Mark Lewis <mlewis@altera.com>

I have developed a plugin for Pro-MPEG FEC packets over RTP (see
previous posts on ethereal-dev). I have added a page and example capture
file to the Wiki (http://wiki.wireshark.org/2dParityFEC). The source and
Windows makefile for the plugin are attached. Unfortunately I do not
have access to other systems so this plugin has been tested on Windows
only.


The attached version of my plug-in has only had the copyright header
added.
I will translate this into a proper dissector rather than a plug-in as
requested, but this may take a little time as I have a lot of other
things
to do at the moment.

Me:

Convert into a normal dissector
Reorder / reformat code a bit
Added Marks name to the top of the file.



svn path=/trunk/; revision=18908

1 files changed, 358 insertions, 0 deletions

diff --git a/epan/dissectors/packet-2dparityfec.c b/epan/dissectors/packet-2dparityfec.c
new file mode 100644
index 0000000000..ce9859e9a1
--- /dev/null
+++ b/epan/dissectors/packet-2dparityfec.c
@@ -0,0 +1,358 @@
+/* packet-2dparityfec.c
+ * Mark Lewis <mlewis@altera.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+** RTP Payload dissector for packets as specified in:
+** Pro-MPEG Code of Practice #3 release 2
+**
+** This protocol defines a format for FEC data embedded within RTP packets with
+** a payload type of 96 (0x60). The format of the FEC packets, which reside within
+** the RTP payload, is as follows...
+**
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**   |         SNBase low bits       |        Length Recovery        |
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**   |E| PT recovery |                    Mask                       |
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**   |                           TS recovery                         |
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**   |X|D|type |index|    Offset     |       NA      |SNBase ext bits|
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**   |                                                               |
+**   :                          FEC Payload                          :
+**   |                                                               |
+**   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+**
+** For more information on this protocol see...
+** http://www.pro-mpeg.org/publications/pdf/Vid-on-IP-CoP3-r2.pdf
+**
+**
+** Notes:
+**
+** This protocol always resides in RTP packets with payload type 96. However,
+** type 96 is dynamic and may refer to other protocols. As Pro-MPEG FEC must
+** function in the absence of a control channel, and because this data is
+** likely to be transmitted within closed networks, no automatic mechanism
+** exists for specifying the existance of Pro-MPEG FEC on payload type 96.
+** This dissector is thus disabled by default. Dissection of this protocol
+** may be enabled from the 2dparityfec panel under Preferences->Protocols.
+**
+** Mark Lewis - 20th June 2006
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+/* forward reference */
+void proto_register_2dparityfec(void);
+void proto_reg_handoff_2dparityfec(void);
+
+static gboolean dissect_fec = FALSE;
+
+static int proto_2dparityfec = -1;
+static int fec_rtp_payload_type = 96;
+static gint ett_2dparityfec = -1;
+
+static int hf_2dparityfec_snbase_low      = -1;
+static int hf_2dparityfec_length_recovery = -1;
+static int hf_2dparityfec_rfc2733_ext     = -1;
+static int hf_2dparityfec_pt_recovery     = -1;
+static int hf_2dparityfec_mask            = -1;
+static int hf_2dparityfec_ts_recovery     = -1;
+static int hf_2dparityfec_ts_pro_mpeg_ext = -1;
+static int hf_2dparityfec_row_flag        = -1;
+static int hf_2dparityfec_type            = -1;
+static int hf_2dparityfec_index           = -1;
+static int hf_2dparityfec_offset          = -1;
+static int hf_2dparityfec_na              = -1;
+static int hf_2dparityfec_snbase_ext      = -1;
+static int hf_2dparityfec_payload         = -1;
+
+static const value_string fec_type_names[] = {
+      {0, "XOR"},
+      {1, "Hamming"},
+      {2, "Reed-Solomon"}};
+
+static void dissect_2dparityfec(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+   guint8   OffsetField;
+   guint8   NAField;
+   guint32  SNBase;
+   guint8   D;
+
+   /* Extract SNBase */
+   SNBase  = (guint32)tvb_get_guint8(tvb, 0)<<8;
+   SNBase |= (guint32)tvb_get_guint8(tvb, 1);
+   SNBase |= (guint32)tvb_get_guint8(tvb, 15)<<16;
+
+   /* Extract D */
+   D = (tvb_get_guint8(tvb, 12)>>6) & 0x1;
+
+   /* Extract Offset and NA */
+   OffsetField    = tvb_get_guint8(tvb, 13);
+   NAField        = tvb_get_guint8(tvb, 14);
+
+   if(check_col(pinfo->cinfo, COL_PROTOCOL))
+   {
+      col_set_str(pinfo->cinfo, COL_PROTOCOL, "2dFEC");
+   }
+
+   /* Configure the info column */
+   if(check_col(pinfo->cinfo, COL_INFO))
+   {
+      col_clear(pinfo->cinfo, COL_INFO);
+
+      if(D)
+      {
+         col_add_fstr(pinfo->cinfo, COL_INFO, "Row FEC - SNBase=%u, Offset=%u, NA=%u",
+                                                SNBase, OffsetField, NAField);
+      }
+      else
+      {
+         col_add_fstr(pinfo->cinfo, COL_INFO, "Column FEC - SNBase=%u, Offset=%u, NA=%u",
+                                                SNBase, OffsetField, NAField);
+      }
+   }
+
+   if(tree)
+   {
+      /* we are being asked for details */
+      proto_item *ti = NULL;
+      proto_tree *tree_2dparityfec = NULL;
+      gint offset = 0;
+
+      ti = proto_tree_add_item(tree, proto_2dparityfec, tvb, 0, -1, FALSE);
+      tree_2dparityfec = proto_item_add_subtree(ti, ett_2dparityfec);
+
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_snbase_low,      tvb, offset, 2, FALSE); offset += 2;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_length_recovery, tvb, offset, 2, FALSE); offset += 2;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_rfc2733_ext,     tvb, offset, 1, FALSE);
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_pt_recovery,     tvb, offset, 1, FALSE); offset += 1;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_mask,            tvb, offset, 3, FALSE); offset += 3;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_ts_recovery,     tvb, offset, 4, FALSE); offset += 4;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_ts_pro_mpeg_ext, tvb, offset, 1, FALSE);
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_row_flag,        tvb, offset, 1, FALSE);
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_type,            tvb, offset, 1, FALSE);
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_index,           tvb, offset, 1, FALSE); offset += 1;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_offset,          tvb, offset, 1, FALSE); offset += 1;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_na,              tvb, offset, 1, FALSE); offset += 1;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_snbase_ext,      tvb, offset, 1, FALSE); offset += 1;
+      proto_tree_add_item(tree_2dparityfec, hf_2dparityfec_payload,         tvb, offset, -1, FALSE);
+   }
+}
+
+/* Payload type definitions */
+static hf_register_info hf[] = {
+	{&hf_2dparityfec_snbase_low,
+		{  "SNBase low",
+			"2dparityfec.snbase_low",
+			FT_UINT16,
+			BASE_DEC,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_length_recovery,
+		{  "Length recovery",
+			"2dparityfec.lr",
+			FT_UINT16,
+			BASE_HEX,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_rfc2733_ext,
+		{  "RFC2733 Extension (E)",
+			"2dparityfec.e",
+			FT_BOOLEAN,
+			8,
+			NULL,
+			0x80,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_pt_recovery,
+		{  "Payload Type recovery",
+			"2dparityfec.ptr",
+			FT_UINT8,
+			BASE_HEX,
+			NULL,
+			0x7f,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_mask,
+		{  "Mask",
+			"2dparityfec.mask",
+			/*FT_UINT32*/FT_UINT24,
+			BASE_HEX,
+			NULL,
+			/*0x00ffffff*/0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_ts_recovery,
+		{  "Timestamp recovery",
+			"2dparityfec.tsr",
+			FT_UINT32,
+			BASE_HEX,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_ts_pro_mpeg_ext,
+		{  "Pro-MPEG Extension (X)",
+			"2dparityfec.x",
+			FT_BOOLEAN,
+			8,
+			NULL,
+			0x80,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_row_flag,
+		{  "Row FEC (D)",
+			"2dparityfec.d",
+			FT_BOOLEAN,
+			8,
+			NULL,
+			0x40,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_type,
+		{  "Type",
+			"2dparityfec.type",
+			FT_UINT8,
+			BASE_DEC,
+			VALS(fec_type_names),
+			0x38,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_index,
+		{  "Index",
+			"2dparityfec.index",
+			FT_UINT8,
+			BASE_DEC,
+			NULL,
+			0x07,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_offset,
+		{  "Offset",
+			"2dparityfec.offset",
+			FT_UINT8,
+			BASE_DEC,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_na,
+		{  "NA",
+			"2dparityfec.na",
+			FT_UINT8,
+			BASE_DEC,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_snbase_ext,
+		{  "SNBase ext",
+			"2dparityfec.snbase_ext",
+			FT_UINT8,
+			BASE_DEC,
+			NULL,
+			0x0,
+			"",
+			HFILL}   },
+
+	{&hf_2dparityfec_payload,
+		{  "FEC Payload",
+			"2dparityfec.payload",
+			FT_BYTES,
+			BASE_HEX,
+			NULL,
+			0x0,
+			"",
+			HFILL}   }
+
+
+};
+
+/* Setup protocol subtree array */
+static gint *ett[] = {
+	&ett_2dparityfec,
+};
+
+void proto_register_2dparityfec(void)
+{
+   module_t *module_2dparityfec;
+
+   proto_register_field_array(proto_2dparityfec, hf, array_length(hf));
+   proto_register_subtree_array(ett, array_length(ett));
+
+   if(proto_2dparityfec == -1) {
+      proto_2dparityfec = proto_register_protocol(
+	"Pro-MPEG Code of Practice #3 release 2 FEC Protocol",   /* name */
+        "2dparityfec",            /* short name */
+        "2dparityfec");           /* abbrev */
+   }
+
+   module_2dparityfec = prefs_register_protocol(proto_2dparityfec,
+						proto_reg_handoff_2dparityfec);
+
+   prefs_register_bool_preference(module_2dparityfec, "enable",
+      "Decode Pro-MPEG FEC on RTP dynamic payload type 96",
+      "Enable this option to recognise all traffic on RTP dynamic payload type 96 (0x60) "
+      "as FEC data corresponding to Pro-MPEG Code of Practice #3 release 2",
+      &dissect_fec);
+
+}
+
+void proto_reg_handoff_2dparityfec(void)
+{
+      static dissector_handle_t handle_2dparityfec = NULL;
+ 
+      if (!handle_2dparityfec) {
+      	handle_2dparityfec = create_dissector_handle(dissect_2dparityfec,
+							proto_2dparityfec);
+      }
+
+      if (dissect_fec) {
+        dissector_add("rtp.pt", fec_rtp_payload_type, handle_2dparityfec);
+      } else {
+        dissector_delete("rtp.pt", fec_rtp_payload_type, handle_2dparityfec);
+      }
+}