#!/bin/sh

set -e

[ "$1" = "configure" ] || exit 0
[ "$DEBIAN_SCRIPT_DEBUG" ] && set -vx

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

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

# check to see if fail2ban is installed
if dpkg-query -f '${Status}' -W fail2ban | grep -q installed; 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 /etc/iptables/rules.v4"
    iptables-save > /etc/iptables/rules.v4
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 /etc/iptables/rules.v4 ]; 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 /etc/iptables/rules.v4"
        iptables-save > /etc/iptables/rules.v4
    fi
fi

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

#DEBHELPER#

exit 0