summaryrefslogtreecommitdiffstats
path: root/etc/rc.firewall
blob: eeedc39549223ac12e3c03b94d487fa56ad41c81 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
############
# Setup system for firewall service.
# $Id: rc.firewall,v 1.13 1997/09/11 10:59:00 danny Exp $

############
# Define the firewall type in /etc/rc.conf.  Valid values are:
#   open     - will allow anyone in
#   client   - will try to protect just this machine
#   simple   - will try to protect a whole network
#   closed   - totally disables IP services except via lo0 interface
#   UNKNOWN  - disables the loading of firewall rules.
#   filename - will load the rules in the given filename (full path required)
#
# For ``client'' and ``simple'' the entries below should be customized 
# appropriately.

############
#
# If you don't know enough about packet filtering, we suggest that you
# take time to read this book:
#
#	Building Internet Firewalls
#	Brent Chapman and Elizabeth Zwicky
#
#	O'Reilly & Associates, Inc
#	ISBN 1-56592-124-0
#	http://www.ora.com/
#
# For a more advanced treatment of Internet Security read:
#
#	Firewalls & Internet Security
#	Repelling the wily hacker
#	William R. Cheswick, Steven M. Bellowin
#
#	Addison-Wesley
#	ISBN 0-201-6337-4
#	http://www.awl.com/
#

if [ "x$1" != "x" ]; then
	firewall_type=$1
fi

############
# Set quiet mode if requested
if [ "x$firewall_quiet" = "xYES" ]; then
	fwcmd="/sbin/ipfw -q"
else
	fwcmd="/sbin/ipfw"
fi

############
# Flush out the list before we begin.
$fwcmd -f flush

############
# If you just configured ipfw in the kernel as a tool to solve network
# problems or you just want to disallow some particular kinds of traffic
# they you will want to change the default policy to open.  You can also
# do this as your only action by setting the firewall_type to ``open''.

# $fwcmd add 65000 pass all from any to any

############
# Only in rare cases do you want to change this rule
$fwcmd add 1000 pass all from 127.0.0.1 to 127.0.0.1


# Prototype setups.
if [ "${firewall_type}" = "open" ]; then

	$fwcmd add 65000 pass all from any to any

elif [ "${firewall_type}" = "simple" ]; then

	$fwcmd add 65000 pass all from any to any via lo0

elif [ "${firewall_type}" = "client" ]; then

    ############
    # This is a prototype setup that will protect your system somewhat against
    # people from outside your own network.
    ############

    # set these to your network and netmask and ip
    net="192.168.4.0"
    mask="255.255.255.0"
    ip="192.168.4.17"

    # Allow any traffic to or from my own net.
    $fwcmd add pass all from ${ip} to ${net}:${mask}
    $fwcmd add pass all from ${net}:${mask} to ${ip}

    # Allow TCP through if setup succeeded
    $fwcmd add pass tcp from any to any established

    # Allow setup of incoming email 
    $fwcmd add pass tcp from any to ${ip} 25 setup

    # Allow setup of outgoing TCP connections only
    $fwcmd add pass tcp from ${ip} to any setup

    # Disallow setup of all other TCP connections
    $fwcmd add deny tcp from any to any setup

    # Allow DNS queries out in the world
    $fwcmd add pass udp from any 53 to ${ip}
    $fwcmd add pass udp from ${ip} to any 53

    # Allow NTP queries out in the world
    $fwcmd add pass udp from any 123 to ${ip}
    $fwcmd add pass udp from ${ip} to any 123

    # Everything else is denied as default.

elif [ "${firewall_type}" = "simple" ]; then

    ############
    # This is a prototype setup for a simple firewall.  Configure this machine 
    # as a named server and ntp server, and point all the machines on the inside
    # at this machine for those services.
    ############

    # set these to your outside interface network and netmask and ip
    oif="ed0"
    onet="192.168.4.0"
    omask="255.255.255.0"
    oip="192.168.4.17"

    # set these to your inside interface network and netmask and ip
    iif="ed1"
    inet="192.168.3.0"
    imask="255.255.255.0"
    iip="192.168.3.17"

    # Stop spoofing
    $fwcmd add deny all from ${inet}:${imask} to any in via ${oif}
    $fwcmd add deny all from ${onet}:${omask} to any in via ${iif}

    # Stop RFC1918 nets on the outside interface
    $fwcmd add deny all from 192.168.0.0:255.255.0.0 to any via ${oif}
    $fwcmd add deny all from 172.16.0.0:255.240.0.0 to any via ${oif}
    $fwcmd add deny all from 10.0.0.0:255.0.0.0 to any via ${oif}

    # Allow TCP through if setup succeeded
    $fwcmd add pass tcp from any to any established

    # Allow setup of incoming email 
    $fwcmd add pass tcp from any to ${oip} 25 setup

    # Allow access to our DNS
    $fwcmd add pass tcp from any to ${oip} 53 setup

    # Allow access to our WWW
    $fwcmd add pass tcp from any to ${oip} 80 setup

    # Reject&Log all setup of incoming connections from the outside
    $fwcmd add deny log tcp from any to any in via ${oif} setup

    # Allow setup of any other TCP connection
    $fwcmd add pass tcp from any to any setup

    # Allow DNS queries out in the world
    $fwcmd add pass udp from any 53 to ${oip}
    $fwcmd add pass udp from ${oip} to any 53

    # Allow NTP queries out in the world
    $fwcmd add pass udp from any 123 to ${oip}
    $fwcmd add pass udp from ${oip} to any 123

    # Everything else is denied as default.

elif [ "${firewall_type}" != "NONE" -a -r "${firewall_type}" ]; then
	$fwcmd ${firewall_type}
fi
OpenPOWER on IntegriCloud