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