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 set --match-set CC_XD src -j HOSTILE
 151                 iptables -A FORWARD -i $IFACE -m set --match-set CC_XD src -j HOSTILE
 152                 iptables -A FORWARD -o $IFACE -m set --match-set CC_XD dst -j HOSTILE
 153                 iptables -A OUTPUT  -o $IFACE -m set --match-set CC_XD src -j HOSTILE
 154         fi
 155         iptables -A HOSTILE -j DROP -m comment --comment "DROP_HOSTILE"
 156
 157         # IPS (Guardian) chains
 158         iptables -N GUARDIAN
 159         iptables -A INPUT -j GUARDIAN
 160         iptables -A FORWARD -j GUARDIAN
 161
 162         # Block non-established IPsec networks
 163         iptables -N IPSECBLOCK
 164         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 165         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 166
 167         # Block OpenVPN transfer networks
 168         iptables -N OVPNBLOCK
 169         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 170         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 171         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 172
 173         # IPS (Suricata) chains
 174         iptables -N IPS_INPUT
 175         iptables -N IPS_FORWARD
 176         iptables -N IPS_OUTPUT
 177
 178         for chain in INPUT FORWARD OUTPUT; do
 179                 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
 180         done
 181
 182         # OpenVPN transfer network translation
 183         iptables -t nat -N OVPNNAT
 184         iptables -t nat -A POSTROUTING -j OVPNNAT
 185
 186         # IPTV chains for IGMPPROXY
 187         iptables -N IPTVINPUT
 188         iptables -A INPUT -j IPTVINPUT
 189         iptables -N IPTVFORWARD
 190         iptables -A FORWARD -j IPTVFORWARD
 191
 192         # Allow to ping the firewall.
 193         iptables -N ICMPINPUT
 194         iptables -A INPUT -j ICMPINPUT
 195         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 196
 197         # Accept everything on loopback
 198         iptables -N LOOPBACK
 199         iptables -A LOOPBACK -i lo -j ACCEPT
 200         iptables -A LOOPBACK -o lo -j ACCEPT
 201
 202         # Filter all packets with loopback addresses on non-loopback interfaces (spoofed)
 203         iptables -A LOOPBACK -s 127.0.0.0/8 -j SPOOFED_MARTIAN
 204         iptables -A LOOPBACK -d 127.0.0.0/8 -j SPOOFED_MARTIAN
 205
 206         for i in INPUT FORWARD OUTPUT; do
 207                 iptables -A ${i} -j LOOPBACK
 208         done
 209
 210         # Captive portal
 211         iptables -N CAPTIVE_PORTAL
 212         iptables -N CAPTIVE_PORTAL_CLIENTS
 213         for i in INPUT FORWARD; do
 214                 iptables -A ${i} -j CAPTIVE_PORTAL
 215         done
 216
 217         # Accept everything connected
 218         for i in INPUT FORWARD OUTPUT; do
 219                 iptables -A ${i} -j CONNTRACK
 220         done
 221
 222         # Allow DHCP
 223         iptables -N DHCPINPUT
 224         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 225         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 226
 227         iptables -N DHCPOUTPUT
 228         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 229         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 230
 231         # Allow DHCP on GREEN
 232         iptables -N DHCPGREENINPUT
 233         iptables -N DHCPGREENOUTPUT
 234         if [ -n "${GREEN_DEV}" ]; then
 235                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 236                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 237         fi
 238
 239         # Allow DHCP on BLUE to be turned on/off
 240         iptables -N DHCPBLUEINPUT
 241         iptables -N DHCPBLUEOUTPUT
 242         if [ -n "${BLUE_DEV}" ]; then
 243                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 244                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 245         fi
 246
 247         # Tor (inbound)
 248         iptables -N TOR_INPUT
 249         iptables -A INPUT -j TOR_INPUT
 250
 251         # Location Block
 252         iptables -N LOCATIONBLOCK
 253         iptables -A INPUT -j LOCATIONBLOCK
 254         iptables -A FORWARD -j LOCATIONBLOCK
 255
 256         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 257         iptables -N IPSECINPUT
 258         iptables -N IPSECFORWARD
 259         iptables -N IPSECOUTPUT
 260         iptables -A INPUT -j IPSECINPUT
 261         iptables -A FORWARD -j IPSECFORWARD
 262         iptables -A OUTPUT -j IPSECOUTPUT
 263         iptables -t nat -N IPSECNAT
 264         iptables -t nat -A POSTROUTING -j IPSECNAT
 265
 266         # localhost and ethernet.
 267         # Always allow accessing the web GUI from GREEN.
 268         iptables -N GUIINPUT
 269         iptables -A INPUT -j GUIINPUT
 270         if [ -n "${GREEN_DEV}" ]; then
 271                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 272         fi
 273
 274         # WIRELESS chains
 275         iptables -N WIRELESSINPUT
 276         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 277         iptables -N WIRELESSFORWARD
 278         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 279
 280         # OpenVPN
 281         iptables -N OVPNINPUT
 282         iptables -A INPUT -j OVPNINPUT
 283
 284         # Tor (outbound)
 285         iptables -N TOR_OUTPUT
 286         iptables -A OUTPUT -j TOR_OUTPUT
 287
 288         # Jump into the actual firewall ruleset.
 289         iptables -N INPUTFW
 290         iptables -A INPUT -j INPUTFW
 291
 292         iptables -N OUTGOINGFW
 293         iptables -A OUTPUT -j OUTGOINGFW
 294
 295         iptables -N FORWARDFW
 296         iptables -A FORWARD -j FORWARDFW
 297
 298         # SNAT rules
 299         iptables -t nat -N NAT_SOURCE
 300         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 301
 302         # Captive Portal
 303         iptables -t nat -N CAPTIVE_PORTAL
 304         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 305
 306         # Custom prerouting chains (for transparent proxy)
 307         iptables -t nat -N SQUID
 308         iptables -t nat -A PREROUTING -j SQUID
 309
 310         # DNAT rules
 311         iptables -t nat -N NAT_DESTINATION
 312         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 313         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 314
 315         iptables -t mangle -N NAT_DESTINATION
 316         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 317
 318         iptables -t nat -N NAT_DESTINATION_FIX
 319         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 320
 321         if [ -n "${GREEN_ADDRESS}" ]; then
 322                 iptables -t nat -A NAT_DESTINATION_FIX \
 323                         -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
 324         fi
 325
 326         if [ -n "${BLUE_ADDRESS}" ]; then
 327                 iptables -t nat -A NAT_DESTINATION_FIX \
 328                         -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
 329         fi
 330
 331         if [ -n "${ORANGE_ADDRESS}" ]; then
 332                 iptables -t nat -A NAT_DESTINATION_FIX \
 333                         -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
 334         fi
 335
 336         # RED chain, used for the red interface
 337         iptables -N REDINPUT
 338         iptables -A INPUT -j REDINPUT
 339         iptables -N REDFORWARD
 340         iptables -A FORWARD -j REDFORWARD
 341         iptables -t nat -N REDNAT
 342         iptables -t nat -A POSTROUTING -j REDNAT
 343
 344         # Populate IPsec chains
 345         /usr/lib/firewall/ipsec-policy
 346
 347         # Apply OpenVPN firewall rules
 348         /usr/local/bin/openvpnctrl --firewall-rules
 349
 350         # run wirelessctrl
 351         /usr/local/bin/wirelessctrl
 352
 353         # run captivectrl
 354         /usr/local/bin/captivectrl
 355
 356         # POLICY CHAIN
 357         iptables -N POLICYIN
 358         iptables -A INPUT -j POLICYIN
 359         iptables -N POLICYFWD
 360         iptables -A FORWARD -j POLICYFWD
 361         iptables -N POLICYOUT
 362         iptables -A OUTPUT -j POLICYOUT
 363
 364         # Initialize firewall policies.
 365         /usr/sbin/firewall-policy
 366
 367         # Install firewall rules for the red interface.
 368         iptables_red_up
 369
 370         # If red has not been brought up yet, we will
 371         # add the blocking rules for MASQUERADE
 372         if [ ! -e "/var/ipfire/red/active" ]; then
 373                 iptables_red_down
 374         fi
 375 }
 376
 377 iptables_red_up() {
 378         iptables -F REDINPUT
 379         iptables -F REDFORWARD
 380         iptables -t nat -F REDNAT
 381
 382         # Prohibit spoofing our own IP address on RED
 383         if [ -f /var/ipfire/red/active ]; then
 384                 REDIP="$( cat /var/ipfire/red/local-ipaddress )";
 385
 386                 if [ "$IFACE" != "" ]; then
 387                         iptables -A REDINPUT -s $REDIP -i $IFACE -j SPOOFED_MARTIAN
 388                 elif [ "$DEVICE" != "" ]; then
 389                         iptables -A REDINPUT -s $REDIP -i $DEVICE -j SPOOFED_MARTIAN
 390                 fi
 391         fi
 392
 393         # PPPoE / PPTP Device
 394         if [ "$IFACE" != "" ]; then
 395                 # PPPoE / PPTP
 396                 if [ "$DEVICE" != "" ]; then
 397                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 398                 fi
 399                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 400                         if [ "$RED_DEV" != "" ]; then
 401                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 402                         fi
 403                 fi
 404         fi
 405
 406         # PPTP over DHCP
 407         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 408                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 409                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 410         fi
 411
 412         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 413                 # DHCP
 414                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 415                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 416                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 417                 fi
 418                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 419                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 420                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 421                 fi
 422
 423                 # Outgoing masquerading (don't masqerade IPsec)
 424                 iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
 425
 426                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 427                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 428                 fi
 429
 430                 local NO_MASQ_NETWORKS
 431
 432                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 433                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 434                 fi
 435
 436                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 437                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 438                 fi
 439
 440                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 441                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 442                 fi
 443
 444                 local network
 445                 for network in ${NO_MASQ_NETWORKS}; do
 446                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 447                 done
 448
 449                 # Masquerade everything else
 450                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 451         fi
 452
 453         # Reload all rules.
 454         /usr/local/bin/firewallctrl
 455 }
 456
 457 iptables_red_down() {
 458         # Prohibit packets to reach the masquerading rule
 459         # while the WAN interface is down - this is required to
 460         # circumvent udp related NAT issues
 461         # http://forum.ipfire.org/index.php?topic=11127.0
 462         if [ -n "${IFACE}" ]; then
 463                 iptables -F REDFORWARD
 464                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 465         fi
 466
 467         # Reload all rules.
 468         /usr/local/bin/firewallctrl
 469 }
 470
 471 # See how we were called.
 472 case "$1" in
 473   start)
 474         boot_mesg "Setting up firewall"
 475         iptables_init
 476         evaluate_retval
 477         ;;
 478   reload|up)
 479         boot_mesg "Reloading firewall"
 480         iptables_red_up
 481         evaluate_retval
 482         ;;
 483   down)
 484         boot_mesg "Disabling firewall access to RED"
 485         iptables_red_down
 486         evaluate_retval
 487         ;;
 488   restart)
 489         $0 start
 490         ;;
 491   *)
 492         echo "Usage: $0 {start|reload|restart}"
 493         exit 1
 494         ;;
 495 esac
 496
 497 exit 0