Fix unnecessary DNS query in hostByName and deadlock in ssl_client (#7351)

* Fix hostByName to avoid asking DNS when valid IP is passed via hostname param
* Fix hanging in send_ssl_data

Author: cziter15

Diff for: libraries/WiFi/src/WiFiGeneric.cpp

@@ -1447,28 +1447,31 @@ static void wifi_dns_found_callback(const char *name, const ip_addr_t *ipaddr, v
 }
 
 /**
- * Resolve the given hostname to an IP address.
- * @param aHostname     Name to be resolved
+ * Resolve the given hostname to an IP address. If passed hostname is an IP address, it will be parsed into IPAddress structure.
+ * @param aHostname     Name to be resolved or string containing IP address
  * @param aResult       IPAddress structure to store the returned IP address
  * @return 1 if aIPAddrString was successfully converted to an IP address,
  *          else error code
  */
 int WiFiGenericClass::hostByName(const char* aHostname, IPAddress& aResult)
 {
-    ip_addr_t addr;
-    aResult = static_cast<uint32_t>(0);
-    waitStatusBits(WIFI_DNS_IDLE_BIT, 16000);
-    clearStatusBits(WIFI_DNS_IDLE_BIT | WIFI_DNS_DONE_BIT);
-    err_t err = dns_gethostbyname(aHostname, &addr, &wifi_dns_found_callback, &aResult);
-    if(err == ERR_OK && addr.u_addr.ip4.addr) {
-        aResult = addr.u_addr.ip4.addr;
-    } else if(err == ERR_INPROGRESS) {
-        waitStatusBits(WIFI_DNS_DONE_BIT, 15000);  //real internal timeout in lwip library is 14[s]
-        clearStatusBits(WIFI_DNS_DONE_BIT);
-    }
-    setStatusBits(WIFI_DNS_IDLE_BIT);
-    if((uint32_t)aResult == 0){
-        log_e("DNS Failed for %s", aHostname);
+    if (!aResult.fromString(aHostname))
+    {
+        ip_addr_t addr;
+        aResult = static_cast<uint32_t>(0);
+        waitStatusBits(WIFI_DNS_IDLE_BIT, 16000);
+        clearStatusBits(WIFI_DNS_IDLE_BIT | WIFI_DNS_DONE_BIT);
+        err_t err = dns_gethostbyname(aHostname, &addr, &wifi_dns_found_callback, &aResult);
+        if(err == ERR_OK && addr.u_addr.ip4.addr) {
+            aResult = addr.u_addr.ip4.addr;
+        } else if(err == ERR_INPROGRESS) {
+            waitStatusBits(WIFI_DNS_DONE_BIT, 15000);  //real internal timeout in lwip library is 14[s]
+            clearStatusBits(WIFI_DNS_DONE_BIT);
+        }
+        setStatusBits(WIFI_DNS_IDLE_BIT);
+        if((uint32_t)aResult == 0){
+            log_e("DNS Failed for %s", aHostname);
+        }
     }
     return (uint32_t)aResult != 0;
 }

Diff for: libraries/WiFiClientSecure/src/ssl_client.cpp

@@ -90,6 +90,8 @@ int start_ssl_client(sslclient_context *ssl_client, const char *host, uint32_t p
         timeout = 30000; // Milli seconds.
     }
 
+    ssl_client->socket_timeout = timeout;
+
     fd_set fdset;
     struct timeval tv;
     FD_ZERO(&fdset);
@@ -341,12 +343,15 @@ void stop_ssl_socket(sslclient_context *ssl_client, const char *rootCABuff, cons
     mbedtls_ctr_drbg_free(&ssl_client->drbg_ctx);
     mbedtls_entropy_free(&ssl_client->entropy_ctx);
 
-    // save only interesting field
-    int timeout = ssl_client->handshake_timeout;
+    // save only interesting fields
+    int handshake_timeout = ssl_client->handshake_timeout;
+    int socket_timeout = ssl_client->socket_timeout;
+
     // reset embedded pointers to zero
     memset(ssl_client, 0, sizeof(sslclient_context));
 
-    ssl_client->handshake_timeout = timeout;
+    ssl_client->handshake_timeout = handshake_timeout;
+    ssl_client->socket_timeout = socket_timeout;
 }
 
 
@@ -369,11 +374,19 @@ int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, size_t len
     log_v("Writing HTTP request with %d bytes...", len); //for low level debug
     int ret = -1;
 
+    unsigned long write_start_time=millis();
+
     while ((ret = mbedtls_ssl_write(&ssl_client->ssl_ctx, data, len)) <= 0) {
+        if((millis()-write_start_time)>ssl_client->socket_timeout) {
+            log_v("SSL write timed out.");
+            return -1;
+        }
+
         if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret < 0) {
             log_v("Handling error %d", ret); //for low level debug
             return handle_error(ret);
         }
+        
         //wait for space to become available
         vTaskDelay(2);
     }

Diff for: libraries/WiFiClientSecure/src/ssl_client.h

@@ -24,6 +24,7 @@ typedef struct sslclient_context {
     mbedtls_x509_crt client_cert;
     mbedtls_pk_context client_key;
 
+    unsigned long socket_timeout;
     unsigned long handshake_timeout;
 } sslclient_context;