/* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
* See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */
/**
* .. _pubsub-tutorial:
*
* Working with Publish/Subscribe
* ------------------------------
*
* Work in progress: This Tutorial will be continuously extended during the next
* PubSub batches. More details about the PubSub extension and corresponding
* open62541 API are located here: :ref:`pubsub`.
*
* Publishing Fields
* ^^^^^^^^^^^^^^^^^
* The PubSub MQTT publish example demonstrate the simplest way to publish
* informations from the information model over MQTT using the UADP (or later
* JSON) encoding. To receive information the subscribe functionality of mqtt is
* used. A periodical call to yield is necessary to update the mqtt stack.
*
* **Connection handling**
* PubSubConnections can be created and deleted on runtime. More details about
* the system preconfiguration and connection can be found in
* ``tutorial_pubsub_connection.c``.
*/
#include "open62541/server.h"
#include "open62541/server_config_default.h"
#include "ua_pubsub.h"
#include "ua_network_pubsub_mqtt.h"
#include "open62541/plugin/log_stdout.h"
#include <signal.h>
#define CONNECTION_NAME "MQTT Publisher Connection"
#define TRANSPORT_PROFILE_URI "http://opcfoundation.org/UA-Profile/Transport/pubsub-mqtt"
#define MQTT_CLIENT_ID "TESTCLIENTPUBSUBMQTT"
#define CONNECTIONOPTION_NAME "mqttClientId"
#define PUBLISHER_TOPIC "customTopic"
#define PUBLISHER_METADATAQUEUENAME "MetaDataTopic"
#define PUBLISHER_METADATAUPDATETIME 0
#define BROKER_ADDRESS_URL "opc.mqtt://127.0.0.1:1883"
#define PUBLISH_INTERVAL 500
static UA_Boolean useJson = false;
static UA_NodeId connectionIdent;
static UA_NodeId publishedDataSetIdent;
static UA_NodeId writerGroupIdent;
static void
addPubSubConnection(UA_Server *server, char *addressUrl) {
/* Details about the connection configuration and handling are located
* in the pubsub connection tutorial */
UA_PubSubConnectionConfig connectionConfig;
memset(&connectionConfig, 0, sizeof(connectionConfig));
connectionConfig.name = UA_STRING(CONNECTION_NAME);
connectionConfig.transportProfileUri = UA_STRING(TRANSPORT_PROFILE_URI);
connectionConfig.enabled = UA_TRUE;
/* configure address of the mqtt broker (local on default port) */
UA_NetworkAddressUrlDataType networkAddressUrl = {UA_STRING_NULL , UA_STRING(addressUrl)};
UA_Variant_setScalar(&connectionConfig.address, &networkAddressUrl,
&UA_TYPES[UA_TYPES_NETWORKADDRESSURLDATATYPE]);
/* Changed to static publisherId from random generation to identify
* the publisher on Subscriber side */
connectionConfig.publisherId.numeric = 2234;
/* configure options, set mqtt client id */
UA_KeyValuePair connectionOptions[1];
connectionOptions[0].key = UA_QUALIFIEDNAME(0, CONNECTIONOPTION_NAME);
UA_String mqttClientId = UA_STRING(MQTT_CLIENT_ID);
UA_Variant_setScalar(&connectionOptions[0].value, &mqttClientId, &UA_TYPES[UA_TYPES_STRING]);
connectionConfig.connectionProperties = connectionOptions;
connectionConfig.connectionPropertiesSize = 1;
UA_Server_addPubSubConnection(server, &connectionConfig, &connectionIdent);
}
/**
* **PublishedDataSet handling**
* The PublishedDataSet (PDS) and PubSubConnection are the toplevel entities and
* can exist alone. The PDS contains the collection of the published fields. All
* other PubSub elements are directly or indirectly linked with the PDS or
* connection.
*/
static void
addPublishedDataSet(UA_Server *server) {
/* The PublishedDataSetConfig contains all necessary public
* informations for the creation of a new PublishedDataSet */
UA_PublishedDataSetConfig publishedDataSetConfig;
memset(&publishedDataSetConfig, 0, sizeof(UA_PublishedDataSetConfig));
publishedDataSetConfig.publishedDataSetType = UA_PUBSUB_DATASET_PUBLISHEDITEMS;
publishedDataSetConfig.name = UA_STRING("Demo PDS");
/* Create new PublishedDataSet based on the PublishedDataSetConfig. */
UA_Server_addPublishedDataSet(server, &publishedDataSetConfig, &publishedDataSetIdent);
}
/**
* **DataSetField handling**
* The DataSetField (DSF) is part of the PDS and describes exactly one published field.
*/
static void
addDataSetField(UA_Server *server) {
/* Add a field to the previous created PublishedDataSet */
UA_DataSetFieldConfig dataSetFieldConfig;
memset(&dataSetFieldConfig, 0, sizeof(UA_DataSetFieldConfig));
dataSetFieldConfig.dataSetFieldType = UA_PUBSUB_DATASETFIELD_VARIABLE;
dataSetFieldConfig.field.variable.fieldNameAlias = UA_STRING("Server localtime");
dataSetFieldConfig.field.variable.promotedField = UA_FALSE;
dataSetFieldConfig.field.variable.publishParameters.publishedVariable =
UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME);
dataSetFieldConfig.field.variable.publishParameters.attributeId = UA_ATTRIBUTEID_VALUE;
UA_Server_addDataSetField(server, publishedDataSetIdent, &dataSetFieldConfig, NULL);
}
/**
* **WriterGroup handling**
* The WriterGroup (WG) is part of the connection and contains the primary configuration
* parameters for the message creation.
*/
static void
addWriterGroup(UA_Server *server, char *topic, int interval) {
/* Now we create a new WriterGroupConfig and add the group to the existing PubSubConnection. */
UA_WriterGroupConfig writerGroupConfig;
memset(&writerGroupConfig, 0, sizeof(UA_WriterGroupConfig));
writerGroupConfig.name = UA_STRING("Demo WriterGroup");
writerGroupConfig.publishingInterval = interval;
writerGroupConfig.enabled = UA_FALSE;
writerGroupConfig.writerGroupId = 100;
/* decide whether to use JSON or UADP encoding*/
#ifdef UA_ENABLE_JSON_ENCODING
if(useJson)
writerGroupConfig.encodingMimeType = UA_PUBSUB_ENCODING_JSON;
else
#endif
writerGroupConfig.encodingMimeType = UA_PUBSUB_ENCODING_UADP;
writerGroupConfig.messageSettings.encoding = UA_EXTENSIONOBJECT_DECODED;
writerGroupConfig.messageSettings.content.decoded.type = &UA_TYPES[UA_TYPES_UADPWRITERGROUPMESSAGEDATATYPE];
/* The configuration flags for the messages are encapsulated inside the
* message- and transport settings extension objects. These extension
* objects are defined by the standard. e.g.
* UadpWriterGroupMessageDataType */
UA_UadpWriterGroupMessageDataType *writerGroupMessage = UA_UadpWriterGroupMessageDataType_new();
/* Change message settings of writerGroup to send PublisherId,
* WriterGroupId in GroupHeader and DataSetWriterId in PayloadHeader
* of NetworkMessage */
writerGroupMessage->networkMessageContentMask =
(UA_UadpNetworkMessageContentMask)(UA_UADPNETWORKMESSAGECONTENTMASK_PUBLISHERID |
(UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_GROUPHEADER |
(UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_WRITERGROUPID |
(UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_PAYLOADHEADER);
writerGroupConfig.messageSettings.content.decoded.data = writerGroupMessage;
/* configure the mqtt publish topic */
UA_BrokerWriterGroupTransportDataType brokerTransportSettings;
memset(&brokerTransportSettings, 0, sizeof(UA_BrokerWriterGroupTransportDataType));
/* Assign the Topic at which MQTT publish should happen */
/*ToDo: Pass the topic as argument from the writer group */
brokerTransportSettings.queueName = UA_STRING(topic);
brokerTransportSettings.resourceUri = UA_STRING_NULL;
brokerTransportSettings.authenticationProfileUri = UA_STRING_NULL;
/* Choose the QOS Level for MQTT */
brokerTransportSettings.requestedDeliveryGuarantee = UA_BROKERTRANSPORTQUALITYOFSERVICE_BESTEFFORT;
/* Encapsulate config in transportSettings */
UA_ExtensionObject transportSettings;
memset(&transportSettings, 0, sizeof(UA_ExtensionObject));
transportSettings.encoding = UA_EXTENSIONOBJECT_DECODED;
transportSettings.content.decoded.type = &UA_TYPES[UA_TYPES_BROKERWRITERGROUPTRANSPORTDATATYPE];
transportSettings.content.decoded.data = &brokerTransportSettings;
writerGroupConfig.transportSettings = transportSettings;
UA_Server_addWriterGroup(server, connectionIdent, &writerGroupConfig, &writerGroupIdent);
UA_Server_setWriterGroupOperational(server, writerGroupIdent);
UA_UadpWriterGroupMessageDataType_delete(writerGroupMessage);
}
/**
* **DataSetWriter handling**
* A DataSetWriter (DSW) is the glue between the WG and the PDS. The DSW is
* linked to exactly one PDS and contains additional informations for the
* message generation.
*/
static void
addDataSetWriter(UA_Server *server, char *topic) {
/* We need now a DataSetWriter within the WriterGroup. This means we must
* create a new DataSetWriterConfig and add call the addWriterGroup function. */
UA_NodeId dataSetWriterIdent;
UA_DataSetWriterConfig dataSetWriterConfig;
memset(&dataSetWriterConfig, 0, sizeof(UA_DataSetWriterConfig));
dataSetWriterConfig.name = UA_STRING("Demo DataSetWriter");
dataSetWriterConfig.dataSetWriterId = 62541;
dataSetWriterConfig.keyFrameCount = 10;
#ifdef UA_ENABLE_JSON_ENCODING
UA_JsonDataSetWriterMessageDataType jsonDswMd;
UA_ExtensionObject messageSettings;
if(useJson) {
/* JSON config for the dataSetWriter */
jsonDswMd.dataSetMessageContentMask = (UA_JsonDataSetMessageContentMask)
(UA_JSONDATASETMESSAGECONTENTMASK_DATASETWRITERID |
UA_JSONDATASETMESSAGECONTENTMASK_SEQUENCENUMBER |
UA_JSONDATASETMESSAGECONTENTMASK_STATUS |
UA_JSONDATASETMESSAGECONTENTMASK_METADATAVERSION |
UA_JSONDATASETMESSAGECONTENTMASK_TIMESTAMP);
messageSettings.encoding = UA_EXTENSIONOBJECT_DECODED;
messageSettings.content.decoded.type = &UA_TYPES[UA_TYPES_JSONDATASETWRITERMESSAGEDATATYPE];
messageSettings.content.decoded.data = &jsonDswMd;
dataSetWriterConfig.messageSettings = messageSettings;
}
#endif
/*TODO: Modify MQTT send to add DataSetWriters broker transport settings */
/*TODO: Pass the topic as argument from the writer group */
/*TODO: Publish Metadata to metaDataQueueName */
/* configure the mqtt publish topic */
UA_BrokerDataSetWriterTransportDataType brokerTransportSettings;
memset(&brokerTransportSettings, 0, sizeof(UA_BrokerDataSetWriterTransportDataType));
/* Assign the Topic at which MQTT publish should happen */
brokerTransportSettings.queueName = UA_STRING(topic);
brokerTransportSettings.resourceUri = UA_STRING_NULL;
brokerTransportSettings.authenticationProfileUri = UA_STRING_NULL;
brokerTransportSettings.metaDataQueueName = UA_STRING(PUBLISHER_METADATAQUEUENAME);
brokerTransportSettings.metaDataUpdateTime = PUBLISHER_METADATAUPDATETIME;
/* Choose the QOS Level for MQTT */
brokerTransportSettings.requestedDeliveryGuarantee = UA_BROKERTRANSPORTQUALITYOFSERVICE_BESTEFFORT;
/* Encapsulate config in transportSettings */
UA_ExtensionObject transportSettings;
memset(&transportSettings, 0, sizeof(UA_ExtensionObject));
transportSettings.encoding = UA_EXTENSIONOBJECT_DECODED;
transportSettings.content.decoded.type = &UA_TYPES[UA_TYPES_BROKERDATASETWRITERTRANSPORTDATATYPE];
transportSettings.content.decoded.data = &brokerTransportSettings;
dataSetWriterConfig.transportSettings = transportSettings;
UA_Server_addDataSetWriter(server, writerGroupIdent, publishedDataSetIdent,
&dataSetWriterConfig, &dataSetWriterIdent);
}
/**
* That's it! You're now publishing the selected fields. Open a packet
* inspection tool of trust e.g. wireshark and take a look on the outgoing
* packages. The following graphic figures out the packages created by this
* tutorial.
*
* .. figure:: ua-wireshark-pubsub.png
* :figwidth: 100 %
* :alt: OPC UA PubSub communication in wireshark
*
* The open62541 subscriber API will be released later. If you want to process
* the the datagrams, take a look on the ua_network_pubsub_networkmessage.c
* which already contains the decoding code for UADP messages.
*
* It follows the main server code, making use of the above definitions. */
UA_Boolean running = true;
static void stopHandler(int sign) {
UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "received ctrl-c");
running = false;
}
static void usage(void) {
printf("Usage: tutorial_pubsub_mqtt [--url <opc.mqtt://hostname:port>] "
"[--topic <mqttTopic>] "
"[--freq <frequency in ms> "
"[--json]\n"
" Defaults are:\n"
" - Url: opc.mqtt://127.0.0.1:1883\n"
" - Topic: customTopic\n"
" - Frequency: 500\n"
" - JSON: Off\n");
}
int main(int argc, char **argv) {
signal(SIGINT, stopHandler);
signal(SIGTERM, stopHandler);
/* TODO: Change to secure mqtt port:8883 */
char *addressUrl = BROKER_ADDRESS_URL;
char *topic = PUBLISHER_TOPIC;
int interval = PUBLISH_INTERVAL;
/* Parse arguments */
for(int argpos = 1; argpos < argc; argpos++) {
if(strcmp(argv[argpos], "--help") == 0) {
usage();
return 0;
}
if(strcmp(argv[argpos], "--json") == 0) {
useJson = true;
continue;
}
if(strcmp(argv[argpos], "--url") == 0) {
if(argpos + 1 == argc) {
usage();
return -1;
}
argpos++;
addressUrl = argv[argpos];
continue;
}
if(strcmp(argv[argpos], "--topic") == 0) {
if(argpos + 1 == argc) {
usage();
return -1;
}
argpos++;
topic = argv[argpos];
continue;
}
if(strcmp(argv[argpos], "--freq") == 0) {
if(argpos + 1 == argc) {
usage();
return -1;
}
if(sscanf(argv[argpos], "%d", &interval) != 1) {
usage();
return -1;
}
if(interval <= 10) {
UA_LOG_WARNING(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
"Publication interval too small");
return -1;
}
continue;
}
usage();
return -1;
}
/* Set up the server config */
UA_Server *server = UA_Server_new();
UA_ServerConfig *config = UA_Server_getConfig(server);
/* Details about the connection configuration and handling are located in
* the pubsub connection tutorial */
UA_ServerConfig_setDefault(config);
config->pubsubTransportLayers = (UA_PubSubTransportLayer *)
UA_malloc(1 * sizeof(UA_PubSubTransportLayer));
if(!config->pubsubTransportLayers) {
return -1;
}
config->pubsubTransportLayers[0] = UA_PubSubTransportLayerMQTT();
config->pubsubTransportLayersSize++;
addPubSubConnection(server, addressUrl);
addPublishedDataSet(server);
addDataSetField(server);
addWriterGroup(server, topic, interval);
addDataSetWriter(server, topic);
UA_PubSubConnection *connection = UA_PubSubConnection_findConnectionbyId(server, connectionIdent);
if(!connection) {
UA_LOG_WARNING(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
"Could not create a PubSubConnection");
UA_Server_delete(server);
return -1;
}
UA_Server_run(server, &running);
UA_Server_delete(server);
return 0;
}