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1 /* GDBus - GLib D-Bus Library
2  *
3  * Copyright (C) 2008-2010 Red Hat, Inc.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General
16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17  *
18  * Author: David Zeuthen <davidz@redhat.com>
19  */
20 
21 #include "config.h"
22 
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "giotypes.h"
27 #include "gioenumtypes.h"
28 #include "gsocket.h"
29 #include "gdbusauthobserver.h"
30 #include "gdbusprivate.h"
31 #include "gdbusmessage.h"
32 #include "gdbusconnection.h"
33 #include "gdbusproxy.h"
34 #include "gdbuserror.h"
35 #include "gdbusintrospection.h"
36 #include "gdbusdaemon.h"
37 #include "giomodule-priv.h"
38 #include "gtask.h"
39 #include "ginputstream.h"
40 #include "gmemoryinputstream.h"
41 #include "giostream.h"
42 #include "glib/gstdio.h"
43 #include "gsocketaddress.h"
44 #include "gsocketcontrolmessage.h"
45 #include "gsocketconnection.h"
46 #include "gsocketoutputstream.h"
47 
48 #ifdef G_OS_UNIX
49 #include "gunixfdmessage.h"
50 #include "gunixconnection.h"
51 #include "gunixcredentialsmessage.h"
52 #endif
53 
54 #ifdef G_OS_WIN32
55 #include <windows.h>
56 #include <io.h>
57 #include <conio.h>
58 #endif
59 
60 #include "glibintl.h"
61 
62 static gboolean _g_dbus_worker_do_initial_read (gpointer data);
63 static void schedule_pending_close (GDBusWorker *worker);
64 
65 /* ---------------------------------------------------------------------------------------------------- */
66 
67 gchar *
_g_dbus_hexdump(const gchar * data,gsize len,guint indent)68 _g_dbus_hexdump (const gchar *data, gsize len, guint indent)
69 {
70  guint n, m;
71  GString *ret;
72 
73  ret = g_string_new (NULL);
74 
75  for (n = 0; n < len; n += 16)
76    {
77      g_string_append_printf (ret, "%*s%04x: ", indent, "", n);
78 
79      for (m = n; m < n + 16; m++)
80        {
81          if (m > n && (m%4) == 0)
82            g_string_append_c (ret, ' ');
83          if (m < len)
84            g_string_append_printf (ret, "%02x ", (guchar) data[m]);
85          else
86            g_string_append (ret, "   ");
87        }
88 
89      g_string_append (ret, "   ");
90 
91      for (m = n; m < len && m < n + 16; m++)
92        g_string_append_c (ret, g_ascii_isprint (data[m]) ? data[m] : '.');
93 
94      g_string_append_c (ret, '\n');
95    }
96 
97  return g_string_free (ret, FALSE);
98 }
99 
100 /* ---------------------------------------------------------------------------------------------------- */
101 
102 /* Unfortunately ancillary messages are discarded when reading from a
103  * socket using the GSocketInputStream abstraction. So we provide a
104  * very GInputStream-ish API that uses GSocket in this case (very
105  * similar to GSocketInputStream).
106  */
107 
108 typedef struct
109 {
110   void *buffer;
111   gsize count;
112 
113   GSocketControlMessage ***messages;
114   gint *num_messages;
115 } ReadWithControlData;
116 
117 static void
read_with_control_data_free(ReadWithControlData * data)118 read_with_control_data_free (ReadWithControlData *data)
119 {
120   g_slice_free (ReadWithControlData, data);
121 }
122 
123 static gboolean
_g_socket_read_with_control_messages_ready(GSocket * socket,GIOCondition condition,gpointer user_data)124 _g_socket_read_with_control_messages_ready (GSocket      *socket,
125                                             GIOCondition  condition,
126                                             gpointer      user_data)
127 {
128   GTask *task = user_data;
129   ReadWithControlData *data = g_task_get_task_data (task);
130   GError *error;
131   gssize result;
132   GInputVector vector;
133 
134   error = NULL;
135   vector.buffer = data->buffer;
136   vector.size = data->count;
137   result = g_socket_receive_message (socket,
138                                      NULL, /* address */
139                                      &vector,
140                                      1,
141                                      data->messages,
142                                      data->num_messages,
143                                      NULL,
144                                      g_task_get_cancellable (task),
145                                      &error);
146 
147   if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
148     {
149       g_error_free (error);
150       return TRUE;
151     }
152 
153   g_assert (result >= 0 || error != NULL);
154   if (result >= 0)
155     g_task_return_int (task, result);
156   else
157     g_task_return_error (task, error);
158   g_object_unref (task);
159 
160   return FALSE;
161 }
162 
163 static void
_g_socket_read_with_control_messages(GSocket * socket,void * buffer,gsize count,GSocketControlMessage *** messages,gint * num_messages,gint io_priority,GCancellable * cancellable,GAsyncReadyCallback callback,gpointer user_data)164 _g_socket_read_with_control_messages (GSocket                 *socket,
165                                       void                    *buffer,
166                                       gsize                    count,
167                                       GSocketControlMessage ***messages,
168                                       gint                    *num_messages,
169                                       gint                     io_priority,
170                                       GCancellable            *cancellable,
171                                       GAsyncReadyCallback      callback,
172                                       gpointer                 user_data)
173 {
174   GTask *task;
175   ReadWithControlData *data;
176   GSource *source;
177 
178   data = g_slice_new0 (ReadWithControlData);
179   data->buffer = buffer;
180   data->count = count;
181   data->messages = messages;
182   data->num_messages = num_messages;
183 
184   task = g_task_new (socket, cancellable, callback, user_data);
185   g_task_set_source_tag (task, _g_socket_read_with_control_messages);
186   g_task_set_name (task, "[gio] D-Bus read");
187   g_task_set_task_data (task, data, (GDestroyNotify) read_with_control_data_free);
188 
189   if (g_socket_condition_check (socket, G_IO_IN))
190     {
191       if (!_g_socket_read_with_control_messages_ready (socket, G_IO_IN, task))
192         return;
193     }
194 
195   source = g_socket_create_source (socket,
196                                    G_IO_IN | G_IO_HUP | G_IO_ERR,
197                                    cancellable);
198   g_task_attach_source (task, source, (GSourceFunc) _g_socket_read_with_control_messages_ready);
199   g_source_unref (source);
200 }
201 
202 static gssize
_g_socket_read_with_control_messages_finish(GSocket * socket,GAsyncResult * result,GError ** error)203 _g_socket_read_with_control_messages_finish (GSocket       *socket,
204                                              GAsyncResult  *result,
205                                              GError       **error)
206 {
207   g_return_val_if_fail (G_IS_SOCKET (socket), -1);
208   g_return_val_if_fail (g_task_is_valid (result, socket), -1);
209 
210   return g_task_propagate_int (G_TASK (result), error);
211 }
212 
213 /* ---------------------------------------------------------------------------------------------------- */
214 
215 /* Work-around for https://bugzilla.gnome.org/show_bug.cgi?id=674885
216    and see also the original https://bugzilla.gnome.org/show_bug.cgi?id=627724  */
217 
218 static GPtrArray *ensured_classes = NULL;
219 
220 static void
ensure_type(GType gtype)221 ensure_type (GType gtype)
222 {
223   g_ptr_array_add (ensured_classes, g_type_class_ref (gtype));
224 }
225 
226 static void
release_required_types(void)227 release_required_types (void)
228 {
229   g_ptr_array_foreach (ensured_classes, (GFunc) g_type_class_unref, NULL);
230   g_ptr_array_unref (ensured_classes);
231   ensured_classes = NULL;
232 }
233 
234 static void
ensure_required_types(void)235 ensure_required_types (void)
236 {
237   g_assert (ensured_classes == NULL);
238   ensured_classes = g_ptr_array_new ();
239   /* Generally in this list, you should initialize types which are used as
240    * properties first, then the class which has them. For example, GDBusProxy
241    * has a type of GDBusConnection, so we initialize GDBusConnection first.
242    * And because GDBusConnection has a property of type GDBusConnectionFlags,
243    * we initialize that first.
244    *
245    * Similarly, GSocket has a type of GSocketAddress.
246    *
247    * We don't fill out the whole dependency tree right now because in practice
248    * it tends to be just types that GDBus use that cause pain, and there
249    * is work on a more general approach in https://bugzilla.gnome.org/show_bug.cgi?id=674885
250    */
251   ensure_type (G_TYPE_TASK);
252   ensure_type (G_TYPE_MEMORY_INPUT_STREAM);
253   ensure_type (G_TYPE_DBUS_CONNECTION_FLAGS);
254   ensure_type (G_TYPE_DBUS_CAPABILITY_FLAGS);
255   ensure_type (G_TYPE_DBUS_AUTH_OBSERVER);
256   ensure_type (G_TYPE_DBUS_CONNECTION);
257   ensure_type (G_TYPE_DBUS_PROXY);
258   ensure_type (G_TYPE_SOCKET_FAMILY);
259   ensure_type (G_TYPE_SOCKET_TYPE);
260   ensure_type (G_TYPE_SOCKET_PROTOCOL);
261   ensure_type (G_TYPE_SOCKET_ADDRESS);
262   ensure_type (G_TYPE_SOCKET);
263 }
264 /* ---------------------------------------------------------------------------------------------------- */
265 
266 typedef struct
267 {
268   gint refcount;  /* (atomic) */
269   GThread *thread;
270   GMainContext *context;
271   GMainLoop *loop;
272 } SharedThreadData;
273 
274 static gpointer
gdbus_shared_thread_func(gpointer user_data)275 gdbus_shared_thread_func (gpointer user_data)
276 {
277   SharedThreadData *data = user_data;
278 
279   g_main_context_push_thread_default (data->context);
280   g_main_loop_run (data->loop);
281   g_main_context_pop_thread_default (data->context);
282 
283   release_required_types ();
284 
285   return NULL;
286 }
287 
288 /* ---------------------------------------------------------------------------------------------------- */
289 
290 static SharedThreadData *
_g_dbus_shared_thread_ref(void)291 _g_dbus_shared_thread_ref (void)
292 {
293   static gsize shared_thread_data = 0;
294   SharedThreadData *ret;
295 
296   if (g_once_init_enter (&shared_thread_data))
297     {
298       SharedThreadData *data;
299 
300       data = g_new0 (SharedThreadData, 1);
301       data->refcount = 0;
302 
303       data->context = g_main_context_new ();
304       data->loop = g_main_loop_new (data->context, FALSE);
305       data->thread = g_thread_new ("gdbus",
306                                    gdbus_shared_thread_func,
307                                    data);
308       /* We can cast between gsize and gpointer safely */
309       g_once_init_leave (&shared_thread_data, (gsize) data);
310     }
311 
312   ret = (SharedThreadData*) shared_thread_data;
313   g_atomic_int_inc (&ret->refcount);
314   return ret;
315 }
316 
317 static void
_g_dbus_shared_thread_unref(SharedThreadData * data)318 _g_dbus_shared_thread_unref (SharedThreadData *data)
319 {
320   /* TODO: actually destroy the shared thread here */
321 #if 0
322   g_assert (data != NULL);
323   if (g_atomic_int_dec_and_test (&data->refcount))
324     {
325       g_main_loop_quit (data->loop);
326       //g_thread_join (data->thread);
327       g_main_loop_unref (data->loop);
328       g_main_context_unref (data->context);
329     }
330 #endif
331 }
332 
333 /* ---------------------------------------------------------------------------------------------------- */
334 
335 typedef enum {
336     PENDING_NONE = 0,
337     PENDING_WRITE,
338     PENDING_FLUSH,
339     PENDING_CLOSE
340 } OutputPending;
341 
342 struct GDBusWorker
343 {
344   gint                                ref_count;  /* (atomic) */
345 
346   SharedThreadData                   *shared_thread_data;
347 
348   /* really a boolean, but GLib 2.28 lacks atomic boolean ops */
349   gint                                stopped;  /* (atomic) */
350 
351   /* TODO: frozen (e.g. G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING) currently
352    * only affects messages received from the other peer (since GDBusServer is the
353    * only user) - we might want it to affect messages sent to the other peer too?
354    */
355   gboolean                            frozen;
356   GDBusCapabilityFlags                capabilities;
357   GQueue                             *received_messages_while_frozen;
358 
359   GIOStream                          *stream;
360   GCancellable                       *cancellable;
361   GDBusWorkerMessageReceivedCallback  message_received_callback;
362   GDBusWorkerMessageAboutToBeSentCallback message_about_to_be_sent_callback;
363   GDBusWorkerDisconnectedCallback     disconnected_callback;
364   gpointer                            user_data;
365 
366   /* if not NULL, stream is GSocketConnection */
367   GSocket *socket;
368 
369   /* used for reading */
370   GMutex                              read_lock;
371   gchar                              *read_buffer;
372   gsize                               read_buffer_allocated_size;
373   gsize                               read_buffer_cur_size;
374   gsize                               read_buffer_bytes_wanted;
375   GUnixFDList                        *read_fd_list;
376   GSocketControlMessage             **read_ancillary_messages;
377   gint                                read_num_ancillary_messages;
378 
379   /* Whether an async write, flush or close, or none of those, is pending.
380    * Only the worker thread may change its value, and only with the write_lock.
381    * Other threads may read its value when holding the write_lock.
382    * The worker thread may read its value at any time.
383    */
384   OutputPending                       output_pending;
385   /* used for writing */
386   GMutex                              write_lock;
387   /* queue of MessageToWriteData, protected by write_lock */
388   GQueue                             *write_queue;
389   /* protected by write_lock */
390   guint64                             write_num_messages_written;
391   /* number of messages we'd written out last time we flushed;
392    * protected by write_lock
393    */
394   guint64                             write_num_messages_flushed;
395   /* list of FlushData, protected by write_lock */
396   GList                              *write_pending_flushes;
397   /* list of CloseData, protected by write_lock */
398   GList                              *pending_close_attempts;
399   /* no lock - only used from the worker thread */
400   gboolean                            close_expected;
401 };
402 
403 static void _g_dbus_worker_unref (GDBusWorker *worker);
404 
405 /* ---------------------------------------------------------------------------------------------------- */
406 
407 typedef struct
408 {
409   GMutex  mutex;
410   GCond   cond;
411   guint64 number_to_wait_for;
412   gboolean finished;
413   GError *error;
414 } FlushData;
415 
416 struct _MessageToWriteData ;
417 typedef struct _MessageToWriteData MessageToWriteData;
418 
419 static void message_to_write_data_free (MessageToWriteData *data);
420 
421 static void read_message_print_transport_debug (gssize bytes_read,
422                                                 GDBusWorker *worker);
423 
424 static void write_message_print_transport_debug (gssize bytes_written,
425                                                  MessageToWriteData *data);
426 
427 typedef struct {
428     GDBusWorker *worker;
429     GTask *task;
430 } CloseData;
431 
close_data_free(CloseData * close_data)432 static void close_data_free (CloseData *close_data)
433 {
434   g_clear_object (&close_data->task);
435 
436   _g_dbus_worker_unref (close_data->worker);
437   g_slice_free (CloseData, close_data);
438 }
439 
440 /* ---------------------------------------------------------------------------------------------------- */
441 
442 static GDBusWorker *
_g_dbus_worker_ref(GDBusWorker * worker)443 _g_dbus_worker_ref (GDBusWorker *worker)
444 {
445   g_atomic_int_inc (&worker->ref_count);
446   return worker;
447 }
448 
449 static void
_g_dbus_worker_unref(GDBusWorker * worker)450 _g_dbus_worker_unref (GDBusWorker *worker)
451 {
452   if (g_atomic_int_dec_and_test (&worker->ref_count))
453     {
454       g_assert (worker->write_pending_flushes == NULL);
455 
456       _g_dbus_shared_thread_unref (worker->shared_thread_data);
457 
458       g_object_unref (worker->stream);
459 
460       g_mutex_clear (&worker->read_lock);
461       g_object_unref (worker->cancellable);
462       if (worker->read_fd_list != NULL)
463         g_object_unref (worker->read_fd_list);
464 
465       g_queue_free_full (worker->received_messages_while_frozen, (GDestroyNotify) g_object_unref);
466       g_mutex_clear (&worker->write_lock);
467       g_queue_free_full (worker->write_queue, (GDestroyNotify) message_to_write_data_free);
468       g_free (worker->read_buffer);
469 
470       g_free (worker);
471     }
472 }
473 
474 static void
_g_dbus_worker_emit_disconnected(GDBusWorker * worker,gboolean remote_peer_vanished,GError * error)475 _g_dbus_worker_emit_disconnected (GDBusWorker  *worker,
476                                   gboolean      remote_peer_vanished,
477                                   GError       *error)
478 {
479   if (!g_atomic_int_get (&worker->stopped))
480     worker->disconnected_callback (worker, remote_peer_vanished, error, worker->user_data);
481 }
482 
483 static void
_g_dbus_worker_emit_message_received(GDBusWorker * worker,GDBusMessage * message)484 _g_dbus_worker_emit_message_received (GDBusWorker  *worker,
485                                       GDBusMessage *message)
486 {
487   if (!g_atomic_int_get (&worker->stopped))
488     worker->message_received_callback (worker, message, worker->user_data);
489 }
490 
491 static GDBusMessage *
_g_dbus_worker_emit_message_about_to_be_sent(GDBusWorker * worker,GDBusMessage * message)492 _g_dbus_worker_emit_message_about_to_be_sent (GDBusWorker  *worker,
493                                               GDBusMessage *message)
494 {
495   GDBusMessage *ret;
496   if (!g_atomic_int_get (&worker->stopped))
497     ret = worker->message_about_to_be_sent_callback (worker, g_steal_pointer (&message), worker->user_data);
498   else
499     ret = g_steal_pointer (&message);
500   return ret;
501 }
502 
503 /* can only be called from private thread with read-lock held - takes ownership of @message */
504 static void
_g_dbus_worker_queue_or_deliver_received_message(GDBusWorker * worker,GDBusMessage * message)505 _g_dbus_worker_queue_or_deliver_received_message (GDBusWorker  *worker,
506                                                   GDBusMessage *message)
507 {
508   if (worker->frozen || g_queue_get_length (worker->received_messages_while_frozen) > 0)
509     {
510       /* queue up */
511       g_queue_push_tail (worker->received_messages_while_frozen, g_steal_pointer (&message));
512     }
513   else
514     {
515       /* not frozen, nor anything in queue */
516       _g_dbus_worker_emit_message_received (worker, message);
517       g_clear_object (&message);
518     }
519 }
520 
521 /* called in private thread shared by all GDBusConnection instances (without read-lock held) */
522 static gboolean
unfreeze_in_idle_cb(gpointer user_data)523 unfreeze_in_idle_cb (gpointer user_data)
524 {
525   GDBusWorker *worker = user_data;
526   GDBusMessage *message;
527 
528   g_mutex_lock (&worker->read_lock);
529   if (worker->frozen)
530     {
531       while ((message = g_queue_pop_head (worker->received_messages_while_frozen)) != NULL)
532         {
533           _g_dbus_worker_emit_message_received (worker, message);
534           g_clear_object (&message);
535         }
536       worker->frozen = FALSE;
537     }
538   else
539     {
540       g_assert (g_queue_get_length (worker->received_messages_while_frozen) == 0);
541     }
542   g_mutex_unlock (&worker->read_lock);
543   return FALSE;
544 }
545 
546 /* can be called from any thread */
547 void
_g_dbus_worker_unfreeze(GDBusWorker * worker)548 _g_dbus_worker_unfreeze (GDBusWorker *worker)
549 {
550   GSource *idle_source;
551   idle_source = g_idle_source_new ();
552   g_source_set_priority (idle_source, G_PRIORITY_DEFAULT);
553   g_source_set_callback (idle_source,
554                          unfreeze_in_idle_cb,
555                          _g_dbus_worker_ref (worker),
556                          (GDestroyNotify) _g_dbus_worker_unref);
557   g_source_set_name (idle_source, "[gio] unfreeze_in_idle_cb");
558   g_source_attach (idle_source, worker->shared_thread_data->context);
559   g_source_unref (idle_source);
560 }
561 
562 /* ---------------------------------------------------------------------------------------------------- */
563 
564 static void _g_dbus_worker_do_read_unlocked (GDBusWorker *worker);
565 
566 /* called in private thread shared by all GDBusConnection instances (without read-lock held) */
567 static void
_g_dbus_worker_do_read_cb(GInputStream * input_stream,GAsyncResult * res,gpointer user_data)568 _g_dbus_worker_do_read_cb (GInputStream  *input_stream,
569                            GAsyncResult  *res,
570                            gpointer       user_data)
571 {
572   GDBusWorker *worker = user_data;
573   GError *error;
574   gssize bytes_read;
575 
576   g_mutex_lock (&worker->read_lock);
577 
578   /* If already stopped, don't even process the reply */
579   if (g_atomic_int_get (&worker->stopped))
580     goto out;
581 
582   error = NULL;
583   if (worker->socket == NULL)
584     bytes_read = g_input_stream_read_finish (g_io_stream_get_input_stream (worker->stream),
585                                              res,
586                                              &error);
587   else
588     bytes_read = _g_socket_read_with_control_messages_finish (worker->socket,
589                                                               res,
590                                                               &error);
591   if (worker->read_num_ancillary_messages > 0)
592     {
593       gint n;
594       for (n = 0; n < worker->read_num_ancillary_messages; n++)
595         {
596           GSocketControlMessage *control_message = G_SOCKET_CONTROL_MESSAGE (worker->read_ancillary_messages[n]);
597 
598           if (FALSE)
599             {
600             }
601 #ifdef G_OS_UNIX
602           else if (G_IS_UNIX_FD_MESSAGE (control_message))
603             {
604               GUnixFDMessage *fd_message;
605               gint *fds;
606               gint num_fds;
607 
608               fd_message = G_UNIX_FD_MESSAGE (control_message);
609               fds = g_unix_fd_message_steal_fds (fd_message, &num_fds);
610               if (worker->read_fd_list == NULL)
611                 {
612                   worker->read_fd_list = g_unix_fd_list_new_from_array (fds, num_fds);
613                 }
614               else
615                 {
616                   gint n;
617                   for (n = 0; n < num_fds; n++)
618                     {
619                       /* TODO: really want a append_steal() */
620                       g_unix_fd_list_append (worker->read_fd_list, fds[n], NULL);
621                       (void) g_close (fds[n], NULL);
622                     }
623                 }
624               g_free (fds);
625             }
626           else if (G_IS_UNIX_CREDENTIALS_MESSAGE (control_message))
627             {
628               /* do nothing */
629             }
630 #endif
631           else
632             {
633               if (error == NULL)
634                 {
635                   g_set_error (&error,
636                                G_IO_ERROR,
637                                G_IO_ERROR_FAILED,
638                                "Unexpected ancillary message of type %s received from peer",
639                                g_type_name (G_TYPE_FROM_INSTANCE (control_message)));
640                   _g_dbus_worker_emit_disconnected (worker, TRUE, error);
641                   g_error_free (error);
642                   g_object_unref (control_message);
643                   n++;
644                   while (n < worker->read_num_ancillary_messages)
645                     g_object_unref (worker->read_ancillary_messages[n++]);
646                   g_free (worker->read_ancillary_messages);
647                   goto out;
648                 }
649             }
650           g_object_unref (control_message);
651         }
652       g_free (worker->read_ancillary_messages);
653     }
654 
655   if (bytes_read == -1)
656     {
657       if (G_UNLIKELY (_g_dbus_debug_transport ()))
658         {
659           _g_dbus_debug_print_lock ();
660           g_print ("========================================================================\n"
661                    "GDBus-debug:Transport:\n"
662                    "  ---- READ ERROR on stream of type %s:\n"
663                    "  ---- %s %d: %s\n",
664                    g_type_name (G_TYPE_FROM_INSTANCE (g_io_stream_get_input_stream (worker->stream))),
665                    g_quark_to_string (error->domain), error->code,
666                    error->message);
667           _g_dbus_debug_print_unlock ();
668         }
669 
670       /* Every async read that uses this callback uses worker->cancellable
671        * as its GCancellable. worker->cancellable gets cancelled if and only
672        * if the GDBusConnection tells us to close (either via
673        * _g_dbus_worker_stop, which is called on last-unref, or directly),
674        * so a cancelled read must mean our connection was closed locally.
675        *
676        * If we're closing, other errors are possible - notably,
677        * G_IO_ERROR_CLOSED can be seen if we close the stream with an async
678        * read in-flight. It seems sensible to treat all read errors during
679        * closing as an expected thing that doesn't trip exit-on-close.
680        *
681        * Because close_expected can't be set until we get into the worker
682        * thread, but the cancellable is signalled sooner (from another
683        * thread), we do still need to check the error.
684        */
685       if (worker->close_expected ||
686           g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
687         _g_dbus_worker_emit_disconnected (worker, FALSE, NULL);
688       else
689         _g_dbus_worker_emit_disconnected (worker, TRUE, error);
690 
691       g_error_free (error);
692       goto out;
693     }
694 
695 #if 0
696   g_debug ("read %d bytes (is_closed=%d blocking=%d condition=0x%02x) stream %p, %p",
697            (gint) bytes_read,
698            g_socket_is_closed (g_socket_connection_get_socket (G_SOCKET_CONNECTION (worker->stream))),
699            g_socket_get_blocking (g_socket_connection_get_socket (G_SOCKET_CONNECTION (worker->stream))),
700            g_socket_condition_check (g_socket_connection_get_socket (G_SOCKET_CONNECTION (worker->stream)),
701                                      G_IO_IN | G_IO_OUT | G_IO_HUP),
702            worker->stream,
703            worker);
704 #endif
705 
706   /* The read failed, which could mean the dbus-daemon was sent SIGTERM. */
707   if (bytes_read == 0)
708     {
709       g_set_error (&error,
710                    G_IO_ERROR,
711                    G_IO_ERROR_FAILED,
712                    "Underlying GIOStream returned 0 bytes on an async read");
713       _g_dbus_worker_emit_disconnected (worker, TRUE, error);
714       g_error_free (error);
715       goto out;
716     }
717 
718   read_message_print_transport_debug (bytes_read, worker);
719 
720   worker->read_buffer_cur_size += bytes_read;
721   if (worker->read_buffer_bytes_wanted == worker->read_buffer_cur_size)
722     {
723       /* OK, got what we asked for! */
724       if (worker->read_buffer_bytes_wanted == 16)
725         {
726           gssize message_len;
727           /* OK, got the header - determine how many more bytes are needed */
728           error = NULL;
729           message_len = g_dbus_message_bytes_needed ((guchar *) worker->read_buffer,
730                                                      16,
731                                                      &error);
732           if (message_len == -1)
733             {
734               g_warning ("_g_dbus_worker_do_read_cb: error determining bytes needed: %s", error->message);
735               _g_dbus_worker_emit_disconnected (worker, FALSE, error);
736               g_error_free (error);
737               goto out;
738             }
739 
740           worker->read_buffer_bytes_wanted = message_len;
741           _g_dbus_worker_do_read_unlocked (worker);
742         }
743       else
744         {
745           GDBusMessage *message;
746           error = NULL;
747 
748           /* TODO: use connection->priv->auth to decode the message */
749 
750           message = g_dbus_message_new_from_blob ((guchar *) worker->read_buffer,
751                                                   worker->read_buffer_cur_size,
752                                                   worker->capabilities,
753                                                   &error);
754           if (message == NULL)
755             {
756               gchar *s;
757               s = _g_dbus_hexdump (worker->read_buffer, worker->read_buffer_cur_size, 2);
758               g_warning ("Error decoding D-Bus message of %" G_GSIZE_FORMAT " bytes\n"
759                          "The error is: %s\n"
760                          "The payload is as follows:\n"
761                          "%s",
762                          worker->read_buffer_cur_size,
763                          error->message,
764                          s);
765               g_free (s);
766               _g_dbus_worker_emit_disconnected (worker, FALSE, error);
767               g_error_free (error);
768               goto out;
769             }
770 
771 #ifdef G_OS_UNIX
772           if (worker->read_fd_list != NULL)
773             {
774               g_dbus_message_set_unix_fd_list (message, worker->read_fd_list);
775               g_object_unref (worker->read_fd_list);
776               worker->read_fd_list = NULL;
777             }
778 #endif
779 
780           if (G_UNLIKELY (_g_dbus_debug_message ()))
781             {
782               gchar *s;
783               _g_dbus_debug_print_lock ();
784               g_print ("========================================================================\n"
785                        "GDBus-debug:Message:\n"
786                        "  <<<< RECEIVED D-Bus message (%" G_GSIZE_FORMAT " bytes)\n",
787                        worker->read_buffer_cur_size);
788               s = g_dbus_message_print (message, 2);
789               g_print ("%s", s);
790               g_free (s);
791               if (G_UNLIKELY (_g_dbus_debug_payload ()))
792                 {
793                   s = _g_dbus_hexdump (worker->read_buffer, worker->read_buffer_cur_size, 2);
794                   g_print ("%s\n", s);
795                   g_free (s);
796                 }
797               _g_dbus_debug_print_unlock ();
798             }
799 
800           /* yay, got a message, go deliver it */
801           _g_dbus_worker_queue_or_deliver_received_message (worker, g_steal_pointer (&message));
802 
803           /* start reading another message! */
804           worker->read_buffer_bytes_wanted = 0;
805           worker->read_buffer_cur_size = 0;
806           _g_dbus_worker_do_read_unlocked (worker);
807         }
808     }
809   else
810     {
811       /* didn't get all the bytes we requested - so repeat the request... */
812       _g_dbus_worker_do_read_unlocked (worker);
813     }
814 
815  out:
816   g_mutex_unlock (&worker->read_lock);
817 
818   /* check if there is any pending close */
819   schedule_pending_close (worker);
820 
821   /* gives up the reference acquired when calling g_input_stream_read_async() */
822   _g_dbus_worker_unref (worker);
823 }
824 
825 /* called in private thread shared by all GDBusConnection instances (with read-lock held) */
826 static void
_g_dbus_worker_do_read_unlocked(GDBusWorker * worker)827 _g_dbus_worker_do_read_unlocked (GDBusWorker *worker)
828 {
829   /* Note that we do need to keep trying to read even if close_expected is
830    * true, because only failing a read causes us to signal 'closed'.
831    */
832 
833   /* if bytes_wanted is zero, it means start reading a message */
834   if (worker->read_buffer_bytes_wanted == 0)
835     {
836       worker->read_buffer_cur_size = 0;
837       worker->read_buffer_bytes_wanted = 16;
838     }
839 
840   /* ensure we have a (big enough) buffer */
841   if (worker->read_buffer == NULL || worker->read_buffer_bytes_wanted > worker->read_buffer_allocated_size)
842     {
843       /* TODO: 4096 is randomly chosen; might want a better chosen default minimum */
844       worker->read_buffer_allocated_size = MAX (worker->read_buffer_bytes_wanted, 4096);
845       worker->read_buffer = g_realloc (worker->read_buffer, worker->read_buffer_allocated_size);
846     }
847 
848   if (worker->socket == NULL)
849     g_input_stream_read_async (g_io_stream_get_input_stream (worker->stream),
850                                worker->read_buffer + worker->read_buffer_cur_size,
851                                worker->read_buffer_bytes_wanted - worker->read_buffer_cur_size,
852                                G_PRIORITY_DEFAULT,
853                                worker->cancellable,
854                                (GAsyncReadyCallback) _g_dbus_worker_do_read_cb,
855                                _g_dbus_worker_ref (worker));
856   else
857     {
858       worker->read_ancillary_messages = NULL;
859       worker->read_num_ancillary_messages = 0;
860       _g_socket_read_with_control_messages (worker->socket,
861                                             worker->read_buffer + worker->read_buffer_cur_size,
862                                             worker->read_buffer_bytes_wanted - worker->read_buffer_cur_size,
863                                             &worker->read_ancillary_messages,
864                                             &worker->read_num_ancillary_messages,
865                                             G_PRIORITY_DEFAULT,
866                                             worker->cancellable,
867                                             (GAsyncReadyCallback) _g_dbus_worker_do_read_cb,
868                                             _g_dbus_worker_ref (worker));
869     }
870 }
871 
872 /* called in private thread shared by all GDBusConnection instances (without read-lock held) */
873 static gboolean
_g_dbus_worker_do_initial_read(gpointer data)874 _g_dbus_worker_do_initial_read (gpointer data)
875 {
876   GDBusWorker *worker = data;
877   g_mutex_lock (&worker->read_lock);
878   _g_dbus_worker_do_read_unlocked (worker);
879   g_mutex_unlock (&worker->read_lock);
880   return FALSE;
881 }
882 
883 /* ---------------------------------------------------------------------------------------------------- */
884 
885 struct _MessageToWriteData
886 {
887   GDBusWorker  *worker;
888   GDBusMessage *message;
889   gchar        *blob;
890   gsize         blob_size;
891 
892   gsize         total_written;
893   GTask        *task;
894 };
895 
896 static void
message_to_write_data_free(MessageToWriteData * data)897 message_to_write_data_free (MessageToWriteData *data)
898 {
899   _g_dbus_worker_unref (data->worker);
900   if (data->message)
901     g_object_unref (data->message);
902   g_free (data->blob);
903   g_slice_free (MessageToWriteData, data);
904 }
905 
906 /* ---------------------------------------------------------------------------------------------------- */
907 
908 static void write_message_continue_writing (MessageToWriteData *data);
909 
910 /* called in private thread shared by all GDBusConnection instances
911  *
912  * write-lock is not held on entry
913  * output_pending is PENDING_WRITE on entry
914  */
915 static void
write_message_async_cb(GObject * source_object,GAsyncResult * res,gpointer user_data)916 write_message_async_cb (GObject      *source_object,
917                         GAsyncResult *res,
918                         gpointer      user_data)
919 {
920   MessageToWriteData *data = user_data;
921   GTask *task;
922   gssize bytes_written;
923   GError *error;
924 
925   /* Note: we can't access data->task after calling g_task_return_* () because the
926    * callback can free @data and we're not completing in idle. So use a copy of the pointer.
927    */
928   task = data->task;
929 
930   error = NULL;
931   bytes_written = g_output_stream_write_finish (G_OUTPUT_STREAM (source_object),
932                                                 res,
933                                                 &error);
934   if (bytes_written == -1)
935     {
936       g_task_return_error (task, error);
937       g_object_unref (task);
938       goto out;
939     }
940   g_assert (bytes_written > 0); /* zero is never returned */
941 
942   write_message_print_transport_debug (bytes_written, data);
943 
944   data->total_written += bytes_written;
945   g_assert (data->total_written <= data->blob_size);
946   if (data->total_written == data->blob_size)
947     {
948       g_task_return_boolean (task, TRUE);
949       g_object_unref (task);
950       goto out;
951     }
952 
953   write_message_continue_writing (data);
954 
955  out:
956   ;
957 }
958 
959 /* called in private thread shared by all GDBusConnection instances
960  *
961  * write-lock is not held on entry
962  * output_pending is PENDING_WRITE on entry
963  */
964 #ifdef G_OS_UNIX
965 static gboolean
on_socket_ready(GSocket * socket,GIOCondition condition,gpointer user_data)966 on_socket_ready (GSocket      *socket,
967                  GIOCondition  condition,
968                  gpointer      user_data)
969 {
970   MessageToWriteData *data = user_data;
971   write_message_continue_writing (data);
972   return FALSE; /* remove source */
973 }
974 #endif
975 
976 /* called in private thread shared by all GDBusConnection instances
977  *
978  * write-lock is not held on entry
979  * output_pending is PENDING_WRITE on entry
980  */
981 static void
write_message_continue_writing(MessageToWriteData * data)982 write_message_continue_writing (MessageToWriteData *data)
983 {
984   GOutputStream *ostream;
985 #ifdef G_OS_UNIX
986   GTask *task;
987   GUnixFDList *fd_list;
988 #endif
989 
990 #ifdef G_OS_UNIX
991   /* Note: we can't access data->task after calling g_task_return_* () because the
992    * callback can free @data and we're not completing in idle. So use a copy of the pointer.
993    */
994   task = data->task;
995 #endif
996 
997   ostream = g_io_stream_get_output_stream (data->worker->stream);
998 #ifdef G_OS_UNIX
999   fd_list = g_dbus_message_get_unix_fd_list (data->message);
1000 #endif
1001 
1002   g_assert (!g_output_stream_has_pending (ostream));
1003   g_assert_cmpint (data->total_written, <, data->blob_size);
1004 
1005   if (FALSE)
1006     {
1007     }
1008 #ifdef G_OS_UNIX
1009   else if (G_IS_SOCKET_OUTPUT_STREAM (ostream) && data->total_written == 0)
1010     {
1011       GOutputVector vector;
1012       GSocketControlMessage *control_message;
1013       gssize bytes_written;
1014       GError *error;
1015 
1016       vector.buffer = data->blob;
1017       vector.size = data->blob_size;
1018 
1019       control_message = NULL;
1020       if (fd_list != NULL && g_unix_fd_list_get_length (fd_list) > 0)
1021         {
1022           if (!(data->worker->capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING))
1023             {
1024               g_task_return_new_error (task,
1025                                        G_IO_ERROR,
1026                                        G_IO_ERROR_FAILED,
1027                                        "Tried sending a file descriptor but remote peer does not support this capability");
1028               g_object_unref (task);
1029               goto out;
1030             }
1031           control_message = g_unix_fd_message_new_with_fd_list (fd_list);
1032         }
1033 
1034       error = NULL;
1035       bytes_written = g_socket_send_message (data->worker->socket,
1036                                              NULL, /* address */
1037                                              &vector,
1038                                              1,
1039                                              control_message != NULL ? &control_message : NULL,
1040                                              control_message != NULL ? 1 : 0,
1041                                              G_SOCKET_MSG_NONE,
1042                                              data->worker->cancellable,
1043                                              &error);
1044       if (control_message != NULL)
1045         g_object_unref (control_message);
1046 
1047       if (bytes_written == -1)
1048         {
1049           /* Handle WOULD_BLOCK by waiting until there's room in the buffer */
1050           if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1051             {
1052               GSource *source;
1053               source = g_socket_create_source (data->worker->socket,
1054                                                G_IO_OUT | G_IO_HUP | G_IO_ERR,
1055                                                data->worker->cancellable);
1056               g_source_set_callback (source,
1057                                      (GSourceFunc) on_socket_ready,
1058                                      data,
1059                                      NULL); /* GDestroyNotify */
1060               g_source_attach (source, g_main_context_get_thread_default ());
1061               g_source_unref (source);
1062               g_error_free (error);
1063               goto out;
1064             }
1065           g_task_return_error (task, error);
1066           g_object_unref (task);
1067           goto out;
1068         }
1069       g_assert (bytes_written > 0); /* zero is never returned */
1070 
1071       write_message_print_transport_debug (bytes_written, data);
1072 
1073       data->total_written += bytes_written;
1074       g_assert (data->total_written <= data->blob_size);
1075       if (data->total_written == data->blob_size)
1076         {
1077           g_task_return_boolean (task, TRUE);
1078           g_object_unref (task);
1079           goto out;
1080         }
1081 
1082       write_message_continue_writing (data);
1083     }
1084 #endif
1085   else
1086     {
1087 #ifdef G_OS_UNIX
1088       if (data->total_written == 0 && fd_list != NULL)
1089         {
1090           /* We were trying to write byte 0 of the message, which needs
1091            * the fd list to be attached to it, but this connection doesn't
1092            * support doing that. */
1093           g_task_return_new_error (task,
1094                                    G_IO_ERROR,
1095                                    G_IO_ERROR_FAILED,
1096                                    "Tried sending a file descriptor on unsupported stream of type %s",
1097                                    g_type_name (G_TYPE_FROM_INSTANCE (ostream)));
1098           g_object_unref (task);
1099           goto out;
1100         }
1101 #endif
1102 
1103       g_output_stream_write_async (ostream,
1104                                    (const gchar *) data->blob + data->total_written,
1105                                    data->blob_size - data->total_written,
1106                                    G_PRIORITY_DEFAULT,
1107                                    data->worker->cancellable,
1108                                    write_message_async_cb,
1109                                    data);
1110     }
1111 #ifdef G_OS_UNIX
1112  out:
1113 #endif
1114   ;
1115 }
1116 
1117 /* called in private thread shared by all GDBusConnection instances
1118  *
1119  * write-lock is not held on entry
1120  * output_pending is PENDING_WRITE on entry
1121  */
1122 static void
write_message_async(GDBusWorker * worker,MessageToWriteData * data,GAsyncReadyCallback callback,gpointer user_data)1123 write_message_async (GDBusWorker         *worker,
1124                      MessageToWriteData  *data,
1125                      GAsyncReadyCallback  callback,
1126                      gpointer             user_data)
1127 {
1128   data->task = g_task_new (NULL, NULL, callback, user_data);
1129   g_task_set_source_tag (data->task, write_message_async);
1130   g_task_set_name (data->task, "[gio] D-Bus write message");
1131   data->total_written = 0;
1132   write_message_continue_writing (data);
1133 }
1134 
1135 /* called in private thread shared by all GDBusConnection instances (with write-lock held) */
1136 static gboolean
write_message_finish(GAsyncResult * res,GError ** error)1137 write_message_finish (GAsyncResult   *res,
1138                       GError        **error)
1139 {
1140   g_return_val_if_fail (g_task_is_valid (res, NULL), FALSE);
1141 
1142   return g_task_propagate_boolean (G_TASK (res), error);
1143 }
1144 /* ---------------------------------------------------------------------------------------------------- */
1145 
1146 static void continue_writing (GDBusWorker *worker);
1147 
1148 typedef struct
1149 {
1150   GDBusWorker *worker;
1151   GList *flushers;
1152 } FlushAsyncData;
1153 
1154 static void
flush_data_list_complete(const GList * flushers,const GError * error)1155 flush_data_list_complete (const GList  *flushers,
1156                           const GError *error)
1157 {
1158   const GList *l;
1159 
1160   for (l = flushers; l != NULL; l = l->next)
1161     {
1162       FlushData *f = l->data;
1163 
1164       f->error = error != NULL ? g_error_copy (error) : NULL;
1165 
1166       g_mutex_lock (&f->mutex);
1167       f->finished = TRUE;
1168       g_cond_signal (&f->cond);
1169       g_mutex_unlock (&f->mutex);
1170     }
1171 }
1172 
1173 /* called in private thread shared by all GDBusConnection instances
1174  *
1175  * write-lock is not held on entry
1176  * output_pending is PENDING_FLUSH on entry
1177  */
1178 static void
ostream_flush_cb(GObject * source_object,GAsyncResult * res,gpointer user_data)1179 ostream_flush_cb (GObject      *source_object,
1180                   GAsyncResult *res,
1181                   gpointer      user_data)
1182 {
1183   FlushAsyncData *data = user_data;
1184   GError *error;
1185 
1186   error = NULL;
1187   g_output_stream_flush_finish (G_OUTPUT_STREAM (source_object),
1188                                 res,
1189                                 &error);
1190 
1191   if (error == NULL)
1192     {
1193       if (G_UNLIKELY (_g_dbus_debug_transport ()))
1194         {
1195           _g_dbus_debug_print_lock ();
1196           g_print ("========================================================================\n"
1197                    "GDBus-debug:Transport:\n"
1198                    "  ---- FLUSHED stream of type %s\n",
1199                    g_type_name (G_TYPE_FROM_INSTANCE (g_io_stream_get_output_stream (data->worker->stream))));
1200           _g_dbus_debug_print_unlock ();
1201         }
1202     }
1203 
1204   /* Make sure we tell folks that we don't have additional
1205      flushes pending */
1206   g_mutex_lock (&data->worker->write_lock);
1207   data->worker->write_num_messages_flushed = data->worker->write_num_messages_written;
1208   g_assert (data->worker->output_pending == PENDING_FLUSH);
1209   data->worker->output_pending = PENDING_NONE;
1210   g_mutex_unlock (&data->worker->write_lock);
1211 
1212   g_assert (data->flushers != NULL);
1213   flush_data_list_complete (data->flushers, error);
1214   g_list_free (data->flushers);
1215   if (error != NULL)
1216     g_error_free (error);
1217 
1218   /* OK, cool, finally kick off the next write */
1219   continue_writing (data->worker);
1220 
1221   _g_dbus_worker_unref (data->worker);
1222   g_free (data);
1223 }
1224 
1225 /* called in private thread shared by all GDBusConnection instances
1226  *
1227  * write-lock is not held on entry
1228  * output_pending is PENDING_FLUSH on entry
1229  */
1230 static void
start_flush(FlushAsyncData * data)1231 start_flush (FlushAsyncData *data)
1232 {
1233   g_output_stream_flush_async (g_io_stream_get_output_stream (data->worker->stream),
1234                                G_PRIORITY_DEFAULT,
1235                                data->worker->cancellable,
1236                                ostream_flush_cb,
1237                                data);
1238 }
1239 
1240 /* called in private thread shared by all GDBusConnection instances
1241  *
1242  * write-lock is held on entry
1243  * output_pending is PENDING_NONE on entry
1244  */
1245 static void
message_written_unlocked(GDBusWorker * worker,MessageToWriteData * message_data)1246 message_written_unlocked (GDBusWorker *worker,
1247                           MessageToWriteData *message_data)
1248 {
1249   if (G_UNLIKELY (_g_dbus_debug_message ()))
1250     {
1251       gchar *s;
1252       _g_dbus_debug_print_lock ();
1253       g_print ("========================================================================\n"
1254                "GDBus-debug:Message:\n"
1255                "  >>>> SENT D-Bus message (%" G_GSIZE_FORMAT " bytes)\n",
1256                message_data->blob_size);
1257       s = g_dbus_message_print (message_data->message, 2);
1258       g_print ("%s", s);
1259       g_free (s);
1260       if (G_UNLIKELY (_g_dbus_debug_payload ()))
1261         {
1262           s = _g_dbus_hexdump (message_data->blob, message_data->blob_size, 2);
1263           g_print ("%s\n", s);
1264           g_free (s);
1265         }
1266       _g_dbus_debug_print_unlock ();
1267     }
1268 
1269   worker->write_num_messages_written += 1;
1270 }
1271 
1272 /* called in private thread shared by all GDBusConnection instances
1273  *
1274  * write-lock is held on entry
1275  * output_pending is PENDING_NONE on entry
1276  *
1277  * Returns: non-%NULL, setting @output_pending, if we need to flush now
1278  */
1279 static FlushAsyncData *
prepare_flush_unlocked(GDBusWorker * worker)1280 prepare_flush_unlocked (GDBusWorker *worker)
1281 {
1282   GList *l;
1283   GList *ll;
1284   GList *flushers;
1285 
1286   flushers = NULL;
1287   for (l = worker->write_pending_flushes; l != NULL; l = ll)
1288     {
1289       FlushData *f = l->data;
1290       ll = l->next;
1291 
1292       if (f->number_to_wait_for == worker->write_num_messages_written)
1293         {
1294           flushers = g_list_append (flushers, f);
1295           worker->write_pending_flushes = g_list_delete_link (worker->write_pending_flushes, l);
1296         }
1297     }
1298   if (flushers != NULL)
1299     {
1300       g_assert (worker->output_pending == PENDING_NONE);
1301       worker->output_pending = PENDING_FLUSH;
1302     }
1303 
1304   if (flushers != NULL)
1305     {
1306       FlushAsyncData *data;
1307 
1308       data = g_new0 (FlushAsyncData, 1);
1309       data->worker = _g_dbus_worker_ref (worker);
1310       data->flushers = flushers;
1311       return data;
1312     }
1313 
1314   return NULL;
1315 }
1316 
1317 /* called in private thread shared by all GDBusConnection instances
1318  *
1319  * write-lock is not held on entry
1320  * output_pending is PENDING_WRITE on entry
1321  */
1322 static void
write_message_cb(GObject * source_object,GAsyncResult * res,gpointer user_data)1323 write_message_cb (GObject       *source_object,
1324                   GAsyncResult  *res,
1325                   gpointer       user_data)
1326 {
1327   MessageToWriteData *data = user_data;
1328   GError *error;
1329 
1330   g_mutex_lock (&data->worker->write_lock);
1331   g_assert (data->worker->output_pending == PENDING_WRITE);
1332   data->worker->output_pending = PENDING_NONE;
1333 
1334   error = NULL;
1335   if (!write_message_finish (res, &error))
1336     {
1337       g_mutex_unlock (&data->worker->write_lock);
1338 
1339       /* TODO: handle */
1340       _g_dbus_worker_emit_disconnected (data->worker, TRUE, error);
1341       g_error_free (error);
1342 
1343       g_mutex_lock (&data->worker->write_lock);
1344     }
1345 
1346   message_written_unlocked (data->worker, data);
1347 
1348   g_mutex_unlock (&data->worker->write_lock);
1349 
1350   continue_writing (data->worker);
1351 
1352   message_to_write_data_free (data);
1353 }
1354 
1355 /* called in private thread shared by all GDBusConnection instances
1356  *
1357  * write-lock is not held on entry
1358  * output_pending is PENDING_CLOSE on entry
1359  */
1360 static void
iostream_close_cb(GObject * source_object,GAsyncResult * res,gpointer user_data)1361 iostream_close_cb (GObject      *source_object,
1362                    GAsyncResult *res,
1363                    gpointer      user_data)
1364 {
1365   GDBusWorker *worker = user_data;
1366   GError *error = NULL;
1367   GList *pending_close_attempts, *pending_flush_attempts;
1368   GQueue *send_queue;
1369 
1370   g_io_stream_close_finish (worker->stream, res, &error);
1371 
1372   g_mutex_lock (&worker->write_lock);
1373 
1374   pending_close_attempts = worker->pending_close_attempts;
1375   worker->pending_close_attempts = NULL;
1376 
1377   pending_flush_attempts = worker->write_pending_flushes;
1378   worker->write_pending_flushes = NULL;
1379 
1380   send_queue = worker->write_queue;
1381   worker->write_queue = g_queue_new ();
1382 
1383   g_assert (worker->output_pending == PENDING_CLOSE);
1384   worker->output_pending = PENDING_NONE;
1385 
1386   /* Ensure threads waiting for pending flushes to finish will be unblocked. */
1387   worker->write_num_messages_flushed =
1388     worker->write_num_messages_written + g_list_length(pending_flush_attempts);
1389 
1390   g_mutex_unlock (&worker->write_lock);
1391 
1392   while (pending_close_attempts != NULL)
1393     {
1394       CloseData *close_data = pending_close_attempts->data;
1395 
1396       pending_close_attempts = g_list_delete_link (pending_close_attempts,
1397                                                    pending_close_attempts);
1398 
1399       if (close_data->task != NULL)
1400         {
1401           if (error != NULL)
1402             g_task_return_error (close_data->task, g_error_copy (error));
1403           else
1404             g_task_return_boolean (close_data->task, TRUE);
1405         }
1406 
1407       close_data_free (close_data);
1408     }
1409 
1410   g_clear_error (&error);
1411 
1412   /* all messages queued for sending are discarded */
1413   g_queue_free_full (send_queue, (GDestroyNotify) message_to_write_data_free);
1414   /* all queued flushes fail */
1415   error = g_error_new (G_IO_ERROR, G_IO_ERROR_CANCELLED,
1416                        _("Operation was cancelled"));
1417   flush_data_list_complete (pending_flush_attempts, error);
1418   g_list_free (pending_flush_attempts);
1419   g_clear_error (&error);
1420 
1421   _g_dbus_worker_unref (worker);
1422 }
1423 
1424 /* called in private thread shared by all GDBusConnection instances
1425  *
1426  * write-lock is not held on entry
1427  * output_pending must be PENDING_NONE on entry
1428  */
1429 static void
continue_writing(GDBusWorker * worker)1430 continue_writing (GDBusWorker *worker)
1431 {
1432   MessageToWriteData *data;
1433   FlushAsyncData *flush_async_data;
1434 
1435  write_next:
1436   /* we mustn't try to write two things at once */
1437   g_assert (worker->output_pending == PENDING_NONE);
1438 
1439   g_mutex_lock (&worker->write_lock);
1440 
1441   data = NULL;
1442   flush_async_data = NULL;
1443 
1444   /* if we want to close the connection, that takes precedence */
1445   if (worker->pending_close_attempts != NULL)
1446     {
1447       GInputStream *input = g_io_stream_get_input_stream (worker->stream);
1448 
1449       if (!g_input_stream_has_pending (input))
1450         {
1451           worker->close_expected = TRUE;
1452           worker->output_pending = PENDING_CLOSE;
1453 
1454           g_io_stream_close_async (worker->stream, G_PRIORITY_DEFAULT,
1455                                    NULL, iostream_close_cb,
1456                                    _g_dbus_worker_ref (worker));
1457         }
1458     }
1459   else
1460     {
1461       flush_async_data = prepare_flush_unlocked (worker);
1462 
1463       if (flush_async_data == NULL)
1464         {
1465           data = g_queue_pop_head (worker->write_queue);
1466 
1467           if (data != NULL)
1468             worker->output_pending = PENDING_WRITE;
1469         }
1470     }
1471 
1472   g_mutex_unlock (&worker->write_lock);
1473 
1474   /* Note that write_lock is only used for protecting the @write_queue
1475    * and @output_pending fields of the GDBusWorker struct ... which we
1476    * need to modify from arbitrary threads in _g_dbus_worker_send_message().
1477    *
1478    * Therefore, it's fine to drop it here when calling back into user
1479    * code and then writing the message out onto the GIOStream since this
1480    * function only runs on the worker thread.
1481    */
1482 
1483   if (flush_async_data != NULL)
1484     {
1485       start_flush (flush_async_data);
1486       g_assert (data == NULL);
1487     }
1488   else if (data != NULL)
1489     {
1490       GDBusMessage *old_message;
1491       guchar *new_blob;
1492       gsize new_blob_size;
1493       GError *error;
1494 
1495       old_message = data->message;
1496       data->message = _g_dbus_worker_emit_message_about_to_be_sent (worker, data->message);
1497       if (data->message == old_message)
1498         {
1499           /* filters had no effect - do nothing */
1500         }
1501       else if (data->message == NULL)
1502         {
1503           /* filters dropped message */
1504           g_mutex_lock (&worker->write_lock);
1505           worker->output_pending = PENDING_NONE;
1506           g_mutex_unlock (&worker->write_lock);
1507           message_to_write_data_free (data);
1508           goto write_next;
1509         }
1510       else
1511         {
1512           /* filters altered the message -> re-encode */
1513           error = NULL;
1514           new_blob = g_dbus_message_to_blob (data->message,
1515                                              &new_blob_size,
1516                                              worker->capabilities,
1517                                              &error);
1518           if (new_blob == NULL)
1519             {
1520               /* if filter make the GDBusMessage unencodeable, just complain on stderr and send
1521                * the old message instead
1522                */
1523               g_warning ("Error encoding GDBusMessage with serial %d altered by filter function: %s",
1524                          g_dbus_message_get_serial (data->message),
1525                          error->message);
1526               g_error_free (error);
1527             }
1528           else
1529             {
1530               g_free (data->blob);
1531               data->blob = (gchar *) new_blob;
1532               data->blob_size = new_blob_size;
1533             }
1534         }
1535 
1536       write_message_async (worker,
1537                            data,
1538                            write_message_cb,
1539                            data);
1540     }
1541 }
1542 
1543 /* called in private thread shared by all GDBusConnection instances
1544  *
1545  * write-lock is not held on entry
1546  * output_pending may be anything
1547  */
1548 static gboolean
continue_writing_in_idle_cb(gpointer user_data)1549 continue_writing_in_idle_cb (gpointer user_data)
1550 {
1551   GDBusWorker *worker = user_data;
1552 
1553   /* Because this is the worker thread, we can read this struct member
1554    * without holding the lock: no other thread ever modifies it.
1555    */
1556   if (worker->output_pending == PENDING_NONE)
1557     continue_writing (worker);
1558 
1559   return FALSE;
1560 }
1561 
1562 /*
1563  * @write_data: (transfer full) (nullable):
1564  * @flush_data: (transfer full) (nullable):
1565  * @close_data: (transfer full) (nullable):
1566  *
1567  * Can be called from any thread
1568  *
1569  * write_lock is held on entry
1570  * output_pending may be anything
1571  */
1572 static void
schedule_writing_unlocked(GDBusWorker * worker,MessageToWriteData * write_data,FlushData * flush_data,CloseData * close_data)1573 schedule_writing_unlocked (GDBusWorker        *worker,
1574                            MessageToWriteData *write_data,
1575                            FlushData          *flush_data,
1576                            CloseData          *close_data)
1577 {
1578   if (write_data != NULL)
1579     g_queue_push_tail (worker->write_queue, write_data);
1580 
1581   if (flush_data != NULL)
1582     worker->write_pending_flushes = g_list_prepend (worker->write_pending_flushes, flush_data);
1583 
1584   if (close_data != NULL)
1585     worker->pending_close_attempts = g_list_prepend (worker->pending_close_attempts,
1586                                                      close_data);
1587 
1588   /* If we had output pending, the next bit of output will happen
1589    * automatically when it finishes, so we only need to do this
1590    * if nothing was pending.
1591    *
1592    * The idle callback will re-check that output_pending is still
1593    * PENDING_NONE, to guard against output starting before the idle.
1594    */
1595   if (worker->output_pending == PENDING_NONE)
1596     {
1597       GSource *idle_source;
1598       idle_source = g_idle_source_new ();
1599       g_source_set_priority (idle_source, G_PRIORITY_DEFAULT);
1600       g_source_set_callback (idle_source,
1601                              continue_writing_in_idle_cb,
1602                              _g_dbus_worker_ref (worker),
1603                              (GDestroyNotify) _g_dbus_worker_unref);
1604       g_source_set_name (idle_source, "[gio] continue_writing_in_idle_cb");
1605       g_source_attach (idle_source, worker->shared_thread_data->context);
1606       g_source_unref (idle_source);
1607     }
1608 }
1609 
1610 static void
schedule_pending_close(GDBusWorker * worker)1611 schedule_pending_close (GDBusWorker *worker)
1612 {
1613   g_mutex_lock (&worker->write_lock);
1614   if (worker->pending_close_attempts)
1615     schedule_writing_unlocked (worker, NULL, NULL, NULL);
1616   g_mutex_unlock (&worker->write_lock);
1617 }
1618 
1619 /* ---------------------------------------------------------------------------------------------------- */
1620 
1621 /* can be called from any thread - steals blob
1622  *
1623  * write_lock is not held on entry
1624  * output_pending may be anything
1625  */
1626 void
_g_dbus_worker_send_message(GDBusWorker * worker,GDBusMessage * message,gchar * blob,gsize blob_len)1627 _g_dbus_worker_send_message (GDBusWorker    *worker,
1628                              GDBusMessage   *message,
1629                              gchar          *blob,
1630                              gsize           blob_len)
1631 {
1632   MessageToWriteData *data;
1633 
1634   g_return_if_fail (G_IS_DBUS_MESSAGE (message));
1635   g_return_if_fail (blob != NULL);
1636   g_return_if_fail (blob_len > 16);
1637 
1638   data = g_slice_new0 (MessageToWriteData);
1639   data->worker = _g_dbus_worker_ref (worker);
1640   data->message = g_object_ref (message);
1641   data->blob = blob; /* steal! */
1642   data->blob_size = blob_len;
1643 
1644   g_mutex_lock (&worker->write_lock);
1645   schedule_writing_unlocked (worker, data, NULL, NULL);
1646   g_mutex_unlock (&worker->write_lock);
1647 }
1648 
1649 /* ---------------------------------------------------------------------------------------------------- */
1650 
1651 GDBusWorker *
_g_dbus_worker_new(GIOStream * stream,GDBusCapabilityFlags capabilities,gboolean initially_frozen,GDBusWorkerMessageReceivedCallback message_received_callback,GDBusWorkerMessageAboutToBeSentCallback message_about_to_be_sent_callback,GDBusWorkerDisconnectedCallback disconnected_callback,gpointer user_data)1652 _g_dbus_worker_new (GIOStream                              *stream,
1653                     GDBusCapabilityFlags                    capabilities,
1654                     gboolean                                initially_frozen,
1655                     GDBusWorkerMessageReceivedCallback      message_received_callback,
1656                     GDBusWorkerMessageAboutToBeSentCallback message_about_to_be_sent_callback,
1657                     GDBusWorkerDisconnectedCallback         disconnected_callback,
1658                     gpointer                                user_data)
1659 {
1660   GDBusWorker *worker;
1661   GSource *idle_source;
1662 
1663   g_return_val_if_fail (G_IS_IO_STREAM (stream), NULL);
1664   g_return_val_if_fail (message_received_callback != NULL, NULL);
1665   g_return_val_if_fail (message_about_to_be_sent_callback != NULL, NULL);
1666   g_return_val_if_fail (disconnected_callback != NULL, NULL);
1667 
1668   worker = g_new0 (GDBusWorker, 1);
1669   worker->ref_count = 1;
1670 
1671   g_mutex_init (&worker->read_lock);
1672   worker->message_received_callback = message_received_callback;
1673   worker->message_about_to_be_sent_callback = message_about_to_be_sent_callback;
1674   worker->disconnected_callback = disconnected_callback;
1675   worker->user_data = user_data;
1676   worker->stream = g_object_ref (stream);
1677   worker->capabilities = capabilities;
1678   worker->cancellable = g_cancellable_new ();
1679   worker->output_pending = PENDING_NONE;
1680 
1681   worker->frozen = initially_frozen;
1682   worker->received_messages_while_frozen = g_queue_new ();
1683 
1684   g_mutex_init (&worker->write_lock);
1685   worker->write_queue = g_queue_new ();
1686 
1687   if (G_IS_SOCKET_CONNECTION (worker->stream))
1688     worker->socket = g_socket_connection_get_socket (G_SOCKET_CONNECTION (worker->stream));
1689 
1690   worker->shared_thread_data = _g_dbus_shared_thread_ref ();
1691 
1692   /* begin reading */
1693   idle_source = g_idle_source_new ();
1694   g_source_set_priority (idle_source, G_PRIORITY_DEFAULT);
1695   g_source_set_callback (idle_source,
1696                          _g_dbus_worker_do_initial_read,
1697                          _g_dbus_worker_ref (worker),
1698                          (GDestroyNotify) _g_dbus_worker_unref);
1699   g_source_set_name (idle_source, "[gio] _g_dbus_worker_do_initial_read");
1700   g_source_attach (idle_source, worker->shared_thread_data->context);
1701   g_source_unref (idle_source);
1702 
1703   return worker;
1704 }
1705 
1706 /* ---------------------------------------------------------------------------------------------------- */
1707 
1708 /* can be called from any thread
1709  *
1710  * write_lock is not held on entry
1711  * output_pending may be anything
1712  */
1713 void
_g_dbus_worker_close(GDBusWorker * worker,GTask * task)1714 _g_dbus_worker_close (GDBusWorker         *worker,
1715                       GTask               *task)
1716 {
1717   CloseData *close_data;
1718 
1719   close_data = g_slice_new0 (CloseData);
1720   close_data->worker = _g_dbus_worker_ref (worker);
1721   close_data->task = (task == NULL ? NULL : g_object_ref (task));
1722 
1723   /* Don't set worker->close_expected here - we're in the wrong thread.
1724    * It'll be set before the actual close happens.
1725    */
1726   g_cancellable_cancel (worker->cancellable);
1727   g_mutex_lock (&worker->write_lock);
1728   schedule_writing_unlocked (worker, NULL, NULL, close_data);
1729   g_mutex_unlock (&worker->write_lock);
1730 }
1731 
1732 /* This can be called from any thread - frees worker. Note that
1733  * callbacks might still happen if called from another thread than the
1734  * worker - use your own synchronization primitive in the callbacks.
1735  *
1736  * write_lock is not held on entry
1737  * output_pending may be anything
1738  */
1739 void
_g_dbus_worker_stop(GDBusWorker * worker)1740 _g_dbus_worker_stop (GDBusWorker *worker)
1741 {
1742   g_atomic_int_set (&worker->stopped, TRUE);
1743 
1744   /* Cancel any pending operations and schedule a close of the underlying I/O
1745    * stream in the worker thread
1746    */
1747   _g_dbus_worker_close (worker, NULL);
1748 
1749   /* _g_dbus_worker_close holds a ref until after an idle in the worker
1750    * thread has run, so we no longer need to unref in an idle like in
1751    * commit 322e25b535
1752    */
1753   _g_dbus_worker_unref (worker);
1754 }
1755 
1756 /* ---------------------------------------------------------------------------------------------------- */
1757 
1758 /* can be called from any thread (except the worker thread) - blocks
1759  * calling thread until all queued outgoing messages are written and
1760  * the transport has been flushed
1761  *
1762  * write_lock is not held on entry
1763  * output_pending may be anything
1764  */
1765 gboolean
_g_dbus_worker_flush_sync(GDBusWorker * worker,GCancellable * cancellable,GError ** error)1766 _g_dbus_worker_flush_sync (GDBusWorker    *worker,
1767                            GCancellable   *cancellable,
1768                            GError        **error)
1769 {
1770   gboolean ret;
1771   FlushData *data;
1772   guint64 pending_writes;
1773 
1774   data = NULL;
1775   ret = TRUE;
1776 
1777   g_mutex_lock (&worker->write_lock);
1778 
1779   /* if the queue is empty, no write is in-flight and we haven't written
1780    * anything since the last flush, then there's nothing to wait for
1781    */
1782   pending_writes = g_queue_get_length (worker->write_queue);
1783 
1784   /* if a write is in-flight, we shouldn't be satisfied until the first
1785    * flush operation that follows it
1786    */
1787   if (worker->output_pending == PENDING_WRITE)
1788     pending_writes += 1;
1789 
1790   if (pending_writes > 0 ||
1791       worker->write_num_messages_written != worker->write_num_messages_flushed)
1792     {
1793       data = g_new0 (FlushData, 1);
1794       g_mutex_init (&data->mutex);
1795       g_cond_init (&data->cond);
1796       data->number_to_wait_for = worker->write_num_messages_written + pending_writes;
1797       data->finished = FALSE;
1798       g_mutex_lock (&data->mutex);
1799 
1800       schedule_writing_unlocked (worker, NULL, data, NULL);
1801     }
1802   g_mutex_unlock (&worker->write_lock);
1803 
1804   if (data != NULL)
1805     {
1806       /* Wait for flush operations to finish. */
1807       while (!data->finished)
1808         {
1809           g_cond_wait (&data->cond, &data->mutex);
1810         }
1811 
1812       g_mutex_unlock (&data->mutex);
1813       g_cond_clear (&data->cond);
1814       g_mutex_clear (&data->mutex);
1815       if (data->error != NULL)
1816         {
1817           ret = FALSE;
1818           g_propagate_error (error, data->error);
1819         }
1820       g_free (data);
1821     }
1822 
1823   return ret;
1824 }
1825 
1826 /* ---------------------------------------------------------------------------------------------------- */
1827 
1828 #define G_DBUS_DEBUG_AUTHENTICATION (1<<0)
1829 #define G_DBUS_DEBUG_TRANSPORT      (1<<1)
1830 #define G_DBUS_DEBUG_MESSAGE        (1<<2)
1831 #define G_DBUS_DEBUG_PAYLOAD        (1<<3)
1832 #define G_DBUS_DEBUG_CALL           (1<<4)
1833 #define G_DBUS_DEBUG_SIGNAL         (1<<5)
1834 #define G_DBUS_DEBUG_INCOMING       (1<<6)
1835 #define G_DBUS_DEBUG_RETURN         (1<<7)
1836 #define G_DBUS_DEBUG_EMISSION       (1<<8)
1837 #define G_DBUS_DEBUG_ADDRESS        (1<<9)
1838 #define G_DBUS_DEBUG_PROXY          (1<<10)
1839 
1840 static gint _gdbus_debug_flags = 0;
1841 
1842 gboolean
_g_dbus_debug_authentication(void)1843 _g_dbus_debug_authentication (void)
1844 {
1845   _g_dbus_initialize ();
1846   return (_gdbus_debug_flags & G_DBUS_DEBUG_AUTHENTICATION) != 0;
1847 }
1848 
1849 gboolean
_g_dbus_debug_transport(void)1850 _g_dbus_debug_transport (void)
1851 {
1852   _g_dbus_initialize ();
1853   return (_gdbus_debug_flags & G_DBUS_DEBUG_TRANSPORT) != 0;
1854 }
1855 
1856 gboolean
_g_dbus_debug_message(void)1857 _g_dbus_debug_message (void)
1858 {
1859   _g_dbus_initialize ();
1860   return (_gdbus_debug_flags & G_DBUS_DEBUG_MESSAGE) != 0;
1861 }
1862 
1863 gboolean
_g_dbus_debug_payload(void)1864 _g_dbus_debug_payload (void)
1865 {
1866   _g_dbus_initialize ();
1867   return (_gdbus_debug_flags & G_DBUS_DEBUG_PAYLOAD) != 0;
1868 }
1869 
1870 gboolean
_g_dbus_debug_call(void)1871 _g_dbus_debug_call (void)
1872 {
1873   _g_dbus_initialize ();
1874   return (_gdbus_debug_flags & G_DBUS_DEBUG_CALL) != 0;
1875 }
1876 
1877 gboolean
_g_dbus_debug_signal(void)1878 _g_dbus_debug_signal (void)
1879 {
1880   _g_dbus_initialize ();
1881   return (_gdbus_debug_flags & G_DBUS_DEBUG_SIGNAL) != 0;
1882 }
1883 
1884 gboolean
_g_dbus_debug_incoming(void)1885 _g_dbus_debug_incoming (void)
1886 {
1887   _g_dbus_initialize ();
1888   return (_gdbus_debug_flags & G_DBUS_DEBUG_INCOMING) != 0;
1889 }
1890 
1891 gboolean
_g_dbus_debug_return(void)1892 _g_dbus_debug_return (void)
1893 {
1894   _g_dbus_initialize ();
1895   return (_gdbus_debug_flags & G_DBUS_DEBUG_RETURN) != 0;
1896 }
1897 
1898 gboolean
_g_dbus_debug_emission(void)1899 _g_dbus_debug_emission (void)
1900 {
1901   _g_dbus_initialize ();
1902   return (_gdbus_debug_flags & G_DBUS_DEBUG_EMISSION) != 0;
1903 }
1904 
1905 gboolean
_g_dbus_debug_address(void)1906 _g_dbus_debug_address (void)
1907 {
1908   _g_dbus_initialize ();
1909   return (_gdbus_debug_flags & G_DBUS_DEBUG_ADDRESS) != 0;
1910 }
1911 
1912 gboolean
_g_dbus_debug_proxy(void)1913 _g_dbus_debug_proxy (void)
1914 {
1915   _g_dbus_initialize ();
1916   return (_gdbus_debug_flags & G_DBUS_DEBUG_PROXY) != 0;
1917 }
1918 
1919 G_LOCK_DEFINE_STATIC (print_lock);
1920 
1921 void
_g_dbus_debug_print_lock(void)1922 _g_dbus_debug_print_lock (void)
1923 {
1924   G_LOCK (print_lock);
1925 }
1926 
1927 void
_g_dbus_debug_print_unlock(void)1928 _g_dbus_debug_print_unlock (void)
1929 {
1930   G_UNLOCK (print_lock);
1931 }
1932 
1933 /**
1934  * _g_dbus_initialize:
1935  *
1936  * Does various one-time init things such as
1937  *
1938  *  - registering the G_DBUS_ERROR error domain
1939  *  - parses the G_DBUS_DEBUG environment variable
1940  */
1941 void
_g_dbus_initialize(void)1942 _g_dbus_initialize (void)
1943 {
1944   static gsize initialized = 0;
1945 
1946   if (g_once_init_enter (&initialized))
1947     {
1948       const gchar *debug;
1949 
1950       /* Ensure the domain is registered. */
1951       g_dbus_error_quark ();
1952 
1953       debug = g_getenv ("G_DBUS_DEBUG");
1954       if (debug != NULL)
1955         {
1956           const GDebugKey keys[] = {
1957             { "authentication", G_DBUS_DEBUG_AUTHENTICATION },
1958             { "transport",      G_DBUS_DEBUG_TRANSPORT      },
1959             { "message",        G_DBUS_DEBUG_MESSAGE        },
1960             { "payload",        G_DBUS_DEBUG_PAYLOAD        },
1961             { "call",           G_DBUS_DEBUG_CALL           },
1962             { "signal",         G_DBUS_DEBUG_SIGNAL         },
1963             { "incoming",       G_DBUS_DEBUG_INCOMING       },
1964             { "return",         G_DBUS_DEBUG_RETURN         },
1965             { "emission",       G_DBUS_DEBUG_EMISSION       },
1966             { "address",        G_DBUS_DEBUG_ADDRESS        },
1967             { "proxy",          G_DBUS_DEBUG_PROXY          }
1968           };
1969 
1970           _gdbus_debug_flags = g_parse_debug_string (debug, keys, G_N_ELEMENTS (keys));
1971           if (_gdbus_debug_flags & G_DBUS_DEBUG_PAYLOAD)
1972             _gdbus_debug_flags |= G_DBUS_DEBUG_MESSAGE;
1973         }
1974 
1975       /* Work-around for https://bugzilla.gnome.org/show_bug.cgi?id=627724 */
1976       ensure_required_types ();
1977 
1978       g_once_init_leave (&initialized, 1);
1979     }
1980 }
1981 
1982 /* ---------------------------------------------------------------------------------------------------- */
1983 
1984 GVariantType *
_g_dbus_compute_complete_signature(GDBusArgInfo ** args)1985 _g_dbus_compute_complete_signature (GDBusArgInfo **args)
1986 {
1987   const GVariantType *arg_types[256];
1988   guint n;
1989 
1990   if (args)
1991     for (n = 0; args[n] != NULL; n++)
1992       {
1993         /* DBus places a hard limit of 255 on signature length.
1994          * therefore number of args must be less than 256.
1995          */
1996         g_assert (n < 256);
1997 
1998         arg_types[n] = G_VARIANT_TYPE (args[n]->signature);
1999 
2000         if G_UNLIKELY (arg_types[n] == NULL)
2001           return NULL;
2002       }
2003   else
2004     n = 0;
2005 
2006   return g_variant_type_new_tuple (arg_types, n);
2007 }
2008 
2009 /* ---------------------------------------------------------------------------------------------------- */
2010 
2011 #ifdef G_OS_WIN32
2012 
2013 extern BOOL WINAPI ConvertSidToStringSidA (PSID Sid, LPSTR *StringSid);
2014 
2015 gchar *
_g_dbus_win32_get_user_sid(void)2016 _g_dbus_win32_get_user_sid (void)
2017 {
2018   HANDLE h;
2019   TOKEN_USER *user;
2020   DWORD token_information_len;
2021   PSID psid;
2022   gchar *sid;
2023   gchar *ret;
2024 
2025   ret = NULL;
2026   user = NULL;
2027   h = INVALID_HANDLE_VALUE;
2028 
2029   if (!OpenProcessToken (GetCurrentProcess (), TOKEN_QUERY, &h))
2030     {
2031       g_warning ("OpenProcessToken failed with error code %d", (gint) GetLastError ());
2032       goto out;
2033     }
2034 
2035   /* Get length of buffer */
2036   token_information_len = 0;
2037   if (!GetTokenInformation (h, TokenUser, NULL, 0, &token_information_len))
2038     {
2039       if (GetLastError () != ERROR_INSUFFICIENT_BUFFER)
2040         {
2041           g_warning ("GetTokenInformation() failed with error code %d", (gint) GetLastError ());
2042           goto out;
2043         }
2044     }
2045   user = g_malloc (token_information_len);
2046   if (!GetTokenInformation (h, TokenUser, user, token_information_len, &token_information_len))
2047     {
2048       g_warning ("GetTokenInformation() failed with error code %d", (gint) GetLastError ());
2049       goto out;
2050     }
2051 
2052   psid = user->User.Sid;
2053   if (!IsValidSid (psid))
2054     {
2055       g_warning ("Invalid SID");
2056       goto out;
2057     }
2058 
2059   if (!ConvertSidToStringSidA (psid, &sid))
2060     {
2061       g_warning ("Invalid SID");
2062       goto out;
2063     }
2064 
2065   ret = g_strdup (sid);
2066   LocalFree (sid);
2067 
2068 out:
2069   g_free (user);
2070   if (h != INVALID_HANDLE_VALUE)
2071     CloseHandle (h);
2072   return ret;
2073 }
2074 
2075 
2076 #define DBUS_DAEMON_ADDRESS_INFO "DBusDaemonAddressInfo"
2077 #define DBUS_DAEMON_MUTEX "DBusDaemonMutex"
2078 #define UNIQUE_DBUS_INIT_MUTEX "UniqueDBusInitMutex"
2079 #define DBUS_AUTOLAUNCH_MUTEX "DBusAutolaunchMutex"
2080 
2081 static void
release_mutex(HANDLE mutex)2082 release_mutex (HANDLE mutex)
2083 {
2084   ReleaseMutex (mutex);
2085   CloseHandle (mutex);
2086 }
2087 
2088 static HANDLE
acquire_mutex(const char * mutexname)2089 acquire_mutex (const char *mutexname)
2090 {
2091   HANDLE mutex;
2092   DWORD res;
2093 
2094   mutex = CreateMutexA (NULL, FALSE, mutexname);
2095   if (!mutex)
2096     return 0;
2097 
2098   res = WaitForSingleObject (mutex, INFINITE);
2099   switch (res)
2100     {
2101     case WAIT_ABANDONED:
2102       release_mutex (mutex);
2103       return 0;
2104     case WAIT_FAILED:
2105     case WAIT_TIMEOUT:
2106       return 0;
2107     }
2108 
2109   return mutex;
2110 }
2111 
2112 static gboolean
is_mutex_owned(const char * mutexname)2113 is_mutex_owned (const char *mutexname)
2114 {
2115   HANDLE mutex;
2116   gboolean res = FALSE;
2117 
2118   mutex = CreateMutexA (NULL, FALSE, mutexname);
2119   if (WaitForSingleObject (mutex, 10) == WAIT_TIMEOUT)
2120     res = TRUE;
2121   else
2122     ReleaseMutex (mutex);
2123   CloseHandle (mutex);
2124 
2125   return res;
2126 }
2127 
2128 static char *
read_shm(const char * shm_name)2129 read_shm (const char *shm_name)
2130 {
2131   HANDLE shared_mem;
2132   char *shared_data;
2133   char *res;
2134   int i;
2135 
2136   res = NULL;
2137 
2138   for (i = 0; i < 20; i++)
2139     {
2140       shared_mem = OpenFileMappingA (FILE_MAP_READ, FALSE, shm_name);
2141       if (shared_mem != 0)
2142 	break;
2143       Sleep (100);
2144     }
2145 
2146   if (shared_mem != 0)
2147     {
2148       shared_data = MapViewOfFile (shared_mem, FILE_MAP_READ, 0, 0, 0);
2149       /* It looks that a race is possible here:
2150        * if the dbus process already created mapping but didn't fill it
2151        * the code below may read incorrect address.
2152        * Also this is a bit complicated by the fact that
2153        * any change in the "synchronization contract" between processes
2154        * should be accompanied with renaming all of used win32 named objects:
2155        * otherwise libgio-2.0-0.dll of different versions shipped with
2156        * different apps may break each other due to protocol difference.
2157        */
2158       if (shared_data != NULL)
2159 	{
2160 	  res = g_strdup (shared_data);
2161 	  UnmapViewOfFile (shared_data);
2162 	}
2163       CloseHandle (shared_mem);
2164     }
2165 
2166   return res;
2167 }
2168 
2169 static HANDLE
set_shm(const char * shm_name,const char * value)2170 set_shm (const char *shm_name, const char *value)
2171 {
2172   HANDLE shared_mem;
2173   char *shared_data;
2174 
2175   shared_mem = CreateFileMappingA (INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE,
2176 				   0, strlen (value) + 1, shm_name);
2177   if (shared_mem == 0)
2178     return 0;
2179 
2180   shared_data = MapViewOfFile (shared_mem, FILE_MAP_WRITE, 0, 0, 0 );
2181   if (shared_data == NULL)
2182     return 0;
2183 
2184   strcpy (shared_data, value);
2185 
2186   UnmapViewOfFile (shared_data);
2187 
2188   return shared_mem;
2189 }
2190 
2191 /* These keep state between publish_session_bus and unpublish_session_bus */
2192 static HANDLE published_daemon_mutex;
2193 static HANDLE published_shared_mem;
2194 
2195 static gboolean
publish_session_bus(const char * address)2196 publish_session_bus (const char *address)
2197 {
2198   HANDLE init_mutex;
2199 
2200   init_mutex = acquire_mutex (UNIQUE_DBUS_INIT_MUTEX);
2201 
2202   published_daemon_mutex = CreateMutexA (NULL, FALSE, DBUS_DAEMON_MUTEX);
2203   if (WaitForSingleObject (published_daemon_mutex, 10 ) != WAIT_OBJECT_0)
2204     {
2205       release_mutex (init_mutex);
2206       CloseHandle (published_daemon_mutex);
2207       published_daemon_mutex = NULL;
2208       return FALSE;
2209     }
2210 
2211   published_shared_mem = set_shm (DBUS_DAEMON_ADDRESS_INFO, address);
2212   if (!published_shared_mem)
2213     {
2214       release_mutex (init_mutex);
2215       CloseHandle (published_daemon_mutex);
2216       published_daemon_mutex = NULL;
2217       return FALSE;
2218     }
2219 
2220   release_mutex (init_mutex);
2221   return TRUE;
2222 }
2223 
2224 static void
unpublish_session_bus(void)2225 unpublish_session_bus (void)
2226 {
2227   HANDLE init_mutex;
2228 
2229   init_mutex = acquire_mutex (UNIQUE_DBUS_INIT_MUTEX);
2230 
2231   CloseHandle (published_shared_mem);
2232   published_shared_mem = NULL;
2233 
2234   release_mutex (published_daemon_mutex);
2235   published_daemon_mutex = NULL;
2236 
2237   release_mutex (init_mutex);
2238 }
2239 
2240 static void
wait_console_window(void)2241 wait_console_window (void)
2242 {
2243   FILE *console = fopen ("CONOUT$", "w");
2244 
2245   SetConsoleTitleW (L"gdbus-daemon output. Type any character to close this window.");
2246   fprintf (console, _("(Type any character to close this window)\n"));
2247   fflush (console);
2248   _getch ();
2249 }
2250 
2251 static void
open_console_window(void)2252 open_console_window (void)
2253 {
2254   if (((HANDLE) _get_osfhandle (fileno (stdout)) == INVALID_HANDLE_VALUE ||
2255        (HANDLE) _get_osfhandle (fileno (stderr)) == INVALID_HANDLE_VALUE) && AllocConsole ())
2256     {
2257       if ((HANDLE) _get_osfhandle (fileno (stdout)) == INVALID_HANDLE_VALUE)
2258         freopen ("CONOUT$", "w", stdout);
2259 
2260       if ((HANDLE) _get_osfhandle (fileno (stderr)) == INVALID_HANDLE_VALUE)
2261         freopen ("CONOUT$", "w", stderr);
2262 
2263       SetConsoleTitleW (L"gdbus-daemon debug output.");
2264 
2265       atexit (wait_console_window);
2266     }
2267 }
2268 
2269 static void
idle_timeout_cb(GDBusDaemon * daemon,gpointer user_data)2270 idle_timeout_cb (GDBusDaemon *daemon, gpointer user_data)
2271 {
2272   GMainLoop *loop = user_data;
2273   g_main_loop_quit (loop);
2274 }
2275 
2276 /* Satisfies STARTF_FORCEONFEEDBACK */
2277 static void
turn_off_the_starting_cursor(void)2278 turn_off_the_starting_cursor (void)
2279 {
2280   MSG msg;
2281   BOOL bRet;
2282 
2283   PostQuitMessage (0);
2284 
2285   while ((bRet = GetMessage (&msg, 0, 0, 0)) != 0)
2286     {
2287       if (bRet == -1)
2288         continue;
2289 
2290       TranslateMessage (&msg);
2291       DispatchMessage (&msg);
2292     }
2293 }
2294 
2295 __declspec(dllexport) void __stdcall
g_win32_run_session_bus(void * hwnd,void * hinst,const char * cmdline,int cmdshow)2296 g_win32_run_session_bus (void* hwnd, void* hinst, const char* cmdline, int cmdshow)
2297 {
2298   GDBusDaemon *daemon;
2299   GMainLoop *loop;
2300   const char *address;
2301   GError *error = NULL;
2302 
2303   turn_off_the_starting_cursor ();
2304 
2305   if (g_getenv ("GDBUS_DAEMON_DEBUG") != NULL)
2306     open_console_window ();
2307 
2308   address = "nonce-tcp:";
2309   daemon = _g_dbus_daemon_new (address, NULL, &error);
2310   if (daemon == NULL)
2311     {
2312       g_printerr ("Can't init bus: %s\n", error->message);
2313       g_error_free (error);
2314       return;
2315     }
2316 
2317   loop = g_main_loop_new (NULL, FALSE);
2318 
2319   /* There is a subtle detail with "idle-timeout" signal of dbus daemon:
2320    * It is fired on idle after last client disconnection,
2321    * but (at least with glib 2.59.1) it is NEVER fired
2322    * if no clients connect to daemon at all.
2323    * This may lead to infinite run of this daemon process.
2324    */
2325   g_signal_connect (daemon, "idle-timeout", G_CALLBACK (idle_timeout_cb), loop);
2326 
2327   if (publish_session_bus (_g_dbus_daemon_get_address (daemon)))
2328     {
2329       g_main_loop_run (loop);
2330 
2331       unpublish_session_bus ();
2332     }
2333 
2334   g_main_loop_unref (loop);
2335   g_object_unref (daemon);
2336 }
2337 
2338 static gboolean autolaunch_binary_absent = FALSE;
2339 
2340 gchar *
_g_dbus_win32_get_session_address_dbus_launch(GError ** error)2341 _g_dbus_win32_get_session_address_dbus_launch (GError **error)
2342 {
2343   HANDLE autolaunch_mutex, init_mutex;
2344   char *address = NULL;
2345 
2346   autolaunch_mutex = acquire_mutex (DBUS_AUTOLAUNCH_MUTEX);
2347 
2348   init_mutex = acquire_mutex (UNIQUE_DBUS_INIT_MUTEX);
2349 
2350   if (is_mutex_owned (DBUS_DAEMON_MUTEX))
2351     address = read_shm (DBUS_DAEMON_ADDRESS_INFO);
2352 
2353   release_mutex (init_mutex);
2354 
2355   if (address == NULL && !autolaunch_binary_absent)
2356     {
2357       wchar_t gio_path[MAX_PATH + 2] = { 0 };
2358       int gio_path_len = GetModuleFileNameW (_g_io_win32_get_module (), gio_path, MAX_PATH + 1);
2359 
2360       /* The <= MAX_PATH check prevents truncated path usage */
2361       if (gio_path_len > 0 && gio_path_len <= MAX_PATH)
2362 	{
2363 	  PROCESS_INFORMATION pi = { 0 };
2364 	  STARTUPINFOW si = { 0 };
2365 	  BOOL res = FALSE;
2366 	  wchar_t exe_path[MAX_PATH + 100] = { 0 };
2367 	  /* calculate index of first char of dll file name inside full path */
2368 	  int gio_name_index = gio_path_len;
2369 	  for (; gio_name_index > 0; --gio_name_index)
2370 	  {
2371 	    wchar_t prev_char = gio_path[gio_name_index - 1];
2372 	    if (prev_char == L'\\' || prev_char == L'/')
2373 	      break;
2374 	  }
2375 	  gio_path[gio_name_index] = L'\0';
2376 	  wcscpy (exe_path, gio_path);
2377 	  wcscat (exe_path, L"\\gdbus.exe");
2378 
2379 	  if (GetFileAttributesW (exe_path) == INVALID_FILE_ATTRIBUTES)
2380 	    {
2381 	      /* warning won't be raised another time
2382 	       * since autolaunch_binary_absent would be already set.
2383 	       */
2384 	      autolaunch_binary_absent = TRUE;
2385 	      g_warning ("win32 session dbus binary not found: %S", exe_path );
2386 	    }
2387 	  else
2388 	    {
2389 	      wchar_t args[MAX_PATH*2 + 100] = { 0 };
2390 	      wcscpy (args, L"\"");
2391 	      wcscat (args, exe_path);
2392 	      wcscat (args, L"\" ");
2393 #define _L_PREFIX_FOR_EXPANDED(arg) L##arg
2394 #define _L_PREFIX(arg) _L_PREFIX_FOR_EXPANDED (arg)
2395 	      wcscat (args, _L_PREFIX (_GDBUS_ARG_WIN32_RUN_SESSION_BUS));
2396 #undef _L_PREFIX
2397 #undef _L_PREFIX_FOR_EXPANDED
2398 
2399 	      res = CreateProcessW (exe_path, args,
2400 				    0, 0, FALSE,
2401 				    NORMAL_PRIORITY_CLASS | CREATE_NO_WINDOW | DETACHED_PROCESS,
2402 				    0, gio_path,
2403 				    &si, &pi);
2404 	    }
2405 	  if (res)
2406 	    {
2407 	      address = read_shm (DBUS_DAEMON_ADDRESS_INFO);
2408 	      if (address == NULL)
2409 		g_warning ("%S dbus binary failed to launch bus, maybe incompatible version", exe_path );
2410 	    }
2411 	}
2412     }
2413 
2414   release_mutex (autolaunch_mutex);
2415 
2416   if (address == NULL)
2417     g_set_error (error,
2418 		 G_IO_ERROR,
2419 		 G_IO_ERROR_FAILED,
2420 		 _("Session dbus not running, and autolaunch failed"));
2421 
2422   return address;
2423 }
2424 
2425 #endif
2426 
2427 /* ---------------------------------------------------------------------------------------------------- */
2428 
2429 gchar *
_g_dbus_get_machine_id(GError ** error)2430 _g_dbus_get_machine_id (GError **error)
2431 {
2432 #ifdef G_OS_WIN32
2433   HW_PROFILE_INFOA info;
2434   char *src, *dest, *res;
2435   int i;
2436 
2437   if (!GetCurrentHwProfileA (&info))
2438     {
2439       char *message = g_win32_error_message (GetLastError ());
2440       g_set_error (error,
2441 		   G_IO_ERROR,
2442 		   G_IO_ERROR_FAILED,
2443 		   _("Unable to get Hardware profile: %s"), message);
2444       g_free (message);
2445       return NULL;
2446     }
2447 
2448   /* Form: {12340001-4980-1920-6788-123456789012} */
2449   src = &info.szHwProfileGuid[0];
2450 
2451   res = g_malloc (32+1);
2452   dest = res;
2453 
2454   src++; /* Skip { */
2455   for (i = 0; i < 8; i++)
2456     *dest++ = *src++;
2457   src++; /* Skip - */
2458   for (i = 0; i < 4; i++)
2459     *dest++ = *src++;
2460   src++; /* Skip - */
2461   for (i = 0; i < 4; i++)
2462     *dest++ = *src++;
2463   src++; /* Skip - */
2464   for (i = 0; i < 4; i++)
2465     *dest++ = *src++;
2466   src++; /* Skip - */
2467   for (i = 0; i < 12; i++)
2468     *dest++ = *src++;
2469   *dest = 0;
2470 
2471   return res;
2472 #else
2473   gchar *ret = NULL;
2474   GError *first_error = NULL;
2475   gsize i;
2476   gboolean non_zero = FALSE;
2477 
2478   /* Copy what dbus.git does: allow the /var/lib path to be configurable at
2479    * build time, but hard-code the system-wide machine ID path in /etc. */
2480   const gchar *var_lib_path = LOCALSTATEDIR "/lib/dbus/machine-id";
2481   const gchar *etc_path = "/etc/machine-id";
2482 
2483   if (!g_file_get_contents (var_lib_path,
2484                             &ret,
2485                             NULL,
2486                             &first_error) &&
2487       !g_file_get_contents (etc_path,
2488                             &ret,
2489                             NULL,
2490                             NULL))
2491     {
2492       g_propagate_prefixed_error (error, g_steal_pointer (&first_error),
2493                                   /* Translators: Both placeholders are file paths */
2494                                   _("Unable to load %s or %s: "),
2495                                   var_lib_path, etc_path);
2496       return NULL;
2497     }
2498 
2499   /* ignore the error from the first try, if any */
2500   g_clear_error (&first_error);
2501 
2502   /* Validate the machine ID. From `man 5 machine-id`:
2503    * > The machine ID is a single newline-terminated, hexadecimal, 32-character,
2504    * > lowercase ID. When decoded from hexadecimal, this corresponds to a
2505    * > 16-byte/128-bit value. This ID may not be all zeros.
2506    */
2507   for (i = 0; ret[i] != '\0' && ret[i] != '\n'; i++)
2508     {
2509       /* Break early if it’s invalid. */
2510       if (!g_ascii_isxdigit (ret[i]) || g_ascii_isupper (ret[i]))
2511         break;
2512 
2513       if (ret[i] != '0')
2514         non_zero = TRUE;
2515     }
2516 
2517   if (i != 32 || ret[i] != '\n' || ret[i + 1] != '\0' || !non_zero)
2518     {
2519       g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
2520                    "Invalid machine ID in %s or %s",
2521                    var_lib_path, etc_path);
2522       g_free (ret);
2523       return NULL;
2524     }
2525 
2526   /* Strip trailing newline. */
2527   ret[32] = '\0';
2528 
2529   return g_steal_pointer (&ret);
2530 #endif
2531 }
2532 
2533 /* ---------------------------------------------------------------------------------------------------- */
2534 
2535 gchar *
_g_dbus_enum_to_string(GType enum_type,gint value)2536 _g_dbus_enum_to_string (GType enum_type, gint value)
2537 {
2538   gchar *ret;
2539   GEnumClass *klass;
2540   GEnumValue *enum_value;
2541 
2542   klass = g_type_class_ref (enum_type);
2543   enum_value = g_enum_get_value (klass, value);
2544   if (enum_value != NULL)
2545     ret = g_strdup (enum_value->value_nick);
2546   else
2547     ret = g_strdup_printf ("unknown (value %d)", value);
2548   g_type_class_unref (klass);
2549   return ret;
2550 }
2551 
2552 /* ---------------------------------------------------------------------------------------------------- */
2553 
2554 static void
write_message_print_transport_debug(gssize bytes_written,MessageToWriteData * data)2555 write_message_print_transport_debug (gssize bytes_written,
2556                                      MessageToWriteData *data)
2557 {
2558   if (G_LIKELY (!_g_dbus_debug_transport ()))
2559     goto out;
2560 
2561   _g_dbus_debug_print_lock ();
2562   g_print ("========================================================================\n"
2563            "GDBus-debug:Transport:\n"
2564            "  >>>> WROTE %" G_GSSIZE_FORMAT " bytes of message with serial %d and\n"
2565            "       size %" G_GSIZE_FORMAT " from offset %" G_GSIZE_FORMAT " on a %s\n",
2566            bytes_written,
2567            g_dbus_message_get_serial (data->message),
2568            data->blob_size,
2569            data->total_written,
2570            g_type_name (G_TYPE_FROM_INSTANCE (g_io_stream_get_output_stream (data->worker->stream))));
2571   _g_dbus_debug_print_unlock ();
2572  out:
2573   ;
2574 }
2575 
2576 /* ---------------------------------------------------------------------------------------------------- */
2577 
2578 static void
read_message_print_transport_debug(gssize bytes_read,GDBusWorker * worker)2579 read_message_print_transport_debug (gssize bytes_read,
2580                                     GDBusWorker *worker)
2581 {
2582   gsize size;
2583   gint32 serial;
2584   gint32 message_length;
2585 
2586   if (G_LIKELY (!_g_dbus_debug_transport ()))
2587     goto out;
2588 
2589   size = bytes_read + worker->read_buffer_cur_size;
2590   serial = 0;
2591   message_length = 0;
2592   if (size >= 16)
2593     message_length = g_dbus_message_bytes_needed ((guchar *) worker->read_buffer, size, NULL);
2594   if (size >= 1)
2595     {
2596       switch (worker->read_buffer[0])
2597         {
2598         case 'l':
2599           if (size >= 12)
2600             serial = GUINT32_FROM_LE (((guint32 *) worker->read_buffer)[2]);
2601           break;
2602         case 'B':
2603           if (size >= 12)
2604             serial = GUINT32_FROM_BE (((guint32 *) worker->read_buffer)[2]);
2605           break;
2606         default:
2607           /* an error will be set elsewhere if this happens */
2608           goto out;
2609         }
2610     }
2611 
2612     _g_dbus_debug_print_lock ();
2613   g_print ("========================================================================\n"
2614            "GDBus-debug:Transport:\n"
2615            "  <<<< READ %" G_GSSIZE_FORMAT " bytes of message with serial %d and\n"
2616            "       size %d to offset %" G_GSIZE_FORMAT " from a %s\n",
2617            bytes_read,
2618            serial,
2619            message_length,
2620            worker->read_buffer_cur_size,
2621            g_type_name (G_TYPE_FROM_INSTANCE (g_io_stream_get_input_stream (worker->stream))));
2622   _g_dbus_debug_print_unlock ();
2623  out:
2624   ;
2625 }
2626 
2627 /* ---------------------------------------------------------------------------------------------------- */
2628 
2629 gboolean
_g_signal_accumulator_false_handled(GSignalInvocationHint * ihint,GValue * return_accu,const GValue * handler_return,gpointer dummy)2630 _g_signal_accumulator_false_handled (GSignalInvocationHint *ihint,
2631                                      GValue                *return_accu,
2632                                      const GValue          *handler_return,
2633                                      gpointer               dummy)
2634 {
2635   gboolean continue_emission;
2636   gboolean signal_return;
2637 
2638   signal_return = g_value_get_boolean (handler_return);
2639   g_value_set_boolean (return_accu, signal_return);
2640   continue_emission = signal_return;
2641 
2642   return continue_emission;
2643 }
2644 
2645 /* ---------------------------------------------------------------------------------------------------- */
2646 
2647 static void
append_nibble(GString * s,gint val)2648 append_nibble (GString *s, gint val)
2649 {
2650   g_string_append_c (s, val >= 10 ? ('a' + val - 10) : ('0' + val));
2651 }
2652 
2653 /* ---------------------------------------------------------------------------------------------------- */
2654 
2655 gchar *
_g_dbus_hexencode(const gchar * str,gsize str_len)2656 _g_dbus_hexencode (const gchar *str,
2657                    gsize        str_len)
2658 {
2659   gsize n;
2660   GString *s;
2661 
2662   s = g_string_new (NULL);
2663   for (n = 0; n < str_len; n++)
2664     {
2665       gint val;
2666       gint upper_nibble;
2667       gint lower_nibble;
2668 
2669       val = ((const guchar *) str)[n];
2670       upper_nibble = val >> 4;
2671       lower_nibble = val & 0x0f;
2672 
2673       append_nibble (s, upper_nibble);
2674       append_nibble (s, lower_nibble);
2675     }
2676 
2677   return g_string_free (s, FALSE);
2678 }
2679