epan/dissectors/packet-echo.c

   1 /* packet-echo.c
   2  * Routines for ECHO packet disassembly (RFC862)
   3  *
   4  * Only useful to mark the packets as ECHO in the summary and in the
   5  * protocol hierarchy statistics (since not so many fields to decode ;-)
   6  *
   7  * Laurent Deniel <laurent.deniel@free.fr>
   8  *
   9  * Wireshark - Network traffic analyzer
  10  * By Gerald Combs <gerald@wireshark.org>
  11  * Copyright 1998 Gerald Combs
  12  *
  13  * SPDX-License-Identifier: GPL-2.0-or-later
  14  */
  15
  16 #include "config.h"
  17
  18 #include <epan/packet.h>
  19
  20 #define ECHO_PORT  7
  21
  22 void proto_register_echo(void);
  23 void proto_reg_handoff_echo(void);
  24
  25 static dissector_handle_t echo_handle;
  26 static int proto_echo;
  27
  28 static int hf_echo_data;
  29 static int hf_echo_request;
  30 static int hf_echo_response;
  31
  32 static int ett_echo;
  33
  34 static int dissect_echo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  35 {
  36   bool        request;
  37   proto_tree *echo_tree;
  38   proto_item *ti, *hidden_item;
  39
  40   request = (pinfo->destport == pinfo->match_uint);
  41
  42   col_set_str(pinfo->cinfo, COL_PROTOCOL, "ECHO");
  43   col_set_str(pinfo->cinfo, COL_INFO, request ? "Request" : "Response");
  44
  45   ti = proto_tree_add_item(tree, proto_echo, tvb, 0, -1, ENC_NA);
  46   echo_tree = proto_item_add_subtree(ti, ett_echo);
  47
  48   hidden_item = proto_tree_add_boolean(echo_tree,
  49       request ?  hf_echo_request : hf_echo_response, tvb, 0, 0, 1);
  50   proto_item_set_hidden(hidden_item);
  51
  52   proto_tree_add_item(echo_tree, hf_echo_data, tvb, 0, -1, ENC_NA);
  53
  54   return tvb_captured_length(tvb);
  55 }
  56
  57 void proto_register_echo(void)
  58 {
  59
  60   static hf_register_info hf[] = {
  61     { &hf_echo_data,
  62       { "Echo data", "echo.data", FT_BYTES, BASE_NONE,
  63         NULL, 0x0, NULL, HFILL }},
  64     { &hf_echo_request,
  65       { "Echo request", "echo.request", FT_BOOLEAN, BASE_NONE,
  66         NULL, 0x0, NULL, HFILL }},
  67     { &hf_echo_response,
  68       { "Echo response","echo.response", FT_BOOLEAN, BASE_NONE,
  69         NULL, 0x0, NULL, HFILL }}
  70   };
  71
  72   static int *ett[] = {
  73     &ett_echo
  74   };
  75
  76   proto_echo = proto_register_protocol("Echo", "ECHO", "echo");
  77   proto_register_field_array(proto_echo, hf, array_length(hf));
  78   proto_register_subtree_array(ett, array_length(ett));
  79   echo_handle = register_dissector("echo", dissect_echo, proto_echo);
  80 }
  81
  82 void proto_reg_handoff_echo(void)
  83 {
  84   dissector_add_uint_with_preference("udp.port", ECHO_PORT, echo_handle);
  85   dissector_add_uint_with_preference("tcp.port", ECHO_PORT, echo_handle);
  86 }
  87
  88 /*
  89  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  90  *
  91  * Local Variables:
  92  * c-basic-offset: 2
  93  * tab-width: 8
  94  * indent-tabs-mode: nil
  95  * End:
  96  *
  97  * ex: set shiftwidth=2 tabstop=8 expandtab:
  98  * :indentSize=2:tabSize=8:noTabs=true:
  99  */