imux

imux

imux is a go library and corresponding command line tool for inverse multiplexing sockets

An imux client will create a listener and forward data from any connections to that listener to an imux server, using a configurable number of sockets. An imux server receives data and opens corresponding sockets to the final destination. Encryption is done with self-signed TLS and Trust Of First Use (TOFU).

installation

go get github.com/hkparker/imux/...

example

let's say you wanted to expose an SSH server over imux

server

serve imux on 0.0.0.0:443 and connect out to localhost:22

imux -server --listen=0.0.0.0:443 --dial=localhost:22

client

inverse multiplex over 10 sockets bound to any interface and connect to the server

imux -client --binds='{"0.0.0.0": 10}' --listen=localhost:22 --dial=server:443

now on the client, connect to localhost:22 to ssh to the sever's localhost:22 over the imux connection

ssh localhost

multiple routes

imux can be used to transport a single socket over multiple internet connections using source routing in linux

For example, consider simultaneously using two interfaces:

create routing tables

echo '128    imux0' >> /etc/iproute2/rt_tables
echo '129    imux1' >> /etc/iproute2/rt_tables

add routes

ip route add default via 192.168.1.1 table imux0 dev eth0
ip route add default via 10.0.0.1 table imux1 dev eth1

add rules

ip rule add from 192.168.1.2 table imux0
ip rule add from 10.0.0.2 table imux1

flush cache

ip route flush cache

connect with binds

here we choose 20 sockets on each interface

imux -client --binds='{"192.168.1.2": 20, "10.0.0.2": 20}' --listen=localhost:22 --dial=server:443