epan/dissectors/packet-dmx-text.c

   1 /* packet-dmx-text.c
   2  * DMX Text packet disassembly.
   3  *
   4  * This dissector is written by
   5  *
   6  *  Erwin Rol <erwin@erwinrol.com>
   7  *  Copyright 2011 Erwin Rol
   8  *
   9  *  Wireshark - Network traffic analyzer
  10  *  Gerald Combs <gerald@wireshark.org>
  11  *  Copyright 1999 Gerald Combs
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor
  26  * Boston, MA  02110-1301, USA.
  27  */
  28
  29 /*
  30  * This dissector is based on;
  31  * American National Standard E1.11 - 2004
  32  * Entertainment Technology USITT DMX512-A
  33  * Asynchronous Serial Digital Data Transmission Standard
  34  * for Controlling Lighting Equipment and Accessories
  35  */
  36
  37 #include "config.h"
  38
  39 #include <epan/packet.h>
  40
  41 void proto_register_dmx_text(void);
  42
  43 static int proto_dmx_text = -1;
  44
  45 static int hf_dmx_text_page_nr = -1;
  46 static int hf_dmx_text_line_len = -1;
  47 static int hf_dmx_text_string = -1;
  48
  49 static int ett_dmx_text = -1;
  50
  51 static void
  52 dissect_dmx_text(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  53 {
  54         col_set_str(pinfo->cinfo, COL_PROTOCOL, "DMX Text");
  55         col_clear(pinfo->cinfo, COL_INFO);
  56
  57         if (tree != NULL) {
  58                 guint offset = 0;
  59                 guint size;
  60
  61                 proto_tree *ti = proto_tree_add_item(tree, proto_dmx_text, tvb,
  62                                                         offset, -1, FALSE);
  63                 proto_tree *dmx_text_tree = proto_item_add_subtree(ti, ett_dmx_text);
  64
  65                 proto_tree_add_item(dmx_text_tree, hf_dmx_text_page_nr, tvb,
  66                                                         offset, 1, ENC_BIG_ENDIAN);
  67                 offset++;
  68
  69                 proto_tree_add_item(dmx_text_tree, hf_dmx_text_line_len, tvb,
  70                                                         offset, 1, ENC_BIG_ENDIAN);
  71                 offset++;
  72
  73                 size = tvb_reported_length_remaining(tvb, offset);
  74
  75                 proto_tree_add_item(dmx_text_tree, hf_dmx_text_string, tvb,
  76                                                         offset, size, ENC_BIG_ENDIAN);
  77         }
  78 }
  79
  80 void
  81 proto_register_dmx_text(void)
  82 {
  83         static hf_register_info hf[] = {
  84                 { &hf_dmx_text_page_nr,
  85                         { "Page Number",
  86                                 "dmx_text.page_nr",
  87                                 FT_UINT8, BASE_DEC, NULL, 0x0,
  88                                 NULL, HFILL }},
  89                 { &hf_dmx_text_line_len,
  90                         { "Line Length",
  91                                 "dmx_text.line_length",
  92                                 FT_UINT8, BASE_DEC, NULL, 0x0,
  93                                 NULL, HFILL }},
  94                 { &hf_dmx_text_string,
  95                         { "Text String",
  96                                 "dmx_text.string",
  97                                 FT_STRING, BASE_NONE, NULL, 0x0,
  98                                 NULL, HFILL }},
  99         };
 100
 101         static gint *ett[] = {
 102                 &ett_dmx_text
 103         };
 104
 105         proto_dmx_text = proto_register_protocol("DMX Text Frame", "DMX Text Frame", "dmx-text");
 106         proto_register_field_array(proto_dmx_text, hf, array_length(hf));
 107         proto_register_subtree_array(ett, array_length(ett));
 108         register_dissector("dmx-text", dissect_dmx_text, proto_dmx_text);
 109 }
 110