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 ##      .160/27         untrusted virtual network
  58 ##
  59 ## 172.29.199.0/24  Trusted networks.
  60 ##      .0/25           house wired network
  61 ##      .128/27         mobile VPN hosts
  62 ##      .160/28         reserved, except .160/30 allocated for ITS
  63 ##      .176/28         internal colocated network
  64 ##      .192/27         house safe network
  65 ##      .224/27         anycast services
  66
  67 ## IPv6 addressing.
  68 ##
  69 ## There are five blocks of publicly routable IPv6 addresses, though some of
  70 ## them aren't very interesting.  The ranges are as follows.
  71 ##
  72 ## 2001:470:1f08:1b98::/64
  73 ##              Hurricane Electric tunnel network: only :1 (HE) and :2
  74 ##              (radius) are used.
  75 ##
  76 ## 2001:470:1f09:1b98::/64
  77 ##              House border network (dmz).
  78 ##
  79 ## 2001:470:9740::/48
  80 ##              Main house range.  See below for allocation policy.
  81 ##
  82 ## 2001:ba8:0:1d9::/64
  83 ##              Jump border network (jump): :1 is the router (supplied by
  84 ##              Jump); other addresses are ours.
  85 ##
  86 ## 2001:ba8:1d9::/48
  87 ##              Main colocated range.  See below for allocation policy.
  88 ##
  89 ## Addresses in the /64 networks are simply allocated in ascending order.
  90 ## The /48s are split into /64s by appending a 16-bit network number.  The
  91 ## top nibble of the network number classifies the network, as follows.
  92 ##
  93 ## axxx         Virtual, untrusted
  94 ## 8xxx         Untrusted
  95 ## 6xxx         Virtual, safe
  96 ## 4xxx         Safe
  97 ## 0xxx         Unsafe, trusted
  98 ##
  99 ## These have been chosen so that network properties can be deduced by
 100 ## inspecting bits of the network number:
 101 ##
 102 ## Bit 15       If set, the network is untrusted; otherwise it is trusted.
 103 ## Bit 14       If set, the network is safe; otherwise it is unsafe.
 104 ##
 105 ## Finally, the low-order nibbles identify the site.
 106 ##
 107 ## 0            No specific site: mobile VPN endpoints or anycast addresses.
 108 ## 1            House.
 109 ## 2            Jump colocation.
 110 ##
 111 ## Usually site-0 networks are allocated from the Jump range to improve
 112 ## expected performance from/to external sites which don't engage in our
 113 ## dynamic routing protocols.
 114
 115 ## Define the available network classes.
 116 m4_divert(42)m4_dnl
 117 defnetclass scary       scary           trusted             mcast
 118 defnetclass untrusted   scary untrusted trusted             mcast
 119 defnetclass trusted     scary untrusted trusted safe noloop mcast
 120 defnetclass safe                        trusted safe noloop mcast
 121 defnetclass noloop                      trusted safe        mcast
 122
 123 defnetclass link
 124 defnetclass mcast
 125 m4_divert(-1)
 126
 127 m4_divert(26)m4_dnl
 128 ###--------------------------------------------------------------------------
 129 ### Network layout.
 130
 131 ## House networks.
 132 defnet dmz trusted
 133         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 134         via unsafe untrusted
 135 defnet unsafe trusted
 136         addr 172.29.199.0/25 2001:470:9740:1::/64
 137         via househub
 138 defnet safe safe
 139         addr 172.29.199.192/27 2001:470:9740:4001::/64
 140         via househub
 141 defnet untrusted untrusted
 142         addr 172.29.198.0/25 2001:470:9740:8001::/64
 143         via househub
 144
 145 defnet househub virtual
 146         via housebdry dmz unsafe safe untrusted
 147 defnet housebdry virtual
 148         via househub hub
 149
 150 ## House hosts.
 151 defhost radius
 152         hosttype router
 153         iface eth0 dmz unsafe safe untrusted vpn sgo colobdry default
 154         iface eth1 dmz unsafe safe untrusted vpn sgo colobdry default
 155         iface eth2 dmz unsafe safe untrusted vpn sgo colobdry
 156         iface eth3 unsafe untrusted vpn default
 157         iface ppp0 default
 158         iface t6-he default
 159         iface vpn-precision colobdry vpn sgo
 160         iface vpn-chiark sgo
 161         iface vpn-+ vpn
 162 defhost roadstar
 163         iface eth0 dmz unsafe
 164         iface eth1 dmz unsafe
 165 defhost jem
 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 eth0.5 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
 212 ## Colocated hosts.
 213 defhost fender
 214         iface br-jump jump colo
 215         iface br-colo jump colo
 216 defhost precision
 217         hosttype router
 218         iface eth0 jump colo vpn sgo
 219         iface eth1 jump colo vpn sgo
 220         iface vpn-mango binswood
 221         iface vpn-radius housebdry vpn sgo
 222         iface vpn-chiark sgo
 223         iface vpn-national upn
 224         iface vpn-+ vpn
 225 defhost telecaster
 226         iface eth0 jump colo
 227         iface eth1 jump colo
 228 defhost stratocaster
 229         iface eth0 jump colo
 230         iface eth1 jump colo
 231 defhost jazz
 232         hosttype router
 233         iface eth0 jump colo vpn
 234         iface eth1 jump colo vpn
 235         iface dns0 iodine
 236         iface vpn-+ vpn
 237
 238 ## Other networks.
 239 defnet hub virtual
 240         via housebdry colobdry
 241 defnet sgo noloop
 242         addr !172.29.198.0/23
 243         addr 10.0.0.0/8
 244         addr 172.16.0.0/12
 245         addr 192.168.0.0/16
 246         via househub colohub
 247 defnet vpn safe
 248         addr 172.29.199.128/27 2001:ba8:1d9:6000::/64
 249         via househub colohub
 250         host crybaby 1 ::1:1
 251         host terror 2 ::2:1
 252         host orange 3 ::3:1
 253         host haze 4 ::4:1
 254         host groove 5 ::5:1
 255 defnet anycast trusted
 256         addr 172.29.199.224/27 2001:ba8:1d9:0::/64
 257         via dmz unsafe safe untrusted jump colo vpn
 258 defnet default scary
 259         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 260         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 261         addr 2001:ba8:1d9::/48 #temporary
 262         via dmz unsafe untrusted jump colo
 263 defnet upn untrusted
 264         addr 172.29.198.160/27 2001:ba8:1d9:a000::/64
 265         via colohub
 266         host national 1 ::1:1
 267
 268 ## Linode hosts.
 269 defhost national
 270         iface eth0 default
 271         iface vpn-precision colohub
 272
 273 ## Satellite networks.
 274 defnet binswood noloop
 275         addr 10.165.27.0/24
 276         via colohub
 277 defhost mango
 278         hosttype router
 279         iface eth0 binswood default
 280         iface vpn-precision colo
 281
 282 m4_divert(80)m4_dnl
 283 ###--------------------------------------------------------------------------
 284 ### Connection tracking helper modules.
 285
 286 for i in ftp; do
 287   modprobe nf_conntrack_$i
 288 done
 289
 290 m4_divert(80)m4_dnl
 291 ###--------------------------------------------------------------------------
 292 ### Special forwarding exemptions.
 293
 294 case $forward in
 295   1)
 296
 297     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 298     ## hosts's fragment reassembly to be robust against malicious fragments.)
 299     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 300     ## of `! -f', so we do the negation using early return from a subchain.
 301     clearchain fwd-spec-nofrag
 302     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 303     run ip6tables -A fwd-spec-nofrag -j RETURN \
 304             -m ipv6header --soft --header frag
 305     run ip46tables -A FORWARD -j fwd-spec-nofrag
 306
 307     ## Allow ping from safe/noloop to untrusted networks.
 308     run iptables -A fwd-spec-nofrag -j ACCEPT \
 309             -p icmp --icmp-type echo-request \
 310             -m mark --mark $to_untrusted/$MASK_TO
 311     run iptables -A fwd-spec-nofrag -j ACCEPT \
 312             -p icmp --icmp-type echo-reply \
 313             -m mark --mark $from_untrusted/$MASK_FROM \
 314             -m state --state ESTABLISHED
 315     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 316             -p icmpv6 --icmpv6-type echo-request \
 317             -m mark --mark $to_untrusted/$MASK_TO
 318     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 319             -p icmpv6 --icmpv6-type echo-reply \
 320             -m mark --mark $from_untrusted/$MASK_FROM \
 321             -m state --state ESTABLISHED
 322
 323     ## Allow SSH from safe/noloop to untrusted networks.
 324     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 325             -p tcp --destination-port $port_ssh \
 326             -m mark --mark $to_untrusted/$MASK_TO
 327     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 328             -p tcp --source-port $port_ssh \
 329             -m mark --mark $from_untrusted/$MASK_FROM \
 330             -m state --state ESTABLISHED
 331
 332     ;;
 333 esac
 334
 335 m4_divert(80)m4_dnl
 336 ###--------------------------------------------------------------------------
 337 ### Kill things we don't understand properly.
 338 ###
 339 ### I don't like having to do this, but since I don't know how to do proper
 340 ### multicast filtering, I'm just going to ban it from being forwarded.
 341
 342 errorchain poorly-understood REJECT
 343
 344 ## Ban multicast destination addresses in forwarding.
 345 case $forward in
 346   1)
 347     run iptables -A FORWARD -g poorly-understood \
 348             -d 224.0.0.0/4
 349     run ip6tables -A FORWARD -g poorly-understood \
 350             -d ff::/8
 351     ;;
 352 esac
 353
 354 m4_divert(84)m4_dnl
 355 ###--------------------------------------------------------------------------
 356 ### Locally-bound packet inspection.
 357
 358 clearchain inbound
 359
 360 ## Track connections.
 361 commonrules inbound
 362 conntrack inbound
 363
 364 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 365 ## local request.
 366 run iptables -A inbound -j ACCEPT \
 367         -s 0.0.0.0 -d 255.255.255.255 \
 368         -p udp --source-port $port_bootpc --destination-port $port_bootps
 369 run iptables -A inbound -j ACCEPT \
 370         -s 172.29.198.0/23 \
 371         -p udp --source-port $port_bootpc --destination-port $port_bootps
 372
 373 ## Allow incoming ping.  This is the only ICMP left.
 374 run iptables -A inbound -j ACCEPT -p icmp
 375 run ip6tables -A inbound -j ACCEPT -p icmpv6
 376
 377 m4_divert(88)m4_dnl
 378 ## Allow unusual things.
 379 openports inbound
 380
 381 ## Inspect inbound packets from untrusted sources.
 382 run ip46tables -A inbound -j forbidden
 383 run ip46tables -A INPUT -m mark --mark $from_scary/$MASK_FROM -g inbound
 384 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 385
 386 ## Allow responses from the scary outside world into the untrusted net, but
 387 ## don't let untrusted things run services.
 388 case $forward in
 389   1)
 390     run ip46tables -A FORWARD -j ACCEPT \
 391         -m mark --mark $(( $from_scary | $to_untrusted ))/$(( $MASK_FROM | $MASK_TO )) \
 392         -m state --state ESTABLISHED,RELATED
 393     ;;
 394 esac
 395
 396 ## Otherwise process as indicated by the mark.
 397 for i in $inchains; do
 398   run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 399 done
 400
 401 m4_divert(-1)
 402 ###----- That's all, folks --------------------------------------------------