change_rules.sh revision 77815 
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: head/share/examples/ipfw/change_rules.sh 77815 2001-06-06 15:45:04Z dcs $
28
29# Change ipfw(8) rules with safety guarantees for remote operation
30#
31# Invoke this script to edit rc.firewall. It will call ${EDITOR}, or
32# vi(1) if the environment variable is not set, for you to edit rc.firewall,
33# asks for confirmation and then run rc.firewall. You can then examine
34# the output of ipfw list and confirm whether you want the new version or
35# not.
36#
37# If no answer is received in 30 seconds, the previous rc.firewall is
38# run, restoring the old rules (this assumes ipfw flush is present in
39# it).
40#
41# If the new rules are confirmed, they'll replace rc.firewall and the
42# previous ones will be copied to rc.firewall.{date}. A mail will also
43# be sent to root with the unified diffs of the rule change.
44#
45# Non-approved rules are kept in rc.firewall.new, and you are offered
46# the option of changing them instead of the present rules when you
47# call this script.
48#
49# It is suggested improving this script by using some version control
50# software.
51
52get_yes_no() {
53	while true
54	do
55		echo -n "$1 (Y/N) ? " 
56		read -t 30 a
57		if [ $? != 0 ]; then
58			a="No";
59		        return;
60		fi
61		case $a in
62			[Yy]) a="Yes";
63			      return;;
64			[Nn]) a="No";
65			      return;;
66			*);;
67		esac
68	done
69}
70
71restore_rules() {
72	nohup sh /etc/rc.firewall >/dev/null 2>&1 
73	exit
74}
75
76if [ -f /etc/rc.firewall.new ]; then
77	get_yes_no "A new rules file already exists, do you want to use it"
78	[ $a = 'No' ] && cp /etc/rc.firewall /etc/rc.firewall.new
79else 
80	cp /etc/rc.firewall /etc/rc.firewall.new
81fi
82
83trap restore_rules SIGHUP
84
85vi /etc/rc.firewall.new
86
87get_yes_no "Do you want to install the new rules"
88
89[ $a = 'No' ] && exit
90
91cat <<!
92The rules will be changed now. If the message 'Type y to keep the new rules'
93do not appear on the screen or the y key is not pressed in 30 seconds, the
94former rules will be restored.
95The TCP/IP connections might be broken during the change. If so, restore
96the ssh/telnet connection being used.
97!
98
99nohup sh /etc/rc.firewall.new > /tmp/rc.firewall.out 2>&1;
100sleep 2;
101get_yes_no "Would you like to see the resulting new rules"
102[ $a = 'Yes' ] && vi /tmp/rc.firewall.out
103get_yes_no "Type y to keep the new rules"
104[ $a != 'Yes' ] && restore_rules
105
106DATE=`date "+%Y%m%d%H%M"`
107cp /etc/rc.firewall /etc/rc.firewall.$DATE
108mv /etc/rc.firewall.new /etc/rc.firewall
109cat <<!
110The new rules are now default. The previous rules have been preserved
111in the file /etc/rc.firewall.$DATE
112!
113diff -F "^# .*[A-Za-z]" -u /etc/rc.firewall.$DATE /etc/rc.firewall | mail -s "`hostname` Firewall rule change" root
114
115