epan/conv_id.h

   1 /** @file
   2  *
   3  * conv_id   2011 Robert Bullen
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #ifndef __CONV_ID_H__
  13 #define __CONV_ID_H__
  14
  15 #include <stdint.h>
  16
  17 /** conv_id_t is a type that can aid in conversation identification. When
  18  *  included in a "conversation key", whatever that may be, in addition to the
  19  *  typical { address, port, address, port } quadruple, it helps differentiate
  20  *  in case the quadruple is not sufficiently unique. For example, it is not
  21  *  uncommon to see a TCP quadruple reused these days, and employing a
  22  *  conv_id_t field ensures that each instance of a reused TCP conversation is
  23  *  tracked independently. Currently this type is used in both Wireshark's and
  24  *  tshark's conversation tables implementations (they are different, hence
  25  *  the need for a whole header file for this one silly type alias).
  26  *
  27  *  The "protocol" or "statistic" code responsible for instantiating the
  28  *  "conversation key" is also responsible for assigning its conv_id_t, and
  29  *  therefore its interpretation is specific to its assignor. For example, the
  30  *  TCP conversations tables in Wireshark and tshark assign the value of
  31  *  tcp.stream. If a conv_id_t field is not used, it should be assigned the
  32  *  value CONV_ID_UNSET.
  33  */
  34 typedef uint32_t conv_id_t;
  35 #define CONV_ID_UNSET UINT32_MAX
  36
  37 #endif /* __CONV_ID_H__ */