reactos/ntoskrnl/ldr/rtl.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/ldr/loader.c
   6  * PURPOSE:         Loader utilities
   7  * PROGRAMMERS:     Jean Michault
   8  *                  Rex Jolliff (rex@lvcablemodem.com)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* FUNCTIONS ****************************************************************/
  18
  19
  20 /*
  21  * @implemented
  22  */
  23 PIMAGE_NT_HEADERS STDCALL
  24 RtlImageNtHeader (IN PVOID BaseAddress)
  25 {
  26    PIMAGE_DOS_HEADER DosHeader;
  27    PIMAGE_NT_HEADERS NTHeaders;
  28
  29    DosHeader = (PIMAGE_DOS_HEADER)BaseAddress;
  30    NTHeaders = (PIMAGE_NT_HEADERS)((char*)BaseAddress + DosHeader->e_lfanew);
  31    if ((DosHeader->e_magic != IMAGE_DOS_SIGNATURE)
  32        || (DosHeader->e_lfanew == 0L)
  33        || (*(PULONG) NTHeaders != IMAGE_NT_SIGNATURE))
  34      {
  35         return(NULL);
  36      }
  37    return(NTHeaders);
  38 }
  39
  40
  41 /*
  42  * @implemented
  43  */
  44 PVOID STDCALL
  45 RtlImageDirectoryEntryToData (IN PVOID  BaseAddress,
  46                               IN BOOLEAN        ImageLoaded,
  47                               IN ULONG  Directory,
  48                               OUT PULONG        Size)
  49 {
  50         PIMAGE_NT_HEADERS NtHeader;
  51         PIMAGE_SECTION_HEADER SectionHeader;
  52         ULONG Va;
  53         ULONG Count;
  54
  55         NtHeader = RtlImageNtHeader (BaseAddress);
  56         if (NtHeader == NULL)
  57                 return NULL;
  58
  59         if (Directory >= NtHeader->OptionalHeader.NumberOfRvaAndSizes)
  60                 return NULL;
  61
  62         Va = NtHeader->OptionalHeader.DataDirectory[Directory].VirtualAddress;
  63         if (Va == 0)
  64                 return NULL;
  65
  66         if (Size)
  67                 *Size = NtHeader->OptionalHeader.DataDirectory[Directory].Size;
  68
  69         if (ImageLoaded)
  70                 return (PVOID)((char*)BaseAddress + Va);
  71
  72         /* image mapped as ordinary file, we must find raw pointer */
  73         SectionHeader = (PIMAGE_SECTION_HEADER)(NtHeader + 1);
  74         Count = NtHeader->FileHeader.NumberOfSections;
  75         while (Count--)
  76         {
  77                 if (SectionHeader->VirtualAddress == Va)
  78                         return (PVOID)((char*)BaseAddress + SectionHeader->PointerToRawData);
  79                 SectionHeader++;
  80         }
  81
  82         return NULL;
  83 }
  84
  85
  86 PIMAGE_SECTION_HEADER
  87 STDCALL
  88 RtlImageRvaToSection (
  89         PIMAGE_NT_HEADERS       NtHeader,
  90         PVOID                   BaseAddress,
  91         ULONG                   Rva
  92         )
  93 {
  94         PIMAGE_SECTION_HEADER Section;
  95         ULONG Va;
  96         ULONG Count;
  97
  98         Count = NtHeader->FileHeader.NumberOfSections;
  99         Section = (PIMAGE_SECTION_HEADER)((ULONG)&NtHeader->OptionalHeader +
 100                                           NtHeader->FileHeader.SizeOfOptionalHeader);
 101         while (Count)
 102         {
 103                 Va = Section->VirtualAddress;
 104                 if ((Va <= Rva) &&
 105                     (Rva < Va + Section->SizeOfRawData))
 106                         return Section;
 107                 Section++;
 108         }
 109         return NULL;
 110 }
 111
 112
 113 ULONG
 114 STDCALL
 115 RtlImageRvaToVa (
 116         PIMAGE_NT_HEADERS       NtHeader,
 117         PVOID                   BaseAddress,
 118         ULONG                   Rva,
 119         PIMAGE_SECTION_HEADER   *SectionHeader
 120         )
 121 {
 122         PIMAGE_SECTION_HEADER Section = NULL;
 123
 124         if (SectionHeader)
 125                 Section = *SectionHeader;
 126
 127         if (Section == NULL ||
 128             Rva < Section->VirtualAddress ||
 129             Rva >= Section->VirtualAddress + Section->SizeOfRawData)
 130         {
 131                 Section = RtlImageRvaToSection (NtHeader, BaseAddress, Rva);
 132                 if (Section == NULL)
 133                         return 0;
 134
 135                 if (SectionHeader)
 136                         *SectionHeader = Section;
 137         }
 138
 139         return (ULONG)((char*)BaseAddress +
 140                        Rva +
 141                        Section->PointerToRawData -
 142                        Section->VirtualAddress);
 143 }
 144
 145 #define RVA(m, b) ((ULONG)b + m)
 146
 147 NTSTATUS STDCALL
 148 LdrGetProcedureAddress (IN PVOID BaseAddress,
 149                         IN PANSI_STRING Name,
 150                         IN ULONG Ordinal,
 151                         OUT PVOID *ProcedureAddress)
 152 {
 153    PIMAGE_EXPORT_DIRECTORY ExportDir;
 154    PUSHORT OrdinalPtr;
 155    PULONG NamePtr;
 156    PULONG AddressPtr;
 157    ULONG i = 0;
 158
 159    /* get the pointer to the export directory */
 160    ExportDir = (PIMAGE_EXPORT_DIRECTORY)
 161         RtlImageDirectoryEntryToData (BaseAddress, TRUE,
 162                                       IMAGE_DIRECTORY_ENTRY_EXPORT, &i);
 163
 164    if (!ExportDir || !i || !ProcedureAddress)
 165      {
 166         return(STATUS_INVALID_PARAMETER);
 167      }
 168
 169    AddressPtr = (PULONG)RVA((char*)BaseAddress, ExportDir->AddressOfFunctions);
 170    if (Name && Name->Length)
 171      {
 172        LONG minn, maxn;
 173
 174         /* by name */
 175        OrdinalPtr =
 176          (PUSHORT)RVA((char*)BaseAddress, ExportDir->AddressOfNameOrdinals);
 177        NamePtr = (PULONG)RVA((char*)BaseAddress, ExportDir->AddressOfNames);
 178
 179         minn = 0; maxn = ExportDir->NumberOfNames;
 180         while (minn <= maxn)
 181           {
 182             LONG mid;
 183             LONG res;
 184
 185             mid = (minn + maxn) / 2;
 186             res = _strnicmp(Name->Buffer, (PCH)RVA((char*)BaseAddress, NamePtr[mid]),
 187                             Name->Length);
 188             if (res == 0)
 189               {
 190                 *ProcedureAddress =
 191                   (PVOID)RVA((char*)BaseAddress, AddressPtr[OrdinalPtr[mid]]);
 192                 return(STATUS_SUCCESS);
 193               }
 194             else if (res > 0)
 195               {
 196                 maxn = mid - 1;
 197               }
 198             else
 199               {
 200                 minn = mid + 1;
 201               }
 202           }
 203
 204         for (i = 0; i < ExportDir->NumberOfNames; i++, NamePtr++, OrdinalPtr++)
 205           {
 206              if (!_strnicmp(Name->Buffer,
 207                             (char*)((char*)BaseAddress + *NamePtr), Name->Length))
 208                {
 209                   *ProcedureAddress =
 210                     (PVOID)((ULONG)BaseAddress +
 211                             (ULONG)AddressPtr[*OrdinalPtr]);
 212                   return STATUS_SUCCESS;
 213                }
 214           }
 215         CPRINT("LdrGetProcedureAddress: Can't resolve symbol '%Z'\n", Name);
 216      }
 217    else
 218      {
 219         /* by ordinal */
 220         Ordinal &= 0x0000FFFF;
 221         if (Ordinal - ExportDir->Base < ExportDir->NumberOfFunctions)
 222           {
 223              *ProcedureAddress =
 224                (PVOID)((ULONG)BaseAddress +
 225                        (ULONG)AddressPtr[Ordinal - ExportDir->Base]);
 226              return STATUS_SUCCESS;
 227           }
 228         CPRINT("LdrGetProcedureAddress: Can't resolve symbol @%d\n",
 229                  Ordinal);
 230   }
 231
 232    return STATUS_PROCEDURE_NOT_FOUND;
 233 }
 234
 235 /* EOF */