* Copyright (C) 2005 iptelorg GmbH
* This file is part of ser, a free SIP server.
* ser is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
* For a license to use the ser software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* ser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
/** Retrieves the UID of the callee. This function retrieves the UID (unique
* identifier) of the party being called. The function first searches the list
* of available attributes and if it finds an attribute with name "uid" then
* the value of the attribute is returned. If no such attribute can be found
* then the function retrieves the username from To header field of REGISTER
* requests (because that is the party being registered), or the username from
* the Reqeuest-URI of other requests. The username is then used as the UID
* string identifying the callee. If no attribute with the UID was found and
* the function successfully retrieved the UID from the SIP message then, in
* addition to storing the result in the first parameter, the function will
* also create the attribute named "uid" which will contain the UID. The
* function is not reentrant because it uses an internal static buffer to
* store the result.
* @param uid A pointer to ::str variable where the result will be stored, the
* pointer in the variable will be updated to point to a static
* buffer in the function.
* @param msg The SIP message being processed.
* @return 1 is returned when the attribute with UID exists and it is used, 0
* is returned when the function retrieved the UID from the SIP
* message and created the attribute, -1 is returned on error.