NAME

       Net::SIP::ReceiveChain - handle incoming packet by multiple receivers

SYNOPSIS

         # create proxy which works as a registrar too, but
         # all register requests should be authorized

         my $registrar = Net::SIP::Registrar->new...
         my $auth = Net::SIP::Authorize->new ....
         my $reg_chain = Net::SIP::ReceiveChain->new(
               [ $auth,$registrar ],
               methods => [ 'REGISTER' ],
         );

         my $proxy = Net::SIP::StatelessProxy->new...
         my $chain = Net::SIP::ReceiveChain->new(
               [ $registrar,$proxy ]
         );

DESCRIPTION

       This package is used to handle incoming packets by multiple receivers, e.g. make sure that
       requests for Net::SIP::Registrar will be authorized by Net::SIP::Authorize.

       Objects in the chain might be Net::SIP::Registrar, Net::SIP::StatelessProxy,
       Net::SIP::Authorize, Net::SIP::ReceiveChain itself and every other object which handles
       "receive" like described below.

CONSTRUCTOR

       new ( OBJECTS, %ARGS )
           This creates a new registar object, OBJECTS is a reference to an array of objects
           implementing the "receive" method.

           %ARGS can have the following keys:

           filter  A callback which gets called during "receive" with all arguments of the
                   method. If it returns TRUE the packet will be handled by the chain, otherwise
                   not.

           methods If filter is not given but methods is it will set filter to a callback which
                   accepts only the methods specified in the array reference given to methods.

METHODS

       receive ( PACKET,LEG,FROM )
           PACKET is the incoming packet, LEG is the Net::SIP::Leg where the packet arrived and
           FROM is the "ip:port" of the sender. Responses will be send back to the sender through
           the same leg.

           Called from the managing Net::SIP::Dispatcher object if a new packet arrives.

           Returns TRUE if the packet was fully handled by one of the objects in the chain, else
           FALSE:

           •       If a filter was given checks the packet against the filter and returns FALSE
                   if the filter does return FALSE.

           •       Otherwise it will call "receive" on all objects in the chain until one of
                   these returns TRUE. In this case it will return TRUE.

           •       If no object in the chain handled the packet it will return FALSE.