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Give rc.firewall a polish and a new method.
Factor out the loopback setup Use "me" instead of hardcoded $ip where possible. Add "workstation" which protects just this machine with stateful firewalling. Put the variables for this in rc.conf. Submitted by: Flemming Jacobsen <fj@batmule.dk> Reviewed by: cperciva
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=163749
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@ -104,6 +104,16 @@ firewall_type="UNKNOWN" # Firewall type (see /etc/rc.firewall)
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firewall_quiet="NO" # Set to YES to suppress rule display
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firewall_logging="NO" # Set to YES to enable events logging
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firewall_flags="" # Flags passed to ipfw when type is a file
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firewall_myservices="" # List of TCP ports on which this host
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# offers services
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firewall_allowservices="" # List of IPs which has access to
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# $firewall_myservices
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firewall_trusted="" # List of IPs which has full access to this host
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firewall_logdeny="NO" # Set to YES to log default denied incoming
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# packets.
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firewall_nologports="135-139,445 1026,1027 1433,1434" # List of TCP/UDP ports
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# for which denied incoming packets are not
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# logged.
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ip_portrange_first="NO" # Set first dynamically allocated port
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ip_portrange_last="NO" # Set last dynamically allocated port
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ike_enable="NO" # Enable IKE daemon (usually racoon or isakmpd)
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123
etc/rc.firewall
123
etc/rc.firewall
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@ -42,12 +42,14 @@ fi
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############
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# Define the firewall type in /etc/rc.conf. Valid values are:
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# open - will allow anyone in
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# client - will try to protect just this machine
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# simple - will try to protect a whole network
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# closed - totally disables IP services except via lo0 interface
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# UNKNOWN - disables the loading of firewall rules.
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# filename - will load the rules in the given filename (full path required)
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# open - will allow anyone in
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# client - will try to protect just this machine
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# simple - will try to protect a whole network
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# closed - totally disables IP services except via lo0 interface
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# workstation - will try to protect just this machine using statefull
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# firewalling. See below for rc.conf variables used
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# UNKNOWN - disables the loading of firewall rules.
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# filename - will load the rules in the given filename (full path required)
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#
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# For ``client'' and ``simple'' the entries below should be customized
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# appropriately.
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@ -107,6 +109,8 @@ esac
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#
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${fwcmd} -f flush
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setup_loopback
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############
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# Network Address Translation. All packets are passed to natd(8)
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# before they encounter your remaining rules. The firewall rules
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@ -140,7 +144,6 @@ esac
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#
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case ${firewall_type} in
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[Oo][Pp][Ee][Nn])
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setup_loopback
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${fwcmd} add 65000 pass all from any to any
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;;
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@ -155,8 +158,6 @@ case ${firewall_type} in
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mask="255.255.255.0"
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ip="192.0.2.1"
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setup_loopback
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# Allow any traffic to or from my own net.
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${fwcmd} add pass all from ${ip} to ${net}:${mask}
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${fwcmd} add pass all from ${net}:${mask} to ${ip}
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@ -168,19 +169,19 @@ case ${firewall_type} in
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${fwcmd} add pass all from any to any frag
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# Allow setup of incoming email
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${fwcmd} add pass tcp from any to ${ip} 25 setup
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${fwcmd} add pass tcp from any to me 25 setup
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# Allow setup of outgoing TCP connections only
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${fwcmd} add pass tcp from ${ip} to any setup
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${fwcmd} add pass tcp from me to any setup
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# Disallow setup of all other TCP connections
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${fwcmd} add deny tcp from any to any setup
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# Allow DNS queries out in the world
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${fwcmd} add pass udp from ${ip} to any 53 keep-state
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${fwcmd} add pass udp from me to any 53 keep-state
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# Allow NTP queries out in the world
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${fwcmd} add pass udp from ${ip} to any 123 keep-state
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${fwcmd} add pass udp from me to any 123 keep-state
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# Everything else is denied by default, unless the
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# IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
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@ -206,8 +207,6 @@ case ${firewall_type} in
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imask="255.255.255.240"
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iip="192.0.2.17"
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setup_loopback
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# Stop spoofing
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${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
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${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
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@ -289,8 +288,100 @@ case ${firewall_type} in
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# config file.
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;;
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[Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
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# Configuration:
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# firewall_myservices: List of TCP ports on which this host
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# offers services.
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# firewall_allowservices: List of IPs which has access to
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# $firewall_myservices.
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# firewall_trusted: List of IPs which has full access
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# to this host. Be very carefull
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# when setting this. This option can
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# seriously degrade the level of
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# protection provided by the firewall.
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# firewall_logdeny: Boolean (YES/NO) specifying if the
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# default denied packets should be
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# logged (in /var/log/security).
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# firewall_nologports: List of TCP/UDP ports for which
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# denied incomming packets are not
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# logged.
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# Allow packets for which a state has been built.
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${fwcmd} add check-state
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# For services permitted below.
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${fwcmd} add pass tcp from me to any established
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# Allow any connection out, adding state for each.
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${fwcmd} add pass tcp from me to any setup keep-state
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${fwcmd} add pass udp from me to any keep-state
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${fwcmd} add pass icmp from me to any keep-state
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# Allow DHCP.
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${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
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${fwcmd} add pass udp from any 67 to me 68 in
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${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
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# Some servers will ping the IP while trying to decide if it's
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# still in use.
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${fwcmd} add pass icmp from any to any icmptype 8
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# Allow "mandatory" ICMP in.
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${fwcmd} add pass icmp from any to any icmptype 3,4,11
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# Add permits for this workstations published services below
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# Only IPs and nets in firewall_allowservices is allowed in.
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# If you really wish to let anyone use services on your
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# workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
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#
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# Note: We don't use keep-state as that would allow DoS of
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# our statetable.
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# You can add 'keep-state' to the lines for slightly
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# better performance if you fell that DoS of your
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# workstation won't be a problem.
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#
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for i in ${firewall_allowservices} ; do
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for j in ${firewall_myservices} ; do
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${fwcmd} add pass tcp from $i to me $j
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done
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done
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# Allow all connections from trusted IPs.
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# Playing with the content of firewall_trusted could seriously
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# degrade the level of protection provided by the firewall.
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for i in ${firewall_trusted} ; do
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${fwcmd} add pass ip from $i to me
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done
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${fwcmd} add 65000 count ip from any to any
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# Drop packets to ports where we don't want logging
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for i in ${firewall_nologports} ; do
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${fwcmd} add deny { tcp or udp } from any to any $i in
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done
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# Broadcasts and muticasts
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${fwcmd} add deny ip from any to 255.255.255.255
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${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
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# Noise from routers
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${fwcmd} add deny udp from any to any 520 in
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# Noise from webbrowsing.
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# The statefull filter is a bit agressive, and will cause some
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# connection teardowns to be logged.
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${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
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# Deny and (if wanted) log the rest unconditionally.
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log=""
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if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
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log="log logamount 500" # The default of 100 is too low.
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sysctl net.inet.ip.fw.verbose=1 >/dev/null
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fi
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${fwcmd} add deny $log ip from any to any
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;;
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[Cc][Ll][Oo][Ss][Ee][Dd])
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setup_loopback
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${fwcmd} add 65000 deny ip from any to any
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;;
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[Uu][Nn][Kk][Nn][Oo][Ww][Nn])
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;;
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