Method parseDHCPResponse

Arduino/libraries/Ethernet2/src/Dhcp.cpp:256–410

}

uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId)
{
    uint8_t type = 0;
    uint8_t opt_len = 0;
	
    unsigned long startTime = millis();
    
	
	
    while(_dhcpUdpSocket.parsePacket() <= 0)
    {
        if((millis() - startTime) > responseTimeout)
        {
            
			return 255;
        }
        delay(50);
    }
	
    // start reading in the packet
    RIP_MSG_FIXED fixedMsg;
    _dhcpUdpSocket.read((uint8_t*)&fixedMsg, sizeof(RIP_MSG_FIXED));
  
    if(fixedMsg.op == DHCP_BOOTREPLY && _dhcpUdpSocket.remotePort() == DHCP_SERVER_PORT)
    {
        transactionId = ntohl(fixedMsg.xid);
        if(memcmp(fixedMsg.chaddr, _dhcpMacAddr, 6) != 0 || (transactionId < _dhcpInitialTransactionId) || (transactionId > _dhcpTransactionId))
        {
            // Need to read the rest of the packet here regardless
            _dhcpUdpSocket.flush();
            return 0;
        }

        memcpy(_dhcpLocalIp, fixedMsg.yiaddr, 4);

        // Skip to the option part
        // Doing this a byte at a time so we don't have to put a big buffer
        // on the stack (as we don't have lots of memory lying around)
        for (int i =0; i < (240 - (int)sizeof(RIP_MSG_FIXED)); i++)
        {
            _dhcpUdpSocket.read(); // we don't care about the returned byte
        }

        while (_dhcpUdpSocket.available() > 0) 
        {
            switch (_dhcpUdpSocket.read()) 
            {
                case endOption :
                    
					break;
                    
                case padOption :
					 
                    break;
                
                case dhcpMessageType :
					 
                    opt_len = _dhcpUdpSocket.read();