source: branches/samba-3.5.x/source3/smbd/mangle_hash.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 18.5 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Name mangling
4 Copyright (C) Andrew Tridgell 1992-2002
5 Copyright (C) Simo Sorce 2001
6 Copyright (C) Andrew Bartlett 2002
7 Copyright (C) Jeremy Allison 2007
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
21*/
22
23#include "includes.h"
24#include "smbd/globals.h"
25
26/* -------------------------------------------------------------------------- **
27 * Other stuff...
28 *
29 * magic_char - This is the magic char used for mangling. It's
30 * global. There is a call to lp_magicchar() in server.c
31 * that is used to override the initial value.
32 *
33 * MANGLE_BASE - This is the number of characters we use for name mangling.
34 *
35 * basechars - The set characters used for name mangling. This
36 * is static (scope is this file only).
37 *
38 * mangle() - Macro used to select a character from basechars (i.e.,
39 * mangle(n) will return the nth digit, modulo MANGLE_BASE).
40 *
41 * chartest - array 0..255. The index range is the set of all possible
42 * values of a byte. For each byte value, the content is a
43 * two nibble pair. See BASECHAR_MASK below.
44 *
45 * ct_initialized - False until the chartest array has been initialized via
46 * a call to init_chartest().
47 *
48 * BASECHAR_MASK - Masks the upper nibble of a one-byte value.
49 *
50 * isbasecahr() - Given a character, check the chartest array to see
51 * if that character is in the basechars set. This is
52 * faster than using strchr_m().
53 *
54 */
55
56static const char basechars[43]="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
57#define MANGLE_BASE (sizeof(basechars)/sizeof(char)-1)
58
59#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
60#define BASECHAR_MASK 0xf0
61#define isbasechar(C) ( (chartest[ ((C) & 0xff) ]) & BASECHAR_MASK )
62
63/* -------------------------------------------------------------------- */
64
65static NTSTATUS has_valid_83_chars(const smb_ucs2_t *s, bool allow_wildcards)
66{
67 if (!*s) {
68 return NT_STATUS_INVALID_PARAMETER;
69 }
70
71 if (!allow_wildcards && ms_has_wild_w(s)) {
72 return NT_STATUS_UNSUCCESSFUL;
73 }
74
75 while (*s) {
76 if(!isvalid83_w(*s)) {
77 return NT_STATUS_UNSUCCESSFUL;
78 }
79 s++;
80 }
81
82 return NT_STATUS_OK;
83}
84
85static NTSTATUS has_illegal_chars(const smb_ucs2_t *s, bool allow_wildcards)
86{
87 if (!allow_wildcards && ms_has_wild_w(s)) {
88 return NT_STATUS_UNSUCCESSFUL;
89 }
90
91 while (*s) {
92 if (*s <= 0x1f) {
93 /* Control characters. */
94 return NT_STATUS_UNSUCCESSFUL;
95 }
96 switch(*s) {
97 case UCS2_CHAR('\\'):
98 case UCS2_CHAR('/'):
99 case UCS2_CHAR('|'):
100 case UCS2_CHAR(':'):
101 return NT_STATUS_UNSUCCESSFUL;
102 }
103 s++;
104 }
105
106 return NT_STATUS_OK;
107}
108
109/* return False if something fail and
110 * return 2 alloced unicode strings that contain prefix and extension
111 */
112
113static NTSTATUS mangle_get_prefix(const smb_ucs2_t *ucs2_string, smb_ucs2_t **prefix,
114 smb_ucs2_t **extension, bool allow_wildcards)
115{
116 size_t ext_len;
117 smb_ucs2_t *p;
118
119 *extension = 0;
120 *prefix = strdup_w(ucs2_string);
121 if (!*prefix) {
122 return NT_STATUS_NO_MEMORY;
123 }
124 if ((p = strrchr_w(*prefix, UCS2_CHAR('.')))) {
125 ext_len = strlen_w(p+1);
126 if ((ext_len > 0) && (ext_len < 4) && (p != *prefix) &&
127 (NT_STATUS_IS_OK(has_valid_83_chars(p+1,allow_wildcards)))) /* check extension */ {
128 *p = 0;
129 *extension = strdup_w(p+1);
130 if (!*extension) {
131 SAFE_FREE(*prefix);
132 return NT_STATUS_NO_MEMORY;
133 }
134 }
135 }
136 return NT_STATUS_OK;
137}
138
139/* ************************************************************************** **
140 * Return NT_STATUS_UNSUCCESSFUL if a name is a special msdos reserved name.
141 * or contains illegal characters.
142 *
143 * Input: fname - String containing the name to be tested.
144 *
145 * Output: NT_STATUS_UNSUCCESSFUL, if the condition above is true.
146 *
147 * Notes: This is a static function called by is_8_3(), below.
148 *
149 * ************************************************************************** **
150 */
151
152static NTSTATUS is_valid_name(const smb_ucs2_t *fname, bool allow_wildcards, bool only_8_3)
153{
154 smb_ucs2_t *str, *p;
155 size_t num_ucs2_chars;
156 NTSTATUS ret = NT_STATUS_OK;
157
158 if (!fname || !*fname)
159 return NT_STATUS_INVALID_PARAMETER;
160
161 /* . and .. are valid names. */
162 if (strcmp_wa(fname, ".")==0 || strcmp_wa(fname, "..")==0)
163 return NT_STATUS_OK;
164
165 if (only_8_3) {
166 ret = has_valid_83_chars(fname, allow_wildcards);
167 if (!NT_STATUS_IS_OK(ret))
168 return ret;
169 }
170
171 ret = has_illegal_chars(fname, allow_wildcards);
172 if (!NT_STATUS_IS_OK(ret))
173 return ret;
174
175 /* Name can't end in '.' or ' ' */
176 num_ucs2_chars = strlen_w(fname);
177 if (fname[num_ucs2_chars-1] == UCS2_CHAR('.') || fname[num_ucs2_chars-1] == UCS2_CHAR(' ')) {
178 return NT_STATUS_UNSUCCESSFUL;
179 }
180
181 str = strdup_w(fname);
182
183 /* Truncate copy after the first dot. */
184 p = strchr_w(str, UCS2_CHAR('.'));
185 if (p) {
186 *p = 0;
187 }
188
189 strupper_w(str);
190 p = &str[1];
191
192 switch(str[0])
193 {
194 case UCS2_CHAR('A'):
195 if(strcmp_wa(p, "UX") == 0)
196 ret = NT_STATUS_UNSUCCESSFUL;
197 break;
198 case UCS2_CHAR('C'):
199 if((strcmp_wa(p, "LOCK$") == 0)
200 || (strcmp_wa(p, "ON") == 0)
201 || (strcmp_wa(p, "OM1") == 0)
202 || (strcmp_wa(p, "OM2") == 0)
203 || (strcmp_wa(p, "OM3") == 0)
204 || (strcmp_wa(p, "OM4") == 0)
205 )
206 ret = NT_STATUS_UNSUCCESSFUL;
207 break;
208 case UCS2_CHAR('L'):
209 if((strcmp_wa(p, "PT1") == 0)
210 || (strcmp_wa(p, "PT2") == 0)
211 || (strcmp_wa(p, "PT3") == 0)
212 )
213 ret = NT_STATUS_UNSUCCESSFUL;
214 break;
215 case UCS2_CHAR('N'):
216 if(strcmp_wa(p, "UL") == 0)
217 ret = NT_STATUS_UNSUCCESSFUL;
218 break;
219 case UCS2_CHAR('P'):
220 if(strcmp_wa(p, "RN") == 0)
221 ret = NT_STATUS_UNSUCCESSFUL;
222 break;
223 default:
224 break;
225 }
226
227 SAFE_FREE(str);
228 return ret;
229}
230
231static NTSTATUS is_8_3_w(const smb_ucs2_t *fname, bool allow_wildcards)
232{
233 smb_ucs2_t *pref = 0, *ext = 0;
234 size_t plen;
235 NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
236
237 if (!fname || !*fname)
238 return NT_STATUS_INVALID_PARAMETER;
239
240 if (strlen_w(fname) > 12)
241 return NT_STATUS_UNSUCCESSFUL;
242
243 if (strcmp_wa(fname, ".") == 0 || strcmp_wa(fname, "..") == 0)
244 return NT_STATUS_OK;
245
246 /* Name cannot start with '.' */
247 if (*fname == UCS2_CHAR('.'))
248 return NT_STATUS_UNSUCCESSFUL;
249
250 if (!NT_STATUS_IS_OK(is_valid_name(fname, allow_wildcards, True)))
251 goto done;
252
253 if (!NT_STATUS_IS_OK(mangle_get_prefix(fname, &pref, &ext, allow_wildcards)))
254 goto done;
255 plen = strlen_w(pref);
256
257 if (strchr_wa(pref, '.'))
258 goto done;
259 if (plen < 1 || plen > 8)
260 goto done;
261 if (ext && (strlen_w(ext) > 3))
262 goto done;
263
264 ret = NT_STATUS_OK;
265
266done:
267 SAFE_FREE(pref);
268 SAFE_FREE(ext);
269 return ret;
270}
271
272static bool is_8_3(const char *fname, bool check_case, bool allow_wildcards,
273 const struct share_params *p)
274{
275 const char *f;
276 smb_ucs2_t *ucs2name;
277 NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
278 size_t size;
279 char magic_char;
280
281 magic_char = lp_magicchar(p);
282
283 if (!fname || !*fname)
284 return False;
285 if ((f = strrchr(fname, '/')) == NULL)
286 f = fname;
287 else
288 f++;
289
290 if (strlen(f) > 12)
291 return False;
292
293 if (!push_ucs2_talloc(NULL, &ucs2name, f, &size)) {
294 DEBUG(0,("is_8_3: internal error push_ucs2_talloc() failed!\n"));
295 goto done;
296 }
297
298 ret = is_8_3_w(ucs2name, allow_wildcards);
299
300done:
301 TALLOC_FREE(ucs2name);
302
303 if (!NT_STATUS_IS_OK(ret)) {
304 return False;
305 }
306
307 return True;
308}
309
310/* -------------------------------------------------------------------------- **
311 * Functions...
312 */
313
314/* ************************************************************************** **
315 * Initialize the static character test array.
316 *
317 * Input: none
318 *
319 * Output: none
320 *
321 * Notes: This function changes (loads) the contents of the <chartest>
322 * array. The scope of <chartest> is this file.
323 *
324 * ************************************************************************** **
325 */
326
327static void init_chartest( void )
328{
329 const unsigned char *s;
330
331 chartest = SMB_MALLOC_ARRAY(unsigned char, 256);
332
333 SMB_ASSERT(chartest != NULL);
334 memset(chartest, '\0', 256);
335
336 for( s = (const unsigned char *)basechars; *s; s++ ) {
337 chartest[*s] |= BASECHAR_MASK;
338 }
339}
340
341/* ************************************************************************** **
342 * Return True if the name *could be* a mangled name.
343 *
344 * Input: s - A path name - in UNIX pathname format.
345 *
346 * Output: True if the name matches the pattern described below in the
347 * notes, else False.
348 *
349 * Notes: The input name is *not* tested for 8.3 compliance. This must be
350 * done separately. This function returns true if the name contains
351 * a magic character followed by excactly two characters from the
352 * basechars list (above), which in turn are followed either by the
353 * nul (end of string) byte or a dot (extension) or by a '/' (end of
354 * a directory name).
355 *
356 * ************************************************************************** **
357 */
358
359static bool is_mangled(const char *s, const struct share_params *p)
360{
361 char *magic;
362 char magic_char;
363
364 magic_char = lp_magicchar(p);
365
366 if (chartest == NULL) {
367 init_chartest();
368 }
369
370 magic = strchr_m( s, magic_char );
371 while( magic && magic[1] && magic[2] ) { /* 3 chars, 1st is magic. */
372 if( ('.' == magic[3] || '/' == magic[3] || !(magic[3])) /* Ends with '.' or nul or '/' ? */
373 && isbasechar( toupper_ascii(magic[1]) ) /* is 2nd char basechar? */
374 && isbasechar( toupper_ascii(magic[2]) ) ) /* is 3rd char basechar? */
375 return( True ); /* If all above, then true, */
376 magic = strchr_m( magic+1, magic_char ); /* else seek next magic. */
377 }
378 return( False );
379}
380
381/***************************************************************************
382 Initializes or clears the mangled cache.
383***************************************************************************/
384
385static void mangle_reset( void )
386{
387 /* We could close and re-open the tdb here... should we ? The old code did
388 the equivalent... JRA. */
389}
390
391/***************************************************************************
392 Add a mangled name into the cache.
393 If the extension of the raw name maps directly to the
394 extension of the mangled name, then we'll store both names
395 *without* extensions. That way, we can provide consistent
396 reverse mangling for all names that match. The test here is
397 a bit more careful than the one done in earlier versions of
398 mangle.c:
399
400 - the extension must exist on the raw name,
401 - it must be all lower case
402 - it must match the mangled extension (to prove that no
403 mangling occurred).
404 crh 07-Apr-1998
405**************************************************************************/
406
407static void cache_mangled_name( const char mangled_name[13],
408 const char *raw_name )
409{
410 TDB_DATA data_val;
411 char mangled_name_key[13];
412 char *s1 = NULL;
413 char *s2 = NULL;
414
415 /* If the cache isn't initialized, give up. */
416 if( !tdb_mangled_cache )
417 return;
418
419 /* Init the string lengths. */
420 safe_strcpy(mangled_name_key, mangled_name, sizeof(mangled_name_key)-1);
421
422 /* See if the extensions are unmangled. If so, store the entry
423 * without the extension, thus creating a "group" reverse map.
424 */
425 s1 = strrchr( mangled_name_key, '.' );
426 if( s1 && (s2 = strrchr( raw_name, '.' )) ) {
427 size_t i = 1;
428 while( s1[i] && (tolower_ascii( s1[i] ) == s2[i]) )
429 i++;
430 if( !s1[i] && !s2[i] ) {
431 /* Truncate at the '.' */
432 *s1 = '\0';
433 /*
434 * DANGER WILL ROBINSON - this
435 * is changing a const string via
436 * an aliased pointer ! Remember to
437 * put it back once we've used it.
438 * JRA
439 */
440 *s2 = '\0';
441 }
442 }
443
444 /* Allocate a new cache entry. If the allocation fails, just return. */
445 data_val = string_term_tdb_data(raw_name);
446 if (tdb_store_bystring(tdb_mangled_cache, mangled_name_key, data_val, TDB_REPLACE) != 0) {
447 DEBUG(0,("cache_mangled_name: Error storing entry %s -> %s\n", mangled_name_key, raw_name));
448 } else {
449 DEBUG(5,("cache_mangled_name: Stored entry %s -> %s\n", mangled_name_key, raw_name));
450 }
451 /* Restore the change we made to the const string. */
452 if (s2) {
453 *s2 = '.';
454 }
455}
456
457/* ************************************************************************** **
458 * Check for a name on the mangled name stack
459 *
460 * Input: s - Input *and* output string buffer.
461 * maxlen - space in i/o string buffer.
462 * Output: True if the name was found in the cache, else False.
463 *
464 * Notes: If a reverse map is found, the function will overwrite the string
465 * space indicated by the input pointer <s>. This is frightening.
466 * It should be rewritten to return NULL if the long name was not
467 * found, and a pointer to the long name if it was found.
468 *
469 * ************************************************************************** **
470 */
471
472static bool lookup_name_from_8_3(TALLOC_CTX *ctx,
473 const char *in,
474 char **out, /* talloced on the given context. */
475 const struct share_params *p)
476{
477 TDB_DATA data_val;
478 char *saved_ext = NULL;
479 char *s = talloc_strdup(ctx, in);
480 char magic_char;
481
482 magic_char = lp_magicchar(p);
483
484 /* If the cache isn't initialized, give up. */
485 if(!s || !tdb_mangled_cache ) {
486 TALLOC_FREE(s);
487 return False;
488 }
489
490 data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
491
492 /* If we didn't find the name *with* the extension, try without. */
493 if(data_val.dptr == NULL || data_val.dsize == 0) {
494 char *ext_start = strrchr( s, '.' );
495 if( ext_start ) {
496 if((saved_ext = talloc_strdup(ctx,ext_start)) == NULL) {
497 TALLOC_FREE(s);
498 return False;
499 }
500
501 *ext_start = '\0';
502 data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
503 /*
504 * At this point s is the name without the
505 * extension. We re-add the extension if saved_ext
506 * is not null, before freeing saved_ext.
507 */
508 }
509 }
510
511 /* Okay, if we haven't found it we're done. */
512 if(data_val.dptr == NULL || data_val.dsize == 0) {
513 TALLOC_FREE(saved_ext);
514 TALLOC_FREE(s);
515 return False;
516 }
517
518 /* If we *did* find it, we need to talloc it on the given ctx. */
519 if (saved_ext) {
520 *out = talloc_asprintf(ctx, "%s%s",
521 (char *)data_val.dptr,
522 saved_ext);
523 } else {
524 *out = talloc_strdup(ctx, (char *)data_val.dptr);
525 }
526
527 TALLOC_FREE(s);
528 TALLOC_FREE(saved_ext);
529 SAFE_FREE(data_val.dptr);
530
531 return *out ? True : False;
532}
533
534/*****************************************************************************
535 Do the actual mangling to 8.3 format.
536*****************************************************************************/
537
538static bool to_8_3(char magic_char, const char *in, char out[13], int default_case)
539{
540 int csum;
541 char *p;
542 char extension[4];
543 char base[9];
544 int baselen = 0;
545 int extlen = 0;
546 char *s = SMB_STRDUP(in);
547
548 extension[0] = 0;
549 base[0] = 0;
550
551 if (!s) {
552 return False;
553 }
554
555 p = strrchr(s,'.');
556 if( p && (strlen(p+1) < (size_t)4) ) {
557 bool all_normal = ( strisnormal(p+1, default_case) ); /* XXXXXXXXX */
558
559 if( all_normal && p[1] != 0 ) {
560 *p = 0;
561 csum = str_checksum( s );
562 *p = '.';
563 } else
564 csum = str_checksum(s);
565 } else
566 csum = str_checksum(s);
567
568 strupper_m( s );
569
570 if( p ) {
571 if( p == s )
572 safe_strcpy( extension, "___", 3 );
573 else {
574 *p++ = 0;
575 while( *p && extlen < 3 ) {
576 if ( *p != '.') {
577 extension[extlen++] = p[0];
578 }
579 p++;
580 }
581 extension[extlen] = 0;
582 }
583 }
584
585 p = s;
586
587 while( *p && baselen < 5 ) {
588 if (isbasechar(*p)) {
589 base[baselen++] = p[0];
590 }
591 p++;
592 }
593 base[baselen] = 0;
594
595 csum = csum % (MANGLE_BASE*MANGLE_BASE);
596
597 memcpy(out, base, baselen);
598 out[baselen] = magic_char;
599 out[baselen+1] = mangle( csum/MANGLE_BASE );
600 out[baselen+2] = mangle( csum );
601
602 if( *extension ) {
603 out[baselen+3] = '.';
604 safe_strcpy(&out[baselen+4], extension, 3);
605 }
606
607 SAFE_FREE(s);
608 return True;
609}
610
611static bool must_mangle(const char *name,
612 const struct share_params *p)
613{
614 smb_ucs2_t *name_ucs2 = NULL;
615 NTSTATUS status;
616 size_t converted_size;
617 char magic_char;
618
619 magic_char = lp_magicchar(p);
620
621 if (!push_ucs2_talloc(NULL, &name_ucs2, name, &converted_size)) {
622 DEBUG(0, ("push_ucs2_talloc failed!\n"));
623 return False;
624 }
625 status = is_valid_name(name_ucs2, False, False);
626 TALLOC_FREE(name_ucs2);
627 /* We return true if we *must* mangle, so if it's
628 * a valid name (status == OK) then we must return
629 * false. Bug #6939. */
630 return !NT_STATUS_IS_OK(status);
631}
632
633/*****************************************************************************
634 * Convert a filename to DOS format. Return True if successful.
635 * Input: in Incoming name.
636 *
637 * out 8.3 DOS name.
638 *
639 * cache83 - If False, the mangled name cache will not be updated.
640 * This is usually used to prevent that we overwrite
641 * a conflicting cache entry prematurely, i.e. before
642 * we know whether the client is really interested in the
643 * current name. (See PR#13758). UKD.
644 *
645 * ****************************************************************************
646 */
647
648static bool hash_name_to_8_3(const char *in,
649 char out[13],
650 bool cache83,
651 int default_case,
652 const struct share_params *p)
653{
654 smb_ucs2_t *in_ucs2 = NULL;
655 size_t converted_size;
656 char magic_char;
657
658 magic_char = lp_magicchar(p);
659
660 DEBUG(5,("hash_name_to_8_3( %s, cache83 = %s)\n", in,
661 cache83 ? "True" : "False"));
662
663 if (!push_ucs2_talloc(NULL, &in_ucs2, in, &converted_size)) {
664 DEBUG(0, ("push_ucs2_talloc failed!\n"));
665 return False;
666 }
667
668 /* If it's already 8.3, just copy. */
669 if (NT_STATUS_IS_OK(is_valid_name(in_ucs2, False, False)) &&
670 NT_STATUS_IS_OK(is_8_3_w(in_ucs2, False))) {
671 TALLOC_FREE(in_ucs2);
672 safe_strcpy(out, in, 12);
673 return True;
674 }
675
676 TALLOC_FREE(in_ucs2);
677 if (!to_8_3(magic_char, in, out, default_case)) {
678 return False;
679 }
680
681 cache_mangled_name(out, in);
682
683 DEBUG(5,("hash_name_to_8_3(%s) ==> [%s]\n", in, out));
684 return True;
685}
686
687/*
688 the following provides the abstraction layer to make it easier
689 to drop in an alternative mangling implementation
690*/
691static const struct mangle_fns mangle_hash_fns = {
692 mangle_reset,
693 is_mangled,
694 must_mangle,
695 is_8_3,
696 lookup_name_from_8_3,
697 hash_name_to_8_3
698};
699
700/* return the methods for this mangling implementation */
701const struct mangle_fns *mangle_hash_init(void)
702{
703 mangle_reset();
704
705 /* Create the in-memory tdb using our custom hash function. */
706 tdb_mangled_cache = tdb_open_ex("mangled_cache", 1031, TDB_INTERNAL,
707 (O_RDWR|O_CREAT), 0644, NULL, fast_string_hash);
708
709 return &mangle_hash_fns;
710}
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