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 OUTPUT  -o tun+ -j OVPNBLOCK
 111         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 112         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 113
 114         # OpenVPN transfer network translation
 115         iptables -t nat -N OVPNNAT
 116         iptables -t nat -A POSTROUTING -j OVPNNAT
 117
 118         # IPTV chains for IGMPPROXY
 119         iptables -N IPTVINPUT
 120         iptables -A INPUT -j IPTVINPUT
 121         iptables -N IPTVFORWARD
 122         iptables -A FORWARD -j IPTVFORWARD
 123
 124         # filtering from GUI
 125         iptables -N GUIINPUT
 126         iptables -A INPUT -j GUIINPUT
 127         iptables -A GUIINPUT -p icmp --icmp-type 8 -j ACCEPT
 128
 129         # Accept everything on loopback
 130         iptables -N LOOPBACK
 131         iptables -A LOOPBACK -i lo -j ACCEPT
 132         iptables -A LOOPBACK -o lo -j ACCEPT
 133
 134         # Filter all packets with loopback addresses on non-loopback interfaces.
 135         iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
 136         iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
 137
 138         for i in INPUT FORWARD OUTPUT; do
 139                 iptables -A ${i} -j LOOPBACK
 140         done
 141
 142         # Accept everything connected
 143         for i in INPUT FORWARD OUTPUT; do
 144                 iptables -A ${i} -j CONNTRACK
 145         done
 146
 147         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 148         iptables -N IPSECINPUT
 149         iptables -N IPSECFORWARD
 150         iptables -N IPSECOUTPUT
 151         iptables -A INPUT -j IPSECINPUT
 152         iptables -A FORWARD -j IPSECFORWARD
 153         iptables -A OUTPUT -j IPSECOUTPUT
 154         iptables -t nat -N IPSECNAT
 155         iptables -t nat -A POSTROUTING -j IPSECNAT
 156
 157         # localhost and ethernet.
 158         iptables -A INPUT   -i $GREEN_DEV  -m conntrack --ctstate NEW -j ACCEPT ! -p icmp
 159
 160         # allow DHCP on BLUE to be turned on/off
 161         iptables -N DHCPBLUEINPUT
 162         iptables -A INPUT -j DHCPBLUEINPUT
 163
 164         # WIRELESS chains
 165         iptables -N WIRELESSINPUT
 166         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 167         iptables -N WIRELESSFORWARD
 168         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 169
 170         # OpenVPN
 171         iptables -N OVPNINPUT
 172         iptables -A INPUT -j OVPNINPUT
 173
 174         # TOR
 175         iptables -N TOR_INPUT
 176         iptables -A INPUT -j TOR_INPUT
 177
 178         # Jump into the actual firewall ruleset.
 179         iptables -N INPUTFW
 180         iptables -A INPUT -j INPUTFW
 181
 182         iptables -N OUTGOINGFW
 183         iptables -A OUTPUT -j OUTGOINGFW
 184
 185         iptables -N FORWARDFW
 186         iptables -A FORWARD -j FORWARDFW
 187
 188         # SNAT rules
 189         iptables -t nat -N NAT_SOURCE
 190         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 191
 192         # RED chain, used for the red interface
 193         iptables -N REDINPUT
 194         iptables -A INPUT -j REDINPUT
 195         iptables -N REDFORWARD
 196         iptables -A FORWARD -j REDFORWARD
 197         iptables -t nat -N REDNAT
 198         iptables -t nat -A POSTROUTING -j REDNAT
 199
 200         # Custom prerouting chains (for transparent proxy)
 201         iptables -t nat -N SQUID
 202         iptables -t nat -A PREROUTING -j SQUID
 203
 204         # DNAT rules
 205         iptables -t nat -N NAT_DESTINATION
 206         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 207
 208         # upnp chain for our upnp daemon
 209         iptables -t nat -N UPNPFW
 210         iptables -t nat -A PREROUTING -j UPNPFW
 211         iptables -N UPNPFW
 212         iptables -A FORWARD -m conntrack --ctstate NEW -j UPNPFW
 213
 214         # Apply OpenVPN firewall rules
 215         /usr/local/bin/openvpnctrl --firewall-rules
 216
 217         # run wirelessctrl
 218         /usr/local/bin/wirelessctrl
 219
 220         # POLICY CHAIN
 221         iptables -N POLICYIN
 222         iptables -A INPUT -j POLICYIN
 223         iptables -N POLICYFWD
 224         iptables -A FORWARD -j POLICYFWD
 225         iptables -N POLICYOUT
 226         iptables -A OUTPUT -j POLICYOUT
 227
 228         # Initialize firewall policies.
 229         /usr/sbin/firewall-policy
 230
 231         # Install firewall rules for the red interface.
 232         iptables_red
 233 }
 234
 235 iptables_red() {
 236         iptables -F REDINPUT
 237         iptables -F REDFORWARD
 238         iptables -t nat -F REDNAT
 239
 240         # PPPoE / PPTP Device
 241         if [ "$IFACE" != "" ]; then
 242                 # PPPoE / PPTP
 243                 if [ "$DEVICE" != "" ]; then
 244                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 245                 fi
 246                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 247                         if [ "$RED_DEV" != "" ]; then
 248                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 249                         fi
 250                 fi
 251         fi
 252
 253         # PPTP over DHCP
 254         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 255                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 256                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 257         fi
 258
 259         # Orange pinholes
 260         if [ "$ORANGE_DEV" != "" ]; then
 261                 # This rule enables a host on ORANGE network to connect to the outside
 262                 # (only if we have a red connection)
 263                 if [ "$IFACE" != "" ]; then
 264                         iptables -A REDFORWARD -i $ORANGE_DEV -o $IFACE -j ACCEPT
 265                 fi
 266         fi
 267
 268         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 269                 # DHCP
 270                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 271                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 272                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 273                 fi
 274                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 275                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 276                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 277                 fi
 278
 279                 # Outgoing masquerading (don't masqerade IPSEC (mark 50))
 280                 iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
 281                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 282
 283         fi
 284
 285         # Reload all rules.
 286         /usr/local/bin/firewallctrl
 287 }
 288
 289 # See how we were called.
 290 case "$1" in
 291   start)
 292         boot_mesg "Loading firewall modules into the kernel"
 293         modprobe iptable_nat || failed=1
 294         for i in $(find /lib/modules/$(uname -r) -name nf_conntrack*); do
 295                 modprobe $(basename $i | cut -d. -f1) || failed=1
 296         done
 297         for i in $(find /lib/modules/$(uname -r) -name nf_nat*); do
 298                 modprobe $(basename $i | cut -d. -f1) || failed=1
 299         done
 300         (exit ${failed})
 301         evaluate_retval
 302
 303         if [ -e /var/ipfire/main/disable_nf_sip ]; then
 304                 rmmod nf_nat_sip
 305                 rmmod nf_conntrack_sip
 306                 rmmod nf_nat_h323
 307                 rmmod nf_conntrack_h323
 308         fi
 309
 310         boot_mesg "Setting up firewall"
 311         iptables_init
 312         evaluate_retval
 313
 314         # run local firewall configuration, if present
 315         if [ -x /etc/sysconfig/firewall.local ]; then
 316                 /etc/sysconfig/firewall.local start
 317         fi
 318         ;;
 319   reload)
 320         boot_mesg "Reloading firewall"
 321         iptables_red
 322         evaluate_retval
 323
 324         # run local firewall configuration, if present
 325         if [ -x /etc/sysconfig/firewall.local ]; then
 326                 /etc/sysconfig/firewall.local reload
 327         fi
 328         ;;
 329   restart)
 330         # run local firewall configuration, if present
 331         if [ -x /etc/sysconfig/firewall.local ]; then
 332                 /etc/sysconfig/firewall.local stop
 333         fi
 334         $0 start
 335         ;;
 336   *)
 337         echo "Usage: $0 {start|reload|restart}"
 338         exit 1
 339         ;;
 340 esac
 341
 342 exit 0