Complete rewrite.

- use strict;
- modularize code
- refactor application logic
- more verbose output
- test MXes in order of precedence
- cope with multi-line responses
- slightly change meaning of exit status
- batch processing: set exit status to highest generated value

Fixes #9.
Fixes #10.

Signed-off-by: Thomas Hochstein <thh@inter.net>
This commit is contained in:
Thomas Hochstein 2010-06-16 16:38:06 +02:00
parent dd6d3ea1aa
commit 431fbb1233

View file

@ -1,224 +1,337 @@
#!/usr/bin/perl -w #! /usr/bin/perl -W
# #
# checkmail.pl # checkmail Version 0.3 by Thomas Hochstein
##############
# (c) 2002-2005 Thomas Hochstein <thh@inter.net>
# #
# This program is free software; you can redistribute it and/or modify it under # This script tries to verify the deliverability of (a) mail address(es).
# 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) # Copyright (c) 2002-2010 Thomas Hochstein <thh@inter.net>
# any later version. #
# This program is distributed in the hope that it will be useful, but WITHOUT # It can be redistributed and/or modified under the same terms under
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or # which Perl itself is published.
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
# more details.
# Versionsnummer ###################### our $VERSION = "0.3";
$ver = '0.2 beta (20050803)';
# Modules ############################# ################################# Configuration ################################
# Please fill in a working configuration!
my %config=(
# value used for HELO/EHLO - a valid hostname you own
helo => 'testhost.domain.example',
# value used for MAIL FROM: - a valid address under your control
from => 'mailtest@testhost.domain.example',
# a syntactically valid "random" - reliably not existing - localpart
rand => 'ZOq62fow1i'
);
################################### Modules ####################################
use strict;
use File::Basename;
use Getopt::Std; use Getopt::Std;
use Net::DNS; use Net::DNS;
use Net::SMTP; use Net::SMTP;
# Konfiguration ####################### ################################# Main program #################################
# Hier passende Werte einsetzen! #
#######################################
%config=();
# HELO-/EHLO-Parameter - a valid hostname you own
$config{'helo'} = 'testhost.domain.example';
# MAIL FROM:-Parameter - a valid address you control
$config{'from'} = 'mailtest@testhost.domain.example';
# Zufaelliger Localpart fuer -r - a valid random localpart
$config{'rand'} = 'ZOq62fow1i';
################################################################ $Getopt::Std::STANDARD_HELP_VERSION = 1;
# Hauptprogramm ####################### my $myself = basename($0);
# Konfiguration einlesen # read commandline options
my %options; my %options;
getopts('hqlrf:m:', \%options); getopts('Vhqlrf:m:', \%options);
if ($options{'h'} or (!$options{'f'} and !$ARGV[0])) { # -V: display version
print "$0 v $ver\nUsage: $0 [-hqlr] [-m <host>] -f <file>|<address>\n"; if ($options{'V'}) {
print "Options: -h display this notice\n"; print "$myself v $VERSION\nCopyright (c) 2010 Thomas Hochstein <thh\@inter.net>\n";
print " -q quiet (no output, just exit with 0/1/2/3)\n"; print "This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself.\n";
print " -l extended logging\n"; exit(100);
print " -r test random address to verify verification\n";
print " -m <host> no DNS lookup, just test this host\n";
print " -f <file> parse file (one address per line)\n";
print " <address> mail address to check\n\n";
exit(100);
}; };
# -h: feed myself to perldoc
if ($options{'h'}) {
exec('perldoc', $0);
exit(100);
};
# display usage information if neither -f nor an address are present
if (!$options{'f'} and !$ARGV[0]) {
print "Usage: $myself [-hqlr] [-m <host>] <address>|-f <file>\n";
print "Options: -V display copyright and version\n";
print " -h show documentation\n";
print " -q quiet (no output, just exit with 0/1/2/3)\n";
print " -l extended logging\n";
print " -r test random address to verify verification\n";
print " -m <host> no DNS lookup, just test this host\n";
print " <address> mail address to check\n\n";
print " -f <file> parse file (one address per line)\n";
exit(100);
};
# -f: open file and read addresses to @adresses
my @addresses;
if ($options{'f'}) { if ($options{'f'}) {
if (-e $options{'f'}) { if (-e $options{'f'}) {
open FILE, "<$options{'f'}" or die("ERROR: Could not open file $options{'f'} for reading: $!"); open FILE, "<$options{'f'}" or die("$myself ERROR: Could not open file $options{'f'} for reading: $!");
} else { } else {
die("ERROR: File $options{'f'} does not exist!\n"); die("$myself ERROR: File $options{'f'} does not exist!\n");
}; };
$log = '';
while(<FILE>) { while(<FILE>) {
chomp; chomp;
($status,$log) = checkdns($_,$log); push(@addresses,$_);
}; };
close FILE; close FILE;
# force exit(0) # fill @adresses with single address to check
$status = 0; } else {
} else { push(@addresses,$ARGV[0]);
($status,$log) = checkdns($ARGV[0]); };
# loop over each address and test it
my (%targets,$curstat,$status,$log,$message);
foreach (@addresses) {
my $address = $_;
(undef,my $domain) = splitaddress($address);
printf(" * Testing %s ...\n",$address) if !($options{'q'});
$log .= "\n===== BEGIN $address =====\n";
# get list of target hosts or take host forced via -m
if (!$options{'m'}) {
%targets = %{gettargets($domain,\$log)};
} else {
$message = sprintf("Connection to %s forced by -m.\n",$options{'m'});
$log .= $message;
print " $message" if !($options{'q'});
# just one target host with preference 0
$targets{$options{'m'}} = 0;
};
if (%targets) {
$curstat = checkaddress($address,\%targets,\$log);
} else {
$curstat = 2;
$message = 'DNS lookup failure';
printf(" > Address is INVALID (%s).\n",$message) if !($options{'q'});
$log .= $message . '.';
};
$log .= "====== END $address ======\n";
$status = $curstat if (!defined($status) or $curstat > $status);
}; };
print $log if ($options{'l'}); print $log if ($options{'l'});
# status 0: valid / batch processing # status 0: valid / batch processing
# 1: invalid # 1: connection failed or temporary failure
# 2: cannot verify # 2: invalid
# 3: temporary (?) failure # 3: cannot verify
#D print "\n-> EXIT $status\n";
exit($status); exit($status);
################################################################ ################################## gettargets ##################################
# Subroutinen ######################### # get mail exchanger(s) or A record(s) for a domain
# IN : $domain: domain to query the DNS for
# OUT: \%targets: reference to a hash containing a list of target hosts
sub gettargets {
my ($domain,$logr) = @_;
# resolver objekt
my $resolver = Net::DNS::Resolver->new(udp_timeout => 15, tcp_timeout => 15);
sub checkdns { my %targets;
# - fester Host angegeben (-m)? # get MX record(s) as a list sorted by preference
# - sonst: MX-Record ermitteln if (my @mxrr = mx($resolver,$domain)) {
# - bei Verbindungsproblemen naechsten MX versuchen print_dns_result($domain,'MX',scalar(@mxrr),undef,$logr);
# - falls kein MX vorhanden, Fallback auf A foreach my $rr (@mxrr) {
# -> jeweils Adresse testen via checksmtp() $targets{$rr->exchange} = $rr->preference;
my ($address,$logging) = @_; $$logr .= sprintf("(%d) %s\n",$rr->preference,$rr->exchange);
my ($rr,$mailhost,$status,@mx);
my $dnsresult = 'okay';
# (my $lp = $address) =~ s/^([^@]+)@.*/$1/;
(my $domain = $address) =~ s/[^@]+\@(\S*)$/$1/;
$logging .= "\n----- BEGIN $address -----\n";
# DNS-Lookup unterdrueckt?
if ($options{'m'}) {
print " Connection to $options{'m'} forced by -m.\n";
$logging .= "Connection to $options{'m'} forced by -m.\n";
($status,$logging) = checksmtp($options{'m'},$address,$domain,$logging);
$logging .= "----- END $address -----\n";
return ($status,$logging);
};
# Resolver-Objekt
$resolve = Net::DNS::Resolver -> new();
$resolve->usevc(1);
$resolve->tcp_timeout(15);
# MX-Record feststellen
@mx = mx($resolve,$domain) or $dnsresult = $resolve->errorstring;
print " $domain (MX: $dnsresult)\n" if !($options{'q'});
if (@mx) {
WALKMX: foreach $rr (@mx) {
$mailhost = $rr->exchange;
print " MX: $mailhost / $address\n" if !($options{'q'});
$logging .= "Try MX: $mailhost\n";
($status,$logging) = checksmtp($mailhost,$address,$domain,$logging);
last WALKMX if ($status < 3);
};
} elsif ($dnsresult eq 'NXDOMAIN' or $dnsresult eq 'NOERROR' or $dnsresult eq 'REFUSED') {
# wenn kein MX-Record: A-Record feststellen
$logging .= "MX error: $dnsresult\n";
$dnsresult = 'okay';
$query = $resolve->search($domain) or $dnsresult = $resolve->errorstring;
print " $domain (A: $dnsresult)\n" if !($options{'q'});
if ($query) {
foreach $rr ($query->answer) {
next unless $rr->type eq "A";
$mailhost = $rr->address;
print " A: $mailhost / $address\n" if !($options{'q'});
$logging .= "Try A: $mailhost\n";
($status,$logging) = checksmtp($mailhost,$address,$domain,$logging);
};
} elsif ($dnsresult eq 'NXDOMAIN' or $dnsresult eq 'NOERROR' or $dnsresult eq 'REFUSED') {
# wenn auch kein A-Record: what a pity ...
print " > NO DNS-RECORD (MX/A) FOUND.\n" if !($options{'q'});
$logging .= "A error: $dnsresult\n";
$status = 1;
};
};
$logging .= "----- END $address -----\n";
return ($status,$logging);
};
sub checksmtp {
# - zu $mailhost verbinden, $adresse testen (SMTP-Dialog bis RCPT TO)
# - ggf. (-r) testen, ob sicher ungueltige Adresse abgelehnt oder
# alles angenommen wird
my($mailhost,$address,$domain,$logging)=@_;
my($smtp,$status,$valid);
$logging .= "-------------------------\n";
CONNECT: if ($smtp = Net::SMTP->new($mailhost,Hello => $config{'helo'},Timeout => 30)) {
$logging .= $smtp->banner;
$logging .= "EHLO $config{'helo'}\n";
$logging .= parse_reply($smtp->code,$smtp->message);
$smtp->mail($config{'from'});
$logging .= "MAIL FROM:<$config{'from'}>\n";
$logging .= parse_reply($smtp->code,$smtp->message);
# wird RCPT TO akzeptiert?
$valid = $smtp->to($address);
$logging .= "RCPT TO:<$address>\n";
if ($smtp->code > 0) {
# es kam eine Antwort auf RCPT TO
$logging .= parse_reply($smtp->code,$smtp->message);
if ($valid) {
# RCPT TO akzeptiert
$status = 0;
if ($options{'r'}) {
# werden sicher ungueltige Adressen abgewiesen?
$valid = $smtp->to($config{'rand'}.'@'.$domain);
$logging .= 'RCPT TO:<'.$config{'rand'}.'@'.$domain.">\n";
if ($smtp->code > 0) {
# es kam eine Antwort auf RCPT TO (fuer $rand)
$logging .= parse_reply($smtp->code,$smtp->message);
if ($valid) {
# ungueltiges RCPT TO akzeptiert
print " > Sorry, cannot verify. You'll have to send a testmail ...\n" if !($options{'q'});
$status = 2;
};
} else {
# Timeout nach RCPT TO (fuer $rand)
print " > Temporary failure.\n" if !($options{'q'});
$logging .= "---Timeout---\n";
$smtp->quit;
$status = 3;
};
}; };
print " > Address is valid.\n" if (!$status and !$options{'q'}); # no MX record found; log and try A record(s)
} else {
# RCPT TO nicht akzeptiert
print " > Address is INVALID.\n" if !($options{'q'});
$status = 1;
};
# Verbindung beenden
$smtp->quit;
$logging .= "QUIT\n";
$logging .= parse_reply($smtp->code,$smtp->message);
} else { } else {
# Timeout nach RCPT TO print_dns_result($domain,'MX',undef,$resolver->errorstring,$logr);
print " > Temporary failure.\n" if !($options{'q'}); print(" Falling back to A record ...\n") if !($options{'q'});
$logging .= "---Timeout---\n"; # get A record(s)
$smtp->quit; if (my $query = $resolver->query($domain,'A','IN')) {
$status = 3; print_dns_result($domain,'A',$query->header->ancount,undef,$logr);
foreach my $rr ($query->answer) {
$targets{$rr->address} = 0;
$$logr .= sprintf("- %s\n",$rr->address);
};
# no A record found either; log and fail
} else {
print_dns_result($domain,'A',undef,$resolver->errorstring,$logr);
printf(" %s has neither MX nor A records - mail cannot be delivered.\n",$domain) if !($options{'q'});
};
}; };
} else { return \%targets;
# Verbindung fehlgeschlagen
print " > Temporary failure.\n" if !($options{'q'});
$logging .= "---Timeout---\n";
$status = 3;
};
return ($status,$logging);
}; };
sub parse_reply { ################################# checkaddress #################################
my($code,$message)=@_; # test address for deliverability
my($reply); # IN : $address: adress to be tested
$reply = $code . ' ' . $message; # \%targets: reference to a hash containing a list of MX hosts
return $reply; # \$log : reference to the log (to be printed out via -l)
# OUT: ---
# \$log will be changed
sub checkaddress {
my ($address,$targetsr,$logr) = @_;
my %targets = %{$targetsr};
my $status;
# walk %targets in order of preference
foreach my $host (sort { $targets{$a} <=> $targets{$b} } keys %targets) {
printf(" / Trying %s (%s) with %s\n",$host,$targets{$host} || 'A',$address) if !($options{'q'});
$$logr .= sprintf("%s:\n%s\n",$host,"-" x (length($host)+1));
$status = checksmtp($address,$host,$logr);
last if ($status != 1);
};
return $status;
};
################################### checksmtp ##################################
# connect to a remote machine on port 25 and test deliverability of a mail
# address by doing the SMTP dialog until RCPT TO stage
# IN : $address: address to test
# $target : target host
# \$log : reference to the log (to be printed out via -l)
# OUT: .........: reference to a hash containing a list of target hosts
# \$log will be changed
sub checksmtp {
my ($address,$target,$logr) = @_;
my ($status);
# start SMTP connection
if (my $smtp = Net::SMTP->new($target,Hello => $config{'helo'},Timeout => 30)) {
$$logr .= $smtp->banner; # Net::SMTP doesn't seem to support multiline greetings.
$$logr .= "EHLO $config{'helo'}\n";
log_smtp_reply($logr,$smtp->code,$smtp->message);
$smtp->mail($config{'from'});
$$logr .= "MAIL FROM:<$config{'from'}>\n";
log_smtp_reply($logr,$smtp->code,$smtp->message);
# test address
my ($success,$code,@message) = try_rcpt_to(\$smtp,$address,$logr);
# connection failure?
if ($success < 0) {
$status = connection_failed();
# delivery attempt was successful?
} elsif ($success) {
# -r: try random address (which should be guaranteed to be invalid)
if ($options{'r'}) {
(undef,my $domain) = splitaddress($address);
my ($success,$code,@message) = try_rcpt_to(\$smtp,$config{'rand'}.'@'.$domain,$logr);
# connection failure?
if ($success < 0) {
$status = connection_failed();
# verification impossible?
} elsif ($success) {
$status = 3;
print " > Address verificaton impossible. You'll have to send a test mail ...\n" if !($options{'q'});
}
}
# if -r is not set or status was not set to 3: valid address
if (!defined($status)) {
$status = 0;
print " > Address is valid.\n" if !($options{'q'});
};
# delivery attempt failed?
} else {
$status = 2;
print " > Address is INVALID:\n" if !($options{'q'});
print ' ' . join(' ',@message) if !($options{'q'});
}
# terminate SMTP connection
$smtp->quit;
$$logr .= "QUIT\n";
log_smtp_reply($logr,$smtp->code,$smtp->message);
} else {
# SMTP connection failed / timeout
$status = connection_failed();
$$logr .= "---Connection failure---\n";
};
return $status;
} }
################################# splitaddress #################################
# split mail address into local and domain part
# IN : $address: a mail address
# OUT: $local : local part
# $domain: domain part
sub splitaddress {
my($address)=@_;
(my $lp = $address) =~ s/^([^@]+)@.*/$1/;
(my $domain = $address) =~ s/[^@]+\@(\S*)$/$1/;
return ($lp,$domain);
};
################################ parse_dns_reply ###############################
# parse DNS response codes and return code and description
# IN : $response: a DNS response code
# OUT: "$response ($desciption)"
sub parse_dns_reply {
my($response)=@_;
my %dnsrespcodes = (NOERROR => 'empty response',
NXDOMAIN => 'non-existent domain',
SERVFAIL => 'DNS server failure',
REFUSED => 'DNS query refused',
FORMERR => 'format error',
NOTIMP => 'not implemented');
if(defined($dnsrespcodes{$response})) {
return sprintf('%s (%s)',$response,$dnsrespcodes{$response});
} else {
return $response;
};
};
############################### print_dns_result ###############################
# print and log result of DNS query
# IN : $domain: domain the DNS was queried for
# $type : record type (MX, A, ...)
# $count : number of records found
# $error : DNS response code
# \$log : reference to the log (to be printed out via -l)
# OUT: ---
# \$log will be changed
sub print_dns_result {
my ($domain,$type,$count,$error,$logr) = @_;
if (defined($count)) {
printf(" %d %s record(s) found for %s\n",$count,$type,$domain) if !($options{'q'});
$$logr .= sprintf("%s DNS record(s):\n",$type);
} else {
printf(" No %s records found for %s: %s\n",$type,$domain,parse_dns_reply($error)) if !($options{'q'});
$$logr .= sprintf("No %s records found: %s\n",$type,parse_dns_reply($error));
};
return;
};
################################## try_rcpt_to #################################
# send RCPT TO and return replies
# IN : \$smtp : a reference to an SMTP object
# $recipient: a mail address
# \$log : reference to the log (to be printed out via -l)
# OUT: $success: true or false
# $code : SMTP status code
# $message: SMTP status message
# \$log will be changed
sub try_rcpt_to {
my($smtpr,$recipient,$logr)=@_;
$$logr .= sprintf("RCPT TO:<%s>\n",$recipient);
my $success = $$smtpr->to($recipient);
if ($$smtpr->code) {
log_smtp_reply($logr,$$smtpr->code,$$smtpr->message);
} else {
$success = -1;
$$logr .= "---Connection failure---\n";
};
return ($success,$$smtpr->code,$$smtpr->message);
};
################################ log_smtp_reply ################################
# log result of SMTP command
# IN : \$log : reference to the log (to be printed out via -l)
# $code : SMTP status code
# @message : SMTP status message
# OUT: ---
# \$log will be changed
sub log_smtp_reply {
my($logr,$code,@message)=@_;
$$logr .= sprintf('%s %s',$code,join('- ',@message));
return;
}
############################## connection_failed ###############################
# print failure message and return status 1
# OUT: 1
sub connection_failed {
print " > Connection failure.\n" if !($options{'q'});
return 1;
}