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 defhost groove
 186         iface eth0 unsafe
 187
 188 defhost gibson
 189         hosttype client
 190         iface eth0 unsafe
 191
 192 ## Colocated networks.
 193 defnet jump trusted
 194         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 195         via colohub
 196 defnet colo trusted
 197         addr 172.29.199.176/28 2001:ba8:1d9:2::/64
 198         via colohub
 199 defnet colohub virtual
 200         via colobdry jump colo
 201 defnet colobdry virtual
 202         via colohub hub
 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-mango binswood
 216         iface vpn-radius housebdry vpn sgo
 217         iface vpn-chiark sgo
 218         iface vpn-+ vpn
 219 defhost telecaster
 220         iface eth0 jump colo
 221         iface eth1 jump colo
 222 defhost stratocaster
 223         iface eth0 jump colo
 224         iface eth1 jump colo
 225 defhost jaguar
 226         iface eth0 jump
 227 defhost jazz
 228         hosttype router
 229         iface eth0 jump colo vpn
 230         iface eth1 jump colo vpn
 231         iface dns0 iodine
 232         iface vpn-+ vpn
 233
 234 ## Other networks.
 235 defnet hub virtual
 236         via housebdry colobdry
 237 defnet sgo noloop
 238         addr !172.29.198.0/23
 239         addr 10.0.0.0/8
 240         addr 172.16.0.0/12
 241         addr 192.168.0.0/16
 242         via househub colohub
 243 defnet vpn safe
 244         addr 172.29.199.128/27 2001:ba8:1d9:6000::/64
 245         via househub colohub
 246         host crybaby 1 ::1:1
 247         host terror 2 ::2:1
 248         host orange 3 ::3:1
 249         host haze 4 ::4:1
 250 defnet anycast trusted
 251         addr 172.29.199.224/27 2001:ba8:1d9:0::/64
 252         via dmz unsafe safe untrusted jump colo vpn
 253 defnet default untrusted
 254         addr 62.49.204.144/28 2001:470:1f09:1b98::/64
 255         addr 212.13.198.64/28 2001:ba8:0:1d9::/64
 256         addr 2001:ba8:1d9::/48 #temporary
 257         via dmz unsafe untrusted jump colo
 258
 259 ## Satellite networks.
 260 defnet binswood noloop
 261         addr 10.165.27.0/24
 262         via colohub
 263
 264 defhost mango
 265         hosttype router
 266         iface eth0 binswood default
 267         iface vpn-precision colo
 268
 269 m4_divert(80)m4_dnl
 270 ###--------------------------------------------------------------------------
 271 ### Connection tracking helper modules.
 272
 273 for i in ftp; do
 274   modprobe nf_conntrack_$i
 275 done
 276
 277 m4_divert(80)m4_dnl
 278 ###--------------------------------------------------------------------------
 279 ### Special forwarding exemptions.
 280
 281 case $forward in
 282   1)
 283
 284     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 285     ## hosts's fragment reassembly to be robust against malicious fragments.)
 286     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 287     ## of `! -f', so we do the negation using early return from a subchain.
 288     clearchain fwd-spec-nofrag
 289     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 290     run ip6tables -A fwd-spec-nofrag -j RETURN \
 291             -m ipv6header --soft --header frag
 292     run ip46tables -A FORWARD -j fwd-spec-nofrag
 293
 294     ## Allow ping from safe/noloop to untrusted networks.
 295     run iptables -A fwd-spec-nofrag -j ACCEPT \
 296             -p icmp --icmp-type echo-request \
 297             -m mark --mark $to_untrusted/$MASK_TO
 298     run iptables -A fwd-spec-nofrag -j ACCEPT \
 299             -p icmp --icmp-type echo-reply \
 300             -m mark --mark $from_untrusted/$MASK_FROM \
 301             -m state --state ESTABLISHED
 302     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 303             -p icmpv6 --icmpv6-type echo-request \
 304             -m mark --mark $to_untrusted/$MASK_TO
 305     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 306             -p icmpv6 --icmpv6-type echo-reply \
 307             -m mark --mark $from_untrusted/$MASK_FROM \
 308             -m state --state ESTABLISHED
 309
 310     ## Allow SSH from safe/noloop to untrusted networks.
 311     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 312             -p tcp --destination-port $port_ssh \
 313             -m mark --mark $to_untrusted/$MASK_TO
 314     run ip46tables -A fwd-spec-nofrag -j ACCEPT \
 315             -p tcp --source-port $port_ssh \
 316             -m mark --mark $from_untrusted/$MASK_FROM \
 317             -m state --state ESTABLISHED
 318
 319     ;;
 320 esac
 321
 322 m4_divert(80)m4_dnl
 323 ###--------------------------------------------------------------------------
 324 ### Kill things we don't understand properly.
 325 ###
 326 ### I don't like having to do this, but since I don't know how to do proper
 327 ### multicast filtering, I'm just going to ban it from being forwarded.
 328
 329 errorchain poorly-understood REJECT
 330
 331 ## Ban multicast destination addresses in forwarding.
 332 case $forward in
 333   1)
 334     run iptables -A FORWARD -g poorly-understood \
 335             -d 224.0.0.0/4
 336     run ip6tables -A FORWARD -g poorly-understood \
 337             -d ff::/8
 338     ;;
 339 esac
 340
 341 m4_divert(84)m4_dnl
 342 ###--------------------------------------------------------------------------
 343 ### Locally-bound packet inspection.
 344
 345 clearchain inbound
 346
 347 ## Track connections.
 348 commonrules inbound
 349 conntrack inbound
 350
 351 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 352 ## local request.
 353 run iptables -A inbound -j ACCEPT \
 354         -s 0.0.0.0 -d 255.255.255.255 \
 355         -p udp --source-port $port_bootpc --destination-port $port_bootps
 356 run iptables -A inbound -j ACCEPT \
 357         -s 172.29.198.0/23 \
 358         -p udp --source-port $port_bootpc --destination-port $port_bootps
 359
 360 ## Allow incoming ping.  This is the only ICMP left.
 361 run ip46tables -A inbound -j ACCEPT -p icmp
 362
 363 m4_divert(88)m4_dnl
 364 ## Allow unusual things.
 365 openports inbound
 366
 367 ## Inspect inbound packets from untrusted sources.
 368 run ip46tables -A inbound -j forbidden
 369 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 370
 371 ## Otherwise process as indicated by the mark.
 372 for i in $inchains; do
 373   run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 374 done
 375
 376 m4_divert(-1)
 377 ###----- That's all, folks --------------------------------------------------