thomaschevalier/yacit

Yet Another Crappy ICMP Tunnel

yacit - Yet Another Crappy ICMP Tunnel

yacit is a simple icmp tunnel that forwards all the traffic of the client to the server via ICMP Echo Request (aka ping).

Made in collaboration with @japius

Goals of this project:

• Gain experience with Rust
• Try to configure everything via system calls, without the help of existing programs (such as iproute2)
• Create a working prototype in a time-constrained context

The logic for the VPN is largely inspired from davlxd's excellent demo.

Installation

cargo build

Running

Server side

nft 'flush ruleset
  table inet nat {
        chain postrouting {
                type nat hook postrouting priority filter; policy accept;
                  ip saddr 10.0.0.0/16 ip daddr != 10.0.0.0/16 masquerade
        }
        chain forward{
           type filter hook forward priority 0; policy accept
        }
  }'

sudo ./target/debug/yacit --mtu 1500 --server --internal-ip 10.0.0.1

Client side

nft 'flush ruleset
  table inet nat {
        chain postrouting {
                type nat hook postrouting priority filter; policy accept;
                oifname "yacit0" masquerade
        }
        chain forward{
           type filter hook forward priority 0; policy accept
        }
  }'

sudo ./target/debug/yacit --mtu 1500 --remote-ip <SERVER IP> --out-iface-name <OUTPUT INTERFACE NAME>