Bridge support for MQTT v3.1.1.

ChangeLog.txt

@@ -19,6 +19,7 @@ Important changes:
 - Wildcard TLS certificates are now supported for bridges and clients.
 - The clients have support for config files with default options.
 - Client and client libraries have support for MQTT v3.1.1.
+- Bridge support for MQTT v3.1.1.
 
 
 Broker:
@@ -57,6 +58,7 @@ Broker:
 - Wildcard TLS certificates are now supported for bridges.
 - Support for "hour" client expiration lengths for the
   persistent_client_expiration option. Closes bug #425835.
+- Bridge support for MQTT v3.1.1.
 
 Clients:
 - Both clients can now load default configuration options from a file.

man/mosquitto.conf.5.xml

@@ -899,6 +899,31 @@
 						with multiple addresses.</para>
 				</listitem>
 			</varlistentry>
+			<varlistentry>
+				<term><option>bridge_attempt_unsubscribe</option> [ true | false ]</term>
+				<listitem>
+					<para>If a bridge has topics that have "out" direction, the
+						default behaviour is to send an unsubscribe request to
+						the remote broker on that topic. This means that
+						changing a topic direction from "in" to "out" will not
+						keep receiving incoming messages. Sending these
+						unsubscribe requests is not always desirable, setting
+						<option>bridge_attempt_unsubscribe</option> to
+						<replaceable>false</replaceable> will disable sending
+						the unsubscribe request. Defaults to
+						<replaceable>true</replaceable>.</para>
+				</listitem>
+			</varlistentry>
+			<varlistentry>
+				<term><option>bridge_protocol_version</option> <replaceable>version</replaceable></term>
+				<listitem>
+					<para>Set the version of the MQTT protocol to use with for
+						this bridge. Can be one of
+						<replaceable>mqttv31</replaceable> or
+						<replaceable>mqttv311</replaceable>. Defaults to
+						<replaceable>mqttv31</replaceable>.</para>
+				</listitem>
+			</varlistentry>
 			<varlistentry>
 				<term><option>cleansession</option> [ true | false ]</term>
 				<listitem>

mosquitto.conf

@@ -631,6 +631,10 @@
 #address <host>[:<port>] [<host>[:<port>]]
 #topic <topic> [[[out | in | both] qos-level] local-prefix remote-prefix]
 
+# Set the version of the MQTT protocol to use with for this bridge. Can be one
+# of mqttv31 or mqttv311. Defaults to mqttv31.
+#bridge_protocol_version mqttv31
+
 # If a bridge has topics that have "out" direction, the default behaviour is to
 # send an unsubscribe request to the remote broker on that topic. This means
 # that changing a topic direction from "in" to "out" will not keep receiving

src/bridge.c

@@ -120,6 +120,7 @@ int mqtt3_bridge_new(struct mosquitto_db *db, struct _mqtt3_bridge *bridge)
 #endif
 
 	bridge->try_private_accepted = true;
+	new_context->protocol = bridge->protocol_version;
 
 	bridges = _mosquitto_realloc(db->bridges, (db->bridge_count+1)*sizeof(struct mosquitto *));
 	if(bridges){

src/conf.c

@@ -858,6 +858,30 @@ int _config_read_file_core(struct mqtt3_config *config, bool reload, const char
 					}
 #else
 					_mosquitto_log_printf(NULL, MOSQ_LOG_WARNING, "Warning: Bridge and/or TLS support not available.");
+#endif
+				}else if(!strcmp(token, "bridge_protocol_version")){
+#ifdef WITH_BRIDGE
+					if(reload) continue; // FIXME
+					if(!cur_bridge){
+						_mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Invalid bridge configuration.");
+						return MOSQ_ERR_INVAL;
+					}
+					token = strtok_r(NULL, " ", &saveptr);
+					if(token){
+						if(!strcmp(token, "mqttv31")){
+							cur_bridge->protocol_version = mosq_p_mqtt31;
+						}else if(!strcmp(token, "mqttv311")){
+							cur_bridge->protocol_version = mosq_p_mqtt311;
+						}else{
+							_mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Invalid bridge_protocol_version value (%s).", token);
+							return MOSQ_ERR_INVAL;
+						}
+					}else{
+						_mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Empty bridge_protocol_version value in configuration.");
+						return MOSQ_ERR_INVAL;
+					}
+#else
+					_mosquitto_log_printf(NULL, MOSQ_LOG_WARNING, "Warning: Bridge support not available.");
 #endif
 				}else if(!strcmp(token, "bridge_psk")){
 #if defined(WITH_BRIDGE) && defined(REAL_WITH_TLS_PSK)
@@ -1019,6 +1043,7 @@ int _config_read_file_core(struct mqtt3_config *config, bool reload, const char
 						cur_bridge->threshold = 10;
 						cur_bridge->try_private = true;
 						cur_bridge->attempt_unsubscribe = true;
+						cur_bridge->protocol_version = mosq_p_mqtt31;
 					}else{
 						_mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Empty connection value in configuration.");
 						return MOSQ_ERR_INVAL;

src/mosquitto_broker.h

@@ -286,6 +286,7 @@ struct _mqtt3_bridge{
 	struct _mqtt3_bridge_topic *topics;
 	int topic_count;
 	bool topic_remapping;
+	enum _mosquitto_protocol protocol_version;
 	time_t restart_t;
 	char *remote_clientid;
 	char *remote_username;