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 -t raw -N CONNTRACK
  94         iptables -t raw -A PREROUTING -j CONNTRACK
  95
  96         # Conntrack helpers (https://home.regit.org/netfilter-en/secure-use-of-helpers/)
  97
  98         # SIP
  99         iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 100                 -m helper --helper sip -j ACCEPT
 101         for proto in udp tcp; do
 102                 iptables -t raw -A CONNTRACK -p "${proto}" --dport 5060 -j CT --helper sip
 103         done
 104
 105         # FTP
 106         iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 107                 -m helper --helper ftp -p tcp --dport 1024: -j ACCEPT
 108         iptables -t raw -A CONNTRACK -p tcp --dport 21 -j CT --helper ftp
 109
 110         # PPTP
 111         iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 112                 -m helper --helper pptp -j ACCEPT
 113         iptables -t raw -A CONNTRACK -p udp --dport 1723 -j CT --helper pptp
 114
 115         # TFTP
 116         iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 117                 -m helper --helper tftp -j ACCEPT
 118         iptables -t raw -A CONNTRACK -p udp --dport 69 -j CT --helper tftp
 119
 120         # Fix for braindead ISP's
 121         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 122
 123         # CUSTOM chains, can be used by the users themselves
 124         iptables -N CUSTOMINPUT
 125         iptables -A INPUT -j CUSTOMINPUT
 126         iptables -N CUSTOMFORWARD
 127         iptables -A FORWARD -j CUSTOMFORWARD
 128         iptables -N CUSTOMOUTPUT
 129         iptables -A OUTPUT -j CUSTOMOUTPUT
 130         iptables -t nat -N CUSTOMPREROUTING
 131         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 132         iptables -t nat -N CUSTOMPOSTROUTING
 133         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 134
 135         # P2PBLOCK
 136         iptables -N P2PBLOCK
 137         iptables -A INPUT -j P2PBLOCK
 138         iptables -A FORWARD -j P2PBLOCK
 139         iptables -A OUTPUT -j P2PBLOCK
 140
 141         # Guardian (IPS) chains
 142         iptables -N GUARDIAN
 143         iptables -A INPUT -j GUARDIAN
 144         iptables -A FORWARD -j GUARDIAN
 145
 146         # Block OpenVPN transfer networks
 147         iptables -N OVPNBLOCK
 148         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 149         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 150         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 151
 152         # OpenVPN transfer network translation
 153         iptables -t nat -N OVPNNAT
 154         iptables -t nat -A POSTROUTING -j OVPNNAT
 155
 156         # IPTV chains for IGMPPROXY
 157         iptables -N IPTVINPUT
 158         iptables -A INPUT -j IPTVINPUT
 159         iptables -N IPTVFORWARD
 160         iptables -A FORWARD -j IPTVFORWARD
 161
 162         # Allow to ping the firewall.
 163         iptables -N ICMPINPUT
 164         iptables -A INPUT -j ICMPINPUT
 165         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 166
 167         # Accept everything on loopback
 168         iptables -N LOOPBACK
 169         iptables -A LOOPBACK -i lo -j ACCEPT
 170         iptables -A LOOPBACK -o lo -j ACCEPT
 171
 172         # Filter all packets with loopback addresses on non-loopback interfaces.
 173         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 174         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 175
 176         for i in INPUT FORWARD OUTPUT; do
 177                 iptables -A ${i} -j LOOPBACK
 178         done
 179
 180         # Accept everything connected
 181         for i in INPUT FORWARD OUTPUT; do
 182                 iptables -A ${i} -j CONNTRACK
 183         done
 184
 185         # Allow DHCP
 186         iptables -N DHCPINPUT
 187         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 188         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 189
 190         iptables -N DHCPOUTPUT
 191         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 192         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 193
 194         # Allow DHCP on GREEN
 195         iptables -N DHCPGREENINPUT
 196         iptables -N DHCPGREENOUTPUT
 197         if [ -n "${GREEN_DEV}" ]; then
 198                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 199                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 200         fi
 201
 202         # allow DHCP on BLUE to be turned on/off
 203         iptables -N DHCPBLUEINPUT
 204         iptables -N DHCPBLUEOUTPUT
 205         if [ -n "${BLUE_DEV}" ]; then
 206                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 207                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 208         fi
 209
 210         # GeoIP block
 211         iptables -N GEOIPBLOCK
 212         iptables -A INPUT -j GEOIPBLOCK
 213         iptables -A FORWARD -j GEOIPBLOCK
 214
 215         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 216         iptables -N IPSECINPUT
 217         iptables -N IPSECFORWARD
 218         iptables -N IPSECOUTPUT
 219         iptables -A INPUT -j IPSECINPUT
 220         iptables -A FORWARD -j IPSECFORWARD
 221         iptables -A OUTPUT -j IPSECOUTPUT
 222         iptables -t nat -N IPSECNAT
 223         iptables -t nat -A POSTROUTING -j IPSECNAT
 224
 225         # localhost and ethernet.
 226         # Always allow accessing the web GUI from GREEN.
 227         iptables -N GUIINPUT
 228         iptables -A INPUT -j GUIINPUT
 229         iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 230
 231         # WIRELESS chains
 232         iptables -N WIRELESSINPUT
 233         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 234         iptables -N WIRELESSFORWARD
 235         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 236
 237         # OpenVPN
 238         iptables -N OVPNINPUT
 239         iptables -A INPUT -j OVPNINPUT
 240
 241         # TOR
 242         iptables -N TOR_INPUT
 243         iptables -A INPUT -j TOR_INPUT
 244
 245         # Jump into the actual firewall ruleset.
 246         iptables -N INPUTFW
 247         iptables -A INPUT -j INPUTFW
 248
 249         iptables -N OUTGOINGFW
 250         iptables -A OUTPUT -j OUTGOINGFW
 251
 252         iptables -N FORWARDFW
 253         iptables -A FORWARD -j FORWARDFW
 254
 255         # SNAT rules
 256         iptables -t nat -N NAT_SOURCE
 257         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 258
 259         # Custom prerouting chains (for transparent proxy)
 260         iptables -t nat -N SQUID
 261         iptables -t nat -A PREROUTING -j SQUID
 262
 263         # DNAT rules
 264         iptables -t nat -N NAT_DESTINATION
 265         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 266         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 267
 268         iptables -t mangle -N NAT_DESTINATION
 269         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 270
 271         iptables -t nat -N NAT_DESTINATION_FIX
 272         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 273
 274         iptables -t nat -A NAT_DESTINATION_FIX \
 275                 -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 276
 277         if [ -n "${BLUE_ADDRESS}" ]; then
 278                 iptables -t nat -A NAT_DESTINATION_FIX \
 279                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 280         fi
 281
 282         if [ -n "${ORANGE_ADDRESS}" ]; then
 283                 iptables -t nat -A NAT_DESTINATION_FIX \
 284                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 285         fi
 286
 287         # upnp chain for our upnp daemon
 288         iptables -t nat -N UPNPFW
 289         iptables -t nat -A PREROUTING -j UPNPFW
 290         iptables -N UPNPFW
 291         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 292
 293         # RED chain, used for the red interface
 294         iptables -N REDINPUT
 295         iptables -A INPUT -j REDINPUT
 296         iptables -N REDFORWARD
 297         iptables -A FORWARD -j REDFORWARD
 298         iptables -t nat -N REDNAT
 299         iptables -t nat -A POSTROUTING -j REDNAT
 300
 301         # Apply OpenVPN firewall rules
 302         /usr/local/bin/openvpnctrl --firewall-rules
 303
 304         # run wirelessctrl
 305         /usr/local/bin/wirelessctrl
 306
 307         # POLICY CHAIN
 308         iptables -N POLICYIN
 309         iptables -A INPUT -j POLICYIN
 310         iptables -N POLICYFWD
 311         iptables -A FORWARD -j POLICYFWD
 312         iptables -N POLICYOUT
 313         iptables -A OUTPUT -j POLICYOUT
 314
 315         # Initialize firewall policies.
 316         /usr/sbin/firewall-policy
 317
 318         # Install firewall rules for the red interface.
 319         iptables_red_up
 320
 321         # If red has not been brought up yet, we will
 322         # add the blocking rules for MASQUERADE
 323         if [ ! -e "/var/ipfire/red/active" ]; then
 324                 iptables_red_down
 325         fi
 326 }
 327
 328 iptables_red_up() {
 329         iptables -F REDINPUT
 330         iptables -F REDFORWARD
 331         iptables -t nat -F REDNAT
 332
 333         # PPPoE / PPTP Device
 334         if [ "$IFACE" != "" ]; then
 335                 # PPPoE / PPTP
 336                 if [ "$DEVICE" != "" ]; then
 337                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 338                 fi
 339                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 340                         if [ "$RED_DEV" != "" ]; then
 341                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 342                         fi
 343                 fi
 344         fi
 345
 346         # PPTP over DHCP
 347         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 348                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 349                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 350         fi
 351
 352         # Orange pinholes
 353         if [ "$ORANGE_DEV" != "" ]; then
 354                 # This rule enables a host on ORANGE network to connect to the outside
 355                 # (only if we have a red connection)
 356                 if [ "$IFACE" != "" ]; then
 357                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 358                 fi
 359         fi
 360
 361         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 362                 # DHCP
 363                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 364                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 365                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 366                 fi
 367                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 368                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 369                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 370                 fi
 371
 372                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 373                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 374
 375                 if [ "$IFACE" = "$GREEN_DEV" ]; then
 376                         MASQUERADE_GREEN="off"
 377                 fi
 378
 379                 local NO_MASQ_NETWORKS
 380
 381                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 382                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 383                 fi
 384
 385                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 386                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 387                 fi
 388
 389                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 390                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 391                 fi
 392
 393                 local network
 394                 for network in ${NO_MASQ_NETWORKS}; do
 395                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 396                 done
 397
 398                 # Masquerade everything else
 399                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 400         fi
 401
 402         # Reload all rules.
 403         /usr/local/bin/firewallctrl
 404 }
 405
 406 iptables_red_down() {
 407         # Prohibit packets to reach the masquerading rule
 408         # while the wan interface is down - this is required to
 409         # circumvent udp related NAT issues
 410         # http://forum.ipfire.org/index.php?topic=11127.0
 411         if [ -n "${IFACE}" ]; then
 412                 iptables -F REDFORWARD
 413                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 414         fi
 415
 416         # Reload all rules.
 417         /usr/local/bin/firewallctrl
 418 }
 419
 420 # See how we were called.
 421 case "$1" in
 422   start)
 423         boot_mesg "Loading firewall modules into the kernel"
 424         modprobe iptable_nat || failed=1
 425         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 426                 modprobe $(basename $i | cut -d. -f1) || failed=1
 427         done
 428         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 429                 modprobe $(basename $i | cut -d. -f1) || failed=1
 430         done
 431         (exit ${failed})
 432         evaluate_retval
 433
 434         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 435                 rmmod nf_nat_sip
 436                 rmmod nf_conntrack_sip
 437                 rmmod nf_nat_h323
 438                 rmmod nf_conntrack_h323
 439         fi
 440
 441         boot_mesg "Setting up firewall"
 442         iptables_init
 443         evaluate_retval
 444         ;;
 445   reload|up)
 446         boot_mesg "Reloading firewall"
 447         iptables_red_up
 448         evaluate_retval
 449         ;;
 450   down)
 451         boot_mesg "Disabling firewall access to RED"
 452         iptables_red_down
 453         evaluate_retval
 454         ;;
 455   restart)
 456         $0 start
 457         ;;
 458   *)
 459         echo "Usage: $0 {start|reload|restart}"
 460         exit 1
 461         ;;
 462 esac
 463
 464 exit 0