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         [ "$4" ] && $IPTABLES -A output -j zone_$1_$4
  60         $IPTABLES -N zone_$1_nat -t nat
  61         $IPTABLES -N zone_$1_prerouting -t nat
  62         $IPTABLES -t raw -N zone_$1_notrack
  63         [ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat
  64         [ "$7" == "1" ] && $IPTABLES -I FORWARD 1 -j zone_$1_MSSFIX
  65 }
  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" "$zone"
  99         ACTION=add ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
 100 }
 101
 102 delif() {
 103         local network="$1"
 104         local ifname="$2"
 105         local zone="$3"
 106
 107         logger "removing $network ($ifname) from firewall zone $zone"
 108         $IPTABLES -D input -i "$ifname" -j zone_$zone
 109         $IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 110         $IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
 111         $IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
 112         $IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
 113         $IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
 114         $IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
 115         $IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
 116         $IPTABLES -D zone_${zone}_nat -t nat -o "$ifname" -j MASQUERADE
 117         $IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting
 118         $IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
 119         uci_revert_state firewall core "${network}_ifname"
 120         uci_revert_state firewall core "${network}_zone"
 121         ACTION=remove ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
 122 }
 123
 124 load_synflood() {
 125         local rate=${1:-25}
 126         local burst=${2:-50}
 127         echo "Loading synflood protection"
 128         $IPTABLES -N syn_flood
 129         $IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
 130         $IPTABLES -A syn_flood -j DROP
 131         $IPTABLES -A INPUT -p tcp --syn -j syn_flood
 132 }
 133
 134 fw_set_chain_policy() {
 135         local chain=$1
 136         local target=$2
 137         [ "$target" == "REJECT" ] && {
 138                 $IPTABLES -A $chain -j reject
 139                 target=DROP
 140         }
 141         $IPTABLES -P $chain $target
 142 }
 143
 144 fw_clear() {
 145         $IPTABLES -F
 146         $IPTABLES -t nat -F
 147         $IPTABLES -t nat -X
 148         $IPTABLES -t raw -F
 149         $IPTABLES -t raw -X
 150         $IPTABLES -X
 151 }
 152
 153 fw_defaults() {
 154         [ -n "$DEFAULTS_APPLIED" ] && {
 155                 echo "Error: multiple defaults sections detected"
 156                 return;
 157         }
 158         DEFAULTS_APPLIED=1
 159
 160         load_policy "$1"
 161
 162         echo 1 > /proc/sys/net/ipv4/tcp_syncookies
 163         for f in /proc/sys/net/ipv4/conf/*/accept_redirects
 164         do
 165                 echo 0 > $f
 166         done
 167         for f in /proc/sys/net/ipv4/conf/*/accept_source_route
 168         do
 169                 echo 0 > $f
 170         done
 171
 172         uci_revert_state firewall core
 173         uci_set_state firewall core "" firewall_state
 174
 175         $IPTABLES -P INPUT DROP
 176         $IPTABLES -P OUTPUT DROP
 177         $IPTABLES -P FORWARD DROP
 178
 179         fw_clear
 180         config_get_bool drop_invalid $1 drop_invalid 0
 181
 182         [ "$drop_invalid" -gt 0 ] && {
 183                 $IPTABLES -A INPUT -m state --state INVALID -j DROP
 184                 $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
 185                 $IPTABLES -A FORWARD -m state --state INVALID -j DROP
 186                 NOTRACK_DISABLED=1
 187         }
 188
 189         $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 190         $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 191         $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
 192
 193         $IPTABLES -A INPUT -i lo -j ACCEPT
 194         $IPTABLES -A OUTPUT -o lo -j ACCEPT
 195
 196         config_get syn_flood $1 syn_flood
 197         config_get syn_rate $1 syn_rate
 198         config_get syn_burst $1 syn_burst
 199         [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
 200
 201         echo "Adding custom chains"
 202         fw_custom_chains
 203
 204         $IPTABLES -N input
 205         $IPTABLES -N output
 206         $IPTABLES -N forward
 207
 208         $IPTABLES -A INPUT -j input
 209         $IPTABLES -A OUTPUT -j output
 210         $IPTABLES -A FORWARD -j forward
 211
 212         $IPTABLES -N reject
 213         $IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
 214         $IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable
 215
 216         fw_set_chain_policy INPUT "$DEF_INPUT"
 217         fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
 218         fw_set_chain_policy FORWARD "$DEF_FORWARD"
 219 }
 220
 221 fw_zone_defaults() {
 222         local name
 223         local network
 224         local masq
 225
 226         config_get name $1 name
 227         config_get network $1 network
 228         config_get_bool masq $1 masq "0"
 229         config_get_bool conntrack $1 conntrack "0"
 230         config_get_bool mtu_fix $1 mtu_fix 0
 231
 232         load_policy $1
 233         [ "$forward" ] && $IPTABLES -A zone_${name}_forward -j zone_${name}_${forward}
 234         [ "$input" ] && $IPTABLES -A zone_${name} -j zone_${name}_${input}
 235 }
 236
 237 fw_zone() {
 238         local name
 239         local network
 240         local masq
 241
 242         config_get name $1 name
 243         config_get network $1 network
 244         config_get_bool masq $1 masq "0"
 245         config_get_bool conntrack $1 conntrack "0"
 246         config_get_bool mtu_fix $1 mtu_fix 0
 247
 248         load_policy $1
 249         [ "$conntrack" = "1" -o "$masq" = "1" ] && append CONNTRACK_ZONES "$name"
 250         [ -z "$network" ] && network=$name
 251         create_zone "$name" "$network" "$input" "$output" "$forward" "$masq" "$mtu_fix"
 252         fw_custom_chains_zone "$name"
 253 }
 254
 255 fw_rule() {
 256         local src
 257         local src_ip
 258         local src_mac
 259         local src_port
 260         local src_mac
 261         local dest
 262         local dest_ip
 263         local dest_port
 264         local proto
 265         local icmp_type
 266         local target
 267         local ruleset
 268
 269         config_get src $1 src
 270         config_get src_ip $1 src_ip
 271         config_get src_mac $1 src_mac
 272         config_get src_port $1 src_port
 273         config_get dest $1 dest
 274         config_get dest_ip $1 dest_ip
 275         config_get dest_port $1 dest_port
 276         config_get proto $1 proto
 277         config_get icmp_type $1 icmp_type
 278         config_get target $1 target
 279         config_get ruleset $1 ruleset
 280
 281         src_port_first=${src_port%-*}
 282         src_port_last=${src_port#*-}
 283         [ "$src_port_first" -ne "$src_port_last" ] && { \
 284                 src_port="$src_port_first:$src_port_last"; }
 285
 286         dest_port_first=${dest_port%-*}
 287         dest_port_last=${dest_port#*-}
 288         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 289                 dest_port="$dest_port_first:$dest_port_last"; }
 290
 291         ZONE=input
 292         TARGET=$target
 293         [ -z "$target" ] && target=DROP
 294         [ -n "$src" -a -z "$dest" ] && ZONE=zone_$src
 295         [ -n "$src" -a -n "$dest" ] && ZONE=zone_${src}_forward
 296         [ -n "$dest" ] && TARGET=zone_${dest}_$target
 297         add_rule() {
 298                 $IPTABLES -A $ZONE \
 299                         ${proto:+-p $proto} \
 300                         ${icmp_type:+--icmp-type $icmp_type} \
 301                         ${src_ip:+-s $src_ip} \
 302                         ${src_port:+--sport $src_port} \
 303                         ${src_mac:+-m mac --mac-source $src_mac} \
 304                         ${dest_ip:+-d $dest_ip} \
 305                         ${dest_port:+--dport $dest_port} \
 306                         -j $TARGET
 307         }
 308         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 309                 proto=tcp
 310                 add_rule
 311                 proto=udp
 312                 add_rule
 313                 return
 314         }
 315         add_rule
 316 }
 317
 318 fw_forwarding() {
 319         local src
 320         local dest
 321         local masq
 322
 323         config_get src $1 src
 324         config_get dest $1 dest
 325         [ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
 326         [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
 327         $IPTABLES -I $z_src 1 -j $z_dest
 328
 329         # propagate masq zone flag
 330         find_item "$src" $CONNTRACK_ZONES && append CONNTRACK_ZONES $dest
 331         find_item "$dest" $CONNTRACK_ZONES && append CONNTRACK_ZONES $src
 332 }
 333
 334 fw_redirect() {
 335         local src
 336         local src_ip
 337         local src_port
 338         local src_dport
 339         local src_mac
 340         local dest_ip
 341         local dest_port dest_port2
 342         local proto
 343
 344         config_get src $1 src
 345         config_get src_ip $1 src_ip
 346         config_get src_port $1 src_port
 347         config_get src_dport $1 src_dport
 348         config_get src_mac $1 src_mac
 349         config_get dest_ip $1 dest_ip
 350         config_get dest_port $1 dest_port
 351         config_get proto $1 proto
 352         [ -z "$src" -o -z "$dest_ip" ] && { \
 353                 echo "redirect needs src and dest_ip"; return ; }
 354
 355         src_port_first=${src_port%-*}
 356         src_port_last=${src_port#*-}
 357         [ "$src_port_first" -ne "$src_port_last" ] && { \
 358                 src_port="$src_port_first:$src_port_last"; }
 359
 360         src_dport_first=${src_dport%-*}
 361         src_dport_last=${src_dport#*-}
 362         [ "$src_dport_first" -ne "$src_dport_last" ] && { \
 363                 src_dport="$src_dport_first:$src_dport_last"; }
 364
 365         dest_port2=${dest_port:-$src_dport}
 366         dest_port_first=${dest_port2%-*}
 367         dest_port_last=${dest_port2#*-}
 368         [ "$dest_port_first" -ne "$dest_port_last" ] && { \
 369                 dest_port2="$dest_port_first:$dest_port_last"; }
 370
 371         add_rule() {
 372                 $IPTABLES -A zone_${src}_prerouting -t nat \
 373                         ${proto:+-p $proto} \
 374                         ${src_ip:+-s $src_ip} \
 375                         ${src_port:+--sport $src_port} \
 376                         ${src_dport:+--dport $src_dport} \
 377                         ${src_mac:+-m mac --mac-source $src_mac} \
 378                         -j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}
 379
 380                 $IPTABLES -I zone_${src}_forward 1 \
 381                         ${proto:+-p $proto} \
 382                         -d $dest_ip \
 383                         ${src_ip:+-s $src_ip} \
 384                         ${src_port:+--sport $src_port} \
 385                         ${dest_port2:+--dport $dest_port2} \
 386                         ${src_mac:+-m mac --mac-source $src_mac} \
 387                         -j ACCEPT
 388         }
 389         [ "$proto" == "tcpudp" -o -z "$proto" ] && {
 390                 proto=tcp
 391                 add_rule
 392                 proto=udp
 393                 add_rule
 394                 return
 395         }
 396         add_rule
 397 }
 398
 399 fw_include() {
 400         local path
 401         config_get path $1 path
 402         [ -e $path ] && . $path
 403 }
 404
 405 get_interface_zones() {
 406         local interface="$2"
 407         local name
 408         local network
 409         config_get name $1 name
 410         config_get network $1 network
 411         [ -z "$network" ] && network=$name
 412         for n in $network; do
 413                 [ "$n" = "$interface" ] && append add_zone "$name"
 414         done
 415 }
 416
 417 fw_event() {
 418         local action="$1"
 419         local interface="$2"
 420         local ifname="$(sh -c ". /etc/functions.sh; include /lib/network; scan_interfaces; config_get "$interface" ifname")"
 421         add_zone=
 422         local up
 423
 424         [ -z "$ifname" ] && return 0
 425         config_foreach get_interface_zones zone "$interface"
 426         [ -z "$add_zone" ] && return 0
 427
 428         case "$action" in
 429                 ifup)
 430                         for z in $add_zone; do
 431                                 local loaded
 432                                 config_get loaded core loaded
 433                                 [ -n "$loaded" ] && addif "$interface" "$ifname" "$z"
 434                         done
 435                 ;;
 436                 ifdown)
 437                         config_get up "$interface" up
 438
 439                         for z in $ZONE; do
 440                                 [ "$up" == "1" ] && delif "$interface" "$ifname" "$z"
 441                         done
 442                 ;;
 443         esac
 444 }
 445
 446 fw_addif() {
 447         local up
 448         local ifname
 449         config_get up $1 up
 450         [ -n "$up" ] || return 0
 451         fw_event ifup "$1"
 452 }
 453
 454 fw_custom_chains() {
 455         [ -n "$CUSTOM_CHAINS" ] || return 0
 456         $IPTABLES -N input_rule
 457         $IPTABLES -N output_rule
 458         $IPTABLES -N forwarding_rule
 459         $IPTABLES -N prerouting_rule -t nat
 460         $IPTABLES -N postrouting_rule -t nat
 461
 462         $IPTABLES -A INPUT -j input_rule
 463         $IPTABLES -A OUTPUT -j output_rule
 464         $IPTABLES -A FORWARD -j forwarding_rule
 465         $IPTABLES -A PREROUTING -t nat -j prerouting_rule
 466         $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
 467 }
 468
 469 fw_custom_chains_zone() {
 470         local zone="$1"
 471
 472         [ -n "$CUSTOM_CHAINS" ] || return 0
 473         $IPTABLES -N input_${zone}
 474         $IPTABLES -N forwarding_${zone}
 475         $IPTABLES -N prerouting_${zone} -t nat
 476         $IPTABLES -I zone_${zone} 1 -j input_${zone}
 477         $IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
 478         $IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
 479 }
 480
 481 fw_check_notrack() {
 482         local zone="$1"
 483         config_get name "$zone" name
 484         [ -n "$NOTRACK_DISABLED" ] || \
 485                 find_item "$name" $CONNTRACK_ZONES || \
 486                 $IPTABLES -t raw -A zone_${name}_notrack -j NOTRACK
 487 }
 488
 489 fw_init() {
 490         DEFAULTS_APPLIED=
 491
 492         echo "Loading defaults"
 493         config_foreach fw_defaults defaults
 494         echo "Loading zones"
 495         config_foreach fw_zone zone
 496         echo "Loading forwarding"
 497         config_foreach fw_forwarding forwarding
 498         echo "Loading redirects"
 499         config_foreach fw_redirect redirect
 500         echo "Loading rules"
 501         config_foreach fw_rule rule
 502         echo "Loading includes"
 503         config_foreach fw_include include
 504         echo "Loading zone defaults"
 505         config_foreach fw_zone_defaults zone
 506         uci_set_state firewall core loaded 1
 507         config_set core loaded 1
 508         config_foreach fw_check_notrack zone
 509         INTERFACES="$(sh -c '
 510                 . /etc/functions.sh; config_load network
 511                 echo_up() { local up; config_get_bool up "$1" up 0; [ $up = 1 ] && echo "$1"; }
 512                 config_foreach echo_up interface
 513         ')"
 514         for interface in $INTERFACES; do
 515                 fw_event ifup "$interface"
 516         done
 517 }
 518
 519 fw_stop() {
 520         fw_clear
 521         $IPTABLES -P INPUT ACCEPT
 522         $IPTABLES -P OUTPUT ACCEPT
 523         $IPTABLES -P FORWARD ACCEPT
 524         uci_revert_state firewall
 525 }