Bugfix: Expose config to error handler to be able to change and reconnect

Re #16

Readme.md

@@ -19,7 +19,6 @@ MQTT library for multiple platforms including embedded targets.
 
 - [ ] QoS testing, client -> server QoS partly works, server -> client does not
 - [ ] Running in MQTT Broker mode
-- [ ] Last will is implemented but not exposed in API
 - [ ] Implement Protocol level 3 (low prio)
 - [ ] Implement Draft Protocol level 5 (somewhat low prio as it's a draft spec)
 - [ ] Support ESP8266 (RTOS)
@@ -79,10 +78,15 @@ typedef struct {
     char *hostname;  /**< Hostname to connect to, will do DNS resolution */
     uint16_t port;   /**< Port the broker listens on, set to 0 for 1883 default */
 
-    char *client_id; /**< Client identification */
+    char *client_id;    /**< Client identification max 23 chars */
+    bool clean_session; /**< Set to true to reset the session on reconnect */
 
     char *username;  /**< User name, set to NULL to connect anonymously */
     char *password;  /**< Password, set to NULL to connect without password */
+
+    char *last_will_topic;   /**< last will topic that is automatically published on connection loss */
+    char *last_will_message; /**< last will message */
+    bool last_will_retain;   /**< tell server to retain last will message */
 } MQTTConfig;
 ```
 
@@ -104,7 +108,7 @@ or re-trying by changing settings and calling mqtt_reconnect() and returning fal
 The error handler should be defined like this:
 
 ```c
-bool error_handler(MQTTHandle *handle, MQTTErrorCode code) {
+bool error_handler(MQTTHandle *handle, MQTTConfig *config, MQTTErrorCode code) {
 
     return true; // kill the handle, return false to keep it
 }
@@ -138,10 +142,11 @@ a successful reconnect.
 #### Subscribe to a topic
 
 ```c
-MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTPublishEventHandler callback);
+MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTQosLevel qos_level, MQTTPublishEventHandler callback);
 ```
 - `handle`: MQTT Handle from `mqtt_connect`
 - `topic`: Topic to subscribe
+- `qos_level`: Maximum QoS level to subscribe for
 - `callback`: Callback function to call when receiving something for that topic
 - Returns status code
 
@@ -174,6 +179,7 @@ MQTTStatus mqtt_publish(MQTTHandle *handle, char *topic, char *payload, MQTTQosL
 - `handle`: MQTT Handle from `mqtt_connect`
 - `topic`: Topic to publish to
 - `payload`: Message payload to publish
+- `qos_level`: QoS Level for the publish (0 = Fire and forget, 1 = At least once, 2 = One time for sure)
 - Returns status code
 
 This uses a c-string as the payload, theoretically the protocol would allow for binary payloads, but this is currently

src/mqtt.c

@@ -137,7 +137,7 @@ static void _mqtt_connect(MQTTHandle *handle, MQTTEventHandler callback, void *c
 
     char ip[40];
     if (!hostname_to_ip(handle->config->hostname, ip)) {
-        bool free_handle = handle->error_handler(handle, MQTT_Error_Host_Not_Found);
+        bool free_handle = handle->error_handler(handle, handle->config, MQTT_Error_Host_Not_Found);
         if (free_handle) {
             mqtt_free(handle);
         }
@@ -147,7 +147,7 @@ static void _mqtt_connect(MQTTHandle *handle, MQTTEventHandler callback, void *c
     }
     ret = inet_pton(AF_INET, ip, &(servaddr.sin_addr));
     if (ret == 0) {
-        bool free_handle = handle->error_handler(handle, MQTT_Error_Host_Not_Found);
+        bool free_handle = handle->error_handler(handle, handle->config, MQTT_Error_Host_Not_Found);
         if (free_handle) {
             mqtt_free(handle);
         }
@@ -158,7 +158,7 @@ static void _mqtt_connect(MQTTHandle *handle, MQTTEventHandler callback, void *c
 
     ret = connect(handle->sock, (struct sockaddr *)&servaddr, sizeof(servaddr));
     if (ret != 0) {
-        bool free_handle = handle->error_handler(handle, MQTT_Error_Connection_Refused);
+        bool free_handle = handle->error_handler(handle, handle->config, MQTT_Error_Connection_Refused);
         if (free_handle) {
             mqtt_free(handle);
         }
@@ -174,7 +174,7 @@ static void _mqtt_connect(MQTTHandle *handle, MQTTEventHandler callback, void *c
     bool result = send_connect_packet(handle);
     if (result == false) {
         DEBUG_LOG("Sending connect packet failed, running error handler");
-        bool free_handle = handle->error_handler(handle, MQTT_Error_Broker_Disconnected);
+        bool free_handle = handle->error_handler(handle, handle->config, MQTT_Error_Broker_Disconnected);
         if (free_handle) {
             mqtt_free(handle);
         }
@@ -223,7 +223,7 @@ MQTTStatus mqtt_reconnect(MQTTHandle *handle, MQTTEventHandler callback, void *c
 
 MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTQosLevel qos_level, MQTTPublishEventHandler callback) {
     if (!handle->reader_alive) {
-        handle->error_handler(handle, MQTT_Error_Connection_Reset);
+        handle->error_handler(handle, handle->config, MQTT_Error_Connection_Reset);
         return MQTT_STATUS_ERROR;
     }
     add_subscription(handle, topic, qos_level, callback);
@@ -232,7 +232,7 @@ MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTQosLevel qos_leve
 
 MQTTStatus mqtt_unsubscribe(MQTTHandle *handle, char *topic) {
     if (!handle->reader_alive) {
-        handle->error_handler(handle, MQTT_Error_Connection_Reset);
+        handle->error_handler(handle, handle->config, MQTT_Error_Connection_Reset);
         return MQTT_STATUS_ERROR;
     }
     remove_subscription(handle, topic);
@@ -241,7 +241,7 @@ MQTTStatus mqtt_unsubscribe(MQTTHandle *handle, char *topic) {
 
 MQTTStatus mqtt_publish(MQTTHandle *handle, char *topic, char *payload, MQTTQosLevel qos_level) {
     if (!handle->reader_alive) {
-        handle->error_handler(handle, MQTT_Error_Connection_Reset);
+        handle->error_handler(handle, handle->config, MQTT_Error_Connection_Reset);
         return MQTT_STATUS_ERROR;
     }
     return (send_publish_packet(handle, topic, payload, qos_level) ? MQTT_STATUS_OK : MQTT_STATUS_ERROR);

src/mqtt.h

@@ -45,7 +45,7 @@ typedef enum {
  *
  * Return true if the handle should be freed, false to keep it
  */
-typedef bool (*MQTTErrorHandler)(MQTTHandle *handle, MQTTErrorCode code);
+typedef bool (*MQTTErrorHandler)(MQTTHandle *handle, MQTTConfig *config, MQTTErrorCode code);
 
 /** Event handler callback */
 typedef void (*MQTTEventHandler)(MQTTHandle *handle, void *context);

tests/connect_publish.c

@@ -8,7 +8,7 @@ bool leave = false;
 
 #define LOG(fmt, ...) fprintf(stdout, fmt "\n", ## __VA_ARGS__)
 
-bool err_handler(MQTTHandle *handle, MQTTErrorCode error) {
+bool err_handler(MQTTHandle *handle, MQTTConfig *config, MQTTErrorCode error) {
     LOG("Error received: %d", error);
     exit(1);
 

tests/connect_subscribe.c

@@ -8,7 +8,7 @@ bool leave = false;
 
 #define LOG(fmt, ...) fprintf(stdout, fmt "\n", ## __VA_ARGS__)
 
-bool err_handler(MQTTHandle *handle, MQTTErrorCode error) {
+bool err_handler(MQTTHandle *handle, MQTTConfig *config, MQTTErrorCode error) {
     LOG("Error received: %d", error);
 
     return 1;

tests/encode_packet.c

@@ -286,6 +286,7 @@ TestResult test_encode_publish_dup_qos0(void) {
     Buffer *encoded = mqtt_packet_encode(&(MQTTPacket){ PacketTypePublish, payload });
     free(payload);
     TESTASSERT(encoded == NULL, "DUP and QoS level 0 is an incompatible combination");
+    TEST_OK();
 }
 
 TestResult test_encode_publish_with_msg(void) {