epan/dissectors/packet-dmx-test.c

   1 /* packet-dmx-test.c
   2  * DMX Test packet disassembly.
   3  *
   4  * $Id$
   5  *
   6  * This dissector is written by
   7  *
   8  *  Erwin Rol <erwin@erwinrol.com>
   9  *  Copyright 2011 Erwin Rol
  10  *
  11  *  Wireshark - Network traffic analyzer
  12  *  Gerald Combs <gerald@wireshark.org>
  13  *  Copyright 1999 Gerald Combs
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 51 Franklin Street, Fifth Floor
  28  * Boston, MA  02110-1301, USA.
  29  */
  30
  31 /*
  32  * This dissector is based on;
  33  * American National Standard E1.11 - 2004
  34  * Entertainment Technology USITT DMX512-A
  35  * Asynchronous Serial Digital Data Transmission Standard
  36  * for Controlling Lighting Equipment and Accessories
  37  */
  38
  39 #include "config.h"
  40
  41 #include <epan/packet.h>
  42
  43 #define DMX_TEST_PACKET_SIZE  512
  44 #define DMX_TEST_VALUE       0x55
  45
  46 void proto_register_dmx_test(void);
  47
  48 static int proto_dmx_test = -1;
  49
  50 static int hf_dmx_test_data = -1;
  51 static int hf_dmx_test_data_good = -1;
  52 static int hf_dmx_test_data_bad = -1;
  53
  54 static int ett_dmx_test = -1;
  55
  56 static void
  57 dissect_dmx_test(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  58 {
  59         col_set_str(pinfo->cinfo, COL_PROTOCOL, "DMX Test Frame");
  60         col_clear(pinfo->cinfo, COL_INFO);
  61
  62         if (tree != NULL) {
  63                 guint    offset = 0;
  64                 guint    size, i, test_data_is_ok;
  65                 proto_tree *test_data_tree;
  66                 proto_item *item;
  67
  68                 proto_tree *ti = proto_tree_add_item(tree, proto_dmx_test, tvb,
  69                                                         offset, -1, FALSE);
  70                 proto_tree *dmx_test_tree = proto_item_add_subtree(ti, ett_dmx_test);
  71
  72                 size = tvb_reported_length_remaining(tvb, offset);
  73
  74                 item = proto_tree_add_item(dmx_test_tree, hf_dmx_test_data, tvb,
  75                                                         offset, size, ENC_BIG_ENDIAN);
  76                 offset += size;
  77
  78                 if (size == DMX_TEST_PACKET_SIZE) {
  79                         test_data_is_ok = TRUE;
  80                         for (i = 0; i < DMX_TEST_PACKET_SIZE; i++) {
  81                                 if (tvb_get_guint8(tvb, i) != DMX_TEST_VALUE) {
  82                                         test_data_is_ok = FALSE;
  83                                         break;
  84                                 }
  85                         }
  86                 } else {
  87                         test_data_is_ok = FALSE;
  88                 }
  89
  90                 if (test_data_is_ok) {
  91                         proto_item_append_text(ti, ", Data correct");
  92                         proto_item_append_text(item, " [correct]");
  93
  94                         test_data_tree = proto_item_add_subtree(item, ett_dmx_test);
  95                         item = proto_tree_add_boolean(test_data_tree, hf_dmx_test_data_good, tvb,
  96                                                         offset, size, TRUE);
  97                         PROTO_ITEM_SET_GENERATED(item);
  98                         item = proto_tree_add_boolean(test_data_tree, hf_dmx_test_data_bad, tvb,
  99                                                         offset, size, FALSE);
 100                         PROTO_ITEM_SET_GENERATED(item);
 101                 } else {
 102                         proto_item_append_text(ti, ", Data incorrect");
 103                         proto_item_append_text(item, " [incorrect]");
 104
 105                         test_data_tree = proto_item_add_subtree(item, ett_dmx_test);
 106                         item = proto_tree_add_boolean(test_data_tree, hf_dmx_test_data_good, tvb,
 107                                                         offset, size, FALSE);
 108                         PROTO_ITEM_SET_GENERATED(item);
 109                         item = proto_tree_add_boolean(test_data_tree, hf_dmx_test_data_bad, tvb,
 110                                                                 offset, size, TRUE);
 111                         PROTO_ITEM_SET_GENERATED(item);
 112                 }
 113         }
 114 }
 115
 116 void
 117 proto_register_dmx_test(void)
 118 {
 119         static hf_register_info hf[] = {
 120                 { &hf_dmx_test_data,
 121                         { "Test Data", "dmx_test.data",
 122                                 FT_BYTES, BASE_NONE, NULL, 0x0,
 123                                 NULL, HFILL }},
 124
 125                 { &hf_dmx_test_data_good,
 126                         { "Data Good", "dmx_test.data_good",
 127                                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 128                                 "True: test data is correct; False: test data is incorrect", HFILL }},
 129
 130                 { &hf_dmx_test_data_bad,
 131                         { "Data Bad", "dmx_test.data_bad",
 132                                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 133                                 "True: test data is incorrect; False: test data is correct", HFILL }},
 134         };
 135
 136         static gint *ett[] = {
 137                 &ett_dmx_test
 138         };
 139
 140         proto_dmx_test = proto_register_protocol("DMX Test Frame", "DMX Test Frame", "dmx-test");
 141         proto_register_field_array(proto_dmx_test, hf, array_length(hf));
 142         proto_register_subtree_array(ett, array_length(ett));
 143         register_dissector("dmx-test", dissect_dmx_test, proto_dmx_test);
 144 }