr, "Mount point string too long\n");
253 return NULL;
254 }
255
256 if (path == NULL)
257 return NULL;
258
259 if (realpath (path, canonical))
260 return canonical;
261
262 strncpy (canonical, path, PATH_MAX);
263 canonical[PATH_MAX] = '\0';
264 return canonical;
265}
266
267int main(int argc, char ** argv)
268{
269 int c;
270 int rc;
271 int flags = 0;
272 int nomtab = 0;
273 int retry_remount = 0;
274 struct statfs statbuf;
275 char * mountpoint;
276
277 if(argc && argv) {
278 thisprogram = argv[0];
279 } else {
280 umount_cifs_usage();
281 return -EINVAL;
282 }
283
284 if(argc < 2) {
285 umount_cifs_usage();
286 return -EINVAL;
287 }
288
289 if(thisprogram == NULL)
290 thisprogram = "umount.cifs";
291
292 /* add sharename in opts string as unc= parm */
293
294 while ((c = getopt_long (argc, argv, "afhilnrvV",
295 longopts, NULL)) != -1) {
296 switch (c) {
297/* No code to do the following option yet */
298/* case 'a':
299 ++umount_all;
300 break; */
301 case '?':
302 case 'h': /* help */
303 umount_cifs_usage();
304 exit(1);
305 case 'n':
306 ++nomtab;
307 break;
308 case 'f':
309 flags |= MNT_FORCE;
310 break;
311 case 'l':
312 flags |= MNT_DETACH; /* lazy unmount */
313 break;
314 case 'e':
315 flags |= MNT_EXPIRE; /* gradually timeout */
316 break;
317 case 'r':
318 ++retry_remount;
319 break;
320 case 'v':
321 ++verboseflg;
322 break;
323 case 'V':
324 printf ("umount.cifs version: %s.%s%s\n",
325 UNMOUNT_CIFS_VERSION_MAJOR,
326 UNMOUNT_CIFS_VERSION_MINOR,
327 UNMOUNT_CIFS_VENDOR_SUFFIX);
328 exit (0);
329 default:
330 printf("unknown unmount option %c\n",c);
331 umount_cifs_usage();
332 exit(1);
333 }
334 }
335
336 /* move past the umount options */
337 argv += optind;
338 argc -= optind;
339
340 mountpoint = canonicalize(argv[0]);
341
342 if((argc < 1) || (argv[0] == NULL)) {
343 printf("\nMissing name of unmount directory\n");
344 umount_cifs_usage();
345 return -EINVAL;
346 }
347
348 if(verboseflg)
349 printf("optind %d unmount dir %s\n",optind, mountpoint);
350
351 /* check if running effectively root */
352 if(geteuid() != 0) {
353 printf("Trying to unmount when %s not installed suid\n",thisprogram);
354 if(verboseflg)
355 printf("euid = %d\n",geteuid());
356 return -EACCES;
357 }
358
359 /* fixup path if needed */
360
361 /* Trim any trailing slashes */
362 while ((strlen(mountpoint) > 1) &&
363 (mountpoint[strlen(mountpoint)-1] == '/'))
364 {
365 mountpoint[strlen(mountpoint)-1] = '\0';
366 }
367
368 /* make sure that this is a cifs filesystem */
369 rc = statfs(mountpoint, &statbuf);
370
371 if(rc || (statbuf.f_type != CIFS_MAGIC_NUMBER)) {
372 printf("This utility only unmounts cifs filesystems.\n");
373 return -EINVAL;
374 }
375
376 /* check if our uid was the one who mounted */
377 rc = umount_check_perm(mountpoint);
378 if (rc) {
379 printf("Not permitted to unmount\n");
380 return rc;
381 }
382
383 if(umount2(mountpoint, flags)) {
384 /* remember to kill daemon on error */
385 switch (errno) {
386 case 0:
387 printf("unmount failed but no error number set\n");
388 break;
389 default:
390 printf("unmount error %d = %s\n",errno,strerror(errno));
391 }
392 printf("Refer to the umount.cifs(8) manual page (man 8 umount.cifs)\n");
393 return -1;
394 } else {
395 if(verboseflg)
396 printf("umount2 succeeded\n");
397 if(nomtab == 0)
398 remove_from_mtab(mountpoint);
399 }
400
401 return 0;
402}
403
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