src/initscripts/init.d/firewall

   1 #!/bin/sh
   2
   3 eval $(/usr/local/bin/readhash /var/ipfire/ppp/settings)
   4 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
   5 eval $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
   6 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
   7
   8 if [ -f /var/ipfire/red/device ]; then
   9         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  10 fi
  11
  12 function iptables() {
  13         /sbin/iptables --wait "$@"
  14 }
  15
  16 iptables_init() {
  17         # Flush all rules and delete all custom chains
  18         iptables -F
  19         iptables -t nat -F
  20         iptables -t mangle -F
  21         iptables -X
  22         iptables -t nat -X
  23         iptables -t mangle -X
  24
  25         # Set up policies
  26         iptables -P INPUT DROP
  27         iptables -P FORWARD DROP
  28         iptables -P OUTPUT ACCEPT
  29
  30         # Empty LOG_DROP and LOG_REJECT chains
  31         iptables -N LOG_DROP
  32         iptables -A LOG_DROP   -m limit --limit 10/minute -j LOG
  33         iptables -A LOG_DROP   -j DROP
  34         iptables -N LOG_REJECT
  35         iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG
  36         iptables -A LOG_REJECT -j REJECT
  37
  38         # This chain will log, then DROPs packets with certain bad combinations
  39         # of flags might indicate a port-scan attempt (xmas, null, etc)
  40         iptables -N PSCAN
  41         if [ "$DROPPORTSCAN" == "on" ]; then
  42                 iptables -A PSCAN -p tcp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan"
  43                 iptables -A PSCAN -p udp  -m limit --limit 10/minute -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan"
  44                 iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  45                 iptables -A PSCAN -f      -m limit --limit 10/minute -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  46         fi
  47         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  48
  49         # New tcp packets without SYN set - could well be an obscure type of port scan
  50         # that's not covered above, may just be a broken windows machine
  51         iptables -N NEWNOTSYN
  52         if [ "$DROPNEWNOTSYN" == "on" ]; then
  53                 iptables -A NEWNOTSYN  -m limit --limit 10/minute -j LOG  --log-prefix "DROP_NEWNOTSYN "
  54         fi
  55         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  56
  57         # Chain to contain all the rules relating to bad TCP flags
  58         iptables -N BADTCP
  59
  60         # Don't check loopback
  61         iptables -A BADTCP -i lo -j RETURN
  62
  63         # Disallow packets frequently used by port-scanners
  64         # nmap xmas
  65         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH  -j PSCAN
  66         # Null
  67         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  68         # FIN
  69         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  70         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  71         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  72         # SYN/FIN (QueSO or nmap OS probe)
  73         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  74         # NEW TCP without SYN
  75         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
  76
  77         iptables -A INPUT   -p tcp -j BADTCP
  78         iptables -A FORWARD -p tcp -j BADTCP
  79
  80         # Connection tracking chain
  81         iptables -N CONNTRACK
  82         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
  83
  84         # Fix for braindead ISP's
  85         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
  86
  87         # CUSTOM chains, can be used by the users themselves
  88         iptables -N CUSTOMINPUT
  89         iptables -A INPUT -j CUSTOMINPUT
  90         iptables -N CUSTOMFORWARD
  91         iptables -A FORWARD -j CUSTOMFORWARD
  92         iptables -N CUSTOMOUTPUT
  93         iptables -A OUTPUT -j CUSTOMOUTPUT
  94         iptables -t nat -N CUSTOMPREROUTING
  95         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
  96         iptables -t nat -N CUSTOMPOSTROUTING
  97         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
  98
  99         # Guardian (IPS) chains
 100         iptables -N GUARDIAN
 101         iptables -A INPUT -j GUARDIAN
 102         iptables -A FORWARD -j GUARDIAN
 103
 104         # Block OpenVPN transfer networks
 105         iptables -N OVPNBLOCK
 106         for i in INPUT FORWARD; do
 107                 iptables -A ${i} -j OVPNBLOCK
 108         done
 109
 110         # OpenVPN transfer network translation
 111         iptables -t nat -N OVPNNAT
 112         iptables -t nat -A POSTROUTING -j OVPNNAT
 113
 114         # IPTV chains for IGMPPROXY
 115         iptables -N IPTVINPUT
 116         iptables -A INPUT -j IPTVINPUT
 117         iptables -N IPTVFORWARD
 118         iptables -A FORWARD -j IPTVFORWARD
 119
 120         # filtering from GUI
 121         iptables -N GUIINPUT
 122         iptables -A INPUT -j GUIINPUT
 123         iptables -A GUIINPUT -p icmp --icmp-type 8 -j ACCEPT
 124
 125         # Accept everything on loopback
 126         iptables -N LOOPBACK
 127         iptables -A LOOPBACK -i lo -j ACCEPT
 128         iptables -A LOOPBACK -o lo -j ACCEPT
 129
 130         # Filter all packets with loopback addresses on non-loopback interfaces.
 131         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 132         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 133
 134         for i in INPUT FORWARD OUTPUT; do
 135                 iptables -A ${i} -j LOOPBACK
 136         done
 137
 138         # Accept everything connected
 139         for i in INPUT FORWARD OUTPUT; do
 140                 iptables -A ${i} -j CONNTRACK
 141         done
 142
 143         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 144         iptables -N IPSECINPUT
 145         iptables -N IPSECFORWARD
 146         iptables -N IPSECOUTPUT
 147         iptables -A INPUT -j IPSECINPUT
 148         iptables -A FORWARD -j IPSECFORWARD
 149         iptables -A OUTPUT -j IPSECOUTPUT
 150         iptables -t nat -N IPSECNAT
 151         iptables -t nat -A POSTROUTING -j IPSECNAT
 152
 153         # localhost and ethernet.
 154         iptables -A INPUT   -i $GREEN_DEV  -m conntrack --ctstate NEW -j ACCEPT ! -p icmp
 155
 156         # allow DHCP on BLUE to be turned on/off
 157         iptables -N DHCPBLUEINPUT
 158         iptables -A INPUT -j DHCPBLUEINPUT
 159
 160         # WIRELESS chains
 161         iptables -N WIRELESSINPUT
 162         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 163         iptables -N WIRELESSFORWARD
 164         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 165
 166         # OpenVPN
 167         iptables -N OVPNINPUT
 168         iptables -A INPUT -j OVPNINPUT
 169
 170         # TOR
 171         iptables -N TOR_INPUT
 172         iptables -A INPUT -j TOR_INPUT
 173
 174         # Jump into the actual firewall ruleset.
 175         iptables -N INPUTFW
 176         iptables -A INPUT -j INPUTFW
 177
 178         iptables -N OUTGOINGFW
 179         iptables -A OUTPUT -j OUTGOINGFW
 180
 181         iptables -N FORWARDFW
 182         iptables -A FORWARD -j FORWARDFW
 183
 184         # SNAT rules
 185         iptables -t nat -N NAT_SOURCE
 186         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 187
 188         # RED chain, used for the red interface
 189         iptables -N REDINPUT
 190         iptables -A INPUT -j REDINPUT
 191         iptables -N REDFORWARD
 192         iptables -A FORWARD -j REDFORWARD
 193         iptables -t nat -N REDNAT
 194         iptables -t nat -A POSTROUTING -j REDNAT
 195
 196         iptables_red
 197
 198         # Custom prerouting chains (for transparent proxy)
 199         iptables -t nat -N SQUID
 200         iptables -t nat -A PREROUTING -j SQUID
 201
 202         # DNAT rules
 203         iptables -t nat -N NAT_DESTINATION
 204         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 205
 206         # upnp chain for our upnp daemon
 207         iptables -t nat -N UPNPFW
 208         iptables -t nat -A PREROUTING -j UPNPFW
 209         iptables -N UPNPFW
 210         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 211
 212         # Apply OpenVPN firewall rules
 213         /usr/local/bin/openvpnctrl --firewall-rules
 214
 215         # run wirelessctrl
 216         /usr/local/bin/wirelessctrl
 217
 218         # POLICY CHAIN
 219         iptables -N POLICYIN
 220         iptables -A INPUT -j POLICYIN
 221         iptables -N POLICYFWD
 222         iptables -A FORWARD -j POLICYFWD
 223         iptables -N POLICYOUT
 224         iptables -A OUTPUT -j POLICYOUT
 225
 226         /usr/sbin/firewall-policy
 227
 228         # read new firewall
 229         /usr/local/bin/firewallctrl
 230
 231         if [ "$DROPINPUT" == "on" ]; then
 232                 iptables -A INPUT   -m limit --limit 10/minute -j LOG --log-prefix "DROP_INPUT"
 233         fi
 234         iptables -A INPUT -j DROP -m comment --comment "DROP_INPUT"
 235         if [ "$DROPFORWARD" == "on" ]; then
 236                 iptables -A FORWARD -m limit --limit 10/minute -j LOG --log-prefix "DROP_FORWARD"
 237         fi
 238         iptables -A FORWARD -j DROP -m comment --comment "DROP_FORWARD"
 239 }
 240
 241 iptables_red() {
 242         iptables -F REDINPUT
 243         iptables -F REDFORWARD
 244         iptables -t nat -F REDNAT
 245
 246         # PPPoE / PPTP Device
 247         if [ "$IFACE" != "" ]; then
 248                 # PPPoE / PPTP
 249                 if [ "$DEVICE" != "" ]; then
 250                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 251                 fi
 252                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 253                         if [ "$RED_DEV" != "" ]; then
 254                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 255                         fi
 256                 fi
 257         fi
 258
 259         # PPTP over DHCP
 260         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 261                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 262                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 263         fi
 264
 265         # Orange pinholes
 266         if [ "$ORANGE_DEV" != "" ]; then
 267                 # This rule enables a host on ORANGE network to connect to the outside
 268                 # (only if we have a red connection)
 269                 if [ "$IFACE" != "" ]; then
 270                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 271                 fi
 272         fi
 273
 274         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 275                 # DHCP
 276                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 277                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 278                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 279                 fi
 280                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 281                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 282                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 283                 fi
 284
 285                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 286                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 287                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 288
 289         fi
 290 }
 291
 292 # See how we were called.
 293 case "$1" in
 294   start)
 295         boot_mesg "Loading firewall modules into the kernel"
 296         modprobe iptable_nat || failed=1
 297         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 298                 modprobe $(basename $i | cut -d. -f1) || failed=1
 299         done
 300         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 301                 modprobe $(basename $i | cut -d. -f1) || failed=1
 302         done
 303         (exit ${failed})
 304         evaluate_retval
 305
 306         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 307                 rmmod nf_nat_sip
 308                 rmmod nf_conntrack_sip
 309                 rmmod nf_nat_h323
 310                 rmmod nf_conntrack_h323
 311         fi
 312
 313         boot_mesg "Setting up firewall"
 314         iptables_init
 315         evaluate_retval
 316
 317         # run local firewall configuration, if present
 318         if [ -x /etc/sysconfig/firewall.local ]; then
 319                 /etc/sysconfig/firewall.local start
 320         fi
 321         ;;
 322   reload)
 323         boot_mesg "Reloading firewall"
 324         iptables_red
 325         evaluate_retval
 326
 327         # run local firewall configuration, if present
 328         if [ -x /etc/sysconfig/firewall.local ]; then
 329                 /etc/sysconfig/firewall.local reload
 330         fi
 331         ;;
 332   restart)
 333         # run local firewall configuration, if present
 334         if [ -x /etc/sysconfig/firewall.local ]; then
 335                 /etc/sysconfig/firewall.local stop
 336         fi
 337         $0 start
 338         ;;
 339   *)
 340         echo "Usage: $0 {start|reload|restart}"
 341         exit 1
 342         ;;
 343 esac
 344
 345 exit 0