Add initial support for

http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-03
I'll improve the dissector as the ID evolves...


svn path=/trunk/; revision=46809

2 files changed, 238 insertions, 0 deletions

diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 9c4dbfba3a..e8ba915080 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -983,6 +983,7 @@ DISSECTOR_SRC = \
 	packet-rstat.c		\
 	packet-rsvp.c		\
 	packet-rsync.c		\
+	packet-rtcdc.c		\
 	packet-rtcp.c		\
 	packet-rtmpt.c		\
 	packet-rtnet.c		\
diff --git a/epan/dissectors/packet-rtcdc.c b/epan/dissectors/packet-rtcdc.c
new file mode 100644
index 0000000000..843902303d
--- /dev/null
+++ b/epan/dissectors/packet-rtcdc.c
@@ -0,0 +1,237 @@
+/* packet-rtcdc.c
+ * Routines for the RTCWeb Data Channel Protocol dissection
+ * as specified in 
+ * http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-03
+ *
+ * Copyright 2012, Michael Tuexen <tuexen@wireshark.org>
+ *
+ * $Id$
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include <epan/expert.h>
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+void proto_reg_handoff_rtcdc(void);
+
+/* PPID used for this protocol */
+static guint32 rtcdc_ppid = 50;
+
+/* Initialize the protocol and registered fields */
+static int proto_rtcdc = -1;
+static int hf_message_type = -1;
+static int hf_channel_type = -1;
+static int hf_flags = -1;
+static int hf_flags_reserved = -1;
+static int hf_unordered_allowed = -1;
+static int hf_reliability = -1;
+static int hf_priority = -1;
+static int hf_label = -1;
+static int hf_error = -1;
+static int hf_sid = -1;
+
+/* Initialize the subtree pointers */
+static gint ett_rtcdc = -1;
+static gint ett_flags = -1;
+
+#define DATA_CHANNEL_OPEN_REQUEST   0x00
+#define DATA_CHANNEL_OPEN_RESPONSE  0x01
+#define DATA_CHANNEL_ACK            0x02
+
+static const value_string message_type_values[] = {
+	{ DATA_CHANNEL_OPEN_REQUEST,  "DATA_CHANNEL_OPEN_REQUEST"  },
+	{ DATA_CHANNEL_OPEN_RESPONSE, "DATA_CHANNEL_OPEN_RESPONSE" },
+	{ DATA_CHANNEL_ACK,           "DATA_CHANNEL_ACK"           },
+	{ 0,                          NULL                         }
+};
+
+#define DATA_CHANNEL_RELIABLE                0x00
+#define DATA_CHANNEL_PARTIAL_RELIABLE_REXMIT 0x01
+#define DATA_CHANNEL_PARTIAL_RELIABLE_TIMED  0x02
+
+static const value_string channel_type_values[] = {
+	{ DATA_CHANNEL_RELIABLE,                "DATA_CHANNEL_RELIABLE"                },
+	{ DATA_CHANNEL_PARTIAL_RELIABLE_REXMIT, "DATA_CHANNEL_PARTIAL_RELIABLE_REXMIT" },
+	{ DATA_CHANNEL_PARTIAL_RELIABLE_TIMED,  "DATA_CHANNEL_PARTIAL_RELIABLE_TIMED"  },
+	{ 0,                                    NULL                                   }
+};
+
+#define MESSAGE_TYPE_LENGTH 1
+#define CHANNEL_TYPE_LENGTH 1
+#define FLAGS_LENGTH        2
+#define RELIABILITY_LENGTH  2
+#define PRIORITY_LENGTH     2
+
+#define MESSAGE_TYPE_OFFSET 0
+#define CHANNEL_TYPE_OFFSET (MESSAGE_TYPE_OFFSET + MESSAGE_TYPE_LENGTH)
+#define FLAGS_OFFSET        (CHANNEL_TYPE_OFFSET + CHANNEL_TYPE_LENGTH)
+#define RELIABILITY_OFFSET  (FLAGS_OFFSET + FLAGS_LENGTH)
+#define PRIORITY_OFFSET     (RELIABILITY_OFFSET + RELIABILITY_LENGTH)
+#define LABEL_OFFSET        (PRIORITY_OFFSET + PRIORITY_LENGTH)
+
+#define DATA_CHANNEL_FLAG_OUT_OF_ORDER_ALLOWED_MASK 0x0001
+#define DATA_CHANNEL_FLAG_RESERVED_MASK             0xFFFE
+
+static void
+dissect_open_request_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *rtcdc_tree, proto_item *rtcdc_item _U_) {
+	if (rtcdc_tree) {
+		proto_tree *flags_tree;
+		proto_item *flags_item;
+
+		proto_tree_add_item(rtcdc_tree, hf_channel_type, tvb, CHANNEL_TYPE_OFFSET, CHANNEL_TYPE_LENGTH, ENC_BIG_ENDIAN);
+		flags_item = proto_tree_add_item(rtcdc_tree, hf_flags, tvb, FLAGS_OFFSET, FLAGS_LENGTH, ENC_BIG_ENDIAN);
+		flags_tree = proto_item_add_subtree(flags_item, ett_flags);
+		proto_tree_add_item(flags_tree, hf_flags_reserved, tvb, FLAGS_OFFSET, FLAGS_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(flags_tree, hf_unordered_allowed, tvb, FLAGS_OFFSET, FLAGS_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(rtcdc_tree, hf_reliability, tvb, RELIABILITY_OFFSET, RELIABILITY_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(rtcdc_tree, hf_priority, tvb, PRIORITY_OFFSET, PRIORITY_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(rtcdc_tree, hf_label, tvb, LABEL_OFFSET, -1, ENC_BIG_ENDIAN);
+	}
+	return;
+}
+
+#define ERROR_LENGTH                 1
+#define SID_LENGTH                   2
+#define DATA_CHANNEL_RESPONSE_LENGTH (MESSAGE_TYPE_LENGTH + ERROR_LENGTH + FLAGS_LENGTH + SID_LENGTH)
+
+#define ERROR_OFFSET                 (MESSAGE_TYPE_OFFSET + MESSAGE_TYPE_LENGTH)
+#define SID_OFFSET                   (FLAGS_OFFSET + FLAGS_LENGTH)
+
+static void
+dissect_open_response_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *rtcdc_tree, proto_item *rtcdc_item) {
+	if (tvb_length(tvb) > DATA_CHANNEL_RESPONSE_LENGTH) {
+		expert_add_info_format(pinfo, rtcdc_item, PI_MALFORMED, PI_ERROR, "Message too long");
+	}
+	if (rtcdc_tree) {
+		proto_tree_add_item(rtcdc_tree, hf_error, tvb, ERROR_OFFSET, ERROR_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(rtcdc_tree, hf_flags, tvb, FLAGS_OFFSET, FLAGS_LENGTH, ENC_BIG_ENDIAN);
+		proto_tree_add_item(rtcdc_tree, hf_sid, tvb, SID_OFFSET, SID_LENGTH, ENC_BIG_ENDIAN);
+	}
+	return;
+}
+
+#define DATA_CHANNEL_ACK_LENGTH MESSAGE_TYPE_LENGTH
+
+static void
+dissect_open_ack_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *rtcdc_tree _U_, proto_item *rtcdc_item) {
+	if (tvb_length(tvb) > DATA_CHANNEL_ACK_LENGTH) {
+		expert_add_info_format(pinfo, rtcdc_item, PI_MALFORMED, PI_ERROR, "Message too long");
+	}
+	return;
+}
+
+static int
+dissect_rtcdc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+	proto_item *rtcdc_item;
+	proto_tree *rtcdc_tree;
+	guint8 message_type;
+
+	message_type  = tvb_get_guint8(tvb, MESSAGE_TYPE_OFFSET);
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "RTCDC");
+	col_add_fstr(pinfo->cinfo, COL_INFO, "%s ", val_to_str_const(message_type, message_type_values, "reserved"));
+	if (tree) {
+		rtcdc_item = proto_tree_add_item(tree, proto_rtcdc, tvb, 0, -1, ENC_NA);
+		rtcdc_tree = proto_item_add_subtree(rtcdc_item, ett_rtcdc);
+		proto_tree_add_item(rtcdc_tree, hf_message_type, tvb, MESSAGE_TYPE_OFFSET, MESSAGE_TYPE_LENGTH, ENC_BIG_ENDIAN);
+	} else {
+		rtcdc_item = NULL;
+		rtcdc_tree = NULL;
+	}
+	switch (message_type) {
+	case DATA_CHANNEL_OPEN_REQUEST:
+		dissect_open_request_message(tvb, pinfo, rtcdc_tree, rtcdc_item);
+		break;
+	case DATA_CHANNEL_OPEN_RESPONSE:
+		dissect_open_response_message(tvb, pinfo, rtcdc_tree, rtcdc_item);
+		break;
+	case DATA_CHANNEL_ACK:
+		dissect_open_ack_message(tvb, pinfo, rtcdc_tree, rtcdc_item);
+		break;
+	default:
+		expert_add_info_format(pinfo, rtcdc_item, PI_MALFORMED, PI_ERROR, "Unknown message type");
+		break;
+	}
+	return tvb_length(tvb);
+}
+
+void
+proto_register_rtcdc(void)
+{
+	module_t *rtcdc_module;
+	static hf_register_info hf[] = {
+		{ &hf_message_type,      { "Message type",              "rtcdc.message_type",            FT_UINT8,   BASE_DEC,  VALS(message_type_values), 0x0,                                         NULL, HFILL } },
+		{ &hf_channel_type,      { "Channel type",              "rtcdc.channel_type",            FT_UINT8,   BASE_DEC,  VALS(channel_type_values), 0x0,                                         NULL, HFILL } },
+		{ &hf_flags,             { "Flags",                     "rtcdc.flags",                   FT_UINT16,  BASE_HEX,  NULL,                      0x0,                                         NULL, HFILL } },
+		{ &hf_flags_reserved,    { "Reserved",                  "rtcdc.flags_reserved",          FT_UINT16,  BASE_HEX,  NULL,                      DATA_CHANNEL_FLAG_RESERVED_MASK,             NULL, HFILL } },
+		{ &hf_unordered_allowed, { "Unordered allowed",         "rtcdc.flags_unordered_allowed", FT_BOOLEAN, 16,        NULL,                      DATA_CHANNEL_FLAG_OUT_OF_ORDER_ALLOWED_MASK, NULL, HFILL } },
+		{ &hf_reliability,       { "Reliability parameter",     "rtcdc.reliability_parameter",   FT_UINT16,  BASE_DEC,  NULL,                      0x0,                                         NULL, HFILL } },
+		{ &hf_priority,          { "Priority",                  "rtcdc.priority",                FT_UINT16,  BASE_DEC,  NULL,                      0x0,                                         NULL, HFILL } },
+		{ &hf_label,             { "Label",                     "rtcdc.label",                   FT_STRING,  BASE_NONE, NULL,                      0x0,                                         NULL, HFILL } },
+		{ &hf_error,             { "Error",                     "rtcdc.error",                   FT_UINT8,   BASE_DEC,  NULL,                      0x0,                                         NULL, HFILL } },
+		{ &hf_sid,               { "Reverse stream identifier", "rtcdc.reverse_stream_id",       FT_UINT16,  BASE_DEC,  NULL,                      0x0,                                         NULL, HFILL } }
+	};
+	static gint *ett[] = {
+		&ett_rtcdc,
+		&ett_flags
+	};
+
+	proto_rtcdc = proto_register_protocol("WebRTC Datachannel Protocol", "RTCDC", "rtcdc");
+	proto_register_field_array(proto_rtcdc, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+	rtcdc_module = prefs_register_protocol(proto_rtcdc, proto_reg_handoff_rtcdc);
+	prefs_register_uint_preference(rtcdc_module, "sctp.ppi", "RTCDC SCTP PPID", "RTCDC SCTP PPID if other than the default", 10, &rtcdc_ppid);
+}
+
+void
+proto_reg_handoff_rtcdc(void)
+{
+	static gboolean initialized = FALSE;
+	static dissector_handle_t rtcdc_handle;
+	static guint32 current_ppid;
+
+	if (!initialized) {
+		rtcdc_handle = new_create_dissector_handle(dissect_rtcdc, proto_rtcdc);
+		initialized = TRUE;
+	} else {
+		dissector_delete_uint("sctp.ppi", current_ppid, rtcdc_handle);
+	}
+	current_ppid = rtcdc_ppid;
+	dissector_add_uint("sctp.ppi", current_ppid, rtcdc_handle);
+}
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */