NAME

Net::SIP::Dropper::ByIPPort - drops SIP messages based on senders IP and port

SYNOPSIS

    use Net::SIP::Dropper::ByIPPort;
    my $drop_by_ipport = Net::SIP::Dropper::ByIPPort->new(
	database => '/path/to/database.drop',
	methods => [ 'REGISTER', '...', '' ],
	attempts => 10,
	interval => 60,
    );

    my $dropper = Net::SIP::Dropper->new( cb => $drop_by_ipport );
    my $chain = Net::SIP::ReceiveChain->new([ $dropper, ... ]);

DESCRIPTION

With Net::SIP::Dropper::ByIPPort one can drop packets, if too much packets are received from the same IP and port within a specific interval. This is to stop bad behaving clients.

CONSTRUCTOR

new ( ARGS )

ARGS is a hash with the following keys:

database

Optional file name of database or callback for storing/retrieving the data.

If it is a callback it will be called with $callback->(\%data) to retrieve the data (%data will be updated) and $callback->(\%data,true) to save the data. No return value will be expected from the callback.

%data contains the number of attempts from a specific IP, port at a specific time in the following format: $data{ip}{port}{time} = count

attempts

After how many attempts within the specific interval the packet will be dropped. Argument is required.

interval

The interval for attempts. Argument is required.

methods

Optional argument to restrict dropping to specific methods.

Is array reference of method names, if one of the names is empty also responses will be considered. If not given all packets will be checked.

METHODS

run ( PACKET, LEG, FROM )

This method is called as a callback from the Net::SIP::Dropper object. It returns true if the packet should be dropped, e.g. if there are too much packets from the same ip,port within the given interval.

expire

This method is called from within run but can also be called by hand. It will expire all entries which are outside of the interval.

savedb

This method is called from expire and run for saving to the database after changes, but can be called by hand to, useful if you made manual changes using the data method.

data

This method gives access to the internal hash which stores the attempts. An attempt from a specific IP and port and a specific time (as int, like time() gives) will be added to $self->data->{ip}{port}{time}.

By manually manipulating the hash one can restrict a specific IP,port forever (just set time to a large value and add a high number of attempts) or even restrict access for the whole IP (all ports) until time by using a port number of 0.

After changes to the data it is advised to call savedb.