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