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 CUSTOM_CHAINS=1
  20 DEF_INPUT=DROP
  21 DEF_OUTPUT=DROP
  22 DEF_FORWARD=DROP
  23
  24 load_policy() {
  25         config_get input $1 input
  26         config_get output $1 output
  27         config_get forward $1 forward
  28
  29         DEF_INPUT="${input:-$DEF_INPUT}"
  30         DEF_OUTPUT="${output:-$DEF_OUTPUT}"
  31         DEF_FORWARD="${forward:-$DEF_FORWARD}"
  32 }
  33
  34 create_zone() {
  35         local exists
  36
  37         [ "$1" == "loopback" ] && return
  38
  39         config_get exists $ZONE_LIST $1
  40         [ -n "$exists" ] && return
  41         config_set $ZONE_LIST $1 1
  42
  43         $IPTABLES -N zone_$1
  44         $IPTABLES -N zone_$1_MSSFIX
  45         $IPTABLES -N zone_$1_ACCEPT
  46         $IPTABLES -N zone_$1_DROP
  47         $IPTABLES -N zone_$1_REJECT
  48         $IPTABLES -N zone_$1_forward
  49         $IPTABLES -A zone_$1_forward -j zone_$1_$5
  50         $IPTABLES -A zone_$1 -j zone_$1_$3
  51         $IPTABLES -A output -j zone_$1_$4
  52         $IPTABLES -N zone_$1_nat -t nat
  53         $IPTABLES -N zone_$1_prerouting -t nat
  54         [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat
  55 }
  56
  57 addif() {
  58         local network="$1"
  59         local ifname="$2"
  60         local zone="$3"
  61
  62         local n_if n_zone
  63         config_get n_if core "${network}_ifname"
  64         config_get n_zone core "${network}_zone"
  65         [ -n "$n_zone" ] && {
  66                 if [ "$n_zone" != "$zone" ]; then
  67                         delif "$network" "$n_if" "$n_zone"
  68                 else
  69                         return
  70                 fi
  71         }
  72
  73         logger "adding $network ($ifname) to firewall zone $zone"
  74         $IPTABLES -A input -i "$ifname" -j zone_${zone}
  75         $IPTABLES -I zone_${zone}_MSSFIX 1 -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  76         $IPTABLES -I zone_${zone}_ACCEPT 1 -o "$ifname" -j ACCEPT
  77         $IPTABLES -I zone_${zone}_DROP 1 -o "$ifname" -j DROP
  78         $IPTABLES -I zone_${zone}_REJECT 1 -o "$ifname" -j reject
  79         $IPTABLES -I zone_${zone}_ACCEPT 1 -i "$ifname" -j ACCEPT
  80         $IPTABLES -I zone_${zone}_DROP 1 -i "$ifname" -j DROP
  81         $IPTABLES -I zone_${zone}_REJECT 1 -i "$ifname" -j reject
  82         $IPTABLES -I zone_${zone}_nat 1 -t nat -o "$ifname" -j MASQUERADE
  83         $IPTABLES -I PREROUTING 1 -t nat -i "$ifname" -j zone_${zone}_prerouting
  84         $IPTABLES -A forward -i "$ifname" -j zone_${zone}_forward
  85         uci_set_state firewall core "${network}_ifname" "$ifname"
  86         uci_set_state firewall core "${network}_zone" "$zone"
  87         ACTION=add ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
  88 }
  89
  90 delif() {
  91         local network="$1"
  92         local ifname="$2"
  93         local zone="$3"
  94
  95         logger "removing $network ($ifname) from firewall zone $zone"
  96         $IPTABLES -D input -i "$ifname" -j zone_$zone
  97         $IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  98         $IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
  99         $IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
 100         $IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
 101         $IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
 102         $IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
 103         $IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
 104         $IPTABLES -D zone_${zone}_nat -t nat -o "$ifname" -j MASQUERADE
 105         $IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting
 106         $IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
 107         uci_revert_state firewall core "${network}_ifname"
 108         uci_revert_state firewall core "${network}_zone"
 109         ACTION=remove ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
 110 }
 111
 112 load_synflood() {
 113         local rate=${1:-25}
 114         local burst=${2:-50}
 115         echo "Loading synflood protection"
 116         $IPTABLES -N syn_flood
 117         $IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
 118         $IPTABLES -A syn_flood -j DROP
 119         $IPTABLES -A INPUT -p tcp --syn -j syn_flood
 120 }
 121
 122 fw_set_chain_policy() {
 123         local chain=$1
 124         local target=$2
 125         [ "$target" == "REJECT" ] && {
 126                 $IPTABLES -A $chain -j reject
 127                 target=DROP
 128         }
 129         $IPTABLES -P $chain $target
 130 }
 131
 132 fw_clear() {
 133         $IPTABLES -F
 134         $IPTABLES -t nat -F
 135         $IPTABLES -t nat -X
 136         $IPTABLES -X
 137 }
 138
 139 fw_defaults() {
 140         [ -n "$DEFAULTS_APPLIED" ] && {
 141                 echo "Error: multiple defaults sections detected"
 142                 return;
 143         }
 144         DEFAULTS_APPLIED=1
 145
 146         load_policy "$1"
 147
 148         echo 1 > /proc/sys/net/ipv4/tcp_syncookies
 149         for f in /proc/sys/net/ipv4/conf/*/accept_redirects
 150         do
 151                 echo 0 > $f
 152         done
 153         for f in /proc/sys/net/ipv4/conf/*/accept_source_route
 154         do
 155                 echo 0 > $f
 156         done
 157
 158         uci_revert_state firewall core
 159         uci_set_state firewall core "" firewall_state
 160
 161         $IPTABLES -P INPUT DROP
 162         $IPTABLES -P OUTPUT DROP
 163         $IPTABLES -P FORWARD DROP
 164
 165         fw_clear
 166
 167         config_get_bool drop_invalid $1 drop_invalid 1
 168
 169         [ "$drop_invalid" -gt 0 ] && {
 170                 $IPTABLES -A INPUT -m state --state INVALID -j DROP
 171                 $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
 172                 $IPTABLES -A FORWARD -m state --state INVALID -j DROP
 173         }
 174
 175         $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 176         $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 177         $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
 178
 179         $IPTABLES -A INPUT -i lo -j ACCEPT
 180         $IPTABLES -A OUTPUT -o lo -j ACCEPT
 181
 182         config_get syn_flood $1 syn_flood
 183         config_get syn_rate $1 syn_rate
 184         config_get syn_burst $1 syn_burst
 185         [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
 186
 187         echo "Adding custom chains"
 188         fw_custom_chains
 189
 190         $IPTABLES -N input
 191         $IPTABLES -N output
 192         $IPTABLES -N forward
 193
 194         $IPTABLES -A INPUT -j input
 195         $IPTABLES -A OUTPUT -j output
 196         $IPTABLES -A FORWARD -j forward
 197
 198         $IPTABLES -N reject
 199         $IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
 200         $IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable
 201
 202         fw_set_chain_policy INPUT "$DEF_INPUT"
 203         fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
 204         fw_set_chain_policy FORWARD "$DEF_FORWARD"
 205 }
 206
 207 fw_zone() {
 208         local name
 209         local network
 210         local masq
 211
 212         config_get name $1 name
 213         config_get network $1 network
 214         config_get masq $1 masq
 215         load_policy $1
 216
 217         [ -z "$network" ] && network=$name
 218         create_zone "$name" "$network" "$input" "$output" "$forward" "$masq"
 219         fw_custom_chains_zone "$name"
 220 }
 221
 222 fw_rule() {
 223         local src
 224         local src_ip
 225         local src_mac
 226         local src_port
 227         local src_mac
 228         local dest
 229         local dest_ip
 230         local dest_port
 231         local proto
 232         local target
 233         local ruleset
 234
 235         config_get src $1 src
 236         config_get src_ip $1 src_ip
 237         config_get src_mac $1 src_mac
 238         config_get src_port $1 src_port
 239         config_get dest $1 dest
 240         config_get dest_ip $1 dest_ip
 241         config_get dest_port $1 dest_port
 242         config_get proto $1 proto
 243         config_get target $1 target
 244         config_get ruleset $1 ruleset
 245
 246         src_port_first=${src_port%-*}
 247         src_port_last=${src_port#*-}
 248         [ "$src_port_first" -ne "$src_port_last" ] && { \
 249                 src_port="$src_port_first:$src_port_last"; }
 250
 251         dest_port_first=${dest_port%-*}
 252         dest_port_last=${dest_port#*-}
 253         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 254                 dest_port="$dest_port_first:$dest_port_last"; }
 255
 256         ZONE=input
 257         TARGET=$target
 258         [ -z "$target" ] && target=DROP
 259         [ -n "$src" -a -z "$dest" ] && ZONE=zone_$src
 260         [ -n "$src" -a -n "$dest" ] && ZONE=zone_${src}_forward
 261         [ -n "$dest" ] && TARGET=zone_${dest}_$target
 262         add_rule() {
 263                 $IPTABLES -I $ZONE 1 \
 264                         ${proto:+-p $proto} \
 265                         ${src_ip:+-s $src_ip} \
 266                         ${src_port:+--sport $src_port} \
 267                         ${src_mac:+-m mac --mac-source $src_mac} \
 268                         ${dest_ip:+-d $dest_ip} \
 269                         ${dest_port:+--dport $dest_port} \
 270                         -j $TARGET
 271         }
 272         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 273                 proto=tcp
 274                 add_rule
 275                 proto=udp
 276                 add_rule
 277                 return
 278         }
 279         add_rule
 280 }
 281
 282 fw_forwarding() {
 283         local src
 284         local dest
 285         local masq
 286
 287         config_get src $1 src
 288         config_get dest $1 dest
 289         config_get_bool mtu_fix $1 mtu_fix 0
 290         [ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
 291         [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
 292         $IPTABLES -I $z_src 1 -j $z_dest
 293         [ "$mtu_fix" -gt 0 -a -n "$dest" ] && $IPTABLES -I $z_src 1 -j zone_${dest}_MSSFIX
 294 }
 295
 296 fw_redirect() {
 297         local src
 298         local src_ip
 299         local src_port
 300         local src_dport
 301         local src_mac
 302         local dest_ip
 303         local dest_port dest_port2
 304         local proto
 305
 306         config_get src $1 src
 307         config_get src_ip $1 src_ip
 308         config_get src_port $1 src_port
 309         config_get src_dport $1 src_dport
 310         config_get src_mac $1 src_mac
 311         config_get dest_ip $1 dest_ip
 312         config_get dest_port $1 dest_port
 313         config_get proto $1 proto
 314         [ -z "$src" -o -z "$dest_ip" ] && { \
 315                 echo "redirect needs src and dest_ip"; return ; }
 316
 317         src_port_first=${src_port%-*}
 318         src_port_last=${src_port#*-}
 319         [ "$src_port_first" -ne "$src_port_last" ] && { \
 320                 src_port="$src_port_first:$src_port_last"; }
 321
 322         src_dport_first=${src_dport%-*}
 323         src_dport_last=${src_dport#*-}
 324         [ "$src_dport_first" -ne "$src_dport_last" ] && { \
 325                 src_dport="$src_dport_first:$src_dport_last"; }
 326
 327         dest_port2=$dest_port
 328         dest_port_first=${dest_port2%-*}
 329         dest_port_last=${dest_port2#*-}
 330         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 331                 dest_port2="$dest_port_first:$dest_port_last"; }
 332
 333         add_rule() {
 334                 $IPTABLES -A zone_${src}_prerouting -t nat \
 335                         ${proto:+-p $proto} \
 336                         ${src_ip:+-s $src_ip} \
 337                         ${src_port:+--sport $src_port} \
 338                         ${src_dport:+--dport $src_dport} \
 339                         ${src_mac:+-m mac --mac-source $src_mac} \
 340                         -j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}
 341
 342                 $IPTABLES -I zone_${src}_forward 1 \
 343                         ${proto:+-p $proto} \
 344                         -d $dest_ip \
 345                         ${src_ip:+-s $src_ip} \
 346                         ${src_port:+--sport $src_port} \
 347                         ${dest_port2:+--dport $dest_port2} \
 348                         ${src_mac:+-m mac --mac-source $src_mac} \
 349                         -j ACCEPT
 350         }
 351         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 352                 proto=tcp
 353                 add_rule
 354                 proto=udp
 355                 add_rule
 356                 return
 357         }
 358         add_rule
 359 }
 360
 361 fw_include() {
 362         local path
 363         config_get path $1 path
 364         [ -e $path ] && . $path
 365 }
 366
 367 fw_addif() {
 368         local up
 369         local ifname
 370         config_get up $1 up
 371         config_get ifname $1 ifname
 372         [ -n "$up" ] || return 0
 373         (ACTION="ifup" INTERFACE="$1" . /etc/hotplug.d/iface/20-firewall)
 374 }
 375
 376 fw_custom_chains() {
 377         [ -n "$CUSTOM_CHAINS" ] || return 0
 378         $IPTABLES -N input_rule
 379         $IPTABLES -N output_rule
 380         $IPTABLES -N forwarding_rule
 381         $IPTABLES -N prerouting_rule -t nat
 382         $IPTABLES -N postrouting_rule -t nat
 383
 384         $IPTABLES -A INPUT -j input_rule
 385         $IPTABLES -A OUTPUT -j output_rule
 386         $IPTABLES -A FORWARD -j forwarding_rule
 387         $IPTABLES -A PREROUTING -t nat -j prerouting_rule
 388         $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
 389 }
 390
 391 fw_custom_chains_zone() {
 392         local zone="$1"
 393
 394         [ -n "$CUSTOM_CHAINS" ] || return 0
 395         $IPTABLES -N input_${zone}
 396         $IPTABLES -N forwarding_${zone}
 397         $IPTABLES -N prerouting_${zone} -t nat
 398         $IPTABLES -I zone_${zone} 1 -j input_${zone}
 399         $IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
 400         $IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
 401 }
 402
 403 fw_init() {
 404         DEFAULTS_APPLIED=
 405
 406         echo "Loading defaults"
 407         config_foreach fw_defaults defaults
 408         echo "Loading zones"
 409         config_foreach fw_zone zone
 410         echo "Loading forwarding"
 411         config_foreach fw_forwarding forwarding
 412         echo "Loading redirects"
 413         config_foreach fw_redirect redirect
 414         echo "Loading rules"
 415         config_foreach fw_rule rule
 416         echo "Loading includes"
 417         config_foreach fw_include include
 418         uci_set_state firewall core loaded 1
 419         unset CONFIG_APPEND
 420         config_load network
 421         config_foreach fw_addif interface
 422 }
 423
 424 fw_stop() {
 425         fw_clear
 426         $IPTABLES -P INPUT ACCEPT
 427         $IPTABLES -P OUTPUT ACCEPT
 428         $IPTABLES -P FORWARD ACCEPT
 429         uci_revert_state firewall core
 430 }