firewall: - allow multiple ports, protocols, macs, icmp types per rule - implement "limit" and "limit_burst" options for rules - implement "extra" option to rules and redirects for passing arbritary flags to iptables - implement negations for "src_port", "dest_port", "src_dport", "src_mac", "proto" and "icmp_type" options - allow wildcard (*) "src" and "dest" options in rules to allow specifying "any" source or destination - validate symbolic icmp-type names against the selected iptables binary - properly handle forwarded ICMPv6 traffic in the default configuration

SVN-Revision: 27317
lede-17.01
Jo-Philipp Wich 2011-06-30 01:31:23 +00:00
parent 8976fa2622
commit 68a1c8e1e3
6 changed files with 219 additions and 73 deletions

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@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=firewall
PKG_VERSION:=2
PKG_RELEASE:=26
PKG_RELEASE:=27
include $(INCLUDE_DIR)/package.mk

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@ -35,13 +35,40 @@ config rule
option target ACCEPT
option family ipv4
#Allow ping
# Allow IPv4 ping
config rule
option src wan
option proto icmp
option icmp_type echo-request
option family ipv4
option target ACCEPT
# Allow essential incoming IPv6 ICMP traffic
config rule
option src wan
option dest *
option proto icmp
list icmp_type router-solicitation
list icmp_type router-advertisement
list icmp_type neighbour-solicitation
list icmp_type neighbour-advertisement
list icmp_type echo-request
list icmp_type destination-unreachable
list icmp_type packet-too-big
list icmp_type time-exceeded
option limit 1000/sec
option family ipv6
option target ACCEPT
# Drop leaking router advertisements on WAN
config rule
option src *
option dest wan
option proto icmp
option icmp_type router-advertisement
option family ipv6
option target DROP
# include a file with users custom iptables rules
config include
option path /etc/firewall.user

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@ -13,11 +13,11 @@ fw_config_get_redirect() {
string src_dport "" \
string dest "" \
ipaddr dest_ip "" \
string dest_mac "" \
string dest_port "" \
string proto "tcpudp" \
string family "" \
string target "DNAT" \
string extra "" \
} || return
[ -n "$redirect_name" ] || redirect_name=$redirect__name
}
@ -29,26 +29,27 @@ fw_load_redirect() {
local fwdchain natchain natopt nataddr natports srcdaddr srcdports
if [ "$redirect_target" == "DNAT" ]; then
[ -n "$redirect_src" -a -n "$redirect_dest_ip$redirect_dest_port" ] || {
[ -n "${redirect_src#*}" -a -n "$redirect_dest_ip$redirect_dest_port" ] || {
fw_log error "DNAT redirect ${redirect_name}: needs src and dest_ip or dest_port, skipping"
return 0
}
fwdchain="zone_${redirect_src}${redirect_dest_ip:+_forward}"
fwdchain="zone_${redirect_src}_forward"
natopt="--to-destination"
natchain="zone_${redirect_src}_prerouting"
nataddr="$redirect_dest_ip"
fw_get_port_range natports "$redirect_dest_port" "-"
fw_get_port_range natports "${redirect_dest_port#!}" "-"
fw_get_negation srcdaddr '-d' "${redirect_src_dip:+$redirect_src_dip/$redirect_src_dip_prefixlen}"
fw_get_port_range srcdports "$redirect_src_dport" ":"
fw_get_negation srcdports '--dport' "$srcdports"
list_contains FW_CONNTRACK_ZONES $redirect_src || \
append FW_CONNTRACK_ZONES $redirect_src
elif [ "$redirect_target" == "SNAT" ]; then
[ -n "$redirect_dest" -a -n "$redirect_src_dip" ] || {
[ -n "${redirect_dest#*}" -a -n "$redirect_src_dip" ] || {
fw_log error "SNAT redirect ${redirect_name}: needs dest and src_dip, skipping"
return 0
}
@ -58,10 +59,11 @@ fw_load_redirect() {
natopt="--to-source"
natchain="zone_${redirect_dest}_nat"
nataddr="$redirect_src_dip"
fw_get_port_range natports "$redirect_src_dport" "-"
fw_get_port_range natports "${redirect_src_dport#!}" "-"
fw_get_negation srcdaddr '-d' "${redirect_dest_ip:+$redirect_dest_ip/$redirect_dest_ip_prefixlen}"
fw_get_port_range srcdports "$redirect_dest_port" ":"
fw_get_negation srcdports '--dport' "$srcdports"
list_contains FW_CONNTRACK_ZONES $redirect_dest || \
append FW_CONNTRACK_ZONES $redirect_dest
@ -79,35 +81,39 @@ fw_load_redirect() {
local srcports
fw_get_port_range srcports "$redirect_src_port" ":"
fw_get_negation srcports '--sport' "$srcports"
local destaddr
fw_get_negation destaddr '-d' "${redirect_dest_ip:+$redirect_dest_ip/$redirect_dest_ip_prefixlen}"
local destports
fw_get_port_range destports "${redirect_dest_port:-$redirect_src_dport}" ":"
fw_get_negation destports '--dport' "$destports"
[ "$redirect_proto" == "tcpudp" ] && redirect_proto="tcp udp"
for redirect_proto in $redirect_proto; do
local pos
eval 'pos=$((++FW__REDIR_COUNT_'${mode#G}'_'$natchain'))'
fw add $mode n $natchain $redirect_target $pos { $redirect_src_ip $redirect_dest_ip } { \
$srcaddr $srcdaddr \
${redirect_proto:+-p $redirect_proto} \
${srcports:+--sport $srcports} \
${srcdports:+--dport $srcdports} \
${redirect_src_mac:+-m mac --mac-source $redirect_src_mac} \
fw_get_negation redirect_proto '-p' "$redirect_proto"
for redirect_src_mac in ${redirect_src_mac:-""}; do
fw_get_negation redirect_src_mac '--mac-source' "$redirect_src_mac"
fw add $mode n $natchain $redirect_target + \
{ $redirect_src_ip $redirect_dest_ip } { \
$srcaddr $srcdaddr $redirect_proto \
$srcports $srcdports \
${redirect_src_mac:+-m mac $redirect_src_mac} \
$natopt $nataddr${natports:+:$natports} \
$redirect_options \
}
fw add $mode f ${fwdchain:-forward} ACCEPT ^ { $redirect_src_ip $redirect_dest_ip } { \
$srcaddr ${destaddr:--m conntrack --ctstate DNAT} \
${redirect_proto:+-p $redirect_proto} \
${srcports:+--sport $srcports} \
${destports:+--dport $destports} \
${redirect_src_mac:+-m mac --mac-source $redirect_src_mac} \
[ -n "$destaddr" ] && \
fw add $mode f ${fwdchain:-forward} ACCEPT + \
{ $redirect_src_ip $redirect_dest_ip } { \
$srcaddr $destaddr $redirect_proto \
$srcports $destports \
$redirect_src_mac \
$redirect_extra \
}
done
done
fw_callback post redirect
}

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@ -16,24 +16,23 @@ fw_config_get_rule() {
string proto "tcpudp" \
string target "" \
string family "" \
string limit "" \
string limit_burst "" \
string extra "" \
} || return
[ -n "$rule_name" ] || rule_name=$rule__name
[ "$rule_proto" == "icmp" ] || rule_icmp_type=
}
fw_load_rule() {
fw_config_get_rule "$1"
[ "$rule_target" != "NOTRACK" ] || [ -n "$rule_src" ] || {
[ "$rule_target" != "NOTRACK" ] || [ -n "$rule_src" ] || [ "$rule_src" != "*" ] || {
fw_log error "NOTRACK rule ${rule_name}: needs src, skipping"
return 0
}
fw_callback pre rule
fw_get_port_range rule_src_port $rule_src_port
fw_get_port_range rule_dest_port $rule_dest_port
local table=f
local chain=input
local target="${rule_target:-REJECT}"
@ -41,8 +40,22 @@ fw_load_rule() {
table=r
chain="zone_${rule_src}_notrack"
else
[ -n "$rule_src" ] && chain="zone_${rule_src}${rule_dest:+_forward}"
[ -n "$rule_dest" ] && target="zone_${rule_dest}_${target}"
if [ -n "$rule_src" ]; then
if [ "$rule_src" != "*" ]; then
chain="zone_${rule_src}${rule_dest:+_forward}"
else
chain="${rule_dest:+forward}"
chain="${chain:-input}"
fi
fi
if [ -n "$rule_dest" ]; then
if [ "$rule_dest" != "*" ]; then
target="zone_${rule_dest}_${target}"
elif [ "$target" = REJECT ]; then
target=reject
fi
fi
fi
local mode
@ -54,18 +67,32 @@ fw_load_rule() {
[ "$rule_proto" == "tcpudp" ] && rule_proto="tcp udp"
for rule_proto in $rule_proto; do
local rule_pos
eval 'rule_pos=$((++FW__RULE_COUNT_'${mode#G}'_'$chain'))'
fw add $mode $table $chain $target $rule_pos { $rule_src_ip $rule_dest_ip } { \
$src_spec $dest_spec \
${rule_proto:+-p $rule_proto} \
${rule_src_port:+--sport $rule_src_port} \
${rule_src_mac:+-m mac --mac-source $rule_src_mac} \
${rule_dest_port:+--dport $rule_dest_port} \
fw_get_negation rule_proto '-p' "$rule_proto"
for rule_src_port in ${rule_src_port:-""}; do
fw_get_port_range rule_src_port $rule_src_port
fw_get_negation rule_src_port '--sport' "$rule_src_port"
for rule_dest_port in ${rule_dest_port:-""}; do
fw_get_port_range rule_dest_port $rule_dest_port
fw_get_negation rule_dest_port '--dport' "$rule_dest_port"
for rule_src_mac in ${rule_src_mac:-""}; do
fw_get_negation rule_src_mac '--mac-source' "$rule_src_mac"
for rule_icmp_type in ${rule_icmp_type:-""}; do
[ "$rule_proto" = "-p icmp" ] || rule_icmp_type=""
fw add $mode $table $chain $target + \
{ $rule_src_ip $rule_dest_ip } { \
$src_spec $dest_spec $rule_proto \
$rule_src_port $rule_dest_port \
${rule_src_mac:+-m mac $rule_src_mac} \
${rule_icmp_type:+--icmp-type $rule_icmp_type} \
${rule_limit:+-m limit --limit $rule_limit \
${rule_limit_burst:+--limit-burst $rule_limit_burst}} \
$rule_extra \
}
done
done
done
done
done
fw_callback post rule
}

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@ -137,10 +137,13 @@ fw__exec() { # <action> <family> <table> <chain> <target> <position> { <rules> }
case "$tgt" in
-) tgt= ;;
esac
local rule_offset
case "$pos" in
^) pos=1 ;;
$) pos= ;;
-) pos= ;;
+) eval "rule_offset=\${FW__RULE_OFS_${app}_${tab}_${chn}:-1}" ;;
esac
if ! fw__has - family || ! fw__has $tab ; then
@ -159,13 +162,29 @@ fw__exec() { # <action> <family> <table> <chain> <target> <position> { <rules> }
fi
fi
local cmdline="$app --table ${tab} --${cmd} ${chn} ${pol} ${pos} ${tgt:+--jump "$tgt"}"
local cmdline="$app --table ${tab} --${cmd} ${chn} ${pol} ${rule_offset:-${pos}} ${tgt:+--jump "$tgt"}"
while [ $# -gt 1 ]; do
case "$app:$1" in
ip6tables:--icmp-type) cmdline="$cmdline --icmpv6-type" ;;
ip6tables:icmp|ip6tables:ICMP) cmdline="$cmdline icmpv6" ;;
iptables:--icmpv6-type) cmdline="$cmdline --icmp-type" ;;
iptables:icmpv6) cmdline="$cmdline icmp" ;;
# special parameter handling
case "$1:$2" in
-p:icmp*|--protocol:icmp*)
[ "$app" = ip6tables ] && \
cmdline="$cmdline -p icmpv6" || \
cmdline="$cmdline -p icmp"
shift
;;
--icmp-type:*|--icmpv6-type:*)
local icmp_type
if [ "$app" = ip6tables ] && fw_check_icmptype6 icmp_type "$2"; then
cmdline="$cmdline $icmp_type"
elif [ "$app" = iptables ] && fw_check_icmptype4 icmp_type "$2"; then
cmdline="$cmdline $icmp_type"
else
local fam=IPv4; [ "$app" = ip6tables ] && fam=IPv6
fw_log info "ICMP type '$2' is not valid for $fam address family, skipping rule"
return 1
fi
shift
;;
*) cmdline="$cmdline $1" ;;
esac
shift
@ -175,7 +194,10 @@ fw__exec() { # <action> <family> <table> <chain> <target> <position> { <rules> }
$cmdline
fw__rc $?
local rv=$?
[ $rv -eq 0 ] && [ -n "$rule_offset" ] && \
export -- "FW__RULE_OFS_${app}_${tab}_${chn}=$(($rule_offset + 1))"
fw__rc $rv
}
fw_get_port_range() {
@ -189,8 +211,8 @@ fw_get_port_range() {
local _first=${_ports%-*}
local _last=${_ports#*-}
if [ "$_first" != "$_last" ]; then
export -- "$_var=$_first$_delim$_last"
if [ "${_first#!}" != "${_last#!}" ]; then
export -- "$_var=$_first$_delim${_last#!}"
else
export -- "$_var=$_first"
fi
@ -221,11 +243,11 @@ fw_get_family_mode() {
fw_get_negation() {
local _var="$1"
local _flag="$2"
local _ipaddr="$3"
local _value="$3"
[ "${_ipaddr#!}" != "$_ipaddr" ] && \
export -n -- "$_var=! $_flag ${_ipaddr#!}" || \
export -n -- "$_var=${_ipaddr:+$_flag $_ipaddr}"
[ "${_value#!}" != "$_value" ] && \
export -n -- "$_var=! $_flag ${_value#!}" || \
export -n -- "$_var=${_value:+$_flag $_value}"
}
fw_get_subnet4() {
@ -245,3 +267,66 @@ fw_get_subnet4() {
*) export -n -- "$_var=" ;;
esac
}
fw_check_icmptype4() {
local _var="$1"
local _type="$2"
case "$_type" in
![0-9]*) export -n -- "$_var=! --icmp-type ${_type#!}"; return 0 ;;
[0-9]*) export -n -- "$_var=--icmp-type $_type"; return 0 ;;
esac
[ -z "$FW_ICMP4_TYPES" ] && \
export FW_ICMP4_TYPES=$(
iptables -p icmp -h 2>/dev/null | \
sed -n -e '/^Valid ICMP Types:/ {
n; :r;
/router-advertisement/d;
/router-solicitation/d;
s/[()]/ /g; s/[[:space:]]\+/\n/g; p; n; b r
}' | sort -u
)
local _check
for _check in $FW_ICMP4_TYPES; do
if [ "$_check" = "${_type#!}" ]; then
[ "${_type#!}" != "$_type" ] && \
export -n -- "$_var=! --icmp-type ${_type#!}" || \
export -n -- "$_var=--icmp-type $_type"
return 0
fi
done
export -n -- "$_var="
return 1
}
fw_check_icmptype6() {
local _var="$1"
local _type="$2"
case "$_type" in
![0-9]*) export -n -- "$_var=! --icmpv6-type ${_type#!}"; return 0 ;;
[0-9]*) export -n -- "$_var=--icmpv6-type $_type"; return 0 ;;
esac
[ -z "$FW_ICMP6_TYPES" ] && \
export FW_ICMP6_TYPES=$(
ip6tables -p icmpv6 -h 2>/dev/null | \
sed -n -e '/^Valid ICMPv6 Types:/ {
n; :r; s/[()]/ /g; s/[[:space:]]\+/\n/g; p; n; b r
}' | sort -u
)
local _check
for _check in $FW_ICMP6_TYPES; do
if [ "$_check" = "${_type#!}" ]; then
[ "${_type#!}" != "$_type" ] && \
export -n -- "$_var=! --icmpv6-type ${_type#!}" || \
export -n -- "$_var=--icmpv6-type $_type"
return 0
fi
done
export -n -- "$_var="
return 1
}

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@ -56,6 +56,7 @@ if [ "$ACTION" = "add" ] && [ "$INTERFACE" = "wan" ]; then
[ "$src" = wan ] && [ "$target" = DNAT ] && {
local dest
config_get dest "$cfg" dest "lan"
[ "$dest" != "*" ] || return
local net
for net in $(find_networks "$dest"); do