IPAddress.h

/*
 IPAddress.h - Base class that provides IPAddress
 Copyright (c) 2011 Adrian McEwen.  All right reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef IPAddress_h
#define IPAddress_h

#include <stdint.h>
#include <WString.h>
#include <Printable.h>

// A class to make it easier to handle and pass around IP addresses

class IPAddress: public Printable
{
private:
    union {
        uint8_t bytes[4];  // IPv4 address
        uint32_t dword;
    } _address;

    // Access the raw byte array containing the address.  Because this returns a pointer
    // to the internal structure rather than a copy of the address this function should only
    // be used when you know that the usage of the returned uint8_t* will be transient and not
    // stored.
    uint8_t* raw_address()
    {
        return _address.bytes;
    }

public:
    // Constructors
    IPAddress();
    IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet);
    IPAddress(uint32_t address);
    IPAddress(const uint8_t *address);
    virtual ~IPAddress() {}

    bool fromString(const char *address);
    bool fromString(const String &address) { return fromString(address.c_str()); }

    // Overloaded cast operator to allow IPAddress objects to be used where a pointer
    // to a four-byte uint8_t array is expected
    operator uint32_t() const
    {
        return _address.dword;
    }
    bool operator==(const IPAddress& addr) const
    {
        return _address.dword == addr._address.dword;
    }
    bool operator==(const uint8_t* addr) const;

    // Overloaded index operator to allow getting and setting individual octets of the address
    uint8_t operator[](int index) const
    {
        return _address.bytes[index];
    }
    uint8_t& operator[](int index)
    {
        return _address.bytes[index];
    }

    // Overloaded copy operators to allow initialisation of IPAddress objects from other types
    IPAddress& operator=(const uint8_t *address);
    IPAddress& operator=(uint32_t address);

    virtual size_t printTo(Print& p) const;
    String toString() const;

    friend class EthernetClass;
    friend class UDP;
    friend class Client;
    friend class Server;
    friend class DhcpClass;
    friend class DNSClient;
};

// changed to extern because const declaration creates copies in BSS of INADDR_NONE for each CPP unit that includes it
extern IPAddress INADDR_NONE;
#endif