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 $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
   9 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
  10
  11 if [ -f /var/ipfire/red/device ]; then
  12         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  13 fi
  14
  15 NAT_MASK="0x0f000000"
  16
  17 IPSEC_MARK="0x00800000"
  18 IPSEC_MASK="${IPSEC_MARK}"
  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         # Chain to contain all the rules relating to bad TCP flags
  87         iptables -N BADTCP
  88
  89         # Don't check loopback
  90         iptables -A BADTCP -i lo -j RETURN
  91
  92         # Disallow packets frequently used by port-scanners
  93         # NMAP FIN/URG/PSH (XMAS scan)
  94         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  95         # SYN/RST/ACK/FIN/URG
  96         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  97         # ALL/ALL
  98         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  99         # FIN Stealth
 100         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
 101         # SYN/RST (also catches xmas variants that set SYN+RST+...)
 102         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
 103         # SYN/FIN (QueSO or nmap OS probe)
 104         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
 105         # Null
 106         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
 107         # NEW TCP without SYN
 108         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
 109
 110         iptables -A INPUT   -p tcp -j BADTCP
 111         iptables -A FORWARD -p tcp -j BADTCP
 112
 113         # Connection tracking chains
 114         iptables -N CONNTRACK
 115         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
 116         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
 117         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
 118         iptables -t raw -N CONNTRACK
 119         iptables -t raw -A PREROUTING -j CONNTRACK
 120
 121         # Restore any connection marks
 122         iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
 123
 124         # Fix for braindead ISPs
 125         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 126
 127         # CUSTOM chains, can be used by the users themselves
 128         iptables -N CUSTOMINPUT
 129         iptables -A INPUT -j CUSTOMINPUT
 130         iptables -N CUSTOMFORWARD
 131         iptables -A FORWARD -j CUSTOMFORWARD
 132         iptables -N CUSTOMOUTPUT
 133         iptables -A OUTPUT -j CUSTOMOUTPUT
 134         iptables -t nat -N CUSTOMPREROUTING
 135         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 136         iptables -t nat -N CUSTOMPOSTROUTING
 137         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 138
 139         # P2PBLOCK
 140         iptables -N P2PBLOCK
 141         iptables -A INPUT -j P2PBLOCK
 142         iptables -A FORWARD -j P2PBLOCK
 143         iptables -A OUTPUT -j P2PBLOCK
 144
 145         # IPS (Guardian) chains
 146         iptables -N GUARDIAN
 147         iptables -A INPUT -j GUARDIAN
 148         iptables -A FORWARD -j GUARDIAN
 149
 150         # Block non-established IPsec networks
 151         iptables -N IPSECBLOCK
 152         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 153         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 154
 155         # Block OpenVPN transfer networks
 156         iptables -N OVPNBLOCK
 157         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 158         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 159         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 160
 161         # IPS (Suricata) chains
 162         iptables -N IPS_INPUT
 163         iptables -N IPS_FORWARD
 164         iptables -N IPS_OUTPUT
 165
 166         for chain in INPUT FORWARD OUTPUT; do
 167                 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
 168         done
 169
 170         # OpenVPN transfer network translation
 171         iptables -t nat -N OVPNNAT
 172         iptables -t nat -A POSTROUTING -j OVPNNAT
 173
 174         # IPTV chains for IGMPPROXY
 175         iptables -N IPTVINPUT
 176         iptables -A INPUT -j IPTVINPUT
 177         iptables -N IPTVFORWARD
 178         iptables -A FORWARD -j IPTVFORWARD
 179
 180         # Allow to ping the firewall.
 181         iptables -N ICMPINPUT
 182         iptables -A INPUT -j ICMPINPUT
 183         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 184
 185         # Accept everything on loopback
 186         iptables -N LOOPBACK
 187         iptables -A LOOPBACK -i lo -j ACCEPT
 188         iptables -A LOOPBACK -o lo -j ACCEPT
 189
 190         # Filter all packets with loopback addresses on non-loopback interfaces.
 191         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 192         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 193
 194         for i in INPUT FORWARD OUTPUT; do
 195                 iptables -A ${i} -j LOOPBACK
 196         done
 197
 198         # Captive portal
 199         iptables -N CAPTIVE_PORTAL
 200         iptables -N CAPTIVE_PORTAL_CLIENTS
 201         for i in INPUT FORWARD; do
 202                 iptables -A ${i} -j CAPTIVE_PORTAL
 203         done
 204
 205         # Accept everything connected
 206         for i in INPUT FORWARD OUTPUT; do
 207                 iptables -A ${i} -j CONNTRACK
 208         done
 209
 210         # Allow DHCP
 211         iptables -N DHCPINPUT
 212         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 213         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 214
 215         iptables -N DHCPOUTPUT
 216         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 217         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 218
 219         # Allow DHCP on GREEN
 220         iptables -N DHCPGREENINPUT
 221         iptables -N DHCPGREENOUTPUT
 222         if [ -n "${GREEN_DEV}" ]; then
 223                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 224                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 225         fi
 226
 227         # Allow DHCP on BLUE to be turned on/off
 228         iptables -N DHCPBLUEINPUT
 229         iptables -N DHCPBLUEOUTPUT
 230         if [ -n "${BLUE_DEV}" ]; then
 231                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 232                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 233         fi
 234
 235         # Location Block
 236         iptables -N LOCATIONBLOCK
 237         iptables -A INPUT -j LOCATIONBLOCK
 238         iptables -A FORWARD -j LOCATIONBLOCK
 239
 240         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 241         iptables -N IPSECINPUT
 242         iptables -N IPSECFORWARD
 243         iptables -N IPSECOUTPUT
 244         iptables -A INPUT -j IPSECINPUT
 245         iptables -A FORWARD -j IPSECFORWARD
 246         iptables -A OUTPUT -j IPSECOUTPUT
 247         iptables -t nat -N IPSECNAT
 248         iptables -t nat -A POSTROUTING -j IPSECNAT
 249
 250         # localhost and ethernet.
 251         # Always allow accessing the web GUI from GREEN.
 252         iptables -N GUIINPUT
 253         iptables -A INPUT -j GUIINPUT
 254         if [ -n "${GREEN_DEV}" ]; then
 255                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 256         fi
 257
 258         # WIRELESS chains
 259         iptables -N WIRELESSINPUT
 260         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 261         iptables -N WIRELESSFORWARD
 262         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 263
 264         # OpenVPN
 265         iptables -N OVPNINPUT
 266         iptables -A INPUT -j OVPNINPUT
 267
 268         # Tor (inbound and outbound)
 269         iptables -N TOR_INPUT
 270         iptables -A INPUT -j TOR_INPUT
 271         iptables -N TOR_OUTPUT
 272         iptables -A OUTPUT -j TOR_OUTPUT
 273
 274         # Jump into the actual firewall ruleset.
 275         iptables -N INPUTFW
 276         iptables -A INPUT -j INPUTFW
 277
 278         iptables -N OUTGOINGFW
 279         iptables -A OUTPUT -j OUTGOINGFW
 280
 281         iptables -N FORWARDFW
 282         iptables -A FORWARD -j FORWARDFW
 283
 284         # SNAT rules
 285         iptables -t nat -N NAT_SOURCE
 286         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 287
 288         # Captive Portal
 289         iptables -t nat -N CAPTIVE_PORTAL
 290         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 291
 292         # Custom prerouting chains (for transparent proxy)
 293         iptables -t nat -N SQUID
 294         iptables -t nat -A PREROUTING -j SQUID
 295
 296         # DNAT rules
 297         iptables -t nat -N NAT_DESTINATION
 298         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 299         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 300
 301         iptables -t mangle -N NAT_DESTINATION
 302         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 303
 304         iptables -t nat -N NAT_DESTINATION_FIX
 305         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 306
 307         if [ -n "${GREEN_ADDRESS}" ]; then
 308                 iptables -t nat -A NAT_DESTINATION_FIX \
 309                         -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
 310         fi
 311
 312         if [ -n "${BLUE_ADDRESS}" ]; then
 313                 iptables -t nat -A NAT_DESTINATION_FIX \
 314                         -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
 315         fi
 316
 317         if [ -n "${ORANGE_ADDRESS}" ]; then
 318                 iptables -t nat -A NAT_DESTINATION_FIX \
 319                         -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
 320         fi
 321
 322         # RED chain, used for the red interface
 323         iptables -N REDINPUT
 324         iptables -A INPUT -j REDINPUT
 325         iptables -N REDFORWARD
 326         iptables -A FORWARD -j REDFORWARD
 327         iptables -t nat -N REDNAT
 328         iptables -t nat -A POSTROUTING -j REDNAT
 329
 330         # Populate IPsec chains
 331         /usr/lib/firewall/ipsec-policy
 332
 333         # Apply OpenVPN firewall rules
 334         /usr/local/bin/openvpnctrl --firewall-rules
 335
 336         # run wirelessctrl
 337         /usr/local/bin/wirelessctrl
 338
 339         # run captivectrl
 340         /usr/local/bin/captivectrl
 341
 342         # POLICY CHAIN
 343         iptables -N POLICYIN
 344         iptables -A INPUT -j POLICYIN
 345         iptables -N POLICYFWD
 346         iptables -A FORWARD -j POLICYFWD
 347         iptables -N POLICYOUT
 348         iptables -A OUTPUT -j POLICYOUT
 349
 350         # Initialize firewall policies.
 351         /usr/sbin/firewall-policy
 352
 353         # Install firewall rules for the red interface.
 354         iptables_red_up
 355
 356         # If red has not been brought up yet, we will
 357         # add the blocking rules for MASQUERADE
 358         if [ ! -e "/var/ipfire/red/active" ]; then
 359                 iptables_red_down
 360         fi
 361 }
 362
 363 iptables_red_up() {
 364         iptables -F REDINPUT
 365         iptables -F REDFORWARD
 366         iptables -t nat -F REDNAT
 367
 368         # PPPoE / PPTP Device
 369         if [ "$IFACE" != "" ]; then
 370                 # PPPoE / PPTP
 371                 if [ "$DEVICE" != "" ]; then
 372                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 373                 fi
 374                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 375                         if [ "$RED_DEV" != "" ]; then
 376                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 377                         fi
 378                 fi
 379         fi
 380
 381         # PPTP over DHCP
 382         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 383                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 384                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 385         fi
 386
 387         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 388                 # DHCP
 389                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 390                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 391                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 392                 fi
 393                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 394                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 395                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 396                 fi
 397
 398                 # Outgoing masquerading (don't masqerade IPsec)
 399                 iptables -t nat -A REDNAT -m mark --mark "${IPSEC_MARK}/${IPSEC_MASK}" -o "${IFACE}" -j RETURN
 400
 401                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 402                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 403                 fi
 404
 405                 local NO_MASQ_NETWORKS
 406
 407                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 408                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 409                 fi
 410
 411                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 412                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 413                 fi
 414
 415                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 416                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 417                 fi
 418
 419                 local network
 420                 for network in ${NO_MASQ_NETWORKS}; do
 421                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 422                 done
 423
 424                 # Masquerade everything else
 425                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 426         fi
 427
 428         # Reload all rules.
 429         /usr/local/bin/firewallctrl
 430 }
 431
 432 iptables_red_down() {
 433         # Prohibit packets to reach the masquerading rule
 434         # while the WAN interface is down - this is required to
 435         # circumvent udp related NAT issues
 436         # http://forum.ipfire.org/index.php?topic=11127.0
 437         if [ -n "${IFACE}" ]; then
 438                 iptables -F REDFORWARD
 439                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 440         fi
 441
 442         # Reload all rules.
 443         /usr/local/bin/firewallctrl
 444 }
 445
 446 # See how we were called.
 447 case "$1" in
 448   start)
 449         boot_mesg "Setting up firewall"
 450         iptables_init
 451         evaluate_retval
 452         ;;
 453   reload|up)
 454         boot_mesg "Reloading firewall"
 455         iptables_red_up
 456         evaluate_retval
 457         ;;
 458   down)
 459         boot_mesg "Disabling firewall access to RED"
 460         iptables_red_down
 461         evaluate_retval
 462         ;;
 463   restart)
 464         $0 start
 465         ;;
 466   *)
 467         echo "Usage: $0 {start|reload|restart}"
 468         exit 1
 469         ;;
 470 esac
 471
 472 exit 0