Launch shipped dbus-daemon if first connection attempt was unsuccessful

share/dbus-1/session.conf

@@ -0,0 +1,80 @@
+<!-- This configuration file controls the per-user-login-session message bus.
+     Add a session-local.conf and edit that rather than changing this 
+     file directly. -->
+
+<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-Bus Bus Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+  <!-- Our well-known bus type, don't change this -->
+  <type>session</type>
+
+  <!-- If we fork, keep the user's original umask to avoid affecting
+       the behavior of child processes. -->
+  <keep_umask/>
+
+  <listen>autolaunch:</listen>
+
+  <!-- On Unix systems, the most secure authentication mechanism is
+  EXTERNAL, which uses credential-passing over Unix sockets.
+
+  This authentication mechanism is not available on Windows,
+  is not suitable for use with the tcp: or nonce-tcp: transports,
+  and will not work on obscure flavours of Unix that do not have
+  a supported credentials-passing mechanism. On those platforms/transports,
+  comment out the <auth> element to allow fallback to DBUS_COOKIE_SHA1. -->
+  <!--<auth>EXTERNAL</auth>-->
+
+  <standard_session_servicedirs />
+
+  <policy context="default">
+    <!-- Allow everything to be sent -->
+    <allow send_destination="*" eavesdrop="true"/>
+    <!-- Allow everything to be received -->
+    <allow eavesdrop="true"/>
+    <!-- Allow anyone to own anything -->
+    <allow own="*"/>
+  </policy>
+
+  <!-- Include legacy configuration location -->
+  <include ignore_missing="yes">../../etc/dbus-1/session.conf</include>
+
+  <!-- Config files are placed here that among other things, 
+       further restrict the above policy for specific services. -->
+  <includedir>session.d</includedir>
+
+  <includedir>../../etc/dbus-1/session.d</includedir>
+
+  <!-- This is included last so local configuration can override what's 
+       in this standard file -->
+  <include ignore_missing="yes">../../etc/dbus-1/session-local.conf</include>
+
+  <include if_selinux_enabled="yes" selinux_root_relative="yes">contexts/dbus_contexts</include>
+
+  <!-- For the session bus, override the default relatively-low limits 
+       with essentially infinite limits, since the bus is just running 
+       as the user anyway, using up bus resources is not something we need 
+       to worry about. In some cases, we do set the limits lower than 
+       "all available memory" if exceeding the limit is almost certainly a bug, 
+       having the bus enforce a limit is nicer than a huge memory leak. But the 
+       intent is that these limits should never be hit. -->
+
+  <!-- the memory limits are 1G instead of say 4G because they can't exceed 32-bit signed int max -->
+  <limit name="max_incoming_bytes">1000000000</limit>
+  <limit name="max_incoming_unix_fds">250000000</limit>
+  <limit name="max_outgoing_bytes">1000000000</limit>
+  <limit name="max_outgoing_unix_fds">250000000</limit>
+  <limit name="max_message_size">1000000000</limit>
+  <!-- We do not override max_message_unix_fds here since the in-kernel
+       limit is also relatively low -->
+  <limit name="service_start_timeout">120000</limit>  
+  <limit name="auth_timeout">240000</limit>
+  <limit name="pending_fd_timeout">150000</limit>
+  <limit name="max_completed_connections">100000</limit>  
+  <limit name="max_incomplete_connections">10000</limit>
+  <limit name="max_connections_per_user">100000</limit>
+  <limit name="max_pending_service_starts">10000</limit>
+  <limit name="max_names_per_connection">50000</limit>
+  <limit name="max_match_rules_per_connection">50000</limit>
+  <limit name="max_replies_per_connection">50000</limit>
+
+</busconfig>

src/blackcore/dbus_server.cpp

@@ -10,7 +10,7 @@
 #include "blackmisc/logmessage.h"
 #include "blackmisc/network/networkutils.h"
 #include "dbus_server.h"
-#include <QDebug>
+#include <QProcess>
 #include <QMetaClassInfo>
 
 using namespace BlackMisc;
@@ -35,6 +35,12 @@ namespace BlackCore
                 // we use a session bus connection instead of a real P2P connection
                 this->m_serverMode = CDBusServer::SERVERMODE_SESSIONBUS;
                 QDBusConnection connection = QDBusConnection::connectToBus(QDBusConnection::SessionBus, ServiceName());
+                if (!connection.isConnected())
+                {
+                    launchDbusDaemon();
+                    connection = QDBusConnection::connectToBus(QDBusConnection::SessionBus, ServiceName());
+                }
+
                 if (!connection.registerService(service))
                 {
                     // registration fails can either mean something wrong with DBus or service already exists
@@ -48,6 +54,12 @@ namespace BlackCore
                 // we use a system bus connection instead of a real P2P connection
                 this->m_serverMode = CDBusServer::SERVERMODE_SYSTEMBUS;
                 QDBusConnection connection = QDBusConnection::systemBus();
+                if (!connection.isConnected())
+                {
+                    launchDbusDaemon();
+                    connection = QDBusConnection::systemBus();
+                }
+
                 if (!connection.registerService(service))
                 {
                     // registration fails can either mean something wrong with DBus or service already exists
@@ -91,6 +103,14 @@ namespace BlackCore
         return sn;
     }
 
+    void CDBusServer::launchDbusDaemon()
+    {
+        const QString program = QStringLiteral("dbus-daemon");
+        const QStringList arguments = { QStringLiteral("--config-file=../share/dbus-1/session.conf") };
+        bool success = QProcess::startDetached(program, arguments);
+        if (!success) { CLogMessage(this).warning("Failed to launch dbus-daemon!"); }
+    }
+
     /*
      * Check for P2P address
      */

src/blackcore/dbus_server.h

@@ -113,6 +113,9 @@ namespace BlackCore
         QMap<QString, QObject *> m_objects;      //!< Mapping of all exposed objects, for P2P registration when connection establishes, also to later unregister objects
         QMap<QString, QDBusConnection> m_DBusConnections; //!< Mapping of all DBusConnection objects
 
+        //! Manually launch our shipped dbus daemon
+        void launchDbusDaemon();
+
         //! Check if address means a real server with P2P connection
         static bool isP2P(const QString &address);