QoS handling and packet expectations in protocol implementation

src/protocol.c

@@ -8,20 +8,14 @@
 #include "debug.h"
 
 static bool send_buffer(MQTTHandle *handle, Buffer *buffer) {
-    DEBUG_LOG("Attempting to send:");
-    buffer_hexdump(buffer, 2);
-
-    while (buffer_free_space(buffer) > 0) {
+    while (!buffer_eof(buffer)) {
         ssize_t bytes = write(handle->sock, buffer->data + buffer->position, buffer_free_space(buffer));
         if (bytes <= 0) {
-            DEBUG_LOG("write error, %s", strerror(errno));
             buffer_release(buffer);
             return false;
         }
-        DEBUG_LOG("Wrote %zu bytes...", bytes);
         buffer->position += bytes;
     }
-    DEBUG_LOG("Buffer written...");
     buffer_release(buffer);
     return true;
 }
@@ -45,23 +39,32 @@ bool send_connect_packet(MQTTHandle *handle) {
     Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypeConnect, payload });
     free(payload);
 
-    // TODO: add waiting ConnAck to queue
+    // ConnAck waiting packet added to queue from _mqtt_connect
 
     encoded->position = 0;
     return send_buffer(handle, encoded);
 }
 
+void remove_pending(MQTTHandle *handle, void *context) {
+    SubscribePayload *payload = (SubscribePayload *)context;
+
+    subscription_set_pending(handle, payload->topic, false);
+
+    free(payload->topic);
+    free(payload);
+}
+
 bool send_subscribe_packet(MQTTHandle *handle, char *topic, MQTTQosLevel qos) {
     SubscribePayload *payload = calloc(1, sizeof(SubscribePayload));
 
     payload->packet_id = handle->packet_id_counter++;
-    payload->topic = topic;
+    payload->topic = strdup(topic);
     payload->qos = qos;
 
     Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypeSubscribe, payload });
-    free(payload);
 
-    // TODO: add waiting SubAck to queue
+    // add waiting for SubAck to queue
+    expect_packet(handle, PacketTypeSubAck, payload->packet_id, remove_pending, payload);
 
     encoded->position = 0;
     return send_buffer(handle, encoded);
@@ -74,13 +77,31 @@ bool send_unsubscribe_packet(MQTTHandle *handle, char *topic) {
     payload->topic = "test/topic";
 
     Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypeUnsubscribe, payload });
+
+    // add waiting for UnsubAck to queue
+    expect_packet(handle, PacketTypeUnsubAck, payload->packet_id, NULL, NULL);
     free(payload);
 
-    // TODO: add waiting UnsubAck to queue
     encoded->position = 0;
     return send_buffer(handle, encoded);
 }
 
+void handle_pubrec(MQTTHandle *handle, void *context) {
+    PublishPayload *payload = (PublishPayload *)context;
+
+    PubRelPayload newPayload = {
+        .packet_id = payload->packet_id
+    };
+
+    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePubRel, &newPayload });
+
+    expect_packet(handle, PacketTypePubComp, payload->packet_id, NULL, NULL);
+    free(payload);
+
+    encoded->position = 0;
+    send_buffer(handle, encoded);
+}
+
 bool send_publish_packet(MQTTHandle *handle, char *topic, char *message, MQTTQosLevel qos) {
     PublishPayload *payload = calloc(1, sizeof(PublishPayload));
 
@@ -91,10 +112,28 @@ bool send_publish_packet(MQTTHandle *handle, char *topic, char *message, MQTTQos
     payload->message = message;
 
     Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePublish, payload });
-    free(payload);
 
-    // TODO: Handle QoS and add waiting packets to queue
+    // Handle QoS and add waiting packets to queue
+    switch(payload->qos) {
+        case MQTT_QOS_0:
+            // fire and forget
+            free(payload);
+            break;
+        case MQTT_QOS_1:
+            expect_packet(handle, PacketTypePubAck, payload->packet_id, NULL, NULL);
+            free(payload);
+            break;
+        case MQTT_QOS_2:
+            expect_packet(handle, PacketTypePubRec, payload->packet_id, handle_pubrec, payload);
+            break;
+    }
 
     encoded->position = 0;
     return send_buffer(handle, encoded);
 }
+
+bool send_disconnect_packet(MQTTHandle *handle) {
+    Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypeDisconnect, NULL });
+    encoded->position = 0;
+    return send_buffer(handle, encoded);
+}

src/protocol.h

@@ -7,5 +7,6 @@ bool send_connect_packet(MQTTHandle *handle);
 bool send_subscribe_packet(MQTTHandle *handle, char *topic);
 bool send_unsubscribe_packet(MQTTHandle *handle, char *topic);
 bool send_publish_packet(MQTTHandle *handle, char *topic, char *message, MQTTQosLevel qos);
+bool send_disconnect_packet(MQTTHandle *handle);
 
 #endif