/*++
Copyright (c) 1991 Microsoft Corporation
Module Name:
imagedir.c
Abstract:
The module contains the code to translate an image directory type to
the address of the data for that entry.
Author:
Steve Wood (stevewo) 18-Aug-1989
Environment:
User Mode or Kernel Mode
Revision History:
--*/
#include "ntrtlp.h"
PIMAGE_NT_HEADERS
RtlImageNtHeader (
IN PVOID Base
)
/*++
Routine Description:
This function returns the address of the NT Header.
Arguments:
Base - Supplies the base of the image.
Return Value:
Returns the address of the NT Header.
--*/
{
PIMAGE_NT_HEADERS NtHeaders;
if (Base != NULL && Base != (PVOID)-1) {
try {
if (((PIMAGE_DOS_HEADER)Base)->e_magic == IMAGE_DOS_SIGNATURE) {
NtHeaders = (PIMAGE_NT_HEADERS)((PCHAR)Base + ((PIMAGE_DOS_HEADER)Base)->e_lfanew);
if (NtHeaders->Signature == IMAGE_NT_SIGNATURE) {
return NtHeaders;
}
}
}
except(EXCEPTION_EXECUTE_HANDLER) {
return NULL;
}
}
return NULL;
}
PIMAGE_SECTION_HEADER
RtlSectionTableFromVirtualAddress (
IN PIMAGE_NT_HEADERS NtHeaders,
IN PVOID Base,
IN PVOID Address
)
/*++
Routine Description:
This function locates a VirtualAddress within the image header
of a file that is mapped as a file and returns a pointer to the
section table entry for that virtual address
Arguments:
NtHeaders - Supplies the pointer to the image or data file.
Base - Supplies the base of the image or data file.
Address - Supplies the virtual address to locate.
Return Value:
NULL - The file does not contain data for the specified directory entry.
NON-NULL - Returns the pointer of the section entry containing the data.
--*/
{
ULONG i;
PIMAGE_SECTION_HEADER NtSection;
NtSection = IMAGE_FIRST_SECTION( NtHeaders );
for (i=0; i<NtHeaders->FileHeader.NumberOfSections; i++) {
if ((ULONG)Address >= NtSection->VirtualAddress &&
(ULONG)Address < NtSection->VirtualAddress + NtSection->SizeOfRawData
) {
return NtSection;
}
++NtSection;
}
return NULL;
}
PVOID
RtlAddressInSectionTable (
IN PIMAGE_NT_HEADERS NtHeaders,
IN PVOID Base,
IN PVOID Address
)
/*++
Routine Description:
This function locates a VirtualAddress within the image header
of a file that is mapped as a file and returns the seek address
of the data the Directory describes.
Arguments:
NtHeaders - Supplies the pointer to the image or data file.
Base - Supplies the base of the image or data file.
Address - Supplies the virtual address to locate.
Return Value:
NULL - The file does not contain data for the specified directory entry.
NON-NULL - Returns the address of the raw data the directory describes.
--*/
{
PIMAGE_SECTION_HEADER NtSection;
NtSection = RtlSectionTableFromVirtualAddress( NtHeaders,
Base,
Address
);
if (NtSection != NULL) {
return( (PVOID)((ULONG)Base + ((ULONG)Address - NtSection->VirtualAddress) + NtSection->PointerToRawData) );
}
else {
return( NULL );
}
}
PVOID
RtlImageDirectoryEntryToData (
IN PVOID Base,
IN BOOLEAN MappedAsImage,
IN USHORT DirectoryEntry,
OUT PULONG Size
)
/*++
Routine Description:
This function locates a Directory Entry within the image header
and returns either the virtual address or seek address of the
data the Directory describes.
Arguments:
Base - Supplies the base of the image or data file.
MappedAsImage - FALSE if the file is mapped as a data file.
- TRUE if the file is mapped as an image.
DirectoryEntry - Supplies the directory entry to locate.
Size - Return the size of the directory.
Return Value:
NULL - The file does not contain data for the specified directory entry.
NON-NULL - Returns the address of the raw data the directory describes.
--*/
{
ULONG i, DirectoryAddress;
PIMAGE_NT_HEADERS NtHeaders;
if ((ULONG)Base & 0x00000001) {
Base = (PVOID)((ULONG)Base & ~0x00000001);
MappedAsImage = FALSE;
}
NtHeaders = RtlImageNtHeader(Base);
if ((!NtHeaders) ||
(DirectoryEntry >= NtHeaders->OptionalHeader.NumberOfRvaAndSizes)) {
return( NULL );
}
if (!(DirectoryAddress = NtHeaders->OptionalHeader.DataDirectory[ DirectoryEntry ].VirtualAddress)) {
return( NULL );
}
*Size = NtHeaders->OptionalHeader.DataDirectory[ DirectoryEntry ].Size;
if (MappedAsImage || DirectoryAddress < NtHeaders->OptionalHeader.SizeOfHeaders) {
return( (PVOID)((ULONG)Base + DirectoryAddress) );
}
return( RtlAddressInSectionTable(NtHeaders, Base, (PVOID)DirectoryAddress ));
}
#if !defined(NTOS_KERNEL_RUNTIME) && !defined(BLDR_KERNEL_RUNTIME)
PIMAGE_SECTION_HEADER
RtlImageRvaToSection(
IN PIMAGE_NT_HEADERS NtHeaders,
IN PVOID Base,
IN ULONG Rva
)
/*++
Routine Description:
This function locates an RVA within the image header of a file
that is mapped as a file and returns a pointer to the section
table entry for that virtual address
Arguments:
NtHeaders - Supplies the pointer to the image or data file.
Base - Supplies the base of the image or data file. The image
was mapped as a data file.
Rva - Supplies the relative virtual address (RVA) to locate.
Return Value:
NULL - The RVA was not found within any of the sections of the image.
NON-NULL - Returns the pointer to the image section that contains
the RVA
--*/
{
ULONG i;
PIMAGE_SECTION_HEADER NtSection;
NtSection = IMAGE_FIRST_SECTION( NtHeaders );
for (i=0; i<NtHeaders->FileHeader.NumberOfSections; i++) {
if (Rva >= NtSection->VirtualAddress &&
Rva < NtSection->VirtualAddress + NtSection->SizeOfRawData
) {
return NtSection;
}
++NtSection;
}
return NULL;
}
PVOID
RtlImageRvaToVa(
IN PIMAGE_NT_HEADERS NtHeaders,
IN PVOID Base,
IN ULONG Rva,
IN OUT PIMAGE_SECTION_HEADER *LastRvaSection OPTIONAL
)
/*++
Routine Description:
This function locates an RVA within the image header of a file that
is mapped as a file and returns the virtual addrees of the
corresponding byte in the file.
Arguments:
NtHeaders - Supplies the pointer to the image or data file.
Base - Supplies the base of the image or data file. The image
was mapped as a data file.
Rva - Supplies the relative virtual address (RVA) to locate.
LastRvaSection - Optional parameter that if specified, points
to a variable that contains the last section value used for
the specified image to translate and RVA to a VA.
Return Value:
NULL - The file does not contain the specified RVA
NON-NULL - Returns the virtual addrees in the mapped file.
--*/
{
PIMAGE_SECTION_HEADER NtSection;
if (!ARGUMENT_PRESENT( LastRvaSection ) ||
(NtSection = *LastRvaSection) == NULL ||
Rva < NtSection->VirtualAddress ||
Rva >= NtSection->VirtualAddress + NtSection->SizeOfRawData
) {
NtSection = RtlImageRvaToSection( NtHeaders,
Base,
Rva
);
}
if (NtSection != NULL) {
if (LastRvaSection != NULL) {
*LastRvaSection = NtSection;
}
return (PVOID)((ULONG)Base +
(Rva - NtSection->VirtualAddress) +
NtSection->PointerToRawData
);
}
else {
return NULL;
}
}
#endif
