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 -X
  25         iptables -t nat -X
  26         iptables -t mangle -X
  27
  28         # Set up policies
  29         iptables -P INPUT DROP
  30         iptables -P FORWARD DROP
  31         iptables -P OUTPUT ACCEPT
  32
  33         # Empty LOG_DROP and LOG_REJECT chains
  34         iptables -N LOG_DROP
  35         iptables -A LOG_DROP   -m limit --limit 10/minute -j LOG
  36         iptables -A LOG_DROP   -j DROP
  37         iptables -N LOG_REJECT
  38         iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG
  39         iptables -A LOG_REJECT -j REJECT
  40
  41         # This chain will log, then DROPs packets with certain bad combinations
  42         # of flags might indicate a port-scan attempt (xmas, null, etc)
  43         iptables -N PSCAN
  44         if [ "$DROPPORTSCAN" == "on" ]; then
  45                 iptables -A PSCAN -p tcp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan"
  46                 iptables -A PSCAN -p udp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan"
  47                 iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  48                 iptables -A PSCAN -f      -m limit --limit 10/minute -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  49         fi
  50         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  51
  52         # New tcp packets without SYN set - could well be an obscure type of port scan
  53         # that's not covered above, may just be a broken windows machine
  54         iptables -N NEWNOTSYN
  55         if [ "$DROPNEWNOTSYN" == "on" ]; then
  56                 iptables -A NEWNOTSYN  -m limit --limit 10/minute -j LOG  --log-prefix "DROP_NEWNOTSYN "
  57         fi
  58         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  59
  60         # Chain to contain all the rules relating to bad TCP flags
  61         iptables -N BADTCP
  62
  63         # Don't check loopback
  64         iptables -A BADTCP -i lo -j RETURN
  65
  66         # Disallow packets frequently used by port-scanners
  67         # NMAP FIN/URG/PSH (XMAS scan)
  68         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  69         # SYN/RST/ACK/FIN/URG
  70         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  71         # ALL/ALL
  72         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  73         # FIN Stealth
  74         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  75         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  76         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  77         # SYN/FIN (QueSO or nmap OS probe)
  78         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  79         # Null
  80         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  81         # NEW TCP without SYN
  82         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  83
  84         iptables -A INPUT   -p tcp -j BADTCP
  85         iptables -A FORWARD -p tcp -j BADTCP
  86
  87         # Connection tracking chain
  88         iptables -N CONNTRACK
  89         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
  90         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
  91
  92         # Fix for braindead ISP's
  93         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  94
  95         # CUSTOM chains, can be used by the users themselves
  96         iptables -N CUSTOMINPUT
  97         iptables -A INPUT -j CUSTOMINPUT
  98         iptables -N CUSTOMFORWARD
  99         iptables -A FORWARD -j CUSTOMFORWARD
 100         iptables -N CUSTOMOUTPUT
 101         iptables -A OUTPUT -j CUSTOMOUTPUT
 102         iptables -t nat -N CUSTOMPREROUTING
 103         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 104         iptables -t nat -N CUSTOMPOSTROUTING
 105         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 106
 107         # P2PBLOCK
 108         iptables -N P2PBLOCK
 109         iptables -A INPUT -j P2PBLOCK
 110         iptables -A FORWARD -j P2PBLOCK
 111         iptables -A OUTPUT -j P2PBLOCK
 112
 113         # Guardian (IPS) chains
 114         iptables -N GUARDIAN
 115         iptables -A INPUT -j GUARDIAN
 116         iptables -A FORWARD -j GUARDIAN
 117
 118         # Block non-established IPsec networks
 119         iptables -N IPSECBLOCK
 120         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 121         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 122
 123         # Block OpenVPN transfer networks
 124         iptables -N OVPNBLOCK
 125         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 126         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 127         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 128
 129         # OpenVPN transfer network translation
 130         iptables -t nat -N OVPNNAT
 131         iptables -t nat -A POSTROUTING -j OVPNNAT
 132
 133         # IPTV chains for IGMPPROXY
 134         iptables -N IPTVINPUT
 135         iptables -A INPUT -j IPTVINPUT
 136         iptables -N IPTVFORWARD
 137         iptables -A FORWARD -j IPTVFORWARD
 138
 139         # Allow to ping the firewall.
 140         iptables -N ICMPINPUT
 141         iptables -A INPUT -j ICMPINPUT
 142         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 143
 144         # Accept everything on loopback
 145         iptables -N LOOPBACK
 146         iptables -A LOOPBACK -i lo -j ACCEPT
 147         iptables -A LOOPBACK -o lo -j ACCEPT
 148
 149         # Filter all packets with loopback addresses on non-loopback interfaces.
 150         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 151         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 152
 153         for i in INPUT FORWARD OUTPUT; do
 154                 iptables -A ${i} -j LOOPBACK
 155         done
 156
 157         # Accept everything connected
 158         for i in INPUT FORWARD OUTPUT; do
 159                 iptables -A ${i} -j CONNTRACK
 160         done
 161
 162         # Allow DHCP
 163         iptables -N DHCPINPUT
 164         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 165         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 166
 167         iptables -N DHCPOUTPUT
 168         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 169         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 170
 171         # Allow DHCP on GREEN
 172         iptables -N DHCPGREENINPUT
 173         iptables -N DHCPGREENOUTPUT
 174         if [ -n "${GREEN_DEV}" ]; then
 175                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 176                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 177         fi
 178
 179         # allow DHCP on BLUE to be turned on/off
 180         iptables -N DHCPBLUEINPUT
 181         iptables -N DHCPBLUEOUTPUT
 182         if [ -n "${BLUE_DEV}" ]; then
 183                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 184                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 185         fi
 186
 187         # GeoIP block
 188         iptables -N GEOIPBLOCK
 189         iptables -A INPUT -j GEOIPBLOCK
 190         iptables -A FORWARD -j GEOIPBLOCK
 191
 192         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 193         iptables -N IPSECINPUT
 194         iptables -N IPSECFORWARD
 195         iptables -N IPSECOUTPUT
 196         iptables -A INPUT -j IPSECINPUT
 197         iptables -A FORWARD -j IPSECFORWARD
 198         iptables -A OUTPUT -j IPSECOUTPUT
 199         iptables -t nat -N IPSECNAT
 200         iptables -t nat -A POSTROUTING -j IPSECNAT
 201
 202         # localhost and ethernet.
 203         # Always allow accessing the web GUI from GREEN.
 204         iptables -N GUIINPUT
 205         iptables -A INPUT -j GUIINPUT
 206         iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 207
 208         # WIRELESS chains
 209         iptables -N WIRELESSINPUT
 210         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 211         iptables -N WIRELESSFORWARD
 212         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 213
 214         # OpenVPN
 215         iptables -N OVPNINPUT
 216         iptables -A INPUT -j OVPNINPUT
 217
 218         # TOR
 219         iptables -N TOR_INPUT
 220         iptables -A INPUT -j TOR_INPUT
 221
 222         # Jump into the actual firewall ruleset.
 223         iptables -N INPUTFW
 224         iptables -A INPUT -j INPUTFW
 225
 226         iptables -N OUTGOINGFW
 227         iptables -A OUTPUT -j OUTGOINGFW
 228
 229         iptables -N FORWARDFW
 230         iptables -A FORWARD -j FORWARDFW
 231
 232         # SNAT rules
 233         iptables -t nat -N NAT_SOURCE
 234         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 235
 236         # Custom prerouting chains (for transparent proxy)
 237         iptables -t nat -N SQUID
 238         iptables -t nat -A PREROUTING -j SQUID
 239
 240         # DNAT rules
 241         iptables -t nat -N NAT_DESTINATION
 242         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 243         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 244
 245         iptables -t mangle -N NAT_DESTINATION
 246         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 247
 248         iptables -t nat -N NAT_DESTINATION_FIX
 249         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 250
 251         iptables -t nat -A NAT_DESTINATION_FIX \
 252                 -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 253
 254         if [ -n "${BLUE_ADDRESS}" ]; then
 255                 iptables -t nat -A NAT_DESTINATION_FIX \
 256                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 257         fi
 258
 259         if [ -n "${ORANGE_ADDRESS}" ]; then
 260                 iptables -t nat -A NAT_DESTINATION_FIX \
 261                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 262         fi
 263
 264         # upnp chain for our upnp daemon
 265         iptables -t nat -N UPNPFW
 266         iptables -t nat -A PREROUTING -j UPNPFW
 267         iptables -N UPNPFW
 268         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 269
 270         # RED chain, used for the red interface
 271         iptables -N REDINPUT
 272         iptables -A INPUT -j REDINPUT
 273         iptables -N REDFORWARD
 274         iptables -A FORWARD -j REDFORWARD
 275         iptables -t nat -N REDNAT
 276         iptables -t nat -A POSTROUTING -j REDNAT
 277
 278         # Populate IPsec block chain
 279         /usr/lib/firewall/ipsec-block
 280
 281         # Apply OpenVPN firewall rules
 282         /usr/local/bin/openvpnctrl --firewall-rules
 283
 284         # run wirelessctrl
 285         /usr/local/bin/wirelessctrl
 286
 287         # POLICY CHAIN
 288         iptables -N POLICYIN
 289         iptables -A INPUT -j POLICYIN
 290         iptables -N POLICYFWD
 291         iptables -A FORWARD -j POLICYFWD
 292         iptables -N POLICYOUT
 293         iptables -A OUTPUT -j POLICYOUT
 294
 295         # Initialize firewall policies.
 296         /usr/sbin/firewall-policy
 297
 298         # Install firewall rules for the red interface.
 299         iptables_red_up
 300
 301         # If red has not been brought up yet, we will
 302         # add the blocking rules for MASQUERADE
 303         if [ ! -e "/var/ipfire/red/active" ]; then
 304                 iptables_red_down
 305         fi
 306 }
 307
 308 iptables_red_up() {
 309         iptables -F REDINPUT
 310         iptables -F REDFORWARD
 311         iptables -t nat -F REDNAT
 312
 313         # PPPoE / PPTP Device
 314         if [ "$IFACE" != "" ]; then
 315                 # PPPoE / PPTP
 316                 if [ "$DEVICE" != "" ]; then
 317                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 318                 fi
 319                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 320                         if [ "$RED_DEV" != "" ]; then
 321                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 322                         fi
 323                 fi
 324         fi
 325
 326         # PPTP over DHCP
 327         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 328                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 329                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 330         fi
 331
 332         # Orange pinholes
 333         if [ "$ORANGE_DEV" != "" ]; then
 334                 # This rule enables a host on ORANGE network to connect to the outside
 335                 # (only if we have a red connection)
 336                 if [ "$IFACE" != "" ]; then
 337                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 338                 fi
 339         fi
 340
 341         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 342                 # DHCP
 343                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 344                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 345                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 346                 fi
 347                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 348                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 349                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 350                 fi
 351
 352                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 353                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 354
 355                 if [ "$IFACE" = "$GREEN_DEV" ]; then
 356                         MASQUERADE_GREEN="off"
 357                 fi
 358
 359                 local NO_MASQ_NETWORKS
 360
 361                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 362                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 363                 fi
 364
 365                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 366                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 367                 fi
 368
 369                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 370                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 371                 fi
 372
 373                 local network
 374                 for network in ${NO_MASQ_NETWORKS}; do
 375                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 376                 done
 377
 378                 # Masquerade everything else
 379                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 380         fi
 381
 382         # Reload all rules.
 383         /usr/local/bin/firewallctrl
 384 }
 385
 386 iptables_red_down() {
 387         # Prohibit packets to reach the masquerading rule
 388         # while the wan interface is down - this is required to
 389         # circumvent udp related NAT issues
 390         # http://forum.ipfire.org/index.php?topic=11127.0
 391         if [ -n "${IFACE}" ]; then
 392                 iptables -F REDFORWARD
 393                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 394         fi
 395
 396         # Reload all rules.
 397         /usr/local/bin/firewallctrl
 398 }
 399
 400 # See how we were called.
 401 case "$1" in
 402   start)
 403         boot_mesg "Loading firewall modules into the kernel"
 404         modprobe iptable_nat || failed=1
 405         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 406                 modprobe $(basename $i | cut -d. -f1) || failed=1
 407         done
 408         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 409                 modprobe $(basename $i | cut -d. -f1) || failed=1
 410         done
 411         (exit ${failed})
 412         evaluate_retval
 413
 414         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 415                 rmmod nf_nat_sip
 416                 rmmod nf_conntrack_sip
 417                 rmmod nf_nat_h323
 418                 rmmod nf_conntrack_h323
 419         fi
 420
 421         boot_mesg "Setting up firewall"
 422         iptables_init
 423         evaluate_retval
 424         ;;
 425   reload|up)
 426         boot_mesg "Reloading firewall"
 427         iptables_red_up
 428         evaluate_retval
 429         ;;
 430   down)
 431         boot_mesg "Disabling firewall access to RED"
 432         iptables_red_down
 433         evaluate_retval
 434         ;;
 435   restart)
 436         $0 start
 437         ;;
 438   *)
 439         echo "Usage: $0 {start|reload|restart}"
 440         exit 1
 441         ;;
 442 esac
 443
 444 exit 0