path: root/TAO/examples/PluggableUDP/DIOP/DIOP_Transport.cpp

// This may look like C, but it's really -*- C++ -*-
// $Id$

#include "tao/Acceptor_Registry.h"
#include "tao/operation_details.h"
#include "tao/Timeprobe.h"
#include "tao/CDR.h"
#include "tao/Transport_Mux_Strategy.h"
#include "tao/Wait_Strategy.h"
#include "tao/Sync_Strategies.h"
#include "tao/Stub.h"
#include "tao/ORB_Core.h"
#include "tao/debug.h"
#include "tao/GIOP_Message_Base.h"
#include "tao/GIOP_Message_Lite.h"


#include "DIOP_Transport.h"
#include "DIOP_Connection_Handler.h"
#include "DIOP_Acceptor.h"
#include "DIOP_Profile.h"

#if !defined (__ACE_INLINE__)
# include "DIOP_Transport.i"
#endif /* ! __ACE_INLINE__ */

ACE_RCSID (tao, DIOP_Transport, "$Id$")

TAO_DIOP_Transport::TAO_DIOP_Transport (TAO_DIOP_Connection_Handler *handler,
                                        TAO_ORB_Core *orb_core,
                                        CORBA::Boolean flag)
  : TAO_Transport (TAO_TAG_UDP_PROFILE,
                   orb_core)
  , connection_handler_ (handler)
  , messaging_object_ (0)
{
  // @@ Michael: Set the input CDR size to ACE_MAX_DGRAM_SIZE so that
  //             we read the whole UDP packet on a single read.
  if (flag)
    {
      // Use the lite version of the protocol
      ACE_NEW (this->messaging_object_,
               TAO_GIOP_Message_Lite (orb_core,
                                      ACE_MAX_DGRAM_SIZE));
    }
    else
    {
      // Use the normal GIOP object
      ACE_NEW (this->messaging_object_,
               TAO_GIOP_Message_Base (orb_core,
                                      ACE_MAX_DGRAM_SIZE));
    }
}

TAO_DIOP_Transport::~TAO_DIOP_Transport (void)
{
  delete this->messaging_object_;
}

ACE_Event_Handler *
TAO_DIOP_Transport::event_handler_i (void)
{
  return this->connection_handler_;
}

TAO_Pluggable_Messaging *
TAO_DIOP_Transport::messaging_object (void)
{
  return this->messaging_object_;
}


ssize_t
TAO_DIOP_Transport::send_i (const ACE_Message_Block *message_block,
                            const ACE_Time_Value * /*max_wait_time*/,
                            size_t *bt)
{
  const ACE_INET_Addr &addr = this->connection_handler_->addr ();

  /*size_t temp = 0;
  size_t &bytes_transferred = bt == 0 ? temp : *bt;
  bytes_transferred = 0;*/
  ssize_t bytes_transferred = 0;
  if (bt)
    {
      bytes_transferred = *bt;
    }

  char stack_buffer[ACE_MAX_DGRAM_SIZE];
  size_t stack_offset=0;
  size_t message_length=0;

  iovec iov[IOV_MAX];
  int iovcnt = 0;

  while (message_block != 0)
    {
      // Our current message block chain.
      const ACE_Message_Block *current_message_block = message_block;

      while (current_message_block != 0)
        {
          size_t current_message_block_length =
                        current_message_block->length ();

          message_length += current_message_block_length;

          if(message_length > ACE_MAX_DGRAM_SIZE)
            {
              // This is an error as we do not send more.
              // Silently drop the message but log an error.

              // Pluggable_Messaging::transport_message only
              // cares if it gets -1 or 0 so we can return a
              // partial length and it will think all has gone
              // well.


              if (TAO_debug_level > 0)
                {
                  ACE_DEBUG ((LM_DEBUG,
                              ACE_TEXT ("\n\nTAO (%P|%t) ")
                              ACE_TEXT ("DIOP_Transport::send ")
                              ACE_TEXT ("Message length %d exceeds ACE_MAX_DGRAM_SIZE=%d\n"),
                              message_length,
                              ACE_MAX_DGRAM_SIZE));
                }

              return 1;                 // Pretend it is o.k.
              // This is a problem in the message
              // catalogue.
            }

          // Check if this block has any data to be sent.
          if (current_message_block_length > 0)
            {
              if(iovcnt < (IOV_MAX-1))
                {
                  // Collect the data in the iovec.
                  iov[iovcnt].iov_base = current_message_block->rd_ptr ();
                  iov[iovcnt].iov_len  = current_message_block_length;

                  // Increment iovec counter.
                  iovcnt++;

                  // The buffer is full make a OS call.  @@ TODO find a way to
                  // find IOV_MAX for platforms that do not define it rather
                  // than simply setting IOV_MAX to some arbitrary value such
                  // as 16.
                }
              else
                {
                  // @@ John Mackenzie. If we reach IOVMAX-1 we need to pack
                  // the remanining blocks into the last available buffer.

                  ACE_OS::memcpy(stack_buffer+stack_offset,
                  current_message_block->rd_ptr (),
                  current_message_block_length);
                  stack_offset +=  current_message_block_length;

                  iovcnt = IOV_MAX;     // We just stay with the last buffer.
                  iov[iovcnt-1].iov_base = stack_buffer;
                  iov[iovcnt-1].iov_len  = stack_offset;
                }
            }

          // Select the next message block in the chain.
          current_message_block = current_message_block->cont ();
        }

      // Selection of the next message block chain.
      message_block = message_block->next ();
    }

  if (TAO_debug_level > 0)
    {
      ACE_DEBUG ((LM_DEBUG,
                  ACE_TEXT ("\n\nTAO (%P|%t) ")
                  ACE_TEXT ("iovcnt is %d \n."),iovcnt));
    }

  // Send the buffers.

  if (iovcnt != 0)
    {
      bytes_transferred =
        this->connection_handler_->dgram ().send (iov,
                                                  iovcnt,
                                                  addr);

      /*
      ACE_DEBUG ((LM_DEBUG,
                  "TAO_DIOP_Transport::send_i: sent %d bytes to %s:%d\n",
                  bytes_transferred,
                  addr.get_host_name (),
                  addr.get_port_number ()));
      */

      // Errors.
      // @@ John Mackenzie. We cannot propogate errors up in DIOP
      // as it will cause transport recycle which makes no sense
      // Error could be ECONNREFUSED if transport reports ICMP errors.
    }

   if (bytes_transferred == -1 || bytes_transferred == 0)
    {
      if (TAO_debug_level > 0)
        {
          ACE_DEBUG ((LM_DEBUG,
                      ACE_TEXT ("\n\nTAO (%P|%t) ")
                      ACE_TEXT ("DIOP_Transport::send")
                      ACE_TEXT (" %p\n\n"),
                      ACE_TEXT ("Error returned from transport:")));
        }
      return 1; // Fake a good return.
    }

  // Return total bytes transferred.
  return bytes_transferred;
}

ssize_t
TAO_DIOP_Transport::recv_i (char *buf,
                            size_t len,
                            const ACE_Time_Value * /* max_wait_time */)
{
  ACE_INET_Addr from_addr;

  ssize_t n = this->connection_handler_->dgram ().recv (buf,
                                                        len,
                                                        from_addr);

  ACE_DEBUG ((LM_DEBUG,
              "TAO_DIOP_Transport::recv_i: received %d bytes from %s:%d %d\n",
              n,
              from_addr.get_host_name (),
              from_addr.get_port_number (),
              errno));

  // Remember the from addr to eventually use it as remote
  // addr for the reply.
  this->connection_handler_->addr (from_addr);

  return n;
}


int
TAO_DIOP_Transport::read_process_message (ACE_Time_Value *max_wait_time,
                                          int block)
{
  // Read the message of the socket
  int result =  this->messaging_object_->read_message (this,
                                                       block,
                                                       max_wait_time);

  if (result == -1)
    {
      if (TAO_debug_level > 0)
        ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("TAO (%P|%t) - %p\n"),
                    ACE_TEXT ("DIOP_Transport::read_process_message, failure in read_message ()")));

      this->tms_->connection_closed ();
      return -1;
    }
  if (result == 0)
    return result;

  // Now we know that we have been able to read the complete message
  // here.. We loop here to see whether we have read more than one
  // message in our read.
  do
    {
      result = this->process_message ();
    }
  while (result > 1);

  return result;
}


int
TAO_DIOP_Transport::register_handler_i (void)
{
  // @@ Michael:
  // 
  // We do never register register the handler with the reactor
  // as we never need to be informed about any incoming data,
  // assuming we only use one-ways.
  // If we would register and ICMP Messages would arrive, e.g
  // due to a not reachable server, we would get informed - as this
  // disturbs the general DIOP assumptions of not being
  // interested in any network failures, we ignore ICMP messages.
  return 0;
  /*
  // @@ It seems like this method should go away, the right reactor is
  //    picked at object creation time.
  ACE_Reactor *r = this->orb_core_->reactor ();

  if (r == this->connection_handler_->reactor ())
    return 0;

  // Set the flag in the Connection Handler
  this->connection_handler_->is_registered (1);


  // Register the handler with the reactor
  return  r->register_handler (this->connection_handler_,
                               ACE_Event_Handler::READ_MASK);
  */
}


int
TAO_DIOP_Transport::send_request (TAO_Stub *stub,
                                  TAO_ORB_Core *orb_core,
                                  TAO_OutputCDR &stream,
                                  int two_way,
                                  ACE_Time_Value *max_wait_time)
{
  if (this->ws_->sending_request (orb_core,
                                  two_way) == -1)
    return -1;

  if (this->send_message (stream,
                          stub,
                          two_way,
                          max_wait_time) == -1)

    return -1;

  return this->idle_after_send ();
}

int
TAO_DIOP_Transport::send_message (TAO_OutputCDR &stream,
                                  TAO_Stub *stub,
                                  int twoway,
                                  ACE_Time_Value *max_wait_time)
{
  // Format the message in the stream first
  if (this->messaging_object_->format_message (stream) != 0)
    return -1;

  // Strictly speaking, should not need to loop here because the
  // socket never gets set to a nonblocking mode ... some Linux
  // versions seem to need it though.  Leaving it costs little.

  // This guarantees to send all data (bytes) or return an error.
  ssize_t n = this->send_or_buffer (stub,
                                    twoway,
                                    stream.begin (),
                                    max_wait_time);

  if (n == -1)
    {
      if (TAO_debug_level)
        ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("TAO: (%P|%t|%N|%l) closing transport %d after fault %p\n"),
                    this->id (),
                    ACE_TEXT ("send_message ()\n")));

      return -1;
    }

  // EOF.
  if (n == 0)
    {
      if (TAO_debug_level)
        ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("TAO: (%P|%t|%N|%l) send_message () \n")
                    ACE_TEXT ("EOF, closing transport %d\n"),
                    this->id ()));
      return -1;
    }

  return 1;
}



int
TAO_DIOP_Transport::messaging_init (CORBA::Octet major,
                                    CORBA::Octet minor)
{
  this->messaging_object_->init (major,
                                 minor);
  return 1;
}

// @@ Frank: Hopefully DIOP doesn't need this
/*
int
TAO_DIOP_Transport::tear_listen_point_list (TAO_InputCDR &cdr)
{
  CORBA::Boolean byte_order;
  if ((cdr >> ACE_InputCDR::to_boolean (byte_order)) == 0)
    return -1;

  cdr.reset_byte_order (ACE_static_cast(int,byte_order));

  DIOP::ListenPointList listen_list;
  if ((cdr >> listen_list) == 0)
    return -1;

  // As we have received a bidirectional information, set the flag to
  // 1
  this->bidirectional_flag (1);
  return this->connection_handler_->process_listen_point_list (listen_list);
}
*/

int
TAO_DIOP_Transport::process_message (void)
{
  // Get the <message_type> that we have received
  TAO_Pluggable_Message_Type t =
    this->messaging_object_->message_type ();


  int result = 0;
  if (t == TAO_PLUGGABLE_MESSAGE_CLOSECONNECTION)
    {
      if (TAO_debug_level > 0)
        ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("TAO (%P|%t) - %p\n"),
                    ACE_TEXT ("Close Connection Message recd \n")));

      this->tms_->connection_closed ();
    }
  else if (t == TAO_PLUGGABLE_MESSAGE_REQUEST)
    {
      if (this->messaging_object_->process_request_message (this,
                                                            this->orb_core ()) == -1)
        return -1;
    }
  else if (t == TAO_PLUGGABLE_MESSAGE_REPLY)
    {
      TAO_Pluggable_Reply_Params params (this->orb_core ());
      if (this->messaging_object_->process_reply_message (params)  == -1)
        {

          if (TAO_debug_level > 0)
            ACE_DEBUG ((LM_DEBUG,
                        ACE_TEXT ("TAO (%P|%t) - %p\n"),
                        ACE_TEXT ("DIOP_Transport::process_message, process_reply_message ()")));

          this->messaging_object_->reset ();
          this->tms_->connection_closed ();
          return -1;
        }


      result =
        this->tms_->dispatch_reply (params);

      // @@ Somehow it seems dangerous to reset the state *after*
      //    dispatching the request, what if another threads receives
      //    another reply in the same connection?
      //    My guess is that it works as follows:
      //    - For the exclusive case there can be no such thread.
      //    - The the muxed case each thread has its own message_state.
      //    I'm pretty sure this comment is right.  Could somebody else
      //    please look at it and confirm my guess?

      // @@ The above comment was found in the older versions of the
      //    code. The code was also written in such a way that, when
      //    the client thread on a call from handle_input () from the
      //    reactor a call would be made on the handle_client_input
      //    (). The implementation of handle_client_input () looked so
      //    flaky. It used to create a message state upon entry in to
      //    the function using the TMS and destroy that on exit. All
      //    this was fine _theoretically_ for multiple threads. But
      //    the flakiness was originating in the implementation of
      //    get_message_state () where we were creating message state
      //    only once and dishing it out for every thread till one of
      //    them destroy's it. So, it looked broken. That has been
      //    changed. Why?. To my knowledge, the reactor does not call
      //    handle_input () on two threads at the same time. So, IMHO
      //    that defeats the purpose of creating a message state for
      //    every thread. This is just my guess. If we run in to
      //    problems this place needs to be revisited. If someone else
      //    is going to take a look please contact bala@cs.wustl.edu
      //    for details on this-- Bala



      if (result == -1)
        {
          // Something really critical happened, we will forget about
          // every reply on this connection.
          if (TAO_debug_level > 0)
            ACE_ERROR ((LM_ERROR,
                        ACE_TEXT ("TAO (%P|%t) : DIOP_Transport::")
                        ACE_TEXT ("process_message - ")
                        ACE_TEXT ("dispatch reply failed\n")));

          this->messaging_object_->reset ();
          this->tms_->connection_closed ();
          return -1;
        }

      if (result == 0)
        {
          this->messaging_object_->reset ();

          // The reply dispatcher was no longer registered.
          // This can happened when the request/reply
          // times out.
          // To throw away all registered reply handlers is
          // not the right thing, as there might be just one
          // old reply coming in and several valid new ones
          // pending. If we would invoke <connection_closed>
          // we would throw away also the valid ones.
          //return 0;
        }


      // This is a NOOP for the Exclusive request case, but it actually
      // destroys the stream in the muxed case.
      //this->tms_->destroy_message_state (message_state);
    }
  else if (t == TAO_PLUGGABLE_MESSAGE_MESSAGERROR)
    {
      return -1;
    }

  return this->messaging_object_->more_messages ();
}

// @@ Frank: Hopefully DIOP doesn't need this
/*
void
TAO_DIOP_Transport::set_bidir_context_info (TAO_Operation_Details &opdetails)
{

  // Get a handle on to the acceptor registry
  TAO_Acceptor_Registry * ar =
    this->orb_core ()->acceptor_registry ();


  // Get the first acceptor in the registry
  TAO_AcceptorSetIterator acceptor = ar->begin ();

  DIOP::ListenPointList listen_point_list;

  for (;
       acceptor != ar->end ();
       acceptor++)
    {
      // Check whether it is a DIOP acceptor
      if ((*acceptor)->tag () == TAO_TAG_UDP_PROFILE)
        {
          this->get_listen_point (listen_point_list,
                                  *acceptor);
        }
    }

  // We have the ListenPointList at this point. Create a output CDR
  // stream at this point
  TAO_OutputCDR cdr;

  // Marshall the information into the stream
  if ((cdr << ACE_OutputCDR::from_boolean (TAO_ENCAP_BYTE_ORDER)== 0)
      || (cdr << listen_point_list) == 0)
    return;

  // Add this info in to the svc_list
  opdetails.service_context ().set_context (IOP::BI_DIR_DIOP,
                                            cdr);

  return;
}


int
TAO_DIOP_Transport::get_listen_point (
    DIOP::ListenPointList &listen_point_list,
    TAO_Acceptor *acceptor)
{
  TAO_DIOP_Acceptor *iiop_acceptor =
    ACE_dynamic_cast (TAO_DIOP_Acceptor *,
                      acceptor );

  // Get the array of endpoints serviced by <iiop_acceptor>
  const ACE_INET_Addr *endpoint_addr =
    iiop_acceptor->endpoints ();

  // Get the count
  size_t count =
    iiop_acceptor->endpoint_count ();

  // Get the local address of the connection
  ACE_INET_Addr local_addr;

  if (this->connection_handler_->peer ().get_local_addr (local_addr)
      == -1)
    {
      ACE_ERROR_RETURN ((LM_ERROR,
                         ACE_TEXT ("(%P|%t) Could not resolve local host")
                         ACE_TEXT (" address in set_bidir_context_info () \n")),
                        -1);
    }


  // Note: Looks like there is no point in sending the list of
  // endpoints on interfaces on which this connection has not
  // been established. If this is wrong, please correct me.
  char *local_interface = 0;

  // Get the hostname for the local address
  if (iiop_acceptor->hostname (this->orb_core_,
                               local_addr,
                               local_interface) == -1)
    {
      ACE_ERROR_RETURN ((LM_ERROR,
                         ACE_TEXT ("(%P|%t) Could not resolve local host")
                         ACE_TEXT (" name \n")),
                        -1);
    }

  ACE_INET_Addr *tmp_addr = ACE_const_cast (ACE_INET_Addr *,
                                            endpoint_addr);

  for (size_t index = 0;
       index <= count;
       index++)
    {
      // Get the listen point on that acceptor if it has the same
      // interface on which this connection is established
      char *acceptor_interface = 0;

      if (iiop_acceptor->hostname (this->orb_core_,
                                   tmp_addr[index],
                                   acceptor_interface) == -1)
          continue;

      // @@ This is very bad for performance, but it is a one time
      // affair
      if (ACE_OS::strcmp (local_interface,
                          acceptor_interface) == 0)
        {
          // We have the connection and the acceptor endpoint on the
          // same interface
          DIOP::ListenPoint point;
          point.host = CORBA::string_dup (local_interface);
          point.port = endpoint_addr[index].get_port_number ();

          // Get the count of the number of elements
          CORBA::ULong len = listen_point_list.length ();

          // Increase the length by 1
          listen_point_list.length (len + 1);

          // Add the new length to the list
          listen_point_list[len] = point;
        }

      // @@ This is bad....
      CORBA::string_free (acceptor_interface);
    }

  CORBA::string_free (local_interface);
  return 1;
}
*/

void
TAO_DIOP_Transport::transition_handler_state_i (void)
{
  this->connection_handler_ = 0;
}