summaryrefslogtreecommitdiff
path: root/source3/smbd/mangle_hash.c
blob: 8b1b6bf915d9c47191e4d9be9ac9dcf5164ba461 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
/*
   Unix SMB/CIFS implementation.
   Name mangling
   Copyright (C) Andrew Tridgell 1992-2002
   Copyright (C) Simo Sorce 2001
   Copyright (C) Andrew Bartlett 2002
   Copyright (C) Jeremy Allison 2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/filesys.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "mangle.h"
#include "util_tdb.h"

/* -------------------------------------------------------------------------- **
 * Other stuff...
 *
 * magic_char     - This is the magic char used for mangling.  It's
 *                  global.  There is a call to lp_magicchar() in server.c
 *                  that is used to override the initial value.
 *
 * MANGLE_BASE    - This is the number of characters we use for name mangling.
 *
 * basechars      - The set characters used for name mangling.  This
 *                  is static (scope is this file only).
 *
 * mangle()       - Macro used to select a character from basechars (i.e.,
 *                  mangle(n) will return the nth digit, modulo MANGLE_BASE).
 *
 * chartest       - array 0..255.  The index range is the set of all possible
 *                  values of a byte.  For each byte value, the content is a
 *                  two nibble pair.  See BASECHAR_MASK below.
 *
 * ct_initialized - False until the chartest array has been initialized via
 *                  a call to init_chartest().
 *
 * BASECHAR_MASK  - Masks the upper nibble of a one-byte value.
 *
 * isbasecahr()   - Given a character, check the chartest array to see
 *                  if that character is in the basechars set.  This is
 *                  faster than using strchr_m().
 *
 */

static const char basechars[43]="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
#define MANGLE_BASE       (sizeof(basechars)/sizeof(char)-1)

#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
#define BASECHAR_MASK 0xf0
#define isbasechar(C) ( (chartest[ ((C) & 0xff) ]) & BASECHAR_MASK )

/* -------------------------------------------------------------------- */


/*******************************************************************
 Determine if a character is valid in a 8.3 name.
********************************************************************/

/**
 * Load the valid character map table from <tt>valid.dat</tt> or
 * create from the configured codepage.
 *
 * This function is called whenever the configuration is reloaded.
 * However, the valid character table is not changed if it's loaded
 * from a file, because we can't unmap files.
 **/

static uint8 *valid_table;
static void init_valid_table(void)
{
	if (valid_table) {
		return;
	}

	valid_table = (uint8 *)map_file(data_path(talloc_tos(), "valid.dat"), 0x10000);
	if (!valid_table) {
		smb_panic("Could not load valid.dat file required for mangle method=hash");
		return;
	}
}

static bool isvalid83_w(smb_ucs2_t c)
{
	init_valid_table();
	return valid_table[SVAL(&c,0)] != 0;
}

static NTSTATUS has_valid_83_chars(const smb_ucs2_t *s, bool allow_wildcards)
{
	if (!*s) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (!allow_wildcards && ms_has_wild_w(s)) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	while (*s) {
		if(!isvalid83_w(*s)) {
			return NT_STATUS_UNSUCCESSFUL;
		}
		s++;
	}

	return NT_STATUS_OK;
}

static NTSTATUS has_illegal_chars(const smb_ucs2_t *s, bool allow_wildcards)
{
	if (!allow_wildcards && ms_has_wild_w(s)) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	while (*s) {
		if (*s <= 0x1f) {
			/* Control characters. */
			return NT_STATUS_UNSUCCESSFUL;
		}
		switch(*s) {
			case UCS2_CHAR('\\'):
			case UCS2_CHAR('/'):
			case UCS2_CHAR('|'):
			case UCS2_CHAR(':'):
				return NT_STATUS_UNSUCCESSFUL;
		}
		s++;
	}

	return NT_STATUS_OK;
}

/*******************************************************************
 Duplicate string.
********************************************************************/

static smb_ucs2_t *strdup_w(const smb_ucs2_t *src)
{
	smb_ucs2_t *dest;
	size_t len = strlen_w(src);
	dest = SMB_MALLOC_ARRAY(smb_ucs2_t, len + 1);
	if (!dest) {
		DEBUG(0,("strdup_w: out of memory!\n"));
		return NULL;
	}

	memcpy(dest, src, len * sizeof(smb_ucs2_t));
	dest[len] = 0;
	return dest;
}

/* return False if something fail and
 * return 2 alloced unicode strings that contain prefix and extension
 */

static NTSTATUS mangle_get_prefix(const smb_ucs2_t *ucs2_string, smb_ucs2_t **prefix,
		smb_ucs2_t **extension, bool allow_wildcards)
{
	size_t ext_len;
	smb_ucs2_t *p;

	*extension = 0;
	*prefix = strdup_w(ucs2_string);
	if (!*prefix) {
		return NT_STATUS_NO_MEMORY;
	}
	if ((p = strrchr_w(*prefix, UCS2_CHAR('.')))) {
		ext_len = strlen_w(p+1);
		if ((ext_len > 0) && (ext_len < 4) && (p != *prefix) &&
		    (NT_STATUS_IS_OK(has_valid_83_chars(p+1,allow_wildcards)))) /* check extension */ {
			*p = 0;
			*extension = strdup_w(p+1);
			if (!*extension) {
				SAFE_FREE(*prefix);
				return NT_STATUS_NO_MEMORY;
			}
		}
	}
	return NT_STATUS_OK;
}

/* ************************************************************************** **
 * Return NT_STATUS_UNSUCCESSFUL if a name is a special msdos reserved name.
 * or contains illegal characters.
 *
 *  Input:  fname - String containing the name to be tested.
 *
 *  Output: NT_STATUS_UNSUCCESSFUL, if the condition above is true.
 *
 *  Notes:  This is a static function called by is_8_3(), below.
 *
 * ************************************************************************** **
 */

static NTSTATUS is_valid_name(const smb_ucs2_t *fname, bool allow_wildcards, bool only_8_3)
{
	smb_ucs2_t *str, *p;
	size_t num_ucs2_chars;
	NTSTATUS ret = NT_STATUS_OK;

	if (!fname || !*fname)
		return NT_STATUS_INVALID_PARAMETER;

	/* . and .. are valid names. */
	if (strcmp_wa(fname, ".")==0 || strcmp_wa(fname, "..")==0)
		return NT_STATUS_OK;

	if (only_8_3) {
		ret = has_valid_83_chars(fname, allow_wildcards);
		if (!NT_STATUS_IS_OK(ret))
			return ret;
	}

	ret = has_illegal_chars(fname, allow_wildcards);
	if (!NT_STATUS_IS_OK(ret))
		return ret;

	/* Name can't end in '.' or ' ' */
	num_ucs2_chars = strlen_w(fname);
	if (fname[num_ucs2_chars-1] == UCS2_CHAR('.') || fname[num_ucs2_chars-1] == UCS2_CHAR(' ')) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	str = strdup_w(fname);

	/* Truncate copy after the first dot. */
	p = strchr_w(str, UCS2_CHAR('.'));
	if (p) {
		*p = 0;
	}

	strupper_w(str);
	p = &str[1];

	switch(str[0])
	{
	case UCS2_CHAR('A'):
		if(strcmp_wa(p, "UX") == 0)
			ret = NT_STATUS_UNSUCCESSFUL;
		break;
	case UCS2_CHAR('C'):
		if((strcmp_wa(p, "LOCK$") == 0)
		|| (strcmp_wa(p, "ON") == 0)
		|| (strcmp_wa(p, "OM1") == 0)
		|| (strcmp_wa(p, "OM2") == 0)
		|| (strcmp_wa(p, "OM3") == 0)
		|| (strcmp_wa(p, "OM4") == 0)
		)
			ret = NT_STATUS_UNSUCCESSFUL;
		break;
	case UCS2_CHAR('L'):
		if((strcmp_wa(p, "PT1") == 0)
		|| (strcmp_wa(p, "PT2") == 0)
		|| (strcmp_wa(p, "PT3") == 0)
		)
			ret = NT_STATUS_UNSUCCESSFUL;
		break;
	case UCS2_CHAR('N'):
		if(strcmp_wa(p, "UL") == 0)
			ret = NT_STATUS_UNSUCCESSFUL;
		break;
	case UCS2_CHAR('P'):
		if(strcmp_wa(p, "RN") == 0)
			ret = NT_STATUS_UNSUCCESSFUL;
		break;
	default:
		break;
	}

	SAFE_FREE(str);
	return ret;
}

static NTSTATUS is_8_3_w(const smb_ucs2_t *fname, bool allow_wildcards)
{
	smb_ucs2_t *pref = 0, *ext = 0;
	size_t plen;
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;

	if (!fname || !*fname)
		return NT_STATUS_INVALID_PARAMETER;

	if (strlen_w(fname) > 12)
		return NT_STATUS_UNSUCCESSFUL;

	if (strcmp_wa(fname, ".") == 0 || strcmp_wa(fname, "..") == 0)
		return NT_STATUS_OK;

	/* Name cannot start with '.' */
	if (*fname == UCS2_CHAR('.'))
		return NT_STATUS_UNSUCCESSFUL;

	if (!NT_STATUS_IS_OK(is_valid_name(fname, allow_wildcards, True)))
		goto done;

	if (!NT_STATUS_IS_OK(mangle_get_prefix(fname, &pref, &ext, allow_wildcards)))
		goto done;
	plen = strlen_w(pref);

	if (strchr_wa(pref, '.'))
		goto done;
	if (plen < 1 || plen > 8)
		goto done;
	if (ext && (strlen_w(ext) > 3))
		goto done;

	ret = NT_STATUS_OK;

done:
	SAFE_FREE(pref);
	SAFE_FREE(ext);
	return ret;
}

static bool is_8_3(const char *fname, bool check_case, bool allow_wildcards,
		   const struct share_params *p)
{
	const char *f;
	smb_ucs2_t *ucs2name;
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	size_t size;

	if (!fname || !*fname)
		return False;
	if ((f = strrchr(fname, '/')) == NULL)
		f = fname;
	else
		f++;

	if (strlen(f) > 12)
		return False;

	if (!push_ucs2_talloc(NULL, &ucs2name, f, &size)) {
		DEBUG(0,("is_8_3: internal error push_ucs2_talloc() failed!\n"));
		goto done;
	}

	ret = is_8_3_w(ucs2name, allow_wildcards);

done:
	TALLOC_FREE(ucs2name);

	if (!NT_STATUS_IS_OK(ret)) {
		return False;
	}

	return True;
}

/* -------------------------------------------------------------------------- **
 * Functions...
 */

/* ************************************************************************** **
 * Initialize the static character test array.
 *
 *  Input:  none
 *
 *  Output: none
 *
 *  Notes:  This function changes (loads) the contents of the <chartest>
 *          array.  The scope of <chartest> is this file.
 *
 * ************************************************************************** **
 */

static void init_chartest( void )
{
	const unsigned char *s;

	chartest = SMB_MALLOC_ARRAY(unsigned char, 256);

	SMB_ASSERT(chartest != NULL);
	memset(chartest, '\0', 256);

	for( s = (const unsigned char *)basechars; *s; s++ ) {
		chartest[*s] |= BASECHAR_MASK;
	}
}

/* ************************************************************************** **
 * Return True if the name *could be* a mangled name.
 *
 *  Input:  s - A path name - in UNIX pathname format.
 *
 *  Output: True if the name matches the pattern described below in the
 *          notes, else False.
 *
 *  Notes:  The input name is *not* tested for 8.3 compliance.  This must be
 *          done separately.  This function returns true if the name contains
 *          a magic character followed by excactly two characters from the
 *          basechars list (above), which in turn are followed either by the
 *          nul (end of string) byte or a dot (extension) or by a '/' (end of
 *          a directory name).
 *
 * ************************************************************************** **
 */

static bool is_mangled(const char *s, const struct share_params *p)
{
	char *magic;
	char magic_char;

	magic_char = lp_magicchar(p);

	if (chartest == NULL) {
		init_chartest();
	}

	magic = strchr_m( s, magic_char );
	while( magic && magic[1] && magic[2] ) {         /* 3 chars, 1st is magic. */
		if( ('.' == magic[3] || '/' == magic[3] || !(magic[3]))          /* Ends with '.' or nul or '/' ?  */
				&& isbasechar( toupper_m(magic[1]) )           /* is 2nd char basechar?  */
				&& isbasechar( toupper_m(magic[2]) ) )         /* is 3rd char basechar?  */
			return( True );                           /* If all above, then true, */
		magic = strchr_m( magic+1, magic_char );      /*    else seek next magic. */
	}
	return( False );
}

/***************************************************************************
 Initializes or clears the mangled cache.
***************************************************************************/

static void mangle_reset( void )
{
	/* We could close and re-open the tdb here... should we ? The old code did
	   the equivalent... JRA. */
}

/***************************************************************************
 Add a mangled name into the cache.
 If the extension of the raw name maps directly to the
 extension of the mangled name, then we'll store both names
 *without* extensions.  That way, we can provide consistent
 reverse mangling for all names that match.  The test here is
 a bit more careful than the one done in earlier versions of
 mangle.c:

    - the extension must exist on the raw name,
    - it must be all lower case
    - it must match the mangled extension (to prove that no
      mangling occurred).
  crh 07-Apr-1998
**************************************************************************/

static void cache_mangled_name( const char mangled_name[13],
				const char *raw_name )
{
	TDB_DATA data_val;
	char mangled_name_key[13];
	char *s1 = NULL;
	char *s2 = NULL;

	/* If the cache isn't initialized, give up. */
	if( !tdb_mangled_cache )
		return;

	/* Init the string lengths. */
	strlcpy(mangled_name_key, mangled_name, sizeof(mangled_name_key));

	/* See if the extensions are unmangled.  If so, store the entry
	 * without the extension, thus creating a "group" reverse map.
	 */
	s1 = strrchr( mangled_name_key, '.' );
	if( s1 && (s2 = strrchr( raw_name, '.' )) ) {
		size_t i = 1;
		while( s1[i] && (tolower_m( s1[i] ) == s2[i]) )
			i++;
		if( !s1[i] && !s2[i] ) {
			/* Truncate at the '.' */
			*s1 = '\0';
			/*
			 * DANGER WILL ROBINSON - this
			 * is changing a const string via
			 * an aliased pointer ! Remember to
			 * put it back once we've used it.
			 * JRA
			 */
			*s2 = '\0';
		}
	}

	/* Allocate a new cache entry.  If the allocation fails, just return. */
	data_val = string_term_tdb_data(raw_name);
	if (tdb_store_bystring(tdb_mangled_cache, mangled_name_key, data_val, TDB_REPLACE) != 0) {
		DEBUG(0,("cache_mangled_name: Error storing entry %s -> %s\n", mangled_name_key, raw_name));
	} else {
		DEBUG(5,("cache_mangled_name: Stored entry %s -> %s\n", mangled_name_key, raw_name));
	}
	/* Restore the change we made to the const string. */
	if (s2) {
		*s2 = '.';
	}
}

/* ************************************************************************** **
 * Check for a name on the mangled name stack
 *
 *  Input:  s - Input *and* output string buffer.
 *	    maxlen - space in i/o string buffer.
 *  Output: True if the name was found in the cache, else False.
 *
 *  Notes:  If a reverse map is found, the function will overwrite the string
 *          space indicated by the input pointer <s>.  This is frightening.
 *          It should be rewritten to return NULL if the long name was not
 *          found, and a pointer to the long name if it was found.
 *
 * ************************************************************************** **
 */

static bool lookup_name_from_8_3(TALLOC_CTX *ctx,
				const char *in,
				char **out, /* talloced on the given context. */
				const struct share_params *p)
{
	TDB_DATA data_val;
	char *saved_ext = NULL;
	char *s = talloc_strdup(ctx, in);

	/* If the cache isn't initialized, give up. */
	if(!s || !tdb_mangled_cache ) {
		TALLOC_FREE(s);
		return False;
	}

	data_val = tdb_fetch_bystring(tdb_mangled_cache, s);

	/* If we didn't find the name *with* the extension, try without. */
	if(data_val.dptr == NULL || data_val.dsize == 0) {
		char *ext_start = strrchr( s, '.' );
		if( ext_start ) {
			if((saved_ext = talloc_strdup(ctx,ext_start)) == NULL) {
				TALLOC_FREE(s);
				return False;
			}

			*ext_start = '\0';
			data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
			/*
			 * At this point s is the name without the
			 * extension. We re-add the extension if saved_ext
			 * is not null, before freeing saved_ext.
			 */
		}
	}

	/* Okay, if we haven't found it we're done. */
	if(data_val.dptr == NULL || data_val.dsize == 0) {
		TALLOC_FREE(saved_ext);
		TALLOC_FREE(s);
		return False;
	}

	/* If we *did* find it, we need to talloc it on the given ctx. */
	if (saved_ext) {
		*out = talloc_asprintf(ctx, "%s%s",
					(char *)data_val.dptr,
					saved_ext);
	} else {
		*out = talloc_strdup(ctx, (char *)data_val.dptr);
	}

	TALLOC_FREE(s);
	TALLOC_FREE(saved_ext);
	SAFE_FREE(data_val.dptr);

	return *out ? True : False;
}

/**
 Check if a string is in "normal" case.
**/

static bool strisnormal(const char *s, int case_default)
{
	if (case_default == CASE_UPPER)
		return(!strhaslower(s));

	return(!strhasupper(s));
}


/*****************************************************************************
 Do the actual mangling to 8.3 format.
*****************************************************************************/

static bool to_8_3(char magic_char, const char *in, char out[13], int default_case)
{
	int csum;
	char *p;
	char extension[4];
	char base[9];
	int baselen = 0;
	int extlen = 0;
	char *s = SMB_STRDUP(in);

	extension[0] = 0;
	base[0] = 0;

	if (!s) {
		return False;
	}

	p = strrchr(s,'.');
	if( p && (strlen(p+1) < (size_t)4) ) {
		bool all_normal = ( strisnormal(p+1, default_case) ); /* XXXXXXXXX */

		if( all_normal && p[1] != 0 ) {
			*p = 0;
			csum = str_checksum( s );
			*p = '.';
		} else
			csum = str_checksum(s);
	} else
		csum = str_checksum(s);

	strupper_m( s );

	if( p ) {
		if( p == s )
			strlcpy( extension, "___", 4);
		else {
			*p++ = 0;
			while( *p && extlen < 3 ) {
				if ( *p != '.') {
					extension[extlen++] = p[0];
				}
				p++;
			}
			extension[extlen] = 0;
		}
	}

	p = s;

	while( *p && baselen < 5 ) {
		if (isbasechar(*p)) {
			base[baselen++] = p[0];
		}
		p++;
	}
	base[baselen] = 0;

	csum = csum % (MANGLE_BASE*MANGLE_BASE);

	memcpy(out, base, baselen);
	out[baselen] = magic_char;
	out[baselen+1] = mangle( csum/MANGLE_BASE );
	out[baselen+2] = mangle( csum );

	if( *extension ) {
		out[baselen+3] = '.';
		strlcpy(&out[baselen+4], extension, 4);
	}

	SAFE_FREE(s);
	return True;
}

static bool must_mangle(const char *name,
			const struct share_params *p)
{
	smb_ucs2_t *name_ucs2 = NULL;
	NTSTATUS status;
	size_t converted_size;

	if (!push_ucs2_talloc(NULL, &name_ucs2, name, &converted_size)) {
		DEBUG(0, ("push_ucs2_talloc failed!\n"));
		return False;
	}
	status = is_valid_name(name_ucs2, False, False);
	TALLOC_FREE(name_ucs2);
	/* We return true if we *must* mangle, so if it's
	 * a valid name (status == OK) then we must return
	 * false. Bug #6939. */
	return !NT_STATUS_IS_OK(status);
}

/*****************************************************************************
 * Convert a filename to DOS format.  Return True if successful.
 *  Input:  in        Incoming name.
 *
 *          out       8.3 DOS name.
 *
 *          cache83 - If False, the mangled name cache will not be updated.
 *                    This is usually used to prevent that we overwrite
 *                    a conflicting cache entry prematurely, i.e. before
 *                    we know whether the client is really interested in the
 *                    current name.  (See PR#13758).  UKD.
 *
 * ****************************************************************************
 */

static bool hash_name_to_8_3(const char *in,
			char out[13],
			bool cache83,
			int default_case,
			const struct share_params *p)
{
	smb_ucs2_t *in_ucs2 = NULL;
	size_t converted_size;
	char magic_char;

	magic_char = lp_magicchar(p);

	DEBUG(5,("hash_name_to_8_3( %s, cache83 = %s)\n", in,
		 cache83 ? "True" : "False"));

	if (!push_ucs2_talloc(NULL, &in_ucs2, in, &converted_size)) {
		DEBUG(0, ("push_ucs2_talloc failed!\n"));
		return False;
	}

	/* If it's already 8.3, just copy. */
	if (NT_STATUS_IS_OK(is_valid_name(in_ucs2, False, False)) &&
				NT_STATUS_IS_OK(is_8_3_w(in_ucs2, False))) {
		TALLOC_FREE(in_ucs2);
		strlcpy(out, in, 13);
		return True;
	}

	TALLOC_FREE(in_ucs2);
	if (!to_8_3(magic_char, in, out, default_case)) {
		return False;
	}

	cache_mangled_name(out, in);

	DEBUG(5,("hash_name_to_8_3(%s) ==> [%s]\n", in, out));
	return True;
}

/*
  the following provides the abstraction layer to make it easier
  to drop in an alternative mangling implementation
*/
static const struct mangle_fns mangle_hash_fns = {
	mangle_reset,
	is_mangled,
	must_mangle,
	is_8_3,
	lookup_name_from_8_3,
	hash_name_to_8_3
};

/* return the methods for this mangling implementation */
const struct mangle_fns *mangle_hash_init(void)
{
	mangle_reset();

	/* Create the in-memory tdb using our custom hash function. */
	tdb_mangled_cache = tdb_open_ex("mangled_cache", 1031, TDB_INTERNAL,
				(O_RDWR|O_CREAT), 0644, NULL, fast_string_hash);

	return &mangle_hash_fns;
}