Gabriel 0.1

Gabriel is a simple utility to enable D-Bus clients to connect to a D-Bus daemon running on a remote machine, through SSH.

Installing Gabriel

(0) To build Gabriel client, you need to have libssh (>= 0.2) [1] and glib (> 2.10) installed.

For Gabriel server scripts, you need socat and D-Bus (> 1.0.2) installed on your machine.

(1) Type:

./configure

(2) make
(3) make install

Usage Notes

Gabriel is composed of a client-side and a server side:

The server side is actually just a small dbus configuration file and a pair of scripts that start and shut-down a dbus-daemon with that configuration file.

Here is the usage for the Gabriel server scripts:

gabriel-server-start [PID_FILE]
gabriel-server-stop [PID_FILE]

Where PID_FILE is the path to the file where the PID of the dbus-daemon will be stored. If no PID_FILE is specified, /tmp/gabriel-server.pid is assumed.

The client side is the actual thing and is therefore a binary named, gabriel. Following is its usage:

gabriel [OPTION...] - Gabriel

Help Options:

-?, --help Show help options

Application Options:

-h, --host=HOSTNAME Hostname or IP of the remote host
-u, --username=USERNAME Username on the remote host
-p, --password=PASSWORD Password on the remote host
-b, --bind=LOCALHOST The address to listen for DBus client connections on
-t, --port=PORT The TCP port to listen for DBus client connections on

Upon successful launch, gabriel will inform you about the D-Bus Bus address you need to use for your D-Bus clients. If you launch gabriel without any arguments, it will try to connect to the localhost, bind TCP socket it listens on to the localhost at port 1337. The output from gabriel on successful launch in this case would be:

Listening to D-Bus clients on: "tcp:host=localhost,port=1337"

Now to make your D-Bus clients connect to it, you either pass this as an argument to dbus_connection_open() in the clients code or simply set the environment variable DBUS_SESSION_BUS_ADDRESS like this:

DBUS_SESSION_BUS_ADDRESS="tcp:host=localhost,port=1337" your_dbus_client

Tada! Your dbus client is manipulating objects on a remote machine over a secure channel.

Known Issues

* Only one client can connect at one time. I already have a fix for this but unfortunately it doesnt work since libssh is not thread-safe. However the developer has promised to make things better in this respect in the next release.

* The server (dbus-daemon actually) should be launched by the same user account as used by gabriel to authenticate to the server. This is because of some strange authentication mechanism of D-Bus that I dont really understand.