1#!/bin/sh 2# 3# Copyright (c) 2000 Alexandre Peixoto 4# All rights reserved. 5# 6# Redistribution and use in source and binary forms, with or without 7# modification, are permitted provided that the following conditions 8# are met: 9# 1. Redistributions of source code must retain the above copyright 10# notice, this list of conditions and the following disclaimer. 11# 2. Redistributions in binary form must reproduce the above copyright 12# notice, this list of conditions and the following disclaimer in the 13# documentation and/or other materials provided with the distribution. 14# 15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25# SUCH DAMAGE. 26# 27# $FreeBSD$ 28 29# Change ipfw(8) rules with safety guarantees for remote operation 30# 31# Invoke this script to edit ${firewall_script}. It will call ${EDITOR}, 32# or vi(1) if the environment variable is not set, for you to edit 33# ${firewall_script}, asks for confirmation and then run 34# ${firewall_script}. You can then examine the output of ipfw list and 35# confirm whether you want the new version or not. 36# 37# If no answer is received in 30 seconds, the previous 38# ${firewall_script} is run, restoring the old rules (this assumes ipfw 39# flush is present in it). 40# 41# If the new rules are confirmed, they'll replace ${firewall_script} and 42# the previous ones will be copied to ${firewall_script}.{date}. A mail 43# will also be sent to root with the unified diffs of the rule change. 44# 45# Non-approved rules are kept in ${firewall_script}.new, and you are 46# offered the option of changing them instead of the present rules when 47# you call this script. 48# 49# It is suggested improving this script by using some version control 50# software. 51 52if [ -r /etc/defaults/rc.conf ]; then 53 . /etc/defaults/rc.conf 54 source_rc_confs 55elif [ -r /etc/rc.conf ]; then 56 . /etc/rc.conf 57fi 58 59EDITOR=${EDITOR:-/usr/bin/vi} 60 61get_yes_no() { 62 while true 63 do 64 echo -n "$1 (Y/N) ? " 65 read -t 30 a 66 if [ $? != 0 ]; then 67 a="No"; 68 return; 69 fi 70 case $a in 71 [Yy]) a="Yes"; 72 return;; 73 [Nn]) a="No"; 74 return;; 75 *);; 76 esac 77 done 78} 79 80restore_rules() { 81 nohup sh ${firewall_script} >/dev/null 2>&1 82 exit 83} 84 85if [ -f ${firewall_script}.new ]; then 86 get_yes_no "A new rules file already exists, do you want to use it" 87 [ $a = 'No' ] && cp ${firewall_script} ${firewall_script}.new 88else 89 cp ${firewall_script} ${firewall_script}.new 90fi 91 92trap restore_rules SIGHUP 93 94${EDITOR} ${firewall_script}.new 95 96get_yes_no "Do you want to install the new rules" 97 98[ $a = 'No' ] && exit 99 100cat <<! 101The rules will be changed now. If the message 'Type y to keep the new 102rules' do not appear on the screen or the y key is not pressed in 30 103seconds, the former rules will be restored. 104The TCP/IP connections might be broken during the change. If so, restore 105the ssh/telnet connection being used. 106! 107 108nohup sh ${firewall_script}.new > /tmp/`basename ${firewall_script}`.out 2>&1; 109sleep 2; 110get_yes_no "Would you like to see the resulting new rules" 111[ $a = 'Yes' ] && ${EDITOR} /tmp/`basename ${firewall_script}`.out 112get_yes_no "Type y to keep the new rules" 113[ $a != 'Yes' ] && restore_rules 114 115DATE=`date "+%Y%m%d%H%M"` 116cp ${firewall_script} ${firewall_script}.$DATE 117mv ${firewall_script}.new ${firewall_script} 118cat <<! 119The new rules are now default. The previous rules have been preserved in 120the file ${firewall_script}.$DATE 121! 122diff -F "^# .*[A-Za-z]" -u ${firewall_script}.$DATE ${firewall_script} | mail -s "`hostname` Firewall rule change" root 123 124