kerneltest/e32test/secure/t_ipcsafety.cpp
changeset 0 a41df078684a
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     1 // Copyright (c) 2007-2009 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 the License "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 // e32test\secure\t_ipcsafety.cpp
       
    15 // Overview:
       
    16 // Test if it's possible for a thread in a server process to access the IPC alias
       
    17 // region outside the control of the kernel.
       
    18 // API Information:
       
    19 // RMessage2
       
    20 // Details:
       
    21 // - Create a server which will take a long time IPCing any client request.
       
    22 // - Create a high priority thread which will attempt to write to a given
       
    23 // location in the IPC region, with an exception handler to retry if it fails.
       
    24 // - Create a client process which connects to the server and offers a
       
    25 // stack-based descriptor for IPC, as well as the address of another stack
       
    26 // variable that should not be able to be accessed.
       
    27 // - The bad writer will attempt to jump in and overwrite the variable,
       
    28 // causing the client to return a detectable error.
       
    29 // - Verify that this does not happen.
       
    30 // Platforms/Drives/Compatibility:
       
    31 // ARM with multiple memory model only.
       
    32 // Assumptions/Requirement/Pre-requisites:
       
    33 // Failures and causes:
       
    34 // Base Port information:
       
    35 // 
       
    36 //
       
    37 
       
    38 #define __E32TEST_EXTENSION__
       
    39 #include <e32test.h>
       
    40 #include <e32debug.h>
       
    41 #include <e32base.h>
       
    42 #include <e32base_private.h>
       
    43 #include "mmudetect.h"
       
    44 
       
    45 LOCAL_D RTest test(_L("T_IPCSAFETY"));
       
    46 
       
    47 void GoodExitWithError();
       
    48 
       
    49 TInt* DataToSplat;
       
    50 RSemaphore BadSemaphore;
       
    51 
       
    52 // Server stuff
       
    53 
       
    54 _LIT(KBadServerName,"BadServer");
       
    55 
       
    56 class CBadSession : public CSession2
       
    57 	{
       
    58 	virtual void ServiceL(const RMessage2& aMessage);
       
    59 	};
       
    60 
       
    61 class CBadServer : public CServer2
       
    62 	{
       
    63 public:
       
    64 	CBadServer(CActive::TPriority aPriority) : CServer2(aPriority)
       
    65 		{}
       
    66 	virtual CBadSession* NewSessionL(const TVersion& aVersion, const RMessage2& aMessage) const
       
    67 		{
       
    68 		return new (ELeave) CBadSession();
       
    69 		}
       
    70 	};
       
    71 
       
    72 void CBadSession::ServiceL(const RMessage2& aMessage)
       
    73 	{
       
    74 	TBuf16<1024> buf;
       
    75 	DataToSplat = (TInt*)aMessage.Ptr1();
       
    76 	BadSemaphore.Signal();
       
    77 	// Read the buffer lots of times to widen the time window
       
    78 	for (TInt i=0; i<1024; i++)
       
    79 		aMessage.Read(0, buf, 0);
       
    80 	CActiveScheduler::Stop();
       
    81 	aMessage.Complete(KErrNone);
       
    82 	}
       
    83 
       
    84 TInt BadServerThread(TAny*)
       
    85 	{
       
    86 	CTrapCleanup* cleanup=CTrapCleanup::New();
       
    87 	if (!cleanup)
       
    88 		return KErrNoMemory;
       
    89 	CActiveScheduler* scheduler = new CActiveScheduler();
       
    90 	if (!scheduler)
       
    91 		return KErrNoMemory;
       
    92 	CActiveScheduler::Install(scheduler);
       
    93 	CBadServer* server = new CBadServer(CActive::EPriorityStandard);
       
    94 	if (!server)
       
    95 		return KErrNoMemory;
       
    96 	TInt r = server->Start(KBadServerName);
       
    97 	if (r != KErrNone)
       
    98 		return r;
       
    99 	RThread::Rendezvous(KErrNone);
       
   100 	CActiveScheduler::Start();
       
   101 	delete server;
       
   102 	delete scheduler;
       
   103 	delete cleanup;
       
   104 	return KErrNone;
       
   105 	}
       
   106 
       
   107 class RBadSession : public RSessionBase
       
   108 	{
       
   109 public:
       
   110 	TInt Connect()
       
   111 		{
       
   112 		return CreateSession(KBadServerName, TVersion(0,0,0));
       
   113 		}
       
   114 	void AccessMe(TDesC* aBuf, TInt* aValue);
       
   115 	};
       
   116 
       
   117 void RBadSession::AccessMe(TDesC* aBuf, TInt* aValue)
       
   118 	{
       
   119 	SendReceive(0, TIpcArgs(aBuf, aValue));
       
   120 	};
       
   121 
       
   122 // Bad writer thread
       
   123 
       
   124 TInt * const KAliasRegion = (TInt*)0x00200000;
       
   125 const TUint KAliasMask = 0x000fffff;
       
   126 
       
   127 void BadExceptionHandler(TExcType, TInt, TInt, TInt, TUint aStackArgument)
       
   128 	{
       
   129 	// just retry the instruction after a delay
       
   130 	User::AfterHighRes(0);
       
   131 	return;
       
   132 	}
       
   133 
       
   134 TInt BadWriterThread(TAny*)
       
   135 	{
       
   136 	// set the exception handler so that we don't die when touching the ipc region
       
   137 	// as it won't be mapped until an unpredictable time
       
   138 	User::SetExceptionHandler((TExceptionHandler)BadExceptionHandler, KExceptionFault);
       
   139 	// wait for the server to tell us where to overwrite
       
   140 	BadSemaphore.Wait();
       
   141 
       
   142 	TInt* target = (TInt*)(((TUint)DataToSplat&KAliasMask)|(TUint)KAliasRegion);
       
   143 	*target = KErrGeneral;
       
   144 
       
   145 	return KErrNone;
       
   146 	}
       
   147 
       
   148 // The server process
       
   149 
       
   150 TInt BadServerProcess()
       
   151 	{
       
   152 	test.Title();
       
   153 	test.Start(_L("Test bad server overwriting good client memory"));
       
   154 
       
   155 	BadSemaphore.CreateLocal(0);
       
   156 
       
   157 	test.Next(_L("Setup bad server"));
       
   158 	RThread serverThread;
       
   159 	TRequestStatus serverStatus, serverRendezvous;
       
   160 	test_KErrNone(serverThread.Create(_L("BadServer"), BadServerThread, KDefaultStackSize, NULL, NULL));
       
   161 	serverThread.Logon(serverStatus);
       
   162 	serverThread.Rendezvous(serverRendezvous);
       
   163 	serverThread.Resume();
       
   164 	User::WaitForRequest(serverRendezvous);
       
   165 
       
   166 	test.Next(_L("Start bad writer thread"));
       
   167 	RThread writerThread;
       
   168 	TRequestStatus writerStatus;
       
   169 	test_KErrNone(writerThread.Create(_L("BadWriter"), BadWriterThread, KDefaultStackSize, NULL, NULL));
       
   170 	writerThread.Logon(writerStatus);
       
   171 	writerThread.SetPriority(EPriorityMore);
       
   172 	writerThread.Resume();
       
   173 
       
   174 	test.Next(_L("Run the good client"));
       
   175 	RProcess goodProcess;
       
   176 	TRequestStatus goodStatus;
       
   177 	test_KErrNone(goodProcess.Create(_L("T_IPCSAFETY"), _L("client")));
       
   178 	goodProcess.Logon(goodStatus);
       
   179 	goodProcess.Resume();
       
   180 
       
   181 	test.Next(_L("Wait for server to die"));
       
   182 	User::WaitForRequest(serverStatus);
       
   183 	test_Equal(EExitKill, serverThread.ExitType());
       
   184 	test_KErrNone(serverThread.ExitReason());
       
   185 
       
   186 	test.Next(_L("Check if client had memory overwritten"));
       
   187 	User::WaitForRequest(goodStatus);
       
   188 	test_Equal(EExitKill, goodProcess.ExitType());
       
   189 	test_KErrNone(goodProcess.ExitReason());
       
   190 
       
   191 	test.Next(_L("Kill off writer thread"));
       
   192 	writerThread.Kill(KErrNone);
       
   193 	User::WaitForRequest(writerStatus);
       
   194 	test_Equal(EExitKill, writerThread.ExitType());
       
   195 	test_KErrNone(writerThread.ExitReason());
       
   196 
       
   197 	test.End();
       
   198 	return KErrNone;
       
   199 	}
       
   200 
       
   201 // The client process
       
   202 
       
   203 TInt GoodClientProcess()
       
   204 	{
       
   205 	RBadSession bad;
       
   206 	TBuf16<1024> buf;
       
   207 	TInt r = KErrNone;
       
   208 	buf.SetLength(1024);
       
   209 	// just keep trying to connect if the server isn't talkative yet
       
   210 	while (bad.Connect() != KErrNone)
       
   211 		User::After(1);
       
   212 	bad.AccessMe(&buf, &r);
       
   213 	// Returns r, which logically should be KErrNone as servers aren't
       
   214 	// supposed to be able to modify
       
   215 	return r;
       
   216 	}
       
   217 
       
   218 // Main
       
   219 
       
   220 GLDEF_C TInt E32Main()
       
   221     {
       
   222 	TBuf16<512> cmd;
       
   223 	User::CommandLine(cmd);
       
   224 
       
   225 	// this test hardcodes various multiple memory model parameters
       
   226 	// and the moving model's aliasing technique is not susceptible to
       
   227 	// the problem in the first place
       
   228 	TUint32 memmodel = MemModelAttributes();
       
   229 	if ((memmodel & EMemModelTypeMask) != EMemModelTypeMultiple)
       
   230 		return KErrNone;
       
   231 
       
   232 	if(cmd.Length())
       
   233 		return GoodClientProcess();
       
   234 	else
       
   235 		return BadServerProcess();
       
   236     }
       
   237