dlls/urlmon/urlmon_main.c

   1 /*
   2  * UrlMon
   3  *
   4  * Copyright (c) 2000 Patrik Stridvall
   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 <stdarg.h>
  22
  23 #define COBJMACROS
  24
  25 #include "windef.h"
  26 #include "winbase.h"
  27 #include "winreg.h"
  28
  29 #define NO_SHLWAPI_REG
  30 #include "shlwapi.h"
  31 #include "wine/debug.h"
  32 #include "wine/unicode.h"
  33
  34 #include "winuser.h"
  35 #include "urlmon.h"
  36 #include "urlmon_main.h"
  37 #include "ole2.h"
  38
  39 WINE_DEFAULT_DEBUG_CHANNEL(urlmon);
  40
  41 LONG URLMON_refCount = 0;
  42
  43 HINSTANCE URLMON_hInstance = 0;
  44 static HMODULE hCabinet = NULL;
  45
  46 DWORD urlmon_tls = 0;
  47
  48 static void init_session(BOOL);
  49
  50 /***********************************************************************
  51  *              DllMain (URLMON.init)
  52  */
  53 BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID fImpLoad)
  54 {
  55     TRACE("%p 0x%x %p\n", hinstDLL, fdwReason, fImpLoad);
  56
  57     switch(fdwReason) {
  58     case DLL_PROCESS_ATTACH:
  59         DisableThreadLibraryCalls(hinstDLL);
  60         URLMON_hInstance = hinstDLL;
  61         init_session(TRUE);
  62         break;
  63
  64     case DLL_PROCESS_DETACH:
  65         if(urlmon_tls)
  66             TlsFree(urlmon_tls);
  67         if (hCabinet)
  68             FreeLibrary(hCabinet);
  69         hCabinet = NULL;
  70         init_session(FALSE);
  71         URLMON_hInstance = 0;
  72         break;
  73     }
  74     return TRUE;
  75 }
  76
  77
  78 /***********************************************************************
  79  *              DllInstall (URLMON.@)
  80  */
  81 HRESULT WINAPI DllInstall(BOOL bInstall, LPCWSTR cmdline)
  82 {
  83   FIXME("(%s, %s): stub\n", bInstall?"TRUE":"FALSE",
  84         debugstr_w(cmdline));
  85
  86   return S_OK;
  87 }
  88
  89 /***********************************************************************
  90  *              DllCanUnloadNow (URLMON.@)
  91  */
  92 HRESULT WINAPI DllCanUnloadNow(void)
  93 {
  94     return URLMON_refCount != 0 ? S_FALSE : S_OK;
  95 }
  96
  97
  98
  99 /******************************************************************************
 100  * Urlmon ClassFactory
 101  */
 102 typedef struct {
 103     const IClassFactoryVtbl *lpClassFactoryVtbl;
 104
 105     HRESULT (*pfnCreateInstance)(IUnknown *pUnkOuter, LPVOID *ppObj);
 106 } ClassFactory;
 107
 108 #define CLASSFACTORY(x)  ((IClassFactory*)  &(x)->lpClassFactoryVtbl)
 109
 110 static HRESULT WINAPI CF_QueryInterface(IClassFactory *iface, REFIID riid, LPVOID *ppv)
 111 {
 112     *ppv = NULL;
 113
 114     if(IsEqualGUID(riid, &IID_IUnknown)) {
 115         TRACE("(%p)->(IID_IUnknown %p)\n", iface, ppv);
 116         *ppv = iface;
 117     }else if(IsEqualGUID(riid, &IID_IClassFactory)) {
 118         TRACE("(%p)->(IID_IClassFactory %p)\n", iface, ppv);
 119         *ppv = iface;
 120     }
 121
 122     if(*ppv) {
 123         IUnknown_AddRef((IUnknown*)*ppv);
 124         return S_OK;
 125     }
 126
 127     WARN("(%p)->(%s,%p),not found\n", iface, debugstr_guid(riid), ppv);
 128     return E_NOINTERFACE;
 129 }
 130
 131 static ULONG WINAPI CF_AddRef(IClassFactory *iface)
 132 {
 133     URLMON_LockModule();
 134     return 2;
 135 }
 136
 137 static ULONG WINAPI CF_Release(IClassFactory *iface)
 138 {
 139     URLMON_UnlockModule();
 140     return 1;
 141 }
 142
 143
 144 static HRESULT WINAPI CF_CreateInstance(IClassFactory *iface, IUnknown *pOuter,
 145                                         REFIID riid, LPVOID *ppobj)
 146 {
 147     ClassFactory *This = (ClassFactory*)iface;
 148     HRESULT hres;
 149     LPUNKNOWN punk;
 150
 151     TRACE("(%p)->(%p,%s,%p)\n",This,pOuter,debugstr_guid(riid),ppobj);
 152
 153     *ppobj = NULL;
 154     if(SUCCEEDED(hres = This->pfnCreateInstance(pOuter, (LPVOID *) &punk))) {
 155         hres = IUnknown_QueryInterface(punk, riid, ppobj);
 156         IUnknown_Release(punk);
 157     }
 158     return hres;
 159 }
 160
 161 static HRESULT WINAPI CF_LockServer(LPCLASSFACTORY iface,BOOL dolock)
 162 {
 163     TRACE("(%d)\n", dolock);
 164
 165     if (dolock)
 166            URLMON_LockModule();
 167     else
 168            URLMON_UnlockModule();
 169
 170     return S_OK;
 171 }
 172
 173 static const IClassFactoryVtbl ClassFactoryVtbl =
 174 {
 175     CF_QueryInterface,
 176     CF_AddRef,
 177     CF_Release,
 178     CF_CreateInstance,
 179     CF_LockServer
 180 };
 181
 182 static const ClassFactory FileProtocolCF =
 183     { &ClassFactoryVtbl, FileProtocol_Construct};
 184 static const ClassFactory FtpProtocolCF =
 185     { &ClassFactoryVtbl, FtpProtocol_Construct};
 186 static const ClassFactory HttpProtocolCF =
 187     { &ClassFactoryVtbl, HttpProtocol_Construct};
 188 static const ClassFactory SecurityManagerCF =
 189     { &ClassFactoryVtbl, SecManagerImpl_Construct};
 190 static const ClassFactory ZoneManagerCF =
 191     { &ClassFactoryVtbl, ZoneMgrImpl_Construct};
 192
 193 struct object_creation_info
 194 {
 195     const CLSID *clsid;
 196     IClassFactory *cf;
 197     LPCWSTR protocol;
 198 };
 199
 200 static const WCHAR wszFile[] = {'f','i','l','e',0};
 201 static const WCHAR wszFtp[]  = {'f','t','p',0};
 202 static const WCHAR wszHttp[] = {'h','t','t','p',0};
 203
 204 static const struct object_creation_info object_creation[] =
 205 {
 206     { &CLSID_FileProtocol,            CLASSFACTORY(&FileProtocolCF),    wszFile },
 207     { &CLSID_FtpProtocol,             CLASSFACTORY(&FtpProtocolCF),     wszFtp  },
 208     { &CLSID_HttpProtocol,            CLASSFACTORY(&HttpProtocolCF),    wszHttp },
 209     { &CLSID_InternetSecurityManager, CLASSFACTORY(&SecurityManagerCF), NULL    },
 210     { &CLSID_InternetZoneManager,     CLASSFACTORY(&ZoneManagerCF),     NULL    }
 211 };
 212
 213 static void init_session(BOOL init)
 214 {
 215     IInternetSession *session;
 216     int i;
 217
 218     CoInternetGetSession(0, &session, 0);
 219
 220     for(i=0; i < sizeof(object_creation)/sizeof(object_creation[0]); i++) {
 221         if(object_creation[i].protocol) {
 222             if(init)
 223                 IInternetSession_RegisterNameSpace(session, object_creation[i].cf,
 224                         object_creation[i].clsid, object_creation[i].protocol, 0, NULL, 0);
 225             else
 226                 IInternetSession_UnregisterNameSpace(session, object_creation[i].cf,
 227                         object_creation[i].protocol);
 228         }
 229     }
 230
 231     IInternetSession_Release(session);
 232 }
 233
 234 /*******************************************************************************
 235  * DllGetClassObject [URLMON.@]
 236  * Retrieves class object from a DLL object
 237  *
 238  * NOTES
 239  *    Docs say returns STDAPI
 240  *
 241  * PARAMS
 242  *    rclsid [I] CLSID for the class object
 243  *    riid   [I] Reference to identifier of interface for class object
 244  *    ppv    [O] Address of variable to receive interface pointer for riid
 245  *
 246  * RETURNS
 247  *    Success: S_OK
 248  *    Failure: CLASS_E_CLASSNOTAVAILABLE, E_OUTOFMEMORY, E_INVALIDARG,
 249  *             E_UNEXPECTED
 250  */
 251
 252 HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 253 {
 254     int i;
 255
 256     TRACE("(%s,%s,%p)\n", debugstr_guid(rclsid), debugstr_guid(riid), ppv);
 257
 258     for (i=0; i < sizeof(object_creation)/sizeof(object_creation[0]); i++)
 259     {
 260         if (IsEqualGUID(object_creation[i].clsid, rclsid))
 261             return IClassFactory_QueryInterface(object_creation[i].cf, riid, ppv);
 262     }
 263
 264     FIXME("%s: no class found.\n", debugstr_guid(rclsid));
 265     return CLASS_E_CLASSNOTAVAILABLE;
 266 }
 267
 268
 269 /***********************************************************************
 270  *              DllRegisterServerEx (URLMON.@)
 271  */
 272 HRESULT WINAPI DllRegisterServerEx(void)
 273 {
 274     FIXME("(void): stub\n");
 275
 276     return E_FAIL;
 277 }
 278
 279 /**************************************************************************
 280  *                 UrlMkSetSessionOption (URLMON.@)
 281  */
 282 HRESULT WINAPI UrlMkSetSessionOption(DWORD dwOption, LPVOID pBuffer, DWORD dwBufferLength,
 283                                         DWORD Reserved)
 284 {
 285     FIXME("(%#x, %p, %#x): stub\n", dwOption, pBuffer, dwBufferLength);
 286
 287     return S_OK;
 288 }
 289
 290 static const CHAR Agent[] = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)";
 291
 292 /**************************************************************************
 293  *                 ObtainUserAgentString (URLMON.@)
 294  */
 295 HRESULT WINAPI ObtainUserAgentString(DWORD dwOption, LPSTR pcszUAOut, DWORD *cbSize)
 296 {
 297     FIXME("(%d, %p, %p): stub\n", dwOption, pcszUAOut, cbSize);
 298
 299     if(dwOption) {
 300       ERR("dwOption: %d, must be zero\n", dwOption);
 301     }
 302
 303     if (sizeof(Agent) < *cbSize)
 304         *cbSize = sizeof(Agent);
 305     lstrcpynA(pcszUAOut, Agent, *cbSize);
 306
 307     return S_OK;
 308 }
 309
 310 HRESULT WINAPI CoInternetCompareUrl(LPCWSTR pwzUrl1, LPCWSTR pwzUrl2, DWORD dwCompareFlags)
 311 {
 312     TRACE("(%s,%s,%08x)\n", debugstr_w(pwzUrl1), debugstr_w(pwzUrl2), dwCompareFlags);
 313     return UrlCompareW(pwzUrl1, pwzUrl2, dwCompareFlags)==0?S_OK:S_FALSE;
 314 }
 315
 316 /**************************************************************************
 317  *                 IsValidURL (URLMON.@)
 318  *
 319  * Determines if a specified string is a valid URL.
 320  *
 321  * PARAMS
 322  *  pBC        [I] ignored, must be NULL.
 323  *  szURL      [I] string that represents the URL in question.
 324  *  dwReserved [I] reserved and must be zero.
 325  *
 326  * RETURNS
 327  *  Success: S_OK.
 328  *  Failure: S_FALSE.
 329  *  returns E_INVALIDARG if one or more of the args is invalid.
 330  *
 331  * TODO:
 332  *  test functionality against windows to see what a valid URL is.
 333  */
 334 HRESULT WINAPI IsValidURL(LPBC pBC, LPCWSTR szURL, DWORD dwReserved)
 335 {
 336     FIXME("(%p, %s, %d): stub\n", pBC, debugstr_w(szURL), dwReserved);
 337
 338     if (pBC != NULL || dwReserved != 0)
 339         return E_INVALIDARG;
 340
 341     return S_OK;
 342 }
 343
 344 /**************************************************************************
 345  *                 FaultInIEFeature (URLMON.@)
 346  *
 347  *  Undocumented.  Appears to be used by native shdocvw.dll.
 348  */
 349 HRESULT WINAPI FaultInIEFeature( HWND hwnd, uCLSSPEC * pClassSpec,
 350                                  QUERYCONTEXT *pQuery, DWORD flags )
 351 {
 352     FIXME("%p %p %p %08x\n", hwnd, pClassSpec, pQuery, flags);
 353     return E_NOTIMPL;
 354 }
 355
 356 /**************************************************************************
 357  *                 CoGetClassObjectFromURL (URLMON.@)
 358  */
 359 HRESULT WINAPI CoGetClassObjectFromURL( REFCLSID rclsid, LPCWSTR szCodeURL, DWORD dwFileVersionMS,
 360                                         DWORD dwFileVersionLS, LPCWSTR szContentType,
 361                                         LPBINDCTX pBindCtx, DWORD dwClsContext, LPVOID pvReserved,
 362                                         REFIID riid, LPVOID *ppv )
 363 {
 364     FIXME("(%s %s %d %d %s %p %d %p %s %p) Stub!\n", debugstr_guid(rclsid), debugstr_w(szCodeURL),
 365         dwFileVersionMS, dwFileVersionLS, debugstr_w(szContentType), pBindCtx, dwClsContext, pvReserved,
 366         debugstr_guid(riid), ppv);
 367     return E_NOINTERFACE;
 368 }
 369
 370 /***********************************************************************
 371  *           ReleaseBindInfo (URLMON.@)
 372  *
 373  * Release the resources used by the specified BINDINFO structure.
 374  *
 375  * PARAMS
 376  *  pbindinfo [I] BINDINFO to release.
 377  *
 378  * RETURNS
 379  *  Nothing.
 380  */
 381 void WINAPI ReleaseBindInfo(BINDINFO* pbindinfo)
 382 {
 383     DWORD size;
 384
 385     TRACE("(%p)\n", pbindinfo);
 386
 387     if(!pbindinfo || !(size = pbindinfo->cbSize))
 388         return;
 389
 390     CoTaskMemFree(pbindinfo->szExtraInfo);
 391     ReleaseStgMedium(&pbindinfo->stgmedData);
 392
 393     if(offsetof(BINDINFO, szExtraInfo) < size)
 394         CoTaskMemFree(pbindinfo->szCustomVerb);
 395
 396
 397     if(pbindinfo->pUnk && offsetof(BINDINFO, pUnk) < size)
 398         IUnknown_Release(pbindinfo->pUnk);
 399
 400     memset(pbindinfo, 0, size);
 401     pbindinfo->cbSize = size;
 402 }
 403
 404 /***********************************************************************
 405  *           FindMimeFromData (URLMON.@)
 406  *
 407  * Determines the Multipurpose Internet Mail Extensions (MIME) type from the data provided.
 408  */
 409 static BOOL text_html_filter(LPVOID buf, DWORD size)
 410 {
 411     const char *b = buf;
 412     int i;
 413
 414     if(size < 5)
 415         return FALSE;
 416
 417     for(i=0; i < size-5; i++) {
 418         if(b[i] == '<'
 419            && (b[i+1] == 'h' || b[i+1] == 'H')
 420            && (b[i+2] == 't' || b[i+2] == 'T')
 421            && (b[i+3] == 'm' || b[i+3] == 'M')
 422            && (b[i+4] == 'l' || b[i+4] == 'L'))
 423             return TRUE;
 424     }
 425
 426     return FALSE;
 427 }
 428
 429 static BOOL image_gif_filter(LPVOID buf, DWORD size)
 430 {
 431     const BYTE const *b = buf;
 432
 433     return size >= 6
 434         && (b[0] == 'G' || b[0] == 'g')
 435         && (b[1] == 'I' || b[1] == 'i')
 436         && (b[2] == 'F' || b[2] == 'f')
 437         &&  b[3] == '8'
 438         && (b[4] == '7' || b[4] == '9')
 439         && (b[5] == 'A' || b[5] == 'a');
 440 }
 441
 442 static BOOL image_pjpeg_filter(LPVOID buf, DWORD size)
 443 {
 444     return size > 2 && *(BYTE*)buf == 0xff && *((BYTE*)buf+1) == 0xd8;
 445 }
 446
 447 static BOOL image_xpng_filter(LPVOID buf, DWORD size)
 448 {
 449     static const BYTE xpng_header[] = {0x89,'P','N','G',0x0d,0x0a,0x1a,0x0a};
 450     return size > sizeof(xpng_header) && !memcmp(buf, xpng_header, sizeof(xpng_header));
 451 }
 452
 453 static BOOL image_bmp_filter(LPVOID buf, DWORD size)
 454 {
 455     return size >= 14
 456         && *(BYTE*)buf == 0x42
 457         && *((BYTE*)buf+1) == 0x4d
 458         && *(DWORD*)((BYTE*)buf+6) == 0;
 459 }
 460
 461 static BOOL text_plain_filter(LPVOID buf, DWORD size)
 462 {
 463     UCHAR *ptr;
 464
 465     for(ptr = buf; ptr < (UCHAR*)buf+size-1; ptr++) {
 466         if(*ptr < 0x20 && *ptr != '\n' && *ptr != '\r' && *ptr != '\t')
 467             return FALSE;
 468     }
 469
 470     return TRUE;
 471 }
 472
 473 static BOOL application_octet_stream_filter(LPVOID buf, DWORD size)
 474 {
 475     return TRUE;
 476 }
 477
 478 HRESULT WINAPI FindMimeFromData(LPBC pBC, LPCWSTR pwzUrl, LPVOID pBuffer,
 479         DWORD cbSize, LPCWSTR pwzMimeProposed, DWORD dwMimeFlags,
 480         LPWSTR* ppwzMimeOut, DWORD dwReserved)
 481 {
 482     TRACE("(%p,%s,%p,%d,%s,0x%x,%p,0x%x)\n", pBC, debugstr_w(pwzUrl), pBuffer, cbSize,
 483             debugstr_w(pwzMimeProposed), dwMimeFlags, ppwzMimeOut, dwReserved);
 484
 485     if(dwMimeFlags)
 486         WARN("dwMimeFlags=%08x\n", dwMimeFlags);
 487     if(dwReserved)
 488         WARN("dwReserved=%d\n", dwReserved);
 489
 490     /* pBC seams to not be used */
 491
 492     if(!ppwzMimeOut || (!pwzUrl && !pBuffer))
 493         return E_INVALIDARG;
 494
 495     if(pwzMimeProposed && (!pBuffer || (pBuffer && !cbSize))) {
 496         DWORD len;
 497
 498         if(!pwzMimeProposed)
 499             return E_FAIL;
 500
 501         len = strlenW(pwzMimeProposed)+1;
 502         *ppwzMimeOut = CoTaskMemAlloc(len*sizeof(WCHAR));
 503         memcpy(*ppwzMimeOut, pwzMimeProposed, len*sizeof(WCHAR));
 504         return S_OK;
 505     }
 506
 507     if(pBuffer) {
 508         DWORD len;
 509         LPCWSTR ret = NULL;
 510         int i;
 511
 512         static const WCHAR wszTextHtml[] = {'t','e','x','t','/','h','t','m','l',0};
 513         static const WCHAR wszImageGif[] = {'i','m','a','g','e','/','g','i','f',0};
 514         static const WCHAR wszImagePjpeg[] = {'i','m','a','g','e','/','p','j','p','e','g',0};
 515         static const WCHAR wszImageXPng[] = {'i','m','a','g','e','/','x','-','p','n','g',0};
 516         static const WCHAR wszImageBmp[] = {'i','m','a','g','e','/','b','m','p',0};
 517         static const WCHAR wszTextPlain[] = {'t','e','x','t','/','p','l','a','i','n','\0'};
 518         static const WCHAR wszAppOctetStream[] = {'a','p','p','l','i','c','a','t','i','o','n','/',
 519             'o','c','t','e','t','-','s','t','r','e','a','m','\0'};
 520
 521         static const struct {
 522             LPCWSTR mime;
 523             BOOL (*filter)(LPVOID,DWORD);
 524         } mime_filters[] = {
 525             {wszTextHtml,       text_html_filter},
 526             {wszImageGif,       image_gif_filter},
 527             {wszImagePjpeg,     image_pjpeg_filter},
 528             {wszImageXPng,      image_xpng_filter},
 529             {wszImageBmp,       image_bmp_filter},
 530             {wszTextPlain,      text_plain_filter},
 531             {wszAppOctetStream, application_octet_stream_filter}
 532         };
 533
 534         if(!cbSize)
 535             return E_FAIL;
 536
 537         if(pwzMimeProposed && strcmpW(pwzMimeProposed, wszAppOctetStream)) {
 538             for(i=0; i < sizeof(mime_filters)/sizeof(*mime_filters); i++) {
 539                 if(!strcmpW(pwzMimeProposed, mime_filters[i].mime))
 540                     break;
 541             }
 542
 543             if(i == sizeof(mime_filters)/sizeof(*mime_filters)
 544                     || mime_filters[i].filter(pBuffer, cbSize)) {
 545                 len = strlenW(pwzMimeProposed)+1;
 546                 *ppwzMimeOut = CoTaskMemAlloc(len*sizeof(WCHAR));
 547                 memcpy(*ppwzMimeOut, pwzMimeProposed, len*sizeof(WCHAR));
 548                 return S_OK;
 549             }
 550         }
 551
 552         i=0;
 553         while(!ret) {
 554             if(mime_filters[i].filter(pBuffer, cbSize))
 555                 ret = mime_filters[i].mime;
 556             i++;
 557         }
 558
 559         if(pwzMimeProposed) {
 560             if(i == sizeof(mime_filters)/sizeof(*mime_filters))
 561                 ret = pwzMimeProposed;
 562
 563             /* text/html is a special case */
 564            if(!strcmpW(pwzMimeProposed, wszTextHtml) && !strcmpW(ret, wszTextPlain))
 565                 ret = wszTextHtml;
 566         }
 567
 568         len = strlenW(ret)+1;
 569         *ppwzMimeOut = CoTaskMemAlloc(len*sizeof(WCHAR));
 570         memcpy(*ppwzMimeOut, ret, len*sizeof(WCHAR));
 571         return S_OK;
 572     }
 573
 574     if(pwzUrl) {
 575         HKEY hkey;
 576         DWORD res, size;
 577         LPCWSTR ptr;
 578         WCHAR mime[64];
 579
 580         static const WCHAR wszContentType[] =
 581                 {'C','o','n','t','e','n','t',' ','T','y','p','e','\0'};
 582
 583         ptr = strrchrW(pwzUrl, '.');
 584         if(!ptr)
 585             return E_FAIL;
 586
 587         res = RegOpenKeyW(HKEY_CLASSES_ROOT, ptr, &hkey);
 588         if(res != ERROR_SUCCESS)
 589             return E_FAIL;
 590
 591         size = sizeof(mime);
 592         res = RegQueryValueExW(hkey, wszContentType, NULL, NULL, (LPBYTE)mime, &size);
 593         RegCloseKey(hkey);
 594         if(res != ERROR_SUCCESS)
 595             return E_FAIL;
 596
 597         *ppwzMimeOut = CoTaskMemAlloc(size);
 598         memcpy(*ppwzMimeOut, mime, size);
 599         return S_OK;
 600     }
 601
 602     return E_FAIL;
 603 }
 604
 605 /***********************************************************************
 606  * Extract (URLMON.@)
 607  */
 608 HRESULT WINAPI Extract(void *dest, LPCSTR szCabName)
 609 {
 610     HRESULT (WINAPI *pExtract)(void *, LPCSTR);
 611
 612     if (!hCabinet)
 613         hCabinet = LoadLibraryA("cabinet.dll");
 614
 615     if (!hCabinet) return HRESULT_FROM_WIN32(GetLastError());
 616     pExtract = (void *)GetProcAddress(hCabinet, "Extract");
 617     if (!pExtract) return HRESULT_FROM_WIN32(GetLastError());
 618
 619     return pExtract(dest, szCabName);
 620 }