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