InfoMagic Internet Tools 1993 July/Internet Tools.iso/RockRidge/ip/dns/ddt2.0/cmd/mxc

Text File | 1993-05-24 | 4.7 KB | 202 lines

#! /usr/local/bin/perl
#
#  mxc - mail exchange (MX) checker
#
#  invoke as:
#    mxc [-l msglevel]
#
#  Copyright (C) 1992, 1993 PUUG - Grupo Portugues de Utilizadores
#                   do Sistema UNIX
#             1992, 1993 FCCN - Fundacao para o Desenvolvimento dos Meios
#                        Nacionais de Calculo Cientifico
#
#  Authors: Jorge Frazao de Oliveira <[e-mail]>
#        Artur Romao <[e-mail]>
#
#  This file is part of the DDT package, Version 2.0.
#
#  Permission to use, copy, modify, and distribute this software and its
#  documentation for any purpose and without any fee is hereby granted,
#  provided that the above copyright notice appear in all copies.  Neither
#  PUUG nor FCCN make any representations about the suitability of this
#  software for any purpose.  It is provided "as is" without express or
#  implied warranty.


# =()<push(@INC, "@<LIBDIR>@");>()=
push(@INC, "/usr/local/lib/ddt/cmd");

require "ddt.pl";


# scan the standard input
while (<STDIN>) {
    next if /^;/;            # ignore commented lines

    chop;                # strip record separator
    @Field = split(/\s+/, $_);    # break the input line

    if (/^\$ORIGIN/) {
        $Origin = $Field[2];    # set to a different origin

        next;
        }

    if (/^[*\.\-0-9A-Za-z]+/) {
        $Name = &make_name($Field[1], $Origin);
    }

    if (/\tIN\tSOA\t/) {
        $Zone = $Name;        # there's a new zone
    }
        elsif (/\tIN\tMX\t/) {
        # add a new MX RR to the list
        &new_MX($Zone, $Name, $Field[$#Field - 1], $Field[$#Field]);
        }
        elsif (/\tIN\tCNAME\t/) {
            $IsAlias{$Name} = 1;    # this name is an alias
        }
}

foreach $Zone (keys %MX) {
    &show_zone($Zone);
}

exit 0;


#
# examine each of the $zone's MX's, and print the anomalies
#
sub show_zone {
    local($zone) = @_;
    local(@MXlist, $name, $rest, @NMX);

        print " ### ", &toupper($zone), " ###";

    @MXlist = split($LISTsep, $MX{$zone});    # this is the list of
                        # the zone's MX's

        undef %NMX;    # or else it survives between calls

    while ($mx = shift(@MXlist)) {
        # get the values of the RR...
                ($name, $rest) = split($ELEMsep2, $mx);

        # ... and put them in the "private" list for this name
                $NMX{$name} = &add_list($NMX{$name}, $rest);
        }

        foreach $name (keys %NMX) {
                &check_MX($name, $NMX{$name});
        }

    print "\n";
}


#
# find out if there's anything wrong with the MX's for this $name
#
sub check_MX {
    local($name, $MXlist) = @_;
    local($mx, $str);
    local($weight, $pointer, *Xmx, *Amx, *MXarray);
    local($min_out, $s, $a, $e);

    $min_out = -1;
    @MXarray = split($LISTsep, $MXlist);

    # scan the records and get those pointing to external hosts
        foreach $mx ($[ .. $#MXarray) {
        ($weight, $pointer) = split($ELEMsep1, $MXarray[$mx]);

        if (!&is_below_cut($zone, $pointer)) {
                $str = sprintf("%s%-20s IN  MX %4d  %s",
                        $Lpad[4], $name, $weight, $pointer);

            push(@Xmx, $str);

            # find the value for the most preferable external host
                if (($min_out > $weight) || ($min_out < 0)) {
                $min_out = $weight
                }
        }
        }

        if ($#Xmx && $Level >= 4) {
        ($s, $a) = $#Xmx > 1 ? ("s", "") : ("", " an");

            print "\n$Lpad[4]MX record$s pointing to$a external host$s";

        foreach $str ($[ .. $#Xmx) {
            print shift(@Xmx);
        }
    }

    # get the internal hosts which are less preferred than external ones
        if ($min_out >= 0 && $Level >= 4) {
        foreach $mx ($[ .. $#MXarray) {
            ($weight, $pointer) = split($ELEMsep1, $MXarray[$mx]);

                if (&is_below_cut($zone, $pointer) &&
                    ($weight >= $min_out)) {
                $str = sprintf("%s%-20s IN  MX %4d  %s",
                                            $Lpad[4], $name,
                        $weight, $pointer);

                push(@Xmx, $str);
            }
        }

        if ($#Xmx) {
            $s = $#Xmx > 1 ? "s" : "";

            print "\n$Lpad[4]MX record$s to local or delegated host$s after MX records to external hosts";

                    foreach $str ($[ .. $#Xmx) {
                            print shift(@Xmx);
                    }
        }
    }

    if ($Level >= 2) {
        # get the MX RR's pointing to aliases
            foreach $mx ($[ .. $#MXarray) {
            ($weight, $pointer) = split($ELEMsep1, $MXarray[$mx]);

            if ($IsAlias{$pointer}) {
                $str = sprintf("%s%-20s IN  MX %4d  %s",
                    $Lpad[2], $name, $weight, $pointer);

                push(@Amx, $str);
            }
            }

        if ($#Amx) {
            ($s, $e, $a) = $#Amx > 1 ? ("s", "es", "") :
                           ("", "", " an");

            print "\n$Lpad[2]MX record$s pointing to$a alias$e";

            foreach $str ($[ .. $#Amx) {
                print shift(@Amx);
            }
        }
    }
}


#
# add ($name, $weight, $pointer) tupple to the list of MX record for this $zone
#
sub new_MX {
    local($zone, $name, $weight, $pointer) = @_;
    local($tuple);

    $tuple = join($ELEMsep2, $name, join($ELEMsep1, $weight, $pointer));

        $MX{$zone} = &add_list($MX{$zone}, $tuple);
}