shorewall_code/Shorewall-common/firewall
2008-12-07 18:17:26 +00:00

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#!/bin/sh
#
# The Shoreline Firewall (Shorewall) Packet Filtering Firewall - V4.2
#
# This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
# (c) 1999,2000,2001,2002,2003,2004,2005,2006,2007 - Tom Eastep (teastep@shorewall.net)
#
# Complete documentation is available at http://shorewall.net
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of Version 2 of the GNU General Public License
# as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# If an error occurs while starting or restarting the firewall, the
# firewall is automatically stopped.
#
# Commands are:
#
# firewall stop Stops the firewall
# firewall reset Resets iptables packet and
# byte counts
# firewall clear Remove all Shorewall chains
# and rules/policies.
# firewall add <iface>[:<host>] zone Adds a host or subnet to a zone
# firewall delete <iface>[:<host>] zone Deletes a host or subnet from a zone
#
#
# Fatal error -- stops the firewall after issuing the error message
#
fatal_error() # $* = Error Message
{
echo " ERROR: $@" >&2
stop_firewall
exit 2
}
#
# Fatal error during startup -- generate an error message and abend without
# altering the state of the firewall
#
startup_error() # $* = Error Message
{
echo " ERROR: $@" >&2
[ -n "$TMP_DIR" ] && rm -rf $TMP_DIR
[ -n "$RESTOREBASE" ] && rm -f $RESTOREBASE
kill $$
exit 2
}
#
# Send a message to STDOUT and the System Log
#
report () { # $* = message
progress_message3 "$@"
logger -p kern.info "$@"
}
#
# Run iptables and if an error occurs, stop the firewall and quit
#
run_iptables() {
if [ -z "$KLUDGEFREE" ]; then
#
# Purge the temporary files that we use to prevent duplicate '-m' specifications
#
[ -n "$PHYSDEV_MATCH" ] && [ -f $TMP_DIR/physdev ] && rm -f $TMP_DIR/physdev
[ -n "$IPRANGE_MATCH" ] && [ -f $TMP_DIR/iprange ] && rm -f $TMP_DIR/iprange
fi
if ! $IPTABLES $@ ; then
if [ -z "$STOPPING" ]; then
error_message "ERROR: Command \"$IPTABLES $@\" Failed"
stop_firewall
exit 2
fi
fi
}
#
# Version of 'run_iptables' that inserts white space after "!" in the arg list
#
run_iptables2() {
case "$@" in
*!*)
run_iptables $(fix_bang $@)
;;
*)
run_iptables $@
;;
esac
}
#
# Quietly run iptables
#
qt_iptables() {
if [ -z "$KLUDGEFREE" ]; then
#
# Purge the temporary files that we use to prevent duplicate '-m' specifications
#
[ -n "$PHYSDEV_MATCH" ] && [ -f $TMP_DIR/physdev ] && rm -f $TMP_DIR/physdev
[ -n "$IPRANGE_MATCH" ] && [ -f $TMP_DIR/iprange ] && rm -f $TMP_DIR/iprange
fi
qt $IPTABLES $@
}
#
# Run ip and if an error occurs, stop the firewall and quit
#
run_ip() {
if ! ip $@ ; then
if [ -z "$STOPPING" ]; then
error_message "ERROR: Command \"ip $@\" Failed"
stop_firewall
exit 2
fi
fi
}
#
# Run tc and if an error occurs, stop the firewall and quit
#
run_tc() {
if ! tc $@ ; then
if [ -z "$STOPPING" ]; then
error_message "ERROR: Command \"tc $@\" Failed"
stop_firewall
exit 2
fi
fi
}
#
# Delete a chain if it exists
#
deletechain() # $1 = name of chain
{
qt $IPTABLES -L $1 -n && qt $IPTABLES -F $1 && qt $IPTABLES -X $1
}
#
# Find broadcast addresses -- if we are compiling a script and 'detect' is specified for an interface
# the function returns nothing for that interface
#
find_broadcasts() {
for interface in $ALL_INTERFACES; do
eval bcast=\$$(chain_base $interface)_broadcast
if [ "x$bcast" = "xdetect" ]; then
ip -f inet addr show $interface 2> /dev/null | grep 'inet.*brd' | sed 's/inet.*brd //; s/scope.*//;' | sort -u
elif [ "x${bcast}" != "x-" ]; then
echo $(separate_list $bcast)
fi
done
}
#
# For each entry in the CRITICALHOSTS global list, add INPUT and OUTPUT rules to
# enable traffic to/from those hosts.
#
enable_critical_hosts()
{
for host in $CRITICALHOSTS; do
interface=${host%:*}
networks=${host#*:}
$IPTABLES -A INPUT -i $interface $(source_ip_range $networks) -j ACCEPT
$IPTABLES -A OUTPUT -o $interface $(dest_ip_range $networks) -j ACCEPT
done
}
#
# For each entry in the CRITICALHOSTS global list, delete the INPUT and OUTPUT rules that
# enable traffic to/from those hosts.
#
disable_critical_hosts()
{
for host in $CRITICALHOSTS; do
interface=${host%:*}
networks=${host#*:}
$IPTABLES -D INPUT -i $interface $(source_ip_range $networks) -j ACCEPT
$IPTABLES -D OUTPUT -o $interface $(dest_ip_range $networks) -j ACCEPT
done
}
#
# Undo changes to routing
#
undo_routing() {
#
# Restore rt_tables database
#
if [ -f ${VARDIR}/rt_tables ]; then
[ -w /etc/iproute2/rt_table -a -z "$KEEP_RT_TABLES" ] && cp -f ${VARDIR}/rt_tables /etc/iproute2/ && progress_message "/etc/iproute2/rt_tables database restored"
rm -f ${VARDIR}/rt_tables
fi
#
# Restore the rest of the routing table
#
if [ -f ${VARDIR}/undo_routing ]; then
. ${VARDIR}/undo_routing
progress_message "Shorewall-generated routing tables and routing rules removed"
rm -f ${VARDIR}/undo_routing
fi
}
restore_default_route() {
if [ -f ${VARDIR}/default_route ]; then
local default_route
default_route=
local route
while read route ; do
case $route in
default*)
if [ -n "$default_route" ]; then
case "$default_route" in
*metric*)
#
# Don't restore a route with a metric -- we only replace the one with metric == 0
#
qt ip route delete default metric 0 && \
progress_message "Default Route with metric 0 deleted"
;;
*)
qt ip route replace $default_route && \
progress_message "Default Route (${default_route# }) restored"
;;
esac
break
fi
default_route="$default_route $route"
;;
*)
default_route="$default_route $route"
;;
esac
done < ${VARDIR}/default_route
rm -f ${VARDIR}/default_route
fi
}
#
# Stop the Firewall
#
stop_firewall() {
#
# Turn off trace unless we were tracing "stop" or "clear"
#
[ -n "$RESTOREBASE" ] && rm -f $RESTOREBASE
case $COMMAND in
stop|clear)
;;
*)
set +x
[ -n "${RESTOREFILE:=restore}" ]
RESTOREPATH=${VARDIR}/$RESTOREFILE
if [ -x $RESTOREPATH ]; then
if [ -x ${RESTOREPATH}-ipsets ]; then
progress_message2 Restoring Ipsets...
#
# We must purge iptables to be sure that there are no
# references to ipsets
#
for table in mangle nat filter; do
iptables -t $table -F
iptables -t $table -X
done
${RESTOREPATH}-ipsets
fi
echo Restoring Shorewall...
if $RESTOREPATH restore; then
echo "Shorewall restored from $RESTOREPATH"
set_state "Started"
else
set_state "Unknown"
fi
kill $$
exit 2
fi
;;
esac
set_state "Stopping"
STOPPING="Yes"
TERMINATOR=
deletechain shorewall
run_user_exit stop
if [ -n "$MANGLE_ENABLED" ]; then
run_iptables -t mangle -F
run_iptables -t mangle -X
for chain in PREROUTING INPUT FORWARD POSTROUTING; do
qt $IPTABLES -t mangle -P $chain ACCEPT
done
fi
if [ -n "$RAW_TABLE" ]; then
run_iptables -t raw -F
run_iptables -t raw -X
for chain in PREROUTING OUTPUT; do
qt $IPTABLES -t raw -P $chain ACCEPT
done
fi
if [ -n "$NAT_ENABLED" ]; then
delete_nat
for chain in PREROUTING POSTROUTING OUTPUT; do
qt $IPTABLES -t nat -P $chain ACCEPT
done
fi
delete_proxy_arp
[ -n "$CLEAR_TC" ] && delete_tc1
undo_routing
restore_default_route
[ -n "$DISABLE_IPV6" ] && disable_ipv6
undo_routing
restore_default_route
process_criticalhosts
if [ -n "$CRITICALHOSTS" ]; then
if [ -z "$ADMINISABSENTMINDED" ]; then
for chain in INPUT OUTPUT; do
setpolicy $chain ACCEPT
done
setpolicy FORWARD DROP
deleteallchains
enable_critical_hosts
for chain in INPUT OUTPUT; do
setpolicy $chain DROP
done
else
for chain in INPUT OUTPUT; do
setpolicy $chain ACCEPT
done
setpolicy FORWARD DROP
deleteallchains
enable_critical_hosts
setpolicy INPUT DROP
for chain in INPUT FORWARD; do
setcontinue $chain
done
fi
elif [ -z "$ADMINISABSENTMINDED" ]; then
for chain in INPUT OUTPUT FORWARD; do
setpolicy $chain DROP
done
deleteallchains
else
for chain in INPUT FORWARD; do
setpolicy $chain DROP
done
setpolicy OUTPUT ACCEPT
deleteallchains
for chain in INPUT FORWARD; do
setcontinue $chain
done
fi
process_routestopped -A
$IPTABLES -A INPUT -i lo -j ACCEPT
[ -z "$ADMINISABSENTMINDED" ] && \
$IPTABLES -A OUTPUT -o lo -j ACCEPT
for interface in $(find_interfaces_by_option dhcp); do
$IPTABLES -A INPUT -p udp -i $interface --dport 67:68 -j ACCEPT
[ -z "$ADMINISABSENTMINDED" ] && \
$IPTABLES -A OUTPUT -p udp -o $interface --dport 67:68 -j ACCEPT
#
# This might be a bridge
#
$IPTABLES -A FORWARD -p udp -i $interface -o $interface --dport 67:68 -j ACCEPT
done
case "$IP_FORWARDING" in
On|on|ON|Yes|yes|YES)
echo 1 > /proc/sys/net/ipv4/ip_forward
progress_message2 "IP Forwarding Enabled"
;;
Off|off|OFF|No|no|NO)
echo 0 > /proc/sys/net/ipv4/ip_forward
progress_message2 "IP Forwarding Disabled!"
;;
esac
run_user_exit stopped
set_state "Stopped"
logger -p kern.info "Shorewall Stopped"
rm -rf $TMP_DIR
case $COMMAND in
stop|clear)
;;
*)
#
# The firewall is being stopped when we were trying to do something
# else. Remove the lock file and Kill the shell in case we're in a
# subshell
#
kill $$
;;
esac
}
#
# Remove all rules and remove all user-defined chains
#
clear_firewall() {
stop_firewall
setpolicy INPUT ACCEPT
setpolicy FORWARD ACCEPT
setpolicy OUTPUT ACCEPT
run_iptables -F
echo 1 > /proc/sys/net/ipv4/ip_forward
if [ -n "$DISABLE_IPV6" ] && qt mywhich ip6tables; then
ip6tables -P INPUT ACCEPT 2> /dev/null
ip6tables -P OUTPUT ACCEPT 2> /dev/null
ip6tables -P FORWARD ACCEPT 2> /dev/null
fi
run_user_exit clear
set_state "Cleared"
logger -p kern.info "Shorewall Cleared"
}
#
# Delete existing Proxy ARP
#
delete_proxy_arp() {
if [ -f ${VARDIR}/proxyarp ]; then
while read address interface external haveroute; do
qt arp -i $external -d $address pub
[ -z "${haveroute}${NOROUTES}" ] && qt ip route del $address dev $interface
f=/proc/sys/net/ipv4/conf/$interface/proxy_arp
[ -f $f ] && echo 0 > $f
done < ${VARDIR}/proxyarp
fi
rm -f ${VARDIR}/proxyarp
}
#
# Delete existing Static NAT
#
delete_nat() {
run_iptables -t nat -F
run_iptables -t nat -X
if [ -f ${VARDIR}/nat ]; then
while read external interface; do
qt ip addr del $external dev $interface
done < ${VARDIR}/nat
rm -f ${VARDIR}/nat
fi
[ -d ${VARDIR} ] && touch ${VARDIR}/nat
}
#
# Check for disabled startup
#
check_disabled_startup() {
if [ -z "$STARTUP_ENABLED" ]; then
echo " Shorewall Startup is disabled -- to enable startup"
echo " after you have completed Shorewall configuration,"
echo " change the setting of STARTUP_ENABLED to Yes in"
echo " ${CONFDIR}/shorewall.conf"
[ -n "$TMP_DIR" ] && rm -rf $TMP_DIR
exit 2
fi
}
#
# Give Usage Information
#
usage() {
echo "Usage: $0 [debug] {start|stop|reset|restart|clear}"
exit 1
}
#
# E X E C U T I O N B E G I N S H E R E
#
#
# Start trace if first arg is "debug" or "trace"
#
[ $# -gt 1 ] && [ "x$1" = xdebug -o "$x$1" = xtrace ] && { set -x ; shift ; }
NOLOCK=
[ $# -gt 1 ] && [ "$1" = "nolock" ] && { NOLOCK=Yes; shift ; }
SHAREDIR=/usr/share/shorewall
CONFDIR=/etc/shorewall
[ -f ${CONFDIR}/vardir ] && . ${CONFDIR}/vardir ]
[ -n "${VARDIR:=/var/lib/shorewall}" ]
for library in lib.base lib.config; do
FUNCTIONS=${SHAREDIR}/${library}
if [ -f $FUNCTIONS ]; then
[ $VERBOSE -ge 2 ] && echo "Loading $FUNCTIONS..."
. $FUNCTIONS
else
fatal_error "Installation error: $FUNCTIONS does not exist!"
fi
done
PROGRAM=firewall
COMMAND="$1"
case "$COMMAND" in
stop)
[ $# -ne 1 ] && usage
do_initialize
#
# Don't want to do a 'stop' when startup is disabled
#
check_disabled_startup
progress_message3 "Stopping Shorewall..."
stop_firewall
[ -n "$SUBSYSLOCK" ] && rm -f $SUBSYSLOCK
progress_message3 "done."
;;
reset)
do_initialize
if ! shorewall_is_started ; then
echo "Shorewall Not Started"
[ -n "$TMP_DIR" ] && rm -rf $TMP_DIR
exit 2;
fi
if [ $# -eq 1 ]; then
$IPTABLES -Z
$IPTABLES -t nat -Z
$IPTABLES -t mangle -Z
report "Shorewall Counters Reset"
date > ${VARDIR}/restarted
else
shift;
for chain in $@; do
if chain_exists $chain; then
if qt $IPTABLES -Z $chain; then
progress_message3 "Filter table $chain Counters Reset"
else
error_message "ERROR: Reset of chain $chain failed"
status=2
break
fi
else
error_message "WARNING: Filter Chain $chain does not exist"
fi
done
fi
;;
clear)
[ $# -ne 1 ] && usage
do_initialize
progress_message3 "Clearing Shorewall..."
clear_firewall
[ -n "$SUBSYSLOCK" ] && rm -f $SUBSYSLOCK
progress_message3 "done."
;;
add)
[ $# -lt 3 ] && usage
do_initialize
lib_load dynamiczones "The add command"
if ! shorewall_is_started ; then
echo "Shorewall Not Started"
[ -n "$TMP_DIR" ] && rm -rf $TMP_DIR
exit 2;
fi
shift
add_to_zone $@
;;
delete)
[ $# -lt 3 ] && usage
lib_load dynamiczones "The delete command"
do_initialize
if ! shorewall_is_started ; then
echo "Shorewall Not Started"
[ -n "$TMP_DIR" ] && rm -rf $TMP_DIR
exit 2;
fi
shift
delete_from_zone $@
;;
call)
#
# Undocumented way to call functions in ${SHAREDIR}/firewall directly
#
shift
do_initialize
EMPTY=
$@
;;
*)
usage
;;
esac