Member Avatar for XR_

Hi, i'm searching for a way to know the hostname of a machine connected to my twisted-server.
I use to know the host the method self.transport.getPeer().host, and i have the IP in this way.
But i need to know the hostname. I'm searching for a way like socket.gethostname().

Waiting your answer :D

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  • Latest Post Latest Post by Beat_Slayer

Dani AI

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Short answer: self.transport.getPeer() gives you an address object (an IPv4Address/IPv6Address) whose host attribute is the remote IP — Twisted does not automatically give you a resolved hostname for that peer. (docs.twistedmatrix.com)

Recommended options (pick one):

  • Use Twisted’s asynchronous DNS client (twisted.names) to perform a PTR lookup (reverse DNS). This is non‑blocking and returns a Deferred you can attach callbacks to; it’s the Twisted‑native way to ask DNS “what name maps to this IP?”. (docs.twistedmatrix.com)

  • If you prefer the system resolver (e.g. socket.gethostbyaddr) you must not call it directly in connectionMade because it blocks the reactor. Run it in a thread with threads.deferToThread and handle failures/timeout there, then receive the result via a Deferred callback. (docs.python.org)

Practical notes and pitfalls:

  • Reverse DNS often isn’t configured on LAN hosts (so lookups can fail or return the IP). Always have a fallback to the raw IP.
  • Don’t rely on methods like getDestination() — Twisted transports expose getPeer() and getHost(); getPeer() is the remote endpoint and getHost() is the local endpoint. That resolves the AttributeError you saw when trying non‑existent methods. (docs.twistedmatrix.com)
  • If you expect many simultaneous resolves, prefer twisted.names (scales better) or tune the reactor thread pool rather than spawning unbounded threads. (docs.twistedmatrix.com)

Example patterns (concepts only — adapt to your protocol):

  • Asynchronous DNS (returns Deferred): call client.lookupPointer(reverseName(ip)) and extract the PTR answer in your callback. (docs.twistedmatrix.com)
  • System resolver off the reactor thread: threads.deferToThread(lambda: socket.gethostbyaddr(ip)[0]) and then addCallback to receive the hostname. (docs.python.org)

Context for the thread of posts: was correct to use self.transport.getPeer().host to obtain the IP; ’s suggestion of getDestination() isn’t present on the IPv4Address/transport objects — use getPeer()/getHost() and then perform a reverse lookup as shown above. (docs.twistedmatrix.com)

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Member Avatar for Beat_Slayer

Something like...

self.transport.getDestination()

Cheers and Happy coding

Member Avatar for XR_ 
self.nick = self.transport.getDestination()
exceptions.AttributeError: 'Server' object has no attribute 'getDestination
Member Avatar for Beat_Slayer

How about showing some code??

Anyway the getDestination() should retrieve you the hostname.

Try something like...

peer = self.transport.getPeer()
nick = peer.getDestination()

Cheers and Happy coding

Member Avatar for XR_

Nothing to do, always the same error:

File "Server.py", line 21, in name
    self.nick = peer.getDestination()
exceptions.AttributeError: 'IPv4Address' object has no attribute 'getDestination

This is the source:

Member Avatar for Beat_Slayer

And like this?

def name(self):
    connector = self.transport.connector
    return connector.getDestination()

I'll install twisted to take a look.

Cheers and Happy coding

Member Avatar for XR_ 
File "Server.py", line 20, in name
    connector = self.transport.connector
exceptions.AttributeError: 'Server' object has no attribute 'connector'

=(

Member Avatar for Beat_Slayer

I've installed twisted mate.

Do you have client code? Can you post it, or PM it to me?

Cheers and Happy coding

Member Avatar for XR_

The client is telnet :D
But, i don't think that client is the reason. This method getDestination() doesn't exist in accordance with the interpreter's error.

Member Avatar for Beat_Slayer

Wait, this is the server code, right?

How do you connect to it?

Cheers and Happy coding

Member Avatar for XR_

By telnet

Member Avatar for Beat_Slayer

Sorry mate, now I got it! :D

I made consfusion, the country I'm in now has a provider named 'Telnet', and I just stupidlly thought you were talking about it. I'm very sorry.

I'll take a look.

Cheers and Happy coding

Member Avatar for XR_

Lol, no problem man, i'll wait :)

Member Avatar for Beat_Slayer

I'm new ot twisted, but thats all I was able by now to extract as peer info.

But, your implementation does'nt seem right to me.

I'll take a look into twisted, I think I'll write something, meanwhile...

from twisted.protocols.basic import LineOnlyReceiver
from twisted.internet  import reactor
from twisted.internet.protocol import ServerFactory
import time


class ChatConnection(LineOnlyReceiver):

    def __init__(self):
        self.hostlist = []
        self.hostname = ""
        self.master = ""

    def sendLine(self, line):
        self.transport.write(line + '\n')

    def print_time(self):
        return time.strftime("[%H:%M] ", time.localtime(time.time()))

    def name(self):
        self.nick = self.transport.getPeer()
        return ' '.join([str(item) for item in self.nick])
    
    def connectionMade(self):
        print  self.print_time() + "New connection from " + self.name()
    
        if self.name == self.hostname:
            self.master = self.transport.getPeer().host
        else:
            self.factory.IDandIP[self.name] = self.transport.getPeer().host
            self.hostlist.append(self.name())

        def connectionLost(self, reason):
            print self.print_time() + "Connection lost by", self.name()
            del self.factory.IDandIP[self.name]
            self.hostlist.remove(self.name())

          
        def lineReceived(self, line):
        
            if line == "/list":
                self.sendLine(self.print_time() + "Online users: \n\t" + str(self.hostlist))
    
            if line[:6] == "zombie":
                self.master.sendLine(line[:6])
            else:
                ID = line.split(" : ")[0]
        
                if ID in self.hostlist:
                      self.IDandIP[ID].sendLine(line)
        
                 
class Chat(ServerFactory):
     
    protocol = ChatConnection
    
    def __init__(self):
        
        self.IDandIP = {}

print "Waiting connection from clients..."
main = Chat()
reactor.listenTCP(8000, main)
reactor.run()

Cheers and Happy coding

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