1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 */
8 #include <linux/fs.h>
9 #include <linux/stat.h>
10 #include <linux/slab.h>
11 #include <linux/namei.h>
12 #include "cifsfs.h"
13 #include "cifspdu.h"
14 #include "cifsglob.h"
15 #include "cifsproto.h"
16 #include "cifs_debug.h"
17 #include "cifs_fs_sb.h"
18 #include "cifs_unicode.h"
19 #include "smb2proto.h"
20 #include "cifs_ioctl.h"
21
22 /*
23 * M-F Symlink Functions - Begin
24 */
25
26 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
27 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
28 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
29 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
30 #define CIFS_MF_SYMLINK_FILE_SIZE \
31 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
32
33 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
34 #define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
35 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
36
37 static int
symlink_hash(unsigned int link_len,const char * link_str,u8 * md5_hash)38 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
39 {
40 int rc;
41 struct crypto_shash *md5 = NULL;
42 struct sdesc *sdescmd5 = NULL;
43
44 rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
45 if (rc)
46 goto symlink_hash_err;
47
48 rc = crypto_shash_init(&sdescmd5->shash);
49 if (rc) {
50 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
51 goto symlink_hash_err;
52 }
53 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
54 if (rc) {
55 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
56 goto symlink_hash_err;
57 }
58 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
59 if (rc)
60 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
61
62 symlink_hash_err:
63 cifs_free_hash(&md5, &sdescmd5);
64 return rc;
65 }
66
67 static int
parse_mf_symlink(const u8 * buf,unsigned int buf_len,unsigned int * _link_len,char ** _link_str)68 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
69 char **_link_str)
70 {
71 int rc;
72 unsigned int link_len;
73 const char *md5_str1;
74 const char *link_str;
75 u8 md5_hash[16];
76 char md5_str2[34];
77
78 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
79 return -EINVAL;
80
81 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
82 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
83
84 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
85 if (rc != 1)
86 return -EINVAL;
87
88 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
89 return -EINVAL;
90
91 rc = symlink_hash(link_len, link_str, md5_hash);
92 if (rc) {
93 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
94 return rc;
95 }
96
97 scnprintf(md5_str2, sizeof(md5_str2),
98 CIFS_MF_SYMLINK_MD5_FORMAT,
99 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
100
101 if (strncmp(md5_str1, md5_str2, 17) != 0)
102 return -EINVAL;
103
104 if (_link_str) {
105 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
106 if (!*_link_str)
107 return -ENOMEM;
108 }
109
110 *_link_len = link_len;
111 return 0;
112 }
113
114 static int
format_mf_symlink(u8 * buf,unsigned int buf_len,const char * link_str)115 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
116 {
117 int rc;
118 unsigned int link_len;
119 unsigned int ofs;
120 u8 md5_hash[16];
121
122 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
123 return -EINVAL;
124
125 link_len = strlen(link_str);
126
127 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
128 return -ENAMETOOLONG;
129
130 rc = symlink_hash(link_len, link_str, md5_hash);
131 if (rc) {
132 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
133 return rc;
134 }
135
136 scnprintf(buf, buf_len,
137 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
138 link_len,
139 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
140
141 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
142 memcpy(buf + ofs, link_str, link_len);
143
144 ofs += link_len;
145 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
146 buf[ofs] = '\n';
147 ofs++;
148 }
149
150 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
151 buf[ofs] = ' ';
152 ofs++;
153 }
154
155 return 0;
156 }
157
158 bool
couldbe_mf_symlink(const struct cifs_fattr * fattr)159 couldbe_mf_symlink(const struct cifs_fattr *fattr)
160 {
161 if (!S_ISREG(fattr->cf_mode))
162 /* it's not a symlink */
163 return false;
164
165 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
166 /* it's not a symlink */
167 return false;
168
169 return true;
170 }
171
172 static int
create_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const char * fromName,const char * toName)173 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
174 struct cifs_sb_info *cifs_sb, const char *fromName,
175 const char *toName)
176 {
177 int rc;
178 u8 *buf;
179 unsigned int bytes_written = 0;
180
181 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
182 if (!buf)
183 return -ENOMEM;
184
185 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
186 if (rc)
187 goto out;
188
189 if (tcon->ses->server->ops->create_mf_symlink)
190 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
191 cifs_sb, fromName, buf, &bytes_written);
192 else
193 rc = -EOPNOTSUPP;
194
195 if (rc)
196 goto out;
197
198 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
199 rc = -EIO;
200 out:
201 kfree(buf);
202 return rc;
203 }
204
205 static int
query_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char ** symlinkinfo)206 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
207 struct cifs_sb_info *cifs_sb, const unsigned char *path,
208 char **symlinkinfo)
209 {
210 int rc;
211 u8 *buf = NULL;
212 unsigned int link_len = 0;
213 unsigned int bytes_read = 0;
214
215 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
216 if (!buf)
217 return -ENOMEM;
218
219 if (tcon->ses->server->ops->query_mf_symlink)
220 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
221 cifs_sb, path, buf, &bytes_read);
222 else
223 rc = -ENOSYS;
224
225 if (rc)
226 goto out;
227
228 if (bytes_read == 0) { /* not a symlink */
229 rc = -EINVAL;
230 goto out;
231 }
232
233 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
234 out:
235 kfree(buf);
236 return rc;
237 }
238
239 int
check_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,struct cifs_fattr * fattr,const unsigned char * path)240 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
241 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
242 const unsigned char *path)
243 {
244 int rc;
245 u8 *buf = NULL;
246 unsigned int link_len = 0;
247 unsigned int bytes_read = 0;
248
249 if (!couldbe_mf_symlink(fattr))
250 /* it's not a symlink */
251 return 0;
252
253 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
254 if (!buf)
255 return -ENOMEM;
256
257 if (tcon->ses->server->ops->query_mf_symlink)
258 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
259 cifs_sb, path, buf, &bytes_read);
260 else
261 rc = -ENOSYS;
262
263 if (rc)
264 goto out;
265
266 if (bytes_read == 0) /* not a symlink */
267 goto out;
268
269 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
270 if (rc == -EINVAL) {
271 /* it's not a symlink */
272 rc = 0;
273 goto out;
274 }
275
276 if (rc != 0)
277 goto out;
278
279 /* it is a symlink */
280 fattr->cf_eof = link_len;
281 fattr->cf_mode &= ~S_IFMT;
282 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
283 fattr->cf_dtype = DT_LNK;
284 out:
285 kfree(buf);
286 return rc;
287 }
288
289 /*
290 * SMB 1.0 Protocol specific functions
291 */
292
293 int
cifs_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)294 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
295 struct cifs_sb_info *cifs_sb, const unsigned char *path,
296 char *pbuf, unsigned int *pbytes_read)
297 {
298 int rc;
299 int oplock = 0;
300 struct cifs_fid fid;
301 struct cifs_open_parms oparms;
302 struct cifs_io_parms io_parms = {0};
303 int buf_type = CIFS_NO_BUFFER;
304 FILE_ALL_INFO file_info;
305
306 oparms.tcon = tcon;
307 oparms.cifs_sb = cifs_sb;
308 oparms.desired_access = GENERIC_READ;
309 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
310 oparms.disposition = FILE_OPEN;
311 oparms.path = path;
312 oparms.fid = &fid;
313 oparms.reconnect = false;
314
315 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
316 if (rc)
317 return rc;
318
319 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
320 rc = -ENOENT;
321 /* it's not a symlink */
322 goto out;
323 }
324
325 io_parms.netfid = fid.netfid;
326 io_parms.pid = current->tgid;
327 io_parms.tcon = tcon;
328 io_parms.offset = 0;
329 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
330
331 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
332 out:
333 CIFSSMBClose(xid, tcon, fid.netfid);
334 return rc;
335 }
336
337 int
cifs_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)338 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
339 struct cifs_sb_info *cifs_sb, const unsigned char *path,
340 char *pbuf, unsigned int *pbytes_written)
341 {
342 int rc;
343 int oplock = 0;
344 struct cifs_fid fid;
345 struct cifs_open_parms oparms;
346 struct cifs_io_parms io_parms = {0};
347
348 oparms.tcon = tcon;
349 oparms.cifs_sb = cifs_sb;
350 oparms.desired_access = GENERIC_WRITE;
351 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
352 oparms.disposition = FILE_CREATE;
353 oparms.path = path;
354 oparms.fid = &fid;
355 oparms.reconnect = false;
356
357 rc = CIFS_open(xid, &oparms, &oplock, NULL);
358 if (rc)
359 return rc;
360
361 io_parms.netfid = fid.netfid;
362 io_parms.pid = current->tgid;
363 io_parms.tcon = tcon;
364 io_parms.offset = 0;
365 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
366
367 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
368 CIFSSMBClose(xid, tcon, fid.netfid);
369 return rc;
370 }
371
372 /*
373 * SMB 2.1/SMB3 Protocol specific functions
374 */
375 int
smb3_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)376 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
377 struct cifs_sb_info *cifs_sb, const unsigned char *path,
378 char *pbuf, unsigned int *pbytes_read)
379 {
380 int rc;
381 struct cifs_fid fid;
382 struct cifs_open_parms oparms;
383 struct cifs_io_parms io_parms = {0};
384 int buf_type = CIFS_NO_BUFFER;
385 __le16 *utf16_path;
386 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
387 struct smb2_file_all_info *pfile_info = NULL;
388
389 oparms.tcon = tcon;
390 oparms.cifs_sb = cifs_sb;
391 oparms.desired_access = GENERIC_READ;
392 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
393 oparms.disposition = FILE_OPEN;
394 oparms.fid = &fid;
395 oparms.reconnect = false;
396
397 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
398 if (utf16_path == NULL)
399 return -ENOMEM;
400
401 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
402 GFP_KERNEL);
403
404 if (pfile_info == NULL) {
405 kfree(utf16_path);
406 return -ENOMEM;
407 }
408
409 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
410 NULL, NULL);
411 if (rc)
412 goto qmf_out_open_fail;
413
414 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
415 /* it's not a symlink */
416 rc = -ENOENT; /* Is there a better rc to return? */
417 goto qmf_out;
418 }
419
420 io_parms.netfid = fid.netfid;
421 io_parms.pid = current->tgid;
422 io_parms.tcon = tcon;
423 io_parms.offset = 0;
424 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
425 io_parms.persistent_fid = fid.persistent_fid;
426 io_parms.volatile_fid = fid.volatile_fid;
427 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
428 qmf_out:
429 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
430 qmf_out_open_fail:
431 kfree(utf16_path);
432 kfree(pfile_info);
433 return rc;
434 }
435
436 int
smb3_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)437 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
438 struct cifs_sb_info *cifs_sb, const unsigned char *path,
439 char *pbuf, unsigned int *pbytes_written)
440 {
441 int rc;
442 struct cifs_fid fid;
443 struct cifs_open_parms oparms;
444 struct cifs_io_parms io_parms = {0};
445 __le16 *utf16_path;
446 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
447 struct kvec iov[2];
448
449 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
450
451 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
452 if (!utf16_path)
453 return -ENOMEM;
454
455 oparms.tcon = tcon;
456 oparms.cifs_sb = cifs_sb;
457 oparms.desired_access = GENERIC_WRITE;
458 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
459 oparms.disposition = FILE_CREATE;
460 oparms.fid = &fid;
461 oparms.reconnect = false;
462 oparms.mode = 0644;
463
464 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
465 NULL, NULL);
466 if (rc) {
467 kfree(utf16_path);
468 return rc;
469 }
470
471 io_parms.netfid = fid.netfid;
472 io_parms.pid = current->tgid;
473 io_parms.tcon = tcon;
474 io_parms.offset = 0;
475 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
476 io_parms.persistent_fid = fid.persistent_fid;
477 io_parms.volatile_fid = fid.volatile_fid;
478
479 /* iov[0] is reserved for smb header */
480 iov[1].iov_base = pbuf;
481 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
482
483 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
484
485 /* Make sure we wrote all of the symlink data */
486 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
487 rc = -EIO;
488
489 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
490
491 kfree(utf16_path);
492 return rc;
493 }
494
495 /*
496 * M-F Symlink Functions - End
497 */
498
499 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)500 cifs_hardlink(struct dentry *old_file, struct inode *inode,
501 struct dentry *direntry)
502 {
503 int rc = -EACCES;
504 unsigned int xid;
505 const char *from_name, *to_name;
506 void *page1, *page2;
507 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
508 struct tcon_link *tlink;
509 struct cifs_tcon *tcon;
510 struct TCP_Server_Info *server;
511 struct cifsInodeInfo *cifsInode;
512
513 if (unlikely(cifs_forced_shutdown(cifs_sb)))
514 return -EIO;
515
516 tlink = cifs_sb_tlink(cifs_sb);
517 if (IS_ERR(tlink))
518 return PTR_ERR(tlink);
519 tcon = tlink_tcon(tlink);
520
521 xid = get_xid();
522 page1 = alloc_dentry_path();
523 page2 = alloc_dentry_path();
524
525 from_name = build_path_from_dentry(old_file, page1);
526 if (IS_ERR(from_name)) {
527 rc = PTR_ERR(from_name);
528 goto cifs_hl_exit;
529 }
530 to_name = build_path_from_dentry(direntry, page2);
531 if (IS_ERR(to_name)) {
532 rc = PTR_ERR(to_name);
533 goto cifs_hl_exit;
534 }
535
536 if (tcon->unix_ext)
537 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
538 cifs_sb->local_nls,
539 cifs_remap(cifs_sb));
540 else {
541 server = tcon->ses->server;
542 if (!server->ops->create_hardlink) {
543 rc = -ENOSYS;
544 goto cifs_hl_exit;
545 }
546 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
547 cifs_sb);
548 if ((rc == -EIO) || (rc == -EINVAL))
549 rc = -EOPNOTSUPP;
550 }
551
552 d_drop(direntry); /* force new lookup from server of target */
553
554 /*
555 * if source file is cached (oplocked) revalidate will not go to server
556 * until the file is closed or oplock broken so update nlinks locally
557 */
558 if (d_really_is_positive(old_file)) {
559 cifsInode = CIFS_I(d_inode(old_file));
560 if (rc == 0) {
561 spin_lock(&d_inode(old_file)->i_lock);
562 inc_nlink(d_inode(old_file));
563 spin_unlock(&d_inode(old_file)->i_lock);
564
565 /*
566 * parent dir timestamps will update from srv within a
567 * second, would it really be worth it to set the parent
568 * dir cifs inode time to zero to force revalidate
569 * (faster) for it too?
570 */
571 }
572 /*
573 * if not oplocked will force revalidate to get info on source
574 * file from srv. Note Samba server prior to 4.2 has bug -
575 * not updating src file ctime on hardlinks but Windows servers
576 * handle it properly
577 */
578 cifsInode->time = 0;
579
580 /*
581 * Will update parent dir timestamps from srv within a second.
582 * Would it really be worth it to set the parent dir (cifs
583 * inode) time field to zero to force revalidate on parent
584 * directory faster ie
585 *
586 * CIFS_I(inode)->time = 0;
587 */
588 }
589
590 cifs_hl_exit:
591 free_dentry_path(page1);
592 free_dentry_path(page2);
593 free_xid(xid);
594 cifs_put_tlink(tlink);
595 return rc;
596 }
597
598 const char *
cifs_get_link(struct dentry * direntry,struct inode * inode,struct delayed_call * done)599 cifs_get_link(struct dentry *direntry, struct inode *inode,
600 struct delayed_call *done)
601 {
602 int rc = -ENOMEM;
603 unsigned int xid;
604 const char *full_path;
605 void *page;
606 char *target_path = NULL;
607 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
608 struct tcon_link *tlink = NULL;
609 struct cifs_tcon *tcon;
610 struct TCP_Server_Info *server;
611
612 if (!direntry)
613 return ERR_PTR(-ECHILD);
614
615 xid = get_xid();
616
617 tlink = cifs_sb_tlink(cifs_sb);
618 if (IS_ERR(tlink)) {
619 free_xid(xid);
620 return ERR_CAST(tlink);
621 }
622 tcon = tlink_tcon(tlink);
623 server = tcon->ses->server;
624
625 page = alloc_dentry_path();
626 full_path = build_path_from_dentry(direntry, page);
627 if (IS_ERR(full_path)) {
628 free_xid(xid);
629 cifs_put_tlink(tlink);
630 free_dentry_path(page);
631 return ERR_CAST(full_path);
632 }
633
634 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
635
636 rc = -EACCES;
637 /*
638 * First try Minshall+French Symlinks, if configured
639 * and fallback to UNIX Extensions Symlinks.
640 */
641 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
642 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
643 &target_path);
644
645 if (rc != 0 && server->ops->query_symlink) {
646 struct cifsInodeInfo *cifsi = CIFS_I(inode);
647 bool reparse_point = false;
648
649 if (cifsi->cifsAttrs & ATTR_REPARSE)
650 reparse_point = true;
651
652 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
653 &target_path, reparse_point);
654 }
655
656 free_dentry_path(page);
657 free_xid(xid);
658 cifs_put_tlink(tlink);
659 if (rc != 0) {
660 kfree(target_path);
661 return ERR_PTR(rc);
662 }
663 set_delayed_call(done, kfree_link, target_path);
664 return target_path;
665 }
666
667 int
cifs_symlink(struct user_namespace * mnt_userns,struct inode * inode,struct dentry * direntry,const char * symname)668 cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
669 struct dentry *direntry, const char *symname)
670 {
671 int rc = -EOPNOTSUPP;
672 unsigned int xid;
673 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
674 struct tcon_link *tlink;
675 struct cifs_tcon *pTcon;
676 const char *full_path;
677 void *page;
678 struct inode *newinode = NULL;
679
680 if (unlikely(cifs_forced_shutdown(cifs_sb)))
681 return -EIO;
682
683 page = alloc_dentry_path();
684 if (!page)
685 return -ENOMEM;
686
687 xid = get_xid();
688
689 tlink = cifs_sb_tlink(cifs_sb);
690 if (IS_ERR(tlink)) {
691 rc = PTR_ERR(tlink);
692 goto symlink_exit;
693 }
694 pTcon = tlink_tcon(tlink);
695
696 full_path = build_path_from_dentry(direntry, page);
697 if (IS_ERR(full_path)) {
698 rc = PTR_ERR(full_path);
699 goto symlink_exit;
700 }
701
702 cifs_dbg(FYI, "Full path: %s\n", full_path);
703 cifs_dbg(FYI, "symname is %s\n", symname);
704
705 /* BB what if DFS and this volume is on different share? BB */
706 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
707 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
708 else if (pTcon->unix_ext)
709 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
710 cifs_sb->local_nls,
711 cifs_remap(cifs_sb));
712 /* else
713 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
714 cifs_sb_target->local_nls); */
715
716 if (rc == 0) {
717 if (pTcon->posix_extensions)
718 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
719 else if (pTcon->unix_ext)
720 rc = cifs_get_inode_info_unix(&newinode, full_path,
721 inode->i_sb, xid);
722 else
723 rc = cifs_get_inode_info(&newinode, full_path, NULL,
724 inode->i_sb, xid, NULL);
725
726 if (rc != 0) {
727 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
728 rc);
729 } else {
730 d_instantiate(direntry, newinode);
731 }
732 }
733 symlink_exit:
734 free_dentry_path(page);
735 cifs_put_tlink(tlink);
736 free_xid(xid);
737 return rc;
738 }
739