share/examples/ipfw/change_rules.sh

   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: src/share/examples/ipfw/change_rules.sh,v 1.2.2.4 2003/02/16 10:02:42 brueffer Exp $
  28 # $DragonFly: src/share/examples/ipfw/change_rules.sh,v 1.2 2003/06/17 04:36:57 dillon Exp $
  29
  30 # Change ipfw(8) rules with safety guarantees for remote operation
  31 #
  32 # Invoke this script to edit ${firewall_script}. It will call ${EDITOR},
  33 # or vi(1) if the environment variable is not set, for you to edit
  34 # ${firewall_script}, ask for confirmation, and then run
  35 # ${firewall_script}. You can then examine the output of ipfw list and
  36 # confirm whether you want the new version or not.
  37 #
  38 # If no answer is received in 30 seconds, the previous
  39 # ${firewall_script} is run, restoring the old rules (this assumes ipfw
  40 # flush is present in it).
  41 #
  42 # If the new rules are confirmed, they'll replace ${firewall_script} and
  43 # the previous ones will be copied to ${firewall_script}.{date}. Mail
  44 # will also be sent to root with a unified diff of the rule change.
  45 #
  46 # Unapproved rules are kept in ${firewall_script}.new, and you are
  47 # offered the option of changing them instead of the present rules when
  48 # you call this script.
  49 #
  50 # This script could be improved by using version control
  51 # software.
  52
  53 if [ -r /etc/defaults/rc.conf ]; then
  54         . /etc/defaults/rc.conf
  55         source_rc_confs
  56 elif [ -r /etc/rc.conf ]; then
  57         . /etc/rc.conf
  58 fi
  59
  60 EDITOR=${EDITOR:-/usr/bin/vi}
  61 PAGER=${PAGER:-/usr/bin/more}
  62
  63 tempfoo=`basename $0`
  64 TMPFILE=`mktemp -t ${tempfoo}` || exit 1
  65
  66 get_yes_no() {
  67         while true
  68         do
  69                 echo -n "$1 (Y/N) ? "
  70                 read -t 30 a
  71                 if [ $? != 0 ]; then
  72                         a="No";
  73                         return;
  74                 fi
  75                 case $a in
  76                         [Yy]) a="Yes";
  77                               return;;
  78                         [Nn]) a="No";
  79                               return;;
  80                         *);;
  81                 esac
  82         done
  83 }
  84
  85 restore_rules() {
  86         nohup sh ${firewall_script} >/dev/null 2>&1
  87         rm ${TMPFILE}
  88         exit 1
  89 }
  90
  91 case "${firewall_type}" in
  92 [Cc][Ll][Ii][Ee][Nn][Tt]|\
  93 [Cc][Ll][Oo][Ss][Ee][Dd]|\
  94 [Oo][Pp][Ee][Nn]|\
  95 [Ss][Ii][Mm][Pp][Ll][Ee]|\
  96 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
  97         edit_file="${firewall_script}"
  98         rules_edit=no
  99         ;;
 100 *)
 101         if [ -r "${firewall_type}" ]; then
 102                 edit_file="${firewall_type}"
 103                 rules_edit=yes
 104         fi
 105         ;;
 106 esac
 107
 108 if [ -f ${edit_file}.new ]; then
 109         get_yes_no "A new rules file already exists, do you want to use it"
 110         [ $a = 'No' ] && cp ${edit_file} ${edit_file}.new
 111 else
 112         cp ${edit_file} ${edit_file}.new
 113 fi
 114
 115 trap restore_rules SIGHUP
 116
 117 ${EDITOR} ${edit_file}.new
 118
 119 get_yes_no "Do you want to install the new rules"
 120
 121 [ $a = 'No' ] && exit 1
 122
 123 cat <<!
 124 The rules will be changed now. If the message 'Type y to keep the new
 125 rules' does not appear on the screen or the y key is not pressed in 30
 126 seconds, the original rules will be restored.
 127 The TCP/IP connections might be broken during the change. If so, restore
 128 the ssh/telnet connection being used.
 129 !
 130
 131 if [ ${rules_edit} = yes ]; then
 132         nohup sh ${firewall_script} ${firewall_type}.new \
 133             > ${TMPFILE} 2>&1
 134 else
 135         nohup sh ${firewall_script}.new \
 136             > ${TMPFILE} 2>&1
 137 fi
 138 sleep 2;
 139 get_yes_no "Would you like to see the resulting new rules"
 140 [ $a = 'Yes' ] && ${PAGER} ${TMPFILE}
 141 get_yes_no "Type y to keep the new rules"
 142 [ $a != 'Yes' ] && restore_rules
 143
 144 DATE=`date "+%Y%m%d%H%M"`
 145 cp ${edit_file} ${edit_file}.$DATE
 146 mv ${edit_file}.new ${edit_file}
 147 cat <<!
 148 The new rules are now installed. The previous rules have been preserved in
 149 the file ${edit_file}.$DATE
 150 !
 151 diff -F "^# .*[A-Za-z]" -u ${edit_file}.$DATE ${edit_file} \
 152     | mail -s "`hostname` Firewall rule change" root
 153 rm ${TMPFILE}
 154 exit 0