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

   1 /*
   2  AcessOS 1 - Dynamic Loader
   3  By thePowersGang
   4 */
   5 #include "common.h"
   6
   7 #define DEBUG   0
   8
   9 #if DEBUG
  10 # define DEBUGS(v...)   SysDebug(v)
  11 #else
  12 # define DEBUGS(v...)
  13 #endif
  14
  15 // === PROTOTYPES ===
  16 void    *IsFileLoaded(char *file);
  17  int    GetSymbolFromBase(void *base, const char *name, void **ret);
  18
  19 // === IMPORTS ===
  20 extern const struct {
  21         void    *Value;
  22         char    *Name;
  23 }       caLocalExports[];
  24 extern const int        ciNumLocalExports;
  25
  26 // === GLOABLS ===
  27 tLoadedLib      gLoadedLibraries[MAX_LOADED_LIBRARIES];
  28 char    gsLoadedStrings[MAX_STRINGS_BYTES];
  29 char    *gsNextAvailString = gsLoadedStrings;
  30 //tLoadLib      *gpLoadedLibraries = NULL;
  31
  32 // === CODE ===
  33 char *FindLibrary(char *DestBuf, char *SoName, char *ExtraSearchDir)
  34 {
  35         // -- #1: Executable Specified
  36         if(ExtraSearchDir)
  37         {
  38                 strcpy(DestBuf, ExtraSearchDir);
  39                 strcat(DestBuf, "/");
  40                 strcat(DestBuf, SoName);
  41                 if(file_exists(DestBuf))        return DestBuf;
  42         }
  43
  44         // -- #2: System
  45         strcpy(DestBuf, SYSTEM_LIB_DIR);
  46         strcat(DestBuf, SoName);
  47         if(file_exists(DestBuf))        return DestBuf;
  48
  49         // -- #3: Current Directory
  50         if(file_exists(SoName)) return SoName;
  51
  52         return NULL;
  53 }
  54
  55 /**
  56  */
  57 void *LoadLibrary(char *SoName, char *SearchDir, char **envp)
  58 {
  59         char    sTmpName[1024];
  60         char    *filename;
  61         void    *base;
  62         void    (*fEntry)(void *, int, char *[], char**);
  63
  64         DEBUGS("LoadLibrary: (filename='%s', envp=0x%x)\n", filename, envp);
  65
  66         // Create Temp Name
  67         filename = FindLibrary(sTmpName, SoName, SearchDir);
  68         if(filename == NULL) {
  69                 DEBUGS("LoadLibrary: RETURN 0\n");
  70                 return 0;
  71         }
  72         DEBUGS(" LoadLibrary: filename='%s'\n", filename);
  73
  74         if( (base = IsFileLoaded(filename)) )
  75                 return base;
  76
  77         // Load Library
  78         base = SysLoadBin(filename, (void**)&fEntry);
  79         if(!base) {
  80                 DEBUGS("LoadLibrary: RETURN 0\n");
  81                 return 0;
  82         }
  83
  84         DEBUGS(" LoadLibrary: iArg=%p, iEntry=0x%x\n", base, fEntry);
  85
  86         // Load Symbols
  87         fEntry = DoRelocate( base, envp, filename );
  88
  89         // Call Entrypoint
  90         DEBUGS(" LoadLibrary: '%s' Entry 0x%x\n", SoName, fEntry);
  91         fEntry(base, 0, NULL, envp);
  92
  93         DEBUGS("LoadLibrary: RETURN 1\n");
  94         return base;
  95 }
  96
  97 /**
  98  * \fn Uint IsFileLoaded(char *file)
  99  * \brief Determine if a file is already loaded
 100  */
 101 void *IsFileLoaded(char *file)
 102 {
 103          int    i;
 104         DEBUGS("IsFileLoaded: (file='%s')", file);
 105         for( i = 0; i < MAX_LOADED_LIBRARIES; i++ )
 106         {
 107                 if(gLoadedLibraries[i].Base == 0)       break;  // Last entry has Base set to NULL
 108                 DEBUGS(" strcmp('%s', '%s')", gLoadedLibraries[i].Name, file);
 109                 if(strcmp(gLoadedLibraries[i].Name, file) == 0) {
 110                         DEBUGS("IsFileLoaded: Found %i (0x%x)", i, gLoadedLibraries[i].Base);
 111                         return gLoadedLibraries[i].Base;
 112                 }
 113         }
 114         DEBUGS("IsFileLoaded: Not Found");
 115         return 0;
 116 }
 117
 118 /**
 119  * \fn void AddLoaded(char *File, Uint base)
 120  * \brief Add a file to the loaded list
 121  */
 122 void AddLoaded(char *File, void *base)
 123 {
 124          int    i, length;
 125         char    *name = gsNextAvailString;
 126
 127         DEBUGS("AddLoaded: (File='%s', base=0x%x)", File, base);
 128
 129         // Find a free slot
 130         for( i = 0; i < MAX_LOADED_LIBRARIES; i ++ )
 131         {
 132                 if(gLoadedLibraries[i].Base == 0)       break;
 133         }
 134         if(i == MAX_LOADED_LIBRARIES) {
 135                 SysDebug("ERROR - ld-acess.so has run out of load slots!");
 136                 return;
 137         }
 138
 139         // Check space in string buffer
 140         length = strlen(File);
 141         if(&name[length+1] >= &gsLoadedStrings[MAX_STRINGS_BYTES]) {
 142                 SysDebug("ERROR - ld-acess.so has run out of string buffer memory!");
 143                 return;
 144         }
 145
 146         // Set information
 147         gLoadedLibraries[i].Base = base;
 148         strcpy(name, File);
 149         gLoadedLibraries[i].Name = name;
 150         gsNextAvailString = &name[length+1];
 151         DEBUGS("'%s' (0x%x) loaded as %i\n", name, base, i);
 152         return;
 153 }
 154
 155 /**
 156  * \fn void Unload(Uint Base)
 157  */
 158 void Unload(void *Base)
 159 {
 160          int    i, j;
 161          int    id;
 162         char    *str;
 163         for( id = 0; id < MAX_LOADED_LIBRARIES; id++ )
 164         {
 165                 if(gLoadedLibraries[id].Base == Base)   break;
 166         }
 167         if(id == MAX_LOADED_LIBRARIES)  return;
 168
 169         // Unload Binary
 170         SysUnloadBin( Base );
 171         // Save String Pointer
 172         str = gLoadedLibraries[id].Name;
 173
 174         // Compact Loaded List
 175         j = id;
 176         for( i = j + 1; i < MAX_LOADED_LIBRARIES; i++, j++ )
 177         {
 178                 if(gLoadedLibraries[i].Base == 0)       break;
 179                 // Compact String
 180                 strcpy(str, gLoadedLibraries[i].Name);
 181                 str += strlen(str)+1;
 182                 // Compact Entry
 183                 gLoadedLibraries[j].Base = gLoadedLibraries[i].Base;
 184                 gLoadedLibraries[j].Name = str;
 185         }
 186
 187         // NULL Last Entry
 188         gLoadedLibraries[j].Base = 0;
 189         gLoadedLibraries[j].Name = NULL;
 190         // Save next string
 191         gsNextAvailString = str;
 192 }
 193
 194 /**
 195  \fn Uint GetSymbol(const char *name)
 196  \brief Gets a symbol value from a loaded library
 197 */
 198 void *GetSymbol(const char *name)
 199 {
 200          int    i;
 201         void    *ret;
 202
 203         //SysDebug("ciNumLocalExports = %i", ciNumLocalExports);
 204         for(i=0;i<ciNumLocalExports;i++)
 205         {
 206                 if( strcmp(caLocalExports[i].Name, name) == 0 )
 207                         return caLocalExports[i].Value;
 208         }
 209
 210         // Entry 0 is ld-acess, ignore it
 211         for(i = 1; i < MAX_LOADED_LIBRARIES; i ++)
 212         {
 213                 if(gLoadedLibraries[i].Base == 0)       break;
 214
 215                 //SysDebug(" GetSymbol: Trying 0x%x, '%s'",
 216                 //      gLoadedLibraries[i].Base, gLoadedLibraries[i].Name);
 217                 if(GetSymbolFromBase(gLoadedLibraries[i].Base, name, &ret))     return ret;
 218         }
 219         SysDebug("GetSymbol: === Symbol '%s' not found ===", name);
 220         return 0;
 221 }
 222
 223 /**
 224  \fn int GetSymbolFromBase(Uint base, char *name, Uint *ret)
 225  \breif Gets a symbol from a specified library
 226 */
 227 int GetSymbolFromBase(void *base, const char *name, void **ret)
 228 {
 229         if(*(Uint32*)base == (0x7F|('E'<<8)|('L'<<16)|('F'<<24)))
 230                 return ElfGetSymbol(base, name, ret);
 231         if(*(Uint16*)base == ('M'|('Z'<<8)))
 232                 return PE_GetSymbol(base, name, ret);
 233         SysDebug("Unknown type at %p", base);
 234         return 0;
 235 }
 236