Adding TTYPE support (allows server to query client for information such as name and capabilities, assuming the client supports ttype).

src/server/ttype.py

@@ -0,0 +1,91 @@
+"""
+This module implements the TTYPE telnet protocol as per
+http://tintin.sourceforge.net/mtts/. It allows the server to ask the
+client about its capabilities. If the client also supports TTYPE, it
+will return with information such as its name, if it supports colour
+etc. If the client does not support TTYPE, this will be ignored.
+
+All data will be stored on the protocol's protocol_flags dictionary,
+under the 'TTYPE' key.
+"""
+
+# telnet option codes
+TTYPE =  chr(24)
+IS = chr(0)
+SEND = chr(1)
+
+# terminal capabilities and their codes
+MTTS = [(128,'PROXY'), 
+        (64, 'SCREEN READER'), 
+        (32, 'OSC COLOR PALETTE'), 
+        (16, 'MOUSE TRACKING'), 
+        (8, '256 COLORS'), 
+        (4, 'UTF-8'),
+        (2, 'VT100'),
+        (1, 'ANSI')]
+
+class Ttype(object):
+    """
+    Handles ttype negotiations. Called and initiated by the 
+    telnet protocol.
+    """
+    def __init__(self, protocol):
+        """
+        initialize ttype by storing protocol on ourselves and calling
+        the client to see if it supporst ttype.
+
+        the ttype_step indicates how far in the data retrieval we've
+        gotten.
+        """
+        self.ttype_step = 0 
+        self.protocol = protocol
+        self.protocol.protocol_flags['TTYPE'] = {}
+
+        # setup protocol to handle ttype initialization and negotiation
+        self.protocol.negotiationMap[TTYPE] = self.negotiate_ttype                
+        # ask if client will ttype, connect callback if it does.
+        self.protocol.will(TTYPE).addCallbacks(self.negotiate_ttype, self.no_ttype)
+
+    def no_ttype(self, option):
+        """
+        Callback if ttype is not supported by client. 
+        """
+        pass
+
+    def negotiate_ttype(self, option):
+        """
+        Handles negotiation of the ttype protocol once the 
+        client has confirmed that it supports the ttype 
+        protocol.  
+
+        The negotiation proceeds in several steps, each returning a
+        certain piece of information about the client. All data is
+        stored on protocol.protocol_flags under the TTYPE key.
+        """
+
+        self.ttype_step += 1
+
+        if self.ttype_step == 1: 
+            # set up info storage and initialize subnegotiation     
+            self.protocol.requestNegotiation(TTYPE, SEND)
+        else:
+            # receive data 
+            option = "".join(option).lstrip(IS)
+            if self.ttype_step == 2:
+                self.protocol.protocol_flags['TTYPE']['CLIENTNAME'] = option
+                self.protocol.requestNegotiation(TTYPE, SEND)
+            elif self.ttype_step == 3:
+                self.protocol.protocol_flags['TTYPE']['TERM'] = option
+                self.protocol.requestNegotiation(TTYPE, SEND)
+            elif self.ttype_step == 4 and option.startswith('MTTS'):                
+                option = int(option.strip('MTTS '))
+                self.protocol.protocol_flags['TTYPE']['MTTS'] = option                
+                for codenum, standard in MTTS: 
+                    if option == 0:
+                        break 
+                    status = option % codenum < option
+                    self.protocol.protocol_flags['TTYPE'][standard] = status
+                    if status: 
+                        option = option % codenum
+            #print "ttype results:", self.protocol.protocol_flags['TTYPE']
+