OS X tunnelr script

tunnelr.sh

#!/bin/bash -e

USERNAME=mitmatt
NODE=seattle
INTERFACE=AirPort
LOCAL_PORT=1080
CONTROL_SOCKET=~/.ssh/control-tunnelr

CONNECT_COMMAND=connect
DISCONNECT_COMMAND=disconnect

CONFIG_FILE_COMMENT='auto-added by tunnelr script'

usage()
{
    echo "usage: ${0##*/} {${CONNECT_COMMAND}|${DISCONNECT_COMMAND}}"
}

if [ $# != 1 ]
then
    usage
    exit 0
fi

if [ ! -e ~/.ssh/config ] || ! grep -q "${CONFIG_FILE_COMMENT}" ~/.ssh/config
then
    mkdir -p ~/.ssh
    cat >> ~/.ssh/config << EOF
# ${CONFIG_FILE_COMMENT}
Host *.tunnelr.com
    ControlMaster auto

EOF
fi

case "$(echo $1 | tr [:upper:] [:lower:])" in
    ${CONNECT_COMMAND:0:${#1}})
        echo "setting SOCKS proxy to ${NODE}.tunnelr.com..."
        networksetup -setsocksfirewallproxy ${INTERFACE} 127.0.0.1 ${LOCAL_PORT} off
        ssh "${USERNAME}@${NODE}.tunnelr.com" -S ${CONTROL_SOCKET} -f -p 22 -N -D localhost:${LOCAL_PORT}
        ;;
    ${DISCONNECT_COMMAND:0:${#1}})
        echo "disconnecting SOCKS proxy from ${NODE}.tunnelr.com..."
        if [ -e ${CONTROL_SOCKET} ]
        then
            ssh -S ${CONTROL_SOCKET} -O exit localhost
        else
            echo "WARNING: could not find control socket; no ssh processes killed" > /dev/stderr
        fi
        networksetup -setsocksfirewallproxystate ${INTERFACE} off
        ;;
    *)
        usage
        exit 1
        ;;
esac