62 lines
1.6 KiB
Perl
62 lines
1.6 KiB
Perl
#!perl -w
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=head1 NAME
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noop_counter - disconnect after too many consecutive NOOPs, example plugin for the hook_noop()
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=head1 DESCRIPTION
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The B<noop_counter> counts the number of consecutive C<NOOP> commands given
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by a client and disconnects after a given number.
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Any other command than a C<NOOP> resets the counter.
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One argument may be given: the number of C<NOOP>s after which the client will
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be disconnected.
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=head1 NOTE
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This plugin should be loaded early to be able to reset the counter on any other
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command.
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=cut
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sub register {
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my ($self, $qp, @args) = @_;
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$self->{_noop_count} = 0;
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$self->{_max_noop} = 3;
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if ($args[0] && $args[0] =~ /^\d+$/) {
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$self->{_max_noop} = shift @args;
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}
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}
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sub hook_noop {
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my ($self, $transaction, @args) = @_;
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++$self->{_noop_count};
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### the following block is not used, RFC 2821 says we SHOULD ignore
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### any arguments... so we MAY return an error if we want to :-)
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# return DENY, "Syntax error, NOOP does not take any arguments"
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# if $args[0];
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if ($self->{_noop_count} >= $self->{_max_noop}) {
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return DENY_DISCONNECT, "Stop wasting my time, too many consecutive NOOPs";
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}
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return DECLINED;
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}
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sub reset_noop_counter {
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$_[0]->{_noop_count} = 0;
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return DECLINED;
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}
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# and bind the counter reset to the hooks, QUIT not useful here:
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*hook_helo = *hook_ehlo = # HELO / EHLO
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*hook_mail = # MAIL FROM:
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*hook_rcpt = # RCPT TO:
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*hook_data = # DATA
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*hook_reset_transaction = # RSET
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*hook_vrfy = # VRFY
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*hook_help = # HELP
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\&reset_noop_counter;
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