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