windows-nt/Source/XPSP1/NT/base/fs/dfs/driver/sitesup.c
2020-09-26 16:20:57 +08:00

684 lines
18 KiB
C

//+-------------------------------------------------------------------------
//
// Copyright (C) 1997, Microsoft Corporation.
//
// File: sitesup.c
//
// Contents: Support routines for managing DFS_SITE_INFO entries
//
// Functions: DfsInitSites - Initialize the hash table for DFS_SITE_INFO lookup
// DfsLookupSiteInfo - Lookup a DFS_SITE_INFO
// DfsAllocateSiteInfo - Allocate a DFS_SITE_INFO
// DfsInsertSiteInfo - Put a DFS_SITE_INFO into the table
// DfsDeleteSiteInfo - Remove a DFS_SITE_INFO from the table
// DfsReleaseSiteInfo - Stop using a DFS_SITE_INFO
//
// DfsFsctrlCreateSiteInfo - Load a Site table entry
// DfsFsctrlDeleteSiteInfo - Remove a Site table entry
//
//--------------------------------------------------------------------------
#include "dfsprocs.h"
#include "attach.h"
#include "sitesup.h"
#include "fsctrl.h"
#define Dbg 0x1000
#define DEFAULT_HASH_SIZE 16 // default size of hash table
NTSTATUS
DfsInitSiteInfoHashTable(
IN ULONG cHash,
OUT PSITE_HASH_TABLE *ppHashTable
);
NTSTATUS
DfsAllocateSiteInfo(
IN PUNICODE_STRING pServerName,
IN ULONG SiteCount,
IN PUNICODE_STRING pSiteNames,
OUT PDFS_SITE_INFO *ppSiteInfo
);
PDFS_SITE_INFO
DfsLookupSiteInfo(
IN PUNICODE_STRING ServerName
);
VOID
DfsInsertSiteInfo(
IN PUNICODE_STRING pServerName,
IN PDFS_SITE_INFO pSiteInfo
);
VOID
DfsDeleteSiteInfo(
PDFS_SITE_INFO pSiteInfo
);
VOID
DfsReleaseSiteInfo(
IN PDFS_SITE_INFO pSiteInfo
);
ULONG
DfsHashSiteName(
IN PUNICODE_STRING ServerName,
IN DWORD HashMask
);
#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT, DfsInitSites)
#pragma alloc_text(PAGE, DfsUninitSites)
#pragma alloc_text(PAGE, DfsInitSiteInfoHashTable)
#pragma alloc_text(PAGE, DfsAllocateSiteInfo)
#pragma alloc_text(PAGE, DfsReleaseSiteInfo)
#pragma alloc_text(PAGE, DfsHashSiteName)
#pragma alloc_text(PAGE, DfsFsctrlCreateSiteInfo)
#pragma alloc_text(PAGE, DfsFsctrlDeleteSiteInfo)
#pragma alloc_text(PAGE, DfsLookupSiteInfo)
#pragma alloc_text(PAGE, DfsInsertSiteInfo)
#pragma alloc_text(PAGE, DfsDeleteSiteInfo)
#endif
#ifdef DBG
VOID
DfsDumpSiteTable(void);
#endif
//+-------------------------------------------------------------------------
//
// Function: DfsInitSiteHashTable - Initialize the DFS_SITE_INFO lookup hash table
//
// Synopsis: This function initializes data structures which are
// used for looking up a DFS_SITE_INFO associated with some site.
//
// Arguments: [cHash] -- Size of the hash table to be allocated. Must be
// a power of two. If zero, a default size is used.
//
// Returns: NTSTATUS -- STATUS_SUCCESS, unless memory allocation
// fails.
//
// Note: The hash buckets are initialized to zero, then later
// initialized to a list head when used. This is a debugging
// aid to determine if some hash buckets are never used.
//
//--------------------------------------------------------------------------
NTSTATUS
DfsInitSiteHashTable(
ULONG cHash,
PSITE_HASH_TABLE *ppHashTable)
{
PSITE_HASH_TABLE pHashTable;
ULONG cbHashTable;
if (cHash == 0) {
cHash = DEFAULT_HASH_SIZE;
}
ASSERT ((cHash & (cHash-1)) == 0); // Assure cHash is a power of two
cbHashTable = sizeof(SITE_HASH_TABLE) + (cHash-1) * sizeof(LIST_ENTRY);
pHashTable = ExAllocatePoolWithTag(NonPagedPool, cbHashTable, ' sfD');
if (pHashTable == NULL) {
return STATUS_NO_MEMORY;
}
pHashTable->NodeTypeCode = DFS_NTC_SITE_HASH;
pHashTable->NodeByteSize = (NODE_BYTE_SIZE) cbHashTable;
pHashTable->HashMask = (cHash-1);
ExInitializeFastMutex( &pHashTable->HashListMutex );
RtlZeroMemory(&pHashTable->HashBuckets[0], cHash * sizeof(LIST_ENTRY));
*ppHashTable = pHashTable;
return(STATUS_SUCCESS);
}
NTSTATUS
DfsInitSites(
ULONG cHash)
{
NTSTATUS status;
status = DfsInitSiteHashTable( cHash, &DfsData.SiteHashTable );
return status;
}
VOID
DfsUninitSites(
VOID)
{
ExFreePool (DfsData.SiteHashTable);
}
//+-------------------------------------------------------------------------
//
// Function: DfsLookupSiteInfo - Lookup a DFS_SITE_INFO in the hash table
//
// Synopsis: This function will lookup a DFS_SITE_INFO.
// It will increment the UseCount on the DFS_SITE_INFO.
//
// Arguments: [ServerName] -- Servername for which the DFS_SITE_INFO is
// being looked up.
//
// Returns: PVOID -- pointer to the DFS_SITE_INFO found, or NULL if none
//
// Algorithm: Knuth would call it hashing with conflict resoulution
// by chaining.
//
// History: 20 Feb 1993 Alanw Created
// 11 Nov 1997 JHarper Modified for sites (used fcbsup.c as template)
//
//--------------------------------------------------------------------------
PDFS_SITE_INFO
DfsLookupSiteInfo(
PUNICODE_STRING ServerName)
{
PLIST_ENTRY pListHead, pLink;
PDFS_SITE_INFO pSiteInfo;
PSITE_HASH_TABLE pHashTable = DfsData.SiteHashTable;
ExAcquireFastMutex( &pHashTable->HashListMutex );
pListHead = &pHashTable->HashBuckets[ DfsHashSiteName(ServerName, pHashTable->HashMask) ];
if ((pListHead->Flink == NULL) || // list not initialized
(pListHead->Flink == pListHead)) { // list empty
ExReleaseFastMutex( &pHashTable->HashListMutex );
return NULL;
}
for (pLink = pListHead->Flink; pLink != pListHead; pLink = pLink->Flink) {
pSiteInfo = CONTAINING_RECORD(pLink, DFS_SITE_INFO, HashChain);
if (RtlCompareUnicodeString(&pSiteInfo->ServerName,ServerName,TRUE) == 0) {
pSiteInfo->UseCount++;
ExReleaseFastMutex( &pHashTable->HashListMutex );
return pSiteInfo;
}
}
ExReleaseFastMutex( &pHashTable->HashListMutex );
return NULL;
}
//+-------------------------------------------------------------------------
//
// Function: DfsInsertSiteInfo - Inserts a DFS_SITE_INFO into the hash table
//
// Synopsis: This function associates a DFS_SITE_INFO to a Server. This
// involves removing any existing entry, and adding the new.
//
// Arguments: [pSiteInfo] -- Pointer to the DFS_SITE_INFO to be inserted.
// [pServerName] -- Pointer to the corresponding server name, used
// as the hash key.
//
// Returns: -nothing-
//
//--------------------------------------------------------------------------
VOID
DfsInsertSiteInfo(
PUNICODE_STRING pServerName,
PDFS_SITE_INFO pSiteInfo)
{
PSITE_HASH_TABLE pHashTable = (PSITE_HASH_TABLE) DfsData.SiteHashTable;
PLIST_ENTRY pListHead;
PDFS_SITE_INFO pExistingSiteInfo;
pExistingSiteInfo = DfsLookupSiteInfo( &pSiteInfo->ServerName);
//
// Put the new one in
//
ExAcquireFastMutex( &pHashTable->HashListMutex );
pListHead = &pHashTable->HashBuckets[ DfsHashSiteName(pServerName, pHashTable->HashMask) ];
if (pListHead->Flink == NULL) {
InitializeListHead(pListHead);
}
InsertHeadList(pListHead, &pSiteInfo->HashChain);
ExReleaseFastMutex( &pHashTable->HashListMutex );
if (pExistingSiteInfo != NULL) {
DfsDeleteSiteInfo(
pExistingSiteInfo);
DfsReleaseSiteInfo(
pExistingSiteInfo);
}
DebugTrace(0, Dbg, "Added SiteInfo %08lx ", pSiteInfo);
DebugTrace(0, Dbg, "For Server %wZ ", pServerName);
}
//+-------------------------------------------------------------------------
//
// Function: DfsDeleteSiteInfo - Delete a DFS_SITE_INFO from the lookup hash table
//
// Synopsis: This function Deletes a DFS_SITE_INFO from the hash table.
//
// Arguments: [pSiteInfo] -- Pointer to the DFS_SITE_INFO to delete
//
// Returns: -nothing-
//
//--------------------------------------------------------------------------
VOID
DfsDeleteSiteInfo(
PDFS_SITE_INFO pSiteInfo)
{
PSITE_HASH_TABLE pHashTable = (PSITE_HASH_TABLE) DfsData.SiteHashTable;
ExAcquireFastMutex( &pHashTable->HashListMutex);
pSiteInfo->Flags |= SITE_INFO_DELETE_PENDING;
RemoveEntryList(&pSiteInfo->HashChain);
InitializeListHead(&pSiteInfo->HashChain);
ExReleaseFastMutex( &pHashTable->HashListMutex );
DebugTrace(0, Dbg, "deleted SiteInfo %08lx ", pSiteInfo);
DebugTrace(0, Dbg, "For server %wZ ", &pSiteInfo->ServerName);
}
//+----------------------------------------------------------------------------
//
// Function: DfsAllocateSiteInfo - Allocate a DFS_SITE_INFO
//
// Synopsis: This function allocates a contiguous DFS_SITE_INFO struct. The
// strings are stored in the allocated buffer after the DFS_SITE_INFO
// structure.
//
// Arguments: [pServerName] -- The server name for the site list
// [ppSiteInfo] -- On successful return, has pointer to newly allocated
// DFS_SITE_INFO.
//
// Returns: [STATUS_SUCCESS] -- Successfully allocated DFS_SITE_INFO
//
// [STATUS_INSUFFICIENT_RESOURCES] -- Out of memory condition
//
//-----------------------------------------------------------------------------
NTSTATUS
DfsAllocateSiteInfo(
PUNICODE_STRING pServerName,
ULONG SiteCount,
PUNICODE_STRING pSiteNames,
PDFS_SITE_INFO *ppSiteInfo)
{
NTSTATUS status;
PDFS_SITE_INFO pSiteInfo;
ULONG Size;
ULONG i;
LPWSTR pwCh;
PUNICODE_STRING pustr;
if (SiteCount < 1) {
DebugTrace(0, Dbg, "DfsAllocateSiteInfo SiteCount = %d\n", ULongToPtr( SiteCount ));
return STATUS_INSUFFICIENT_RESOURCES;
}
DebugTrace(0, Dbg, "DfsAllocateSiteInfo(%wZ)\n", pServerName);
//
// Size the buffer - include storage for the unicode strings after the
// DFS_SITE_INFO structure.
//
Size = sizeof(DFS_SITE_INFO) +
pServerName->Length +
sizeof(UNICODE_STRING) * (SiteCount - 1);
for (i = 0; i < SiteCount; i++) {
Size += pSiteNames[i].Length;
}
pSiteInfo = (PDFS_SITE_INFO) ExAllocatePoolWithTag( NonPagedPool, Size, ' sfD' );
if (pSiteInfo != NULL) {
RtlZeroMemory( pSiteInfo, Size );
pSiteInfo->NodeTypeCode = DFS_NTC_SITE_INFO;
pSiteInfo->NodeByteSize = (USHORT)Size;
pwCh = (LPWSTR) &pSiteInfo->SiteName[SiteCount];
pustr = &pSiteInfo->ServerName;
pustr->Length = pustr->MaximumLength = pServerName->Length;
pustr->Buffer = pwCh;
RtlCopyMemory(pwCh, pServerName->Buffer, pServerName->Length);
pwCh += pustr->Length / sizeof(WCHAR);
pSiteInfo->SiteCount = SiteCount;
for (i = 0; i < SiteCount; i++) {
pustr = &pSiteInfo->SiteName[i];
pustr->Length = pustr->MaximumLength = pSiteNames[i].Length;
pustr->Buffer = pwCh;
RtlCopyMemory(pwCh, pSiteNames[i].Buffer, pSiteNames[i].Length);
pwCh += pustr->Length / sizeof(WCHAR);
}
*ppSiteInfo = pSiteInfo;
status = STATUS_SUCCESS;
DebugTrace(0, Dbg, "DfsAllocateSiteInfo pSiteInfo = %d\n", pSiteInfo);
} else {
status = STATUS_INSUFFICIENT_RESOURCES;
}
return( status );
}
//+----------------------------------------------------------------------------
//
// Function: DfsReleaseSiteInfo
//
// Synopsis: Decrements UseCount of and possibly frees a DFS_SITE_INFO
//
// Arguments: [pSiteInfo] -- The DFS_SITE_INFO to release
//
// Returns: Nothing
//
//-----------------------------------------------------------------------------
VOID
DfsReleaseSiteInfo(
PDFS_SITE_INFO pSiteInfo)
{
PSITE_HASH_TABLE pHashTable = (PSITE_HASH_TABLE) DfsData.SiteHashTable;
//
// There's a potential race with DfsDeleteSiteInfo's setting of the
// DELETE_PENDING and the test below of DELETE_PENDING, so we still have
// to acquire the lock to safely test the DELETE_PENDING bit.
//
ExAcquireFastMutex( &pHashTable->HashListMutex );
pSiteInfo->UseCount--;
if ((pSiteInfo->Flags & SITE_INFO_DELETE_PENDING) != 0 && pSiteInfo->UseCount == 0) {
ExFreePool(pSiteInfo);
}
ExReleaseFastMutex( &pHashTable->HashListMutex );
}
//+----------------------------------------------------------------------------
//
// Function: DfsHashSiteNames
//
// Synopsis: Generates a hash 0-N - ignores case
//
// Arguments: [pServerName] -- The Server name to hash
//
// Returns: Nothing
//
// Notes: Might need to convert DNS-style names to short names (??)
//
//-----------------------------------------------------------------------------
ULONG
DfsHashSiteName(
PUNICODE_STRING ServerName,
DWORD HashMask)
{
ULONG BucketNo = 0;
WCHAR *pBuffer = ServerName->Buffer;
WCHAR *pBufferEnd = &pBuffer[ServerName->Length / sizeof(WCHAR)];
ULONG wCh;
BucketNo = 0;
while (pBuffer != pBufferEnd) {
wCh = (*pBuffer < L'a')
? *pBuffer
: ((*pBuffer < L'z')
? (*pBuffer - L'a' + L'A')
: RtlUpcaseUnicodeChar(*pBuffer));
BucketNo *= 131;
BucketNo += wCh;
pBuffer++;
}
BucketNo = BucketNo & HashMask;
return BucketNo;
}
//+-------------------------------------------------------------------------
//
// Function: DfsFsctrlCreateSiteInfo, public
//
// Synopsis:
//
// Arguments:
//
// Returns:
//
// Notes: We only process this FSCTRL from the file system process,
// never from the driver.
//
//--------------------------------------------------------------------------
NTSTATUS
DfsFsctrlCreateSiteInfo(
PIRP Irp,
PVOID InputBuffer,
ULONG InputBufferLength)
{
NTSTATUS status = STATUS_SUCCESS;
PDFS_CREATE_SITE_INFO_ARG arg;
PDFS_SITE_INFO pSiteInfo;
ULONG i;
ULONG Size;
STD_FSCTRL_PROLOGUE(DfsFsctrlCreateSiteInfo, TRUE, FALSE);
if (InputBufferLength < sizeof(DFS_CREATE_SITE_INFO_ARG)) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
//
// unmarshal the arguments...
//
arg = (PDFS_CREATE_SITE_INFO_ARG) InputBuffer;
Size = InputBufferLength - FIELD_OFFSET(DFS_CREATE_SITE_INFO_ARG, SiteName);
if ( (Size / sizeof(arg->SiteName[0])) < arg->SiteCount ) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
OFFSET_TO_POINTER(arg->ServerName.Buffer, arg);
if (!UNICODESTRING_IS_VALID(arg->ServerName, InputBuffer, InputBufferLength)) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
for (i = 0; i < arg->SiteCount; i++) {
OFFSET_TO_POINTER(arg->SiteName[i].Buffer, arg);
if (!UNICODESTRING_IS_VALID(arg->SiteName[i], InputBuffer, InputBufferLength)) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
}
if (NT_SUCCESS(status)) {
status = DfsAllocateSiteInfo(
&arg->ServerName,
arg->SiteCount,
&arg->SiteName[0],
&pSiteInfo);
if (NT_SUCCESS(status)) {
DfsInsertSiteInfo(
&arg->ServerName,
pSiteInfo);
}
}
exit_with_status:
DfsCompleteRequest( Irp, status );
DebugTrace(-1, Dbg,
"DfsFsctrlCreateSiteInfo: Exit -> %08lx\n", ULongToPtr( status ) );
return status;
}
//+-------------------------------------------------------------------------
//
// Function: DfsFsctrlDeleteSiteInfo, public
//
// Synopsis:
//
// Arguments:
//
// Returns:
//
// Notes: We only process this FSCTRL from the file system process,
// never from the driver.
//
//--------------------------------------------------------------------------
NTSTATUS
DfsFsctrlDeleteSiteInfo(
PIRP Irp,
PVOID InputBuffer,
ULONG InputBufferLength)
{
NTSTATUS status = STATUS_SUCCESS;
PDFS_DELETE_SITE_INFO_ARG arg;
PDFS_SITE_INFO pSiteInfo;
STD_FSCTRL_PROLOGUE(DfsFsctrlDeleteSiteInfo, TRUE, FALSE);
if (InputBufferLength < sizeof(DFS_DELETE_SITE_INFO_ARG)) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
//
// unmarshal the arguments...
//
arg = (PDFS_DELETE_SITE_INFO_ARG) InputBuffer;
OFFSET_TO_POINTER(arg->ServerName.Buffer, arg);
if (!UNICODESTRING_IS_VALID(arg->ServerName, InputBuffer, InputBufferLength)) {
status = STATUS_INVALID_PARAMETER;
goto exit_with_status;
}
pSiteInfo = DfsLookupSiteInfo(
&arg->ServerName);
//
// The DfsLookupSiteInfo() call bumped the usecount, so we're sure pSiteInfo
// won't become invalid as we're using it.
//
if (pSiteInfo != NULL) {
//
// Removes from the table, but doesn't free the memory
//
DfsDeleteSiteInfo(
pSiteInfo);
//
// This will decrement the usecount, and if it goes to zero, frees the memory
//
DfsReleaseSiteInfo(
pSiteInfo);
}
exit_with_status:
DfsCompleteRequest( Irp, status );
DebugTrace(-1, Dbg,
"DfsFsctrlDeleteSiteInfo: Exit -> %08lx\n", ULongToPtr( status ) );
return status;
}
#ifdef DBG
VOID
DfsDumpSiteTable(void)
{
PLIST_ENTRY pListHead, pLink;
PDFS_SITE_INFO pSiteInfo;
PSITE_HASH_TABLE pHashTable = DfsData.SiteHashTable;
ULONG i, j;
DbgPrint("---------Site Table----------\n");
for (i = 0; i <= pHashTable->HashMask; i++) {
pListHead = &pHashTable->HashBuckets[i];
if ((pListHead->Flink == NULL) || // list not initialized
(pListHead->Flink == pListHead)) { // list empty
continue;
}
for (pLink = pListHead->Flink; pLink != pListHead; pLink = pLink->Flink) {
pSiteInfo = CONTAINING_RECORD(pLink, DFS_SITE_INFO, HashChain);
DbgPrint("\t[%02d][%wZ][%d]", i, &pSiteInfo->ServerName, pSiteInfo->SiteCount);
for (j = 0; j < pSiteInfo->SiteCount; j++) {
DbgPrint("(%wZ)", &pSiteInfo->SiteName[j]);
}
DbgPrint("\n");
}
}
DbgPrint("-----------------------------\n");
}
#endif