src/egl/main/egldriver.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
   5  * Copyright 2010-2011 LunarG, Inc.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30
  31 /**
  32  * Functions for choosing and opening/loading device drivers.
  33  */
  34
  35
  36 #include <assert.h>
  37 #include <string.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40
  41 #include "eglstring.h"
  42 #include "egldefines.h"
  43 #include "egldisplay.h"
  44 #include "egldriver.h"
  45 #include "egllog.h"
  46 #include "eglmutex.h"
  47
  48 #if defined(_EGL_OS_UNIX)
  49 #include <dlfcn.h>
  50 #include <sys/types.h>
  51 #include <dirent.h>
  52 #include <unistd.h>
  53 #endif
  54
  55
  56 typedef struct _egl_module {
  57    char *Path;
  58    _EGLMain_t BuiltIn;
  59    void *Handle;
  60    _EGLDriver *Driver;
  61 } _EGLModule;
  62
  63 static _EGLMutex _eglModuleMutex = _EGL_MUTEX_INITIALIZER;
  64 static _EGLArray *_eglModules;
  65
  66 const struct {
  67    const char *name;
  68    _EGLMain_t main;
  69 } _eglBuiltInDrivers[] = {
  70 #ifdef _EGL_BUILT_IN_DRIVER_GALLIUM
  71    { "egl_gallium", _eglBuiltInDriverGALLIUM },
  72 #endif
  73 #ifdef _EGL_BUILT_IN_DRIVER_DRI2
  74    { "egl_dri2", _eglBuiltInDriverDRI2 },
  75 #endif
  76    { NULL, NULL }
  77 };
  78
  79 /**
  80  * Wrappers for dlopen/dlclose()
  81  */
  82 #if defined(_EGL_OS_WINDOWS)
  83
  84
  85 typedef HMODULE lib_handle;
  86
  87 static HMODULE
  88 open_library(const char *filename)
  89 {
  90    return LoadLibrary(filename);
  91 }
  92
  93 static void
  94 close_library(HMODULE lib)
  95 {
  96    FreeLibrary(lib);
  97 }
  98
  99
 100 static const char *
 101 library_suffix(void)
 102 {
 103    return ".dll";
 104 }
 105
 106
 107 #elif defined(_EGL_OS_UNIX)
 108
 109
 110 typedef void * lib_handle;
 111
 112 static void *
 113 open_library(const char *filename)
 114 {
 115    return dlopen(filename, RTLD_LAZY);
 116 }
 117
 118 static void
 119 close_library(void *lib)
 120 {
 121    dlclose(lib);
 122 }
 123
 124
 125 static const char *
 126 library_suffix(void)
 127 {
 128    return ".so";
 129 }
 130
 131
 132 #endif
 133
 134
 135 /**
 136  * Open the named driver and find its bootstrap function: _eglMain().
 137  */
 138 static _EGLMain_t
 139 _eglOpenLibrary(const char *driverPath, lib_handle *handle)
 140 {
 141    lib_handle lib;
 142    _EGLMain_t mainFunc = NULL;
 143    const char *error = "unknown error";
 144
 145    assert(driverPath);
 146
 147    _eglLog(_EGL_DEBUG, "dlopen(%s)", driverPath);
 148    lib = open_library(driverPath);
 149
 150 #if defined(_EGL_OS_WINDOWS)
 151    /* XXX untested */
 152    if (lib)
 153       mainFunc = (_EGLMain_t) GetProcAddress(lib, "_eglMain");
 154 #elif defined(_EGL_OS_UNIX)
 155    if (lib) {
 156       union {
 157          _EGLMain_t func;
 158          void *ptr;
 159       } tmp = { NULL };
 160       /* direct cast gives a warning when compiled with -pedantic */
 161       tmp.ptr = dlsym(lib, "_eglMain");
 162       mainFunc = tmp.func;
 163       if (!mainFunc)
 164          error = dlerror();
 165    }
 166    else {
 167       error = dlerror();
 168    }
 169 #endif
 170
 171    if (!lib) {
 172       _eglLog(_EGL_WARNING, "Could not open driver %s (%s)",
 173               driverPath, error);
 174       return NULL;
 175    }
 176
 177    if (!mainFunc) {
 178       _eglLog(_EGL_WARNING, "_eglMain not found in %s (%s)",
 179               driverPath, error);
 180       if (lib)
 181          close_library(lib);
 182       return NULL;
 183    }
 184
 185    *handle = lib;
 186    return mainFunc;
 187 }
 188
 189
 190 /**
 191  * Load a module and create the driver object.
 192  */
 193 static EGLBoolean
 194 _eglLoadModule(_EGLModule *mod)
 195 {
 196    _EGLMain_t mainFunc;
 197    lib_handle lib;
 198    _EGLDriver *drv;
 199
 200    if (mod->Driver)
 201       return EGL_TRUE;
 202
 203    if (mod->BuiltIn) {
 204       lib = (lib_handle) NULL;
 205       mainFunc = mod->BuiltIn;
 206    }
 207    else {
 208       mainFunc = _eglOpenLibrary(mod->Path, &lib);
 209       if (!mainFunc)
 210          return EGL_FALSE;
 211    }
 212
 213    drv = mainFunc(NULL);
 214    if (!drv) {
 215       if (lib)
 216          close_library(lib);
 217       return EGL_FALSE;
 218    }
 219
 220    if (!drv->Name) {
 221       _eglLog(_EGL_WARNING, "Driver loaded from %s has no name", mod->Path);
 222       drv->Name = "UNNAMED";
 223    }
 224
 225    mod->Handle = (void *) lib;
 226    mod->Driver = drv;
 227
 228    return EGL_TRUE;
 229 }
 230
 231
 232 /**
 233  * Unload a module.
 234  */
 235 static void
 236 _eglUnloadModule(_EGLModule *mod)
 237 {
 238 #if defined(_EGL_OS_UNIX)
 239    /* destroy the driver */
 240    if (mod->Driver && mod->Driver->Unload)
 241       mod->Driver->Unload(mod->Driver);
 242
 243    /*
 244     * XXX At this point (atexit), the module might be the last reference to
 245     * libEGL.  Closing the module might unmap libEGL and give problems.
 246     */
 247 #if 0
 248    if (mod->Handle)
 249       close_library(mod->Handle);
 250 #endif
 251 #elif defined(_EGL_OS_WINDOWS)
 252    /* XXX Windows unloads DLLs before atexit */
 253 #endif
 254
 255    mod->Driver = NULL;
 256    mod->Handle = NULL;
 257 }
 258
 259
 260 /**
 261  * Add a module to the module array.
 262  */
 263 static _EGLModule *
 264 _eglAddModule(const char *path)
 265 {
 266    _EGLModule *mod;
 267    EGLint i;
 268
 269    if (!_eglModules) {
 270       _eglModules = _eglCreateArray("Module", 8);
 271       if (!_eglModules)
 272          return NULL;
 273    }
 274
 275    /* find duplicates */
 276    for (i = 0; i < _eglModules->Size; i++) {
 277       mod = _eglModules->Elements[i];
 278       if (strcmp(mod->Path, path) == 0)
 279          return mod;
 280    }
 281
 282    /* allocate a new one */
 283    mod = calloc(1, sizeof(*mod));
 284    if (mod) {
 285       mod->Path = _eglstrdup(path);
 286       if (!mod->Path) {
 287          free(mod);
 288          mod = NULL;
 289       }
 290    }
 291    if (mod) {
 292       _eglAppendArray(_eglModules, (void *) mod);
 293       _eglLog(_EGL_DEBUG, "added %s to module array", mod->Path);
 294    }
 295
 296    return mod;
 297 }
 298
 299
 300 /**
 301  * Free a module.
 302  */
 303 static void
 304 _eglFreeModule(void *module)
 305 {
 306    _EGLModule *mod = (_EGLModule *) module;
 307
 308    _eglUnloadModule(mod);
 309    free(mod->Path);
 310    free(mod);
 311 }
 312
 313
 314 /**
 315  * A loader function for use with _eglPreloadForEach.  The loader data is the
 316  * filename of the driver.   This function stops on the first valid driver.
 317  */
 318 static EGLBoolean
 319 _eglLoaderFile(const char *dir, size_t len, void *loader_data)
 320 {
 321    char path[1024];
 322    const char *filename = (const char *) loader_data;
 323    size_t flen = strlen(filename);
 324
 325    /* make a full path */
 326    if (len + flen + 2 > sizeof(path))
 327       return EGL_TRUE;
 328    if (len) {
 329       memcpy(path, dir, len);
 330       path[len++] = '/';
 331    }
 332    memcpy(path + len, filename, flen);
 333    len += flen;
 334    path[len] = '\0';
 335
 336    if (library_suffix()) {
 337       const char *suffix = library_suffix();
 338       size_t slen = strlen(suffix);
 339       const char *p;
 340       EGLBoolean need_suffix;
 341
 342       p = filename + flen - slen;
 343       need_suffix = (p < filename || strcmp(p, suffix) != 0);
 344       if (need_suffix) {
 345          /* overflow */
 346          if (len + slen + 1 > sizeof(path))
 347             return EGL_TRUE;
 348          strcpy(path + len, suffix);
 349       }
 350    }
 351
 352 #if defined(_EGL_OS_UNIX)
 353    /* check if the file exists */
 354    if (access(path, F_OK))
 355       return EGL_TRUE;
 356 #endif
 357
 358    _eglAddModule(path);
 359
 360    return EGL_TRUE;
 361 }
 362
 363
 364 /**
 365  * Run the callback function on each driver directory.
 366  *
 367  * The process may end prematurely if the callback function returns false.
 368  */
 369 static void
 370 _eglPreloadForEach(const char *search_path,
 371                    EGLBoolean (*loader)(const char *, size_t, void *),
 372                    void *loader_data)
 373 {
 374    const char *cur, *next;
 375    size_t len;
 376
 377    cur = search_path;
 378    while (cur) {
 379       next = strchr(cur, ':');
 380       len = (next) ? next - cur : strlen(cur);
 381
 382       if (!loader(cur, len, loader_data))
 383          break;
 384
 385       cur = (next) ? next + 1 : NULL;
 386    }
 387 }
 388
 389
 390 /**
 391  * Return a list of colon-separated driver directories.
 392  */
 393 static const char *
 394 _eglGetSearchPath(void)
 395 {
 396    static char search_path[1024];
 397
 398 #if defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS)
 399    if (search_path[0] == '\0') {
 400       char *buf = search_path;
 401       size_t len = sizeof(search_path);
 402       EGLBoolean use_env;
 403       char dir_sep;
 404       int ret;
 405
 406 #if defined(_EGL_OS_UNIX)
 407       use_env = (geteuid() == getuid() && getegid() == getgid());
 408       dir_sep = '/';
 409 #else
 410       use_env = EGL_TRUE;
 411       dir_sep = '\\';
 412 #endif
 413
 414       if (use_env) {
 415          char *p;
 416
 417          /* extract the dirname from EGL_DRIVER */
 418          p = getenv("EGL_DRIVER");
 419          if (p && strchr(p, dir_sep)) {
 420             ret = _eglsnprintf(buf, len, "%s", p);
 421             if (ret > 0 && ret < len) {
 422                p = strrchr(buf, dir_sep);
 423                *p++ = ':';
 424
 425                len -= p - buf;
 426                buf = p;
 427             }
 428          }
 429
 430          /* append EGL_DRIVERS_PATH */
 431          p = getenv("EGL_DRIVERS_PATH");
 432          if (p) {
 433             ret = _eglsnprintf(buf, len, "%s:", p);
 434             if (ret > 0 && ret < len) {
 435                buf += ret;
 436                len -= ret;
 437             }
 438          }
 439       }
 440       else {
 441          _eglLog(_EGL_DEBUG,
 442                "ignore EGL_DRIVERS_PATH for setuid/setgid binaries");
 443       }
 444
 445       ret = _eglsnprintf(buf, len, "%s", _EGL_DRIVER_SEARCH_DIR);
 446       if (ret < 0 || ret >= len)
 447          search_path[0] = '\0';
 448
 449       _eglLog(_EGL_DEBUG, "EGL search path is %s", search_path);
 450    }
 451 #endif /* defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS) */
 452
 453    return search_path;
 454 }
 455
 456
 457 /**
 458  * Add the user driver to the module array.
 459  *
 460  * The user driver is specified by EGL_DRIVER.
 461  */
 462 static EGLBoolean
 463 _eglAddUserDriver(void)
 464 {
 465    const char *search_path = _eglGetSearchPath();
 466    char *env;
 467    size_t name_len = 0;
 468
 469    env = getenv("EGL_DRIVER");
 470 #if defined(_EGL_OS_UNIX)
 471    if (env && strchr(env, '/')) {
 472       search_path = "";
 473       if ((geteuid() != getuid() || getegid() != getgid())) {
 474          _eglLog(_EGL_DEBUG,
 475                "ignore EGL_DRIVER for setuid/setgid binaries");
 476          env = NULL;
 477       }
 478    }
 479    else if (env) {
 480       char *suffix = strchr(env, '.');
 481       name_len = (suffix) ? suffix - env : strlen(env);
 482    }
 483 #else
 484    if (env)
 485       name_len = strlen(env);
 486 #endif /* _EGL_OS_UNIX */
 487
 488    /*
 489     * Try built-in drivers first if we know the driver name.  This makes sure
 490     * we do not load the outdated external driver that is still on the
 491     * filesystem.
 492     */
 493    if (name_len) {
 494       _EGLModule *mod;
 495       EGLint i;
 496
 497       for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 498          if (strlen(_eglBuiltInDrivers[i].name) == name_len &&
 499              !strncmp(_eglBuiltInDrivers[i].name, env, name_len)) {
 500             mod = _eglAddModule(env);
 501             if (mod)
 502                mod->BuiltIn = _eglBuiltInDrivers[i].main;
 503
 504             return EGL_TRUE;
 505          }
 506       }
 507    }
 508
 509    /* otherwise, treat env as a path */
 510    if (env) {
 511       _eglPreloadForEach(search_path, _eglLoaderFile, (void *) env);
 512
 513       return EGL_TRUE;
 514    }
 515
 516    return EGL_FALSE;
 517 }
 518
 519
 520 /**
 521  * Add built-in drivers to the module array.
 522  */
 523 static void
 524 _eglAddBuiltInDrivers(void)
 525 {
 526    _EGLModule *mod;
 527    EGLint i;
 528
 529    for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 530       mod = _eglAddModule(_eglBuiltInDrivers[i].name);
 531       if (mod)
 532          mod->BuiltIn = _eglBuiltInDrivers[i].main;
 533    }
 534 }
 535
 536
 537 /**
 538  * Add drivers to the module array.  Drivers will be loaded as they are matched
 539  * to displays.
 540  */
 541 static EGLBoolean
 542 _eglAddDrivers(void)
 543 {
 544    if (_eglModules)
 545       return EGL_TRUE;
 546
 547    if (!_eglAddUserDriver()) {
 548       /*
 549        * Add other drivers only when EGL_DRIVER is not set.  The order here
 550        * decides the priorities.
 551        */
 552       _eglAddBuiltInDrivers();
 553    }
 554
 555    return (_eglModules != NULL);
 556 }
 557
 558
 559 /**
 560  * A helper function for _eglMatchDriver.  It finds the first driver that can
 561  * initialize the display and return.
 562  */
 563 static _EGLDriver *
 564 _eglMatchAndInitialize(_EGLDisplay *dpy)
 565 {
 566    _EGLDriver *drv = NULL;
 567    EGLint i = 0;
 568
 569    if (!_eglAddDrivers()) {
 570       _eglLog(_EGL_WARNING, "failed to find any driver");
 571       return NULL;
 572    }
 573
 574    if (dpy->Driver) {
 575       drv = dpy->Driver;
 576       /* no re-matching? */
 577       if (!drv->API.Initialize(drv, dpy))
 578          drv = NULL;
 579       return drv;
 580    }
 581
 582    while (i < _eglModules->Size) {
 583       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 584
 585       if (!_eglLoadModule(mod)) {
 586          /* remove invalid modules */
 587          _eglEraseArray(_eglModules, i, _eglFreeModule);
 588          continue;
 589       }
 590
 591       if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
 592          drv = mod->Driver;
 593          break;
 594       }
 595       else {
 596          i++;
 597       }
 598    }
 599
 600    return drv;
 601 }
 602
 603
 604 /**
 605  * Match a display to a driver.  The display is initialized unless test_only is
 606  * true.  The matching is done by finding the first driver that can initialize
 607  * the display.
 608  */
 609 _EGLDriver *
 610 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
 611 {
 612    _EGLDriver *best_drv;
 613
 614    assert(!dpy->Initialized);
 615
 616    _eglLockMutex(&_eglModuleMutex);
 617
 618    /* set options */
 619    dpy->Options.TestOnly = test_only;
 620    dpy->Options.UseFallback = EGL_FALSE;
 621
 622    best_drv = _eglMatchAndInitialize(dpy);
 623    if (!best_drv) {
 624       dpy->Options.UseFallback = EGL_TRUE;
 625       best_drv = _eglMatchAndInitialize(dpy);
 626    }
 627
 628    _eglUnlockMutex(&_eglModuleMutex);
 629
 630    if (best_drv) {
 631       _eglLog(_EGL_DEBUG, "the best driver is %s%s",
 632             best_drv->Name, (test_only) ? " (test only) " : "");
 633       if (!test_only) {
 634          dpy->Driver = best_drv;
 635          dpy->Initialized = EGL_TRUE;
 636       }
 637    }
 638
 639    return best_drv;
 640 }
 641
 642
 643 __eglMustCastToProperFunctionPointerType
 644 _eglGetDriverProc(const char *procname)
 645 {
 646    EGLint i;
 647    _EGLProc proc = NULL;
 648
 649    if (!_eglModules) {
 650       /* load the driver for the default display */
 651       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 652       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 653       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 654          return NULL;
 655    }
 656
 657    for (i = 0; i < _eglModules->Size; i++) {
 658       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 659
 660       if (!mod->Driver)
 661          break;
 662       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 663       if (proc)
 664          break;
 665    }
 666
 667    return proc;
 668 }
 669
 670
 671 /**
 672  * Unload all drivers.
 673  */
 674 void
 675 _eglUnloadDrivers(void)
 676 {
 677    /* this is called at atexit time */
 678    if (_eglModules) {
 679       _eglDestroyArray(_eglModules, _eglFreeModule);
 680       _eglModules = NULL;
 681    }
 682 }
 683
 684
 685 /**
 686  * Invoke a callback function on each EGL search path.
 687  *
 688  * The first argument of the callback function is the name of the search path.
 689  * The second argument is the length of the name.
 690  */
 691 void
 692 _eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
 693                       void *callback_data)
 694 {
 695    const char *search_path = _eglGetSearchPath();
 696    _eglPreloadForEach(search_path, callback, callback_data);
 697 }