/*
   Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program 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 General Public License for more details.

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

#include <ndb_global.h>

#include <NdbTCP.h>
#include "TCP_Transporter.hpp"
#include <NdbOut.hpp>
#include <NdbSleep.h>

#include <EventLogger.hpp>
extern EventLogger * g_eventLogger;
// End of stuff to be moved

#ifdef NDB_WIN32
class ndbstrerror
{
public:
  ndbstrerror(int iError);
  ~ndbstrerror(void);
  operator char*(void) { return m_szError; };

private:
  int m_iError;
  char* m_szError;
};

ndbstrerror::ndbstrerror(int iError)
: m_iError(iError)
{
  FormatMessage( 
    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
    0,
    iError,
    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
    (LPTSTR)&m_szError,
    0,
    0);
}

ndbstrerror::~ndbstrerror(void)
{
  LocalFree( m_szError );
  m_szError = 0;
}
#else
#define ndbstrerror strerror
#endif

static
void
setIf(int& ref, Uint32 val, Uint32 def)
{
  if (val)
    ref = val;
  else
    ref = def;
}


static
Uint32 overload_limit(const TransporterConfiguration* conf)
{
  return (conf->tcp.tcpOverloadLimit ?
          conf->tcp.tcpOverloadLimit :
          conf->tcp.sendBufferSize*4/5);
}


TCP_Transporter::TCP_Transporter(TransporterRegistry &t_reg,
				 const TransporterConfiguration* conf)
  :
  Transporter(t_reg, tt_TCP_TRANSPORTER,
	      conf->localHostName,
	      conf->remoteHostName,
	      conf->s_port,
	      conf->isMgmConnection,
	      conf->localNodeId,
	      conf->remoteNodeId,
	      conf->serverNodeId,
	      0, false, 
	      conf->checksum,
	      conf->signalId,
	      conf->tcp.sendBufferSize),
  reportFreq(4096),
  receiveCount(0), receiveSize(0),
  sendCount(0), sendSize(0), 
  receiveBuffer()
{
  maxReceiveSize = conf->tcp.maxReceiveSize;
  
  // Initialize member variables
  my_socket_invalidate(&theSocket);

  sockOptNodelay    = 1;
  setIf(sockOptRcvBufSize, conf->tcp.tcpRcvBufSize, 70080);
  setIf(sockOptSndBufSize, conf->tcp.tcpSndBufSize, 71540);
  setIf(sockOptTcpMaxSeg, conf->tcp.tcpMaxsegSize, 0);

  m_overload_limit = overload_limit(conf);
  /**
   * Always set slowdown limit to 60% of overload limit
   */
  m_slowdown_limit = m_overload_limit * 6 / 10;
}


bool
TCP_Transporter::configure_derived(const TransporterConfiguration* conf)
{
  if (conf->tcp.sendBufferSize == m_max_send_buffer &&
      conf->tcp.maxReceiveSize == maxReceiveSize &&
      (int)conf->tcp.tcpSndBufSize == sockOptSndBufSize &&
      (int)conf->tcp.tcpRcvBufSize == sockOptRcvBufSize &&
      (int)conf->tcp.tcpMaxsegSize == sockOptTcpMaxSeg &&
      overload_limit(conf) == m_overload_limit)
    return true; // No change

  return false; // Can't reconfigure
}


TCP_Transporter::~TCP_Transporter() {
  
  // Disconnect
  if (my_socket_valid(theSocket))
    doDisconnect();
  
  // Delete receive buffer!!
  assert(!isConnected());
  receiveBuffer.destroy();
}

void
TCP_Transporter::resetBuffers()
{
  assert(!isConnected());
  receiveBuffer.clear();
}

bool TCP_Transporter::connect_server_impl(NDB_SOCKET_TYPE sockfd)
{
  DBUG_ENTER("TCP_Transpporter::connect_server_impl");
  DBUG_RETURN(connect_common(sockfd));
}

bool TCP_Transporter::connect_client_impl(NDB_SOCKET_TYPE sockfd)
{
  DBUG_ENTER("TCP_Transpporter::connect_client_impl");
  DBUG_RETURN(connect_common(sockfd));
}

bool TCP_Transporter::connect_common(NDB_SOCKET_TYPE sockfd)
{
  setSocketOptions(sockfd);
  setSocketNonBlocking(sockfd);

  get_callback_obj()->lock_transporter(remoteNodeId);
  theSocket = sockfd;
  get_callback_obj()->unlock_transporter(remoteNodeId);

  DBUG_PRINT("info", ("Successfully set-up TCP transporter to node %d",
              remoteNodeId));
  return true;
}

bool
TCP_Transporter::initTransporter() {
  
  // Allocate buffer for receiving
  // Let it be the maximum size we receive plus 8 kB for any earlier received
  // incomplete messages (slack)
  Uint32 recBufSize = maxReceiveSize;
  if(recBufSize < MAX_RECV_MESSAGE_BYTESIZE){
    recBufSize = MAX_RECV_MESSAGE_BYTESIZE;
  }
  
  if(!receiveBuffer.init(recBufSize+MAX_RECV_MESSAGE_BYTESIZE)){
    return false;
  }
  
  return true;
}

static
void
set_get(NDB_SOCKET_TYPE fd, int level, int optval, const char *optname, 
	int val)
{
  int actual = 0, defval = 0;
  SOCKET_SIZE_TYPE len = sizeof(actual);

  my_getsockopt(fd, level, optval, (char*)&defval, &len);

  if (my_setsockopt(fd, level, optval,
                    (char*)&val, sizeof(val)) < 0)
  {
#ifdef DEBUG_TRANSPORTER
    g_eventLogger->error("setsockopt(%s, %d) errno: %d %s",
                         optname, val, errno, strerror(errno));
#endif
  }
  
  len = sizeof(actual);
  if ((my_getsockopt(fd, level, optval,
                     (char*)&actual, &len) == 0) &&
      actual != val)
  {
#ifdef DEBUG_TRANSPORTER
    g_eventLogger->error("setsockopt(%s, %d) - actual %d default: %d",
                         optname, val, actual, defval);
#endif
  }
}

int
TCP_Transporter::pre_connect_options(NDB_SOCKET_TYPE sockfd)
{
  if (sockOptTcpMaxSeg)
  {
#ifdef TCP_MAXSEG
    set_get(sockfd, IPPROTO_TCP, TCP_MAXSEG, "TCP_MAXSEG", sockOptTcpMaxSeg);
#endif
  }
  return 0;
}

void
TCP_Transporter::setSocketOptions(NDB_SOCKET_TYPE socket)
{
  set_get(socket, SOL_SOCKET, SO_RCVBUF, "SO_RCVBUF", sockOptRcvBufSize);
  set_get(socket, SOL_SOCKET, SO_SNDBUF, "SO_SNDBUF", sockOptSndBufSize);
  set_get(socket, IPPROTO_TCP, TCP_NODELAY, "TCP_NODELAY", sockOptNodelay);
  set_get(socket, SOL_SOCKET, SO_KEEPALIVE, "SO_KEEPALIVE", 1);

  if (sockOptTcpMaxSeg)
  {
#ifdef TCP_MAXSEG
    set_get(socket, IPPROTO_TCP, TCP_MAXSEG, "TCP_MAXSEG", sockOptTcpMaxSeg);
#endif
  }
}

bool TCP_Transporter::setSocketNonBlocking(NDB_SOCKET_TYPE socket)
{
  if(my_socket_nonblock(socket, true)==0)
    return true;
  return false;
}

bool
TCP_Transporter::send_is_possible(int timeout_millisec) const
{
  return send_is_possible(theSocket, timeout_millisec);
}

bool
TCP_Transporter::send_is_possible(NDB_SOCKET_TYPE fd,int timeout_millisec) const
{
  ndb_socket_poller poller;

  if (!my_socket_valid(fd))
    return false;

  poller.clear();
  poller.add(fd, false, true, false);

  if (poller.poll_unsafe(timeout_millisec) <= 0)
    return false; // Timeout or error occured

  return true;
}

#define DISCONNECT_ERRNO(e, sz) ((sz == 0) || \
                                 (!((sz == -1) && ((e == SOCKET_EAGAIN) || (e == SOCKET_EWOULDBLOCK) || (e == SOCKET_EINTR)))))


bool
TCP_Transporter::doSend() {
  struct iovec iov[64];
  Uint32 cnt = fetch_send_iovec_data(iov, NDB_ARRAY_SIZE(iov));

  if (cnt == 0)
  {
    return false;
  }

  Uint32 sum = 0;
  for(Uint32 i = 0; i<cnt; i++)
  {
    assert(iov[i].iov_len);
    sum += iov[i].iov_len;
  }

  Uint32 pos = 0;
  Uint32 sum_sent = 0;
  Uint32 send_cnt = 0;
  Uint32 remain = sum;

  if (cnt == NDB_ARRAY_SIZE(iov))
  {
    // If pulling all iov's make sure that we never return everyting
    // flushed
    sum++;
  }

  while (send_cnt < 5)
  {
    send_cnt++;
    Uint32 iovcnt = cnt > m_os_max_iovec ? m_os_max_iovec : cnt;
    int nBytesSent = (int)my_socket_writev(theSocket, iov+pos, iovcnt);
    assert(nBytesSent <= (int)remain);

    if (Uint32(nBytesSent) == remain)  //Completed this send
    {
      sum_sent += nBytesSent;
      assert(sum >= sum_sent);
      remain = sum - sum_sent;
      break;
    }
    else if (nBytesSent > 0)           //Sent some, more pending
    {
      sum_sent += nBytesSent;
      remain -= nBytesSent;

      /**
       * Forward in iovec
       */
      while (Uint32(nBytesSent) >= iov[pos].iov_len)
      {
        assert(iov[pos].iov_len > 0);
        nBytesSent -= iov[pos].iov_len;
        pos++;
        cnt--;
      }

      if (nBytesSent > 0)
      {
        assert(iov[pos].iov_len > Uint32(nBytesSent));
        iov[pos].iov_len -= nBytesSent;
        iov[pos].iov_base = ((char*)(iov[pos].iov_base))+nBytesSent;
      }
    }
    else                               //Send failed, terminate
    {
      const int err = my_socket_errno();

#if defined DEBUG_TRANSPORTER
      g_eventLogger->error("Send Failure(disconnect==%d) to node = %d "
                           "nBytesSent = %d "
                           "errno = %d strerror = %s",
                           DISCONNECT_ERRNO(err, nBytesSent),
                           remoteNodeId, nBytesSent, my_socket_errno(),
                           (char*)ndbstrerror(err));
#endif

      if ((DISCONNECT_ERRNO(err, nBytesSent)))
      {
        do_disconnect(err); //Initiate pending disconnect
        remain = 0;
      }
      break;
    }
  }

  if (sum_sent > 0)
  {
    iovec_data_sent(sum_sent);
  }
  sendCount += send_cnt;
  sendSize  += sum_sent;
  m_bytes_sent += sum_sent;
  if(sendCount >= reportFreq)
  {
    get_callback_obj()->reportSendLen(remoteNodeId, sendCount, sendSize);
    sendCount = 0;
    sendSize  = 0;
  }

  return (remain>0); // false if nothing remains or disconnected, else true
}

int
TCP_Transporter::doReceive(TransporterReceiveHandle& recvdata)
{
  // Select-function must return the socket for read
  // before this method is called
  // It reads the external TCP/IP interface once
  Uint32 size = receiveBuffer.sizeOfBuffer - receiveBuffer.sizeOfData;
  if(size > 0){
    const int nBytesRead = (int)my_recv(theSocket,
				receiveBuffer.insertPtr,
				size < maxReceiveSize ? size : maxReceiveSize,
				0);

    if (nBytesRead > 0) {
      receiveBuffer.sizeOfData += nBytesRead;
      receiveBuffer.insertPtr  += nBytesRead;
      
      if(receiveBuffer.sizeOfData > receiveBuffer.sizeOfBuffer){
#ifdef DEBUG_TRANSPORTER
        g_eventLogger->error("receiveBuffer.sizeOfData(%d) > receiveBuffer.sizeOfBuffer(%d)",
                             receiveBuffer.sizeOfData, receiveBuffer.sizeOfBuffer);
        g_eventLogger->error("nBytesRead = %d", nBytesRead);
#endif
        g_eventLogger->error("receiveBuffer.sizeOfData(%d) > receiveBuffer.sizeOfBuffer(%d)",
                             receiveBuffer.sizeOfData, receiveBuffer.sizeOfBuffer);
	report_error(TE_INVALID_MESSAGE_LENGTH);
	return 0;
      }
      
      receiveCount ++;
      receiveSize  += nBytesRead;
      m_bytes_received += nBytesRead;
      
      if(receiveCount == reportFreq){
        recvdata.reportReceiveLen(remoteNodeId,
                                  receiveCount, receiveSize);
	receiveCount = 0;
	receiveSize  = 0;
      }
      return nBytesRead;
    } else {
#if defined DEBUG_TRANSPORTER
      g_eventLogger->error("Receive Failure(disconnect==%d) to node = %d nBytesSent = %d "
                           "errno = %d strerror = %s",
                           DISCONNECT_ERRNO(my_socket_errno(), nBytesRead),
                           remoteNodeId, nBytesRead, my_socket_errno(),
                           (char*)ndbstrerror(my_socket_errno()));
#endif   
      if(DISCONNECT_ERRNO(my_socket_errno(), nBytesRead)){
	do_disconnect(my_socket_errno());
      } 
    }
    return nBytesRead;
  } else {
    return 0;
  }
}

void
TCP_Transporter::disconnectImpl()
{
  get_callback_obj()->lock_transporter(remoteNodeId);

  NDB_SOCKET_TYPE sock = theSocket;
  my_socket_invalidate(&theSocket);

  get_callback_obj()->unlock_transporter(remoteNodeId);

  if(my_socket_valid(sock))
  {
    if(my_socket_close(sock) < 0){
      report_error(TE_ERROR_CLOSING_SOCKET);
    }
  }
}
