From 584d85650ed44c5b205a74364591af87012e4455 Mon Sep 17 00:00:00 2001
From: Eric Blankenhorn <eric@wolfssl.com>
Date: Thu, 20 Aug 2020 11:40:50 -0500
Subject: [PATCH] Fix for publish with short topic name and example

---
 examples/sn-client/sn-client.c | 56 ++++++++++++++++++++++++++++++++--
 src/mqtt_client.c              | 11 ++-----
 src/mqtt_packet.c              | 12 +++++++-
 3 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/examples/sn-client/sn-client.c b/examples/sn-client/sn-client.c
index 4d86b71..cbc7438 100644
--- a/examples/sn-client/sn-client.c
+++ b/examples/sn-client/sn-client.c
@@ -38,7 +38,7 @@ static int mStopRead = 0;
 /* Maximum size for network read/write callbacks. */
 #define MAX_BUFFER_SIZE 1024
 #define TEST_MESSAGE    "test"
-
+#define SHORT_TOPIC_NAME "s1"
 
 static int sn_message_cb(MqttClient *client, MqttMessage *msg,
     byte msg_new, byte msg_done)
@@ -247,6 +247,53 @@ int sn_test(MQTTCtx *mqttCtx)
         }
     }
 
+    {
+        /* Short Topic Name Subscribe */
+        SN_Subscribe subscribe;
+        SN_Publish publish;
+
+        XMEMSET(&subscribe, 0, sizeof(SN_Subscribe));
+
+        subscribe.duplicate = 0;
+        subscribe.qos = MQTT_QOS_0;
+        subscribe.topic_type = SN_TOPIC_ID_TYPE_SHORT;
+        subscribe.topicNameId = SHORT_TOPIC_NAME;
+        subscribe.packet_id = mqtt_get_packetid();
+
+        PRINTF("MQTT-SN Subscribe: topic name = %s", subscribe.topicNameId);
+        rc = SN_Client_Subscribe(&mqttCtx->client, &subscribe);
+
+        PRINTF("....MQTT-SN Subscribe Ack: topic id = %d, rc = %d",
+                subscribe.subAck.topicId, subscribe.subAck.return_code);
+
+        /* Short Topic Name Publish */
+        XMEMSET(&publish, 0, sizeof(SN_Publish));
+        publish.retain = 0;
+        publish.qos = mqttCtx->qos;
+        publish.duplicate = 0;
+        publish.topic_type = SN_TOPIC_ID_TYPE_SHORT;
+        publish.topic_name = SHORT_TOPIC_NAME;
+        if (publish.qos > MQTT_QOS_0) {
+            publish.packet_id = mqtt_get_packetid();
+        }
+        else {
+            publish.packet_id = 0x00;
+        }
+
+        publish.buffer = (byte*)TEST_MESSAGE;
+        publish.total_len = (word16)XSTRLEN(TEST_MESSAGE);
+
+        rc = SN_Client_Publish(&mqttCtx->client, &publish);
+
+        PRINTF("MQTT-SN Publish: topic id = %d, rc = %d\r\nPayload = %s",
+            (word16)*publish.topic_name,
+            publish.return_code,
+            publish.buffer);
+        if (rc != MQTT_CODE_SUCCESS) {
+            goto disconn;
+        }
+    }
+
     /* Read Loop */
     PRINTF("MQTT Waiting for message...");
 
@@ -279,7 +326,12 @@ int sn_test(MQTTCtx *mqttCtx)
                 mqttCtx->publishSN.duplicate = 0;
                 mqttCtx->publishSN.topic_type = SN_TOPIC_ID_TYPE_NORMAL;
                 mqttCtx->publishSN.topic_name = (char*)&topicID;
-                mqttCtx->publishSN.packet_id = mqtt_get_packetid();
+                if (mqttCtx->publishSN.qos > MQTT_QOS_0) {
+                    mqttCtx->publishSN.packet_id = mqtt_get_packetid();
+                }
+                else {
+                    mqttCtx->publishSN.packet_id = 0x00;
+                }
                 mqttCtx->publishSN.buffer = mqttCtx->rx_buf;
                 mqttCtx->publishSN.total_len = (word16)rc;
                 rc = SN_Client_Publish(&mqttCtx->client,
diff --git a/src/mqtt_client.c b/src/mqtt_client.c
index 532f60d..885f5c5 100644
--- a/src/mqtt_client.c
+++ b/src/mqtt_client.c
@@ -2417,9 +2417,6 @@ wait_again:
             goto wait_again;
         }
 
-    #ifdef WOLFMQTT_V5
-        case MQTT_MSG_AUTH:
-    #endif
         case MQTT_MSG_WRITE:
         default:
         {
@@ -2735,9 +2732,6 @@ int SN_Client_Publish(MqttClient *client, SN_Publish *publish)
             break;
         }
 
-    #ifdef WOLFMQTT_V5
-        case MQTT_MSG_AUTH:
-    #endif
         case MQTT_MSG_READ:
         case MQTT_MSG_READ_PAYLOAD:
         #ifdef WOLFMQTT_DEBUG_CLIENT
@@ -2822,6 +2816,7 @@ int SN_Client_Register(MqttClient *client, SN_Register *regist)
 int SN_Client_Ping(MqttClient *client, SN_PingReq *ping)
 {
     int rc, len;
+    SN_PingReq loc_ping;
 
     /* Validate required arguments */
     if (client == NULL) {
@@ -2829,8 +2824,8 @@ int SN_Client_Ping(MqttClient *client, SN_PingReq *ping)
     }
 
     if (ping == NULL) {
-        /* use client global */
-        ping = &client->msgSN.pingReq;
+        XMEMSET(&loc_ping, 0, sizeof(SN_PingReq));
+        ping = &loc_ping;
     }
 
     if (ping->stat == MQTT_MSG_BEGIN) {
diff --git a/src/mqtt_packet.c b/src/mqtt_packet.c
index 9423d08..e77d214 100755
--- a/src/mqtt_packet.c
+++ b/src/mqtt_packet.c
@@ -2712,7 +2712,17 @@ int SN_Encode_Publish(byte *tx_buf, int tx_buf_len, SN_Publish *publish)
 
     *tx_payload++ = flags;
 
-    tx_payload += MqttEncode_Num(tx_payload, (word16)*publish->topic_name);
+    /* Encode topic */
+    if (publish->topic_type == SN_TOPIC_ID_TYPE_SHORT) {
+        /* Short topic name is 2 chars */
+        XMEMCPY(tx_payload, publish->topic_name, 2);
+        tx_payload += 2;
+    }
+    else {
+        /* Topic ID */
+        tx_payload += MqttEncode_Num(tx_payload, (word16)*publish->topic_name);
+    }
+
     tx_payload += MqttEncode_Num(tx_payload, publish->packet_id);
 
     /* Encode payload */