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 -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         # Empty LOG_DROP and LOG_REJECT chains
  36         iptables -N LOG_DROP
  37         iptables -A LOG_DROP   -m limit --limit 10/minute -j LOG
  38         iptables -A LOG_DROP   -j DROP
  39         iptables -N LOG_REJECT
  40         iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG
  41         iptables -A LOG_REJECT -j REJECT
  42
  43         # This chain will log, then DROPs packets with certain bad combinations
  44         # of flags might indicate a port-scan attempt (xmas, null, etc)
  45         iptables -N PSCAN
  46         if [ "$DROPPORTSCAN" == "on" ]; then
  47                 iptables -A PSCAN -p tcp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan"
  48                 iptables -A PSCAN -p udp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan"
  49                 iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  50                 iptables -A PSCAN -f      -m limit --limit 10/minute -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  51         fi
  52         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  53
  54         # New tcp packets without SYN set - could well be an obscure type of port scan
  55         # that's not covered above, may just be a broken windows machine
  56         iptables -N NEWNOTSYN
  57         if [ "$DROPNEWNOTSYN" == "on" ]; then
  58                 iptables -A NEWNOTSYN  -m limit --limit 10/minute -j LOG  --log-prefix "DROP_NEWNOTSYN "
  59         fi
  60         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  61
  62         # Chain to contain all the rules relating to bad TCP flags
  63         iptables -N BADTCP
  64
  65         # Don't check loopback
  66         iptables -A BADTCP -i lo -j RETURN
  67
  68         # Disallow packets frequently used by port-scanners
  69         # NMAP FIN/URG/PSH (XMAS scan)
  70         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
  71         # SYN/RST/ACK/FIN/URG
  72         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
  73         # ALL/ALL
  74         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
  75         # FIN Stealth
  76         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  77         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  78         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  79         # SYN/FIN (QueSO or nmap OS probe)
  80         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  81         # Null
  82         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  83         # NEW TCP without SYN
  84         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  85
  86         iptables -A INPUT   -p tcp -j BADTCP
  87         iptables -A FORWARD -p tcp -j BADTCP
  88
  89         # Connection tracking chains
  90         iptables -N CONNTRACK
  91         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
  92         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
  93         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
  94         iptables -t raw -N CONNTRACK
  95         iptables -t raw -A PREROUTING -j CONNTRACK
  96
  97         # Conntrack helpers (https://home.regit.org/netfilter-en/secure-use-of-helpers/)
  98
  99         # SIP
 100         if [ "${CONNTRACK_SIP}" = "on" ]; then
 101                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 102                         -m helper --helper sip -j ACCEPT
 103                 for proto in udp tcp; do
 104                         iptables -t raw -A CONNTRACK -p "${proto}" --dport 5060 -j CT --helper sip
 105                 done
 106         fi
 107
 108         # FTP
 109         if [ "${CONNTRACK_FTP}" = "on" ]; then
 110                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 111                         -m helper --helper ftp -p tcp --dport 1024: -j ACCEPT
 112                 iptables -t raw -A CONNTRACK -p tcp --dport 21 -j CT --helper ftp
 113         fi
 114
 115         # PPTP
 116         if [ "${CONNTRACK_PPTP}" = "on" ]; then
 117                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 118                         -m helper --helper pptp -j ACCEPT
 119                 iptables -t raw -A CONNTRACK -p udp --dport 1723 -j CT --helper pptp
 120         fi
 121
 122         # TFTP
 123         if [ "${CONNTRACK_TFTP}" = "on" ]; then
 124                 iptables -A CONNTRACK -m conntrack --ctstate RELATED \
 125                         -m helper --helper tftp -j ACCEPT
 126                 iptables -t raw -A CONNTRACK -p udp --dport 69 -j CT --helper tftp
 127         fi
 128
 129         # Fix for braindead ISP's
 130         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 131
 132         # CUSTOM chains, can be used by the users themselves
 133         iptables -N CUSTOMINPUT
 134         iptables -A INPUT -j CUSTOMINPUT
 135         iptables -N CUSTOMFORWARD
 136         iptables -A FORWARD -j CUSTOMFORWARD
 137         iptables -N CUSTOMOUTPUT
 138         iptables -A OUTPUT -j CUSTOMOUTPUT
 139         iptables -t nat -N CUSTOMPREROUTING
 140         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 141         iptables -t nat -N CUSTOMPOSTROUTING
 142         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 143
 144         # P2PBLOCK
 145         iptables -N P2PBLOCK
 146         iptables -A INPUT -j P2PBLOCK
 147         iptables -A FORWARD -j P2PBLOCK
 148         iptables -A OUTPUT -j P2PBLOCK
 149
 150         # Guardian (IPS) chains
 151         iptables -N GUARDIAN
 152         iptables -A INPUT -j GUARDIAN
 153         iptables -A FORWARD -j GUARDIAN
 154
 155         # Block OpenVPN transfer networks
 156         iptables -N OVPNBLOCK
 157         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 158         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 159         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 160
 161         # OpenVPN transfer network translation
 162         iptables -t nat -N OVPNNAT
 163         iptables -t nat -A POSTROUTING -j OVPNNAT
 164
 165         # IPTV chains for IGMPPROXY
 166         iptables -N IPTVINPUT
 167         iptables -A INPUT -j IPTVINPUT
 168         iptables -N IPTVFORWARD
 169         iptables -A FORWARD -j IPTVFORWARD
 170
 171         # Allow to ping the firewall.
 172         iptables -N ICMPINPUT
 173         iptables -A INPUT -j ICMPINPUT
 174         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 175
 176         # Accept everything on loopback
 177         iptables -N LOOPBACK
 178         iptables -A LOOPBACK -i lo -j ACCEPT
 179         iptables -A LOOPBACK -o lo -j ACCEPT
 180
 181         # Filter all packets with loopback addresses on non-loopback interfaces.
 182         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 183         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 184
 185         for i in INPUT FORWARD OUTPUT; do
 186                 iptables -A ${i} -j LOOPBACK
 187         done
 188
 189         # Accept everything connected
 190         for i in INPUT FORWARD OUTPUT; do
 191                 iptables -A ${i} -j CONNTRACK
 192         done
 193
 194         # Allow DHCP
 195         iptables -N DHCPINPUT
 196         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 197         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 198
 199         iptables -N DHCPOUTPUT
 200         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 201         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 202
 203         # Allow DHCP on GREEN
 204         iptables -N DHCPGREENINPUT
 205         iptables -N DHCPGREENOUTPUT
 206         if [ -n "${GREEN_DEV}" ]; then
 207                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 208                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 209         fi
 210
 211         # allow DHCP on BLUE to be turned on/off
 212         iptables -N DHCPBLUEINPUT
 213         iptables -N DHCPBLUEOUTPUT
 214         if [ -n "${BLUE_DEV}" ]; then
 215                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 216                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 217         fi
 218
 219         # GeoIP block
 220         iptables -N GEOIPBLOCK
 221         iptables -A INPUT -j GEOIPBLOCK
 222         iptables -A FORWARD -j GEOIPBLOCK
 223
 224         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 225         iptables -N IPSECINPUT
 226         iptables -N IPSECFORWARD
 227         iptables -N IPSECOUTPUT
 228         iptables -A INPUT -j IPSECINPUT
 229         iptables -A FORWARD -j IPSECFORWARD
 230         iptables -A OUTPUT -j IPSECOUTPUT
 231         iptables -t nat -N IPSECNAT
 232         iptables -t nat -A POSTROUTING -j IPSECNAT
 233
 234         # localhost and ethernet.
 235         # Always allow accessing the web GUI from GREEN.
 236         iptables -N GUIINPUT
 237         iptables -A INPUT -j GUIINPUT
 238         iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 239
 240         # WIRELESS chains
 241         iptables -N WIRELESSINPUT
 242         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 243         iptables -N WIRELESSFORWARD
 244         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 245
 246         # OpenVPN
 247         iptables -N OVPNINPUT
 248         iptables -A INPUT -j OVPNINPUT
 249
 250         # TOR
 251         iptables -N TOR_INPUT
 252         iptables -A INPUT -j TOR_INPUT
 253
 254         # Jump into the actual firewall ruleset.
 255         iptables -N INPUTFW
 256         iptables -A INPUT -j INPUTFW
 257
 258         iptables -N OUTGOINGFW
 259         iptables -A OUTPUT -j OUTGOINGFW
 260
 261         iptables -N FORWARDFW
 262         iptables -A FORWARD -j FORWARDFW
 263
 264         # SNAT rules
 265         iptables -t nat -N NAT_SOURCE
 266         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 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         iptables -t nat -A NAT_DESTINATION_FIX \
 284                 -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
 285
 286         if [ -n "${BLUE_ADDRESS}" ]; then
 287                 iptables -t nat -A NAT_DESTINATION_FIX \
 288                         -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
 289         fi
 290
 291         if [ -n "${ORANGE_ADDRESS}" ]; then
 292                 iptables -t nat -A NAT_DESTINATION_FIX \
 293                         -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
 294         fi
 295
 296         # upnp chain for our upnp daemon
 297         iptables -t nat -N UPNPFW
 298         iptables -t nat -A PREROUTING -j UPNPFW
 299         iptables -N UPNPFW
 300         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 301
 302         # RED chain, used for the red interface
 303         iptables -N REDINPUT
 304         iptables -A INPUT -j REDINPUT
 305         iptables -N REDFORWARD
 306         iptables -A FORWARD -j REDFORWARD
 307         iptables -t nat -N REDNAT
 308         iptables -t nat -A POSTROUTING -j REDNAT
 309
 310         # Apply OpenVPN firewall rules
 311         /usr/local/bin/openvpnctrl --firewall-rules
 312
 313         # run wirelessctrl
 314         /usr/local/bin/wirelessctrl
 315
 316         # POLICY CHAIN
 317         iptables -N POLICYIN
 318         iptables -A INPUT -j POLICYIN
 319         iptables -N POLICYFWD
 320         iptables -A FORWARD -j POLICYFWD
 321         iptables -N POLICYOUT
 322         iptables -A OUTPUT -j POLICYOUT
 323
 324         # Initialize firewall policies.
 325         /usr/sbin/firewall-policy
 326
 327         # Install firewall rules for the red interface.
 328         iptables_red_up
 329
 330         # If red has not been brought up yet, we will
 331         # add the blocking rules for MASQUERADE
 332         if [ ! -e "/var/ipfire/red/active" ]; then
 333                 iptables_red_down
 334         fi
 335 }
 336
 337 iptables_red_up() {
 338         iptables -F REDINPUT
 339         iptables -F REDFORWARD
 340         iptables -t nat -F REDNAT
 341
 342         # PPPoE / PPTP Device
 343         if [ "$IFACE" != "" ]; then
 344                 # PPPoE / PPTP
 345                 if [ "$DEVICE" != "" ]; then
 346                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 347                 fi
 348                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 349                         if [ "$RED_DEV" != "" ]; then
 350                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 351                         fi
 352                 fi
 353         fi
 354
 355         # PPTP over DHCP
 356         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 357                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 358                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 359         fi
 360
 361         # Orange pinholes
 362         if [ "$ORANGE_DEV" != "" ]; then
 363                 # This rule enables a host on ORANGE network to connect to the outside
 364                 # (only if we have a red connection)
 365                 if [ "$IFACE" != "" ]; then
 366                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 367                 fi
 368         fi
 369
 370         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 371                 # DHCP
 372                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 373                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 374                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 375                 fi
 376                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 377                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 378                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 379                 fi
 380
 381                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 382                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 383
 384                 if [ "$IFACE" = "$GREEN_DEV" ]; then
 385                         MASQUERADE_GREEN="off"
 386                 fi
 387
 388                 local NO_MASQ_NETWORKS
 389
 390                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 391                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 392                 fi
 393
 394                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 395                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 396                 fi
 397
 398                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 399                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 400                 fi
 401
 402                 local network
 403                 for network in ${NO_MASQ_NETWORKS}; do
 404                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 405                 done
 406
 407                 # Masquerade everything else
 408                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 409         fi
 410
 411         # Reload all rules.
 412         /usr/local/bin/firewallctrl
 413 }
 414
 415 iptables_red_down() {
 416         # Prohibit packets to reach the masquerading rule
 417         # while the wan interface is down - this is required to
 418         # circumvent udp related NAT issues
 419         # http://forum.ipfire.org/index.php?topic=11127.0
 420         if [ -n "${IFACE}" ]; then
 421                 iptables -F REDFORWARD
 422                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 423         fi
 424
 425         # Reload all rules.
 426         /usr/local/bin/firewallctrl
 427 }
 428
 429 # See how we were called.
 430 case "$1" in
 431   start)
 432         boot_mesg "Setting up firewall"
 433         iptables_init
 434         evaluate_retval
 435         ;;
 436   reload|up)
 437         boot_mesg "Reloading firewall"
 438         iptables_red_up
 439         evaluate_retval
 440         ;;
 441   down)
 442         boot_mesg "Disabling firewall access to RED"
 443         iptables_red_down
 444         evaluate_retval
 445         ;;
 446   restart)
 447         $0 start
 448         ;;
 449   *)
 450         echo "Usage: $0 {start|reload|restart}"
 451         exit 1
 452         ;;
 453 esac
 454
 455 exit 0