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
  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         noxit dmz
 147
 148 ## House hosts.
 149 defhost radius
 150         hosttype router
 151         iface eth0 dmz unsafe safe untrusted vpn sgo colobdry default
 152         iface eth1 dmz unsafe safe untrusted vpn sgo colobdry default
 153         iface eth2 dmz unsafe safe untrusted vpn sgo colobdry
 154         iface eth3 untrusted vpn default
 155         iface ppp0 default
 156         iface t6-he default
 157         iface vpn-precision colobdry vpn sgo
 158         iface vpn-chiark sgo
 159         iface vpn-+ vpn
 160 defhost roadstar
 161         iface eth0 dmz unsafe
 162         iface eth1 dmz unsafe
 163 defhost jem
 164         iface eth0 dmz unsafe
 165         iface eth1 dmz unsafe
 166 defhost artist
 167         hosttype router
 168         iface eth0 dmz unsafe untrusted
 169         iface eth1 dmz unsafe untrusted
 170         iface eth3 untrusted
 171 defhost vampire
 172         hosttype router
 173         iface eth0.4 dmz unsafe untrusted safe vpn sgo colobdry
 174         iface eth0.5 dmz unsafe untrusted safe vpn sgo colobdry
 175         iface eth0.6 dmz unsafe safe untrusted vpn sgo colobdry
 176         iface eth0.7 untrusted
 177         iface vpn-precision colobdry vpn sgo
 178         iface vpn-chiark sgo
 179         iface vpn-+ vpn
 180 defhost ibanez
 181         iface br-dmz dmz unsafe
 182         iface br-unsafe unsafe
 183 defhost orange
 184         iface wlan0 untrusted
 185         iface vpn-radius unsafe
 186
 187 defhost gibson
 188         hosttype client
 189         iface eth0 unsafe
 190
 191 ## Colocated networks.
 192 defnet jump trusted
 193         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 194         via colohub
 195 defnet colo trusted
 196         addr 172.29.199.176/28 2001:ba8:1d9:2::/64
 197         via colohub
 198 defnet colohub virtual
 199         via colobdry jump colo
 200 defnet colobdry virtual
 201         via colohub hub
 202         noxit jump
 203 defnet iodine untrusted
 204         addr 172.29.198.128/28
 205         via colohub
 206
 207 ## Colocated hosts.
 208 defhost fender
 209         iface br-jump jump colo
 210         iface br-colo jump colo
 211 defhost precision
 212         hosttype router
 213         iface eth0 jump colo vpn sgo
 214         iface eth1 jump colo vpn sgo
 215         iface vpn-radius housebdry vpn sgo
 216         iface vpn-chiark sgo
 217         iface vpn-+ vpn
 218 defhost telecaster
 219         iface eth0 jump colo
 220         iface eth1 jump colo
 221 defhost stratocaster
 222         iface eth0 jump colo
 223         iface eth1 jump colo
 224 defhost jazz
 225         hosttype router
 226         iface eth0 jump colo vpn
 227         iface eth1 jump colo vpn
 228         iface dns0 iodine
 229         iface vpn-+ vpn
 230
 231 ## Other networks.
 232 defnet hub virtual
 233         via housebdry colobdry
 234 defnet sgo noloop
 235         addr !172.29.198.0/23
 236         addr 10.0.0.0/8
 237         addr 172.16.0.0/12
 238         addr 192.168.0.0/16
 239         via househub colohub
 240 defnet vpn safe
 241         addr 172.29.199.128/27 2001:ba8:1d9:6000::/64
 242         via househub colohub
 243         host crybaby 1
 244         host terror 2
 245         host orange 3
 246 defnet anycast trusted
 247         addr 172.29.199.224/27 2001:ba8:1d9:0::/64
 248         via dmz unsafe safe untrusted jump colo vpn
 249 defnet default untrusted
 250         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 251         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 252         addr 2001:ba8:1d9::/48 #temporary
 253         via dmz unsafe untrusted jump colo
 254
 255 m4_divert(80)m4_dnl
 256 ###--------------------------------------------------------------------------
 257 ### Special forwarding exemptions.
 258
 259 case $forward in
 260   1)
 261
 262     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 263     ## hosts's fragment reassembly to be robust against malicious fragments.)
 264     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 265     ## of `! -f', so we do the negation using early return from a subchain.
 266     clearchain fwd-spec-nofrag
 267     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 268     run ip6tables -A fwd-spec-nofrag -j RETURN \
 269             -m ipv6header --soft --header frag
 270     run ip46tables -A FORWARD -j fwd-spec-nofrag
 271
 272     ## Allow ping from safe/noloop to untrusted networks.
 273     run iptables -A fwd-spec-nofrag -j ACCEPT \
 274             -p icmp --icmp-type echo-request \
 275             -m mark --mark $to_untrusted/$MASK_TO
 276     run iptables -A fwd-spec-nofrag -j ACCEPT \
 277             -p icmp --icmp-type echo-reply \
 278             -m mark --mark $from_untrusted/$MASK_FROM \
 279             -m state --state ESTABLISHED
 280     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 281             -p icmpv6 --icmpv6-type echo-request \
 282             -m mark --mark $to_untrusted/$MASK_TO
 283     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 284             -p icmpv6 --icmpv6-type echo-reply \
 285             -m mark --mark $from_untrusted/$MASK_FROM \
 286             -m state --state ESTABLISHED
 287
 288     ## Allow SSH from safe/noloop to untrusted networks.
 289     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 290             -p tcp --destination-port $port_ssh \
 291             -m mark --mark $to_untrusted/$MASK_TO
 292     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 293             -p tcp --source-port $port_ssh \
 294             -m mark --mark $from_untrusted/$MASK_FROM \
 295             -m state --state ESTABLISHED
 296
 297     ;;
 298 esac
 299
 300 m4_divert(80)m4_dnl
 301 ###--------------------------------------------------------------------------
 302 ### Kill things we don't understand properly.
 303 ###
 304 ### I don't like having to do this, but since I don't know how to do proper
 305 ### multicast filtering, I'm just going to ban it from being forwarded.
 306
 307 errorchain poorly-understood REJECT
 308
 309 ## Ban multicast destination addresses in forwarding.
 310 case $forward in
 311   1)
 312     run iptables -A FORWARD -g poorly-understood \
 313             -d 224.0.0.0/4
 314     run ip6tables -A FORWARD -g poorly-understood \
 315             -d ff::/8
 316     ;;
 317 esac
 318
 319 m4_divert(84)m4_dnl
 320 ###--------------------------------------------------------------------------
 321 ### Locally-bound packet inspection.
 322
 323 clearchain inbound
 324
 325 ## Track connections.
 326 commonrules inbound
 327 conntrack inbound
 328
 329 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 330 ## local request.
 331 run iptables -A inbound -j ACCEPT \
 332         -s 0.0.0.0 -d 255.255.255.255 \
 333         -p udp --source-port $port_bootpc --destination-port $port_bootps
 334 run iptables -A inbound -j ACCEPT \
 335         -s 172.29.198.0/23 \
 336         -p udp --source-port $port_bootpc --destination-port $port_bootps
 337
 338 ## Allow incoming ping.  This is the only ICMP left.
 339 run ip46tables -A inbound -j ACCEPT -p icmp
 340
 341 m4_divert(88)m4_dnl
 342 ## Allow unusual things.
 343 openports inbound
 344
 345 ## Inspect inbound packets from untrusted sources.
 346 run ip46tables -A inbound -j forbidden
 347 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 348
 349 ## Otherwise process as indicated by the mark.
 350 for i in $inchains; do
 351   run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 352 done
 353
 354 m4_divert(-1)
 355 ###----- That's all, folks --------------------------------------------------