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