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".