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