epan/dissectors/packet-dmx-chan.c

   1 /* packet-dmx-chan.c
   2  * DMX Channel Data 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 #include <epan/prefs.h>
  41
  42 void proto_register_dmx_chan(void);
  43
  44 static int proto_dmx_chan = -1;
  45
  46 static int hf_dmx_chan_output_dmx_data = -1;
  47 static int hf_dmx_chan_output_data_filter = -1;
  48
  49 static int ett_dmx_chan = -1;
  50
  51 /*
  52  * Here are the global variables associated with the preferences for DMX
  53  */
  54 static gint global_disp_chan_val_type = 0;
  55 static gint global_disp_col_count     = 16;
  56 static gint global_disp_chan_nr_type  = 0;
  57
  58 static void
  59 dissect_dmx_chan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  60 {
  61         col_set_str(pinfo->cinfo, COL_PROTOCOL, "DMX Channels");
  62         col_clear(pinfo->cinfo, COL_INFO);
  63
  64         if (tree != NULL) {
  65                 static const char *chan_format[]   = {
  66                         "%2u%% ",
  67                         "0x%02x ",
  68                         "%3u "
  69                 };
  70                 static const char *string_format[] = {
  71                         "0x%03x: %s",
  72                         "%3u: %s"
  73                 };
  74                 wmem_strbuf_t *chan_str = wmem_strbuf_new_label(wmem_packet_scope());
  75                 proto_item    *item;
  76                 guint16        length,r,c,row_count;
  77                 guint8         v;
  78                 guint          offset   = 0;
  79
  80                 proto_tree    *ti = proto_tree_add_item(tree, proto_dmx_chan, tvb, offset, -1, ENC_NA);
  81                 proto_tree    *dmx_chan_tree = proto_item_add_subtree(ti, ett_dmx_chan);
  82
  83                 length = tvb_reported_length_remaining(tvb, offset);
  84
  85                 row_count = (length / global_disp_col_count) + ((length % global_disp_col_count) == 0 ? 0 : 1);
  86                 for (r = 0; r < row_count;r++) {
  87                         wmem_strbuf_truncate(chan_str, 0);
  88                         for (c = 0;(c < global_disp_col_count) && (((r * global_disp_col_count) + c) < length);c++) {
  89                                 if ((global_disp_col_count >= 2) && ((c % (global_disp_col_count / 2)) == 0)) {
  90                                         wmem_strbuf_append(chan_str, " ");
  91                                 }
  92
  93                                 v = tvb_get_guint8(tvb, (offset + (r * global_disp_col_count) + c));
  94                                 if (global_disp_chan_val_type == 0) {
  95                                         v = (v * 100) / 255;
  96                                         if (v == 100) {
  97                                                 wmem_strbuf_append(chan_str, "FL ");
  98                                         } else {
  99                                                 wmem_strbuf_append_printf(chan_str, chan_format[global_disp_chan_val_type], v);
 100                                         }
 101                                 } else {
 102                                         wmem_strbuf_append_printf(chan_str, chan_format[global_disp_chan_val_type], v);
 103                                 }
 104                         }
 105
 106                         proto_tree_add_none_format(dmx_chan_tree, hf_dmx_chan_output_dmx_data, tvb,
 107                                                         offset+(r * global_disp_col_count), c,
 108                                                         string_format[global_disp_chan_nr_type],
 109                                                         (r * global_disp_col_count) + 1, wmem_strbuf_get_str(chan_str));
 110                 }
 111
 112                 /* Add the real type hidden */
 113                 item = proto_tree_add_item(dmx_chan_tree, hf_dmx_chan_output_data_filter, tvb,
 114                                                 offset, length, ENC_NA );
 115                 PROTO_ITEM_SET_HIDDEN(item);
 116         }
 117 }
 118
 119 void
 120 proto_register_dmx_chan(void)
 121 {
 122         static hf_register_info hf[] = {
 123                 { &hf_dmx_chan_output_data_filter,
 124                         { "DMX data filter",
 125                                 "dmx_chan.data_filter",
 126                                 FT_BYTES, BASE_NONE, NULL, 0x0,
 127                                 NULL, HFILL }},
 128
 129                 { &hf_dmx_chan_output_dmx_data,
 130                         { "DMX data",
 131                                 "dmx_chan.dmx_data",
 132                                 FT_NONE, BASE_NONE, NULL, 0x0,
 133                                 NULL, HFILL }},
 134         };
 135
 136         static gint *ett[] = {
 137                 &ett_dmx_chan
 138         };
 139
 140         module_t *dmx_chan_module;
 141
 142         static const enum_val_t disp_chan_val_types[] = {
 143                 { "pro", "Percent", 0 },
 144                 { "hex", "Hexadecimal", 1 },
 145                 { "dec", "Decimal", 2 },
 146                 { NULL, NULL, 0 }
 147         };
 148
 149         static const enum_val_t disp_chan_nr_types[] = {
 150                 { "hex", "Hexadecimal", 0 },
 151                 { "dec", "Decimal", 1 },
 152                 { NULL, NULL, 0 }
 153         };
 154
 155         static const enum_val_t col_count[] = {
 156                 {  "6",  "6",  6 },
 157                 { "10", "10", 10 },
 158                 { "12", "12", 12 },
 159                 { "16", "16", 16 },
 160                 { "24", "24", 24 },
 161                 { NULL, NULL, 0 }
 162         };
 163
 164         proto_dmx_chan = proto_register_protocol("DMX Channels","DMX Channels", "dmx-chan");
 165         proto_register_field_array(proto_dmx_chan, hf, array_length(hf));
 166         proto_register_subtree_array(ett, array_length(ett));
 167         register_dissector("dmx-chan", dissect_dmx_chan, proto_dmx_chan);
 168
 169         dmx_chan_module = prefs_register_protocol(proto_dmx_chan, NULL);
 170
 171         prefs_register_enum_preference(dmx_chan_module, "dmx_disp_chan_val_type",
 172                                         "DMX Display channel value type",
 173                                         "The way DMX values are displayed",
 174                                         &global_disp_chan_val_type,
 175                                         disp_chan_val_types, FALSE);
 176
 177         prefs_register_enum_preference(dmx_chan_module, "dmx_disp_chan_nr_type",
 178                                         "DMX Display channel nr. type",
 179                                         "The way DMX channel numbers are displayed",
 180                                         &global_disp_chan_nr_type,
 181                                         disp_chan_nr_types, FALSE);
 182
 183         prefs_register_enum_preference(dmx_chan_module, "dmx_disp_col_count",
 184                                         "DMX Display Column Count",
 185                                         "The number of columns for the DMX display",
 186                                         &global_disp_col_count,
 187                                         col_count, FALSE);
 188 }
 189
 190 /*
 191  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 192  *
 193  * Local variables:
 194  * c-basic-offset: 8
 195  * tab-width: 8
 196  * indent-tabs-mode: t
 197  * End:
 198  *
 199  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 200  * :indentSize=8:tabSize=8:noTabs=false:
 201  */