src/initscripts/system/firewall

   1 #!/bin/sh
   2
   3 . /etc/sysconfig/rc
   4 . ${rc_functions}
   5
   6 eval $(/usr/local/bin/readhash /var/ipfire/ppp/settings)
   7 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
   8 eval $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
   9 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
  10
  11 if [ -f /var/ipfire/red/device ]; then
  12         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  13 fi
  14
  15 NAT_MASK="0x0f000000"
  16
  17 IPS_REPEAT_MARK="0x80000000"
  18 IPS_REPEAT_MASK="0x80000000"
  19 IPS_BYPASS_MARK="0x40000000"
  20 IPS_BYPASS_MASK="0x40000000"
  21
  22 function iptables() {
  23         /sbin/iptables --wait "$@"
  24 }
  25
  26 iptables_init() {
  27         # Flush all rules and delete all custom chains
  28         iptables -F
  29         iptables -t nat -F
  30         iptables -t mangle -F
  31         iptables -t raw -F
  32         iptables -X
  33         iptables -t nat -X
  34         iptables -t mangle -X
  35         iptables -t raw -X
  36
  37         # Set up policies
  38         iptables -P INPUT DROP
  39         iptables -P FORWARD DROP
  40         iptables -P OUTPUT ACCEPT
  41
  42         # Enable TRACE logging to syslog
  43         modprobe nf_log_ipv4
  44         sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
  45
  46         # IPS Bypass Chain which stores the BYPASS bit in connection tracking
  47         iptables -N IPSBYPASS
  48         iptables -A IPSBYPASS -j CONNMARK --save-mark --mask "$(( ~IPS_REPEAT_MASK & 0xffffffff ))"
  49
  50         # Jump into bypass chain when the BYPASS bit is set
  51         for chain in INPUT FORWARD OUTPUT; do
  52                 iptables -A "${chain}" -m mark \
  53                         --mark "$(( IPS_REPEAT_MARK | IPS_BYPASS_MARK ))/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j IPSBYPASS
  54         done
  55
  56         # Empty LOG_DROP and LOG_REJECT chains
  57         iptables -N LOG_DROP
  58         iptables -A LOG_DROP   -m limit --limit 10/second -j LOG
  59         iptables -A LOG_DROP   -j DROP
  60         iptables -N LOG_REJECT
  61         iptables -A LOG_REJECT -m limit --limit 10/second -j LOG
  62         iptables -A LOG_REJECT -j REJECT
  63
  64         # This chain will log, then DROPs packets with certain bad combinations
  65         # of flags might indicate a port-scan attempt (xmas, null, etc.)
  66         iptables -N PSCAN
  67         if [ "$DROPPORTSCAN" == "on" ]; then
  68                 iptables -A PSCAN -p tcp  -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan "  -m comment --comment "DROP_TCP PScan"
  69                 iptables -A PSCAN -p udp  -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan "  -m comment --comment "DROP_UDP PScan"
  70                 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  71                 iptables -A PSCAN -f      -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  72         fi
  73         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  74
  75         # New tcp packets without SYN set - could well be an obscure type of port scan
  76         # that's not covered above, may just be a broken Windows machine
  77         iptables -N NEWNOTSYN
  78         if [ "$DROPNEWNOTSYN" == "on" ]; then
  79                 iptables -A NEWNOTSYN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_NEWNOTSYN "
  80         fi
  81         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  82
  83         # Chain to contain all the rules relating to bad TCP flags
  84         iptables -N BADTCP
  85
  86         # Don't check loopback
  87         iptables -A BADTCP -i lo -j RETURN
  88
  89         # Disallow packets frequently used by port-scanners
  90         # NMAP FIN/URG/PSH (XMAS scan)
  91         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  92         # SYN/RST/ACK/FIN/URG
  93         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  94         # ALL/ALL
  95         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  96         # FIN Stealth
  97         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  98         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  99         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
 100         # SYN/FIN (QueSO or nmap OS probe)
 101         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
 102         # Null
 103         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
 104         # NEW TCP without SYN
 105         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
 106
 107         iptables -A INPUT   -p tcp -j BADTCP
 108         iptables -A FORWARD -p tcp -j BADTCP
 109
 110         # Connection tracking chains
 111         iptables -N CONNTRACK
 112         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
 113         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j LOG_DROP
 114         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
 115
 116         # Restore any connection marks
 117         iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
 118
 119         # Fix for braindead ISPs
 120         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 121
 122         # CUSTOM chains, can be used by the users themselves
 123         iptables -N CUSTOMINPUT
 124         iptables -A INPUT -j CUSTOMINPUT
 125         iptables -N CUSTOMFORWARD
 126         iptables -A FORWARD -j CUSTOMFORWARD
 127         iptables -N CUSTOMOUTPUT
 128         iptables -A OUTPUT -j CUSTOMOUTPUT
 129         iptables -t nat -N CUSTOMPREROUTING
 130         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 131         iptables -t nat -N CUSTOMPOSTROUTING
 132         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 133
 134         # P2PBLOCK
 135         iptables -N P2PBLOCK
 136         iptables -A INPUT -j P2PBLOCK
 137         iptables -A FORWARD -j P2PBLOCK
 138         iptables -A OUTPUT -j P2PBLOCK
 139
 140         # IPS (Guardian) chains
 141         iptables -N GUARDIAN
 142         iptables -A INPUT -j GUARDIAN
 143         iptables -A FORWARD -j GUARDIAN
 144
 145         # Block non-established IPsec networks
 146         iptables -N IPSECBLOCK
 147         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 148         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 149
 150         # Block OpenVPN transfer networks
 151         iptables -N OVPNBLOCK
 152         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 153         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 154         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 155
 156         # IPS (Suricata) chains
 157         iptables -N IPS_INPUT
 158         iptables -N IPS_FORWARD
 159         iptables -N IPS_OUTPUT
 160
 161         for chain in INPUT FORWARD OUTPUT; do
 162                 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
 163         done
 164
 165         # OpenVPN transfer network translation
 166         iptables -t nat -N OVPNNAT
 167         iptables -t nat -A POSTROUTING -j OVPNNAT
 168
 169         # IPTV chains for IGMPPROXY
 170         iptables -N IPTVINPUT
 171         iptables -A INPUT -j IPTVINPUT
 172         iptables -N IPTVFORWARD
 173         iptables -A FORWARD -j IPTVFORWARD
 174
 175         # Allow to ping the firewall.
 176         iptables -N ICMPINPUT
 177         iptables -A INPUT -j ICMPINPUT
 178         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 179
 180         # Accept everything on loopback
 181         iptables -N LOOPBACK
 182         iptables -A LOOPBACK -i lo -j ACCEPT
 183         iptables -A LOOPBACK -o lo -j ACCEPT
 184
 185         # Filter all packets with loopback addresses on non-loopback interfaces.
 186         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 187         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 188
 189         for i in INPUT FORWARD OUTPUT; do
 190                 iptables -A ${i} -j LOOPBACK
 191         done
 192
 193         # Captive portal
 194         iptables -N CAPTIVE_PORTAL
 195         iptables -N CAPTIVE_PORTAL_CLIENTS
 196         for i in INPUT FORWARD; do
 197                 iptables -A ${i} -j CAPTIVE_PORTAL
 198         done
 199
 200         # Accept everything connected
 201         for i in INPUT FORWARD OUTPUT; do
 202                 iptables -A ${i} -j CONNTRACK
 203         done
 204
 205         # Allow DHCP
 206         iptables -N DHCPINPUT
 207         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 208         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 209
 210         iptables -N DHCPOUTPUT
 211         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 212         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 213
 214         # Allow DHCP on GREEN
 215         iptables -N DHCPGREENINPUT
 216         iptables -N DHCPGREENOUTPUT
 217         if [ -n "${GREEN_DEV}" ]; then
 218                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 219                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 220         fi
 221
 222         # Allow DHCP on BLUE to be turned on/off
 223         iptables -N DHCPBLUEINPUT
 224         iptables -N DHCPBLUEOUTPUT
 225         if [ -n "${BLUE_DEV}" ]; then
 226                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 227                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 228         fi
 229
 230         # Location Block
 231         iptables -N LOCATIONBLOCK
 232         iptables -A INPUT -j LOCATIONBLOCK
 233         iptables -A FORWARD -j LOCATIONBLOCK
 234
 235         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 236         iptables -N IPSECINPUT
 237         iptables -N IPSECFORWARD
 238         iptables -N IPSECOUTPUT
 239         iptables -A INPUT -j IPSECINPUT
 240         iptables -A FORWARD -j IPSECFORWARD
 241         iptables -A OUTPUT -j IPSECOUTPUT
 242         iptables -t nat -N IPSECNAT
 243         iptables -t nat -A POSTROUTING -j IPSECNAT
 244
 245         # localhost and ethernet.
 246         # Always allow accessing the web GUI from GREEN.
 247         iptables -N GUIINPUT
 248         iptables -A INPUT -j GUIINPUT
 249         if [ -n "${GREEN_DEV}" ]; then
 250                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 251         fi
 252
 253         # WIRELESS chains
 254         iptables -N WIRELESSINPUT
 255         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 256         iptables -N WIRELESSFORWARD
 257         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 258
 259         # OpenVPN
 260         iptables -N OVPNINPUT
 261         iptables -A INPUT -j OVPNINPUT
 262
 263         # Tor (inbound and outbound)
 264         iptables -N TOR_INPUT
 265         iptables -A INPUT -j TOR_INPUT
 266         iptables -N TOR_OUTPUT
 267         iptables -A OUTPUT -j TOR_OUTPUT
 268
 269         # Jump into the actual firewall ruleset.
 270         iptables -N INPUTFW
 271         iptables -A INPUT -j INPUTFW
 272
 273         iptables -N OUTGOINGFW
 274         iptables -A OUTPUT -j OUTGOINGFW
 275
 276         iptables -N FORWARDFW
 277         iptables -A FORWARD -j FORWARDFW
 278
 279         # SNAT rules
 280         iptables -t nat -N NAT_SOURCE
 281         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 282
 283         # Captive Portal
 284         iptables -t nat -N CAPTIVE_PORTAL
 285         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 286
 287         # Custom prerouting chains (for transparent proxy)
 288         iptables -t nat -N SQUID
 289         iptables -t nat -A PREROUTING -j SQUID
 290
 291         # DNAT rules
 292         iptables -t nat -N NAT_DESTINATION
 293         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 294         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 295
 296         iptables -t mangle -N NAT_DESTINATION
 297         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 298
 299         iptables -t nat -N NAT_DESTINATION_FIX
 300         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 301
 302         if [ -n "${GREEN_ADDRESS}" ]; then
 303                 iptables -t nat -A NAT_DESTINATION_FIX \
 304                         -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
 305         fi
 306
 307         if [ -n "${BLUE_ADDRESS}" ]; then
 308                 iptables -t nat -A NAT_DESTINATION_FIX \
 309                         -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
 310         fi
 311
 312         if [ -n "${ORANGE_ADDRESS}" ]; then
 313                 iptables -t nat -A NAT_DESTINATION_FIX \
 314                         -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
 315         fi
 316
 317         # RED chain, used for the red interface
 318         iptables -N REDINPUT
 319         iptables -A INPUT -j REDINPUT
 320         iptables -N REDFORWARD
 321         iptables -A FORWARD -j REDFORWARD
 322         iptables -t nat -N REDNAT
 323         iptables -t nat -A POSTROUTING -j REDNAT
 324
 325         # Populate IPsec chains
 326         /usr/lib/firewall/ipsec-policy
 327
 328         # Apply OpenVPN firewall rules
 329         /usr/local/bin/openvpnctrl --firewall-rules
 330
 331         # run wirelessctrl
 332         /usr/local/bin/wirelessctrl
 333
 334         # run captivectrl
 335         /usr/local/bin/captivectrl
 336
 337         # POLICY CHAIN
 338         iptables -N POLICYIN
 339         iptables -A INPUT -j POLICYIN
 340         iptables -N POLICYFWD
 341         iptables -A FORWARD -j POLICYFWD
 342         iptables -N POLICYOUT
 343         iptables -A OUTPUT -j POLICYOUT
 344
 345         # Initialize firewall policies.
 346         /usr/sbin/firewall-policy
 347
 348         # Install firewall rules for the red interface.
 349         iptables_red_up
 350
 351         # If red has not been brought up yet, we will
 352         # add the blocking rules for MASQUERADE
 353         if [ ! -e "/var/ipfire/red/active" ]; then
 354                 iptables_red_down
 355         fi
 356 }
 357
 358 iptables_red_up() {
 359         iptables -F REDINPUT
 360         iptables -F REDFORWARD
 361         iptables -t nat -F REDNAT
 362
 363         # PPPoE / PPTP Device
 364         if [ "$IFACE" != "" ]; then
 365                 # PPPoE / PPTP
 366                 if [ "$DEVICE" != "" ]; then
 367                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 368                 fi
 369                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 370                         if [ "$RED_DEV" != "" ]; then
 371                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 372                         fi
 373                 fi
 374         fi
 375
 376         # PPTP over DHCP
 377         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 378                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 379                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 380         fi
 381
 382         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 383                 # DHCP
 384                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 385                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 386                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 387                 fi
 388                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 389                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 390                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 391                 fi
 392
 393                 # Outgoing masquerading (don't masqerade IPsec)
 394                 iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
 395
 396                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 397                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 398                 fi
 399
 400                 local NO_MASQ_NETWORKS
 401
 402                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 403                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 404                 fi
 405
 406                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 407                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 408                 fi
 409
 410                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 411                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 412                 fi
 413
 414                 local network
 415                 for network in ${NO_MASQ_NETWORKS}; do
 416                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 417                 done
 418
 419                 # Masquerade everything else
 420                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 421         fi
 422
 423         # Reload all rules.
 424         /usr/local/bin/firewallctrl
 425 }
 426
 427 iptables_red_down() {
 428         # Prohibit packets to reach the masquerading rule
 429         # while the WAN interface is down - this is required to
 430         # circumvent udp related NAT issues
 431         # http://forum.ipfire.org/index.php?topic=11127.0
 432         if [ -n "${IFACE}" ]; then
 433                 iptables -F REDFORWARD
 434                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 435         fi
 436
 437         # Reload all rules.
 438         /usr/local/bin/firewallctrl
 439 }
 440
 441 # See how we were called.
 442 case "$1" in
 443   start)
 444         boot_mesg "Setting up firewall"
 445         iptables_init
 446         evaluate_retval
 447         ;;
 448   reload|up)
 449         boot_mesg "Reloading firewall"
 450         iptables_red_up
 451         evaluate_retval
 452         ;;
 453   down)
 454         boot_mesg "Disabling firewall access to RED"
 455         iptables_red_down
 456         evaluate_retval
 457         ;;
 458   restart)
 459         $0 start
 460         ;;
 461   *)
 462         echo "Usage: $0 {start|reload|restart}"
 463         exit 1
 464         ;;
 465 esac
 466
 467 exit 0