From d490ff27adbbee741ebd9616cb04028ecd069a89 Mon Sep 17 00:00:00 2001
From: Flavio Santes <flavio.santes@intel.com>
Date: Thu, 15 Dec 2016 23:17:12 -0600
Subject: [PATCH] net/mqtt: Add the mqtt_rx_publish routine

The mqtt_rx_publish is used to process incoming MQTT PUBLISH
messages. This routine performes the following steps:

- take ownership of the rx buffer containing the MQTT PUBLISH msg,
- call the MQTT parser routine, and
- determine, based on the incoming message's MQTT QoS,
  the next action.

Change-Id: I3cc011cf0c280205161d0484f12a2cfa79fdf44a
Signed-off-by: Flavio Santes <flavio.santes@intel.com>
---
 include/net/mqtt.h         | 10 ++++++++++
 subsys/net/lib/mqtt/mqtt.c | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/include/net/mqtt.h b/include/net/mqtt.h
index 14214e61016..5b682bd62f6 100644
--- a/include/net/mqtt.h
+++ b/include/net/mqtt.h
@@ -403,4 +403,14 @@ int mqtt_rx_suback(struct mqtt_ctx *ctx, struct net_buf *rx);
  */
 int mqtt_rx_unsuback(struct mqtt_ctx *ctx, struct net_buf *rx);
 
+/**
+ * @brief mqtt_rx_publish	Parses the MQTT PUBLISH message
+ * @param [in] ctx		MQTT context structure
+ * @param [in] rx		RX buffer from the IP stack
+ * @return			0 on success
+ * @return			-EINVAL on error
+ * @return			-ENOMEM if no data buffer is available
+ */
+int mqtt_rx_publish(struct mqtt_ctx *ctx, struct net_buf *rx);
+
 #endif
diff --git a/subsys/net/lib/mqtt/mqtt.c b/subsys/net/lib/mqtt/mqtt.c
index d88011268c2..f8d868807fb 100644
--- a/subsys/net/lib/mqtt/mqtt.c
+++ b/subsys/net/lib/mqtt/mqtt.c
@@ -595,3 +595,37 @@ int mqtt_rx_unsuback(struct mqtt_ctx *ctx, struct net_buf *rx)
 
 	return 0;
 }
+
+int mqtt_rx_publish(struct mqtt_ctx *ctx, struct net_buf *rx)
+{
+	struct mqtt_publish_msg msg;
+	int rc;
+
+	rc = mqtt_unpack_publish(rx->data, rx->len, &msg);
+	if (rc != 0) {
+		return -EINVAL;
+	}
+
+	rc = ctx->publish_rx(ctx->publish_rx_data, &msg, msg.pkt_id,
+			     MQTT_PUBLISH);
+	if (rc != 0) {
+		return -EINVAL;
+	}
+
+	switch (msg.qos) {
+	case MQTT_QoS2:
+		rc = mqtt_tx_pubrec(ctx, msg.pkt_id);
+		break;
+	case MQTT_QoS1:
+		rc = mqtt_tx_puback(ctx, msg.pkt_id);
+		break;
+	case MQTT_QoS0:
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+