baijum / sshtunnel

SSH tunneling daemon

sshtunnel SSH tunnelling SystemD daemon.

This is a port of OpenWrt sshtunnel. So basic documentation is same but implementation differ.

Usage

Create /etc/sshtunnel.config.sh file and configure server and a tunnel:

server "srv_us"
  HostName="srv.us"
  User="root"
  IdentityFile="/root/.ssh/id_ed25519"

tunnelR "srv_us_http"
  servername="srv_us"
  remoteaddress="1"
  remoteport=80
  localaddress="127.0.0.1"
  localport=8080

Then restart with systemctl restart sshtunnel.

Then you'll have ssh started you can check with ps ax | grep ssh:

ssh [e-mail] -i /root/.ssh/id_ed25519 -o StrictHostKeyChecking=accept-new -R 1:80:127.0.0.1:8080 -N -o ExitOnForwardFailure=yes -o BatchMode=yes

To read logs use:

sudo journalctl -f -n 50 -u sshtunnel

See sshtunnel.config.sh for more samples. The file is a DSL over a plain shell script.

Supported options

• server specify SSH server options. One server may have multiple tunnels.
  • HostName IP or domain. Required
  • User default root
  • Port
  • IdentityFile you better to specify. If empty then will try /root/.ssh/id_rsa, then /root/.ssh/id_ed25519
  • StrictHostKeyChecking default accept-new, or if you are afraid that server change it in future then set to no
• tunnelR remote to local tunnel
  • remoteaddress, remoteport, localaddress, localport
• tunnelL local to remote tunnel
  • remoteaddress, remoteport, localaddress, localport
• tunnelD dynamic tunnel e.g. SOCKS proxy
  • localaddress, localport
• tunnelW VPN
  • Tunnel point-to-point (default) or ethernet. See Tunnel in man ssh_config
  • localdev, remotedev tun devices. See TunnelDevice in man ssh_config

Options from SSH config file are starting from Upper case but the sshtunnel specific options starts with lowercase.

Installation

sudo cp sshtunnel.sh /usr/bin/sshtunnel
sudo chmod +x /usr/bin/sshtunnel
sudo cp sshtunnel.service /etc/systemd/system/
sudo systemctl daemon-reload

See also

• SystemD SSH client unit based on SystemD templates. Configure port forwardings in the SSH config