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