loadlib.c

   1 /*\r
   2  AcessOS 1 - Dynamic Loader\r
   3  By thePowersGang\r
   4 */\r
   5 #include "common.h"\r
   6 \r
   7 #define DEBUG   0\r
   8 \r
   9 #if DEBUG\r
  10 # define DEBUGS(v...)   SysDebug(v)\r
  11 #else\r
  12 # define DEBUGS(v...)   \r
  13 #endif\r
  14 \r
  15 // === CONSTANTS ===\r
  16 #define MAX_LOADED_LIBRARIES    64\r
  17 #define MAX_STRINGS_BYTES       4096\r
  18 #define SYSTEM_LIB_DIR  "/Acess/Libs/"\r
  19 \r
  20 // === PROTOTYPES ===\r
  21 Uint    IsFileLoaded(char *file);
  22  int    GetSymbolFromBase(Uint base, char *name, Uint *ret);\r
  23 \r
  24 // === GLOABLS ===\r
  25 struct {\r
  26         Uint    Base;\r
  27         char    *Name;\r
  28 }       gLoadedLibraries[MAX_LOADED_LIBRARIES];\r
  29 char    gsLoadedStrings[MAX_STRINGS_BYTES];\r
  30 char    *gsNextAvailString = gsLoadedStrings;\r
  31 //tLoadLib      *gpLoadedLibraries = NULL;\r
  32 \r
  33 // === CODE ===\r
  34 char *FindLibrary(char *DestBuf, char *SoName, char *ExtraSearchDir)\r
  35 {       \r
  36         // -- #1: Executable Specified\r
  37         if(ExtraSearchDir)\r
  38         {\r
  39                 strcpy(DestBuf, ExtraSearchDir);\r
  40                 strcat(DestBuf, "/");\r
  41                 strcat(DestBuf, SoName);\r
  42                 if(file_exists(DestBuf))        return DestBuf;\r
  43         }\r
  44         \r
  45         // -- #2: System\r
  46         strcpy(DestBuf, SYSTEM_LIB_DIR);\r
  47         strcat(DestBuf, SoName);\r
  48         if(file_exists(DestBuf))        return DestBuf;\r
  49         \r
  50         // -- #3: Current Directory\r
  51         if(file_exists(SoName)) return SoName;\r
  52         \r
  53         return NULL;\r
  54 }\r
  55 \r
  56 /**\r
  57  */\r
  58 Uint LoadLibrary(char *SoName, char *SearchDir, char **envp)\r
  59 {\r
  60         char    sTmpName[1024];\r
  61         char    *filename;\r
  62         Uint    iArg;\r
  63         void    (*fEntry)(int, int, char *[], char**);\r
  64         \r
  65         DEBUGS("LoadLibrary: (filename='%s', envp=0x%x)\n", filename, envp);\r
  66         \r
  67         // Create Temp Name\r
  68         filename = FindLibrary(sTmpName, SoName, SearchDir);\r
  69         DEBUGS(" LoadLibrary: filename='%s'\n", filename);\r
  70         \r
  71         if( (iArg = IsFileLoaded(filename)) )\r
  72                 return iArg;\r
  73         \r
  74         // Load Library\r
  75         iArg = SysLoadBin(filename, (Uint*)&fEntry);\r
  76         if(iArg == 0) {\r
  77                 DEBUGS("LoadLibrary: RETURN 0\n");\r
  78                 return 0;\r
  79         }\r
  80         \r
  81         DEBUGS(" LoadLibrary: iArg=0x%x, iEntry=0x%x\n", iArg, fEntry);\r
  82         \r
  83         // Load Symbols\r
  84         fEntry = (void*)DoRelocate( iArg, envp, filename );\r
  85         \r
  86         // Call Entrypoint\r
  87         DEBUGS(" LoadLibrary: '%s' Entry 0x%x\n", SoName, fEntry);\r
  88         fEntry(iArg, 0, NULL, envp);\r
  89         \r
  90         DEBUGS("LoadLibrary: RETURN 1\n");\r
  91         return iArg;\r
  92 }
  93 \r
  94 /**\r
  95  * \fn Uint IsFileLoaded(char *file)\r
  96  * \brief Determine if a file is already loaded\r
  97  */\r
  98 Uint IsFileLoaded(char *file)\r
  99 {\r
 100          int    i;\r
 101         DEBUGS("IsFileLoaded: (file='%s')", file);\r
 102         for( i = 0; i < MAX_LOADED_LIBRARIES; i++ )\r
 103         {\r
 104                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL\r
 105                 DEBUGS(" strcmp('%s', '%s')", gLoadedLibraries[i].Name, file);\r
 106                 if(strcmp(gLoadedLibraries[i].Name, file) == 0) {\r
 107                         DEBUGS("IsFileLoaded: Found %i (0x%x)", i, gLoadedLibraries[i].Base);\r
 108                         return gLoadedLibraries[i].Base;\r
 109                 }\r
 110         }\r
 111         DEBUGS("IsFileLoaded: Not Found");\r
 112         return 0;\r
 113 }\r
 114 \r
 115 /**\r
 116  * \fn void AddLoaded(char *File, Uint base)\r
 117  * \brief Add a file to the loaded list\r
 118  */
 119 void AddLoaded(char *File, Uint base)
 120 {\r
 121          int    i, length;\r
 122         char    *name = gsNextAvailString;\r
 123         \r
 124         DEBUGS("AddLoaded: (File='%s', base=0x%x)", File, base);\r
 125         \r
 126         // Find a free slot\r
 127         for( i = 0; i < MAX_LOADED_LIBRARIES; i ++ )\r
 128         {\r
 129                 if(gLoadedLibraries[i].Base == 0)       break;\r
 130         }\r
 131         if(i == MAX_LOADED_LIBRARIES) {\r
 132                 SysDebug("ERROR - ld-acess.so has run out of load slots!");\r
 133                 return;\r
 134         }\r
 135         \r
 136         // Check space in string buffer\r
 137         length = strlen(File);\r
 138         if(&name[length+1] >= &gsLoadedStrings[MAX_STRINGS_BYTES]) {\r
 139                 SysDebug("ERROR - ld-acess.so has run out of string buffer memory!");\r
 140                 return;\r
 141         }\r
 142         \r
 143         // Set information\r
 144         gLoadedLibraries[i].Base = base;\r
 145         strcpy(name, File);\r
 146         gLoadedLibraries[i].Name = name;\r
 147         gsNextAvailString = &name[length+1];\r
 148         DEBUGS("'%s' (0x%x) loaded as %i\n", name, base, i);\r
 149         return;
 150 }\r
 151 \r
 152 /**\r
 153  * \fn void Unload(Uint Base)\r
 154  */\r
 155 void Unload(Uint Base)\r
 156 {       \r
 157          int    i, j;\r
 158          int    id;\r
 159         char    *str;\r
 160         for( id = 0; id < MAX_LOADED_LIBRARIES; id++ )\r
 161         {\r
 162                 if(gLoadedLibraries[id].Base == Base)   break;\r
 163         }\r
 164         if(id == MAX_LOADED_LIBRARIES)  return;\r
 165         \r
 166         // Unload Binary\r
 167         SysUnloadBin( Base );\r
 168         // Save String Pointer\r
 169         str = gLoadedLibraries[id].Name;\r
 170         \r
 171         // Compact Loaded List\r
 172         j = id;\r
 173         for( i = j + 1; i < MAX_LOADED_LIBRARIES; i++, j++ )\r
 174         {\r
 175                 if(gLoadedLibraries[i].Base == 0)       break;\r
 176                 // Compact String\r
 177                 strcpy(str, gLoadedLibraries[i].Name);\r
 178                 str += strlen(str)+1;\r
 179                 // Compact Entry\r
 180                 gLoadedLibraries[j].Base = gLoadedLibraries[i].Base;\r
 181                 gLoadedLibraries[j].Name = str;\r
 182         }\r
 183         \r
 184         // NULL Last Entry\r
 185         gLoadedLibraries[j].Base = 0;\r
 186         gLoadedLibraries[j].Name = NULL;\r
 187         // Save next string\r
 188         gsNextAvailString = str;\r
 189 }\r
 190 \r
 191 /**
 192  \fn Uint GetSymbol(char *name)
 193  \brief Gets a symbol value from a loaded library
 194 */
 195 Uint GetSymbol(char *name)
 196 {\r
 197          int    i;
 198         Uint    ret;\r
 199         for(i=0;i<sizeof(gLoadedLibraries)/sizeof(gLoadedLibraries[0]);i++)\r
 200         {\r
 201                 if(gLoadedLibraries[i].Base == 0)       break;\r
 202
 203                 //SysDebug(" GetSymbol: Trying 0x%x, '%s'\n",\r
 204                 //      gLoadedLibraries[i].Base, gLoadedLibraries[i].Name);
 205                 if(GetSymbolFromBase(gLoadedLibraries[i].Base, name, &ret))     return ret;\r
 206         }\r
 207         SysDebug("GetSymbol: === Symbol '%s' not found ===\n", name);\r
 208         return 0;
 209 }
 210
 211 /**
 212  \fn int GetSymbolFromBase(Uint base, char *name, Uint *ret)
 213  \breif Gets a symbol from a specified library
 214 */
 215 int GetSymbolFromBase(Uint base, char *name, Uint *ret)
 216 {
 217         if(*(Uint32*)base == (0x7F|('E'<<8)|('L'<<16)|('F'<<24)))
 218                 return ElfGetSymbol(base, name, ret);
 219         if(*(Uint16*)base == ('M'|('Z'<<8)))
 220                 return PE_GetSymbol(base, name, ret);
 221         return 0;
 222 }
 223