78 lines
3.4 KiB
Plaintext
78 lines
3.4 KiB
Plaintext
IrcVPN - Irc Virtual Public Network
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===================================
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This is an ethernet tunnel providing basic hubbed or switchet networks via irc.
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Warning: If you use this software on a "real" (read: not your own) network:
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1. You might run into various flood protections
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2. Your IRC-OP might kill you for that
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Furthermore: All of your data will go kind-of plaintext over an Irc-channel.
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While this is a rather uncommon way of ip transit, everybody who
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is able to join the channel might be able to eavesdrop.
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Installation and requirements
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=============================
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* python-irclib
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* ether2any
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For configuration take a look at conf.py, it has some comments to give you a
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hint of what this switch will do. Some of the security settings are rather
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untested, keep that in mind. After configuration, start the tunnel with
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python ircvpn.py. A tap-device will open and the tunnel should be ready to run.
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What it does and how it works
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=============================
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IrcVPN uses an ircchannel as its transport medium. When starting this tunnel,
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it makes a connection to the configured irc-server, joins a channel and starts
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pushing all outgoing network traffic (base64 encoded with a small header) to
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that channel. The nick will be a combination of the configured prefix and
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the TAP interfaces mac-address.
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There are two network-modes available:
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.Hubbed Network
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In a hubbed network topology all the clients share one broadcast medium, the
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irc channel.
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.Switchet Network
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In a switched network topology still all the clients join the irc channel and
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use it for broadcast messages but unicast traffic goes directly to the user
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it is intended for, as it is sent to the nickprefix-macaddress combination.
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Wether the user with the specific mac actually IS in the network is not
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checked.
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Flood protection is kind of the biggest issue for irc as ether: After a
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configured amount of messages most irc-servers queue the incoming messages
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and send them out as one per second. If the send-queue is overflowed the user
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gets kicked from the server. So this tunnel is not going to perform very well
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on normal servers out there. Setting up an own server, the flood protection CAN
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be turned off but irc-server with configurable flood protections tend to allow
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flooding only in channels and only if the user is either voiced, half-op or op.
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This is where voicebot.py comes in: The voicebot voices everyone who joins the
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channel and utters a certain phrase. Therefore it is kind of ensured that every
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bot has the right to flood the ether as much as it wants with network packets.
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Ircs right management can always be used to mute, rate-limit or remove spamming
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or otherwise unwanted clients.
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Header Format
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=============
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<fragmentation flag><packet id> <base64 encoded message>
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The *fragmentation flag* can be either of o, b, c, e. *o* stands for oneliner,
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which means that afterwards there is a complete ethernet frame (no
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fragmentation). *b*, *c*, *e* stand for begin, continue, end and mark packets
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which are broken into several pieces (as of irc does not support infinit line
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length).
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The packet id is just a randon generated number between 0, 99999 (incl.).
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What could be done
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==================
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* replace base64 with something more fitting for Irc
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* test security settings
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* find static linkable irc server, patch flood protection out of it
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* VVLAN - a Virtual VLAN between irc-channels/servers
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