Automatic SOCKS proxy setup through SSH connection on Mac OS X

proxy.sh

#!/usr/bin/env bash
# Script for automatic setup of SOCKS proxy through SSH connection.
# It automatically teardowns SOCKS configuration before stopping.
# It's supposed to work on Mac OS X 10.6+
#
# Author: Adam Stankiewicz (@sheerun)
#

[[ -n "$1" ]] || { echo "Usage: proxy user@example.com"; exit 1; }

# get service GUID and NAME (like Wi-Fi) to set SOCKS proxy

SERVICE_GUID=`printf "open\nget State:/Network/Global/IPv4\nd.show" | \
scutil | grep "PrimaryService" | awk '{print $3}'`

SERVICE_NAME=`printf "open\nget Setup:/Network/Service/$SERVICE_GUID\nd.show" |\
scutil | grep "UserDefinedName" | awk -F': ' '{print $2}'`

# command to disble socks proxy after at the end
finally() { sudo networksetup -setsocksfirewallproxystate "$SERVICE_NAME" off; }

# enable socks proxy in system configuration
sudo networksetup -setsocksfirewallproxy "$SERVICE_NAME" 127.0.0.1 1080 &&
  ssh $1 -N -D 1080

trap finally INT

finally