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