blob: e8804d3734044f578da6d4427e4961431d61ae5a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/cifs/link.c
3 *
Steve French366781c2008-01-25 10:12:41 +00004 * Copyright (C) International Business Machines Corp., 2002,2008
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21#include <linux/fs.h>
22#include <linux/stat.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/namei.h>
25#include "cifsfs.h"
26#include "cifspdu.h"
27#include "cifsglob.h"
28#include "cifsproto.h"
29#include "cifs_debug.h"
30#include "cifs_fs_sb.h"
Stefan Metzmacherc69c1b62010-07-31 09:14:16 +020031
32#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
33#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
34#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
35#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
36#define CIFS_MF_SYMLINK_FILE_SIZE \
37 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
38
39#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
40#define CIFS_MF_SYMLINK_MD5_FORMAT \
41 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
42#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
43 md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
44 md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
45 md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
46 md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
47
48static int
Steve French93c100c2011-01-25 19:28:43 +000049symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
50{
51 int rc;
52 unsigned int size;
53 struct crypto_shash *md5;
54 struct sdesc *sdescmd5;
55
56 md5 = crypto_alloc_shash("md5", 0, 0);
Shirish Pargaonkaree2c9252011-01-27 09:58:04 -060057 if (IS_ERR(md5)) {
Jeff Laytonffeb4142011-01-29 07:03:02 -050058 rc = PTR_ERR(md5);
Steve French93c100c2011-01-25 19:28:43 +000059 cERROR(1, "%s: Crypto md5 allocation error %d\n", __func__, rc);
Jeff Laytonffeb4142011-01-29 07:03:02 -050060 return rc;
Steve French93c100c2011-01-25 19:28:43 +000061 }
62 size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
63 sdescmd5 = kmalloc(size, GFP_KERNEL);
64 if (!sdescmd5) {
65 rc = -ENOMEM;
66 cERROR(1, "%s: Memory allocation failure\n", __func__);
67 goto symlink_hash_err;
68 }
69 sdescmd5->shash.tfm = md5;
70 sdescmd5->shash.flags = 0x0;
71
72 rc = crypto_shash_init(&sdescmd5->shash);
73 if (rc) {
74 cERROR(1, "%s: Could not init md5 shash\n", __func__);
75 goto symlink_hash_err;
76 }
77 crypto_shash_update(&sdescmd5->shash, link_str, link_len);
78 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
79
80symlink_hash_err:
81 crypto_free_shash(md5);
82 kfree(sdescmd5);
83
84 return rc;
85}
86
87static int
Stefan Metzmacherc69c1b62010-07-31 09:14:16 +020088CIFSParseMFSymlink(const u8 *buf,
89 unsigned int buf_len,
90 unsigned int *_link_len,
91 char **_link_str)
92{
93 int rc;
94 unsigned int link_len;
95 const char *md5_str1;
96 const char *link_str;
Stefan Metzmacherc69c1b62010-07-31 09:14:16 +020097 u8 md5_hash[16];
98 char md5_str2[34];
99
100 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
101 return -EINVAL;
102
103 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
104 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
105
106 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
107 if (rc != 1)
108 return -EINVAL;
109
Steve French93c100c2011-01-25 19:28:43 +0000110 rc = symlink_hash(link_len, link_str, md5_hash);
111 if (rc) {
112 cFYI(1, "%s: MD5 hash failure: %d\n", __func__, rc);
113 return rc;
114 }
Stefan Metzmacherc69c1b62010-07-31 09:14:16 +0200115
116 snprintf(md5_str2, sizeof(md5_str2),
117 CIFS_MF_SYMLINK_MD5_FORMAT,
118 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
119
120 if (strncmp(md5_str1, md5_str2, 17) != 0)
121 return -EINVAL;
122
123 if (_link_str) {
124 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
125 if (!*_link_str)
126 return -ENOMEM;
127 }
128
129 *_link_len = link_len;
130 return 0;
131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Stefan Metzmacher0fd43ae2010-08-05 21:13:44 +0200133static int
Stefan Metzmacher18bddd12010-08-03 11:24:22 +0200134CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str)
135{
Steve French93c100c2011-01-25 19:28:43 +0000136 int rc;
Stefan Metzmacher18bddd12010-08-03 11:24:22 +0200137 unsigned int link_len;
138 unsigned int ofs;
Stefan Metzmacher18bddd12010-08-03 11:24:22 +0200139 u8 md5_hash[16];
140
141 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
142 return -EINVAL;
143
144 link_len = strlen(link_str);
145
146 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
147 return -ENAMETOOLONG;
148
Steve French93c100c2011-01-25 19:28:43 +0000149 rc = symlink_hash(link_len, link_str, md5_hash);
150 if (rc) {
151 cFYI(1, "%s: MD5 hash failure: %d\n", __func__, rc);
152 return rc;
153 }
Stefan Metzmacher18bddd12010-08-03 11:24:22 +0200154
155 snprintf(buf, buf_len,
156 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
157 link_len,
158 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
159
160 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
161 memcpy(buf + ofs, link_str, link_len);
162
163 ofs += link_len;
164 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
165 buf[ofs] = '\n';
166 ofs++;
167 }
168
169 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
170 buf[ofs] = ' ';
171 ofs++;
172 }
173
174 return 0;
175}
176
Stefan Metzmacher8713d012010-08-05 21:15:22 +0200177static int
178CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon,
179 const char *fromName, const char *toName,
180 const struct nls_table *nls_codepage, int remap)
181{
182 int rc;
183 int oplock = 0;
184 __u16 netfid = 0;
185 u8 *buf;
186 unsigned int bytes_written = 0;
187
188 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
189 if (!buf)
190 return -ENOMEM;
191
192 rc = CIFSFormatMFSymlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
193 if (rc != 0) {
194 kfree(buf);
195 return rc;
196 }
197
198 rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
199 CREATE_NOT_DIR, &netfid, &oplock, NULL,
200 nls_codepage, remap);
201 if (rc != 0) {
202 kfree(buf);
203 return rc;
204 }
205
206 rc = CIFSSMBWrite(xid, tcon, netfid,
207 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
208 0 /* offset */,
209 &bytes_written, buf, NULL, 0);
210 CIFSSMBClose(xid, tcon, netfid);
211 kfree(buf);
212 if (rc != 0)
213 return rc;
214
215 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
216 return -EIO;
217
218 return 0;
219}
220
221static int
Stefan Metzmacher0fd43ae2010-08-05 21:13:44 +0200222CIFSQueryMFSymLink(const int xid, struct cifsTconInfo *tcon,
223 const unsigned char *searchName, char **symlinkinfo,
224 const struct nls_table *nls_codepage, int remap)
225{
226 int rc;
227 int oplock = 0;
228 __u16 netfid = 0;
229 u8 *buf;
230 char *pbuf;
231 unsigned int bytes_read = 0;
232 int buf_type = CIFS_NO_BUFFER;
233 unsigned int link_len = 0;
234 FILE_ALL_INFO file_info;
235
236 rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ,
237 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
238 nls_codepage, remap);
239 if (rc != 0)
240 return rc;
241
242 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
243 CIFSSMBClose(xid, tcon, netfid);
244 /* it's not a symlink */
245 return -EINVAL;
246 }
247
248 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
249 if (!buf)
250 return -ENOMEM;
251 pbuf = buf;
252
253 rc = CIFSSMBRead(xid, tcon, netfid,
254 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
255 0 /* offset */,
256 &bytes_read, &pbuf, &buf_type);
257 CIFSSMBClose(xid, tcon, netfid);
258 if (rc != 0) {
259 kfree(buf);
260 return rc;
261 }
262
263 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo);
264 kfree(buf);
265 if (rc != 0)
266 return rc;
267
268 return 0;
269}
270
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200271bool
272CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
273{
274 if (!(fattr->cf_mode & S_IFREG))
275 /* it's not a symlink */
276 return false;
277
278 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
279 /* it's not a symlink */
280 return false;
281
282 return true;
283}
284
285int
286CIFSCheckMFSymlink(struct cifs_fattr *fattr,
287 const unsigned char *path,
288 struct cifs_sb_info *cifs_sb, int xid)
289{
290 int rc;
291 int oplock = 0;
292 __u16 netfid = 0;
Jeff Layton7ffec372010-09-29 19:51:11 -0400293 struct tcon_link *tlink;
294 struct cifsTconInfo *pTcon;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200295 u8 *buf;
296 char *pbuf;
297 unsigned int bytes_read = 0;
298 int buf_type = CIFS_NO_BUFFER;
299 unsigned int link_len = 0;
300 FILE_ALL_INFO file_info;
301
302 if (!CIFSCouldBeMFSymlink(fattr))
303 /* it's not a symlink */
304 return 0;
305
Jeff Layton7ffec372010-09-29 19:51:11 -0400306 tlink = cifs_sb_tlink(cifs_sb);
307 if (IS_ERR(tlink))
308 return PTR_ERR(tlink);
309 pTcon = tlink_tcon(tlink);
310
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200311 rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
312 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
313 cifs_sb->local_nls,
314 cifs_sb->mnt_cifs_flags &
315 CIFS_MOUNT_MAP_SPECIAL_CHR);
316 if (rc != 0)
Jeff Layton7ffec372010-09-29 19:51:11 -0400317 goto out;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200318
319 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
320 CIFSSMBClose(xid, pTcon, netfid);
321 /* it's not a symlink */
Jeff Layton7ffec372010-09-29 19:51:11 -0400322 goto out;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200323 }
324
325 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
Jeff Layton7ffec372010-09-29 19:51:11 -0400326 if (!buf) {
327 rc = -ENOMEM;
328 goto out;
329 }
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200330 pbuf = buf;
331
332 rc = CIFSSMBRead(xid, pTcon, netfid,
333 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
334 0 /* offset */,
335 &bytes_read, &pbuf, &buf_type);
336 CIFSSMBClose(xid, pTcon, netfid);
337 if (rc != 0) {
338 kfree(buf);
Jeff Layton7ffec372010-09-29 19:51:11 -0400339 goto out;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200340 }
341
342 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
343 kfree(buf);
Jeff Layton7ffec372010-09-29 19:51:11 -0400344 if (rc == -EINVAL) {
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200345 /* it's not a symlink */
Jeff Layton7ffec372010-09-29 19:51:11 -0400346 rc = 0;
347 goto out;
348 }
349
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200350 if (rc != 0)
Jeff Layton7ffec372010-09-29 19:51:11 -0400351 goto out;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200352
353 /* it is a symlink */
354 fattr->cf_eof = link_len;
355 fattr->cf_mode &= ~S_IFMT;
356 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
357 fattr->cf_dtype = DT_LNK;
Jeff Layton7ffec372010-09-29 19:51:11 -0400358out:
359 cifs_put_tlink(tlink);
360 return rc;
Stefan Metzmacher8bfb50a2010-07-31 09:15:10 +0200361}
362
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363int
364cifs_hardlink(struct dentry *old_file, struct inode *inode,
365 struct dentry *direntry)
366{
367 int rc = -EACCES;
368 int xid;
369 char *fromName = NULL;
370 char *toName = NULL;
Jeff Layton7ffec372010-09-29 19:51:11 -0400371 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
372 struct tcon_link *tlink;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 struct cifsTconInfo *pTcon;
374 struct cifsInodeInfo *cifsInode;
375
Jeff Layton7ffec372010-09-29 19:51:11 -0400376 tlink = cifs_sb_tlink(cifs_sb);
377 if (IS_ERR(tlink))
378 return PTR_ERR(tlink);
379 pTcon = tlink_tcon(tlink);
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 xid = GetXid();
382
Steve French7f573562005-08-30 11:32:14 -0700383 fromName = build_path_from_dentry(old_file);
384 toName = build_path_from_dentry(direntry);
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000385 if ((fromName == NULL) || (toName == NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 rc = -ENOMEM;
387 goto cifs_hl_exit;
388 }
389
Steve Frenchc18c8422007-07-18 23:21:09 +0000390 if (pTcon->unix_ext)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
Jeff Layton7ffec372010-09-29 19:51:11 -0400392 cifs_sb->local_nls,
393 cifs_sb->mnt_cifs_flags &
Steve French737b7582005-04-28 22:41:06 -0700394 CIFS_MOUNT_MAP_SPECIAL_CHR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 else {
396 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
Jeff Layton7ffec372010-09-29 19:51:11 -0400397 cifs_sb->local_nls,
398 cifs_sb->mnt_cifs_flags &
Steve French737b7582005-04-28 22:41:06 -0700399 CIFS_MOUNT_MAP_SPECIAL_CHR);
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000400 if ((rc == -EIO) || (rc == -EINVAL))
401 rc = -EOPNOTSUPP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 }
403
Steve French31ec35d2006-11-16 20:54:20 +0000404 d_drop(direntry); /* force new lookup from server of target */
405
406 /* if source file is cached (oplocked) revalidate will not go to server
407 until the file is closed or oplock broken so update nlinks locally */
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000408 if (old_file->d_inode) {
Steve French31ec35d2006-11-16 20:54:20 +0000409 cifsInode = CIFS_I(old_file->d_inode);
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000410 if (rc == 0) {
Steve French31ec35d2006-11-16 20:54:20 +0000411 old_file->d_inode->i_nlink++;
Steve French1b2b2122007-02-17 04:30:54 +0000412/* BB should we make this contingent on superblock flag NOATIME? */
413/* old_file->d_inode->i_ctime = CURRENT_TIME;*/
Steve French31ec35d2006-11-16 20:54:20 +0000414 /* parent dir timestamps will update from srv
415 within a second, would it really be worth it
416 to set the parent dir cifs inode time to zero
417 to force revalidate (faster) for it too? */
418 }
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000419 /* if not oplocked will force revalidate to get info
Steve French31ec35d2006-11-16 20:54:20 +0000420 on source file from srv */
421 cifsInode->time = 0;
422
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000423 /* Will update parent dir timestamps from srv within a second.
Steve French31ec35d2006-11-16 20:54:20 +0000424 Would it really be worth it to set the parent dir (cifs
425 inode) time field to zero to force revalidate on parent
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000426 directory faster ie
Steve French31ec35d2006-11-16 20:54:20 +0000427 CIFS_I(inode)->time = 0; */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
430cifs_hl_exit:
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800431 kfree(fromName);
432 kfree(toName);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 FreeXid(xid);
Jeff Layton7ffec372010-09-29 19:51:11 -0400434 cifs_put_tlink(tlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 return rc;
436}
437
Linus Torvaldscc314ee2005-08-19 18:02:56 -0700438void *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
440{
441 struct inode *inode = direntry->d_inode;
Jeff Layton8b6427a2009-05-19 09:57:03 -0400442 int rc = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 int xid;
444 char *full_path = NULL;
Jeff Layton8b6427a2009-05-19 09:57:03 -0400445 char *target_path = NULL;
446 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
Jeff Layton7ffec372010-09-29 19:51:11 -0400447 struct tcon_link *tlink = NULL;
448 struct cifsTconInfo *tcon;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450 xid = GetXid();
451
Jeff Layton7ffec372010-09-29 19:51:11 -0400452 tlink = cifs_sb_tlink(cifs_sb);
453 if (IS_ERR(tlink)) {
454 rc = PTR_ERR(tlink);
455 tlink = NULL;
456 goto out;
457 }
458 tcon = tlink_tcon(tlink);
459
Jeff Layton8b6427a2009-05-19 09:57:03 -0400460 /*
461 * For now, we just handle symlinks with unix extensions enabled.
462 * Eventually we should handle NTFS reparse points, and MacOS
463 * symlink support. For instance...
464 *
465 * rc = CIFSSMBQueryReparseLinkInfo(...)
466 *
467 * For now, just return -EACCES when the server doesn't support posix
468 * extensions. Note that we still allow querying symlinks when posix
469 * extensions are manually disabled. We could disable these as well
470 * but there doesn't seem to be any harm in allowing the client to
471 * read them.
472 */
Stefan Metzmacher1b12b9c2010-08-05 21:19:56 +0200473 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
474 && !(tcon->ses->capabilities & CAP_UNIX)) {
Jeff Layton8b6427a2009-05-19 09:57:03 -0400475 rc = -EACCES;
476 goto out;
477 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Jeff Layton8b6427a2009-05-19 09:57:03 -0400479 full_path = build_path_from_dentry(direntry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 if (!full_path)
Jeff Layton460b9692009-04-30 07:17:56 -0400481 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
Joe Perchesb6b38f72010-04-21 03:50:45 +0000483 cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Stefan Metzmacher1b12b9c2010-08-05 21:19:56 +0200485 rc = -EACCES;
486 /*
487 * First try Minshall+French Symlinks, if configured
488 * and fallback to UNIX Extensions Symlinks.
489 */
490 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
491 rc = CIFSQueryMFSymLink(xid, tcon, full_path, &target_path,
492 cifs_sb->local_nls,
493 cifs_sb->mnt_cifs_flags &
494 CIFS_MOUNT_MAP_SPECIAL_CHR);
495
496 if ((rc != 0) && (tcon->ses->capabilities & CAP_UNIX))
497 rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
498 cifs_sb->local_nls);
499
Jeff Layton8b6427a2009-05-19 09:57:03 -0400500 kfree(full_path);
501out:
Jeff Layton460b9692009-04-30 07:17:56 -0400502 if (rc != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 kfree(target_path);
504 target_path = ERR_PTR(rc);
505 }
506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 FreeXid(xid);
Jeff Layton7ffec372010-09-29 19:51:11 -0400508 if (tlink)
509 cifs_put_tlink(tlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 nd_set_link(nd, target_path);
Jeff Layton460b9692009-04-30 07:17:56 -0400511 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512}
513
514int
515cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
516{
517 int rc = -EOPNOTSUPP;
518 int xid;
Jeff Layton7ffec372010-09-29 19:51:11 -0400519 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
520 struct tcon_link *tlink;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 struct cifsTconInfo *pTcon;
522 char *full_path = NULL;
523 struct inode *newinode = NULL;
524
525 xid = GetXid();
526
Jeff Layton7ffec372010-09-29 19:51:11 -0400527 tlink = cifs_sb_tlink(cifs_sb);
528 if (IS_ERR(tlink)) {
529 rc = PTR_ERR(tlink);
530 goto symlink_exit;
531 }
532 pTcon = tlink_tcon(tlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Steve French7f573562005-08-30 11:32:14 -0700534 full_path = build_path_from_dentry(direntry);
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000535 if (full_path == NULL) {
Suresh Jayaraman0f3bc092009-06-25 18:12:34 +0530536 rc = -ENOMEM;
Jeff Layton7ffec372010-09-29 19:51:11 -0400537 goto symlink_exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 }
539
Joe Perchesb6b38f72010-04-21 03:50:45 +0000540 cFYI(1, "Full path: %s", full_path);
541 cFYI(1, "symname is %s", symname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542
543 /* BB what if DFS and this volume is on different share? BB */
Stefan Metzmacher1b12b9c2010-08-05 21:19:56 +0200544 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
545 rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname,
546 cifs_sb->local_nls,
547 cifs_sb->mnt_cifs_flags &
548 CIFS_MOUNT_MAP_SPECIAL_CHR);
549 else if (pTcon->unix_ext)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
551 cifs_sb->local_nls);
552 /* else
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000553 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
554 cifs_sb_target->local_nls); */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
556 if (rc == 0) {
Steve Frenchc18c8422007-07-18 23:21:09 +0000557 if (pTcon->unix_ext)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 rc = cifs_get_inode_info_unix(&newinode, full_path,
Steve Frenchfb8c4b12007-07-10 01:16:18 +0000559 inode->i_sb, xid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 else
561 rc = cifs_get_inode_info(&newinode, full_path, NULL,
Steve French8b1327f2008-03-14 22:37:16 +0000562 inode->i_sb, xid, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
564 if (rc != 0) {
Joe Perchesb6b38f72010-04-21 03:50:45 +0000565 cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
566 rc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 d_instantiate(direntry, newinode);
569 }
570 }
Jeff Layton7ffec372010-09-29 19:51:11 -0400571symlink_exit:
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800572 kfree(full_path);
Jeff Layton7ffec372010-09-29 19:51:11 -0400573 cifs_put_tlink(tlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 FreeXid(xid);
575 return rc;
576}
577
Linus Torvaldscc314ee2005-08-19 18:02:56 -0700578void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579{
580 char *p = nd_get_link(nd);
581 if (!IS_ERR(p))
582 kfree(p);
583}