firewall: do not process rules in reverse

[openwrt.git] / package / firewall / files / uci_firewall.sh

diff --git a/package/firewall/files/uci_firewall.sh b/package/firewall/files/uci_firewall.sh
index 22731af..64e052f 100755 (executable)
--- a/package/firewall/files/uci_firewall.sh
+++ b/package/firewall/files/uci_firewall.sh
@@ -16,18 +16,29 @@ config_load firewall
 config fw_zones
 ZONE_LIST=$CONFIG_SECTION
 
 config fw_zones
 ZONE_LIST=$CONFIG_SECTION
 

+CUSTOM_CHAINS=1

 DEF_INPUT=DROP
 DEF_OUTPUT=DROP
 DEF_FORWARD=DROP
 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
 
 
 load_policy() {
        config_get input $1 input
        config_get output $1 output
        config_get forward $1 forward
 

-       [ -z "$input" ] && input=$DEF_INPUT
-       [ -z "$output" ] && output=$DEF_OUTPUT
-       [ -z "$forward" ] && forward=$DEF_FORWARD
+       DEF_INPUT="${input:-$DEF_INPUT}"
+       DEF_OUTPUT="${output:-$DEF_OUTPUT}"
+       DEF_FORWARD="${forward:-$DEF_FORWARD}"

 }
 
 create_zone() {
 }
 
 create_zone() {


@@ -40,68 +51,114 @@ create_zone() {
        config_set $ZONE_LIST $1 1 
 
        $IPTABLES -N zone_$1
        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
        $IPTABLES -N zone_$1_ACCEPT
        $IPTABLES -N zone_$1_DROP
        $IPTABLES -N zone_$1_REJECT
        $IPTABLES -N zone_$1_forward

-       $IPTABLES -A zone_$1_forward -j zone_$1_$5
-       $IPTABLES -A zone_$1 -j zone_$1_$3
-       $IPTABLES -A OUTPUT -j zone_$1_$4
+       [ "$5" ] && $IPTABLES -A zone_$1_forward -j zone_$1_$5
+       [ "$3" ] && $IPTABLES -A zone_$1 -j zone_$1_$3
+       [ "$4" ] && $IPTABLES -A output -j zone_$1_$4

        $IPTABLES -N zone_$1_nat -t nat
        $IPTABLES -N zone_$1_prerouting -t nat
        $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
        [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat

+       [ "$7" == "1" ] && $IPTABLES -I FORWARD 1 -j zone_$1_MSSFIX

 }
 
 addif() {
 }
 
 addif() {

-       local dev
-       config_get dev core $2
-       [ -n "$dev" -a "$dev" != "$1" ] && delif "$dev" "$2"
-       [ -n "$dev" -a "$dev" == "$1" ] && return
-       logger "adding $1 to firewall zone $2"
-       $IPTABLES -A INPUT -i $1 -j zone_$2
-       $IPTABLES -I zone_$2_ACCEPT 1 -o $1 -j ACCEPT
-       $IPTABLES -I zone_$2_DROP 1 -o $1 -j DROP
-       $IPTABLES -I zone_$2_REJECT 1 -o $1 -j REJECT
-       $IPTABLES -I zone_$2_ACCEPT 1 -i $1 -j ACCEPT
-       $IPTABLES -I zone_$2_DROP 1 -i $1 -j DROP
-       $IPTABLES -I zone_$2_REJECT 1 -i $1 -j REJECT
-       $IPTABLES -I zone_$2_nat 1 -t nat -o $1 -j MASQUERADE 
-       $IPTABLES -I PREROUTING 1 -t nat -i $1 -j zone_$2_prerouting 
-       $IPTABLES -A FORWARD -i $1 -j zone_$2_forward
-       uci_set_state firewall core "$2" "$1"
+       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() {
 }
 
 delif() {

-       logger "removing $1 from firewall zone $2"
-       $IPTABLES -D INPUT -i $1 -j zone_$2
-       $IPTABLES -D zone_$2_ACCEPT -o $1 -j ACCEPT
-       $IPTABLES -D zone_$2_DROP -o $1 -j DROP
-       $IPTABLES -D zone_$2_REJECT -o $1 -j REJECT
-       $IPTABLES -D zone_$2_ACCEPT -i $1 -j ACCEPT
-       $IPTABLES -D zone_$2_DROP -i $1 -j DROP
-       $IPTABLES -D zone_$2_REJECT -i $1 -j REJECT
-       $IPTABLES -D zone_$2_nat -t nat -o $1 -j MASQUERADE 
-       $IPTABLES -D PREROUTING -t nat -i $1 -j zone_$2_prerouting 
-       $IPTABLES -D FORWARD -i $1 -j zone_$2_forward
-       uci_revert_state firewall core "$2"
+       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() {
 }
 
 load_synflood() {

+       local rate=${1:-25}
+       local burst=${2:-50}

        echo "Loading synflood protection"
        echo "Loading synflood protection"

-       $IPTABLES -N SYN_FLOOD
-       $IPTABLES -A SYN_FLOOD -p tcp --syn -m limit --limit ${1}/second --limit-burst $2 -j RETURN
-       $IPTABLES -A SYN_FLOOD -p ! tcp -j RETURN
-       $IPTABLES -A SYN_FLOOD -p tcp ! --syn -j RETURN
-       $IPTABLES -A SYN_FLOOD -j LOG --log-prefix "syn_flood: " 
-       $IPTABLES -A SYN_FLOOD -j DROP
-       $IPTABLES -A INPUT -p tcp --syn -j SYN_FLOOD
+       $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() {
 }
 
 fw_defaults() {

-       load_policy $1
-       DEF_INPUT=$input
-       DEF_OUTPUT=$output
-       DEF_FORWARD=$forward
+       [ -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 
 
        echo 1 > /proc/sys/net/ipv4/tcp_syncookies
        for f in /proc/sys/net/ipv4/conf/*/accept_redirects 


@@ -116,35 +173,50 @@ fw_defaults() {
        uci_revert_state firewall core
        uci_set_state firewall core "" firewall_state 
 
        uci_revert_state firewall core
        uci_set_state firewall core "" firewall_state 
 

-       $IPTABLES -F
-       $IPTABLES -t nat -F
-       $IPTABLES -t mangle -F
-       $IPTABLES -X -t nat
-       $IPTABLES -X
-       
-       $IPTABLES -P INPUT $input
-       $IPTABLES -A INPUT -m state --state INVALID -j DROP
+       $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 INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

-               
-       $IPTABLES -P OUTPUT $output
-       $IPTABLES -A OUTPUT -m state --state INVALID -j DROP

        $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
        $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

-       
-       $IPTABLES -P FORWARD $forward
-       $IPTABLES -A FORWARD -m state --state INVALID -j DROP
-       $IPTABLES -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

        $IPTABLES -A FORWARD -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
        $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

-
-       [ -z "$syn_rate" ] && syn_rate=25
-       [ -z "$syn_burst" ] && syn_burst=50

        [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
        [ "$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() {
 }
 
 fw_zone() {


@@ -154,11 +226,15 @@ fw_zone() {
 
        config_get name $1 name
        config_get network $1 network
 
        config_get name $1 name
        config_get network $1 network

-       config_get masq $1 masq
-       load_policy $1
+       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
        [ -z "$network" ] && network=$name

-       create_zone "$name" "$network" "$input" "$output" "$forward" "$masq"
+       create_zone "$name" "$network" "$input" "$output" "$forward" "$masq" "$mtu_fix"
+       fw_custom_chains_zone "$name"

 }
 
 fw_rule() {
 }
 
 fw_rule() {


@@ -171,6 +247,7 @@ fw_rule() {
        local dest_ip
        local dest_port
        local proto
        local dest_ip
        local dest_port
        local proto

+       local icmp_type

        local target
        local ruleset
 
        local target
        local ruleset
 


@@ -182,15 +259,30 @@ fw_rule() {
        config_get dest_ip $1 dest_ip
        config_get dest_port $1 dest_port
        config_get proto $1 proto
        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
 
        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 "$target" ] && target=DROP
        [ -z "$target" ] && target=DROP

-       [ -n "$src" ] && ZONE=zone_$src || ZONE=INPUT
-       [ -n "$dest" ] && TARGET=zone_${dest}_$target || TARGET=$target
+       [ -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() {
        add_rule() {

-               $IPTABLES -I $ZONE 1 \
+               $IPTABLES -A $ZONE \

                        ${proto:+-p $proto} \
                        ${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} \
                        ${src_ip:+-s $src_ip} \
                        ${src_port:+--sport $src_port} \
                        ${src_mac:+-m mac --mac-source $src_mac} \


@@ -215,9 +307,13 @@ fw_forwarding() {
 
        config_get src $1 src
        config_get dest $1 dest
 
        config_get src $1 src
        config_get dest $1 dest

-       [ -n "$src" ] && z_src=zone_${src}_forward || z_src=FORWARD
+       [ -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 $z_dest
        [ -n "$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() {
 }
 
 fw_redirect() {


@@ -301,54 +397,66 @@ fw_addif() {
 }
 
 fw_custom_chains() {
 }
 
 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 -N input_rule
        $IPTABLES -N output_rule
        $IPTABLES -N forwarding_rule
        $IPTABLES -N prerouting_rule -t nat
        $IPTABLES -N postrouting_rule -t nat

-       $IPTABLES -N input_wan
-       $IPTABLES -N forwarding_wan
-       $IPTABLES -N prerouting_wan -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
                        
        $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

-       $IPTABLES -A zone_wan -j input_wan
-       $IPTABLES -A zone_wan_forward -j forwarding_wan
-       $IPTABLES -A zone_wan_prerouting -t nat -j prerouting_wan
+}
+
+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() {
 }
 
 fw_init() {

+       DEFAULTS_APPLIED=
+

        echo "Loading defaults"
        config_foreach fw_defaults defaults
        echo "Loading zones"
        config_foreach fw_zone zone
        echo "Loading defaults"
        config_foreach fw_defaults defaults
        echo "Loading zones"
        config_foreach fw_zone zone

-       echo "Loading rules"
-       config_foreach fw_rule rule

        echo "Loading forwarding"
        config_foreach fw_forwarding forwarding
        echo "Loading redirects"
        config_foreach fw_redirect redirect
        echo "Loading forwarding"
        config_foreach fw_forwarding forwarding
        echo "Loading redirects"
        config_foreach fw_redirect redirect

-       echo "Adding custom chains"
-       fw_custom_chains
+       echo "Loading rules"
+       config_foreach fw_rule rule

        echo "Loading includes"
        config_foreach fw_include include
        uci_set_state firewall core loaded 1
        echo "Loading includes"
        config_foreach fw_include include
        uci_set_state firewall core loaded 1

+       config_foreach fw_check_notrack zone

        unset CONFIG_APPEND
        config_load network
        config_foreach fw_addif interface
 }
 
 fw_stop() {
        unset CONFIG_APPEND
        config_load network
        config_foreach fw_addif interface
 }
 
 fw_stop() {

-       $IPTABLES -F
-       $IPTABLES -t nat -F
-       $IPTABLES -t mangle -F
-       $IPTABLES -X -t nat
-       $IPTABLES -X
+       fw_clear

        $IPTABLES -P INPUT ACCEPT
        $IPTABLES -P OUTPUT ACCEPT
        $IPTABLES -P FORWARD ACCEPT
        $IPTABLES -P INPUT ACCEPT
        $IPTABLES -P OUTPUT ACCEPT
        $IPTABLES -P FORWARD ACCEPT

-       uci_revert_state firewall core
+       uci_revert_state firewall

 }
 }