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