# Partial list from http://www.iana.org/assignments/ethernet-numbers
my %Ethernet_Type_Name = (
           (ETH_TYPE_IP)        =>{NAME=>'IP', DECODER => \&Decode_IP},
           (ETH_TYPE_ARP)       =>{NAME=>'ARP', DECODER => \&Decode_ARP},
           (ETH_TYPE_APPLETALK) =>{NAME=>'APPLETALK', DECODER => 0},
            0x8035     =>{NAME=>'RARP', DECODER => \&Decode_ARP}, # (ETH_TYPE_RARP is NOT exported!!!)
           (ETH_TYPE_SNMP)      =>{NAME=>'SNMP', DECODER => 0},
           (ETH_TYPE_IPv6)      =>{NAME=>'IPv6', DECODER => 0},
           (ETH_TYPE_PPP)       =>{NAME=>'PPP' ,DECODER => 0}
           );
...snip ...

   if (&Dispach_Decoder_If_Any(\%Ethernet_Type_Name, $eth_obj->{type},
                                 $eth_obj,\$buf)){
        # Decoder call failed..
....snip ....

###############################################################
sub Dispach_Decoder_If_Any(){
    # Call the appropriate decoder, depending on pkt type
    my ($NameRef, $index, $Parent_obj, $bufref) = @_;
    my $Decode_Subroutine = $NameRef->{$index}{DECODER};
    if ($Decode_Subroutine){
       # Decoder for this proto has been specified !!, call it
       &$Decode_Subroutine($Parent_obj, $bufref);
       return 0; # Found the decoder & called it
     };
     
     return 1; # Did not find a decoder..
}