Demos (master): viewmemory: view uninitialized video memory

[Brian Paul]

Module: Demos
Branch: master
Commit: fcb4d445169989d5ddcceb26ffbff3406587e372
URL:    http://cgit.freedesktop.org/mesa/demos/commit/?id=fcb4d445169989d5ddcceb26ffbff3406587e372

Author: Brian Paul <brianp at vmware.com>
Date:   Fri Jun 17 09:56:15 2011 -0600

viewmemory: view uninitialized video memory

See comments for details.

---

 src/tests/CMakeLists.txt |    1 +
 src/tests/Makefile.am    |    1 +
 src/tests/viewmemory.c   |  206 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 208 insertions(+), 0 deletions(-)

diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 53aac25..32187bc 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -115,6 +115,7 @@ set (targets
 	texobj
 	texrect
 	unfilledclip
+	viewmemory
 	vparray
 	vpeval
 	vptest1
diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index ef1a207..4c0985a 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -149,6 +149,7 @@ noinst_PROGRAMS = \
 	texobjshare \
 	texrect \
 	unfilledclip \
+	viewmemory \
 	vparray \
 	vpeval \
 	vptest1 \
diff --git a/src/tests/viewmemory.c b/src/tests/viewmemory.c
new file mode 100644
index 0000000..d87a8d0
--- /dev/null
+++ b/src/tests/viewmemory.c
@@ -0,0 +1,206 @@
+/**
+ * Try to see other parts of the user's video memory by creating textures
+ * with uninitialized contents.  Display those textures in the window.
+ * Insprired by stories of WebGL security issues.
+ *
+ * The OpenGL driver should probably initialize all memory allocations
+ * to zero (textures, renderbuffers, buffer objects, etc).
+ *
+ * Brian Paul
+ * June 2011
+ */
+
+#define GL_GLEXT_PROTOTYPES
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "glut_wrap.h"
+
+static int Win;
+static int WinWidth = 1024, WinHeight = 512;
+static GLboolean Anim = GL_FALSE;
+
+static GLuint *Textures;
+static GLuint TexWidth = 1024, TexHeight = 512;
+static GLuint NumTextures = 50, CurTexture;
+
+
+static void
+Idle(void)
+{
+   static int prevTime = 0;
+   int curTime = glutGet(GLUT_ELAPSED_TIME);
+
+   if (!prevTime) {
+      prevTime = curTime;
+   }
+   else {
+      if (curTime - prevTime > 250) {
+         prevTime = curTime;
+         CurTexture = (CurTexture + 1) % NumTextures;
+         glutPostRedisplay();
+      }
+   }
+}
+
+
+static void
+MakeTextures(void)
+{
+   GLuint i;
+
+   Textures = (GLuint *) malloc(NumTextures * sizeof(GLuint));
+
+   glGenTextures(NumTextures, Textures);
+   for (i = 0; i < NumTextures; i++) {
+      glBindTexture(GL_TEXTURE_2D, Textures[i]);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TexWidth, TexHeight, 0,
+                   GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+   }
+}
+
+
+static void
+PrintString(const char *s)
+{
+   while (*s) {
+      glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
+      s++;
+   }
+}
+
+
+static void
+Draw(void)
+{
+   char s[100];
+
+   sprintf(s, "Texture %u", CurTexture);
+
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   glEnable(GL_TEXTURE_2D);
+   glBindTexture(GL_TEXTURE_2D, CurTexture);
+
+   glBegin(GL_POLYGON);
+   glTexCoord2f(0, 0);  glVertex2f(0, 0);
+   glTexCoord2f(1, 0);  glVertex2f(WinWidth, 0);
+   glTexCoord2f(1, 1);  glVertex2f(WinWidth, WinHeight);
+   glTexCoord2f(0, 1);  glVertex2f(0, WinHeight);
+   glEnd();
+
+   glDisable(GL_TEXTURE_2D);
+   glColor3f(0, 1, 0);
+   glWindowPos2iARB(10, 10);
+   PrintString(s);
+
+   glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+   WinWidth = width;
+   WinHeight = height;
+   glViewport(0, 0, width, height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glOrtho(0, WinWidth, 0, WinHeight, -1, 1);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+   switch (key) {
+   case 'a':
+   case 'A':
+      Anim = !Anim;
+      if (Anim)
+         glutIdleFunc(Idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   case 27:
+      glutDestroyWindow(Win);
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+   case GLUT_KEY_LEFT:
+      if (CurTexture > 0)
+         CurTexture--;
+      break;
+   case GLUT_KEY_RIGHT:
+      if (CurTexture + 1 < NumTextures)
+         CurTexture++;
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+Init(void)
+{
+   printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
+   if (glutExtensionSupported("GL_ARB_robustness"))
+      printf("GL_ARB_robustness supported\n");
+   else
+      printf("GL_ARB_robustness not supported\n");
+
+   MakeTextures();
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+   printf("Keys:\n");
+   printf("  a: toggle animation\n");
+   printf("  Left/Right: back / next frame\n");
+   printf("  Esc: exit\n");
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+
+   if (argc > 1) {
+      NumTextures = atoi(argv[1]);
+      if (NumTextures < 1) {
+         printf("Invalid argument (number of textures)\n");
+         return 1;
+      }
+   }
+   printf("Creating %u textures\n", NumTextures);
+
+   glutInitWindowSize(WinWidth, WinHeight);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+   Win = glutCreateWindow(argv[0]);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutSpecialFunc(SpecialKey);
+   glutDisplayFunc(Draw);
+
+   if (Anim)
+      glutIdleFunc(Idle);
+
+   Init();
+
+   glutMainLoop();
+   return 0;
+}