1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-internals.c random utility stuff (internal to D-Bus implementation)
4 * Copyright (C) 2002, 2003 Red Hat, Inc.
6 * Licensed under the Academic Free License version 2.1
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.
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.
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
25 #include "dbus-internals.h"
26 #include "dbus-protocol.h"
27 #include "dbus-marshal-basic.h"
28 #include "dbus-test.h"
29 #include "dbus-valgrind-internal.h"
34 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
40 * @defgroup DBusInternals D-Bus secret internal implementation details
41 * @brief Documentation useful when developing or debugging D-Bus itself.
46 * @defgroup DBusInternalsUtils Utilities and portability
47 * @ingroup DBusInternals
48 * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.)
55 * Aborts with an error message if the condition is false.
57 * @param condition condition which must be true.
61 * @def _dbus_assert_not_reached
63 * Aborts with an error message if called.
64 * The given explanation will be printed.
66 * @param explanation explanation of what happened if the code was reached.
70 * @def _DBUS_N_ELEMENTS
72 * Computes the number of elements in a fixed-size array using
75 * @param array the array to count elements in.
79 * @def _DBUS_POINTER_TO_INT
81 * Safely casts a void* to an integer; should only be used on void*
82 * that actually contain integers, for example one created with
83 * _DBUS_INT_TO_POINTER. Only guaranteed to preserve 32 bits.
84 * (i.e. it's used to store 32-bit ints in pointers, but
85 * can't be used to store 64-bit pointers in ints.)
87 * @param pointer pointer to extract an integer from.
90 * @def _DBUS_INT_TO_POINTER
92 * Safely stuffs an integer into a pointer, to be extracted later with
93 * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits.
95 * @param integer the integer to stuff into a pointer.
100 * Sets all bits in an object to zero.
102 * @param object the object to be zeroed.
105 * @def _DBUS_INT16_MIN
107 * Minimum value of type "int16"
110 * @def _DBUS_INT16_MAX
112 * Maximum value of type "int16"
115 * @def _DBUS_UINT16_MAX
117 * Maximum value of type "uint16"
121 * @def _DBUS_INT32_MIN
123 * Minimum value of type "int32"
126 * @def _DBUS_INT32_MAX
128 * Maximum value of type "int32"
131 * @def _DBUS_UINT32_MAX
133 * Maximum value of type "uint32"
139 * Minimum value of type "int"
144 * Maximum value of type "int"
147 * @def _DBUS_UINT_MAX
149 * Maximum value of type "uint"
153 * @typedef DBusForeachFunction
155 * Used to iterate over each item in a collection, such as
160 * @def _DBUS_LOCK_NAME
162 * Expands to name of a global lock variable.
168 * Locks a global lock
174 * Unlocks a global lock
178 * Fixed "out of memory" error message, just to avoid
179 * making up a different string every time and wasting
182 const char *_dbus_no_memory_message = "Not enough memory";
184 static dbus_bool_t warn_initted = FALSE;
185 static dbus_bool_t fatal_warnings = FALSE;
186 static dbus_bool_t fatal_warnings_on_check_failed = TRUE;
194 s = _dbus_getenv ("DBUS_FATAL_WARNINGS");
199 fatal_warnings = FALSE;
200 fatal_warnings_on_check_failed = FALSE;
204 fatal_warnings = TRUE;
205 fatal_warnings_on_check_failed = TRUE;
209 fprintf(stderr, "DBUS_FATAL_WARNINGS should be set to 0 or 1 if set, not '%s'",
219 * Prints a warning message to stderr. Can optionally be made to exit
220 * fatally by setting DBUS_FATAL_WARNINGS, but this is rarely
221 * used. This function should be considered pretty much equivalent to
222 * fprintf(stderr). _dbus_warn_check_failed() on the other hand is
223 * suitable for use when a programming mistake has been made.
225 * @param format printf-style format string.
228 _dbus_warn (const char *format,
236 va_start (args, format);
237 vfprintf (stderr, format, args);
248 * Prints a "critical" warning to stderr when an assertion fails;
249 * differs from _dbus_warn primarily in that it prefixes the pid and
250 * defaults to fatal. This should be used only when a programming
251 * error has been detected. (NOT for unavoidable errors that an app
252 * might handle - those should be returned as DBusError.) Calling this
253 * means "there is a bug"
256 _dbus_warn_check_failed(const char *format,
264 fprintf (stderr, "process %lu: ", _dbus_pid_for_log ());
266 va_start (args, format);
267 vfprintf (stderr, format, args);
270 if (fatal_warnings_on_check_failed)
277 #ifdef DBUS_ENABLE_VERBOSE_MODE
279 static dbus_bool_t verbose_initted = FALSE;
280 static dbus_bool_t verbose = TRUE;
282 /** Whether to show the current thread in verbose messages */
283 #define PTHREAD_IN_VERBOSE 0
284 #if PTHREAD_IN_VERBOSE
288 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
289 static char module_name[1024];
293 _dbus_verbose_init (void)
295 if (!verbose_initted)
297 const char *p = _dbus_getenv ("DBUS_VERBOSE");
298 verbose = p != NULL && *p == '1';
299 verbose_initted = TRUE;
300 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
302 char *last_period, *last_slash;
303 GetModuleFileName(0,module_name,sizeof(module_name)-1);
304 last_period = _mbsrchr(module_name,'.');
307 last_slash = _mbsrchr(module_name,'\\');
309 strcpy(module_name,last_slash+1);
310 strcat(module_name,": ");
316 /** @def DBUS_IS_DIR_SEPARATOR(c)
317 * macro for checking if character c is a patch separator
319 * @todo move to a header file so that others can use this too
322 #define DBUS_IS_DIR_SEPARATOR(c) (c == '\\' || c == '/')
324 #define DBUS_IS_DIR_SEPARATOR(c) (c == '/')
328 remove source root from file path
329 the source root is determined by
331 static char *_dbus_file_path_extract_elements_from_tail(const char *file,int level)
333 static int prefix = -1;
337 char *p = (char *)file + strlen(file);
342 if (DBUS_IS_DIR_SEPARATOR(*p))
352 return (char *)file+prefix;
356 * Implementation of dbus_is_verbose() macro if built with verbose logging
358 * @returns whether verbose logging is active.
361 _dbus_is_verbose_real (void)
363 _dbus_verbose_init ();
368 * Prints a warning message to stderr
369 * if the user has enabled verbose mode.
370 * This is the real function implementation,
371 * use _dbus_verbose() macro in code.
373 * @param format printf-style format string.
377 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
380 const char *function,
386 static dbus_bool_t need_pid = TRUE;
389 /* things are written a bit oddly here so that
390 * in the non-verbose case we just have the one
391 * conditional and return immediately.
393 if (!_dbus_is_verbose_real())
396 #ifndef DBUS_USE_OUTPUT_DEBUG_STRING
397 /* Print out pid before the line */
400 #if PTHREAD_IN_VERBOSE
401 fprintf (stderr, "%lu: 0x%lx: ", _dbus_pid_for_log (), pthread_self ());
403 fprintf (stderr, "%lu: ", _dbus_pid_for_log ());
408 /* Only print pid again if the next line is a new line */
409 len = strlen (format);
410 if (format[len-1] == '\n')
415 va_start (args, format);
416 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
419 strcpy(buf,module_name);
420 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
421 sprintf (buf+strlen(buf), "[%s(%d):%s] ",_dbus_file_path_extract_elements_from_tail(file,2),line,function);
423 vsprintf (buf+strlen(buf),format, args);
425 OutputDebugStringA(buf);
428 #ifdef DBUS_CPP_SUPPORTS_VARIABLE_MACRO_ARGUMENTS
429 fprintf (stderr, "[%s(%d):%s] ",_dbus_file_path_extract_elements_from_tail(file,2),line,function);
432 vfprintf (stderr, format, args);
440 * Reinitializes the verbose logging code, used
441 * as a hack in dbus-spawn.c so that a child
442 * process re-reads its pid
446 _dbus_verbose_reset_real (void)
448 verbose_initted = FALSE;
452 _dbus_trace_ref (const char *obj_name,
460 _dbus_assert (obj_name != NULL);
461 _dbus_assert (obj != NULL);
462 _dbus_assert (old_refcount >= -1);
463 _dbus_assert (new_refcount >= -1);
465 if (old_refcount == -1)
467 _dbus_assert (new_refcount == -1);
471 _dbus_assert (new_refcount >= 0);
472 _dbus_assert (old_refcount >= 0);
473 _dbus_assert (old_refcount > 0 || new_refcount > 0);
476 _dbus_assert (why != NULL);
477 _dbus_assert (env_var != NULL);
478 _dbus_assert (enabled != NULL);
482 const char *s = _dbus_getenv (env_var);
493 _dbus_warn ("%s should be 0 or 1 if set, not '%s'", env_var, s);
499 if (old_refcount == -1)
501 VALGRIND_PRINTF_BACKTRACE ("%s %p ref stolen (%s)",
503 _dbus_verbose ("%s %p ref stolen (%s)",
508 VALGRIND_PRINTF_BACKTRACE ("%s %p %d -> %d refs (%s)",
510 old_refcount, new_refcount, why);
511 _dbus_verbose ("%s %p %d -> %d refs (%s)",
512 obj_name, obj, old_refcount, new_refcount, why);
517 #endif /* DBUS_ENABLE_VERBOSE_MODE */
520 * Duplicates a string. Result must be freed with
521 * dbus_free(). Returns #NULL if memory allocation fails.
522 * If the string to be duplicated is #NULL, returns #NULL.
524 * @param str string to duplicate.
525 * @returns newly-allocated copy.
528 _dbus_strdup (const char *str)
538 copy = dbus_malloc (len + 1);
542 memcpy (copy, str, len + 1);
548 * Duplicates a block of memory. Returns
551 * @param mem memory to copy
552 * @param n_bytes number of bytes to copy
556 _dbus_memdup (const void *mem,
561 copy = dbus_malloc (n_bytes);
565 memcpy (copy, mem, n_bytes);
571 * Duplicates a string array. Result may be freed with
572 * dbus_free_string_array(). Returns #NULL if memory allocation fails.
573 * If the array to be duplicated is #NULL, returns #NULL.
575 * @param array array to duplicate.
576 * @returns newly-allocated copy.
579 _dbus_dup_string_array (const char **array)
588 for (len = 0; array[len] != NULL; ++len)
591 copy = dbus_new0 (char*, len + 1);
598 copy[i] = _dbus_strdup (array[i]);
601 dbus_free_string_array (copy);
612 * Checks whether a string array contains the given string.
614 * @param array array to search.
615 * @param str string to look for
616 * @returns #TRUE if array contains string
619 _dbus_string_array_contains (const char **array,
625 while (array[i] != NULL)
627 if (strcmp (array[i], str) == 0)
636 * Generates a new UUID. If you change how this is done,
637 * there's some text about it in the spec that should also change.
639 * @param uuid the uuid to initialize
642 _dbus_generate_uuid (DBusGUID *uuid)
646 /* don't use monotonic time because the UUID may be saved to disk, e.g.
647 * it may persist across reboots
649 _dbus_get_real_time (&now, NULL);
651 uuid->as_uint32s[DBUS_UUID_LENGTH_WORDS - 1] = DBUS_UINT32_TO_BE (now);
653 _dbus_generate_random_bytes_buffer (uuid->as_bytes, DBUS_UUID_LENGTH_BYTES - 4);
659 * @param uuid the uuid
660 * @param encoded string to append hex uuid to
661 * @returns #FALSE if no memory
664 _dbus_uuid_encode (const DBusGUID *uuid,
668 _dbus_string_init_const_len (&binary, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
669 return _dbus_string_hex_encode (&binary, 0, encoded, _dbus_string_get_length (encoded));
673 _dbus_read_uuid_file_without_creating (const DBusString *filename,
681 if (!_dbus_string_init (&contents))
683 _DBUS_SET_OOM (error);
687 if (!_dbus_string_init (&decoded))
689 _dbus_string_free (&contents);
690 _DBUS_SET_OOM (error);
694 if (!_dbus_file_get_contents (&contents, filename, error))
697 _dbus_string_chop_white (&contents);
699 if (_dbus_string_get_length (&contents) != DBUS_UUID_LENGTH_HEX)
701 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
702 "UUID file '%s' should contain a hex string of length %d, not length %d, with no other text",
703 _dbus_string_get_const_data (filename),
704 DBUS_UUID_LENGTH_HEX,
705 _dbus_string_get_length (&contents));
709 if (!_dbus_string_hex_decode (&contents, 0, &end, &decoded, 0))
711 _DBUS_SET_OOM (error);
717 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
718 "UUID file '%s' contains invalid hex data",
719 _dbus_string_get_const_data (filename));
723 if (_dbus_string_get_length (&decoded) != DBUS_UUID_LENGTH_BYTES)
725 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
726 "UUID file '%s' contains %d bytes of hex-encoded data instead of %d",
727 _dbus_string_get_const_data (filename),
728 _dbus_string_get_length (&decoded),
729 DBUS_UUID_LENGTH_BYTES);
733 _dbus_string_copy_to_buffer (&decoded, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
735 _dbus_string_free (&decoded);
736 _dbus_string_free (&contents);
738 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
743 _DBUS_ASSERT_ERROR_IS_SET (error);
744 _dbus_string_free (&contents);
745 _dbus_string_free (&decoded);
750 _dbus_create_uuid_file_exclusively (const DBusString *filename,
756 if (!_dbus_string_init (&encoded))
758 _DBUS_SET_OOM (error);
762 _dbus_generate_uuid (uuid);
764 if (!_dbus_uuid_encode (uuid, &encoded))
766 _DBUS_SET_OOM (error);
770 if (!_dbus_string_append_byte (&encoded, '\n'))
772 _DBUS_SET_OOM (error);
776 if (!_dbus_string_save_to_file (&encoded, filename, TRUE, error))
779 _dbus_string_free (&encoded);
781 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
785 _DBUS_ASSERT_ERROR_IS_SET (error);
786 _dbus_string_free (&encoded);
791 * Reads (and optionally writes) a uuid to a file. Initializes the uuid
792 * unless an error is returned.
794 * @param filename the name of the file
795 * @param uuid uuid to be initialized with the loaded uuid
796 * @param create_if_not_found #TRUE to create a new uuid and save it if the file doesn't exist
797 * @param error the error return
798 * @returns #FALSE if the error is set
801 _dbus_read_uuid_file (const DBusString *filename,
803 dbus_bool_t create_if_not_found,
806 DBusError read_error = DBUS_ERROR_INIT;
808 if (_dbus_read_uuid_file_without_creating (filename, uuid, &read_error))
811 if (!create_if_not_found)
813 dbus_move_error (&read_error, error);
817 /* If the file exists and contains junk, we want to keep that error
818 * message instead of overwriting it with a "file exists" error
819 * message when we try to write
821 if (dbus_error_has_name (&read_error, DBUS_ERROR_INVALID_FILE_CONTENT))
823 dbus_move_error (&read_error, error);
828 dbus_error_free (&read_error);
829 return _dbus_create_uuid_file_exclusively (filename, uuid, error);
833 /* Protected by _DBUS_LOCK (machine_uuid) */
834 static int machine_uuid_initialized_generation = 0;
835 static DBusGUID machine_uuid;
838 * Gets the hex-encoded UUID of the machine this function is
839 * executed on. This UUID is guaranteed to be the same for a given
840 * machine at least until it next reboots, though it also
841 * makes some effort to be the same forever, it may change if the
842 * machine is reconfigured or its hardware is modified.
844 * @param uuid_str string to append hex-encoded machine uuid to
845 * @returns #FALSE if no memory
848 _dbus_get_local_machine_uuid_encoded (DBusString *uuid_str)
852 _DBUS_LOCK (machine_uuid);
853 if (machine_uuid_initialized_generation != _dbus_current_generation)
855 DBusError error = DBUS_ERROR_INIT;
857 if (!_dbus_read_local_machine_uuid (&machine_uuid, FALSE,
860 #ifndef DBUS_BUILD_TESTS
861 /* For the test suite, we may not be installed so just continue silently
862 * here. But in a production build, we want to be nice and loud about
865 _dbus_warn_check_failed ("D-Bus library appears to be incorrectly set up; failed to read machine uuid: %s\n"
866 "See the manual page for dbus-uuidgen to correct this issue.\n",
870 dbus_error_free (&error);
872 _dbus_generate_uuid (&machine_uuid);
876 ok = _dbus_uuid_encode (&machine_uuid, uuid_str);
878 _DBUS_UNLOCK (machine_uuid);
883 #ifndef DBUS_DISABLE_CHECKS
884 /** String used in _dbus_return_if_fail macro */
885 const char *_dbus_return_if_fail_warning_format =
886 "arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\n"
887 "This is normally a bug in some application using the D-Bus library.\n";
890 #ifndef DBUS_DISABLE_ASSERT
892 * Internals of _dbus_assert(); it's a function
893 * rather than a macro with the inline code so
894 * that the assertion failure blocks don't show up
895 * in test suite coverage, and to shrink code size.
897 * @param condition TRUE if assertion succeeded
898 * @param condition_text condition as a string
899 * @param file file the assertion is in
900 * @param line line the assertion is in
901 * @param func function the assertion is in
904 _dbus_real_assert (dbus_bool_t condition,
905 const char *condition_text,
910 if (_DBUS_UNLIKELY (!condition))
912 _dbus_warn ("%lu: assertion failed \"%s\" file \"%s\" line %d function %s\n",
913 _dbus_pid_for_log (), condition_text, file, line, func);
919 * Internals of _dbus_assert_not_reached(); it's a function
920 * rather than a macro with the inline code so
921 * that the assertion failure blocks don't show up
922 * in test suite coverage, and to shrink code size.
924 * @param explanation what was reached that shouldn't have been
925 * @param file file the assertion is in
926 * @param line line the assertion is in
929 _dbus_real_assert_not_reached (const char *explanation,
933 _dbus_warn ("File \"%s\" line %d process %lu should not have been reached: %s\n",
934 file, line, _dbus_pid_for_log (), explanation);
937 #endif /* DBUS_DISABLE_ASSERT */
939 #ifdef DBUS_BUILD_TESTS
941 run_failing_each_malloc (int n_mallocs,
942 const char *description,
943 DBusTestMemoryFunction func,
946 n_mallocs += 10; /* fudge factor to ensure reallocs etc. are covered */
948 while (n_mallocs >= 0)
950 _dbus_set_fail_alloc_counter (n_mallocs);
952 _dbus_verbose ("\n===\n%s: (will fail malloc %d with %d failures)\n===\n",
953 description, n_mallocs,
954 _dbus_get_fail_alloc_failures ());
956 if (!(* func) (data))
962 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
968 * Tests how well the given function responds to out-of-memory
969 * situations. Calls the function repeatedly, failing a different
970 * call to malloc() each time. If the function ever returns #FALSE,
971 * the test fails. The function should return #TRUE whenever something
972 * valid (such as returning an error, or succeeding) occurs, and #FALSE
973 * if it gets confused in some way.
975 * @param description description of the test used in verbose output
976 * @param func function to call
977 * @param data data to pass to function
978 * @returns #TRUE if the function never returns FALSE
981 _dbus_test_oom_handling (const char *description,
982 DBusTestMemoryFunction func,
987 int max_failures_to_try;
990 /* Run once to see about how many mallocs are involved */
992 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
994 _dbus_verbose ("Running once to count mallocs\n");
996 if (!(* func) (data))
999 approx_mallocs = _DBUS_INT_MAX - _dbus_get_fail_alloc_counter ();
1001 _dbus_verbose ("\n=================\n%s: about %d mallocs total\n=================\n",
1002 description, approx_mallocs);
1004 setting = _dbus_getenv ("DBUS_TEST_MALLOC_FAILURES");
1005 if (setting != NULL)
1009 _dbus_string_init_const (&str, setting);
1011 if (!_dbus_string_parse_int (&str, 0, &v, NULL))
1012 _dbus_warn ("couldn't parse '%s' as integer\n", setting);
1013 max_failures_to_try = v;
1017 max_failures_to_try = 4;
1020 i = setting ? max_failures_to_try - 1 : 1;
1021 while (i < max_failures_to_try)
1023 _dbus_set_fail_alloc_failures (i);
1024 if (!run_failing_each_malloc (approx_mallocs, description, func, data))
1029 _dbus_verbose ("\n=================\n%s: all iterations passed\n=================\n",
1034 #endif /* DBUS_BUILD_TESTS */