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         # Block non-established IPsec networks
 189         iptables -N IPSECBLOCK
 190         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 191         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 192
 193         # Block OpenVPN transfer networks
 194         iptables -N OVPNBLOCK
 195         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 196         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 197         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 198
 199         # OpenVPN transfer network translation
 200         iptables -t nat -N OVPNNAT
 201         iptables -t nat -A POSTROUTING -j OVPNNAT
 202
 203         # IPTV chains for IGMPPROXY
 204         iptables -N IPTVINPUT
 205         iptables -A INPUT -j IPTVINPUT
 206         iptables -N IPTVFORWARD
 207         iptables -A FORWARD -j IPTVFORWARD
 208
 209         # Allow to ping the firewall.
 210         iptables -N ICMPINPUT
 211         iptables -A INPUT -j ICMPINPUT
 212         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 213
 214         # Accept everything on loopback
 215         iptables -N LOOPBACK
 216         iptables -A LOOPBACK -i lo -j ACCEPT
 217         iptables -A LOOPBACK -o lo -j ACCEPT
 218
 219         # Filter all packets with loopback addresses on non-loopback interfaces.
 220         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 221         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 222
 223         for i in INPUT FORWARD OUTPUT; do
 224                 iptables -A ${i} -j LOOPBACK
 225         done
 226
 227         # Captive portal
 228         iptables -N CAPTIVE_PORTAL
 229         iptables -N CAPTIVE_PORTAL_CLIENTS
 230         for i in INPUT FORWARD; do
 231                 iptables -A ${i} -j CAPTIVE_PORTAL
 232         done
 233
 234         # Accept everything connected
 235         for i in INPUT FORWARD OUTPUT; do
 236                 iptables -A ${i} -j CONNTRACK
 237         done
 238
 239         # Allow DHCP
 240         iptables -N DHCPINPUT
 241         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 242         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 243
 244         iptables -N DHCPOUTPUT
 245         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 246         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 247
 248         # Allow DHCP on GREEN
 249         iptables -N DHCPGREENINPUT
 250         iptables -N DHCPGREENOUTPUT
 251         if [ -n "${GREEN_DEV}" ]; then
 252                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 253                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 254         fi
 255
 256         # allow DHCP on BLUE to be turned on/off
 257         iptables -N DHCPBLUEINPUT
 258         iptables -N DHCPBLUEOUTPUT
 259         if [ -n "${BLUE_DEV}" ]; then
 260                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 261                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 262         fi
 263
 264         # GeoIP block
 265         iptables -N GEOIPBLOCK
 266         iptables -A INPUT -j GEOIPBLOCK
 267         iptables -A FORWARD -j GEOIPBLOCK
 268
 269         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 270         iptables -N IPSECINPUT
 271         iptables -N IPSECFORWARD
 272         iptables -N IPSECOUTPUT
 273         iptables -A INPUT -j IPSECINPUT
 274         iptables -A FORWARD -j IPSECFORWARD
 275         iptables -A OUTPUT -j IPSECOUTPUT
 276         iptables -t nat -N IPSECNAT
 277         iptables -t nat -A POSTROUTING -j IPSECNAT
 278
 279         # localhost and ethernet.
 280         # Always allow accessing the web GUI from GREEN.
 281         iptables -N GUIINPUT
 282         iptables -A INPUT -j GUIINPUT
 283         if [ -n "${GREEN_DEV}" ]; then
 284                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 285         fi
 286
 287         # WIRELESS chains
 288         iptables -N WIRELESSINPUT
 289         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 290         iptables -N WIRELESSFORWARD
 291         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 292
 293         # OpenVPN
 294         iptables -N OVPNINPUT
 295         iptables -A INPUT -j OVPNINPUT
 296
 297         # Tor
 298         iptables -N TOR_INPUT
 299         iptables -A INPUT -j TOR_INPUT
 300
 301         # Jump into the actual firewall ruleset.
 302         iptables -N INPUTFW
 303         iptables -A INPUT -j INPUTFW
 304
 305         iptables -N OUTGOINGFW
 306         iptables -A OUTPUT -j OUTGOINGFW
 307
 308         iptables -N FORWARDFW
 309         iptables -A FORWARD -j FORWARDFW
 310
 311         # SNAT rules
 312         iptables -t nat -N NAT_SOURCE
 313         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 314
 315         # Captive Portal
 316         iptables -t nat -N CAPTIVE_PORTAL
 317         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 318
 319         # Custom prerouting chains (for transparent proxy)
 320         iptables -t nat -N SQUID
 321         iptables -t nat -A PREROUTING -j SQUID
 322
 323         # DNAT rules
 324         iptables -t nat -N NAT_DESTINATION
 325         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 326         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 327
 328         iptables -t mangle -N NAT_DESTINATION
 329         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 330
 331         iptables -t nat -N NAT_DESTINATION_FIX
 332         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 333
 334         if [ -n "${GREEN_ADDRESS}" ]; then
 335                 iptables -t nat -A NAT_DESTINATION_FIX \
 336                         -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 337         fi
 338
 339         if [ -n "${BLUE_ADDRESS}" ]; then
 340                 iptables -t nat -A NAT_DESTINATION_FIX \
 341                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 342         fi
 343
 344         if [ -n "${ORANGE_ADDRESS}" ]; then
 345                 iptables -t nat -A NAT_DESTINATION_FIX \
 346                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 347         fi
 348
 349         # upnp chain for our upnp daemon
 350         iptables -t nat -N UPNPFW
 351         iptables -t nat -A PREROUTING -j UPNPFW
 352         iptables -N UPNPFW
 353         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 354
 355         # RED chain, used for the red interface
 356         iptables -N REDINPUT
 357         iptables -A INPUT -j REDINPUT
 358         iptables -N REDFORWARD
 359         iptables -A FORWARD -j REDFORWARD
 360         iptables -t nat -N REDNAT
 361         iptables -t nat -A POSTROUTING -j REDNAT
 362
 363         # Populate IPsec chains
 364         /usr/lib/firewall/ipsec-policy
 365
 366         # Apply OpenVPN firewall rules
 367         /usr/local/bin/openvpnctrl --firewall-rules
 368
 369         # run wirelessctrl
 370         /usr/local/bin/wirelessctrl
 371
 372         # POLICY CHAIN
 373         iptables -N POLICYIN
 374         iptables -A INPUT -j POLICYIN
 375         iptables -N POLICYFWD
 376         iptables -A FORWARD -j POLICYFWD
 377         iptables -N POLICYOUT
 378         iptables -A OUTPUT -j POLICYOUT
 379
 380         # Initialize firewall policies.
 381         /usr/sbin/firewall-policy
 382
 383         # Install firewall rules for the red interface.
 384         iptables_red_up
 385
 386         # If red has not been brought up yet, we will
 387         # add the blocking rules for MASQUERADE
 388         if [ ! -e "/var/ipfire/red/active" ]; then
 389                 iptables_red_down
 390         fi
 391 }
 392
 393 iptables_red_up() {
 394         iptables -F REDINPUT
 395         iptables -F REDFORWARD
 396         iptables -t nat -F REDNAT
 397
 398         # PPPoE / PPTP Device
 399         if [ "$IFACE" != "" ]; then
 400                 # PPPoE / PPTP
 401                 if [ "$DEVICE" != "" ]; then
 402                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 403                 fi
 404                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 405                         if [ "$RED_DEV" != "" ]; then
 406                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 407                         fi
 408                 fi
 409         fi
 410
 411         # PPTP over DHCP
 412         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 413                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 414                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 415         fi
 416
 417         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 418                 # DHCP
 419                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 420                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 421                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 422                 fi
 423                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 424                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 425                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 426                 fi
 427
 428                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 429                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 430
 431                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 432                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 433                 fi
 434
 435                 local NO_MASQ_NETWORKS
 436
 437                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 438                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 439                 fi
 440
 441                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 442                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 443                 fi
 444
 445                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 446                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 447                 fi
 448
 449                 local network
 450                 for network in ${NO_MASQ_NETWORKS}; do
 451                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 452                 done
 453
 454                 # Masquerade everything else
 455                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 456         fi
 457
 458         # Reload all rules.
 459         /usr/local/bin/firewallctrl
 460 }
 461
 462 iptables_red_down() {
 463         # Prohibit packets to reach the masquerading rule
 464         # while the WAN interface is down - this is required to
 465         # circumvent udp related NAT issues
 466         # http://forum.ipfire.org/index.php?topic=11127.0
 467         if [ -n "${IFACE}" ]; then
 468                 iptables -F REDFORWARD
 469                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 470         fi
 471
 472         # Reload all rules.
 473         /usr/local/bin/firewallctrl
 474 }
 475
 476 # See how we were called.
 477 case "$1" in
 478   start)
 479         boot_mesg "Setting up firewall"
 480         iptables_init
 481         evaluate_retval
 482         ;;
 483   reload|up)
 484         boot_mesg "Reloading firewall"
 485         iptables_red_up
 486         evaluate_retval
 487         ;;
 488   down)
 489         boot_mesg "Disabling firewall access to RED"
 490         iptables_red_down
 491         evaluate_retval
 492         ;;
 493   restart)
 494         $0 start
 495         ;;
 496   *)
 497         echo "Usage: $0 {start|reload|restart}"
 498         exit 1
 499         ;;
 500 esac
 501
 502 exit 0