### 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: allowlocalhost.template,v 2.16 1999-05-24 13:18:54-07 jhardin Exp $


proc allowlocalhosts {} {
    # Allow / Services (Per-Host, Local Hosts)

    Desc "Per-Local-Host Services Allowed"

    ShortDesc "Per-Local-Host Services Allowed"

    Header head1 -text "Per-Local-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."

    Label label4 -text "IP Forwarding support"\
            -textafter "compiled into the kernel."\
            -default "is"\
            -packFrame:anchor center \
            -help "Forwarding support must be compiled into the kernel if you wish to transfer"\
            "packets between the local network and the Internet. If it is not,"\
            "then you must configure and build a new kernel; see the Kernel HOWTO for"\
            "instructions."

    Label label5 -text "Masquerading"\
            -textafter "been enabled."\
            -default "has not"\
            -packFrame:anchor center \
            -help "If IP Masquerade is in use, then all local-net host controls must be configured in the"\
            "Masquerade screen."

    Label label6 -text "A local network"\
            -textafter "been detected."\
            -default "has not"\
            -packFrame:anchor center \
            -help "You must have a local network to control access permissions for computers on the local network..."

    Entry hostIP -text "Local Host"\
            -help "The name or unique IP address of a computer on the local network."\
            "\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 local hosts permitted to access the Internet without having to"\
            "regenerate the firewall script; simply edit the IP address file and re-run the"\
            "generated firewall script."

    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 Intenet."\
            "Outbound" "Service requests going out to host(s) on the Internet."\
            }

    Line line1

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

    ExtEntry allowedhosts -entries frame3 -count 5

    ShowPage {
      Enable allowedhosts
      global FirewallInKernel
      if {$FirewallInKernel == 0} {
        set label1 "is not"
        Disable allowedhosts
      } else {
        set label1 "is"
      }
      global ForwardInKernel
      if {$ForwardInKernel == 0} {
        set label4 "is not"
        Disable allowedhosts
      } else {
        set label4 "is"
      }
      if {${masq@masquerade} && ${isp@on_internet}} {
        set label5 "has"
        Disable allowedhosts
      } else {
        set label5 "has not"
      }
      global LocalNetIP
      if {$LocalNetIP == ""} {
        set label6 "has not"
        Disable allowedhosts
      } else {
        set label6 "has"
      }
    }

    Save {
      global IPFWADM
      global ISPPort
      global LocalNetIP
      global LocalNetMask
      global PERL
      global ParseIP
      global MatchService
      global MatchPort
      if {$IPFWADM == "" || $ISPPort == ""} {
        # nothing
      } else {
        if {${masq@masquerade} && ${isp@on_internet}} {
          print "# Masquerading is in use. Hosts on the local net will be controlled through"
          print "# the masquerade options."
        } else {
          if {$LocalNetIP == ""} {
            print "# No local network has been detected."
          } 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 local 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 local host rules from $hostIP."
                  print "# Install perl, then regenerate the firewall file."
                  # generate do-nothing rules
                  set host "0.0.0.0/32"
                }
              } else {
                set host "$hostIP/32"
              }

              set service $allowservice
              if {[regexp "$MatchPort" $service junk port junk prot]} {
                set ACK [pick {$prot == "tcp"} " \$ConnEstablished" ""]
                # if there's a description before or after the port spec, retrieve it.
                set descr ""
                if {![regexp "^(\[ A-Za-z0-9\\-_\]+)\[ \t\]+" $service junk descr]} {
                  # not before. try after.
                  regexp "\[ \t(\]+(\[ A-Za-z0-9\\-_\]+)" $service junk descr
                }
                if {$descr != ""} {
                  set descr " ($descr)"
                }

                if {$direction(index) == 0} {	# inbound (specified host is DEST)
                  if {$prot == "icmp"} {
                    print "# Allow ICMP message $port$descr to host $host from anyone on the Internet"
                    print $IPFWADM "-I -a accept \$INET -P $prot -S \$ANY $port -D $host"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-F -a accept \$LETH -P $prot -S \$ANY $port -D $host"
                        print $IPFWADM "-O -a accept \$LETH -P $prot -S \$ANY $port -D $host"
                      }
                    }
                  } else {
                    # TCP or UDP
                    print "# Allow host $host to receive $prot port $port$descr from anyone on the Internet"
                    print $IPFWADM "-I -a accept \$INET -P $prot -S \$ANY -D $host $port"
                    print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D \$ANY -S $host $port"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-F -a accept \$LETH -P $prot -S \$ANY -D $host $port"
                        print $IPFWADM "-O -a accept \$LETH -P $prot -S \$ANY -D $host $port"
                        print $IPFWADM "-I -a accept \$LETH -P $prot$ACK -D \$ANY -S $host $port"
                        print $IPFWADM "-F -a accept \$INET -P $prot$ACK -D \$ANY -S $host $port"
                      }
                    }
                  }
                } else {	# outbound (specified host is SOURCE)
                  if {$prot == "icmp"} {
                    print "# Allow anyone on the Internet to receive ICMP message $port$descr from local host $host"
                    print $IPFWADM "-O -a accept \$INET -P $prot -S $host $port -D \$ANY"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-I -a accept \$LETH -P $prot -S $host $port -D \$ANY"
                        print $IPFWADM "-F -a accept \$INET -P $prot -S $host $port -D \$ANY"
                      }
                    }
                  } else {
                    # TCP or UDP
                    print "# Allow anyone on the Internet to receive $prot port $port$descr from local host $host"
                    print $IPFWADM "-O -a accept \$INET -P $prot -S $host -D \$ANY $port"
                    print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D $host -S \$ANY $port"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-I -a accept \$LETH -P $prot -S $host -D \$ANY $port"
                        print $IPFWADM "-F -a accept \$INET -P $prot -S $host -D \$ANY $port"
                        print $IPFWADM "-F -a accept \$LETH -P $prot$ACK -D $host -S \$ANY $port"
                        print $IPFWADM "-O -a accept \$LETH -P $prot$ACK -D $host -S \$ANY $port"
                      }
                    }
                  }
                }

                if {$prot == "tcp" && $port == "21"} {
                  # ftp service...
                  # add special handling for ftp-data "reverse connection"
                  # with type-of-service adjustment for bulk data
                  print "#  The previous was an FTP control channel - permit the FTP data channel,"
                  print "#  with Type-of-Service set to bulk data"
                  if {$direction(index) == 0} {	# inbound (specified host is DEST)
                    print $IPFWADM "-O -a accept \$INET -P $prot -S $host 20 -D \$ANY 1025:65535 -t 0xE1 0x08"
                    print $IPFWADM "-I -a accept \$INET -P $prot$ACK -D $host 20 -S \$ANY 1025:65535 -t 0xE1 0x08"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-I -a accept \$LETH -P $prot -S $host 20 -D \$ANY 1025:65535 -t 0xE1 0x08"
                        print $IPFWADM "-F -a accept \$INET -P $prot -S $host 20 -D \$ANY 1025:65535"
                        print $IPFWADM "-F -a accept \$LETH -P $prot$ACK -D $host 20 -S \$ANY 1025:65535"
                        print $IPFWADM "-O -a accept \$LETH -P $prot$ACK -D $host 20 -S \$ANY 1025:65535"
                      }
                    }
                  } else {	# outbound (specified host is SOURCE)
                    print $IPFWADM "-I -a accept \$INET -P $prot -S \$ANY 20 -D $host 1025:65535 -t 0xE1 0x08"
                    print $IPFWADM "-O -a accept \$INET -P $prot$ACK -D \$ANY 20 -S $host 1025:65535 -t 0xE1 0x08"
                    if {${isp@on_internet}} {
                      if {$LocalNetIP != "" && ${masq@masquerade} == 0} {
                        print $IPFWADM "-F -a accept \$LETH -P $prot -S \$ANY 20 -D $host 1025:65535"
                        print $IPFWADM "-O -a accept \$LETH -P $prot -S \$ANY 20 -D $host 1025:65535"
                        print $IPFWADM "-I -a accept \$LETH -P $prot$ACK -D \$ANY 20 -S $host 1025:65535 -t 0xE1 0x08"
                        print $IPFWADM "-F -a accept \$INET -P $prot$ACK -D \$ANY 20 -S $host 1025:65535"
                      }
                    }
                  }
                }

              } else {
                print "# Syntax error on host $host: service \"$service\" unparseable."
                tk_dialog .warning "Warning" "Syntax error on host $host: service \"$service\" unparseable." info 0 OK
              }

              if {$fromfile != 0} {
                # finish up the shell script loop
                print "  done"
                print "fi"
                print
              }
            }
          }
        }
      }
    }
}  
