1 /*
2 * fs/cifs/link.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * 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>
23 #include <linux/slab.h>
24 #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"
31 #include "cifs_unicode.h"
32 #ifdef CONFIG_CIFS_SMB2
33 #include "smb2proto.h"
34 #endif
35
36 /*
37 * M-F Symlink Functions - Begin
38 */
39
40 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
41 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
42 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
43 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
44 #define CIFS_MF_SYMLINK_FILE_SIZE \
45 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
46
47 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
48 #define CIFS_MF_SYMLINK_MD5_FORMAT \
49 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
50 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
51 md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
52 md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
53 md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
54 md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
55
56 static int
symlink_hash(unsigned int link_len,const char * link_str,u8 * md5_hash)57 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
58 {
59 int rc;
60 unsigned int size;
61 struct crypto_shash *md5;
62 struct sdesc *sdescmd5;
63
64 md5 = crypto_alloc_shash("md5", 0, 0);
65 if (IS_ERR(md5)) {
66 rc = PTR_ERR(md5);
67 cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
68 __func__, rc);
69 return rc;
70 }
71 size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
72 sdescmd5 = kmalloc(size, GFP_KERNEL);
73 if (!sdescmd5) {
74 rc = -ENOMEM;
75 goto symlink_hash_err;
76 }
77 sdescmd5->shash.tfm = md5;
78 sdescmd5->shash.flags = 0x0;
79
80 rc = crypto_shash_init(&sdescmd5->shash);
81 if (rc) {
82 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
83 goto symlink_hash_err;
84 }
85 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
86 if (rc) {
87 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
88 goto symlink_hash_err;
89 }
90 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
91 if (rc)
92 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
93
94 symlink_hash_err:
95 crypto_free_shash(md5);
96 kfree(sdescmd5);
97
98 return rc;
99 }
100
101 static int
parse_mf_symlink(const u8 * buf,unsigned int buf_len,unsigned int * _link_len,char ** _link_str)102 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
103 char **_link_str)
104 {
105 int rc;
106 unsigned int link_len;
107 const char *md5_str1;
108 const char *link_str;
109 u8 md5_hash[16];
110 char md5_str2[34];
111
112 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
113 return -EINVAL;
114
115 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
116 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
117
118 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
119 if (rc != 1)
120 return -EINVAL;
121
122 rc = symlink_hash(link_len, link_str, md5_hash);
123 if (rc) {
124 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
125 return rc;
126 }
127
128 snprintf(md5_str2, sizeof(md5_str2),
129 CIFS_MF_SYMLINK_MD5_FORMAT,
130 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
131
132 if (strncmp(md5_str1, md5_str2, 17) != 0)
133 return -EINVAL;
134
135 if (_link_str) {
136 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
137 if (!*_link_str)
138 return -ENOMEM;
139 }
140
141 *_link_len = link_len;
142 return 0;
143 }
144
145 static int
format_mf_symlink(u8 * buf,unsigned int buf_len,const char * link_str)146 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
147 {
148 int rc;
149 unsigned int link_len;
150 unsigned int ofs;
151 u8 md5_hash[16];
152
153 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
154 return -EINVAL;
155
156 link_len = strlen(link_str);
157
158 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
159 return -ENAMETOOLONG;
160
161 rc = symlink_hash(link_len, link_str, md5_hash);
162 if (rc) {
163 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
164 return rc;
165 }
166
167 snprintf(buf, buf_len,
168 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
169 link_len,
170 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
171
172 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
173 memcpy(buf + ofs, link_str, link_len);
174
175 ofs += link_len;
176 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
177 buf[ofs] = '\n';
178 ofs++;
179 }
180
181 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
182 buf[ofs] = ' ';
183 ofs++;
184 }
185
186 return 0;
187 }
188
189 bool
couldbe_mf_symlink(const struct cifs_fattr * fattr)190 couldbe_mf_symlink(const struct cifs_fattr *fattr)
191 {
192 if (!S_ISREG(fattr->cf_mode))
193 /* it's not a symlink */
194 return false;
195
196 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
197 /* it's not a symlink */
198 return false;
199
200 return true;
201 }
202
203 static int
create_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const char * fromName,const char * toName)204 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
205 struct cifs_sb_info *cifs_sb, const char *fromName,
206 const char *toName)
207 {
208 int rc;
209 u8 *buf;
210 unsigned int bytes_written = 0;
211
212 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
213 if (!buf)
214 return -ENOMEM;
215
216 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
217 if (rc)
218 goto out;
219
220 if (tcon->ses->server->ops->create_mf_symlink)
221 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
222 cifs_sb, fromName, buf, &bytes_written);
223 else
224 rc = -EOPNOTSUPP;
225
226 if (rc)
227 goto out;
228
229 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
230 rc = -EIO;
231 out:
232 kfree(buf);
233 return rc;
234 }
235
236 static int
query_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char ** symlinkinfo)237 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
238 struct cifs_sb_info *cifs_sb, const unsigned char *path,
239 char **symlinkinfo)
240 {
241 int rc;
242 u8 *buf = NULL;
243 unsigned int link_len = 0;
244 unsigned int bytes_read = 0;
245
246 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
247 if (!buf)
248 return -ENOMEM;
249
250 if (tcon->ses->server->ops->query_mf_symlink)
251 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
252 cifs_sb, path, buf, &bytes_read);
253 else
254 rc = -ENOSYS;
255
256 if (rc)
257 goto out;
258
259 if (bytes_read == 0) { /* not a symlink */
260 rc = -EINVAL;
261 goto out;
262 }
263
264 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
265 out:
266 kfree(buf);
267 return rc;
268 }
269
270 int
check_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,struct cifs_fattr * fattr,const unsigned char * path)271 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
272 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
273 const unsigned char *path)
274 {
275 int rc;
276 u8 *buf = NULL;
277 unsigned int link_len = 0;
278 unsigned int bytes_read = 0;
279
280 if (!couldbe_mf_symlink(fattr))
281 /* it's not a symlink */
282 return 0;
283
284 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
285 if (!buf)
286 return -ENOMEM;
287
288 if (tcon->ses->server->ops->query_mf_symlink)
289 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
290 cifs_sb, path, buf, &bytes_read);
291 else
292 rc = -ENOSYS;
293
294 if (rc)
295 goto out;
296
297 if (bytes_read == 0) /* not a symlink */
298 goto out;
299
300 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
301 if (rc == -EINVAL) {
302 /* it's not a symlink */
303 rc = 0;
304 goto out;
305 }
306
307 if (rc != 0)
308 goto out;
309
310 /* it is a symlink */
311 fattr->cf_eof = link_len;
312 fattr->cf_mode &= ~S_IFMT;
313 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
314 fattr->cf_dtype = DT_LNK;
315 out:
316 kfree(buf);
317 return rc;
318 }
319
320 /*
321 * SMB 1.0 Protocol specific functions
322 */
323
324 int
cifs_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)325 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
326 struct cifs_sb_info *cifs_sb, const unsigned char *path,
327 char *pbuf, unsigned int *pbytes_read)
328 {
329 int rc;
330 int oplock = 0;
331 struct cifs_fid fid;
332 struct cifs_open_parms oparms;
333 struct cifs_io_parms io_parms;
334 int buf_type = CIFS_NO_BUFFER;
335 FILE_ALL_INFO file_info;
336
337 oparms.tcon = tcon;
338 oparms.cifs_sb = cifs_sb;
339 oparms.desired_access = GENERIC_READ;
340 oparms.create_options = CREATE_NOT_DIR;
341 oparms.disposition = FILE_OPEN;
342 oparms.path = path;
343 oparms.fid = &fid;
344 oparms.reconnect = false;
345
346 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
347 if (rc)
348 return rc;
349
350 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
351 rc = -ENOENT;
352 /* it's not a symlink */
353 goto out;
354 }
355
356 io_parms.netfid = fid.netfid;
357 io_parms.pid = current->tgid;
358 io_parms.tcon = tcon;
359 io_parms.offset = 0;
360 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
361
362 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
363 out:
364 CIFSSMBClose(xid, tcon, fid.netfid);
365 return rc;
366 }
367
368 int
cifs_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)369 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
370 struct cifs_sb_info *cifs_sb, const unsigned char *path,
371 char *pbuf, unsigned int *pbytes_written)
372 {
373 int rc;
374 int oplock = 0;
375 struct cifs_fid fid;
376 struct cifs_open_parms oparms;
377 struct cifs_io_parms io_parms;
378 int create_options = CREATE_NOT_DIR;
379
380 if (backup_cred(cifs_sb))
381 create_options |= CREATE_OPEN_BACKUP_INTENT;
382
383 oparms.tcon = tcon;
384 oparms.cifs_sb = cifs_sb;
385 oparms.desired_access = GENERIC_WRITE;
386 oparms.create_options = create_options;
387 oparms.disposition = FILE_CREATE;
388 oparms.path = path;
389 oparms.fid = &fid;
390 oparms.reconnect = false;
391
392 rc = CIFS_open(xid, &oparms, &oplock, NULL);
393 if (rc)
394 return rc;
395
396 io_parms.netfid = fid.netfid;
397 io_parms.pid = current->tgid;
398 io_parms.tcon = tcon;
399 io_parms.offset = 0;
400 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
401
402 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
403 CIFSSMBClose(xid, tcon, fid.netfid);
404 return rc;
405 }
406
407 /*
408 * SMB 2.1/SMB3 Protocol specific functions
409 */
410 #ifdef CONFIG_CIFS_SMB2
411 int
smb3_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)412 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
413 struct cifs_sb_info *cifs_sb, const unsigned char *path,
414 char *pbuf, unsigned int *pbytes_read)
415 {
416 int rc;
417 struct cifs_fid fid;
418 struct cifs_open_parms oparms;
419 struct cifs_io_parms io_parms;
420 int buf_type = CIFS_NO_BUFFER;
421 __le16 *utf16_path;
422 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
423 struct smb2_file_all_info *pfile_info = NULL;
424
425 oparms.tcon = tcon;
426 oparms.cifs_sb = cifs_sb;
427 oparms.desired_access = GENERIC_READ;
428 oparms.create_options = CREATE_NOT_DIR;
429 if (backup_cred(cifs_sb))
430 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
431 oparms.disposition = FILE_OPEN;
432 oparms.fid = &fid;
433 oparms.reconnect = false;
434
435 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
436 if (utf16_path == NULL)
437 return -ENOMEM;
438
439 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
440 GFP_KERNEL);
441
442 if (pfile_info == NULL) {
443 kfree(utf16_path);
444 return -ENOMEM;
445 }
446
447 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
448 if (rc)
449 goto qmf_out_open_fail;
450
451 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
452 /* it's not a symlink */
453 rc = -ENOENT; /* Is there a better rc to return? */
454 goto qmf_out;
455 }
456
457 io_parms.netfid = fid.netfid;
458 io_parms.pid = current->tgid;
459 io_parms.tcon = tcon;
460 io_parms.offset = 0;
461 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
462 io_parms.persistent_fid = fid.persistent_fid;
463 io_parms.volatile_fid = fid.volatile_fid;
464 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
465 qmf_out:
466 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
467 qmf_out_open_fail:
468 kfree(utf16_path);
469 kfree(pfile_info);
470 return rc;
471 }
472
473 int
smb3_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)474 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
475 struct cifs_sb_info *cifs_sb, const unsigned char *path,
476 char *pbuf, unsigned int *pbytes_written)
477 {
478 int rc;
479 struct cifs_fid fid;
480 struct cifs_open_parms oparms;
481 struct cifs_io_parms io_parms;
482 int create_options = CREATE_NOT_DIR;
483 __le16 *utf16_path;
484 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
485 struct kvec iov[2];
486
487 if (backup_cred(cifs_sb))
488 create_options |= CREATE_OPEN_BACKUP_INTENT;
489
490 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
491
492 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
493 if (!utf16_path)
494 return -ENOMEM;
495
496 oparms.tcon = tcon;
497 oparms.cifs_sb = cifs_sb;
498 oparms.desired_access = GENERIC_WRITE;
499 oparms.create_options = create_options;
500 oparms.disposition = FILE_CREATE;
501 oparms.fid = &fid;
502 oparms.reconnect = false;
503
504 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
505 if (rc) {
506 kfree(utf16_path);
507 return rc;
508 }
509
510 io_parms.netfid = fid.netfid;
511 io_parms.pid = current->tgid;
512 io_parms.tcon = tcon;
513 io_parms.offset = 0;
514 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
515 io_parms.persistent_fid = fid.persistent_fid;
516 io_parms.volatile_fid = fid.volatile_fid;
517
518 /* iov[0] is reserved for smb header */
519 iov[1].iov_base = pbuf;
520 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
521
522 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
523
524 /* Make sure we wrote all of the symlink data */
525 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
526 rc = -EIO;
527
528 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
529
530 kfree(utf16_path);
531 return rc;
532 }
533 #endif /* CONFIG_CIFS_SMB2 */
534
535 /*
536 * M-F Symlink Functions - End
537 */
538
539 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)540 cifs_hardlink(struct dentry *old_file, struct inode *inode,
541 struct dentry *direntry)
542 {
543 int rc = -EACCES;
544 unsigned int xid;
545 char *from_name = NULL;
546 char *to_name = NULL;
547 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
548 struct tcon_link *tlink;
549 struct cifs_tcon *tcon;
550 struct TCP_Server_Info *server;
551 struct cifsInodeInfo *cifsInode;
552
553 tlink = cifs_sb_tlink(cifs_sb);
554 if (IS_ERR(tlink))
555 return PTR_ERR(tlink);
556 tcon = tlink_tcon(tlink);
557
558 xid = get_xid();
559
560 from_name = build_path_from_dentry(old_file);
561 to_name = build_path_from_dentry(direntry);
562 if ((from_name == NULL) || (to_name == NULL)) {
563 rc = -ENOMEM;
564 goto cifs_hl_exit;
565 }
566
567 if (tcon->unix_ext)
568 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
569 cifs_sb->local_nls,
570 cifs_remap(cifs_sb));
571 else {
572 server = tcon->ses->server;
573 if (!server->ops->create_hardlink) {
574 rc = -ENOSYS;
575 goto cifs_hl_exit;
576 }
577 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
578 cifs_sb);
579 if ((rc == -EIO) || (rc == -EINVAL))
580 rc = -EOPNOTSUPP;
581 }
582
583 d_drop(direntry); /* force new lookup from server of target */
584
585 /*
586 * if source file is cached (oplocked) revalidate will not go to server
587 * until the file is closed or oplock broken so update nlinks locally
588 */
589 if (d_really_is_positive(old_file)) {
590 cifsInode = CIFS_I(d_inode(old_file));
591 if (rc == 0) {
592 spin_lock(&d_inode(old_file)->i_lock);
593 inc_nlink(d_inode(old_file));
594 spin_unlock(&d_inode(old_file)->i_lock);
595
596 /*
597 * parent dir timestamps will update from srv within a
598 * second, would it really be worth it to set the parent
599 * dir cifs inode time to zero to force revalidate
600 * (faster) for it too?
601 */
602 }
603 /*
604 * if not oplocked will force revalidate to get info on source
605 * file from srv. Note Samba server prior to 4.2 has bug -
606 * not updating src file ctime on hardlinks but Windows servers
607 * handle it properly
608 */
609 cifsInode->time = 0;
610
611 /*
612 * Will update parent dir timestamps from srv within a second.
613 * Would it really be worth it to set the parent dir (cifs
614 * inode) time field to zero to force revalidate on parent
615 * directory faster ie
616 *
617 * CIFS_I(inode)->time = 0;
618 */
619 }
620
621 cifs_hl_exit:
622 kfree(from_name);
623 kfree(to_name);
624 free_xid(xid);
625 cifs_put_tlink(tlink);
626 return rc;
627 }
628
629 const char *
cifs_follow_link(struct dentry * direntry,void ** cookie)630 cifs_follow_link(struct dentry *direntry, void **cookie)
631 {
632 struct inode *inode = d_inode(direntry);
633 int rc = -ENOMEM;
634 unsigned int xid;
635 char *full_path = NULL;
636 char *target_path = NULL;
637 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
638 struct tcon_link *tlink = NULL;
639 struct cifs_tcon *tcon;
640 struct TCP_Server_Info *server;
641
642 xid = get_xid();
643
644 tlink = cifs_sb_tlink(cifs_sb);
645 if (IS_ERR(tlink)) {
646 free_xid(xid);
647 return ERR_CAST(tlink);
648 }
649 tcon = tlink_tcon(tlink);
650 server = tcon->ses->server;
651
652 full_path = build_path_from_dentry(direntry);
653 if (!full_path) {
654 free_xid(xid);
655 cifs_put_tlink(tlink);
656 return ERR_PTR(-ENOMEM);
657 }
658
659 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
660
661 rc = -EACCES;
662 /*
663 * First try Minshall+French Symlinks, if configured
664 * and fallback to UNIX Extensions Symlinks.
665 */
666 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
667 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
668 &target_path);
669
670 if (rc != 0 && server->ops->query_symlink)
671 rc = server->ops->query_symlink(xid, tcon, full_path,
672 &target_path, cifs_sb);
673
674 kfree(full_path);
675 free_xid(xid);
676 cifs_put_tlink(tlink);
677 if (rc != 0) {
678 kfree(target_path);
679 return ERR_PTR(rc);
680 }
681 return *cookie = target_path;
682 }
683
684 int
cifs_symlink(struct inode * inode,struct dentry * direntry,const char * symname)685 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
686 {
687 int rc = -EOPNOTSUPP;
688 unsigned int xid;
689 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
690 struct tcon_link *tlink;
691 struct cifs_tcon *pTcon;
692 char *full_path = NULL;
693 struct inode *newinode = NULL;
694
695 xid = get_xid();
696
697 tlink = cifs_sb_tlink(cifs_sb);
698 if (IS_ERR(tlink)) {
699 rc = PTR_ERR(tlink);
700 goto symlink_exit;
701 }
702 pTcon = tlink_tcon(tlink);
703
704 full_path = build_path_from_dentry(direntry);
705 if (full_path == NULL) {
706 rc = -ENOMEM;
707 goto symlink_exit;
708 }
709
710 cifs_dbg(FYI, "Full path: %s\n", full_path);
711 cifs_dbg(FYI, "symname is %s\n", symname);
712
713 /* BB what if DFS and this volume is on different share? BB */
714 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
715 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
716 else if (pTcon->unix_ext)
717 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
718 cifs_sb->local_nls,
719 cifs_remap(cifs_sb));
720 /* else
721 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
722 cifs_sb_target->local_nls); */
723
724 if (rc == 0) {
725 if (pTcon->unix_ext)
726 rc = cifs_get_inode_info_unix(&newinode, full_path,
727 inode->i_sb, xid);
728 else
729 rc = cifs_get_inode_info(&newinode, full_path, NULL,
730 inode->i_sb, xid, NULL);
731
732 if (rc != 0) {
733 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
734 rc);
735 } else {
736 d_instantiate(direntry, newinode);
737 }
738 }
739 symlink_exit:
740 kfree(full_path);
741 cifs_put_tlink(tlink);
742 free_xid(xid);
743 return rc;
744 }
745