#!/usr/bin/env bash


working_dir="$(dirname $(realpath $0))"
conf_file="${working_dir}/conf/bind.conf"

log_file="$(mktemp)"

backup_date="$(date +%Y-%m-%d-%H%M)"

_serial_new=`date +%Y%m%d01`


#---------------------------------------
#-----------------------------
# Base Function(s)
#-----------------------------
#---------------------------------------

clean_up() {

   # Perform program exit housekeeping
   rm $log_file
   blank_line
   exit $1
}

echononl(){
   echo X\\c > /tmp/shprompt$$
   if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
      echo -e -n "$*\\c" 1>&2
   else
       echo -e -n "$*" 1>&2
   fi
   rm /tmp/shprompt$$
}

fatal(){
   echo ""
   echo -e "[ \033[31m\033[1mError\033[m ]: $*"
   echo ""
   echo -e "\t\033[31m\033[1mScript is canceled\033[m\033[m"
   echo ""
   clean_up 1
}

warn (){
   echo ""
   echo -e "\t[ \033[33m\033[1mWarning\033[m ]: $*"
   echo ""
}

info (){
   echo ""
   echo -e "\t[ \033[33m\033[1mInfo\033[m ]: $*"
   echo ""
}

ok (){
   echo ""
   echo -e "\t[ \033[36m\033[1mOk\033[m ]: $*"
   echo ""
}

error(){
   echo ""
   echo -e "\t[ \033[31m\033[1mFehler\033[m ]: $*"
   echo ""
}

echo_ok() {
   echo -e "\033[75G[ \033[32mok\033[m ]"
}
echo_done() {
   echo -e "\033[75G[ \033[32mok\033[m ]"
}
echo_failed(){
   echo -e "\033[75G[ \033[1;31mfailed\033[m ]"
}
echo_skipped() {
   echo -e "\033[75G[ \033[33m\033[1mskipped\033[m ]"
}

containsElement () {
   local e
   for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
   return 1
}

blank_line() {
   if $terminal ; then
      echo ""
   fi
}


## - Test of valid IPv4 Address
## -
## -    Returns 0 if valid, > 0 otherwise
## -
is_valid_ipv4() {
  local -a octets=( ${1//\./ } )
  local RETURNVALUE=0

  # return an error if the IP doesn't have exactly 4 octets
  [[ ${#octets[@]} -ne 4 ]] && return 1

  for octet in ${octets[@]}
  do
    if [[ ${octet} =~ ^[0-9]{1,3}$ ]]
    then # shift number by 8 bits, anything larger than 255 will be > 0
      ((RETURNVALUE += octet>>8 ))
    else # octet wasn't numeric, return error
      return 1
    fi
  done
  return ${RETURNVALUE}
}

is_valid_ipv6() {
   local _ipv6=$1

   if [ "$1" != "${1#[0-9a-f]*:}" ] \
      && [ "$1" = "${1#*[^0-9a-f:]}" ] \
      && [ "${1#*[0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f]}" = "${1#*:*:*:*:*:*:*:*:*:}" ]; then
      return 0
   else
      return 1
   fi
}



# ----------
# - Jobhandling 
# ----------

# - Run 'clean_up' for signals SIGHUP SIGINT SIGTERM
# -
trap clean_up SIGHUP SIGINT SIGTERM



# =============
# --- Some checks
# =============

# - Running in a terminal?
# -
if [[ -t 1 ]] ; then
   terminal=true
else
   terminal=false
fi




#---------------------------------------
#-----------------------------
# Setting Defaults
#-----------------------------
#---------------------------------------

DEFAULT_CONF_FILE_DIR="/etc/bind"
DEFAULT_BIND_USER="bind"
DEFAULT_BIND_GROUP="bind"



#---------------------------------------
#-----------------------------
# Load default values from bind.conf
#
# Overwrites the settings above
# 
#-----------------------------
#---------------------------------------

#clear
echo ""
echo ""
echononl "   Loading default Configuration values from $(basename ${conf_file}).."
if [[ ! -f "$conf_file" ]]; then
   echo_skipped
else
   source "${conf_file}" > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      fatal "$(cat $log_file)"
   fi
fi

[[ -n "$BIND_USER" ]] || BIND_USER="$DEFAULT_BIND_USER"
[[ -n "$BIND_GROUP" ]] || BIND_GROUP="$DEFAULT_BIND_GROUP"

#[[ -n "$BIND_CACHE_DIR" ]] && DEFAULT_BIND_CACHE_DIR="$BIND_CACHE_DIR"
#
#
#if [[ -n "$ZONE_FILE_MASTER_DIR" ]] ; then
#   DEFAULT_ZONE_FILE_MASTER_DIR="$ZONE_FILE_MASTER_DIR"
#else
#   DEFAULT_ZONE_FILE_MASTER_DIR="${DEFAULT_CONF_FILE_DIR}/master"
#fi
#
#if [[ -n "$ZONE_FILE_SLAVE_DIR" ]] ; then
#   DEFAULT_ZONE_FILE_SLAVE_DIR="$ZONE_FILE_SLAVE_DIR"
#else
#   DEFAULT_ZONE_FILE_SLAVE_DIR="${DEFAULT_BIND_CACHE_DIR}"
#fi
#
#if [[ -n "$ZONES_DECLARATION_FILE" ]] ; then
#   DEFAULT_ZONES_DECLARATION_FILE="$ZONES_DECLARATION_FILE"
#else
#   DEFAULT_ZONES_DECLARATION_FILE="${CONF_FILE_DIR}/named.conf.local"
#fi
   



echo ""
echo ""
echo -e "\033[32m--\033[m"
echo "Common parameters"
echo -e "\033[32m--\033[m"


echo ""
echo "Insert directory containing the bind configuration files."
echo ""
CONF_FILE_DIR=""
if [[ -n "$DEFAULT_CONF_FILE_DIR" ]] ; then
   echononl "Bind Configuration Directory [${DEFAULT_CONF_FILE_DIR}]: "
   read CONF_FILE_DIR
   if [[ "X$CONF_FILE_DIR" = "X" ]]; then
      CONF_FILE_DIR="$DEFAULT_CONF_FILE_DIR"
   fi
else
   echononl "Bind Configuration Directory: "
   read CONF_FILE_DIR
   while [ "X$CONF_FILE_DIR" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Bind Configuration Directory' is required!\033[m\n"
      echononl "Bind Configuration Directory: "
      read CONF_FILE_DIR
   done
fi

[[ -n "$ZONES_DECLARATION_FILE" ]] || DEFAULT_ZONES_DECLARATION_FILE="${CONF_FILE_DIR}/named.conf.local"
[[ -n "$ZONE_FILE_MASTER_DIR" ]] || DEFAULT_ZONE_FILE_MASTER_DIR="${CONF_FILE_DIR}/master"


echo ""
echo -e "\033[32m--\033[m"

echo ""
echo "Insert zones declaration file."
echo ""
ZONES_DECLARATION_FILE=""
if [[ -n "$DEFAULT_ZONES_DECLARATION_FILE" ]] ; then
   echononl "Zones Declaration File [${DEFAULT_ZONES_DECLARATION_FILE}]: "
   read ZONES_DECLARATION_FILE
   if [[ "X$ZONES_DECLARATION_FILE" = "X" ]]; then
      ZONES_DECLARATION_FILE="$DEFAULT_ZONES_DECLARATION_FILE"
   fi
else
   echononl "Zones Declaration File: "
   read ZONES_DECLARATION_FILE
   while [ "X$ZONES_DECLARATION_FILE" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Zones Declaration File' is required!\033[m\n"
      echononl "Zones Declaration File: "
      read ZONES_DECLARATION_FILE
   done
fi


echo ""
echo -e "\033[32m--\033[m"

echo ""
echo "Insert the directory, where your zone-files resides."
echo ""
echo ""
ZONE_FILE_MASTER_DIR=""
if [[ -n "$DEFAULT_ZONE_FILE_MASTER_DIR" ]] ; then
   echononl "Zone File Directory (master) [${DEFAULT_ZONE_FILE_MASTER_DIR}]: "
   read ZONE_FILE_MASTER_DIR
   if [[ "X$ZONE_FILE_MASTER_DIR" = "X" ]]; then
      ZONE_FILE_MASTER_DIR="$DEFAULT_ZONE_FILE_MASTER_DIR"
   fi
else
   echononl "Zone File Directory (master): "
   read ZONE_FILE_MASTER_DIR
   while [ "X$ZONE_FILE_MASTER_DIR" = "X" ] ; do
      echo -e "\n\t\033[33m\033[1mSetting 'Zone File Directory (master)' is required!\033[m\n"
      echononl "Zone File Directory (master): "
      read ZONE_FILE_MASTER_DIR
   done
fi


clear
echo ""
echo ""
echo -e "\033[21G\033[32mAdd SPF recotd if not exists\033[m"
echo ""

echo ""
echo "   Bind Configuration Directory...............: $CONF_FILE_DIR"
echo "   Zones Declaration File.....................: $ZONES_DECLARATION_FILE"
echo "   Zone File Directory (master)...............: $ZONE_FILE_MASTER_DIR"
echo ""
echo "   Bind user..................................: ${BIND_USER}"
echo "   Bind group.................................: ${BIND_GROUP}"

echo ""
OK=
while [ "$OK" != "yes" -o "$OK" != "no" ] ; do
   echononl "Parameters ok? [yes/no]: "
   read OK
   ## - To lower case
   OK=${OK,,}
   if [ "X$OK" = "X" ]; then
      echo -e "\n\t\033[33m\033[1mAn entry is required!\033[m\n"
      OK=""
      continue
   fi
   if [ "$OK" != "yes" -o "$OK" != "no" ] ; then
      break
   fi
   echo -e "\n\t\033[33m\033[1mWrong entry!\033[m\n"
done
[[ $OK = "yes" ]] || fatal Repeat execution with different parameters

echo ""


echononl "\tBackup directory '${ZONE_FILE_MASTER_DIR}'.."
cp -a "${ZONE_FILE_MASTER_DIR}" "${ZONE_FILE_MASTER_DIR}.${backup_date}" > $log_file 2>&1
if [[ $? -eq 0 ]]; then
   echo_ok
else
   echo_failed
   fatal "$(cat $log_file)"
fi

echo ""
echo ""
echo -e "\033[37m\033[1mDetermine zone files for adding a DMARC Record ..\033[m"

_found=false
_is_master=false
zonefiles_arr=()
zone_file=""
regex_master="type[[:space:]]+master"
regex_file="^[[:space:]]*file"
regex_mx="^[^;].+\s+IN\s+MX"
while IFS='' read -r _line || [[ -n $_line ]] ; do

   if [[ $_line  =~ ^[[:space:]]*zone[[:space:]]+ ]]; then
      _found=true
      zone="$(echo $_line | awk '{print$2}')"
      shopt -s extglob
      if [[ $zone =~ \; ]]; then
         zone=${zone%%*(\;)}
      fi
      if [[ $zone =~ ^\" ]]; then
         zone=${zone##*(\")}
         zone=${zone%%*(\")}
      fi
      shopt -u extglob
   fi
   if $_found ; then
      if [[ $_line  =~ $regex_file ]]; then
         zone_file=$(echo $_line | awk '{print$2}')
         shopt -s extglob
         if [[ $zone_file =~ \; ]]; then
            zone_file=${zone_file%%*(\;)}
         fi
         if [[ $zone_file =~ ^\" ]]; then
            zone_file=${zone_file##*(\")}
            zone_file=${zone_file%%*(\")}
         fi
         shopt -u extglob
      fi
      if [[ $_line  =~ $regex_master ]]; then
         _is_master=true
      fi
      if [[ "$_line"  =~ ^[[:space:]]*\}[[:space:]]*\; ]]; then
         if $_is_master && [[ -n "$zone_file" ]]; then

            if $(grep -q -E "${regex_mx}" "$zone_file" 2> /dev/null) ; then

               if $(grep -q -E "^\s*_dmarc\s*IN\s+TXT\s+\"v=DMARC1.*" "$zone_file") ; then
                  :
               else

                  if [ ${#zonefiles_arr[@]} -eq 0 ] ; then
                     zonefiles_arr+=("${zone_file}:$zone")
                  else
                     if ! containsElement "${zone_file}:$zone"  "${zonefiles_arr[@]}" ; then
                        zonefiles_arr+=("${zone_file}:$zone")
                     fi
                  fi
               fi
            fi
         fi
         _is_master=false
         _found=false
         zone_file=""
      fi
   fi
done < "$ZONES_DECLARATION_FILE"

echo ""


for _val in ${zonefiles_arr[@]} ; do

   echo ""

   IFS=':' read -a _val_arr <<< "${_val}"

   zone_file="${_val_arr[0]}"
   zone="${_val_arr[1]}"
 
   CUR_IFS=$IFS
   IFS=''
   #_tmpfile=`mktemp`
   _tmpfile="/tmp/$(basename "${zone_file}")"
   > $_tmpfile

   echo -e "\tEditing \033[1m$zone_file\033[m .."
      
   _replaced=false

   ## - Add SPF record
   ## -
   echononl "\t   Add (default) DMARC TXT record for zone '${zone}'.."

   # - We will place the new SPF Record after the last existing MX record.
   # -
   # - first we will count the number ox existing MX records
   # -
   declare -i _count
   search_string="^[^;].+\s+IN\s+TXT\s+\""
   _count=$(grep -Eo "$search_string" $zone_file | wc -l)
   if [[ $_count -eq 0 ]]; then
      echo_skipped
      warn "No existing MX record found. Check and add subdomain SPF record manually!"
      continue
   fi


   _failed=false
   while read -r line || [[ -n "$line" ]]; do

      echo $line >> $_tmpfile

      if echo "$line" | grep -E "$search_string" > /dev/null 2>&1 ; then
         let _count--
      fi
      if [[ $_count -eq 0 ]]; then
         cat << EOF >> $_tmpfile

;
; DMARC
;
_dmarc               IN TXT   "v=DMARC1; p=none;"

EOF
         _count=-1

      fi
      [[ $? -ne 0 ]] && _failed=true
   done < "$zone_file"
   if $_failed ; then
      echo_failed
      rm $_tmpfile
   else
      echo_ok
      _replaced=true
   fi

   IFS=$CUR_IFS
   mv $_tmpfile $zone_file

   # - Set Correct Owner/Permission
   # -
   blank_line
   echononl "\t   Correct Owner for $(basename "$zone_file") .."
   chown $BIND_USER:$BIND_GROUP $zone_file
   if [[ $? -eq 0 ]] ; then
      echo_ok
   else
      echo_failed
      error "Setting ownership for '$zone_file' failed!"
   fi
   echononl "\t   Correct permissions on $(basename "$zone_file") .."
   chmod 644 $zone_file
   if [[ $? -eq 0 ]] ; then
      echo_ok
   else
      echo_failed
      error "Correct permissions on '$zone_file' failed!"
   fi


   # - Calculate new serial
   # -
   echo ""
   echononl "\t   Calculate new serial"
   if $_replaced ; then
      declare -i __serial=`grep -e "[0-9]\{10\}" $zone_file | grep serial | awk '{print$1}'`
      while [ ! $_serial_new -gt $__serial ]; do
         let _serial_new++
      done
      echo_done
   else
      echo_skipped
   fi

   # - Set new serial
   # -
   echononl "\t   Increase Serial for zone file \"`basename $zone_file`\""
   if $_replaced ; then
      perl -i -n -p -e "s#^(\s*)\s$__serial(.*)#\1 $_serial_new\2#" $zone_file > /dev/null 2>&1
      if [ "$?" = "0" ]; then
         echo_ok
      else
         echo_failed
         error "Increasing Serial for zone file \"`basename $zone_file`\" failed!"
      fi
   else
      echo_skipped
   fi

   # - Reload Zone
   # -
   echononl "\t   Reload zone '${zone}'"
   if $_replaced ; then
      /usr/sbin/rndc reload $zone > /dev/null 2>&1
      if [[ $? -gt 0 ]]; then
         echo_failed
      else
         echo_ok
      fi
   else
      echo_skipped
   fi

   echo

done

if [[ -d "${ZONE_FILE_MASTER_DIR}.${backup_date}" ]] ; then
   diff -Nur "${ZONE_FILE_MASTER_DIR}" "${ZONE_FILE_MASTER_DIR}.${backup_date}" > /dev/null 2>&1
   if [[ $? -eq 0 ]]; then
      info "No zone file has changed.\n\t          Removing previously created backup"
      echononl "\tDelete '${ZONE_FILE_MASTER_DIR}.${backup_date}'.."
      rm -rf "${ZONE_FILE_MASTER_DIR}.${backup_date}" > $log_file 2>&1
      if [[ $? -eq 0 ]]; then
         echo_ok
      else
         echo_failed
      fi
   fi
fi


echo ""
clean_up 0