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 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
   6
   7 if [ -f /var/ipfire/red/device ]; then
   8         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
   9 fi
  10
  11 iptables_init() {
  12         # Flush all rules and delete all custom chains
  13         /sbin/iptables -F
  14         /sbin/iptables -t nat -F
  15         /sbin/iptables -t mangle -F
  16         /sbin/iptables -X
  17         /sbin/iptables -t nat -X
  18         /sbin/iptables -t mangle -X
  19
  20         # Set up policies
  21         /sbin/iptables -P INPUT DROP
  22         /sbin/iptables -P FORWARD DROP
  23         /sbin/iptables -P OUTPUT ACCEPT
  24
  25         # Empty LOG_DROP and LOG_REJECT chains
  26         /sbin/iptables -N LOG_DROP
  27         /sbin/iptables -A LOG_DROP   -m limit --limit 10/minute -j LOG
  28         /sbin/iptables -A LOG_DROP   -j DROP
  29         /sbin/iptables -N LOG_REJECT
  30         /sbin/iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG
  31         /sbin/iptables -A LOG_REJECT -j REJECT
  32
  33         # This chain will log, then DROPs packets with certain bad combinations
  34         # of flags might indicate a port-scan attempt (xmas, null, etc)
  35         /sbin/iptables -N PSCAN
  36         /sbin/iptables -A PSCAN -p tcp  -m limit --limit 10/minute -j LOG --log-prefix "TCP Scan? "
  37         /sbin/iptables -A PSCAN -p udp  -m limit --limit 10/minute -j LOG --log-prefix "UDP Scan? "
  38         /sbin/iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "ICMP Scan? "
  39         /sbin/iptables -A PSCAN -f      -m limit --limit 10/minute -j LOG --log-prefix "FRAG Scan? "
  40         /sbin/iptables -A PSCAN -j DROP
  41
  42         # New tcp packets without SYN set - could well be an obscure type of port scan
  43         # that's not covered above, may just be a broken windows machine
  44         /sbin/iptables -N NEWNOTSYN
  45         /sbin/iptables -A NEWNOTSYN  -m limit --limit 10/minute -j LOG  --log-prefix "NEW not SYN? "
  46         /sbin/iptables -A NEWNOTSYN  -j DROP
  47
  48         # Chain to contain all the rules relating to bad TCP flags
  49         /sbin/iptables -N BADTCP
  50
  51         # Disallow packets frequently used by port-scanners
  52         # nmap xmas
  53         /sbin/iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH  -j PSCAN
  54         # Null
  55         /sbin/iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
  56         # FIN
  57         /sbin/iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
  58         # SYN/RST (also catches xmas variants that set SYN+RST+...)
  59         /sbin/iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
  60         # SYN/FIN (QueSO or nmap OS probe)
  61         /sbin/iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
  62         # NEW TCP without SYN
  63         /sbin/iptables -A BADTCP -p tcp ! --syn -m state --state NEW -j NEWNOTSYN
  64
  65         /sbin/iptables -A INPUT   -j BADTCP
  66         /sbin/iptables -A FORWARD -j BADTCP
  67
  68 }
  69
  70 iptables_red() {
  71         /sbin/iptables -F REDINPUT
  72         /sbin/iptables -F REDFORWARD
  73         /sbin/iptables -t nat -F REDNAT
  74
  75         # PPPoE / PPTP Device
  76         if [ "$IFACE" != "" ]; then
  77                 # PPPoE / PPTP
  78                 if [ "$DEVICE" != "" ]; then
  79                         /sbin/iptables -A REDINPUT -i $DEVICE -j ACCEPT
  80                 fi
  81                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
  82                         if [ "$RED_DEV" != "" ]; then
  83                                 /sbin/iptables -A REDINPUT -i $RED_DEV -j ACCEPT
  84                         fi
  85                 fi
  86         fi
  87
  88         # PPTP over DHCP
  89         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
  90                 /sbin/iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
  91                 /sbin/iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
  92         fi
  93
  94         # Orange pinholes
  95         if [ "$ORANGE_DEV" != "" ]; then
  96                 # This rule enables a host on ORANGE network to connect to the outside
  97                 # (only if we have a red connection)
  98                 if [ "$IFACE" != "" ]; then
  99                         /sbin/iptables -A REDFORWARD -i $ORANGE_DEV -p tcp -o $IFACE -j ACCEPT
 100                         /sbin/iptables -A REDFORWARD -i $ORANGE_DEV -p udp -o $IFACE -j ACCEPT
 101                 fi
 102         fi
 103
 104         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 105                 # DHCP
 106                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 107                         /sbin/iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 108                         /sbin/iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 109                 fi
 110                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 111                         /sbin/iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 112                         /sbin/iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 113                 fi
 114
 115                 # Outgoing masquerading
 116                 /sbin/iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 117
 118         fi
 119 }
 120
 121 # See how we were called.
 122 case "$1" in
 123   start)
 124         iptables_init
 125
 126         # Limit Packets- helps reduce dos/syn attacks
 127         # original do nothing line
 128         #/sbin/iptables -A INPUT -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -m limit --limit 10/sec
 129         # the correct one, but the negative '!' do nothing...
 130         #/sbin/iptables -A INPUT -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -m limit ! --limit 10/sec -j DROP
 131
 132         # Fix for braindead ISP's
 133         /sbin/iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 134
 135         # CUSTOM chains, can be used by the users themselves
 136         /sbin/iptables -N CUSTOMINPUT
 137         /sbin/iptables -A INPUT -j CUSTOMINPUT
 138         /sbin/iptables -N CUSTOMFORWARD
 139         /sbin/iptables -A FORWARD -j CUSTOMFORWARD
 140         /sbin/iptables -N CUSTOMOUTPUT
 141         /sbin/iptables -A OUTPUT -j CUSTOMOUTPUT
 142         /sbin/iptables -N OUTGOINGFW
 143         /sbin/iptables -A OUTPUT -j OUTGOINGFW
 144         /sbin/iptables -t nat -N CUSTOMPREROUTING
 145         /sbin/iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 146         /sbin/iptables -t nat -N CUSTOMPOSTROUTING
 147         /sbin/iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 148
 149         # filtering from GUI
 150         /sbin/iptables -N GUIINPUT
 151         /sbin/iptables -A INPUT -j GUIINPUT
 152         /sbin/iptables -A GUIINPUT -p icmp --icmp-type 8 -j ACCEPT
 153
 154         # Accept everything connected
 155         /sbin/iptables -A INPUT   -m state --state ESTABLISHED,RELATED -j ACCEPT
 156         /sbin/iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
 157
 158         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 159         /sbin/iptables -N IPSECVIRTUAL
 160         /sbin/iptables -N OPENSSLVIRTUAL
 161         /sbin/iptables -A INPUT -j IPSECVIRTUAL
 162         /sbin/iptables -A INPUT -j OPENSSLVIRTUAL
 163         /sbin/iptables -A FORWARD -j IPSECVIRTUAL
 164         /sbin/iptables -A FORWARD -j OPENSSLVIRTUAL
 165
 166         # Outgoing Firewall
 167         /sbin/iptables -A FORWARD -j OUTGOINGFW
 168
 169         # localhost and ethernet.
 170         /sbin/iptables -A INPUT   -i lo          -m state --state NEW -j ACCEPT
 171         /sbin/iptables -A INPUT   -s 127.0.0.0/8 -m state --state NEW -j DROP   # Loopback not on lo
 172         /sbin/iptables -A INPUT   -d 127.0.0.0/8 -m state --state NEW -j DROP
 173         /sbin/iptables -A FORWARD -i lo          -m state --state NEW -j ACCEPT
 174         /sbin/iptables -A FORWARD -s 127.0.0.0/8 -m state --state NEW -j DROP
 175         /sbin/iptables -A FORWARD -d 127.0.0.0/8 -m state --state NEW -j DROP
 176         /sbin/iptables -A INPUT   -i $GREEN_DEV  -m state --state NEW -j ACCEPT -p ! icmp
 177         /sbin/iptables -A FORWARD -i $GREEN_DEV  -m state --state NEW -j ACCEPT
 178
 179         # If a host on orange tries to initiate a connection to IPFire's red IP and
 180         # the connection gets DNATed back through a port forward to a server on orange
 181         # we end up with orange -> orange traffic passing through IPFire
 182         [ "$ORANGE_DEV" != "" ] && /sbin/iptables -A FORWARD -i $ORANGE_DEV -o $ORANGE_DEV -m state --state NEW -j ACCEPT
 183
 184         # allow DHCP on BLUE to be turned on/off
 185         /sbin/iptables -N DHCPBLUEINPUT
 186         /sbin/iptables -A INPUT -j DHCPBLUEINPUT
 187
 188         # IPSec
 189         /sbin/iptables -N IPSECPHYSICAL
 190         /sbin/iptables -A INPUT -j IPSECPHYSICAL
 191
 192         # OPenSSL
 193         /sbin/iptables -N OPENSSLPHYSICAL
 194         /sbin/iptables -A INPUT -j OPENSSLPHYSICAL
 195
 196         # WIRELESS chains
 197         /sbin/iptables -N WIRELESSINPUT
 198         /sbin/iptables -A INPUT -m state --state NEW -j WIRELESSINPUT
 199         /sbin/iptables -N WIRELESSFORWARD
 200         /sbin/iptables -A FORWARD -m state --state NEW -j WIRELESSFORWARD
 201
 202         # RED chain, used for the red interface
 203         /sbin/iptables -N REDINPUT
 204         /sbin/iptables -A INPUT -j REDINPUT
 205         /sbin/iptables -N REDFORWARD
 206         /sbin/iptables -A FORWARD -j REDFORWARD
 207         /sbin/iptables -t nat -N REDNAT
 208         /sbin/iptables -t nat -A POSTROUTING -j REDNAT
 209
 210         iptables_red
 211
 212         # DMZ pinhole chain.  setdmzholes setuid prog adds rules here to allow
 213         # ORANGE to talk to GREEN / BLUE.
 214         /sbin/iptables -N DMZHOLES
 215         if [ "$ORANGE_DEV" != "" ]; then
 216                 /sbin/iptables -A FORWARD -i $ORANGE_DEV -m state --state NEW -j DMZHOLES
 217         fi
 218
 219         # XTACCESS chain, used for external access
 220         /sbin/iptables -N XTACCESS
 221         /sbin/iptables -A INPUT -m state --state NEW -j XTACCESS
 222
 223         # PORTFWACCESS chain, used for portforwarding
 224         /sbin/iptables -N PORTFWACCESS
 225         /sbin/iptables -A FORWARD -m state --state NEW -j PORTFWACCESS
 226
 227         # Custom prerouting chains (for transparent proxy and port forwarding)
 228         /sbin/iptables -t nat -N SQUID
 229         /sbin/iptables -t nat -A PREROUTING -j SQUID
 230         /sbin/iptables -t nat -N PORTFW
 231         /sbin/iptables -t nat -A PREROUTING -j PORTFW
 232
 233         # upnp chain for our upnp daemon
 234         /sbin/iptables -t nat -N UPNPFW
 235         /sbin/iptables -t nat -A PREROUTING -j UPNPFW
 236
 237
 238         # Custom mangle chain (for port fowarding)
 239         /sbin/iptables -t mangle -N PORTFWMANGLE
 240         /sbin/iptables -t mangle -A PREROUTING -j PORTFWMANGLE
 241
 242         # Postrouting rules (for port forwarding)
 243         /sbin/iptables -t nat -A POSTROUTING -m mark --mark 1 -j SNAT \
 244          --to-source $GREEN_ADDRESS
 245         if [ "$BLUE_DEV" != "" ]; then
 246                 /sbin/iptables -t nat -A POSTROUTING -m mark --mark 2 -j SNAT --to-source $BLUE_ADDRESS
 247         fi
 248         if [ "$ORANGE_DEV" != "" ]; then
 249                 /sbin/iptables -t nat -A POSTROUTING -m mark --mark 3 -j SNAT --to-source $ORANGE_ADDRESS
 250         fi
 251
 252         # run local firewall configuration, if present
 253         if [ -x /etc/sysconfig/firewall.local ]; then
 254                 /etc/sysconfig/firewall.local start
 255         fi
 256
 257         # last rule in input and forward chain is for logging.
 258         /sbin/iptables -A INPUT   -m limit --limit 10/minute -j LOG --log-prefix "INPUT "
 259         /sbin/iptables -A FORWARD -m limit --limit 10/minute -j LOG --log-prefix "OUTPUT "
 260         ;;
 261   startovpn)
 262         # run openvpn
 263         /usr/local/bin/openvpnctrl --create-chains-and-rules
 264         ;;
 265   stop)
 266         iptables_init
 267         # Accept everyting connected
 268         /sbin/iptables -A INPUT   -m state --state ESTABLISHED,RELATED -j ACCEPT
 269
 270         # localhost and ethernet.
 271         /sbin/iptables -A INPUT -i lo -j ACCEPT
 272         /sbin/iptables -A INPUT -i $GREEN_DEV -m state --state NEW -j ACCEPT
 273
 274         if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 275                 /sbin/iptables -A INPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 276                 /sbin/iptables -A INPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 277         fi
 278         if [ "$PROTOCOL" == "RFC1483" -a "$METHOD" == "DHCP" ]; then
 279                 /sbin/iptables -A INPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 280                 /sbin/iptables -A INPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 281         fi
 282
 283         # run local firewall configuration, if present
 284         if [ -x /etc/sysconfig/firewall.local ]; then
 285                 /etc/sysconfig/firewall.local stop
 286         fi
 287
 288         /sbin/iptables -A INPUT   -m limit --limit 10/minute -j LOG --log-prefix "INPUT "
 289         /sbin/iptables -A FORWARD -m limit --limit 10/minute -j LOG --log-prefix "OUTPUT "
 290         ;;
 291   stopovpn)
 292         # stop openvpn
 293         /usr/local/bin/openvpnctrl --delete-chains-and-rules
 294         ;;
 295   reload)
 296         iptables_red
 297
 298         # run local firewall configuration, if present
 299         if [ -x /etc/sysconfig/firewall.local ]; then
 300                 /etc/sysconfig/firewall.local reload
 301         fi
 302         ;;
 303   restart)
 304         $0 stop
 305         $0 start
 306         ;;
 307   *)
 308         echo "Usage: $0 {start|stop|reload|restart}"
 309         exit 1
 310         ;;
 311 esac
 312
 313 exit 0