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
|
#!/sbin/runscript
# Copyright 2007 Roy Marples
# All rights reserved
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
# This is based on /etc/rc.firewall and /etc/rc.firewall6 from FreeBSD
ipfw_ip_in=${ipfw_ip_in-any}
ipfw_ports_in=${ipfw_ports_in-auth ssh}
ipfw_ports_nolog=${ipfw_ports_nolog-135-139,445 1026,1027 1433,1434}
opts="panic showstatus"
depend() {
before net
provide firewall
}
ipfw() {
/sbin/ipfw -f -q "$@"
}
init() {
# Load the kernel module
if ! sysctl net.inet.ip.fw.enable=1 >/dev/null 2>/dev/null; then
if ! kldload ipfw ; then
eend 1 "Unable to load firewall module"
return 1
fi
fi
# Now all rules and give a good base
ipfw flush
ipfw add pass all from any to any via lo0
ipfw add deny all from any to 127.0.0.0/8
ipfw add deny ip from 127.0.0.0/8 to any
ipfw add pass ip6 from any to any via lo0
ipfw add deny ip6 from any to ::1
ipfw add deny ip6 from ::1 to any
ipfw add pass ip6 from :: to ff02::/16 proto ipv6-icmp
ipfw add pass ip6 from fe80::/10 to fe80::/10 proto ipv6-icmp
ipfw add pass ip6 from fe80::/10 to ff02::/16 proto ipv6-icmp
}
start() {
local i= p= log=
ebegin "Starting firewall rules"
if ! init ; then
eend 1 "Failed to flush firewall ruleset"
return 1
fi
# Use a statefull firewall
ipfw add check-state
ipfw add pass tcp from me to any established
# Allow any connection out, adding state for each.
ipfw add pass tcp from me to any setup keep-state
ipfw add pass udp from me to any keep-state
ipfw add pass icmp from me to any keep-state
ipfw add pass tcp from me6 to any setup keep-state
ipfw add pass udp from me6 to any keep-state
ipfw add pass icmp from me6 to any keep-state
# Allow DHCP.
ipfw add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
ipfw add pass udp from any 67 to me 68 in
ipfw add pass udp from any 67 to 255.255.255.255 68 in
# Some servers will ping the IP while trying to decide if it's
# still in use.
ipfw add pass icmp from any to any icmptype 8
# Allow "mandatory" ICMP in.
ipfw add pass icmp from any to any icmptype 3,4,11
# Allow ICMPv6 destination unreach
ipfw add pass ip6 from any to any icmp6types 1 proto ipv6-icmp
# Allow NS/NA/toobig (don't filter it out)
ipfw add pass ip6 from any to any icmp6types 2,135,136 proto ipv6-icmp
# Add permits for this workstations published services below
# Only IPs and nets in firewall_allowservices is allowed in.
for i in ${ipfw_ip_in}; do
for p in ${ipfw_ports_in}; do
ipfw add pass tcp from ${i} to me ${p}
done
done
# Allow all connections from trusted IPs.
# Playing with the content of firewall_trusted could seriously
# degrade the level of protection provided by the firewall.
for i in ${ipfw_ip_trust}; do
ipfw add pass ip from ${i} to me
done
ipfw add 65000 count ip from any to any
# Drop packets to ports where we don't want logging
for p in ${ipfw_ports_nolog}; do
ipfw add deny { tcp or udp } from any to any ${p} in
done
# Broadcasts and muticasts
ipfw add deny ip from any to 255.255.255.255
ipfw add deny ip from any to 224.0.0.0/24
# Noise from routers
ipfw add deny udp from any to any 520 in
# Noise from webbrowsing.
# The statefull filter is a bit agressive, and will cause some
# connection teardowns to be logged.
ipfw add deny tcp from any 80,443 to any 1024-65535 in
# Deny and (if wanted) log the rest unconditionally.
if yesno ${ipfw_log_deny:-no}; then
log="log"
sysctl net.inet.ip.fw.verbose=1 >/dev/null
fi
ipfw add deny ${log} ip from any to any
eend 0
}
stop() {
ebegin "Stopping firewall rules"
# We don't unload the kernel module as that action
# can cause memory leaks as of FreeBSD 6.x
sysctl net.inet.ip.fw.enable=0 >/dev/null
eend $?
}
panic() {
ebegin "Stopping firewall rules - hard"
if ! init ; then
eend 1 "Failed to flush firewall ruleset"
return 1
fi
eend 0
}
showstatus() {
ipfw show
}
|
