diff options
author | nico <nico@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2008-09-24 15:10:16 +0000 |
---|---|---|
committer | nico <nico@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2008-09-24 15:10:16 +0000 |
commit | 1fa1f8e7d8a80c2fc893dd7c104a4977a30d3004 (patch) | |
tree | 0b83a91c7f2413667c7238fa94624316b2c779d6 /package | |
parent | ac9e683f8ac61059469b09ef4981f4a9ddf66b92 (diff) |
firewall changes:
- implement a REJECT policy and enable it by default, reject packets with approriate response (closes: #3970)
- cleanup syn_flood and remove logging
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@12688 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'package')
-rwxr-xr-x | package/firewall/files/firewall.config | 10 | ||||
-rwxr-xr-x | package/firewall/files/uci_firewall.sh | 80 |
2 files changed, 57 insertions, 33 deletions
diff --git a/package/firewall/files/firewall.config b/package/firewall/files/firewall.config index fe5d38d2b..8ac904955 100755 --- a/package/firewall/files/firewall.config +++ b/package/firewall/files/firewall.config @@ -1,20 +1,20 @@ config defaults option syn_flood 1 - option input DROP + option input REJECT option output ACCEPT - option forward DROP + option forward REJECT config zone option name lan option input ACCEPT option output ACCEPT - option forward DROP + option forward REJECT config zone option name wan - option input DROP + option input REJECT option output ACCEPT - option forward DROP + option forward REJECT option masq 1 config forwarding diff --git a/package/firewall/files/uci_firewall.sh b/package/firewall/files/uci_firewall.sh index 22731af98..884b59639 100755 --- a/package/firewall/files/uci_firewall.sh +++ b/package/firewall/files/uci_firewall.sh @@ -46,7 +46,7 @@ create_zone() { $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 + $IPTABLES -A output -j zone_$1_$4 $IPTABLES -N zone_$1_nat -t nat $IPTABLES -N zone_$1_prerouting -t nat [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat @@ -58,43 +58,52 @@ addif() { [ -n "$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 -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_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_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 + $IPTABLES -A forward -i $1 -j zone_$2_forward uci_set_state firewall core "$2" "$1" } delif() { logger "removing $1 from firewall zone $2" - $IPTABLES -D INPUT -i $1 -j 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_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_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 + $IPTABLES -D forward -i $1 -j zone_$2_forward uci_revert_state firewall core "$2" } load_synflood() { + local rate=${1:-25} + local burst=${2:-50} echo "Loading synflood protection" - $IPTABLES -N SYN_FLOOD - $IPTABLES -A SYN_FLOOD -p tcp --syn -m limit --limit ${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_defaults() { @@ -116,21 +125,23 @@ fw_defaults() { uci_revert_state firewall core uci_set_state firewall core "" firewall_state + $IPTABLES -P INPUT DROP + $IPTABLES -P OUTPUT DROP + $IPTABLES -P FORWARD DROP + $IPTABLES -F - $IPTABLES -t nat -F $IPTABLES -t mangle -F - $IPTABLES -X -t nat + $IPTABLES -t nat -F + $IPTABLES -t mangle -X + $IPTABLES -t nat -X $IPTABLES -X - $IPTABLES -P INPUT $input $IPTABLES -A INPUT -m state --state INVALID -j DROP $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 -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 @@ -141,10 +152,19 @@ fw_defaults() { 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 + + $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_zone() { @@ -186,7 +206,7 @@ fw_rule() { config_get ruleset $1 ruleset [ -z "$target" ] && target=DROP - [ -n "$src" ] && ZONE=zone_$src || ZONE=INPUT + [ -n "$src" ] && ZONE=zone_$src || ZONE=input [ -n "$dest" ] && TARGET=zone_${dest}_$target || TARGET=$target add_rule() { $IPTABLES -I $ZONE 1 \ @@ -215,7 +235,7 @@ fw_forwarding() { 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 } @@ -339,13 +359,17 @@ fw_init() { unset CONFIG_APPEND config_load network config_foreach fw_addif interface + fw_set_chain_policy INPUT $input + fw_set_chain_policy OUTPUT $output + fw_set_chain_policy FORWARD $forward } fw_stop() { $IPTABLES -F - $IPTABLES -t nat -F $IPTABLES -t mangle -F - $IPTABLES -X -t nat + $IPTABLES -t nat -F + $IPTABLES -t mangle -X + $IPTABLES -t nat -X $IPTABLES -X $IPTABLES -P INPUT ACCEPT $IPTABLES -P OUTPUT ACCEPT |