pe.c

   1 /*\r
   2  * Acess v1\r
   3  * Portable Executable Loader\r
   4  */\r
   5 #include "common.h"\r
   6 #include "pe.h"\r
   7 \r
   8 #define PE_DEBUG        0\r
   9 #define DEBUG   (ACESS_DEBUG|PE_DEBUG)\r
  10 \r
  11 //#define DLL_BASE_PATH "/Acess/Windows/"\r
  12 #define DLL_BASE_PATH   NULL\r
  13 \r
  14 #if DEBUG\r
  15 # define DEBUGS(v...)   SysDebug(v)\r
  16 #else\r
  17 # define DEBUGS(v...)\r
  18 #endif\r
  19 \r
  20 // === PROTOTYPES ===\r
  21  int    PE_Relocate(void *Base, char **envp, char *Filename);\r
  22 char    *PE_int_GetTrueFile(char *file);\r
  23  int    PE_int_GetForwardSymbol(char *Fwd, Uint *Value);\r
  24 \r
  25 // === CODE ===\r
  26 int PE_Relocate(void *Base, char *envp[], char *Filename)\r
  27 {\r
  28         tPE_DOS_HEADER          *dosHdr = Base;\r
  29         tPE_IMAGE_HEADERS       *peHeaders;\r
  30         tPE_DATA_DIR    *directory;\r
  31         tPE_IMPORT_DIR  *impDir;\r
  32         tPE_HINT_NAME   *name;\r
  33         Uint32  *importTab, *aIAT;\r
  34          int    i, j;\r
  35         Uint    iBase = (Uint)Base;\r
  36         Uint    iLibBase;\r
  37         \r
  38         DEBUGS("PE_Relocate: (Base=0x%x)\n", Base);\r
  39         \r
  40         peHeaders = Base + dosHdr->PeHdrOffs;\r
  41         \r
  42         directory = peHeaders->OptHeader.Directory;\r
  43         \r
  44         // === Load Import Tables\r
  45         impDir = Base + directory[PE_DIR_IMPORT].RVA;\r
  46         for( i = 0; impDir[i].DLLName != NULL; i++ )\r
  47         {\r
  48                 impDir[i].DLLName += iBase;\r
  49                 impDir[i].ImportLookupTable += iBase/4;\r
  50                 impDir[i].ImportAddressTable += iBase/4;\r
  51                 DEBUGS(" PE_Relocate: DLL Required '%s'(0x%x)\n", impDir[i].DLLName, impDir[i].DLLName);\r
  52                 iLibBase = LoadLibrary(PE_int_GetTrueFile(impDir[i].DLLName), DLL_BASE_PATH, envp);\r
  53                 if(iLibBase == 0) {\r
  54                         SysDebug("Unable to load required library '%s'\n", impDir[i].DLLName);\r
  55                         return 0;\r
  56                 }\r
  57                 DEBUGS(" PE_Relocate: Loaded as 0x%x\n", iLibBase);\r
  58                 importTab = impDir[i].ImportLookupTable;\r
  59                 aIAT = impDir[i].ImportAddressTable;\r
  60                 for( j = 0; importTab[j] != 0; j++ )\r
  61                 {\r
  62                         if( importTab[j] & 0x80000000 )\r
  63                                 DEBUGS(" PE_Relocate: Import Ordinal %i\n", importTab[j] & 0x7FFFFFFF);\r
  64                         else\r
  65                         {\r
  66                                 name = (void*)( iBase + importTab[j] );\r
  67                                 DEBUGS(" PE_Relocate: Import Name '%s', Hint 0x%x\n", name->Name, name->Hint);\r
  68                                 if( GetSymbolFromBase(iLibBase, name->Name, (Uint*)&aIAT[j]) == 0 ) {\r
  69                                         SysDebug("Unable to find symbol '%s' in library '%s'\n", name->Name, impDir[i].DLLName);\r
  70                                         return 0;\r
  71                                 }\r
  72                         }\r
  73                 }\r
  74         }\r
  75         \r
  76         #if DEBUG\r
  77         for(i=0;i<PE_DIR_LAST;i++) {\r
  78                 if(directory[i].RVA == 0)       continue;\r
  79                 SysDebug("directory[%i] = {RVA=0x%x,Size=0x%x}\n", i, directory[i].RVA, directory[i].Size);\r
  80         }\r
  81         #endif\r
  82         \r
  83         DEBUGS("PE_Relocate: RETURN 0x%x\n", iBase + peHeaders->OptHeader.EntryPoint);\r
  84         \r
  85         return iBase + peHeaders->OptHeader.EntryPoint;\r
  86 }\r
  87 \r
  88 /**\r
  89  * \fn int PE_GetSymbol(Uint Base, char *Name, Uint *Ret)\r
  90  */\r
  91 int PE_GetSymbol(Uint Base, char *Name, Uint *Ret)\r
  92 {\r
  93         tPE_DOS_HEADER          *dosHdr = (void*)Base;\r
  94         tPE_IMAGE_HEADERS       *peHeaders;\r
  95         tPE_DATA_DIR    *directory;\r
  96         tPE_EXPORT_DIR  *expDir;\r
  97         Uint32  *nameTable, *addrTable;\r
  98         Uint16  *ordTable;\r
  99          int    i;\r
 100          int    symbolCount;\r
 101         char    *name;\r
 102         Uint    retVal;\r
 103         Uint    expLen;\r
 104         \r
 105         peHeaders = (void*)( Base + dosHdr->PeHdrOffs );\r
 106         directory = peHeaders->OptHeader.Directory;\r
 107         \r
 108         expDir = (void*)( Base + directory[PE_DIR_EXPORT].RVA );\r
 109         expLen = directory[PE_DIR_EXPORT].Size;\r
 110         symbolCount = expDir->NumNamePointers;\r
 111         nameTable = (void*)( Base + expDir->NamePointerRVA );\r
 112         ordTable = (void*)( Base + expDir->OrdinalTableRVA );\r
 113         addrTable = (void*)( Base + expDir->AddressRVA );\r
 114         //DEBUGS(" PE_GetSymbol: %i Symbols\n", symbolCount);\r
 115         for(i=0;i<symbolCount;i++)\r
 116         {\r
 117                 name = (char*)( Base + nameTable[i] );\r
 118                 //DEBUGS(" PE_GetSymbol: '%s' = 0x%x\n", name, Base + addrTable[ ordTable[i] ]);\r
 119                 if(strcmp(name, Name) == 0)\r
 120                 {\r
 121                         retVal = Base + addrTable[ ordTable[i] ];\r
 122                         // Check for forwarding\r
 123                         if((Uint)expDir < retVal && retVal < (Uint)expDir + expLen) {\r
 124                                 char *fwd = (char*)retVal;\r
 125                                 DEBUGS(" PE_GetSymbol: '%s' forwards to '%s'\n", name, fwd);\r
 126                                 return PE_int_GetForwardSymbol(fwd, Ret);\r
 127                         }\r
 128                         *Ret = retVal;\r
 129                         return 1;\r
 130                 }\r
 131         }\r
 132         return 0;\r
 133 }\r
 134 \r
 135 /**\r
 136  * \fn char *PE_int_GetTrueFile(char *file)\r
 137  * \brief Get the true file name\r
 138  */\r
 139 char *PE_int_GetTrueFile(char *file)\r
 140 {\r
 141          int    i;\r
 142         if(file[0] != ':')      return file;\r
 143 \r
 144         // Translate name\r
 145         for(i=1;file[i];i++)\r
 146                 if(file[i] == '_')\r
 147                         file[i] = '.';\r
 148         \r
 149         return &file[1];\r
 150 }\r
 151 \r
 152 int PE_int_GetForwardSymbol(char *Fwd, Uint *Value)\r
 153 {\r
 154         char    *libname;\r
 155         char    *sym;\r
 156          int    i;\r
 157         Uint    libbase;\r
 158          int    ret;\r
 159         \r
 160         // -- Find seperator\r
 161         // PE spec says that there sould only be one, but the string may\r
 162         // be mutilated in the loader\r
 163         for(i=0;Fwd[i]!='\0';i++);\r
 164         for(;i&&Fwd[i]!='.';i--);\r
 165         \r
 166         Fwd[i] = '\0';\r
 167         sym = &Fwd[i+1];\r
 168         \r
 169         libname = PE_int_GetTrueFile(Fwd);\r
 170         \r
 171         DEBUGS(" PE_int_GetForwardSymbol: Get '%s' from '%s'\n", sym, libname);\r
 172         \r
 173         libbase = LoadLibrary(libname, DLL_BASE_PATH, NULL);\r
 174         ret = GetSymbolFromBase(libbase, sym, Value);\r
 175         if(!ret) {\r
 176                 SysDebug(" PE_int_GetForwardSymbol: Unable to find '%s' in '%s'\n", sym, libname);\r
 177         }\r
 178         Fwd[i] = '.';\r
 179         return ret;\r
 180 }\r