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775bd287 | 1 | ### -*-sh-*- |
bfdc045d MW |
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 | ###-------------------------------------------------------------------------- | |
335b2afe MW |
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 | ###-------------------------------------------------------------------------- | |
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34 | ### Packet classification. |
35 | ||
36 | ## Define the available network classes. | |
37 | m4_divert(42)m4_dnl | |
b1a5b8b4 | 38 | defnetclass untrusted untrusted mcast |
951e7943 | 39 | |
44f95827 MW |
40 | defnetclass link |
41 | defnetclass mcast | |
a4d8cae3 | 42 | m4_divert(-1) |
bfdc045d | 43 | |
a4d8cae3 | 44 | m4_divert(26)m4_dnl |
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45 | ###-------------------------------------------------------------------------- |
46 | ### Network layout. | |
47 | ||
b1a5b8b4 | 48 | defnet default untrusted |
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49 | |
50 | ## Colocated hosts. | |
b4654819 | 51 | defhost jaguar |
b1a5b8b4 MW |
52 | defhost jaguar |
53 | iface eth0 default | |
31c0a107 | 54 | |
a4d8cae3 | 55 | m4_divert(80)m4_dnl |
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56 | ###-------------------------------------------------------------------------- |
57 | ### Special forwarding exemptions. | |
58 | ||
78af294c MW |
59 | case $forward in |
60 | 1) | |
61 | ||
62 | ## Only allow these packets if they're not fragmented. (Don't trust safe | |
63 | ## hosts's fragment reassembly to be robust against malicious fragments.) | |
64 | ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning | |
65 | ## of `! -f', so we do the negation using early return from a subchain. | |
66 | clearchain fwd-spec-nofrag | |
67 | run iptables -A fwd-spec-nofrag -j RETURN --fragment | |
68 | run ip6tables -A fwd-spec-nofrag -j RETURN \ | |
69 | -m ipv6header --soft --header frag | |
87bf1592 | 70 | run ip46tables -A FORWARD -j fwd-spec-nofrag |
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71 | |
72 | ## Allow ping from safe/noloop to untrusted networks. | |
73 | run iptables -A fwd-spec-nofrag -j ACCEPT \ | |
74 | -p icmp --icmp-type echo-request \ | |
75 | -m mark --mark $to_untrusted/$MASK_TO | |
76 | run iptables -A fwd-spec-nofrag -j ACCEPT \ | |
77 | -p icmp --icmp-type echo-reply \ | |
78 | -m mark --mark $from_untrusted/$MASK_FROM \ | |
79 | -m state --state ESTABLISHED | |
80 | run ip6tables -A fwd-spec-nofrag -j ACCEPT \ | |
8b021091 | 81 | -p icmpv6 --icmpv6-type echo-request \ |
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82 | -m mark --mark $to_untrusted/$MASK_TO |
83 | run ip6tables -A fwd-spec-nofrag -j ACCEPT \ | |
8b021091 | 84 | -p icmpv6 --icmpv6-type echo-reply \ |
78af294c MW |
85 | -m mark --mark $from_untrusted/$MASK_FROM \ |
86 | -m state --state ESTABLISHED | |
87 | ||
88 | ## Allow SSH from safe/noloop to untrusted networks. | |
cbbd5e39 | 89 | run ip46tables -A fwd-spec-nofrag -j ACCEPT \ |
78af294c MW |
90 | -p tcp --destination-port $port_ssh \ |
91 | -m mark --mark $to_untrusted/$MASK_TO | |
cbbd5e39 | 92 | run ip46tables -A fwd-spec-nofrag -j ACCEPT \ |
78af294c MW |
93 | -p tcp --source-port $port_ssh \ |
94 | -m mark --mark $from_untrusted/$MASK_FROM \ | |
95 | -m state --state ESTABLISHED | |
96 | ||
97 | ;; | |
98 | esac | |
99 | ||
a4d8cae3 | 100 | m4_divert(80)m4_dnl |
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101 | ###-------------------------------------------------------------------------- |
102 | ### Kill things we don't understand properly. | |
103 | ### | |
104 | ### I don't like having to do this, but since I don't know how to do proper | |
105 | ### multicast filtering, I'm just going to ban it from being forwarded. | |
106 | ||
107 | errorchain poorly-understood REJECT | |
108 | ||
109 | ## Ban multicast destination addresses in forwarding. | |
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110 | case $forward in |
111 | 1) | |
112 | run iptables -A FORWARD -g poorly-understood \ | |
113 | -d 224.0.0.0/4 | |
114 | run ip6tables -A FORWARD -g poorly-understood \ | |
115 | -d ff::/8 | |
116 | ;; | |
117 | esac | |
ade2c052 | 118 | |
a4d8cae3 | 119 | m4_divert(84)m4_dnl |
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120 | ###-------------------------------------------------------------------------- |
121 | ### Locally-bound packet inspection. | |
122 | ||
123 | clearchain inbound | |
124 | ||
125 | ## Track connections. | |
ecdca131 | 126 | commonrules inbound |
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127 | conntrack inbound |
128 | ||
129 | ## Allow incoming bootp. Bootp won't be forwarded, so this is obviously a | |
130 | ## local request. | |
131 | run iptables -A inbound -j ACCEPT \ | |
132 | -s 0.0.0.0 -d 255.255.255.255 \ | |
133 | -p udp --source-port $port_bootpc --destination-port $port_bootps | |
134 | run iptables -A inbound -j ACCEPT \ | |
135 | -s 172.29.198.0/23 \ | |
136 | -p udp --source-port $port_bootpc --destination-port $port_bootps | |
137 | ||
138 | ## Allow incoming ping. This is the only ICMP left. | |
0291d6d5 | 139 | run ip46tables -A inbound -j ACCEPT -p icmp |
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140 | |
141 | m4_divert(88)m4_dnl | |
142 | ## Allow unusual things. | |
143 | openports inbound | |
144 | ||
145 | ## Inspect inbound packets from untrusted sources. | |
0291d6d5 MW |
146 | run ip46tables -A inbound -j forbidden |
147 | run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound | |
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148 | |
149 | ## Otherwise process as indicated by the mark. | |
f0033e07 MW |
150 | for i in $inchains; do |
151 | run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT | |
152 | done | |
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153 | |
154 | m4_divert(-1) | |
155 | ###----- That's all, folks -------------------------------------------------- |