path: root/src/DuetNG/DuetEthernet/Ethernet3/EthernetUdp3.cpp

/*
 *  Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
 *  This version only offers minimal wrapping of socket.c/socket.h
 *  Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/ 
 *
 * MIT License:
 * Copyright (c) 2008 Bjoern Hartmann
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * bjoern@cs.stanford.edu 12/30/2008
 *
 * - 10 Apr. 2015
 * Added support for Arduino Ethernet Shield 2
 * by Arduino.org team
 */

#include "utility/w5500.h"
#include "utility/socket.h"
#include "Ethernet3.h"
#include "Udp.h"
#include "Dns.h"

#undef UDP

/* Constructor */
EthernetUDP::EthernetUDP() : _sock(MAX_SOCK_NUM) {}

/* Start EthernetUDP socket, listening at local port PORT */
uint8_t EthernetUDP::begin(uint16_t port)
{
	if (_sock != MAX_SOCK_NUM)
	{
		return 0;
	}

	for (int i = 0; i < MAX_SOCK_NUM; i++)
	{
		uint8_t s = w5500.readSnSR(i);
		if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT)
		{
			_sock = i;
			break;
		}
	}

	if (_sock == MAX_SOCK_NUM)
	{
		return 0;
	}

	_port = port;
	_remaining = 0;
	socket(_sock, SnMR::UDP, _port, 0);

	return 1;
}

/* return number of bytes available in the current packet,
   will return zero if parsePacket hasn't been called yet */
int EthernetUDP::available()
{
	return _remaining;
}

/* Release any resources being used by this EthernetUDP instance */
void EthernetUDP::stop()
{
	if (_sock == MAX_SOCK_NUM)
	{
		return;
	}

	close(_sock);

	EthernetClass::_server_port[_sock] = 0;
	_sock = MAX_SOCK_NUM;
}

int EthernetUDP::beginPacket(const char *host, uint16_t port)
{
	// Look up the host first
	DNSClient dns;
	IPAddress remote_addr;

	dns.begin(Ethernet.dnsServerIP());
	const int ret = dns.getHostByName(host, remote_addr);
	if (ret == 1)
	{
		return beginPacket(remote_addr, port);
	}
	else
	{
		return ret;
	}
}

int EthernetUDP::beginPacket(IPAddress ip, uint16_t port)
{
	_offset = 0;
	return startUDP(_sock, rawIPAddress(ip), port);
}

int EthernetUDP::endPacket()
{
	return sendUDP(_sock);
}

size_t EthernetUDP::write(uint8_t byte)
{
	return write(&byte, 1);
}

size_t EthernetUDP::write(const uint8_t *buffer, size_t size)
{
	uint16_t bytes_written = bufferData(_sock, _offset, buffer, size);
	_offset += bytes_written;
	return bytes_written;
}

int EthernetUDP::parsePacket()
{
	// discard any remaining bytes in the last packet
	flush();

	if (w5500.getRXReceivedSize(_sock) > 0)
	{
		//HACK - hand-parse the UDP packet using TCP recv method
		uint8_t tmpBuf[8];
		//read 8 header bytes and get IP and port from it
		int ret = recv(_sock, tmpBuf, 8);
		if (ret > 0)
		{
			_remoteIP = tmpBuf;
			_remotePort = tmpBuf[4];
			_remotePort = (_remotePort << 8) + tmpBuf[5];
			_remaining = tmpBuf[6];
			_remaining = (_remaining << 8) + tmpBuf[7];

			// When we get here, any remaining bytes are the data
			ret = _remaining;
		}
		return ret;
	}
	// There aren't any packets available
	return 0;
}

int EthernetUDP::read()
{
	uint8_t byte;

	if ((_remaining > 0) && (recv(_sock, &byte, 1) > 0))
	{
		// We read things without any problems
		_remaining--;
		return byte;
	}

	// If we get here, there's no data available
	return -1;
}

int EthernetUDP::read(unsigned char* buffer, size_t len)
{
	if (_remaining > 0)
	{
		int got;
		if (_remaining <= len)
		{
			// data should fit in the buffer
			got = recv(_sock, buffer, _remaining);
		}
		else
		{
			// too much data for the buffer,
			// grab as much as will fit
			got = recv(_sock, buffer, len);
		}

		if (got > 0)
		{
			_remaining -= got;
			return got;
		}
	}

	// If we get here, there's no data available or recv failed
	return -1;
}

int EthernetUDP::peek()
{
	uint8_t b;
	// Unlike recv, peek doesn't check to see if there's any data available, so we must.
	// If the user hasn't called parsePacket yet then return nothing otherwise they
	// may get the UDP header
	if (!_remaining)
	{
		return -1;
	}
	::peek(_sock, &b);
	return b;
}

void EthernetUDP::flush()
{
	// could this fail (loop endlessly) if _remaining > 0 and recv in read fails?
	// should only occur if recv fails after telling us the data is there, lets
	// hope the w5500 always behaves :)
	while (_remaining)
	{
		read();
	}
}

/* Start EthernetUDP socket, listening at local port PORT */
uint8_t EthernetUDP::beginMulticast(IPAddress ip, uint16_t port)
{
    if (_sock != MAX_SOCK_NUM)
    {
        return 0;
    }
    
    for (int i = 0; i < MAX_SOCK_NUM; i++)
    {
        const uint8_t s = w5500.readSnSR(i);
        if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT)
        {
            _sock = i;
            break;
        }
    }
    
    if (_sock == MAX_SOCK_NUM)
    {
        return 0;
    }
    
    // Calculate MAC address from Multicast IP Address
    byte mac[] = {  0x01, 0x00, 0x5E, 0x00, 0x00, 0x00 };
    
    mac[3] = ip[1] & 0x7F;
    mac[4] = ip[2];
    mac[5] = ip[3];
    
    w5500.writeSnDIPR(_sock, rawIPAddress(ip));   //239.255.0.1
    w5500.writeSnDPORT(_sock, port);
    w5500.writeSnDHAR(_sock,mac);
    
    _remaining = 0;
    socket(_sock, SnMR::UDP, port, SnMR::MULTI);
    return 1;
}

// End