dbus-internals.c revision 8ab042b9571dda44a5afcfe50e0d29dc9b58ecae 
1/* -*- mode: C; c-file-style: "gnu" -*- */
2/* dbus-internals.c  random utility stuff (internal to D-BUS implementation)
3 *
4 * Copyright (C) 2002  Red Hat, Inc.
5 *
6 * Licensed under the Academic Free License version 1.2
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#include "dbus-internals.h"
24#include "dbus-protocol.h"
25#include "dbus-test.h"
26#include <stdio.h>
27#include <stdarg.h>
28#include <string.h>
29#include <sys/types.h>
30#include <errno.h>
31#include <unistd.h>
32#include <fcntl.h>
33#include <stdlib.h>
34
35/**
36 * @defgroup DBusInternals D-BUS internal implementation details
37 * @brief Documentation useful when developing or debugging D-BUS itself.
38 *
39 */
40
41/**
42 * @defgroup DBusInternalsUtils Utilities and portability
43 * @ingroup DBusInternals
44 * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.)
45 * @{
46 */
47
48/**
49 * @def _dbus_assert
50 *
51 * Aborts with an error message if the condition is false.
52 *
53 * @param condition condition which must be true.
54 */
55
56/**
57 * @def _dbus_assert_not_reached
58 *
59 * Aborts with an error message if called.
60 * The given explanation will be printed.
61 *
62 * @param explanation explanation of what happened if the code was reached.
63 */
64
65/**
66 * @def _DBUS_N_ELEMENTS
67 *
68 * Computes the number of elements in a fixed-size array using
69 * sizeof().
70 *
71 * @param array the array to count elements in.
72 */
73
74/**
75 * @def _DBUS_POINTER_TO_INT
76 *
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.)
82 *
83 * @param pointer pointer to extract an integer from.
84 */
85/**
86 * @def _DBUS_INT_TO_POINTER
87 *
88 * Safely stuffs an integer into a pointer, to be extracted later with
89 * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits.
90 *
91 * @param integer the integer to stuff into a pointer.
92 */
93/**
94 * @def _DBUS_ZERO
95 *
96 * Sets all bits in an object to zero.
97 *
98 * @param object the object to be zeroed.
99 */
100/**
101 * @def _DBUS_INT_MIN
102 *
103 * Minimum value of type "int"
104 */
105/**
106 * @def _DBUS_INT_MAX
107 *
108 * Maximum value of type "int"
109 */
110/**
111 * @def _DBUS_MAX_SUN_PATH_LENGTH
112 *
113 * Maximum length of the path to a UNIX domain socket,
114 * sockaddr_un::sun_path member. POSIX requires that all systems
115 * support at least 100 bytes here, including the nul termination.
116 * We use 99 for the max value to allow for the nul.
117 *
118 * We could probably also do sizeof (addr.sun_path)
119 * but this way we are the same on all platforms
120 * which is probably a good idea.
121 */
122
123/**
124 * @typedef DBusForeachFunction
125 *
126 * Used to iterate over each item in a collection, such as
127 * a DBusList.
128 */
129
130/**
131 * Prints a warning message to stderr.
132 *
133 * @param format printf-style format string.
134 */
135void
136_dbus_warn (const char *format,
137            ...)
138{
139  /* FIXME not portable enough? */
140  va_list args;
141
142  va_start (args, format);
143  vfprintf (stderr, format, args);
144  va_end (args);
145}
146
147/**
148 * Prints a warning message to stderr
149 * if the user has enabled verbose mode.
150 * This is the real function implementation,
151 * use _dbus_verbose() macro in code.
152 *
153 * @param format printf-style format string.
154 */
155void
156_dbus_verbose_real (const char *format,
157                    ...)
158{
159  va_list args;
160  static dbus_bool_t verbose = TRUE;
161  static dbus_bool_t initted = FALSE;
162
163  /* things are written a bit oddly here so that
164   * in the non-verbose case we just have the one
165   * conditional and return immediately.
166   */
167  if (!verbose)
168    return;
169
170  if (!initted)
171    {
172      verbose = _dbus_getenv ("DBUS_VERBOSE") != NULL;
173      initted = TRUE;
174      if (!verbose)
175        return;
176    }
177
178  va_start (args, format);
179  vfprintf (stderr, format, args);
180  va_end (args);
181}
182
183/**
184 * A wrapper around strerror() because some platforms
185 * may be lame and not have strerror().
186 *
187 * @param error_number errno.
188 * @returns error description.
189 */
190const char*
191_dbus_strerror (int error_number)
192{
193  return strerror (error_number);
194}
195
196/**
197 * Converts a UNIX errno into a DBusResultCode.
198 *
199 * @todo should cover more errnos, specifically those
200 * from open().
201 *
202 * @param error_number the errno.
203 * @returns the result code.
204 */
205DBusResultCode
206_dbus_result_from_errno (int error_number)
207{
208  switch (error_number)
209    {
210    case 0:
211      return DBUS_RESULT_SUCCESS;
212
213#ifdef EPROTONOSUPPORT
214    case EPROTONOSUPPORT:
215      return DBUS_RESULT_NOT_SUPPORTED;
216#endif
217#ifdef EAFNOSUPPORT
218    case EAFNOSUPPORT:
219      return DBUS_RESULT_NOT_SUPPORTED;
220#endif
221#ifdef ENFILE
222    case ENFILE:
223      return DBUS_RESULT_LIMITS_EXCEEDED; /* kernel out of memory */
224#endif
225#ifdef EMFILE
226    case EMFILE:
227      return DBUS_RESULT_LIMITS_EXCEEDED;
228#endif
229#ifdef EACCES
230    case EACCES:
231      return DBUS_RESULT_ACCESS_DENIED;
232#endif
233#ifdef EPERM
234    case EPERM:
235      return DBUS_RESULT_ACCESS_DENIED;
236#endif
237#ifdef ENOBUFS
238    case ENOBUFS:
239      return DBUS_RESULT_NO_MEMORY;
240#endif
241#ifdef ENOMEM
242    case ENOMEM:
243      return DBUS_RESULT_NO_MEMORY;
244#endif
245#ifdef EINVAL
246    case EINVAL:
247      return DBUS_RESULT_FAILED;
248#endif
249#ifdef EBADF
250    case EBADF:
251      return DBUS_RESULT_FAILED;
252#endif
253#ifdef EFAULT
254    case EFAULT:
255      return DBUS_RESULT_FAILED;
256#endif
257#ifdef ENOTSOCK
258    case ENOTSOCK:
259      return DBUS_RESULT_FAILED;
260#endif
261#ifdef EISCONN
262    case EISCONN:
263      return DBUS_RESULT_FAILED;
264#endif
265#ifdef ECONNREFUSED
266    case ECONNREFUSED:
267      return DBUS_RESULT_NO_SERVER;
268#endif
269#ifdef ETIMEDOUT
270    case ETIMEDOUT:
271      return DBUS_RESULT_TIMEOUT;
272#endif
273#ifdef ENETUNREACH
274    case ENETUNREACH:
275      return DBUS_RESULT_NO_NETWORK;
276#endif
277#ifdef EADDRINUSE
278    case EADDRINUSE:
279      return DBUS_RESULT_ADDRESS_IN_USE;
280#endif
281#ifdef EEXIST
282    case EEXIST:
283      return DBUS_RESULT_FILE_NOT_FOUND;
284#endif
285#ifdef ENOENT
286    case ENOENT:
287      return DBUS_RESULT_FILE_NOT_FOUND;
288#endif
289    }
290
291  return DBUS_RESULT_FAILED;
292}
293
294/**
295 * Duplicates a string. Result must be freed with
296 * dbus_free(). Returns #NULL if memory allocation fails.
297 * If the string to be duplicated is #NULL, returns #NULL.
298 *
299 * @param str string to duplicate.
300 * @returns newly-allocated copy.
301 */
302char*
303_dbus_strdup (const char *str)
304{
305  int len;
306  char *copy;
307
308  if (str == NULL)
309    return NULL;
310
311  len = strlen (str);
312
313  copy = dbus_malloc (len + 1);
314  if (copy == NULL)
315    return NULL;
316
317  memcpy (copy, str, len + 1);
318
319  return copy;
320}
321
322/**
323 * Sets a file descriptor to be nonblocking.
324 *
325 * @param fd the file descriptor.
326 * @param result address of result code.
327 * @returns #TRUE on success.
328 */
329dbus_bool_t
330_dbus_set_fd_nonblocking (int             fd,
331                          DBusResultCode *result)
332{
333  int val;
334
335  val = fcntl (fd, F_GETFL, 0);
336  if (val < 0)
337    {
338      dbus_set_result (result, _dbus_result_from_errno (errno));
339      _dbus_verbose ("Failed to get flags for fd %d: %s\n", fd,
340                     _dbus_strerror (errno));
341      return FALSE;
342    }
343
344  if (fcntl (fd, F_SETFL, val | O_NONBLOCK) < 0)
345    {
346      dbus_set_result (result, _dbus_result_from_errno (errno));
347      _dbus_verbose ("Failed to set fd %d nonblocking: %s\n",
348                     fd, _dbus_strerror (errno));
349
350      return FALSE;
351    }
352
353  return TRUE;
354}
355
356/**
357 * Returns a string describing the given type.
358 *
359 * @param type the type to describe
360 * @returns a constant string describing the type
361 */
362const char *
363_dbus_type_to_string (int type)
364{
365  switch (type)
366    {
367    case DBUS_TYPE_INVALID:
368      return "invalid";
369    case DBUS_TYPE_NIL:
370      return "nil";
371    case DBUS_TYPE_INT32:
372      return "int32";
373    case DBUS_TYPE_UINT32:
374      return "uint32";
375    case DBUS_TYPE_DOUBLE:
376      return "double";
377    case DBUS_TYPE_STRING:
378      return "string";
379    case DBUS_TYPE_INT32_ARRAY:
380      return "int32 array";
381    case DBUS_TYPE_UINT32_ARRAY:
382      return "uint32 array";
383    case DBUS_TYPE_DOUBLE_ARRAY:
384      return "double array";
385    case DBUS_TYPE_BYTE_ARRAY:
386      return "byte array";
387    case DBUS_TYPE_STRING_ARRAY:
388      return "string array";
389    default:
390      return "unknown";
391    }
392}
393
394/** @} */
395