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         # Enable TRACE logging to syslog
  36         modprobe nf_log_ipv4
  37         sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
  38
  39         # Empty LOG_DROP and LOG_REJECT chains
  40         iptables -N LOG_DROP
  41         iptables -A LOG_DROP   -m limit --limit 10/second -j LOG
  42         iptables -A LOG_DROP   -j DROP
  43         iptables -N LOG_REJECT
  44         iptables -A LOG_REJECT -m limit --limit 10/second -j LOG
  45         iptables -A LOG_REJECT -j REJECT
  46
  47         # This chain will log, then DROPs packets with certain bad combinations
  48         # of flags might indicate a port-scan attempt (xmas, null, etc.)
  49         iptables -N PSCAN
  50         if [ "$DROPPORTSCAN" == "on" ]; then
  51                 iptables -A PSCAN -p tcp  -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan "  -m comment --comment "DROP_TCP PScan"
  52                 iptables -A PSCAN -p udp  -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan "  -m comment --comment "DROP_UDP PScan"
  53                 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  54                 iptables -A PSCAN -f      -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  55         fi
  56         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  57
  58         # New tcp packets without SYN set - could well be an obscure type of port scan
  59         # that's not covered above, may just be a broken Windows machine
  60         iptables -N NEWNOTSYN
  61         if [ "$DROPNEWNOTSYN" == "on" ]; then
  62                 iptables -A NEWNOTSYN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_NEWNOTSYN "
  63         fi
  64         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  65
  66         # Chain to contain all the rules relating to bad TCP flags
  67         iptables -N BADTCP
  68
  69         # Don't check loopback
  70         iptables -A BADTCP -i lo -j RETURN
  71
  72         # Disallow packets frequently used by port-scanners
  73         # NMAP FIN/URG/PSH (XMAS scan)
  74         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  75         # SYN/RST/ACK/FIN/URG
  76         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  77         # ALL/ALL
  78         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  79         # FIN Stealth
  80         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  81         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  82         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  83         # SYN/FIN (QueSO or nmap OS probe)
  84         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  85         # Null
  86         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  87         # NEW TCP without SYN
  88         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  89
  90         iptables -A INPUT   -p tcp -j BADTCP
  91         iptables -A FORWARD -p tcp -j BADTCP
  92
  93         # Connection tracking chains
  94         iptables -N CONNTRACK
  95         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
  96         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
  97         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
  98         iptables -t raw -N CONNTRACK
  99         iptables -t raw -A PREROUTING -j CONNTRACK
 100
 101         # Fix for braindead ISPs
 102         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 103
 104         # CUSTOM chains, can be used by the users themselves
 105         iptables -N CUSTOMINPUT
 106         iptables -A INPUT -j CUSTOMINPUT
 107         iptables -N CUSTOMFORWARD
 108         iptables -A FORWARD -j CUSTOMFORWARD
 109         iptables -N CUSTOMOUTPUT
 110         iptables -A OUTPUT -j CUSTOMOUTPUT
 111         iptables -t nat -N CUSTOMPREROUTING
 112         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 113         iptables -t nat -N CUSTOMPOSTROUTING
 114         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 115
 116         # P2PBLOCK
 117         iptables -N P2PBLOCK
 118         iptables -A INPUT -j P2PBLOCK
 119         iptables -A FORWARD -j P2PBLOCK
 120         iptables -A OUTPUT -j P2PBLOCK
 121
 122         # IPS (Guardian) chains
 123         iptables -N GUARDIAN
 124         iptables -A INPUT -j GUARDIAN
 125         iptables -A FORWARD -j GUARDIAN
 126
 127         # Block non-established IPsec networks
 128         iptables -N IPSECBLOCK
 129         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 130         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 131
 132         # Block OpenVPN transfer networks
 133         iptables -N OVPNBLOCK
 134         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 135         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 136         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 137
 138         # IPS (Suricata) chains
 139         iptables -N IPS_INPUT
 140         iptables -N IPS_FORWARD
 141         iptables -N IPS_OUTPUT
 142         iptables -A INPUT -j IPS_INPUT
 143         iptables -A FORWARD -j IPS_FORWARD
 144         iptables -A OUTPUT -j IPS_OUTPUT
 145
 146         # OpenVPN transfer network translation
 147         iptables -t nat -N OVPNNAT
 148         iptables -t nat -A POSTROUTING -j OVPNNAT
 149
 150         # IPTV chains for IGMPPROXY
 151         iptables -N IPTVINPUT
 152         iptables -A INPUT -j IPTVINPUT
 153         iptables -N IPTVFORWARD
 154         iptables -A FORWARD -j IPTVFORWARD
 155
 156         # Allow to ping the firewall.
 157         iptables -N ICMPINPUT
 158         iptables -A INPUT -j ICMPINPUT
 159         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 160
 161         # Accept everything on loopback
 162         iptables -N LOOPBACK
 163         iptables -A LOOPBACK -i lo -j ACCEPT
 164         iptables -A LOOPBACK -o lo -j ACCEPT
 165
 166         # Filter all packets with loopback addresses on non-loopback interfaces.
 167         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 168         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 169
 170         for i in INPUT FORWARD OUTPUT; do
 171                 iptables -A ${i} -j LOOPBACK
 172         done
 173
 174         # Captive portal
 175         iptables -N CAPTIVE_PORTAL
 176         iptables -N CAPTIVE_PORTAL_CLIENTS
 177         for i in INPUT FORWARD; do
 178                 iptables -A ${i} -j CAPTIVE_PORTAL
 179         done
 180
 181         # Accept everything connected
 182         for i in INPUT FORWARD OUTPUT; do
 183                 iptables -A ${i} -j CONNTRACK
 184         done
 185
 186         # Allow DHCP
 187         iptables -N DHCPINPUT
 188         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 189         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 190
 191         iptables -N DHCPOUTPUT
 192         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 193         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 194
 195         # Allow DHCP on GREEN
 196         iptables -N DHCPGREENINPUT
 197         iptables -N DHCPGREENOUTPUT
 198         if [ -n "${GREEN_DEV}" ]; then
 199                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 200                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 201         fi
 202
 203         # Allow DHCP on BLUE to be turned on/off
 204         iptables -N DHCPBLUEINPUT
 205         iptables -N DHCPBLUEOUTPUT
 206         if [ -n "${BLUE_DEV}" ]; then
 207                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 208                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 209         fi
 210
 211         # Location Block
 212         iptables -N LOCATIONBLOCK
 213         iptables -A INPUT -j LOCATIONBLOCK
 214         iptables -A FORWARD -j LOCATIONBLOCK
 215
 216         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 217         iptables -N IPSECINPUT
 218         iptables -N IPSECFORWARD
 219         iptables -N IPSECOUTPUT
 220         iptables -A INPUT -j IPSECINPUT
 221         iptables -A FORWARD -j IPSECFORWARD
 222         iptables -A OUTPUT -j IPSECOUTPUT
 223         iptables -t nat -N IPSECNAT
 224         iptables -t nat -A POSTROUTING -j IPSECNAT
 225
 226         # localhost and ethernet.
 227         # Always allow accessing the web GUI from GREEN.
 228         iptables -N GUIINPUT
 229         iptables -A INPUT -j GUIINPUT
 230         if [ -n "${GREEN_DEV}" ]; then
 231                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 232         fi
 233
 234         # WIRELESS chains
 235         iptables -N WIRELESSINPUT
 236         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 237         iptables -N WIRELESSFORWARD
 238         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 239
 240         # OpenVPN
 241         iptables -N OVPNINPUT
 242         iptables -A INPUT -j OVPNINPUT
 243
 244         # Tor (inbound and outbound)
 245         iptables -N TOR_INPUT
 246         iptables -A INPUT -j TOR_INPUT
 247         iptables -N TOR_OUTPUT
 248         iptables -A OUTPUT -j TOR_OUTPUT
 249
 250         # Jump into the actual firewall ruleset.
 251         iptables -N INPUTFW
 252         iptables -A INPUT -j INPUTFW
 253
 254         iptables -N OUTGOINGFW
 255         iptables -A OUTPUT -j OUTGOINGFW
 256
 257         iptables -N FORWARDFW
 258         iptables -A FORWARD -j FORWARDFW
 259
 260         # SNAT rules
 261         iptables -t nat -N NAT_SOURCE
 262         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 263
 264         # Captive Portal
 265         iptables -t nat -N CAPTIVE_PORTAL
 266         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 267
 268         # Custom prerouting chains (for transparent proxy)
 269         iptables -t nat -N SQUID
 270         iptables -t nat -A PREROUTING -j SQUID
 271
 272         # DNAT rules
 273         iptables -t nat -N NAT_DESTINATION
 274         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 275         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 276
 277         iptables -t mangle -N NAT_DESTINATION
 278         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 279
 280         iptables -t nat -N NAT_DESTINATION_FIX
 281         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 282
 283         if [ -n "${GREEN_ADDRESS}" ]; then
 284                 iptables -t nat -A NAT_DESTINATION_FIX \
 285                         -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 286         fi
 287
 288         if [ -n "${BLUE_ADDRESS}" ]; then
 289                 iptables -t nat -A NAT_DESTINATION_FIX \
 290                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 291         fi
 292
 293         if [ -n "${ORANGE_ADDRESS}" ]; then
 294                 iptables -t nat -A NAT_DESTINATION_FIX \
 295                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 296         fi
 297
 298         # RED chain, used for the red interface
 299         iptables -N REDINPUT
 300         iptables -A INPUT -j REDINPUT
 301         iptables -N REDFORWARD
 302         iptables -A FORWARD -j REDFORWARD
 303         iptables -t nat -N REDNAT
 304         iptables -t nat -A POSTROUTING -j REDNAT
 305
 306         # Populate IPsec chains
 307         /usr/lib/firewall/ipsec-policy
 308
 309         # Apply OpenVPN firewall rules
 310         /usr/local/bin/openvpnctrl --firewall-rules
 311
 312         # run wirelessctrl
 313         /usr/local/bin/wirelessctrl
 314
 315         # run captivectrl
 316         /usr/local/bin/captivectrl
 317
 318         # POLICY CHAIN
 319         iptables -N POLICYIN
 320         iptables -A INPUT -j POLICYIN
 321         iptables -N POLICYFWD
 322         iptables -A FORWARD -j POLICYFWD
 323         iptables -N POLICYOUT
 324         iptables -A OUTPUT -j POLICYOUT
 325
 326         # Initialize firewall policies.
 327         /usr/sbin/firewall-policy
 328
 329         # Install firewall rules for the red interface.
 330         iptables_red_up
 331
 332         # If red has not been brought up yet, we will
 333         # add the blocking rules for MASQUERADE
 334         if [ ! -e "/var/ipfire/red/active" ]; then
 335                 iptables_red_down
 336         fi
 337 }
 338
 339 iptables_red_up() {
 340         iptables -F REDINPUT
 341         iptables -F REDFORWARD
 342         iptables -t nat -F REDNAT
 343
 344         # PPPoE / PPTP Device
 345         if [ "$IFACE" != "" ]; then
 346                 # PPPoE / PPTP
 347                 if [ "$DEVICE" != "" ]; then
 348                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 349                 fi
 350                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 351                         if [ "$RED_DEV" != "" ]; then
 352                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 353                         fi
 354                 fi
 355         fi
 356
 357         # PPTP over DHCP
 358         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 359                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 360                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 361         fi
 362
 363         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 364                 # DHCP
 365                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 366                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 367                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 368                 fi
 369                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 370                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 371                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 372                 fi
 373
 374                 # Outgoing masquerading (don't masqerade IPsec (mark 50))
 375                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 376
 377                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 378                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 379                 fi
 380
 381                 local NO_MASQ_NETWORKS
 382
 383                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 384                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 385                 fi
 386
 387                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 388                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 389                 fi
 390
 391                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 392                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 393                 fi
 394
 395                 local network
 396                 for network in ${NO_MASQ_NETWORKS}; do
 397                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 398                 done
 399
 400                 # Masquerade everything else
 401                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 402         fi
 403
 404         # Reload all rules.
 405         /usr/local/bin/firewallctrl
 406 }
 407
 408 iptables_red_down() {
 409         # Prohibit packets to reach the masquerading rule
 410         # while the WAN interface is down - this is required to
 411         # circumvent udp related NAT issues
 412         # http://forum.ipfire.org/index.php?topic=11127.0
 413         if [ -n "${IFACE}" ]; then
 414                 iptables -F REDFORWARD
 415                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 416         fi
 417
 418         # Reload all rules.
 419         /usr/local/bin/firewallctrl
 420 }
 421
 422 # See how we were called.
 423 case "$1" in
 424   start)
 425         boot_mesg "Setting up firewall"
 426         iptables_init
 427         evaluate_retval
 428         ;;
 429   reload|up)
 430         boot_mesg "Reloading firewall"
 431         iptables_red_up
 432         evaluate_retval
 433         ;;
 434   down)
 435         boot_mesg "Disabling firewall access to RED"
 436         iptables_red_down
 437         evaluate_retval
 438         ;;
 439   restart)
 440         $0 start
 441         ;;
 442   *)
 443         echo "Usage: $0 {start|reload|restart}"
 444         exit 1
 445         ;;
 446 esac
 447
 448 exit 0