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         "81.187.26.174 90.155.23.205 2001:8b0:0:23::205 185.73.44.6 2001:ba8:0:2c06::")
  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 ## 81.2.113.195, 81.187.238.128/28
  43 ##              House border network (dmz).  We have all of these; the loose
  44 ##              address is 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 ##      .144/28         hippotat (IP-over-HTTP) network
  58 ##      .160/27         untrusted virtual network
  59 ##
  60 ## 172.29.199.0/24  Trusted networks.
  61 ##      .0/25           house wired network
  62 ##      .128/27         mobile VPN hosts
  63 ##      .160/28         reserved, except .160/30 allocated for ITS
  64 ##      .176/28         internal colocated network
  65 ##      .192/27         house safe network
  66 ##      .224/27         anycast services
  67
  68 ## IPv6 addressing.
  69 ##
  70 ## There are five blocks of publicly routable IPv6 addresses, though some of
  71 ## them aren't very interesting.  The ranges are as follows.
  72 ##
  73 ## 2001:8b0:c92::/48
  74 ##              Main house range (aaisp).  See below for allocation policy.
  75 ##              There is no explicit DMZ allocation (and no need for one).
  76 ##
  77 ## 2001:ba8:0:1d9::/64
  78 ##              Jump border network (jump): :1 is the router (supplied by
  79 ##              Jump); other addresses are ours.
  80 ##
  81 ## 2001:ba8:1d9::/48
  82 ##              Main colocated range.  See below for allocation policy.
  83 ##
  84 ## Addresses in the /64 networks are simply allocated in ascending order.
  85 ## The /48s are split into /64s by appending a 16-bit network number.  The
  86 ## top nibble of the network number classifies the network, as follows.
  87 ##
  88 ## axxx         Virtual, untrusted
  89 ## 8xxx         Untrusted
  90 ## 6xxx         Virtual, safe
  91 ## 4xxx         Safe
  92 ## 0xxx         Unsafe, trusted
  93 ##
  94 ## These have been chosen so that network properties can be deduced by
  95 ## inspecting bits of the network number:
  96 ##
  97 ## Bit 15       If set, the network is untrusted; otherwise it is trusted.
  98 ## Bit 14       If set, the network is safe; otherwise it is unsafe.
  99 ##
 100 ## Finally, the low-order nibbles identify the site.
 101 ##
 102 ## 0            No specific site: mobile VPN endpoints or anycast addresses.
 103 ## 1            House.
 104 ## 2            Jump colocation.
 105 ## fff          Local border network.
 106 ##
 107 ## Usually site-0 networks are allocated from the Jump range to improve
 108 ## expected performance from/to external sites which don't engage in our
 109 ## dynamic routing protocols.
 110
 111 ## Define the available network classes.
 112 m4_divert(42)m4_dnl
 113 defnetclass scary       scary           trusted             vpnnat mcast
 114 defnetclass untrusted   scary untrusted trusted                    mcast
 115 defnetclass trusted     scary untrusted trusted safe noloop vpnnat mcast
 116 defnetclass safe                        trusted safe noloop vpnnat mcast
 117 defnetclass noloop                      trusted safe               mcast
 118 defnetclass vpnnat      scary           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 81.2.113.195 81.187.238.128/28 2001:8b0:c92:fff::/64
 131         via unsafe untrusted
 132 defnet unsafe trusted
 133         addr 172.29.199.0/25 2001:8b0:c92:1::/64
 134         via househub
 135 defnet safe safe
 136         addr 172.29.199.192/27 2001:8b0:c92:4001::/64
 137         via househub
 138 defnet untrusted untrusted
 139         addr 172.29.198.0/25 2001:8b0:c92:8001::/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 universe
 166         iface eth0 dmz unsafe
 167         iface eth1 dmz unsafe
 168 defhost artist
 169         hosttype router
 170         iface eth0 dmz unsafe untrusted
 171         iface eth1 dmz unsafe untrusted
 172         iface eth3 unsafe untrusted
 173 defhost vampire
 174         hosttype router
 175         iface eth0.4 dmz unsafe untrusted safe vpn sgo colobdry
 176         iface eth0.5 dmz unsafe untrusted safe vpn sgo colobdry
 177         iface eth0.6 dmz unsafe safe untrusted vpn sgo colobdry
 178         iface eth0.7 unsafe untrusted vpn
 179         iface vpn-precision colobdry vpn sgo
 180         iface vpn-chiark sgo
 181         iface vpn-+ vpn
 182 defhost ibanez
 183         iface br-dmz dmz unsafe
 184         iface br-unsafe unsafe
 185 defhost orange
 186         iface wlan0 untrusted
 187         iface vpn-radius unsafe
 188 defhost groove
 189         iface eth0 unsafe
 190         iface wlan0 untrusted
 191         iface vpn-radius unsafe
 192
 193 defhost gibson
 194         hosttype client
 195         iface eth0 unsafe
 196
 197 ## Colocated networks.
 198 defnet jump trusted
 199         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 200         via colohub
 201 defnet colo trusted
 202         addr 172.29.199.176/28 2001:ba8:1d9:2::/64
 203         via colohub
 204 defnet colohub virtual
 205         via colobdry jump colo
 206 defnet colobdry virtual
 207         via colohub hub
 208 defnet iodine untrusted
 209         addr 172.29.198.128/28
 210         via colohub
 211 defnet hippotat untrusted
 212         addr 172.29.198.144/28
 213         via colohub
 214
 215 ## Colocated hosts.
 216 defhost fender
 217         iface br-jump jump colo
 218         iface br-colo jump colo
 219 defhost precision
 220         hosttype router
 221         iface eth0 jump colo vpn sgo
 222         iface eth1 jump colo vpn sgo
 223         iface vpn-mango binswood
 224         iface vpn-radius housebdry vpn sgo
 225         iface vpn-chiark sgo
 226         iface vpn-national upn
 227         iface vpn-mdwdev upn
 228         iface vpn-+ vpn
 229 defhost telecaster
 230         iface eth0 jump colo
 231         iface eth1 jump colo
 232 defhost stratocaster
 233         iface eth0 jump colo
 234         iface eth1 jump colo
 235 defhost jazz
 236         hosttype router
 237         iface eth0 jump colo vpn
 238         iface eth1 jump colo vpn
 239         iface dns0 iodine
 240         iface hippo-svc hippotat
 241         iface vpn-+ vpn
 242
 243 ## Other networks.
 244 defnet hub virtual
 245         via housebdry colobdry
 246 defnet sgo noloop
 247         addr !172.29.198.0/23
 248         addr !10.165.27.0/24
 249         addr 10.0.0.0/8
 250         addr 172.16.0.0/12
 251         addr 192.168.0.0/16
 252         via househub colohub
 253 defnet vpn trusted
 254         addr 172.29.199.128/27 2001:ba8:1d9:6000::/64
 255         via househub colohub
 256         host crybaby 1 ::1:1
 257         host terror 2 ::2:1
 258         host orange 3 ::3:1
 259         host haze 4 ::4:1
 260         host spirit 9 ::9:1
 261 defnet anycast trusted
 262         addr 172.29.199.224/27 2001:ba8:1d9:0::/64
 263         via dmz unsafe safe untrusted jump colo vpn
 264 defnet default scary
 265         addr 81.2.113.195 81.187.238.128/28 2001:8b0:c92::/48
 266         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 267         addr 2001:ba8:1d9::/48 #temporary
 268         via dmz unsafe untrusted jump colo
 269 defnet upn untrusted
 270         addr 172.29.198.160/27 2001:ba8:1d9:a000::/64
 271         via colohub
 272         host national 1 ::1:1
 273         host mdwdev 2 ::2:1
 274
 275 ## Linode hosts.
 276 defhost national
 277         iface eth0 default
 278         iface vpn-precision colohub
 279
 280 ## Satellite networks.
 281 defnet binswood vpnnat
 282         addr 10.165.27.0/24
 283         via colohub
 284 defhost mango
 285         hosttype router
 286         iface eth0 binswood default
 287         iface vpn-precision colo default
 288
 289 m4_divert(80)m4_dnl
 290 ###--------------------------------------------------------------------------
 291 ### Connection tracking helper modules.
 292
 293 for i in ftp; do
 294   modprobe nf_conntrack_$i
 295 done
 296
 297 m4_divert(80)m4_dnl
 298 ###--------------------------------------------------------------------------
 299 ### Special forwarding exemptions.
 300
 301 case $forward in
 302   1)
 303
 304     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 305     ## hosts's fragment reassembly to be robust against malicious fragments.)
 306     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 307     ## of `! -f', so we do the negation using early return from a subchain.
 308     clearchain fwd-spec-nofrag
 309     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 310     run ip6tables -A fwd-spec-nofrag -j RETURN \
 311             -m ipv6header --soft --header frag
 312     run ip46tables -A FORWARD -j fwd-spec-nofrag
 313
 314     ## Allow ping from safe/noloop to untrusted networks.
 315     run iptables -A fwd-spec-nofrag -j ACCEPT \
 316             -p icmp --icmp-type echo-request \
 317             -m mark --mark $to_untrusted/$MASK_TO
 318     run iptables -A fwd-spec-nofrag -j ACCEPT \
 319             -p icmp --icmp-type echo-reply \
 320             -m mark --mark $from_untrusted/$MASK_FROM \
 321             -m state --state ESTABLISHED
 322     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 323             -p icmpv6 --icmpv6-type echo-request \
 324             -m mark --mark $to_untrusted/$MASK_TO
 325     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 326             -p icmpv6 --icmpv6-type echo-reply \
 327             -m mark --mark $from_untrusted/$MASK_FROM \
 328             -m state --state ESTABLISHED
 329
 330     ## Allow SSH from safe/noloop to untrusted networks.
 331     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 332             -p tcp --destination-port $port_ssh \
 333             -m mark --mark $to_untrusted/$MASK_TO
 334     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 335             -p tcp --source-port $port_ssh \
 336             -m mark --mark $from_untrusted/$MASK_FROM \
 337             -m state --state ESTABLISHED
 338
 339     ;;
 340 esac
 341
 342 m4_divert(80)m4_dnl
 343 ###--------------------------------------------------------------------------
 344 ### Kill things we don't understand properly.
 345 ###
 346 ### I don't like having to do this, but since I don't know how to do proper
 347 ### multicast filtering, I'm just going to ban it from being forwarded.
 348
 349 errorchain poorly-understood REJECT
 350
 351 ## Ban multicast destination addresses in forwarding.
 352 case $forward in
 353   1)
 354     run iptables -A FORWARD -g poorly-understood \
 355             -d 224.0.0.0/4
 356     run ip6tables -A FORWARD -g poorly-understood \
 357             -d ff::/8
 358     ;;
 359 esac
 360
 361 m4_divert(82)m4_dnl
 362 ###--------------------------------------------------------------------------
 363 ### Check for source routing.
 364
 365 clearchain check-srcroute
 366
 367 run iptables -A check-srcroute -g forbidden \
 368     -m ipv4options --any --flags lsrr,ssrr
 369 run ip6tables -A check-srcroute -g forbidden \
 370     -m rt
 371
 372 for c in INPUT FORWARD; do
 373   for m in $from_scary $from_untrusted; do
 374     run ip46tables -A $c -m mark --mark $m/$MASK_FROM -j check-srcroute
 375   done
 376 done
 377
 378 m4_divert(84)m4_dnl
 379 ###--------------------------------------------------------------------------
 380 ### Locally-bound packet inspection.
 381
 382 clearchain inbound
 383 clearchain inbound-untrusted
 384
 385 ## Track connections.
 386 commonrules inbound
 387 conntrack inbound
 388
 389 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 390 ## local request.
 391 run iptables -A inbound -j ACCEPT \
 392         -s 0.0.0.0 -d 255.255.255.255 \
 393         -p udp --source-port $port_bootpc --destination-port $port_bootps
 394 run iptables -A inbound -j ACCEPT \
 395         -s 172.29.198.0/23 \
 396         -p udp --source-port $port_bootpc --destination-port $port_bootps
 397
 398 ## Allow incoming ping.  This is the only ICMP left.
 399 run iptables -A inbound -j ACCEPT -p icmp
 400 run ip6tables -A inbound -j ACCEPT -p icmpv6
 401
 402 m4_divert(88)m4_dnl
 403 ## Allow unusual things.
 404 openports inbound
 405
 406 ## Inspect inbound packets from untrusted sources.
 407 run iptables -A inbound -s 172.29.198.0/24 -g inbound-untrusted
 408 run ip6tables -A inbound -s 2001:8b0:c92:8000::/49 -g inbound-untrusted
 409 run ip6tables -A inbound -s 2001:ba8:1d9:8000::/49 -g inbound-untrusted
 410 run ip46tables -A inbound-untrusted -g forbidden
 411 run ip46tables -A inbound -g forbidden
 412 run ip46tables -A INPUT -m mark --mark $from_scary/$MASK_FROM -g inbound
 413 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 414
 415 ## Allow responses from the scary outside world into the untrusted net, but
 416 ## don't let untrusted things run services.
 417 case $forward in
 418   1)
 419     run ip46tables -A FORWARD -j ACCEPT \
 420         -m mark --mark $(( $from_scary | $to_untrusted ))/$(( $MASK_FROM | $MASK_TO )) \
 421         -m state --state ESTABLISHED,RELATED
 422     ;;
 423 esac
 424
 425 ## Otherwise process as indicated by the mark.
 426 for i in $inchains; do
 427   run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 428 done
 429
 430 m4_divert(-1)
 431 ###----- That's all, folks --------------------------------------------------