epan/conv_id.h

   1 /* conv_id.h
   2  * conv_id   2011 Robert Bullen
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24
  25 #ifndef __CONV_ID_H__
  26 #define __CONV_ID_H__
  27
  28 /** conv_id_t is a type that can aid in conversation identification. When
  29  *  included in a "conversation key", whatever that may be, in addition to the
  30  *  typical { address, port, address, port } quadruple, it helps differentiate
  31  *  in case the quadruple is not sufficiently unique. For example, it is not
  32  *  uncommon to see a TCP quadruple reused these days, and employing a
  33  *  conv_id_t field ensures that each instance of a reused TCP conversation is
  34  *  tracked independently. Currently this type is used in both Wireshark's and
  35  *  tshark's conversation tables implementations (they are different, hence
  36  *  the need for a whole header file for this one silly type alias).
  37  *
  38  *  The "protocol" or "statistic" code responsible for instantiating the
  39  *  "conversation key" is also responsible for assigning its conv_id_t, and
  40  *  therefore its interpretation is specific to its assignor. For example, the
  41  *  TCP conversations tables in Wireshark and tshark assign the value of
  42  *  tcp.stream. If a conv_id_t field is not used, it should be assigned the
  43  *  value CONV_ID_UNSET.
  44  */
  45 typedef guint32 conv_id_t;
  46 #define CONV_ID_UNSET G_MAXUINT32
  47
  48 #endif /* __CONV_ID_H__ */