internal void _Init(String path, int fAccess, FileShare share, UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs, FileIOPermissionAccess secAccess,
FileMode mode, int flagsAndAttributes, bool seekToEnd)
{
String filePath = Path.GetFullPath(path);
_fileName = filePath;
new FileIOPermission(secAccess, new String[] { filePath }).Demand();
// Don't pop up a dialog for reading from an emtpy floppy drive
int oldMode = UnsafeNativeMethods.SetErrorMode(UnsafeNativeMethods.SEM_FAILCRITICALERRORS);
try {
_handle = UnsafeNativeMethods.SafeCreateFile(filePath, fAccess, share, secAttrs, mode, flagsAndAttributes, UnsafeNativeMethods.NULL);
int errorCode = Marshal.GetLastWin32Error();
if (_handle.IsInvalid)
{
// Return a meaningful exception, using the RELATIVE path to
// the file to avoid returning extra information to the caller
// unless they have path discovery permission, in which case
// the full path is fine & useful.
// We need to give an exception, and preferably it would include
// the fully qualified path name. Do security check here. If
// we fail, give back the msgPath, which should not reveal much.
// While this logic is largely duplicated in
// __Error.WinIOError, we need this for
// IsolatedStorageLogFileStream.
bool canGiveFullPath = false;
try {
new FileIOPermission(FileIOPermissionAccess.PathDiscovery, new String[] { _fileName }).Demand();
canGiveFullPath = true;
}
catch (SecurityException) {}
if (canGiveFullPath)
{
__Error.WinIOError(errorCode, _fileName);
}
else
{
__Error.WinIOError(errorCode, Path.GetFileName(_fileName));
}
}
}
finally {
UnsafeNativeMethods.SetErrorMode(oldMode);
}
Debug.Assert(UnsafeNativeMethods.GetFileType(_handle) == UnsafeNativeMethods.FILE_TYPE_DISK, "did someone accidentally removed the device type check from SafeCreateFile P/Invoke wrapper?");
pos = 0;
// For Append mode...
if (seekToEnd)
{
SeekCore(0, SeekOrigin.End);
}
}
private unsafe static UnsafeNativeMethods.SECURITY_ATTRIBUTES GetSecAttrs(HandleInheritability inheritability,
MemoryMappedFileSecurity memoryMappedFileSecurity, out Object pinningHandle)
{
pinningHandle = null;
UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs = null;
if ((inheritability & HandleInheritability.Inheritable) != 0 ||
memoryMappedFileSecurity != null)
{
secAttrs = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
secAttrs.nLength = (Int32)Marshal.SizeOf(secAttrs);
if ((inheritability & HandleInheritability.Inheritable) != 0)
{
secAttrs.bInheritHandle = 1;
}
// For ACLs, get the security descriptor from the MemoryMappedFileSecurity.
if (memoryMappedFileSecurity != null)
{
byte[] sd = memoryMappedFileSecurity.GetSecurityDescriptorBinaryForm();
pinningHandle = GCHandle.Alloc(sd, GCHandleType.Pinned);
fixed(byte *pSecDescriptor = sd)
secAttrs.pSecurityDescriptor = pSecDescriptor;
}
}
return(secAttrs);
}
private static UnsafeNativeMethods.SECURITY_ATTRIBUTES GetSecAttrs(FileShare share)
{
UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs = null;
if ((share & FileShare.Inheritable) != 0)
{
secAttrs = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
secAttrs.nLength = (int)Marshal.SizeOf(secAttrs);
secAttrs.bInheritHandle = 1;
}
return(secAttrs);
}
internal LogStream(String path, int bufferSize, LogRetentionOption retention, long maxFileSize, int maxNumOfFiles)
{
Debug.Assert(!String.IsNullOrEmpty(path));
// Get absolute path - Security needs this to prevent something
// like trying to create a file in c:\tmp with the name
// "..\WinNT\System32\ntoskrnl.exe". Store it for user convenience.
//String filePath = Path.GetFullPathInternal(path);
String filePath = Path.GetFullPath(path);
_fileName = filePath;
// Prevent access to your disk drives as raw block devices.
if (filePath.StartsWith("\\\\.\\", StringComparison.Ordinal))
{
throw new NotSupportedException(SR.GetString(SR.NotSupported_IONonFileDevices));
}
UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs = GetSecAttrs(FileShare.Read);
// For mitigating local elevation of privilege attack through named pipes
// make sure we always call CreateFile with SECURITY_ANONYMOUS so that the
// named pipe server can't impersonate a high privileged client security context
int flagsAndAttributes = (int)FileOptions.None | (UnsafeNativeMethods.SECURITY_SQOS_PRESENT | UnsafeNativeMethods.SECURITY_ANONYMOUS);
// Only write is enabled
//_canRead = false;
//_canSeek = false;
_canWrite = true;
_pathSav = filePath;
_fAccessSav = UnsafeNativeMethods.GENERIC_WRITE;
_shareSav = FileShare.Read;
_secAttrsSav = secAttrs;
_secAccessSav = FileIOPermissionAccess.Write;
_modeSav = (retention != LogRetentionOption.SingleFileUnboundedSize)? FileMode.Create : FileMode.OpenOrCreate;
_flagsAndAttributesSav = flagsAndAttributes;
_seekToEndSav = (retention != LogRetentionOption.SingleFileUnboundedSize)? false : true;
this.bufferSize = bufferSize;
_retention = retention;
_maxFileSize = maxFileSize;
_maxNumberOfFiles = maxNumOfFiles;
_Init(filePath, _fAccessSav, _shareSav, _secAttrsSav, _secAccessSav, _modeSav, _flagsAndAttributesSav, _seekToEndSav);
}
public static unsafe SharedMemory Create(string name, Guid content, List <SecurityIdentifier> allowedSids)
{
int errorCode = UnsafeNativeMethods.ERROR_SUCCESS;
byte[] binarySecurityDescriptor = SecurityDescriptorHelper.FromSecurityIdentifiers(allowedSids, UnsafeNativeMethods.GENERIC_READ);
SafeFileMappingHandle fileMapping;
UnsafeNativeMethods.SECURITY_ATTRIBUTES securityAttributes = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
fixed(byte *pinnedSecurityDescriptor = binarySecurityDescriptor)
{
securityAttributes.lpSecurityDescriptor = (IntPtr)pinnedSecurityDescriptor;
fileMapping = UnsafeNativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes, UnsafeNativeMethods.PAGE_READWRITE, 0, sizeof(SharedMemoryContents), name);
errorCode = Marshal.GetLastWin32Error();
}
if (fileMapping.IsInvalid)
{
fileMapping.SetHandleAsInvalid();
fileMapping.Close();
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
}
SharedMemory sharedMemory = new SharedMemory(fileMapping);
SafeViewOfFileHandle view;
// Ignore return value.
GetView(fileMapping, true, out view);
try
{
SharedMemoryContents *contents = (SharedMemoryContents *)view.DangerousGetHandle();
contents->pipeGuid = content;
Thread.MemoryBarrier();
contents->isInitialized = true;
return(sharedMemory);
}
finally
{
view.Close();
}
}
private static SafeMemoryMappedFileHandle CreateCore(SafeFileHandle fileHandle, String mapName,
HandleInheritability inheritability,
MemoryMappedFileSecurity memoryMappedFileSecurity,
MemoryMappedFileAccess access, MemoryMappedFileOptions options,
Int64 capacity)
{
SafeMemoryMappedFileHandle handle = null;
Object pinningHandle;
UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs = GetSecAttrs(inheritability, memoryMappedFileSecurity, out pinningHandle);
// split the long into two ints
Int32 capacityLow = (Int32)(capacity & 0x00000000FFFFFFFFL);
Int32 capacityHigh = (Int32)(capacity >> 32);
try {
handle = UnsafeNativeMethods.CreateFileMapping(fileHandle, secAttrs, GetPageAccess(access) | (int)options,
capacityHigh, capacityLow, mapName);
Int32 errorCode = Marshal.GetLastWin32Error();
if (!handle.IsInvalid && errorCode == UnsafeNativeMethods.ERROR_ALREADY_EXISTS)
{
handle.Dispose();
__Error.WinIOError(errorCode, String.Empty);
}
else if (handle.IsInvalid)
{
__Error.WinIOError(errorCode, String.Empty);
}
}
finally {
if (pinningHandle != null)
{
GCHandle pinHandle = (GCHandle)pinningHandle;
pinHandle.Free();
}
}
return(handle);
}
public static unsafe SharedMemory Create(string name, Guid content, List <SecurityIdentifier> allowedSids)
{
SafeFileMappingHandle handle;
SafeViewOfFileHandle handle2;
SharedMemory memory2;
int error = 0;
byte[] buffer = SecurityDescriptorHelper.FromSecurityIdentifiers(allowedSids, -2147483648);
UnsafeNativeMethods.SECURITY_ATTRIBUTES securityAttributes = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
fixed(byte *numRef = buffer)
{
securityAttributes.lpSecurityDescriptor = (IntPtr)numRef;
handle = UnsafeNativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes, 4, 0, sizeof(SharedMemoryContents), name);
error = Marshal.GetLastWin32Error();
}
if (handle.IsInvalid)
{
handle.SetHandleAsInvalid();
handle.Close();
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(error));
}
SharedMemory memory = new SharedMemory(handle);
GetView(handle, true, out handle2);
try
{
SharedMemoryContents *contentsPtr = (SharedMemoryContents *)handle2.DangerousGetHandle();
contentsPtr->pipeGuid = content;
Thread.MemoryBarrier();
contentsPtr->isInitialized = true;
memory2 = memory;
}
finally
{
handle2.Close();
}
return(memory2);
}
private static SafeMemoryMappedFileHandle CreateOrOpenCore(SafeFileHandle fileHandle, String mapName,
HandleInheritability inheritability,
MemoryMappedFileSecurity memoryMappedFileSecurity,
MemoryMappedFileAccess access, MemoryMappedFileOptions options,
Int64 capacity)
{
Debug.Assert(access != MemoryMappedFileAccess.Write, "Callers requesting write access shouldn't try to create a mmf");
SafeMemoryMappedFileHandle handle = null;
Object pinningHandle;
UnsafeNativeMethods.SECURITY_ATTRIBUTES secAttrs = GetSecAttrs(inheritability, memoryMappedFileSecurity, out pinningHandle);
// split the long into two ints
Int32 capacityLow = (Int32)(capacity & 0x00000000FFFFFFFFL);
Int32 capacityHigh = (Int32)(capacity >> 32);
try {
int waitRetries = 14; //((2^13)-1)*10ms == approximately 1.4mins
int waitSleep = 0;
// keep looping until we've exhausted retries or break as soon we we get valid handle
while (waitRetries > 0)
{
// try to create
handle = UnsafeNativeMethods.CreateFileMapping(fileHandle, secAttrs,
GetPageAccess(access) | (int)options, capacityHigh, capacityLow, mapName);
Int32 createErrorCode = Marshal.GetLastWin32Error();
if (!handle.IsInvalid)
{
break;
}
else
{
if (createErrorCode != UnsafeNativeMethods.ERROR_ACCESS_DENIED)
{
__Error.WinIOError(createErrorCode, String.Empty);
}
// the mapname exists but our ACL is preventing us from opening it with CreateFileMapping.
// Let's try to open it with OpenFileMapping.
handle.SetHandleAsInvalid();
}
// try to open
handle = UnsafeNativeMethods.OpenFileMapping(GetFileMapAccess(access), (inheritability &
HandleInheritability.Inheritable) != 0, mapName);
Int32 openErrorCode = Marshal.GetLastWin32Error();
// valid handle
if (!handle.IsInvalid)
{
break;
}
// didn't get valid handle; have to retry
else
{
if (openErrorCode != UnsafeNativeMethods.ERROR_FILE_NOT_FOUND)
{
__Error.WinIOError(openErrorCode, String.Empty);
}
// increase wait time
--waitRetries;
if (waitSleep == 0)
{
waitSleep = 10;
}
else
{
System.Threading.Thread.Sleep(waitSleep);
waitSleep *= 2;
}
}
}
// finished retrying but couldn't create or open
if (handle == null || handle.IsInvalid)
{
throw new InvalidOperationException(SR.GetString(SR.InvalidOperation_CantCreateFileMapping));
}
}
finally {
if (pinningHandle != null)
{
GCHandle pinHandle = (GCHandle)pinningHandle;
pinHandle.Free();
}
}
return(handle);
}
