Illustrate

• It is a tool implementation of peer to peer chat through NAT.
  • communication method : udp
  • principle : mid-man transfer

Current version: 1.2.1 | G++

User Guide

Prerequisites

gcc must support c++ 11, only c++0x support not enough
you should has one linux server with public ip

Get the latest source code

git clone https://github.com/xiangp126/uchat
cd uchat
make
# will generate p2pserver & p2pclient

Setup your server

on your server

vim config.h
# change PORTNUM if needed
# and ensure the listening port was not blocked by your company or ISP

/* listen port on the server side */
#define PORTNUM    13000

make
./bin/p2pserver
Now listening on port 13000...

Setup your client

on your client

make

./bin/p2pclient [SERVER_IP] [LISTEN_PORT]
>>>
# type 'help'
>>> help
NAME
    p2pclient --- Client End of Peer to Peer communication Through NAT

USAGE
    >>> COMMAND [PARAM]
    type COMMANDS before any word you typed. If you want to type COMMANDS
    as a word itself, just leave a blank before it. Default you chat with
    the server, after punched, you chat directly with the peer you punched.

COMMAND:
    help
    list
    whoami
    punch [ip] [port]
    login
    logout
    setname [hostname]
    exit

DESCRIPTION
    HELP:    print this help info, you can type 'help' when needed.
    LIST:    print logined and punched info. It's useful before 'punch'.
    WHOAMI:  show who you are, namely the ip address & port through NAT.
    PUNCH:   establish connection between you and the peer you want to talk with.
             After punched, you talked directly to punched peer.
             punch [ip] [port], such as: punch [64.0.1.5] [12400]
    LOGIN:   login you existence to the server, may type 'list' when logined.
    LOGOUT:  clear your login info and stop sending heartbeat to the server.
    SETNAME: set hostname to make peer more identified. When logined, setname will
             take effect at once. The hostname will be back to Annoymous after
             logout. Format: setname [hostname], suck as: setname corsair
             That is: setname only take effect after logined.
    EXIT:    exit this program on your machine, same as CTRL + D.

AUTHORS
       p2pclient is a DEMO for either further study or research purpose, you
       can modify or redistribute it whatever you want.

EXAMPLE

This example illustrates both the client and server side. On server side, the message reveived was pretty printed as default.

Client Side

>>> list
>>> Message From (127.0.0.1 13000):
-------------------------- *** Login Info
  PEERINFO-IP-PORT       TTL   HOSTNAME
  127.0.0.1 35079        10    arthur     <= already logined
  127.0.0.1 47061        9     corsair    <= already logined
*** --------------------------------------

-------------------------- *** Punch Info
*** --------------------------------------

# arthur was another peer name set by >>> setname arthur
# default name is Annoymous
>>> punch arthur
Usage Format: punch 127.0.0.1 18974
Notice Not Leave any blank before 'punch'.
>>> whoami
>>> You Are: (64.104.169.98 58404)
>>> punch 127.0.0.1 35079
Want To Punch (127.0.0.1 35079)
Sending PUNCH Packet To Server...
>>> NOTICE: First, You Two Must All Be Logined.
Just Type 'list' to See Info.

>>> login
>>> list
>>> Message From (10.124.10.102 13000):
-------------------------- *** Login Info
  PEERINFO-IP-PORT       TTL   HOSTNAME
  64.104.169.98 58404    10    Annoymous   <= it's me, newly logined
  127.0.0.1 35079        9     arthur
  127.0.0.1 47061        9     corsair
*** --------------------------------------

-------------------------- *** Punch Info
*** --------------------------------------

>>> setname giggle
>>> list
>>> Message From (10.124.10.102 13000):
-------------------------- *** Login Info
  PEERINFO-IP-PORT       TTL   HOSTNAME
  64.104.169.98 58404    10    giggle     <= rename default 'Annoymous' to giggle
  127.0.0.1 35079        10    arthur
  127.0.0.1 47061        10    corsair
*** --------------------------------------

-------------------------- *** Punch Info
*** --------------------------------------

>>> punch 127.0.0.1 35079
Want To Punch (127.0.0.1 35079)
Sending PUNCH Packet To Server...
>>> list
>>> Message From (10.124.10.102 13000):
-------------------------- *** Login Info
  PEERINFO-IP-PORT       TTL   HOSTNAME
  64.104.169.98 58404    9     giggle
  127.0.0.1 35079        9     arthur
  127.0.0.1 47061        10    corsair
*** --------------------------------------

-------------------------- *** Punch Info
  127.0.0.1 35079   ===>>   64.104.169.98 58404     <= newly punched info (one pair)
  64.104.169.98 58404   ===>>   127.0.0.1 35079
*** --------------------------------------

On My Side:
>>> can you speak English?
>>> I am LiLei.
>>> Message From (127.0.0.1 35079): My name is HanMeiMei.
>>>

Meanwhile On the Peer Side:
>>> Peer (64.104.169.98 58404) Want To Chat With You.
By Default, Auto Send Accept.

>>> Message From (64.104.169.98 58404): can you speak English?
>>> Message From (64.104.169.98 58404): I am LiLei.
>>> My name is HanMeiMei.
>>>

Server Side

Head Type = MESSAGE
Payload length = 424 (Had + '\0')
Head PeerInfo = (0.0.0.0 0)
Packet Payload:
-------------------------- *** Login Info
  PEERINFO-IP-PORT       TTL   HOSTNAME
  64.104.169.98 58404    10    giggle
  127.0.0.1 35079        8    arthur
  127.0.0.1 47061        9    corsair
*** --------------------------------------

-------------------------- *** Punch Info
  127.0.0.1 35079   ===>>   64.104.169.98 58404
  64.104.169.98 58404   ===>>   127.0.0.1 35079
*** --------------------------------------

Head Type = SETNAME
Payload length = 15 (Had + '\0')
Head PeerInfo = (0.0.0.0 0)
Packet Payload: setname giggle

Heart Beat Received From (64.104.169.98 58404)
Head Type = HEARTBEAT
Payload length = 11 (Had + '\0')
Head PeerInfo = (0.0.0.0 0)
Packet Payload: HI Server.

License

The MIT License(MIT)