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/second -j LOG
  38         iptables -A LOG_DROP   -j DROP
  39         iptables -N LOG_REJECT
  40         iptables -A LOG_REJECT -m limit --limit 10/second -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 [ "$DROPPORTSCAN" == "on" ]; then
  47                 iptables -A PSCAN -p tcp  -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan "  -m comment --comment "DROP_TCP PScan"
  48                 iptables -A PSCAN -p udp  -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan "  -m comment --comment "DROP_UDP PScan"
  49                 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  50                 iptables -A PSCAN -f      -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  51         fi
  52         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  53
  54         # New tcp packets without SYN set - could well be an obscure type of port scan
  55         # that's not covered above, may just be a broken Windows machine
  56         iptables -N NEWNOTSYN
  57         if [ "$DROPNEWNOTSYN" == "on" ]; then
  58                 iptables -A NEWNOTSYN  -m limit --limit 10/second -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         # GRE (always enabled)
 100         modprobe nf_conntrack_proto_gre
 101
 102         # SIP
 103         if [ "${CONNTRACK_SIP}" = "on" ]; then
 104                 modprobe nf_nat_sip
 105                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 106                         -m helper --helper sip -j ACCEPT
 107                 for proto in udp tcp; do
 108                         iptables -t raw -A CONNTRACK -p "${proto}" --dport 5060 -j CT --helper sip
 109                 done
 110         fi
 111
 112         # H.323
 113         if [ "${CONNTRACK_H323}" = "on" ]; then
 114                 modprobe nf_nat_h323
 115                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 116                         -m helper --helper h323 -j ACCEPT
 117
 118                 # Gatekeeper RAS
 119                 iptables -t raw -A CONNTRACK -p udp --dport 1719 -j CT --helper RAS
 120
 121                 # Q.931
 122                 iptables -t raw -A CONNTRACK -p tcp --dport 1720 -j CT --helper Q.931
 123         fi
 124
 125         # FTP
 126         if [ "${CONNTRACK_FTP}" = "on" ]; then
 127                 modprobe nf_nat_ftp
 128                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 129                         -m helper --helper ftp -p tcp --dport 1024: -j ACCEPT
 130                 iptables -t raw -A CONNTRACK -p tcp --dport 21 -j CT --helper ftp
 131         fi
 132
 133         # PPTP
 134         if [ "${CONNTRACK_PPTP}" = "on" ]; then
 135                 modprobe nf_nat_pptp
 136                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 137                         -m helper --helper pptp -j ACCEPT
 138                 iptables -t raw -A CONNTRACK -p tcp --dport 1723 -j CT --helper pptp
 139         fi
 140
 141         # TFTP
 142         if [ "${CONNTRACK_TFTP}" = "on" ]; then
 143                 modprobe nf_nat_tftp
 144                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 145                         -m helper --helper tftp -j ACCEPT
 146                 iptables -t raw -A CONNTRACK -p udp --dport 69 -j CT --helper tftp
 147         fi
 148
 149         # IRC
 150         if [ "${CONNTRACK_IRC}" = "on" ]; then
 151                 modprobe nf_nat_irc
 152                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 153                         -m helper --helper irc -j ACCEPT
 154                 iptables -t raw -A CONNTRACK -p tcp --dport 6667 -j CT --helper irc
 155         fi
 156
 157         # Amanda
 158         if [ "${CONNTRACK_AMANDA}" = "on" ]; then
 159                 modprobe nf_nat_amanda
 160                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 161                         -m helper --helper amanda -j ACCEPT
 162                 iptables -t raw -A CONNTRACK -p tcp -j CT --helper amanda
 163         fi
 164
 165         # Fix for braindead ISPs
 166         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 167
 168         # CUSTOM chains, can be used by the users themselves
 169         iptables -N CUSTOMINPUT
 170         iptables -A INPUT -j CUSTOMINPUT
 171         iptables -N CUSTOMFORWARD
 172         iptables -A FORWARD -j CUSTOMFORWARD
 173         iptables -N CUSTOMOUTPUT
 174         iptables -A OUTPUT -j CUSTOMOUTPUT
 175         iptables -t nat -N CUSTOMPREROUTING
 176         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 177         iptables -t nat -N CUSTOMPOSTROUTING
 178         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 179
 180         # P2PBLOCK
 181         iptables -N P2PBLOCK
 182         iptables -A INPUT -j P2PBLOCK
 183         iptables -A FORWARD -j P2PBLOCK
 184         iptables -A OUTPUT -j P2PBLOCK
 185
 186         # IPS (Guardian) chains
 187         iptables -N GUARDIAN
 188         iptables -A INPUT -j GUARDIAN
 189         iptables -A FORWARD -j GUARDIAN
 190
 191         # Block non-established IPsec networks
 192         iptables -N IPSECBLOCK
 193         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 194         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 195
 196         # Block OpenVPN transfer networks
 197         iptables -N OVPNBLOCK
 198         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 199         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 200         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 201
 202         # IPS (Suricata) chains
 203         iptables -N IPS_INPUT
 204         iptables -N IPS_FORWARD
 205         iptables -N IPS_OUTPUT
 206         iptables -A INPUT -j IPS_INPUT
 207         iptables -A FORWARD -j IPS_FORWARD
 208         iptables -A OUTPUT -j IPS_OUTPUT
 209
 210         # OpenVPN transfer network translation
 211         iptables -t nat -N OVPNNAT
 212         iptables -t nat -A POSTROUTING -j OVPNNAT
 213
 214         # IPTV chains for IGMPPROXY
 215         iptables -N IPTVINPUT
 216         iptables -A INPUT -j IPTVINPUT
 217         iptables -N IPTVFORWARD
 218         iptables -A FORWARD -j IPTVFORWARD
 219
 220         # Allow to ping the firewall.
 221         iptables -N ICMPINPUT
 222         iptables -A INPUT -j ICMPINPUT
 223         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 224
 225         # Accept everything on loopback
 226         iptables -N LOOPBACK
 227         iptables -A LOOPBACK -i lo -j ACCEPT
 228         iptables -A LOOPBACK -o lo -j ACCEPT
 229
 230         # Filter all packets with loopback addresses on non-loopback interfaces.
 231         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 232         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 233
 234         for i in INPUT FORWARD OUTPUT; do
 235                 iptables -A ${i} -j LOOPBACK
 236         done
 237
 238         # Captive portal
 239         iptables -N CAPTIVE_PORTAL
 240         iptables -N CAPTIVE_PORTAL_CLIENTS
 241         for i in INPUT FORWARD; do
 242                 iptables -A ${i} -j CAPTIVE_PORTAL
 243         done
 244
 245         # Accept everything connected
 246         for i in INPUT FORWARD OUTPUT; do
 247                 iptables -A ${i} -j CONNTRACK
 248         done
 249
 250         # Allow DHCP
 251         iptables -N DHCPINPUT
 252         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 253         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 254
 255         iptables -N DHCPOUTPUT
 256         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 257         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 258
 259         # Allow DHCP on GREEN
 260         iptables -N DHCPGREENINPUT
 261         iptables -N DHCPGREENOUTPUT
 262         if [ -n "${GREEN_DEV}" ]; then
 263                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 264                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 265         fi
 266
 267         # Allow DHCP on BLUE to be turned on/off
 268         iptables -N DHCPBLUEINPUT
 269         iptables -N DHCPBLUEOUTPUT
 270         if [ -n "${BLUE_DEV}" ]; then
 271                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 272                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 273         fi
 274
 275         # GeoIP block
 276         iptables -N GEOIPBLOCK
 277         iptables -A INPUT -j GEOIPBLOCK
 278         iptables -A FORWARD -j GEOIPBLOCK
 279
 280         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 281         iptables -N IPSECINPUT
 282         iptables -N IPSECFORWARD
 283         iptables -N IPSECOUTPUT
 284         iptables -A INPUT -j IPSECINPUT
 285         iptables -A FORWARD -j IPSECFORWARD
 286         iptables -A OUTPUT -j IPSECOUTPUT
 287         iptables -t nat -N IPSECNAT
 288         iptables -t nat -A POSTROUTING -j IPSECNAT
 289
 290         # localhost and ethernet.
 291         # Always allow accessing the web GUI from GREEN.
 292         iptables -N GUIINPUT
 293         iptables -A INPUT -j GUIINPUT
 294         if [ -n "${GREEN_DEV}" ]; then
 295                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 296         fi
 297
 298         # WIRELESS chains
 299         iptables -N WIRELESSINPUT
 300         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 301         iptables -N WIRELESSFORWARD
 302         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 303
 304         # OpenVPN
 305         iptables -N OVPNINPUT
 306         iptables -A INPUT -j OVPNINPUT
 307
 308         # Tor (inbound and outbound)
 309         iptables -N TOR_INPUT
 310         iptables -A INPUT -j TOR_INPUT
 311         iptables -N TOR_OUTPUT
 312         iptables -A OUTPUT -j TOR_OUTPUT
 313
 314         # Jump into the actual firewall ruleset.
 315         iptables -N INPUTFW
 316         iptables -A INPUT -j INPUTFW
 317
 318         iptables -N OUTGOINGFW
 319         iptables -A OUTPUT -j OUTGOINGFW
 320
 321         iptables -N FORWARDFW
 322         iptables -A FORWARD -j FORWARDFW
 323
 324         # SNAT rules
 325         iptables -t nat -N NAT_SOURCE
 326         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 327
 328         # Captive Portal
 329         iptables -t nat -N CAPTIVE_PORTAL
 330         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 331
 332         # Custom prerouting chains (for transparent proxy)
 333         iptables -t nat -N SQUID
 334         iptables -t nat -A PREROUTING -j SQUID
 335
 336         # DNAT rules
 337         iptables -t nat -N NAT_DESTINATION
 338         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 339         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 340
 341         iptables -t mangle -N NAT_DESTINATION
 342         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 343
 344         iptables -t nat -N NAT_DESTINATION_FIX
 345         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 346
 347         if [ -n "${GREEN_ADDRESS}" ]; then
 348                 iptables -t nat -A NAT_DESTINATION_FIX \
 349                         -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 350         fi
 351
 352         if [ -n "${BLUE_ADDRESS}" ]; then
 353                 iptables -t nat -A NAT_DESTINATION_FIX \
 354                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 355         fi
 356
 357         if [ -n "${ORANGE_ADDRESS}" ]; then
 358                 iptables -t nat -A NAT_DESTINATION_FIX \
 359                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 360         fi
 361
 362         # upnp chain for our upnp daemon
 363         iptables -t nat -N UPNPFW
 364         iptables -t nat -A PREROUTING -j UPNPFW
 365         iptables -N UPNPFW
 366         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 367
 368         # RED chain, used for the red interface
 369         iptables -N REDINPUT
 370         iptables -A INPUT -j REDINPUT
 371         iptables -N REDFORWARD
 372         iptables -A FORWARD -j REDFORWARD
 373         iptables -t nat -N REDNAT
 374         iptables -t nat -A POSTROUTING -j REDNAT
 375
 376         # Populate IPsec chains
 377         /usr/lib/firewall/ipsec-policy
 378
 379         # Apply OpenVPN firewall rules
 380         /usr/local/bin/openvpnctrl --firewall-rules
 381
 382         # run wirelessctrl
 383         /usr/local/bin/wirelessctrl
 384
 385         # run captivectrl
 386         /usr/local/bin/captivectrl
 387
 388         # POLICY CHAIN
 389         iptables -N POLICYIN
 390         iptables -A INPUT -j POLICYIN
 391         iptables -N POLICYFWD
 392         iptables -A FORWARD -j POLICYFWD
 393         iptables -N POLICYOUT
 394         iptables -A OUTPUT -j POLICYOUT
 395
 396         # Initialize firewall policies.
 397         /usr/sbin/firewall-policy
 398
 399         # Install firewall rules for the red interface.
 400         iptables_red_up
 401
 402         # If red has not been brought up yet, we will
 403         # add the blocking rules for MASQUERADE
 404         if [ ! -e "/var/ipfire/red/active" ]; then
 405                 iptables_red_down
 406         fi
 407 }
 408
 409 iptables_red_up() {
 410         iptables -F REDINPUT
 411         iptables -F REDFORWARD
 412         iptables -t nat -F REDNAT
 413
 414         # PPPoE / PPTP Device
 415         if [ "$IFACE" != "" ]; then
 416                 # PPPoE / PPTP
 417                 if [ "$DEVICE" != "" ]; then
 418                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 419                 fi
 420                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 421                         if [ "$RED_DEV" != "" ]; then
 422                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 423                         fi
 424                 fi
 425         fi
 426
 427         # PPTP over DHCP
 428         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 429                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 430                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 431         fi
 432
 433         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 434                 # DHCP
 435                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 436                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 437                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 438                 fi
 439                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 440                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 441                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 442                 fi
 443
 444                 # Outgoing masquerading (don't masqerade IPsec (mark 50))
 445                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 446
 447                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 448                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 449                 fi
 450
 451                 local NO_MASQ_NETWORKS
 452
 453                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 454                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 455                 fi
 456
 457                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 458                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 459                 fi
 460
 461                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 462                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 463                 fi
 464
 465                 local network
 466                 for network in ${NO_MASQ_NETWORKS}; do
 467                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 468                 done
 469
 470                 # Masquerade everything else
 471                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 472         fi
 473
 474         # Reload all rules.
 475         /usr/local/bin/firewallctrl
 476 }
 477
 478 iptables_red_down() {
 479         # Prohibit packets to reach the masquerading rule
 480         # while the WAN interface is down - this is required to
 481         # circumvent udp related NAT issues
 482         # http://forum.ipfire.org/index.php?topic=11127.0
 483         if [ -n "${IFACE}" ]; then
 484                 iptables -F REDFORWARD
 485                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 486         fi
 487
 488         # Reload all rules.
 489         /usr/local/bin/firewallctrl
 490 }
 491
 492 # See how we were called.
 493 case "$1" in
 494   start)
 495         boot_mesg "Setting up firewall"
 496         iptables_init
 497         evaluate_retval
 498         ;;
 499   reload|up)
 500         boot_mesg "Reloading firewall"
 501         iptables_red_up
 502         evaluate_retval
 503         ;;
 504   down)
 505         boot_mesg "Disabling firewall access to RED"
 506         iptables_red_down
 507         evaluate_retval
 508         ;;
 509   restart)
 510         $0 start
 511         ;;
 512   *)
 513         echo "Usage: $0 {start|reload|restart}"
 514         exit 1
 515         ;;
 516 esac
 517
 518 exit 0