packet-mdp.c: New dissector for Cisco Meraki Discovery Protocol

Bug: 14912
Change-Id: I2f99931abde331d087a994a22c74cf8d4dd8d53a
Reviewed-on: https://code.wireshark.org/review/28478
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>

3 files changed, 162 insertions, 0 deletions

diff --git a/docbook/release-notes.asciidoc b/docbook/release-notes.asciidoc
index fc9b15eeac..c9129ca317 100644
--- a/docbook/release-notes.asciidoc
+++ b/docbook/release-notes.asciidoc
@@ -76,6 +76,7 @@ GLOW Lawo Emberplus Data format
 STCSIG (Spirent Test Center Signature decoding for Ethernet and FibreChannel, disabled by default)
 Exablaze trailers
 Ubiquiti Discovery Protocol (UBDP)
+Cisco Meraki Discovery Protocol (MDP)
 --
 
 === Updated Protocol Support
diff --git a/epan/dissectors/CMakeLists.txt b/epan/dissectors/CMakeLists.txt
index ac70b1f323..165673ac65 100644
--- a/epan/dissectors/CMakeLists.txt
+++ b/epan/dissectors/CMakeLists.txt
@@ -1308,6 +1308,7 @@ set(DISSECTOR_SRC
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-mbim.c
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-mbtcp.c
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-mcpe.c
+	${CMAKE_CURRENT_SOURCE_DIR}/packet-mdp.c
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-mdshdr.c
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-media.c
 	${CMAKE_CURRENT_SOURCE_DIR}/packet-megaco.c
diff --git a/epan/dissectors/packet-mdp.c b/epan/dissectors/packet-mdp.c
new file mode 100644
index 0000000000..5d64ebdd65
--- /dev/null
+++ b/epan/dissectors/packet-mdp.c
@@ -0,0 +1,160 @@
+/* packet-mdp.c
+ * Routines for the disassembly of the "Meraki Discovery Protocol (MDP)"
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <epan/packet.h>
+
+#define MDP_TLV_TYPE            0
+#define MDP_TLV_LENGTH          1
+#define MDP_TLV_DEVICE_INFO     2
+#define MDP_TLV_NETWORK_INFO    3
+#define MDP_TLV_LONGITUDE       4
+#define MDP_TLV_LATITUDE        5
+#define MDP_TLV_TYPE_SIX        6
+#define MDP_TLV_TYPE_SEVEN      7
+#define MDP_TLV_END             255
+
+void proto_register_mdp(void);
+
+static int proto_mdp = -1;
+static int hf_mdp_preamble_data = -1;
+static int hf_mdp_device_info = -1;
+static int hf_mdp_network_info = -1;
+static int hf_mdp_type = -1;
+static int hf_mdp_length = -1;
+static int hf_mdp_longitude = -1;
+static int hf_mdp_latitude = -1;
+static int hf_mdp_type_six = -1;
+static int hf_mdp_type_seven = -1;
+static int hf_mdp_data = -1;
+
+static gint ett_mdp = -1;
+static gint ett_mdp_tlv = -1;
+
+static dissector_handle_t mdp_handle;
+
+/* Format Identifier */
+static const value_string type_vals[] = {
+    { MDP_TLV_DEVICE_INFO, "Device Info" },
+    { MDP_TLV_NETWORK_INFO, "Network Info" },
+    { MDP_TLV_LONGITUDE, "Longitude" },
+    { MDP_TLV_LATITUDE, "Latitude" },
+    { MDP_TLV_TYPE_SIX, "Type 6 UID" },
+    { MDP_TLV_TYPE_SEVEN, "Type 7 UID" },
+    { MDP_TLV_END, "End" },
+    { 0, NULL }
+};
+
+static int
+dissect_mdp(tvbuff_t *mdp_tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+    proto_tree  *mdp_tree, *tlv_tree;
+    proto_item  *mdp_item, *tlv_item;
+    guint32     mdp_type, mdp_length;
+    gint offset = 0;
+
+    col_set_str(pinfo->cinfo, COL_PROTOCOL, "MDP");
+    col_clear(pinfo->cinfo, COL_INFO);
+    col_add_fstr(pinfo->cinfo, COL_INFO, "MDP");
+
+    mdp_item = proto_tree_add_item(tree, proto_mdp, mdp_tvb, 0, -1, ENC_NA);
+    mdp_tree = proto_item_add_subtree(mdp_item, ett_mdp);
+
+    proto_tree_add_item(mdp_tree, hf_mdp_preamble_data, mdp_tvb, 0, 28, ENC_NA);
+    offset += 28;
+
+    while(tvb_reported_length_remaining(mdp_tvb, offset) != 0){
+	tlv_tree = proto_tree_add_subtree(mdp_tree, mdp_tvb, offset + MDP_TLV_TYPE, -1, ett_mdp_tlv, &tlv_item, "");
+        proto_tree_add_item_ret_uint(tlv_tree, hf_mdp_type, mdp_tvb, offset + MDP_TLV_TYPE, 1, ENC_BIG_ENDIAN, &mdp_type);
+        proto_item_set_text(tlv_tree, "%s", val_to_str_const(mdp_type, type_vals, "Unknown type"));
+        proto_tree_add_item_ret_uint(tlv_tree, hf_mdp_length, mdp_tvb, offset + MDP_TLV_LENGTH, 1, ENC_BIG_ENDIAN, &mdp_length);
+
+        offset += 2;
+
+        switch(mdp_type){
+          case MDP_TLV_DEVICE_INFO:
+            proto_tree_add_item(tlv_tree, hf_mdp_device_info, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+            break;
+          case MDP_TLV_NETWORK_INFO:
+            proto_tree_add_item(tlv_tree, hf_mdp_network_info, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+             break;
+          case MDP_TLV_LONGITUDE:
+            proto_tree_add_item(tlv_tree, hf_mdp_longitude, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+            break;
+          case MDP_TLV_LATITUDE:
+            proto_tree_add_item(tlv_tree, hf_mdp_latitude, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+            break;
+          case MDP_TLV_TYPE_SIX:
+            proto_tree_add_item(tlv_tree, hf_mdp_type_six, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+            break;
+          case MDP_TLV_TYPE_SEVEN:
+            proto_tree_add_item(tlv_tree, hf_mdp_type_seven, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
+            break;
+          case MDP_TLV_END:
+            break;
+          default:
+            proto_tree_add_item(mdp_tree, hf_mdp_data, mdp_tvb, offset, mdp_length, ENC_NA);
+            break;
+        }
+        proto_item_set_len(tlv_item, mdp_length + 2);
+        offset += mdp_length;
+    }
+    return tvb_captured_length(mdp_tvb);
+}
+
+void
+proto_register_mdp(void)
+{
+
+    static hf_register_info hf[] = {
+        { &hf_mdp_preamble_data, {"Preamble Data","mdp.preamble_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_device_info, {"Device Info", "mdp.device_info", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_network_info, {"Network Info", "mdp.network_info", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_longitude, {"Longitude", "mdp.longitude", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_latitude, {"Latitude", "mdp.latitude", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_type, {"Type", "mdp.type", FT_UINT8, BASE_DEC, VALS(type_vals), 0x0, NULL, HFILL }},
+        { &hf_mdp_type_six, {"Type 6 UID", "mdp.type_six", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_type_seven, {"Type 7 UID", "mdp.type_seven", FT_STRING, STR_UNICODE, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_length, {"Length", "mdp.length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
+        { &hf_mdp_data, {"Unknown Data", "mdp.data", FT_BYTES, BASE_NONE, NULL, 0X0, NULL, HFILL }}
+    };
+
+    static gint *ett[] = {
+        &ett_mdp,
+        &ett_mdp_tlv
+    };
+
+    proto_mdp = proto_register_protocol("Meraki Discovery Protocol", "MDP", "mdp");
+    proto_register_field_array(proto_mdp, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+
+    mdp_handle = register_dissector("mdp", dissect_mdp, proto_mdp);
+}
+
+void
+proto_reg_handoff_mdp(void)
+{
+    dissector_add_uint("ethertype", 0x0712, mdp_handle);
+    dissector_add_uint("ethertype", 0x0713, mdp_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:
+ */