/home/jander/temp/etherdune/DHCP.h

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// EtherDune DHCP Service
// Author: Javier Peletier <jm@friendev.com>
// Summary: Implements the basics of DHCP so as to obtain and maintain an IP lease
// along with DNS, gateway IP and netmask.
//
// Copyright (c) 2015 All Rights Reserved, http://friendev.com
//
// This source is subject to the GPLv2 license.
// Please see the License.txt file for more information.
// All other rights reserved.
//
// THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY 
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.


#ifndef _DHCP_H_
#define _DHCP_H_

#include <ACross.h>
#include "UDPSocket.h"
#include "Stateful.h"


static const uint8_t DHCP_DISCOVER = 1;
static const uint8_t DHCP_OFFER = 2;
static const uint8_t DHCP_REQUEST = 3;
static const uint8_t DHCP_DECLINE = 4;
static const uint8_t DHCP_ACK = 5;
static const uint8_t DHCP_NACK = 6;
static const uint8_t DHCP_RELEASE = 7;
static const uint8_t DHCP_INFORM = 8;

static const uint8_t DHCP_OPTIONS_PAD = 0;
static const uint8_t DHCP_OPTIONS_SUBNET = 1;
static const uint8_t DHCP_OPTIONS_ROUTER = 3;
static const uint8_t DHCP_OPTIONS_DNS = 6;
static const uint8_t DHCP_OPTIONS_HOSTNAME = 12;
static const uint8_t DHCP_OPTIONS_REQUESTED_IP = 50;
static const uint8_t DHCP_OPTIONS_MESSAGETYPE = 53;
static const uint8_t DHCP_OPTIONS_SERVER_IDENTIFIER = 54;
static const uint8_t DHCP_OPTIONS_RENEWAL_TIME = 58;
static const uint8_t DHCP_OPTIONS_CLIENT_IDENTIFIER = 61;
static const uint8_t DHCP_OPTIONS_END = 255;

static const uint8_t DHCP_HARDWARE_TYPE_ETHERNET = 1;

struct DHCPOptionHeader
{
    uint8_t code;
    uint8_t length;
    DHCPOptionHeader(uint8_t optionCode, uint8_t optionLength) : code(optionCode), length(optionLength){}
    DHCPOptionHeader(){}

};

template<uint8_t CODE, uint8_t LENGTH>
struct DHCPOption : public DHCPOptionHeader
{
    DHCPOption() : DHCPOptionHeader(CODE, LENGTH){}

};

struct DHCPIPOption : DHCPOptionHeader
{
    IPAddress ip;
};

struct DHCPRequestedIPOption : public DHCPOption < DHCP_OPTIONS_REQUESTED_IP, sizeof(IPAddress) >
{
    IPAddress ip;
};

struct DHCPTimerOption :DHCPOptionHeader
{
    nint32_t timer;
};

struct DHCPClientIdentifierOptionHeader : DHCPOption<DHCP_OPTIONS_CLIENT_IDENTIFIER, sizeof(uint8_t) + sizeof(MACAddress)>
{
    uint8_t hardwareType;
    DHCPClientIdentifierOptionHeader() :hardwareType(DHCP_HARDWARE_TYPE_ETHERNET){}
};




template <uint8_t MESSAGETYPE>
struct DHCPMessageTypeOption : public DHCPOption <DHCP_OPTIONS_MESSAGETYPE, 1>
{
    uint8_t messageType;
    DHCPMessageTypeOption() : messageType(MESSAGETYPE){}

};

typedef  DHCPMessageTypeOption<DHCP_DISCOVER> DHCPDiscoverMessageTypeOption;
typedef  DHCPMessageTypeOption<DHCP_REQUEST> DHCPRequestMessageTypeOption;




class DHCP : private UDPSocket, Stateful
{
private:

    uint8_t attempts;
    uint16_t renewalTimer;

    void onReceive(uint16_t len);
    void setMagicCookie();
    void sendDHCPDiscover();
    void initDHCP();
    void writeAdditionalFields();
    NOINLINE DHCPOptionHeader* findOption(uint8_t searchCode);
    void prepareDHCPRequest();
    uint8_t getMessageType();
    __FlashStringHelper* getStateString();
    void tick();

public:

    DHCP();
    bool dhcpSetup();

};







#endif