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 "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 169         fi
 170
 171         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 172         iptables -N IPSECINPUT
 173         iptables -N IPSECFORWARD
 174         iptables -N IPSECOUTPUT
 175         iptables -A INPUT -j IPSECINPUT
 176         iptables -A FORWARD -j IPSECFORWARD
 177         iptables -A OUTPUT -j IPSECOUTPUT
 178         iptables -t nat -N IPSECNAT
 179         iptables -t nat -A POSTROUTING -j IPSECNAT
 180
 181         # localhost and ethernet.
 182         # Always allow accessing the web GUI from GREEN.
 183         iptables -N GUIINPUT
 184         iptables -A INPUT -j GUIINPUT
 185         iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 186
 187         # WIRELESS chains
 188         iptables -N WIRELESSINPUT
 189         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 190         iptables -N WIRELESSFORWARD
 191         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 192
 193         # OpenVPN
 194         iptables -N OVPNINPUT
 195         iptables -A INPUT -j OVPNINPUT
 196
 197         # TOR
 198         iptables -N TOR_INPUT
 199         iptables -A INPUT -j TOR_INPUT
 200
 201         # Jump into the actual firewall ruleset.
 202         iptables -N INPUTFW
 203         iptables -A INPUT -j INPUTFW
 204
 205         iptables -N OUTGOINGFW
 206         iptables -A OUTPUT -j OUTGOINGFW
 207
 208         iptables -N FORWARDFW
 209         iptables -A FORWARD -j FORWARDFW
 210
 211         # SNAT rules
 212         iptables -t nat -N NAT_SOURCE
 213         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 214
 215         # Custom prerouting chains (for transparent proxy)
 216         iptables -t nat -N SQUID
 217         iptables -t nat -A PREROUTING -j SQUID
 218
 219         # DNAT rules
 220         iptables -t nat -N NAT_DESTINATION
 221         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 222         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 223
 224         iptables -t mangle -N NAT_DESTINATION
 225         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 226
 227         iptables -t nat -N NAT_DESTINATION_FIX
 228         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 229
 230         iptables -t nat -A NAT_DESTINATION_FIX \
 231                 -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 232
 233         if [ -n "${BLUE_ADDRESS}" ]; then
 234                 iptables -t nat -A NAT_DESTINATION_FIX \
 235                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 236         fi
 237
 238         if [ -n "${ORANGE_ADDRESS}" ]; then
 239                 iptables -t nat -A NAT_DESTINATION_FIX \
 240                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 241         fi
 242
 243         # upnp chain for our upnp daemon
 244         iptables -t nat -N UPNPFW
 245         iptables -t nat -A PREROUTING -j UPNPFW
 246         iptables -N UPNPFW
 247         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 248
 249         # RED chain, used for the red interface
 250         iptables -N REDINPUT
 251         iptables -A INPUT -j REDINPUT
 252         iptables -N REDFORWARD
 253         iptables -A FORWARD -j REDFORWARD
 254         iptables -t nat -N REDNAT
 255         iptables -t nat -A POSTROUTING -j REDNAT
 256
 257         # Filter logging of incoming broadcasts.
 258         iptables -N BROADCAST_FILTER
 259         iptables -A INPUT -j BROADCAST_FILTER
 260
 261         iptables -A BROADCAST_FILTER -i "${GREEN_DEV}" -d "${GREEN_BROADCAST}" -j DROP
 262
 263         if [ -n "${BLUE_DEV}" -a -n "${BLUE_BROADCAST}" ]; then
 264                 iptables -A BROADCAST_FILTER -i "${BLUE_DEV}" -d "${BLUE_BROADCAST}" -j DROP
 265         fi
 266
 267         if [ -n "${ORANGE_DEV}" -a -n "${ORANGE_BROADCAST}" ]; then
 268                 iptables -A BROADCAST_FILTER -i "${ORANGE_DEV}" -d "${ORANGE_BROADCAST}" -j DROP
 269         fi
 270
 271         # Apply OpenVPN firewall rules
 272         /usr/local/bin/openvpnctrl --firewall-rules
 273
 274         # run wirelessctrl
 275         /usr/local/bin/wirelessctrl
 276
 277         # POLICY CHAIN
 278         iptables -N POLICYIN
 279         iptables -A INPUT -j POLICYIN
 280         iptables -N POLICYFWD
 281         iptables -A FORWARD -j POLICYFWD
 282         iptables -N POLICYOUT
 283         iptables -A OUTPUT -j POLICYOUT
 284
 285         # Initialize firewall policies.
 286         /usr/sbin/firewall-policy
 287
 288         # Install firewall rules for the red interface.
 289         iptables_red
 290 }
 291
 292 iptables_red() {
 293         iptables -F REDINPUT
 294         iptables -F REDFORWARD
 295         iptables -t nat -F REDNAT
 296
 297         # PPPoE / PPTP Device
 298         if [ "$IFACE" != "" ]; then
 299                 # PPPoE / PPTP
 300                 if [ "$DEVICE" != "" ]; then
 301                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 302                 fi
 303                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 304                         if [ "$RED_DEV" != "" ]; then
 305                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 306                         fi
 307                 fi
 308         fi
 309
 310         # PPTP over DHCP
 311         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 312                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 313                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 314         fi
 315
 316         # Orange pinholes
 317         if [ "$ORANGE_DEV" != "" ]; then
 318                 # This rule enables a host on ORANGE network to connect to the outside
 319                 # (only if we have a red connection)
 320                 if [ "$IFACE" != "" ]; then
 321                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 322                 fi
 323         fi
 324
 325         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 326                 # DHCP
 327                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 328                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 329                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 330                 fi
 331                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 332                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 333                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 334                 fi
 335
 336                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 337                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 338
 339                 if [ "$IFACE" != "$GREEN_DEV" ]; then
 340                         iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 341                 fi
 342
 343         fi
 344
 345         # Reload all rules.
 346         /usr/local/bin/firewallctrl
 347 }
 348
 349 # See how we were called.
 350 case "$1" in
 351   start)
 352         boot_mesg "Loading firewall modules into the kernel"
 353         modprobe iptable_nat || failed=1
 354         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 355                 modprobe $(basename $i | cut -d. -f1) || failed=1
 356         done
 357         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 358                 modprobe $(basename $i | cut -d. -f1) || failed=1
 359         done
 360         (exit ${failed})
 361         evaluate_retval
 362
 363         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 364                 rmmod nf_nat_sip
 365                 rmmod nf_conntrack_sip
 366                 rmmod nf_nat_h323
 367                 rmmod nf_conntrack_h323
 368         fi
 369
 370         boot_mesg "Setting up firewall"
 371         iptables_init
 372         evaluate_retval
 373
 374         # run local firewall configuration, if present
 375         if [ -x /etc/sysconfig/firewall.local ]; then
 376                 /etc/sysconfig/firewall.local start
 377         fi
 378         ;;
 379   reload)
 380         boot_mesg "Reloading firewall"
 381         iptables_red
 382         evaluate_retval
 383
 384         # run local firewall configuration, if present
 385         if [ -x /etc/sysconfig/firewall.local ]; then
 386                 /etc/sysconfig/firewall.local reload
 387         fi
 388         ;;
 389   restart)
 390         # run local firewall configuration, if present
 391         if [ -x /etc/sysconfig/firewall.local ]; then
 392                 /etc/sysconfig/firewall.local stop
 393         fi
 394         $0 start
 395         ;;
 396   *)
 397         echo "Usage: $0 {start|reload|restart}"
 398         exit 1
 399         ;;
 400 esac
 401
 402 exit 0