dbus-marshal-validate.c revision e61f13cf328d131ddbd8b49842fcd0f49847dbff
1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-marshal-validate.c Validation routines for marshaled data
3 *
4 * Copyright (C) 2005 Red Hat, Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 *
22 */
23
24#include "dbus-internals.h"
25#include "dbus-marshal-validate.h"
26#include "dbus-marshal-recursive.h"
27#include "dbus-marshal-basic.h"
28#include "dbus-signature.h"
29#include "dbus-string.h"
30
31/**
32 * @addtogroup DBusMarshal
33 *
34 * @{
35 */
36
37/**
38 * Verifies that the range of type_str from type_pos to type_end is a
39 * valid signature.  If this function returns #TRUE, it will be safe
40 * to iterate over the signature with a types-only #DBusTypeReader.
41 * The range passed in should NOT include the terminating
42 * nul/DBUS_TYPE_INVALID.
43 *
44 * @param type_str the string
45 * @param type_pos where the typecodes start
46 * @param len length of typecodes
47 * @returns #DBUS_VALID if valid, reason why invalid otherwise
48 */
49DBusValidity
50_dbus_validate_signature_with_reason (const DBusString *type_str,
51                                      int               type_pos,
52                                      int               len)
53{
54  const unsigned char *p;
55  const unsigned char *end;
56  int last;
57  int struct_depth;
58  int array_depth;
59  int dict_entry_depth;
60  DBusValidity result;
61
62  int element_count;
63  DBusList *element_count_stack;
64
65  result = DBUS_VALID;
66  element_count_stack = NULL;
67
68  if (!_dbus_list_append (&element_count_stack, _DBUS_INT_TO_POINTER (0)))
69    {
70      result = DBUS_VALIDITY_UNKNOWN_OOM_ERROR;
71      goto out;
72    }
73
74  _dbus_assert (type_str != NULL);
75  _dbus_assert (type_pos < _DBUS_INT32_MAX - len);
76  _dbus_assert (len >= 0);
77  _dbus_assert (type_pos >= 0);
78
79  if (len > DBUS_MAXIMUM_SIGNATURE_LENGTH)
80    {
81      result = DBUS_INVALID_SIGNATURE_TOO_LONG;
82      goto out;
83    }
84
85  p = _dbus_string_get_const_data_len (type_str, type_pos, 0);
86
87  end = _dbus_string_get_const_data_len (type_str, type_pos + len, 0);
88  struct_depth = 0;
89  array_depth = 0;
90  dict_entry_depth = 0;
91  last = DBUS_TYPE_INVALID;
92
93  while (p != end)
94    {
95      switch (*p)
96        {
97        case DBUS_TYPE_BYTE:
98        case DBUS_TYPE_BOOLEAN:
99        case DBUS_TYPE_INT16:
100        case DBUS_TYPE_UINT16:
101        case DBUS_TYPE_INT32:
102        case DBUS_TYPE_UINT32:
103        case DBUS_TYPE_INT64:
104        case DBUS_TYPE_UINT64:
105        case DBUS_TYPE_DOUBLE:
106        case DBUS_TYPE_STRING:
107        case DBUS_TYPE_OBJECT_PATH:
108        case DBUS_TYPE_SIGNATURE:
109        case DBUS_TYPE_VARIANT:
110          break;
111
112        case DBUS_TYPE_ARRAY:
113          array_depth += 1;
114          if (array_depth > DBUS_MAXIMUM_TYPE_RECURSION_DEPTH)
115            {
116              result = DBUS_INVALID_EXCEEDED_MAXIMUM_ARRAY_RECURSION;
117              goto out;
118            }
119          break;
120
121        case DBUS_STRUCT_BEGIN_CHAR:
122          struct_depth += 1;
123
124          if (struct_depth > DBUS_MAXIMUM_TYPE_RECURSION_DEPTH)
125            {
126              result = DBUS_INVALID_EXCEEDED_MAXIMUM_STRUCT_RECURSION;
127              goto out;
128            }
129
130          if (!_dbus_list_append (&element_count_stack,
131                             _DBUS_INT_TO_POINTER (0)))
132            {
133              result = DBUS_VALIDITY_UNKNOWN_OOM_ERROR;
134              goto out;
135            }
136
137          break;
138
139        case DBUS_STRUCT_END_CHAR:
140          if (struct_depth == 0)
141            {
142              result = DBUS_INVALID_STRUCT_ENDED_BUT_NOT_STARTED;
143              goto out;
144            }
145
146          if (last == DBUS_STRUCT_BEGIN_CHAR)
147            {
148              result = DBUS_INVALID_STRUCT_HAS_NO_FIELDS;
149              goto out;
150            }
151
152          _dbus_list_pop_last (&element_count_stack);
153
154          struct_depth -= 1;
155          break;
156
157        case DBUS_DICT_ENTRY_BEGIN_CHAR:
158          if (last != DBUS_TYPE_ARRAY)
159            {
160              result = DBUS_INVALID_DICT_ENTRY_NOT_INSIDE_ARRAY;
161              goto out;
162            }
163
164          dict_entry_depth += 1;
165
166          if (dict_entry_depth > DBUS_MAXIMUM_TYPE_RECURSION_DEPTH)
167            {
168              result = DBUS_INVALID_EXCEEDED_MAXIMUM_DICT_ENTRY_RECURSION;
169              goto out;
170            }
171
172          if (!_dbus_list_append (&element_count_stack,
173                             _DBUS_INT_TO_POINTER (0)))
174            {
175              result = DBUS_VALIDITY_UNKNOWN_OOM_ERROR;
176              goto out;
177            }
178
179          break;
180
181        case DBUS_DICT_ENTRY_END_CHAR:
182          if (dict_entry_depth == 0)
183            {
184              result = DBUS_INVALID_DICT_ENTRY_ENDED_BUT_NOT_STARTED;
185              goto out;
186            }
187
188          dict_entry_depth -= 1;
189
190          element_count =
191            _DBUS_POINTER_TO_INT (_dbus_list_pop_last (&element_count_stack));
192
193          if (element_count != 2)
194            {
195              if (element_count == 0)
196                result = DBUS_INVALID_DICT_ENTRY_HAS_NO_FIELDS;
197              else if (element_count == 1)
198                result = DBUS_INVALID_DICT_ENTRY_HAS_ONLY_ONE_FIELD;
199              else
200                result = DBUS_INVALID_DICT_ENTRY_HAS_TOO_MANY_FIELDS;
201
202              goto out;
203            }
204          break;
205
206        case DBUS_TYPE_STRUCT:     /* doesn't appear in signatures */
207        case DBUS_TYPE_DICT_ENTRY: /* ditto */
208        default:
209          result = DBUS_INVALID_UNKNOWN_TYPECODE;
210	  goto out;
211        }
212
213      if (*p != DBUS_TYPE_ARRAY &&
214          *p != DBUS_DICT_ENTRY_BEGIN_CHAR &&
215	  *p != DBUS_STRUCT_BEGIN_CHAR)
216        {
217          element_count =
218            _DBUS_POINTER_TO_INT (_dbus_list_pop_last (&element_count_stack));
219
220          ++element_count;
221
222          if (!_dbus_list_append (&element_count_stack,
223                             _DBUS_INT_TO_POINTER (element_count)))
224            {
225              result = DBUS_VALIDITY_UNKNOWN_OOM_ERROR;
226              goto out;
227            }
228        }
229
230      if (array_depth > 0)
231        {
232          if (*p == DBUS_TYPE_ARRAY && p != end)
233            {
234	       const char *p1;
235	       p1 = p + 1;
236               if (*p1 == DBUS_STRUCT_END_CHAR ||
237                   *p1 == DBUS_DICT_ENTRY_END_CHAR)
238                 {
239                   result = DBUS_INVALID_MISSING_ARRAY_ELEMENT_TYPE;
240                   goto out;
241                 }
242            }
243          else
244	    {
245              array_depth = 0;
246	    }
247        }
248
249      if (last == DBUS_DICT_ENTRY_BEGIN_CHAR &&
250          _dbus_type_is_valid (*p) &&
251          !dbus_type_is_basic (*p))
252        {
253          result = DBUS_INVALID_DICT_KEY_MUST_BE_BASIC_TYPE;
254          goto out;
255        }
256
257      last = *p;
258      ++p;
259    }
260
261
262  if (array_depth > 0)
263    {
264      result = DBUS_INVALID_MISSING_ARRAY_ELEMENT_TYPE;
265      goto out;
266    }
267
268  if (struct_depth > 0)
269    {
270       result = DBUS_INVALID_STRUCT_STARTED_BUT_NOT_ENDED;
271       goto out;
272    }
273
274  if (dict_entry_depth > 0)
275    {
276      result =  DBUS_INVALID_DICT_ENTRY_STARTED_BUT_NOT_ENDED;
277      goto out;
278    }
279
280  _dbus_assert (last != DBUS_TYPE_ARRAY);
281  _dbus_assert (last != DBUS_STRUCT_BEGIN_CHAR);
282  _dbus_assert (last != DBUS_DICT_ENTRY_BEGIN_CHAR);
283
284  result = DBUS_VALID;
285
286out:
287  _dbus_list_clear (&element_count_stack);
288  return result;
289}
290
291static DBusValidity
292validate_body_helper (DBusTypeReader       *reader,
293                      int                   byte_order,
294                      dbus_bool_t           walk_reader_to_end,
295                      const unsigned char  *p,
296                      const unsigned char  *end,
297                      const unsigned char **new_p)
298{
299  int current_type;
300
301  while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)
302    {
303      const unsigned char *a;
304      int alignment;
305
306#if 0
307      _dbus_verbose ("   validating value of type %s type reader %p type_pos %d p %p end %p %d remain\n",
308                     _dbus_type_to_string (current_type), reader, reader->type_pos, p, end,
309                     (int) (end - p));
310#endif
311
312      /* Guarantee that p has one byte to look at */
313      if (p == end)
314        return DBUS_INVALID_NOT_ENOUGH_DATA;
315
316      switch (current_type)
317        {
318        case DBUS_TYPE_BYTE:
319          ++p;
320          break;
321
322        case DBUS_TYPE_BOOLEAN:
323        case DBUS_TYPE_INT16:
324        case DBUS_TYPE_UINT16:
325        case DBUS_TYPE_INT32:
326        case DBUS_TYPE_UINT32:
327        case DBUS_TYPE_INT64:
328        case DBUS_TYPE_UINT64:
329        case DBUS_TYPE_DOUBLE:
330          alignment = _dbus_type_get_alignment (current_type);
331          a = _DBUS_ALIGN_ADDRESS (p, alignment);
332          if (a >= end)
333            return DBUS_INVALID_NOT_ENOUGH_DATA;
334          while (p != a)
335            {
336              if (*p != '\0')
337                return DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
338              ++p;
339            }
340
341          if (current_type == DBUS_TYPE_BOOLEAN)
342            {
343              dbus_uint32_t v = _dbus_unpack_uint32 (byte_order,
344                                                     p);
345              if (!(v == 0 || v == 1))
346                return DBUS_INVALID_BOOLEAN_NOT_ZERO_OR_ONE;
347            }
348
349          p += alignment;
350          break;
351
352        case DBUS_TYPE_ARRAY:
353        case DBUS_TYPE_STRING:
354        case DBUS_TYPE_OBJECT_PATH:
355          {
356            dbus_uint32_t claimed_len;
357
358            a = _DBUS_ALIGN_ADDRESS (p, 4);
359            if (a + 4 > end)
360              return DBUS_INVALID_NOT_ENOUGH_DATA;
361            while (p != a)
362              {
363                if (*p != '\0')
364                  return DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
365                ++p;
366              }
367
368            claimed_len = _dbus_unpack_uint32 (byte_order, p);
369            p += 4;
370
371            /* p may now be == end */
372            _dbus_assert (p <= end);
373
374            if (current_type == DBUS_TYPE_ARRAY)
375              {
376                int array_elem_type = _dbus_type_reader_get_element_type (reader);
377
378                if (!_dbus_type_is_valid (array_elem_type))
379                  {
380                    return DBUS_INVALID_UNKNOWN_TYPECODE;
381                  }
382
383                alignment = _dbus_type_get_alignment (array_elem_type);
384
385                a = _DBUS_ALIGN_ADDRESS (p, alignment);
386
387                /* a may now be == end */
388                if (a > end)
389                  return DBUS_INVALID_NOT_ENOUGH_DATA;
390
391                while (p != a)
392                  {
393                    if (*p != '\0')
394                      return DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
395                    ++p;
396                  }
397              }
398
399            if (claimed_len > (unsigned long) (end - p))
400              return DBUS_INVALID_LENGTH_OUT_OF_BOUNDS;
401
402            if (current_type == DBUS_TYPE_OBJECT_PATH)
403              {
404                DBusString str;
405                _dbus_string_init_const_len (&str, p, claimed_len);
406                if (!_dbus_validate_path (&str, 0,
407                                          _dbus_string_get_length (&str)))
408                  return DBUS_INVALID_BAD_PATH;
409
410                p += claimed_len;
411              }
412            else if (current_type == DBUS_TYPE_STRING)
413              {
414                DBusString str;
415                _dbus_string_init_const_len (&str, p, claimed_len);
416                if (!_dbus_string_validate_utf8 (&str, 0,
417                                                 _dbus_string_get_length (&str)))
418                  return DBUS_INVALID_BAD_UTF8_IN_STRING;
419
420                p += claimed_len;
421              }
422            else if (current_type == DBUS_TYPE_ARRAY && claimed_len > 0)
423              {
424                DBusTypeReader sub;
425                DBusValidity validity;
426                const unsigned char *array_end;
427                int array_elem_type;
428
429                if (claimed_len > DBUS_MAXIMUM_ARRAY_LENGTH)
430                  return DBUS_INVALID_ARRAY_LENGTH_EXCEEDS_MAXIMUM;
431
432                /* Remember that the reader is types only, so we can't
433                 * use it to iterate over elements. It stays the same
434                 * for all elements.
435                 */
436                _dbus_type_reader_recurse (reader, &sub);
437
438                array_end = p + claimed_len;
439
440                array_elem_type = _dbus_type_reader_get_element_type (reader);
441
442                /* avoid recursive call to validate_body_helper if this is an array
443                 * of fixed-size elements
444                 */
445                if (dbus_type_is_fixed (array_elem_type))
446                  {
447                    /* bools need to be handled differently, because they can
448                     * have an invalid value
449                     */
450                    if (array_elem_type == DBUS_TYPE_BOOLEAN)
451                      {
452                        dbus_uint32_t v;
453                        alignment = _dbus_type_get_alignment (array_elem_type);
454
455                        while (p < array_end)
456                          {
457                            v = _dbus_unpack_uint32 (byte_order, p);
458
459                            if (!(v == 0 || v == 1))
460                              return DBUS_INVALID_BOOLEAN_NOT_ZERO_OR_ONE;
461
462                            p += alignment;
463                          }
464                      }
465
466                    else
467                      {
468                        p = array_end;
469                      }
470                  }
471
472                else
473                  {
474                    while (p < array_end)
475                      {
476                        validity = validate_body_helper (&sub, byte_order, FALSE, p, end, &p);
477                        if (validity != DBUS_VALID)
478                          return validity;
479                      }
480                  }
481
482                if (p != array_end)
483                  return DBUS_INVALID_ARRAY_LENGTH_INCORRECT;
484              }
485
486            /* check nul termination */
487            if (current_type != DBUS_TYPE_ARRAY)
488              {
489                if (p == end)
490                  return DBUS_INVALID_NOT_ENOUGH_DATA;
491
492                if (*p != '\0')
493                  return DBUS_INVALID_STRING_MISSING_NUL;
494                ++p;
495              }
496          }
497          break;
498
499        case DBUS_TYPE_SIGNATURE:
500          {
501            dbus_uint32_t claimed_len;
502            DBusString str;
503            DBusValidity validity;
504
505            claimed_len = *p;
506            ++p;
507
508            /* 1 is for nul termination */
509            if (claimed_len + 1 > (unsigned long) (end - p))
510              return DBUS_INVALID_SIGNATURE_LENGTH_OUT_OF_BOUNDS;
511
512            _dbus_string_init_const_len (&str, p, claimed_len);
513            validity =
514              _dbus_validate_signature_with_reason (&str, 0,
515                                                    _dbus_string_get_length (&str));
516
517            if (validity != DBUS_VALID)
518              return validity;
519
520            p += claimed_len;
521
522            _dbus_assert (p < end);
523            if (*p != DBUS_TYPE_INVALID)
524              return DBUS_INVALID_SIGNATURE_MISSING_NUL;
525
526            ++p;
527
528            _dbus_verbose ("p = %p end = %p claimed_len %u\n", p, end, claimed_len);
529          }
530          break;
531
532        case DBUS_TYPE_VARIANT:
533          {
534            /* 1 byte sig len, sig typecodes, align to
535             * contained-type-boundary, values.
536             */
537
538            /* In addition to normal signature validation, we need to be sure
539             * the signature contains only a single (possibly container) type.
540             */
541            dbus_uint32_t claimed_len;
542            DBusString sig;
543            DBusTypeReader sub;
544            DBusValidity validity;
545            int contained_alignment;
546            int contained_type;
547            DBusValidity reason;
548
549            claimed_len = *p;
550            ++p;
551
552            /* + 1 for nul */
553            if (claimed_len + 1 > (unsigned long) (end - p))
554              return DBUS_INVALID_VARIANT_SIGNATURE_LENGTH_OUT_OF_BOUNDS;
555
556            _dbus_string_init_const_len (&sig, p, claimed_len);
557            reason = _dbus_validate_signature_with_reason (&sig, 0,
558                                           _dbus_string_get_length (&sig));
559            if (!(reason == DBUS_VALID))
560              {
561                if (reason == DBUS_VALIDITY_UNKNOWN_OOM_ERROR)
562                  return reason;
563                else
564                  return DBUS_INVALID_VARIANT_SIGNATURE_BAD;
565              }
566
567            p += claimed_len;
568
569            if (*p != DBUS_TYPE_INVALID)
570              return DBUS_INVALID_VARIANT_SIGNATURE_MISSING_NUL;
571            ++p;
572
573            contained_type = _dbus_first_type_in_signature (&sig, 0);
574            if (contained_type == DBUS_TYPE_INVALID)
575              return DBUS_INVALID_VARIANT_SIGNATURE_EMPTY;
576
577            contained_alignment = _dbus_type_get_alignment (contained_type);
578
579            a = _DBUS_ALIGN_ADDRESS (p, contained_alignment);
580            if (a > end)
581              return DBUS_INVALID_NOT_ENOUGH_DATA;
582            while (p != a)
583              {
584                if (*p != '\0')
585                  return DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
586                ++p;
587              }
588
589            _dbus_type_reader_init_types_only (&sub, &sig, 0);
590
591            _dbus_assert (_dbus_type_reader_get_current_type (&sub) != DBUS_TYPE_INVALID);
592
593            validity = validate_body_helper (&sub, byte_order, FALSE, p, end, &p);
594            if (validity != DBUS_VALID)
595              return validity;
596
597            if (_dbus_type_reader_next (&sub))
598              return DBUS_INVALID_VARIANT_SIGNATURE_SPECIFIES_MULTIPLE_VALUES;
599
600            _dbus_assert (_dbus_type_reader_get_current_type (&sub) == DBUS_TYPE_INVALID);
601          }
602          break;
603
604        case DBUS_TYPE_DICT_ENTRY:
605        case DBUS_TYPE_STRUCT:
606          {
607            DBusTypeReader sub;
608            DBusValidity validity;
609
610            a = _DBUS_ALIGN_ADDRESS (p, 8);
611            if (a > end)
612              return DBUS_INVALID_NOT_ENOUGH_DATA;
613            while (p != a)
614              {
615                if (*p != '\0')
616                  return DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
617                ++p;
618              }
619
620            _dbus_type_reader_recurse (reader, &sub);
621
622            validity = validate_body_helper (&sub, byte_order, TRUE, p, end, &p);
623            if (validity != DBUS_VALID)
624              return validity;
625          }
626          break;
627
628        default:
629          _dbus_assert_not_reached ("invalid typecode in supposedly-validated signature");
630          break;
631        }
632
633#if 0
634      _dbus_verbose ("   validated value of type %s type reader %p type_pos %d p %p end %p %d remain\n",
635                     _dbus_type_to_string (current_type), reader, reader->type_pos, p, end,
636                     (int) (end - p));
637#endif
638
639      if (p > end)
640        {
641          _dbus_verbose ("not enough data!!! p = %p end = %p end-p = %d\n",
642                         p, end, (int) (end - p));
643          return DBUS_INVALID_NOT_ENOUGH_DATA;
644        }
645
646      if (walk_reader_to_end)
647        _dbus_type_reader_next (reader);
648      else
649        break;
650    }
651
652  if (new_p)
653    *new_p = p;
654
655  return DBUS_VALID;
656}
657
658/**
659 * Verifies that the range of value_str from value_pos to value_end is
660 * a legitimate value of type expected_signature.  If this function
661 * returns #TRUE, it will be safe to iterate over the values with
662 * #DBusTypeReader. The signature is assumed to be already valid.
663 *
664 * If bytes_remaining is not #NULL, then leftover bytes will be stored
665 * there and #DBUS_VALID returned. If it is #NULL, then
666 * #DBUS_INVALID_TOO_MUCH_DATA will be returned if bytes are left
667 * over.
668 *
669 * @param expected_signature the expected types in the value_str
670 * @param expected_signature_start where in expected_signature is the signature
671 * @param byte_order the byte order
672 * @param bytes_remaining place to store leftover bytes
673 * @param value_str the string containing the body
674 * @param value_pos where the values start
675 * @param len length of values after value_pos
676 * @returns #DBUS_VALID if valid, reason why invalid otherwise
677 */
678DBusValidity
679_dbus_validate_body_with_reason (const DBusString *expected_signature,
680                                 int               expected_signature_start,
681                                 int               byte_order,
682                                 int              *bytes_remaining,
683                                 const DBusString *value_str,
684                                 int               value_pos,
685                                 int               len)
686{
687  DBusTypeReader reader;
688  const unsigned char *p;
689  const unsigned char *end;
690  DBusValidity validity;
691
692  _dbus_assert (len >= 0);
693  _dbus_assert (value_pos >= 0);
694  _dbus_assert (value_pos <= _dbus_string_get_length (value_str) - len);
695
696  _dbus_verbose ("validating body from pos %d len %d sig '%s'\n",
697                 value_pos, len, _dbus_string_get_const_data_len (expected_signature,
698                                                                  expected_signature_start,
699                                                                  0));
700
701  _dbus_type_reader_init_types_only (&reader,
702                                     expected_signature, expected_signature_start);
703
704  p = _dbus_string_get_const_data_len (value_str, value_pos, len);
705  end = p + len;
706
707  validity = validate_body_helper (&reader, byte_order, TRUE, p, end, &p);
708  if (validity != DBUS_VALID)
709    return validity;
710
711  if (bytes_remaining)
712    {
713      *bytes_remaining = end - p;
714      return DBUS_VALID;
715    }
716  else if (p < end)
717    return DBUS_INVALID_TOO_MUCH_DATA;
718  else
719    {
720      _dbus_assert (p == end);
721      return DBUS_VALID;
722    }
723}
724
725/**
726 * Determine wether the given character is valid as the first character
727 * in a name.
728 */
729#define VALID_INITIAL_NAME_CHARACTER(c)         \
730  ( ((c) >= 'A' && (c) <= 'Z') ||               \
731    ((c) >= 'a' && (c) <= 'z') ||               \
732    ((c) == '_') )
733
734/**
735 * Determine wether the given character is valid as a second or later
736 * character in a name
737 */
738#define VALID_NAME_CHARACTER(c)                 \
739  ( ((c) >= '0' && (c) <= '9') ||               \
740    ((c) >= 'A' && (c) <= 'Z') ||               \
741    ((c) >= 'a' && (c) <= 'z') ||               \
742    ((c) == '_') )
743
744/**
745 * Checks that the given range of the string is a valid object path
746 * name in the D-Bus protocol. Part of the validation ensures that
747 * the object path contains only ASCII.
748 *
749 * @todo this is inconsistent with most of DBusString in that
750 * it allows a start,len range that extends past the string end.
751 *
752 * @todo change spec to disallow more things, such as spaces in the
753 * path name
754 *
755 * @param str the string
756 * @param start first byte index to check
757 * @param len number of bytes to check
758 * @returns #TRUE if the byte range exists and is a valid name
759 */
760dbus_bool_t
761_dbus_validate_path (const DBusString  *str,
762                     int                start,
763                     int                len)
764{
765  const unsigned char *s;
766  const unsigned char *end;
767  const unsigned char *last_slash;
768
769  _dbus_assert (start >= 0);
770  _dbus_assert (len >= 0);
771  _dbus_assert (start <= _dbus_string_get_length (str));
772
773  if (len > _dbus_string_get_length (str) - start)
774    return FALSE;
775
776  if (len == 0)
777    return FALSE;
778
779  s = _dbus_string_get_const_data (str) + start;
780  end = s + len;
781
782  if (*s != '/')
783    return FALSE;
784  last_slash = s;
785  ++s;
786
787  while (s != end)
788    {
789      if (*s == '/')
790        {
791          if ((s - last_slash) < 2)
792            return FALSE; /* no empty path components allowed */
793
794          last_slash = s;
795        }
796      else
797        {
798          if (_DBUS_UNLIKELY (!VALID_NAME_CHARACTER (*s)))
799            return FALSE;
800        }
801
802      ++s;
803    }
804
805  if ((end - last_slash) < 2 &&
806      len > 1)
807    return FALSE; /* trailing slash not allowed unless the string is "/" */
808
809  return TRUE;
810}
811
812/**
813 * Checks that the given range of the string is a valid interface name
814 * in the D-Bus protocol. This includes a length restriction and an
815 * ASCII subset, see the specification.
816 *
817 * @todo this is inconsistent with most of DBusString in that
818 * it allows a start,len range that extends past the string end.
819 *
820 * @param str the string
821 * @param start first byte index to check
822 * @param len number of bytes to check
823 * @returns #TRUE if the byte range exists and is a valid name
824 */
825dbus_bool_t
826_dbus_validate_interface (const DBusString  *str,
827                          int                start,
828                          int                len)
829{
830  const unsigned char *s;
831  const unsigned char *end;
832  const unsigned char *iface;
833  const unsigned char *last_dot;
834
835  _dbus_assert (start >= 0);
836  _dbus_assert (len >= 0);
837  _dbus_assert (start <= _dbus_string_get_length (str));
838
839  if (len > _dbus_string_get_length (str) - start)
840    return FALSE;
841
842  if (len > DBUS_MAXIMUM_NAME_LENGTH)
843    return FALSE;
844
845  if (len == 0)
846    return FALSE;
847
848  last_dot = NULL;
849  iface = _dbus_string_get_const_data (str) + start;
850  end = iface + len;
851  s = iface;
852
853  /* check special cases of first char so it doesn't have to be done
854   * in the loop. Note we know len > 0
855   */
856  if (_DBUS_UNLIKELY (*s == '.')) /* disallow starting with a . */
857    return FALSE;
858  else if (_DBUS_UNLIKELY (!VALID_INITIAL_NAME_CHARACTER (*s)))
859    return FALSE;
860  else
861    ++s;
862
863  while (s != end)
864    {
865      if (*s == '.')
866        {
867          if (_DBUS_UNLIKELY ((s + 1) == end))
868            return FALSE;
869          else if (_DBUS_UNLIKELY (!VALID_INITIAL_NAME_CHARACTER (*(s + 1))))
870            return FALSE;
871          last_dot = s;
872          ++s; /* we just validated the next char, so skip two */
873        }
874      else if (_DBUS_UNLIKELY (!VALID_NAME_CHARACTER (*s)))
875        {
876          return FALSE;
877        }
878
879      ++s;
880    }
881
882  if (_DBUS_UNLIKELY (last_dot == NULL))
883    return FALSE;
884
885  return TRUE;
886}
887
888/**
889 * Checks that the given range of the string is a valid member name
890 * in the D-Bus protocol. This includes a length restriction, etc.,
891 * see the specification.
892 *
893 * @todo this is inconsistent with most of DBusString in that
894 * it allows a start,len range that extends past the string end.
895 *
896 * @param str the string
897 * @param start first byte index to check
898 * @param len number of bytes to check
899 * @returns #TRUE if the byte range exists and is a valid name
900 */
901dbus_bool_t
902_dbus_validate_member (const DBusString  *str,
903                       int                start,
904                       int                len)
905{
906  const unsigned char *s;
907  const unsigned char *end;
908  const unsigned char *member;
909
910  _dbus_assert (start >= 0);
911  _dbus_assert (len >= 0);
912  _dbus_assert (start <= _dbus_string_get_length (str));
913
914  if (len > _dbus_string_get_length (str) - start)
915    return FALSE;
916
917  if (len > DBUS_MAXIMUM_NAME_LENGTH)
918    return FALSE;
919
920  if (len == 0)
921    return FALSE;
922
923  member = _dbus_string_get_const_data (str) + start;
924  end = member + len;
925  s = member;
926
927  /* check special cases of first char so it doesn't have to be done
928   * in the loop. Note we know len > 0
929   */
930
931  if (_DBUS_UNLIKELY (!VALID_INITIAL_NAME_CHARACTER (*s)))
932    return FALSE;
933  else
934    ++s;
935
936  while (s != end)
937    {
938      if (_DBUS_UNLIKELY (!VALID_NAME_CHARACTER (*s)))
939        {
940          return FALSE;
941        }
942
943      ++s;
944    }
945
946  return TRUE;
947}
948
949/**
950 * Checks that the given range of the string is a valid error name
951 * in the D-Bus protocol. This includes a length restriction, etc.,
952 * see the specification.
953 *
954 * @todo this is inconsistent with most of DBusString in that
955 * it allows a start,len range that extends past the string end.
956 *
957 * @param str the string
958 * @param start first byte index to check
959 * @param len number of bytes to check
960 * @returns #TRUE if the byte range exists and is a valid name
961 */
962dbus_bool_t
963_dbus_validate_error_name (const DBusString  *str,
964                           int                start,
965                           int                len)
966{
967  /* Same restrictions as interface name at the moment */
968  return _dbus_validate_interface (str, start, len);
969}
970
971/**
972 * Determine wether the given character is valid as the first character
973 * in a bus name.
974 */
975#define VALID_INITIAL_BUS_NAME_CHARACTER(c)         \
976  ( ((c) >= 'A' && (c) <= 'Z') ||               \
977    ((c) >= 'a' && (c) <= 'z') ||               \
978    ((c) == '_') || ((c) == '-'))
979
980/**
981 * Determine wether the given character is valid as a second or later
982 * character in a bus name
983 */
984#define VALID_BUS_NAME_CHARACTER(c)                 \
985  ( ((c) >= '0' && (c) <= '9') ||               \
986    ((c) >= 'A' && (c) <= 'Z') ||               \
987    ((c) >= 'a' && (c) <= 'z') ||               \
988    ((c) == '_') || ((c) == '-'))
989
990/**
991 * Checks that the given range of the string is a valid bus name in
992 * the D-Bus protocol. This includes a length restriction, etc., see
993 * the specification.
994 *
995 * @todo this is inconsistent with most of DBusString in that
996 * it allows a start,len range that extends past the string end.
997 *
998 * @param str the string
999 * @param start first byte index to check
1000 * @param len number of bytes to check
1001 * @returns #TRUE if the byte range exists and is a valid name
1002 */
1003dbus_bool_t
1004_dbus_validate_bus_name (const DBusString  *str,
1005                         int                start,
1006                         int                len)
1007{
1008  const unsigned char *s;
1009  const unsigned char *end;
1010  const unsigned char *iface;
1011  const unsigned char *last_dot;
1012
1013  _dbus_assert (start >= 0);
1014  _dbus_assert (len >= 0);
1015  _dbus_assert (start <= _dbus_string_get_length (str));
1016
1017  if (len > _dbus_string_get_length (str) - start)
1018    return FALSE;
1019
1020  if (len > DBUS_MAXIMUM_NAME_LENGTH)
1021    return FALSE;
1022
1023  if (len == 0)
1024    return FALSE;
1025
1026  last_dot = NULL;
1027  iface = _dbus_string_get_const_data (str) + start;
1028  end = iface + len;
1029  s = iface;
1030
1031  /* check special cases of first char so it doesn't have to be done
1032   * in the loop. Note we know len > 0
1033   */
1034  if (*s == ':')
1035  {
1036    /* unique name */
1037    ++s;
1038    while (s != end)
1039      {
1040        if (*s == '.')
1041          {
1042            if (_DBUS_UNLIKELY ((s + 1) == end))
1043              return FALSE;
1044            if (_DBUS_UNLIKELY (!VALID_BUS_NAME_CHARACTER (*(s + 1))))
1045              return FALSE;
1046            ++s; /* we just validated the next char, so skip two */
1047          }
1048        else if (_DBUS_UNLIKELY (!VALID_BUS_NAME_CHARACTER (*s)))
1049          {
1050            return FALSE;
1051          }
1052
1053        ++s;
1054      }
1055
1056    return TRUE;
1057  }
1058  else if (_DBUS_UNLIKELY (*s == '.')) /* disallow starting with a . */
1059    return FALSE;
1060  else if (_DBUS_UNLIKELY (!VALID_INITIAL_BUS_NAME_CHARACTER (*s)))
1061    return FALSE;
1062  else
1063    ++s;
1064
1065  while (s != end)
1066    {
1067      if (*s == '.')
1068        {
1069          if (_DBUS_UNLIKELY ((s + 1) == end))
1070            return FALSE;
1071          else if (_DBUS_UNLIKELY (!VALID_INITIAL_BUS_NAME_CHARACTER (*(s + 1))))
1072            return FALSE;
1073          last_dot = s;
1074          ++s; /* we just validated the next char, so skip two */
1075        }
1076      else if (_DBUS_UNLIKELY (!VALID_BUS_NAME_CHARACTER (*s)))
1077        {
1078          return FALSE;
1079        }
1080
1081      ++s;
1082    }
1083
1084  if (_DBUS_UNLIKELY (last_dot == NULL))
1085    return FALSE;
1086
1087  return TRUE;
1088}
1089
1090/**
1091 * Checks that the given range of the string is a valid message type
1092 * signature in the D-Bus protocol.
1093 *
1094 * @todo this is inconsistent with most of DBusString in that
1095 * it allows a start,len range that extends past the string end.
1096 *
1097 * @param str the string
1098 * @param start first byte index to check
1099 * @param len number of bytes to check
1100 * @returns #TRUE if the byte range exists and is a valid signature
1101 */
1102dbus_bool_t
1103_dbus_validate_signature (const DBusString  *str,
1104                          int                start,
1105                          int                len)
1106{
1107  _dbus_assert (start >= 0);
1108  _dbus_assert (start <= _dbus_string_get_length (str));
1109  _dbus_assert (len >= 0);
1110
1111  if (len > _dbus_string_get_length (str) - start)
1112    return FALSE;
1113
1114  return _dbus_validate_signature_with_reason (str, start, len) == DBUS_VALID;
1115}
1116
1117/** define _dbus_check_is_valid_path() */
1118DEFINE_DBUS_NAME_CHECK(path)
1119/** define _dbus_check_is_valid_interface() */
1120DEFINE_DBUS_NAME_CHECK(interface)
1121/** define _dbus_check_is_valid_member() */
1122DEFINE_DBUS_NAME_CHECK(member)
1123/** define _dbus_check_is_valid_error_name() */
1124DEFINE_DBUS_NAME_CHECK(error_name)
1125/** define _dbus_check_is_valid_bus_name() */
1126DEFINE_DBUS_NAME_CHECK(bus_name)
1127/** define _dbus_check_is_valid_signature() */
1128DEFINE_DBUS_NAME_CHECK(signature)
1129
1130/** @} */
1131
1132/* tests in dbus-marshal-validate-util.c */
1133