az_iot_hub_client.h

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// Copyright (c) Microsoft Corporation. All rights reserved.
// SPDX-License-Identifier: MIT
 
#ifndef _az_IOT_HUB_CLIENT_H
#define _az_IOT_HUB_CLIENT_H
 
#include <azure/core/az_result.h>
#include <azure/core/az_span.h>
#include <azure/iot/az_iot_common.h>
 
#include <stdbool.h>
#include <stdint.h>
 
#include <azure/core/_az_cfg_prefix.h>
 
enum
{
  AZ_HUB_CLIENT_DEFAULT_MQTT_TELEMETRY_QOS = 0
};
 
typedef struct
{
  az_span module_id; 
  az_span user_agent; 
  az_span model_id; 
} az_iot_hub_client_options;
 
typedef struct
{
  struct
  {
    az_span iot_hub_hostname;
    az_span device_id;
    az_iot_hub_client_options options;
  } _internal;
} az_iot_hub_client;
 
AZ_NODISCARD az_iot_hub_client_options az_iot_hub_client_options_default();
 
AZ_NODISCARD az_result az_iot_hub_client_init(
    az_iot_hub_client* client,
    az_span iot_hub_hostname,
    az_span device_id,
    az_iot_hub_client_options const* options);
 
#define AZ_IOT_HUB_CLIENT_WEB_SOCKET_PATH "/$iothub/websocket"
 
#define AZ_IOT_HUB_CLIENT_WEB_SOCKET_PATH_NO_X509_CLIENT_CERT \
  AZ_IOT_HUB_CLIENT_WEB_SOCKET_PATH "?iothub-no-client-cert=true"
 
AZ_NODISCARD az_result az_iot_hub_client_get_user_name(
    az_iot_hub_client const* client,
    char* mqtt_user_name,
    size_t mqtt_user_name_size,
    size_t* out_mqtt_user_name_length);
 
AZ_NODISCARD az_result az_iot_hub_client_get_client_id(
    az_iot_hub_client const* client,
    char* mqtt_client_id,
    size_t mqtt_client_id_size,
    size_t* out_mqtt_client_id_length);
 
/*
 *
 * SAS Token APIs
 *
 *   Use the following APIs when the Shared Access Key is available to the application or stored
 *   within a Hardware Security Module. The APIs are not necessary if X509 Client Certificate
 *   Authentication is used.
 */
 
AZ_NODISCARD az_result az_iot_hub_client_sas_get_signature(
    az_iot_hub_client const* client,
    uint64_t token_expiration_epoch_time,
    az_span signature,
    az_span* out_signature);
 
AZ_NODISCARD az_result az_iot_hub_client_sas_get_password(
    az_iot_hub_client const* client,
    uint64_t token_expiration_epoch_time,
    az_span base64_hmac_sha256_signature,
    az_span key_name,
    char* mqtt_password,
    size_t mqtt_password_size,
    size_t* out_mqtt_password_length);
 
/*
 *
 * Telemetry APIs
 *
 */
 
AZ_NODISCARD az_result az_iot_hub_client_telemetry_get_publish_topic(
    az_iot_hub_client const* client,
    az_iot_message_properties const* properties,
    char* mqtt_topic,
    size_t mqtt_topic_size,
    size_t* out_mqtt_topic_length);
 
/*
 *
 * Cloud-to-device (C2D) APIs
 *
 */
 
#define AZ_IOT_HUB_CLIENT_C2D_SUBSCRIBE_TOPIC "devices/+/messages/devicebound/#"
 
typedef struct
{
  az_iot_message_properties properties; 
} az_iot_hub_client_c2d_request;
 
AZ_NODISCARD az_result az_iot_hub_client_c2d_parse_received_topic(
    az_iot_hub_client const* client,
    az_span received_topic,
    az_iot_hub_client_c2d_request* out_request);
 
/*
 *
 * Methods APIs
 *
 */
 
#define AZ_IOT_HUB_CLIENT_METHODS_SUBSCRIBE_TOPIC "$iothub/methods/POST/#"
 
typedef struct
{
  az_span request_id; 
  az_span name; 
} az_iot_hub_client_method_request;
 
AZ_NODISCARD az_result az_iot_hub_client_methods_parse_received_topic(
    az_iot_hub_client const* client,
    az_span received_topic,
    az_iot_hub_client_method_request* out_request);
 
AZ_NODISCARD az_result az_iot_hub_client_methods_response_get_publish_topic(
    az_iot_hub_client const* client,
    az_span request_id,
    uint16_t status,
    char* mqtt_topic,
    size_t mqtt_topic_size,
    size_t* out_mqtt_topic_length);
 
/*
 *
 * Twin APIs
 *
 */
 
#define AZ_IOT_HUB_CLIENT_TWIN_RESPONSE_SUBSCRIBE_TOPIC "$iothub/twin/res/#"
 
#define AZ_IOT_HUB_CLIENT_TWIN_PATCH_SUBSCRIBE_TOPIC "$iothub/twin/PATCH/properties/desired/#"
 
typedef enum
{
  AZ_IOT_HUB_CLIENT_TWIN_RESPONSE_TYPE_GET = 1,
  AZ_IOT_HUB_CLIENT_TWIN_RESPONSE_TYPE_DESIRED_PROPERTIES = 2,
  AZ_IOT_HUB_CLIENT_TWIN_RESPONSE_TYPE_REPORTED_PROPERTIES = 3,
} az_iot_hub_client_twin_response_type;
 
typedef struct
{
  az_span
      request_id; 
  // Avoid using enum as the first field within structs, to allow for { 0 } initialization.
  // This is a workaround for IAR compiler warning [Pe188]: enumerated type mixed with another type.
 
  az_iot_hub_client_twin_response_type response_type; 
  az_iot_status status; 
  az_span version; 
} az_iot_hub_client_twin_response;
 
AZ_NODISCARD az_result az_iot_hub_client_twin_parse_received_topic(
    az_iot_hub_client const* client,
    az_span received_topic,
    az_iot_hub_client_twin_response* out_response);
 
AZ_NODISCARD az_result az_iot_hub_client_twin_document_get_publish_topic(
    az_iot_hub_client const* client,
    az_span request_id,
    char* mqtt_topic,
    size_t mqtt_topic_size,
    size_t* out_mqtt_topic_length);
 
AZ_NODISCARD az_result az_iot_hub_client_twin_patch_get_publish_topic(
    az_iot_hub_client const* client,
    az_span request_id,
    char* mqtt_topic,
    size_t mqtt_topic_size,
    size_t* out_mqtt_topic_length);
 
#include <azure/core/_az_cfg_suffix.h>
 
#endif // _az_IOT_HUB_CLIENT_H