Re: Modern implementations of control messages (ping, pong etc.)

Hi there,
You said in your reply:
> Not all servents will send it out though, as it is not mandatory to initiate
> a connection (since you know the remote IP and port).

How do you know the remote IP and Port?  Is this just the IP and Port that replies to the GNUTELLA CONNECT message were sent to?
Thanks,
Rik


--- In [email protected], Raphael_Manfredi@... wrote:
>
> Quoting rik_saunderson <rik.saunderson@...> from ml.gnutella.dev-forum:
> :Hi there,
> :I'm trying to understand how modern gnutella clients send and recieve control
> :messages (i.e. ping, pong, query, queryhit, push, bye and vendor specific). 
> :Older clients send them over tcp on port 6346, but most modern clients (e.g.
> :Limewire, Frostwire etc.) no longer do this because it's incredibly easy to block
> :with a firewall.  Additionally, some send control messages over UDP.
> :
> :I've looked on the Limewire wiki, and I've tried reading a spec for GUESS that I
> :found, but I cant find an exact spec.
> :
> :My questions are these:
> :1.  How do modern gnutella clients agree on which port to use as the destination
> :port?  It can't just be the Listen-IP filed of a GNUTELLA CONNECT because I have
> :pcap files of transfers where this data does not appear.
> 
> Yes, it is the value of Listen-IP or Node headers.
> 
> Not all servents will send it out though, as it is not mandatory to initiate
> a connection (since you know the remote IP and port).
> 
> :2.  Is there a spec document with the format of the most common vendor specific
> :messages (i.e. bytes 0-15 are the servent ID, byte 16 is the length etc.)?
> 
> Each vendor message will specify the meaning of its payload.
> 
> For instance, here is the definition of the "GTKG/7v2" message:
> 
>     Name: UDP Connect Back
>     Vendor: GTKG
>     ID: 7   
>     Version: 2
>     TTL: 1
>     Payload:
>         unsigned short: port number (little-endian)
> 
> You see, it clearly mentions that the payload is a single little-endian 2-byte
> word.
> 
> :3.  Both of the above questions for UDP control messages.
> 
> UDP control messages are simply Gnutella messages, there are no differences
> with the ones sent over TCP.
> 
> Raphael
>