1 // Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // Implementation of pipes

    15 // 

    16 //

    17 

    18 #include "POSIXIF.H"

    19 #include <sys/errno.h>

    20 #include <sys/stat.h>

    21 

    22 // Child end of the pipe

    23 

    24 CPipeChildDesc::CPipeChildDesc(TInt anIndex, RPosixSession& aSession)

    25 		: CFileDescBase(), iIndex(anIndex), iSession(aSession), iParamDes(0,0,0)

    26 	{}

    27 

    28 TInt CPipeChildDesc::LSeek (int&, int)

    29 	{

    30 	return ESPIPE;	// can't seek on a pipe

    31 	}

    32 

    33 TInt CPipeChildDesc::FStat(struct stat *st)

    34 	{

    35 	// I am a fifo about which little is known

    36 	st->st_mode = S_IFIFO;

    37 	st->st_blksize=0;

    38 	return KErrNone;

    39 	}

    40 

    41 void CPipeChildDesc::Read (TDes8& aBuf, TRequestStatus& aStatus)

    42 	{

    43 	if (iClientClosed || !IsReadable())

    44 		{

    45 		Complete(aStatus,KErrEof);

    46 		return;

    47 		}

    48 	TIpcArgs args(iIndex,&aBuf,aBuf.MaxLength());

    49 	iSession.Request(PMPipeRead,args,aStatus);	// asynchronous request

    50 	}

    51 

    52 void CPipeChildDesc::ReadCancel()

    53 	{

    54 	Cancel(PMPipeRead);

    55 	}

    56 

    57 TInt CPipeChildDesc::ReadCompletion(TDes8& aDesc, TInt aStatus)

    58 	{

    59 	if (aStatus==KErrEof)

    60 		{

    61 		ClientClose();

    62 		aDesc.Zero();		// set read length to zero

    63 		return KErrNone;	// indicates graceful close at the other end

    64 		}

    65 	return aStatus;

    66 	}

    67 

    68 void CPipeChildDesc::Write(TDes8& aDesc, TRequestStatus& aStatus)

    69 	{

    70 	if (iClientClosed || !IsWriteable())

    71 		{

    72 		Complete(aStatus,KErrEof);

    73 		return;

    74 		}

    75 	TIpcArgs args(iIndex,&aDesc,aDesc.Length());

    76 	iSession.Request(PMPipeWrite,args,aStatus);	// asynchronous request

    77 	}

    78 

    79 void CPipeChildDesc::WriteCancel()

    80 	{

    81 	Cancel(PMPipeWrite);

    82 	}

    83 

    84 TInt CPipeChildDesc::WriteCompletion(TDes8& /*aDesc*/, TInt aStatus)

    85 	{

    86 	if (aStatus==KErrEof)

    87 		ClientClose();

    88 	return aStatus;

    89 	}

    90 

    91 void CPipeChildDesc::Ioctl(int aCmd, void* aParam, TRequestStatus& aStatus)

    92 //

    93 // The work of the Ioctl is done in the parent, including writing back to aParam?

    94 // Use the default completion which just returns aStatus.Int()

    95 //

    96 	{

    97 	if (iClientClosed)

    98 		{

    99 		Complete(aStatus,KErrEof);

   100 		return;

   101 		}

   102 	iParamDes.Set((TText8*)aParam,4,4);

   103 	TIpcArgs args(iIndex,aCmd,&iParamDes);	

   104 	if (aCmd==E32IOSELECT)

   105 		args.Set(3, *((TInt*)aParam));

   106 	iSession.Request(PMPipeIoctl,args,aStatus);	// asynchronous request

   107 	}

   108 

   109 void CPipeChildDesc::IoctlCancel()

   110 	{

   111 	Cancel(PMPipeIoctl);

   112 	}

   113 

   114 void CPipeChildDesc::Cancel(TInt aType)

   115 	{

   116 	if (iClientClosed)

   117 		return;

   118 	TIpcArgs args(iIndex,aType);

   119 	iSession.Request(PMPipeCancel,args);

   120 	}	

   121 

   122 TInt CPipeChildDesc::FinalClose()

   123 	{

   124 	ClientClose();

   125 	TIpcArgs args(iIndex);

   126 	return iSession.Request(PMPipeClose,args);		// synchronous request

   127 	}

   128 

   129 // 

   130 // Parent end of the pipe, where the real work is done

   131 //

   132 

   133 CPipeDesc::CPipeDesc(TInt anIndex) : CFileDescBase()

   134 	{

   135 	iIndex=anIndex;

   136 	}

   137 

   138 void CPipeDesc::SetClientSide(CPipeDesc*& aClientPointer)

   139 	{

   140 	iClientSide=&aClientPointer;

   141 	}

   142 

   143 _LIT(KCPipeDescPanic, "CPipeDesc");

   144 void CPipeDesc::Panic(TInt aReason)

   145 	{

   146 	User::Panic(KCPipeDescPanic,aReason);

   147 	}

   148 

   149 void CPipeDesc::Panic(RMessage2& aMessage, TInt aReason)

   150 	{

   151 	aMessage.Panic(KCPipeDescPanic,aReason);

   152 	}

   153 

   154 TInt CPipeDesc::LSeek (int&, int)

   155 	{

   156 	return ESPIPE;	// can't seek on a pipe

   157 	}

   158 

   159 TInt CPipeDesc::FStat(struct stat *st)

   160 	{

   161 	// I am a fifo about which little is known

   162 	st->st_mode = S_IFIFO;

   163 	st->st_blksize=0;

   164 	return KErrNone;

   165 	}

   166 

   167 void CPipeDesc::Read (TDes8& aBuf, TRequestStatus& aStatus)

   168 	{

   169 	if (!IsReadable())

   170 		{

   171 		Complete(aStatus, KErrEof);	// avoids treading on iStatus of pending Write

   172 		return;

   173 		}

   174 	__ASSERT_DEBUG(iStatus==0,Panic(1));

   175 	iStatus=&aStatus;

   176 	if (iClientClosed)

   177 		{

   178 		User::RequestComplete(iStatus,KErrEof);

   179 		return;

   180 		}

   181 	iReadBuf=&aBuf;

   182 	if (ClientIoctlPending())

   183 		CompleteClientIoctl();

   184 	if (iClientLength!=0)

   185 		TransferFromClient();

   186 	}

   187 

   188 void CPipeDesc::ReadCancel()

   189 	{

   190 	Cancel();

   191 	}

   192 

   193 TInt CPipeDesc::ReadCompletion(TDes8& aDesc, TInt aStatus)

   194 	{

   195 	if (aStatus==KErrEof)

   196 		{

   197 		ClientClose();

   198 		aDesc.Zero();		// set read length to zero

   199 		return KErrNone;	// indicates graceful close at the other end

   200 		}

   201 	return aStatus;

   202 	}

   203 

   204 void CPipeDesc::Write(TDes8& aDesc, TRequestStatus& aStatus)

   205 	{

   206 	if (!IsWriteable())

   207 		{

   208 		Complete(aStatus, KErrEof);	// avoids treading on iStatus of pending Read

   209 		return;

   210 		}

   211 	__ASSERT_DEBUG(iStatus==0,Panic(2));

   212 	iStatus=&aStatus;

   213 	if (iClientClosed)

   214 		{

   215 		User::RequestComplete(iStatus,KErrEof);

   216 		return;

   217 		}

   218 	iWriteBuf.Set(aDesc);

   219 	if (ClientIoctlPending())

   220 		CompleteClientIoctl();

   221 	if (iClientLength!=0)

   222 		TransferToClient();

   223 	}

   224 

   225 void CPipeDesc::WriteCancel()

   226 	{

   227 	Cancel();

   228 	}

   229 

   230 TInt CPipeDesc::WriteCompletion(TDes8& /*aDesc*/, TInt aStatus)

   231 	{

   232 	if (aStatus==KErrEof)

   233 		ClientClose();

   234 	return aStatus;

   235 	}

   236 

   237 void CPipeDesc::Ioctl(int aCmd, void* aParam, TRequestStatus& aStatus)

   238 	{

   239 	TInt ret=KErrNone;

   240 	iIoctlStatus=&aStatus;

   241 	int *param=REINTERPRET_CAST(int*,aParam);

   242 	switch (aCmd)

   243 		{

   244 	case E32IONREAD:

   245 		// synchronous ioctls are handled in the completion routine.

   246 		break;

   247 	case E32IOSELECT:

   248 		{

   249 		int mask=(*param)&SelectMask();

   250 		if (mask!=0 && iClientLength==0)

   251 			return;	// wait for client to show up

   252 		}

   253 		break;

   254 	default:

   255 		ret=KErrNotSupported;

   256 		break;

   257 		}

   258 	User::RequestComplete(iIoctlStatus,ret);

   259 	}

   260 

   261 TInt CPipeDesc::IoctlCompletion(int aCmd, void* aParam, TInt aStatus)

   262 	{

   263 	TInt ret=aStatus;

   264 	if (ret!=KErrNone)

   265 		return ret;

   266 	int *param=REINTERPRET_CAST(int*,aParam);

   267 	switch (aCmd)

   268 		{

   269 	case E32IONREAD:

   270 		if (IsReadable())

   271 			*param=iClientLength;	// 0 if no outstanding client data

   272 		else

   273 			*param=0;	// claim that no data is available

   274 		break;

   275 	case E32IOSELECT:

   276 		{

   277 		int mask=0;

   278 		if (iClientLength!=0)

   279 			mask = SelectMask();

   280 		*param=(*param)&mask;

   281 		}

   282 		break;

   283 	default:

   284 		ret=KErrNotSupported;

   285 		break;

   286 		}

   287 	return ret;

   288 	}

   289 

   290 void CPipeDesc::IoctlCancel()

   291 	{

   292 	User::RequestComplete(iIoctlStatus,KErrCancel);

   293 	}

   294 

   295 void CPipeDesc::Cancel()

   296 	{

   297 	// Pipes are unidirectional, so don't need to distinguish between

   298 	// ReadCancel and WriteCancel

   299 	User::RequestComplete(iStatus,KErrCancel);

   300 	}

   301 

   302 // Client-side interface

   303 

   304 void CPipeDesc::ClientWrite(const RMessage2& aMessage)

   305 	{

   306 	__ASSERT_DEBUG(iClientLength==0,Panic(3));

   307 	if (iClientClosed)

   308 		{

   309 		aMessage.Complete(KErrEof);

   310 		return;

   311 		}

   312 	iClientLength=aMessage.Int2();

   313 	iClientOffset=0;

   314 	iMessage=aMessage;

   315 	if (iIoctlStatus!=0)

   316 		User::RequestComplete(iIoctlStatus,KErrNone);

   317 	if (iStatus!=0)

   318 		TransferFromClient();

   319 	}

   320 

   321 void CPipeDesc::ClientRead(const RMessage2& aMessage)

   322 	{

   323 	__ASSERT_DEBUG(iClientLength==0,Panic(4));

   324 	if (iClientClosed)

   325 		{

   326 		aMessage.Complete(KErrEof);

   327 		return;

   328 		}

   329 	iClientLength=aMessage.Int2();

   330 	iMessage=aMessage;

   331 	if (iIoctlStatus!=0)

   332 		User::RequestComplete(iIoctlStatus,KErrNone);

   333 	if (iStatus!=0)

   334 		TransferToClient();

   335 	}

   336 

   337 void CPipeDesc::ClientIoctl(const RMessage2& aMessage)

   338 	{

   339 	__ASSERT_DEBUG(!ClientIoctlPending(),Panic(7));

   340 	if (iClientClosed)

   341 		{

   342 		aMessage.Complete(KErrEof);

   343 		return;

   344 		}

   345 	iClientIoctlPending=1;

   346 	iIoctlMessage=aMessage;

   347 	TInt ret=KErrNone;

   348 	switch (aMessage.Int1())

   349 		{

   350 	case E32IONREAD:

   351 		// synchronous ioctls are handled in the completion routine.

   352 		break;

   353 	case E32IOSELECT:

   354 		{

   355 		int mask=aMessage.Int3();

   356 		mask&=ClientSelectMask();

   357 		if (mask!=0 && iStatus==0)

   358 			return;	// wait for parent activity

   359 		}

   360 		break;

   361 	default:

   362 		ret=KErrNotSupported;

   363 		break;

   364 		}

   365 	CompleteClientIoctl(ret);

   366 	}

   367 

   368 void CPipeDesc::ClientCancel(const RMessage2& aMessage)

   369 	{

   370 	if (aMessage.Int1()==PMPipeIoctl)

   371 		{

   372 		if (ClientIoctlPending())

   373 			CompleteClientIoctl(KErrCancel);

   374 		return;

   375 		}

   376 	// Pipes are unidirectional, so Read and Write are cancelled by

   377 	// cancelling the current client operation.

   378 	//

   379 	if (iClientLength!=0)

   380 		{

   381 		iMessage.Complete(KErrCancel);

   382 		iClientLength=0;

   383 		}

   384 	}

   385 

   386 void CPipeDesc::ClientClose()

   387 	{

   388 	iClientClosed=1;

   389 	// terminate any pending requests

   390 	if (iStatus!=0)

   391 		User::RequestComplete(iStatus,KErrEof);

   392 	if (ClientIoctlPending())

   393 		CompleteClientIoctl(KErrEof);

   394 	if (iClientLength!=0)

   395 		{

   396 		iMessage.Complete(KErrEof);

   397 		iClientLength=0;

   398 		}

   399 	}

   400 

   401 TInt CPipeDesc::FinalClose()

   402 	{

   403 	ClientClose();

   404 	if (iClientSide)

   405 		{

   406 		*iClientSide=0;

   407 		iClientSide=0;

   408 		}

   409 	return KErrNone;

   410 	}

   411 

   412 void CPipeDesc::TransferFromClient()

   413 //

   414 // Handle transfer of data from client to parent.

   415 // Always complete the parent read, but only complete the child write when

   416 // all of the data has been consumed.

   417 //

   418 	{

   419 	TRAPD(err,iMessage.ReadL(1,*iReadBuf,iClientOffset));

   420 	if (err)

   421 		{

   422 		Panic(iMessage,5);

   423 		iClientLength=0;

   424 		ClientClose();	// will complete the parent read

   425 		return;

   426 		}

   427 	TInt length=iReadBuf->Length();	// record the amount of data transferred

   428 	User::RequestComplete(iStatus,KErrNone);

   429 	iClientOffset+=length;

   430 	iClientLength-=length;

   431 	if (iClientLength==0)

   432 		iMessage.Complete(KErrNone);

   433 	}

   434 

   435 void CPipeDesc::TransferToClient()

   436 //

   437 // Handle transfer from parent to client

   438 // Always complete the client read, but only complete the parent write when

   439 // all of the data has been consumed.

   440 //

   441 	{

   442 	TInt err=KErrNone;

   443 	TInt length=iWriteBuf.Length();

   444 	TInt written=length;

   445 	if (iClientLength >= length)

   446 		{

   447 		TRAP(err,iMessage.WriteL(1,iWriteBuf,0));

   448 		}

   449 	else

   450 		{

   451 		written=iClientLength;

   452 		TRAP(err,iMessage.WriteL(1,iWriteBuf.Left(written),0));

   453 		}

   454 	iClientLength=0;

   455 	if (err)

   456 		{

   457 		Panic(iMessage,6);

   458 		ClientClose();	// will complete the parent write

   459 		return;

   460 		}

   461 	iMessage.Complete(KErrNone);

   462 	length-=written;

   463 	if (length==0)

   464 		User::RequestComplete(iStatus,KErrNone);

   465 	else

   466 		iWriteBuf.Set(iWriteBuf.Right(length));

   467 	}

   468 

   469 void CPipeDesc::CompleteClientIoctl(TInt ret)

   470 	{

   471 	if (ret!=KErrNone)

   472 		{

   473 		iIoctlMessage.Complete(ret);

   474 		iClientIoctlPending=0;

   475 		return;

   476 		}

   477 	CompleteClientIoctl();

   478 	}

   479 

   480 void CPipeDesc::CompleteClientIoctl()

   481 //

   482 // Complete outstanding PMPipeIoctl message

   483 //

   484 	{

   485 	TInt ret=KErrNone;

   486 	int param=0;

   487 	switch (iIoctlMessage.Int1())

   488 		{

   489 	case E32IONREAD:

   490 		if (IsWriteable() && iStatus!=0)

   491 			param=iWriteBuf.Length();

   492 		else

   493 			param=0;	// claim that no data is available

   494 		break;

   495 	case E32IOSELECT:

   496 		{

   497 		int mask=0;

   498 		if (iStatus!=0)

   499 			mask=ClientSelectMask();

   500 		param=(iIoctlMessage.Int3())&mask;

   501 		}

   502 		break;

   503 	default:

   504 		ret=KErrNotSupported;

   505 		break;

   506 		}

   507 	if (ret==KErrNone)

   508 		{

   509 		TPtrC8 paramReturn((const TText8*)&param,4);

   510 		TRAP(ret,iIoctlMessage.WriteL(2,paramReturn,0));

   511 		}

   512 	iIoctlMessage.Complete(ret);

   513 	iClientIoctlPending=0;

   514 	}