Adding the beginnings of IMC2 support. We are now able to connect and authenticate with an IMC2 network, theoretically without blocking our server thread. We can't actually do anything useful just yet, but stay tuned.

src/imc2/connection.py

@@ -0,0 +1,97 @@
+"""
+IMC2 client module. Handles connecting to and communicating with an IMC2 server.
+"""
+import telnetlib
+import time
+from twisted.internet.protocol import ClientFactory
+from twisted.protocols.basic import LineReceiver
+from twisted.internet import reactor, task
+from twisted.conch.telnet import StatefulTelnetProtocol
+from django.conf import settings
+from src.imc2.packets import *
+
+# The active instance of IMC2Protocol. Set at server startup.
+IMC2_PROTOCOL_INSTANCE = None
+
+class IMC2Protocol(StatefulTelnetProtocol):
+    """
+    Provides the abstraction for the IMC2 protocol. Handles connection,
+    authentication, and all necessary packets.
+    """
+    def __init__(self):
+        print "IMC2: Client connecting to %s:%s..." % (settings.IMC2_SERVER_ADDRESS,
+                                                       settings.IMC2_SERVER_PORT)
+        global IMC2_PROTOCOL_INSTANCE
+        IMC2_PROTOCOL_INSTANCE = self
+        self.is_authenticated = False
+        self.auth_type = None
+        self.network_name = None
+        self.sequence = None
+           
+    def connectionMade(self):
+        """
+        Triggered after connecting to the IMC2 network.
+        """
+        print "IMC2: Connected to network server."
+        self.auth_type = "plaintext"
+        print "IMC2: Sending authentication packet."
+        self.send_packet(IMC2PacketAuthPlaintext())
+        
+    def send_packet(self, packet):
+        """
+        Given a sub-class of IMC2Packet, assemble the packet and send it
+        on its way.
+        """
+        if self.sequence:
+            # This gets incremented with every command.
+            self.sequence += 1
+            
+        packet.imc2_protocol = self
+        packet_str = packet.assemble()
+        print "IMC2: SENT> %s" % packet_str
+        self.sendLine(packet_str)
+        
+    def _parse_auth_response(self, line):
+        """
+        Parses the IMC2 network authentication packet.
+        """
+        if self.auth_type == "plaintext":
+            """
+            SERVER Sends: PW <servername> <serverpw> version=<version#> <networkname> 
+            """
+            if line[:2] == "PW":
+                line_split = line.split(' ')
+                self.network_name = line_split[4]
+                self.is_authenticated = True
+                self.sequence = time.time()
+                print "IMC2: Successfully authenticated to the '%s' network." % self.network_name
+
+    def lineReceived(self, line):
+        """
+        Triggered when text is received from the IMC2 network. Figures out
+        what to do with the packet.
+        """
+        if not self.is_authenticated:
+            self._parse_auth_response(line)
+        else:
+            split_line = line.split(' ')
+            packet_type = split_line[3]
+            if packet_type == "is-alive":
+                pass
+            elif packet_type == "user-cache":
+                pass
+            else:
+                print "receive:", line
+
+class IMC2ClientFactory(ClientFactory):
+    """
+    Creates instances of the IMC2Protocol. Should really only ever create one
+    in our particular instance. Tied in via src/server.py.
+    """
+    protocol = IMC2Protocol
+
+    def clientConnectionFailed(self, connector, reason):
+        print 'connection failed:', reason.getErrorMessage()
+
+    def clientConnectionLost(self, connector, reason):
+        print 'connection lost:', reason.getErrorMessage()