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