686 lines
14 KiB
C
686 lines
14 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: t -*-*/
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/***
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Copyright 2009 Lennart Poettering
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Permission is hereby granted, free of charge, to any person
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obtaining a copy of this software and associated documentation files
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(the "Software"), to deal in the Software without restriction,
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including without limitation the rights to use, copy, modify, merge,
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publish, distribute, sublicense, and/or sell copies of the Software,
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and to permit persons to whom the Software is furnished to do so,
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subject to the following conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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***/
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <assert.h>
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#include "ardouralsautil/reserve.h"
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#ifndef DBUS_TIMEOUT_USE_DEFAULT
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#define DBUS_TIMEOUT_USE_DEFAULT (-1)
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#endif
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struct rd_device {
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int ref;
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char *device_name;
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char *application_name;
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char *application_device_name;
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char *service_name;
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char *object_path;
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int32_t priority;
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DBusConnection *connection;
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unsigned owning:1;
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unsigned registered:1;
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unsigned filtering:1;
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unsigned gave_up:1;
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rd_request_cb_t request_cb;
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void *userdata;
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};
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#define SERVICE_PREFIX "org.freedesktop.ReserveDevice1."
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#define OBJECT_PREFIX "/org/freedesktop/ReserveDevice1/"
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static const char introspection[] =
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DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
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"<node>"
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" <!-- If you are looking for documentation make sure to check out\n"
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" http://git.0pointer.de/?p=reserve.git;a=blob;f=reserve.txt -->\n"
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" <interface name=\"org.freedesktop.ReserveDevice1\">"
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" <method name=\"RequestRelease\">"
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" <arg name=\"priority\" type=\"i\" direction=\"in\"/>"
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" <arg name=\"result\" type=\"b\" direction=\"out\"/>"
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" </method>"
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" <property name=\"Priority\" type=\"i\" access=\"read\"/>"
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" <property name=\"ApplicationName\" type=\"s\" access=\"read\"/>"
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" <property name=\"ApplicationDeviceName\" type=\"s\" access=\"read\"/>"
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" </interface>"
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" <interface name=\"org.freedesktop.DBus.Properties\">"
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" <method name=\"Get\">"
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" <arg name=\"interface\" direction=\"in\" type=\"s\"/>"
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" <arg name=\"property\" direction=\"in\" type=\"s\"/>"
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" <arg name=\"value\" direction=\"out\" type=\"v\"/>"
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" </method>"
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" </interface>"
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" <interface name=\"org.freedesktop.DBus.Introspectable\">"
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" <method name=\"Introspect\">"
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" <arg name=\"data\" type=\"s\" direction=\"out\"/>"
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" </method>"
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" </interface>"
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"</node>";
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static dbus_bool_t add_variant(
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DBusMessage *m,
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int type,
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const void *data) {
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DBusMessageIter iter, sub;
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char t[2];
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t[0] = (char) type;
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t[1] = 0;
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dbus_message_iter_init_append(m, &iter);
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if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, t, &sub))
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return FALSE;
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if (!dbus_message_iter_append_basic(&sub, type, data))
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return FALSE;
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if (!dbus_message_iter_close_container(&iter, &sub))
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return FALSE;
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return TRUE;
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}
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static DBusHandlerResult object_handler(
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DBusConnection *c,
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DBusMessage *m,
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void *userdata) {
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rd_device *d;
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DBusError error;
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DBusMessage *reply = NULL;
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dbus_error_init(&error);
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d = userdata;
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assert(d->ref >= 1);
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if (dbus_message_is_method_call(
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m,
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"org.freedesktop.ReserveDevice1",
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"RequestRelease")) {
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int32_t priority;
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dbus_bool_t ret;
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if (!dbus_message_get_args(
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m,
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&error,
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DBUS_TYPE_INT32, &priority,
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DBUS_TYPE_INVALID))
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goto invalid;
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ret = FALSE;
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if (priority > d->priority && d->request_cb) {
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d->ref++;
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if (d->request_cb(d, 0) > 0) {
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ret = TRUE;
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d->gave_up = 1;
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}
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rd_release(d);
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}
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if (!(reply = dbus_message_new_method_return(m)))
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goto oom;
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if (!dbus_message_append_args(
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reply,
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DBUS_TYPE_BOOLEAN, &ret,
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DBUS_TYPE_INVALID))
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goto oom;
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if (!dbus_connection_send(c, reply, NULL))
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goto oom;
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dbus_message_unref(reply);
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return DBUS_HANDLER_RESULT_HANDLED;
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} else if (dbus_message_is_method_call(
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m,
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"org.freedesktop.DBus.Properties",
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"Get")) {
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const char *interface, *property;
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if (!dbus_message_get_args(
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m,
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&error,
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DBUS_TYPE_STRING, &interface,
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DBUS_TYPE_STRING, &property,
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DBUS_TYPE_INVALID))
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goto invalid;
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if (strcmp(interface, "org.freedesktop.ReserveDevice1") == 0) {
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const char *empty = "";
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if (strcmp(property, "ApplicationName") == 0 && d->application_name) {
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if (!(reply = dbus_message_new_method_return(m)))
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goto oom;
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if (!add_variant(
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reply,
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DBUS_TYPE_STRING,
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d->application_name ? (const char * const *) &d->application_name : &empty))
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goto oom;
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} else if (strcmp(property, "ApplicationDeviceName") == 0) {
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if (!(reply = dbus_message_new_method_return(m)))
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goto oom;
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if (!add_variant(
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reply,
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DBUS_TYPE_STRING,
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d->application_device_name ? (const char * const *) &d->application_device_name : &empty))
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goto oom;
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} else if (strcmp(property, "Priority") == 0) {
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if (!(reply = dbus_message_new_method_return(m)))
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goto oom;
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if (!add_variant(
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reply,
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DBUS_TYPE_INT32,
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&d->priority))
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goto oom;
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} else {
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if (!(reply = dbus_message_new_error_printf(
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m,
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DBUS_ERROR_UNKNOWN_METHOD,
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"Unknown property %s",
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property)))
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goto oom;
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}
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if (!dbus_connection_send(c, reply, NULL))
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goto oom;
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dbus_message_unref(reply);
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return DBUS_HANDLER_RESULT_HANDLED;
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}
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} else if (dbus_message_is_method_call(
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m,
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"org.freedesktop.DBus.Introspectable",
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"Introspect")) {
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const char *i = introspection;
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if (!(reply = dbus_message_new_method_return(m)))
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goto oom;
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if (!dbus_message_append_args(
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reply,
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DBUS_TYPE_STRING,
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&i,
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DBUS_TYPE_INVALID))
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goto oom;
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if (!dbus_connection_send(c, reply, NULL))
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goto oom;
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dbus_message_unref(reply);
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return DBUS_HANDLER_RESULT_HANDLED;
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}
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return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
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invalid:
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if (reply)
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dbus_message_unref(reply);
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if (!(reply = dbus_message_new_error(
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m,
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DBUS_ERROR_INVALID_ARGS,
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"Invalid arguments")))
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goto oom;
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if (!dbus_connection_send(c, reply, NULL))
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goto oom;
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dbus_message_unref(reply);
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dbus_error_free(&error);
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return DBUS_HANDLER_RESULT_HANDLED;
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oom:
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if (reply)
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dbus_message_unref(reply);
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dbus_error_free(&error);
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return DBUS_HANDLER_RESULT_NEED_MEMORY;
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}
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static DBusHandlerResult filter_handler(
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DBusConnection *c,
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DBusMessage *m,
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void *userdata) {
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rd_device *d;
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DBusError error;
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char *name_owner = NULL;
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dbus_error_init(&error);
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d = userdata;
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assert(d->ref >= 1);
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if (dbus_message_is_signal(m, "org.freedesktop.DBus", "NameLost")) {
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const char *name;
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if (!dbus_message_get_args(
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m,
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&error,
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DBUS_TYPE_STRING, &name,
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DBUS_TYPE_INVALID))
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goto invalid;
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if (strcmp(name, d->service_name) == 0 && d->owning) {
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/* Verify the actual owner of the name to avoid leaked NameLost
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* signals from previous reservations. The D-Bus daemon will send
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* all messages asynchronously in the correct order, but we could
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* potentially process them too late due to the pseudo-blocking
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* call mechanism used during both acquisition and release. This
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* can happen if we release the device and immediately after
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* reacquire it before NameLost is processed. */
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if (!d->gave_up) {
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const char *un;
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if ((un = dbus_bus_get_unique_name(c)) && rd_dbus_get_name_owner(c, d->service_name, &name_owner, &error) == 0)
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if (name_owner && strcmp(name_owner, un) == 0)
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goto invalid; /* Name still owned by us */
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}
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d->owning = 0;
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if (!d->gave_up) {
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d->ref++;
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if (d->request_cb)
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d->request_cb(d, 1);
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d->gave_up = 1;
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rd_release(d);
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}
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}
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}
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invalid:
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free(name_owner);
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dbus_error_free(&error);
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return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
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}
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static const struct DBusObjectPathVTable vtable ={
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.message_function = object_handler
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};
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int rd_acquire(
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rd_device **_d,
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DBusConnection *connection,
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const char *device_name,
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const char *application_name,
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int32_t priority,
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rd_request_cb_t request_cb,
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DBusError *error) {
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rd_device *d = NULL;
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int r, k;
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DBusError _error;
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DBusMessage *m = NULL, *reply = NULL;
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dbus_bool_t good;
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if (!error)
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error = &_error;
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dbus_error_init(error);
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if (!_d)
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return -EINVAL;
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if (!connection)
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return -EINVAL;
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if (!device_name)
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return -EINVAL;
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if (!request_cb && priority != INT32_MAX)
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return -EINVAL;
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if (!(d = calloc(sizeof(rd_device), 1)))
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return -ENOMEM;
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d->ref = 1;
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if (!(d->device_name = strdup(device_name))) {
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r = -ENOMEM;
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goto fail;
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}
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if (!(d->application_name = strdup(application_name))) {
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r = -ENOMEM;
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goto fail;
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}
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d->priority = priority;
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d->connection = dbus_connection_ref(connection);
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d->request_cb = request_cb;
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if (!(d->service_name = malloc(sizeof(SERVICE_PREFIX) + strlen(device_name)))) {
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r = -ENOMEM;
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goto fail;
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}
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sprintf(d->service_name, SERVICE_PREFIX "%s", d->device_name);
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if (!(d->object_path = malloc(sizeof(OBJECT_PREFIX) + strlen(device_name)))) {
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r = -ENOMEM;
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goto fail;
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}
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sprintf(d->object_path, OBJECT_PREFIX "%s", d->device_name);
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if ((k = dbus_bus_request_name(
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d->connection,
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d->service_name,
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DBUS_NAME_FLAG_DO_NOT_QUEUE|
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(priority < INT32_MAX ? DBUS_NAME_FLAG_ALLOW_REPLACEMENT : 0),
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error)) < 0) {
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r = -EIO;
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goto fail;
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}
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if (k == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER)
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goto success;
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if (k != DBUS_REQUEST_NAME_REPLY_EXISTS) {
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r = -EIO;
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goto fail;
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}
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if (priority <= INT32_MIN) {
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r = -EBUSY;
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goto fail;
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}
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if (!(m = dbus_message_new_method_call(
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d->service_name,
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d->object_path,
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"org.freedesktop.ReserveDevice1",
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"RequestRelease"))) {
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r = -ENOMEM;
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goto fail;
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}
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if (!dbus_message_append_args(
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m,
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DBUS_TYPE_INT32, &d->priority,
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DBUS_TYPE_INVALID)) {
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r = -ENOMEM;
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goto fail;
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}
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if (!(reply = dbus_connection_send_with_reply_and_block(
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d->connection,
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m,
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5000, /* 5s */
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error))) {
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if (dbus_error_has_name(error, DBUS_ERROR_TIMED_OUT) ||
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dbus_error_has_name(error, DBUS_ERROR_UNKNOWN_METHOD) ||
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dbus_error_has_name(error, DBUS_ERROR_NO_REPLY)) {
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/* This must be treated as denied. */
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r = -EBUSY;
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goto fail;
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}
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r = -EIO;
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goto fail;
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}
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if (!dbus_message_get_args(
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reply,
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error,
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DBUS_TYPE_BOOLEAN, &good,
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DBUS_TYPE_INVALID)) {
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r = -EIO;
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goto fail;
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}
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if (!good) {
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r = -EBUSY;
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goto fail;
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}
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if ((k = dbus_bus_request_name(
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d->connection,
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d->service_name,
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DBUS_NAME_FLAG_DO_NOT_QUEUE|
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(priority < INT32_MAX ? DBUS_NAME_FLAG_ALLOW_REPLACEMENT : 0)|
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DBUS_NAME_FLAG_REPLACE_EXISTING,
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error)) < 0) {
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r = -EIO;
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goto fail;
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}
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if (k != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER) {
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r = -EIO;
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goto fail;
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}
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success:
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d->owning = 1;
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if (!(dbus_connection_register_object_path(
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d->connection,
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d->object_path,
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&vtable,
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d))) {
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r = -ENOMEM;
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goto fail;
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}
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d->registered = 1;
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|
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if (!dbus_connection_add_filter(
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d->connection,
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filter_handler,
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d,
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NULL)) {
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r = -ENOMEM;
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goto fail;
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}
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d->filtering = 1;
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*_d = d;
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return 0;
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fail:
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if (m)
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dbus_message_unref(m);
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|
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if (reply)
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dbus_message_unref(reply);
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|
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if (&_error == error)
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dbus_error_free(&_error);
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if (d)
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rd_release(d);
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return r;
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}
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|
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void rd_release(
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rd_device *d) {
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|
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if (!d)
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return;
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assert(d->ref > 0);
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if (--d->ref > 0)
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return;
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|
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if (d->filtering)
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dbus_connection_remove_filter(
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d->connection,
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filter_handler,
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d);
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|
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if (d->registered)
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dbus_connection_unregister_object_path(
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d->connection,
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d->object_path);
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|
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if (d->owning)
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dbus_bus_release_name(
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d->connection,
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d->service_name,
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NULL);
|
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|
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free(d->device_name);
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free(d->application_name);
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free(d->application_device_name);
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free(d->service_name);
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free(d->object_path);
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|
|
if (d->connection)
|
|
dbus_connection_unref(d->connection);
|
|
|
|
free(d);
|
|
}
|
|
|
|
int rd_set_application_device_name(rd_device *d, const char *n) {
|
|
char *t;
|
|
|
|
if (!d)
|
|
return -EINVAL;
|
|
|
|
assert(d->ref > 0);
|
|
|
|
if (!(t = strdup(n)))
|
|
return -ENOMEM;
|
|
|
|
free(d->application_device_name);
|
|
d->application_device_name = t;
|
|
return 0;
|
|
}
|
|
|
|
void rd_set_userdata(rd_device *d, void *userdata) {
|
|
|
|
if (!d)
|
|
return;
|
|
|
|
assert(d->ref > 0);
|
|
d->userdata = userdata;
|
|
}
|
|
|
|
void* rd_get_userdata(rd_device *d) {
|
|
|
|
if (!d)
|
|
return NULL;
|
|
|
|
assert(d->ref > 0);
|
|
|
|
return d->userdata;
|
|
}
|
|
|
|
int rd_dbus_get_name_owner(
|
|
DBusConnection *connection,
|
|
const char *name,
|
|
char **name_owner,
|
|
DBusError *error) {
|
|
|
|
DBusMessage *msg, *reply;
|
|
int r;
|
|
|
|
*name_owner = NULL;
|
|
|
|
if (!(msg = dbus_message_new_method_call(DBUS_SERVICE_DBUS, DBUS_PATH_DBUS, DBUS_INTERFACE_DBUS, "GetNameOwner"))) {
|
|
r = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
if (!dbus_message_append_args(msg, DBUS_TYPE_STRING, &name, DBUS_TYPE_INVALID)) {
|
|
r = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
reply = dbus_connection_send_with_reply_and_block(connection, msg, DBUS_TIMEOUT_USE_DEFAULT, error);
|
|
dbus_message_unref(msg);
|
|
msg = NULL;
|
|
|
|
if (reply) {
|
|
if (!dbus_message_get_args(reply, error, DBUS_TYPE_STRING, name_owner, DBUS_TYPE_INVALID)) {
|
|
dbus_message_unref(reply);
|
|
r = -EIO;
|
|
goto fail;
|
|
}
|
|
|
|
*name_owner = strdup(*name_owner);
|
|
dbus_message_unref(reply);
|
|
|
|
if (!*name_owner) {
|
|
r = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
} else if (dbus_error_has_name(error, "org.freedesktop.DBus.Error.NameHasNoOwner"))
|
|
dbus_error_free(error);
|
|
else {
|
|
r = -EIO;
|
|
goto fail;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
if (msg)
|
|
dbus_message_unref(msg);
|
|
|
|
return r;
|
|
}
|