Adding softAP SSID & PSK query API (#4138)

* softAP SSID & PSK query API added.
Signatures:
String ESP8266WiFiAP::softAPSSID() const;
String ESP8266WiFiAP::softAPPSK() const;

* Fix for proper C-style string copy

* add API to validate input ip as string
Signatures:
static bool IPAddress::isValid(const String& arg);
static bool IPAddress::isValid(const char* arg, size_t len);

* fix indentation

* fix ip string validation to use built-in implementation.
signatures:
static bool isValid(const String& arg);
static bool isValid(const char* arg);

cores/esp8266/IPAddress.cpp

@@ -112,4 +112,12 @@ String IPAddress::toString() const
     return String(szRet);
 }
 
+bool IPAddress::isValid(const String& arg) {
+	return IPAddress().fromString(arg);
+}
+
+bool IPAddress::isValid(const char* arg) {
+	return IPAddress().fromString(arg);
+}
+
 const IPAddress INADDR_NONE(0, 0, 0, 0);

cores/esp8266/IPAddress.h

@@ -79,6 +79,14 @@ class IPAddress: public Printable {
         virtual size_t printTo(Print& p) const;
         String toString() const;
 
+	/* 
+		check if input string(arg) is a valid IPV4 address or not.
+		return true on valid.
+		return false on invalid.
+	*/
+	static bool isValid(const String& arg);
+	static bool isValid(const char* arg);
+
         friend class EthernetClass;
         friend class UDP;
         friend class Client;

libraries/ESP8266WiFi/src/ESP8266WiFiAP.cpp

@@ -339,3 +339,33 @@ String ESP8266WiFiAPClass::softAPmacAddress(void) {
     sprintf(macStr, "%02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
     return String(macStr);
 }
+
+/**
+ * Get the configured(Not-In-Flash) softAP SSID name.
+ * @return String SSID.
+ */
+String ESP8266WiFiAPClass::softAPSSID() const {
+	struct softap_config config;
+	wifi_softap_get_config(&config);
+	char* name = reinterpret_cast<char*>(config.ssid);
+	char ssid[sizeof(config.ssid) + 1];
+	memcpy(ssid, name, sizeof(config.ssid));
+	ssid[sizeof(config.ssid)] = '\0';
+
+	return String(ssid);
+}
+
+/**
+ * Get the configured(Not-In-Flash) softAP PSK or PASSWORD.
+ * @return String psk.
+ */
+String ESP8266WiFiAPClass::softAPPSK() const {
+	struct softap_config config;
+	wifi_softap_get_config(&config);
+	char* pass = reinterpret_cast<char*>(config.password);
+	char psk[sizeof(config.password) + 1];
+	memcpy(psk, pass, sizeof(config.password));
+	psk[sizeof(config.password)] = '\0';
+
+	return String(psk);
+}

libraries/ESP8266WiFi/src/ESP8266WiFiAP.h

@@ -47,6 +47,9 @@ class ESP8266WiFiAPClass {
         uint8_t* softAPmacAddress(uint8_t* mac);
         String softAPmacAddress(void);
 
+	String softAPSSID() const;
+	String softAPPSK() const;
+
     protected:
 
 };