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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 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}
1// SPDX-License-Identifier: LGPL-2.1
2/*
3 * fs/cifs/link.c
4 *
5 * Copyright (C) International Business Machines Corp., 2002,2008
6 * Author(s): Steve French (sfrench@us.ibm.com)
7 *
8 */
9#include <linux/fs.h>
10#include <linux/stat.h>
11#include <linux/slab.h>
12#include <linux/namei.h>
13#include "cifsfs.h"
14#include "cifspdu.h"
15#include "cifsglob.h"
16#include "cifsproto.h"
17#include "cifs_debug.h"
18#include "cifs_fs_sb.h"
19#include "cifs_unicode.h"
20#include "smb2proto.h"
21#include "cifs_ioctl.h"
22
23/*
24 * M-F Symlink Functions - Begin
25 */
26
27#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
28#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
29#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
30#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
31#define CIFS_MF_SYMLINK_FILE_SIZE \
32 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
33
34#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
35#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
36#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
37
38static int
39symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
40{
41 int rc;
42 struct crypto_shash *md5 = NULL;
43 struct sdesc *sdescmd5 = NULL;
44
45 rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
46 if (rc)
47 goto symlink_hash_err;
48
49 rc = crypto_shash_init(&sdescmd5->shash);
50 if (rc) {
51 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
52 goto symlink_hash_err;
53 }
54 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
55 if (rc) {
56 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
57 goto symlink_hash_err;
58 }
59 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
60 if (rc)
61 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
62
63symlink_hash_err:
64 cifs_free_hash(&md5, &sdescmd5);
65 return rc;
66}
67
68static int
69parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
70 char **_link_str)
71{
72 int rc;
73 unsigned int link_len;
74 const char *md5_str1;
75 const char *link_str;
76 u8 md5_hash[16];
77 char md5_str2[34];
78
79 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
80 return -EINVAL;
81
82 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
83 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
84
85 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
86 if (rc != 1)
87 return -EINVAL;
88
89 rc = symlink_hash(link_len, link_str, md5_hash);
90 if (rc) {
91 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
92 return rc;
93 }
94
95 scnprintf(md5_str2, sizeof(md5_str2),
96 CIFS_MF_SYMLINK_MD5_FORMAT,
97 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
98
99 if (strncmp(md5_str1, md5_str2, 17) != 0)
100 return -EINVAL;
101
102 if (_link_str) {
103 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
104 if (!*_link_str)
105 return -ENOMEM;
106 }
107
108 *_link_len = link_len;
109 return 0;
110}
111
112static int
113format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
114{
115 int rc;
116 unsigned int link_len;
117 unsigned int ofs;
118 u8 md5_hash[16];
119
120 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
121 return -EINVAL;
122
123 link_len = strlen(link_str);
124
125 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
126 return -ENAMETOOLONG;
127
128 rc = symlink_hash(link_len, link_str, md5_hash);
129 if (rc) {
130 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
131 return rc;
132 }
133
134 scnprintf(buf, buf_len,
135 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
136 link_len,
137 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
138
139 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
140 memcpy(buf + ofs, link_str, link_len);
141
142 ofs += link_len;
143 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
144 buf[ofs] = '\n';
145 ofs++;
146 }
147
148 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
149 buf[ofs] = ' ';
150 ofs++;
151 }
152
153 return 0;
154}
155
156bool
157couldbe_mf_symlink(const struct cifs_fattr *fattr)
158{
159 if (!S_ISREG(fattr->cf_mode))
160 /* it's not a symlink */
161 return false;
162
163 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
164 /* it's not a symlink */
165 return false;
166
167 return true;
168}
169
170static int
171create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
172 struct cifs_sb_info *cifs_sb, const char *fromName,
173 const char *toName)
174{
175 int rc;
176 u8 *buf;
177 unsigned int bytes_written = 0;
178
179 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
180 if (!buf)
181 return -ENOMEM;
182
183 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
184 if (rc)
185 goto out;
186
187 if (tcon->ses->server->ops->create_mf_symlink)
188 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
189 cifs_sb, fromName, buf, &bytes_written);
190 else
191 rc = -EOPNOTSUPP;
192
193 if (rc)
194 goto out;
195
196 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
197 rc = -EIO;
198out:
199 kfree(buf);
200 return rc;
201}
202
203static int
204query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
205 struct cifs_sb_info *cifs_sb, const unsigned char *path,
206 char **symlinkinfo)
207{
208 int rc;
209 u8 *buf = NULL;
210 unsigned int link_len = 0;
211 unsigned int bytes_read = 0;
212
213 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
214 if (!buf)
215 return -ENOMEM;
216
217 if (tcon->ses->server->ops->query_mf_symlink)
218 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
219 cifs_sb, path, buf, &bytes_read);
220 else
221 rc = -ENOSYS;
222
223 if (rc)
224 goto out;
225
226 if (bytes_read == 0) { /* not a symlink */
227 rc = -EINVAL;
228 goto out;
229 }
230
231 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
232out:
233 kfree(buf);
234 return rc;
235}
236
237int
238check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
239 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
240 const unsigned char *path)
241{
242 int rc;
243 u8 *buf = NULL;
244 unsigned int link_len = 0;
245 unsigned int bytes_read = 0;
246
247 if (!couldbe_mf_symlink(fattr))
248 /* it's not a symlink */
249 return 0;
250
251 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
252 if (!buf)
253 return -ENOMEM;
254
255 if (tcon->ses->server->ops->query_mf_symlink)
256 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
257 cifs_sb, path, buf, &bytes_read);
258 else
259 rc = -ENOSYS;
260
261 if (rc)
262 goto out;
263
264 if (bytes_read == 0) /* not a symlink */
265 goto out;
266
267 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
268 if (rc == -EINVAL) {
269 /* it's not a symlink */
270 rc = 0;
271 goto out;
272 }
273
274 if (rc != 0)
275 goto out;
276
277 /* it is a symlink */
278 fattr->cf_eof = link_len;
279 fattr->cf_mode &= ~S_IFMT;
280 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
281 fattr->cf_dtype = DT_LNK;
282out:
283 kfree(buf);
284 return rc;
285}
286
287/*
288 * SMB 1.0 Protocol specific functions
289 */
290
291int
292cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
293 struct cifs_sb_info *cifs_sb, const unsigned char *path,
294 char *pbuf, unsigned int *pbytes_read)
295{
296 int rc;
297 int oplock = 0;
298 struct cifs_fid fid;
299 struct cifs_open_parms oparms;
300 struct cifs_io_parms io_parms = {0};
301 int buf_type = CIFS_NO_BUFFER;
302 FILE_ALL_INFO file_info;
303
304 oparms.tcon = tcon;
305 oparms.cifs_sb = cifs_sb;
306 oparms.desired_access = GENERIC_READ;
307 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
308 oparms.disposition = FILE_OPEN;
309 oparms.path = path;
310 oparms.fid = &fid;
311 oparms.reconnect = false;
312
313 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
314 if (rc)
315 return rc;
316
317 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
318 rc = -ENOENT;
319 /* it's not a symlink */
320 goto out;
321 }
322
323 io_parms.netfid = fid.netfid;
324 io_parms.pid = current->tgid;
325 io_parms.tcon = tcon;
326 io_parms.offset = 0;
327 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
328
329 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
330out:
331 CIFSSMBClose(xid, tcon, fid.netfid);
332 return rc;
333}
334
335int
336cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
337 struct cifs_sb_info *cifs_sb, const unsigned char *path,
338 char *pbuf, unsigned int *pbytes_written)
339{
340 int rc;
341 int oplock = 0;
342 struct cifs_fid fid;
343 struct cifs_open_parms oparms;
344 struct cifs_io_parms io_parms = {0};
345
346 oparms.tcon = tcon;
347 oparms.cifs_sb = cifs_sb;
348 oparms.desired_access = GENERIC_WRITE;
349 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
350 oparms.disposition = FILE_CREATE;
351 oparms.path = path;
352 oparms.fid = &fid;
353 oparms.reconnect = false;
354
355 rc = CIFS_open(xid, &oparms, &oplock, NULL);
356 if (rc)
357 return rc;
358
359 io_parms.netfid = fid.netfid;
360 io_parms.pid = current->tgid;
361 io_parms.tcon = tcon;
362 io_parms.offset = 0;
363 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
364
365 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
366 CIFSSMBClose(xid, tcon, fid.netfid);
367 return rc;
368}
369
370/*
371 * SMB 2.1/SMB3 Protocol specific functions
372 */
373int
374smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
375 struct cifs_sb_info *cifs_sb, const unsigned char *path,
376 char *pbuf, unsigned int *pbytes_read)
377{
378 int rc;
379 struct cifs_fid fid;
380 struct cifs_open_parms oparms;
381 struct cifs_io_parms io_parms = {0};
382 int buf_type = CIFS_NO_BUFFER;
383 __le16 *utf16_path;
384 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
385 struct smb2_file_all_info *pfile_info = NULL;
386
387 oparms.tcon = tcon;
388 oparms.cifs_sb = cifs_sb;
389 oparms.desired_access = GENERIC_READ;
390 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
391 oparms.disposition = FILE_OPEN;
392 oparms.fid = &fid;
393 oparms.reconnect = false;
394
395 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
396 if (utf16_path == NULL)
397 return -ENOMEM;
398
399 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
400 GFP_KERNEL);
401
402 if (pfile_info == NULL) {
403 kfree(utf16_path);
404 return -ENOMEM;
405 }
406
407 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
408 NULL, NULL);
409 if (rc)
410 goto qmf_out_open_fail;
411
412 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
413 /* it's not a symlink */
414 rc = -ENOENT; /* Is there a better rc to return? */
415 goto qmf_out;
416 }
417
418 io_parms.netfid = fid.netfid;
419 io_parms.pid = current->tgid;
420 io_parms.tcon = tcon;
421 io_parms.offset = 0;
422 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
423 io_parms.persistent_fid = fid.persistent_fid;
424 io_parms.volatile_fid = fid.volatile_fid;
425 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
426qmf_out:
427 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
428qmf_out_open_fail:
429 kfree(utf16_path);
430 kfree(pfile_info);
431 return rc;
432}
433
434int
435smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
436 struct cifs_sb_info *cifs_sb, const unsigned char *path,
437 char *pbuf, unsigned int *pbytes_written)
438{
439 int rc;
440 struct cifs_fid fid;
441 struct cifs_open_parms oparms;
442 struct cifs_io_parms io_parms = {0};
443 __le16 *utf16_path;
444 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
445 struct kvec iov[2];
446
447 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
448
449 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
450 if (!utf16_path)
451 return -ENOMEM;
452
453 oparms.tcon = tcon;
454 oparms.cifs_sb = cifs_sb;
455 oparms.desired_access = GENERIC_WRITE;
456 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
457 oparms.disposition = FILE_CREATE;
458 oparms.fid = &fid;
459 oparms.reconnect = false;
460
461 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
462 NULL, NULL);
463 if (rc) {
464 kfree(utf16_path);
465 return rc;
466 }
467
468 io_parms.netfid = fid.netfid;
469 io_parms.pid = current->tgid;
470 io_parms.tcon = tcon;
471 io_parms.offset = 0;
472 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
473 io_parms.persistent_fid = fid.persistent_fid;
474 io_parms.volatile_fid = fid.volatile_fid;
475
476 /* iov[0] is reserved for smb header */
477 iov[1].iov_base = pbuf;
478 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
479
480 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
481
482 /* Make sure we wrote all of the symlink data */
483 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
484 rc = -EIO;
485
486 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
487
488 kfree(utf16_path);
489 return rc;
490}
491
492/*
493 * M-F Symlink Functions - End
494 */
495
496int
497cifs_hardlink(struct dentry *old_file, struct inode *inode,
498 struct dentry *direntry)
499{
500 int rc = -EACCES;
501 unsigned int xid;
502 const char *from_name, *to_name;
503 void *page1, *page2;
504 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
505 struct tcon_link *tlink;
506 struct cifs_tcon *tcon;
507 struct TCP_Server_Info *server;
508 struct cifsInodeInfo *cifsInode;
509
510 if (unlikely(cifs_forced_shutdown(cifs_sb)))
511 return -EIO;
512
513 tlink = cifs_sb_tlink(cifs_sb);
514 if (IS_ERR(tlink))
515 return PTR_ERR(tlink);
516 tcon = tlink_tcon(tlink);
517
518 xid = get_xid();
519 page1 = alloc_dentry_path();
520 page2 = alloc_dentry_path();
521
522 from_name = build_path_from_dentry(old_file, page1);
523 if (IS_ERR(from_name)) {
524 rc = PTR_ERR(from_name);
525 goto cifs_hl_exit;
526 }
527 to_name = build_path_from_dentry(direntry, page2);
528 if (IS_ERR(to_name)) {
529 rc = PTR_ERR(to_name);
530 goto cifs_hl_exit;
531 }
532
533 if (tcon->unix_ext)
534 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
535 cifs_sb->local_nls,
536 cifs_remap(cifs_sb));
537 else {
538 server = tcon->ses->server;
539 if (!server->ops->create_hardlink) {
540 rc = -ENOSYS;
541 goto cifs_hl_exit;
542 }
543 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
544 cifs_sb);
545 if ((rc == -EIO) || (rc == -EINVAL))
546 rc = -EOPNOTSUPP;
547 }
548
549 d_drop(direntry); /* force new lookup from server of target */
550
551 /*
552 * if source file is cached (oplocked) revalidate will not go to server
553 * until the file is closed or oplock broken so update nlinks locally
554 */
555 if (d_really_is_positive(old_file)) {
556 cifsInode = CIFS_I(d_inode(old_file));
557 if (rc == 0) {
558 spin_lock(&d_inode(old_file)->i_lock);
559 inc_nlink(d_inode(old_file));
560 spin_unlock(&d_inode(old_file)->i_lock);
561
562 /*
563 * parent dir timestamps will update from srv within a
564 * second, would it really be worth it to set the parent
565 * dir cifs inode time to zero to force revalidate
566 * (faster) for it too?
567 */
568 }
569 /*
570 * if not oplocked will force revalidate to get info on source
571 * file from srv. Note Samba server prior to 4.2 has bug -
572 * not updating src file ctime on hardlinks but Windows servers
573 * handle it properly
574 */
575 cifsInode->time = 0;
576
577 /*
578 * Will update parent dir timestamps from srv within a second.
579 * Would it really be worth it to set the parent dir (cifs
580 * inode) time field to zero to force revalidate on parent
581 * directory faster ie
582 *
583 * CIFS_I(inode)->time = 0;
584 */
585 }
586
587cifs_hl_exit:
588 free_dentry_path(page1);
589 free_dentry_path(page2);
590 free_xid(xid);
591 cifs_put_tlink(tlink);
592 return rc;
593}
594
595const char *
596cifs_get_link(struct dentry *direntry, struct inode *inode,
597 struct delayed_call *done)
598{
599 int rc = -ENOMEM;
600 unsigned int xid;
601 const char *full_path;
602 void *page;
603 char *target_path = NULL;
604 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
605 struct tcon_link *tlink = NULL;
606 struct cifs_tcon *tcon;
607 struct TCP_Server_Info *server;
608
609 if (!direntry)
610 return ERR_PTR(-ECHILD);
611
612 xid = get_xid();
613
614 tlink = cifs_sb_tlink(cifs_sb);
615 if (IS_ERR(tlink)) {
616 free_xid(xid);
617 return ERR_CAST(tlink);
618 }
619 tcon = tlink_tcon(tlink);
620 server = tcon->ses->server;
621
622 page = alloc_dentry_path();
623 full_path = build_path_from_dentry(direntry, page);
624 if (IS_ERR(full_path)) {
625 free_xid(xid);
626 cifs_put_tlink(tlink);
627 free_dentry_path(page);
628 return ERR_CAST(full_path);
629 }
630
631 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
632
633 rc = -EACCES;
634 /*
635 * First try Minshall+French Symlinks, if configured
636 * and fallback to UNIX Extensions Symlinks.
637 */
638 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
639 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
640 &target_path);
641
642 if (rc != 0 && server->ops->query_symlink) {
643 struct cifsInodeInfo *cifsi = CIFS_I(inode);
644 bool reparse_point = false;
645
646 if (cifsi->cifsAttrs & ATTR_REPARSE)
647 reparse_point = true;
648
649 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
650 &target_path, reparse_point);
651 }
652
653 free_dentry_path(page);
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 user_namespace *mnt_userns, struct inode *inode,
666 struct dentry *direntry, const char *symname)
667{
668 int rc = -EOPNOTSUPP;
669 unsigned int xid;
670 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
671 struct tcon_link *tlink;
672 struct cifs_tcon *pTcon;
673 const char *full_path;
674 void *page;
675 struct inode *newinode = NULL;
676
677 if (unlikely(cifs_forced_shutdown(cifs_sb)))
678 return -EIO;
679
680 page = alloc_dentry_path();
681 if (!page)
682 return -ENOMEM;
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, page);
694 if (IS_ERR(full_path)) {
695 rc = PTR_ERR(full_path);
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->posix_extensions)
715 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
716 else if (pTcon->unix_ext)
717 rc = cifs_get_inode_info_unix(&newinode, full_path,
718 inode->i_sb, xid);
719 else
720 rc = cifs_get_inode_info(&newinode, full_path, NULL,
721 inode->i_sb, xid, NULL);
722
723 if (rc != 0) {
724 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
725 rc);
726 } else {
727 d_instantiate(direntry, newinode);
728 }
729 }
730symlink_exit:
731 free_dentry_path(page);
732 cifs_put_tlink(tlink);
733 free_xid(xid);
734 return rc;
735}