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- #!/bin/sh
- # Copyright (C) 2008 John Crispin <[email protected]>
- . /etc/functions.sh
- IPTABLES="echo iptables"
- IPTABLES=iptables
- config_clear
- include /lib/network
- scan_interfaces
- CONFIG_APPEND=1
- config_load firewall
- config fw_zones
- ZONE_LIST=$CONFIG_SECTION
- CUSTOM_CHAINS=1
- DEF_INPUT=DROP
- DEF_OUTPUT=DROP
- DEF_FORWARD=DROP
- CONNTRACK_ZONES=
- NOTRACK_DISABLED=
- find_item() {
- local item="$1"; shift
- for i in "$@"; do
- [ "$i" = "$item" ] && return 0
- done
- return 1
- }
- load_policy() {
- config_get input $1 input
- config_get output $1 output
- config_get forward $1 forward
- DEF_INPUT="${input:-$DEF_INPUT}"
- DEF_OUTPUT="${output:-$DEF_OUTPUT}"
- DEF_FORWARD="${forward:-$DEF_FORWARD}"
- }
- create_zone() {
- local exists
- [ "$1" == "loopback" ] && return
- config_get exists $ZONE_LIST $1
- [ -n "$exists" ] && return
- config_set $ZONE_LIST $1 1
- $IPTABLES -N zone_$1
- $IPTABLES -N zone_$1_MSSFIX
- $IPTABLES -N zone_$1_ACCEPT
- $IPTABLES -N zone_$1_DROP
- $IPTABLES -N zone_$1_REJECT
- $IPTABLES -N zone_$1_forward
- [ "$4" ] && $IPTABLES -A output -j zone_$1_$4
- $IPTABLES -N zone_$1_nat -t nat
- $IPTABLES -N zone_$1_prerouting -t nat
- $IPTABLES -t raw -N zone_$1_notrack
- [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat
- [ "$7" == "1" ] && $IPTABLES -I FORWARD 1 -j zone_$1_MSSFIX
- }
- addif() {
- local network="$1"
- local ifname="$2"
- local zone="$3"
- local n_if n_zone
- config_get n_if core "${network}_ifname"
- config_get n_zone core "${network}_zone"
- [ -n "$n_zone" ] && {
- if [ "$n_zone" != "$zone" ]; then
- delif "$network" "$n_if" "$n_zone"
- else
- return
- fi
- }
- logger "adding $network ($ifname) to firewall zone $zone"
- $IPTABLES -A input -i "$ifname" -j zone_${zone}
- $IPTABLES -I zone_${zone}_MSSFIX 1 -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
- $IPTABLES -I zone_${zone}_ACCEPT 1 -o "$ifname" -j ACCEPT
- $IPTABLES -I zone_${zone}_DROP 1 -o "$ifname" -j DROP
- $IPTABLES -I zone_${zone}_REJECT 1 -o "$ifname" -j reject
- $IPTABLES -I zone_${zone}_ACCEPT 1 -i "$ifname" -j ACCEPT
- $IPTABLES -I zone_${zone}_DROP 1 -i "$ifname" -j DROP
- $IPTABLES -I zone_${zone}_REJECT 1 -i "$ifname" -j reject
- $IPTABLES -I zone_${zone}_nat 1 -t nat -o "$ifname" -j MASQUERADE
- $IPTABLES -I PREROUTING 1 -t nat -i "$ifname" -j zone_${zone}_prerouting
- $IPTABLES -A forward -i "$ifname" -j zone_${zone}_forward
- $IPTABLES -t raw -I PREROUTING 1 -i "$ifname" -j zone_${zone}_notrack
- uci_set_state firewall core "${network}_ifname" "$ifname"
- uci_set_state firewall core "${network}_zone" "$zone"
- ACTION=add ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
- }
- delif() {
- local network="$1"
- local ifname="$2"
- local zone="$3"
- logger "removing $network ($ifname) from firewall zone $zone"
- $IPTABLES -D input -i "$ifname" -j zone_$zone
- $IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
- $IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
- $IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
- $IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
- $IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
- $IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
- $IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
- $IPTABLES -D zone_${zone}_nat -t nat -o "$ifname" -j MASQUERADE
- $IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting
- $IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
- uci_revert_state firewall core "${network}_ifname"
- uci_revert_state firewall core "${network}_zone"
- ACTION=remove ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
- }
- load_synflood() {
- local rate=${1:-25}
- local burst=${2:-50}
- echo "Loading synflood protection"
- $IPTABLES -N syn_flood
- $IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
- $IPTABLES -A syn_flood -j DROP
- $IPTABLES -A INPUT -p tcp --syn -j syn_flood
- }
- fw_set_chain_policy() {
- local chain=$1
- local target=$2
- [ "$target" == "REJECT" ] && {
- $IPTABLES -A $chain -j reject
- target=DROP
- }
- $IPTABLES -P $chain $target
- }
- fw_clear() {
- $IPTABLES -F
- $IPTABLES -t nat -F
- $IPTABLES -t nat -X
- $IPTABLES -t raw -F
- $IPTABLES -t raw -X
- $IPTABLES -X
- }
- fw_defaults() {
- [ -n "$DEFAULTS_APPLIED" ] && {
- echo "Error: multiple defaults sections detected"
- return;
- }
- DEFAULTS_APPLIED=1
- load_policy "$1"
- echo 1 > /proc/sys/net/ipv4/tcp_syncookies
- for f in /proc/sys/net/ipv4/conf/*/accept_redirects
- do
- echo 0 > $f
- done
- for f in /proc/sys/net/ipv4/conf/*/accept_source_route
- do
- echo 0 > $f
- done
- uci_revert_state firewall core
- uci_set_state firewall core "" firewall_state
- $IPTABLES -P INPUT DROP
- $IPTABLES -P OUTPUT DROP
- $IPTABLES -P FORWARD DROP
- fw_clear
- config_get_bool drop_invalid $1 drop_invalid 0
- [ "$drop_invalid" -gt 0 ] && {
- $IPTABLES -A INPUT -m state --state INVALID -j DROP
- $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
- $IPTABLES -A FORWARD -m state --state INVALID -j DROP
- NOTRACK_DISABLED=1
- }
- $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
- $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
- $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
- $IPTABLES -A INPUT -i lo -j ACCEPT
- $IPTABLES -A OUTPUT -o lo -j ACCEPT
- config_get syn_flood $1 syn_flood
- config_get syn_rate $1 syn_rate
- config_get syn_burst $1 syn_burst
- [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
- echo "Adding custom chains"
- fw_custom_chains
- $IPTABLES -N input
- $IPTABLES -N output
- $IPTABLES -N forward
- $IPTABLES -A INPUT -j input
- $IPTABLES -A OUTPUT -j output
- $IPTABLES -A FORWARD -j forward
- $IPTABLES -N reject
- $IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
- $IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable
- fw_set_chain_policy INPUT "$DEF_INPUT"
- fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
- fw_set_chain_policy FORWARD "$DEF_FORWARD"
- }
- fw_zone_defaults() {
- local name
- local network
- local masq
- config_get name $1 name
- config_get network $1 network
- config_get_bool masq $1 masq "0"
- config_get_bool conntrack $1 conntrack "0"
- config_get_bool mtu_fix $1 mtu_fix 0
- load_policy $1
- [ "$forward" ] && $IPTABLES -A zone_${name}_forward -j zone_${name}_${forward}
- [ "$input" ] && $IPTABLES -A zone_${name} -j zone_${name}_${input}
- }
- fw_zone() {
- local name
- local network
- local masq
- config_get name $1 name
- config_get network $1 network
- config_get_bool masq $1 masq "0"
- config_get_bool conntrack $1 conntrack "0"
- config_get_bool mtu_fix $1 mtu_fix 0
- load_policy $1
- [ "$conntrack" = "1" -o "$masq" = "1" ] && append CONNTRACK_ZONES "$name"
- [ -z "$network" ] && network=$name
- create_zone "$name" "$network" "$input" "$output" "$forward" "$masq" "$mtu_fix"
- fw_custom_chains_zone "$name"
- }
- fw_rule() {
- local src
- local src_ip
- local src_mac
- local src_port
- local src_mac
- local dest
- local dest_ip
- local dest_port
- local proto
- local icmp_type
- local target
- local ruleset
- config_get src $1 src
- config_get src_ip $1 src_ip
- config_get src_mac $1 src_mac
- config_get src_port $1 src_port
- config_get dest $1 dest
- config_get dest_ip $1 dest_ip
- config_get dest_port $1 dest_port
- config_get proto $1 proto
- config_get icmp_type $1 icmp_type
- config_get target $1 target
- config_get ruleset $1 ruleset
- src_port_first=${src_port%-*}
- src_port_last=${src_port#*-}
- [ "$src_port_first" -ne "$src_port_last" ] && { \
- src_port="$src_port_first:$src_port_last"; }
- dest_port_first=${dest_port%-*}
- dest_port_last=${dest_port#*-}
- [ "$dest_port_first" -ne "$dest_port_last" ] && { \
- dest_port="$dest_port_first:$dest_port_last"; }
- ZONE=input
- TARGET=$target
- [ -z "$target" ] && target=DROP
- [ -n "$src" -a -z "$dest" ] && ZONE=zone_$src
- [ -n "$src" -a -n "$dest" ] && ZONE=zone_${src}_forward
- [ -n "$dest" ] && TARGET=zone_${dest}_$target
- add_rule() {
- $IPTABLES -A $ZONE \
- ${proto:+-p $proto} \
- ${icmp_type:+--icmp-type $icmp_type} \
- ${src_ip:+-s $src_ip} \
- ${src_port:+--sport $src_port} \
- ${src_mac:+-m mac --mac-source $src_mac} \
- ${dest_ip:+-d $dest_ip} \
- ${dest_port:+--dport $dest_port} \
- -j $TARGET
- }
- [ "$proto" == "tcpudp" -o -z "$proto" ] && {
- proto=tcp
- add_rule
- proto=udp
- add_rule
- return
- }
- add_rule
- }
- fw_forwarding() {
- local src
- local dest
- local masq
- config_get src $1 src
- config_get dest $1 dest
- [ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
- [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
- $IPTABLES -I $z_src 1 -j $z_dest
- # propagate masq zone flag
- find_item "$src" $CONNTRACK_ZONES && append CONNTRACK_ZONES $dest
- find_item "$dest" $CONNTRACK_ZONES && append CONNTRACK_ZONES $src
- }
- fw_redirect() {
- local src
- local src_ip
- local src_port
- local src_dport
- local src_mac
- local dest_ip
- local dest_port dest_port2
- local proto
- config_get src $1 src
- config_get src_ip $1 src_ip
- config_get src_port $1 src_port
- config_get src_dport $1 src_dport
- config_get src_mac $1 src_mac
- config_get dest_ip $1 dest_ip
- config_get dest_port $1 dest_port
- config_get proto $1 proto
- [ -z "$src" -o -z "$dest_ip" ] && { \
- echo "redirect needs src and dest_ip"; return ; }
- src_port_first=${src_port%-*}
- src_port_last=${src_port#*-}
- [ "$src_port_first" -ne "$src_port_last" ] && { \
- src_port="$src_port_first:$src_port_last"; }
- src_dport_first=${src_dport%-*}
- src_dport_last=${src_dport#*-}
- [ "$src_dport_first" -ne "$src_dport_last" ] && { \
- src_dport="$src_dport_first:$src_dport_last"; }
- dest_port2=${dest_port:-$src_dport}
- dest_port_first=${dest_port2%-*}
- dest_port_last=${dest_port2#*-}
- [ "$dest_port_first" -ne "$dest_port_last" ] && { \
- dest_port2="$dest_port_first:$dest_port_last"; }
- add_rule() {
- $IPTABLES -A zone_${src}_prerouting -t nat \
- ${proto:+-p $proto} \
- ${src_ip:+-s $src_ip} \
- ${src_port:+--sport $src_port} \
- ${src_dport:+--dport $src_dport} \
- ${src_mac:+-m mac --mac-source $src_mac} \
- -j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}
- $IPTABLES -I zone_${src}_forward 1 \
- ${proto:+-p $proto} \
- -d $dest_ip \
- ${src_ip:+-s $src_ip} \
- ${src_port:+--sport $src_port} \
- ${dest_port2:+--dport $dest_port2} \
- ${src_mac:+-m mac --mac-source $src_mac} \
- -j ACCEPT
- }
- [ "$proto" == "tcpudp" -o -z "$proto" ] && {
- proto=tcp
- add_rule
- proto=udp
- add_rule
- return
- }
- add_rule
- }
- fw_include() {
- local path
- config_get path $1 path
- [ -e $path ] && . $path
- }
- get_interface_zones() {
- local interface="$2"
- local name
- local network
- config_get name $1 name
- config_get network $1 network
- [ -z "$network" ] && network=$name
- for n in $network; do
- [ "$n" = "$interface" ] && append add_zone "$name"
- done
- }
- fw_event() {
- local action="$1"
- local interface="$2"
- local ifname="$(sh -c ". /etc/functions.sh; include /lib/network; scan_interfaces; config_get "$interface" ifname")"
- add_zone=
- local up
- [ -z "$ifname" ] && return 0
- config_foreach get_interface_zones zone "$interface"
- [ -z "$add_zone" ] && return 0
- case "$action" in
- ifup)
- for z in $add_zone; do
- local loaded
- config_get loaded core loaded
- [ -n "$loaded" ] && addif "$interface" "$ifname" "$z"
- done
- ;;
- ifdown)
- config_get up "$interface" up
- for z in $ZONE; do
- [ "$up" == "1" ] && delif "$interface" "$ifname" "$z"
- done
- ;;
- esac
- }
- fw_addif() {
- local up
- local ifname
- config_get up $1 up
- [ -n "$up" ] || return 0
- fw_event ifup "$1"
- }
- fw_custom_chains() {
- [ -n "$CUSTOM_CHAINS" ] || return 0
- $IPTABLES -N input_rule
- $IPTABLES -N output_rule
- $IPTABLES -N forwarding_rule
- $IPTABLES -N prerouting_rule -t nat
- $IPTABLES -N postrouting_rule -t nat
- $IPTABLES -A INPUT -j input_rule
- $IPTABLES -A OUTPUT -j output_rule
- $IPTABLES -A FORWARD -j forwarding_rule
- $IPTABLES -A PREROUTING -t nat -j prerouting_rule
- $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
- }
- fw_custom_chains_zone() {
- local zone="$1"
- [ -n "$CUSTOM_CHAINS" ] || return 0
- $IPTABLES -N input_${zone}
- $IPTABLES -N forwarding_${zone}
- $IPTABLES -N prerouting_${zone} -t nat
- $IPTABLES -I zone_${zone} 1 -j input_${zone}
- $IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
- $IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
- }
- fw_check_notrack() {
- local zone="$1"
- config_get name "$zone" name
- [ -n "$NOTRACK_DISABLED" ] || \
- find_item "$name" $CONNTRACK_ZONES || \
- $IPTABLES -t raw -A zone_${name}_notrack -j NOTRACK
- }
- fw_init() {
- DEFAULTS_APPLIED=
- echo "Loading defaults"
- config_foreach fw_defaults defaults
- echo "Loading zones"
- config_foreach fw_zone zone
- echo "Loading forwarding"
- config_foreach fw_forwarding forwarding
- echo "Loading redirects"
- config_foreach fw_redirect redirect
- echo "Loading rules"
- config_foreach fw_rule rule
- echo "Loading includes"
- config_foreach fw_include include
- echo "Loading zone defaults"
- config_foreach fw_zone_defaults zone
- uci_set_state firewall core loaded 1
- config_set core loaded 1
- config_foreach fw_check_notrack zone
- INTERFACES="$(sh -c '. /etc/functions.sh; config_load network; config_foreach echo interface')"
- for interface in $INTERFACES; do
- fw_addif "$interface"
- done
- }
- fw_stop() {
- fw_clear
- $IPTABLES -P INPUT ACCEPT
- $IPTABLES -P OUTPUT ACCEPT
- $IPTABLES -P FORWARD ACCEPT
- uci_revert_state firewall
- }
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