windows-nt/Source/XPSP1/NT/net/mcast/pgm/sys/fileio.c
2020-09-26 16:20:57 +08:00

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/*++
Copyright (c) 2000-2000 Microsoft Corporation
Module Name:
FileIo.c
Abstract:
This module implements various FileSystem routines used by
the PGM Transport
Author:
Mohammad Shabbir Alam (MAlam) 3-30-2000
Revision History:
--*/
#include "precomp.h"
//******************* Pageable Routine Declarations ****************
#ifdef ALLOC_PRAGMA
#endif
//******************* Pageable Routine Declarations ****************
//----------------------------------------------------------------------------
NTSTATUS
BuildPgmDataFileName(
IN tSEND_SESSION *pSend
)
/*++
Routine Description:
This routine build the string for the file name used for buffering
data packets.
Arguments:
IN pSend -- the Send object
Return Value:
NONE -- since we don't expect any error
--*/
{
UNICODE_STRING ucPortNumber;
WCHAR wcPortNumber[10];
USHORT MaxFileLength;
ULONG RandomNumber;
PAGED_CODE();
if (pPgmRegistryConfig->Flags & PGM_REGISTRY_SENDER_FILE_SPECIFIED)
{
MaxFileLength = pPgmRegistryConfig->ucSenderFileLocation.Length / sizeof(WCHAR);
}
else
{
MaxFileLength = sizeof (WS_DEFAULT_SENDER_FILE_LOCATION) / sizeof (WCHAR);
}
//
// The file name is composed of the following:
// "\\T" + 2DigitRandom# + UptoMAX_USHORTPort# + ".PGM" + "\0"
//
MaxFileLength += 2 + 2 + 5 + 4 + 1;
if (!(pSend->pSender->DataFileName.Buffer = PgmAllocMem ((sizeof (WCHAR) * MaxFileLength), PGM_TAG('2'))))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "BuildPgmDataFileName",
"STATUS_INSUFFICIENT_RESOURCES allocating <%d> bytes\n", MaxFileLength);
return (STATUS_INSUFFICIENT_RESOURCES);
}
pSend->pSender->DataFileName.MaximumLength = sizeof (WCHAR) * MaxFileLength;
pSend->pSender->DataFileName.Length = 0;
//
// First, set the root directory
//
if (pPgmRegistryConfig->Flags & PGM_REGISTRY_SENDER_FILE_SPECIFIED)
{
RtlAppendUnicodeToString (&pSend->pSender->DataFileName, pPgmRegistryConfig->ucSenderFileLocation.Buffer);
}
else
{
RtlAppendUnicodeToString (&pSend->pSender->DataFileName, WS_DEFAULT_SENDER_FILE_LOCATION);
}
RtlAppendUnicodeToString (&pSend->pSender->DataFileName, L"\\T");
//
// Now, Append a random 2 digit value
//
ucPortNumber.MaximumLength = sizeof (wcPortNumber);
ucPortNumber.Buffer = wcPortNumber;
RandomNumber = GetRandomInteger (0, 99);
if (RandomNumber < 10)
{
RtlAppendUnicodeToString (&pSend->pSender->DataFileName, L"0");
}
RtlIntegerToUnicodeString (RandomNumber, 10, &ucPortNumber);
RtlAppendUnicodeStringToString (&pSend->pSender->DataFileName, &ucPortNumber);
//
// Append the Port#
//
RtlIntegerToUnicodeString ((ULONG) pSend->TSIPort, 10, &ucPortNumber);
RtlAppendUnicodeStringToString (&pSend->pSender->DataFileName, &ucPortNumber);
//
// Now, add the file name extension for id
//
RtlAppendUnicodeToString (&pSend->pSender->DataFileName, L".PGM");
return (STATUS_SUCCESS);
}
//----------------------------------------------------------------------------
NTSTATUS
PgmCreateDataFileAndMapSection(
IN tSEND_SESSION *pSend
)
/*++
Routine Description:
This routine creates the file and creates a section mapping for it.
This file is used for buffering the data packets on behalf of the sender
Arguments:
IN pSend -- the Send object
Return Value:
NTSTATUS - Final status of the create operation
--*/
{
OBJECT_ATTRIBUTES ObjectAttributes;
IO_STATUS_BLOCK IoStatusBlock;
LARGE_INTEGER lgMaxDataFileSize;
NTSTATUS Status;
ULONGLONG Size, BlockSize, PacketsInWindow;
ULONG DesiredAccess;
ULONG FileAttributes, AllocationAttributes;
ULONG ShareAccess;
ULONG CreateDisposition;
ULONG CreateOptions;
ULONG Protection;
SIZE_T ViewSize;
KAPC_STATE ApcState;
BOOLEAN fAttached;
PAGED_CODE();
//
// Make sure we are currently attached to the Application process
//
PgmAttachToProcessForVMAccess (pSend, &ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
//
// First build the File name string
//
Status = BuildPgmDataFileName (pSend);
if (!NT_SUCCESS (Status))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"BuildPgmDataFileName returned <%x>\n", Status);
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
return (Status);
}
//
// Compute the size of the Data file required to hold 2 * Window size
// Also make it a multiple of the MTU and the FECGroupSize (if applicable)
//
PacketsInWindow = pSend->pAssociatedAddress->WindowSizeInBytes / pSend->pAssociatedAddress->OutIfMTU;
PacketsInWindow += PacketsInWindow + pSend->FECGroupSize - 1;
if (PacketsInWindow > SENDER_MAX_WINDOW_SIZE_PACKETS)
{
PacketsInWindow = SENDER_MAX_WINDOW_SIZE_PACKETS;
if (pSend->pAssociatedAddress->WindowSizeInBytes > ((PacketsInWindow >> 1) *
pSend->pAssociatedAddress->OutIfMTU))
{
pSend->pAssociatedAddress->WindowSizeInBytes = (PacketsInWindow >> 1) * pSend->pAssociatedAddress->OutIfMTU;
pSend->pAssociatedAddress->WindowSizeInMSecs = (BITS_PER_BYTE *
pSend->pAssociatedAddress->WindowSizeInBytes) /
pSend->pAssociatedAddress->RateKbitsPerSec;
}
}
BlockSize = pSend->FECGroupSize * pSend->pSender->PacketBufferSize;
Size = PacketsInWindow * pSend->pSender->PacketBufferSize;
Size = (Size / BlockSize) * BlockSize;
pSend->pSender->MaxDataFileSize = Size;
pSend->pSender->MaxPacketsInBuffer = Size / pSend->pSender->PacketBufferSize;
lgMaxDataFileSize.QuadPart = Size;
PgmZeroMemory (&ObjectAttributes, sizeof(OBJECT_ATTRIBUTES));
InitializeObjectAttributes (&ObjectAttributes,
&pSend->pSender->DataFileName,
OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE,
NULL,
NULL);
//
// We need to open the data file. This file contains data
// and will be mapped into memory. Read and Write access
// are requested.
//
DesiredAccess = FILE_NON_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT |
FILE_GENERIC_READ | FILE_GENERIC_WRITE;
// Using the FILE_ATTRIBUTE_TEMPORARY flag:
// you let the system know that the file is likely to be short lived.
// The temporary file is created as a normal file. The system needs to do
// a minimal amount of lazy writes to the file system to keep the disk
// structures (directories and so forth) consistent. This gives the
// appearance that the file has been written to the disk. However, unless
// the Memory Manager detects an inadequate supply of free pages and
// starts writing modified pages to the disk, the Cache Manager's Lazy
// Writer may never write the data pages of this file to the disk.
// If the system has enough memory, the pages may remain in memory for
// any arbitrary amount of time. Because temporary files are generally
// short lived, there is a good chance the system will never write the pages to the disk.
FileAttributes = FILE_ATTRIBUTE_TEMPORARY;
ShareAccess = 0; // Gives the caller exclusive access to the open file
CreateDisposition = FILE_CREATE; // If the file already exists, fail the request and do not create or
// open the given file. If it does not, create the given file.
// Delete the file when the last handle to it is is passed to ZwClose.
CreateOptions = FILE_NON_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT | FILE_DELETE_ON_CLOSE;
PgmZeroMemory (&IoStatusBlock, sizeof(IO_STATUS_BLOCK));
Status = ZwCreateFile (&pSend->pSender->FileHandle,
DesiredAccess,
&ObjectAttributes,
&IoStatusBlock,
&lgMaxDataFileSize, // AllocationSize
FileAttributes,
ShareAccess,
CreateDisposition,
CreateOptions,
NULL, // EaBuffer
0); // EaLength
if (!NT_SUCCESS (Status))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"ZwCreateFile for <%wZ> returned <%x>\n", &pSend->pSender->DataFileName, Status);
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
pSend->pSender->FileHandle = NULL;
return (Status);
}
//
// Now we have a handle to our open test file. We now create a section
// object with this handle.
//
DesiredAccess = STANDARD_RIGHTS_REQUIRED |
SECTION_QUERY |
SECTION_MAP_READ |
SECTION_MAP_WRITE;
Protection = PAGE_READWRITE;
AllocationAttributes = SEC_COMMIT;
PgmZeroMemory (&ObjectAttributes, sizeof (OBJECT_ATTRIBUTES));
InitializeObjectAttributes (&ObjectAttributes,
NULL,
OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE,
NULL,
NULL);
Status = ZwCreateSection (&pSend->pSender->SectionHandle,
DesiredAccess,
&ObjectAttributes, // NULL ?
&lgMaxDataFileSize,
Protection,
AllocationAttributes,
pSend->pSender->FileHandle);
if (!NT_SUCCESS (Status))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"ZwCreateSection for <%wZ> returned <%x>\n", &pSend->pSender->DataFileName, Status);
ZwClose (pSend->pSender->FileHandle);
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
return (Status);
}
//
// Reference the section object, if a view is mapped to the section
// object, the object is not dereferenced as the virtual address
// descriptor contains a pointer to the section object.
//
Status = ObReferenceObjectByHandle (pSend->pSender->SectionHandle,
0,
0,
KernelMode,
&pSend->pSender->pSectionObject,
NULL );
if (!NT_SUCCESS (Status))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"ObReferenceObjectByHandle for SectionHandle=<%x> returned <%x>\n",
pSend->pSender->SectionHandle, Status);
ZwClose (pSend->pSender->SectionHandle);
ZwClose (pSend->pSender->FileHandle);
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
return (Status);
}
//
// Our section object has been created and linked to the file
// object that was previous opened. Now we map a view on
// this section.
//
ViewSize = 0;
Protection = PAGE_READWRITE;
Status = ZwMapViewOfSection (pSend->pSender->SectionHandle,
NtCurrentProcess(),
&pSend->pSender->SendDataBufferMapping,
0L, // ZeroBits
0L, // CommitSize (initially committed region)
NULL, // &SectionOffset
&ViewSize,
ViewUnmap, // InheritDisposition: for child processes
0L, // AllocationType
Protection);
if (!NT_SUCCESS (Status))
{
PgmLog (PGM_LOG_ERROR, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"ZwMapViewOfSection for <%wZ> returned <%x>\n", &pSend->pSender->DataFileName, Status);
ObDereferenceObject (pSend->pSender->pSectionObject);
pSend->pSender->pSectionObject = NULL;
ZwClose (pSend->pSender->SectionHandle);
pSend->pSender->SectionHandle = NULL;
ZwClose (pSend->pSender->FileHandle);
pSend->pSender->FileHandle = NULL;
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
return (Status);
}
PgmLog (PGM_LOG_INFORM_STATUS, DBG_FILEIO, "PgmCreateDataFileAndMapSection",
"Mapped <%wZ> to address<%x>, Filelength=<%d>\n",
&pSend->pSender->DataFileName, pSend->pSender->SendDataBufferMapping, Size);
pSend->pSender->BufferSizeAvailable = pSend->pSender->MaxDataFileSize;
pSend->pSender->LeadingWindowOffset = pSend->pSender->TrailingWindowOffset = 0;
//
// Now, reference the process
//
ObReferenceObject (pSend->Process);
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CREATE_DATA_FILE);
return (STATUS_SUCCESS);
}
//----------------------------------------------------------------------------
NTSTATUS
PgmUnmapAndCloseDataFile(
IN tSEND_SESSION *pSend
)
/*++
Routine Description:
This routine cleansup the file mapping and closes the file
handles. The file should automatically get deleted on closing
the handle since we used the FILE_DELETE_ON_CLOSE option while
creating the file.
Arguments:
IN pSend -- the Send object
Return Value:
NTSTATUS - Final status of the operation (STATUS_SUCCESS)
--*/
{
NTSTATUS Status;
KAPC_STATE ApcState;
BOOLEAN fAttached;
PgmAttachToProcessForVMAccess (pSend, &ApcState, &fAttached, REF_PROCESS_ATTACH_CLOSE_DATA_FILE);
Status = ZwUnmapViewOfSection (NtCurrentProcess(), (PVOID) pSend->pSender->SendDataBufferMapping);
ASSERT (NT_SUCCESS (Status));
Status = ObDereferenceObject (pSend->pSender->pSectionObject);
ASSERT (NT_SUCCESS (Status));
pSend->pSender->pSectionObject = NULL;
Status = ZwClose (pSend->pSender->SectionHandle);
ASSERT (NT_SUCCESS (Status));
pSend->pSender->SectionHandle = NULL;
Status = ZwClose (pSend->pSender->FileHandle);
ASSERT (NT_SUCCESS (Status));
PgmDetachProcess (&ApcState, &fAttached, REF_PROCESS_ATTACH_CLOSE_DATA_FILE);
ObDereferenceObject (pSend->Process); // Since we had referenced it when the file was created
pSend->pSender->SendDataBufferMapping = NULL;
pSend->pSender->pSectionObject = NULL;
pSend->pSender->SectionHandle = NULL;
pSend->pSender->FileHandle = NULL;
PgmLog (PGM_LOG_INFORM_STATUS, DBG_SEND, "PgmUnmapAndCloseDataFile",
"pSend = <%x>\n", pSend);
return (STATUS_SUCCESS);
}