proxy (socks ssh proxy)

proxy

#!/bin/bash
#
# proxy -- simple socks proxy for those open wifi networks.
#
# Usage is simple:
#
#   proxy <up|down|watch|show|ssh> [alt remote port] [alt remote host]
#
# `proxy up` will create a socks proxy listening locally on 8000 by
# default, through a rhost server via ssh over port 53 (dns/domain).
# When successfully connected, it will configure networking to use
# the socks proxy when attempting to browse HTTP/HTTPS and disable it
# when the proxy disconnects.
#

# Tweak these defaults to match your setup

BIND=8000
HOST=
PORT=53

ICON_UP="network-wireless-encrypted.png"
ICON_DOWN="connect_no.png"
ICON_BASE="/usr/share/icons/Tango/32x32/status"

# The stuff below should mostly be fine as is

bport=$BIND
rport=${2:-`(ps ax | grep -v grep | egrep -q "ssh.*D.$bport.*p.*LocalCommand") && (ps ax | grep -v grep | egrep "ssh.*D.$bport.*p.*LocalCommand" | sed 's/^.*ssh.*-p.\([0-9]*\).-.*-.*\$/\1/') || echo $PORT`}
rhost=${3:-$HOST}
fname=`readlink -f $0`
logfile="/tmp/.proxy.$rhost.$rport.log"
pattern="ssh.*D.$bport.*p.$rport.*o.LocalCommand.*$rhost"
statcmd="pkill -0 -f $pattern"

[[ "$rhost" == "" && "$1" != "show" ]] && shift $#

# Display a bubble alert
function notice_please() {
  icon="$ICON_BASE/$1"
  subject=$2
  msg=$3
  level=${4:-low}

  notify-send -a plskthx -u $level -i $icon "$subject" "$msg"
  echo
  echo "$subject: $msg"
}

# Toggle socks proxy on/off in system configuration
function socks_toggle() {
  dconf write /system/proxy/socks/host "'localhost'"
  dconf write /system/proxy/socks/port $bport

  if [ "$1" = "up" ]; then
    dconf write /system/proxy/http/enabled true
    dconf write /system/proxy/mode "'manual'"
  else
    dconf write /system/proxy/mode "'none'"
    dconf write /system/proxy/http/enabled false
  fi
}

case $1 in
  up)
    $statcmd && proxy down $rport
    {
      ssh -vvvv -N                             \
          -D $bport                            \
          -p $rport                            \
          -o PermitLocalCommand=yes            \
          -o ExitOnForwardFailure=yes          \
          -o ServerAliveInterval=5             \
          -o ServerAliveCountMax=2             \
          -o TCPKeepAlive=yes                  \
          -o LocalCommand="$fname show $rport $rhost" \
          $rhost > $logfile 2>&1 &

      socks_toggle up
      wait
      socks_toggle down
      proxy show $rport $rhost
    } &
    ;;

  down)
    socks_toggle down

    pkill -f "$pattern"
    ;;

  watch)
    test -f $logfile && cat $logfile && tail -n 0 -f $logfile || echo "no proxy to watch"
    ;;

  ssh)
    ssh -p $rport $rhost
    ;;

  show)
   $statcmd && {
     notice_please $ICON_UP "proxy($bport) -> ssh($rport)" "connected to $rhost"
   } || {
     notice_please $ICON_DOWN "proxy($bport) -> ssh($rport)" "disconnected from $rhost"
   }
   ;;

  *)
    echo
    echo "usage:"
    echo
    echo "  `basename $0` <up|down|watch|show|ssh> [alt remote port] [alt remote host]"
    echo
    echo "default:"
    echo
    echo "  socks  port: $BIND"
    echo "  remote port: $PORT"
    echo "  remote host: $HOST"
    echo

    if [ "$HOST" == "" ]; then
      echo "  default 'remote host' (HOST) is not set"
      echo "  to fix this, edit HOST variable in $fname"
    fi

    echo
    ;;
esac