1 /**************************************************************************
3 * Copyright 2011 Jose Fonseca
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 **************************************************************************/
31 #include <unistd.h> // for symlink
37 * Handle to the true OpenGL library.
40 HMODULE _libGlHandle = NULL;
42 void *_libGlHandle = NULL;
50 _getPublicProcAddress(const char *procName)
53 char szDll[MAX_PATH] = {0};
55 if (!GetSystemDirectoryA(szDll, MAX_PATH)) {
59 strcat(szDll, "\\\\opengl32.dll");
61 _libGlHandle = LoadLibraryA(szDll);
63 os::log("apitrace: error: couldn't load %s\n", szDll);
68 return (void *)GetProcAddress(_libGlHandle, procName);
73 _getPrivateProcAddress(const char *procName) {
74 return (void *)_wglGetProcAddress(procName);
78 #elif defined(__APPLE__)
82 * Path to the true OpenGL framework
84 static const char *libgl_filename = "/System/Library/Frameworks/OpenGL.framework/OpenGL";
88 * Lookup a libGL symbol
90 void * _libgl_sym(const char *symbol)
96 * Unfortunately we can't just dlopen the true dynamic library because
97 * DYLD_LIBRARY_PATH/DYLD_FRAMEWORK_PATH take precedence, even for
98 * absolute paths. So we create a temporary symlink, and dlopen that
102 char temp_filename[] = "/tmp/tmp.XXXXXX";
104 if (mktemp(temp_filename) != NULL) {
105 if (symlink(libgl_filename, temp_filename) == 0) {
106 _libGlHandle = dlopen(temp_filename, RTLD_LOCAL | RTLD_NOW | RTLD_FIRST);
107 remove(temp_filename);
112 os::log("apitrace: error: couldn't load %s\n", libgl_filename);
118 result = dlsym(_libGlHandle, symbol);
121 if (result && result == dlsym(RTLD_SELF, symbol)) {
122 os::log("apitrace: error: symbol lookup recursion\n");
133 _getPublicProcAddress(const char *procName)
135 return _libgl_sym(procName);
139 _getPrivateProcAddress(const char *procName)
141 return _libgl_sym(procName);
149 logSymbol(const char *name, void *ptr) {
153 if (ptr && dladdr(ptr, &info)) {
154 os::log("apitrace: %s -> \"%s\"\n", name, info.dli_fname);
157 os::log("apitrace: %s -> NULL\n", name);
164 extern "C" void * __libc_dlsym(void *, const char *);
169 * Protect against dlsym interception.
171 * We implement the whole API, so we don't need to intercept dlsym -- dlopen is
172 * enough. However we need to protect against other dynamic libraries
173 * intercepting dlsym, to prevent infinite recursion,
175 * In particular the Steam Community Overlay advertises dlsym. See also
176 * http://lists.freedesktop.org/archives/apitrace/2013-March/000573.html
179 _dlsym(void *handle, const char *symbol)
185 * We rely on glibc's internal __libc_dlsym. See also
186 * http://www.linuxforu.com/2011/08/lets-hook-a-library-function/
188 * Use use it to obtain the true dlsym. We don't use __libc_dlsym directly
189 * because it does not support things such as RTLD_NEXT.
191 typedef void * (*PFN_DLSYM)(void *, const char *);
192 static PFN_DLSYM dlsym_ptr = NULL;
194 void *libdl_handle = _dlopen("libdl.so.2", RTLD_LOCAL | RTLD_NOW);
196 dlsym_ptr = (PFN_DLSYM)__libc_dlsym(libdl_handle, "dlsym");
199 os::log("apitrace: error: failed to look up real dlsym\n");
203 logSymbol("dlsym", (void*)dlsym_ptr);
206 result = dlsym_ptr(handle, symbol);
208 result = dlsym(handle, symbol);
216 * Lookup a libGL symbol
218 void * _libgl_sym(const char *symbol)
224 * The app doesn't directly link against libGL.so, nor does it directly
225 * dlopen it. So we have to load it ourselves.
228 const char * libgl_filename = getenv("TRACE_LIBGL");
230 if (!libgl_filename) {
232 * Try to use whatever libGL.so the library is linked against.
235 result = dlsym(RTLD_NEXT, symbol);
237 _libGlHandle = RTLD_NEXT;
241 libgl_filename = "libGL.so.1";
245 * It would have been preferable to use RTLD_LOCAL to ensure that the
246 * application can never access libGL.so symbols directly, but this
247 * won't work, given libGL.so often loads a driver specific SO and
248 * exposes symbols to it.
251 _libGlHandle = _dlopen(libgl_filename, RTLD_GLOBAL | RTLD_LAZY);
253 os::log("apitrace: error: couldn't find libGL.so\n");
258 result = _dlsym(_libGlHandle, symbol);
260 logSymbol(symbol, result);
267 _getPublicProcAddress(const char *procName)
269 return _libgl_sym(procName);
273 _getPrivateProcAddress(const char *procName)
275 return (void *)_glXGetProcAddressARB((const GLubyte *)procName);