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Diffstat (limited to 'epan/dissectors/packet-sparkplug.c')
| -rw-r--r-- | epan/dissectors/packet-sparkplug.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/epan/dissectors/packet-sparkplug.c b/epan/dissectors/packet-sparkplug.c new file mode 100644 index 0000000000..86d888acfe --- /dev/null +++ b/epan/dissectors/packet-sparkplug.c @@ -0,0 +1,169 @@ +/* packet-sparkplug.c + * Routines for Sparkplug dissection + * Copyright 2021 Graham Bloice <graham.bloice<at>trihedral.com> + * + * 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 <epan/packet.h> +#include <epan/expert.h> + +/* + * 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); + +/* Initialize the protocol field */ +static int proto_sparkplugb = -1; + +/* Initialize the subtree pointers */ +static gint ett_sparkplugb = -1; +static gint ett_sparkplugb_namespace = -1; + +/* The handle to the protobuf dissector */ +dissector_handle_t protobuf_handle = NULL; + +/* The hf items */ +static int hf_sparkplugb_namespace = -1; +static int hf_sparkplugb_groupid = -1; +static int hf_sparkplugb_messagetype = -1; +static int hf_sparkplugb_edgenodeid = -1; +static int hf_sparkplugb_deviceid = -1; + +/* The expert info items */ +static expert_field ei_sparkplugb_missing_groupid = EI_INIT; +static expert_field ei_sparkplugb_missing_messagetype = EI_INIT; +static expert_field ei_sparkplugb_missing_edgenodeid = EI_INIT; + +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; + + /* 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 || (strcmp("spBv1.0", topic_elements[0]) != 0)) { + 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_set_str(pinfo->cinfo, COL_INFO, "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; + ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_groupid, tvb, 0, 0, current_element[0]); + proto_item_set_generated(ti); + if (!current_element[0]) { + expert_add_info(pinfo, ti, &ei_sparkplugb_missing_groupid); + } + + /* 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); + if (!current_element[0]) { + expert_add_info(pinfo, ti, &ei_sparkplugb_missing_messagetype); + } + + current_element += 1; + ti = proto_tree_add_string(namespace_tree, hf_sparkplugb_edgenodeid, tvb, 0, 0, current_element[0]); + proto_item_set_generated(ti); + if (!current_element[0]) { + expert_add_info(pinfo, ti, &ei_sparkplugb_missing_edgenodeid); + } + + /* Device ID is optional */ + current_element += 1; + 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); +} |