qpsmtpd/plugins/count_unrecognized_commands
Ask Bjørn Hansen f27b77ae61 unrecognized_command hook and a count_unrecognized_commands
plugin. (Rasjid Wilcox)


git-svn-id: https://svn.perl.org/qpsmtpd/trunk@134 958fd67b-6ff1-0310-b445-bb7760255be9
2003-04-15 17:39:03 +00:00

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=head1 NAME
count_unrecognized_commands - Count unrecognized commands and disconnect when we have too many
=head1 DESCRIPTION
Disconnect the client if it sends too many unrecognized commands.
Good for rejecting spam sent through open HTTP proxies.
=head1 CONFIGURATION
Takes one parameter, the number of allowed unrecognized commands
before we disconnect the client. Defaults to 4.
=cut
sub register {
my ($self, $qp, @args) = @_;
$self->register_hook("unrecognized_command", "check_unrec_cmd");
if (@args > 0) {
$self->{_unrec_cmd_max} = $args[0];
$self->log(1, "WARNING: Ignoring additional arguments.") if (@args > 1);
} else {
$self->{_unrec_cmd_max} = 4;
}
$self->{_unrec_cmd_count} = 0;
}
sub check_unrec_cmd {
my ($self, $transaction, $cmd) = @_;
$self->log(5, "Unrecognized command '$cmd'");
$self->{_unrec_cmd_count}++;
my $badcmdcount = $self->{_unrec_cmd_count};
if ($badcmdcount >= $self->{_unrec_cmd_max}) {
$self->log(5, "Closing connection. Too many unrecognized commands.");
return (DENY, "Closing connection. $badcmdcount unrecognized commands. Perhaps you should read RFC 2821?");
}
return DECLINED;
}