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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/*
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 "%16phN\n"
49#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
50
51static int
52symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
53{
54 int rc;
55 unsigned int size;
56 struct crypto_shash *md5;
57 struct sdesc *sdescmd5;
58
59 md5 = crypto_alloc_shash("md5", 0, 0);
60 if (IS_ERR(md5)) {
61 rc = PTR_ERR(md5);
62 cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
63 __func__, rc);
64 return rc;
65 }
66 size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
67 sdescmd5 = kmalloc(size, GFP_KERNEL);
68 if (!sdescmd5) {
69 rc = -ENOMEM;
70 goto symlink_hash_err;
71 }
72 sdescmd5->shash.tfm = md5;
73 sdescmd5->shash.flags = 0x0;
74
75 rc = crypto_shash_init(&sdescmd5->shash);
76 if (rc) {
77 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
78 goto symlink_hash_err;
79 }
80 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
81 if (rc) {
82 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
83 goto symlink_hash_err;
84 }
85 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
86 if (rc)
87 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
88
89symlink_hash_err:
90 crypto_free_shash(md5);
91 kfree(sdescmd5);
92
93 return rc;
94}
95
96static int
97parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
98 char **_link_str)
99{
100 int rc;
101 unsigned int link_len;
102 const char *md5_str1;
103 const char *link_str;
104 u8 md5_hash[16];
105 char md5_str2[34];
106
107 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
108 return -EINVAL;
109
110 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
111 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
112
113 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
114 if (rc != 1)
115 return -EINVAL;
116
117 rc = symlink_hash(link_len, link_str, md5_hash);
118 if (rc) {
119 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
120 return rc;
121 }
122
123 snprintf(md5_str2, sizeof(md5_str2),
124 CIFS_MF_SYMLINK_MD5_FORMAT,
125 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
126
127 if (strncmp(md5_str1, md5_str2, 17) != 0)
128 return -EINVAL;
129
130 if (_link_str) {
131 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
132 if (!*_link_str)
133 return -ENOMEM;
134 }
135
136 *_link_len = link_len;
137 return 0;
138}
139
140static int
141format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
142{
143 int rc;
144 unsigned int link_len;
145 unsigned int ofs;
146 u8 md5_hash[16];
147
148 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
149 return -EINVAL;
150
151 link_len = strlen(link_str);
152
153 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
154 return -ENAMETOOLONG;
155
156 rc = symlink_hash(link_len, link_str, md5_hash);
157 if (rc) {
158 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
159 return rc;
160 }
161
162 snprintf(buf, buf_len,
163 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
164 link_len,
165 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
166
167 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
168 memcpy(buf + ofs, link_str, link_len);
169
170 ofs += link_len;
171 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
172 buf[ofs] = '\n';
173 ofs++;
174 }
175
176 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
177 buf[ofs] = ' ';
178 ofs++;
179 }
180
181 return 0;
182}
183
184bool
185couldbe_mf_symlink(const struct cifs_fattr *fattr)
186{
187 if (!S_ISREG(fattr->cf_mode))
188 /* it's not a symlink */
189 return false;
190
191 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
192 /* it's not a symlink */
193 return false;
194
195 return true;
196}
197
198static int
199create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
200 struct cifs_sb_info *cifs_sb, const char *fromName,
201 const char *toName)
202{
203 int rc;
204 u8 *buf;
205 unsigned int bytes_written = 0;
206
207 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
208 if (!buf)
209 return -ENOMEM;
210
211 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
212 if (rc)
213 goto out;
214
215 if (tcon->ses->server->ops->create_mf_symlink)
216 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
217 cifs_sb, fromName, buf, &bytes_written);
218 else
219 rc = -EOPNOTSUPP;
220
221 if (rc)
222 goto out;
223
224 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
225 rc = -EIO;
226out:
227 kfree(buf);
228 return rc;
229}
230
231static int
232query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
233 struct cifs_sb_info *cifs_sb, const unsigned char *path,
234 char **symlinkinfo)
235{
236 int rc;
237 u8 *buf = NULL;
238 unsigned int link_len = 0;
239 unsigned int bytes_read = 0;
240
241 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
242 if (!buf)
243 return -ENOMEM;
244
245 if (tcon->ses->server->ops->query_mf_symlink)
246 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
247 cifs_sb, path, buf, &bytes_read);
248 else
249 rc = -ENOSYS;
250
251 if (rc)
252 goto out;
253
254 if (bytes_read == 0) { /* not a symlink */
255 rc = -EINVAL;
256 goto out;
257 }
258
259 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
260out:
261 kfree(buf);
262 return rc;
263}
264
265int
266check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
267 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
268 const unsigned char *path)
269{
270 int rc;
271 u8 *buf = NULL;
272 unsigned int link_len = 0;
273 unsigned int bytes_read = 0;
274
275 if (!couldbe_mf_symlink(fattr))
276 /* it's not a symlink */
277 return 0;
278
279 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
280 if (!buf)
281 return -ENOMEM;
282
283 if (tcon->ses->server->ops->query_mf_symlink)
284 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
285 cifs_sb, path, buf, &bytes_read);
286 else
287 rc = -ENOSYS;
288
289 if (rc)
290 goto out;
291
292 if (bytes_read == 0) /* not a symlink */
293 goto out;
294
295 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
296 if (rc == -EINVAL) {
297 /* it's not a symlink */
298 rc = 0;
299 goto out;
300 }
301
302 if (rc != 0)
303 goto out;
304
305 /* it is a symlink */
306 fattr->cf_eof = link_len;
307 fattr->cf_mode &= ~S_IFMT;
308 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
309 fattr->cf_dtype = DT_LNK;
310out:
311 kfree(buf);
312 return rc;
313}
314
315/*
316 * SMB 1.0 Protocol specific functions
317 */
318
319int
320cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
321 struct cifs_sb_info *cifs_sb, const unsigned char *path,
322 char *pbuf, unsigned int *pbytes_read)
323{
324 int rc;
325 int oplock = 0;
326 struct cifs_fid fid;
327 struct cifs_open_parms oparms;
328 struct cifs_io_parms io_parms;
329 int buf_type = CIFS_NO_BUFFER;
330 FILE_ALL_INFO file_info;
331
332 oparms.tcon = tcon;
333 oparms.cifs_sb = cifs_sb;
334 oparms.desired_access = GENERIC_READ;
335 oparms.create_options = CREATE_NOT_DIR;
336 oparms.disposition = FILE_OPEN;
337 oparms.path = path;
338 oparms.fid = &fid;
339 oparms.reconnect = false;
340
341 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
342 if (rc)
343 return rc;
344
345 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
346 rc = -ENOENT;
347 /* it's not a symlink */
348 goto out;
349 }
350
351 io_parms.netfid = fid.netfid;
352 io_parms.pid = current->tgid;
353 io_parms.tcon = tcon;
354 io_parms.offset = 0;
355 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
356
357 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
358out:
359 CIFSSMBClose(xid, tcon, fid.netfid);
360 return rc;
361}
362
363int
364cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
365 struct cifs_sb_info *cifs_sb, const unsigned char *path,
366 char *pbuf, unsigned int *pbytes_written)
367{
368 int rc;
369 int oplock = 0;
370 struct cifs_fid fid;
371 struct cifs_open_parms oparms;
372 struct cifs_io_parms io_parms;
373 int create_options = CREATE_NOT_DIR;
374
375 if (backup_cred(cifs_sb))
376 create_options |= CREATE_OPEN_BACKUP_INTENT;
377
378 oparms.tcon = tcon;
379 oparms.cifs_sb = cifs_sb;
380 oparms.desired_access = GENERIC_WRITE;
381 oparms.create_options = create_options;
382 oparms.disposition = FILE_CREATE;
383 oparms.path = path;
384 oparms.fid = &fid;
385 oparms.reconnect = false;
386
387 rc = CIFS_open(xid, &oparms, &oplock, NULL);
388 if (rc)
389 return rc;
390
391 io_parms.netfid = fid.netfid;
392 io_parms.pid = current->tgid;
393 io_parms.tcon = tcon;
394 io_parms.offset = 0;
395 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
396
397 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
398 CIFSSMBClose(xid, tcon, fid.netfid);
399 return rc;
400}
401
402/*
403 * SMB 2.1/SMB3 Protocol specific functions
404 */
405#ifdef CONFIG_CIFS_SMB2
406int
407smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
408 struct cifs_sb_info *cifs_sb, const unsigned char *path,
409 char *pbuf, unsigned int *pbytes_read)
410{
411 int rc;
412 struct cifs_fid fid;
413 struct cifs_open_parms oparms;
414 struct cifs_io_parms io_parms;
415 int buf_type = CIFS_NO_BUFFER;
416 __le16 *utf16_path;
417 __u8 oplock = SMB2_OPLOCK_LEVEL_II;
418 struct smb2_file_all_info *pfile_info = NULL;
419
420 oparms.tcon = tcon;
421 oparms.cifs_sb = cifs_sb;
422 oparms.desired_access = GENERIC_READ;
423 oparms.create_options = CREATE_NOT_DIR;
424 if (backup_cred(cifs_sb))
425 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
426 oparms.disposition = FILE_OPEN;
427 oparms.fid = &fid;
428 oparms.reconnect = false;
429
430 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
431 if (utf16_path == NULL)
432 return -ENOMEM;
433
434 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
435 GFP_KERNEL);
436
437 if (pfile_info == NULL) {
438 kfree(utf16_path);
439 return -ENOMEM;
440 }
441
442 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
443 if (rc)
444 goto qmf_out_open_fail;
445
446 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
447 /* it's not a symlink */
448 rc = -ENOENT; /* Is there a better rc to return? */
449 goto qmf_out;
450 }
451
452 io_parms.netfid = fid.netfid;
453 io_parms.pid = current->tgid;
454 io_parms.tcon = tcon;
455 io_parms.offset = 0;
456 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
457 io_parms.persistent_fid = fid.persistent_fid;
458 io_parms.volatile_fid = fid.volatile_fid;
459 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
460qmf_out:
461 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
462qmf_out_open_fail:
463 kfree(utf16_path);
464 kfree(pfile_info);
465 return rc;
466}
467
468int
469smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
470 struct cifs_sb_info *cifs_sb, const unsigned char *path,
471 char *pbuf, unsigned int *pbytes_written)
472{
473 int rc;
474 struct cifs_fid fid;
475 struct cifs_open_parms oparms;
476 struct cifs_io_parms io_parms;
477 int create_options = CREATE_NOT_DIR;
478 __le16 *utf16_path;
479 __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
480 struct kvec iov[2];
481
482 if (backup_cred(cifs_sb))
483 create_options |= CREATE_OPEN_BACKUP_INTENT;
484
485 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
486
487 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
488 if (!utf16_path)
489 return -ENOMEM;
490
491 oparms.tcon = tcon;
492 oparms.cifs_sb = cifs_sb;
493 oparms.desired_access = GENERIC_WRITE;
494 oparms.create_options = create_options;
495 oparms.disposition = FILE_CREATE;
496 oparms.fid = &fid;
497 oparms.reconnect = false;
498
499 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
500 if (rc) {
501 kfree(utf16_path);
502 return rc;
503 }
504
505 io_parms.netfid = fid.netfid;
506 io_parms.pid = current->tgid;
507 io_parms.tcon = tcon;
508 io_parms.offset = 0;
509 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
510 io_parms.persistent_fid = fid.persistent_fid;
511 io_parms.volatile_fid = fid.volatile_fid;
512
513 /* iov[0] is reserved for smb header */
514 iov[1].iov_base = pbuf;
515 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
516
517 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
518
519 /* Make sure we wrote all of the symlink data */
520 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
521 rc = -EIO;
522
523 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
524
525 kfree(utf16_path);
526 return rc;
527}
528#endif /* CONFIG_CIFS_SMB2 */
529
530/*
531 * M-F Symlink Functions - End
532 */
533
534int
535cifs_hardlink(struct dentry *old_file, struct inode *inode,
536 struct dentry *direntry)
537{
538 int rc = -EACCES;
539 unsigned int xid;
540 char *from_name = NULL;
541 char *to_name = NULL;
542 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
543 struct tcon_link *tlink;
544 struct cifs_tcon *tcon;
545 struct TCP_Server_Info *server;
546 struct cifsInodeInfo *cifsInode;
547
548 tlink = cifs_sb_tlink(cifs_sb);
549 if (IS_ERR(tlink))
550 return PTR_ERR(tlink);
551 tcon = tlink_tcon(tlink);
552
553 xid = get_xid();
554
555 from_name = build_path_from_dentry(old_file);
556 to_name = build_path_from_dentry(direntry);
557 if ((from_name == NULL) || (to_name == NULL)) {
558 rc = -ENOMEM;
559 goto cifs_hl_exit;
560 }
561
562 if (tcon->unix_ext)
563 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
564 cifs_sb->local_nls,
565 cifs_remap(cifs_sb));
566 else {
567 server = tcon->ses->server;
568 if (!server->ops->create_hardlink) {
569 rc = -ENOSYS;
570 goto cifs_hl_exit;
571 }
572 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
573 cifs_sb);
574 if ((rc == -EIO) || (rc == -EINVAL))
575 rc = -EOPNOTSUPP;
576 }
577
578 d_drop(direntry); /* force new lookup from server of target */
579
580 /*
581 * if source file is cached (oplocked) revalidate will not go to server
582 * until the file is closed or oplock broken so update nlinks locally
583 */
584 if (d_really_is_positive(old_file)) {
585 cifsInode = CIFS_I(d_inode(old_file));
586 if (rc == 0) {
587 spin_lock(&d_inode(old_file)->i_lock);
588 inc_nlink(d_inode(old_file));
589 spin_unlock(&d_inode(old_file)->i_lock);
590
591 /*
592 * parent dir timestamps will update from srv within a
593 * second, would it really be worth it to set the parent
594 * dir cifs inode time to zero to force revalidate
595 * (faster) for it too?
596 */
597 }
598 /*
599 * if not oplocked will force revalidate to get info on source
600 * file from srv. Note Samba server prior to 4.2 has bug -
601 * not updating src file ctime on hardlinks but Windows servers
602 * handle it properly
603 */
604 cifsInode->time = 0;
605
606 /*
607 * Will update parent dir timestamps from srv within a second.
608 * Would it really be worth it to set the parent dir (cifs
609 * inode) time field to zero to force revalidate on parent
610 * directory faster ie
611 *
612 * CIFS_I(inode)->time = 0;
613 */
614 }
615
616cifs_hl_exit:
617 kfree(from_name);
618 kfree(to_name);
619 free_xid(xid);
620 cifs_put_tlink(tlink);
621 return rc;
622}
623
624const char *
625cifs_get_link(struct dentry *direntry, struct inode *inode,
626 struct delayed_call *done)
627{
628 int rc = -ENOMEM;
629 unsigned int xid;
630 char *full_path = NULL;
631 char *target_path = NULL;
632 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
633 struct tcon_link *tlink = NULL;
634 struct cifs_tcon *tcon;
635 struct TCP_Server_Info *server;
636
637 if (!direntry)
638 return ERR_PTR(-ECHILD);
639
640 xid = get_xid();
641
642 tlink = cifs_sb_tlink(cifs_sb);
643 if (IS_ERR(tlink)) {
644 free_xid(xid);
645 return ERR_CAST(tlink);
646 }
647 tcon = tlink_tcon(tlink);
648 server = tcon->ses->server;
649
650 full_path = build_path_from_dentry(direntry);
651 if (!full_path) {
652 free_xid(xid);
653 cifs_put_tlink(tlink);
654 return ERR_PTR(-ENOMEM);
655 }
656
657 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
658
659 rc = -EACCES;
660 /*
661 * First try Minshall+French Symlinks, if configured
662 * and fallback to UNIX Extensions Symlinks.
663 */
664 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
665 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
666 &target_path);
667
668 if (rc != 0 && server->ops->query_symlink)
669 rc = server->ops->query_symlink(xid, tcon, full_path,
670 &target_path, cifs_sb);
671
672 kfree(full_path);
673 free_xid(xid);
674 cifs_put_tlink(tlink);
675 if (rc != 0) {
676 kfree(target_path);
677 return ERR_PTR(rc);
678 }
679 set_delayed_call(done, kfree_link, target_path);
680 return target_path;
681}
682
683int
684cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
685{
686 int rc = -EOPNOTSUPP;
687 unsigned int xid;
688 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
689 struct tcon_link *tlink;
690 struct cifs_tcon *pTcon;
691 char *full_path = NULL;
692 struct inode *newinode = NULL;
693
694 xid = get_xid();
695
696 tlink = cifs_sb_tlink(cifs_sb);
697 if (IS_ERR(tlink)) {
698 rc = PTR_ERR(tlink);
699 goto symlink_exit;
700 }
701 pTcon = tlink_tcon(tlink);
702
703 full_path = build_path_from_dentry(direntry);
704 if (full_path == NULL) {
705 rc = -ENOMEM;
706 goto symlink_exit;
707 }
708
709 cifs_dbg(FYI, "Full path: %s\n", full_path);
710 cifs_dbg(FYI, "symname is %s\n", symname);
711
712 /* BB what if DFS and this volume is on different share? BB */
713 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
714 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
715 else if (pTcon->unix_ext)
716 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
717 cifs_sb->local_nls,
718 cifs_remap(cifs_sb));
719 /* else
720 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
721 cifs_sb_target->local_nls); */
722
723 if (rc == 0) {
724 if (pTcon->unix_ext)
725 rc = cifs_get_inode_info_unix(&newinode, full_path,
726 inode->i_sb, xid);
727 else
728 rc = cifs_get_inode_info(&newinode, full_path, NULL,
729 inode->i_sb, xid, NULL);
730
731 if (rc != 0) {
732 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
733 rc);
734 } else {
735 d_instantiate(direntry, newinode);
736 }
737 }
738symlink_exit:
739 kfree(full_path);
740 cifs_put_tlink(tlink);
741 free_xid(xid);
742 return rc;
743}