_dbus_bindings/conn-methods.c

   1 /* Implementation of normal Python-accessible methods on the _dbus_bindings
   2  * Connection type; separated out to keep the file size manageable.
   3  *
   4  * Copyright (C) 2006 Collabora Ltd. <http://www.collabora.co.uk/>
   5  *
   6  * Licensed under the Academic Free License version 2.1
   7  *
   8  * This library is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  */
  23
  24 #include "dbus_bindings-internal.h"
  25 #include "conn-internal.h"
  26
  27 static void
  28 _object_path_unregister(DBusConnection *conn, void *user_data)
  29 {
  30     PyGILState_STATE gil = PyGILState_Ensure();
  31     PyObject *tuple = NULL;
  32     Connection *conn_obj = NULL;
  33     PyObject *callable;
  34
  35     conn_obj = (Connection *)DBusPyConnection_ExistingFromDBusConnection(conn);
  36     if (!conn_obj) goto out;
  37     TRACE(conn_obj);
  38
  39     DBG("Connection at %p unregistering object path %s",
  40         conn_obj, PyString_AS_STRING((PyObject *)user_data));
  41     tuple = DBusPyConnection_GetObjectPathHandlers((PyObject *)conn_obj, (PyObject *)user_data);
  42     if (!tuple) goto out;
  43     if (tuple == Py_None) goto out;
  44
  45     DBG("%s", "... yes we have handlers for that object path");
  46
  47     /* 0'th item is the unregisterer (if that's a word) */
  48     callable = PyTuple_GetItem(tuple, 0);
  49     if (callable && callable != Py_None) {
  50         DBG("%s", "... and we even have an unregisterer");
  51         /* any return from the unregisterer is ignored */
  52         Py_XDECREF(PyObject_CallFunctionObjArgs(callable, conn_obj, NULL));
  53     }
  54 out:
  55     Py_XDECREF(conn_obj);
  56     Py_XDECREF(tuple);
  57     /* the user_data (a Python str) is no longer ref'd by the DBusConnection */
  58     Py_XDECREF((PyObject *)user_data);
  59     if (PyErr_Occurred()) {
  60         PyErr_Print();
  61     }
  62     PyGILState_Release(gil);
  63 }
  64
  65 static DBusHandlerResult
  66 _object_path_message(DBusConnection *conn, DBusMessage *message,
  67                      void *user_data)
  68 {
  69     DBusHandlerResult ret;
  70     PyGILState_STATE gil = PyGILState_Ensure();
  71     Connection *conn_obj = NULL;
  72     PyObject *tuple = NULL;
  73     PyObject *msg_obj;
  74     PyObject *callable;             /* borrowed */
  75
  76     dbus_message_ref(message);
  77     msg_obj = DBusPyMessage_ConsumeDBusMessage(message);
  78     if (!msg_obj) {
  79         ret = DBUS_HANDLER_RESULT_NEED_MEMORY;
  80         goto out;
  81     }
  82
  83     conn_obj = (Connection *)DBusPyConnection_ExistingFromDBusConnection(conn);
  84     if (!conn_obj) {
  85         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
  86         goto out;
  87     }
  88     TRACE(conn_obj);
  89
  90     DBG("Connection at %p messaging object path %s",
  91         conn_obj, PyString_AS_STRING((PyObject *)user_data));
  92     DBG_DUMP_MESSAGE(message);
  93     tuple = DBusPyConnection_GetObjectPathHandlers((PyObject *)conn_obj, (PyObject *)user_data);
  94     if (!tuple || tuple == Py_None) {
  95         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
  96         goto out;
  97     }
  98
  99     DBG("%s", "... yes we have handlers for that object path");
 100
 101     /* 1st item (0-based) is the message callback */
 102     callable = PyTuple_GetItem(tuple, 1);
 103     if (!callable) {
 104         DBG("%s", "... error getting message handler from tuple");
 105         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 106     }
 107     else if (callable == Py_None) {
 108         /* there was actually no handler after all */
 109         DBG("%s", "... but those handlers don't do messages");
 110         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 111     }
 112     else {
 113         DBG("%s", "... and we have a message handler for that object path");
 114         ret = DBusPyConnection_HandleMessage(conn_obj, msg_obj, callable);
 115     }
 116
 117 out:
 118     Py_XDECREF(msg_obj);
 119     Py_XDECREF(conn_obj);
 120     Py_XDECREF(tuple);
 121     if (PyErr_Occurred()) {
 122         PyErr_Print();
 123     }
 124     PyGILState_Release(gil);
 125     return ret;
 126 }
 127
 128 static const DBusObjectPathVTable _object_path_vtable = {
 129     _object_path_unregister,
 130     _object_path_message,
 131 };
 132
 133 static DBusHandlerResult
 134 _filter_message(DBusConnection *conn, DBusMessage *message, void *user_data)
 135 {
 136     DBusHandlerResult ret;
 137     PyGILState_STATE gil = PyGILState_Ensure();
 138     Connection *conn_obj = NULL;
 139     PyObject *callable = NULL;
 140     PyObject *msg_obj;
 141 #ifndef DBUS_PYTHON_DISABLE_CHECKS
 142     Py_ssize_t i, size;
 143 #endif
 144
 145     dbus_message_ref(message);
 146     msg_obj = DBusPyMessage_ConsumeDBusMessage(message);
 147     if (!msg_obj) {
 148         DBG("%s", "OOM while trying to construct Message");
 149         ret = DBUS_HANDLER_RESULT_NEED_MEMORY;
 150         goto out;
 151     }
 152
 153     conn_obj = (Connection *)DBusPyConnection_ExistingFromDBusConnection(conn);
 154     if (!conn_obj) {
 155         DBG("%s", "failed to traverse DBusConnection -> Connection weakref");
 156         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 157         goto out;
 158     }
 159     TRACE(conn_obj);
 160
 161     /* The user_data is a pointer to a Python object. To avoid
 162      * cross-library reference cycles, the DBusConnection isn't allowed
 163      * to reference it. However, as long as the Connection is still
 164      * alive, its ->filters list owns a reference to the same Python
 165      * object, so the object should also still be alive.
 166      *
 167      * To ensure that this works, be careful whenever manipulating the
 168      * filters list! (always put things in the list *before* giving
 169      * them to libdbus, etc.)
 170      */
 171 #ifdef DBUS_PYTHON_DISABLE_CHECKS
 172     callable = (PyObject *)user_data;
 173 #else
 174     size = PyList_GET_SIZE(conn_obj->filters);
 175     for (i = 0; i < size; i++) {
 176         callable = PyList_GET_ITEM(conn_obj->filters, i);
 177         if (callable == user_data) {
 178             Py_INCREF(callable);
 179         }
 180         else {
 181             callable = NULL;
 182         }
 183     }
 184
 185     if (!callable) {
 186         DBG("... filter %p has vanished from ->filters, so not calling it",
 187             user_data);
 188         ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 189         goto out;
 190     }
 191 #endif
 192
 193     ret = DBusPyConnection_HandleMessage(conn_obj, msg_obj, callable);
 194 out:
 195     Py_XDECREF(msg_obj);
 196     Py_XDECREF(conn_obj);
 197     Py_XDECREF(callable);
 198     PyGILState_Release(gil);
 199     return ret;
 200 }
 201
 202 PyDoc_STRVAR(Connection__require_main_loop__doc__,
 203 "_require_main_loop()\n\n"
 204 "Raise an exception if this Connection is not bound to any main loop -\n"
 205 "in this state, asynchronous calls, receiving signals and exporting objects\n"
 206 "will not work.\n"
 207 "\n"
 208 "`dbus.mainloop.NULL_MAIN_LOOP` is treated like a valid main loop - if you're\n"
 209 "using that, you presumably know what you're doing.\n");
 210 static PyObject *
 211 Connection__require_main_loop (Connection *self, PyObject *args UNUSED)
 212 {
 213     if (!self->has_mainloop) {
 214         PyErr_SetString(PyExc_RuntimeError,
 215                         "To make asynchronous calls, receive signals or "
 216                         "export objects, D-Bus connections must be attached "
 217                         "to a main loop by passing mainloop=... to the "
 218                         "constructor or calling "
 219                         "dbus.set_default_main_loop(...)");
 220         return NULL;
 221     }
 222     Py_RETURN_NONE;
 223 }
 224
 225 PyDoc_STRVAR(Connection_close__doc__,
 226 "close()\n\n"
 227 "Close the connection.");
 228 static PyObject *
 229 Connection_close (Connection *self, PyObject *args UNUSED)
 230 {
 231     TRACE(self);
 232     /* Because the user explicitly asked to close the connection, we'll even
 233     let them close shared connections. */
 234     if (self->conn) {
 235         Py_BEGIN_ALLOW_THREADS
 236         dbus_connection_close(self->conn);
 237         Py_END_ALLOW_THREADS
 238     }
 239     Py_RETURN_NONE;
 240 }
 241
 242 PyDoc_STRVAR(Connection_get_is_connected__doc__,
 243 "get_is_connected() -> bool\n\n"
 244 "Return true if this Connection is connected.\n");
 245 static PyObject *
 246 Connection_get_is_connected (Connection *self, PyObject *args UNUSED)
 247 {
 248     dbus_bool_t ret;
 249
 250     TRACE(self);
 251     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 252     Py_BEGIN_ALLOW_THREADS
 253     ret = dbus_connection_get_is_connected(self->conn);
 254     Py_END_ALLOW_THREADS
 255     return PyBool_FromLong(ret);
 256 }
 257
 258 PyDoc_STRVAR(Connection_get_is_authenticated__doc__,
 259 "get_is_authenticated() -> bool\n\n"
 260 "Return true if this Connection was ever authenticated.\n");
 261 static PyObject *
 262 Connection_get_is_authenticated (Connection *self, PyObject *args UNUSED)
 263 {
 264     dbus_bool_t ret;
 265
 266     TRACE(self);
 267     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 268     Py_BEGIN_ALLOW_THREADS
 269     ret = dbus_connection_get_is_authenticated(self->conn);
 270     Py_END_ALLOW_THREADS
 271     return PyBool_FromLong(ret);
 272 }
 273
 274 PyDoc_STRVAR(Connection_set_exit_on_disconnect__doc__,
 275 "set_exit_on_disconnect(bool)\n\n"
 276 "Set whether the C function ``_exit`` will be called when this Connection\n"
 277 "becomes disconnected. This will cause the program to exit without calling\n"
 278 "any cleanup code or exit handlers.\n"
 279 "\n"
 280 "The default is for this feature to be disabled for Connections and enabled\n"
 281 "for Buses.\n");
 282 static PyObject *
 283 Connection_set_exit_on_disconnect (Connection *self, PyObject *args)
 284 {
 285     int exit_on_disconnect;
 286
 287     TRACE(self);
 288     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 289     if (!PyArg_ParseTuple(args, "i:set_exit_on_disconnect",
 290                           &exit_on_disconnect)) {
 291         return NULL;
 292     }
 293     Py_BEGIN_ALLOW_THREADS
 294     dbus_connection_set_exit_on_disconnect(self->conn,
 295                                            exit_on_disconnect ? 1 : 0);
 296     Py_END_ALLOW_THREADS
 297     Py_RETURN_NONE;
 298 }
 299
 300 PyDoc_STRVAR(Connection_send_message__doc__,
 301 "send_message(msg) -> long\n\n"
 302 "Queue the given message for sending, and return the message serial number.\n"
 303 "\n"
 304 ":Parameters:\n"
 305 "   `msg` : dbus.lowlevel.Message\n"
 306 "       The message to be sent.\n"
 307 );
 308 static PyObject *
 309 Connection_send_message(Connection *self, PyObject *args)
 310 {
 311     dbus_bool_t ok;
 312     PyObject *obj;
 313     DBusMessage *msg;
 314     dbus_uint32_t serial;
 315
 316     TRACE(self);
 317     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 318     if (!PyArg_ParseTuple(args, "O", &obj)) return NULL;
 319
 320     msg = DBusPyMessage_BorrowDBusMessage(obj);
 321     if (!msg) return NULL;
 322
 323     Py_BEGIN_ALLOW_THREADS
 324     ok = dbus_connection_send(self->conn, msg, &serial);
 325     Py_END_ALLOW_THREADS
 326
 327     if (!ok) {
 328         return PyErr_NoMemory();
 329     }
 330
 331     return PyLong_FromUnsignedLong(serial);
 332 }
 333
 334 /* The timeout is in seconds here, since that's conventional in Python. */
 335 PyDoc_STRVAR(Connection_send_message_with_reply__doc__,
 336 "send_message_with_reply(msg, reply_handler, timeout_s=-1, "
 337 "require_main_loop=False) -> dbus.lowlevel.PendingCall\n\n"
 338 "Queue the message for sending; expect a reply via the returned PendingCall,\n"
 339 "which can also be used to cancel the pending call.\n"
 340 "\n"
 341 ":Parameters:\n"
 342 "   `msg` : dbus.lowlevel.Message\n"
 343 "       The message to be sent\n"
 344 "   `reply_handler` : callable\n"
 345 "       Asynchronous reply handler: will be called with one positional\n"
 346 "       parameter, a Message instance representing the reply.\n"
 347 "   `timeout_s` : float\n"
 348 "       If the reply takes more than this many seconds, a timeout error\n"
 349 "       will be created locally and raised instead. If this timeout is\n"
 350 "       negative (default), a sane default (supplied by libdbus) is used.\n"
 351 "   `require_main_loop` : bool\n"
 352 "       If True, raise RuntimeError if this Connection does not have a main\n"
 353 "       loop configured. If False (default) and there is no main loop, you are\n"
 354 "       responsible for calling block() on the PendingCall.\n"
 355 "\n"
 356 );
 357 static PyObject *
 358 Connection_send_message_with_reply(Connection *self, PyObject *args, PyObject *kw)
 359 {
 360     dbus_bool_t ok;
 361     double timeout_s = -1.0;
 362     int timeout_ms;
 363     PyObject *obj, *callable;
 364     DBusMessage *msg;
 365     DBusPendingCall *pending;
 366     int require_main_loop = 0;
 367     static char *argnames[] = {"msg", "reply_handler", "timeout_s",
 368                                "require_main_loop", NULL};
 369
 370     TRACE(self);
 371     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 372     if (!PyArg_ParseTupleAndKeywords(args, kw,
 373                                      "OO|fi:send_message_with_reply",
 374                                      argnames,
 375                                      &obj, &callable, &timeout_s,
 376                                      &require_main_loop)) {
 377         return NULL;
 378     }
 379     if (require_main_loop && !Connection__require_main_loop(self, NULL)) {
 380         return NULL;
 381     }
 382
 383     msg = DBusPyMessage_BorrowDBusMessage(obj);
 384     if (!msg) return NULL;
 385
 386     if (timeout_s < 0) {
 387         timeout_ms = -1;
 388     }
 389     else {
 390         if (timeout_s > ((double)INT_MAX) / 1000.0) {
 391             PyErr_SetString(PyExc_ValueError, "Timeout too long");
 392             return NULL;
 393         }
 394         timeout_ms = (int)(timeout_s * 1000.0);
 395     }
 396
 397     Py_BEGIN_ALLOW_THREADS
 398     ok = dbus_connection_send_with_reply(self->conn, msg, &pending,
 399                                          timeout_ms);
 400     Py_END_ALLOW_THREADS
 401
 402     if (!ok) {
 403         return PyErr_NoMemory();
 404     }
 405
 406     if (!pending) {
 407         /* connection is disconnected (doesn't return FALSE!) */
 408         PyErr_SetString (DBusPyException, "Connection is disconnected - "
 409                                           "unable to make method call");
 410         return NULL;
 411     }
 412
 413     return DBusPyPendingCall_ConsumeDBusPendingCall(pending, callable);
 414 }
 415
 416 /* Again, the timeout is in seconds, since that's conventional in Python. */
 417 PyDoc_STRVAR(Connection_send_message_with_reply_and_block__doc__,
 418 "send_message_with_reply_and_block(msg, timeout_s=-1)"
 419 " -> dbus.lowlevel.Message\n\n"
 420 "Send the message and block while waiting for a reply.\n"
 421 "\n"
 422 "This does not re-enter the main loop, so it can lead to a deadlock, if\n"
 423 "the called method tries to make a synchronous call to a method in this\n"
 424 "application. As such, it's probably a bad idea.\n"
 425 "\n"
 426 ":Parameters:\n"
 427 "   `msg` : dbus.lowlevel.Message\n"
 428 "       The message to be sent\n"
 429 "   `timeout_s` : float\n"
 430 "       If the reply takes more than this many seconds, a timeout error\n"
 431 "       will be created locally and raised instead. If this timeout is\n"
 432 "       negative (default), a sane default (supplied by libdbus) is used.\n"
 433 ":Returns:\n"
 434 "   A `dbus.lowlevel.Message` instance (probably a `dbus.lowlevel.MethodReturnMessage`) on success\n"
 435 ":Raises dbus.DBusException:\n"
 436 "   On error (including if the reply arrives but is an\n"
 437 "   error message)\n"
 438 "\n"
 439 );
 440 static PyObject *
 441 Connection_send_message_with_reply_and_block(Connection *self, PyObject *args)
 442 {
 443     double timeout_s = -1.0;
 444     int timeout_ms;
 445     PyObject *obj;
 446     DBusMessage *msg, *reply;
 447     DBusError error;
 448
 449     TRACE(self);
 450     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 451     if (!PyArg_ParseTuple(args, "O|f:send_message_with_reply_and_block", &obj,
 452                           &timeout_s)) {
 453         return NULL;
 454     }
 455
 456     msg = DBusPyMessage_BorrowDBusMessage(obj);
 457     if (!msg) return NULL;
 458
 459     if (timeout_s < 0) {
 460         timeout_ms = -1;
 461     }
 462     else {
 463         if (timeout_s > ((double)INT_MAX) / 1000.0) {
 464             PyErr_SetString(PyExc_ValueError, "Timeout too long");
 465             return NULL;
 466         }
 467         timeout_ms = (int)(timeout_s * 1000.0);
 468     }
 469
 470     dbus_error_init(&error);
 471     Py_BEGIN_ALLOW_THREADS
 472     reply = dbus_connection_send_with_reply_and_block(self->conn, msg,
 473                                                       timeout_ms, &error);
 474     Py_END_ALLOW_THREADS
 475
 476     if (!reply) {
 477         return DBusPyException_ConsumeError(&error);
 478     }
 479     return DBusPyMessage_ConsumeDBusMessage(reply);
 480 }
 481
 482 PyDoc_STRVAR(Connection_flush__doc__,
 483 "flush()\n\n"
 484 "Block until the outgoing message queue is empty.\n");
 485 static PyObject *
 486 Connection_flush (Connection *self, PyObject *args UNUSED)
 487 {
 488     TRACE(self);
 489     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 490     Py_BEGIN_ALLOW_THREADS
 491     dbus_connection_flush (self->conn);
 492     Py_END_ALLOW_THREADS
 493     Py_RETURN_NONE;
 494 }
 495
 496 /* Unsupported:
 497  * dbus_connection_preallocate_send
 498  * dbus_connection_free_preallocated_send
 499  * dbus_connection_send_preallocated
 500  * dbus_connection_borrow_message
 501  * dbus_connection_return_message
 502  * dbus_connection_steal_borrowed_message
 503  * dbus_connection_pop_message
 504  */
 505
 506 /* Non-main-loop handling not yet implemented: */
 507     /* dbus_connection_read_write_dispatch */
 508     /* dbus_connection_read_write */
 509
 510 /* Main loop handling not yet implemented: */
 511     /* dbus_connection_get_dispatch_status */
 512     /* dbus_connection_dispatch */
 513     /* dbus_connection_set_watch_functions */
 514     /* dbus_connection_set_timeout_functions */
 515     /* dbus_connection_set_wakeup_main_function */
 516     /* dbus_connection_set_dispatch_status_function */
 517
 518 /* Normally in Python this would be called fileno(), but I don't want to
 519  * encourage people to select() on it */
 520 PyDoc_STRVAR(Connection_get_unix_fd__doc__,
 521 "get_unix_fd() -> int or None\n\n"
 522 "Get the connection's UNIX file descriptor, if any.\n\n"
 523 "This can be used for SELinux access control checks with ``getpeercon()``\n"
 524 "for example. **Do not** read or write to the file descriptor, or try to\n"
 525 "``select()`` on it.\n");
 526 static PyObject *
 527 Connection_get_unix_fd (Connection *self, PyObject *unused UNUSED)
 528 {
 529     int fd;
 530     dbus_bool_t ok;
 531
 532     TRACE(self);
 533     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 534     Py_BEGIN_ALLOW_THREADS
 535     ok = dbus_connection_get_unix_fd (self->conn, &fd);
 536     Py_END_ALLOW_THREADS
 537     if (!ok) Py_RETURN_NONE;
 538     return PyInt_FromLong(fd);
 539 }
 540
 541 PyDoc_STRVAR(Connection_get_peer_unix_user__doc__,
 542 "get_peer_unix_user() -> long or None\n\n"
 543 "Get the UNIX user ID at the other end of the connection, if it has been\n"
 544 "authenticated. Return None if this is a non-UNIX platform or the\n"
 545 "connection has not been authenticated.\n");
 546 static PyObject *
 547 Connection_get_peer_unix_user (Connection *self, PyObject *unused UNUSED)
 548 {
 549     unsigned long uid;
 550     dbus_bool_t ok;
 551
 552     TRACE(self);
 553     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 554     Py_BEGIN_ALLOW_THREADS
 555     ok = dbus_connection_get_unix_user (self->conn, &uid);
 556     Py_END_ALLOW_THREADS
 557     if (!ok) Py_RETURN_NONE;
 558     return PyLong_FromUnsignedLong (uid);
 559 }
 560
 561 PyDoc_STRVAR(Connection_get_peer_unix_process_id__doc__,
 562 "get_peer_unix_process_id() -> long or None\n\n"
 563 "Get the UNIX process ID at the other end of the connection, if it has been\n"
 564 "authenticated. Return None if this is a non-UNIX platform or the\n"
 565 "connection has not been authenticated.\n");
 566 static PyObject *
 567 Connection_get_peer_unix_process_id (Connection *self, PyObject *unused UNUSED)
 568 {
 569     unsigned long pid;
 570     dbus_bool_t ok;
 571
 572     TRACE(self);
 573     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 574     Py_BEGIN_ALLOW_THREADS
 575     ok = dbus_connection_get_unix_process_id (self->conn, &pid);
 576     Py_END_ALLOW_THREADS
 577     if (!ok) Py_RETURN_NONE;
 578     return PyLong_FromUnsignedLong (pid);
 579 }
 580
 581 /* TODO: wrap dbus_connection_set_unix_user_function Pythonically */
 582
 583 PyDoc_STRVAR(Connection_add_message_filter__doc__,
 584 "add_message_filter(callable)\n\n"
 585 "Add the given message filter to the internal list.\n\n"
 586 "Filters are handlers that are run on all incoming messages, prior to the\n"
 587 "objects registered to handle object paths.\n"
 588 "\n"
 589 "Filters are run in the order that they were added. The same handler can\n"
 590 "be added as a filter more than once, in which case it will be run more\n"
 591 "than once. Filters added during a filter callback won't be run on the\n"
 592 "message being processed.\n"
 593 );
 594 static PyObject *
 595 Connection_add_message_filter(Connection *self, PyObject *callable)
 596 {
 597     dbus_bool_t ok;
 598
 599     TRACE(self);
 600     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 601     /* The callable must be referenced by ->filters *before* it is
 602      * given to libdbus, which does not own a reference to it.
 603      */
 604     if (PyList_Append(self->filters, callable) < 0) {
 605         return NULL;
 606     }
 607
 608     Py_BEGIN_ALLOW_THREADS
 609     ok = dbus_connection_add_filter(self->conn, _filter_message, callable,
 610                                     NULL);
 611     Py_END_ALLOW_THREADS
 612
 613     if (!ok) {
 614         Py_XDECREF(PyObject_CallMethod(self->filters, "remove", "(O)",
 615                                        callable));
 616         PyErr_NoMemory();
 617         return NULL;
 618     }
 619     Py_RETURN_NONE;
 620 }
 621
 622 PyDoc_STRVAR(Connection_remove_message_filter__doc__,
 623 "remove_message_filter(callable)\n\n"
 624 "Remove the given message filter (see `add_message_filter` for details).\n"
 625 "\n"
 626 ":Raises LookupError:\n"
 627 "   The given callable is not among the registered filters\n");
 628 static PyObject *
 629 Connection_remove_message_filter(Connection *self, PyObject *callable)
 630 {
 631     PyObject *obj;
 632
 633     TRACE(self);
 634     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 635     /* It's safe to do this before removing it from libdbus, because
 636      * the presence of callable in our arguments means we have a ref
 637      * to it. */
 638     obj = PyObject_CallMethod(self->filters, "remove", "(O)", callable);
 639     if (!obj) return NULL;
 640     Py_DECREF(obj);
 641
 642     Py_BEGIN_ALLOW_THREADS
 643     dbus_connection_remove_filter(self->conn, _filter_message, callable);
 644     Py_END_ALLOW_THREADS
 645
 646     Py_RETURN_NONE;
 647 }
 648
 649 PyDoc_STRVAR(Connection__register_object_path__doc__,
 650 "register_object_path(path, on_message, on_unregister=None, fallback=False)\n"
 651 "\n"
 652 "Register a callback to be called when messages arrive at the given\n"
 653 "object-path. Used to export objects' methods on the bus in a low-level\n"
 654 "way. For the high-level interface to this functionality (usually\n"
 655 "recommended) see the `dbus.service.Object` base class.\n"
 656 "\n"
 657 ":Parameters:\n"
 658 "   `path` : str\n"
 659 "       Object path to be acted on\n"
 660 "   `on_message` : callable\n"
 661 "       Called when a message arrives at the given object-path, with\n"
 662 "       two positional parameters: the first is this Connection,\n"
 663 "       the second is the incoming `dbus.lowlevel.Message`.\n"
 664 "   `on_unregister` : callable or None\n"
 665 "       If not None, called when the callback is unregistered.\n"
 666 "   `fallback` : bool\n"
 667 "       If True (the default is False), when a message arrives for a\n"
 668 "       'subdirectory' of the given path and there is no more specific\n"
 669 "       handler, use this handler. Normally this handler is only run if\n"
 670 "       the paths match exactly.\n"
 671 );
 672 static PyObject *
 673 Connection__register_object_path(Connection *self, PyObject *args,
 674                                  PyObject *kwargs)
 675 {
 676     dbus_bool_t ok;
 677     int fallback = 0;
 678     PyObject *callbacks, *path, *tuple, *on_message, *on_unregister = Py_None;
 679     static char *argnames[] = {"path", "on_message", "on_unregister",
 680                                "fallback", NULL};
 681
 682     TRACE(self);
 683     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 684     if (!Connection__require_main_loop(self, NULL)) {
 685         return NULL;
 686     }
 687     if (!PyArg_ParseTupleAndKeywords(args, kwargs,
 688                                      "OO|Oi:_register_object_path",
 689                                      argnames,
 690                                      &path,
 691                                      &on_message, &on_unregister,
 692                                      &fallback)) return NULL;
 693
 694     /* Take a reference to path, which we give away to libdbus in a moment.
 695
 696     Also, path needs to be a string (not a subclass which could do something
 697     mad) to preserve the desirable property that the DBusConnection can
 698     never strongly reference the Connection, even indirectly.
 699     */
 700     if (PyString_CheckExact(path)) {
 701         Py_INCREF(path);
 702     }
 703     else if (PyUnicode_Check(path)) {
 704         path = PyUnicode_AsUTF8String(path);
 705         if (!path) return NULL;
 706     }
 707     else if (PyString_Check(path)) {
 708         path = PyString_FromString(PyString_AS_STRING(path));
 709         if (!path) return NULL;
 710     }
 711     else {
 712         PyErr_SetString(PyExc_TypeError, "path must be a str or unicode object");
 713         return NULL;
 714     }
 715
 716     if (!dbus_py_validate_object_path(PyString_AS_STRING(path))) {
 717         Py_DECREF(path);
 718         return NULL;
 719     }
 720
 721     tuple = Py_BuildValue("(OO)", on_unregister, on_message);
 722     if (!tuple) {
 723         Py_DECREF(path);
 724         return NULL;
 725     }
 726
 727     /* Guard against registering a handler that already exists. */
 728     callbacks = PyDict_GetItem(self->object_paths, path);
 729     if (callbacks && callbacks != Py_None) {
 730         PyErr_Format(PyExc_KeyError, "Can't register the object-path "
 731                      "handler for '%s': there is already a handler",
 732                      PyString_AS_STRING(path));
 733         Py_DECREF(tuple);
 734         Py_DECREF(path);
 735         return NULL;
 736     }
 737
 738     /* Pre-allocate a slot in the dictionary, so we know we'll be able
 739      * to replace it with the callbacks without OOM.
 740      * This ensures we can keep libdbus' opinion of whether those
 741      * paths are handled in sync with our own. */
 742     if (PyDict_SetItem(self->object_paths, path, Py_None) < 0) {
 743         Py_DECREF(tuple);
 744         Py_DECREF(path);
 745         return NULL;
 746     }
 747
 748     Py_BEGIN_ALLOW_THREADS
 749     if (fallback) {
 750         ok = dbus_connection_register_fallback(self->conn,
 751                                                PyString_AS_STRING(path),
 752                                                &_object_path_vtable,
 753                                                path);
 754     }
 755     else {
 756         ok = dbus_connection_register_object_path(self->conn,
 757                                                   PyString_AS_STRING(path),
 758                                                   &_object_path_vtable,
 759                                                   path);
 760     }
 761     Py_END_ALLOW_THREADS
 762
 763     if (ok) {
 764         if (PyDict_SetItem(self->object_paths, path, tuple) < 0) {
 765             /* That shouldn't have happened, we already allocated enough
 766             memory for it. Oh well, try to undo the registration to keep
 767             things in sync. If this fails too, we've leaked a bit of
 768             memory in libdbus, but tbh we should never get here anyway. */
 769             Py_BEGIN_ALLOW_THREADS
 770             ok = dbus_connection_unregister_object_path(self->conn,
 771                                                     PyString_AS_STRING(path));
 772             Py_END_ALLOW_THREADS
 773             return NULL;
 774         }
 775         /* don't DECREF path: libdbus owns a ref now */
 776         Py_DECREF(tuple);
 777         Py_RETURN_NONE;
 778     }
 779     else {
 780         /* Oops, OOM. Tidy up, if we can, ignoring any error. */
 781         PyDict_DelItem(self->object_paths, path);
 782         PyErr_Clear();
 783         Py_DECREF(tuple);
 784         Py_DECREF(path);
 785         PyErr_NoMemory();
 786         return NULL;
 787     }
 788 }
 789
 790 PyDoc_STRVAR(Connection__unregister_object_path__doc__,
 791 "unregister_object_path(path)\n\n"
 792 "Remove a previously registered handler for the given object path.\n"
 793 "\n"
 794 ":Parameters:\n"
 795 "   `path` : str\n"
 796 "       The object path whose handler is to be removed\n"
 797 ":Raises KeyError: if there is no handler registered for exactly that\n"
 798 "   object path.\n"
 799 );
 800 static PyObject *
 801 Connection__unregister_object_path(Connection *self, PyObject *args,
 802                                    PyObject *kwargs)
 803 {
 804     dbus_bool_t ok;
 805     PyObject *path;
 806     PyObject *callbacks;
 807     static char *argnames[] = {"path", NULL};
 808
 809     TRACE(self);
 810     DBUS_PY_RAISE_VIA_NULL_IF_FAIL(self->conn);
 811     if (!PyArg_ParseTupleAndKeywords(args, kwargs,
 812                                      "O:_unregister_object_path",
 813                                      argnames, &path)) return NULL;
 814
 815     /* Take a ref to the path. Same comments as for _register_object_path. */
 816     if (PyString_CheckExact(path)) {
 817         Py_INCREF(path);
 818     }
 819     else if (PyUnicode_Check(path)) {
 820         path = PyUnicode_AsUTF8String(path);
 821         if (!path) return NULL;
 822     }
 823     else if (PyString_Check(path)) {
 824         path = PyString_FromString(PyString_AS_STRING(path));
 825         if (!path) return NULL;
 826     }
 827     else {
 828         PyErr_SetString(PyExc_TypeError, "path must be a str or unicode object");
 829         return NULL;
 830     }
 831
 832     /* Guard against unregistering a handler that doesn't, in fact, exist,
 833     or whose unregistration is already in progress. */
 834     callbacks = PyDict_GetItem(self->object_paths, path);
 835     if (!callbacks || callbacks == Py_None) {
 836         PyErr_Format(PyExc_KeyError, "Can't unregister the object-path "
 837                      "handler for '%s': there is no such handler",
 838                      PyString_AS_STRING(path));
 839         Py_DECREF(path);
 840         return NULL;
 841     }
 842
 843     /* Hang on to a reference to the callbacks for the moment. */
 844     Py_INCREF(callbacks);
 845
 846     /* Get rid of the object-path while we still have the GIL, to
 847     guard against unregistering twice from different threads (which
 848     causes undefined behaviour in libdbus).
 849
 850     Because deletion would make it possible for the re-insertion below
 851     to fail, we instead set the handler to None as a placeholder.
 852     */
 853     if (PyDict_SetItem(self->object_paths, path, Py_None) < 0) {
 854         /* If that failed, there's no need to be paranoid as below - the
 855         callbacks are still set, so we failed, but at least everything
 856         is in sync. */
 857         Py_DECREF(callbacks);
 858         Py_DECREF(path);
 859         return NULL;
 860     }
 861
 862     /* BEGIN PARANOIA
 863     This is something of a critical section - the dict of object-paths
 864     and libdbus' internal structures are out of sync for a bit. We have
 865     to be able to cope with that.
 866
 867     It's really annoying that dbus_connection_unregister_object_path
 868     can fail, *and* has undefined behaviour if the object path has
 869     already been unregistered. Either/or would be fine.
 870     */
 871
 872     Py_BEGIN_ALLOW_THREADS
 873     ok = dbus_connection_unregister_object_path(self->conn,
 874                                                 PyString_AS_STRING(path));
 875     Py_END_ALLOW_THREADS
 876
 877     if (ok) {
 878         Py_DECREF(callbacks);
 879         PyDict_DelItem(self->object_paths, path);
 880         /* END PARANOIA on successful code path */
 881         /* The above can't fail unless by some strange trickery the key is no
 882         longer present. Ignore any errors. */
 883         Py_DECREF(path);
 884         PyErr_Clear();
 885         Py_RETURN_NONE;
 886     }
 887     else {
 888         /* Oops, OOM. Put the callbacks back in the dict so
 889          * we'll have another go if/when the user frees some memory
 890          * and tries calling this method again. */
 891         PyDict_SetItem(self->object_paths, path, callbacks);
 892         /* END PARANOIA on failing code path */
 893         /* If the SetItem failed, there's nothing we can do about it - but
 894         since we know it's an existing entry, it shouldn't be able to fail
 895         anyway. */
 896         Py_DECREF(path);
 897         Py_DECREF(callbacks);
 898         return PyErr_NoMemory();
 899     }
 900 }
 901
 902     /* dbus_connection_get_object_path_data - not useful to Python,
 903      * the object path data is just a PyString containing the path */
 904     /* dbus_connection_list_registered could be useful, though */
 905
 906 /* dbus_connection_set_change_sigpipe - sets global state */
 907
 908 /* Maxima. Does Python code ever need to manipulate these?
 909  * OTOH they're easy to wrap */
 910     /* dbus_connection_set_max_message_size */
 911     /* dbus_connection_get_max_message_size */
 912     /* dbus_connection_set_max_received_size */
 913     /* dbus_connection_get_max_received_size */
 914
 915 /* dbus_connection_get_outgoing_size - almost certainly unneeded */
 916
 917 struct PyMethodDef DBusPyConnection_tp_methods[] = {
 918 #define ENTRY(name, flags) {#name, (PyCFunction)Connection_##name, flags, Connection_##name##__doc__}
 919     ENTRY(_require_main_loop, METH_NOARGS),
 920     ENTRY(close, METH_NOARGS),
 921     ENTRY(flush, METH_NOARGS),
 922     ENTRY(get_is_connected, METH_NOARGS),
 923     ENTRY(get_is_authenticated, METH_NOARGS),
 924     ENTRY(set_exit_on_disconnect, METH_VARARGS),
 925     ENTRY(get_unix_fd, METH_NOARGS),
 926     ENTRY(get_peer_unix_user, METH_NOARGS),
 927     ENTRY(get_peer_unix_process_id, METH_NOARGS),
 928     ENTRY(add_message_filter, METH_O),
 929     ENTRY(_register_object_path, METH_VARARGS|METH_KEYWORDS),
 930     ENTRY(remove_message_filter, METH_O),
 931     ENTRY(send_message, METH_VARARGS),
 932     ENTRY(send_message_with_reply, METH_VARARGS|METH_KEYWORDS),
 933     ENTRY(send_message_with_reply_and_block, METH_VARARGS),
 934     ENTRY(_unregister_object_path, METH_VARARGS|METH_KEYWORDS),
 935     {NULL},
 936 #undef ENTRY
 937 };
 938
 939 /* vim:set ft=c cino< sw=4 sts=4 et: */