libs/wine/loader.c

   1 /*
   2  * Win32 builtin dlls support
   3  *
   4  * Copyright 2000 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <ctype.h>
  26 #include <fcntl.h>
  27 #include <limits.h>
  28 #include <stdarg.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <sys/types.h>
  32 #ifdef HAVE_SYS_MMAN_H
  33 #include <sys/mman.h>
  34 #endif
  35 #ifdef HAVE_SYS_RESOURCE_H
  36 # include <sys/resource.h>
  37 #endif
  38 #ifdef HAVE_UNISTD_H
  39 # include <unistd.h>
  40 #endif
  41
  42 #define NONAMELESSUNION
  43 #define NONAMELESSSTRUCT
  44 #include "windef.h"
  45 #include "winbase.h"
  46 #include "wine/library.h"
  47
  48 #ifdef __APPLE__
  49 #include <crt_externs.h>
  50 #define environ (*_NSGetEnviron())
  51 #else
  52 extern char **environ;
  53 #endif
  54
  55 /* argc/argv for the Windows application */
  56 int __wine_main_argc = 0;
  57 char **__wine_main_argv = NULL;
  58 WCHAR **__wine_main_wargv = NULL;
  59 char **__wine_main_environ = NULL;
  60
  61 struct dll_path_context
  62 {
  63     unsigned int index; /* current index in the dll path list */
  64     char *buffer;       /* buffer used for storing path names */
  65     char *name;         /* start of file name part in buffer (including leading slash) */
  66     int   namelen;      /* length of file name without .so extension */
  67     int   win16;        /* 16-bit dll search */
  68 };
  69
  70 #define MAX_DLLS 100
  71
  72 static struct
  73 {
  74     const IMAGE_NT_HEADERS *nt;           /* NT header */
  75     const char             *filename;     /* DLL file name */
  76 } builtin_dlls[MAX_DLLS];
  77
  78 static int nb_dlls;
  79
  80 static const IMAGE_NT_HEADERS *main_exe;
  81
  82 static load_dll_callback_t load_dll_callback;
  83
  84 static const char *build_dir;
  85 static const char *default_dlldir;
  86 static const char **dll_paths;
  87 static unsigned int nb_dll_paths;
  88 static int dll_path_maxlen;
  89
  90 extern void mmap_init(void);
  91 extern const char *get_dlldir( const char **default_dlldir );
  92
  93 /* build the dll load path from the WINEDLLPATH variable */
  94 static void build_dll_path(void)
  95 {
  96     int len, count = 0;
  97     char *p, *path = getenv( "WINEDLLPATH" );
  98     const char *dlldir = get_dlldir( &default_dlldir );
  99
 100     if (path)
 101     {
 102         /* count how many path elements we need */
 103         path = strdup(path);
 104         p = path;
 105         while (*p)
 106         {
 107             while (*p == ':') p++;
 108             if (!*p) break;
 109             count++;
 110             while (*p && *p != ':') p++;
 111         }
 112     }
 113
 114     dll_paths = malloc( (count+2) * sizeof(*dll_paths) );
 115     nb_dll_paths = 0;
 116
 117     if (dlldir)
 118     {
 119         dll_path_maxlen = strlen(dlldir);
 120         dll_paths[nb_dll_paths++] = dlldir;
 121     }
 122     else if ((build_dir = wine_get_build_dir()))
 123     {
 124         dll_path_maxlen = strlen(build_dir) + sizeof("/programs");
 125     }
 126
 127     if (count)
 128     {
 129         p = path;
 130         while (*p)
 131         {
 132             while (*p == ':') *p++ = 0;
 133             if (!*p) break;
 134             dll_paths[nb_dll_paths] = p;
 135             while (*p && *p != ':') p++;
 136             if (p - dll_paths[nb_dll_paths] > dll_path_maxlen)
 137                 dll_path_maxlen = p - dll_paths[nb_dll_paths];
 138             nb_dll_paths++;
 139         }
 140     }
 141
 142     /* append default dll dir (if not empty) to path */
 143     if ((len = strlen(default_dlldir)) > 0)
 144     {
 145         if (len > dll_path_maxlen) dll_path_maxlen = len;
 146         dll_paths[nb_dll_paths++] = default_dlldir;
 147     }
 148 }
 149
 150 /* check if a given file can be opened */
 151 static inline int file_exists( const char *name )
 152 {
 153     int fd = open( name, O_RDONLY );
 154     if (fd != -1) close( fd );
 155     return (fd != -1);
 156 }
 157
 158 static inline char *prepend( char *buffer, const char *str, size_t len )
 159 {
 160     return memcpy( buffer - len, str, len );
 161 }
 162
 163 /* get a filename from the next entry in the dll path */
 164 static char *next_dll_path( struct dll_path_context *context )
 165 {
 166     unsigned int index = context->index++;
 167     int namelen = context->namelen;
 168     char *path = context->name;
 169
 170     switch(index)
 171     {
 172     case 0:  /* try dlls dir with subdir prefix */
 173         if (namelen > 4 && !memcmp( context->name + namelen - 4, ".dll", 4 )) namelen -= 4;
 174         if (!context->win16) path = prepend( path, context->name, namelen );
 175         path = prepend( path, "/dlls", sizeof("/dlls") - 1 );
 176         path = prepend( path, build_dir, strlen(build_dir) );
 177         return path;
 178     case 1:  /* try programs dir with subdir prefix */
 179         if (!context->win16)
 180         {
 181             if (namelen > 4 && !memcmp( context->name + namelen - 4, ".exe", 4 )) namelen -= 4;
 182             path = prepend( path, context->name, namelen );
 183             path = prepend( path, "/programs", sizeof("/programs") - 1 );
 184             path = prepend( path, build_dir, strlen(build_dir) );
 185             return path;
 186         }
 187         context->index++;
 188         /* fall through */
 189     default:
 190         index -= 2;
 191         if (index < nb_dll_paths)
 192             return prepend( context->name, dll_paths[index], strlen( dll_paths[index] ));
 193         break;
 194     }
 195     return NULL;
 196 }
 197
 198
 199 /* get a filename from the first entry in the dll path */
 200 static char *first_dll_path( const char *name, int win16, struct dll_path_context *context )
 201 {
 202     char *p;
 203     int namelen = strlen( name );
 204     const char *ext = win16 ? "16" : ".so";
 205
 206     context->buffer = malloc( dll_path_maxlen + 2 * namelen + strlen(ext) + 3 );
 207     context->index = build_dir ? 0 : 2;  /* if no build dir skip all the build dir magic cases */
 208     context->name = context->buffer + dll_path_maxlen + namelen + 1;
 209     context->namelen = namelen + 1;
 210     context->win16 = win16;
 211
 212     /* store the name at the end of the buffer, followed by extension */
 213     p = context->name;
 214     *p++ = '/';
 215     memcpy( p, name, namelen );
 216     strcpy( p + namelen, ext );
 217     return next_dll_path( context );
 218 }
 219
 220
 221 /* free the dll path context created by first_dll_path */
 222 static inline void free_dll_path( struct dll_path_context *context )
 223 {
 224     free( context->buffer );
 225 }
 226
 227
 228 /* open a library for a given dll, searching in the dll path
 229  * 'name' must be the Windows dll name (e.g. "kernel32.dll") */
 230 static void *dlopen_dll( const char *name, char *error, int errorsize,
 231                          int test_only, int *exists )
 232 {
 233     struct dll_path_context context;
 234     char *path;
 235     void *ret = NULL;
 236
 237     *exists = 0;
 238     for (path = first_dll_path( name, 0, &context ); path; path = next_dll_path( &context ))
 239     {
 240         if (!test_only && (ret = wine_dlopen( path, RTLD_NOW, error, errorsize ))) break;
 241         if ((*exists = file_exists( path ))) break; /* exists but cannot be loaded, return the error */
 242     }
 243     free_dll_path( &context );
 244     return ret;
 245 }
 246
 247
 248 /* adjust an array of pointers to make them into RVAs */
 249 static inline void fixup_rva_ptrs( void *array, BYTE *base, unsigned int count )
 250 {
 251     void **src = (void **)array;
 252     DWORD *dst = (DWORD *)array;
 253     while (count--)
 254     {
 255         *dst++ = *src ? (BYTE *)*src - base : 0;
 256         src++;
 257     }
 258 }
 259
 260 /* fixup an array of RVAs by adding the specified delta */
 261 static inline void fixup_rva_dwords( DWORD *ptr, int delta, unsigned int count )
 262 {
 263     while (count--)
 264     {
 265         if (*ptr) *ptr += delta;
 266         ptr++;
 267     }
 268 }
 269
 270
 271 /* fixup RVAs in the import directory */
 272 static void fixup_imports( IMAGE_IMPORT_DESCRIPTOR *dir, BYTE *base, int delta )
 273 {
 274     UINT_PTR *ptr;
 275
 276     while (dir->Name)
 277     {
 278         fixup_rva_dwords( &dir->u.OriginalFirstThunk, delta, 1 );
 279         fixup_rva_dwords( &dir->Name, delta, 1 );
 280         fixup_rva_dwords( &dir->FirstThunk, delta, 1 );
 281         ptr = (UINT_PTR *)(base + (dir->u.OriginalFirstThunk ? dir->u.OriginalFirstThunk : dir->FirstThunk));
 282         while (*ptr)
 283         {
 284             if (!(*ptr & IMAGE_ORDINAL_FLAG)) *ptr += delta;
 285             ptr++;
 286         }
 287         dir++;
 288     }
 289 }
 290
 291
 292 /* fixup RVAs in the export directory */
 293 static void fixup_exports( IMAGE_EXPORT_DIRECTORY *dir, BYTE *base, int delta )
 294 {
 295     fixup_rva_dwords( &dir->Name, delta, 1 );
 296     fixup_rva_dwords( &dir->AddressOfFunctions, delta, 1 );
 297     fixup_rva_dwords( &dir->AddressOfNames, delta, 1 );
 298     fixup_rva_dwords( &dir->AddressOfNameOrdinals, delta, 1 );
 299     fixup_rva_dwords( (DWORD *)(base + dir->AddressOfNames), delta, dir->NumberOfNames );
 300     fixup_rva_ptrs( (base + dir->AddressOfFunctions), base, dir->NumberOfFunctions );
 301 }
 302
 303
 304 /* fixup RVAs in the resource directory */
 305 static void fixup_resources( IMAGE_RESOURCE_DIRECTORY *dir, BYTE *root, int delta )
 306 {
 307     IMAGE_RESOURCE_DIRECTORY_ENTRY *entry;
 308     int i;
 309
 310     entry = (IMAGE_RESOURCE_DIRECTORY_ENTRY *)(dir + 1);
 311     for (i = 0; i < dir->NumberOfNamedEntries + dir->NumberOfIdEntries; i++, entry++)
 312     {
 313         void *ptr = root + entry->u2.s3.OffsetToDirectory;
 314         if (entry->u2.s3.DataIsDirectory) fixup_resources( ptr, root, delta );
 315         else
 316         {
 317             IMAGE_RESOURCE_DATA_ENTRY *data = ptr;
 318             fixup_rva_dwords( &data->OffsetToData, delta, 1 );
 319         }
 320     }
 321 }
 322
 323
 324 /* map a builtin dll in memory and fixup RVAs */
 325 static void *map_dll( const IMAGE_NT_HEADERS *nt_descr )
 326 {
 327 #ifdef HAVE_MMAP
 328     IMAGE_DATA_DIRECTORY *dir;
 329     IMAGE_DOS_HEADER *dos;
 330     IMAGE_NT_HEADERS *nt;
 331     IMAGE_SECTION_HEADER *sec;
 332     BYTE *addr;
 333     DWORD code_start, data_start, data_end;
 334     const size_t page_size = getpagesize();
 335     const size_t page_mask = page_size - 1;
 336     int delta, nb_sections = 2;  /* code + data */
 337     unsigned int i;
 338
 339     size_t size = (sizeof(IMAGE_DOS_HEADER)
 340                    + sizeof(IMAGE_NT_HEADERS)
 341                    + nb_sections * sizeof(IMAGE_SECTION_HEADER));
 342
 343     assert( size <= page_size );
 344
 345     /* module address must be aligned on 64K boundary */
 346     addr = (BYTE *)((nt_descr->OptionalHeader.ImageBase + 0xffff) & ~0xffff);
 347     if (wine_anon_mmap( addr, page_size, PROT_READ|PROT_WRITE, MAP_FIXED ) != addr) return NULL;
 348
 349     dos    = (IMAGE_DOS_HEADER *)addr;
 350     nt     = (IMAGE_NT_HEADERS *)(dos + 1);
 351     sec    = (IMAGE_SECTION_HEADER *)(nt + 1);
 352
 353     /* Build the DOS and NT headers */
 354
 355     dos->e_magic    = IMAGE_DOS_SIGNATURE;
 356     dos->e_cblp     = 0x90;
 357     dos->e_cp       = 3;
 358     dos->e_cparhdr  = (sizeof(*dos)+0xf)/0x10;
 359     dos->e_minalloc = 0;
 360     dos->e_maxalloc = 0xffff;
 361     dos->e_ss       = 0x0000;
 362     dos->e_sp       = 0x00b8;
 363     dos->e_lfarlc   = sizeof(*dos);
 364     dos->e_lfanew   = sizeof(*dos);
 365
 366     *nt = *nt_descr;
 367
 368     delta      = (const BYTE *)nt_descr - addr;
 369     code_start = page_size;
 370     data_start = delta & ~page_mask;
 371     data_end   = (nt->OptionalHeader.SizeOfImage + delta + page_mask) & ~page_mask;
 372
 373     fixup_rva_ptrs( &nt->OptionalHeader.AddressOfEntryPoint, addr, 1 );
 374
 375     nt->FileHeader.NumberOfSections                = nb_sections;
 376     nt->OptionalHeader.BaseOfCode                  = code_start;
 377 #ifndef _WIN64
 378     nt->OptionalHeader.BaseOfData                  = data_start;
 379 #endif
 380     nt->OptionalHeader.SizeOfCode                  = data_start - code_start;
 381     nt->OptionalHeader.SizeOfInitializedData       = data_end - data_start;
 382     nt->OptionalHeader.SizeOfUninitializedData     = 0;
 383     nt->OptionalHeader.SizeOfImage                 = data_end;
 384     nt->OptionalHeader.ImageBase                   = (ULONG_PTR)addr;
 385
 386     /* Build the code section */
 387
 388     memcpy( sec->Name, ".text", sizeof(".text") );
 389     sec->SizeOfRawData = data_start - code_start;
 390     sec->Misc.VirtualSize = sec->SizeOfRawData;
 391     sec->VirtualAddress   = code_start;
 392     sec->PointerToRawData = code_start;
 393     sec->Characteristics  = (IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ);
 394     sec++;
 395
 396     /* Build the data section */
 397
 398     memcpy( sec->Name, ".data", sizeof(".data") );
 399     sec->SizeOfRawData = data_end - data_start;
 400     sec->Misc.VirtualSize = sec->SizeOfRawData;
 401     sec->VirtualAddress   = data_start;
 402     sec->PointerToRawData = data_start;
 403     sec->Characteristics  = (IMAGE_SCN_CNT_INITIALIZED_DATA |
 404                              IMAGE_SCN_MEM_WRITE | IMAGE_SCN_MEM_READ);
 405     sec++;
 406
 407     for (i = 0; i < nt->OptionalHeader.NumberOfRvaAndSizes; i++)
 408         fixup_rva_dwords( &nt->OptionalHeader.DataDirectory[i].VirtualAddress, delta, 1 );
 409
 410     /* Build the import directory */
 411
 412     dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_IMPORT_DIRECTORY];
 413     if (dir->Size)
 414     {
 415         IMAGE_IMPORT_DESCRIPTOR *imports = (void *)(addr + dir->VirtualAddress);
 416         fixup_imports( imports, addr, delta );
 417     }
 418
 419     /* Build the resource directory */
 420
 421     dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_RESOURCE_DIRECTORY];
 422     if (dir->Size)
 423     {
 424         void *ptr = (void *)(addr + dir->VirtualAddress);
 425         fixup_resources( ptr, ptr, delta );
 426     }
 427
 428     /* Build the export directory */
 429
 430     dir = &nt->OptionalHeader.DataDirectory[IMAGE_FILE_EXPORT_DIRECTORY];
 431     if (dir->Size)
 432     {
 433         IMAGE_EXPORT_DIRECTORY *exports = (void *)(addr + dir->VirtualAddress);
 434         fixup_exports( exports, addr, delta );
 435     }
 436     return addr;
 437 #else  /* HAVE_MMAP */
 438     return NULL;
 439 #endif  /* HAVE_MMAP */
 440 }
 441
 442
 443 /***********************************************************************
 444  *           __wine_get_main_environment
 445  *
 446  * Return an environment pointer to work around lack of environ variable.
 447  * Only exported on Mac OS.
 448  */
 449 char **__wine_get_main_environment(void)
 450 {
 451     return environ;
 452 }
 453
 454
 455 /***********************************************************************
 456  *           __wine_dll_register
 457  *
 458  * Register a built-in DLL descriptor.
 459  */
 460 void __wine_dll_register( const IMAGE_NT_HEADERS *header, const char *filename )
 461 {
 462     if (load_dll_callback) load_dll_callback( map_dll(header), filename );
 463     else
 464     {
 465         if (!(header->FileHeader.Characteristics & IMAGE_FILE_DLL))
 466             main_exe = header;
 467         else
 468         {
 469             assert( nb_dlls < MAX_DLLS );
 470             builtin_dlls[nb_dlls].nt = header;
 471             builtin_dlls[nb_dlls].filename = filename;
 472             nb_dlls++;
 473         }
 474     }
 475 }
 476
 477
 478 /***********************************************************************
 479  *           wine_dll_set_callback
 480  *
 481  * Set the callback function for dll loading, and call it
 482  * for all dlls that were implicitly loaded already.
 483  */
 484 void wine_dll_set_callback( load_dll_callback_t load )
 485 {
 486     int i;
 487     load_dll_callback = load;
 488     for (i = 0; i < nb_dlls; i++)
 489     {
 490         const IMAGE_NT_HEADERS *nt = builtin_dlls[i].nt;
 491         if (!nt) continue;
 492         builtin_dlls[i].nt = NULL;
 493         load_dll_callback( map_dll(nt), builtin_dlls[i].filename );
 494     }
 495     nb_dlls = 0;
 496     if (main_exe) load_dll_callback( map_dll(main_exe), "" );
 497 }
 498
 499
 500 /***********************************************************************
 501  *           wine_dll_load
 502  *
 503  * Load a builtin dll.
 504  */
 505 void *wine_dll_load( const char *filename, char *error, int errorsize, int *file_exists )
 506 {
 507     int i;
 508
 509     /* callback must have been set already */
 510     assert( load_dll_callback );
 511
 512     /* check if we have it in the list */
 513     /* this can happen when initializing pre-loaded dlls in wine_dll_set_callback */
 514     for (i = 0; i < nb_dlls; i++)
 515     {
 516         if (!builtin_dlls[i].nt) continue;
 517         if (!strcmp( builtin_dlls[i].filename, filename ))
 518         {
 519             const IMAGE_NT_HEADERS *nt = builtin_dlls[i].nt;
 520             builtin_dlls[i].nt = NULL;
 521             load_dll_callback( map_dll(nt), builtin_dlls[i].filename );
 522             *file_exists = 1;
 523             return (void *)1;
 524         }
 525     }
 526     return dlopen_dll( filename, error, errorsize, 0, file_exists );
 527 }
 528
 529
 530 /***********************************************************************
 531  *           wine_dll_unload
 532  *
 533  * Unload a builtin dll.
 534  */
 535 void wine_dll_unload( void *handle )
 536 {
 537     if (handle != (void *)1)
 538         wine_dlclose( handle, NULL, 0 );
 539 }
 540
 541
 542 /***********************************************************************
 543  *           wine_dll_load_main_exe
 544  *
 545  * Try to load the .so for the main exe.
 546  */
 547 void *wine_dll_load_main_exe( const char *name, char *error, int errorsize,
 548                               int test_only, int *file_exists )
 549 {
 550     return dlopen_dll( name, error, errorsize, test_only, file_exists );
 551 }
 552
 553
 554 /***********************************************************************
 555  *           wine_dll_enum_load_path
 556  *
 557  * Enumerate the dll load path.
 558  */
 559 const char *wine_dll_enum_load_path( unsigned int index )
 560 {
 561     if (index >= nb_dll_paths) return NULL;
 562     return dll_paths[index];
 563 }
 564
 565
 566 /***********************************************************************
 567  *           wine_dll_get_owner
 568  *
 569  * Retrieve the name of the 32-bit owner dll for a 16-bit dll.
 570  * Return 0 if OK, -1 on error.
 571  */
 572 int wine_dll_get_owner( const char *name, char *buffer, int size, int *exists )
 573 {
 574     int ret = -1;
 575     char *path;
 576     struct dll_path_context context;
 577
 578     *exists = 0;
 579
 580     for (path = first_dll_path( name, 1, &context ); path; path = next_dll_path( &context ))
 581     {
 582         int fd = open( path, O_RDONLY );
 583         if (fd != -1)
 584         {
 585             int res = read( fd, buffer, size - 1 );
 586             while (res > 0 && (buffer[res-1] == '\n' || buffer[res-1] == '\r')) res--;
 587             buffer[res] = 0;
 588             close( fd );
 589             *exists = 1;
 590             ret = 0;
 591             break;
 592         }
 593     }
 594     free_dll_path( &context );
 595     return ret;
 596 }
 597
 598
 599 /***********************************************************************
 600  *           set_max_limit
 601  *
 602  * Set a user limit to the maximum allowed value.
 603  */
 604 static void set_max_limit( int limit )
 605 {
 606 #ifdef HAVE_SETRLIMIT
 607     struct rlimit rlimit;
 608
 609     if (!getrlimit( limit, &rlimit ))
 610     {
 611         rlimit.rlim_cur = rlimit.rlim_max;
 612         if (setrlimit( limit, &rlimit ) != 0)
 613         {
 614 #if defined(__APPLE__) && defined(RLIMIT_NOFILE) && defined(OPEN_MAX)
 615             /* On Leopard, setrlimit(RLIMIT_NOFILE, ...) fails on attempts to set
 616              * rlim_cur above OPEN_MAX (even if rlim_max > OPEN_MAX). */
 617             if (limit == RLIMIT_NOFILE && rlimit.rlim_cur > OPEN_MAX)
 618             {
 619                 rlimit.rlim_cur = OPEN_MAX;
 620                 setrlimit( limit, &rlimit );
 621             }
 622 #endif
 623         }
 624     }
 625 #endif
 626 }
 627
 628
 629 /***********************************************************************
 630  *           wine_init
 631  *
 632  * Main Wine initialisation.
 633  */
 634 void wine_init( int argc, char *argv[], char *error, int error_size )
 635 {
 636     struct dll_path_context context;
 637     char *path;
 638     void *ntdll = NULL;
 639     void (*init_func)(void);
 640
 641     /* force a few limits that are set too low on some platforms */
 642 #ifdef RLIMIT_NOFILE
 643     set_max_limit( RLIMIT_NOFILE );
 644 #endif
 645 #ifdef RLIMIT_AS
 646     set_max_limit( RLIMIT_AS );
 647 #endif
 648
 649     wine_init_argv0_path( argv[0] );
 650     build_dll_path();
 651     __wine_main_argc = argc;
 652     __wine_main_argv = argv;
 653     __wine_main_environ = __wine_get_main_environment();
 654     mmap_init();
 655
 656     for (path = first_dll_path( "ntdll.dll", 0, &context ); path; path = next_dll_path( &context ))
 657     {
 658         if ((ntdll = wine_dlopen( path, RTLD_NOW, error, error_size )))
 659         {
 660             /* if we didn't use the default dll dir, remove it from the search path */
 661             if (default_dlldir[0] && context.index < nb_dll_paths + 2) nb_dll_paths--;
 662             break;
 663         }
 664     }
 665     free_dll_path( &context );
 666
 667     if (!ntdll) return;
 668     if (!(init_func = wine_dlsym( ntdll, "__wine_process_init", error, error_size ))) return;
 669     init_func();
 670 }
 671
 672
 673 /*
 674  * These functions provide wrappers around dlopen() and associated
 675  * functions.  They work around a bug in glibc 2.1.x where calling
 676  * a dl*() function after a previous dl*() function has failed
 677  * without a dlerror() call between the two will cause a crash.
 678  * They all take a pointer to a buffer that
 679  * will receive the error description (from dlerror()).  This
 680  * parameter may be NULL if the error description is not required.
 681  */
 682
 683 #ifndef RTLD_FIRST
 684 #define RTLD_FIRST 0
 685 #endif
 686
 687 /***********************************************************************
 688  *              wine_dlopen
 689  */
 690 void *wine_dlopen( const char *filename, int flag, char *error, size_t errorsize )
 691 {
 692 #ifdef HAVE_DLOPEN
 693     void *ret;
 694     const char *s;
 695
 696 #ifdef __APPLE__
 697     /* the Mac OS loader pretends to be able to load PE files, so avoid them here */
 698     unsigned char magic[2];
 699     int fd = open( filename, O_RDONLY );
 700     if (fd != -1)
 701     {
 702         if (pread( fd, magic, 2, 0 ) == 2 && magic[0] == 'M' && magic[1] == 'Z')
 703         {
 704             static const char msg[] = "MZ format";
 705             size_t len = min( errorsize, sizeof(msg) );
 706             memcpy( error, msg, len );
 707             error[len - 1] = 0;
 708             close( fd );
 709             return NULL;
 710         }
 711         close( fd );
 712     }
 713 #endif
 714     dlerror(); dlerror();
 715 #ifdef __sun
 716     if (strchr( filename, ':' ))
 717     {
 718         char path[PATH_MAX];
 719         /* Solaris' brain damaged dlopen() treats ':' as a path separator */
 720         realpath( filename, path );
 721         ret = dlopen( path, flag | RTLD_FIRST );
 722     }
 723     else
 724 #endif
 725     ret = dlopen( filename, flag | RTLD_FIRST );
 726     s = dlerror();
 727     if (error && errorsize)
 728     {
 729         if (s)
 730         {
 731             size_t len = strlen(s);
 732             if (len >= errorsize) len = errorsize - 1;
 733             memcpy( error, s, len );
 734             error[len] = 0;
 735         }
 736         else error[0] = 0;
 737     }
 738     dlerror();
 739     return ret;
 740 #else
 741     if (error)
 742     {
 743         static const char msg[] = "dlopen interface not detected by configure";
 744         size_t len = min( errorsize, sizeof(msg) );
 745         memcpy( error, msg, len );
 746         error[len - 1] = 0;
 747     }
 748     return NULL;
 749 #endif
 750 }
 751
 752 /***********************************************************************
 753  *              wine_dlsym
 754  */
 755 void *wine_dlsym( void *handle, const char *symbol, char *error, size_t errorsize )
 756 {
 757 #ifdef HAVE_DLOPEN
 758     void *ret;
 759     const char *s;
 760     dlerror(); dlerror();
 761     ret = dlsym( handle, symbol );
 762     s = dlerror();
 763     if (error && errorsize)
 764     {
 765         if (s)
 766         {
 767             size_t len = strlen(s);
 768             if (len >= errorsize) len = errorsize - 1;
 769             memcpy( error, s, len );
 770             error[len] = 0;
 771         }
 772         else error[0] = 0;
 773     }
 774     dlerror();
 775     return ret;
 776 #else
 777     if (error)
 778     {
 779         static const char msg[] = "dlopen interface not detected by configure";
 780         size_t len = min( errorsize, sizeof(msg) );
 781         memcpy( error, msg, len );
 782         error[len - 1] = 0;
 783     }
 784     return NULL;
 785 #endif
 786 }
 787
 788 /***********************************************************************
 789  *              wine_dlclose
 790  */
 791 int wine_dlclose( void *handle, char *error, size_t errorsize )
 792 {
 793 #ifdef HAVE_DLOPEN
 794     int ret;
 795     const char *s;
 796     dlerror(); dlerror();
 797     ret = dlclose( handle );
 798     s = dlerror();
 799     if (error && errorsize)
 800     {
 801         if (s)
 802         {
 803             size_t len = strlen(s);
 804             if (len >= errorsize) len = errorsize - 1;
 805             memcpy( error, s, len );
 806             error[len] = 0;
 807         }
 808         else error[0] = 0;
 809     }
 810     dlerror();
 811     return ret;
 812 #else
 813     if (error)
 814     {
 815         static const char msg[] = "dlopen interface not detected by configure";
 816         size_t len = min( errorsize, sizeof(msg) );
 817         memcpy( error, msg, len );
 818         error[len - 1] = 0;
 819     }
 820     return 1;
 821 #endif
 822 }