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 xmas
  68         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH  -j PSCAN
  69         # Null
  70         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  71         # FIN
  72         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  73         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  74         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  75         # SYN/FIN (QueSO or nmap OS probe)
  76         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  77         # NEW TCP without SYN
  78         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  79
  80         iptables -A INPUT   -p tcp -j BADTCP
  81         iptables -A FORWARD -p tcp -j BADTCP
  82
  83         # Connection tracking chain
  84         iptables -N CONNTRACK
  85         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
  86
  87         # Fix for braindead ISP's
  88         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  89
  90         # CUSTOM chains, can be used by the users themselves
  91         iptables -N CUSTOMINPUT
  92         iptables -A INPUT -j CUSTOMINPUT
  93         iptables -N CUSTOMFORWARD
  94         iptables -A FORWARD -j CUSTOMFORWARD
  95         iptables -N CUSTOMOUTPUT
  96         iptables -A OUTPUT -j CUSTOMOUTPUT
  97         iptables -t nat -N CUSTOMPREROUTING
  98         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
  99         iptables -t nat -N CUSTOMPOSTROUTING
 100         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 101
 102         # Guardian (IPS) chains
 103         iptables -N GUARDIAN
 104         iptables -A INPUT -j GUARDIAN
 105         iptables -A FORWARD -j GUARDIAN
 106
 107         # Block OpenVPN transfer networks
 108         iptables -N OVPNBLOCK
 109         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 110         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 111         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 112
 113         # OpenVPN transfer network translation
 114         iptables -t nat -N OVPNNAT
 115         iptables -t nat -A POSTROUTING -j OVPNNAT
 116
 117         # IPTV chains for IGMPPROXY
 118         iptables -N IPTVINPUT
 119         iptables -A INPUT -j IPTVINPUT
 120         iptables -N IPTVFORWARD
 121         iptables -A FORWARD -j IPTVFORWARD
 122
 123         # Allow to ping the firewall.
 124         iptables -N ICMPINPUT
 125         iptables -A INPUT -j ICMPINPUT
 126         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 127
 128         # Accept everything on loopback
 129         iptables -N LOOPBACK
 130         iptables -A LOOPBACK -i lo -j ACCEPT
 131         iptables -A LOOPBACK -o lo -j ACCEPT
 132
 133         # Filter all packets with loopback addresses on non-loopback interfaces.
 134         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 135         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 136
 137         for i in INPUT FORWARD OUTPUT; do
 138                 iptables -A ${i} -j LOOPBACK
 139         done
 140
 141         # Accept everything connected
 142         for i in INPUT FORWARD OUTPUT; do
 143                 iptables -A ${i} -j CONNTRACK
 144         done
 145
 146         # Allow DHCP
 147         iptables -N DHCPINPUT
 148         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 149         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 150
 151         iptables -N DHCPOUTPUT
 152         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 153         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 154
 155         # Allow DHCP on GREEN
 156         iptables -N DHCPGREENINPUT
 157         iptables -N DHCPGREENOUTPUT
 158         if [ -n "${GREEN_DEV}" ]; then
 159                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 160                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 161         fi
 162
 163         # allow DHCP on BLUE to be turned on/off
 164         iptables -N DHCPBLUEINPUT
 165         iptables -N DHCPBLUEOUTPUT
 166         if [ -n "${BLUE_DEV}" ]; then
 167                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 168                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 169         fi
 170
 171         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 172         iptables -N IPSECINPUT
 173         iptables -N IPSECFORWARD
 174         iptables -N IPSECOUTPUT
 175         iptables -A INPUT -j IPSECINPUT
 176         iptables -A FORWARD -j IPSECFORWARD
 177         iptables -A OUTPUT -j IPSECOUTPUT
 178         iptables -t nat -N IPSECNAT
 179         iptables -t nat -A POSTROUTING -j IPSECNAT
 180
 181         # localhost and ethernet.
 182         iptables -A INPUT   -i $GREEN_DEV  -m conntrack --ctstate NEW -j ACCEPT ! -p icmp
 183
 184         # WIRELESS chains
 185         iptables -N WIRELESSINPUT
 186         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 187         iptables -N WIRELESSFORWARD
 188         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 189
 190         # OpenVPN
 191         iptables -N OVPNINPUT
 192         iptables -A INPUT -j OVPNINPUT
 193
 194         # TOR
 195         iptables -N TOR_INPUT
 196         iptables -A INPUT -j TOR_INPUT
 197
 198         # Jump into the actual firewall ruleset.
 199         iptables -N INPUTFW
 200         iptables -A INPUT -j INPUTFW
 201
 202         iptables -N OUTGOINGFW
 203         iptables -A OUTPUT -j OUTGOINGFW
 204
 205         iptables -N FORWARDFW
 206         iptables -A FORWARD -j FORWARDFW
 207
 208         # SNAT rules
 209         iptables -t nat -N NAT_SOURCE
 210         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 211
 212         # Custom prerouting chains (for transparent proxy)
 213         iptables -t nat -N SQUID
 214         iptables -t nat -A PREROUTING -j SQUID
 215
 216         # DNAT rules
 217         iptables -t nat -N NAT_DESTINATION
 218         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 219         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 220
 221         iptables -t mangle -N NAT_DESTINATION
 222         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 223
 224         iptables -t nat -N NAT_DESTINATION_FIX
 225         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 226
 227         iptables -t nat -A NAT_DESTINATION_FIX \
 228                 -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 229
 230         if [ -n "${BLUE_ADDRESS}" ]; then
 231                 iptables -t nat -A NAT_DESTINATION_FIX \
 232                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 233         fi
 234
 235         if [ -n "${ORANGE_ADDRESS}" ]; then
 236                 iptables -t nat -A NAT_DESTINATION_FIX \
 237                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 238         fi
 239
 240         # upnp chain for our upnp daemon
 241         iptables -t nat -N UPNPFW
 242         iptables -t nat -A PREROUTING -j UPNPFW
 243         iptables -N UPNPFW
 244         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 245
 246         # RED chain, used for the red interface
 247         iptables -N REDINPUT
 248         iptables -A INPUT -j REDINPUT
 249         iptables -N REDFORWARD
 250         iptables -A FORWARD -j REDFORWARD
 251         iptables -t nat -N REDNAT
 252         iptables -t nat -A POSTROUTING -j REDNAT
 253
 254         # Filter logging of incoming broadcasts.
 255         iptables -N BROADCAST_FILTER
 256         iptables -A INPUT -j BROADCAST_FILTER
 257
 258         iptables -A BROADCAST_FILTER -i "${GREEN_DEV}" -d "${GREEN_BROADCAST}" -j DROP
 259
 260         if [ -n "${BLUE_DEV}" -a -n "${BLUE_BROADCAST}" ]; then
 261                 iptables -A BROADCAST_FILTER -i "${BLUE_DEV}" -d "${BLUE_BROADCAST}" -j DROP
 262         fi
 263
 264         if [ -n "${ORANGE_DEV}" -a -n "${ORANGE_BROADCAST}" ]; then
 265                 iptables -A BROADCAST_FILTER -i "${ORANGE_DEV}" -d "${ORANGE_BROADCAST}" -j DROP
 266         fi
 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
 287 }
 288
 289 iptables_red() {
 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                         iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 338                 fi
 339
 340         fi
 341
 342         # Reload all rules.
 343         /usr/local/bin/firewallctrl
 344 }
 345
 346 # See how we were called.
 347 case "$1" in
 348   start)
 349         boot_mesg "Loading firewall modules into the kernel"
 350         modprobe iptable_nat || failed=1
 351         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 352                 modprobe $(basename $i | cut -d. -f1) || failed=1
 353         done
 354         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 355                 modprobe $(basename $i | cut -d. -f1) || failed=1
 356         done
 357         (exit ${failed})
 358         evaluate_retval
 359
 360         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 361                 rmmod nf_nat_sip
 362                 rmmod nf_conntrack_sip
 363                 rmmod nf_nat_h323
 364                 rmmod nf_conntrack_h323
 365         fi
 366
 367         boot_mesg "Setting up firewall"
 368         iptables_init
 369         evaluate_retval
 370
 371         # run local firewall configuration, if present
 372         if [ -x /etc/sysconfig/firewall.local ]; then
 373                 /etc/sysconfig/firewall.local start
 374         fi
 375         ;;
 376   reload)
 377         boot_mesg "Reloading firewall"
 378         iptables_red
 379         evaluate_retval
 380
 381         # run local firewall configuration, if present
 382         if [ -x /etc/sysconfig/firewall.local ]; then
 383                 /etc/sysconfig/firewall.local reload
 384         fi
 385         ;;
 386   restart)
 387         # run local firewall configuration, if present
 388         if [ -x /etc/sysconfig/firewall.local ]; then
 389                 /etc/sysconfig/firewall.local stop
 390         fi
 391         $0 start
 392         ;;
 393   *)
 394         echo "Usage: $0 {start|reload|restart}"
 395         exit 1
 396         ;;
 397 esac
 398
 399 exit 0