source: trunk/server/source3/smbd/mangle_hash.c

Last change on this file was 862, checked in by Silvan Scherrer, 11 years ago

Samba Server: update trunk to 3.6.23
File size: 18.6 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 "system/filesys.h"
25#include "smbd/smbd.h"
26#include "smbd/globals.h"
27#include "mangle.h"
28#include "util_tdb.h"
29
30/* -------------------------------------------------------------------------- **
31 * Other stuff...
32 *
33 * magic_char - This is the magic char used for mangling. It's
34 * global. There is a call to lp_magicchar() in server.c
35 * that is used to override the initial value.
36 *
37 * MANGLE_BASE - This is the number of characters we use for name mangling.
38 *
39 * basechars - The set characters used for name mangling. This
40 * is static (scope is this file only).
41 *
42 * mangle() - Macro used to select a character from basechars (i.e.,
43 * mangle(n) will return the nth digit, modulo MANGLE_BASE).
44 *
45 * chartest - array 0..255. The index range is the set of all possible
46 * values of a byte. For each byte value, the content is a
47 * two nibble pair. See BASECHAR_MASK below.
48 *
49 * ct_initialized - False until the chartest array has been initialized via
50 * a call to init_chartest().
51 *
52 * BASECHAR_MASK - Masks the upper nibble of a one-byte value.
53 *
54 * isbasecahr() - Given a character, check the chartest array to see
55 * if that character is in the basechars set. This is
56 * faster than using strchr_m().
57 *
58 */
59
60static const char basechars[43]="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
61#define MANGLE_BASE (sizeof(basechars)/sizeof(char)-1)
62
63#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
64#define BASECHAR_MASK 0xf0
65#define isbasechar(C) ( (chartest[ ((C) & 0xff) ]) & BASECHAR_MASK )
66
67/* -------------------------------------------------------------------- */
68
69static NTSTATUS has_valid_83_chars(const smb_ucs2_t *s, bool allow_wildcards)
70{
71 if (!*s) {
72 return NT_STATUS_INVALID_PARAMETER;
73 }
74
75 if (!allow_wildcards && ms_has_wild_w(s)) {
76 return NT_STATUS_UNSUCCESSFUL;
77 }
78
79 while (*s) {
80 if(!isvalid83_w(*s)) {
81 return NT_STATUS_UNSUCCESSFUL;
82 }
83 s++;
84 }
85
86 return NT_STATUS_OK;
87}
88
89static NTSTATUS has_illegal_chars(const smb_ucs2_t *s, bool allow_wildcards)
90{
91 if (!allow_wildcards && ms_has_wild_w(s)) {
92 return NT_STATUS_UNSUCCESSFUL;
93 }
94
95 while (*s) {
96 if (*s <= 0x1f) {
97 /* Control characters. */
98 return NT_STATUS_UNSUCCESSFUL;
99 }
100 switch(*s) {
101 case UCS2_CHAR('\\'):
102 case UCS2_CHAR('/'):
103 case UCS2_CHAR('|'):
104 case UCS2_CHAR(':'):
105 return NT_STATUS_UNSUCCESSFUL;
106 }
107 s++;
108 }
109
110 return NT_STATUS_OK;
111}
112
113/* return False if something fail and
114 * return 2 alloced unicode strings that contain prefix and extension
115 */
116
117static NTSTATUS mangle_get_prefix(const smb_ucs2_t *ucs2_string, smb_ucs2_t **prefix,
118 smb_ucs2_t **extension, bool allow_wildcards)
119{
120 size_t ext_len;
121 smb_ucs2_t *p;
122
123 *extension = 0;
124 *prefix = strdup_w(ucs2_string);
125 if (!*prefix) {
126 return NT_STATUS_NO_MEMORY;
127 }
128 if ((p = strrchr_w(*prefix, UCS2_CHAR('.')))) {
129 ext_len = strlen_w(p+1);
130 if ((ext_len > 0) && (ext_len < 4) && (p != *prefix) &&
131 (NT_STATUS_IS_OK(has_valid_83_chars(p+1,allow_wildcards)))) /* check extension */ {
132 *p = 0;
133 *extension = strdup_w(p+1);
134 if (!*extension) {
135 SAFE_FREE(*prefix);
136 return NT_STATUS_NO_MEMORY;
137 }
138 }
139 }
140 return NT_STATUS_OK;
141}
142
143/* ************************************************************************** **
144 * Return NT_STATUS_UNSUCCESSFUL if a name is a special msdos reserved name.
145 * or contains illegal characters.
146 *
147 * Input: fname - String containing the name to be tested.
148 *
149 * Output: NT_STATUS_UNSUCCESSFUL, if the condition above is true.
150 *
151 * Notes: This is a static function called by is_8_3(), below.
152 *
153 * ************************************************************************** **
154 */
155
156static NTSTATUS is_valid_name(const smb_ucs2_t *fname, bool allow_wildcards, bool only_8_3)
157{
158 smb_ucs2_t *str, *p;
159 size_t num_ucs2_chars;
160 NTSTATUS ret = NT_STATUS_OK;
161
162 if (!fname || !*fname)
163 return NT_STATUS_INVALID_PARAMETER;
164
165 /* . and .. are valid names. */
166 if (strcmp_wa(fname, ".")==0 || strcmp_wa(fname, "..")==0)
167 return NT_STATUS_OK;
168
169 if (only_8_3) {
170 ret = has_valid_83_chars(fname, allow_wildcards);
171 if (!NT_STATUS_IS_OK(ret))
172 return ret;
173 }
174
175 ret = has_illegal_chars(fname, allow_wildcards);
176 if (!NT_STATUS_IS_OK(ret))
177 return ret;
178
179 /* Name can't end in '.' or ' ' */
180 num_ucs2_chars = strlen_w(fname);
181 if (fname[num_ucs2_chars-1] == UCS2_CHAR('.') || fname[num_ucs2_chars-1] == UCS2_CHAR(' ')) {
182 return NT_STATUS_UNSUCCESSFUL;
183 }
184
185 str = strdup_w(fname);
186
187 /* Truncate copy after the first dot. */
188 p = strchr_w(str, UCS2_CHAR('.'));
189 if (p) {
190 *p = 0;
191 }
192
193 strupper_w(str);
194 p = &str[1];
195
196 switch(str[0])
197 {
198 case UCS2_CHAR('A'):
199 if(strcmp_wa(p, "UX") == 0)
200 ret = NT_STATUS_UNSUCCESSFUL;
201 break;
202 case UCS2_CHAR('C'):
203 if((strcmp_wa(p, "LOCK$") == 0)
204 || (strcmp_wa(p, "ON") == 0)
205 || (strcmp_wa(p, "OM1") == 0)
206 || (strcmp_wa(p, "OM2") == 0)
207 || (strcmp_wa(p, "OM3") == 0)
208 || (strcmp_wa(p, "OM4") == 0)
209 )
210 ret = NT_STATUS_UNSUCCESSFUL;
211 break;
212 case UCS2_CHAR('L'):
213 if((strcmp_wa(p, "PT1") == 0)
214 || (strcmp_wa(p, "PT2") == 0)
215 || (strcmp_wa(p, "PT3") == 0)
216 )
217 ret = NT_STATUS_UNSUCCESSFUL;
218 break;
219 case UCS2_CHAR('N'):
220 if(strcmp_wa(p, "UL") == 0)
221 ret = NT_STATUS_UNSUCCESSFUL;
222 break;
223 case UCS2_CHAR('P'):
224 if(strcmp_wa(p, "RN") == 0)
225 ret = NT_STATUS_UNSUCCESSFUL;
226 break;
227 default:
228 break;
229 }
230
231 SAFE_FREE(str);
232 return ret;
233}
234
235static NTSTATUS is_8_3_w(const smb_ucs2_t *fname, bool allow_wildcards)
236{
237 smb_ucs2_t *pref = 0, *ext = 0;
238 size_t plen;
239 NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
240
241 if (!fname || !*fname)
242 return NT_STATUS_INVALID_PARAMETER;
243
244 if (strlen_w(fname) > 12)
245 return NT_STATUS_UNSUCCESSFUL;
246
247 if (strcmp_wa(fname, ".") == 0 || strcmp_wa(fname, "..") == 0)
248 return NT_STATUS_OK;
249
250 /* Name cannot start with '.' */
251 if (*fname == UCS2_CHAR('.'))
252 return NT_STATUS_UNSUCCESSFUL;
253
254 if (!NT_STATUS_IS_OK(is_valid_name(fname, allow_wildcards, True)))
255 goto done;
256
257 if (!NT_STATUS_IS_OK(mangle_get_prefix(fname, &pref, &ext, allow_wildcards)))
258 goto done;
259 plen = strlen_w(pref);
260
261 if (strchr_wa(pref, '.'))
262 goto done;
263 if (plen < 1 || plen > 8)
264 goto done;
265 if (ext && (strlen_w(ext) > 3))
266 goto done;
267
268 ret = NT_STATUS_OK;
269
270done:
271 SAFE_FREE(pref);
272 SAFE_FREE(ext);
273 return ret;
274}
275
276static bool is_8_3(const char *fname, bool check_case, bool allow_wildcards,
277 const struct share_params *p)
278{
279 const char *f;
280 smb_ucs2_t *ucs2name;
281 NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
282 size_t size;
283 char magic_char;
284
285 magic_char = lp_magicchar(p);
286
287 if (!fname || !*fname)
288 return False;
289 if ((f = strrchr(fname, '/')) == NULL)
290 f = fname;
291 else
292 f++;
293
294 if (strlen(f) > 12)
295 return False;
296
297 if (!push_ucs2_talloc(NULL, &ucs2name, f, &size)) {
298 DEBUG(0,("is_8_3: internal error push_ucs2_talloc() failed!\n"));
299 goto done;
300 }
301
302 ret = is_8_3_w(ucs2name, allow_wildcards);
303
304done:
305 TALLOC_FREE(ucs2name);
306
307 if (!NT_STATUS_IS_OK(ret)) {
308 return False;
309 }
310
311 return True;
312}
313
314/* -------------------------------------------------------------------------- **
315 * Functions...
316 */
317
318/* ************************************************************************** **
319 * Initialize the static character test array.
320 *
321 * Input: none
322 *
323 * Output: none
324 *
325 * Notes: This function changes (loads) the contents of the <chartest>
326 * array. The scope of <chartest> is this file.
327 *
328 * ************************************************************************** **
329 */
330
331static void init_chartest( void )
332{
333 const unsigned char *s;
334
335 chartest = SMB_MALLOC_ARRAY(unsigned char, 256);
336
337 SMB_ASSERT(chartest != NULL);
338 memset(chartest, '\0', 256);
339
340 for( s = (const unsigned char *)basechars; *s; s++ ) {
341 chartest[*s] |= BASECHAR_MASK;
342 }
343}
344
345/* ************************************************************************** **
346 * Return True if the name *could be* a mangled name.
347 *
348 * Input: s - A path name - in UNIX pathname format.
349 *
350 * Output: True if the name matches the pattern described below in the
351 * notes, else False.
352 *
353 * Notes: The input name is *not* tested for 8.3 compliance. This must be
354 * done separately. This function returns true if the name contains
355 * a magic character followed by excactly two characters from the
356 * basechars list (above), which in turn are followed either by the
357 * nul (end of string) byte or a dot (extension) or by a '/' (end of
358 * a directory name).
359 *
360 * ************************************************************************** **
361 */
362
363static bool is_mangled(const char *s, const struct share_params *p)
364{
365 char *magic;
366 char magic_char;
367
368 magic_char = lp_magicchar(p);
369
370 if (chartest == NULL) {
371 init_chartest();
372 }
373
374 magic = strchr_m( s, magic_char );
375 while( magic && magic[1] && magic[2] ) { /* 3 chars, 1st is magic. */
376 if( ('.' == magic[3] || '/' == magic[3] || !(magic[3])) /* Ends with '.' or nul or '/' ? */
377 && isbasechar( toupper_m(magic[1]) ) /* is 2nd char basechar? */
378 && isbasechar( toupper_m(magic[2]) ) ) /* is 3rd char basechar? */
379 return( True ); /* If all above, then true, */
380 magic = strchr_m( magic+1, magic_char ); /* else seek next magic. */
381 }
382 return( False );
383}
384
385/***************************************************************************
386 Initializes or clears the mangled cache.
387***************************************************************************/
388
389static void mangle_reset( void )
390{
391 /* We could close and re-open the tdb here... should we ? The old code did
392 the equivalent... JRA. */
393}
394
395/***************************************************************************
396 Add a mangled name into the cache.
397 If the extension of the raw name maps directly to the
398 extension of the mangled name, then we'll store both names
399 *without* extensions. That way, we can provide consistent
400 reverse mangling for all names that match. The test here is
401 a bit more careful than the one done in earlier versions of
402 mangle.c:
403
404 - the extension must exist on the raw name,
405 - it must be all lower case
406 - it must match the mangled extension (to prove that no
407 mangling occurred).
408 crh 07-Apr-1998
409**************************************************************************/
410
411static void cache_mangled_name( const char mangled_name[13],
412 const char *raw_name )
413{
414 TDB_DATA data_val;
415 char mangled_name_key[13];
416 char *s1 = NULL;
417 char *s2 = NULL;
418
419 /* If the cache isn't initialized, give up. */
420 if( !tdb_mangled_cache )
421 return;
422
423 /* Init the string lengths. */
424 safe_strcpy(mangled_name_key, mangled_name, sizeof(mangled_name_key)-1);
425
426 /* See if the extensions are unmangled. If so, store the entry
427 * without the extension, thus creating a "group" reverse map.
428 */
429 s1 = strrchr( mangled_name_key, '.' );
430 if( s1 && (s2 = strrchr( raw_name, '.' )) ) {
431 size_t i = 1;
432 while( s1[i] && (tolower_m( s1[i] ) == s2[i]) )
433 i++;
434 if( !s1[i] && !s2[i] ) {
435 /* Truncate at the '.' */
436 *s1 = '\0';
437 /*
438 * DANGER WILL ROBINSON - this
439 * is changing a const string via
440 * an aliased pointer ! Remember to
441 * put it back once we've used it.
442 * JRA
443 */
444 *s2 = '\0';
445 }
446 }
447
448 /* Allocate a new cache entry. If the allocation fails, just return. */
449 data_val = string_term_tdb_data(raw_name);
450 if (tdb_store_bystring(tdb_mangled_cache, mangled_name_key, data_val, TDB_REPLACE) != 0) {
451 DEBUG(0,("cache_mangled_name: Error storing entry %s -> %s\n", mangled_name_key, raw_name));
452 } else {
453 DEBUG(5,("cache_mangled_name: Stored entry %s -> %s\n", mangled_name_key, raw_name));
454 }
455 /* Restore the change we made to the const string. */
456 if (s2) {
457 *s2 = '.';
458 }
459}
460
461/* ************************************************************************** **
462 * Check for a name on the mangled name stack
463 *
464 * Input: s - Input *and* output string buffer.
465 * maxlen - space in i/o string buffer.
466 * Output: True if the name was found in the cache, else False.
467 *
468 * Notes: If a reverse map is found, the function will overwrite the string
469 * space indicated by the input pointer <s>. This is frightening.
470 * It should be rewritten to return NULL if the long name was not
471 * found, and a pointer to the long name if it was found.
472 *
473 * ************************************************************************** **
474 */
475
476static bool lookup_name_from_8_3(TALLOC_CTX *ctx,
477 const char *in,
478 char **out, /* talloced on the given context. */
479 const struct share_params *p)
480{
481 TDB_DATA data_val;
482 char *saved_ext = NULL;
483 char *s = talloc_strdup(ctx, in);
484 char magic_char;
485
486 magic_char = lp_magicchar(p);
487
488 /* If the cache isn't initialized, give up. */
489 if(!s || !tdb_mangled_cache ) {
490 TALLOC_FREE(s);
491 return False;
492 }
493
494 data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
495
496 /* If we didn't find the name *with* the extension, try without. */
497 if(data_val.dptr == NULL || data_val.dsize == 0) {
498 char *ext_start = strrchr( s, '.' );
499 if( ext_start ) {
500 if((saved_ext = talloc_strdup(ctx,ext_start)) == NULL) {
501 TALLOC_FREE(s);
502 return False;
503 }
504
505 *ext_start = '\0';
506 data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
507 /*
508 * At this point s is the name without the
509 * extension. We re-add the extension if saved_ext
510 * is not null, before freeing saved_ext.
511 */
512 }
513 }
514
515 /* Okay, if we haven't found it we're done. */
516 if(data_val.dptr == NULL || data_val.dsize == 0) {
517 TALLOC_FREE(saved_ext);
518 TALLOC_FREE(s);
519 return False;
520 }
521
522 /* If we *did* find it, we need to talloc it on the given ctx. */
523 if (saved_ext) {
524 *out = talloc_asprintf(ctx, "%s%s",
525 (char *)data_val.dptr,
526 saved_ext);
527 } else {
528 *out = talloc_strdup(ctx, (char *)data_val.dptr);
529 }
530
531 TALLOC_FREE(s);
532 TALLOC_FREE(saved_ext);
533 SAFE_FREE(data_val.dptr);
534
535 return *out ? True : False;
536}
537
538/*****************************************************************************
539 Do the actual mangling to 8.3 format.
540*****************************************************************************/
541
542static bool to_8_3(char magic_char, const char *in, char out[13], int default_case)
543{
544 int csum;
545 char *p;
546 char extension[4];
547 char base[9];
548 int baselen = 0;
549 int extlen = 0;
550 char *s = SMB_STRDUP(in);
551
552 extension[0] = 0;
553 base[0] = 0;
554
555 if (!s) {
556 return False;
557 }
558
559 p = strrchr(s,'.');
560 if( p && (strlen(p+1) < (size_t)4) ) {
561 bool all_normal = ( strisnormal(p+1, default_case) ); /* XXXXXXXXX */
562
563 if( all_normal && p[1] != 0 ) {
564 *p = 0;
565 csum = str_checksum( s );
566 *p = '.';
567 } else
568 csum = str_checksum(s);
569 } else
570 csum = str_checksum(s);
571
572 strupper_m( s );
573
574 if( p ) {
575 if( p == s )
576 safe_strcpy( extension, "___", 3 );
577 else {
578 *p++ = 0;
579 while( *p && extlen < 3 ) {
580 if ( *p != '.') {
581 extension[extlen++] = p[0];
582 }
583 p++;
584 }
585 extension[extlen] = 0;
586 }
587 }
588
589 p = s;
590
591 while( *p && baselen < 5 ) {
592 if (isbasechar(*p)) {
593 base[baselen++] = p[0];
594 }
595 p++;
596 }
597 base[baselen] = 0;
598
599 csum = csum % (MANGLE_BASE*MANGLE_BASE);
600
601 memcpy(out, base, baselen);
602 out[baselen] = magic_char;
603 out[baselen+1] = mangle( csum/MANGLE_BASE );
604 out[baselen+2] = mangle( csum );
605
606 if( *extension ) {
607 out[baselen+3] = '.';
608 safe_strcpy(&out[baselen+4], extension, 3);
609 }
610
611 SAFE_FREE(s);
612 return True;
613}
614
615static bool must_mangle(const char *name,
616 const struct share_params *p)
617{
618 smb_ucs2_t *name_ucs2 = NULL;
619 NTSTATUS status;
620 size_t converted_size;
621 char magic_char;
622
623 magic_char = lp_magicchar(p);
624
625 if (!push_ucs2_talloc(NULL, &name_ucs2, name, &converted_size)) {
626 DEBUG(0, ("push_ucs2_talloc failed!\n"));
627 return False;
628 }
629 status = is_valid_name(name_ucs2, False, False);
630 TALLOC_FREE(name_ucs2);
631 /* We return true if we *must* mangle, so if it's
632 * a valid name (status == OK) then we must return
633 * false. Bug #6939. */
634 return !NT_STATUS_IS_OK(status);
635}
636
637/*****************************************************************************
638 * Convert a filename to DOS format. Return True if successful.
639 * Input: in Incoming name.
640 *
641 * out 8.3 DOS name.
642 *
643 * cache83 - If False, the mangled name cache will not be updated.
644 * This is usually used to prevent that we overwrite
645 * a conflicting cache entry prematurely, i.e. before
646 * we know whether the client is really interested in the
647 * current name. (See PR#13758). UKD.
648 *
649 * ****************************************************************************
650 */
651
652static bool hash_name_to_8_3(const char *in,
653 char out[13],
654 bool cache83,
655 int default_case,
656 const struct share_params *p)
657{
658 smb_ucs2_t *in_ucs2 = NULL;
659 size_t converted_size;
660 char magic_char;
661
662 magic_char = lp_magicchar(p);
663
664 DEBUG(5,("hash_name_to_8_3( %s, cache83 = %s)\n", in,
665 cache83 ? "True" : "False"));
666
667 if (!push_ucs2_talloc(NULL, &in_ucs2, in, &converted_size)) {
668 DEBUG(0, ("push_ucs2_talloc failed!\n"));
669 return False;
670 }
671
672 /* If it's already 8.3, just copy. */
673 if (NT_STATUS_IS_OK(is_valid_name(in_ucs2, False, False)) &&
674 NT_STATUS_IS_OK(is_8_3_w(in_ucs2, False))) {
675 TALLOC_FREE(in_ucs2);
676 safe_strcpy(out, in, 12);
677 return True;
678 }
679
680 TALLOC_FREE(in_ucs2);
681 if (!to_8_3(magic_char, in, out, default_case)) {
682 return False;
683 }
684
685 cache_mangled_name(out, in);
686
687 DEBUG(5,("hash_name_to_8_3(%s) ==> [%s]\n", in, out));
688 return True;
689}
690
691/*
692 the following provides the abstraction layer to make it easier
693 to drop in an alternative mangling implementation
694*/
695static const struct mangle_fns mangle_hash_fns = {
696 mangle_reset,
697 is_mangled,
698 must_mangle,
699 is_8_3,
700 lookup_name_from_8_3,
701 hash_name_to_8_3
702};
703
704/* return the methods for this mangling implementation */
705const struct mangle_fns *mangle_hash_init(void)
706{
707 mangle_reset();
708
709 /* Create the in-memory tdb using our custom hash function. */
710 tdb_mangled_cache = tdb_open_ex("mangled_cache", 1031, TDB_INTERNAL,
711 (O_RDWR|O_CREAT), 0644, NULL, fast_string_hash);
712
713 return &mangle_hash_fns;
714}
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