#define _GNU_SOURCE
#include <dlfcn.h>
-#include <stdio.h>
-#include <stdlib.h>
+#include <assert.h>
-#include <string.h>
+#include "fips.h"
#include "dlwrap.h"
-#define STRNCMP_LITERAL(var, literal) \
- strncmp ((var), (literal), sizeof (literal) - 1)
+#include "glwrap.h"
void *libfips_handle;
typedef void * (* fips_dlopen_t)(const char * filename, int flag);
typedef void * (* fips_dlsym_t)(void *handle, const char *symbol);
+static const char *wrapped_libs[] = {
+ "libGL.so",
+ "libEGL.so",
+ "libGLESv2.so"
+};
+
+static void *orig_handles[ARRAY_SIZE(wrapped_libs)];
+
+/* Match 'filename' against an internal list of libraries for which
+ * libfips has wrappers.
+ *
+ * Returns true and sets *index_ret if a match is found.
+ * Returns false if no match is found. */
+static bool
+find_wrapped_library_index (const char *filename, unsigned *index_ret)
+{
+ unsigned i;
+
+ for (i = 0; i < ARRAY_SIZE(wrapped_libs); i++) {
+ if (strncmp(wrapped_libs[i], filename,
+ strlen (wrapped_libs[i])) == 0)
+ {
+ *index_ret = i;
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* Perform a dlopen on the libfips library itself.
+ *
+ * Many places in fips need to lookup symbols within the libfips
+ * library itself, (and not in any other library). This function
+ * provides a reliable way to get a handle for performing such
+ * lookups.
+ *
+ * The returned handle can be passed to dlwrap_real_dlsym for the
+ * lookups. */
+void *
+dlwrap_dlopen_libfips (void)
+{
+ Dl_info info;
+
+ /* We first find our own filename by looking up a function
+ * known to exist only in libfips. This function itself
+ * (dlwrap_dlopen_libfips) is a good one for that purpose. */
+ if (dladdr (dlwrap_dlopen_libfips, &info) == 0) {
+ fprintf (stderr, "Internal error: Failed to lookup filename of libfips library with dladdr\n");
+ exit (1);
+ }
+
+ return dlwrap_real_dlopen (info.dli_fname, RTLD_NOW);
+}
+
/* Many (most?) OpenGL programs dlopen libGL.so.1 rather than linking
* against it directly, which means they would not be seeing our
* wrapped GL symbols via LD_PRELOAD. So we catch the dlopen in a
void *
dlopen (const char *filename, int flag)
{
- Dl_info info;
-
- /* Not libGL, so just return real dlopen */
- if (STRNCMP_LITERAL (filename, "libGL.so"))
- return dlwrap_real_dlopen (filename, flag);
-
- /* Redirect all dlopens to libGL to our own wrapper library.
- * We find our own filename by looking up this very function
- * (that is, this "dlopen"), with dladdr).*/
- if (dladdr (dlopen, &info)) {
- libfips_handle = dlwrap_real_dlopen (info.dli_fname, flag);
- return libfips_handle;
- } else {
- fprintf (stderr, "Error: Failed to redirect dlopen of %s:\n",
- filename);
- exit (1);
- }
+ void *ret;
+ unsigned index;
+
+ /* Before deciding whether to redirect this dlopen to our own
+ * library, we call the real dlopen. This assures that any
+ * expected side-effects from loading the intended library are
+ * resolved. Below, we may still return a handle pointing to
+ * our own library, and not what is opened here. */
+ ret = dlwrap_real_dlopen (filename, flag);
+
+ /* If filename is not a wrapped library, just return real dlopen */
+ if (! find_wrapped_library_index (filename, &index))
+ return ret;
+
+ /* When the application dlopens any wrapped library starting
+ * with 'libGL', (whether libGL.so.1 or libGLESv2.so.2), let's
+ * continue to use that library handle for future lookups of
+ * OpenGL functions. */
+ if (STRNCMP_LITERAL (filename, "libGL") == 0)
+ glwrap_set_gl_handle (ret);
+
+ assert (index < ARRAY_SIZE(orig_handles));
+ orig_handles[index] = ret;
+
+ if (libfips_handle == NULL)
+ libfips_handle = dlwrap_dlopen_libfips ();
+
+ /* Otherwise, we return our own handle so that we can intercept
+ * future calls to dlsym. We encode the index in the return value
+ * so that we can later map back to the originally requested
+ * dlopen-handle if necessary. */
+ return libfips_handle + index;
}
void *
dlwrap_real_dlopen (const char *filename, int flag)
{
- fips_dlopen_t real_dlopen = NULL;
+ static fips_dlopen_t real_dlopen = NULL;
if (! real_dlopen) {
real_dlopen = (fips_dlopen_t) dlwrap_real_dlsym (RTLD_NEXT, "dlopen");
return real_dlopen (filename, flag);
}
-/* Since we redirect a dlopen of libGL.so to libfips we need to ensure
- * that dlysm succeeds for all functions that might be defined in the
- * real, underlying libGL library. But we're far too lazy to implement
- * wrappers for function that would simply pass-through, so instead we
- * also wrap dlysm and arrange for it to pass things through with
- * RTLD_next if libfips does not have the function desired.
-*/
+/* Since we redirect dlopens of libGL.so and libEGL.so to libfips we
+ * need to ensure that dlysm succeeds for all functions that might be
+ * defined in the real, underlying libGL library. But we're far too
+ * lazy to implement wrappers for function that would simply
+ * pass-through, so instead we also wrap dlysm and arrange for it to
+ * pass things through with RTLD_next if libfips does not have the
+ * function desired. */
void *
dlsym (void *handle, const char *name)
{
- static void *libgl_handle = NULL;
static void *symbol;
+ unsigned index;
- /* All gl symbols are preferentially looked up in libfips. */
- if (STRNCMP_LITERAL (name, "gl") == 0) {
+ /* All gl* and egl* symbols are preferentially looked up in libfips. */
+ if (STRNCMP_LITERAL (name, "gl") == 0 ||
+ STRNCMP_LITERAL (name, "egl") == 0)
+ {
symbol = dlwrap_real_dlsym (libfips_handle, name);
if (symbol)
return symbol;
/* Failing that, anything specifically requested from the
* libfips library should be redirected to a real GL
* library. */
- if (handle == libfips_handle) {
- if (! libgl_handle)
- libgl_handle = dlwrap_real_dlopen ("libGL.so.1", RTLD_LAZY);
- return dlwrap_real_dlsym (libgl_handle, name);
+
+ /* We subtract the index back out of the handle (see the addition
+ * of the index in our wrapper for dlopen above) to then use the
+ * correct, original dlopen'ed handle for the library of
+ * interest. */
+ index = handle - libfips_handle;
+ if (index < ARRAY_SIZE(orig_handles)) {
+ return dlwrap_real_dlsym (orig_handles[index], name);
}
- /* And anything else is some unrelated dlsym. Just pass it through. */
+ /* And anything else is some unrelated dlsym. Just pass it
+ * through. (This also covers the cases of lookups with
+ * special handles such as RTLD_DEFAULT or RTLD_NEXT.)
+ */
return dlwrap_real_dlsym (handle, name);
}
-extern void *__dlsym (void *handle, const char *name);
void *
dlwrap_real_dlsym (void *handle, const char *name)
{
projects / fips / blobdiff