Usermode/Libraries/ld-acess.so_src/loadlib.c

   1 /*
   2  AcessOS 1 - Dynamic Loader
   3  By thePowersGang
   4 */
   5 #include "common.h"
   6 #include <stdint.h>
   7 #include <acess/sys.h>
   8
   9 #define DEBUG   0
  10
  11 #if DEBUG
  12 # define DEBUGS(v...)   SysDebug(v)
  13 #else
  14 # define DEBUGS(v...)
  15 #endif
  16
  17 // === PROTOTYPES ===
  18 void    *IsFileLoaded(const char *file);
  19
  20 // === IMPORTS ===
  21 extern const struct {
  22         void    *Value;
  23         char    *Name;
  24 }       caLocalExports[];
  25 extern const int        ciNumLocalExports;
  26 extern char     **gEnvP;
  27 extern char     gLinkedBase[];
  28
  29 // === GLOABLS ===
  30 tLoadedLib      gLoadedLibraries[MAX_LOADED_LIBRARIES];
  31 char    gsLoadedStrings[MAX_STRINGS_BYTES];
  32 char    *gsNextAvailString = gsLoadedStrings;
  33 //tLoadLib      *gpLoadedLibraries = NULL;
  34
  35 // === CODE ===
  36 void ldacess_DumpLoadedLibraries(void)
  37 {
  38         for( int i = 0; i < MAX_LOADED_LIBRARIES; i ++ )
  39         {
  40                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL
  41                 _SysDebug("%p: %s",
  42                         gLoadedLibraries[i].Base,
  43                         gLoadedLibraries[i].Name
  44                         );
  45         }
  46 }
  47
  48 const char *FindLibrary(char *DestBuf, const char *SoName, const char *ExtraSearchDir)
  49 {
  50         // -- #1: Executable Specified
  51         if(ExtraSearchDir)
  52         {
  53                 strcpy(DestBuf, ExtraSearchDir);
  54                 strcat(DestBuf, "/");
  55                 strcat(DestBuf, SoName);
  56                 if(file_exists(DestBuf))        return DestBuf;
  57         }
  58
  59         // -- #2: System
  60         strcpy(DestBuf, SYSTEM_LIB_DIR);
  61         strcat(DestBuf, SoName);
  62         if(file_exists(DestBuf))        return DestBuf;
  63
  64         // -- #3: Current Directory
  65         if(file_exists(SoName)) return SoName;
  66
  67         return NULL;
  68 }
  69
  70 /**
  71  */
  72 void *LoadLibrary(const char *SoName, const char *SearchDir, char **envp)
  73 {
  74         char    sTmpName[1024];
  75         const char      *filename;
  76         void    *base;
  77         void    (*fEntry)(void *, int, char *[], char**);
  78
  79         DEBUGS("LoadLibrary: (SoName='%s', SearchDir='%s', envp=%p)", SoName, SearchDir, envp);
  80
  81         // Create Temp Name
  82         filename = FindLibrary(sTmpName, SoName, SearchDir);
  83         if(filename == NULL) {
  84                 DEBUGS("LoadLibrary: RETURN 0");
  85                 return 0;
  86         }
  87         DEBUGS(" LoadLibrary: filename='%s'", filename);
  88
  89         if( (base = IsFileLoaded(filename)) )
  90                 return base;
  91
  92         DEBUGS(" LoadLibrary: SysLoadBin()");
  93         // Load Library
  94         base = _SysLoadBin(filename, (void**)&fEntry);
  95         if(!base) {
  96                 DEBUGS("LoadLibrary: RETURN 0");
  97                 return 0;
  98         }
  99
 100         DEBUGS(" LoadLibrary: iArg=%p, fEntry=%p", base, fEntry);
 101
 102         // Load Symbols
 103         fEntry = DoRelocate( base, envp, filename );
 104         if( !fEntry ) {
 105                 return 0;
 106         }
 107
 108         // Call Entrypoint
 109         DEBUGS(" LoadLibrary: '%s' Entry %p", SoName, fEntry);
 110         fEntry(base, 0, NULL, gEnvP);
 111
 112         DEBUGS("LoadLibrary: RETURN 1");
 113         return base;
 114 }
 115
 116 /**
 117  * \fn Uint IsFileLoaded(char *file)
 118  * \brief Determine if a file is already loaded
 119  */
 120 void *IsFileLoaded(const char *file)
 121 {
 122          int    i;
 123         DEBUGS("IsFileLoaded: (file='%s')", file);
 124
 125         // Applications link against either libld-acess.so or ld-acess.so
 126         if( strcmp(file, "/Acess/Libs/libld-acess.so") == 0
 127          || strcmp(file, "/Acess/Libs/ld-acess.so") == 0 )
 128         {
 129                 DEBUGS("IsFileLoaded: Found local (%p)", &gLinkedBase);
 130                 return &gLinkedBase;
 131         }
 132
 133         for( i = 0; i < MAX_LOADED_LIBRARIES; i++ )
 134         {
 135                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL
 136                 DEBUGS(" strcmp('%s', '%s')", gLoadedLibraries[i].Name, file);
 137                 if(strcmp(gLoadedLibraries[i].Name, file) == 0) {
 138                         DEBUGS("IsFileLoaded: Found %i (%p)", i, gLoadedLibraries[i].Base);
 139                         return gLoadedLibraries[i].Base;
 140                 }
 141         }
 142         DEBUGS("IsFileLoaded: Not Found");
 143         return 0;
 144 }
 145
 146 /**
 147  * \fn void AddLoaded(char *File, Uint base)
 148  * \brief Add a file to the loaded list
 149  */
 150 void AddLoaded(const char *File, void *base)
 151 {
 152          int    i, length;
 153         char    *name = gsNextAvailString;
 154
 155         DEBUGS("AddLoaded: (File='%s', base=%p)", File, base);
 156
 157         // Find a free slot
 158         for( i = 0; i < MAX_LOADED_LIBRARIES; i ++ )
 159         {
 160                 if(gLoadedLibraries[i].Base == 0)       break;
 161         }
 162         if(i == MAX_LOADED_LIBRARIES) {
 163                 SysDebug("ERROR - ld-acess.so has run out of load slots!");
 164                 return;
 165         }
 166
 167         // Check space in string buffer
 168         length = strlen(File);
 169         if(&name[length+1] >= &gsLoadedStrings[MAX_STRINGS_BYTES]) {
 170                 SysDebug("ERROR - ld-acess.so has run out of string buffer memory!");
 171                 return;
 172         }
 173
 174         // Set information
 175         gLoadedLibraries[i].Base = base;
 176         strcpy(name, File);
 177         gLoadedLibraries[i].Name = name;
 178         gsNextAvailString = &name[length+1];
 179         DEBUGS("'%s' (%p) loaded as %i", name, base, i);
 180         return;
 181 }
 182
 183 /**
 184  * \fn void Unload(Uint Base)
 185  */
 186 void Unload(void *Base)
 187 {
 188          int    i, j;
 189          int    id;
 190         char    *str;
 191         for( id = 0; id < MAX_LOADED_LIBRARIES; id++ )
 192         {
 193                 if(gLoadedLibraries[id].Base == Base)   break;
 194         }
 195         if(id == MAX_LOADED_LIBRARIES)  return;
 196
 197         // Unload Binary
 198         _SysUnloadBin( Base );
 199         // Save String Pointer
 200         str = gLoadedLibraries[id].Name;
 201
 202         // Compact Loaded List
 203         j = id;
 204         for( i = j + 1; i < MAX_LOADED_LIBRARIES; i++, j++ )
 205         {
 206                 if(gLoadedLibraries[i].Base == 0)       break;
 207                 // Compact String
 208                 strcpy(str, gLoadedLibraries[i].Name);
 209                 str += strlen(str)+1;
 210                 // Compact Entry
 211                 gLoadedLibraries[j].Base = gLoadedLibraries[i].Base;
 212                 gLoadedLibraries[j].Name = str;
 213         }
 214
 215         // NULL Last Entry
 216         gLoadedLibraries[j].Base = 0;
 217         gLoadedLibraries[j].Name = NULL;
 218         // Save next string
 219         gsNextAvailString = str;
 220 }
 221
 222 /**
 223  \fn Uint GetSymbol(const char *name)
 224  \brief Gets a symbol value from a loaded library
 225 */
 226 int GetSymbol(const char *name, void **Value, size_t *Size)
 227 {
 228          int    i;
 229
 230         //SysDebug("ciNumLocalExports = %i", ciNumLocalExports);
 231         for(i=0;i<ciNumLocalExports;i++)
 232         {
 233                 if( strcmp(caLocalExports[i].Name, name) == 0 ) {
 234                         *Value = caLocalExports[i].Value;
 235                         if(Size)
 236                                 *Size = 0;
 237                         return 1;
 238                 }
 239         }
 240
 241         // Entry 0 is ld-acess, ignore it
 242         for(i = 0; i < MAX_LOADED_LIBRARIES; i ++)
 243         {
 244                 if(gLoadedLibraries[i].Base == 0)
 245                         break;
 246
 247                 //SysDebug(" GetSymbol: Trying 0x%x, '%s'",
 248                 //      gLoadedLibraries[i].Base, gLoadedLibraries[i].Name);
 249                 if(GetSymbolFromBase(gLoadedLibraries[i].Base, name, Value, Size))
 250                         return 1;
 251         }
 252         SysDebug("GetSymbol: === Symbol '%s' not found ===", name);
 253         return 0;
 254 }
 255
 256 /**
 257  \fn int GetSymbolFromBase(Uint base, char *name, Uint *ret)
 258  \breif Gets a symbol from a specified library
 259 */
 260 int GetSymbolFromBase(void *base, const char *name, void **ret, size_t *Size)
 261 {
 262         uint8_t *hdr = base;
 263         if(hdr[0] == 0x7F && hdr[1] == 'E' && hdr[2] == 'L' && hdr[3] == 'F')
 264                 return ElfGetSymbol(base, name, ret, Size);
 265         if(hdr[0] == 'M' && hdr[1] == 'Z')
 266                 return PE_GetSymbol(base, name, ret, Size);
 267         SysDebug("Unknown type at %p (%02x %02x %02x %02x)", base,
 268                 hdr[0], hdr[1], hdr[2], hdr[3]);
 269         return 0;
 270 }
 271