NAME

       Net::SIP::StatelessProxy - Simple implementation of a stateless proxy

SYNOPSIS

       ..

DESCRIPTION

       This package implements a simple stateless SIP proxy.  Basic idea is that the proxy has either a single
       or two legs and that the packets are exchanged between those legs, e.g. packets incoming on one leg will
       be forwarded through the other leg.

       Because this is a stateless proxy no retransmits will be done by the proxy.

       If the proxy should work as a registrar too it should be put after a Net::SIP::Registrar in a
       Net::SIP::ReceiveChain.

       While forwarding the proxy will be insert itself into the packet, e.g. it will add Via and Record-Route
       header while forwarding requests.

       Additionally it will rewrite the Contact header while forwarding packets (see below), e.g. if the Contact
       header points to some client it will rewrite it, so that it points to the proxy and if it already points
       to the proxy it will rewrite it back so that it again points to the client.

CONSTRUCTOR

       new ( %ARGS )
           Creates a new stateless proxy. With %ARGS the behavior can be influenced:

           dispatcher
                   The Net::SIP::Dispatcher object managing the proxy.

           rewrite_contact
                   Callback  which  is  used  in  rewriting Contact headers.  If one puts user@host in it should
                   rewrite it and if one puts something without '@' it should try to rewrite it back (and return
                   () if it cannot rewrite it back).

                   A working default implementation is provided.   If  you  want  to  implement  your  own:  the
                   callbacks  gets the arguments contact, incoming_leg and outgoing_leg. For rewriting a contact
                   of user@host the  legs  will  be  Net::SIP::Leg  objects.  For  rewriting  the  contact  back
                   outgoing_leg can be either a leg object and you should check if it is the expected leg. Or it
                   is  a  scalar  reference  which you should fill with the leg extracted from the contact.  The
                   function should return the new contact or nothing if there was  nothing  to  rewrite  or  the
                   rewrite failed.

           rewrite_crypt
                   If  you  want  to  have  your  own  encryption for the rewritten contact you should defined a
                   subroutine here, which gets "data" as the first and "dir" as the second parameter and  should
                   return the de/encrypted data. If "dir" is +1 it should encrypt and on -1 it should decrypt.

                   If  not  defined, then RC4 will be used with a (pseudo)random key, 4 byte (pseudo)random seed
                   and 4 byte "checksum" (md5) over seed and data.

           nathelper
                   Optional Net::SIP::NATHelper::* object. When given it will be used to do  NAT,  e.g.  if  the
                   incoming  and outgoing legs are different it will rewrite the SDP bodies to use local sockets
                   and the nathelper will transfer the RTP data between the local and the original sockets.

           force_rewrite
                   Usually the contact header will only be rewritten, if  the  incoming  and  outgoing  leg  are
                   different. With this option one can force the rewrite, even if they are the same.

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.

           Called  from  the  dispatcher  on  incoming  packets.  The  packet  will  be  rewritten  ("Via"   and
           "Record-Route" headers added, Contact modified) and then the packet will be forwarded.

           For  requests  it  can  determine the target of the forwarded packet by looking at the route or if no
           route it looks at the URI. For responses it looks at the next Via header.

       do_nat ( PACKET, INCOMING_LEG, OUTGOING_LEG )
           This will be called from receive while forwarding data.  If nathelper is defined it will be  used  to
           rewrite SDP bodies and update nathelpers internal states to forward RTP data.

           Return values are like forward_outgoing in Net::SIP::Leg, e.g.  it will return "[code,text]" on error
           or  "()"  on success, where success can be that the packet was rewritten or that there was no need to
           touch it.

UNDOCUMENTED METHODS

       idside2hash

perl v5.18.2                                       2014-02-11                      Net::SIP::StatelessProxy(3pm)