#!/bin/bash
#
# set-tor-user ( 20120904 )
#
# Configures Tor Browser Bundle to run as the specified user when ownership belongs to root. 
# This script must be placed it TBB's root directory (with start-tor-browser)
# Anyone can freely modify and/or distribute this script without restrictions
#
# Written by Luke Williams ( xocel@iquidus.org )
#
# If set-tor-user encounters a problem, it will return a non-zero error code.
# 1 = invalid arguments
# 2 = user does not exist
# 3 = user does not belong to group
function usage {
    echo "Configures Tor Browser Bundle to be run by the specified user"
    echo "Usage: `basename $0` [options] [username] "
    echo " "
    echo "Options:"
    echo "   -g, --group [groupname] , Sets group"
    echo "                             default: \"users\""
    echo "   -r, --restore           , Removes all files created by `basename $0`" 
    echo "                             from the system and restores TBB to its"
    echo "                             orignal state."
    echo " "
}

if [ $# -eq 0 ]; then
    usage
    exit 0
fi

#Make sure script is being run as root.
if [ "`id -u`" -ne 0 ]; then
    echo "This script needs to be run as root"
    exit 1
fi

#Check if script is being run through a symlink.
MYNAME="$0"
if [ -L "$MYNAME" ]; then
    MYNAME="`readlink -f "$MYNAME" 2>/dev/null`"
    if [ "$?" -ne 0 ]; then
        # Ugh.
        echo "`basename $0` cannot be run using a symlink on this operating system."
    fi
fi

#make sure we are in the right directory.
CWD="`dirname "$MYNAME"`"
test -d "$CWD" && cd "$CWD"

GROUP="users" #Default group
ORIG="$CWD/Data.orig"

while [ 0 ]; do
  if [ "$1" = "-g" -o "$1" = "--group" ]; then
    if [ -z "$2" ]; then
        GROUP=$2
        shift 2
    else
        usage
        exit 1
    fi
  elif [ "$1" = "-r" -o "$1" = "--restore" ]; then
    echo "Removing TBB files from home directories"
    rm -rf /home/*/.TBB
    echo "Removing symlinks"
    rm -rf "$CWD/.config"
    rm -rf "$CWD/.kde"
    rm -rf "$CWD/.mozilla"
    rm -rf "$CWD/.nv"
    echo "Restoring Data directory"
    if [ -e $ORIG ]; then
        rm "$CWD/Data"
        mv $ORIG "$CWD/Data"
    fi
    echo "All operations have completed successfully"
    exit 0
  else
    USERNAME=$1
    break
  fi
done

#Check if user exists
USER_EXISTS=$(grep -c ^$USERNAME: /etc/passwd)
if [ $USER_EXISTS -ne "1" ]; then
    echo "Invalid username: $USERNAME"
    exit 2
fi

#Check user belongs to group
IN_GROUP=0
USER_GROUPS=$(echo $(groups $USERNAME) | tr " " "\n")
for g in $USER_GROUPS
do
    if [ $g == $GROUP ]
    then
        IN_GROUP=1
    fi
done

if [ $IN_GROUP -ne 1 ]; then
    echo "$USERNAME does not belong to group: $GROUP"
    exit 3
fi

#check to see if script has been run before.
#If not, rename Data dir.
if [ ! -d $ORIG ]; then
    mv "$CWD/Data" $ORIG
fi

TBB="/home/$USERNAME/.TBB"

#check to see if .TBB exists in specified users home dir.
#If not, create ~/.TBB, copy Data dir into it and create conf dirs.  
if [ ! -d $TBB ]; then
    mkdir $TBB
    cp -R $ORIG "$TBB/Data"
    mkdir "$TBB/.config"
    mkdir "$TBB/.kde"
    mkdir "$TBB/.mozilla"
    mkdir "$TBB/.nv"
    chown -R $USERNAME.$GROUP $TBB
fi
#check if symlinks exist, if so remove them.
if [ -e "$CWD/Data" ]; then
    rm "$CWD/Data"
    rm "$CWD/.config"
    rm "$CWD/.kde"
    rm "$CWD/.mozilla"
    rm "$CWD/.nv"
fi

#create new symlinks.
ln -s "$TBB/Data" ./
ln -s "$TBB/.kde" ./
ln -s "$TBB/.config" ./
ln -s "$TBB/.mozilla" ./
ln -s "$TBB/.nv" ./

#Configuration complete.
echo "Tor Browser Bundle is now configured to be run by $USERNAME"