### Copyright (C) 1997 John D. Hardin
### This program is free software; you can redistribute it and/or modify
### it under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2 of the License, or
### (at your option) any later version.
###
### This program is distributed in the hope that it will be useful,
### but WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with this program; if not, write to the Free Software
### Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

### $Id: allowhost.template,v 1.1.1.1 1998/11/01 16:46:25 blackie Exp $


proc allowhosts {} {
    # Allow / Services (Per-Host, Internet Hosts)

    Desc "Per-Internet-Host Services Allowed"

    ShortDesc "Per-Internet-Host Services Allowed"

    Header head1 -text "Per-Internet-Host Services Allowed"\
	    -background gray\
	    -help "Services are things like Telnet for logins, SMTP for email, FTP for file transfer,"\
	    "HTTP for Webs, and so forth. Certain services you may want to provide even if your default"\
	    "policy is \"deny\", for example, HTTP to serve web pages."\

    Label label1 -text "Firewall support"\
            -textafter "compiled into the kernel."\
	    -default "is"\
	    -packFrame:anchor center \
	    -help "Firewall support must be compiled into the kernel. If it is not,"\
	    "then you must configure and build a new kernel; see the Kernel HOWTO for"\
	    "instructions."

    Entry hostIP -text "Internet Host"\
            -help "The name or unique IP address of a computer on the Internet,"\
	    "or a network address (to match all hosts on a particular network).\n"\
	    "WARNING: If you enter a name then that name should probably be in your /etc/hosts file."\
	    "If you access the Internet via dialup there is no guarantee that the ipfwadm"\
	    "command will be able to look up the name using DNS."\
            "\n\nIf you provide a file name here, the IP addresses and netmasks will be retrieved"\
            "from that file at the time the firewall script is run. This allows you to modify the"\
            "list of Internet hosts permitted to access your local network without having to"\
            "regenerate the firewall script."

    global MaskList
    ComboBox hostnetmask -text "Network Mask"\
	    -count 8 -noedit 1\
            -entries $MaskList\
	    -help "If you entered the IP address or name for a specific host, select \"32: 255.255.255.255\" -"\
	    "this means that the address must match exactly for the packet to be accepted.\n"\
	    "If you entered a network address, or if you entered a host IP or name and want to match all of the"\
	    "hosts on the same network as that host, select the appropriate netmask for that network.\n"\
	    "WARNING: If you select \"0: 0.0.0.0\" then this rule will apply to *all* hosts on the Internet."

    global ServiceList
    ComboBox allowservice -text "Service to allow"\
	    -count 10\
	    -help "Select a service from the list, or enter one in the form port#(:port#)/\[tcp|udp\]."\
	      "For example, to allow HTTP requests, enter \"80/tcp\". See the file"\
	      "/etc/services (from which this list was generated) for a list of services with some comments,"\
	      "or consult your ISP."\
            -entries $ServiceList

    Radio direction -defaultIndex 0\
	    -entryhelp {\
	    "Inbound" "Service requests coming in from host(s) on the Internet."\
	    "Outbound" "Service requests going out to host(s) on the Internet."\
	    }

    Line line1

    Frame frame1 -entries {hostIP hostnetmask}
    Frame frame2 -entries {allowservice direction}
    Frame frame3 -entries {frame1 frame2 line1} -orient top

    ExtEntry allowedhosts -entries frame3 -count 5

    ShowPage {
      global FirewallInKernel
      if {$FirewallInKernel == 0} {
	set label1 "is not"
	Disable allowedhosts
      } else {
	set label1 "is"
	Enable allowedhosts
      }
    }

    Save {
      global IPFWADM
      global ISPPort
      global LocalNetIP
      global PERL
      global ParseIP
      global MatchService
      if {$IPFWADM == "" || $ISPPort == ""} {
        # nothing
      } else {

        forevery allowedhosts {

          # If host IP is actually a filename, then parse the IP addresses from the file
          set fromfile 0
          if {[file exists $hostIP]} {
            if {$PERL != ""} {
              set fromfile 1
              set host "\$IP_TO_ALLOW"
              print
              print "# process Internet host permissions from file $hostIP"
              print "if \[ -s $hostIP ]"
              print "then"
              print "  $PERL -n -e '$ParseIP' $hostIP | \\"
              print "  while read IP_TO_ALLOW"
              print "  do"
            } else {
              print
              print "# perl not found - cannot set Internet host rules from $hostIP."
              print "# Install perl, then regenerate the firewall file."
	      # generate do-nothing rules
	      set host "0.0.0.0/32"
            }
          } else {
	    # get the net mask for the host
	    regexp {([0-9]+): } $hostnetmask junk maskbits
            set host "$hostIP/$maskbits"
	  }

	  if {[regexp "$MatchService" $allowservice junk serv port prot]} {
	    # retrieved from /etc/services
	    
	    set ACK [pick {$prot == "tcp"} " \$ConnEstablished" ""]

	    if {$direction(index) == 0} {	# inbound (specified host is SOURCE)
              if {$prot == "icmp"} {
                print "# Allow ICMP message $port ($serv) traffic from Internet network/host $host to anyone on the local net"
                print $IPFWADM "-I -a accept \$INET -P $prot -S $host $port -D \$INET_IP"
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-I -a accept \$INET -P $prot -S $host $port -D \$LNET"
                    print $IPFWADM "-F -a accept \$LETH -P $prot -S $host $port -D \$LNET"
                  }
	        }
              } else {
	        print "# allow Internet network/host $host to request $prot service $serv (port $port) from anyone on the local net"
                print $IPFWADM "-I -a accept \$INET -P $prot -S $host -D \$INET_IP" $serv
                print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host -S \$INET_IP" $serv
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-I -a accept \$INET -P $prot -S $host -D \$LNET" $serv
                    print $IPFWADM "-F -a accept \$LETH -P $prot -S $host -D \$LNET" $serv
                    print $IPFWADM "-F -a accept \$INET -P $prot$ACK -D $host -S \$LNET" $serv
                    print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host -S \$LNET" $serv
                  }
	        }
              }
	    } else {				# outbound (specified host is DEST)
              if {$prot == "icmp"} {
	        print "# Allow anyone on the local net to send ICMP message $port traffic ($serv) to Internet network/host $host"
                print $IPFWADM "-O -a accept \$INET -P $prot -S \$INET_IP $port -D $host"
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-O -a accept \$INET -P $prot -S \$LNET $port -D $host"
                    print $IPFWADM "-F -a accept \$INET -P $prot -S \$LNET $port -D $host"
	          }
	        }
              } else {
	        print "# allow anyone on the local net to request $prot service $serv (port $port) from Internet network/host $host"
                print $IPFWADM "-O -a accept \$INET -P $prot -S \$INET_IP -D $host" $serv
                print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$INET_IP -S $host" $serv
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-O -a accept \$INET -P $prot -S \$LNET -D $host" $serv
                    print $IPFWADM "-F -a accept \$INET -P $prot -S \$LNET -D $host" $serv
                    print $IPFWADM "-F -a accept \$LETH -P $prot$ACK -D \$LNET -S $host" $serv
                    print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$LNET -S $host" $serv
                  }
	        }
	      }
	    }

	    if {$serv == "ftp"} {
	      # special handling for ftp-data "reverse connection"
	      if {$direction(index) == 0} {	# inbound (specified host is SOURCE)
                print $IPFWADM "-O -a accept \$INET -P $prot -S \$INET_IP ftp-data -D $host 1024:65535 -t 0x00 0x08"
                print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$INET_IP ftp-data -S $host 1024:65535 -t 0x00 0x08"
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-O -a accept \$INET -P $prot -S \$LNET ftp-data -D $host 1024:65535"
                    print $IPFWADM "-F -a accept \$INET -P $prot -S \$LNET ftp-data -D $host 1024:65535"
                    print $IPFWADM "-F -a accept \$LETH -P $prot$ACK -D \$LNET ftp-data -S $host 1024:65535"
                    print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$LNET ftp-data -S $host 1024:65535"
                  }
	        }
	      } else {				# outbound (specified host is DEST)
                print $IPFWADM "-I -a accept \$INET -P $prot -S $host ftp-data -D \$INET_IP 1024:65535 -t 0x00 0x08"
                print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host ftp-data -S \$INET_IP 1024:65535 -t 0x00 0x08"
                if {${isp@on_internet}} {
	          if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                    print $IPFWADM "-I -a accept \$INET -P $prot -S $host ftp-data -D \$LNET 1024:65535"
                    print $IPFWADM "-F -a accept \$LETH -P $prot -S $host ftp-data -D \$LNET 1024:65535"
                    print $IPFWADM "-F -a accept \$INET -P $prot$ACK -D $host ftp-data -S \$LNET 1024:65535"
                    print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host ftp-data -S \$LNET 1024:65535"
	          }
	        }
	      }
	    }

          } else {

	    if {[regexp {([0-9:]+)/(tcp|udp|icmp)} $allowservice junk port prot]} {
	      # typed in by user

	      set ACK [pick {$prot == "tcp"} " \$ConnEstablished" ""]

	      if {$direction(index) == 0} {	# inbound (specified host is SOURCE)
                if {$prot == "icmp"} {
                  print "# Allow ICMP message $port traffic from Internet network/host $host to anyone on the local net"
                  print $IPFWADM "-I -a accept \$INET -P $prot -S $host $port -D \$INET_IP"
                  if {${isp@on_internet}} {
	            if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                      print $IPFWADM "-I -a accept \$INET -P $prot -S $host $port -D \$LNET"
                      print $IPFWADM "-F -a accept \$LETH -P $prot -S $host $port -D \$LNET"
                    }
                  }
                } else {
	          print "# allow Internet network/host $host to request $prot service on port $port from anyone on the local net"
                  print $IPFWADM "-I -a accept \$INET -P $prot -S $host -D \$INET_IP" $port
                  print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host -S \$INET_IP" $port
                  if {${isp@on_internet}} {
	            if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                      print $IPFWADM "-I -a accept \$INET -P $prot -S $host -D \$LNET" $port
                      print $IPFWADM "-F -a accept \$LETH -P $prot -S $host -D \$LNET" $port
                      print $IPFWADM "-F -a accept \$INET -P $prot$ACK -D $host -S \$LNET" $port
                      print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D $host -S \$LNET" $port
                    }
	          }
	        }
	      } else {				# outbound (specified host is DEST)
                if {$prot == "icmp"} {
	          print "# Allow anyone on the local net to send ICMP message $port traffic to Internet network/host $host"
                  print $IPFWADM "-O -a accept \$INET -P $prot -S \$INET_IP $port -D $host"
                  if {${isp@on_internet}} {
	            if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                      print $IPFWADM "-O -a accept \$INET -P $prot -S \$LNET $port -D $host"
                      print $IPFWADM "-F -a accept \$INET -P $prot -S \$LNET $port -D $host"
                    }
	          }
                } else {
	          print "# allow anyone on the local net to request $prot service on port $port from Internet network/host $host"
                  print $IPFWADM "-O -a accept \$INET -P $prot -S \$INET_IP -D $host" $port
                  print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$INET_IP -S $host" $port
                  if {${isp@on_internet}} {
		    if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                      print $IPFWADM "-O -a accept \$INET -P $prot -S \$LNET -D $host" $port
                      print $IPFWADM "-F -a accept \$INET -P $prot -S \$LNET -D $host" $port
                      print $IPFWADM "-F -a accept \$LETH -P $prot$ACK -D \$LNET -S $host" $port
                      print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D \$LNET -S $host" $port
                    }
	          }
	        }
	      }

            } else {
              print "# Syntax error on host $host: service \"$allowservice\" unparseable."
            }
	  }

          if {$fromfile != 0} {
            print "  done"
            print "fi"
            print
          }
        }
      }
    }
}
