src/common/sckipc.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/sckipc.cpp
   3 // Purpose:     Interprocess communication implementation (wxSocket version)
   4 // Author:      Julian Smart
   5 // Modified by: Guilhem Lavaux (big rewrite) May 1997, 1998
   6 //              Guillermo Rodriguez (updated for wxSocket v2) Jan 2000
   7 //                                  (callbacks deprecated)    Mar 2000
   8 //              Vadim Zeitlin (added support for Unix sockets) Apr 2002
   9 //                            (use buffering, many fixes/cleanup) Oct 2008
  10 // Created:     1993
  11 // RCS-ID:      $Id$
  12 // Copyright:   (c) Julian Smart 1993
  13 //              (c) Guilhem Lavaux 1997, 1998
  14 //              (c) 2000 Guillermo Rodriguez <guille@iies.es>
  15 // Licence:     wxWindows licence
  16 /////////////////////////////////////////////////////////////////////////////
  17
  18 // ==========================================================================
  19 // declarations
  20 // ==========================================================================
  21
  22 // --------------------------------------------------------------------------
  23 // headers
  24 // --------------------------------------------------------------------------
  25
  26 // For compilers that support precompilation, includes "wx.h".
  27 #include "wx/wxprec.h"
  28
  29 #ifdef __BORLANDC__
  30     #pragma hdrstop
  31 #endif
  32
  33 #if wxUSE_SOCKETS && wxUSE_IPC && wxUSE_STREAMS
  34
  35 #include "wx/sckipc.h"
  36
  37 #ifndef WX_PRECOMP
  38     #include "wx/log.h"
  39     #include "wx/event.h"
  40     #include "wx/module.h"
  41 #endif
  42
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45 #include <errno.h>
  46
  47 #include "wx/socket.h"
  48
  49 // --------------------------------------------------------------------------
  50 // macros and constants
  51 // --------------------------------------------------------------------------
  52
  53 namespace
  54 {
  55
  56 // Message codes
  57 enum IPCCode
  58 {
  59     IPC_EXECUTE = 1,
  60     IPC_REQUEST,
  61     IPC_POKE,
  62     IPC_ADVISE_START,
  63     IPC_ADVISE_REQUEST,
  64     IPC_ADVISE,
  65     IPC_ADVISE_STOP,
  66     IPC_REQUEST_REPLY,
  67     IPC_FAIL,
  68     IPC_CONNECT,
  69     IPC_DISCONNECT
  70 };
  71
  72 } // anonymous namespace
  73
  74 // headers needed for umask()
  75 #ifdef __UNIX_LIKE__
  76     #include <sys/types.h>
  77     #include <sys/stat.h>
  78 #endif // __UNIX_LIKE__
  79
  80 // ----------------------------------------------------------------------------
  81 // private functions
  82 // ----------------------------------------------------------------------------
  83
  84 // get the address object for the given server name, the caller must delete it
  85 static wxSockAddress *
  86 GetAddressFromName(const wxString& serverName,
  87                    const wxString& host = wxEmptyString)
  88 {
  89     // we always use INET sockets under non-Unix systems
  90 #if defined(__UNIX__) && !defined(__WINDOWS__) && !defined(__WINE__)
  91     // under Unix, if the server name looks like a path, create a AF_UNIX
  92     // socket instead of AF_INET one
  93     if ( serverName.Find(_T('/')) != wxNOT_FOUND )
  94     {
  95         wxUNIXaddress *addr = new wxUNIXaddress;
  96         addr->Filename(serverName);
  97
  98         return addr;
  99     }
 100 #endif // Unix/!Unix
 101     {
 102         wxIPV4address *addr = new wxIPV4address;
 103         addr->Service(serverName);
 104         if ( !host.empty() )
 105         {
 106             addr->Hostname(host);
 107         }
 108
 109         return addr;
 110     }
 111 }
 112
 113 // --------------------------------------------------------------------------
 114 // wxTCPEventHandler stuff (private class)
 115 // --------------------------------------------------------------------------
 116
 117 class wxTCPEventHandler : public wxEvtHandler
 118 {
 119 public:
 120     wxTCPEventHandler() : wxEvtHandler() {}
 121
 122     void Client_OnRequest(wxSocketEvent& event);
 123     void Server_OnRequest(wxSocketEvent& event);
 124
 125     DECLARE_EVENT_TABLE()
 126     DECLARE_NO_COPY_CLASS(wxTCPEventHandler)
 127 };
 128
 129 enum
 130 {
 131     _CLIENT_ONREQUEST_ID = 1000,
 132     _SERVER_ONREQUEST_ID
 133 };
 134
 135 static wxTCPEventHandler *gs_handler = NULL;
 136
 137 // --------------------------------------------------------------------------
 138 // wxIPCSocketStreams
 139 // --------------------------------------------------------------------------
 140
 141 #define USE_BUFFER
 142
 143 // this class contains the various (related) streams used by wxTCPConnection
 144 // and also provides a way to read from the socket stream directly
 145 //
 146 // for writing to the stream use the IPCOutput class below
 147 class wxIPCSocketStreams
 148 {
 149 public:
 150     // ctor initializes all the streams on top of the given socket
 151     //
 152     // note that we use a bigger than default buffer size which matches the
 153     // typical Ethernet MTU
 154     wxIPCSocketStreams(wxSocketBase& sock)
 155         : m_socketStream(sock),
 156 #ifdef USE_BUFFER
 157           m_bufferedOut(m_socketStream, 1500),
 158 #else
 159           m_bufferedOut(m_socketStream),
 160 #endif
 161           m_dataIn(m_socketStream),
 162           m_dataOut(m_bufferedOut)
 163     {
 164     }
 165
 166     // expose the IO methods needed by IPC code (notice that writing is only
 167     // done via IPCOutput)
 168
 169     // flush output
 170     void Flush()
 171     {
 172 #ifdef USE_BUFFER
 173         m_bufferedOut.Sync();
 174 #endif
 175     }
 176
 177     // simple wrappers around the functions with the same name in
 178     // wxDataInputStream
 179     wxUint8 Read8()
 180     {
 181         Flush();
 182         return m_dataIn.Read8();
 183     }
 184
 185     wxUint32 Read32()
 186     {
 187         Flush();
 188         return m_dataIn.Read32();
 189     }
 190
 191     wxString ReadString()
 192     {
 193         Flush();
 194         return m_dataIn.ReadString();
 195     }
 196
 197     // read arbitrary (size-prepended) data
 198     //
 199     // connection parameter is needed to call its GetBufferAtLeast() method
 200     void *ReadData(wxConnectionBase *conn, size_t *size)
 201     {
 202         Flush();
 203
 204         wxCHECK_MSG( conn, NULL, "NULL connection parameter" );
 205         wxCHECK_MSG( size, NULL, "NULL size parameter" );
 206
 207         *size = Read32();
 208
 209         void * const data = conn->GetBufferAtLeast(*size);
 210         wxCHECK_MSG( data, NULL, "IPC buffer allocation failed" );
 211
 212         m_socketStream.Read(data, *size);
 213
 214         return data;
 215     }
 216
 217     // same as above but for data preceded by the format
 218     void *
 219     ReadFormatData(wxConnectionBase *conn, wxIPCFormat *format, size_t *size)
 220     {
 221         wxCHECK_MSG( format, NULL, "NULL format parameter" );
 222
 223         *format = static_cast<wxIPCFormat>(Read8());
 224
 225         return ReadData(conn, size);
 226     }
 227
 228
 229     // these methods are only used by IPCOutput and not directly
 230     wxDataOutputStream& GetDataOut() { return m_dataOut; }
 231     wxOutputStream& GetUnformattedOut() { return m_bufferedOut; }
 232
 233 private:
 234     // this is the low-level underlying stream using the connection socket
 235     wxSocketStream m_socketStream;
 236
 237     // the buffered stream is used to avoid writing all pieces of an IPC
 238     // request to the socket one by one but to instead do it all at once when
 239     // we're done with it
 240 #ifdef USE_BUFFER
 241     wxBufferedOutputStream m_bufferedOut;
 242 #else
 243     wxOutputStream& m_bufferedOut;
 244 #endif
 245
 246     // finally the data streams are used to be able to write typed data into
 247     // the above streams easily
 248     wxDataInputStream  m_dataIn;
 249     wxDataOutputStream m_dataOut;
 250
 251     DECLARE_NO_COPY_CLASS(wxIPCSocketStreams)
 252 };
 253
 254 namespace
 255 {
 256
 257 // an object of this class should be instantiated on the stack to write to the
 258 // underlying socket stream
 259 //
 260 // this class is intentionally separated from wxIPCSocketStreams to ensure that
 261 // Flush() is always called
 262 class IPCOutput
 263 {
 264 public:
 265     // construct an object associated with the given streams (which must have
 266     // life time greater than ours as we keep a reference to it)
 267     IPCOutput(wxIPCSocketStreams *streams)
 268         : m_streams(*streams)
 269     {
 270         wxASSERT_MSG( streams, "NULL streams pointer" );
 271     }
 272
 273     // dtor calls Flush() really sending the IPC data to the network
 274     ~IPCOutput() { m_streams.Flush(); }
 275
 276
 277     // write a byte
 278     void Write8(wxUint8 i)
 279     {
 280         m_streams.GetDataOut().Write8(i);
 281     }
 282
 283     // write the reply code and a string
 284     void Write(IPCCode code, const wxString& str)
 285     {
 286         Write8(code);
 287         m_streams.GetDataOut().WriteString(str);
 288     }
 289
 290     // write the reply code, a string and a format in this order
 291     void Write(IPCCode code, const wxString& str, wxIPCFormat format)
 292     {
 293         Write(code, str);
 294         Write8(format);
 295     }
 296
 297     // write arbitrary data
 298     void WriteData(const void *data, size_t size)
 299     {
 300         m_streams.GetDataOut().Write32(size);
 301         m_streams.GetUnformattedOut().Write(data, size);
 302     }
 303
 304
 305 private:
 306     wxIPCSocketStreams& m_streams;
 307
 308     DECLARE_NO_COPY_CLASS(IPCOutput)
 309 };
 310
 311 } // anonymous namespace
 312
 313 // ==========================================================================
 314 // implementation
 315 // ==========================================================================
 316
 317 IMPLEMENT_DYNAMIC_CLASS(wxTCPServer, wxServerBase)
 318 IMPLEMENT_DYNAMIC_CLASS(wxTCPClient, wxClientBase)
 319 IMPLEMENT_CLASS(wxTCPConnection, wxConnectionBase)
 320
 321 // --------------------------------------------------------------------------
 322 // wxTCPClient
 323 // --------------------------------------------------------------------------
 324
 325 wxTCPClient::wxTCPClient()
 326            : wxClientBase()
 327 {
 328 }
 329
 330 bool wxTCPClient::ValidHost(const wxString& host)
 331 {
 332     wxIPV4address addr;
 333
 334     return addr.Hostname(host);
 335 }
 336
 337 wxConnectionBase *wxTCPClient::MakeConnection(const wxString& host,
 338                                               const wxString& serverName,
 339                                               const wxString& topic)
 340 {
 341     wxSockAddress *addr = GetAddressFromName(serverName, host);
 342     if ( !addr )
 343         return NULL;
 344
 345     wxSocketClient * const client = new wxSocketClient(wxSOCKET_WAITALL);
 346     wxIPCSocketStreams * const streams = new wxIPCSocketStreams(*client);
 347
 348     bool ok = client->Connect(*addr);
 349     delete addr;
 350
 351     if ( ok )
 352     {
 353         // Send topic name, and enquire whether this has succeeded
 354         IPCOutput(streams).Write(IPC_CONNECT, topic);
 355
 356         unsigned char msg = streams->Read8();
 357
 358         // OK! Confirmation.
 359         if (msg == IPC_CONNECT)
 360         {
 361             wxTCPConnection *
 362                 connection = (wxTCPConnection *)OnMakeConnection ();
 363
 364             if (connection)
 365             {
 366                 if (connection->IsKindOf(CLASSINFO(wxTCPConnection)))
 367                 {
 368                     connection->m_topic = topic;
 369                     connection->m_sock  = client;
 370                     connection->m_streams = streams;
 371                     client->SetEventHandler(*gs_handler, _CLIENT_ONREQUEST_ID);
 372                     client->SetClientData(connection);
 373                     client->SetNotify(wxSOCKET_INPUT_FLAG | wxSOCKET_LOST_FLAG);
 374                     client->Notify(true);
 375                     return connection;
 376                 }
 377                 else
 378                 {
 379                     delete connection;
 380                     // and fall through to delete everything else
 381                 }
 382             }
 383         }
 384     }
 385
 386     // Something went wrong, delete everything
 387     delete streams;
 388     client->Destroy();
 389
 390     return NULL;
 391 }
 392
 393 wxConnectionBase *wxTCPClient::OnMakeConnection()
 394 {
 395     return new wxTCPConnection();
 396 }
 397
 398 // --------------------------------------------------------------------------
 399 // wxTCPServer
 400 // --------------------------------------------------------------------------
 401
 402 wxTCPServer::wxTCPServer()
 403            : wxServerBase()
 404 {
 405     m_server = NULL;
 406 }
 407
 408 bool wxTCPServer::Create(const wxString& serverName)
 409 {
 410     // Destroy previous server, if any
 411     if (m_server)
 412     {
 413         m_server->SetClientData(NULL);
 414         m_server->Destroy();
 415         m_server = NULL;
 416     }
 417
 418     wxSockAddress *addr = GetAddressFromName(serverName);
 419     if ( !addr )
 420         return false;
 421
 422 #ifdef __UNIX_LIKE__
 423     mode_t umaskOld;
 424     if ( addr->Type() == wxSockAddress::UNIX )
 425     {
 426         // ensure that the file doesn't exist as otherwise calling socket()
 427         // would fail
 428         int rc = remove(serverName.fn_str());
 429         if ( rc < 0 && errno != ENOENT )
 430         {
 431             delete addr;
 432
 433             return false;
 434         }
 435
 436         // also set the umask to prevent the others from reading our file
 437         umaskOld = umask(077);
 438     }
 439     else
 440     {
 441         // unused anyhow but shut down the compiler warnings
 442         umaskOld = 0;
 443     }
 444 #endif // __UNIX_LIKE__
 445
 446     // Create a socket listening on the specified port (reusing it to allow
 447     // restarting the server listening on the same port as was used by the
 448     // previous instance of this server)
 449     m_server = new wxSocketServer(*addr, wxSOCKET_WAITALL | wxSOCKET_REUSEADDR);
 450
 451 #ifdef __UNIX_LIKE__
 452     if ( addr->Type() == wxSockAddress::UNIX )
 453     {
 454         // restore the umask
 455         umask(umaskOld);
 456
 457         // save the file name to remove it later
 458         m_filename = serverName;
 459     }
 460 #endif // __UNIX_LIKE__
 461
 462     delete addr;
 463
 464     if (!m_server->Ok())
 465     {
 466         m_server->Destroy();
 467         m_server = NULL;
 468
 469         return false;
 470     }
 471
 472     m_server->SetEventHandler(*gs_handler, _SERVER_ONREQUEST_ID);
 473     m_server->SetClientData(this);
 474     m_server->SetNotify(wxSOCKET_CONNECTION_FLAG);
 475     m_server->Notify(true);
 476
 477     return true;
 478 }
 479
 480 wxTCPServer::~wxTCPServer()
 481 {
 482     if ( m_server )
 483     {
 484         m_server->SetClientData(NULL);
 485         m_server->Destroy();
 486     }
 487
 488 #ifdef __UNIX_LIKE__
 489     if ( !m_filename.empty() )
 490     {
 491         if ( remove(m_filename.fn_str()) != 0 )
 492         {
 493             wxLogDebug(_T("Stale AF_UNIX file '%s' left."), m_filename.c_str());
 494         }
 495     }
 496 #endif // __UNIX_LIKE__
 497 }
 498
 499 wxConnectionBase *
 500 wxTCPServer::OnAcceptConnection(const wxString& WXUNUSED(topic))
 501 {
 502     return new wxTCPConnection();
 503 }
 504
 505 // --------------------------------------------------------------------------
 506 // wxTCPConnection
 507 // --------------------------------------------------------------------------
 508
 509 void wxTCPConnection::Init()
 510 {
 511     m_sock = NULL;
 512     m_streams = NULL;
 513 }
 514
 515 wxTCPConnection::~wxTCPConnection()
 516 {
 517     Disconnect();
 518
 519     if ( m_sock )
 520     {
 521         m_sock->SetClientData(NULL);
 522         m_sock->Destroy();
 523     }
 524
 525     delete m_streams;
 526 }
 527
 528 void wxTCPConnection::Compress(bool WXUNUSED(on))
 529 {
 530     // TODO
 531 }
 532
 533 // Calls that CLIENT can make.
 534 bool wxTCPConnection::Disconnect()
 535 {
 536     if ( !GetConnected() )
 537         return true;
 538
 539     // Send the disconnect message to the peer.
 540     IPCOutput(m_streams).Write8(IPC_DISCONNECT);
 541
 542     if ( m_sock )
 543     {
 544         m_sock->Notify(false);
 545         m_sock->Close();
 546     }
 547
 548     SetConnected(false);
 549
 550     return true;
 551 }
 552
 553 bool wxTCPConnection::DoExecute(const void *data,
 554                                 size_t size,
 555                                 wxIPCFormat format)
 556 {
 557     if ( !m_sock->IsConnected() )
 558         return false;
 559
 560     // Prepare EXECUTE message
 561     IPCOutput out(m_streams);
 562     out.Write8(IPC_EXECUTE);
 563     out.Write8(format);
 564
 565     out.WriteData(data, size);
 566
 567     return true;
 568 }
 569
 570 const void *wxTCPConnection::Request(const wxString& item,
 571                                      size_t *size,
 572                                      wxIPCFormat format)
 573 {
 574     if ( !m_sock->IsConnected() )
 575         return NULL;
 576
 577     IPCOutput(m_streams).Write(IPC_REQUEST, item, format);
 578
 579     int ret = m_streams->Read8();
 580     if ( ret == IPC_FAIL )
 581         return NULL;
 582
 583     return m_streams->ReadData(this, size);
 584 }
 585
 586 bool wxTCPConnection::DoPoke(const wxString& item,
 587                              const void *data,
 588                              size_t size,
 589                              wxIPCFormat format)
 590 {
 591     if ( !m_sock->IsConnected() )
 592         return false;
 593
 594     IPCOutput out(m_streams);
 595     out.Write(IPC_POKE, item, format);
 596     out.WriteData(data, size);
 597
 598     return true;
 599 }
 600
 601 bool wxTCPConnection::StartAdvise(const wxString& item)
 602 {
 603     if ( !m_sock->IsConnected() )
 604         return false;
 605
 606     IPCOutput(m_streams).Write(IPC_ADVISE_START, item);
 607
 608     int ret = m_streams->Read8();
 609     if (ret != IPC_FAIL)
 610         return true;
 611     else
 612         return false;
 613 }
 614
 615 bool wxTCPConnection::StopAdvise (const wxString& item)
 616 {
 617     if ( !m_sock->IsConnected() )
 618         return false;
 619
 620     IPCOutput(m_streams).Write(IPC_ADVISE_STOP, item);
 621
 622     int ret = m_streams->Read8();
 623
 624     if (ret != IPC_FAIL)
 625         return true;
 626     else
 627         return false;
 628 }
 629
 630 // Calls that SERVER can make
 631 bool wxTCPConnection::DoAdvise(const wxString& item,
 632                                const void *data,
 633                                size_t size,
 634                                wxIPCFormat format)
 635 {
 636     if ( !m_sock->IsConnected() )
 637         return false;
 638
 639     IPCOutput out(m_streams);
 640     out.Write(IPC_ADVISE, item, format);
 641     out.WriteData(data, size);
 642
 643     return true;
 644 }
 645
 646 // --------------------------------------------------------------------------
 647 // wxTCPEventHandler (private class)
 648 // --------------------------------------------------------------------------
 649
 650 BEGIN_EVENT_TABLE(wxTCPEventHandler, wxEvtHandler)
 651     EVT_SOCKET(_CLIENT_ONREQUEST_ID, wxTCPEventHandler::Client_OnRequest)
 652     EVT_SOCKET(_SERVER_ONREQUEST_ID, wxTCPEventHandler::Server_OnRequest)
 653 END_EVENT_TABLE()
 654
 655 void wxTCPEventHandler::Client_OnRequest(wxSocketEvent &event)
 656 {
 657     wxSocketBase *sock = event.GetSocket();
 658     if (!sock)
 659         return ;
 660
 661     wxSocketNotify evt = event.GetSocketEvent();
 662     wxTCPConnection *connection = (wxTCPConnection *)(sock->GetClientData());
 663
 664     // This socket is being deleted; skip this event
 665     if (!connection)
 666         return;
 667
 668     // We lost the connection: destroy everything
 669     if (evt == wxSOCKET_LOST)
 670     {
 671         sock->Notify(false);
 672         sock->Close();
 673         connection->OnDisconnect();
 674         return;
 675     }
 676
 677     // Receive message number.
 678     wxIPCSocketStreams * const streams = connection->m_streams;
 679
 680     const wxString topic = connection->m_topic;
 681     wxString item;
 682
 683     const int msg = streams->Read8();
 684     switch ( msg )
 685     {
 686         case IPC_EXECUTE:
 687             {
 688                 wxIPCFormat format;
 689                 size_t size;
 690                 void * const
 691                     data = streams->ReadFormatData(connection, &format, &size);
 692
 693                 connection->OnExecute(topic, data, size, format);
 694             }
 695             break;
 696
 697         case IPC_ADVISE:
 698             {
 699                 item = streams->ReadString();
 700
 701                 wxIPCFormat format;
 702                 size_t size;
 703                 void * const
 704                     data = streams->ReadFormatData(connection, &format, &size);
 705
 706                 connection->OnAdvise(topic, item, data, size, format);
 707             }
 708             break;
 709
 710         case IPC_ADVISE_START:
 711             {
 712                 item = streams->ReadString();
 713
 714                 IPCOutput(streams).Write8(connection->OnStartAdvise(topic, item)
 715                                             ? IPC_ADVISE_START
 716                                             : IPC_FAIL);
 717             }
 718             break;
 719
 720         case IPC_ADVISE_STOP:
 721             {
 722                 item = streams->ReadString();
 723
 724                 IPCOutput(streams).Write8(connection->OnStopAdvise(topic, item)
 725                                              ? IPC_ADVISE_STOP
 726                                              : IPC_FAIL);
 727             }
 728             break;
 729
 730         case IPC_POKE:
 731             {
 732                 item = streams->ReadString();
 733                 wxIPCFormat format = (wxIPCFormat)streams->Read8();
 734
 735                 size_t size;
 736                 void * const data = streams->ReadData(connection, &size);
 737
 738                 connection->OnPoke(topic, item, data, size, format);
 739             }
 740             break;
 741
 742         case IPC_REQUEST:
 743             {
 744                 item = streams->ReadString();
 745
 746                 wxIPCFormat format = (wxIPCFormat)streams->Read8();
 747
 748                 size_t user_size = wxNO_LEN;
 749                 const void *user_data = connection->OnRequest(topic,
 750                                                               item,
 751                                                               &user_size,
 752                                                               format);
 753
 754                 if ( !user_data )
 755                 {
 756                     IPCOutput(streams).Write8(IPC_FAIL);
 757                     break;
 758                 }
 759
 760                 IPCOutput out(streams);
 761                 out.Write8(IPC_REQUEST_REPLY);
 762
 763                 if ( user_size == wxNO_LEN )
 764                 {
 765                     switch ( format )
 766                     {
 767                         case wxIPC_TEXT:
 768                         case wxIPC_UTF8TEXT:
 769                             user_size = strlen((const char *)user_data) + 1;  // includes final NUL
 770                             break;
 771                         case wxIPC_UNICODETEXT:
 772                             user_size = (wcslen((const wchar_t *)user_data) + 1) * sizeof(wchar_t);  // includes final NUL
 773                             break;
 774                         default:
 775                             user_size = 0;
 776                     }
 777                 }
 778
 779                 out.WriteData(user_data, user_size);
 780             }
 781             break;
 782
 783         case IPC_DISCONNECT:
 784             sock->Notify(false);
 785             sock->Close();
 786             connection->SetConnected(false);
 787             connection->OnDisconnect();
 788             break;
 789
 790         default:
 791             wxLogDebug("Unknown message code %d received.", msg);
 792             IPCOutput(streams).Write8(IPC_FAIL);
 793             break;
 794     }
 795 }
 796
 797 void wxTCPEventHandler::Server_OnRequest(wxSocketEvent &event)
 798 {
 799     wxSocketServer *server = (wxSocketServer *) event.GetSocket();
 800     if (!server)
 801         return ;
 802     wxTCPServer *ipcserv = (wxTCPServer *) server->GetClientData();
 803
 804     // This socket is being deleted; skip this event
 805     if (!ipcserv)
 806         return;
 807
 808     if (event.GetSocketEvent() != wxSOCKET_CONNECTION)
 809         return;
 810
 811     // Accept the connection, getting a new socket
 812     wxSocketBase *sock = server->Accept();
 813     if (!sock)
 814         return ;
 815     if (!sock->Ok())
 816     {
 817         sock->Destroy();
 818         return;
 819     }
 820
 821     wxIPCSocketStreams *streams = new wxIPCSocketStreams(*sock);
 822
 823     {
 824         IPCOutput out(streams);
 825
 826         const int msg = streams->Read8();
 827         if ( msg == IPC_CONNECT )
 828         {
 829             const wxString topic = streams->ReadString();
 830
 831             wxTCPConnection *new_connection =
 832                 (wxTCPConnection *)ipcserv->OnAcceptConnection (topic);
 833
 834             if (new_connection)
 835             {
 836                 if (new_connection->IsKindOf(CLASSINFO(wxTCPConnection)))
 837                 {
 838                     // Acknowledge success
 839                     out.Write8(IPC_CONNECT);
 840
 841                     new_connection->m_sock = sock;
 842                     new_connection->m_streams = streams;
 843                     new_connection->m_topic = topic;
 844                     sock->SetEventHandler(*gs_handler, _CLIENT_ONREQUEST_ID);
 845                     sock->SetClientData(new_connection);
 846                     sock->SetNotify(wxSOCKET_INPUT_FLAG | wxSOCKET_LOST_FLAG);
 847                     sock->Notify(true);
 848                     return;
 849                 }
 850                 else
 851                 {
 852                     delete new_connection;
 853                     // and fall through to delete everything else
 854                 }
 855             }
 856         }
 857
 858         // Something went wrong, send failure message and delete everything
 859         out.Write8(IPC_FAIL);
 860     } // IPCOutput object is destroyed here, before destroying stream
 861
 862     delete streams;
 863     sock->Destroy();
 864 }
 865
 866 // --------------------------------------------------------------------------
 867 // wxTCPEventHandlerModule (private class)
 868 // --------------------------------------------------------------------------
 869
 870 class wxTCPEventHandlerModule: public wxModule
 871 {
 872 public:
 873     virtual bool OnInit() { gs_handler = new wxTCPEventHandler; return true; }
 874     virtual void OnExit() { wxDELETE(gs_handler); }
 875
 876     DECLARE_DYNAMIC_CLASS(wxTCPEventHandlerModule)
 877 };
 878
 879 IMPLEMENT_DYNAMIC_CLASS(wxTCPEventHandlerModule, wxModule)
 880
 881 #endif // wxUSE_SOCKETS && wxUSE_IPC && wxUSE_STREAMS