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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
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
172 return false;
173
174 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
175
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) {
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
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)
276 goto out;
277
278 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
279 if (rc == -EINVAL) {
280
281 rc = 0;
282 goto out;
283 }
284
285 if (rc != 0)
286 goto out;
287
288
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
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 = {0};
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 = cifs_create_options(cifs_sb, 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
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 = {0};
356
357 oparms.tcon = tcon;
358 oparms.cifs_sb = cifs_sb;
359 oparms.desired_access = GENERIC_WRITE;
360 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
361 oparms.disposition = FILE_CREATE;
362 oparms.path = path;
363 oparms.fid = &fid;
364 oparms.reconnect = false;
365
366 rc = CIFS_open(xid, &oparms, &oplock, NULL);
367 if (rc)
368 return rc;
369
370 io_parms.netfid = fid.netfid;
371 io_parms.pid = current->tgid;
372 io_parms.tcon = tcon;
373 io_parms.offset = 0;
374 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
375
376 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
377 CIFSSMBClose(xid, tcon, fid.netfid);
378 return rc;
379}
380
381
382
383
384int
385smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
386 struct cifs_sb_info *cifs_sb, const unsigned char *path,
387 char *pbuf, unsigned int *pbytes_read)
388{
389 int rc;
390 struct cifs_fid fid;
391 struct cifs_open_parms oparms;
392 struct cifs_io_parms io_parms = {0};
393 int buf_type = CIFS_NO_BUFFER;
394 __le16 *utf16_path;
395 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
396 struct smb2_file_all_info *pfile_info = NULL;
397
398 oparms.tcon = tcon;
399 oparms.cifs_sb = cifs_sb;
400 oparms.desired_access = GENERIC_READ;
401 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
402 oparms.disposition = FILE_OPEN;
403 oparms.fid = &fid;
404 oparms.reconnect = false;
405
406 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
407 if (utf16_path == NULL)
408 return -ENOMEM;
409
410 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
411 GFP_KERNEL);
412
413 if (pfile_info == NULL) {
414 kfree(utf16_path);
415 return -ENOMEM;
416 }
417
418 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
419 NULL, NULL);
420 if (rc)
421 goto qmf_out_open_fail;
422
423 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
424
425 rc = -ENOENT;
426 goto qmf_out;
427 }
428
429 io_parms.netfid = fid.netfid;
430 io_parms.pid = current->tgid;
431 io_parms.tcon = tcon;
432 io_parms.offset = 0;
433 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
434 io_parms.persistent_fid = fid.persistent_fid;
435 io_parms.volatile_fid = fid.volatile_fid;
436 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
437qmf_out:
438 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
439qmf_out_open_fail:
440 kfree(utf16_path);
441 kfree(pfile_info);
442 return rc;
443}
444
445int
446smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
447 struct cifs_sb_info *cifs_sb, const unsigned char *path,
448 char *pbuf, unsigned int *pbytes_written)
449{
450 int rc;
451 struct cifs_fid fid;
452 struct cifs_open_parms oparms;
453 struct cifs_io_parms io_parms = {0};
454 __le16 *utf16_path;
455 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
456 struct kvec iov[2];
457
458 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
459
460 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
461 if (!utf16_path)
462 return -ENOMEM;
463
464 oparms.tcon = tcon;
465 oparms.cifs_sb = cifs_sb;
466 oparms.desired_access = GENERIC_WRITE;
467 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
468 oparms.disposition = FILE_CREATE;
469 oparms.fid = &fid;
470 oparms.reconnect = false;
471
472 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
473 NULL, NULL);
474 if (rc) {
475 kfree(utf16_path);
476 return rc;
477 }
478
479 io_parms.netfid = fid.netfid;
480 io_parms.pid = current->tgid;
481 io_parms.tcon = tcon;
482 io_parms.offset = 0;
483 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
484 io_parms.persistent_fid = fid.persistent_fid;
485 io_parms.volatile_fid = fid.volatile_fid;
486
487
488 iov[1].iov_base = pbuf;
489 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
490
491 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
492
493
494 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
495 rc = -EIO;
496
497 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
498
499 kfree(utf16_path);
500 return rc;
501}
502
503
504
505
506
507int
508cifs_hardlink(struct dentry *old_file, struct inode *inode,
509 struct dentry *direntry)
510{
511 int rc = -EACCES;
512 unsigned int xid;
513 char *from_name = NULL;
514 char *to_name = NULL;
515 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
516 struct tcon_link *tlink;
517 struct cifs_tcon *tcon;
518 struct TCP_Server_Info *server;
519 struct cifsInodeInfo *cifsInode;
520
521 tlink = cifs_sb_tlink(cifs_sb);
522 if (IS_ERR(tlink))
523 return PTR_ERR(tlink);
524 tcon = tlink_tcon(tlink);
525
526 xid = get_xid();
527
528 from_name = build_path_from_dentry(old_file);
529 to_name = build_path_from_dentry(direntry);
530 if ((from_name == NULL) || (to_name == NULL)) {
531 rc = -ENOMEM;
532 goto cifs_hl_exit;
533 }
534
535 if (tcon->unix_ext)
536 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
537 cifs_sb->local_nls,
538 cifs_remap(cifs_sb));
539 else {
540 server = tcon->ses->server;
541 if (!server->ops->create_hardlink) {
542 rc = -ENOSYS;
543 goto cifs_hl_exit;
544 }
545 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
546 cifs_sb);
547 if ((rc == -EIO) || (rc == -EINVAL))
548 rc = -EOPNOTSUPP;
549 }
550
551 d_drop(direntry);
552
553
554
555
556
557 if (d_really_is_positive(old_file)) {
558 cifsInode = CIFS_I(d_inode(old_file));
559 if (rc == 0) {
560 spin_lock(&d_inode(old_file)->i_lock);
561 inc_nlink(d_inode(old_file));
562 spin_unlock(&d_inode(old_file)->i_lock);
563
564
565
566
567
568
569
570 }
571
572
573
574
575
576
577 cifsInode->time = 0;
578
579
580
581
582
583
584
585
586
587 }
588
589cifs_hl_exit:
590 kfree(from_name);
591 kfree(to_name);
592 free_xid(xid);
593 cifs_put_tlink(tlink);
594 return rc;
595}
596
597const char *
598cifs_get_link(struct dentry *direntry, struct inode *inode,
599 struct delayed_call *done)
600{
601 int rc = -ENOMEM;
602 unsigned int xid;
603 char *full_path = NULL;
604 char *target_path = NULL;
605 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
606 struct tcon_link *tlink = NULL;
607 struct cifs_tcon *tcon;
608 struct TCP_Server_Info *server;
609
610 if (!direntry)
611 return ERR_PTR(-ECHILD);
612
613 xid = get_xid();
614
615 tlink = cifs_sb_tlink(cifs_sb);
616 if (IS_ERR(tlink)) {
617 free_xid(xid);
618 return ERR_CAST(tlink);
619 }
620 tcon = tlink_tcon(tlink);
621 server = tcon->ses->server;
622
623 full_path = build_path_from_dentry(direntry);
624 if (!full_path) {
625 free_xid(xid);
626 cifs_put_tlink(tlink);
627 return ERR_PTR(-ENOMEM);
628 }
629
630 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
631
632 rc = -EACCES;
633
634
635
636
637 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
638 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
639 &target_path);
640
641 if (rc != 0 && server->ops->query_symlink) {
642 struct cifsInodeInfo *cifsi = CIFS_I(inode);
643 bool reparse_point = false;
644
645 if (cifsi->cifsAttrs & ATTR_REPARSE)
646 reparse_point = true;
647
648 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
649 &target_path, reparse_point);
650 }
651
652 kfree(full_path);
653 free_xid(xid);
654 cifs_put_tlink(tlink);
655 if (rc != 0) {
656 kfree(target_path);
657 return ERR_PTR(rc);
658 }
659 set_delayed_call(done, kfree_link, target_path);
660 return target_path;
661}
662
663int
664cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
665{
666 int rc = -EOPNOTSUPP;
667 unsigned int xid;
668 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
669 struct tcon_link *tlink;
670 struct cifs_tcon *pTcon;
671 char *full_path = NULL;
672 struct inode *newinode = NULL;
673
674 xid = get_xid();
675
676 tlink = cifs_sb_tlink(cifs_sb);
677 if (IS_ERR(tlink)) {
678 rc = PTR_ERR(tlink);
679 goto symlink_exit;
680 }
681 pTcon = tlink_tcon(tlink);
682
683 full_path = build_path_from_dentry(direntry);
684 if (full_path == NULL) {
685 rc = -ENOMEM;
686 goto symlink_exit;
687 }
688
689 cifs_dbg(FYI, "Full path: %s\n", full_path);
690 cifs_dbg(FYI, "symname is %s\n", symname);
691
692
693 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
694 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
695 else if (pTcon->unix_ext)
696 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
697 cifs_sb->local_nls,
698 cifs_remap(cifs_sb));
699
700
701
702
703 if (rc == 0) {
704 if (pTcon->posix_extensions)
705 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
706 else if (pTcon->unix_ext)
707 rc = cifs_get_inode_info_unix(&newinode, full_path,
708 inode->i_sb, xid);
709 else
710 rc = cifs_get_inode_info(&newinode, full_path, NULL,
711 inode->i_sb, xid, NULL);
712
713 if (rc != 0) {
714 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
715 rc);
716 } else {
717 d_instantiate(direntry, newinode);
718 }
719 }
720symlink_exit:
721 kfree(full_path);
722 cifs_put_tlink(tlink);
723 free_xid(xid);
724 return rc;
725}
726
