package/firewall/files/uci_firewall.sh

   1 #!/bin/sh
   2 # Copyright (C) 2008 John Crispin <blogic@openwrt.org>
   3
   4 . /etc/functions.sh
   5
   6 IPTABLES="echo iptables"
   7 IPTABLES=iptables
   8
   9 config_clear
  10 include /lib/network
  11 scan_interfaces
  12
  13 CONFIG_APPEND=1
  14 config_load firewall
  15
  16 config fw_zones
  17 ZONE_LIST=$CONFIG_SECTION
  18
  19 DEF_INPUT=DROP
  20 DEF_OUTPUT=DROP
  21 DEF_FORWARD=DROP
  22
  23 load_policy() {
  24         config_get input $1 input
  25         config_get output $1 output
  26         config_get forward $1 forward
  27
  28         [ -z "$input" ] && input=$DEF_INPUT
  29         [ -z "$output" ] && output=$DEF_OUTPUT
  30         [ -z "$forward" ] && forward=$DEF_FORWARD
  31 }
  32
  33 create_zone() {
  34         local exists
  35
  36         [ "$1" == "loopback" ] && return
  37
  38         config_get exists $ZONE_LIST $1
  39         [ -n "$exists" ] && return
  40         config_set $ZONE_LIST $1 1
  41
  42         $IPTABLES -N zone_$1
  43         $IPTABLES -N zone_$1_ACCEPT
  44         $IPTABLES -N zone_$1_DROP
  45         $IPTABLES -N zone_$1_REJECT
  46         $IPTABLES -N zone_$1_forward
  47         $IPTABLES -A zone_$1_forward -j zone_$1_$5
  48         $IPTABLES -A zone_$1 -j zone_$1_$3
  49         $IPTABLES -A OUTPUT -j zone_$1_$4
  50         $IPTABLES -N zone_$1_nat -t nat
  51         $IPTABLES -N zone_$1_prerouting -t nat
  52         [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$2_nat
  53 }
  54
  55 addif() {
  56         local dev
  57         config_get dev core $2
  58         [ -n "$dev" -a "$dev" != "$1" ] && delif "$dev" "$2"
  59         [ -n "$dev" -a "$dev" == "$1" ] && return
  60         logger "adding $1 to firewall zone $2"
  61         $IPTABLES -A INPUT -i $1 -j zone_$2
  62         $IPTABLES -I zone_$2_ACCEPT 1 -o $1 -j ACCEPT
  63         $IPTABLES -I zone_$2_DROP 1 -o $1 -j DROP
  64         $IPTABLES -I zone_$2_REJECT 1 -o $1 -j REJECT
  65         $IPTABLES -I zone_$2_ACCEPT 1 -i $1 -j ACCEPT
  66         $IPTABLES -I zone_$2_DROP 1 -i $1 -j DROP
  67         $IPTABLES -I zone_$2_REJECT 1 -i $1 -j REJECT
  68         $IPTABLES -I zone_$2_nat 1 -t nat -o $1 -j MASQUERADE
  69         $IPTABLES -I PREROUTING 1 -t nat -i $1 -j zone_$2_prerouting
  70         $IPTABLES -A FORWARD -i $1 -j zone_$2_forward
  71         uci_set_state firewall core "$2" "$1"
  72 }
  73
  74 delif() {
  75         logger "removing $1 from firewall zone $2"
  76         $IPTABLES -D INPUT -i $1 -j zone_$2
  77         $IPTABLES -D zone_$2_ACCEPT -o $1 -j ACCEPT
  78         $IPTABLES -D zone_$2_DROP -o $1 -j DROP
  79         $IPTABLES -D zone_$2_REJECT -o $1 -j REJECT
  80         $IPTABLES -D zone_$2_ACCEPT -i $1 -j ACCEPT
  81         $IPTABLES -D zone_$2_DROP -i $1 -j DROP
  82         $IPTABLES -D zone_$2_REJECT -i $1 -j REJECT
  83         $IPTABLES -D zone_$2_nat -t nat -o $1 -j MASQUERADE
  84         $IPTABLES -D PREROUTING -t nat -i $1 -j zone_$2_prerouting
  85         $IPTABLES -D FORWARD -i $1 -j zone_$2_forward
  86         uci_revert_state firewall core "$2"
  87 }
  88
  89 load_synflood() {
  90         echo "Loading synflood protection"
  91         $IPTABLES -N SYN_FLOOD
  92         $IPTABLES -A SYN_FLOOD -p tcp --syn -m limit --limit ${1}/second --limit-burst $2 -j RETURN
  93         $IPTABLES -A SYN_FLOOD -p ! tcp -j RETURN
  94         $IPTABLES -A SYN_FLOOD -p tcp ! --syn -j RETURN
  95         $IPTABLES -A SYN_FLOOD -j LOG --log-prefix "syn_flood: "
  96         $IPTABLES -A SYN_FLOOD -j DROP
  97         $IPTABLES -A INPUT -p tcp --syn -j SYN_FLOOD
  98 }
  99
 100 fw_defaults() {
 101         load_policy $1
 102         DEF_INPUT=$input
 103         DEF_OUTPUT=$output
 104         DEF_FORWARD=$forward
 105
 106         echo 1 > /proc/sys/net/ipv4/tcp_syncookies
 107         for f in /proc/sys/net/ipv4/conf/*/accept_redirects
 108         do
 109                 echo 0 > $f
 110         done
 111         for f in /proc/sys/net/ipv4/conf/*/accept_source_route
 112         do
 113                 echo 0 > $f
 114         done
 115
 116         uci_revert_state firewall core
 117         uci_set_state firewall core "" firewall_state
 118
 119         $IPTABLES -F
 120         $IPTABLES -t nat -F
 121         $IPTABLES -t mangle -F
 122         $IPTABLES -X -t nat
 123         $IPTABLES -X
 124
 125         $IPTABLES -P INPUT $input
 126         $IPTABLES -A INPUT -m state --state INVALID -j DROP
 127         $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 128
 129         $IPTABLES -P OUTPUT $output
 130         $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
 131         $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 132
 133         $IPTABLES -P FORWARD $forward
 134         $IPTABLES -A FORWARD -m state --state INVALID -j DROP
 135         $IPTABLES -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 136         $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
 137
 138         $IPTABLES -A INPUT -i lo -j ACCEPT
 139         $IPTABLES -A OUTPUT -o lo -j ACCEPT
 140
 141         config_get syn_flood $1 syn_flood
 142         config_get syn_rate $1 syn_rate
 143         config_get syn_burst $1 syn_burst
 144
 145         [ -z "$syn_rate" ] && syn_rate=25
 146         [ -z "$syn_burst" ] && syn_burst=50
 147         [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
 148 }
 149
 150 fw_zone() {
 151         local name
 152         local network
 153         local masq
 154
 155         config_get name $1 name
 156         config_get network $1 network
 157         config_get masq $1 masq
 158         load_policy $1
 159
 160         [ -z "$network" ] && network=$name
 161         create_zone "$name" "$network" "$input" "$output" "$forward" "$masq"
 162 }
 163
 164 fw_rule() {
 165         local src
 166         local src_ip
 167         local src_mac
 168         local src_port
 169         local src_mac
 170         local dest
 171         local dest_ip
 172         local dest_port
 173         local proto
 174         local target
 175         local ruleset
 176
 177         config_get src $1 src
 178         config_get src_ip $1 src_ip
 179         config_get src_mac $1 src_mac
 180         config_get src_port $1 src_port
 181         config_get dest $1 dest
 182         config_get dest_ip $1 dest_ip
 183         config_get dest_port $1 dest_port
 184         config_get proto $1 proto
 185         config_get target $1 target
 186         config_get ruleset $1 ruleset
 187
 188         [ -z "$target" ] && target=DROP
 189         [ -n "$src" ] && ZONE=zone_$src || ZONE=INPUT
 190         [ -n "$dest" ] && TARGET=zone_${dest}_$target || TARGET=$target
 191         add_rule() {
 192                 $IPTABLES -I $ZONE 1 \
 193                         ${proto:+-p $proto} \
 194                         ${src_ip:+-s $src_ip} \
 195                         ${src_port:+--sport $src_port} \
 196                         ${src_mac:+-m mac --mac-source $src_mac} \
 197                         ${dest_ip:+-d $dest_ip} \
 198                         ${dest_port:+--dport $dest_port} \
 199                         -j $TARGET
 200         }
 201         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 202                 proto=tcp
 203                 add_rule
 204                 proto=udp
 205                 add_rule
 206                 return
 207         }
 208         add_rule
 209 }
 210
 211 fw_forwarding() {
 212         local src
 213         local dest
 214         local masq
 215
 216         config_get src $1 src
 217         config_get dest $1 dest
 218         [ -n "$src" ] && z_src=zone_${src}_forward || z_src=FORWARD
 219         [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
 220         $IPTABLES -I $z_src 1 -j $z_dest
 221 }
 222
 223 fw_redirect() {
 224         local src
 225         local src_ip
 226         local src_port
 227         local src_dport
 228         local src_mac
 229         local dest_ip
 230         local dest_port dest_port2
 231         local proto
 232
 233         config_get src $1 src
 234         config_get src_ip $1 src_ip
 235         config_get src_port $1 src_port
 236         config_get src_dport $1 src_dport
 237         config_get src_mac $1 src_mac
 238         config_get dest_ip $1 dest_ip
 239         config_get dest_port $1 dest_port
 240         config_get proto $1 proto
 241         [ -z "$src" -o -z "$dest_ip" ] && { \
 242                 echo "redirect needs src and dest_ip"; return ; }
 243
 244         src_port_first=${src_port%-*}
 245         src_port_last=${src_port#*-}
 246         [ "$src_port_first" -ne "$src_port_last" ] && { \
 247                 src_port="$src_port_first:$src_port_last"; }
 248
 249         src_dport_first=${src_dport%-*}
 250         src_dport_last=${src_dport#*-}
 251         [ "$src_dport_first" -ne "$src_dport_last" ] && { \
 252                 src_dport="$src_dport_first:$src_dport_last"; }
 253
 254         destport2=destport
 255         dest_port_first=${dest_port2%-*}
 256         dest_port_last=${dest_port2#*-}
 257         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 258                 dest_port2="$dest_port_first:$dest_port_last"; }
 259
 260         add_rule() {
 261                 $IPTABLES -A zone_${src}_prerouting -t nat \
 262                         ${proto:+-p $proto} \
 263                         ${src_ip:+-s $src_ip} \
 264                         ${src_port:+--sport $src_port} \
 265                         ${src_dport:+--dport $src_dport} \
 266                         ${src_mac:+-m mac --mac-source $src_mac} \
 267                         -j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}
 268
 269                 $IPTABLES -I zone_${src}_forward 1 \
 270                         ${proto:+-p $proto} \
 271                         -d $dest_ip \
 272                         ${src_ip:+-s $src_ip} \
 273                         ${src_port:+--sport $src_port} \
 274                         ${dest_port2:+--dport $dest_port2} \
 275                         ${src_mac:+-m mac --mac-source $src_mac} \
 276                         -j ACCEPT
 277         }
 278         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 279                 proto=tcp
 280                 add_rule
 281                 proto=udp
 282                 add_rule
 283                 return
 284         }
 285         add_rule
 286 }
 287
 288 fw_include() {
 289         local path
 290         config_get path $1 path
 291         [ -e $path ] && . $path
 292 }
 293
 294 fw_addif() {
 295         local up
 296         local ifname
 297         config_get up $1 up
 298         config_get ifname $1 ifname
 299         [ -n "$up" ] || return 0
 300         (ACTION="ifup" INTERFACE="$1" . /etc/hotplug.d/iface/20-firewall)
 301 }
 302
 303 fw_custom_chains() {
 304         $IPTABLES -N input_rule
 305         $IPTABLES -N output_rule
 306         $IPTABLES -N forwarding_rule
 307         $IPTABLES -N prerouting_rule -t nat
 308         $IPTABLES -N postrouting_rule -t nat
 309         $IPTABLES -N input_wan
 310         $IPTABLES -N forwarding_wan
 311         $IPTABLES -N prerouting_wan -t nat
 312
 313         $IPTABLES -A INPUT -j input_rule
 314         $IPTABLES -A OUTPUT -j output_rule
 315         $IPTABLES -A FORWARD -j forwarding_rule
 316         $IPTABLES -A PREROUTING -t nat -j prerouting_rule
 317         $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
 318         $IPTABLES -A zone_wan -j input_wan
 319         $IPTABLES -A zone_wan_forward -j forwarding_wan
 320         $IPTABLES -A zone_wan_prerouting -t nat -j prerouting_wan
 321 }
 322
 323 fw_init() {
 324         echo "Loading defaults"
 325         config_foreach fw_defaults defaults
 326         echo "Loading zones"
 327         config_foreach fw_zone zone
 328         echo "Loading rules"
 329         config_foreach fw_rule rule
 330         echo "Loading forwarding"
 331         config_foreach fw_forwarding forwarding
 332         echo "Loading redirects"
 333         config_foreach fw_redirect redirect
 334         echo "Adding custom chains"
 335         fw_custom_chains
 336         echo "Loading includes"
 337         config_foreach fw_include include
 338         uci_set_state firewall core loaded 1
 339         unset CONFIG_APPEND
 340         config_load network
 341         config_foreach fw_addif interface
 342 }
 343
 344 fw_stop() {
 345         $IPTABLES -F
 346         $IPTABLES -t nat -F
 347         $IPTABLES -t mangle -F
 348         $IPTABLES -X -t nat
 349         $IPTABLES -X
 350         $IPTABLES -P INPUT ACCEPT
 351         $IPTABLES -P OUTPUT ACCEPT
 352         $IPTABLES -P FORWARD ACCEPT
 353         uci_revert_state firewall core
 354 }