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 CONNTRACK_ZONES=
  24 NOTRACK_DISABLED=
  25
  26 find_item() {
  27         local item="$1"; shift
  28         for i in "$@"; do
  29                 [ "$i" = "$item" ] && return 0
  30         done
  31         return 1
  32 }
  33
  34 load_policy() {
  35         config_get input $1 input
  36         config_get output $1 output
  37         config_get forward $1 forward
  38
  39         DEF_INPUT="${input:-$DEF_INPUT}"
  40         DEF_OUTPUT="${output:-$DEF_OUTPUT}"
  41         DEF_FORWARD="${forward:-$DEF_FORWARD}"
  42 }
  43
  44 create_zone() {
  45         local exists
  46
  47         [ "$1" == "loopback" ] && return
  48
  49         config_get exists $ZONE_LIST $1
  50         [ -n "$exists" ] && return
  51         config_set $ZONE_LIST $1 1
  52
  53         $IPTABLES -N zone_$1
  54         $IPTABLES -N zone_$1_MSSFIX
  55         $IPTABLES -N zone_$1_ACCEPT
  56         $IPTABLES -N zone_$1_DROP
  57         $IPTABLES -N zone_$1_REJECT
  58         $IPTABLES -N zone_$1_forward
  59         $IPTABLES -A zone_$1_forward -j zone_$1_$5
  60         $IPTABLES -A zone_$1 -j zone_$1_$3
  61         $IPTABLES -A output -j zone_$1_$4
  62         $IPTABLES -N zone_$1_nat -t nat
  63         $IPTABLES -N zone_$1_prerouting -t nat
  64         $IPTABLES -t raw -N zone_$1_notrack
  65         [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat
  66 }
  67
  68 addif() {
  69         local network="$1"
  70         local ifname="$2"
  71         local zone="$3"
  72
  73         local n_if n_zone
  74         config_get n_if core "${network}_ifname"
  75         config_get n_zone core "${network}_zone"
  76         [ -n "$n_zone" ] && {
  77                 if [ "$n_zone" != "$zone" ]; then
  78                         delif "$network" "$n_if" "$n_zone"
  79                 else
  80                         return
  81                 fi
  82         }
  83
  84         logger "adding $network ($ifname) to firewall zone $zone"
  85         $IPTABLES -A input -i "$ifname" -j zone_${zone}
  86         $IPTABLES -I zone_${zone}_MSSFIX 1 -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  87         $IPTABLES -I zone_${zone}_ACCEPT 1 -o "$ifname" -j ACCEPT
  88         $IPTABLES -I zone_${zone}_DROP 1 -o "$ifname" -j DROP
  89         $IPTABLES -I zone_${zone}_REJECT 1 -o "$ifname" -j reject
  90         $IPTABLES -I zone_${zone}_ACCEPT 1 -i "$ifname" -j ACCEPT
  91         $IPTABLES -I zone_${zone}_DROP 1 -i "$ifname" -j DROP
  92         $IPTABLES -I zone_${zone}_REJECT 1 -i "$ifname" -j reject
  93         $IPTABLES -I zone_${zone}_nat 1 -t nat -o "$ifname" -j MASQUERADE
  94         $IPTABLES -I PREROUTING 1 -t nat -i "$ifname" -j zone_${zone}_prerouting
  95         $IPTABLES -A forward -i "$ifname" -j zone_${zone}_forward
  96         $IPTABLES -t raw -I PREROUTING 1 -i "$ifname" -j zone_${zone}_notrack
  97         uci_set_state firewall core "${network}_ifname" "$ifname"
  98         uci_set_state firewall core "${network}_zone" "$zone"
  99 }
 100
 101 delif() {
 102         local network="$1"
 103         local ifname="$2"
 104         local zone="$3"
 105
 106         logger "removing $network ($ifname) from firewall zone $zone"
 107         $IPTABLES -D input -i "$ifname" -j zone_$zone
 108         $IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 109         $IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
 110         $IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
 111         $IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
 112         $IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
 113         $IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
 114         $IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
 115         $IPTABLES -D zone_${zone}_nat -t nat -o "$ifname" -j MASQUERADE
 116         $IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting
 117         $IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
 118         uci_revert_state firewall core "${network}_ifname"
 119         uci_revert_state firewall core "${network}_zone"
 120 }
 121
 122 load_synflood() {
 123         local rate=${1:-25}
 124         local burst=${2:-50}
 125         echo "Loading synflood protection"
 126         $IPTABLES -N syn_flood
 127         $IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
 128         $IPTABLES -A syn_flood -j DROP
 129         $IPTABLES -A INPUT -p tcp --syn -j syn_flood
 130 }
 131
 132 fw_set_chain_policy() {
 133         local chain=$1
 134         local target=$2
 135         [ "$target" == "REJECT" ] && {
 136                 $IPTABLES -A $chain -j reject
 137                 target=DROP
 138         }
 139         $IPTABLES -P $chain $target
 140 }
 141
 142 fw_clear() {
 143         $IPTABLES -F
 144         $IPTABLES -t nat -F
 145         $IPTABLES -t nat -X
 146         $IPTABLES -t raw -F
 147         $IPTABLES -t raw -X
 148         $IPTABLES -X
 149 }
 150
 151 fw_defaults() {
 152         [ -n "$DEFAULTS_APPLIED" ] && {
 153                 echo "Error: multiple defaults sections detected"
 154                 return;
 155         }
 156         DEFAULTS_APPLIED=1
 157
 158         load_policy "$1"
 159
 160         echo 1 > /proc/sys/net/ipv4/tcp_syncookies
 161         for f in /proc/sys/net/ipv4/conf/*/accept_redirects
 162         do
 163                 echo 0 > $f
 164         done
 165         for f in /proc/sys/net/ipv4/conf/*/accept_source_route
 166         do
 167                 echo 0 > $f
 168         done
 169
 170         uci_revert_state firewall core
 171         uci_set_state firewall core "" firewall_state
 172
 173         $IPTABLES -P INPUT DROP
 174         $IPTABLES -P OUTPUT DROP
 175         $IPTABLES -P FORWARD DROP
 176
 177         fw_clear
 178         config_get_bool drop_invalid $1 drop_invalid 0
 179
 180         [ "$drop_invalid" -gt 0 ] && {
 181                 $IPTABLES -A INPUT -m state --state INVALID -j DROP
 182                 $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
 183                 $IPTABLES -A FORWARD -m state --state INVALID -j DROP
 184                 NOTRACK_DISABLED=1
 185         }
 186
 187         $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 188         $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 189         $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
 190
 191         $IPTABLES -A INPUT -i lo -j ACCEPT
 192         $IPTABLES -A OUTPUT -o lo -j ACCEPT
 193
 194         config_get syn_flood $1 syn_flood
 195         config_get syn_rate $1 syn_rate
 196         config_get syn_burst $1 syn_burst
 197         [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
 198
 199         echo "Adding custom chains"
 200         fw_custom_chains
 201
 202         $IPTABLES -N input
 203         $IPTABLES -N output
 204         $IPTABLES -N forward
 205
 206         $IPTABLES -A INPUT -j input
 207         $IPTABLES -A OUTPUT -j output
 208         $IPTABLES -A FORWARD -j forward
 209
 210         $IPTABLES -N reject
 211         $IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
 212         $IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable
 213
 214         fw_set_chain_policy INPUT "$DEF_INPUT"
 215         fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
 216         fw_set_chain_policy FORWARD "$DEF_FORWARD"
 217 }
 218
 219 fw_zone() {
 220         local name
 221         local network
 222         local masq
 223
 224         config_get name $1 name
 225         config_get network $1 network
 226         config_get_bool masq $1 masq "0"
 227         config_get_bool conntrack $1 conntrack "0"
 228
 229         load_policy $1
 230         [ "$conntrack" = "1" -o "$masq" = "1" ] && append CONNTRACK_ZONES "$name"
 231         [ -z "$network" ] && network=$name
 232         create_zone "$name" "$network" "$input" "$output" "$forward" "$masq"
 233         fw_custom_chains_zone "$name"
 234 }
 235
 236 fw_rule() {
 237         local src
 238         local src_ip
 239         local src_mac
 240         local src_port
 241         local src_mac
 242         local dest
 243         local dest_ip
 244         local dest_port
 245         local proto
 246         local icmp_type
 247         local target
 248         local ruleset
 249
 250         config_get src $1 src
 251         config_get src_ip $1 src_ip
 252         config_get src_mac $1 src_mac
 253         config_get src_port $1 src_port
 254         config_get dest $1 dest
 255         config_get dest_ip $1 dest_ip
 256         config_get dest_port $1 dest_port
 257         config_get proto $1 proto
 258         config_get icmp_type $1 icmp_type
 259         config_get target $1 target
 260         config_get ruleset $1 ruleset
 261
 262         src_port_first=${src_port%-*}
 263         src_port_last=${src_port#*-}
 264         [ "$src_port_first" -ne "$src_port_last" ] && { \
 265                 src_port="$src_port_first:$src_port_last"; }
 266
 267         dest_port_first=${dest_port%-*}
 268         dest_port_last=${dest_port#*-}
 269         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 270                 dest_port="$dest_port_first:$dest_port_last"; }
 271
 272         ZONE=input
 273         TARGET=$target
 274         [ -z "$target" ] && target=DROP
 275         [ -n "$src" -a -z "$dest" ] && ZONE=zone_$src
 276         [ -n "$src" -a -n "$dest" ] && ZONE=zone_${src}_forward
 277         [ -n "$dest" ] && TARGET=zone_${dest}_$target
 278         add_rule() {
 279                 $IPTABLES -I $ZONE 1 \
 280                         ${proto:+-p $proto} \
 281                         ${icmp_type:+--icmp-type $icmp_type} \
 282                         ${src_ip:+-s $src_ip} \
 283                         ${src_port:+--sport $src_port} \
 284                         ${src_mac:+-m mac --mac-source $src_mac} \
 285                         ${dest_ip:+-d $dest_ip} \
 286                         ${dest_port:+--dport $dest_port} \
 287                         -j $TARGET
 288         }
 289         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 290                 proto=tcp
 291                 add_rule
 292                 proto=udp
 293                 add_rule
 294                 return
 295         }
 296         add_rule
 297 }
 298
 299 fw_forwarding() {
 300         local src
 301         local dest
 302         local masq
 303
 304         config_get src $1 src
 305         config_get dest $1 dest
 306         config_get_bool mtu_fix $1 mtu_fix 0
 307         [ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
 308         [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
 309         $IPTABLES -I $z_src 1 -j $z_dest
 310         [ "$mtu_fix" -gt 0 -a -n "$dest" ] && $IPTABLES -I $z_src 1 -j zone_${dest}_MSSFIX
 311
 312         # propagate masq zone flag
 313         find_item "$src" $CONNTRACK_ZONES && append CONNTRACK_ZONES $dest
 314         find_item "$dest" $CONNTRACK_ZONES && append CONNTRACK_ZONES $src
 315 }
 316
 317 fw_redirect() {
 318         local src
 319         local src_ip
 320         local src_port
 321         local src_dport
 322         local src_mac
 323         local dest_ip
 324         local dest_port dest_port2
 325         local proto
 326
 327         config_get src $1 src
 328         config_get src_ip $1 src_ip
 329         config_get src_port $1 src_port
 330         config_get src_dport $1 src_dport
 331         config_get src_mac $1 src_mac
 332         config_get dest_ip $1 dest_ip
 333         config_get dest_port $1 dest_port
 334         config_get proto $1 proto
 335         [ -z "$src" -o -z "$dest_ip" ] && { \
 336                 echo "redirect needs src and dest_ip"; return ; }
 337
 338         src_port_first=${src_port%-*}
 339         src_port_last=${src_port#*-}
 340         [ "$src_port_first" -ne "$src_port_last" ] && { \
 341                 src_port="$src_port_first:$src_port_last"; }
 342
 343         src_dport_first=${src_dport%-*}
 344         src_dport_last=${src_dport#*-}
 345         [ "$src_dport_first" -ne "$src_dport_last" ] && { \
 346                 src_dport="$src_dport_first:$src_dport_last"; }
 347
 348         dest_port2=$dest_port
 349         dest_port_first=${dest_port2%-*}
 350         dest_port_last=${dest_port2#*-}
 351         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 352                 dest_port2="$dest_port_first:$dest_port_last"; }
 353
 354         add_rule() {
 355                 $IPTABLES -A zone_${src}_prerouting -t nat \
 356                         ${proto:+-p $proto} \
 357                         ${src_ip:+-s $src_ip} \
 358                         ${src_port:+--sport $src_port} \
 359                         ${src_dport:+--dport $src_dport} \
 360                         ${src_mac:+-m mac --mac-source $src_mac} \
 361                         -j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}
 362
 363                 $IPTABLES -I zone_${src}_forward 1 \
 364                         ${proto:+-p $proto} \
 365                         -d $dest_ip \
 366                         ${src_ip:+-s $src_ip} \
 367                         ${src_port:+--sport $src_port} \
 368                         ${dest_port2:+--dport $dest_port2} \
 369                         ${src_mac:+-m mac --mac-source $src_mac} \
 370                         -j ACCEPT
 371         }
 372         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 373                 proto=tcp
 374                 add_rule
 375                 proto=udp
 376                 add_rule
 377                 return
 378         }
 379         add_rule
 380 }
 381
 382 fw_include() {
 383         local path
 384         config_get path $1 path
 385         [ -e $path ] && . $path
 386 }
 387
 388 fw_addif() {
 389         local up
 390         local ifname
 391         config_get up $1 up
 392         config_get ifname $1 ifname
 393         [ -n "$up" ] || return 0
 394         (ACTION="ifup" INTERFACE="$1" . /etc/hotplug.d/iface/20-firewall)
 395 }
 396
 397 fw_custom_chains() {
 398         [ -n "$CUSTOM_CHAINS" ] || return 0
 399         $IPTABLES -N input_rule
 400         $IPTABLES -N output_rule
 401         $IPTABLES -N forwarding_rule
 402         $IPTABLES -N prerouting_rule -t nat
 403         $IPTABLES -N postrouting_rule -t nat
 404
 405         $IPTABLES -A INPUT -j input_rule
 406         $IPTABLES -A OUTPUT -j output_rule
 407         $IPTABLES -A FORWARD -j forwarding_rule
 408         $IPTABLES -A PREROUTING -t nat -j prerouting_rule
 409         $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
 410 }
 411
 412 fw_custom_chains_zone() {
 413         local zone="$1"
 414
 415         [ -n "$CUSTOM_CHAINS" ] || return 0
 416         $IPTABLES -N input_${zone}
 417         $IPTABLES -N forwarding_${zone}
 418         $IPTABLES -N prerouting_${zone} -t nat
 419         $IPTABLES -I zone_${zone} 1 -j input_${zone}
 420         $IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
 421         $IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
 422 }
 423
 424 fw_check_notrack() {
 425         local zone="$1"
 426         config_get name "$zone" name
 427         [ -n "$NOTRACK_DISABLED" ] || \
 428                 find_item "$name" $CONNTRACK_ZONES || \
 429                 $IPTABLES -t raw -A zone_${name}_notrack -j NOTRACK
 430 }
 431
 432 fw_init() {
 433         DEFAULTS_APPLIED=
 434
 435         echo "Loading defaults"
 436         config_foreach fw_defaults defaults
 437         echo "Loading zones"
 438         config_foreach fw_zone zone
 439         echo "Loading forwarding"
 440         config_foreach fw_forwarding forwarding
 441         echo "Loading redirects"
 442         config_foreach fw_redirect redirect
 443         echo "Loading rules"
 444         config_foreach fw_rule rule
 445         echo "Loading includes"
 446         config_foreach fw_include include
 447         uci_set_state firewall core loaded 1
 448         config_foreach fw_check_notrack zone
 449         unset CONFIG_APPEND
 450         config_load network
 451         config_foreach fw_addif interface
 452 }
 453
 454 fw_stop() {
 455         fw_clear
 456         $IPTABLES -P INPUT ACCEPT
 457         $IPTABLES -P OUTPUT ACCEPT
 458         $IPTABLES -P FORWARD ACCEPT
 459         uci_revert_state firewall
 460 }