Source code of Windows XP (NT5)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

602 lines
17 KiB

/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
ldrutil.c
Abstract:
This module implements utility functions used by the NT loader.
It was forked from the ldrsnap.c source file since ldrsnap.c
was growing enourmous.
Author:
Michael Grier (MGrier) 04-Apr-2001, derived mostly from
Mike O'Leary (mikeol) 23-Mar-1990
Revision History:
--*/
#define LDRDBG 0
#include "ntos.h"
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <ntpsapi.h>
#include <heap.h>
#include "ldrp.h"
#include "sxstypes.h"
#include <limits.h>
#define DLL_EXTENSION L".DLL"
#define DLL_REDIRECTION_LOCAL_SUFFIX L".Local"
#define INVALID_HANDLE_VALUE ((HANDLE) ((LONG_PTR) -1))
BOOLEAN LdrpBreakOnExceptions = FALSE;
PLDR_DATA_TABLE_ENTRY
LdrpAllocateDataTableEntry(
IN PVOID DllBase
)
/*++
Routine Description:
This function allocates an entry in the loader data table. If the
table is going to overflow, then a new table is allocated.
Arguments:
DllBase - Supplies the address of the base of the DLL Image.
be added to the loader data table.
Return Value:
Returns the address of the allocated loader data table entry
--*/
{
PLDR_DATA_TABLE_ENTRY Entry;
PIMAGE_NT_HEADERS NtHeaders;
NtHeaders = RtlImageNtHeader(DllBase);
Entry = NULL;
if ( NtHeaders ) {
Entry = RtlAllocateHeap(LdrpHeap, MAKE_TAG( LDR_TAG ) | HEAP_ZERO_MEMORY, sizeof(*Entry));
if ( Entry ) {
Entry->DllBase = DllBase;
Entry->SizeOfImage = NtHeaders->OptionalHeader.SizeOfImage;
Entry->TimeDateStamp = NtHeaders->FileHeader.TimeDateStamp;
}
}
return Entry;
}
VOID
LdrpDeallocateDataTableEntry(
IN PLDR_DATA_TABLE_ENTRY Entry
)
{
if (Entry != NULL)
RtlFreeHeap(LdrpHeap, 0, Entry);
}
VOID
LdrpFinalizeAndDeallocateDataTableEntry(
IN PLDR_DATA_TABLE_ENTRY Entry
)
{
if (Entry != NULL) {
if ((Entry->EntryPointActivationContext != NULL) &&
(Entry->EntryPointActivationContext != INVALID_HANDLE_VALUE)) {
RtlReleaseActivationContext(Entry->EntryPointActivationContext);
Entry->EntryPointActivationContext = INVALID_HANDLE_VALUE;
}
if (Entry->FullDllName.Buffer != NULL) {
LdrpFreeUnicodeString(&Entry->FullDllName);
RtlInitEmptyUnicodeString(&Entry->FullDllName, NULL, 0);
RtlInitEmptyUnicodeString(&Entry->BaseDllName, NULL, 0);
}
LdrpDeallocateDataTableEntry(Entry);
}
}
NTSTATUS
RtlComputePrivatizedDllName_U(
IN PCUNICODE_STRING DllName,
IN OUT PUNICODE_STRING NewDllNameUnderImageDir,
IN OUT PUNICODE_STRING NewDllNameUnderLocalDir
)
/*++
Routine Description:
This function computes a fully qualified path to a DLL name. It takes
the path of the current process and the base name from DllName and
puts these together. DllName can have '\' or '/' as separator.
Arguments:
DllName - Points to a string that names the library file. This can be
a fully qualified name or just a base name. We will parse for the base
name (the portion after the last '\' or '/' char. Caller guarantees that
DllName->Buffer is not a NULL pointer!
NewDllName - Has fully qualified path based on GetModuleFileNameW(NULL...)
and the base name from above.
Return Value:
NTSTATUS: Currently: STATUS_NO_MEMORY or STATUS_SUCCESS.
--*/
{
LPWSTR p, pp, pp1, pp2;
PWSTR Dot;
LPWSTR pFullImageName;
USHORT cbFullImageNameLength;
USHORT cbFullImagePathLengthWithTrailingSlash, cbDllFileNameLengthWithTrailingNULL;
USHORT cbDllNameUnderImageDir, cbDllNameUnderLocalDir;
ULONG cbStringLength;
PWSTR Cursor = NULL;
NTSTATUS status = STATUS_SUCCESS;
LPWSTR pDllNameUnderImageDir = NULL;
LPWSTR pDllNameUnderLocalDir = NULL;
LPCWSTR pBuf1 = NewDllNameUnderImageDir->Buffer;
LPCWSTR pBuf2 = NewDllNameUnderLocalDir->Buffer;
cbFullImageNameLength = NtCurrentPeb()->ProcessParameters->ImagePathName.Length;
pFullImageName = (PWSTR)NtCurrentPeb()->ProcessParameters->ImagePathName.Buffer;
if (!(NtCurrentPeb()->ProcessParameters->Flags & RTL_USER_PROC_PARAMS_NORMALIZED)) {
pFullImageName = (PWSTR)((PCHAR)pFullImageName + (ULONG_PTR)(NtCurrentPeb()->ProcessParameters));
}
ASSERT(pFullImageName != NULL);
// Find the end of the EXE path (start of its base-name) in pp1.
// Size1 is number of bytes;
p = pFullImageName + cbFullImageNameLength/sizeof(WCHAR) - 1; // point to last character of this name
pp1 = NULL;
while (p != pFullImageName) {
if (RTL_IS_PATH_SEPARATOR(*p)) {
pp1 = p + 1;
break;
}
p-- ;
}
// Find the basename portion of the DLL to be loaded in pp2 and the
// last '.' character if present in the basename.
pp2 = DllName->Buffer;
Dot = NULL ;
if (DllName->Length) {
ASSERT(RTL_STRING_IS_NUL_TERMINATED(DllName)); // temporary debugging
p = DllName->Buffer + (DllName->Length>>1) - 1; // point to last char
while (p != DllName->Buffer) {
if (*p == (WCHAR) '.') {
if (!Dot) {
Dot = p ;
}
}
else {
if ((*p == (WCHAR) '\\') || (*p == (WCHAR) '/')) {
pp2 = p + 1;
break;
}
}
p--;
}
}
// Create a fully qualified path to the DLL name (using pp1 and pp2)
// Number of bytes (not including NULL or EXE/process folder)
if (((pp1 - pFullImageName) * sizeof(WCHAR)) > ULONG_MAX) {
DbgPrint("ntdll: wants more than ULONG_MAX bytes \n");
goto Exit;
}
cbStringLength = (ULONG)((pp1 - pFullImageName) * sizeof(WCHAR));
if ( cbStringLength > UNICODE_STRING_MAX_BYTES ) {
status = STATUS_NAME_TOO_LONG;
goto Exit;
}
cbFullImagePathLengthWithTrailingSlash = (USHORT)cbStringLength;
// Number of bytes in base DLL name (including trailing null char)
cbDllFileNameLengthWithTrailingNULL = (USHORT)(DllName->Length + sizeof(WCHAR) - ((pp2 - DllName->Buffer) * sizeof(WCHAR)));
cbStringLength = cbFullImagePathLengthWithTrailingSlash
+ cbDllFileNameLengthWithTrailingNULL;
// Allocate room for L".DLL"
if (Dot == NULL)
cbStringLength += sizeof(DLL_EXTENSION) - sizeof(WCHAR);
if ( cbStringLength > UNICODE_STRING_MAX_BYTES ) {
status = STATUS_NAME_TOO_LONG;
goto Exit;
}
cbDllNameUnderImageDir = (USHORT)cbStringLength;
if (cbDllNameUnderImageDir > NewDllNameUnderImageDir->MaximumLength) {
pDllNameUnderImageDir = (*RtlAllocateStringRoutine)(cbDllNameUnderImageDir);
if (pDllNameUnderImageDir == NULL) {
status = STATUS_NO_MEMORY ;
goto Exit;
}
}else
pDllNameUnderImageDir = NewDllNameUnderImageDir->Buffer;
Cursor = pDllNameUnderImageDir;
RtlCopyMemory(Cursor, pFullImageName, cbFullImagePathLengthWithTrailingSlash);
Cursor = pDllNameUnderImageDir + cbFullImagePathLengthWithTrailingSlash / sizeof(WCHAR);
RtlCopyMemory(Cursor, pp2, cbDllFileNameLengthWithTrailingNULL - sizeof(WCHAR)) ;
Cursor += (cbDllFileNameLengthWithTrailingNULL - sizeof(WCHAR)) / sizeof(WCHAR);
if (!Dot) {
// If there is no '.' in the basename add the ".DLL" to it.
//
// The -1 will work just as well as - sizeof(WCHAR) as we are dividing by
// sizeof(WCHAR) and it will be rounded down correctly as Size1 and Size2 are
// even. The -1 could be more optimal than subtracting sizeof(WCHAR)
//
RtlCopyMemory(Cursor, DLL_EXTENSION, sizeof(DLL_EXTENSION));
cbDllFileNameLengthWithTrailingNULL += sizeof(DLL_EXTENSION) - sizeof(WCHAR) ; // Mark base name as being 8 bytes bigger.
} else
*Cursor = L'\0';
cbStringLength = cbFullImageNameLength
+ sizeof(DLL_REDIRECTION_LOCAL_SUFFIX) - sizeof(WCHAR) //.local
+ sizeof(WCHAR) // "\\"
+ cbDllFileNameLengthWithTrailingNULL;
if (cbStringLength > UNICODE_STRING_MAX_BYTES) {
status = STATUS_NAME_TOO_LONG;
goto Exit;
}
cbDllNameUnderLocalDir = (USHORT)cbStringLength;
if ( cbDllNameUnderLocalDir > NewDllNameUnderLocalDir->MaximumLength) {
pDllNameUnderLocalDir = (RtlAllocateStringRoutine)(cbDllNameUnderLocalDir);
if (!pDllNameUnderLocalDir) {
status = STATUS_NO_MEMORY ;
goto Exit;
}
}else
pDllNameUnderLocalDir = NewDllNameUnderLocalDir->Buffer;
Cursor = pDllNameUnderLocalDir;
RtlCopyMemory(Cursor, pFullImageName, cbFullImageNameLength);
Cursor = pDllNameUnderLocalDir + cbFullImageNameLength / sizeof(WCHAR);
RtlCopyMemory(Cursor, DLL_REDIRECTION_LOCAL_SUFFIX, sizeof(DLL_REDIRECTION_LOCAL_SUFFIX) - sizeof(WCHAR)) ;
Cursor += (sizeof(DLL_REDIRECTION_LOCAL_SUFFIX) - sizeof(WCHAR)) / sizeof(WCHAR);
*Cursor = L'\\';
Cursor += 1;
RtlCopyMemory(Cursor,
pDllNameUnderImageDir + cbFullImagePathLengthWithTrailingSlash/sizeof(WCHAR),
cbDllFileNameLengthWithTrailingNULL) ;
NewDllNameUnderImageDir->Buffer = pDllNameUnderImageDir ;
if ( pDllNameUnderImageDir != pBuf1) // if memory is not-reallocated, MaximumLength should be untouched
NewDllNameUnderImageDir->MaximumLength = cbFullImagePathLengthWithTrailingSlash + cbDllFileNameLengthWithTrailingNULL;
NewDllNameUnderImageDir->Length = (USHORT)(cbDllNameUnderImageDir - sizeof(WCHAR));
NewDllNameUnderLocalDir->Buffer = pDllNameUnderLocalDir;
if (pDllNameUnderLocalDir != pBuf2)
NewDllNameUnderLocalDir->MaximumLength = cbDllNameUnderLocalDir;
NewDllNameUnderLocalDir->Length = (USHORT)(cbDllNameUnderLocalDir - sizeof(WCHAR));
status = STATUS_SUCCESS ;
Exit:
if (!NT_SUCCESS(status)) {
if (pDllNameUnderImageDir != pBuf1)
(RtlFreeStringRoutine)(pDllNameUnderImageDir);
if (pDllNameUnderLocalDir != pBuf2)
(RtlFreeStringRoutine)(pDllNameUnderLocalDir);
}
return status;
}
NTSTATUS
LdrpAllocateUnicodeString(
OUT PUNICODE_STRING StringOut,
IN USHORT Length
)
/*++
Routine Description:
This routine allocates space for a UNICODE_STRING from the loader
private heap.
Arguments:
StringOut - Pointer to UNICODE_STRING in which the information about
the allocated string is written. Any previous contents of StringOut
are overwritten and lost.
Length - length, in bytes, of the string which StringOut must be able
to hold.
Return Value:
NTSTATUS indicating success or failure of this function. In general
the only reasons it fails are STATUS_NO_MEMORY when the heap allocation
cannot be performed or STATUS_INVALID_PARAMETER when an invalid parameter
value is passed in.
--*/
{
NTSTATUS st = STATUS_INTERNAL_ERROR; // returned if someone messes up and forgets to otherwise set it
if (StringOut != NULL) {
StringOut->Length = 0;
StringOut->MaximumLength = 0;
StringOut->Buffer = NULL;
}
if ((StringOut == NULL) ||
((Length % sizeof(WCHAR)) != 0)) {
st = STATUS_INVALID_PARAMETER;
goto Exit;
}
StringOut->Buffer = RtlAllocateHeap(LdrpHeap, 0, Length + sizeof(WCHAR));
if (StringOut->Buffer == NULL) {
st = STATUS_NO_MEMORY;
goto Exit;
}
StringOut->Buffer[Length / sizeof(WCHAR)] = L'\0';
StringOut->Length = 0;
// If the true length of the buffer can be represted in 16 bits, store it; otherwise
// store the biggest number we can.
if (Length != UNICODE_STRING_MAX_BYTES)
StringOut->MaximumLength = Length + sizeof(WCHAR);
else
StringOut->MaximumLength = Length;
st = STATUS_SUCCESS;
Exit:
return st;
}
NTSTATUS
LdrpCopyUnicodeString(
OUT PUNICODE_STRING StringOut,
IN PCUNICODE_STRING StringIn
)
/*++
Routine Description:
This function makes a copy of a unicode string; the important aspect
of it is that the string is allocated from the loader private heap.
Arguments:
StringOut - Pointer to UNICODE_STRING in which the information about
the copied string is written. Any previous contents of StringOut
are overwritten and lost.
StringIn - Pointer to constant UNICODE_STRING which is copied.
Return Value:
NTSTATUS indicating success or failure of this function. In general
the only reason it fails is STATUS_NO_MEMORY when the heap allocation
cannot be performed.
--*/
{
NTSTATUS st = STATUS_INTERNAL_ERROR;
ULONG BytesNeeded = 0;
if (StringOut != NULL) {
StringOut->Length = 0;
StringOut->MaximumLength = 0;
StringOut->Buffer = NULL;
}
if ((StringOut == NULL) ||
(StringIn == NULL)) {
st = STATUS_INVALID_PARAMETER;
goto Exit;
}
st = RtlValidateUnicodeString(0, StringIn);
if (!NT_SUCCESS(st))
goto Exit;
st = LdrpAllocateUnicodeString(StringOut, StringIn->Length);
if (!NT_SUCCESS(st))
goto Exit;
RtlCopyMemory(StringOut->Buffer, StringIn->Buffer, StringIn->Length);
StringOut->Length = StringIn->Length;
st = STATUS_SUCCESS;
Exit:
return st;
}
VOID
LdrpFreeUnicodeString(
IN OUT PUNICODE_STRING StringIn
)
/*++
Routine Description:
This function deallocates a string that was allocated using
LdrpCopyUnicodeString.
Arguments:
String - Pointer to UNICODE_STRING which is to be freed. On exit,
all the members are set to 0/null as appropriate.
Return Value:
None
--*/
{
if (StringIn != NULL) {
if (StringIn->Buffer != NULL) {
RtlFreeHeap(LdrpHeap, 0, StringIn->Buffer);
}
StringIn->Length = 0;
StringIn->MaximumLength = 0;
StringIn->Buffer = NULL;
}
}
VOID
LdrpEnsureLoaderLockIsHeld(
VOID
)
{
BOOLEAN LoaderLockIsHeld =
((LdrpInLdrInit) ||
((LdrpShutdownInProgress) &&
(LdrpShutdownThreadId == NtCurrentTeb()->ClientId.UniqueThread)) ||
(LdrpLoaderLock.OwningThread == NtCurrentTeb()->ClientId.UniqueThread));
ASSERT(LoaderLockIsHeld);
if (!LoaderLockIsHeld)
RtlRaiseStatus(STATUS_NOT_LOCKED);
}
int
LdrpGenericExceptionFilter(
IN const struct _EXCEPTION_POINTERS *ExceptionPointers,
IN PCSTR FunctionName
)
/*++
Routine Description:
Exception filter function used in __try block throughout the loader
code instead of just specifying __except(EXCEPTION_EXECUTE_HANDLER).
Arguments:
ExceptionPointers
Pointer to exception information returned by GetExceptionInformation() in the __except()
FunctionName
Name of the function in which the __try block appears.
Return Value:
EXCEPTION_EXECUTE_HANDLER
--*/
{
const ULONG ExceptionCode = ExceptionPointers->ExceptionRecord->ExceptionCode;
DbgPrintEx(
DPFLTR_LDR_ID,
LDR_ERROR_DPFLTR,
"LDR: exception %08lx thrown within function %s\n"
" Exception record: %p\n"
" Context record: %p\n",
ExceptionCode, FunctionName,
ExceptionPointers->ExceptionRecord,
ExceptionPointers->ContextRecord);
#ifdef _X86_
// It would be nice to have a generic context dumper but right now I'm just trying to
// debug X86 and this is the quick thing to do. -mgrier 4/8/2001
DbgPrintEx(
DPFLTR_LDR_ID,
LDR_ERROR_DPFLTR,
" Context->Eip = %p\n"
" Context->Ebp = %p\n"
" Context->Esp = %p\n",
ExceptionPointers->ContextRecord->Eip,
ExceptionPointers->ContextRecord->Ebp,
ExceptionPointers->ContextRecord->Esp);
#endif // _X86_
if (LdrpBreakOnExceptions) {
char Response[2];
for (;;) {
DbgPrint("\n***Exception thrown within loader***\n");
DbgPrompt(
"Break repeatedly, break Once, Ignore, terminate Process or terminate Thread (boipt)? ",
Response,
sizeof(Response));
switch (Response[0]) {
case 'b':
case 'B':
case 'o':
case 'O':
DbgPrint("Execute '.cxr %p' to dump context\n", ExceptionPointers->ContextRecord);
DbgBreakPoint();
if ((Response[0] == 'o') || (Response[0] == 'O'))
return EXCEPTION_EXECUTE_HANDLER;
case 'I':
case 'i':
return EXCEPTION_EXECUTE_HANDLER;
case 'P':
case 'p':
NtTerminateProcess( NtCurrentProcess(), ExceptionCode);
break;
case 'T':
case 't':
NtTerminateThread( NtCurrentThread(), ExceptionCode);
break;
}
}
}
return EXCEPTION_EXECUTE_HANDLER;
}