Modify esp-tls and tcp_transport to support keep alive for tcp and ssl connection

Closes IDFGH-4543

components/tcp_transport/include/esp_transport.h

@@ -16,11 +16,21 @@
 #define _ESP_TRANSPORT_H_
 
 #include <esp_err.h>
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+*  @brief Keep alive parameters structure
+*/
+typedef struct esp_transport_keepalive {
+    bool            keep_alive_enable;      /*!< Enable keep-alive timeout */
+    int             keep_alive_idle;        /*!< Keep-alive idle time (second) */
+    int             keep_alive_interval;    /*!< Keep-alive interval time (second) */
+    int             keep_alive_count;       /*!< Keep-alive packet retry send count */
+} esp_transport_keep_alive_t;
 
 typedef struct esp_transport_internal* esp_transport_list_handle_t;
 typedef struct esp_transport_item_t* esp_transport_handle_t;

components/tcp_transport/include/esp_transport_ssl.h

@@ -165,6 +165,14 @@ void esp_transport_ssl_set_ds_data(esp_transport_handle_t t, void *ds_data);
  */
 void esp_transport_ssl_set_psk_key_hint(esp_transport_handle_t t, const psk_hint_key_t* psk_hint_key);
 
+/**
+ * @brief      Set keep-alive status in current ssl context
+ *
+ * @param[in]  t               ssl transport
+ * @param[in]  keep_alive_cfg  The handle for keep-alive configuration
+ */
+void esp_transport_ssl_set_keep_alive(esp_transport_handle_t t, esp_transport_keep_alive_t *keep_alive_cfg);
+
 #ifdef __cplusplus
 }
 #endif

components/tcp_transport/include/esp_transport_tcp.h

@@ -21,6 +21,15 @@
 extern "C" {
 #endif
 
+/**
+ * @brief      Set TCP keep-alive configuration
+ *
+ * @param[in]  t               The transport handle
+ * @param[in]  keep_alive_cfg  The keep-alive config
+ *
+ */
+void esp_transport_tcp_set_keep_alive(esp_transport_handle_t t, esp_transport_keep_alive_t *keep_alive_cfg);
+
 /**
  * @brief      Create TCP transport, the transport handle must be release esp_transport_destroy callback
  *