1// SPDX-License-Identifier: LGPL-2.1
2/*
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 */
11#include <linux/fs.h>
12#include <linux/namei.h>
13#include <linux/pagemap.h>
14#include <linux/slab.h>
15#include <linux/stat.h>
16#include "cifspdu.h"
17#include "cifsglob.h"
18#include "cifsproto.h"
19#include "cifs_unicode.h"
20#include "cifs_debug.h"
21#include "cifs_fs_sb.h"
22#include "cifsfs.h"
23#include "smb2proto.h"
24#include "fs_context.h"
25#include "cached_dir.h"
26#include "reparse.h"
27
28/*
29 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
30 * characters alloc more to account for such multibyte target UTF-8
31 * characters.
32 */
33#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
34
35#ifdef CONFIG_CIFS_DEBUG2
36static void dump_cifs_file_struct(struct file *file, char *label)
37{
38 struct cifsFileInfo *cf;
39
40 if (file) {
41 cf = file->private_data;
42 if (cf == NULL) {
43 cifs_dbg(FYI, "empty cifs private file data\n");
44 return;
45 }
46 if (cf->invalidHandle)
47 cifs_dbg(FYI, "Invalid handle\n");
48 if (cf->srch_inf.endOfSearch)
49 cifs_dbg(FYI, "end of search\n");
50 if (cf->srch_inf.emptyDir)
51 cifs_dbg(FYI, "empty dir\n");
52 }
53}
54#else
55static inline void dump_cifs_file_struct(struct file *file, char *label)
56{
57}
58#endif /* DEBUG2 */
59
60/*
61 * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
62 *
63 * Find the dentry that matches "name". If there isn't one, create one. If it's
64 * a negative dentry or the uniqueid or filetype(mode) changed,
65 * then drop it and recreate it.
66 */
67static void
68cifs_prime_dcache(struct dentry *parent, struct qstr *name,
69 struct cifs_fattr *fattr)
70{
71 struct dentry *dentry, *alias;
72 struct inode *inode;
73 struct super_block *sb = parent->d_sb;
74 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
75 bool posix = cifs_sb_master_tcon(cifs_sb)->posix_extensions;
76 bool reparse_need_reval = false;
77 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
78 int rc;
79
80 cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
81
82 dentry = try_lookup_noperm(name, parent);
83 if (!dentry) {
84 /*
85 * If we know that the inode will need to be revalidated
86 * immediately, then don't create a new dentry for it.
87 * We'll end up doing an on the wire call either way and
88 * this spares us an invalidation.
89 */
90retry:
91 if (posix) {
92 switch (fattr->cf_mode & S_IFMT) {
93 case S_IFLNK:
94 case S_IFBLK:
95 case S_IFCHR:
96 reparse_need_reval = true;
97 break;
98 default:
99 break;
100 }
101 } else if (fattr->cf_cifsattrs & ATTR_REPARSE_POINT) {
102 reparse_need_reval = true;
103 }
104
105 if (reparse_need_reval ||
106 (fattr->cf_flags & CIFS_FATTR_NEED_REVAL))
107 return;
108
109 dentry = d_alloc_parallel(parent, name, &wq);
110 }
111 if (IS_ERR(ptr: dentry))
112 return;
113 if (!d_in_lookup(dentry)) {
114 inode = d_inode(dentry);
115 if (inode) {
116 if (d_mountpoint(dentry)) {
117 dput(dentry);
118 return;
119 }
120 /*
121 * If we're generating inode numbers, then we don't
122 * want to clobber the existing one with the one that
123 * the readdir code created.
124 */
125 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
126 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
127
128 /*
129 * Update inode in place if both i_ino and i_mode didn't
130 * change.
131 */
132 if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
133 /*
134 * Query dir responses don't provide enough
135 * information about reparse points other than
136 * their reparse tags. Save an invalidation by
137 * not clobbering some existing attributes when
138 * reparse tag and ctime haven't changed.
139 */
140 rc = 0;
141 if (fattr->cf_cifsattrs & ATTR_REPARSE_POINT) {
142 if (likely(reparse_inode_match(inode, fattr))) {
143 fattr->cf_mode = inode->i_mode;
144 fattr->cf_rdev = inode->i_rdev;
145 fattr->cf_uid = inode->i_uid;
146 fattr->cf_gid = inode->i_gid;
147 fattr->cf_eof = CIFS_I(inode)->netfs.remote_i_size;
148 fattr->cf_symlink_target = NULL;
149 } else {
150 CIFS_I(inode)->time = 0;
151 rc = -ESTALE;
152 }
153 }
154 if (!rc && !cifs_fattr_to_inode(inode, fattr, from_readdir: true)) {
155 dput(dentry);
156 return;
157 }
158 }
159 }
160 d_invalidate(dentry);
161 dput(dentry);
162 goto retry;
163 } else {
164 inode = cifs_iget(sb, fattr);
165 if (!inode)
166 inode = ERR_PTR(error: -ENOMEM);
167 alias = d_splice_alias(inode, dentry);
168 d_lookup_done(dentry);
169 if (alias && !IS_ERR(ptr: alias))
170 dput(alias);
171 }
172 dput(dentry);
173}
174
175static void
176cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
177{
178 struct cifs_open_info_data data = {
179 .reparse = { .tag = fattr->cf_cifstag, },
180 };
181
182 fattr->cf_uid = cifs_sb->ctx->linux_uid;
183 fattr->cf_gid = cifs_sb->ctx->linux_gid;
184
185 /*
186 * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
187 * are preferred by the Linux client in some cases since, unlike
188 * the NFS reparse tag (or EAs), they don't require an extra query
189 * to determine which type of special file they represent.
190 * TODO: go through all documented reparse tags to see if we can
191 * reasonably map some of them to directories vs. files vs. symlinks
192 */
193 if ((fattr->cf_cifsattrs & ATTR_REPARSE_POINT) &&
194 cifs_reparse_point_to_fattr(cifs_sb, fattr, data: &data))
195 goto out_reparse;
196
197 if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
198 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
199 fattr->cf_dtype = DT_DIR;
200 } else {
201 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
202 fattr->cf_dtype = DT_REG;
203 }
204
205out_reparse:
206 /* non-unix readdir doesn't provide nlink */
207 fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
208
209 if (fattr->cf_cifsattrs & ATTR_READONLY)
210 fattr->cf_mode &= ~S_IWUGO;
211
212 /*
213 * We of course don't get ACL info in FIND_FIRST/NEXT results, so
214 * mark it for revalidation so that "ls -l" will look right. It might
215 * be super-slow, but if we don't do this then the ownership of files
216 * may look wrong since the inodes may not have timed out by the time
217 * "ls" does a stat() call on them.
218 */
219 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
220 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
221 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
222
223 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
224 fattr->cf_cifsattrs & ATTR_SYSTEM) {
225 if (fattr->cf_eof == 0) {
226 fattr->cf_mode &= ~S_IFMT;
227 fattr->cf_mode |= S_IFIFO;
228 fattr->cf_dtype = DT_FIFO;
229 } else {
230 /*
231 * trying to get the type and mode via SFU can be slow,
232 * so just call those regular files for now, and mark
233 * for reval
234 */
235 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
236 }
237 }
238}
239
240/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
241static void
242cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
243 struct cifs_sb_info *cifs_sb)
244{
245 struct smb2_posix_info_parsed parsed;
246
247 posix_info_parse(beg: info, NULL, out: &parsed);
248
249 memset(fattr, 0, sizeof(*fattr));
250 fattr->cf_uniqueid = le64_to_cpu(info->Inode);
251 fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
252 fattr->cf_eof = le64_to_cpu(info->EndOfFile);
253
254 fattr->cf_atime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: info->LastAccessTime);
255 fattr->cf_mtime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: info->LastWriteTime);
256 fattr->cf_ctime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: info->CreationTime);
257
258 fattr->cf_nlink = le32_to_cpu(info->HardLinks);
259 fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
260
261 if (fattr->cf_cifsattrs & ATTR_REPARSE_POINT)
262 fattr->cf_cifstag = le32_to_cpu(info->ReparseTag);
263
264 /* The Mode field in the response can now include the file type as well */
265 fattr->cf_mode = wire_mode_to_posix(le32_to_cpu(info->Mode),
266 is_dir: fattr->cf_cifsattrs & ATTR_DIRECTORY);
267 fattr->cf_dtype = S_DT(fattr->cf_mode);
268
269 switch (fattr->cf_mode & S_IFMT) {
270 case S_IFLNK:
271 case S_IFBLK:
272 case S_IFCHR:
273 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
274 break;
275 default:
276 break;
277 }
278
279 cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
280 le32_to_cpu(info->DeviceId),
281 le32_to_cpu(info->ReparseTag),
282 le32_to_cpu(info->Mode));
283
284 sid_to_id(cifs_sb, psid: &parsed.owner, fattr, sidtype: SIDOWNER);
285 sid_to_id(cifs_sb, psid: &parsed.group, fattr, sidtype: SIDGROUP);
286}
287
288static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
289{
290 const FILE_DIRECTORY_INFO *fi = info;
291
292 memset(fattr, 0, sizeof(*fattr));
293 fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
294 fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
295 fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
296 fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
297 fattr->cf_atime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: fi->LastAccessTime);
298 fattr->cf_ctime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: fi->ChangeTime);
299 fattr->cf_mtime = cifs_NTtimeToUnix(utc_nanoseconds_since_1601: fi->LastWriteTime);
300}
301
302void
303cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
304 struct cifs_sb_info *cifs_sb)
305{
306 __dir_info_to_fattr(fattr, info);
307 cifs_fill_common_info(fattr, cifs_sb);
308}
309
310static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
311 const void *info,
312 struct cifs_sb_info *cifs_sb)
313{
314 const FILE_FULL_DIRECTORY_INFO *di = info;
315
316 __dir_info_to_fattr(fattr, info);
317
318 /* See MS-FSCC 2.4.14, 2.4.19 */
319 if (fattr->cf_cifsattrs & ATTR_REPARSE_POINT)
320 fattr->cf_cifstag = le32_to_cpu(di->EaSize);
321 cifs_fill_common_info(fattr, cifs_sb);
322}
323
324static void
325cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
326 struct cifs_sb_info *cifs_sb)
327{
328 int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
329
330 memset(fattr, 0, sizeof(*fattr));
331 fattr->cf_atime = cnvrtDosUnixTm(le_date: info->LastAccessDate,
332 le_time: info->LastAccessTime, offset);
333 fattr->cf_ctime = cnvrtDosUnixTm(le_date: info->LastWriteDate,
334 le_time: info->LastWriteTime, offset);
335 fattr->cf_mtime = cnvrtDosUnixTm(le_date: info->LastWriteDate,
336 le_time: info->LastWriteTime, offset);
337
338 fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
339 fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
340 fattr->cf_eof = le32_to_cpu(info->DataSize);
341
342 cifs_fill_common_info(fattr, cifs_sb);
343}
344
345static int
346_initiate_cifs_search(const unsigned int xid, struct file *file,
347 const char *full_path)
348{
349 __u16 search_flags;
350 int rc = 0;
351 struct cifsFileInfo *cifsFile;
352 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
353 struct tcon_link *tlink = NULL;
354 struct cifs_tcon *tcon;
355 struct TCP_Server_Info *server;
356
357 if (file->private_data == NULL) {
358 tlink = cifs_sb_tlink(cifs_sb);
359 if (IS_ERR(ptr: tlink))
360 return PTR_ERR(ptr: tlink);
361
362 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
363 if (cifsFile == NULL) {
364 rc = -ENOMEM;
365 goto error_exit;
366 }
367 spin_lock_init(&cifsFile->file_info_lock);
368 file->private_data = cifsFile;
369 cifsFile->tlink = cifs_get_tlink(tlink);
370 tcon = tlink_tcon(tlink);
371 } else {
372 cifsFile = file->private_data;
373 tcon = tlink_tcon(tlink: cifsFile->tlink);
374 }
375
376 server = tcon->ses->server;
377
378 if (!server->ops->query_dir_first) {
379 rc = -ENOSYS;
380 goto error_exit;
381 }
382
383 cifsFile->invalidHandle = true;
384 cifsFile->srch_inf.endOfSearch = false;
385
386 cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
387
388ffirst_retry:
389 /* test for Unix extensions */
390 /* but now check for them on the share/mount not on the SMB session */
391 /* if (cap_unix(tcon->ses) { */
392 if (tcon->unix_ext)
393 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
394 else if (tcon->posix_extensions)
395 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
396 else if ((tcon->ses->capabilities &
397 tcon->ses->server->vals->cap_nt_find) == 0) {
398 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
399 } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
400 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
401 } else /* not srvinos - BB fixme add check for backlevel? */ {
402 cifsFile->srch_inf.info_level = SMB_FIND_FILE_FULL_DIRECTORY_INFO;
403 }
404
405 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
406 if (backup_cred(cifs_sb))
407 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
408
409 rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
410 &cifsFile->fid, search_flags,
411 &cifsFile->srch_inf);
412
413 if (rc == 0) {
414 cifsFile->invalidHandle = false;
415 } else if ((rc == -EOPNOTSUPP) &&
416 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
417 cifs_autodisable_serverino(cifs_sb);
418 goto ffirst_retry;
419 }
420error_exit:
421 cifs_put_tlink(tlink);
422 return rc;
423}
424
425static int
426initiate_cifs_search(const unsigned int xid, struct file *file,
427 const char *full_path)
428{
429 int rc, retry_count = 0;
430
431 do {
432 rc = _initiate_cifs_search(xid, file, full_path);
433 /*
434 * If we don't have enough credits to start reading the
435 * directory just try again after short wait.
436 */
437 if (rc != -EDEADLK)
438 break;
439
440 usleep_range(min: 512, max: 2048);
441 } while (retry_count++ < 5);
442
443 return rc;
444}
445
446/* return length of unicode string in bytes */
447static int cifs_unicode_bytelen(const char *str)
448{
449 int len;
450 const __le16 *ustr = (const __le16 *)str;
451
452 for (len = 0; len <= PATH_MAX; len++) {
453 if (ustr[len] == 0)
454 return len << 1;
455 }
456 cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
457 return len << 1;
458}
459
460static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
461{
462 char *new_entry;
463 FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
464
465 if (level == SMB_FIND_FILE_INFO_STANDARD) {
466 FIND_FILE_STANDARD_INFO *pfData;
467 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
468
469 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 +
470 pfData->FileNameLength;
471 } else {
472 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
473
474 if (old_entry + next_offset < old_entry) {
475 cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
476 return NULL;
477 }
478 new_entry = old_entry + next_offset;
479 }
480 cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
481 /* validate that new_entry is not past end of SMB */
482 if (new_entry >= end_of_smb) {
483 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
484 new_entry, end_of_smb, old_entry);
485 return NULL;
486 } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
487 (new_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 > end_of_smb))
488 || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
489 (new_entry + sizeof(FILE_DIRECTORY_INFO) + 1 > end_of_smb))) {
490 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
491 new_entry, end_of_smb);
492 return NULL;
493 } else
494 return new_entry;
495
496}
497
498struct cifs_dirent {
499 const char *name;
500 size_t namelen;
501 u32 resume_key;
502 u64 ino;
503};
504
505static void cifs_fill_dirent_posix(struct cifs_dirent *de,
506 const struct smb2_posix_info *info)
507{
508 struct smb2_posix_info_parsed parsed;
509
510 /* payload should have already been checked at this point */
511 if (posix_info_parse(beg: info, NULL, out: &parsed) < 0) {
512 cifs_dbg(VFS, "Invalid POSIX info payload\n");
513 return;
514 }
515
516 de->name = parsed.name;
517 de->namelen = parsed.name_len;
518 de->resume_key = info->Ignored;
519 de->ino = le64_to_cpu(info->Inode);
520}
521
522static void cifs_fill_dirent_unix(struct cifs_dirent *de,
523 const FILE_UNIX_INFO *info, bool is_unicode)
524{
525 de->name = &info->FileName[0];
526 if (is_unicode)
527 de->namelen = cifs_unicode_bytelen(str: de->name);
528 else
529 de->namelen = strnlen(p: de->name, PATH_MAX);
530 de->resume_key = info->ResumeKey;
531 de->ino = le64_to_cpu(info->basic.UniqueId);
532}
533
534static void cifs_fill_dirent_dir(struct cifs_dirent *de,
535 const FILE_DIRECTORY_INFO *info)
536{
537 de->name = &info->FileName[0];
538 de->namelen = le32_to_cpu(info->FileNameLength);
539 de->resume_key = info->FileIndex;
540}
541
542static void cifs_fill_dirent_full(struct cifs_dirent *de,
543 const FILE_FULL_DIRECTORY_INFO *info)
544{
545 de->name = &info->FileName[0];
546 de->namelen = le32_to_cpu(info->FileNameLength);
547 de->resume_key = info->FileIndex;
548}
549
550static void cifs_fill_dirent_search(struct cifs_dirent *de,
551 const FILE_ID_FULL_DIR_INFO *info)
552{
553 de->name = &info->FileName[0];
554 de->namelen = le32_to_cpu(info->FileNameLength);
555 de->resume_key = info->FileIndex;
556 de->ino = le64_to_cpu(info->UniqueId);
557}
558
559static void cifs_fill_dirent_both(struct cifs_dirent *de,
560 const FILE_BOTH_DIRECTORY_INFO *info)
561{
562 de->name = &info->FileName[0];
563 de->namelen = le32_to_cpu(info->FileNameLength);
564 de->resume_key = info->FileIndex;
565}
566
567static void cifs_fill_dirent_std(struct cifs_dirent *de,
568 const FIND_FILE_STANDARD_INFO *info)
569{
570 de->name = &info->FileName[0];
571 /* one byte length, no endianness conversion */
572 de->namelen = info->FileNameLength;
573 de->resume_key = info->ResumeKey;
574}
575
576static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
577 u16 level, bool is_unicode)
578{
579 memset(de, 0, sizeof(*de));
580
581 switch (level) {
582 case SMB_FIND_FILE_POSIX_INFO:
583 cifs_fill_dirent_posix(de, info);
584 break;
585 case SMB_FIND_FILE_UNIX:
586 cifs_fill_dirent_unix(de, info, is_unicode);
587 break;
588 case SMB_FIND_FILE_DIRECTORY_INFO:
589 cifs_fill_dirent_dir(de, info);
590 break;
591 case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
592 cifs_fill_dirent_full(de, info);
593 break;
594 case SMB_FIND_FILE_ID_FULL_DIR_INFO:
595 cifs_fill_dirent_search(de, info);
596 break;
597 case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
598 cifs_fill_dirent_both(de, info);
599 break;
600 case SMB_FIND_FILE_INFO_STANDARD:
601 cifs_fill_dirent_std(de, info);
602 break;
603 default:
604 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
605 return -EINVAL;
606 }
607
608 return 0;
609}
610
611#define UNICODE_DOT cpu_to_le16(0x2e)
612
613/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
614static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
615{
616 int rc = 0;
617
618 if (!de->name)
619 return 0;
620
621 if (is_unicode) {
622 __le16 *ufilename = (__le16 *)de->name;
623 if (de->namelen == 2) {
624 /* check for . */
625 if (ufilename[0] == UNICODE_DOT)
626 rc = 1;
627 } else if (de->namelen == 4) {
628 /* check for .. */
629 if (ufilename[0] == UNICODE_DOT &&
630 ufilename[1] == UNICODE_DOT)
631 rc = 2;
632 }
633 } else /* ASCII */ {
634 if (de->namelen == 1) {
635 if (de->name[0] == '.')
636 rc = 1;
637 } else if (de->namelen == 2) {
638 if (de->name[0] == '.' && de->name[1] == '.')
639 rc = 2;
640 }
641 }
642
643 return rc;
644}
645
646/* Check if directory that we are searching has changed so we can decide
647 whether we can use the cached search results from the previous search */
648static int is_dir_changed(struct file *file)
649{
650 struct inode *inode = file_inode(f: file);
651 struct cifsInodeInfo *cifs_inode_info = CIFS_I(inode);
652
653 if (cifs_inode_info->time == 0)
654 return 1; /* directory was changed, e.g. unlink or new file */
655 else
656 return 0;
657
658}
659
660static int cifs_save_resume_key(const char *current_entry,
661 struct cifsFileInfo *file_info)
662{
663 struct cifs_dirent de;
664 int rc;
665
666 rc = cifs_fill_dirent(de: &de, info: current_entry, level: file_info->srch_inf.info_level,
667 is_unicode: file_info->srch_inf.unicode);
668 if (!rc) {
669 file_info->srch_inf.presume_name = de.name;
670 file_info->srch_inf.resume_name_len = de.namelen;
671 file_info->srch_inf.resume_key = de.resume_key;
672 }
673 return rc;
674}
675
676/*
677 * Find the corresponding entry in the search. Note that the SMB server returns
678 * search entries for . and .. which complicates logic here if we choose to
679 * parse for them and we do not assume that they are located in the findfirst
680 * return buffer. We start counting in the buffer with entry 2 and increment for
681 * every entry (do not increment for . or .. entry).
682 */
683static int
684find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
685 struct file *file, const char *full_path,
686 char **current_entry, int *num_to_ret)
687{
688 __u16 search_flags;
689 int rc = 0;
690 int pos_in_buf = 0;
691 loff_t first_entry_in_buffer;
692 loff_t index_to_find = pos;
693 struct cifsFileInfo *cfile = file->private_data;
694 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
695 struct TCP_Server_Info *server = tcon->ses->server;
696 /* check if index in the buffer */
697
698 if (!server->ops->query_dir_first || !server->ops->query_dir_next)
699 return -ENOSYS;
700
701 if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
702 return -ENOENT;
703
704 *current_entry = NULL;
705 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
706 cfile->srch_inf.entries_in_buffer;
707
708 /*
709 * If first entry in buf is zero then is first buffer
710 * in search response data which means it is likely . and ..
711 * will be in this buffer, although some servers do not return
712 * . and .. for the root of a drive and for those we need
713 * to start two entries earlier.
714 */
715
716 dump_cifs_file_struct(file, label: "In fce ");
717 if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
718 is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
719 /* close and restart search */
720 cifs_dbg(FYI, "search backing up - close and restart search\n");
721 spin_lock(lock: &cfile->file_info_lock);
722 if (server->ops->dir_needs_close(cfile)) {
723 cfile->invalidHandle = true;
724 spin_unlock(lock: &cfile->file_info_lock);
725 if (server->ops->close_dir)
726 server->ops->close_dir(xid, tcon, &cfile->fid);
727 } else
728 spin_unlock(lock: &cfile->file_info_lock);
729 if (cfile->srch_inf.ntwrk_buf_start) {
730 cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
731 if (cfile->srch_inf.smallBuf)
732 cifs_small_buf_release(cfile->srch_inf.
733 ntwrk_buf_start);
734 else
735 cifs_buf_release(cfile->srch_inf.
736 ntwrk_buf_start);
737 /* Reset all pointers to the network buffer to prevent stale references */
738 cfile->srch_inf.ntwrk_buf_start = NULL;
739 cfile->srch_inf.srch_entries_start = NULL;
740 cfile->srch_inf.last_entry = NULL;
741 }
742 rc = initiate_cifs_search(xid, file, full_path);
743 if (rc) {
744 cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
745 rc);
746 return rc;
747 }
748 /* FindFirst/Next set last_entry to NULL on malformed reply */
749 if (cfile->srch_inf.last_entry)
750 cifs_save_resume_key(current_entry: cfile->srch_inf.last_entry, file_info: cfile);
751 }
752
753 search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
754 if (backup_cred(cifs_sb))
755 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
756
757 while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
758 (rc == 0) && !cfile->srch_inf.endOfSearch) {
759 cifs_dbg(FYI, "calling findnext2\n");
760 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
761 search_flags,
762 &cfile->srch_inf);
763 if (rc)
764 return -ENOENT;
765 /* FindFirst/Next set last_entry to NULL on malformed reply */
766 if (cfile->srch_inf.last_entry)
767 cifs_save_resume_key(current_entry: cfile->srch_inf.last_entry, file_info: cfile);
768 }
769 if (index_to_find < cfile->srch_inf.index_of_last_entry) {
770 /* we found the buffer that contains the entry */
771 /* scan and find it */
772 int i;
773 char *cur_ent;
774 char *end_of_smb;
775
776 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
777 cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
778 return smb_EIO(trace: smb_eio_trace_null_pointers);
779 }
780
781 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
782 server->ops->calc_smb_size(
783 cfile->srch_inf.ntwrk_buf_start);
784
785 cur_ent = cfile->srch_inf.srch_entries_start;
786 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
787 - cfile->srch_inf.entries_in_buffer;
788 pos_in_buf = index_to_find - first_entry_in_buffer;
789 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
790
791 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
792 /* go entry by entry figuring out which is first */
793 cur_ent = nxt_dir_entry(old_entry: cur_ent, end_of_smb,
794 level: cfile->srch_inf.info_level);
795 }
796 if ((cur_ent == NULL) && (i < pos_in_buf)) {
797 /* BB fixme - check if we should flag this error */
798 cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
799 pos_in_buf, index_to_find, rc);
800 }
801 rc = 0;
802 *current_entry = cur_ent;
803 } else {
804 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
805 return 0;
806 }
807
808 if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
809 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
810 *num_to_ret = 0;
811 } else
812 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
813
814 return rc;
815}
816
817static bool emit_cached_dirents(struct cached_dirents *cde,
818 struct dir_context *ctx)
819{
820 struct cached_dirent *dirent;
821 bool rc;
822
823 list_for_each_entry(dirent, &cde->entries, entry) {
824 /*
825 * Skip all early entries prior to the current lseek()
826 * position.
827 */
828 if (ctx->pos > dirent->pos)
829 continue;
830 /*
831 * We recorded the current ->pos value for the dirent
832 * when we stored it in the cache.
833 * However, this sequence of ->pos values may have holes
834 * in it, for example dot-dirs returned from the server
835 * are suppressed.
836 * Handle this by forcing ctx->pos to be the same as the
837 * ->pos of the current dirent we emit from the cache.
838 * This means that when we emit these entries from the cache
839 * we now emit them with the same ->pos value as in the
840 * initial scan.
841 */
842 ctx->pos = dirent->pos;
843 rc = dir_emit(ctx, name: dirent->name, namelen: dirent->namelen,
844 ino: dirent->fattr.cf_uniqueid,
845 type: dirent->fattr.cf_dtype);
846 if (!rc)
847 return rc;
848 ctx->pos++;
849 }
850 return true;
851}
852
853static void update_cached_dirents_count(struct cached_dirents *cde,
854 struct file *file)
855{
856 if (cde->file != file)
857 return;
858 if (cde->is_valid || cde->is_failed)
859 return;
860
861 cde->pos++;
862}
863
864static void finished_cached_dirents_count(struct cached_dirents *cde,
865 struct dir_context *ctx, struct file *file)
866{
867 if (cde->file != file)
868 return;
869 if (cde->is_valid || cde->is_failed)
870 return;
871 if (ctx->pos != cde->pos)
872 return;
873
874 cde->is_valid = 1;
875}
876
877static bool add_cached_dirent(struct cached_dirents *cde,
878 struct dir_context *ctx, const char *name,
879 int namelen, struct cifs_fattr *fattr,
880 struct file *file)
881{
882 struct cached_dirent *de;
883
884 if (cde->file != file)
885 return false;
886 if (cde->is_valid || cde->is_failed)
887 return false;
888 if (ctx->pos != cde->pos) {
889 cde->is_failed = 1;
890 return false;
891 }
892 de = kzalloc(sizeof(*de), GFP_ATOMIC);
893 if (de == NULL) {
894 cde->is_failed = 1;
895 return false;
896 }
897 de->namelen = namelen;
898 de->name = kstrndup(s: name, len: namelen, GFP_ATOMIC);
899 if (de->name == NULL) {
900 kfree(objp: de);
901 cde->is_failed = 1;
902 return false;
903 }
904 de->pos = ctx->pos;
905
906 memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr));
907
908 list_add_tail(new: &de->entry, head: &cde->entries);
909 /* update accounting */
910 cde->entries_count++;
911 cde->bytes_used += sizeof(*de) + (size_t)namelen + 1;
912 return true;
913}
914
915static bool cifs_dir_emit(struct dir_context *ctx,
916 const char *name, int namelen,
917 struct cifs_fattr *fattr,
918 struct cached_fid *cfid,
919 struct file *file)
920{
921 size_t delta_bytes = 0;
922 bool rc, added = false;
923 ino_t ino = cifs_uniqueid_to_ino_t(fileid: fattr->cf_uniqueid);
924
925 rc = dir_emit(ctx, name, namelen, ino, type: fattr->cf_dtype);
926 if (!rc)
927 return rc;
928
929 if (cfid) {
930 /* Cost of this entry */
931 delta_bytes = sizeof(struct cached_dirent) + (size_t)namelen + 1;
932
933 mutex_lock(&cfid->dirents.de_mutex);
934 added = add_cached_dirent(cde: &cfid->dirents, ctx, name, namelen,
935 fattr, file);
936 mutex_unlock(lock: &cfid->dirents.de_mutex);
937
938 if (added) {
939 /* per-tcon then global for consistency with free path */
940 atomic64_add(i: (long long)delta_bytes, v: &cfid->cfids->total_dirents_bytes);
941 atomic_long_inc(v: &cfid->cfids->total_dirents_entries);
942 atomic64_add(i: (long long)delta_bytes, v: &cifs_dircache_bytes_used);
943 }
944 }
945
946 return rc;
947}
948
949static int cifs_filldir(char *find_entry, struct file *file,
950 struct dir_context *ctx,
951 char *scratch_buf, unsigned int max_len,
952 struct cached_fid *cfid)
953{
954 struct cifsFileInfo *file_info = file->private_data;
955 struct super_block *sb = file_inode(f: file)->i_sb;
956 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
957 struct cifs_dirent de = { NULL, };
958 struct cifs_fattr fattr;
959 struct qstr name;
960 int rc = 0;
961
962 rc = cifs_fill_dirent(de: &de, info: find_entry, level: file_info->srch_inf.info_level,
963 is_unicode: file_info->srch_inf.unicode);
964 if (rc)
965 return rc;
966
967 if (de.namelen > max_len) {
968 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
969 de.namelen);
970 return -EINVAL;
971 }
972
973 /* skip . and .. since we added them first */
974 if (cifs_entry_is_dot(de: &de, is_unicode: file_info->srch_inf.unicode))
975 return 0;
976
977 if (file_info->srch_inf.unicode) {
978 struct nls_table *nlt = cifs_sb->local_nls;
979 int map_type;
980
981 map_type = cifs_remap(cifs_sb);
982 name.name = scratch_buf;
983 name.len =
984 cifs_from_utf16(to: (char *)name.name, from: (__le16 *)de.name,
985 UNICODE_NAME_MAX,
986 min_t(size_t, de.namelen,
987 (size_t)max_len), cp: nlt, map_type);
988 name.len -= nls_nullsize(codepage: nlt);
989 } else {
990 name.name = de.name;
991 name.len = de.namelen;
992 }
993
994 switch (file_info->srch_inf.info_level) {
995 case SMB_FIND_FILE_POSIX_INFO:
996 cifs_posix_to_fattr(fattr: &fattr,
997 info: (struct smb2_posix_info *)find_entry,
998 cifs_sb);
999 break;
1000 case SMB_FIND_FILE_UNIX:
1001 cifs_unix_basic_to_fattr(fattr: &fattr,
1002 info: &((FILE_UNIX_INFO *)find_entry)->basic,
1003 cifs_sb);
1004 if (S_ISLNK(fattr.cf_mode))
1005 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
1006 break;
1007 case SMB_FIND_FILE_INFO_STANDARD:
1008 cifs_std_info_to_fattr(fattr: &fattr,
1009 info: (FIND_FILE_STANDARD_INFO *)find_entry,
1010 cifs_sb);
1011 break;
1012 case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
1013 case SMB_FIND_FILE_ID_FULL_DIR_INFO:
1014 cifs_fulldir_info_to_fattr(fattr: &fattr, info: find_entry, cifs_sb);
1015 break;
1016 default:
1017 cifs_dir_info_to_fattr(fattr: &fattr,
1018 info: (FILE_DIRECTORY_INFO *)find_entry,
1019 cifs_sb);
1020 break;
1021 }
1022
1023 if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
1024 fattr.cf_uniqueid = de.ino;
1025 } else {
1026 fattr.cf_uniqueid = iunique(sb, ROOT_I);
1027 cifs_autodisable_serverino(cifs_sb);
1028 }
1029
1030 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
1031 couldbe_mf_symlink(fattr: &fattr))
1032 /*
1033 * trying to get the type and mode can be slow,
1034 * so just call those regular files for now, and mark
1035 * for reval
1036 */
1037 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
1038
1039 cifs_prime_dcache(parent: file_dentry(file), name: &name, fattr: &fattr);
1040
1041 return !cifs_dir_emit(ctx, name: name.name, namelen: name.len,
1042 fattr: &fattr, cfid, file);
1043}
1044
1045
1046int cifs_readdir(struct file *file, struct dir_context *ctx)
1047{
1048 int rc = 0;
1049 unsigned int xid;
1050 int i;
1051 struct tcon_link *tlink = NULL;
1052 struct cifs_tcon *tcon;
1053 struct cifsFileInfo *cifsFile;
1054 char *current_entry;
1055 int num_to_fill = 0;
1056 char *tmp_buf = NULL;
1057 char *end_of_smb;
1058 unsigned int max_len;
1059 const char *full_path;
1060 void *page = alloc_dentry_path();
1061 struct cached_fid *cfid = NULL;
1062 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
1063
1064 xid = get_xid();
1065
1066 full_path = build_path_from_dentry(file_dentry(file), page);
1067 if (IS_ERR(ptr: full_path)) {
1068 rc = PTR_ERR(ptr: full_path);
1069 goto rddir2_exit;
1070 }
1071
1072 if (file->private_data == NULL) {
1073 tlink = cifs_sb_tlink(cifs_sb);
1074 if (IS_ERR(ptr: tlink))
1075 goto cache_not_found;
1076 tcon = tlink_tcon(tlink);
1077 } else {
1078 cifsFile = file->private_data;
1079 tcon = tlink_tcon(tlink: cifsFile->tlink);
1080 }
1081
1082 rc = open_cached_dir(xid, tcon, path: full_path, cifs_sb, lookup_only: false, cfid: &cfid);
1083 cifs_put_tlink(tlink);
1084 if (rc)
1085 goto cache_not_found;
1086
1087 mutex_lock(&cfid->dirents.de_mutex);
1088 /*
1089 * If this was reading from the start of the directory
1090 * we need to initialize scanning and storing the
1091 * directory content.
1092 */
1093 if (ctx->pos == 0 && cfid->dirents.file == NULL) {
1094 cfid->dirents.file = file;
1095 cfid->dirents.pos = 2;
1096 }
1097 /*
1098 * If we already have the entire directory cached then
1099 * we can just serve the cache.
1100 */
1101 if (cfid->dirents.is_valid) {
1102 if (!dir_emit_dots(file, ctx)) {
1103 mutex_unlock(lock: &cfid->dirents.de_mutex);
1104 goto rddir2_exit;
1105 }
1106 emit_cached_dirents(cde: &cfid->dirents, ctx);
1107 mutex_unlock(lock: &cfid->dirents.de_mutex);
1108 goto rddir2_exit;
1109 }
1110 mutex_unlock(lock: &cfid->dirents.de_mutex);
1111
1112 /* Drop the cache while calling initiate_cifs_search and
1113 * find_cifs_entry in case there will be reconnects during
1114 * query_directory.
1115 */
1116 close_cached_dir(cfid);
1117 cfid = NULL;
1118
1119 cache_not_found:
1120 /*
1121 * Ensure FindFirst doesn't fail before doing filldir() for '.' and
1122 * '..'. Otherwise we won't be able to notify VFS in case of failure.
1123 */
1124 if (file->private_data == NULL) {
1125 rc = initiate_cifs_search(xid, file, full_path);
1126 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
1127 if (rc)
1128 goto rddir2_exit;
1129 }
1130
1131 if (!dir_emit_dots(file, ctx))
1132 goto rddir2_exit;
1133
1134 /* 1) If search is active,
1135 is in current search buffer?
1136 if it before then restart search
1137 if after then keep searching till find it */
1138 cifsFile = file->private_data;
1139 if (cifsFile->srch_inf.endOfSearch) {
1140 if (cifsFile->srch_inf.emptyDir) {
1141 cifs_dbg(FYI, "End of search, empty dir\n");
1142 rc = 0;
1143 goto rddir2_exit;
1144 }
1145 } /* else {
1146 cifsFile->invalidHandle = true;
1147 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
1148 } */
1149
1150 tcon = tlink_tcon(tlink: cifsFile->tlink);
1151 rc = find_cifs_entry(xid, tcon, pos: ctx->pos, file, full_path,
1152 current_entry: &current_entry, num_to_ret: &num_to_fill);
1153 open_cached_dir(xid, tcon, path: full_path, cifs_sb, lookup_only: false, cfid: &cfid);
1154 if (rc) {
1155 cifs_dbg(FYI, "fce error %d\n", rc);
1156 goto rddir2_exit;
1157 } else if (current_entry != NULL) {
1158 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
1159 } else {
1160 if (cfid) {
1161 mutex_lock(&cfid->dirents.de_mutex);
1162 finished_cached_dirents_count(cde: &cfid->dirents, ctx, file);
1163 mutex_unlock(lock: &cfid->dirents.de_mutex);
1164 }
1165 cifs_dbg(FYI, "Could not find entry\n");
1166 goto rddir2_exit;
1167 }
1168 cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
1169 num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
1170 max_len = tcon->ses->server->ops->calc_smb_size(
1171 cifsFile->srch_inf.ntwrk_buf_start);
1172 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1173
1174 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1175 if (tmp_buf == NULL) {
1176 rc = -ENOMEM;
1177 goto rddir2_exit;
1178 }
1179
1180 for (i = 0; i < num_to_fill; i++) {
1181 if (current_entry == NULL) {
1182 /* evaluate whether this case is an error */
1183 cifs_dbg(VFS, "past SMB end, num to fill %d i %d\n",
1184 num_to_fill, i);
1185 break;
1186 }
1187 /*
1188 * if buggy server returns . and .. late do we want to
1189 * check for that here?
1190 */
1191 *tmp_buf = 0;
1192 rc = cifs_filldir(find_entry: current_entry, file, ctx,
1193 scratch_buf: tmp_buf, max_len, cfid);
1194 if (rc) {
1195 if (rc > 0)
1196 rc = 0;
1197 break;
1198 }
1199
1200 ctx->pos++;
1201 if (cfid) {
1202 mutex_lock(&cfid->dirents.de_mutex);
1203 update_cached_dirents_count(cde: &cfid->dirents, file);
1204 mutex_unlock(lock: &cfid->dirents.de_mutex);
1205 }
1206
1207 if (ctx->pos ==
1208 cifsFile->srch_inf.index_of_last_entry) {
1209 cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1210 ctx->pos, tmp_buf);
1211 cifs_save_resume_key(current_entry, file_info: cifsFile);
1212 break;
1213 }
1214 current_entry =
1215 nxt_dir_entry(old_entry: current_entry, end_of_smb,
1216 level: cifsFile->srch_inf.info_level);
1217 }
1218 kfree(objp: tmp_buf);
1219
1220rddir2_exit:
1221 if (cfid)
1222 close_cached_dir(cfid);
1223 free_dentry_path(page);
1224 free_xid(xid);
1225 return rc;
1226}
1227

source code of linux/fs/smb/client/readdir.c