NAME

Net::SIP::Util - utility functions used by all of Net::SIP

SYNOPSIS

use Net::SIP::Util qw( create_rtp_sockets );
my ($port,@socks) = create_rtp_sockets( '192.168.0.10' ) or die;

DESCRIPTION

This package implements various utility function used within various Net::SIP packages and partly usable for the user of Net::SIP too.

Each of this functions is exportable, but none is exported per default. All functions can be exported at once with the import flag :all.

SUBROUTINES

invoke_callback ( CALLBACK, @ARGS )

Invokes callback CALLBACK with additional args @ARGS. CALLBACK can be:

A code reference

In this case it will be called as $CALLBACK->(@ARGS) and return the return value of this call.

A reference to a scalar

In this case the scalar will be set to $ARGS[0] and the rest of @ARGS will be ignored. If no @ARGS are given the scalar will be set to TRUE. It will return with the value of the scalar.

An object which has a method run

In this case it will call $CALLBACK->run(@ARGS) and return with the return value of this call.

A reference to an array

The first element of the array will be interpreted as code reference, while the rest as args, e.g. it will do:

my ($coderef,@cb_args) = @$CALLBACK;
return $coderef->( @cb_args, @ARGS );

A regular expression

In this case it will try to match all @ARGS against the regex. If anything matches it will return TRUE, else FALSE.

create_socket_to ( ADDR, [ PROTO ] )

Creates socket with protocol PROTO (default 'udp') on a local interface, from where ADDR is reachable. This is done by first creating a UDP socket with target ADDR and using getsockname(2) to find out the local address of this socket. The newly created socket than will be bound to this address.

It will try to bind the socket to port 5060 (default SIP port). If this fails it will try port 5062..5100 and if it cannot bind to any of these ports it will just use any port which gets assigned by the OS.

For multihomed hosts where several addresses are bound to the same interface it will just use one of these addresses. If you need more control about the address the socket is bound to (and which will be used as the local IP in outgoing packets) you need to create the socket yourself.

In scalar context it just returns the newly created socket. In array context it will return the socket and the "ip:port" the created socket is bound to. If the creation of the socket fails it will return () and set $!.

Example:

my ($sock,$ip_port) = create_socket_to ( '192.168.0.1' )
  or die $!;

create_rtp_sockets ( LADDR, [ RANGE, MINPORT, MAXPORT, TRIES ] )

This tries to allocate sockets for RTP. RTP consists usually of a data socket on an even port number and a control socket (RTCP) and the following port. It will try to create these sockets. MINPORT is the minimal port number to use (default 2000), MAXPORT the highest port (default MINPORT+10000), TRIES is the number of attempts it makes to create such socket pairs and defaults to 1000.

RANGE is the number of consecutive ports it needs to allocate and defaults to 2 (e.g. data and control socket).

Allocation will be done by choosing a random even number between MINPORT and MAXPORT and then trying to allocate all the sockets on this and the following port numbers.

If the allocation fails after TRIES attempts were made it will return (), otherwise it will return an array with at first the starting port number followed by all the allocated sockets.

Example:

my ($port,$rtp_sock,$rtcp_sock) = create_rtp_sockets( '192.168.0.10' )
  or die "allocation failed";

sip_hdrval2parts ( KEY, VALUE )

Interprets VALUE as a value for the SIP header field KEY and splits it into the parts (prefix, parameter). Because for most keys the delimiter is ;, but for some keys , the field name KEY need to be known.

KEY needs to be normalized already (lower case, no abbrevation).

Returns array with initial data (up to first delimiter) and the parameters as hash.

Example for key 'to':

'"Silver; John" <silver@example.com>; tag=...; protocol=TCP'
-> ( '"Silver; John" <silver@example.com>', { tag => ..., protocol => 'TCP' } )

Example for key 'www-authenticate':

'Digest method="md5", qop="auth"'
-> ( 'Digest', { method => 'md5', qop => 'auth' } )

sip_parts2hdrval ( KEY, PREFIX, \%PARAMETER )

Inverse function to sip_hdrval2parts, e.g constructs header value for KEY from PREFIX and %PARAMETER and returns value.