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
This commit is contained in:
Poul-Henning Kamp 2006-10-28 20:08:12 +00:00
parent 20ed1b5b1b
commit 891cf3ad81
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=163749
2 changed files with 117 additions and 16 deletions

View file

@ -104,6 +104,16 @@ firewall_type="UNKNOWN" # Firewall type (see /etc/rc.firewall)
firewall_quiet="NO" # Set to YES to suppress rule display
firewall_logging="NO" # Set to YES to enable events logging
firewall_flags="" # Flags passed to ipfw when type is a file
firewall_myservices="" # List of TCP ports on which this host
# offers services
firewall_allowservices="" # List of IPs which has access to
# $firewall_myservices
firewall_trusted="" # List of IPs which has full access to this host
firewall_logdeny="NO" # Set to YES to log default denied incoming
# packets.
firewall_nologports="135-139,445 1026,1027 1433,1434" # List of TCP/UDP ports
# for which denied incoming packets are not
# logged.
ip_portrange_first="NO" # Set first dynamically allocated port
ip_portrange_last="NO" # Set last dynamically allocated port
ike_enable="NO" # Enable IKE daemon (usually racoon or isakmpd)

View file

@ -42,12 +42,14 @@ fi
############
# 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)
# 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
# workstation - will try to protect just this machine using statefull
# firewalling. See below for rc.conf variables used
# 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.
@ -107,6 +109,8 @@ esac
#
${fwcmd} -f flush
setup_loopback
############
# Network Address Translation. All packets are passed to natd(8)
# before they encounter your remaining rules. The firewall rules
@ -140,7 +144,6 @@ esac
#
case ${firewall_type} in
[Oo][Pp][Ee][Nn])
setup_loopback
${fwcmd} add 65000 pass all from any to any
;;
@ -155,8 +158,6 @@ case ${firewall_type} in
mask="255.255.255.0"
ip="192.0.2.1"
setup_loopback
# 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}
@ -168,19 +169,19 @@ case ${firewall_type} in
${fwcmd} add pass all from any to any frag
# Allow setup of incoming email
${fwcmd} add pass tcp from any to ${ip} 25 setup
${fwcmd} add pass tcp from any to me 25 setup
# Allow setup of outgoing TCP connections only
${fwcmd} add pass tcp from ${ip} to any setup
${fwcmd} add pass tcp from me 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 ${ip} to any 53 keep-state
${fwcmd} add pass udp from me to any 53 keep-state
# Allow NTP queries out in the world
${fwcmd} add pass udp from ${ip} to any 123 keep-state
${fwcmd} add pass udp from me to any 123 keep-state
# Everything else is denied by default, unless the
# IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
@ -206,8 +207,6 @@ case ${firewall_type} in
imask="255.255.255.240"
iip="192.0.2.17"
setup_loopback
# 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}
@ -289,8 +288,100 @@ case ${firewall_type} in
# config file.
;;
[Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
# Configuration:
# firewall_myservices: List of TCP ports on which this host
# offers services.
# firewall_allowservices: List of IPs which has access to
# $firewall_myservices.
# firewall_trusted: List of IPs which has full access
# to this host. Be very carefull
# when setting this. This option can
# seriously degrade the level of
# protection provided by the firewall.
# firewall_logdeny: Boolean (YES/NO) specifying if the
# default denied packets should be
# logged (in /var/log/security).
# firewall_nologports: List of TCP/UDP ports for which
# denied incomming packets are not
# logged.
# Allow packets for which a state has been built.
${fwcmd} add check-state
# For services permitted below.
${fwcmd} add pass tcp from me to any established
# Allow any connection out, adding state for each.
${fwcmd} add pass tcp from me to any setup keep-state
${fwcmd} add pass udp from me to any keep-state
${fwcmd} add pass icmp from me to any keep-state
# Allow DHCP.
${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
${fwcmd} add pass udp from any 67 to me 68 in
${fwcmd} 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.
${fwcmd} add pass icmp from any to any icmptype 8
# Allow "mandatory" ICMP in.
${fwcmd} add pass icmp from any to any icmptype 3,4,11
# Add permits for this workstations published services below
# Only IPs and nets in firewall_allowservices is allowed in.
# If you really wish to let anyone use services on your
# workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
#
# Note: We don't use keep-state as that would allow DoS of
# our statetable.
# You can add 'keep-state' to the lines for slightly
# better performance if you fell that DoS of your
# workstation won't be a problem.
#
for i in ${firewall_allowservices} ; do
for j in ${firewall_myservices} ; do
${fwcmd} add pass tcp from $i to me $j
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 ${firewall_trusted} ; do
${fwcmd} add pass ip from $i to me
done
${fwcmd} add 65000 count ip from any to any
# Drop packets to ports where we don't want logging
for i in ${firewall_nologports} ; do
${fwcmd} add deny { tcp or udp } from any to any $i in
done
# Broadcasts and muticasts
${fwcmd} add deny ip from any to 255.255.255.255
${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
# Noise from routers
${fwcmd} 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.
${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
# Deny and (if wanted) log the rest unconditionally.
log=""
if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
log="log logamount 500" # The default of 100 is too low.
sysctl net.inet.ip.fw.verbose=1 >/dev/null
fi
${fwcmd} add deny $log ip from any to any
;;
[Cc][Ll][Oo][Ss][Ee][Dd])
setup_loopback
${fwcmd} add 65000 deny ip from any to any
;;
[Uu][Nn][Kk][Nn][Oo][Ww][Nn])
;;