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