rc.firewall revision 65257
1############ 2# Setup system for firewall service. 3# $FreeBSD: head/etc/rc.firewall 65257 2000-08-30 13:14:32Z ru $ 4 5# Suck in the configuration variables. 6if [ -r /etc/defaults/rc.conf ]; then 7 . /etc/defaults/rc.conf 8 source_rc_confs 9elif [ -r /etc/rc.conf ]; then 10 . /etc/rc.conf 11fi 12 13############ 14# Define the firewall type in /etc/rc.conf. Valid values are: 15# open - will allow anyone in 16# client - will try to protect just this machine 17# simple - will try to protect a whole network 18# closed - totally disables IP services except via lo0 interface 19# UNKNOWN - disables the loading of firewall rules. 20# filename - will load the rules in the given filename (full path required) 21# 22# For ``client'' and ``simple'' the entries below should be customized 23# appropriately. 24 25############ 26# 27# If you don't know enough about packet filtering, we suggest that you 28# take time to read this book: 29# 30# Building Internet Firewalls 31# Brent Chapman and Elizabeth Zwicky 32# 33# O'Reilly & Associates, Inc 34# ISBN 1-56592-124-0 35# http://www.ora.com/ 36# 37# For a more advanced treatment of Internet Security read: 38# 39# Firewalls & Internet Security 40# Repelling the wily hacker 41# William R. Cheswick, Steven M. Bellowin 42# 43# Addison-Wesley 44# ISBN 0-201-6337-4 45# http://www.awl.com/ 46# 47 48if [ -n "${1}" ]; then 49 firewall_type="${1}" 50fi 51 52############ 53# Set quiet mode if requested 54# 55case ${firewall_quiet} in 56[Yy][Ee][Ss]) 57 fwcmd="/sbin/ipfw -q" 58 ;; 59*) 60 fwcmd="/sbin/ipfw" 61 ;; 62esac 63 64############ 65# Flush out the list before we begin. 66# 67${fwcmd} -f flush 68 69############ 70# Network Address Translation. All packets are passed to natd(8) 71# before they encounter your remaining rules. The firewall rules 72# will then be run again on each packet after translation by natd 73# starting at the rule number following the divert rule. 74# 75# For ``simple'' firewall type the divert rule should be put to a 76# different place to not interfere with address-checking rules. 77# 78case ${firewall_type} in 79[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 80 case ${natd_enable} in 81 [Yy][Ee][Ss]) 82 if [ -n "${natd_interface}" ]; then 83 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 84 fi 85 ;; 86 esac 87esac 88 89############ 90# If you just configured ipfw in the kernel as a tool to solve network 91# problems or you just want to disallow some particular kinds of traffic 92# then you will want to change the default policy to open. You can also 93# do this as your only action by setting the firewall_type to ``open''. 94# 95# ${fwcmd} add 65000 pass all from any to any 96 97############ 98# Only in rare cases do you want to change these rules 99# 100${fwcmd} add 100 pass all from any to any via lo0 101${fwcmd} add 200 deny all from any to 127.0.0.0/8 102# If you're using 'options BRIDGE', uncomment the following line to pass ARP 103#${fwcmd} add 300 pass udp from 0.0.0.0 2054 to 0.0.0.0 104 105 106# Prototype setups. 107# 108case ${firewall_type} in 109[Oo][Pp][Ee][Nn]) 110 ${fwcmd} add 65000 pass all from any to any 111 ;; 112 113[Cc][Ll][Ii][Ee][Nn][Tt]) 114 ############ 115 # This is a prototype setup that will protect your system somewhat 116 # against people from outside your own network. 117 ############ 118 119 # set these to your network and netmask and ip 120 net="192.0.2.0" 121 mask="255.255.255.0" 122 ip="192.0.2.1" 123 124 # Allow any traffic to or from my own net. 125 ${fwcmd} add pass all from ${ip} to ${net}:${mask} 126 ${fwcmd} add pass all from ${net}:${mask} to ${ip} 127 128 # Allow TCP through if setup succeeded 129 ${fwcmd} add pass tcp from any to any established 130 131 # Allow IP fragments to pass through 132 ${fwcmd} add pass all from any to any frag 133 134 # Allow setup of incoming email 135 ${fwcmd} add pass tcp from any to ${ip} 25 setup 136 137 # Allow setup of outgoing TCP connections only 138 ${fwcmd} add pass tcp from ${ip} to any setup 139 140 # Disallow setup of all other TCP connections 141 ${fwcmd} add deny tcp from any to any setup 142 143 # Allow DNS queries out in the world 144 ${fwcmd} add pass udp from any 53 to ${ip} 145 ${fwcmd} add pass udp from ${ip} to any 53 146 147 # Allow NTP queries out in the world 148 ${fwcmd} add pass udp from any 123 to ${ip} 149 ${fwcmd} add pass udp from ${ip} to any 123 150 151 # Everything else is denied by default, unless the 152 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 153 # config file. 154 ;; 155 156[Ss][Ii][Mm][Pp][Ll][Ee]) 157 ############ 158 # This is a prototype setup for a simple firewall. Configure this 159 # machine as a named server and ntp server, and point all the machines 160 # on the inside at this machine for those services. 161 ############ 162 163 # set these to your outside interface network and netmask and ip 164 oif="ed0" 165 onet="192.0.2.0" 166 omask="255.255.255.240" 167 oip="192.0.2.1" 168 169 # set these to your inside interface network and netmask and ip 170 iif="ed1" 171 inet="192.0.2.16" 172 imask="255.255.255.240" 173 iip="192.0.2.17" 174 175 # Stop spoofing 176 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 177 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 178 179 # Stop RFC1918 nets on the outside interface 180 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 181 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 182 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 183 184 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 185 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 186 # on the outside interface 187 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 188 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 189 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 190 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 191 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 192 193 # Network Address Translation. This rule is placed here deliberately 194 # so that it does not interfere with the surrounding address-checking 195 # rules. If for example one of your internal LAN machines had its IP 196 # address set to 192.0.2.1 then an incoming packet for it after being 197 # translated by natd(8) would match the `deny' rule above. Similarly 198 # an outgoing packet originated from it before being translated would 199 # match the `deny' rule below. 200 case ${natd_enable} in 201 [Yy][Ee][Ss]) 202 if [ -n "${natd_interface}" ]; then 203 ${fwcmd} add divert natd all from any to any via ${natd_interface} 204 fi 205 ;; 206 esac 207 208 # Stop RFC1918 nets on the outside interface 209 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 210 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 211 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 212 213 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 214 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 215 # on the outside interface 216 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 217 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 218 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 219 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 220 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 221 222 # Allow TCP through if setup succeeded 223 ${fwcmd} add pass tcp from any to any established 224 225 # Allow IP fragments to pass through 226 ${fwcmd} add pass all from any to any frag 227 228 # Allow setup of incoming email 229 ${fwcmd} add pass tcp from any to ${oip} 25 setup 230 231 # Allow access to our DNS 232 ${fwcmd} add pass tcp from any to ${oip} 53 setup 233 ${fwcmd} add pass udp from any to ${oip} 53 234 ${fwcmd} add pass udp from ${oip} 53 to any 235 236 # Allow access to our WWW 237 ${fwcmd} add pass tcp from any to ${oip} 80 setup 238 239 # Reject&Log all setup of incoming connections from the outside 240 ${fwcmd} add deny log tcp from any to any in via ${oif} setup 241 242 # Allow setup of any other TCP connection 243 ${fwcmd} add pass tcp from any to any setup 244 245 # Allow DNS queries out in the world 246 ${fwcmd} add pass udp from any 53 to ${oip} 247 ${fwcmd} add pass udp from ${oip} to any 53 248 249 # Allow NTP queries out in the world 250 ${fwcmd} add pass udp from any 123 to ${oip} 251 ${fwcmd} add pass udp from ${oip} to any 123 252 253 # Everything else is denied by default, unless the 254 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 255 # config file. 256 ;; 257 258[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 259 ;; 260*) 261 if [ -r "${firewall_type}" ]; then 262 ${fwcmd} ${firewall_flags} ${firewall_type} 263 fi 264 ;; 265esac 266