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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#include "smb2proto.h"
33
34/*
35 * M-F Symlink Functions - Begin
36 */
37
38#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
39#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
40#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
41#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
42#define CIFS_MF_SYMLINK_FILE_SIZE \
43 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
44
45#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
46#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
47#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
48
49static int
50symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
51{
52 int rc;
53 struct crypto_shash *md5 = NULL;
54 struct sdesc *sdescmd5 = NULL;
55
56 rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
57 if (rc)
58 goto symlink_hash_err;
59
60 rc = crypto_shash_init(&sdescmd5->shash);
61 if (rc) {
62 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
63 goto symlink_hash_err;
64 }
65 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
66 if (rc) {
67 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
68 goto symlink_hash_err;
69 }
70 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
71 if (rc)
72 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
73
74symlink_hash_err:
75 cifs_free_hash(&md5, &sdescmd5);
76 return rc;
77}
78
79static int
80parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
81 char **_link_str)
82{
83 int rc;
84 unsigned int link_len;
85 const char *md5_str1;
86 const char *link_str;
87 u8 md5_hash[16];
88 char md5_str2[34];
89
90 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
91 return -EINVAL;
92
93 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
94 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
95
96 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
97 if (rc != 1)
98 return -EINVAL;
99
100 rc = symlink_hash(link_len, link_str, md5_hash);
101 if (rc) {
102 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
103 return rc;
104 }
105
106 snprintf(md5_str2, sizeof(md5_str2),
107 CIFS_MF_SYMLINK_MD5_FORMAT,
108 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
109
110 if (strncmp(md5_str1, md5_str2, 17) != 0)
111 return -EINVAL;
112
113 if (_link_str) {
114 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
115 if (!*_link_str)
116 return -ENOMEM;
117 }
118
119 *_link_len = link_len;
120 return 0;
121}
122
123static int
124format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
125{
126 int rc;
127 unsigned int link_len;
128 unsigned int ofs;
129 u8 md5_hash[16];
130
131 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
132 return -EINVAL;
133
134 link_len = strlen(link_str);
135
136 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
137 return -ENAMETOOLONG;
138
139 rc = symlink_hash(link_len, link_str, md5_hash);
140 if (rc) {
141 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
142 return rc;
143 }
144
145 snprintf(buf, buf_len,
146 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
147 link_len,
148 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
149
150 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
151 memcpy(buf + ofs, link_str, link_len);
152
153 ofs += link_len;
154 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
155 buf[ofs] = '\n';
156 ofs++;
157 }
158
159 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
160 buf[ofs] = ' ';
161 ofs++;
162 }
163
164 return 0;
165}
166
167bool
168couldbe_mf_symlink(const struct cifs_fattr *fattr)
169{
170 if (!S_ISREG(fattr->cf_mode))
171 /* it's not a symlink */
172 return false;
173
174 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
175 /* it's not a symlink */
176 return false;
177
178 return true;
179}
180
181static int
182create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
183 struct cifs_sb_info *cifs_sb, const char *fromName,
184 const char *toName)
185{
186 int rc;
187 u8 *buf;
188 unsigned int bytes_written = 0;
189
190 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
191 if (!buf)
192 return -ENOMEM;
193
194 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
195 if (rc)
196 goto out;
197
198 if (tcon->ses->server->ops->create_mf_symlink)
199 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
200 cifs_sb, fromName, buf, &bytes_written);
201 else
202 rc = -EOPNOTSUPP;
203
204 if (rc)
205 goto out;
206
207 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
208 rc = -EIO;
209out:
210 kfree(buf);
211 return rc;
212}
213
214static int
215query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
216 struct cifs_sb_info *cifs_sb, const unsigned char *path,
217 char **symlinkinfo)
218{
219 int rc;
220 u8 *buf = NULL;
221 unsigned int link_len = 0;
222 unsigned int bytes_read = 0;
223
224 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
225 if (!buf)
226 return -ENOMEM;
227
228 if (tcon->ses->server->ops->query_mf_symlink)
229 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
230 cifs_sb, path, buf, &bytes_read);
231 else
232 rc = -ENOSYS;
233
234 if (rc)
235 goto out;
236
237 if (bytes_read == 0) { /* not a symlink */
238 rc = -EINVAL;
239 goto out;
240 }
241
242 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
243out:
244 kfree(buf);
245 return rc;
246}
247
248int
249check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
250 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
251 const unsigned char *path)
252{
253 int rc;
254 u8 *buf = NULL;
255 unsigned int link_len = 0;
256 unsigned int bytes_read = 0;
257
258 if (!couldbe_mf_symlink(fattr))
259 /* it's not a symlink */
260 return 0;
261
262 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
263 if (!buf)
264 return -ENOMEM;
265
266 if (tcon->ses->server->ops->query_mf_symlink)
267 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
268 cifs_sb, path, buf, &bytes_read);
269 else
270 rc = -ENOSYS;
271
272 if (rc)
273 goto out;
274
275 if (bytes_read == 0) /* not a symlink */
276 goto out;
277
278 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
279 if (rc == -EINVAL) {
280 /* it's not a symlink */
281 rc = 0;
282 goto out;
283 }
284
285 if (rc != 0)
286 goto out;
287
288 /* it is a symlink */
289 fattr->cf_eof = link_len;
290 fattr->cf_mode &= ~S_IFMT;
291 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
292 fattr->cf_dtype = DT_LNK;
293out:
294 kfree(buf);
295 return rc;
296}
297
298/*
299 * SMB 1.0 Protocol specific functions
300 */
301
302int
303cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
304 struct cifs_sb_info *cifs_sb, const unsigned char *path,
305 char *pbuf, unsigned int *pbytes_read)
306{
307 int rc;
308 int oplock = 0;
309 struct cifs_fid fid;
310 struct cifs_open_parms oparms;
311 struct cifs_io_parms io_parms;
312 int buf_type = CIFS_NO_BUFFER;
313 FILE_ALL_INFO file_info;
314
315 oparms.tcon = tcon;
316 oparms.cifs_sb = cifs_sb;
317 oparms.desired_access = GENERIC_READ;
318 oparms.create_options = CREATE_NOT_DIR;
319 oparms.disposition = FILE_OPEN;
320 oparms.path = path;
321 oparms.fid = &fid;
322 oparms.reconnect = false;
323
324 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
325 if (rc)
326 return rc;
327
328 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
329 rc = -ENOENT;
330 /* it's not a symlink */
331 goto out;
332 }
333
334 io_parms.netfid = fid.netfid;
335 io_parms.pid = current->tgid;
336 io_parms.tcon = tcon;
337 io_parms.offset = 0;
338 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
339
340 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
341out:
342 CIFSSMBClose(xid, tcon, fid.netfid);
343 return rc;
344}
345
346int
347cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
348 struct cifs_sb_info *cifs_sb, const unsigned char *path,
349 char *pbuf, unsigned int *pbytes_written)
350{
351 int rc;
352 int oplock = 0;
353 struct cifs_fid fid;
354 struct cifs_open_parms oparms;
355 struct cifs_io_parms io_parms;
356 int create_options = CREATE_NOT_DIR;
357
358 if (backup_cred(cifs_sb))
359 create_options |= CREATE_OPEN_BACKUP_INTENT;
360
361 oparms.tcon = tcon;
362 oparms.cifs_sb = cifs_sb;
363 oparms.desired_access = GENERIC_WRITE;
364 oparms.create_options = create_options;
365 oparms.disposition = FILE_CREATE;
366 oparms.path = path;
367 oparms.fid = &fid;
368 oparms.reconnect = false;
369
370 rc = CIFS_open(xid, &oparms, &oplock, NULL);
371 if (rc)
372 return rc;
373
374 io_parms.netfid = fid.netfid;
375 io_parms.pid = current->tgid;
376 io_parms.tcon = tcon;
377 io_parms.offset = 0;
378 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
379
380 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
381 CIFSSMBClose(xid, tcon, fid.netfid);
382 return rc;
383}
384
385/*
386 * SMB 2.1/SMB3 Protocol specific functions
387 */
388int
389smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
390 struct cifs_sb_info *cifs_sb, const unsigned char *path,
391 char *pbuf, unsigned int *pbytes_read)
392{
393 int rc;
394 struct cifs_fid fid;
395 struct cifs_open_parms oparms;
396 struct cifs_io_parms io_parms;
397 int buf_type = CIFS_NO_BUFFER;
398 __le16 *utf16_path;
399 __u8 oplock = SMB2_OPLOCK_LEVEL_II;
400 struct smb2_file_all_info *pfile_info = NULL;
401
402 oparms.tcon = tcon;
403 oparms.cifs_sb = cifs_sb;
404 oparms.desired_access = GENERIC_READ;
405 oparms.create_options = CREATE_NOT_DIR;
406 if (backup_cred(cifs_sb))
407 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
408 oparms.disposition = FILE_OPEN;
409 oparms.fid = &fid;
410 oparms.reconnect = false;
411
412 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
413 if (utf16_path == NULL)
414 return -ENOMEM;
415
416 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
417 GFP_KERNEL);
418
419 if (pfile_info == NULL) {
420 kfree(utf16_path);
421 return -ENOMEM;
422 }
423
424 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
425 if (rc)
426 goto qmf_out_open_fail;
427
428 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
429 /* it's not a symlink */
430 rc = -ENOENT; /* Is there a better rc to return? */
431 goto qmf_out;
432 }
433
434 io_parms.netfid = fid.netfid;
435 io_parms.pid = current->tgid;
436 io_parms.tcon = tcon;
437 io_parms.offset = 0;
438 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
439 io_parms.persistent_fid = fid.persistent_fid;
440 io_parms.volatile_fid = fid.volatile_fid;
441 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
442qmf_out:
443 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
444qmf_out_open_fail:
445 kfree(utf16_path);
446 kfree(pfile_info);
447 return rc;
448}
449
450int
451smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
452 struct cifs_sb_info *cifs_sb, const unsigned char *path,
453 char *pbuf, unsigned int *pbytes_written)
454{
455 int rc;
456 struct cifs_fid fid;
457 struct cifs_open_parms oparms;
458 struct cifs_io_parms io_parms;
459 int create_options = CREATE_NOT_DIR;
460 __le16 *utf16_path;
461 __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
462 struct kvec iov[2];
463
464 if (backup_cred(cifs_sb))
465 create_options |= CREATE_OPEN_BACKUP_INTENT;
466
467 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
468
469 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
470 if (!utf16_path)
471 return -ENOMEM;
472
473 oparms.tcon = tcon;
474 oparms.cifs_sb = cifs_sb;
475 oparms.desired_access = GENERIC_WRITE;
476 oparms.create_options = create_options;
477 oparms.disposition = FILE_CREATE;
478 oparms.fid = &fid;
479 oparms.reconnect = false;
480
481 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
482 if (rc) {
483 kfree(utf16_path);
484 return rc;
485 }
486
487 io_parms.netfid = fid.netfid;
488 io_parms.pid = current->tgid;
489 io_parms.tcon = tcon;
490 io_parms.offset = 0;
491 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
492 io_parms.persistent_fid = fid.persistent_fid;
493 io_parms.volatile_fid = fid.volatile_fid;
494
495 /* iov[0] is reserved for smb header */
496 iov[1].iov_base = pbuf;
497 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
498
499 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
500
501 /* Make sure we wrote all of the symlink data */
502 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
503 rc = -EIO;
504
505 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
506
507 kfree(utf16_path);
508 return rc;
509}
510
511/*
512 * M-F Symlink Functions - End
513 */
514
515int
516cifs_hardlink(struct dentry *old_file, struct inode *inode,
517 struct dentry *direntry)
518{
519 int rc = -EACCES;
520 unsigned int xid;
521 char *from_name = NULL;
522 char *to_name = NULL;
523 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
524 struct tcon_link *tlink;
525 struct cifs_tcon *tcon;
526 struct TCP_Server_Info *server;
527 struct cifsInodeInfo *cifsInode;
528
529 tlink = cifs_sb_tlink(cifs_sb);
530 if (IS_ERR(tlink))
531 return PTR_ERR(tlink);
532 tcon = tlink_tcon(tlink);
533
534 xid = get_xid();
535
536 from_name = build_path_from_dentry(old_file);
537 to_name = build_path_from_dentry(direntry);
538 if ((from_name == NULL) || (to_name == NULL)) {
539 rc = -ENOMEM;
540 goto cifs_hl_exit;
541 }
542
543 if (tcon->unix_ext)
544 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
545 cifs_sb->local_nls,
546 cifs_remap(cifs_sb));
547 else {
548 server = tcon->ses->server;
549 if (!server->ops->create_hardlink) {
550 rc = -ENOSYS;
551 goto cifs_hl_exit;
552 }
553 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
554 cifs_sb);
555 if ((rc == -EIO) || (rc == -EINVAL))
556 rc = -EOPNOTSUPP;
557 }
558
559 d_drop(direntry); /* force new lookup from server of target */
560
561 /*
562 * if source file is cached (oplocked) revalidate will not go to server
563 * until the file is closed or oplock broken so update nlinks locally
564 */
565 if (d_really_is_positive(old_file)) {
566 cifsInode = CIFS_I(d_inode(old_file));
567 if (rc == 0) {
568 spin_lock(&d_inode(old_file)->i_lock);
569 inc_nlink(d_inode(old_file));
570 spin_unlock(&d_inode(old_file)->i_lock);
571
572 /*
573 * parent dir timestamps will update from srv within a
574 * second, would it really be worth it to set the parent
575 * dir cifs inode time to zero to force revalidate
576 * (faster) for it too?
577 */
578 }
579 /*
580 * if not oplocked will force revalidate to get info on source
581 * file from srv. Note Samba server prior to 4.2 has bug -
582 * not updating src file ctime on hardlinks but Windows servers
583 * handle it properly
584 */
585 cifsInode->time = 0;
586
587 /*
588 * Will update parent dir timestamps from srv within a second.
589 * Would it really be worth it to set the parent dir (cifs
590 * inode) time field to zero to force revalidate on parent
591 * directory faster ie
592 *
593 * CIFS_I(inode)->time = 0;
594 */
595 }
596
597cifs_hl_exit:
598 kfree(from_name);
599 kfree(to_name);
600 free_xid(xid);
601 cifs_put_tlink(tlink);
602 return rc;
603}
604
605const char *
606cifs_get_link(struct dentry *direntry, struct inode *inode,
607 struct delayed_call *done)
608{
609 int rc = -ENOMEM;
610 unsigned int xid;
611 char *full_path = NULL;
612 char *target_path = NULL;
613 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
614 struct tcon_link *tlink = NULL;
615 struct cifs_tcon *tcon;
616 struct TCP_Server_Info *server;
617
618 if (!direntry)
619 return ERR_PTR(-ECHILD);
620
621 xid = get_xid();
622
623 tlink = cifs_sb_tlink(cifs_sb);
624 if (IS_ERR(tlink)) {
625 free_xid(xid);
626 return ERR_CAST(tlink);
627 }
628 tcon = tlink_tcon(tlink);
629 server = tcon->ses->server;
630
631 full_path = build_path_from_dentry(direntry);
632 if (!full_path) {
633 free_xid(xid);
634 cifs_put_tlink(tlink);
635 return ERR_PTR(-ENOMEM);
636 }
637
638 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
639
640 rc = -EACCES;
641 /*
642 * First try Minshall+French Symlinks, if configured
643 * and fallback to UNIX Extensions Symlinks.
644 */
645 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
646 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
647 &target_path);
648
649 if (rc != 0 && server->ops->query_symlink)
650 rc = server->ops->query_symlink(xid, tcon, full_path,
651 &target_path, cifs_sb);
652
653 kfree(full_path);
654 free_xid(xid);
655 cifs_put_tlink(tlink);
656 if (rc != 0) {
657 kfree(target_path);
658 return ERR_PTR(rc);
659 }
660 set_delayed_call(done, kfree_link, target_path);
661 return target_path;
662}
663
664int
665cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
666{
667 int rc = -EOPNOTSUPP;
668 unsigned int xid;
669 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
670 struct tcon_link *tlink;
671 struct cifs_tcon *pTcon;
672 char *full_path = NULL;
673 struct inode *newinode = NULL;
674
675 xid = get_xid();
676
677 tlink = cifs_sb_tlink(cifs_sb);
678 if (IS_ERR(tlink)) {
679 rc = PTR_ERR(tlink);
680 goto symlink_exit;
681 }
682 pTcon = tlink_tcon(tlink);
683
684 full_path = build_path_from_dentry(direntry);
685 if (full_path == NULL) {
686 rc = -ENOMEM;
687 goto symlink_exit;
688 }
689
690 cifs_dbg(FYI, "Full path: %s\n", full_path);
691 cifs_dbg(FYI, "symname is %s\n", symname);
692
693 /* BB what if DFS and this volume is on different share? BB */
694 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
695 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
696 else if (pTcon->unix_ext)
697 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
698 cifs_sb->local_nls,
699 cifs_remap(cifs_sb));
700 /* else
701 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
702 cifs_sb_target->local_nls); */
703
704 if (rc == 0) {
705 if (pTcon->unix_ext)
706 rc = cifs_get_inode_info_unix(&newinode, full_path,
707 inode->i_sb, xid);
708 else
709 rc = cifs_get_inode_info(&newinode, full_path, NULL,
710 inode->i_sb, xid, NULL);
711
712 if (rc != 0) {
713 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
714 rc);
715 } else {
716 d_instantiate(direntry, newinode);
717 }
718 }
719symlink_exit:
720 kfree(full_path);
721 cifs_put_tlink(tlink);
722 free_xid(xid);
723 return rc;
724}
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#include "smb2proto.h"
33
34/*
35 * M-F Symlink Functions - Begin
36 */
37
38#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
39#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
40#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
41#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
42#define CIFS_MF_SYMLINK_FILE_SIZE \
43 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
44
45#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
46#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
47#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
48
49static int
50symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
51{
52 int rc;
53 struct crypto_shash *md5 = NULL;
54 struct sdesc *sdescmd5 = NULL;
55
56 rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
57 if (rc)
58 goto symlink_hash_err;
59
60 rc = crypto_shash_init(&sdescmd5->shash);
61 if (rc) {
62 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
63 goto symlink_hash_err;
64 }
65 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
66 if (rc) {
67 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
68 goto symlink_hash_err;
69 }
70 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
71 if (rc)
72 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
73
74symlink_hash_err:
75 cifs_free_hash(&md5, &sdescmd5);
76 return rc;
77}
78
79static int
80parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
81 char **_link_str)
82{
83 int rc;
84 unsigned int link_len;
85 const char *md5_str1;
86 const char *link_str;
87 u8 md5_hash[16];
88 char md5_str2[34];
89
90 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
91 return -EINVAL;
92
93 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
94 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
95
96 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
97 if (rc != 1)
98 return -EINVAL;
99
100 rc = symlink_hash(link_len, link_str, md5_hash);
101 if (rc) {
102 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
103 return rc;
104 }
105
106 scnprintf(md5_str2, sizeof(md5_str2),
107 CIFS_MF_SYMLINK_MD5_FORMAT,
108 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
109
110 if (strncmp(md5_str1, md5_str2, 17) != 0)
111 return -EINVAL;
112
113 if (_link_str) {
114 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
115 if (!*_link_str)
116 return -ENOMEM;
117 }
118
119 *_link_len = link_len;
120 return 0;
121}
122
123static int
124format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
125{
126 int rc;
127 unsigned int link_len;
128 unsigned int ofs;
129 u8 md5_hash[16];
130
131 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
132 return -EINVAL;
133
134 link_len = strlen(link_str);
135
136 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
137 return -ENAMETOOLONG;
138
139 rc = symlink_hash(link_len, link_str, md5_hash);
140 if (rc) {
141 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
142 return rc;
143 }
144
145 scnprintf(buf, buf_len,
146 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
147 link_len,
148 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
149
150 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
151 memcpy(buf + ofs, link_str, link_len);
152
153 ofs += link_len;
154 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
155 buf[ofs] = '\n';
156 ofs++;
157 }
158
159 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
160 buf[ofs] = ' ';
161 ofs++;
162 }
163
164 return 0;
165}
166
167bool
168couldbe_mf_symlink(const struct cifs_fattr *fattr)
169{
170 if (!S_ISREG(fattr->cf_mode))
171 /* it's not a symlink */
172 return false;
173
174 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
175 /* it's not a symlink */
176 return false;
177
178 return true;
179}
180
181static int
182create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
183 struct cifs_sb_info *cifs_sb, const char *fromName,
184 const char *toName)
185{
186 int rc;
187 u8 *buf;
188 unsigned int bytes_written = 0;
189
190 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
191 if (!buf)
192 return -ENOMEM;
193
194 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
195 if (rc)
196 goto out;
197
198 if (tcon->ses->server->ops->create_mf_symlink)
199 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
200 cifs_sb, fromName, buf, &bytes_written);
201 else
202 rc = -EOPNOTSUPP;
203
204 if (rc)
205 goto out;
206
207 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
208 rc = -EIO;
209out:
210 kfree(buf);
211 return rc;
212}
213
214static int
215query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
216 struct cifs_sb_info *cifs_sb, const unsigned char *path,
217 char **symlinkinfo)
218{
219 int rc;
220 u8 *buf = NULL;
221 unsigned int link_len = 0;
222 unsigned int bytes_read = 0;
223
224 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
225 if (!buf)
226 return -ENOMEM;
227
228 if (tcon->ses->server->ops->query_mf_symlink)
229 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
230 cifs_sb, path, buf, &bytes_read);
231 else
232 rc = -ENOSYS;
233
234 if (rc)
235 goto out;
236
237 if (bytes_read == 0) { /* not a symlink */
238 rc = -EINVAL;
239 goto out;
240 }
241
242 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
243out:
244 kfree(buf);
245 return rc;
246}
247
248int
249check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
250 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
251 const unsigned char *path)
252{
253 int rc;
254 u8 *buf = NULL;
255 unsigned int link_len = 0;
256 unsigned int bytes_read = 0;
257
258 if (!couldbe_mf_symlink(fattr))
259 /* it's not a symlink */
260 return 0;
261
262 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
263 if (!buf)
264 return -ENOMEM;
265
266 if (tcon->ses->server->ops->query_mf_symlink)
267 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
268 cifs_sb, path, buf, &bytes_read);
269 else
270 rc = -ENOSYS;
271
272 if (rc)
273 goto out;
274
275 if (bytes_read == 0) /* not a symlink */
276 goto out;
277
278 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
279 if (rc == -EINVAL) {
280 /* it's not a symlink */
281 rc = 0;
282 goto out;
283 }
284
285 if (rc != 0)
286 goto out;
287
288 /* it is a symlink */
289 fattr->cf_eof = link_len;
290 fattr->cf_mode &= ~S_IFMT;
291 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
292 fattr->cf_dtype = DT_LNK;
293out:
294 kfree(buf);
295 return rc;
296}
297
298/*
299 * SMB 1.0 Protocol specific functions
300 */
301
302int
303cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
304 struct cifs_sb_info *cifs_sb, const unsigned char *path,
305 char *pbuf, unsigned int *pbytes_read)
306{
307 int rc;
308 int oplock = 0;
309 struct cifs_fid fid;
310 struct cifs_open_parms oparms;
311 struct cifs_io_parms io_parms;
312 int buf_type = CIFS_NO_BUFFER;
313 FILE_ALL_INFO file_info;
314
315 oparms.tcon = tcon;
316 oparms.cifs_sb = cifs_sb;
317 oparms.desired_access = GENERIC_READ;
318 oparms.create_options = CREATE_NOT_DIR;
319 oparms.disposition = FILE_OPEN;
320 oparms.path = path;
321 oparms.fid = &fid;
322 oparms.reconnect = false;
323
324 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
325 if (rc)
326 return rc;
327
328 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
329 rc = -ENOENT;
330 /* it's not a symlink */
331 goto out;
332 }
333
334 io_parms.netfid = fid.netfid;
335 io_parms.pid = current->tgid;
336 io_parms.tcon = tcon;
337 io_parms.offset = 0;
338 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
339
340 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
341out:
342 CIFSSMBClose(xid, tcon, fid.netfid);
343 return rc;
344}
345
346int
347cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
348 struct cifs_sb_info *cifs_sb, const unsigned char *path,
349 char *pbuf, unsigned int *pbytes_written)
350{
351 int rc;
352 int oplock = 0;
353 struct cifs_fid fid;
354 struct cifs_open_parms oparms;
355 struct cifs_io_parms io_parms;
356 int create_options = CREATE_NOT_DIR;
357
358 if (backup_cred(cifs_sb))
359 create_options |= CREATE_OPEN_BACKUP_INTENT;
360
361 oparms.tcon = tcon;
362 oparms.cifs_sb = cifs_sb;
363 oparms.desired_access = GENERIC_WRITE;
364 oparms.create_options = create_options;
365 oparms.disposition = FILE_CREATE;
366 oparms.path = path;
367 oparms.fid = &fid;
368 oparms.reconnect = false;
369
370 rc = CIFS_open(xid, &oparms, &oplock, NULL);
371 if (rc)
372 return rc;
373
374 io_parms.netfid = fid.netfid;
375 io_parms.pid = current->tgid;
376 io_parms.tcon = tcon;
377 io_parms.offset = 0;
378 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
379
380 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
381 CIFSSMBClose(xid, tcon, fid.netfid);
382 return rc;
383}
384
385/*
386 * SMB 2.1/SMB3 Protocol specific functions
387 */
388int
389smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
390 struct cifs_sb_info *cifs_sb, const unsigned char *path,
391 char *pbuf, unsigned int *pbytes_read)
392{
393 int rc;
394 struct cifs_fid fid;
395 struct cifs_open_parms oparms;
396 struct cifs_io_parms io_parms;
397 int buf_type = CIFS_NO_BUFFER;
398 __le16 *utf16_path;
399 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
400 struct smb2_file_all_info *pfile_info = NULL;
401
402 oparms.tcon = tcon;
403 oparms.cifs_sb = cifs_sb;
404 oparms.desired_access = GENERIC_READ;
405 oparms.create_options = CREATE_NOT_DIR;
406 if (backup_cred(cifs_sb))
407 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
408 oparms.disposition = FILE_OPEN;
409 oparms.fid = &fid;
410 oparms.reconnect = false;
411
412 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
413 if (utf16_path == NULL)
414 return -ENOMEM;
415
416 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
417 GFP_KERNEL);
418
419 if (pfile_info == NULL) {
420 kfree(utf16_path);
421 return -ENOMEM;
422 }
423
424 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
425 NULL);
426 if (rc)
427 goto qmf_out_open_fail;
428
429 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
430 /* it's not a symlink */
431 rc = -ENOENT; /* Is there a better rc to return? */
432 goto qmf_out;
433 }
434
435 io_parms.netfid = fid.netfid;
436 io_parms.pid = current->tgid;
437 io_parms.tcon = tcon;
438 io_parms.offset = 0;
439 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
440 io_parms.persistent_fid = fid.persistent_fid;
441 io_parms.volatile_fid = fid.volatile_fid;
442 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
443qmf_out:
444 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
445qmf_out_open_fail:
446 kfree(utf16_path);
447 kfree(pfile_info);
448 return rc;
449}
450
451int
452smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
453 struct cifs_sb_info *cifs_sb, const unsigned char *path,
454 char *pbuf, unsigned int *pbytes_written)
455{
456 int rc;
457 struct cifs_fid fid;
458 struct cifs_open_parms oparms;
459 struct cifs_io_parms io_parms;
460 int create_options = CREATE_NOT_DIR;
461 __le16 *utf16_path;
462 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
463 struct kvec iov[2];
464
465 if (backup_cred(cifs_sb))
466 create_options |= CREATE_OPEN_BACKUP_INTENT;
467
468 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
469
470 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
471 if (!utf16_path)
472 return -ENOMEM;
473
474 oparms.tcon = tcon;
475 oparms.cifs_sb = cifs_sb;
476 oparms.desired_access = GENERIC_WRITE;
477 oparms.create_options = create_options;
478 oparms.disposition = FILE_CREATE;
479 oparms.fid = &fid;
480 oparms.reconnect = false;
481
482 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
483 NULL);
484 if (rc) {
485 kfree(utf16_path);
486 return rc;
487 }
488
489 io_parms.netfid = fid.netfid;
490 io_parms.pid = current->tgid;
491 io_parms.tcon = tcon;
492 io_parms.offset = 0;
493 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
494 io_parms.persistent_fid = fid.persistent_fid;
495 io_parms.volatile_fid = fid.volatile_fid;
496
497 /* iov[0] is reserved for smb header */
498 iov[1].iov_base = pbuf;
499 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
500
501 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
502
503 /* Make sure we wrote all of the symlink data */
504 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
505 rc = -EIO;
506
507 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
508
509 kfree(utf16_path);
510 return rc;
511}
512
513/*
514 * M-F Symlink Functions - End
515 */
516
517int
518cifs_hardlink(struct dentry *old_file, struct inode *inode,
519 struct dentry *direntry)
520{
521 int rc = -EACCES;
522 unsigned int xid;
523 char *from_name = NULL;
524 char *to_name = NULL;
525 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
526 struct tcon_link *tlink;
527 struct cifs_tcon *tcon;
528 struct TCP_Server_Info *server;
529 struct cifsInodeInfo *cifsInode;
530
531 tlink = cifs_sb_tlink(cifs_sb);
532 if (IS_ERR(tlink))
533 return PTR_ERR(tlink);
534 tcon = tlink_tcon(tlink);
535
536 xid = get_xid();
537
538 from_name = build_path_from_dentry(old_file);
539 to_name = build_path_from_dentry(direntry);
540 if ((from_name == NULL) || (to_name == NULL)) {
541 rc = -ENOMEM;
542 goto cifs_hl_exit;
543 }
544
545 if (tcon->unix_ext)
546 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
547 cifs_sb->local_nls,
548 cifs_remap(cifs_sb));
549 else {
550 server = tcon->ses->server;
551 if (!server->ops->create_hardlink) {
552 rc = -ENOSYS;
553 goto cifs_hl_exit;
554 }
555 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
556 cifs_sb);
557 if ((rc == -EIO) || (rc == -EINVAL))
558 rc = -EOPNOTSUPP;
559 }
560
561 d_drop(direntry); /* force new lookup from server of target */
562
563 /*
564 * if source file is cached (oplocked) revalidate will not go to server
565 * until the file is closed or oplock broken so update nlinks locally
566 */
567 if (d_really_is_positive(old_file)) {
568 cifsInode = CIFS_I(d_inode(old_file));
569 if (rc == 0) {
570 spin_lock(&d_inode(old_file)->i_lock);
571 inc_nlink(d_inode(old_file));
572 spin_unlock(&d_inode(old_file)->i_lock);
573
574 /*
575 * parent dir timestamps will update from srv within a
576 * second, would it really be worth it to set the parent
577 * dir cifs inode time to zero to force revalidate
578 * (faster) for it too?
579 */
580 }
581 /*
582 * if not oplocked will force revalidate to get info on source
583 * file from srv. Note Samba server prior to 4.2 has bug -
584 * not updating src file ctime on hardlinks but Windows servers
585 * handle it properly
586 */
587 cifsInode->time = 0;
588
589 /*
590 * Will update parent dir timestamps from srv within a second.
591 * Would it really be worth it to set the parent dir (cifs
592 * inode) time field to zero to force revalidate on parent
593 * directory faster ie
594 *
595 * CIFS_I(inode)->time = 0;
596 */
597 }
598
599cifs_hl_exit:
600 kfree(from_name);
601 kfree(to_name);
602 free_xid(xid);
603 cifs_put_tlink(tlink);
604 return rc;
605}
606
607const char *
608cifs_get_link(struct dentry *direntry, struct inode *inode,
609 struct delayed_call *done)
610{
611 int rc = -ENOMEM;
612 unsigned int xid;
613 char *full_path = NULL;
614 char *target_path = NULL;
615 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
616 struct tcon_link *tlink = NULL;
617 struct cifs_tcon *tcon;
618 struct TCP_Server_Info *server;
619
620 if (!direntry)
621 return ERR_PTR(-ECHILD);
622
623 xid = get_xid();
624
625 tlink = cifs_sb_tlink(cifs_sb);
626 if (IS_ERR(tlink)) {
627 free_xid(xid);
628 return ERR_CAST(tlink);
629 }
630 tcon = tlink_tcon(tlink);
631 server = tcon->ses->server;
632
633 full_path = build_path_from_dentry(direntry);
634 if (!full_path) {
635 free_xid(xid);
636 cifs_put_tlink(tlink);
637 return ERR_PTR(-ENOMEM);
638 }
639
640 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
641
642 rc = -EACCES;
643 /*
644 * First try Minshall+French Symlinks, if configured
645 * and fallback to UNIX Extensions Symlinks.
646 */
647 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
648 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
649 &target_path);
650
651 if (rc != 0 && server->ops->query_symlink) {
652 struct cifsInodeInfo *cifsi = CIFS_I(inode);
653 bool reparse_point = false;
654
655 if (cifsi->cifsAttrs & ATTR_REPARSE)
656 reparse_point = true;
657
658 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
659 &target_path, reparse_point);
660 }
661
662 kfree(full_path);
663 free_xid(xid);
664 cifs_put_tlink(tlink);
665 if (rc != 0) {
666 kfree(target_path);
667 return ERR_PTR(rc);
668 }
669 set_delayed_call(done, kfree_link, target_path);
670 return target_path;
671}
672
673int
674cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
675{
676 int rc = -EOPNOTSUPP;
677 unsigned int xid;
678 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
679 struct tcon_link *tlink;
680 struct cifs_tcon *pTcon;
681 char *full_path = NULL;
682 struct inode *newinode = NULL;
683
684 xid = get_xid();
685
686 tlink = cifs_sb_tlink(cifs_sb);
687 if (IS_ERR(tlink)) {
688 rc = PTR_ERR(tlink);
689 goto symlink_exit;
690 }
691 pTcon = tlink_tcon(tlink);
692
693 full_path = build_path_from_dentry(direntry);
694 if (full_path == NULL) {
695 rc = -ENOMEM;
696 goto symlink_exit;
697 }
698
699 cifs_dbg(FYI, "Full path: %s\n", full_path);
700 cifs_dbg(FYI, "symname is %s\n", symname);
701
702 /* BB what if DFS and this volume is on different share? BB */
703 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
704 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
705 else if (pTcon->unix_ext)
706 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
707 cifs_sb->local_nls,
708 cifs_remap(cifs_sb));
709 /* else
710 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
711 cifs_sb_target->local_nls); */
712
713 if (rc == 0) {
714 if (pTcon->unix_ext)
715 rc = cifs_get_inode_info_unix(&newinode, full_path,
716 inode->i_sb, xid);
717 else
718 rc = cifs_get_inode_info(&newinode, full_path, NULL,
719 inode->i_sb, xid, NULL);
720
721 if (rc != 0) {
722 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
723 rc);
724 } else {
725 d_instantiate(direntry, newinode);
726 }
727 }
728symlink_exit:
729 kfree(full_path);
730 cifs_put_tlink(tlink);
731 free_xid(xid);
732 return rc;
733}