#!/bin/bash
#
#   Bindle Binaries Linux Firewall
#   Copyright (c) 2019 David M. Syzdek <david@syzdek.net>.
#
#   Redistribution and use in source and binary forms, with or without
#   modification, are permitted provided that the following conditions are
#   met:
#
#      * Redistributions of source code must retain the above copyright
#        notice, this list of conditions and the following disclaimer.
#      * Redistributions in binary form must reproduce the above copyright
#        notice, this list of conditions and the following disclaimer in the
#        documentation and/or other materials provided with the distribution.
#      * Neither the name of David M. Syzdek nor the
#        names of its contributors may be used to endorse or promote products
#        derived from this software without specific prior written permission.
#
#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
#   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
#   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
#   PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DAVID M. SYZDEK BE LIABLE FOR
#   ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
#   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
#   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
#   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
#   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
#   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
#   SUCH DAMAGE.
#
#
#   Possible locations for firewall script:
#
#      /etc/rc.d/rc.firewall  - slackware init script
#      /usr/sbin/bbfw         - generic firewall script location
#
#   Files are processed in the following order:
#
#      /etc/firewall.d/global.d/pre-hook   - centrally maintained pre-hook script
#      /etc/firewall.d/apps.d/*/pre-hook   - app pre-hook script
#      /etc/firewall.d/cluster.d/pre-hook  - cluster specific pre-hook script
#      /etc/firewall.d/pre-hook            - host specific pre-hook script
#
#      /etc/firewall.d/global.d/ipsets     - centrally maintained IP sets
#      /etc/firewall.d/apps.d/*.ipsets     - app specific IP sets
#      /etc/firewall.d/cluster.d/ipsets    - cluster specific IP sets
#      /etc/firewall.d/ipsets              - host specific IP sets
#
#      /etc/firewall.d/apps.d/*.rules4     - app specific IPv4 firewall rules
#      /etc/firewall.d/apps.d/*.rules6     - app specific IPv6 firewall rules
#      /etc/firewall.d/apps.d/*.rules      - app specific IPv4/IPv6 firewall rules
#
#      /etc/firewall.d/rules4              - host specific IPv4 firewall rules
#      /etc/firewall.d/rules6              - host specific IPv6 firewall rules
#      /etc/firewall.d/rules               - host specific IPv4/IPv6 firewall rules
#
#      /etc/firewall.d/cluster.d/rules4    - cluster specific IPv4 firewall rules
#      /etc/firewall.d/cluster.d/rules6    - cluster specific IPv6 firewall rules
#      /etc/firewall.d/cluster.d/rules     - cluster specific IPv4/IPv6 firewall rules
#
#      /etc/firewall.d/global.d/rules4     - centrally maintained IPv4 rules
#      /etc/firewall.d/global.d/rules6     - centrally maintained IPv6 rules
#      /etc/firewall.d/global.d/rules      - centrally maintained IPv4/IPv6 rules
#
#      /etc/firewall.d/global.d/post-hook  - centrally maintained post-hook script
#      /etc/firewall.d/apps.d/*/post-hook  - app post-hook script
#      /etc/firewall.d/cluster.d/post-hook - host specific post-hook script
#      /etc/firewall.d/post-hook           - host specific post-hook script
#


###############
# ENVIRONMENT #
###############

PATH=/usr/bin:/bin:/usr/sbin:/sbin
export PATH


# determine prefix of conf files
FW_PREFIX=@sysconfdir@/firewall.d/
FW_CONF=@sysconfdir@/bbfw.conf
FW_QUIET=no
FW_VERBOSE=no
FW_ORDER_PRE="global apps cluster local"
FW_ORDER_POST="global apps cluster local"
FW_ORDER_IPSETS="global apps cluster local"
FW_ORDER_IPTABLES="apps local cluster global"


###########
# LOGGING #
###########

# sets script/package information
PROGRAM_NAME="$(basename "${0}")"
PACKAGE_NAME="$(echo '@PACKAGE_NAME@' |sed -e 's/[@].*[@]//g')"
PACKAGE_VERSION="$(echo '@PACKAGE_VERSION@' |sed -e 's/[@].*[@]//g')"
PACKAGE_BUGREPORT="$(echo '@PACKAGE_BUGREPORT@' |sed -e 's/[@].*[@]//g')"


# If possible, log events in /var/log/messages:
if [ -f /var/run/syslogd.pid -a -x logger ]; then
  LOGGER="logger -s -t ${PROGRAM_NAME}[$$]"
else # output to stdout/stderr:
  LOGGER="sed -e s/^/${PROGRAM_NAME}:/g"
fi


#############
# FUNCTIONS #
#############

clean_file()
{
   DIRTY_FILE="${1}"
   cut -d# -f1 "${DIRTY_FILE}" \
      |sed -n 'H; ${ x; s/\\\n//g; s/\n //g; p}' \
      |sed -e 's/[[:space:]]\{1,\}/ /g'
}


config_option()
{
   if test ! -f "${FW_CONF}";then
      echo "${2}" |tr "${3:-0}" "${4:-0}"
      return 0
   fi
   TMP_STR="$(
      egrep \
         -i \
         "^[[:space:]]{0,}${1}[[:space:]]{0,}=" \
         "${FW_CONF}" \
         |sed \
            -e "s/^[[:space:]]\{0,\}${1}[[:space:]]\{0,\}=[[:space:]]\{0,\}//g" \
            -e "s/[[:space:]]\{0,\}$//g" \
            -e "s/^[[:space:]]\{0,\}$//g"
   )"
   if test -z "${TMP_STR}";then
      echo "${2}"
   else
      echo "${TMP_STR}"
   fi |tr "${3:-0}" "${4:-0}"
}


dump()
{
   ipset list |sed -e "s/^/ipset: /g"
   echo ""
   for TABLE in $(iptables-save  |grep '^*' |sed -e 's/^*//g' |sort);do
      PREFIX="$(printf "%-9s" "${TABLE}:")"
      iptables -t ${TABLE} -L |sed -e "s/^/iptables ${PREFIX} /g"
      echo ""
   done
   for TABLE in $(ip6tables-save  |grep '^*' |sed -e 's/^*//g' |sort);do
      PREFIX="$(printf "%-9s" "${TABLE}:")"
      ip6tables -t ${TABLE} -L |sed -e "s/^/ip6tables ${PREFIX} /g"
      echo ""
   done
}


name_appfile()
{
   basename "$(dirname "${1}")"
}


find_appfile()
{
   find -L \
      ${FW_PREFIX}/apps.d/ \
      -regextype posix-extended \
      -regex "^${FW_PREFIX}/apps.d/[-.a-zA-Z0-9]+[./]${1}$" \
      -type f \
      2> /dev/null
}


run_hook()
{
   TYPE="${1}"
   FILE="${2}"
   DESC="${3}"

   if test ! -x "${FILE}";then
      return 0;
   fi

   if test ! -z "${DESC}" && test -z "${FW_QUIET}";then
      echo "${DESC}"
   fi

   ${FILE} ${TYPE}
}


load()
{
   TYPE="${1}"
   FILE="${2}"
   DESC="${3}"

   if test ! -f "${FILE}";then
      return 0;
   fi

   if test ! -z "${DESC}" && test -z "${FW_QUIET}";then
      echo "${DESC}"
   fi

   case "${TYPE}" in
      'ipset')     clean_file ${FILE} |ipset -! restore;;
      'iptables')  clean_file ${FILE} |iptables-restore -n ${FW_VERBOSE};;
      'ip6tables') clean_file ${FILE} |ip6tables-restore -n ${FW_VERBOSE};;
      *) ;;
   esac
}


# Function to start the network:
start() {
   # run pre-hooks
   for LEVEL in ${FW_ORDER_PRE};do
      case "${LEVEL}" in
         global)
         run_hook start ${FW_PREFIX}/global.d/pre-hook    "running global pre-hook start ..."
         ;;

         apps)
         for FILE in $( find_appfile pre-hook );do
            run_hook start ${FILE}                        "running app pre-hook start (App: $(name_appfile ${FILE})) ..."
         done
         ;;

         cluster)
         run_hook start ${FW_PREFIX}/cluster.d/pre-hook   "running cluster pre-hook start ..."
         ;;

         local)
         run_hook start ${FW_PREFIX}/pre-hook             "running local pre-hook start ..."
         ;;

         *)
         echo "Unknown pre-hook order \"${LEVEL}\""
         ;;
      esac
   done

   # create IP sets
   for LEVEL in ${FW_ORDER_IPSETS};do
      case "${LEVEL}" in
         global)
         load ipset ${FW_PREFIX}/global.d/ipsets          "adding global IP sets"
         ;;

         apps)
         for FILE in $( find_appfile ipsets );do
            load ipset ${FILE}                            "adding IP sets (App: $(name_appfile ${FILE})) ..."
         done
         ;;

         cluster)
         load ipset ${FW_PREFIX}/cluster.d/ipsets         "adding cluster IP sets"
         ;;

         local)
         load ipset ${FW_PREFIX}/ipsets                   "adding local IP sets"
         ;;

         *)
         echo "Unknown ipsets order \"${LEVEL}\""
         ;;
      esac
   done

   # loads iptables/ip6tables
   for LEVEL in ${FW_ORDER_IPTABLES};do
      case "${LEVEL}" in
         apps)
         for FILE in $( find_appfile rules4 );do
            load iptables ${FILE}                         "adding IPv4 rules (App: $(name_appfile ${FILE})) ..."
         done
         for FILE in $( find_appfile rules6 );do
            load ip6tables ${FILE}                        "adding IPv6 rules (App: $(name_appfile ${FILE})) ..."
         done
         for FILE in $( find_appfile rules );do
            load iptables ${FILE}                         "adding IPv4/IPv6 rules (App: $(name_appfile ${FILE})) ..."
            load ip6tables ${FILE}
         done
         ;;

         local)
         load iptables  ${FW_PREFIX}/rules4               "adding IPv4 local rules"
         load ip6tables ${FW_PREFIX}/rules6               "adding IPv6 local rules"
         load iptables  ${FW_PREFIX}/rules                "adding IPv4/IPv6 local rules"
         load ip6tables ${FW_PREFIX}/rules
         ;;

         cluster)
         load iptables  ${FW_PREFIX}/cluster.d/rules4     "adding IPv4 cluster rules"
         load ip6tables ${FW_PREFIX}/cluster.d/rules6     "adding IPv6 cluster rules"
         load iptables  ${FW_PREFIX}/cluster.d/rules      "adding IPv4/IPv6 cluster rules"
         load ip6tables ${FW_PREFIX}/cluster.d/rules
         ;;

         global)
         load iptables  ${FW_PREFIX}/global.d/rules4      "adding IPv4 global rules"
         load ip6tables ${FW_PREFIX}/global.d/rules6      "adding IPv6 global rules"
         load iptables  ${FW_PREFIX}/global.d/rules       "adding IPv4/IPv6 global rules"
         load ip6tables ${FW_PREFIX}/global.d/rules
         ;;

         *)
         echo "Unknown iptables order \"${LEVEL}\""
         ;;
      esac
   done

   # run post-hooks
   for LEVEL in ${FW_ORDER_POST};do
      case "${LEVEL}" in
         global)
         run_hook start ${FW_PREFIX}/global.d/post-hook   "running global post-hook start ..."
         ;;

         apps)
         for FILE in $( find_appfile post-hook );do
            run_hook start ${FILE}                        "running app post-hook start (App: $(name_appfile ${FILE})) ..."
         done
         ;;

         cluster)
         run_hook start ${FW_PREFIX}/cluster.d/post-hook  "running cluster post-hook start ..."
         ;;

         local)
         run_hook start ${FW_PREFIX}/post-hook            "running local post-hook start ..."
         ;;

         *)
         echo "Unknown post-hook order \"${LEVEL}\""
         ;;
      esac
   done
}


# Function to stop the network:
stop() {
   # run pre-hooks
   for LEVEL in ${FW_ORDER_PRE};do
      case "${LEVEL}" in
         global)
         run_hook stop ${FW_PREFIX}/global.d/pre-hook     "running global pre-hook stop ..."
         ;;

         apps)
         for FILE in $( find_appfile pre-hook );do
            run_hook stop ${FILE}                         "running app pre-hook stop (App: $(name_appfile ${FILE})) ..."
         done
         ;;

         cluster)
         run_hook stop ${FW_PREFIX}/cluster.d/pre-hook    "running cluster pre-hook stop ..."
         ;;

         local)
         run_hook stop ${FW_PREFIX}/pre-hook              "running local pre-hook stop ..."
         ;;

         *)
         echo "Unknown pre-hook order \"${LEVEL}\""
         ;;
      esac
   done

   # flushes iptables
   for TABLE in $(iptables-save  |grep '^*' |sed -e 's/^*//g' |sort);do
      if test -z "${FW_QUIET}";then
         echo "Flushing rules from ${TABLE} table (IPv4)"
      fi
      for CHAIN in $(iptables-save -t ${TABLE} |grep '^:' |cut -d: -f2 |grep -v ' - ' |cut -d\  -f1);do
         iptables -t ${TABLE} -P ${CHAIN} ACCEPT
      done
      iptables -t ${TABLE} -F
      for CHAIN in $(iptables-save -t ${TABLE} |grep '^:' |cut -d: -f2 |grep ' - ' |cut -d\  -f1);do
         iptables -t ${TABLE} -X ${CHAIN}
      done
   done 2> /dev/null

   # flushes ip6tables
   for TABLE in $(ip6tables-save  |grep '^*' |sed -e 's/^*//g' |sort);do
      if test -z "${FW_QUIET}";then
         echo "Flushing rules from ${TABLE} table (IPv6)"
      fi
      for CHAIN in $(ip6tables-save -t ${TABLE} |grep '^:' |cut -d: -f2 |grep -v ' - ' |cut -d\  -f1);do
         ip6tables -t ${TABLE} -P ${CHAIN} ACCEPT
      done
      ip6tables -t ${TABLE} -F
      for CHAIN in $(ip6tables-save -t ${TABLE} |grep '^:' |cut -d: -f2 |grep ' - ' |cut -d\  -f1);do
         ip6tables -t ${TABLE} -X ${CHAIN}
      done
   done 2> /dev/null

   # flushes ipsets
   if test -z "${FW_QUIET}";then
      echo "Destroying all IP sets ..."
   fi
   for SET in $(ipset save |grep '^create' |grep ' list:' |awk '{print$2}');do
      ipset destroy "${SET}"
   done
   for SET in $(ipset save |grep '^create' |awk '{print$2}');do
      ipset destroy "${SET}"
   done

   # run post-hooks
   for LEVEL in ${FW_ORDER_POST};do
      case "${LEVEL}" in
         global)
         run_hook stop ${FW_PREFIX}/global.d/post-hook   "running global post-hook stop ..."
         ;;

         apps)
         for FILE in $( find_appfile post-hook );do
            run_hook stop ${FILE}                        "running app post-hook stop (App: $(name_appfile ${FILE})) ..."
         done
         ;;

         cluster)
         run_hook stop ${FW_PREFIX}/cluster.d/post-hook  "running cluster post-hook stop ..."
         ;;

         local)
         run_hook stop ${FW_PREFIX}/post-hook            "running local post-hook stop ..."
         ;;

         *)
         echo "Unknown post-hook order \"${LEVEL}\""
         ;;
      esac
   done
}


############
### MAIN ###
############

# sets options from configuration file
FW_PREFIX="$(         config_option firewall_dir     "${FW_PREFIX}" )"
FW_QUIET="$(          config_option quiet            "${FW_QUIET}"          A-Z a-z )"
FW_VERBOSE="$(        config_option verbose          "${FW_VERBOSE}"        A-Z a-z )"
FW_ORDER_PRE="$(      config_option order_prehook    "${FW_ORDER_PRE}"      A-Z a-z )"
FW_ORDER_POST="$(     config_option order_posthook   "${FW_ORDER_POST}"     A-Z a-z )"
FW_ORDER_IPTABLES="$( config_option order_iptables   "${FW_ORDER_IPTABLES}" A-Z a-z )"
FW_ORDER_IPSETS="$(   config_option order_ipsets     "${FW_ORDER_IPSETS}"   A-Z a-z )"


# checks and normalizes options
if test "x${FW_QUIET}" == "xno";then
   unset FW_QUIET
elif test "x${FW_QUIET}" != "xyes";then
   echo "${PROGRAM_NAME}: invalid value for option 'quiet'" 1>&2
   exit 1
fi
if test "x${FW_VERBOSE}" == "xno";then
   unset FW_VERBOSE
elif test "x${FW_VERBOSE}" != "xyes";then
   echo "${PROGRAM_NAME}: invalid value for verbose 'quiet'" 1>&2
   exit 1
else
   FW_VERBOSE=-v
fi


case "$1" in
   -h|--help)
      echo "Usage: ${PROGRAM_NAME} [ start | stop | restart | dump ]"
      echo "       ${PROGRAM_NAME} [ -h | --help ]"
      echo "       ${PROGRAM_NAME} [ -v | --version ]"
      echo ""
   ;;

   -v|--version)
      echo "${PACKAGE_NAME} ${PACKAGE_VERSION} (bbfw)"
   ;;

   'dump')
      dump
   ;;

   'start') # "start" brings up all configured interfaces:
      echo "${PACKAGE_NAME} ${PACKAGE_VERSION}" | $LOGGER
      start 2>&1 | $LOGGER
   ;;

   'stop') # "stop" takes down all configured interfaces:
      echo "${PACKAGE_NAME} ${PACKAGE_VERSION}" | $LOGGER
      stop  2>&1 | $LOGGER
   ;;

   'restart') # "restart" restarts the network:
      echo "${PACKAGE_NAME} ${PACKAGE_VERSION}" | $LOGGER
      stop  2>&1 | $LOGGER
      start 2>&1 | $LOGGER
   ;;

   *) # The default is to bring up all configured interfaces:
      echo "Usage: ${PROGRAM_NAME} [ start | stop | restart | dump ]"
      echo "       ${PROGRAM_NAME} [ -h | --help ]"
      echo "       ${PROGRAM_NAME} [ -v | --version ]"
      echo ""
   ;;
esac

# End of scripts