# Copyright (C) 2009-2010 OpenWrt.org # Copyright (C) 2008 John Crispin FW_INITIALIZED= FW_ZONES= FW_ZONES4= FW_ZONES6= FW_CONNTRACK_ZONES= FW_NOTRACK_DISABLED= FW_DEFAULTS_APPLIED= FW_ADD_CUSTOM_CHAINS= FW_ACCEPT_REDIRECTS= FW_ACCEPT_SRC_ROUTE= FW_DEFAULT_INPUT_POLICY=REJECT FW_DEFAULT_OUTPUT_POLICY=REJECT FW_DEFAULT_FORWARD_POLICY=REJECT FW_DISABLE_IPV4=0 FW_DISABLE_IPV6=0 fw_load_defaults() { fw_config_get_section "$1" defaults { \ string input $FW_DEFAULT_INPUT_POLICY \ string output $FW_DEFAULT_OUTPUT_POLICY \ string forward $FW_DEFAULT_FORWARD_POLICY \ boolean drop_invalid 0 \ boolean syn_flood 0 \ boolean synflood_protect 0 \ string synflood_rate 25 \ string synflood_burst 50 \ boolean tcp_syncookies 1 \ boolean tcp_ecn 0 \ boolean tcp_westwood 0 \ boolean tcp_window_scaling 1 \ boolean accept_redirects 0 \ boolean accept_source_route 0 \ boolean custom_chains 1 \ boolean disable_ipv6 0 \ } || return [ -n "$FW_DEFAULTS_APPLIED" ] && { echo "Error: multiple defaults sections detected" return 1 } FW_DEFAULTS_APPLIED=1 FW_DEFAULT_INPUT_POLICY=$defaults_input FW_DEFAULT_OUTPUT_POLICY=$defaults_output FW_DEFAULT_FORWARD_POLICY=$defaults_forward FW_ADD_CUSTOM_CHAINS=$defaults_custom_chains FW_ACCEPT_REDIRECTS=$defaults_accept_redirects FW_ACCEPT_SRC_ROUTE=$defaults_accept_source_route FW_DISABLE_IPV6=$defaults_disable_ipv6 fw_callback pre defaults # Seems like there are only one sysctl for both IP versions. for s in syncookies ecn westwood window_scaling; do eval "sysctl -e -w net.ipv4.tcp_${s}=\$defaults_tcp_${s}" >/dev/null done fw_sysctl_interface all [ $defaults_drop_invalid == 1 ] && { fw add i f INPUT DROP { -m state --state INVALID } fw add i f OUTPUT DROP { -m state --state INVALID } fw add i f FORWARD DROP { -m state --state INVALID } FW_NOTRACK_DISABLED=1 } fw add i f INPUT ACCEPT { -m state --state RELATED,ESTABLISHED } fw add i f OUTPUT ACCEPT { -m state --state RELATED,ESTABLISHED } fw add i f FORWARD ACCEPT { -m state --state RELATED,ESTABLISHED } fw add i f INPUT ACCEPT { -i lo } fw add i f OUTPUT ACCEPT { -o lo } # Compatibility to old 'syn_flood' parameter [ $defaults_syn_flood == 1 ] && \ defaults_synflood_protect=1 [ "${defaults_synflood_rate%/*}" == "$defaults_synflood_rate" ] && \ defaults_synflood_rate="$defaults_synflood_rate/second" [ $defaults_synflood_protect == 1 ] && { echo "Loading synflood protection" fw_callback pre synflood fw add i f syn_flood fw add i f syn_flood RETURN { \ -p tcp --syn \ -m limit --limit "${defaults_synflood_rate}" --limit-burst "${defaults_synflood_burst}" \ } fw add i f syn_flood DROP fw add i f INPUT syn_flood { -p tcp --syn } fw_callback post synflood } [ $defaults_custom_chains == 1 ] && { echo "Adding custom chains" fw add i f input_rule fw add i f output_rule fw add i f forwarding_rule fw add i n prerouting_rule fw add i n postrouting_rule fw add i f INPUT input_rule fw add i f OUTPUT output_rule fw add i f FORWARD forwarding_rule fw add i n PREROUTING prerouting_rule fw add i n POSTROUTING postrouting_rule } fw add i f input fw add i f output fw add i f forward fw add i f INPUT input fw add i f OUTPUT output fw add i f FORWARD forward fw add i f reject fw add i f reject REJECT { --reject-with tcp-reset -p tcp } fw add i f reject REJECT { --reject-with port-unreach } fw_set_filter_policy fw_callback post defaults } fw_config_get_zone() { [ "${zone_NAME}" != "$1" ] || return fw_config_get_section "$1" zone { \ string name "$1" \ string network "" \ string input "$FW_DEFAULT_INPUT_POLICY" \ string output "$FW_DEFAULT_OUTPUT_POLICY" \ string forward "$FW_DEFAULT_FORWARD_POLICY" \ boolean masq 0 \ string masq_src "" \ string masq_dest "" \ boolean conntrack 0 \ boolean mtu_fix 0 \ boolean custom_chains "$FW_ADD_CUSTOM_CHAINS" \ boolean log 0 \ string log_limit 10 \ string family "" \ } || return [ -n "$zone_name" ] || zone_name=$zone_NAME [ -n "$zone_network" ] || zone_network=$zone_name } fw_load_zone() { fw_config_get_zone "$1" list_contains FW_ZONES $zone_name && { fw_die "zone ${zone_name}: duplicated zone" } append FW_ZONES $zone_name fw_callback pre zone [ $zone_conntrack = 1 -o $zone_masq = 1 ] && \ append FW_CONNTRACK_ZONES "$zone_name" local mode case "$zone_family" in *4) mode=4 append FW_ZONES4 $zone_name uci_set_state firewall core ${zone_name}_ipv4 1 ;; *6) mode=6 append FW_ZONES6 $zone_name uci_set_state firewall core ${zone_name}_ipv6 1 ;; *) mode=i append FW_ZONES4 $zone_name append FW_ZONES6 $zone_name uci_set_state firewall core ${zone_name}_ipv4 1 uci_set_state firewall core ${zone_name}_ipv6 1 ;; esac local chain=zone_${zone_name} fw add $mode f ${chain}_ACCEPT fw add $mode f ${chain}_DROP fw add $mode f ${chain}_REJECT fw add $mode f ${chain}_MSSFIX # TODO: Rename to ${chain}_input fw add $mode f ${chain} fw add $mode f ${chain} ${chain}_${zone_input} $ fw add $mode f ${chain}_forward fw add $mode f ${chain}_forward ${chain}_${zone_forward} $ # TODO: add ${chain}_output fw add $mode f output ${chain}_${zone_output} $ # TODO: Rename to ${chain}_MASQUERADE fw add $mode n ${chain}_nat fw add $mode n ${chain}_prerouting fw add $mode r ${chain}_notrack [ $zone_mtu_fix == 1 ] && \ fw add $mode f FORWARD ${chain}_MSSFIX ^ [ $zone_custom_chains == 1 ] && { [ $FW_ADD_CUSTOM_CHAINS == 1 ] || \ fw_die "zone ${zone_name}: custom_chains globally disabled" fw add $mode f input_${zone_name} fw add $mode f ${chain} input_${zone_name} ^ fw add $mode f forwarding_${zone_name} fw add $mode f ${chain}_forward forwarding_${zone_name} ^ fw add $mode n prerouting_${zone_name} fw add $mode n ${chain}_prerouting prerouting_${zone_name} ^ } [ "$zone_log" == 1 ] && { [ "${zone_log_limit%/*}" == "$zone_log_limit" ] && \ zone_log_limit="$zone_log_limit/minute" local t for t in REJECT DROP MSSFIX; do fw add $mode f ${chain}_${t} LOG ^ \ { -m limit --limit $zone_log_limit --log-prefix "$t($zone_name): " } done } # NB: if MASQUERADING for IPv6 becomes available we'll need a family check here if [ "$zone_masq" == 1 ]; then local msrc mdst for msrc in ${zone_masq_src:-0.0.0.0/0}; do [ "${msrc#!}" != "$msrc" ] && msrc="! -s ${msrc#!}" || msrc="-s $msrc" for mdst in ${zone_masq_dest:-0.0.0.0/0}; do [ "${mdst#!}" != "$mdst" ] && mdst="! -d ${mdst#!}" || mdst="-d $mdst" fw add $mode n ${chain}_nat MASQUERADE $ { $msrc $mdst } done done fi fw_callback post zone } fw_load_notrack_zone() { fw_config_get_zone "$1" list_contains FW_CONNTRACK_ZONES "${zone_name}" && return fw_callback pre notrack fw add i r zone_${zone_name}_notrack NOTRACK $ fw_callback post notrack } fw_load_include() { local name="$1" local path; config_get path ${name} path [ -e $path ] && . $path } fw_clear() { local policy=$1 fw_set_filter_policy $policy local tab for tab in f n r; do fw del i $tab done } fw_set_filter_policy() { local policy=$1 local chn tgt for chn in INPUT OUTPUT FORWARD; do eval "tgt=\${policy:-\${FW_DEFAULT_${chn}_POLICY}}" [ $tgt == "REJECT" ] && tgt=reject [ $tgt == "ACCEPT" -o $tgt == "DROP" ] || { fw add i f $chn $tgt $ tgt=DROP } fw policy i f $chn $tgt done } fw_callback() { local pp=$1 local hk=$2 local libs lib eval "libs=\$FW_CB_${pp}_${hk}" [ -n "$libs" ] || return for lib in $libs; do ${lib}_${pp}_${hk}_cb done }