99fb59a7ff
spamassassin plugin. Add documentation to the spamassassin plugin. Add comments to the plugins config git-svn-id: https://svn.perl.org/qpsmtpd/trunk@103 958fd67b-6ff1-0310-b445-bb7760255be9
166 lines
4.3 KiB
Plaintext
166 lines
4.3 KiB
Plaintext
=head1 NAME
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spamassassin
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=head1 DESCRIPTION
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Plugin that checks if the mail is spam by using the "spamd" daemon
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from the SpamAssassin package. L<http://www.spamassassin.org>
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SpamAssassin 2.40 or newer is required.
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=head1 CONFIG
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Configured in the plugins file without any parameters, the
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spamassassin plugin will add relevant headers from the spamd
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(X-Spam-Status etc).
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The format goes like
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spamassassin option value [option value]
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Options being those listed below and the values being parameters to
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the options. Confused yet? :-)
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=over 4
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=item reject_threshold [threshold]
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Set the threshold over which the plugin will reject the mail. Some
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mail servers are so useless that they ignore 55x responses not coming
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after RCPT TO, so they might just keep retrying and retrying and
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retrying until the mail expires from their queue.
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I like to configure this with 15 or 20 as the threshold.
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The default is to never reject mail based on the SpamAssassin score.
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=item munge_subject_threshold [threshold]
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Set the threshold over which we will prefix the subject with
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'***SPAM***'. A messed up subject is easier to filter on than the
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other headers for many people with not so clever mail clients. You
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might want to make another plugin that does this on a per user basis.
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The default is to never munge the subject based on the SpamAssassin score.
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=back
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With both options the configuration line will look like the following
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spamasssasin reject_threshold 18 munge_subject_threshold 8
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=cut
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use Socket qw(:DEFAULT :crlf);
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use IO::Handle;
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sub register {
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my ($self, $qp, @args) = @_;
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$self->register_hook("data_post", "check_spam");
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$self->log(0, "Bad parameters for the spamassassin plugin")
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if @_ % 2;
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%{$self->{_args}} = @args;
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$self->register_hook("data_post", "check_spam_reject")
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if $self->{_args}->{reject_threshold};
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$self->register_hook("data_post", "check_spam_munge_subject")
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if $self->{_args}->{munge_subject_threshold};
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}
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sub check_spam {
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my ($self, $transaction) = @_;
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return (DECLINED) if $transaction->body_size > 500_000;
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my $remote = 'localhost';
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my $port = 783;
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if ($port =~ /\D/) { $port = getservbyname($port, 'tcp') }
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die "No port" unless $port;
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my $iaddr = inet_aton($remote) or
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$self->log(1, "Could not resolve host: $remote") and return (DECLINED);
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my $paddr = sockaddr_in($port, $iaddr);
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my $proto = getprotobyname('tcp');
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socket(SPAMD, PF_INET, SOCK_STREAM, $proto)
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or $self->log(1, "Could not open socket: $!") and return (DECLINED);
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connect(SPAMD, $paddr)
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or $self->log(1, "Could not connect to spamassassin daemon: $!") and return DECLINED;
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SPAMD->autoflush(1);
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$transaction->body_resetpos;
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print SPAMD "REPORT_IFSPAM SPAMC/1.0" . CRLF;
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# or CHECK or REPORT or SYMBOLS
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print SPAMD join CRLF, split /\n/, $transaction->header->as_string
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or warn "Could not print to spamd: $!";
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print SPAMD CRLF
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or warn "Could not print to spamd: $!";
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while (my $line = $transaction->body_getline) {
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chomp $line;
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print SPAMD $line, CRLF
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or warn "Could not print to spamd: $!";
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}
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print SPAMD CRLF;
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shutdown(SPAMD, 1);
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my $line0 = <SPAMD>; # get the first protocol lines out
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if ($line0) {
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$transaction->header->add("X-Spam-Check-By", $self->qp->config('me'));
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}
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while (<SPAMD>) {
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#warn "GOT FROM SPAMD1: $_";
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next unless m/\S/;
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s/\r?\n$/\n/;
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my @h = split /: /, $_, 2;
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$transaction->header->add(@h);
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last if $h[0] eq "Spam" and $h[1] =~ m/^False/;
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}
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return (DECLINED);
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}
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sub check_spam_reject {
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my ($self, $transaction) = @_;
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my $score = $self->get_spam_score($transaction) or return DECLINED;
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return (DENY, "spam score exceeded threshold")
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if $score >= $self->{_args}->{reject_threshold};
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return DECLINED;
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}
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sub check_spam_munge_subject {
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my ($self, $transaction) = @_;
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my $score = $self->get_spam_score($transaction) or return DECLINED;
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return DECLINED unless $score >= $self->{_args}->{munge_subject_threshold};
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my $subject = $transaction->header->get('Subject') || '';
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$transaction->header->replace('Subject', "***SPAM*** $subject");
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return DECLINED;
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}
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sub get_spam_score {
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my ($self, $transaction) = @_;
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my $status = $transaction->header->get('X-Spam-Status') or return;
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my ($score) = ($status =~ m/hits=(\d+\.\d+)/)[0];
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return $score;
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}
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