y10k / unix_socket_tunnel

unix domain socket tunnel utility

unix_socket_tunnel

unix domain socket tunnel utility.

Requirements

Ruby is required because this utility is ruby script.

Description

This script tunnels unix domain socket to another path. It is supposed to tunnel a socket of ssh-agent.

1. Default is quiet. It displays the log on the screen with the -v or -l option.
2. It monitors the parent process and exits when the parent process is finished. It is supposed to start in the background from login shell. It is able to change the process ID to be monitored with the -w option.
3. The default umask(2) is 0077, and the tunnel destination socket refuses access from group and other. It is able to change umask with the -u option.
4. It makes sure that the tunnel destination directory is owned. It is able to ignore its owned with --no-dir-owned option.
5. It checks the security of the tunnel destination directory. It is able to change security check level with --dir-access-deny-mode-mask option.

Usage

$ unix_socket_tunnel -h
Usage: unix_socket_tunnel [options] CONNECT_PATH LISTEN_PATH
    -v, --verbose
    -l, --log-level=LEVEL
    -w, --watch-pid=PID
        --accept-timeout=SECONDS
        --io-chunk-size=BYTES
    -u, --umask=OCTETS
    -m, --unix-socket-mode=OCTETS
        --[no-]dir-owned
        --dir-access-deny-mode-mask=OCTETS

Example

Setting to use ssh-agent in GNU screen. Ssh-agent has already started up at login.

.screenrc:

setenv SCREEN_SESSION 1

.bashrc:

# ssh-agent forwarding in GNU Screen session
if [ -n "$PS1" ]; then          # for interactive shell
  saved_ssh_agent_sock="${HOME}/.ssh/agent_sock"
  unix_socket_tunnel="${HOME}/git_work/unix_socket_tunnel/unix_socket_tunnel"

  if [ -n "${SCREEN_SESSION}" ]; then # add to .screenrc: setenv SCREEN_SESSION 1
    export SSH_AUTH_SOCK="${saved_ssh_agent_sock}"
  elif shopt -q login_shell && [ -n "${SSH_AUTH_SOCK}" ] && [ -S "${SSH_AUTH_SOCK}" ]; then
    rm -f "${saved_ssh_agent_sock}"
    "${unix_socket_tunnel}" "${SSH_AUTH_SOCK}" "${saved_ssh_agent_sock}" &
  fi
fi