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 if [ -z $IFACE ]; then
  11         IFACE="red0"
  12 fi
  13
  14 if [ -f /var/ipfire/red/device ]; then
  15         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  16 fi
  17
  18 NAT_MASK="0x0f000000"
  19
  20 IPS_REPEAT_MARK="0x80000000"
  21 IPS_REPEAT_MASK="0x80000000"
  22 IPS_BYPASS_MARK="0x40000000"
  23 IPS_BYPASS_MASK="0x40000000"
  24
  25 function iptables() {
  26         /sbin/iptables --wait "$@"
  27 }
  28
  29 iptables_init() {
  30         # Flush all rules and delete all custom chains
  31         iptables -F
  32         iptables -t nat -F
  33         iptables -t mangle -F
  34         iptables -t raw -F
  35         iptables -X
  36         iptables -t nat -X
  37         iptables -t mangle -X
  38         iptables -t raw -X
  39
  40         # Set up policies
  41         iptables -P INPUT DROP
  42         iptables -P FORWARD DROP
  43         iptables -P OUTPUT ACCEPT
  44
  45         # Enable TRACE logging to syslog
  46         modprobe nf_log_ipv4
  47         sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
  48
  49         # IPS Bypass Chain which stores the BYPASS bit in connection tracking
  50         iptables -N IPSBYPASS
  51         iptables -A IPSBYPASS -j CONNMARK --save-mark --mask "$(( ~IPS_REPEAT_MASK & 0xffffffff ))"
  52
  53         # Jump into bypass chain when the BYPASS bit is set
  54         for chain in INPUT FORWARD OUTPUT; do
  55                 iptables -A "${chain}" -m mark \
  56                         --mark "$(( IPS_REPEAT_MARK | IPS_BYPASS_MARK ))/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j IPSBYPASS
  57         done
  58
  59         # Empty LOG_DROP and LOG_REJECT chains
  60         iptables -N LOG_DROP
  61         iptables -A LOG_DROP   -m limit --limit 10/second -j LOG
  62         iptables -A LOG_DROP   -j DROP
  63         iptables -N LOG_REJECT
  64         iptables -A LOG_REJECT -m limit --limit 10/second -j LOG
  65         iptables -A LOG_REJECT -j REJECT
  66
  67         # This chain will log, then DROPs packets with certain bad combinations
  68         # of flags might indicate a port-scan attempt (xmas, null, etc.)
  69         iptables -N PSCAN
  70         if [ "$DROPPORTSCAN" == "on" ]; then
  71                 iptables -A PSCAN -p tcp  -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan "  -m comment --comment "DROP_TCP PScan"
  72                 iptables -A PSCAN -p udp  -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan "  -m comment --comment "DROP_UDP PScan"
  73                 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  74                 iptables -A PSCAN -f      -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  75         fi
  76         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  77
  78         # New tcp packets without SYN set - could well be an obscure type of port scan
  79         # that's not covered above, may just be a broken Windows machine
  80         iptables -N NEWNOTSYN
  81         if [ "$DROPNEWNOTSYN" == "on" ]; then
  82                 iptables -A NEWNOTSYN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_NEWNOTSYN "
  83         fi
  84         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  85
  86         # Log and subsequently drop spoofed packets or "martians", arriving from sources
  87         # on interfaces where we don't expect them
  88         iptables -N SPOOFED_MARTIAN
  89         if [ "$DROPSPOOFEDMARTIAN" == "on" ]; then
  90                 iptables -A SPOOFED_MARTIAN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_SPOOFED_MARTIAN "
  91         fi
  92         iptables -A SPOOFED_MARTIAN -j DROP -m comment --comment "DROP_SPOOFED_MARTIAN"
  93
  94         # Chain to contain all the rules relating to bad TCP flags
  95         iptables -N BADTCP
  96
  97         # Don't check loopback
  98         iptables -A BADTCP -i lo -j RETURN
  99
 100         # Disallow packets frequently used by port-scanners
 101         # NMAP FIN/URG/PSH (XMAS scan)
 102         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
 103         # SYN/RST/ACK/FIN/URG
 104         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
 105         # ALL/ALL
 106         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
 107         # FIN Stealth
 108         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
 109         # SYN/RST (also catches xmas variants that set SYN+RST+...)
 110         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
 111         # SYN/FIN (QueSO or nmap OS probe)
 112         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
 113         # Null
 114         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
 115         # NEW TCP without SYN
 116         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
 117
 118         iptables -A INPUT   -p tcp -j BADTCP
 119         iptables -A FORWARD -p tcp -j BADTCP
 120
 121         # Connection tracking chains
 122         iptables -N CONNTRACK
 123         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
 124         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j LOG_DROP
 125         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
 126
 127         # Restore any connection marks
 128         iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
 129
 130         # Fix for braindead ISPs
 131         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 132
 133         # CUSTOM chains, can be used by the users themselves
 134         iptables -N CUSTOMINPUT
 135         iptables -A INPUT -j CUSTOMINPUT
 136         iptables -N CUSTOMFORWARD
 137         iptables -A FORWARD -j CUSTOMFORWARD
 138         iptables -N CUSTOMOUTPUT
 139         iptables -A OUTPUT -j CUSTOMOUTPUT
 140         iptables -t nat -N CUSTOMPREROUTING
 141         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 142         iptables -t nat -N CUSTOMPOSTROUTING
 143         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 144
 145         # Log and drop any traffic from and to networks known as being hostile, posing
 146         # a technical threat to our users (i. e. listed at Spamhaus DROP et al.)
 147         iptables -N HOSTILE
 148         if [ "$DROPHOSTILE" == "on" ]; then
 149                 iptables -A HOSTILE -m limit --limit 10/second -j LOG  --log-prefix "DROP_HOSTILE "
 150                 iptables -A INPUT   -i $IFACE -m geoip --src-cc XD -j HOSTILE
 151                 iptables -A FORWARD -i $IFACE -m geoip --src-cc XD -j HOSTILE
 152                 iptables -A FORWARD -o $IFACE -m geoip --dst-cc XD -j HOSTILE
 153                 iptables -A OUTPUT  -o $IFACE -m geoip --src-cc XD -j HOSTILE
 154         fi
 155         iptables -A HOSTILE -j DROP -m comment --comment "DROP_HOSTILE"
 156
 157         # P2PBLOCK
 158         iptables -N P2PBLOCK
 159         iptables -A INPUT -j P2PBLOCK
 160         iptables -A FORWARD -j P2PBLOCK
 161         iptables -A OUTPUT -j P2PBLOCK
 162
 163         # IPS (Guardian) chains
 164         iptables -N GUARDIAN
 165         iptables -A INPUT -j GUARDIAN
 166         iptables -A FORWARD -j GUARDIAN
 167
 168         # Block non-established IPsec networks
 169         iptables -N IPSECBLOCK
 170         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 171         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 172
 173         # Block OpenVPN transfer networks
 174         iptables -N OVPNBLOCK
 175         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 176         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 177         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 178
 179         # IPS (Suricata) chains
 180         iptables -N IPS_INPUT
 181         iptables -N IPS_FORWARD
 182         iptables -N IPS_OUTPUT
 183
 184         for chain in INPUT FORWARD OUTPUT; do
 185                 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
 186         done
 187
 188         # OpenVPN transfer network translation
 189         iptables -t nat -N OVPNNAT
 190         iptables -t nat -A POSTROUTING -j OVPNNAT
 191
 192         # IPTV chains for IGMPPROXY
 193         iptables -N IPTVINPUT
 194         iptables -A INPUT -j IPTVINPUT
 195         iptables -N IPTVFORWARD
 196         iptables -A FORWARD -j IPTVFORWARD
 197
 198         # Allow to ping the firewall.
 199         iptables -N ICMPINPUT
 200         iptables -A INPUT -j ICMPINPUT
 201         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 202
 203         # Accept everything on loopback
 204         iptables -N LOOPBACK
 205         iptables -A LOOPBACK -i lo -j ACCEPT
 206         iptables -A LOOPBACK -o lo -j ACCEPT
 207
 208         # Filter all packets with loopback addresses on non-loopback interfaces (spoofed)
 209         iptables -A LOOPBACK -s 127.0.0.0/8 -j SPOOFED_MARTIAN
 210         iptables -A LOOPBACK -d 127.0.0.0/8 -j SPOOFED_MARTIAN
 211
 212         for i in INPUT FORWARD OUTPUT; do
 213                 iptables -A ${i} -j LOOPBACK
 214         done
 215
 216         # Captive portal
 217         iptables -N CAPTIVE_PORTAL
 218         iptables -N CAPTIVE_PORTAL_CLIENTS
 219         for i in INPUT FORWARD; do
 220                 iptables -A ${i} -j CAPTIVE_PORTAL
 221         done
 222
 223         # Accept everything connected
 224         for i in INPUT FORWARD OUTPUT; do
 225                 iptables -A ${i} -j CONNTRACK
 226         done
 227
 228         # Allow DHCP
 229         iptables -N DHCPINPUT
 230         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 231         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 232
 233         iptables -N DHCPOUTPUT
 234         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 235         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 236
 237         # Allow DHCP on GREEN
 238         iptables -N DHCPGREENINPUT
 239         iptables -N DHCPGREENOUTPUT
 240         if [ -n "${GREEN_DEV}" ]; then
 241                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 242                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 243         fi
 244
 245         # Allow DHCP on BLUE to be turned on/off
 246         iptables -N DHCPBLUEINPUT
 247         iptables -N DHCPBLUEOUTPUT
 248         if [ -n "${BLUE_DEV}" ]; then
 249                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 250                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 251         fi
 252
 253         # Tor (inbound)
 254         iptables -N TOR_INPUT
 255         iptables -A INPUT -j TOR_INPUT
 256
 257         # Location Block
 258         iptables -N LOCATIONBLOCK
 259         iptables -A INPUT -j LOCATIONBLOCK
 260         iptables -A FORWARD -j LOCATIONBLOCK
 261
 262         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 263         iptables -N IPSECINPUT
 264         iptables -N IPSECFORWARD
 265         iptables -N IPSECOUTPUT
 266         iptables -A INPUT -j IPSECINPUT
 267         iptables -A FORWARD -j IPSECFORWARD
 268         iptables -A OUTPUT -j IPSECOUTPUT
 269         iptables -t nat -N IPSECNAT
 270         iptables -t nat -A POSTROUTING -j IPSECNAT
 271
 272         # localhost and ethernet.
 273         # Always allow accessing the web GUI from GREEN.
 274         iptables -N GUIINPUT
 275         iptables -A INPUT -j GUIINPUT
 276         if [ -n "${GREEN_DEV}" ]; then
 277                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 278         fi
 279
 280         # WIRELESS chains
 281         iptables -N WIRELESSINPUT
 282         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 283         iptables -N WIRELESSFORWARD
 284         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 285
 286         # OpenVPN
 287         iptables -N OVPNINPUT
 288         iptables -A INPUT -j OVPNINPUT
 289
 290         # Tor (outbound)
 291         iptables -N TOR_OUTPUT
 292         iptables -A OUTPUT -j TOR_OUTPUT
 293
 294         # Jump into the actual firewall ruleset.
 295         iptables -N INPUTFW
 296         iptables -A INPUT -j INPUTFW
 297
 298         iptables -N OUTGOINGFW
 299         iptables -A OUTPUT -j OUTGOINGFW
 300
 301         iptables -N FORWARDFW
 302         iptables -A FORWARD -j FORWARDFW
 303
 304         # SNAT rules
 305         iptables -t nat -N NAT_SOURCE
 306         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 307
 308         # Captive Portal
 309         iptables -t nat -N CAPTIVE_PORTAL
 310         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 311
 312         # Custom prerouting chains (for transparent proxy)
 313         iptables -t nat -N SQUID
 314         iptables -t nat -A PREROUTING -j SQUID
 315
 316         # DNAT rules
 317         iptables -t nat -N NAT_DESTINATION
 318         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 319         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 320
 321         iptables -t mangle -N NAT_DESTINATION
 322         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 323
 324         iptables -t nat -N NAT_DESTINATION_FIX
 325         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 326
 327         if [ -n "${GREEN_ADDRESS}" ]; then
 328                 iptables -t nat -A NAT_DESTINATION_FIX \
 329                         -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
 330         fi
 331
 332         if [ -n "${BLUE_ADDRESS}" ]; then
 333                 iptables -t nat -A NAT_DESTINATION_FIX \
 334                         -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
 335         fi
 336
 337         if [ -n "${ORANGE_ADDRESS}" ]; then
 338                 iptables -t nat -A NAT_DESTINATION_FIX \
 339                         -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
 340         fi
 341
 342         # RED chain, used for the red interface
 343         iptables -N REDINPUT
 344         iptables -A INPUT -j REDINPUT
 345         iptables -N REDFORWARD
 346         iptables -A FORWARD -j REDFORWARD
 347         iptables -t nat -N REDNAT
 348         iptables -t nat -A POSTROUTING -j REDNAT
 349
 350         # Populate IPsec chains
 351         /usr/lib/firewall/ipsec-policy
 352
 353         # Apply OpenVPN firewall rules
 354         /usr/local/bin/openvpnctrl --firewall-rules
 355
 356         # run wirelessctrl
 357         /usr/local/bin/wirelessctrl
 358
 359         # run captivectrl
 360         /usr/local/bin/captivectrl
 361
 362         # POLICY CHAIN
 363         iptables -N POLICYIN
 364         iptables -A INPUT -j POLICYIN
 365         iptables -N POLICYFWD
 366         iptables -A FORWARD -j POLICYFWD
 367         iptables -N POLICYOUT
 368         iptables -A OUTPUT -j POLICYOUT
 369
 370         # Initialize firewall policies.
 371         /usr/sbin/firewall-policy
 372
 373         # Install firewall rules for the red interface.
 374         iptables_red_up
 375
 376         # If red has not been brought up yet, we will
 377         # add the blocking rules for MASQUERADE
 378         if [ ! -e "/var/ipfire/red/active" ]; then
 379                 iptables_red_down
 380         fi
 381 }
 382
 383 iptables_red_up() {
 384         iptables -F REDINPUT
 385         iptables -F REDFORWARD
 386         iptables -t nat -F REDNAT
 387
 388         # Prohibit spoofing our own IP address on RED
 389         if [ -f /var/ipfire/red/active ]; then
 390                 REDIP="$( cat /var/ipfire/red/local-ipaddress )";
 391
 392                 if [ "$IFACE" != "" ]; then
 393                         iptables -A REDINPUT -s $REDIP -i $IFACE -j SPOOFED_MARTIAN
 394                 elif [ "$DEVICE" != "" ]; then
 395                         iptables -A REDINPUT -s $REDIP -i $DEVICE -j SPOOFED_MARTIAN
 396                 fi
 397         fi
 398
 399         # PPPoE / PPTP Device
 400         if [ "$IFACE" != "" ]; then
 401                 # PPPoE / PPTP
 402                 if [ "$DEVICE" != "" ]; then
 403                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 404                 fi
 405                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 406                         if [ "$RED_DEV" != "" ]; then
 407                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 408                         fi
 409                 fi
 410         fi
 411
 412         # PPTP over DHCP
 413         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 414                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 415                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 416         fi
 417
 418         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 419                 # DHCP
 420                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 421                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 422                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 423                 fi
 424                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 425                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 426                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 427                 fi
 428
 429                 # Outgoing masquerading (don't masqerade IPsec)
 430                 iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
 431
 432                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 433                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 434                 fi
 435
 436                 local NO_MASQ_NETWORKS
 437
 438                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 439                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 440                 fi
 441
 442                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 443                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 444                 fi
 445
 446                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 447                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 448                 fi
 449
 450                 local network
 451                 for network in ${NO_MASQ_NETWORKS}; do
 452                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 453                 done
 454
 455                 # Masquerade everything else
 456                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 457         fi
 458
 459         # Reload all rules.
 460         /usr/local/bin/firewallctrl
 461 }
 462
 463 iptables_red_down() {
 464         # Prohibit packets to reach the masquerading rule
 465         # while the WAN interface is down - this is required to
 466         # circumvent udp related NAT issues
 467         # http://forum.ipfire.org/index.php?topic=11127.0
 468         if [ -n "${IFACE}" ]; then
 469                 iptables -F REDFORWARD
 470                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 471         fi
 472
 473         # Reload all rules.
 474         /usr/local/bin/firewallctrl
 475 }
 476
 477 # See how we were called.
 478 case "$1" in
 479   start)
 480         boot_mesg "Setting up firewall"
 481         iptables_init
 482         evaluate_retval
 483         ;;
 484   reload|up)
 485         boot_mesg "Reloading firewall"
 486         iptables_red_up
 487         evaluate_retval
 488         ;;
 489   down)
 490         boot_mesg "Disabling firewall access to RED"
 491         iptables_red_down
 492         evaluate_retval
 493         ;;
 494   restart)
 495         $0 start
 496         ;;
 497   *)
 498         echo "Usage: $0 {start|reload|restart}"
 499         exit 1
 500         ;;
 501 esac
 502
 503 exit 0