/* packet-sparkplug.c * Routines for Sparkplug dissection * Copyright 2021 Graham Bloice trihedral.com> * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include /* * See * * https://cirrus-link.com/mqtt-sparkplug-tahu/ * * and the specification is at * * https://www.eclipse.org/tahu/spec/Sparkplug%20Topic%20Namespace%20and%20State%20ManagementV2.2-with%20appendix%20B%20format%20-%20Eclipse.pdf * */ /* Prototypes */ /* (Required to prevent [-Wmissing-prototypes] warnings */ void proto_reg_handoff_sparkplug(void); void proto_register_sparkplug(void); /* Initialize the protocol field */ static int proto_sparkplugb; /* Initialize the subtree pointers */ static gint ett_sparkplugb; static gint ett_sparkplugb_namespace; /* The handle to the protobuf dissector */ dissector_handle_t protobuf_handle = NULL; /* The hf items */ static int hf_sparkplugb_namespace; static int hf_sparkplugb_groupid; static int hf_sparkplugb_messagetype; static int hf_sparkplugb_edgenodeid; static int hf_sparkplugb_deviceid; /* The expert info items */ static expert_field ei_sparkplugb_missing_groupid; static expert_field ei_sparkplugb_missing_messagetype; static expert_field ei_sparkplugb_missing_edgenodeid; static gboolean dissect_sparkplugb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) { proto_item *ti; proto_tree *sparkplugb_tree, *namespace_tree; gchar **topic_elements, **current_element; char *topic = (char *)data; /* Confirm the expected topic data is present */ if (topic == NULL) return FALSE; /* Parse the topic into the elements */ topic_elements = g_strsplit(topic, "/", 5); /* Heuristic check that the first element of the topic is the SparkplugB namespace */ if (!topic_elements || (g_strcmp0("spBv1.0", topic_elements[0]) != 0)) { g_strfreev(topic_elements); return FALSE; } /* Make entries in Protocol column */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "SparkplugB"); /* Adjust the info column */ col_clear(pinfo->cinfo, COL_INFO); col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "SparkplugB"); /* create display subtree for the protocol */ ti = proto_tree_add_item(tree, proto_sparkplugb, tvb, 0, -1, ENC_NA); sparkplugb_tree = proto_item_add_subtree(ti, ett_sparkplugb); /* Add the elements parsed out from the topic string */ namespace_tree = proto_tree_add_subtree(sparkplugb_tree, tvb, 0, 0, ett_sparkplugb_namespace, &ti, "Topic Namespace"); proto_item_set_generated(ti); current_element = topic_elements; ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_namespace, tvb, 0, 0, current_element[0]); proto_item_set_generated(ti); current_element += 1; if (current_element[0]) { ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_groupid, tvb, 0, 0, current_element[0]); proto_item_set_generated(ti); } else { expert_add_info(pinfo, namespace_tree, &ei_sparkplugb_missing_groupid); return FALSE; } /* Adjust the info colum text with the message type */ current_element += 1; if (current_element[0]) { col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, current_element[0]); col_set_fence(pinfo->cinfo, COL_INFO); ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_messagetype, tvb, 0, 0, current_element[0]); proto_item_set_generated(ti); } else { expert_add_info(pinfo, namespace_tree, &ei_sparkplugb_missing_messagetype); return FALSE; } current_element += 1; if (current_element[0]) { ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_edgenodeid, tvb, 0, 0, current_element[0]); proto_item_set_generated(ti); } else { expert_add_info(pinfo, namespace_tree, &ei_sparkplugb_missing_edgenodeid); return FALSE; } /* Device ID is optional */ current_element += 1; if (current_element[0]) { ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_deviceid, tvb, 0, 0, current_element[0]); proto_item_set_generated(ti); } g_strfreev(topic_elements); /* Now handoff the Payload message to the protobuf dissector */ call_dissector_with_data(protobuf_handle, tvb, pinfo, sparkplugb_tree, "message,com.cirruslink.sparkplug.protobuf.Payload"); return TRUE; } void proto_register_sparkplug(void) { expert_module_t* expert_sparkplugb; static gint *ett[] = { &ett_sparkplugb, &ett_sparkplugb_namespace }; static hf_register_info hf[] = { {&hf_sparkplugb_namespace, {"Namespace", "sparkplugb.namespace", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}}, {&hf_sparkplugb_groupid, {"Group ID", "sparkplugb.groupid", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}}, {&hf_sparkplugb_messagetype, {"Message Type", "sparkplugb.messagetype", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}}, {&hf_sparkplugb_edgenodeid, {"Edge Node ID", "sparkplugb.edgenodeid", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}}, {&hf_sparkplugb_deviceid, {"Device ID", "sparkplugb.deviceid", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}}, }; static ei_register_info ei[] = { { &ei_sparkplugb_missing_groupid, { "sparkplugb.missing_groupid", PI_MALFORMED, PI_ERROR, "Missing Group ID", EXPFILL }}, { &ei_sparkplugb_missing_messagetype, { "sparkplugb.missing_messagetype", PI_MALFORMED, PI_ERROR, "Missing Message Type", EXPFILL }}, { &ei_sparkplugb_missing_edgenodeid, { "sparkplugb.missing_edgenodeid", PI_MALFORMED, PI_ERROR, "Missing Edge Node ID", EXPFILL }}, }; /* Register the protocol name and description, fields and trees */ proto_sparkplugb = proto_register_protocol("SparkplugB", "SparkplugB", "sparkplugb"); register_dissector("sparkplugb", dissect_sparkplugb, proto_sparkplugb); proto_register_field_array(proto_sparkplugb, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_sparkplugb = expert_register_protocol(proto_sparkplugb); expert_register_field_array(expert_sparkplugb, ei, array_length(ei)); } void proto_reg_handoff_sparkplug(void) { protobuf_handle = find_dissector_add_dependency("protobuf", proto_sparkplugb); /* register as heuristic dissector with MQTT */ heur_dissector_add("mqtt.topic", dissect_sparkplugb, "SparkplugB over MQTT", "sparkplugb_mqtt", proto_sparkplugb, HEURISTIC_ENABLE); }