Linux kernel mirror (for testing)
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linux
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
37static int
38symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
39{
40 int rc;
41 struct shash_desc *md5 = NULL;
42
43 rc = cifs_alloc_hash("md5", &md5);
44 if (rc)
45 goto symlink_hash_err;
46
47 rc = crypto_shash_init(md5);
48 if (rc) {
49 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
50 goto symlink_hash_err;
51 }
52 rc = crypto_shash_update(md5, link_str, link_len);
53 if (rc) {
54 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
55 goto symlink_hash_err;
56 }
57 rc = crypto_shash_final(md5, md5_hash);
58 if (rc)
59 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
60
61symlink_hash_err:
62 cifs_free_hash(&md5);
63 return rc;
64}
65
66static int
67parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
68 char **_link_str)
69{
70 int rc;
71 unsigned int link_len;
72 const char *md5_str1;
73 const char *link_str;
74 u8 md5_hash[16];
75 char md5_str2[34];
76
77 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
78 return -EINVAL;
79
80 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
81 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
82
83 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
84 if (rc != 1)
85 return -EINVAL;
86
87 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
88 return -EINVAL;
89
90 rc = symlink_hash(link_len, link_str, md5_hash);
91 if (rc) {
92 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
93 return rc;
94 }
95
96 scnprintf(md5_str2, sizeof(md5_str2),
97 CIFS_MF_SYMLINK_MD5_FORMAT,
98 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
99
100 if (strncmp(md5_str1, md5_str2, 17) != 0)
101 return -EINVAL;
102
103 if (_link_str) {
104 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
105 if (!*_link_str)
106 return -ENOMEM;
107 }
108
109 *_link_len = link_len;
110 return 0;
111}
112
113static int
114format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
115{
116 int rc;
117 unsigned int link_len;
118 unsigned int ofs;
119 u8 md5_hash[16];
120
121 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
122 return -EINVAL;
123
124 link_len = strlen(link_str);
125
126 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
127 return -ENAMETOOLONG;
128
129 rc = symlink_hash(link_len, link_str, md5_hash);
130 if (rc) {
131 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
132 return rc;
133 }
134
135 scnprintf(buf, buf_len,
136 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
137 link_len,
138 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
139
140 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
141 memcpy(buf + ofs, link_str, link_len);
142
143 ofs += link_len;
144 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
145 buf[ofs] = '\n';
146 ofs++;
147 }
148
149 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
150 buf[ofs] = ' ';
151 ofs++;
152 }
153
154 return 0;
155}
156
157bool
158couldbe_mf_symlink(const struct cifs_fattr *fattr)
159{
160 if (!S_ISREG(fattr->cf_mode))
161 /* it's not a symlink */
162 return false;
163
164 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
165 /* it's not a symlink */
166 return false;
167
168 return true;
169}
170
171static int
172create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
173 struct cifs_sb_info *cifs_sb, const char *fromName,
174 const char *toName)
175{
176 int rc;
177 u8 *buf;
178 unsigned int bytes_written = 0;
179
180 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
181 if (!buf)
182 return -ENOMEM;
183
184 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
185 if (rc)
186 goto out;
187
188 if (tcon->ses->server->ops->create_mf_symlink)
189 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
190 cifs_sb, fromName, buf, &bytes_written);
191 else
192 rc = -EOPNOTSUPP;
193
194 if (rc)
195 goto out;
196
197 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
198 rc = -EIO;
199out:
200 kfree(buf);
201 return rc;
202}
203
204int
205check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
206 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
207 const unsigned char *path)
208{
209 int rc;
210 u8 *buf = NULL;
211 unsigned int link_len = 0;
212 unsigned int bytes_read = 0;
213 char *symlink = NULL;
214
215 if (!couldbe_mf_symlink(fattr))
216 /* it's not a symlink */
217 return 0;
218
219 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
220 if (!buf)
221 return -ENOMEM;
222
223 if (tcon->ses->server->ops->query_mf_symlink)
224 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
225 cifs_sb, path, buf, &bytes_read);
226 else
227 rc = -ENOSYS;
228
229 if (rc)
230 goto out;
231
232 if (bytes_read == 0) /* not a symlink */
233 goto out;
234
235 rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
236 if (rc == -EINVAL) {
237 /* it's not a symlink */
238 rc = 0;
239 goto out;
240 }
241
242 if (rc != 0)
243 goto out;
244
245 /* it is a symlink */
246 fattr->cf_eof = link_len;
247 fattr->cf_mode &= ~S_IFMT;
248 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
249 fattr->cf_dtype = DT_LNK;
250 fattr->cf_symlink_target = symlink;
251out:
252 kfree(buf);
253 return rc;
254}
255
256#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
257/*
258 * SMB 1.0 Protocol specific functions
259 */
260
261int
262cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
263 struct cifs_sb_info *cifs_sb, const unsigned char *path,
264 char *pbuf, unsigned int *pbytes_read)
265{
266 int rc;
267 int oplock = 0;
268 struct cifs_fid fid;
269 struct cifs_open_parms oparms;
270 struct cifs_io_parms io_parms = {0};
271 int buf_type = CIFS_NO_BUFFER;
272 FILE_ALL_INFO file_info;
273
274 oparms = (struct cifs_open_parms) {
275 .tcon = tcon,
276 .cifs_sb = cifs_sb,
277 .desired_access = GENERIC_READ,
278 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
279 .disposition = FILE_OPEN,
280 .path = path,
281 .fid = &fid,
282 };
283
284 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
285 if (rc)
286 return rc;
287
288 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
289 rc = -ENOENT;
290 /* it's not a symlink */
291 goto out;
292 }
293
294 io_parms.netfid = fid.netfid;
295 io_parms.pid = current->tgid;
296 io_parms.tcon = tcon;
297 io_parms.offset = 0;
298 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
299
300 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
301out:
302 CIFSSMBClose(xid, tcon, fid.netfid);
303 return rc;
304}
305
306int
307cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
308 struct cifs_sb_info *cifs_sb, const unsigned char *path,
309 char *pbuf, unsigned int *pbytes_written)
310{
311 int rc;
312 int oplock = 0;
313 struct cifs_fid fid;
314 struct cifs_open_parms oparms;
315 struct cifs_io_parms io_parms = {0};
316
317 oparms = (struct cifs_open_parms) {
318 .tcon = tcon,
319 .cifs_sb = cifs_sb,
320 .desired_access = GENERIC_WRITE,
321 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
322 .disposition = FILE_CREATE,
323 .path = path,
324 .fid = &fid,
325 };
326
327 rc = CIFS_open(xid, &oparms, &oplock, NULL);
328 if (rc)
329 return rc;
330
331 io_parms.netfid = fid.netfid;
332 io_parms.pid = current->tgid;
333 io_parms.tcon = tcon;
334 io_parms.offset = 0;
335 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
336
337 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
338 CIFSSMBClose(xid, tcon, fid.netfid);
339 return rc;
340}
341#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
342
343/*
344 * SMB 2.1/SMB3 Protocol specific functions
345 */
346int
347smb3_query_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_read)
350{
351 int rc;
352 struct cifs_fid fid;
353 struct cifs_open_parms oparms;
354 struct cifs_io_parms io_parms = {0};
355 int buf_type = CIFS_NO_BUFFER;
356 __le16 *utf16_path;
357 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
358 struct smb2_file_all_info *pfile_info = NULL;
359
360 oparms = (struct cifs_open_parms) {
361 .tcon = tcon,
362 .cifs_sb = cifs_sb,
363 .path = path,
364 .desired_access = GENERIC_READ,
365 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
366 .disposition = FILE_OPEN,
367 .fid = &fid,
368 };
369
370 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
371 if (utf16_path == NULL)
372 return -ENOMEM;
373
374 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
375 GFP_KERNEL);
376
377 if (pfile_info == NULL) {
378 kfree(utf16_path);
379 return -ENOMEM;
380 }
381
382 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
383 NULL, NULL);
384 if (rc)
385 goto qmf_out_open_fail;
386
387 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
388 /* it's not a symlink */
389 rc = -ENOENT; /* Is there a better rc to return? */
390 goto qmf_out;
391 }
392
393 io_parms.netfid = fid.netfid;
394 io_parms.pid = current->tgid;
395 io_parms.tcon = tcon;
396 io_parms.offset = 0;
397 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
398 io_parms.persistent_fid = fid.persistent_fid;
399 io_parms.volatile_fid = fid.volatile_fid;
400 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
401qmf_out:
402 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
403qmf_out_open_fail:
404 kfree(utf16_path);
405 kfree(pfile_info);
406 return rc;
407}
408
409int
410smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
411 struct cifs_sb_info *cifs_sb, const unsigned char *path,
412 char *pbuf, unsigned int *pbytes_written)
413{
414 int rc;
415 struct cifs_fid fid;
416 struct cifs_open_parms oparms;
417 struct cifs_io_parms io_parms = {0};
418 __le16 *utf16_path;
419 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
420 struct kvec iov[2];
421
422 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
423
424 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
425 if (!utf16_path)
426 return -ENOMEM;
427
428 oparms = (struct cifs_open_parms) {
429 .tcon = tcon,
430 .cifs_sb = cifs_sb,
431 .path = path,
432 .desired_access = GENERIC_WRITE,
433 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
434 .disposition = FILE_CREATE,
435 .fid = &fid,
436 .mode = 0644,
437 };
438
439 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
440 NULL, NULL);
441 if (rc) {
442 kfree(utf16_path);
443 return rc;
444 }
445
446 io_parms.netfid = fid.netfid;
447 io_parms.pid = current->tgid;
448 io_parms.tcon = tcon;
449 io_parms.offset = 0;
450 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
451 io_parms.persistent_fid = fid.persistent_fid;
452 io_parms.volatile_fid = fid.volatile_fid;
453
454 /* iov[0] is reserved for smb header */
455 iov[1].iov_base = pbuf;
456 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
457
458 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
459
460 /* Make sure we wrote all of the symlink data */
461 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
462 rc = -EIO;
463
464 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
465
466 kfree(utf16_path);
467 return rc;
468}
469
470/*
471 * M-F Symlink Functions - End
472 */
473
474int
475cifs_hardlink(struct dentry *old_file, struct inode *inode,
476 struct dentry *direntry)
477{
478 int rc = -EACCES;
479 unsigned int xid;
480 const char *from_name, *to_name;
481 void *page1, *page2;
482 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
483 struct tcon_link *tlink;
484 struct cifs_tcon *tcon;
485 struct TCP_Server_Info *server;
486 struct cifsInodeInfo *cifsInode;
487
488 if (unlikely(cifs_forced_shutdown(cifs_sb)))
489 return -EIO;
490
491 tlink = cifs_sb_tlink(cifs_sb);
492 if (IS_ERR(tlink))
493 return PTR_ERR(tlink);
494 tcon = tlink_tcon(tlink);
495
496 xid = get_xid();
497 page1 = alloc_dentry_path();
498 page2 = alloc_dentry_path();
499
500 from_name = build_path_from_dentry(old_file, page1);
501 if (IS_ERR(from_name)) {
502 rc = PTR_ERR(from_name);
503 goto cifs_hl_exit;
504 }
505 to_name = build_path_from_dentry(direntry, page2);
506 if (IS_ERR(to_name)) {
507 rc = PTR_ERR(to_name);
508 goto cifs_hl_exit;
509 }
510
511#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
512 if (tcon->unix_ext)
513 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
514 cifs_sb->local_nls,
515 cifs_remap(cifs_sb));
516 else {
517#else
518 {
519#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
520 server = tcon->ses->server;
521 if (!server->ops->create_hardlink) {
522 rc = -ENOSYS;
523 goto cifs_hl_exit;
524 }
525 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
526 cifs_sb);
527 if ((rc == -EIO) || (rc == -EINVAL))
528 rc = -EOPNOTSUPP;
529 }
530
531 d_drop(direntry); /* force new lookup from server of target */
532
533 /*
534 * if source file is cached (oplocked) revalidate will not go to server
535 * until the file is closed or oplock broken so update nlinks locally
536 */
537 if (d_really_is_positive(old_file)) {
538 cifsInode = CIFS_I(d_inode(old_file));
539 if (rc == 0) {
540 spin_lock(&d_inode(old_file)->i_lock);
541 inc_nlink(d_inode(old_file));
542 spin_unlock(&d_inode(old_file)->i_lock);
543
544 /*
545 * parent dir timestamps will update from srv within a
546 * second, would it really be worth it to set the parent
547 * dir cifs inode time to zero to force revalidate
548 * (faster) for it too?
549 */
550 }
551 /*
552 * if not oplocked will force revalidate to get info on source
553 * file from srv. Note Samba server prior to 4.2 has bug -
554 * not updating src file ctime on hardlinks but Windows servers
555 * handle it properly
556 */
557 cifsInode->time = 0;
558
559 /*
560 * Will update parent dir timestamps from srv within a second.
561 * Would it really be worth it to set the parent dir (cifs
562 * inode) time field to zero to force revalidate on parent
563 * directory faster ie
564 *
565 * CIFS_I(inode)->time = 0;
566 */
567 }
568
569cifs_hl_exit:
570 free_dentry_path(page1);
571 free_dentry_path(page2);
572 free_xid(xid);
573 cifs_put_tlink(tlink);
574 return rc;
575}
576
577int
578cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
579 struct dentry *direntry, const char *symname)
580{
581 int rc = -EOPNOTSUPP;
582 unsigned int xid;
583 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
584 struct tcon_link *tlink;
585 struct cifs_tcon *pTcon;
586 const char *full_path;
587 void *page;
588 struct inode *newinode = NULL;
589
590 if (unlikely(cifs_forced_shutdown(cifs_sb)))
591 return -EIO;
592
593 page = alloc_dentry_path();
594 if (!page)
595 return -ENOMEM;
596
597 xid = get_xid();
598
599 tlink = cifs_sb_tlink(cifs_sb);
600 if (IS_ERR(tlink)) {
601 rc = PTR_ERR(tlink);
602 goto symlink_exit;
603 }
604 pTcon = tlink_tcon(tlink);
605
606 full_path = build_path_from_dentry(direntry, page);
607 if (IS_ERR(full_path)) {
608 rc = PTR_ERR(full_path);
609 goto symlink_exit;
610 }
611
612 cifs_dbg(FYI, "Full path: %s\n", full_path);
613 cifs_dbg(FYI, "symname is %s\n", symname);
614
615 /* BB what if DFS and this volume is on different share? BB */
616 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
617 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
618#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
619 else if (pTcon->unix_ext)
620 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
621 cifs_sb->local_nls,
622 cifs_remap(cifs_sb));
623#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
624 /* else
625 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
626 cifs_sb_target->local_nls); */
627
628 if (rc == 0) {
629 if (pTcon->posix_extensions)
630 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
631 else if (pTcon->unix_ext)
632 rc = cifs_get_inode_info_unix(&newinode, full_path,
633 inode->i_sb, xid);
634 else
635 rc = cifs_get_inode_info(&newinode, full_path, NULL,
636 inode->i_sb, xid, NULL);
637
638 if (rc != 0) {
639 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
640 rc);
641 } else {
642 d_instantiate(direntry, newinode);
643 }
644 }
645symlink_exit:
646 free_dentry_path(page);
647 cifs_put_tlink(tlink);
648 free_xid(xid);
649 return rc;
650}