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1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-internals.c  random utility stuff (internal to D-Bus implementation)
3  *
4  * Copyright (C) 2002, 2003  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
21  *
22  */
23 
24 #include <config.h>
25 #include "dbus-internals.h"
26 #include "dbus-protocol.h"
27 #include "dbus-marshal-basic.h"
28 #include "dbus-test.h"
29 #include <stdio.h>
30 #include <stdarg.h>
31 #include <string.h>
32 #include <stdlib.h>
33 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
34 #include <windows.h>
35 #include <mbstring.h>
36 #endif
37 
38 #ifdef DBUS_ANDROID_LOG
39 #define LOG_TAG "libdbus"
40 #include <cutils/log.h>
41 #endif /* DBUS_ANDROID_LOG */
42 
43 /**
44  * @defgroup DBusInternals D-Bus secret internal implementation details
45  * @brief Documentation useful when developing or debugging D-Bus itself.
46  *
47  */
48 
49 /**
50  * @defgroup DBusInternalsUtils Utilities and portability
51  * @ingroup DBusInternals
52  * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.)
53  * @{
54  */
55 
56 /**
57  * @def _dbus_assert
58  *
59  * Aborts with an error message if the condition is false.
60  *
61  * @param condition condition which must be true.
62  */
63 
64 /**
65  * @def _dbus_assert_not_reached
66  *
67  * Aborts with an error message if called.
68  * The given explanation will be printed.
69  *
70  * @param explanation explanation of what happened if the code was reached.
71  */
72 
73 /**
74  * @def _DBUS_N_ELEMENTS
75  *
76  * Computes the number of elements in a fixed-size array using
77  * sizeof().
78  *
79  * @param array the array to count elements in.
80  */
81 
82 /**
83  * @def _DBUS_POINTER_TO_INT
84  *
85  * Safely casts a void* to an integer; should only be used on void*
86  * that actually contain integers, for example one created with
87  * _DBUS_INT_TO_POINTER.  Only guaranteed to preserve 32 bits.
88  * (i.e. it's used to store 32-bit ints in pointers, but
89  * can't be used to store 64-bit pointers in ints.)
90  *
91  * @param pointer pointer to extract an integer from.
92  */
93 /**
94  * @def _DBUS_INT_TO_POINTER
95  *
96  * Safely stuffs an integer into a pointer, to be extracted later with
97  * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits.
98  *
99  * @param integer the integer to stuff into a pointer.
100  */
101 /**
102  * @def _DBUS_ZERO
103  *
104  * Sets all bits in an object to zero.
105  *
106  * @param object the object to be zeroed.
107  */
108 /**
109  * @def _DBUS_INT16_MIN
110  *
111  * Minimum value of type "int16"
112  */
113 /**
114  * @def _DBUS_INT16_MAX
115  *
116  * Maximum value of type "int16"
117  */
118 /**
119  * @def _DBUS_UINT16_MAX
120  *
121  * Maximum value of type "uint16"
122  */
123 
124 /**
125  * @def _DBUS_INT32_MIN
126  *
127  * Minimum value of type "int32"
128  */
129 /**
130  * @def _DBUS_INT32_MAX
131  *
132  * Maximum value of type "int32"
133  */
134 /**
135  * @def _DBUS_UINT32_MAX
136  *
137  * Maximum value of type "uint32"
138  */
139 
140 /**
141  * @def _DBUS_INT_MIN
142  *
143  * Minimum value of type "int"
144  */
145 /**
146  * @def _DBUS_INT_MAX
147  *
148  * Maximum value of type "int"
149  */
150 /**
151  * @def _DBUS_UINT_MAX
152  *
153  * Maximum value of type "uint"
154  */
155 
156 /**
157  * @typedef DBusForeachFunction
158  *
159  * Used to iterate over each item in a collection, such as
160  * a DBusList.
161  */
162 
163 /**
164  * @def _DBUS_LOCK_NAME
165  *
166  * Expands to name of a global lock variable.
167  */
168 
169 /**
170  * @def _DBUS_DEFINE_GLOBAL_LOCK
171  *
172  * Defines a global lock variable with the given name.
173  * The lock must be added to the list to initialize
174  * in dbus_threads_init().
175  */
176 
177 /**
178  * @def _DBUS_DECLARE_GLOBAL_LOCK
179  *
180  * Expands to declaration of a global lock defined
181  * with _DBUS_DEFINE_GLOBAL_LOCK.
182  * The lock must be added to the list to initialize
183  * in dbus_threads_init().
184  */
185 
186 /**
187  * @def _DBUS_LOCK
188  *
189  * Locks a global lock
190  */
191 
192 /**
193  * @def _DBUS_UNLOCK
194  *
195  * Unlocks a global lock
196  */
197 
198 /**
199  * Fixed "out of memory" error message, just to avoid
200  * making up a different string every time and wasting
201  * space.
202  */
203 const char *_dbus_no_memory_message = "Not enough memory";
204 
205 static dbus_bool_t warn_initted = FALSE;
206 static dbus_bool_t fatal_warnings = FALSE;
207 static dbus_bool_t fatal_warnings_on_check_failed = TRUE;
208 
209 static void
init_warnings(void)210 init_warnings(void)
211 {
212   if (!warn_initted)
213     {
214       const char *s;
215       s = _dbus_getenv ("DBUS_FATAL_WARNINGS");
216       if (s && *s)
217         {
218           if (*s == '0')
219             {
220               fatal_warnings = FALSE;
221               fatal_warnings_on_check_failed = FALSE;
222             }
223           else if (*s == '1')
224             {
225               fatal_warnings = TRUE;
226               fatal_warnings_on_check_failed = TRUE;
227             }
228           else
229             {
230               fprintf(stderr, "DBUS_FATAL_WARNINGS should be set to 0 or 1 if set, not '%s'",
231                       s);
232             }
233         }
234 
235       warn_initted = TRUE;
236     }
237 }
238 
239 /**
240  * Prints a warning message to stderr. Can optionally be made to exit
241  * fatally by setting DBUS_FATAL_WARNINGS, but this is rarely
242  * used. This function should be considered pretty much equivalent to
243  * fprintf(stderr). _dbus_warn_check_failed() on the other hand is
244  * suitable for use when a programming mistake has been made.
245  *
246  * @param format printf-style format string.
247  */
248 void
_dbus_warn(const char * format,...)249 _dbus_warn (const char *format,
250             ...)
251 {
252   va_list args;
253 
254   if (!warn_initted)
255     init_warnings ();
256 
257   va_start (args, format);
258 #ifdef DBUS_ANDROID_LOG
259   LOG_PRI_VA(ANDROID_LOG_WARN, LOG_TAG, format, args);
260 #else
261   vfprintf (stderr, format, args);
262 #endif /* DBUS_ANDROID_LOG */
263   va_end (args);
264 
265   if (fatal_warnings)
266     {
267       fflush (stderr);
268       _dbus_abort ();
269     }
270 }
271 
272 /**
273  * Prints a "critical" warning to stderr when an assertion fails;
274  * differs from _dbus_warn primarily in that it prefixes the pid and
275  * defaults to fatal. This should be used only when a programming
276  * error has been detected. (NOT for unavoidable errors that an app
277  * might handle - those should be returned as DBusError.) Calling this
278  * means "there is a bug"
279  */
280 void
_dbus_warn_check_failed(const char * format,...)281 _dbus_warn_check_failed(const char *format,
282                         ...)
283 {
284   va_list args;
285 
286   if (!warn_initted)
287     init_warnings ();
288 
289   fprintf (stderr, "process %lu: ", _dbus_pid_for_log ());
290 
291   va_start (args, format);
292 #ifdef DBUS_ANDROID_LOG
293   LOG_PRI_VA(ANDROID_LOG_ERROR, LOG_TAG, format, args);
294 #else
295   vfprintf (stderr, format, args);
296 #endif /* DBUS_ANDROID_LOG */
297   va_end (args);
298 
299   if (fatal_warnings_on_check_failed)
300     {
301       fflush (stderr);
302       _dbus_abort ();
303     }
304 }
305 
306 #ifdef DBUS_ENABLE_VERBOSE_MODE
307 
308 static dbus_bool_t verbose_initted = FALSE;
309 static dbus_bool_t verbose = TRUE;
310 
311 /** Whether to show the current thread in verbose messages */
312 #define PTHREAD_IN_VERBOSE 0
313 #if PTHREAD_IN_VERBOSE
314 #include <pthread.h>
315 #endif
316 
317 #ifdef _MSC_VER
318 #define inline
319 #endif
320 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
321 static char module_name[1024];
322 #endif
323 
324 static inline void
_dbus_verbose_init(void)325 _dbus_verbose_init (void)
326 {
327   if (!verbose_initted)
328     {
329 #ifdef DBUS_ANDROID_LOG
330       /* Don't bother checking environment variable - just print the
331          verbose logs (can still be disabled with DBUS_ENABLE_VERBOSE_MODE) */
332       verbose = TRUE;
333 #else
334       const char *p = _dbus_getenv ("DBUS_VERBOSE");
335       verbose = p != NULL && *p == '1';
336 #endif
337       verbose_initted = TRUE;
338 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
339       {
340         char *last_period, *last_slash;
341         GetModuleFileName(0,module_name,sizeof(module_name)-1);
342         last_period = _mbsrchr(module_name,'.');
343         if (last_period)
344           *last_period ='\0';
345         last_slash = _mbsrchr(module_name,'\\');
346         if (last_slash)
347           strcpy(module_name,last_slash+1);
348         strcat(module_name,": ");
349       }
350 #endif
351     }
352 }
353 
354 /** @def DBUS_IS_DIR_SEPARATOR(c)
355  * macro for checking if character c is a patch separator
356  *
357  * @todo move to a header file so that others can use this too
358  */
359 #ifdef DBUS_WIN
360 #define DBUS_IS_DIR_SEPARATOR(c) (c == '\\' || c == '/')
361 #else
362 #define DBUS_IS_DIR_SEPARATOR(c) (c == '/')
363 #endif
364 
365 /**
366  remove source root from file path
367  the source root is determined by
368 */
_dbus_file_path_extract_elements_from_tail(const char * file,int level)369 static char *_dbus_file_path_extract_elements_from_tail(const char *file,int level)
370 {
371   static int prefix = -1;
372   char *p;
373 
374   if (prefix == -1)
375     {
376       char *p = (char *)file + strlen(file);
377       int i = 0;
378       prefix = 0;
379       for (;p >= file;p--)
380         {
381           if (DBUS_IS_DIR_SEPARATOR(*p))
382             {
383               if (++i >= level)
384                 {
385                   prefix = p-file+1;
386                   break;
387                 }
388            }
389         }
390     }
391   return (char *)file+prefix;
392 }
393 
394 /**
395  * Implementation of dbus_is_verbose() macro if built with verbose logging
396  * enabled.
397  * @returns whether verbose logging is active.
398  */
399 dbus_bool_t
_dbus_is_verbose_real(void)400 _dbus_is_verbose_real (void)
401 {
402   _dbus_verbose_init ();
403   return verbose;
404 }
405 
406 /**
407  * Prints a warning message to stderr
408  * if the user has enabled verbose mode.
409  * This is the real function implementation,
410  * use _dbus_verbose() macro in code.
411  *
412  * @param format printf-style format string.
413  */
414 void
415 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
_dbus_verbose_real(const char * file,const int line,const char * function,const char * format,...)416 _dbus_verbose_real (const char *file,
417                     const int line,
418                     const char *function,
419                     const char *format,
420 #else
421 _dbus_verbose_real (const char *format,
422 #endif
423                     ...)
424 {
425   va_list args;
426   static dbus_bool_t need_pid = TRUE;
427   int len;
428 
429   /* things are written a bit oddly here so that
430    * in the non-verbose case we just have the one
431    * conditional and return immediately.
432    */
433   if (!_dbus_is_verbose_real())
434     return;
435 
436 #ifndef DBUS_USE_OUTPUT_DEBUG_STRING
437   /* Print out pid before the line */
438   if (need_pid)
439     {
440 #if PTHREAD_IN_VERBOSE
441       fprintf (stderr, "%lu: 0x%lx: ", _dbus_pid_for_log (), pthread_self ());
442 #else
443       fprintf (stderr, "%lu: ", _dbus_pid_for_log ());
444 #endif
445     }
446 #endif
447 
448   /* Only print pid again if the next line is a new line */
449   len = strlen (format);
450   if (format[len-1] == '\n')
451     need_pid = TRUE;
452   else
453     need_pid = FALSE;
454 
455   va_start (args, format);
456 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
457   {
458   char buf[1024];
459   strcpy(buf,module_name);
460 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
461   sprintf (buf+strlen(buf), "[%s(%d):%s] ",_dbus_file_path_extract_elements_from_tail(file,2),line,function);
462 #endif
463   vsprintf (buf+strlen(buf),format, args);
464   va_end (args);
465   OutputDebugStringA(buf);
466   }
467 #else
468 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
469   fprintf (stderr, "[%s(%d):%s] ",_dbus_file_path_extract_elements_from_tail(file,2),line,function);
470 #endif
471 
472 #ifdef DBUS_ANDROID_LOG
473   LOG_PRI_VA(ANDROID_LOG_DEBUG, LOG_TAG, format, args);
474 #else
475   vfprintf (stderr, format, args);
476 #endif /* DBUS_ANDROID_LOG */
477   va_end (args);
478 
479   fflush (stderr);
480 #endif
481 }
482 
483 /**
484  * Reinitializes the verbose logging code, used
485  * as a hack in dbus-spawn.c so that a child
486  * process re-reads its pid
487  *
488  */
489 void
_dbus_verbose_reset_real(void)490 _dbus_verbose_reset_real (void)
491 {
492   verbose_initted = FALSE;
493 }
494 
495 #endif /* DBUS_ENABLE_VERBOSE_MODE */
496 
497 /**
498  * Duplicates a string. Result must be freed with
499  * dbus_free(). Returns #NULL if memory allocation fails.
500  * If the string to be duplicated is #NULL, returns #NULL.
501  *
502  * @param str string to duplicate.
503  * @returns newly-allocated copy.
504  */
505 char*
_dbus_strdup(const char * str)506 _dbus_strdup (const char *str)
507 {
508   size_t len;
509   char *copy;
510 
511   if (str == NULL)
512     return NULL;
513 
514   len = strlen (str);
515 
516   copy = dbus_malloc (len + 1);
517   if (copy == NULL)
518     return NULL;
519 
520   memcpy (copy, str, len + 1);
521 
522   return copy;
523 }
524 
525 /**
526  * Duplicates a block of memory. Returns
527  * #NULL on failure.
528  *
529  * @param mem memory to copy
530  * @param n_bytes number of bytes to copy
531  * @returns the copy
532  */
533 void*
_dbus_memdup(const void * mem,size_t n_bytes)534 _dbus_memdup (const void  *mem,
535               size_t       n_bytes)
536 {
537   void *copy;
538 
539   copy = dbus_malloc (n_bytes);
540   if (copy == NULL)
541     return NULL;
542 
543   memcpy (copy, mem, n_bytes);
544 
545   return copy;
546 }
547 
548 /**
549  * Duplicates a string array. Result may be freed with
550  * dbus_free_string_array(). Returns #NULL if memory allocation fails.
551  * If the array to be duplicated is #NULL, returns #NULL.
552  *
553  * @param array array to duplicate.
554  * @returns newly-allocated copy.
555  */
556 char**
_dbus_dup_string_array(const char ** array)557 _dbus_dup_string_array (const char **array)
558 {
559   int len;
560   int i;
561   char **copy;
562 
563   if (array == NULL)
564     return NULL;
565 
566   for (len = 0; array[len] != NULL; ++len)
567     ;
568 
569   copy = dbus_new0 (char*, len + 1);
570   if (copy == NULL)
571     return NULL;
572 
573   i = 0;
574   while (i < len)
575     {
576       copy[i] = _dbus_strdup (array[i]);
577       if (copy[i] == NULL)
578         {
579           dbus_free_string_array (copy);
580           return NULL;
581         }
582 
583       ++i;
584     }
585 
586   return copy;
587 }
588 
589 /**
590  * Checks whether a string array contains the given string.
591  *
592  * @param array array to search.
593  * @param str string to look for
594  * @returns #TRUE if array contains string
595  */
596 dbus_bool_t
_dbus_string_array_contains(const char ** array,const char * str)597 _dbus_string_array_contains (const char **array,
598                              const char  *str)
599 {
600   int i;
601 
602   i = 0;
603   while (array[i] != NULL)
604     {
605       if (strcmp (array[i], str) == 0)
606         return TRUE;
607       ++i;
608     }
609 
610   return FALSE;
611 }
612 
613 /**
614  * Generates a new UUID. If you change how this is done,
615  * there's some text about it in the spec that should also change.
616  *
617  * @param uuid the uuid to initialize
618  */
619 void
_dbus_generate_uuid(DBusGUID * uuid)620 _dbus_generate_uuid (DBusGUID *uuid)
621 {
622   long now;
623 
624   _dbus_get_current_time (&now, NULL);
625 
626   uuid->as_uint32s[DBUS_UUID_LENGTH_WORDS - 1] = DBUS_UINT32_TO_BE (now);
627 
628   _dbus_generate_random_bytes_buffer (uuid->as_bytes, DBUS_UUID_LENGTH_BYTES - 4);
629 }
630 
631 /**
632  * Hex-encode a UUID.
633  *
634  * @param uuid the uuid
635  * @param encoded string to append hex uuid to
636  * @returns #FALSE if no memory
637  */
638 dbus_bool_t
_dbus_uuid_encode(const DBusGUID * uuid,DBusString * encoded)639 _dbus_uuid_encode (const DBusGUID *uuid,
640                    DBusString     *encoded)
641 {
642   DBusString binary;
643   _dbus_string_init_const_len (&binary, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
644   return _dbus_string_hex_encode (&binary, 0, encoded, _dbus_string_get_length (encoded));
645 }
646 
647 static dbus_bool_t
_dbus_read_uuid_file_without_creating(const DBusString * filename,DBusGUID * uuid,DBusError * error)648 _dbus_read_uuid_file_without_creating (const DBusString *filename,
649                                        DBusGUID         *uuid,
650                                        DBusError        *error)
651 {
652   DBusString contents;
653   DBusString decoded;
654   int end;
655 
656   if (!_dbus_string_init (&contents))
657     {
658       _DBUS_SET_OOM (error);
659       return FALSE;
660     }
661 
662   if (!_dbus_string_init (&decoded))
663     {
664       _dbus_string_free (&contents);
665       _DBUS_SET_OOM (error);
666       return FALSE;
667     }
668 
669   if (!_dbus_file_get_contents (&contents, filename, error))
670     goto error;
671 
672   _dbus_string_chop_white (&contents);
673 
674   if (_dbus_string_get_length (&contents) != DBUS_UUID_LENGTH_HEX)
675     {
676       dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
677                       "UUID file '%s' should contain a hex string of length %d, not length %d, with no other text",
678                       _dbus_string_get_const_data (filename),
679                       DBUS_UUID_LENGTH_HEX,
680                       _dbus_string_get_length (&contents));
681       goto error;
682     }
683 
684   if (!_dbus_string_hex_decode (&contents, 0, &end, &decoded, 0))
685     {
686       _DBUS_SET_OOM (error);
687       goto error;
688     }
689 
690   if (end == 0)
691     {
692       dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
693                       "UUID file '%s' contains invalid hex data",
694                       _dbus_string_get_const_data (filename));
695       goto error;
696     }
697 
698   if (_dbus_string_get_length (&decoded) != DBUS_UUID_LENGTH_BYTES)
699     {
700       dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
701                       "UUID file '%s' contains %d bytes of hex-encoded data instead of %d",
702                       _dbus_string_get_const_data (filename),
703                       _dbus_string_get_length (&decoded),
704                       DBUS_UUID_LENGTH_BYTES);
705       goto error;
706     }
707 
708   _dbus_string_copy_to_buffer (&decoded, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
709 
710   _dbus_string_free (&decoded);
711   _dbus_string_free (&contents);
712 
713   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
714 
715   return TRUE;
716 
717  error:
718   _DBUS_ASSERT_ERROR_IS_SET (error);
719   _dbus_string_free (&contents);
720   _dbus_string_free (&decoded);
721   return FALSE;
722 }
723 
724 static dbus_bool_t
_dbus_create_uuid_file_exclusively(const DBusString * filename,DBusGUID * uuid,DBusError * error)725 _dbus_create_uuid_file_exclusively (const DBusString *filename,
726                                     DBusGUID         *uuid,
727                                     DBusError        *error)
728 {
729   DBusString encoded;
730 
731   if (!_dbus_string_init (&encoded))
732     {
733       _DBUS_SET_OOM (error);
734       return FALSE;
735     }
736 
737   _dbus_generate_uuid (uuid);
738 
739   if (!_dbus_uuid_encode (uuid, &encoded))
740     {
741       _DBUS_SET_OOM (error);
742       goto error;
743     }
744 
745   if (!_dbus_string_append_byte (&encoded, '\n'))
746     {
747       _DBUS_SET_OOM (error);
748       goto error;
749     }
750 
751   if (!_dbus_string_save_to_file (&encoded, filename, TRUE, error))
752     goto error;
753 
754   _dbus_string_free (&encoded);
755 
756   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
757   return TRUE;
758 
759  error:
760   _DBUS_ASSERT_ERROR_IS_SET (error);
761   _dbus_string_free (&encoded);
762   return FALSE;
763 }
764 
765 /**
766  * Reads (and optionally writes) a uuid to a file. Initializes the uuid
767  * unless an error is returned.
768  *
769  * @param filename the name of the file
770  * @param uuid uuid to be initialized with the loaded uuid
771  * @param create_if_not_found #TRUE to create a new uuid and save it if the file doesn't exist
772  * @param error the error return
773  * @returns #FALSE if the error is set
774  */
775 dbus_bool_t
_dbus_read_uuid_file(const DBusString * filename,DBusGUID * uuid,dbus_bool_t create_if_not_found,DBusError * error)776 _dbus_read_uuid_file (const DBusString *filename,
777                       DBusGUID         *uuid,
778                       dbus_bool_t       create_if_not_found,
779                       DBusError        *error)
780 {
781   DBusError read_error = DBUS_ERROR_INIT;
782 
783   if (_dbus_read_uuid_file_without_creating (filename, uuid, &read_error))
784     return TRUE;
785 
786   if (!create_if_not_found)
787     {
788       dbus_move_error (&read_error, error);
789       return FALSE;
790     }
791 
792   /* If the file exists and contains junk, we want to keep that error
793    * message instead of overwriting it with a "file exists" error
794    * message when we try to write
795    */
796   if (dbus_error_has_name (&read_error, DBUS_ERROR_INVALID_FILE_CONTENT))
797     {
798       dbus_move_error (&read_error, error);
799       return FALSE;
800     }
801   else
802     {
803       dbus_error_free (&read_error);
804       return _dbus_create_uuid_file_exclusively (filename, uuid, error);
805     }
806 }
807 
808 _DBUS_DEFINE_GLOBAL_LOCK (machine_uuid);
809 static int machine_uuid_initialized_generation = 0;
810 static DBusGUID machine_uuid;
811 
812 /**
813  * Gets the hex-encoded UUID of the machine this function is
814  * executed on. This UUID is guaranteed to be the same for a given
815  * machine at least until it next reboots, though it also
816  * makes some effort to be the same forever, it may change if the
817  * machine is reconfigured or its hardware is modified.
818  *
819  * @param uuid_str string to append hex-encoded machine uuid to
820  * @returns #FALSE if no memory
821  */
822 dbus_bool_t
_dbus_get_local_machine_uuid_encoded(DBusString * uuid_str)823 _dbus_get_local_machine_uuid_encoded (DBusString *uuid_str)
824 {
825   dbus_bool_t ok;
826 
827   _DBUS_LOCK (machine_uuid);
828   if (machine_uuid_initialized_generation != _dbus_current_generation)
829     {
830       DBusError error = DBUS_ERROR_INIT;
831 
832       if (!_dbus_read_local_machine_uuid (&machine_uuid, FALSE,
833                                           &error))
834         {
835 #ifndef DBUS_BUILD_TESTS
836           /* For the test suite, we may not be installed so just continue silently
837            * here. But in a production build, we want to be nice and loud about
838            * this.
839            */
840           _dbus_warn_check_failed ("D-Bus library appears to be incorrectly set up; failed to read machine uuid: %s\n"
841                                    "See the manual page for dbus-uuidgen to correct this issue.\n",
842                                    error.message);
843 #endif
844 
845           dbus_error_free (&error);
846 
847           _dbus_generate_uuid (&machine_uuid);
848         }
849     }
850 
851   ok = _dbus_uuid_encode (&machine_uuid, uuid_str);
852 
853   _DBUS_UNLOCK (machine_uuid);
854 
855   return ok;
856 }
857 
858 #ifdef DBUS_BUILD_TESTS
859 /**
860  * Returns a string describing the given name.
861  *
862  * @param header_field the field to describe
863  * @returns a constant string describing the field
864  */
865 const char *
_dbus_header_field_to_string(int header_field)866 _dbus_header_field_to_string (int header_field)
867 {
868   switch (header_field)
869     {
870     case DBUS_HEADER_FIELD_INVALID:
871       return "invalid";
872     case DBUS_HEADER_FIELD_PATH:
873       return "path";
874     case DBUS_HEADER_FIELD_INTERFACE:
875       return "interface";
876     case DBUS_HEADER_FIELD_MEMBER:
877       return "member";
878     case DBUS_HEADER_FIELD_ERROR_NAME:
879       return "error-name";
880     case DBUS_HEADER_FIELD_REPLY_SERIAL:
881       return "reply-serial";
882     case DBUS_HEADER_FIELD_DESTINATION:
883       return "destination";
884     case DBUS_HEADER_FIELD_SENDER:
885       return "sender";
886     case DBUS_HEADER_FIELD_SIGNATURE:
887       return "signature";
888     default:
889       return "unknown";
890     }
891 }
892 #endif /* DBUS_BUILD_TESTS */
893 
894 #ifndef DBUS_DISABLE_CHECKS
895 /** String used in _dbus_return_if_fail macro */
896 const char *_dbus_return_if_fail_warning_format =
897 "arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\n"
898 "This is normally a bug in some application using the D-Bus library.\n";
899 #endif
900 
901 #ifndef DBUS_DISABLE_ASSERT
902 /**
903  * Internals of _dbus_assert(); it's a function
904  * rather than a macro with the inline code so
905  * that the assertion failure blocks don't show up
906  * in test suite coverage, and to shrink code size.
907  *
908  * @param condition TRUE if assertion succeeded
909  * @param condition_text condition as a string
910  * @param file file the assertion is in
911  * @param line line the assertion is in
912  * @param func function the assertion is in
913  */
914 void
_dbus_real_assert(dbus_bool_t condition,const char * condition_text,const char * file,int line,const char * func)915 _dbus_real_assert (dbus_bool_t  condition,
916                    const char  *condition_text,
917                    const char  *file,
918                    int          line,
919                    const char  *func)
920 {
921   if (_DBUS_UNLIKELY (!condition))
922     {
923       _dbus_warn ("%lu: assertion failed \"%s\" file \"%s\" line %d function %s\n",
924                   _dbus_pid_for_log (), condition_text, file, line, func);
925       _dbus_abort ();
926     }
927 }
928 
929 /**
930  * Internals of _dbus_assert_not_reached(); it's a function
931  * rather than a macro with the inline code so
932  * that the assertion failure blocks don't show up
933  * in test suite coverage, and to shrink code size.
934  *
935  * @param explanation what was reached that shouldn't have been
936  * @param file file the assertion is in
937  * @param line line the assertion is in
938  */
939 void
_dbus_real_assert_not_reached(const char * explanation,const char * file,int line)940 _dbus_real_assert_not_reached (const char *explanation,
941                                const char *file,
942                                int         line)
943 {
944   _dbus_warn ("File \"%s\" line %d process %lu should not have been reached: %s\n",
945               file, line, _dbus_pid_for_log (), explanation);
946   _dbus_abort ();
947 }
948 #endif /* DBUS_DISABLE_ASSERT */
949 
950 #ifdef DBUS_BUILD_TESTS
951 static dbus_bool_t
run_failing_each_malloc(int n_mallocs,const char * description,DBusTestMemoryFunction func,void * data)952 run_failing_each_malloc (int                    n_mallocs,
953                          const char            *description,
954                          DBusTestMemoryFunction func,
955                          void                  *data)
956 {
957   n_mallocs += 10; /* fudge factor to ensure reallocs etc. are covered */
958 
959   while (n_mallocs >= 0)
960     {
961       _dbus_set_fail_alloc_counter (n_mallocs);
962 
963       _dbus_verbose ("\n===\n%s: (will fail malloc %d with %d failures)\n===\n",
964                      description, n_mallocs,
965                      _dbus_get_fail_alloc_failures ());
966 
967       if (!(* func) (data))
968         return FALSE;
969 
970       n_mallocs -= 1;
971     }
972 
973   _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
974 
975   return TRUE;
976 }
977 
978 /**
979  * Tests how well the given function responds to out-of-memory
980  * situations. Calls the function repeatedly, failing a different
981  * call to malloc() each time. If the function ever returns #FALSE,
982  * the test fails. The function should return #TRUE whenever something
983  * valid (such as returning an error, or succeeding) occurs, and #FALSE
984  * if it gets confused in some way.
985  *
986  * @param description description of the test used in verbose output
987  * @param func function to call
988  * @param data data to pass to function
989  * @returns #TRUE if the function never returns FALSE
990  */
991 dbus_bool_t
_dbus_test_oom_handling(const char * description,DBusTestMemoryFunction func,void * data)992 _dbus_test_oom_handling (const char             *description,
993                          DBusTestMemoryFunction  func,
994                          void                   *data)
995 {
996   int approx_mallocs;
997   const char *setting;
998   int max_failures_to_try;
999   int i;
1000 
1001   /* Run once to see about how many mallocs are involved */
1002 
1003   _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
1004 
1005   _dbus_verbose ("Running once to count mallocs\n");
1006 
1007   if (!(* func) (data))
1008     return FALSE;
1009 
1010   approx_mallocs = _DBUS_INT_MAX - _dbus_get_fail_alloc_counter ();
1011 
1012   _dbus_verbose ("\n=================\n%s: about %d mallocs total\n=================\n",
1013                  description, approx_mallocs);
1014 
1015   setting = _dbus_getenv ("DBUS_TEST_MALLOC_FAILURES");
1016   if (setting != NULL)
1017     {
1018       DBusString str;
1019       long v;
1020       _dbus_string_init_const (&str, setting);
1021       v = 4;
1022       if (!_dbus_string_parse_int (&str, 0, &v, NULL))
1023         _dbus_warn ("couldn't parse '%s' as integer\n", setting);
1024       max_failures_to_try = v;
1025     }
1026   else
1027     {
1028       max_failures_to_try = 4;
1029     }
1030 
1031   i = setting ? max_failures_to_try - 1 : 1;
1032   while (i < max_failures_to_try)
1033     {
1034       _dbus_set_fail_alloc_failures (i);
1035       if (!run_failing_each_malloc (approx_mallocs, description, func, data))
1036         return FALSE;
1037       ++i;
1038     }
1039 
1040   _dbus_verbose ("\n=================\n%s: all iterations passed\n=================\n",
1041                  description);
1042 
1043   return TRUE;
1044 }
1045 #endif /* DBUS_BUILD_TESTS */
1046 
1047 /** @} */
1048