#!/bin/sh
# postinst script for bind9-cn
#
# see: dh_installdeb(1)

set -e

# summary of how this script can be called:
#        * <postinst> `configure' <most-recently-configured-version>
#        * <old-postinst> `abort-upgrade' <new version>
#        * <conflictor's-postinst> `abort-remove' `in-favour' <package>
#          <new-version>
#        * <deconfigured's-postinst> `abort-deconfigure' `in-favour'
#          <failed-install-package> <version> `removing'
#          <conflicting-package> <version>
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package
#

case "$1" in
    configure|reconfigure)
      # continue below
    ;;

    *)
        exit 0
    ;;
esac

# fix problem with permissions from the old package
if dpkg --compare-versions "$2" lt "2:1.2.11-4"; then
    chown -f -Rh root:root /var/lib/iptables /etc/init.d/iptables \
		/etc/default/iptables >/dev/null 2>&1 || true
fi

# remove old iptables init script
update-rc.d -f iptables remove >/dev/null 2>&1 || true

# check if old default file exists and import it
if [ -e /etc/default/iptables ]; then
    mv /etc/default/iptables /etc/default/iptables-cn
fi

# check to see if fail2ban is installed
if dpkg -l fail2ban | grep -q '^.i'; then
    echo "CN: Detected Fail2Ban installation, will remove SSH bruteforce rules by default"
    iptables -D SSH_Brute_Force -m recent ! --rcheck --seconds 90 \
        --hitcount 3 --name SSH --rsource \
        -j RETURN >/dev/null 2>&1 || true
    iptables -D SSH_Brute_Force -p tcp -j REJECT \
        --reject-with icmp-port-unreachable >/dev/null 2>&1 || true
    iptables -D INPUT -p tcp -m tcp --dport 22 -m state \
        --state NEW -m recent --set --name SSH --rsource \
        -j SSH_Brute_Force >/dev/null 2>&1 || true
    iptables -X SSH_Brute_Force >/dev/null 2>&1 || true

    echo "CN: Saving current Netfilter rules to /var/lib/iptables/active"
    iptables-save > /var/lib/iptables/active
else
    # check if there is any default netfilter policy and install default SSH
    # REJECT recent if there is none..
    # also, save current set of rules into active and inactive configuration
    if [ ! -e /var/lib/iptables/active ]; then
        if ! iptables-save | grep '^-' >/dev/null; then
            echo "CN: Netfilter rules empty: importing SSH bruteforce rules"
            /usr/share/doc/iptables-cn/examples/ssh-bruteforce \
                1>/dev/null 2>&1 || true
        fi
        echo "CN: Saving current Netfilter rules to /var/lib/iptables/active"
        iptables-save > /var/lib/iptables/active
    fi
fi

# create inactive
if [ ! -e /var/lib/iptables/inactive ]; then
    touch /var/lib/iptables/inactive
fi

# dh_installdeb will replace this with shell code automatically
# generated by other debhelper scripts.

#DEBHELPER#

exit 0