mdw@git.distorted.org.uk Git - firewall/blob - local.m4

   1 ### -*-sh-*-
   2 ###
   3 ### Local firewall configuration
   4 ###
   5 ### (c) 2008 Mark Wooding
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This program is free software; you can redistribute it and/or modify
  11 ### it under the terms of the GNU General Public License as published by
  12 ### the Free Software Foundation; either version 2 of the License, or
  13 ### (at your option) any later version.
  14 ###
  15 ### This program is distributed in the hope that it will be useful,
  16 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ### GNU General Public License for more details.
  19 ###
  20 ### You should have received a copy of the GNU General Public License
  21 ### along with this program; if not, write to the Free Software Foundation,
  22 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23
  24 ###--------------------------------------------------------------------------
  25 ### Local configuration.
  26
  27 m4_divert(6)m4_dnl
  28 ## Default NTP servers.
  29 defconf(ntp_servers,
  30         "158.152.1.76 158.152.1.204 194.159.253.2 195.173.57.232")
  31
  32 m4_divert(-1)
  33 ###--------------------------------------------------------------------------
  34 ### Packet classification.
  35
  36 ## IPv4 addressing.
  37 ##
  38 ## There are two small blocks of publicly routable IPv4 addresses, and a
  39 ## block of RFC1918 private-use addresses allocated from the Cambridge G-RIN.
  40 ## The former are as follows.
  41 ##
  42 ## 62.49.204.144/28
  43 ##              House border network (dmz).  We have all of these, but .145
  44 ##              is reserved for the router.
  45 ##
  46 ## 212.13.18.64/28
  47 ##              Jump colocated network (jump).  .65--68 are used by Jump
  48 ##              network infrastructure; we get the rest.
  49 ##
  50 ## The latter is the block 172.29.196.0/22.  Currently the low half is
  51 ## unallocated (and may be returned to the G-RIN); the remaining addresses
  52 ## are allocated as follows.
  53 ##
  54 ## 172.29.198.0/24  Untrusted networks.
  55 ##      .0/25           house wireless net
  56 ##      .128/28         iodine (IP-over-DNS) network
  57 ##
  58 ## 172.29.199.0/24  Trusted networks.
  59 ##      .0/25           house wired network
  60 ##      .128/27         mobile VPN hosts
  61 ##      .160/28         reserved, except .160/30 allocated for ITS
  62 ##      .176/28         internal colocated network
  63 ##      .192/27         house safe network
  64 ##      .224/27         anycast services
  65
  66 ## IPv6 addressing.
  67 ##
  68 ## There are five blocks of publicly routable IPv6 addresses, though some of
  69 ## them aren't very interesting.  The ranges are as follows.
  70 ##
  71 ## 2001:470:1f08:1b98::/64
  72 ##              Hurricane Electric tunnel network: only :1 (HE) and :2
  73 ##              (radius) are used.
  74 ##
  75 ## 2001:470:1f09:1b98::/64
  76 ##              House border network (dmz).
  77 ##
  78 ## 2001:470:9740::/48
  79 ##              Main house range.  See below for allocation policy.
  80 ##
  81 ## 2001:ba8:0:1d9::/64
  82 ##              Jump border network (jump): :1 is the router (supplied by
  83 ##              Jump); other addresses are ours.
  84 ##
  85 ## 2001:ba8:1d9::/48
  86 ##              Main colocated range.  See below for allocation policy.
  87 ##
  88 ## Addresses in the /64 networks are simply allocated in ascending order.
  89 ## The /48s are split into /64s by appending a 16-bit network number.  The
  90 ## top nibble of the network number classifies the network, as follows.
  91 ##
  92 ## 8xxx         Untrusted
  93 ## 6xxx         Virtual, safe
  94 ## 4xxx         Safe
  95 ## 0xxx         Unsafe, trusted
  96 ##
  97 ## These have been chosen so that network properties can be deduced by
  98 ## inspecting bits of the network number:
  99 ##
 100 ## Bit 15       If set, the network is untrusted; otherwise it is trusted.
 101 ## Bit 14       If set, the network is safe; otherwise it is unsafe.
 102 ##
 103 ## Finally, the low-order nibbles identify the site.
 104 ##
 105 ## 0            No specific site: mobile VPN endpoints or anycast addresses.
 106 ## 1            House.
 107 ## 2            Jump colocation.
 108 ##
 109 ## Usually site-0 networks are allocated from the Jump range to improve
 110 ## expected performance from/to external sites which don't engage in our
 111 ## dynamic routing protocols.
 112
 113 ## Define the available network classes.
 114 m4_divert(42)m4_dnl
 115 defnetclass untrusted   untrusted trusted             mcast
 116 defnetclass trusted     untrusted trusted safe noloop mcast
 117 defnetclass safe                  trusted safe noloop mcast
 118 defnetclass noloop                trusted safe        mcast
 119
 120 defnetclass link
 121 defnetclass mcast
 122 m4_divert(-1)
 123
 124 m4_divert(26)m4_dnl
 125 ###--------------------------------------------------------------------------
 126 ### Network layout.
 127
 128 ## House networks.
 129 defnet dmz trusted
 130         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 131         via unsafe untrusted
 132 defnet unsafe trusted
 133         addr 172.29.199.0/25 2001:470:9740:1::/64
 134         via househub
 135 defnet safe safe
 136         addr 172.29.199.192/27 2001:470:9740:4001::/64
 137         via househub
 138 defnet untrusted untrusted
 139         addr 172.29.198.0/25 2001:470:9740:8001::/64
 140         via househub
 141
 142 defnet househub virtual
 143         via housebdry dmz unsafe safe untrusted
 144 defnet housebdry virtual
 145         via househub hub
 146
 147 ## House hosts.
 148 defhost radius
 149         hosttype router
 150         iface eth0 dmz unsafe safe untrusted vpn sgo colobdry default
 151         iface eth1 dmz unsafe safe untrusted vpn sgo colobdry default
 152         iface eth2 dmz unsafe safe untrusted vpn sgo colobdry
 153         iface eth3 unsafe untrusted vpn default
 154         iface ppp0 default
 155         iface t6-he default
 156         iface vpn-precision colobdry vpn sgo
 157         iface vpn-chiark sgo
 158         iface vpn-+ vpn
 159 defhost roadstar
 160         iface eth0 dmz unsafe
 161         iface eth1 dmz unsafe
 162 defhost jem
 163         iface eth0 dmz unsafe
 164         iface eth1 dmz unsafe
 165 defhost artist
 166         hosttype router
 167         iface eth0 dmz unsafe untrusted
 168         iface eth1 dmz unsafe untrusted
 169         iface eth3 unsafe untrusted
 170 defhost vampire
 171         hosttype router
 172         iface eth0.4 dmz unsafe untrusted safe vpn sgo colobdry
 173         iface eth0.5 dmz unsafe untrusted safe vpn sgo colobdry
 174         iface eth0.6 dmz unsafe safe untrusted vpn sgo colobdry
 175         iface eth0.7 unsafe untrusted vpn
 176         iface vpn-precision colobdry vpn sgo
 177         iface vpn-chiark sgo
 178         iface vpn-+ vpn
 179 defhost ibanez
 180         iface br-dmz dmz unsafe
 181         iface br-unsafe unsafe
 182 defhost orange
 183         iface wlan0 untrusted
 184         iface vpn-radius unsafe
 185
 186 defhost gibson
 187         hosttype client
 188         iface eth0 unsafe
 189
 190 ## Colocated networks.
 191 defnet jump trusted
 192         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 193         via colohub
 194 defnet colo trusted
 195         addr 172.29.199.176/28 2001:ba8:1d9:2::/64
 196         via colohub
 197 defnet colohub virtual
 198         via colobdry jump colo
 199 defnet colobdry virtual
 200         via colohub hub
 201 defnet iodine untrusted
 202         addr 172.29.198.128/28
 203         via colohub
 204
 205 ## Colocated hosts.
 206 defhost fender
 207         iface br-jump jump colo
 208         iface br-colo jump colo
 209 defhost precision
 210         hosttype router
 211         iface eth0 jump colo vpn sgo
 212         iface eth1 jump colo vpn sgo
 213         iface vpn-mango binswood
 214         iface vpn-radius housebdry vpn sgo
 215         iface vpn-chiark sgo
 216         iface vpn-+ vpn
 217 defhost telecaster
 218         iface eth0 jump colo
 219         iface eth1 jump colo
 220 defhost stratocaster
 221         iface eth0 jump colo
 222         iface eth1 jump colo
 223 defhost jaguar
 224         iface eth0 jump
 225 defhost jazz
 226         hosttype router
 227         iface eth0 jump colo vpn
 228         iface eth1 jump colo vpn
 229         iface dns0 iodine
 230         iface vpn-+ vpn
 231
 232 ## Other networks.
 233 defnet hub virtual
 234         via housebdry colobdry
 235 defnet sgo noloop
 236         addr !172.29.198.0/23
 237         addr 10.0.0.0/8
 238         addr 172.16.0.0/12
 239         addr 192.168.0.0/16
 240         via househub colohub
 241 defnet vpn safe
 242         addr 172.29.199.128/27 2001:ba8:1d9:6000::/64
 243         via househub colohub
 244         host crybaby 1 ::1:1
 245         host terror 2 ::2:1
 246         host orange 3 ::3:1
 247         host haze 4 ::4:1
 248 defnet anycast trusted
 249         addr 172.29.199.224/27 2001:ba8:1d9:0::/64
 250         via dmz unsafe safe untrusted jump colo vpn
 251 defnet default untrusted
 252         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 253         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 254         addr 2001:ba8:1d9::/48 #temporary
 255         via dmz unsafe untrusted jump colo
 256
 257 ## Satellite networks.
 258 defnet binswood noloop
 259         addr 10.165.27.0/24
 260         via colohub
 261
 262 defhost mango
 263         hosttype router
 264         iface eth0 binswood default
 265         iface vpn-precision colo
 266
 267 m4_divert(80)m4_dnl
 268 ###--------------------------------------------------------------------------
 269 ### Connection tracking helper modules.
 270
 271 for i in ftp; do
 272   modprobe nf_conntrack_$i
 273 done
 274
 275 m4_divert(80)m4_dnl
 276 ###--------------------------------------------------------------------------
 277 ### Special forwarding exemptions.
 278
 279 case $forward in
 280   1)
 281
 282     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 283     ## hosts's fragment reassembly to be robust against malicious fragments.)
 284     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 285     ## of `! -f', so we do the negation using early return from a subchain.
 286     clearchain fwd-spec-nofrag
 287     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 288     run ip6tables -A fwd-spec-nofrag -j RETURN \
 289             -m ipv6header --soft --header frag
 290     run ip46tables -A FORWARD -j fwd-spec-nofrag
 291
 292     ## Allow ping from safe/noloop to untrusted networks.
 293     run iptables -A fwd-spec-nofrag -j ACCEPT \
 294             -p icmp --icmp-type echo-request \
 295             -m mark --mark $to_untrusted/$MASK_TO
 296     run iptables -A fwd-spec-nofrag -j ACCEPT \
 297             -p icmp --icmp-type echo-reply \
 298             -m mark --mark $from_untrusted/$MASK_FROM \
 299             -m state --state ESTABLISHED
 300     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 301             -p icmpv6 --icmpv6-type echo-request \
 302             -m mark --mark $to_untrusted/$MASK_TO
 303     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 304             -p icmpv6 --icmpv6-type echo-reply \
 305             -m mark --mark $from_untrusted/$MASK_FROM \
 306             -m state --state ESTABLISHED
 307
 308     ## Allow SSH from safe/noloop to untrusted networks.
 309     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 310             -p tcp --destination-port $port_ssh \
 311             -m mark --mark $to_untrusted/$MASK_TO
 312     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 313             -p tcp --source-port $port_ssh \
 314             -m mark --mark $from_untrusted/$MASK_FROM \
 315             -m state --state ESTABLISHED
 316
 317     ;;
 318 esac
 319
 320 m4_divert(80)m4_dnl
 321 ###--------------------------------------------------------------------------
 322 ### Kill things we don't understand properly.
 323 ###
 324 ### I don't like having to do this, but since I don't know how to do proper
 325 ### multicast filtering, I'm just going to ban it from being forwarded.
 326
 327 errorchain poorly-understood REJECT
 328
 329 ## Ban multicast destination addresses in forwarding.
 330 case $forward in
 331   1)
 332     run iptables -A FORWARD -g poorly-understood \
 333             -d 224.0.0.0/4
 334     run ip6tables -A FORWARD -g poorly-understood \
 335             -d ff::/8
 336     ;;
 337 esac
 338
 339 m4_divert(84)m4_dnl
 340 ###--------------------------------------------------------------------------
 341 ### Locally-bound packet inspection.
 342
 343 clearchain inbound
 344
 345 ## Track connections.
 346 commonrules inbound
 347 conntrack inbound
 348
 349 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 350 ## local request.
 351 run iptables -A inbound -j ACCEPT \
 352         -s 0.0.0.0 -d 255.255.255.255 \
 353         -p udp --source-port $port_bootpc --destination-port $port_bootps
 354 run iptables -A inbound -j ACCEPT \
 355         -s 172.29.198.0/23 \
 356         -p udp --source-port $port_bootpc --destination-port $port_bootps
 357
 358 ## Allow incoming ping.  This is the only ICMP left.
 359 run ip46tables -A inbound -j ACCEPT -p icmp
 360
 361 m4_divert(88)m4_dnl
 362 ## Allow unusual things.
 363 openports inbound
 364
 365 ## Inspect inbound packets from untrusted sources.
 366 run ip46tables -A inbound -j forbidden
 367 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 368
 369 ## Otherwise process as indicated by the mark.
 370 for i in $inchains; do
 371   run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 372 done
 373
 374 m4_divert(-1)
 375 ###----- That's all, folks --------------------------------------------------