os x ssh proxy

tunnel.sh

#!/bin/sh 
#
#  Copyright (c) 2011 Netsend
#  Released under the MIT license.
#

###
# create a local ssh SOCKS proxy to RHOST and update OS X proxy settings.
# Tip: make your programs use the default OS X proxy.
#####

RHOST=shell.server.com
LPORT=9052

INTERACTIVE=1

echo=/bin/echo

usage() {
  $echo "Setup an ssh proxy"
  $echo ""
  $echo "usage: `basename $0` [hostname]"
  $echo ""
  $echo "hostname    remote ssh host"
  $echo ""
}

PIDS=$(ps auxw | grep '[s]sh -2a' | awk '{ print $2}')

if [[ "$PIDS" != "" ]]; then
  kill $PIDS
fi

if [ ! -z $1 ]; then
  RHOST=$1
fi

set -e

ssh -2a -D127.0.0.1:$LPORT -NnqTxy $RHOST &
sleep 1
PID=$(lsof -tsTCP:LISTEN -i@127.0.0.1:$LPORT)
# suppress "/usr/local/bin/tunnel: line 50: kill: ($PID) - No such process"
trap 'kill $PID 2>/dev/null; sudo networksetup -setsocksfirewallproxystate Ethernet off; sudo networksetup -setsocksfirewallproxystate AirPort off; exit $?' INT TERM EXIT

# update any changes to the local proxy port
sudo networksetup -setsocksfirewallproxy Ethernet 127.0.0.1 $LPORT off
sudo networksetup -setsocksfirewallproxy AirPort 127.0.0.1 $LPORT off
# turn on the proxy
sudo networksetup -setsocksfirewallproxystate Ethernet on
sudo networksetup -setsocksfirewallproxystate AirPort on

# stay open if interactive
if [ "$INTERACTIVE" -eq 1 ]; then
  echo PRESS CTRL-C to abort
  cat
fi

tested on Snow Leopard, for Lion do s/AirPort/Wi-Fi/