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 #define MAX_QUEUED_ENTRYPOINTS  8
  18
  19 // === IMPORTS ===
  20 extern const struct {
  21         void    *Value;
  22         char    *Name;
  23 }       caLocalExports[];
  24 extern const int        ciNumLocalExports;
  25 extern char     **gEnvP;
  26 extern char     gLinkedBase[];
  27
  28 // === TYPES ===
  29 typedef void    tLibEntry(void *, int, char *[], char**);
  30
  31 // === PROTOTYPES ===
  32 void    *IsFileLoaded(const char *file);
  33
  34 // === GLOABLS ===
  35 tLoadedLib      gLoadedLibraries[MAX_LOADED_LIBRARIES];
  36 char    gsLoadedStrings[MAX_STRINGS_BYTES];
  37 char    *gsNextAvailString = gsLoadedStrings;
  38 struct sQueuedEntry {
  39         void    *Base;
  40         tLibEntry       *Entry;
  41 }       gaQueuedEntrypoints[MAX_QUEUED_ENTRYPOINTS];
  42  int    giNumQueuedEntrypoints;
  43 //tLoadLib      *gpLoadedLibraries = NULL;
  44
  45 // === CODE ===
  46 void ldacess_DumpLoadedLibraries(void)
  47 {
  48         for( int i = 0; i < MAX_LOADED_LIBRARIES; i ++ )
  49         {
  50                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL
  51                 _SysDebug("%p: %s",
  52                         gLoadedLibraries[i].Base,
  53                         gLoadedLibraries[i].Name
  54                         );
  55         }
  56 }
  57
  58 /**
  59  * \brief Call queued up entry points (after relocations completed)
  60  */
  61 void CallQueuedEntrypoints(char **EnvP)
  62 {
  63         while( giNumQueuedEntrypoints )
  64         {
  65                 giNumQueuedEntrypoints --;
  66                 const struct sQueuedEntry       *qe = &gaQueuedEntrypoints[giNumQueuedEntrypoints];
  67                 //_SysDebug("Calling EP for %p", qe->Base);
  68                 qe->Entry(qe->Base, 0, NULL, EnvP);
  69         }
  70 }
  71
  72 const char *FindLibrary(char *DestBuf, const char *SoName, const char *ExtraSearchDir)
  73 {
  74         // -- #1: Executable Specified
  75         if(ExtraSearchDir)
  76         {
  77                 strcpy(DestBuf, ExtraSearchDir);
  78                 strcat(DestBuf, "/");
  79                 strcat(DestBuf, SoName);
  80                 if(file_exists(DestBuf))        return DestBuf;
  81         }
  82
  83         // -- #2: System
  84         strcpy(DestBuf, SYSTEM_LIB_DIR);
  85         strcat(DestBuf, SoName);
  86         if(file_exists(DestBuf))        return DestBuf;
  87
  88         // -- #3: Current Directory
  89         if(file_exists(SoName)) return SoName;
  90
  91         return NULL;
  92 }
  93
  94 /**
  95  */
  96 void *LoadLibrary(const char *SoName, const char *SearchDir, char **envp)
  97 {
  98         char    sTmpName[1024];
  99         void    *base;
 100
 101         DEBUGS("LoadLibrary: (SoName='%s', SearchDir='%s', envp=%p)", SoName, SearchDir, envp);
 102
 103         // Create Temp Name
 104         const char *filename = FindLibrary(sTmpName, SoName, SearchDir);
 105         if(filename == NULL) {
 106                 DEBUGS("LoadLibrary: RETURN 0");
 107                 return 0;
 108         }
 109         DEBUGS(" LoadLibrary: filename='%s'", filename);
 110
 111         if( (base = IsFileLoaded(filename)) )
 112                 return base;
 113
 114         DEBUGS(" LoadLibrary: SysLoadBin()");
 115         // Load Library
 116         tLibEntry       *fEntry;
 117         base = _SysLoadBin(filename, (void**)&fEntry);
 118         if(!base) {
 119                 DEBUGS("LoadLibrary: RETURN 0");
 120                 return 0;
 121         }
 122
 123         DEBUGS(" LoadLibrary: iArg=%p, fEntry=%p", base, fEntry);
 124
 125         // Load Symbols
 126         fEntry = DoRelocate( base, envp, filename );
 127         if( !fEntry ) {
 128                 return 0;
 129         }
 130
 131         // Call Entrypoint
 132         // - TODO: Queue entrypoint calls
 133         if( giNumQueuedEntrypoints >= MAX_QUEUED_ENTRYPOINTS ) {
 134                 SysDebug("ERROR - Maximum number of queued entrypoints exceeded on %p '%s'",
 135                         base, SoName);
 136                 return 0;
 137         }
 138         gaQueuedEntrypoints[giNumQueuedEntrypoints].Base  = base;
 139         gaQueuedEntrypoints[giNumQueuedEntrypoints].Entry = fEntry;
 140         giNumQueuedEntrypoints ++;
 141
 142         DEBUGS("LoadLibrary: RETURN success");
 143         return base;
 144 }
 145
 146 /**
 147  * \fn Uint IsFileLoaded(char *file)
 148  * \brief Determine if a file is already loaded
 149  */
 150 void *IsFileLoaded(const char *file)
 151 {
 152          int    i;
 153         DEBUGS("IsFileLoaded: (file='%s')", file);
 154
 155         // Applications link against either libld-acess.so or ld-acess.so
 156         if( strcmp(file, "/Acess/Libs/libld-acess.so") == 0
 157          || strcmp(file, "/Acess/Libs/ld-acess.so") == 0 )
 158         {
 159                 DEBUGS("IsFileLoaded: Found local (%p)", &gLinkedBase);
 160                 return &gLinkedBase;
 161         }
 162
 163         for( i = 0; i < MAX_LOADED_LIBRARIES; i++ )
 164         {
 165                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL
 166                 DEBUGS(" strcmp('%s', '%s')", gLoadedLibraries[i].Name, file);
 167                 if(strcmp(gLoadedLibraries[i].Name, file) == 0) {
 168                         DEBUGS("IsFileLoaded: Found %i (%p)", i, gLoadedLibraries[i].Base);
 169                         return gLoadedLibraries[i].Base;
 170                 }
 171         }
 172         DEBUGS("IsFileLoaded: Not Found");
 173         return 0;
 174 }
 175
 176 /**
 177  * \fn void AddLoaded(char *File, Uint base)
 178  * \brief Add a file to the loaded list
 179  */
 180 void AddLoaded(const char *File, void *base)
 181 {
 182          int    i, length;
 183         char    *name = gsNextAvailString;
 184
 185         DEBUGS("AddLoaded: (File='%s', base=%p)", File, base);
 186
 187         // Find a free slot
 188         for( i = 0; i < MAX_LOADED_LIBRARIES; i ++ )
 189         {
 190                 if(gLoadedLibraries[i].Base == 0)       break;
 191         }
 192         if(i == MAX_LOADED_LIBRARIES) {
 193                 SysDebug("ERROR - ld-acess.so has run out of load slots!");
 194                 return;
 195         }
 196
 197         // Check space in string buffer
 198         length = strlen(File);
 199         if(&name[length+1] >= &gsLoadedStrings[MAX_STRINGS_BYTES]) {
 200                 SysDebug("ERROR - ld-acess.so has run out of string buffer memory!");
 201                 return;
 202         }
 203
 204         // Set information
 205         gLoadedLibraries[i].Base = base;
 206         strcpy(name, File);
 207         gLoadedLibraries[i].Name = name;
 208         gsNextAvailString = &name[length+1];
 209         DEBUGS("'%s' (%p) loaded as %i", name, base, i);
 210         return;
 211 }
 212
 213 /**
 214  * \fn void Unload(Uint Base)
 215  */
 216 void Unload(void *Base)
 217 {
 218          int    i, j;
 219          int    id;
 220         char    *str;
 221         for( id = 0; id < MAX_LOADED_LIBRARIES; id++ )
 222         {
 223                 if(gLoadedLibraries[id].Base == Base)   break;
 224         }
 225         if(id == MAX_LOADED_LIBRARIES)  return;
 226
 227         // Unload Binary
 228         _SysUnloadBin( Base );
 229         // Save String Pointer
 230         str = gLoadedLibraries[id].Name;
 231
 232         // Compact Loaded List
 233         j = id;
 234         for( i = j + 1; i < MAX_LOADED_LIBRARIES; i++, j++ )
 235         {
 236                 if(gLoadedLibraries[i].Base == 0)       break;
 237                 // Compact String
 238                 strcpy(str, gLoadedLibraries[i].Name);
 239                 str += strlen(str)+1;
 240                 // Compact Entry
 241                 gLoadedLibraries[j].Base = gLoadedLibraries[i].Base;
 242                 gLoadedLibraries[j].Name = str;
 243         }
 244
 245         // NULL Last Entry
 246         gLoadedLibraries[j].Base = 0;
 247         gLoadedLibraries[j].Name = NULL;
 248         // Save next string
 249         gsNextAvailString = str;
 250 }
 251
 252 /**
 253  \fn Uint GetSymbol(const char *name)
 254  \brief Gets a symbol value from a loaded library
 255 */
 256 int GetSymbol(const char *name, void **Value, size_t *Size, void *IgnoreBase)
 257 {
 258         //SysDebug("GetSymbol: (%s)");
 259         for( int i = 0; i < ciNumLocalExports; i ++ )
 260         {
 261                 if( strcmp(caLocalExports[i].Name, name) == 0 ) {
 262                         *Value = caLocalExports[i].Value;
 263                         if(Size)
 264                                 *Size = 0;
 265                         //SysDebug("GetSymbol: Local %p+0x%x", *Value, 0);
 266                         return 1;
 267                 }
 268         }
 269
 270         for(int i = 0; i < MAX_LOADED_LIBRARIES && gLoadedLibraries[i].Base != 0; i ++)
 271         {
 272                 // Allow ignoring the current module
 273                 if( gLoadedLibraries[i].Base == IgnoreBase ) {
 274                         //SysDebug("GetSymbol: Ignore %p", gLoadedLibraries[i].Base);
 275                         continue ;
 276                 }
 277
 278                 //SysDebug(" GetSymbol: Trying 0x%x, '%s'",
 279                 //      gLoadedLibraries[i].Base, gLoadedLibraries[i].Name);
 280                 if(GetSymbolFromBase(gLoadedLibraries[i].Base, name, Value, Size)) {
 281                         //SysDebug("GetSymbol: Remote %p - %p", gLoadedLibraries[i].Base, *Value);
 282                         return 1;
 283                 }
 284         }
 285         //SysDebug("GetSymbol: None");
 286         return 0;
 287 }
 288
 289 /**
 290  \fn int GetSymbolFromBase(Uint base, char *name, Uint *ret)
 291  \breif Gets a symbol from a specified library
 292 */
 293 int GetSymbolFromBase(void *base, const char *name, void **ret, size_t *Size)
 294 {
 295         uint8_t *hdr = base;
 296         if(hdr[0] == 0x7F && hdr[1] == 'E' && hdr[2] == 'L' && hdr[3] == 'F')
 297                 return ElfGetSymbol(base, name, ret, Size);
 298         if(hdr[0] == 'M' && hdr[1] == 'Z')
 299                 return PE_GetSymbol(base, name, ret, Size);
 300         SysDebug("Unknown type at %p (%02x %02x %02x %02x)", base,
 301                 hdr[0], hdr[1], hdr[2], hdr[3]);
 302         return 0;
 303 }
 304