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
23 #include "dbus-internals.h"
24 #include "dbus-protocol.h"
25 #include "dbus-marshal-basic.h"
26 #include "dbus-test.h"
31 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
36 * @defgroup DBusInternals D-Bus secret internal implementation details
37 * @brief Documentation useful when developing or debugging D-Bus itself.
42 * @defgroup DBusInternalsUtils Utilities and portability
43 * @ingroup DBusInternals
44 * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.)
51 * Aborts with an error message if the condition is false.
53 * @param condition condition which must be true.
57 * @def _dbus_assert_not_reached
59 * Aborts with an error message if called.
60 * The given explanation will be printed.
62 * @param explanation explanation of what happened if the code was reached.
66 * @def _DBUS_N_ELEMENTS
68 * Computes the number of elements in a fixed-size array using
71 * @param array the array to count elements in.
75 * @def _DBUS_POINTER_TO_INT
77 * Safely casts a void* to an integer; should only be used on void*
78 * that actually contain integers, for example one created with
79 * _DBUS_INT_TO_POINTER. Only guaranteed to preserve 32 bits.
80 * (i.e. it's used to store 32-bit ints in pointers, but
81 * can't be used to store 64-bit pointers in ints.)
83 * @param pointer pointer to extract an integer from.
86 * @def _DBUS_INT_TO_POINTER
88 * Safely stuffs an integer into a pointer, to be extracted later with
89 * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits.
91 * @param integer the integer to stuff into a pointer.
96 * Sets all bits in an object to zero.
98 * @param object the object to be zeroed.
101 * @def _DBUS_INT16_MIN
103 * Minimum value of type "int16"
106 * @def _DBUS_INT16_MAX
108 * Maximum value of type "int16"
111 * @def _DBUS_UINT16_MAX
113 * Maximum value of type "uint16"
117 * @def _DBUS_INT32_MIN
119 * Minimum value of type "int32"
122 * @def _DBUS_INT32_MAX
124 * Maximum value of type "int32"
127 * @def _DBUS_UINT32_MAX
129 * Maximum value of type "uint32"
135 * Minimum value of type "int"
140 * Maximum value of type "int"
143 * @def _DBUS_UINT_MAX
145 * Maximum value of type "uint"
149 * @typedef DBusForeachFunction
151 * Used to iterate over each item in a collection, such as
156 * @def _DBUS_LOCK_NAME
158 * Expands to name of a global lock variable.
162 * @def _DBUS_DEFINE_GLOBAL_LOCK
164 * Defines a global lock variable with the given name.
165 * The lock must be added to the list to initialize
166 * in dbus_threads_init().
170 * @def _DBUS_DECLARE_GLOBAL_LOCK
172 * Expands to declaration of a global lock defined
173 * with _DBUS_DEFINE_GLOBAL_LOCK.
174 * The lock must be added to the list to initialize
175 * in dbus_threads_init().
181 * Locks a global lock
187 * Unlocks a global lock
191 * Fixed "out of memory" error message, just to avoid
192 * making up a different string every time and wasting
195 const char *_dbus_no_memory_message = "Not enough memory";
197 static dbus_bool_t warn_initted = FALSE;
198 static dbus_bool_t fatal_warnings = FALSE;
199 static dbus_bool_t fatal_warnings_on_check_failed = TRUE;
207 s = _dbus_getenv ("DBUS_FATAL_WARNINGS");
212 fatal_warnings = FALSE;
213 fatal_warnings_on_check_failed = FALSE;
217 fatal_warnings = TRUE;
218 fatal_warnings_on_check_failed = TRUE;
222 fprintf(stderr, "DBUS_FATAL_WARNINGS should be set to 0 or 1 if set, not '%s'",
232 * Prints a warning message to stderr. Can optionally be made to exit
233 * fatally by setting DBUS_FATAL_WARNINGS, but this is rarely
234 * used. This function should be considered pretty much equivalent to
235 * fprintf(stderr). _dbus_warn_check_failed() on the other hand is
236 * suitable for use when a programming mistake has been made.
238 * @param format printf-style format string.
241 _dbus_warn (const char *format,
249 va_start (args, format);
250 vfprintf (stderr, format, args);
261 * Prints a "critical" warning to stderr when an assertion fails;
262 * differs from _dbus_warn primarily in that it prefixes the pid and
263 * defaults to fatal. This should be used only when a programming
264 * error has been detected. (NOT for unavoidable errors that an app
265 * might handle - those should be returned as DBusError.) Calling this
266 * means "there is a bug"
269 _dbus_warn_check_failed(const char *format,
277 fprintf (stderr, "process %lu: ", _dbus_pid_for_log ());
279 va_start (args, format);
280 vfprintf (stderr, format, args);
283 if (fatal_warnings_on_check_failed)
290 #ifdef DBUS_ENABLE_VERBOSE_MODE
292 static dbus_bool_t verbose_initted = FALSE;
293 static dbus_bool_t verbose = TRUE;
295 /** Whether to show the current thread in verbose messages */
296 #define PTHREAD_IN_VERBOSE 0
297 #if PTHREAD_IN_VERBOSE
304 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
305 static char module_name[1024];
309 _dbus_verbose_init (void)
311 if (!verbose_initted)
313 char *p = _dbus_getenv ("DBUS_VERBOSE");
314 verbose = p != NULL && *p == '1';
315 verbose_initted = TRUE;
316 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
317 GetModuleFileName(0,module_name,sizeof(module_name)-1);
318 p = strrchr(module_name,'.');
321 p = strrchr(module_name,'\\');
323 strcpy(module_name,p+1);
324 strcat(module_name,": ");
330 * Implementation of dbus_is_verbose() macro if built with verbose logging
332 * @returns whether verbose logging is active.
335 _dbus_is_verbose_real (void)
337 _dbus_verbose_init ();
342 * Prints a warning message to stderr
343 * if the user has enabled verbose mode.
344 * This is the real function implementation,
345 * use _dbus_verbose() macro in code.
347 * @param format printf-style format string.
350 _dbus_verbose_real (const char *format,
354 static dbus_bool_t need_pid = TRUE;
357 /* things are written a bit oddly here so that
358 * in the non-verbose case we just have the one
359 * conditional and return immediately.
361 if (!_dbus_is_verbose_real())
364 #ifndef DBUS_USE_OUTPUT_DEBUG_STRING
365 /* Print out pid before the line */
368 #if PTHREAD_IN_VERBOSE
369 fprintf (stderr, "%lu: 0x%lx: ", _dbus_pid_for_log (), pthread_self ());
371 fprintf (stderr, "%lu: ", _dbus_pid_for_log ());
376 /* Only print pid again if the next line is a new line */
377 len = strlen (format);
378 if (format[len-1] == '\n')
383 va_start (args, format);
384 #ifdef DBUS_USE_OUTPUT_DEBUG_STRING
387 strcpy(buf,module_name);
388 vsprintf (buf+strlen(buf),format, args);
390 OutputDebugString(buf);
393 vfprintf (stderr, format, args);
401 * Reinitializes the verbose logging code, used
402 * as a hack in dbus-spawn.c so that a child
403 * process re-reads its pid
407 _dbus_verbose_reset_real (void)
409 verbose_initted = FALSE;
412 #endif /* DBUS_ENABLE_VERBOSE_MODE */
415 * Duplicates a string. Result must be freed with
416 * dbus_free(). Returns #NULL if memory allocation fails.
417 * If the string to be duplicated is #NULL, returns #NULL.
419 * @param str string to duplicate.
420 * @returns newly-allocated copy.
423 _dbus_strdup (const char *str)
433 copy = dbus_malloc (len + 1);
437 memcpy (copy, str, len + 1);
443 * Duplicates a block of memory. Returns
446 * @param mem memory to copy
447 * @param n_bytes number of bytes to copy
451 _dbus_memdup (const void *mem,
456 copy = dbus_malloc (n_bytes);
460 memcpy (copy, mem, n_bytes);
466 * Duplicates a string array. Result may be freed with
467 * dbus_free_string_array(). Returns #NULL if memory allocation fails.
468 * If the array to be duplicated is #NULL, returns #NULL.
470 * @param array array to duplicate.
471 * @returns newly-allocated copy.
474 _dbus_dup_string_array (const char **array)
483 for (len = 0; array[len] != NULL; ++len)
486 copy = dbus_new0 (char*, len + 1);
493 copy[i] = _dbus_strdup (array[i]);
496 dbus_free_string_array (copy);
507 * Checks whether a string array contains the given string.
509 * @param array array to search.
510 * @param str string to look for
511 * @returns #TRUE if array contains string
514 _dbus_string_array_contains (const char **array,
520 while (array[i] != NULL)
522 if (strcmp (array[i], str) == 0)
531 * Generates a new UUID. If you change how this is done,
532 * there's some text about it in the spec that should also change.
534 * @param uuid the uuid to initialize
537 _dbus_generate_uuid (DBusGUID *uuid)
541 _dbus_get_current_time (&now, NULL);
543 uuid->as_uint32s[DBUS_UUID_LENGTH_WORDS - 1] = DBUS_UINT32_TO_BE (now);
545 _dbus_generate_random_bytes_buffer (uuid->as_bytes, DBUS_UUID_LENGTH_BYTES - 4);
551 * @param uuid the uuid
552 * @param encoded string to append hex uuid to
553 * @returns #FALSE if no memory
556 _dbus_uuid_encode (const DBusGUID *uuid,
560 _dbus_string_init_const_len (&binary, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
561 return _dbus_string_hex_encode (&binary, 0, encoded, _dbus_string_get_length (encoded));
565 _dbus_read_uuid_file_without_creating (const DBusString *filename,
573 if (!_dbus_string_init (&contents))
575 _DBUS_SET_OOM (error);
579 if (!_dbus_string_init (&decoded))
581 _dbus_string_free (&contents);
582 _DBUS_SET_OOM (error);
586 if (!_dbus_file_get_contents (&contents, filename, error))
589 _dbus_string_chop_white (&contents);
591 if (_dbus_string_get_length (&contents) != DBUS_UUID_LENGTH_HEX)
593 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
594 "UUID file '%s' should contain a hex string of length %d, not length %d, with no other text",
595 _dbus_string_get_const_data (filename),
596 DBUS_UUID_LENGTH_HEX,
597 _dbus_string_get_length (&contents));
601 if (!_dbus_string_hex_decode (&contents, 0, &end, &decoded, 0))
603 _DBUS_SET_OOM (error);
609 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
610 "UUID file '%s' contains invalid hex data",
611 _dbus_string_get_const_data (filename));
615 if (_dbus_string_get_length (&decoded) != DBUS_UUID_LENGTH_BYTES)
617 dbus_set_error (error, DBUS_ERROR_INVALID_FILE_CONTENT,
618 "UUID file '%s' contains %d bytes of hex-encoded data instead of %d",
619 _dbus_string_get_const_data (filename),
620 _dbus_string_get_length (&decoded),
621 DBUS_UUID_LENGTH_BYTES);
625 _dbus_string_copy_to_buffer (&decoded, uuid->as_bytes, DBUS_UUID_LENGTH_BYTES);
627 _dbus_string_free (&decoded);
628 _dbus_string_free (&contents);
630 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
635 _DBUS_ASSERT_ERROR_IS_SET (error);
636 _dbus_string_free (&contents);
637 _dbus_string_free (&decoded);
642 _dbus_create_uuid_file_exclusively (const DBusString *filename,
648 if (!_dbus_string_init (&encoded))
650 _DBUS_SET_OOM (error);
654 _dbus_generate_uuid (uuid);
656 if (!_dbus_uuid_encode (uuid, &encoded))
658 _DBUS_SET_OOM (error);
662 /* FIXME this is racy; we need a save_file_exclusively
663 * function. But in practice this should be fine for now.
665 * - first be sure we can create the file and it
666 * doesn't exist by creating it empty with O_EXCL
667 * - then create it by creating a temporary file and
668 * overwriting atomically with rename()
670 if (!_dbus_create_file_exclusively (filename, error))
673 if (!_dbus_string_append_byte (&encoded, '\n'))
675 _DBUS_SET_OOM (error);
679 if (!_dbus_string_save_to_file (&encoded, filename, error))
682 if (!_dbus_make_file_world_readable (filename, error))
685 _dbus_string_free (&encoded);
687 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
691 _DBUS_ASSERT_ERROR_IS_SET (error);
692 _dbus_string_free (&encoded);
697 * Reads (and optionally writes) a uuid to a file. Initializes the uuid
698 * unless an error is returned.
700 * @param filename the name of the file
701 * @param uuid uuid to be initialized with the loaded uuid
702 * @param create_if_not_found #TRUE to create a new uuid and save it if the file doesn't exist
703 * @param error the error return
704 * @returns #FALSE if the error is set
707 _dbus_read_uuid_file (const DBusString *filename,
709 dbus_bool_t create_if_not_found,
712 DBusError read_error = DBUS_ERROR_INIT;
714 if (_dbus_read_uuid_file_without_creating (filename, uuid, &read_error))
717 if (!create_if_not_found)
719 dbus_move_error (&read_error, error);
723 /* If the file exists and contains junk, we want to keep that error
724 * message instead of overwriting it with a "file exists" error
725 * message when we try to write
727 if (dbus_error_has_name (&read_error, DBUS_ERROR_INVALID_FILE_CONTENT))
729 dbus_move_error (&read_error, error);
734 dbus_error_free (&read_error);
735 return _dbus_create_uuid_file_exclusively (filename, uuid, error);
739 _DBUS_DEFINE_GLOBAL_LOCK (machine_uuid);
740 static int machine_uuid_initialized_generation = 0;
741 static DBusGUID machine_uuid;
744 * Gets the hex-encoded UUID of the machine this function is
745 * executed on. This UUID is guaranteed to be the same for a given
746 * machine at least until it next reboots, though it also
747 * makes some effort to be the same forever, it may change if the
748 * machine is reconfigured or its hardware is modified.
750 * @param uuid_str string to append hex-encoded machine uuid to
751 * @returns #FALSE if no memory
754 _dbus_get_local_machine_uuid_encoded (DBusString *uuid_str)
758 _DBUS_LOCK (machine_uuid);
759 if (machine_uuid_initialized_generation != _dbus_current_generation)
761 DBusError error = DBUS_ERROR_INIT;
763 if (!_dbus_read_local_machine_uuid (&machine_uuid, FALSE,
766 #ifndef DBUS_BUILD_TESTS
767 /* For the test suite, we may not be installed so just continue silently
768 * here. But in a production build, we want to be nice and loud about
771 _dbus_warn_check_failed ("D-Bus library appears to be incorrectly set up; failed to read machine uuid: %s\n"
772 "See the manual page for dbus-uuidgen to correct this issue.\n",
776 dbus_error_free (&error);
778 _dbus_generate_uuid (&machine_uuid);
782 ok = _dbus_uuid_encode (&machine_uuid, uuid_str);
784 _DBUS_UNLOCK (machine_uuid);
789 #ifdef DBUS_BUILD_TESTS
791 * Returns a string describing the given name.
793 * @param header_field the field to describe
794 * @returns a constant string describing the field
797 _dbus_header_field_to_string (int header_field)
799 switch (header_field)
801 case DBUS_HEADER_FIELD_INVALID:
803 case DBUS_HEADER_FIELD_PATH:
805 case DBUS_HEADER_FIELD_INTERFACE:
807 case DBUS_HEADER_FIELD_MEMBER:
809 case DBUS_HEADER_FIELD_ERROR_NAME:
811 case DBUS_HEADER_FIELD_REPLY_SERIAL:
812 return "reply-serial";
813 case DBUS_HEADER_FIELD_DESTINATION:
814 return "destination";
815 case DBUS_HEADER_FIELD_SENDER:
817 case DBUS_HEADER_FIELD_SIGNATURE:
823 #endif /* DBUS_BUILD_TESTS */
825 #ifndef DBUS_DISABLE_CHECKS
826 /** String used in _dbus_return_if_fail macro */
827 const char *_dbus_return_if_fail_warning_format =
828 "arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\n"
829 "This is normally a bug in some application using the D-Bus library.\n";
832 #ifndef DBUS_DISABLE_ASSERT
834 * Internals of _dbus_assert(); it's a function
835 * rather than a macro with the inline code so
836 * that the assertion failure blocks don't show up
837 * in test suite coverage, and to shrink code size.
839 * @param condition TRUE if assertion succeeded
840 * @param condition_text condition as a string
841 * @param file file the assertion is in
842 * @param line line the assertion is in
843 * @param func function the assertion is in
846 _dbus_real_assert (dbus_bool_t condition,
847 const char *condition_text,
852 if (_DBUS_UNLIKELY (!condition))
854 _dbus_warn ("%lu: assertion failed \"%s\" file \"%s\" line %d function %s\n",
855 _dbus_pid_for_log (), condition_text, file, line, func);
861 * Internals of _dbus_assert_not_reached(); it's a function
862 * rather than a macro with the inline code so
863 * that the assertion failure blocks don't show up
864 * in test suite coverage, and to shrink code size.
866 * @param explanation what was reached that shouldn't have been
867 * @param file file the assertion is in
868 * @param line line the assertion is in
871 _dbus_real_assert_not_reached (const char *explanation,
875 _dbus_warn ("File \"%s\" line %d process %lu should not have been reached: %s\n",
876 file, line, _dbus_pid_for_log (), explanation);
879 #endif /* DBUS_DISABLE_ASSERT */
881 #ifdef DBUS_BUILD_TESTS
883 run_failing_each_malloc (int n_mallocs,
884 const char *description,
885 DBusTestMemoryFunction func,
888 n_mallocs += 10; /* fudge factor to ensure reallocs etc. are covered */
890 while (n_mallocs >= 0)
892 _dbus_set_fail_alloc_counter (n_mallocs);
894 _dbus_verbose ("\n===\n%s: (will fail malloc %d with %d failures)\n===\n",
895 description, n_mallocs,
896 _dbus_get_fail_alloc_failures ());
898 if (!(* func) (data))
904 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
910 * Tests how well the given function responds to out-of-memory
911 * situations. Calls the function repeatedly, failing a different
912 * call to malloc() each time. If the function ever returns #FALSE,
913 * the test fails. The function should return #TRUE whenever something
914 * valid (such as returning an error, or succeeding) occurs, and #FALSE
915 * if it gets confused in some way.
917 * @param description description of the test used in verbose output
918 * @param func function to call
919 * @param data data to pass to function
920 * @returns #TRUE if the function never returns FALSE
923 _dbus_test_oom_handling (const char *description,
924 DBusTestMemoryFunction func,
929 int max_failures_to_try;
932 /* Run once to see about how many mallocs are involved */
934 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX);
936 _dbus_verbose ("Running once to count mallocs\n");
938 if (!(* func) (data))
941 approx_mallocs = _DBUS_INT_MAX - _dbus_get_fail_alloc_counter ();
943 _dbus_verbose ("\n=================\n%s: about %d mallocs total\n=================\n",
944 description, approx_mallocs);
946 setting = _dbus_getenv ("DBUS_TEST_MALLOC_FAILURES");
951 _dbus_string_init_const (&str, setting);
953 if (!_dbus_string_parse_int (&str, 0, &v, NULL))
954 _dbus_warn ("couldn't parse '%s' as integer\n", setting);
955 max_failures_to_try = v;
959 max_failures_to_try = 4;
962 i = setting ? max_failures_to_try - 1 : 1;
963 while (i < max_failures_to_try)
965 _dbus_set_fail_alloc_failures (i);
966 if (!run_failing_each_malloc (approx_mallocs, description, func, data))
971 _dbus_verbose ("\n=================\n%s: all iterations passed\n=================\n",
976 #endif /* DBUS_BUILD_TESTS */