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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#ifdef CONFIG_CIFS_SMB2
33#include "smb2proto.h"
34#endif
35
36/*
37 * M-F Symlink Functions - Begin
38 */
39
40#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
41#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
42#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
43#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
44#define CIFS_MF_SYMLINK_FILE_SIZE \
45 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
46
47#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
48#define CIFS_MF_SYMLINK_MD5_FORMAT \
49 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
50#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
51 md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
52 md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
53 md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
54 md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
55
56static int
57symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
58{
59 int rc;
60 unsigned int size;
61 struct crypto_shash *md5;
62 struct sdesc *sdescmd5;
63
64 md5 = crypto_alloc_shash("md5", 0, 0);
65 if (IS_ERR(md5)) {
66 rc = PTR_ERR(md5);
67 cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
68 __func__, rc);
69 return rc;
70 }
71 size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
72 sdescmd5 = kmalloc(size, GFP_KERNEL);
73 if (!sdescmd5) {
74 rc = -ENOMEM;
75 goto symlink_hash_err;
76 }
77 sdescmd5->shash.tfm = md5;
78 sdescmd5->shash.flags = 0x0;
79
80 rc = crypto_shash_init(&sdescmd5->shash);
81 if (rc) {
82 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
83 goto symlink_hash_err;
84 }
85 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
86 if (rc) {
87 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
88 goto symlink_hash_err;
89 }
90 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
91 if (rc)
92 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
93
94symlink_hash_err:
95 crypto_free_shash(md5);
96 kfree(sdescmd5);
97
98 return rc;
99}
100
101static int
102parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
103 char **_link_str)
104{
105 int rc;
106 unsigned int link_len;
107 const char *md5_str1;
108 const char *link_str;
109 u8 md5_hash[16];
110 char md5_str2[34];
111
112 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
113 return -EINVAL;
114
115 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
116 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
117
118 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
119 if (rc != 1)
120 return -EINVAL;
121
122 rc = symlink_hash(link_len, link_str, md5_hash);
123 if (rc) {
124 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
125 return rc;
126 }
127
128 snprintf(md5_str2, sizeof(md5_str2),
129 CIFS_MF_SYMLINK_MD5_FORMAT,
130 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
131
132 if (strncmp(md5_str1, md5_str2, 17) != 0)
133 return -EINVAL;
134
135 if (_link_str) {
136 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
137 if (!*_link_str)
138 return -ENOMEM;
139 }
140
141 *_link_len = link_len;
142 return 0;
143}
144
145static int
146format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
147{
148 int rc;
149 unsigned int link_len;
150 unsigned int ofs;
151 u8 md5_hash[16];
152
153 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
154 return -EINVAL;
155
156 link_len = strlen(link_str);
157
158 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
159 return -ENAMETOOLONG;
160
161 rc = symlink_hash(link_len, link_str, md5_hash);
162 if (rc) {
163 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
164 return rc;
165 }
166
167 snprintf(buf, buf_len,
168 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
169 link_len,
170 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
171
172 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
173 memcpy(buf + ofs, link_str, link_len);
174
175 ofs += link_len;
176 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
177 buf[ofs] = '\n';
178 ofs++;
179 }
180
181 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
182 buf[ofs] = ' ';
183 ofs++;
184 }
185
186 return 0;
187}
188
189bool
190couldbe_mf_symlink(const struct cifs_fattr *fattr)
191{
192 if (!S_ISREG(fattr->cf_mode))
193 /* it's not a symlink */
194 return false;
195
196 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
197 /* it's not a symlink */
198 return false;
199
200 return true;
201}
202
203static int
204create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
205 struct cifs_sb_info *cifs_sb, const char *fromName,
206 const char *toName)
207{
208 int rc;
209 u8 *buf;
210 unsigned int bytes_written = 0;
211
212 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
213 if (!buf)
214 return -ENOMEM;
215
216 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
217 if (rc)
218 goto out;
219
220 if (tcon->ses->server->ops->create_mf_symlink)
221 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
222 cifs_sb, fromName, buf, &bytes_written);
223 else
224 rc = -EOPNOTSUPP;
225
226 if (rc)
227 goto out;
228
229 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
230 rc = -EIO;
231out:
232 kfree(buf);
233 return rc;
234}
235
236static int
237query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
238 struct cifs_sb_info *cifs_sb, const unsigned char *path,
239 char **symlinkinfo)
240{
241 int rc;
242 u8 *buf = NULL;
243 unsigned int link_len = 0;
244 unsigned int bytes_read = 0;
245
246 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
247 if (!buf)
248 return -ENOMEM;
249
250 if (tcon->ses->server->ops->query_mf_symlink)
251 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
252 cifs_sb, path, buf, &bytes_read);
253 else
254 rc = -ENOSYS;
255
256 if (rc)
257 goto out;
258
259 if (bytes_read == 0) { /* not a symlink */
260 rc = -EINVAL;
261 goto out;
262 }
263
264 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
265out:
266 kfree(buf);
267 return rc;
268}
269
270int
271check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
272 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
273 const unsigned char *path)
274{
275 int rc;
276 u8 *buf = NULL;
277 unsigned int link_len = 0;
278 unsigned int bytes_read = 0;
279
280 if (!couldbe_mf_symlink(fattr))
281 /* it's not a symlink */
282 return 0;
283
284 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
285 if (!buf)
286 return -ENOMEM;
287
288 if (tcon->ses->server->ops->query_mf_symlink)
289 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
290 cifs_sb, path, buf, &bytes_read);
291 else
292 rc = -ENOSYS;
293
294 if (rc)
295 goto out;
296
297 if (bytes_read == 0) /* not a symlink */
298 goto out;
299
300 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
301 if (rc == -EINVAL) {
302 /* it's not a symlink */
303 rc = 0;
304 goto out;
305 }
306
307 if (rc != 0)
308 goto out;
309
310 /* it is a symlink */
311 fattr->cf_eof = link_len;
312 fattr->cf_mode &= ~S_IFMT;
313 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
314 fattr->cf_dtype = DT_LNK;
315out:
316 kfree(buf);
317 return rc;
318}
319
320/*
321 * SMB 1.0 Protocol specific functions
322 */
323
324int
325cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
326 struct cifs_sb_info *cifs_sb, const unsigned char *path,
327 char *pbuf, unsigned int *pbytes_read)
328{
329 int rc;
330 int oplock = 0;
331 struct cifs_fid fid;
332 struct cifs_open_parms oparms;
333 struct cifs_io_parms io_parms;
334 int buf_type = CIFS_NO_BUFFER;
335 FILE_ALL_INFO file_info;
336
337 oparms.tcon = tcon;
338 oparms.cifs_sb = cifs_sb;
339 oparms.desired_access = GENERIC_READ;
340 oparms.create_options = CREATE_NOT_DIR;
341 oparms.disposition = FILE_OPEN;
342 oparms.path = path;
343 oparms.fid = &fid;
344 oparms.reconnect = false;
345
346 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
347 if (rc)
348 return rc;
349
350 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
351 rc = -ENOENT;
352 /* it's not a symlink */
353 goto out;
354 }
355
356 io_parms.netfid = fid.netfid;
357 io_parms.pid = current->tgid;
358 io_parms.tcon = tcon;
359 io_parms.offset = 0;
360 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
361
362 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
363out:
364 CIFSSMBClose(xid, tcon, fid.netfid);
365 return rc;
366}
367
368int
369cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
370 struct cifs_sb_info *cifs_sb, const unsigned char *path,
371 char *pbuf, unsigned int *pbytes_written)
372{
373 int rc;
374 int oplock = 0;
375 struct cifs_fid fid;
376 struct cifs_open_parms oparms;
377 struct cifs_io_parms io_parms;
378 int create_options = CREATE_NOT_DIR;
379
380 if (backup_cred(cifs_sb))
381 create_options |= CREATE_OPEN_BACKUP_INTENT;
382
383 oparms.tcon = tcon;
384 oparms.cifs_sb = cifs_sb;
385 oparms.desired_access = GENERIC_WRITE;
386 oparms.create_options = create_options;
387 oparms.disposition = FILE_CREATE;
388 oparms.path = path;
389 oparms.fid = &fid;
390 oparms.reconnect = false;
391
392 rc = CIFS_open(xid, &oparms, &oplock, NULL);
393 if (rc)
394 return rc;
395
396 io_parms.netfid = fid.netfid;
397 io_parms.pid = current->tgid;
398 io_parms.tcon = tcon;
399 io_parms.offset = 0;
400 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
401
402 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
403 CIFSSMBClose(xid, tcon, fid.netfid);
404 return rc;
405}
406
407/*
408 * SMB 2.1/SMB3 Protocol specific functions
409 */
410#ifdef CONFIG_CIFS_SMB2
411int
412smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
413 struct cifs_sb_info *cifs_sb, const unsigned char *path,
414 char *pbuf, unsigned int *pbytes_read)
415{
416 int rc;
417 struct cifs_fid fid;
418 struct cifs_open_parms oparms;
419 struct cifs_io_parms io_parms;
420 int buf_type = CIFS_NO_BUFFER;
421 __le16 *utf16_path;
422 __u8 oplock = SMB2_OPLOCK_LEVEL_II;
423 struct smb2_file_all_info *pfile_info = NULL;
424
425 oparms.tcon = tcon;
426 oparms.cifs_sb = cifs_sb;
427 oparms.desired_access = GENERIC_READ;
428 oparms.create_options = CREATE_NOT_DIR;
429 if (backup_cred(cifs_sb))
430 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
431 oparms.disposition = FILE_OPEN;
432 oparms.fid = &fid;
433 oparms.reconnect = false;
434
435 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
436 if (utf16_path == NULL)
437 return -ENOMEM;
438
439 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
440 GFP_KERNEL);
441
442 if (pfile_info == NULL) {
443 kfree(utf16_path);
444 return -ENOMEM;
445 }
446
447 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
448 if (rc)
449 goto qmf_out_open_fail;
450
451 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
452 /* it's not a symlink */
453 rc = -ENOENT; /* Is there a better rc to return? */
454 goto qmf_out;
455 }
456
457 io_parms.netfid = fid.netfid;
458 io_parms.pid = current->tgid;
459 io_parms.tcon = tcon;
460 io_parms.offset = 0;
461 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
462 io_parms.persistent_fid = fid.persistent_fid;
463 io_parms.volatile_fid = fid.volatile_fid;
464 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
465qmf_out:
466 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
467qmf_out_open_fail:
468 kfree(utf16_path);
469 kfree(pfile_info);
470 return rc;
471}
472
473int
474smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
475 struct cifs_sb_info *cifs_sb, const unsigned char *path,
476 char *pbuf, unsigned int *pbytes_written)
477{
478 int rc;
479 struct cifs_fid fid;
480 struct cifs_open_parms oparms;
481 struct cifs_io_parms io_parms;
482 int create_options = CREATE_NOT_DIR;
483 __le16 *utf16_path;
484 __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
485 struct kvec iov[2];
486
487 if (backup_cred(cifs_sb))
488 create_options |= CREATE_OPEN_BACKUP_INTENT;
489
490 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
491
492 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
493 if (!utf16_path)
494 return -ENOMEM;
495
496 oparms.tcon = tcon;
497 oparms.cifs_sb = cifs_sb;
498 oparms.desired_access = GENERIC_WRITE;
499 oparms.create_options = create_options;
500 oparms.disposition = FILE_CREATE;
501 oparms.fid = &fid;
502 oparms.reconnect = false;
503
504 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
505 if (rc) {
506 kfree(utf16_path);
507 return rc;
508 }
509
510 io_parms.netfid = fid.netfid;
511 io_parms.pid = current->tgid;
512 io_parms.tcon = tcon;
513 io_parms.offset = 0;
514 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
515 io_parms.persistent_fid = fid.persistent_fid;
516 io_parms.volatile_fid = fid.volatile_fid;
517
518 /* iov[0] is reserved for smb header */
519 iov[1].iov_base = pbuf;
520 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
521
522 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
523
524 /* Make sure we wrote all of the symlink data */
525 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
526 rc = -EIO;
527
528 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
529
530 kfree(utf16_path);
531 return rc;
532}
533#endif /* CONFIG_CIFS_SMB2 */
534
535/*
536 * M-F Symlink Functions - End
537 */
538
539int
540cifs_hardlink(struct dentry *old_file, struct inode *inode,
541 struct dentry *direntry)
542{
543 int rc = -EACCES;
544 unsigned int xid;
545 char *from_name = NULL;
546 char *to_name = NULL;
547 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
548 struct tcon_link *tlink;
549 struct cifs_tcon *tcon;
550 struct TCP_Server_Info *server;
551 struct cifsInodeInfo *cifsInode;
552
553 tlink = cifs_sb_tlink(cifs_sb);
554 if (IS_ERR(tlink))
555 return PTR_ERR(tlink);
556 tcon = tlink_tcon(tlink);
557
558 xid = get_xid();
559
560 from_name = build_path_from_dentry(old_file);
561 to_name = build_path_from_dentry(direntry);
562 if ((from_name == NULL) || (to_name == NULL)) {
563 rc = -ENOMEM;
564 goto cifs_hl_exit;
565 }
566
567 if (tcon->unix_ext)
568 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
569 cifs_sb->local_nls,
570 cifs_remap(cifs_sb));
571 else {
572 server = tcon->ses->server;
573 if (!server->ops->create_hardlink) {
574 rc = -ENOSYS;
575 goto cifs_hl_exit;
576 }
577 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
578 cifs_sb);
579 if ((rc == -EIO) || (rc == -EINVAL))
580 rc = -EOPNOTSUPP;
581 }
582
583 d_drop(direntry); /* force new lookup from server of target */
584
585 /*
586 * if source file is cached (oplocked) revalidate will not go to server
587 * until the file is closed or oplock broken so update nlinks locally
588 */
589 if (d_really_is_positive(old_file)) {
590 cifsInode = CIFS_I(d_inode(old_file));
591 if (rc == 0) {
592 spin_lock(&d_inode(old_file)->i_lock);
593 inc_nlink(d_inode(old_file));
594 spin_unlock(&d_inode(old_file)->i_lock);
595
596 /*
597 * parent dir timestamps will update from srv within a
598 * second, would it really be worth it to set the parent
599 * dir cifs inode time to zero to force revalidate
600 * (faster) for it too?
601 */
602 }
603 /*
604 * if not oplocked will force revalidate to get info on source
605 * file from srv. Note Samba server prior to 4.2 has bug -
606 * not updating src file ctime on hardlinks but Windows servers
607 * handle it properly
608 */
609 cifsInode->time = 0;
610
611 /*
612 * Will update parent dir timestamps from srv within a second.
613 * Would it really be worth it to set the parent dir (cifs
614 * inode) time field to zero to force revalidate on parent
615 * directory faster ie
616 *
617 * CIFS_I(inode)->time = 0;
618 */
619 }
620
621cifs_hl_exit:
622 kfree(from_name);
623 kfree(to_name);
624 free_xid(xid);
625 cifs_put_tlink(tlink);
626 return rc;
627}
628
629const char *
630cifs_get_link(struct dentry *direntry, struct inode *inode,
631 struct delayed_call *done)
632{
633 int rc = -ENOMEM;
634 unsigned int xid;
635 char *full_path = NULL;
636 char *target_path = NULL;
637 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
638 struct tcon_link *tlink = NULL;
639 struct cifs_tcon *tcon;
640 struct TCP_Server_Info *server;
641
642 if (!direntry)
643 return ERR_PTR(-ECHILD);
644
645 xid = get_xid();
646
647 tlink = cifs_sb_tlink(cifs_sb);
648 if (IS_ERR(tlink)) {
649 free_xid(xid);
650 return ERR_CAST(tlink);
651 }
652 tcon = tlink_tcon(tlink);
653 server = tcon->ses->server;
654
655 full_path = build_path_from_dentry(direntry);
656 if (!full_path) {
657 free_xid(xid);
658 cifs_put_tlink(tlink);
659 return ERR_PTR(-ENOMEM);
660 }
661
662 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
663
664 rc = -EACCES;
665 /*
666 * First try Minshall+French Symlinks, if configured
667 * and fallback to UNIX Extensions Symlinks.
668 */
669 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
670 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
671 &target_path);
672
673 if (rc != 0 && server->ops->query_symlink)
674 rc = server->ops->query_symlink(xid, tcon, full_path,
675 &target_path, cifs_sb);
676
677 kfree(full_path);
678 free_xid(xid);
679 cifs_put_tlink(tlink);
680 if (rc != 0) {
681 kfree(target_path);
682 return ERR_PTR(rc);
683 }
684 set_delayed_call(done, kfree_link, target_path);
685 return target_path;
686}
687
688int
689cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
690{
691 int rc = -EOPNOTSUPP;
692 unsigned int xid;
693 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
694 struct tcon_link *tlink;
695 struct cifs_tcon *pTcon;
696 char *full_path = NULL;
697 struct inode *newinode = NULL;
698
699 xid = get_xid();
700
701 tlink = cifs_sb_tlink(cifs_sb);
702 if (IS_ERR(tlink)) {
703 rc = PTR_ERR(tlink);
704 goto symlink_exit;
705 }
706 pTcon = tlink_tcon(tlink);
707
708 full_path = build_path_from_dentry(direntry);
709 if (full_path == NULL) {
710 rc = -ENOMEM;
711 goto symlink_exit;
712 }
713
714 cifs_dbg(FYI, "Full path: %s\n", full_path);
715 cifs_dbg(FYI, "symname is %s\n", symname);
716
717 /* BB what if DFS and this volume is on different share? BB */
718 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
719 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
720 else if (pTcon->unix_ext)
721 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
722 cifs_sb->local_nls,
723 cifs_remap(cifs_sb));
724 /* else
725 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
726 cifs_sb_target->local_nls); */
727
728 if (rc == 0) {
729 if (pTcon->unix_ext)
730 rc = cifs_get_inode_info_unix(&newinode, full_path,
731 inode->i_sb, xid);
732 else
733 rc = cifs_get_inode_info(&newinode, full_path, NULL,
734 inode->i_sb, xid, NULL);
735
736 if (rc != 0) {
737 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
738 rc);
739 } else {
740 d_instantiate(direntry, newinode);
741 }
742 }
743symlink_exit:
744 kfree(full_path);
745 cifs_put_tlink(tlink);
746 free_xid(xid);
747 return rc;
748}
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}