First stable compilation with ModbusRTU and ModbusTCP

lib/modbus-esp8266/ModbusEthernet.h

@@ -0,0 +1,59 @@
+/*
+    Modbus Library for Arduino
+    ModbusTCP for W5x00 Ethernet
+    Copyright (C) 2022 Alexander Emelianov (a.m.emelianov@gmail.com)
+*/
+
+#pragma once
+#if defined(MODBUSIP_USE_DNS)
+#include <Dns.h>
+#endif
+#include "ModbusAPI.h"
+#include "ModbusTCPTemplate.h"
+#if defined(ARDUINO_PORTENTA_H7_M4) || defined(ARDUINO_PORTENTA_H7_M7) || defined(ARDUINO_PORTENTA_X8)
+#define MODBUS_ETH_WRAP_ACCEPT
+#undef MODBUS_ETH_WRAP_BEGIN
+#elif defined(ESP32)
+#undef MODBUS_ETH_WRAP_ACCEPT
+#define MODBUS_ETH_WRAP_BEGIN
+#else
+#undef MODBUS_ETH_WRAP_ACCEPT
+#undef MODBUS_ETH_WRAP_BEGIN
+#endif
+// Ethernet class wrapper to be able to compile for ESP32
+class EthernetServerWrapper : public EthernetServer {
+    public:
+    EthernetServerWrapper(uint16_t port) : EthernetServer(port) {
+
+    }
+#if defined(MODBUS_ETH_WRAP_BEGIN)
+    void begin(uint16_t port=0) {
+        EthernetServer::begin();
+    }
+#endif
+#if defined(MODBUS_ETH_WRAP_ACCEPT)
+    inline EthernetClient accept() {
+        return available();
+    }
+#endif
+};
+
+class ModbusEthernet : public ModbusAPI<ModbusTCPTemplate<EthernetServerWrapper, EthernetClient>> {
+#if defined(MODBUSIP_USE_DNS)
+    private:
+    static IPAddress resolver (const char* host) {
+        DNSClient dns;
+        IPAddress ip;
+        
+        dns.begin(Ethernet.dnsServerIP());
+        if (dns.getHostByName(host, ip) == 1)
+            return ip;
+        else
+            return IPADDR_NONE;
+    }
+    public:
+    ModbusEthernet() : ModbusAPI() {
+        resolve = resolver;
+    }
+#endif
+};