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 $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
   9 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
  10
  11 if [ -f /var/ipfire/red/device ]; then
  12         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  13 fi
  14
  15 function iptables() {
  16         /sbin/iptables --wait "$@"
  17 }
  18
  19 iptables_init() {
  20         # Flush all rules and delete all custom chains
  21         iptables -F
  22         iptables -t nat -F
  23         iptables -t mangle -F
  24         iptables -t raw -F
  25         iptables -X
  26         iptables -t nat -X
  27         iptables -t mangle -X
  28         iptables -t raw -X
  29
  30         # Set up policies
  31         iptables -P INPUT DROP
  32         iptables -P FORWARD DROP
  33         iptables -P OUTPUT ACCEPT
  34
  35         # Empty LOG_DROP and LOG_REJECT chains
  36         iptables -N LOG_DROP
  37         iptables -A LOG_DROP   -m limit --limit 10/minute -j LOG
  38         iptables -A LOG_DROP   -j DROP
  39         iptables -N LOG_REJECT
  40         iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG
  41         iptables -A LOG_REJECT -j REJECT
  42
  43         # This chain will log, then DROPs packets with certain bad combinations
  44         # of flags might indicate a port-scan attempt (xmas, null, etc)
  45         iptables -N PSCAN
  46         if [ "$DROPPORTSCAN" == "on" ]; then
  47                 iptables -A PSCAN -p tcp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan"
  48                 iptables -A PSCAN -p udp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan"
  49                 iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  50                 iptables -A PSCAN -f      -m limit --limit 10/minute -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  51         fi
  52         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  53
  54         # New tcp packets without SYN set - could well be an obscure type of port scan
  55         # that's not covered above, may just be a broken windows machine
  56         iptables -N NEWNOTSYN
  57         if [ "$DROPNEWNOTSYN" == "on" ]; then
  58                 iptables -A NEWNOTSYN  -m limit --limit 10/minute -j LOG  --log-prefix "DROP_NEWNOTSYN "
  59         fi
  60         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  61
  62         # Chain to contain all the rules relating to bad TCP flags
  63         iptables -N BADTCP
  64
  65         # Don't check loopback
  66         iptables -A BADTCP -i lo -j RETURN
  67
  68         # Disallow packets frequently used by port-scanners
  69         # NMAP FIN/URG/PSH (XMAS scan)
  70         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  71         # SYN/RST/ACK/FIN/URG
  72         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  73         # ALL/ALL
  74         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  75         # FIN Stealth
  76         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  77         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  78         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  79         # SYN/FIN (QueSO or nmap OS probe)
  80         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  81         # Null
  82         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  83         # NEW TCP without SYN
  84         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  85
  86         iptables -A INPUT   -p tcp -j BADTCP
  87         iptables -A FORWARD -p tcp -j BADTCP
  88
  89         # Connection tracking chains
  90         iptables -N CONNTRACK
  91         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
  92         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
  93         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
  94         iptables -t raw -N CONNTRACK
  95         iptables -t raw -A PREROUTING -j CONNTRACK
  96
  97         # Conntrack helpers (https://home.regit.org/netfilter-en/secure-use-of-helpers/)
  98
  99         # SIP
 100         if [ "${CONNTRACK_SIP}" = "on" ]; then
 101                 modprobe nf_nat_sip
 102                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 103                         -m helper --helper sip -j ACCEPT
 104                 for proto in udp tcp; do
 105                         iptables -t raw -A CONNTRACK -p "${proto}" --dport 5060 -j CT --helper sip
 106                 done
 107         fi
 108
 109         # H.323
 110         if [ "${CONNTRACK_H323}" = "on" ]; then
 111                 modprobe nf_nat_h323
 112                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 113                         -m helper --helper h323 -j ACCEPT
 114
 115                 # Gatekeeper RAS
 116                 iptables -t raw -A CONNTRACK -p udp --dport 1719 -j CT --helper RAS
 117
 118                 # Q.931
 119                 iptables -t raw -A CONNTRACK -p tcp --dport 1720 -j CT --helper Q.931
 120         fi
 121
 122         # FTP
 123         if [ "${CONNTRACK_FTP}" = "on" ]; then
 124                 modprobe nf_nat_ftp
 125                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 126                         -m helper --helper ftp -p tcp --dport 1024: -j ACCEPT
 127                 iptables -t raw -A CONNTRACK -p tcp --dport 21 -j CT --helper ftp
 128         fi
 129
 130         # PPTP
 131         if [ "${CONNTRACK_PPTP}" = "on" ]; then
 132                 modprobe nf_nat_pptp
 133                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 134                         -m helper --helper pptp -j ACCEPT
 135                 iptables -t raw -A CONNTRACK -p tcp --dport 1723 -j CT --helper pptp
 136         fi
 137
 138         # TFTP
 139         if [ "${CONNTRACK_TFTP}" = "on" ]; then
 140                 modprobe nf_nat_tftp
 141                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 142                         -m helper --helper tftp -j ACCEPT
 143                 iptables -t raw -A CONNTRACK -p udp --dport 69 -j CT --helper tftp
 144         fi
 145
 146         # IRC
 147         if [ "${CONNTRACK_IRC}" = "on" ]; then
 148                 modprobe nf_nat_irc
 149                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 150                         -m helper --helper irc -j ACCEPT
 151                 iptables -t raw -A CONNTRACK -p tcp --dport 6667 -j CT --helper irc
 152         fi
 153
 154         # Amanda
 155         if [ "${CONNTRACK_AMANDA}" = "on" ]; then
 156                 modprobe nf_nat_amanda
 157                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 158                         -m helper --helper amanda -j ACCEPT
 159                 iptables -t raw -A CONNTRACK -p tcp -j CT --helper amanda
 160         fi
 161
 162         # Fix for braindead ISP's
 163         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 164
 165         # CUSTOM chains, can be used by the users themselves
 166         iptables -N CUSTOMINPUT
 167         iptables -A INPUT -j CUSTOMINPUT
 168         iptables -N CUSTOMFORWARD
 169         iptables -A FORWARD -j CUSTOMFORWARD
 170         iptables -N CUSTOMOUTPUT
 171         iptables -A OUTPUT -j CUSTOMOUTPUT
 172         iptables -t nat -N CUSTOMPREROUTING
 173         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 174         iptables -t nat -N CUSTOMPOSTROUTING
 175         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 176
 177         # P2PBLOCK
 178         iptables -N P2PBLOCK
 179         iptables -A INPUT -j P2PBLOCK
 180         iptables -A FORWARD -j P2PBLOCK
 181         iptables -A OUTPUT -j P2PBLOCK
 182
 183         # Guardian (IPS) chains
 184         iptables -N GUARDIAN
 185         iptables -A INPUT -j GUARDIAN
 186         iptables -A FORWARD -j GUARDIAN
 187
 188         # IPS (suricata) chains
 189         iptables -N IPS
 190         iptables -A INPUT -j IPS
 191         iptables -A FORWARD -j IPS
 192         iptables -A OUTPUT -j IPS
 193
 194         # Block non-established IPsec networks
 195         iptables -N IPSECBLOCK
 196         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 197         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 198
 199         # Block OpenVPN transfer networks
 200         iptables -N OVPNBLOCK
 201         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 202         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 203         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 204
 205         # OpenVPN transfer network translation
 206         iptables -t nat -N OVPNNAT
 207         iptables -t nat -A POSTROUTING -j OVPNNAT
 208
 209         # IPTV chains for IGMPPROXY
 210         iptables -N IPTVINPUT
 211         iptables -A INPUT -j IPTVINPUT
 212         iptables -N IPTVFORWARD
 213         iptables -A FORWARD -j IPTVFORWARD
 214
 215         # Allow to ping the firewall.
 216         iptables -N ICMPINPUT
 217         iptables -A INPUT -j ICMPINPUT
 218         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 219
 220         # Accept everything on loopback
 221         iptables -N LOOPBACK
 222         iptables -A LOOPBACK -i lo -j ACCEPT
 223         iptables -A LOOPBACK -o lo -j ACCEPT
 224
 225         # Filter all packets with loopback addresses on non-loopback interfaces.
 226         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 227         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 228
 229         for i in INPUT FORWARD OUTPUT; do
 230                 iptables -A ${i} -j LOOPBACK
 231         done
 232
 233         # Captive portal
 234         iptables -N CAPTIVE_PORTAL
 235         iptables -N CAPTIVE_PORTAL_CLIENTS
 236         for i in INPUT FORWARD; do
 237                 iptables -A ${i} -j CAPTIVE_PORTAL
 238         done
 239
 240         # Accept everything connected
 241         for i in INPUT FORWARD OUTPUT; do
 242                 iptables -A ${i} -j CONNTRACK
 243         done
 244
 245         # Allow DHCP
 246         iptables -N DHCPINPUT
 247         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 248         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 249
 250         iptables -N DHCPOUTPUT
 251         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 252         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 253
 254         # Allow DHCP on GREEN
 255         iptables -N DHCPGREENINPUT
 256         iptables -N DHCPGREENOUTPUT
 257         if [ -n "${GREEN_DEV}" ]; then
 258                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 259                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 260         fi
 261
 262         # allow DHCP on BLUE to be turned on/off
 263         iptables -N DHCPBLUEINPUT
 264         iptables -N DHCPBLUEOUTPUT
 265         if [ -n "${BLUE_DEV}" ]; then
 266                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 267                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 268         fi
 269
 270         # GeoIP block
 271         iptables -N GEOIPBLOCK
 272         iptables -A INPUT -j GEOIPBLOCK
 273         iptables -A FORWARD -j GEOIPBLOCK
 274
 275         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 276         iptables -N IPSECINPUT
 277         iptables -N IPSECFORWARD
 278         iptables -N IPSECOUTPUT
 279         iptables -A INPUT -j IPSECINPUT
 280         iptables -A FORWARD -j IPSECFORWARD
 281         iptables -A OUTPUT -j IPSECOUTPUT
 282         iptables -t nat -N IPSECNAT
 283         iptables -t nat -A POSTROUTING -j IPSECNAT
 284
 285         # localhost and ethernet.
 286         # Always allow accessing the web GUI from GREEN.
 287         iptables -N GUIINPUT
 288         iptables -A INPUT -j GUIINPUT
 289         if [ -n "${GREEN_DEV}" ]; then
 290                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 291         fi
 292
 293         # WIRELESS chains
 294         iptables -N WIRELESSINPUT
 295         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 296         iptables -N WIRELESSFORWARD
 297         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 298
 299         # OpenVPN
 300         iptables -N OVPNINPUT
 301         iptables -A INPUT -j OVPNINPUT
 302
 303         # Tor
 304         iptables -N TOR_INPUT
 305         iptables -A INPUT -j TOR_INPUT
 306
 307         # Jump into the actual firewall ruleset.
 308         iptables -N INPUTFW
 309         iptables -A INPUT -j INPUTFW
 310
 311         iptables -N OUTGOINGFW
 312         iptables -A OUTPUT -j OUTGOINGFW
 313
 314         iptables -N FORWARDFW
 315         iptables -A FORWARD -j FORWARDFW
 316
 317         # SNAT rules
 318         iptables -t nat -N NAT_SOURCE
 319         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 320
 321         # Captive Portal
 322         iptables -t nat -N CAPTIVE_PORTAL
 323         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 324
 325         # Custom prerouting chains (for transparent proxy)
 326         iptables -t nat -N SQUID
 327         iptables -t nat -A PREROUTING -j SQUID
 328
 329         # DNAT rules
 330         iptables -t nat -N NAT_DESTINATION
 331         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 332         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 333
 334         iptables -t mangle -N NAT_DESTINATION
 335         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 336
 337         iptables -t nat -N NAT_DESTINATION_FIX
 338         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 339
 340         if [ -n "${GREEN_ADDRESS}" ]; then
 341                 iptables -t nat -A NAT_DESTINATION_FIX \
 342                         -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 343         fi
 344
 345         if [ -n "${BLUE_ADDRESS}" ]; then
 346                 iptables -t nat -A NAT_DESTINATION_FIX \
 347                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 348         fi
 349
 350         if [ -n "${ORANGE_ADDRESS}" ]; then
 351                 iptables -t nat -A NAT_DESTINATION_FIX \
 352                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 353         fi
 354
 355         # upnp chain for our upnp daemon
 356         iptables -t nat -N UPNPFW
 357         iptables -t nat -A PREROUTING -j UPNPFW
 358         iptables -N UPNPFW
 359         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 360
 361         # RED chain, used for the red interface
 362         iptables -N REDINPUT
 363         iptables -A INPUT -j REDINPUT
 364         iptables -N REDFORWARD
 365         iptables -A FORWARD -j REDFORWARD
 366         iptables -t nat -N REDNAT
 367         iptables -t nat -A POSTROUTING -j REDNAT
 368
 369         # Populate IPsec block chain
 370         /usr/lib/firewall/ipsec-block
 371
 372         # Apply OpenVPN firewall rules
 373         /usr/local/bin/openvpnctrl --firewall-rules
 374
 375         # run wirelessctrl
 376         /usr/local/bin/wirelessctrl
 377
 378         # POLICY CHAIN
 379         iptables -N POLICYIN
 380         iptables -A INPUT -j POLICYIN
 381         iptables -N POLICYFWD
 382         iptables -A FORWARD -j POLICYFWD
 383         iptables -N POLICYOUT
 384         iptables -A OUTPUT -j POLICYOUT
 385
 386         # Initialize firewall policies.
 387         /usr/sbin/firewall-policy
 388
 389         # Install firewall rules for the red interface.
 390         iptables_red_up
 391
 392         # If red has not been brought up yet, we will
 393         # add the blocking rules for MASQUERADE
 394         if [ ! -e "/var/ipfire/red/active" ]; then
 395                 iptables_red_down
 396         fi
 397 }
 398
 399 iptables_red_up() {
 400         iptables -F REDINPUT
 401         iptables -F REDFORWARD
 402         iptables -t nat -F REDNAT
 403
 404         # PPPoE / PPTP Device
 405         if [ "$IFACE" != "" ]; then
 406                 # PPPoE / PPTP
 407                 if [ "$DEVICE" != "" ]; then
 408                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 409                 fi
 410                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 411                         if [ "$RED_DEV" != "" ]; then
 412                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 413                         fi
 414                 fi
 415         fi
 416
 417         # PPTP over DHCP
 418         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 419                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 420                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 421         fi
 422
 423         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 424                 # DHCP
 425                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 426                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 427                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 428                 fi
 429                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 430                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 431                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 432                 fi
 433
 434                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 435                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 436
 437                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 438                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 439                 fi
 440
 441                 local NO_MASQ_NETWORKS
 442
 443                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 444                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 445                 fi
 446
 447                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 448                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 449                 fi
 450
 451                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 452                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 453                 fi
 454
 455                 local network
 456                 for network in ${NO_MASQ_NETWORKS}; do
 457                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 458                 done
 459
 460                 # Masquerade everything else
 461                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 462         fi
 463
 464         # Reload all rules.
 465         /usr/local/bin/firewallctrl
 466 }
 467
 468 iptables_red_down() {
 469         # Prohibit packets to reach the masquerading rule
 470         # while the WAN interface is down - this is required to
 471         # circumvent udp related NAT issues
 472         # http://forum.ipfire.org/index.php?topic=11127.0
 473         if [ -n "${IFACE}" ]; then
 474                 iptables -F REDFORWARD
 475                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 476         fi
 477
 478         # Reload all rules.
 479         /usr/local/bin/firewallctrl
 480 }
 481
 482 # See how we were called.
 483 case "$1" in
 484   start)
 485         boot_mesg "Setting up firewall"
 486         iptables_init
 487         evaluate_retval
 488         ;;
 489   reload|up)
 490         boot_mesg "Reloading firewall"
 491         iptables_red_up
 492         evaluate_retval
 493         ;;
 494   down)
 495         boot_mesg "Disabling firewall access to RED"
 496         iptables_red_down
 497         evaluate_retval
 498         ;;
 499   restart)
 500         $0 start
 501         ;;
 502   *)
 503         echo "Usage: $0 {start|reload|restart}"
 504         exit 1
 505         ;;
 506 esac
 507
 508 exit 0