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1/*
2 * fs/cifs/readdir.c
3 *
4 * Directory search handling
5 *
6 * Copyright (C) International Business Machines Corp., 2004, 2008
7 * Copyright (C) Red Hat, Inc., 2011
8 * Author(s): Steve French (sfrench@us.ibm.com)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24#include <linux/fs.h>
25#include <linux/pagemap.h>
26#include <linux/slab.h>
27#include <linux/stat.h>
28#include "cifspdu.h"
29#include "cifsglob.h"
30#include "cifsproto.h"
31#include "cifs_unicode.h"
32#include "cifs_debug.h"
33#include "cifs_fs_sb.h"
34#include "cifsfs.h"
35#include "smb2proto.h"
36
37/*
38 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
39 * characters alloc more to account for such multibyte target UTF-8
40 * characters.
41 */
42#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
43
44#ifdef CONFIG_CIFS_DEBUG2
45static void dump_cifs_file_struct(struct file *file, char *label)
46{
47 struct cifsFileInfo *cf;
48
49 if (file) {
50 cf = file->private_data;
51 if (cf == NULL) {
52 cifs_dbg(FYI, "empty cifs private file data\n");
53 return;
54 }
55 if (cf->invalidHandle)
56 cifs_dbg(FYI, "Invalid handle\n");
57 if (cf->srch_inf.endOfSearch)
58 cifs_dbg(FYI, "end of search\n");
59 if (cf->srch_inf.emptyDir)
60 cifs_dbg(FYI, "empty dir\n");
61 }
62}
63#else
64static inline void dump_cifs_file_struct(struct file *file, char *label)
65{
66}
67#endif /* DEBUG2 */
68
69/*
70 * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
71 *
72 * Find the dentry that matches "name". If there isn't one, create one. If it's
73 * a negative dentry or the uniqueid or filetype(mode) changed,
74 * then drop it and recreate it.
75 */
76static void
77cifs_prime_dcache(struct dentry *parent, struct qstr *name,
78 struct cifs_fattr *fattr)
79{
80 struct dentry *dentry, *alias;
81 struct inode *inode;
82 struct super_block *sb = parent->d_sb;
83 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
84 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
85
86 cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
87
88 dentry = d_hash_and_lookup(parent, name);
89 if (!dentry) {
90 /*
91 * If we know that the inode will need to be revalidated
92 * immediately, then don't create a new dentry for it.
93 * We'll end up doing an on the wire call either way and
94 * this spares us an invalidation.
95 */
96 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
97 return;
98retry:
99 dentry = d_alloc_parallel(parent, name, &wq);
100 }
101 if (IS_ERR(dentry))
102 return;
103 if (!d_in_lookup(dentry)) {
104 inode = d_inode(dentry);
105 if (inode) {
106 if (d_mountpoint(dentry)) {
107 dput(dentry);
108 return;
109 }
110 /*
111 * If we're generating inode numbers, then we don't
112 * want to clobber the existing one with the one that
113 * the readdir code created.
114 */
115 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
116 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
117
118 /* update inode in place
119 * if both i_ino and i_mode didn't change */
120 if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
121 (inode->i_mode & S_IFMT) ==
122 (fattr->cf_mode & S_IFMT)) {
123 cifs_fattr_to_inode(inode, fattr);
124 dput(dentry);
125 return;
126 }
127 }
128 d_invalidate(dentry);
129 dput(dentry);
130 goto retry;
131 } else {
132 inode = cifs_iget(sb, fattr);
133 if (!inode)
134 inode = ERR_PTR(-ENOMEM);
135 alias = d_splice_alias(inode, dentry);
136 d_lookup_done(dentry);
137 if (alias && !IS_ERR(alias))
138 dput(alias);
139 }
140 dput(dentry);
141}
142
143static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
144{
145 if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
146 return false;
147 /*
148 * The DFS tags should be only intepreted by server side as per
149 * MS-FSCC 2.1.2.1, but let's include them anyway.
150 *
151 * Besides, if cf_cifstag is unset (0), then we still need it to be
152 * revalidated to know exactly what reparse point it is.
153 */
154 switch (fattr->cf_cifstag) {
155 case IO_REPARSE_TAG_DFS:
156 case IO_REPARSE_TAG_DFSR:
157 case IO_REPARSE_TAG_SYMLINK:
158 case IO_REPARSE_TAG_NFS:
159 case 0:
160 return true;
161 }
162 return false;
163}
164
165static void
166cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
167{
168 fattr->cf_uid = cifs_sb->mnt_uid;
169 fattr->cf_gid = cifs_sb->mnt_gid;
170
171 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
172 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
173 fattr->cf_dtype = DT_DIR;
174 } else {
175 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
176 fattr->cf_dtype = DT_REG;
177 }
178
179 /*
180 * We need to revalidate it further to make a decision about whether it
181 * is a symbolic link, DFS referral or a reparse point with a direct
182 * access like junctions, deduplicated files, NFS symlinks.
183 */
184 if (reparse_file_needs_reval(fattr))
185 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
186
187 /* non-unix readdir doesn't provide nlink */
188 fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
189
190 if (fattr->cf_cifsattrs & ATTR_READONLY)
191 fattr->cf_mode &= ~S_IWUGO;
192
193 /*
194 * We of course don't get ACL info in FIND_FIRST/NEXT results, so
195 * mark it for revalidation so that "ls -l" will look right. It might
196 * be super-slow, but if we don't do this then the ownership of files
197 * may look wrong since the inodes may not have timed out by the time
198 * "ls" does a stat() call on them.
199 */
200 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
201 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
202 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
203
204 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
205 fattr->cf_cifsattrs & ATTR_SYSTEM) {
206 if (fattr->cf_eof == 0) {
207 fattr->cf_mode &= ~S_IFMT;
208 fattr->cf_mode |= S_IFIFO;
209 fattr->cf_dtype = DT_FIFO;
210 } else {
211 /*
212 * trying to get the type and mode via SFU can be slow,
213 * so just call those regular files for now, and mark
214 * for reval
215 */
216 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
217 }
218 }
219}
220
221/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
222static void
223cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
224 struct cifs_sb_info *cifs_sb)
225{
226 struct smb2_posix_info_parsed parsed;
227
228 posix_info_parse(info, NULL, &parsed);
229
230 memset(fattr, 0, sizeof(*fattr));
231 fattr->cf_uniqueid = le64_to_cpu(info->Inode);
232 fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
233 fattr->cf_eof = le64_to_cpu(info->EndOfFile);
234
235 fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
236 fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
237 fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
238
239 fattr->cf_nlink = le32_to_cpu(info->HardLinks);
240 fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
241
242 /*
243 * Since we set the inode type below we need to mask off
244 * to avoid strange results if bits set above.
245 * XXX: why not make server&client use the type bits?
246 */
247 fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
248
249 cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
250 le32_to_cpu(info->DeviceId),
251 le32_to_cpu(info->ReparseTag),
252 le32_to_cpu(info->Mode));
253
254 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
255 fattr->cf_mode |= S_IFDIR;
256 fattr->cf_dtype = DT_DIR;
257 } else {
258 /*
259 * mark anything that is not a dir as regular
260 * file. special files should have the REPARSE
261 * attribute and will be marked as needing revaluation
262 */
263 fattr->cf_mode |= S_IFREG;
264 fattr->cf_dtype = DT_REG;
265 }
266
267 if (reparse_file_needs_reval(fattr))
268 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
269
270 /* TODO map SIDs */
271 fattr->cf_uid = cifs_sb->mnt_uid;
272 fattr->cf_gid = cifs_sb->mnt_gid;
273}
274
275static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
276{
277 const FILE_DIRECTORY_INFO *fi = info;
278
279 memset(fattr, 0, sizeof(*fattr));
280 fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
281 fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
282 fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
283 fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
284 fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
285 fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
286 fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
287}
288
289void
290cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
291 struct cifs_sb_info *cifs_sb)
292{
293 __dir_info_to_fattr(fattr, info);
294 cifs_fill_common_info(fattr, cifs_sb);
295}
296
297static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
298 SEARCH_ID_FULL_DIR_INFO *info,
299 struct cifs_sb_info *cifs_sb)
300{
301 __dir_info_to_fattr(fattr, info);
302
303 /* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */
304 if (fattr->cf_cifsattrs & ATTR_REPARSE)
305 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
306 cifs_fill_common_info(fattr, cifs_sb);
307}
308
309static void
310cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
311 struct cifs_sb_info *cifs_sb)
312{
313 int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
314
315 memset(fattr, 0, sizeof(*fattr));
316 fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
317 info->LastAccessTime, offset);
318 fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
319 info->LastWriteTime, offset);
320 fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
321 info->LastWriteTime, offset);
322
323 fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
324 fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
325 fattr->cf_eof = le32_to_cpu(info->DataSize);
326
327 cifs_fill_common_info(fattr, cifs_sb);
328}
329
330/* BB eventually need to add the following helper function to
331 resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
332 we try to do FindFirst on (NTFS) directory symlinks */
333/*
334int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
335 unsigned int xid)
336{
337 __u16 fid;
338 int len;
339 int oplock = 0;
340 int rc;
341 struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
342 char *tmpbuffer;
343
344 rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
345 OPEN_REPARSE_POINT, &fid, &oplock, NULL,
346 cifs_sb->local_nls,
347 cifs_remap(cifs_sb);
348 if (!rc) {
349 tmpbuffer = kmalloc(maxpath);
350 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
351 tmpbuffer,
352 maxpath -1,
353 fid,
354 cifs_sb->local_nls);
355 if (CIFSSMBClose(xid, ptcon, fid)) {
356 cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
357 }
358 }
359}
360 */
361
362static int
363initiate_cifs_search(const unsigned int xid, struct file *file)
364{
365 __u16 search_flags;
366 int rc = 0;
367 char *full_path = NULL;
368 struct cifsFileInfo *cifsFile;
369 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
370 struct tcon_link *tlink = NULL;
371 struct cifs_tcon *tcon;
372 struct TCP_Server_Info *server;
373
374 if (file->private_data == NULL) {
375 tlink = cifs_sb_tlink(cifs_sb);
376 if (IS_ERR(tlink))
377 return PTR_ERR(tlink);
378
379 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
380 if (cifsFile == NULL) {
381 rc = -ENOMEM;
382 goto error_exit;
383 }
384 spin_lock_init(&cifsFile->file_info_lock);
385 file->private_data = cifsFile;
386 cifsFile->tlink = cifs_get_tlink(tlink);
387 tcon = tlink_tcon(tlink);
388 } else {
389 cifsFile = file->private_data;
390 tcon = tlink_tcon(cifsFile->tlink);
391 }
392
393 server = tcon->ses->server;
394
395 if (!server->ops->query_dir_first) {
396 rc = -ENOSYS;
397 goto error_exit;
398 }
399
400 cifsFile->invalidHandle = true;
401 cifsFile->srch_inf.endOfSearch = false;
402
403 full_path = build_path_from_dentry(file_dentry(file));
404 if (full_path == NULL) {
405 rc = -ENOMEM;
406 goto error_exit;
407 }
408
409 cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
410
411ffirst_retry:
412 /* test for Unix extensions */
413 /* but now check for them on the share/mount not on the SMB session */
414 /* if (cap_unix(tcon->ses) { */
415 if (tcon->unix_ext)
416 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
417 else if (tcon->posix_extensions)
418 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
419 else if ((tcon->ses->capabilities &
420 tcon->ses->server->vals->cap_nt_find) == 0) {
421 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
422 } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
423 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
424 } else /* not srvinos - BB fixme add check for backlevel? */ {
425 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
426 }
427
428 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
429 if (backup_cred(cifs_sb))
430 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
431
432 rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
433 &cifsFile->fid, search_flags,
434 &cifsFile->srch_inf);
435
436 if (rc == 0)
437 cifsFile->invalidHandle = false;
438 /* BB add following call to handle readdir on new NTFS symlink errors
439 else if STATUS_STOPPED_ON_SYMLINK
440 call get_symlink_reparse_path and retry with new path */
441 else if ((rc == -EOPNOTSUPP) &&
442 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
443 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
444 goto ffirst_retry;
445 }
446error_exit:
447 kfree(full_path);
448 cifs_put_tlink(tlink);
449 return rc;
450}
451
452/* return length of unicode string in bytes */
453static int cifs_unicode_bytelen(const char *str)
454{
455 int len;
456 const __le16 *ustr = (const __le16 *)str;
457
458 for (len = 0; len <= PATH_MAX; len++) {
459 if (ustr[len] == 0)
460 return len << 1;
461 }
462 cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
463 return len << 1;
464}
465
466static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
467{
468 char *new_entry;
469 FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
470
471 if (level == SMB_FIND_FILE_INFO_STANDARD) {
472 FIND_FILE_STANDARD_INFO *pfData;
473 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
474
475 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
476 pfData->FileNameLength;
477 } else {
478 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
479
480 if (old_entry + next_offset < old_entry) {
481 cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
482 return NULL;
483 }
484 new_entry = old_entry + next_offset;
485 }
486 cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
487 /* validate that new_entry is not past end of SMB */
488 if (new_entry >= end_of_smb) {
489 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
490 new_entry, end_of_smb, old_entry);
491 return NULL;
492 } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
493 (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
494 || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
495 (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb))) {
496 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
497 new_entry, end_of_smb);
498 return NULL;
499 } else
500 return new_entry;
501
502}
503
504struct cifs_dirent {
505 const char *name;
506 size_t namelen;
507 u32 resume_key;
508 u64 ino;
509};
510
511static void cifs_fill_dirent_posix(struct cifs_dirent *de,
512 const struct smb2_posix_info *info)
513{
514 struct smb2_posix_info_parsed parsed;
515
516 /* payload should have already been checked at this point */
517 if (posix_info_parse(info, NULL, &parsed) < 0) {
518 cifs_dbg(VFS, "Invalid POSIX info payload\n");
519 return;
520 }
521
522 de->name = parsed.name;
523 de->namelen = parsed.name_len;
524 de->resume_key = info->Ignored;
525 de->ino = le64_to_cpu(info->Inode);
526}
527
528static void cifs_fill_dirent_unix(struct cifs_dirent *de,
529 const FILE_UNIX_INFO *info, bool is_unicode)
530{
531 de->name = &info->FileName[0];
532 if (is_unicode)
533 de->namelen = cifs_unicode_bytelen(de->name);
534 else
535 de->namelen = strnlen(de->name, PATH_MAX);
536 de->resume_key = info->ResumeKey;
537 de->ino = le64_to_cpu(info->basic.UniqueId);
538}
539
540static void cifs_fill_dirent_dir(struct cifs_dirent *de,
541 const FILE_DIRECTORY_INFO *info)
542{
543 de->name = &info->FileName[0];
544 de->namelen = le32_to_cpu(info->FileNameLength);
545 de->resume_key = info->FileIndex;
546}
547
548static void cifs_fill_dirent_full(struct cifs_dirent *de,
549 const FILE_FULL_DIRECTORY_INFO *info)
550{
551 de->name = &info->FileName[0];
552 de->namelen = le32_to_cpu(info->FileNameLength);
553 de->resume_key = info->FileIndex;
554}
555
556static void cifs_fill_dirent_search(struct cifs_dirent *de,
557 const SEARCH_ID_FULL_DIR_INFO *info)
558{
559 de->name = &info->FileName[0];
560 de->namelen = le32_to_cpu(info->FileNameLength);
561 de->resume_key = info->FileIndex;
562 de->ino = le64_to_cpu(info->UniqueId);
563}
564
565static void cifs_fill_dirent_both(struct cifs_dirent *de,
566 const FILE_BOTH_DIRECTORY_INFO *info)
567{
568 de->name = &info->FileName[0];
569 de->namelen = le32_to_cpu(info->FileNameLength);
570 de->resume_key = info->FileIndex;
571}
572
573static void cifs_fill_dirent_std(struct cifs_dirent *de,
574 const FIND_FILE_STANDARD_INFO *info)
575{
576 de->name = &info->FileName[0];
577 /* one byte length, no endianess conversion */
578 de->namelen = info->FileNameLength;
579 de->resume_key = info->ResumeKey;
580}
581
582static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
583 u16 level, bool is_unicode)
584{
585 memset(de, 0, sizeof(*de));
586
587 switch (level) {
588 case SMB_FIND_FILE_POSIX_INFO:
589 cifs_fill_dirent_posix(de, info);
590 break;
591 case SMB_FIND_FILE_UNIX:
592 cifs_fill_dirent_unix(de, info, is_unicode);
593 break;
594 case SMB_FIND_FILE_DIRECTORY_INFO:
595 cifs_fill_dirent_dir(de, info);
596 break;
597 case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
598 cifs_fill_dirent_full(de, info);
599 break;
600 case SMB_FIND_FILE_ID_FULL_DIR_INFO:
601 cifs_fill_dirent_search(de, info);
602 break;
603 case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
604 cifs_fill_dirent_both(de, info);
605 break;
606 case SMB_FIND_FILE_INFO_STANDARD:
607 cifs_fill_dirent_std(de, info);
608 break;
609 default:
610 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
611 return -EINVAL;
612 }
613
614 return 0;
615}
616
617#define UNICODE_DOT cpu_to_le16(0x2e)
618
619/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
620static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
621{
622 int rc = 0;
623
624 if (!de->name)
625 return 0;
626
627 if (is_unicode) {
628 __le16 *ufilename = (__le16 *)de->name;
629 if (de->namelen == 2) {
630 /* check for . */
631 if (ufilename[0] == UNICODE_DOT)
632 rc = 1;
633 } else if (de->namelen == 4) {
634 /* check for .. */
635 if (ufilename[0] == UNICODE_DOT &&
636 ufilename[1] == UNICODE_DOT)
637 rc = 2;
638 }
639 } else /* ASCII */ {
640 if (de->namelen == 1) {
641 if (de->name[0] == '.')
642 rc = 1;
643 } else if (de->namelen == 2) {
644 if (de->name[0] == '.' && de->name[1] == '.')
645 rc = 2;
646 }
647 }
648
649 return rc;
650}
651
652/* Check if directory that we are searching has changed so we can decide
653 whether we can use the cached search results from the previous search */
654static int is_dir_changed(struct file *file)
655{
656 struct inode *inode = file_inode(file);
657 struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
658
659 if (cifsInfo->time == 0)
660 return 1; /* directory was changed, perhaps due to unlink */
661 else
662 return 0;
663
664}
665
666static int cifs_save_resume_key(const char *current_entry,
667 struct cifsFileInfo *file_info)
668{
669 struct cifs_dirent de;
670 int rc;
671
672 rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
673 file_info->srch_inf.unicode);
674 if (!rc) {
675 file_info->srch_inf.presume_name = de.name;
676 file_info->srch_inf.resume_name_len = de.namelen;
677 file_info->srch_inf.resume_key = de.resume_key;
678 }
679 return rc;
680}
681
682/*
683 * Find the corresponding entry in the search. Note that the SMB server returns
684 * search entries for . and .. which complicates logic here if we choose to
685 * parse for them and we do not assume that they are located in the findfirst
686 * return buffer. We start counting in the buffer with entry 2 and increment for
687 * every entry (do not increment for . or .. entry).
688 */
689static int
690find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
691 struct file *file, char **current_entry, int *num_to_ret)
692{
693 __u16 search_flags;
694 int rc = 0;
695 int pos_in_buf = 0;
696 loff_t first_entry_in_buffer;
697 loff_t index_to_find = pos;
698 struct cifsFileInfo *cfile = file->private_data;
699 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
700 struct TCP_Server_Info *server = tcon->ses->server;
701 /* check if index in the buffer */
702
703 if (!server->ops->query_dir_first || !server->ops->query_dir_next)
704 return -ENOSYS;
705
706 if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
707 return -ENOENT;
708
709 *current_entry = NULL;
710 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
711 cfile->srch_inf.entries_in_buffer;
712
713 /*
714 * If first entry in buf is zero then is first buffer
715 * in search response data which means it is likely . and ..
716 * will be in this buffer, although some servers do not return
717 * . and .. for the root of a drive and for those we need
718 * to start two entries earlier.
719 */
720
721 dump_cifs_file_struct(file, "In fce ");
722 if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
723 is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
724 /* close and restart search */
725 cifs_dbg(FYI, "search backing up - close and restart search\n");
726 spin_lock(&cfile->file_info_lock);
727 if (server->ops->dir_needs_close(cfile)) {
728 cfile->invalidHandle = true;
729 spin_unlock(&cfile->file_info_lock);
730 if (server->ops->close_dir)
731 server->ops->close_dir(xid, tcon, &cfile->fid);
732 } else
733 spin_unlock(&cfile->file_info_lock);
734 if (cfile->srch_inf.ntwrk_buf_start) {
735 cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
736 if (cfile->srch_inf.smallBuf)
737 cifs_small_buf_release(cfile->srch_inf.
738 ntwrk_buf_start);
739 else
740 cifs_buf_release(cfile->srch_inf.
741 ntwrk_buf_start);
742 cfile->srch_inf.ntwrk_buf_start = NULL;
743 }
744 rc = initiate_cifs_search(xid, file);
745 if (rc) {
746 cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
747 rc);
748 return rc;
749 }
750 /* FindFirst/Next set last_entry to NULL on malformed reply */
751 if (cfile->srch_inf.last_entry)
752 cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
753 }
754
755 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
756 if (backup_cred(cifs_sb))
757 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
758
759 while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
760 (rc == 0) && !cfile->srch_inf.endOfSearch) {
761 cifs_dbg(FYI, "calling findnext2\n");
762 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
763 search_flags,
764 &cfile->srch_inf);
765 /* FindFirst/Next set last_entry to NULL on malformed reply */
766 if (cfile->srch_inf.last_entry)
767 cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
768 if (rc)
769 return -ENOENT;
770 }
771 if (index_to_find < cfile->srch_inf.index_of_last_entry) {
772 /* we found the buffer that contains the entry */
773 /* scan and find it */
774 int i;
775 char *cur_ent;
776 char *end_of_smb;
777
778 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
779 cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
780 return -EIO;
781 }
782
783 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
784 server->ops->calc_smb_size(
785 cfile->srch_inf.ntwrk_buf_start,
786 server);
787
788 cur_ent = cfile->srch_inf.srch_entries_start;
789 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
790 - cfile->srch_inf.entries_in_buffer;
791 pos_in_buf = index_to_find - first_entry_in_buffer;
792 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
793
794 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
795 /* go entry by entry figuring out which is first */
796 cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
797 cfile->srch_inf.info_level);
798 }
799 if ((cur_ent == NULL) && (i < pos_in_buf)) {
800 /* BB fixme - check if we should flag this error */
801 cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
802 pos_in_buf, index_to_find, rc);
803 }
804 rc = 0;
805 *current_entry = cur_ent;
806 } else {
807 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
808 return 0;
809 }
810
811 if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
812 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
813 *num_to_ret = 0;
814 } else
815 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
816
817 return rc;
818}
819
820static int cifs_filldir(char *find_entry, struct file *file,
821 struct dir_context *ctx,
822 char *scratch_buf, unsigned int max_len)
823{
824 struct cifsFileInfo *file_info = file->private_data;
825 struct super_block *sb = file_inode(file)->i_sb;
826 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
827 struct cifs_dirent de = { NULL, };
828 struct cifs_fattr fattr;
829 struct qstr name;
830 int rc = 0;
831 ino_t ino;
832
833 rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
834 file_info->srch_inf.unicode);
835 if (rc)
836 return rc;
837
838 if (de.namelen > max_len) {
839 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
840 de.namelen);
841 return -EINVAL;
842 }
843
844 /* skip . and .. since we added them first */
845 if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
846 return 0;
847
848 if (file_info->srch_inf.unicode) {
849 struct nls_table *nlt = cifs_sb->local_nls;
850 int map_type;
851
852 map_type = cifs_remap(cifs_sb);
853 name.name = scratch_buf;
854 name.len =
855 cifs_from_utf16((char *)name.name, (__le16 *)de.name,
856 UNICODE_NAME_MAX,
857 min_t(size_t, de.namelen,
858 (size_t)max_len), nlt, map_type);
859 name.len -= nls_nullsize(nlt);
860 } else {
861 name.name = de.name;
862 name.len = de.namelen;
863 }
864
865 switch (file_info->srch_inf.info_level) {
866 case SMB_FIND_FILE_POSIX_INFO:
867 cifs_posix_to_fattr(&fattr,
868 (struct smb2_posix_info *)find_entry,
869 cifs_sb);
870 break;
871 case SMB_FIND_FILE_UNIX:
872 cifs_unix_basic_to_fattr(&fattr,
873 &((FILE_UNIX_INFO *)find_entry)->basic,
874 cifs_sb);
875 break;
876 case SMB_FIND_FILE_INFO_STANDARD:
877 cifs_std_info_to_fattr(&fattr,
878 (FIND_FILE_STANDARD_INFO *)find_entry,
879 cifs_sb);
880 break;
881 case SMB_FIND_FILE_ID_FULL_DIR_INFO:
882 cifs_fulldir_info_to_fattr(&fattr,
883 (SEARCH_ID_FULL_DIR_INFO *)find_entry,
884 cifs_sb);
885 break;
886 default:
887 cifs_dir_info_to_fattr(&fattr,
888 (FILE_DIRECTORY_INFO *)find_entry,
889 cifs_sb);
890 break;
891 }
892
893 if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
894 fattr.cf_uniqueid = de.ino;
895 } else {
896 fattr.cf_uniqueid = iunique(sb, ROOT_I);
897 cifs_autodisable_serverino(cifs_sb);
898 }
899
900 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
901 couldbe_mf_symlink(&fattr))
902 /*
903 * trying to get the type and mode can be slow,
904 * so just call those regular files for now, and mark
905 * for reval
906 */
907 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
908
909 cifs_prime_dcache(file_dentry(file), &name, &fattr);
910
911 ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
912 return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
913}
914
915
916int cifs_readdir(struct file *file, struct dir_context *ctx)
917{
918 int rc = 0;
919 unsigned int xid;
920 int i;
921 struct cifs_tcon *tcon;
922 struct cifsFileInfo *cifsFile = NULL;
923 char *current_entry;
924 int num_to_fill = 0;
925 char *tmp_buf = NULL;
926 char *end_of_smb;
927 unsigned int max_len;
928
929 xid = get_xid();
930
931 /*
932 * Ensure FindFirst doesn't fail before doing filldir() for '.' and
933 * '..'. Otherwise we won't be able to notify VFS in case of failure.
934 */
935 if (file->private_data == NULL) {
936 rc = initiate_cifs_search(xid, file);
937 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
938 if (rc)
939 goto rddir2_exit;
940 }
941
942 if (!dir_emit_dots(file, ctx))
943 goto rddir2_exit;
944
945 /* 1) If search is active,
946 is in current search buffer?
947 if it before then restart search
948 if after then keep searching till find it */
949
950 cifsFile = file->private_data;
951 if (cifsFile->srch_inf.endOfSearch) {
952 if (cifsFile->srch_inf.emptyDir) {
953 cifs_dbg(FYI, "End of search, empty dir\n");
954 rc = 0;
955 goto rddir2_exit;
956 }
957 } /* else {
958 cifsFile->invalidHandle = true;
959 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
960 } */
961
962 tcon = tlink_tcon(cifsFile->tlink);
963 rc = find_cifs_entry(xid, tcon, ctx->pos, file, ¤t_entry,
964 &num_to_fill);
965 if (rc) {
966 cifs_dbg(FYI, "fce error %d\n", rc);
967 goto rddir2_exit;
968 } else if (current_entry != NULL) {
969 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
970 } else {
971 cifs_dbg(FYI, "Could not find entry\n");
972 goto rddir2_exit;
973 }
974 cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
975 num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
976 max_len = tcon->ses->server->ops->calc_smb_size(
977 cifsFile->srch_inf.ntwrk_buf_start,
978 tcon->ses->server);
979 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
980
981 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
982 if (tmp_buf == NULL) {
983 rc = -ENOMEM;
984 goto rddir2_exit;
985 }
986
987 for (i = 0; i < num_to_fill; i++) {
988 if (current_entry == NULL) {
989 /* evaluate whether this case is an error */
990 cifs_dbg(VFS, "past SMB end, num to fill %d i %d\n",
991 num_to_fill, i);
992 break;
993 }
994 /*
995 * if buggy server returns . and .. late do we want to
996 * check for that here?
997 */
998 *tmp_buf = 0;
999 rc = cifs_filldir(current_entry, file, ctx,
1000 tmp_buf, max_len);
1001 if (rc) {
1002 if (rc > 0)
1003 rc = 0;
1004 break;
1005 }
1006
1007 ctx->pos++;
1008 if (ctx->pos ==
1009 cifsFile->srch_inf.index_of_last_entry) {
1010 cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1011 ctx->pos, tmp_buf);
1012 cifs_save_resume_key(current_entry, cifsFile);
1013 break;
1014 } else
1015 current_entry =
1016 nxt_dir_entry(current_entry, end_of_smb,
1017 cifsFile->srch_inf.info_level);
1018 }
1019 kfree(tmp_buf);
1020
1021rddir2_exit:
1022 free_xid(xid);
1023 return rc;
1024}