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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
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
37static int
38symlink_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
62symlink_hash_err:
63 cifs_free_hash(&md5, &sdescmd5);
64 return rc;
65}
66
67static int
68parse_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
114static int
115format_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
158bool
159couldbe_mf_symlink(const struct cifs_fattr *fattr)
160{
161 if (!S_ISREG(fattr->cf_mode))
162
163 return false;
164
165 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
166
167 return false;
168
169 return true;
170}
171
172static int
173create_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;
200out:
201 kfree(buf);
202 return rc;
203}
204
205static int
206query_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) {
229 rc = -EINVAL;
230 goto out;
231 }
232
233 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
234out:
235 kfree(buf);
236 return rc;
237}
238
239int
240check_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
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)
267 goto out;
268
269 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
270 if (rc == -EINVAL) {
271
272 rc = 0;
273 goto out;
274 }
275
276 if (rc != 0)
277 goto out;
278
279
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;
284out:
285 kfree(buf);
286 return rc;
287}
288
289
290
291
292
293int
294cifs_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
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);
332out:
333 CIFSSMBClose(xid, tcon, fid.netfid);
334 return rc;
335}
336
337int
338cifs_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
374
375int
376smb3_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
416 rc = -ENOENT;
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);
428qmf_out:
429 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
430qmf_out_open_fail:
431 kfree(utf16_path);
432 kfree(pfile_info);
433 return rc;
434}
435
436int
437smb3_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
463 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
464 NULL, NULL);
465 if (rc) {
466 kfree(utf16_path);
467 return rc;
468 }
469
470 io_parms.netfid = fid.netfid;
471 io_parms.pid = current->tgid;
472 io_parms.tcon = tcon;
473 io_parms.offset = 0;
474 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
475 io_parms.persistent_fid = fid.persistent_fid;
476 io_parms.volatile_fid = fid.volatile_fid;
477
478
479 iov[1].iov_base = pbuf;
480 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
481
482 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
483
484
485 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
486 rc = -EIO;
487
488 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
489
490 kfree(utf16_path);
491 return rc;
492}
493
494
495
496
497
498int
499cifs_hardlink(struct dentry *old_file, struct inode *inode,
500 struct dentry *direntry)
501{
502 int rc = -EACCES;
503 unsigned int xid;
504 const char *from_name, *to_name;
505 void *page1, *page2;
506 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
507 struct tcon_link *tlink;
508 struct cifs_tcon *tcon;
509 struct TCP_Server_Info *server;
510 struct cifsInodeInfo *cifsInode;
511
512 if (unlikely(cifs_forced_shutdown(cifs_sb)))
513 return -EIO;
514
515 tlink = cifs_sb_tlink(cifs_sb);
516 if (IS_ERR(tlink))
517 return PTR_ERR(tlink);
518 tcon = tlink_tcon(tlink);
519
520 xid = get_xid();
521 page1 = alloc_dentry_path();
522 page2 = alloc_dentry_path();
523
524 from_name = build_path_from_dentry(old_file, page1);
525 if (IS_ERR(from_name)) {
526 rc = PTR_ERR(from_name);
527 goto cifs_hl_exit;
528 }
529 to_name = build_path_from_dentry(direntry, page2);
530 if (IS_ERR(to_name)) {
531 rc = PTR_ERR(to_name);
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 free_dentry_path(page1);
591 free_dentry_path(page2);
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 const char *full_path;
604 void *page;
605 char *target_path = NULL;
606 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
607 struct tcon_link *tlink = NULL;
608 struct cifs_tcon *tcon;
609 struct TCP_Server_Info *server;
610
611 if (!direntry)
612 return ERR_PTR(-ECHILD);
613
614 xid = get_xid();
615
616 tlink = cifs_sb_tlink(cifs_sb);
617 if (IS_ERR(tlink)) {
618 free_xid(xid);
619 return ERR_CAST(tlink);
620 }
621 tcon = tlink_tcon(tlink);
622 server = tcon->ses->server;
623
624 page = alloc_dentry_path();
625 full_path = build_path_from_dentry(direntry, page);
626 if (IS_ERR(full_path)) {
627 free_xid(xid);
628 cifs_put_tlink(tlink);
629 free_dentry_path(page);
630 return ERR_CAST(full_path);
631 }
632
633 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
634
635 rc = -EACCES;
636
637
638
639
640 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
641 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
642 &target_path);
643
644 if (rc != 0 && server->ops->query_symlink) {
645 struct cifsInodeInfo *cifsi = CIFS_I(inode);
646 bool reparse_point = false;
647
648 if (cifsi->cifsAttrs & ATTR_REPARSE)
649 reparse_point = true;
650
651 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
652 &target_path, reparse_point);
653 }
654
655 free_dentry_path(page);
656 free_xid(xid);
657 cifs_put_tlink(tlink);
658 if (rc != 0) {
659 kfree(target_path);
660 return ERR_PTR(rc);
661 }
662 set_delayed_call(done, kfree_link, target_path);
663 return target_path;
664}
665
666int
667cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
668 struct dentry *direntry, const char *symname)
669{
670 int rc = -EOPNOTSUPP;
671 unsigned int xid;
672 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
673 struct tcon_link *tlink;
674 struct cifs_tcon *pTcon;
675 const char *full_path;
676 void *page;
677 struct inode *newinode = NULL;
678
679 if (unlikely(cifs_forced_shutdown(cifs_sb)))
680 return -EIO;
681
682 page = alloc_dentry_path();
683 if (!page)
684 return -ENOMEM;
685
686 xid = get_xid();
687
688 tlink = cifs_sb_tlink(cifs_sb);
689 if (IS_ERR(tlink)) {
690 rc = PTR_ERR(tlink);
691 goto symlink_exit;
692 }
693 pTcon = tlink_tcon(tlink);
694
695 full_path = build_path_from_dentry(direntry, page);
696 if (IS_ERR(full_path)) {
697 rc = PTR_ERR(full_path);
698 goto symlink_exit;
699 }
700
701 cifs_dbg(FYI, "Full path: %s\n", full_path);
702 cifs_dbg(FYI, "symname is %s\n", symname);
703
704
705 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
706 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
707 else if (pTcon->unix_ext)
708 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
709 cifs_sb->local_nls,
710 cifs_remap(cifs_sb));
711
712
713
714
715 if (rc == 0) {
716 if (pTcon->posix_extensions)
717 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
718 else if (pTcon->unix_ext)
719 rc = cifs_get_inode_info_unix(&newinode, full_path,
720 inode->i_sb, xid);
721 else
722 rc = cifs_get_inode_info(&newinode, full_path, NULL,
723 inode->i_sb, xid, NULL);
724
725 if (rc != 0) {
726 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
727 rc);
728 } else {
729 d_instantiate(direntry, newinode);
730 }
731 }
732symlink_exit:
733 free_dentry_path(page);
734 cifs_put_tlink(tlink);
735 free_xid(xid);
736 return rc;
737}
738
