Stem Docs

Control Socket

Control Socket

Supports communication with sockets speaking Tor protocols. This allows us to send messages as basic strings, and receive responses as ControlMessage instances.

This module only consists of low level components, and is not intended for users. See our tutorials and Control Module if you're new to Stem and looking to get started.

With that aside, these can still be used for raw socket communication with Tor...

import stem
import stem.connection
import stem.socket

if __name__ == '__main__':
  try:
    control_socket = stem.socket.ControlPort(port = 9051)
    stem.connection.authenticate(control_socket)
  except stem.SocketError as exc:
    print 'Unable to connect to tor on port 9051: %s' % exc
    sys.exit(1)
  except stem.connection.AuthenticationFailure as exc:
    print 'Unable to authenticate: %s' % exc
    sys.exit(1)

  print "Issuing 'GETINFO version' query...\n"
  control_socket.send('GETINFO version')
  print control_socket.recv()

% python example.py
Issuing 'GETINFO version' query...

version=0.2.4.10-alpha-dev (git-8be6058d8f31e578)
OK

Module Overview:

BaseSocket - Thread safe socket.
  |- RelaySocket - Socket for a relay's ORPort.
  |  |- send - sends a message to the socket
  |  +- recv - receives a response from the socket
  |
  |- ControlSocket - Socket wrapper that speaks the tor control protocol.
  |  |- ControlPort - Control connection via a port.
  |  |- ControlSocketFile - Control connection via a local file socket.
  |  |
  |  |- send - sends a message to the socket
  |  +- recv - receives a ControlMessage from the socket
  |
  |- is_alive - reports if the socket is known to be closed
  |- is_localhost - returns if the socket is for the local system or not
  |- connection_time - timestamp when socket last connected or disconnected
  |- connect - connects a new socket
  |- close - shuts down the socket
  +- __enter__ / __exit__ - manages socket connection

send_message - Writes a message to a control socket.
recv_message - Reads a ControlMessage from a control socket.
send_formatting - Performs the formatting expected from sent messages.
class stem.socket.BaseSocket[source]

Bases: object

Thread safe socket, providing common socket functionality.

is_alive()[source]

Checks if the socket is known to be closed. We won't be aware if it is until we either use it or have explicitily shut it down.

In practice a socket derived from a port knows about its disconnection after failing to receive data, whereas socket file derived connections know after either sending or receiving data.

This means that to have reliable detection for when we're disconnected you need to continually pull from the socket (which is part of what the BaseController does).

Returns:bool that's True if our socket is connected and False otherwise
is_localhost()[source]

Returns if the connection is for the local system or not.

Returns:bool that's True if the connection is for the local host and False otherwise
connection_time()[source]

Provides the unix timestamp for when our socket was either connected or disconnected. That is to say, the time we connected if we're currently connected and the time we disconnected if we're not connected.

New in version 1.3.0.

Returns:float for when we last connected or disconnected, zero if we've never connected
connect()[source]

Connects to a new socket, closing our previous one if we're already attached.

Raises :stem.SocketError if unable to make a socket
close()[source]

Shuts down the socket. If it's already closed then this is a no-op.

class stem.socket.RelaySocket(address='127.0.0.1', port=9050, connect=True)[source]

Bases: stem.socket.BaseSocket

Link-level connection to a Tor relay.

New in version 1.7.0.

Variables:
  • address (str) -- address our socket connects to
  • port (int) -- ORPort our socket connects to
send(message)[source]

Sends a message to the relay's ORPort.

Parameters:

message (str) -- message to be formatted and sent to the socket
Raises :
recv(timeout=None)[source]

Receives a message from the relay.

Parameters:

timeout (float) -- maxiumum number of seconds to await a response, this blocks indefinitely if None
Returns:

bytes for the message received
Raises :
is_localhost()[source]
class stem.socket.ControlSocket[source]

Bases: stem.socket.BaseSocket

Wrapper for a socket connection that speaks the Tor control protocol. To the better part this transparently handles the formatting for sending and receiving complete messages.

Callers should not instantiate this class directly, but rather use subclasses which are expected to implement the _make_socket() method.

send(message)[source]

Formats and sends a message to the control socket. For more information see the send_message() function.

Deprecated since version 1.7.0: The raw argument was unhelpful and be removed. Use stem.socket.send_message() if you need this level of control instead.

Parameters:

message (str) -- message to be formatted and sent to the socket
Raises :
recv()[source]

Receives a message from the control socket, blocking until we've received one. For more information see the recv_message() function.

Returns:

ControlMessage for the message received
Raises :
class stem.socket.ControlPort(address='127.0.0.1', port=9051, connect=True)[source]

Bases: stem.socket.ControlSocket

Control connection to tor. For more information see tor's ControlPort torrc option.

Variables:
  • address (str) -- address our socket connects to
  • port (int) -- ControlPort our socket connects to
get_address()[source]

Provides the ip address our socket connects to.

Deprecated since version 1.7.0: Use the address attribute instead.

Returns:str with the ip address of our socket
get_port()[source]

Provides the port our socket connects to.

Deprecated since version 1.7.0: Use the port attribute instead.

Returns:int with the port of our socket
is_localhost()[source]
class stem.socket.ControlSocketFile(path='/var/run/tor/control', connect=True)[source]

Bases: stem.socket.ControlSocket

Control connection to tor. For more information see tor's ControlSocket torrc option.

Variables:path (str) -- filesystem path of the socket we connect to
get_socket_path()[source]

Provides the path our socket connects to.

Deprecated since version 1.7.0: Use the path attribute instead.

Returns:str with the path for our control socket
is_localhost()[source]
stem.socket.send_message(control_file, message, raw=False)[source]

Sends a message to the control socket, adding the expected formatting for single verses multi-line messages. Neither message type should contain an ending newline (if so it'll be treated as a multi-line message with a blank line at the end). If the message doesn't contain a newline then it's sent as...

<message>\r\n

and if it does contain newlines then it's split on \n and sent as...

+<line 1>\r\n
<line 2>\r\n
<line 3>\r\n
.\r\n
Parameters:
  • control_file (file) -- file derived from the control socket (see the socket's makefile() method for more information)
  • message (str) -- message to be sent on the control socket
  • raw (bool) -- leaves the message formatting untouched, passing it to the socket as-is
Raises :
stem.socket.recv_message(control_file, arrived_at=None)[source]

Pulls from a control socket until we either have a complete message or encounter a problem.

Parameters:

control_file (file) -- file derived from the control socket (see the socket's makefile() method for more information)
Returns:

ControlMessage read from the socket
Raises :
stem.socket.send_formatting(message)[source]

Performs the formatting expected from sent control messages. For more information see the send_message() function.

Parameters:message (str) -- message to be formatted
Returns:str of the message wrapped by the formatting expected from controllers