lib/ntdll/rtl/image.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            lib/ntdll/rtl/image.c
   6  * PURPOSE:         Image handling functions
   7  * PROGRAMMER:      Eric Kohl
   8  * UPDATE HISTORY:
   9  *                  17/03/2000 Created
  10  */
  11
  12 #include <ddk/ntddk.h>
  13 #include <ntdll/rtl.h>
  14
  15 #define NDEBUG
  16 #include <ntdll/ntdll.h>
  17
  18 /* FUNCTIONS ****************************************************************/
  19
  20 /*
  21  * @implemented
  22  */
  23 PIMAGE_NT_HEADERS STDCALL
  24 RtlImageNtHeader (IN PVOID BaseAddress)
  25 {
  26   PIMAGE_NT_HEADERS NtHeader;
  27   PIMAGE_DOS_HEADER DosHeader = (PIMAGE_DOS_HEADER)BaseAddress;
  28
  29   if (DosHeader && DosHeader->e_magic != IMAGE_DOS_SIGNATURE)
  30     {
  31       DPRINT1("DosHeader->e_magic %x\n", DosHeader->e_magic);
  32       DPRINT1("NtHeader %x\n", (BaseAddress + DosHeader->e_lfanew));
  33     }
  34
  35   if (DosHeader && DosHeader->e_magic == IMAGE_DOS_SIGNATURE)
  36     {
  37       NtHeader = (PIMAGE_NT_HEADERS)(BaseAddress + DosHeader->e_lfanew);
  38       if (NtHeader->Signature == IMAGE_NT_SIGNATURE)
  39         return NtHeader;
  40     }
  41
  42   return NULL;
  43 }
  44
  45
  46 /*
  47  * @implemented
  48  */
  49 PVOID
  50 STDCALL
  51 RtlImageDirectoryEntryToData (
  52         PVOID   BaseAddress,
  53         BOOLEAN bFlag,
  54         ULONG   Directory,
  55         PULONG  Size
  56         )
  57 {
  58         PIMAGE_NT_HEADERS NtHeader;
  59         PIMAGE_SECTION_HEADER SectionHeader;
  60         ULONG Va;
  61         ULONG Count;
  62
  63         NtHeader = RtlImageNtHeader (BaseAddress);
  64         if (NtHeader == NULL)
  65                 return NULL;
  66
  67         if (Directory >= NtHeader->OptionalHeader.NumberOfRvaAndSizes)
  68                 return NULL;
  69
  70         Va = NtHeader->OptionalHeader.DataDirectory[Directory].VirtualAddress;
  71         if (Va == 0)
  72                 return NULL;
  73
  74         if (Size)
  75                 *Size = NtHeader->OptionalHeader.DataDirectory[Directory].Size;
  76
  77         if (bFlag)
  78                 return (PVOID)(BaseAddress + Va);
  79
  80         /* image mapped as ordinary file, we must find raw pointer */
  81         SectionHeader = (PIMAGE_SECTION_HEADER)(NtHeader + 1);
  82         Count = NtHeader->FileHeader.NumberOfSections;
  83         while (Count--)
  84         {
  85                 if (SectionHeader->VirtualAddress == Va)
  86                         return (PVOID)(BaseAddress + SectionHeader->PointerToRawData);
  87                 SectionHeader++;
  88         }
  89
  90         return NULL;
  91 }
  92
  93
  94 /*
  95  * @implemented
  96  */
  97 PIMAGE_SECTION_HEADER
  98 STDCALL
  99 RtlImageRvaToSection (
 100         PIMAGE_NT_HEADERS       NtHeader,
 101         PVOID                   BaseAddress,
 102         ULONG                   Rva
 103         )
 104 {
 105         PIMAGE_SECTION_HEADER Section;
 106         ULONG Va;
 107         ULONG Count;
 108
 109         Count = NtHeader->FileHeader.NumberOfSections;
 110         Section = (PIMAGE_SECTION_HEADER)((ULONG)&NtHeader->OptionalHeader +
 111                                           NtHeader->FileHeader.SizeOfOptionalHeader);
 112         while (Count)
 113         {
 114                 Va = Section->VirtualAddress;
 115                 if ((Va <= Rva) &&
 116                     (Rva < Va + Section->SizeOfRawData))
 117                         return Section;
 118                 Section++;
 119         }
 120         return NULL;
 121 }
 122
 123
 124 /*
 125  * @implemented
 126  */
 127 ULONG
 128 STDCALL
 129 RtlImageRvaToVa (
 130         PIMAGE_NT_HEADERS       NtHeader,
 131         PVOID                   BaseAddress,
 132         ULONG                   Rva,
 133         PIMAGE_SECTION_HEADER   *SectionHeader
 134         )
 135 {
 136         PIMAGE_SECTION_HEADER Section = NULL;
 137
 138         if (SectionHeader)
 139                 Section = *SectionHeader;
 140
 141         if (Section == NULL ||
 142             Rva < Section->VirtualAddress ||
 143             Rva >= Section->VirtualAddress + Section->SizeOfRawData)
 144         {
 145                 Section = RtlImageRvaToSection (NtHeader, BaseAddress, Rva);
 146                 if (Section == NULL)
 147                         return 0;
 148
 149                 if (SectionHeader)
 150                         *SectionHeader = Section;
 151         }
 152
 153         return (ULONG)(BaseAddress +
 154                        Rva +
 155                        Section->PointerToRawData -
 156                        Section->VirtualAddress);
 157 }
 158
 159 /* EOF */