CCP4 Molecular Graphics Documentation
	Remote Control

CCP4MG is able to receive input from other programs. This is done using sockets. The other program may be on the same machine that CCP4MG is running on or a different one.

CCP4MG executes the instructions which are sent to it via the socket communication. The instructions are in the form of Python code. This poses a security problem, if the program executed arbitrary code then a malicious program could send commands to do really bad things to the machine running CCP4MG.

CCP4MG attempts to address this problem in a variety of ways:

• No socket is opened by default, the user has to go to "Edit->Preferences->Plugins preferences->Socket security options" to open up access.
• The default configuration is only to allow access from the local machine. The user must turn on another option to allow general access.
• Only complete instructions are looked at. A command must be enclosed within <begin> and <end>.
• Only PyQt signal emit commands are allowed. The signals are emitted from the Python object which receives the socket commands. e.g. self.csocket.send("self.emit(QtCore.SIGNAL("setRotation"),(2,0,0))"). The receiving object will emit a signal, this signal must be connected already by CCP4MG. Only commands which begin "self.emit(" and end ")" are executed, all others are ignored.

Program Options

A socket for remote control may be turned on by opening up the preferences pane: Edit->Preferences->Plugins preferences->Socket security options. There are two options:

• "Open socket for remote control". Selecting this (and clicking "Apply") will open up a socket which will allow other programs to send commands.
• "Only accept connections from local machine". If this is selected, only connections from the same machine will be allowed. Unchecking it will allow connections from any computer.