NAME

Net::SIP::Packet - handling of SIP packets

SYNOPSIS

  use Net::SIP::Packet;
  use Net::SIP::Request;
  use Net::SIP::Response;
  my $pkt = eval { Net::SIP::Packet->new( $sip_string ) }
    or die "invalid SIP packet";
  $pkt->get_header( 'call-id' ) || die "no call-id";
  $pkt->set_header( via => \@via );
  print $pkt->as_string;

DESCRIPTION

This module implements the parsing, manipulation and creation of SIP packets according to RFC3261.

NET::SIP::Packet's objects can be created by parsing a string containing the SIP packet or by constructing it from parts, e.g. header keys and values, body, method+URI (requests) or code+text (responses).

All parts can be manipulated and finally the string representation of the manipulated packet can be (re)created.

For dealing with requests and responses directly usually the subclasses Net::SIP::Request or Net::SIP::Response will be used instead.

EXAMPLES

  # create packet from string
  my $invite = Net::SIP::Packet->new(  <<'EOS' );
  INVITE sip:you@example.com SIP/2.0
  From: <sip:me@example.com>
  To: <sip:you@example.com>
  ...
  EOS
  # show and manipulate some header
  print "callid=".$invite->get_header( 'call-id' )."\n";
  print "route=".join( ",", $invite->get_header( 'route' ))."\n";
  $invite->set_header( 'via' => [ $via1,$via2,.. ] );
  # get resulting string representation
  print $invite->as_string;
  # create packet from parts
  my $resp = Net::SIP::Packet->new(
        200, 'Ok',
        { to => '<sip:you@example.com>', from => '<sip:me@example.com>',.. }
        Net::SIP::SDP->new(...)
  );
  # and get the packet as string
  print $resp->as_string;

CONSTRUCTOR

new ( STRING | @PARTS | HASH )

This is the default constructor. Depending on the number of arguments branches into new_from_string or new_from_parts or just creates the object directly from the given HASH.

new_from_string ( STRING )

Interprets STRING as a SIP request or response and creates Net::SIP::Request or Net::SIP::Response object accordingly (these classes must have been loaded already). Will die() if it cannot parse the string as a SIP packet.

new_from_parts ( CODE|METHOD, TEXT|URI, \%HEADER|\@HEADER, [ BODY ] )

If CODE|METHOD is numeric a Net::SIP::Response object will be created with the response code CODE and the text TEXT. Otherwise a Net::SIP::Request object will be created with the method METHOD and the uri URI. Note that the Request or Response class need to be loaded already.

Header data can be given as a hash %HEADER or array @HEADER reference. In case of a hash the key is the SIP field name and the value as either a string or a \@list of strings. The fields on the resulting SIP packet will be sorted by name of the fields and fields with multiple values will be created as seperat lines.

If the header is given as an array the elements of the array are "[ key => value ]" pairs where the keys are the field names and the values are strings or \@list of strings. Each pair will result in a single line in the SIP header. If the value was a list reference the values in the list will be concatened by ','. The order of the fields in the resulting SIP packet will be the same as in the array.

The BODY is optional and can be given either as a string or as an reference to an object which has a method as_string, like Net::SIP::SDP. If the BODY is an object which has a method content_type it will set the "content-type" header of the SIP object based on the result of "BODY->content_type" unless a "content-type" header was explicitly given.

_new_request | _new_response

These work like "new" but assign the new object to the subclasses "Net::SIP::Request" resp. "Net::SIP:.Response". They are not intended to be used directly but only for redefining for using different subclasses when subclassing "Net::SIP::Packet".

METHODS

is_request

Returns TRUE if the SIP packet is a request, otherwise FALSE.

is_response

Returns TRUE if the SIP packet is a response, otherwise FALSE.

tid

Returns a transaction ID created from the sequence number in the "CSeq" header and the "Call-Id" header. All packets with the same tid belong to the same transaction.

cseq

Returns "CSeq" header. Short for "$self->get_header( 'cseq' )".

callid

Returns "Call-Id" header. Short for "$self->get_header( 'call-id' )".

get_header ( [ NAME ] )

If NAME is given it returns the SIP header for NAME. If no header exists returns (). If there is only one value for the header returns this value. In case of multiple values it returns a @list of all values, but if "wantarray" says, that the caller expects only a single value it will croak().

If no NAME is given it will return a reference to a hash which contains all fields and has the format described in new_from_parts.

add_header ( NAME, VAL )

Adds the header at the end of the SIP header. VAL can be a string or a reference to a list of strings.

insert_header ( NAME, VAL )

Like add_header, but the lines will be added on top of the header.

del_header ( NAME )

Delete all lines from header where the field name is NAME.

set_header ( NAME, VAL )

Replaces an existing header, like del_header followed by add_header.

set_body ( VAL )

Sets body to VAL, which can be string or object. The handling for body objects see new_from_parts.

as_string

Returns string representation of SIP packet.

dump ( [ LEVEL ] )

Returns dump of packet as string for debugging. The higher LEVEL is the more details one gets. At the moment a LEVEL of 0 gets a one-line summary and the rest the result from as_string.

as_parts

Returns Array with CODE|METHOD, TEXT|URI, \@HEADER and BODY like used in new_from_parts.

sdp_body( [ SDP ] )

Returns body as Net::SIP::SDP object if there is a body and the content-type is 'application/sdp' or empty. Will also find 'application/sdp' inside a 'multipart/mixed' body.

If body contains invalid SDP it raises an exception (e.g. die()).

If the optional SDP argument is given, it is expected to be a Net::SIP::SDP object. This will be converted into a string and will replace an existing body (also inside multipart/mixed, leaving the rest untouched) or set a new body if none existed before.