Add mosquitto_connect_with_flags_callback_set().

This allows a second connect callback to be used that exposes the
MQTT connect flags parameter.

Closes #738, #128.

ChangeLog.txt

@@ -94,6 +94,9 @@ Client library features:
 - Add mosquitto_pub_topic_check2(), mosquitto_sub_topic_check2(), and
   mosquitto_topic_matches_sub2() which are identical to the similarly named
   functions but also take length arguments.
+- Add mosquitto_connect_with_flags_callback_set(), which allows a second
+  connect callback to be used which also exposes the connect flags parameter.
+  Closes #738 and #128.
 
 Client library fixes:
 - Fix incorrect PSK key being used if it had leading zeroes.

client/sub_client.c

@@ -73,7 +73,7 @@ void my_message_callback(struct mosquitto *mosq, void *obj, const struct mosquit
 	}
 }
 
-void my_connect_callback(struct mosquitto *mosq, void *obj, int result)
+void my_connect_callback(struct mosquitto *mosq, void *obj, int result, int flags)
 {
 	int i;
 	struct mosq_config *cfg;
@@ -261,7 +261,7 @@ int main(int argc, char *argv[])
 		mosquitto_log_callback_set(mosq, my_log_callback);
 		mosquitto_subscribe_callback_set(mosq, my_subscribe_callback);
 	}
-	mosquitto_connect_callback_set(mosq, my_connect_callback);
+	mosquitto_connect_with_flags_callback_set(mosq, my_connect_callback);
 	mosquitto_message_callback_set(mosq, my_message_callback);
 
 	rc = client_connect(mosq, &cfg);

lib/handle_connack.c

@@ -26,12 +26,12 @@ Contributors:
 
 int handle__connack(struct mosquitto *mosq)
 {
-	uint8_t byte;
+	uint8_t connect_flags;
 	uint8_t result;
 	int rc;
 
 	assert(mosq);
-	rc = packet__read_byte(&mosq->in_packet, &byte); // Reserved byte, not used
+	rc = packet__read_byte(&mosq->in_packet, &connect_flags);
 	if(rc) return rc;
 	rc = packet__read_byte(&mosq->in_packet, &result);
 	if(rc) return rc;
@@ -42,6 +42,11 @@ int handle__connack(struct mosquitto *mosq)
 		mosq->on_connect(mosq, mosq->userdata, result);
 		mosq->in_callback = false;
 	}
+	if(mosq->on_connect_with_flags){
+		mosq->in_callback = true;
+		mosq->on_connect_with_flags(mosq, mosq->userdata, result, connect_flags);
+		mosq->in_callback = false;
+	}
 	pthread_mutex_unlock(&mosq->callback_mutex);
 	switch(result){
 		case 0:

lib/linker.version

@@ -89,4 +89,5 @@ MOSQ_1.5 {
 		mosquitto_pub_topic_check2;
 		mosquitto_sub_topic_check2;
 		mosquitto_topic_matches_sub2;
+		mosquitto_connect_with_flags_callback_set;
 } MOSQ_1.4;

lib/mosquitto.c

@@ -1225,6 +1225,13 @@ void mosquitto_connect_callback_set(struct mosquitto *mosq, void (*on_connect)(s
 	pthread_mutex_unlock(&mosq->callback_mutex);
 }
 
+void mosquitto_connect_with_flags_callback_set(struct mosquitto *mosq, void (*on_connect)(struct mosquitto *, void *, int, int))
+{
+	pthread_mutex_lock(&mosq->callback_mutex);
+	mosq->on_connect_with_flags = on_connect;
+	pthread_mutex_unlock(&mosq->callback_mutex);
+}
+
 void mosquitto_disconnect_callback_set(struct mosquitto *mosq, void (*on_disconnect)(struct mosquitto *, void *, int))
 {
 	pthread_mutex_lock(&mosq->callback_mutex);

lib/mosquitto.h

@@ -1133,6 +1133,31 @@ libmosq_EXPORT int mosquitto_tls_psk_set(struct mosquitto *mosq, const char *psk
  */
 libmosq_EXPORT void mosquitto_connect_callback_set(struct mosquitto *mosq, void (*on_connect)(struct mosquitto *, void *, int));
 
+/*
+ * Function: mosquitto_connect_with_flags_callback_set
+ *
+ * Set the connect callback. This is called when the broker sends a CONNACK
+ * message in response to a connection.
+ *
+ * Parameters:
+ *  mosq -       a valid mosquitto instance.
+ *  on_connect - a callback function in the following form:
+ *               void callback(struct mosquitto *mosq, void *obj, int rc)
+ *
+ * Callback Parameters:
+ *  mosq - the mosquitto instance making the callback.
+ *  obj - the user data provided in <mosquitto_new>
+ *  rc -  the return code of the connection response, one of:
+ *  flags - the connect flags.
+ *
+ * * 0 - success
+ * * 1 - connection refused (unacceptable protocol version)
+ * * 2 - connection refused (identifier rejected)
+ * * 3 - connection refused (broker unavailable)
+ * * 4-255 - reserved for future use
+ */
+libmosq_EXPORT void mosquitto_connect_with_flags_callback_set(struct mosquitto *mosq, void (*on_connect)(struct mosquitto *, void *, int, int));
+
 /*
  * Function: mosquitto_disconnect_callback_set
  *

lib/mosquitto_internal.h

@@ -246,6 +246,7 @@ struct mosquitto {
 	struct mosquitto_message_all *out_messages;
 	struct mosquitto_message_all *out_messages_last;
 	void (*on_connect)(struct mosquitto *, void *userdata, int rc);
+	void (*on_connect_with_flags)(struct mosquitto *, void *userdata, int rc, int flags);
 	void (*on_disconnect)(struct mosquitto *, void *userdata, int rc);
 	void (*on_publish)(struct mosquitto *, void *userdata, int mid);
 	void (*on_message)(struct mosquitto *, void *userdata, const struct mosquitto_message *message);