51 lines
1.3 KiB
Perl
51 lines
1.3 KiB
Perl
# -*- perl -*-
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=head1 NAME
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count_unrecognized_commands - Count unrecognized commands and disconnect when we have too many
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=head1 DESCRIPTION
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Disconnect the client if it sends too many unrecognized commands.
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Good for rejecting spam sent through open HTTP proxies.
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=head1 CONFIGURATION
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Takes one parameter, the number of allowed unrecognized commands
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before we disconnect the client. Defaults to 4.
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=cut
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sub register {
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my ($self, $qp, @args) = @_;
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$self->register_hook("unrecognized_command", "check_unrec_cmd");
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if (@args > 0) {
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$self->{_unrec_cmd_max} = $args[0];
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$self->log(LOGWARN, "WARNING: Ignoring additional arguments.") if (@args > 1);
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} else {
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$self->{_unrec_cmd_max} = 4;
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}
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$qp->connection->notes('unrec_cmd_count', 0);
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}
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sub check_unrec_cmd {
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my ($self, $cmd) = @_[0,2];
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$self->log(LOGINFO, "Unrecognized command '$cmd'");
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my $badcmdcount =
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$self->qp->connection->notes('unrec_cmd_count',
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($self->qp->connection->notes('unrec_cmd_count') || 0) + 1
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);
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if ($badcmdcount >= $self->{_unrec_cmd_max}) {
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$self->log(LOGINFO, "Closing connection. Too many unrecognized commands.");
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return (DENY_DISCONNECT, "Closing connection. $badcmdcount unrecognized commands. Perhaps you should read RFC 2821?");
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}
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return DECLINED;
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}
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