glx: Work around wrong request lengths sent by mesa

mesa used to send too long requests for GLXDestroyPixmap,
GLXDestroyWindow, GLXChangeDrawableAttributes, GLXGetDrawableAttributes
and GLXGetFBConfigsSGIX.

Fixes a regression introduced in ec9c97c6bf70b523bc500bd3adf62176f1bb33a4
X.Org bug#33324 <https://bugs.freedesktop.org/show_bug.cgi?id=33324>

Reported-by: xunx.fang@intel.com
Signed-off-by: Julien Cristau <jcristau@debian.org>
Reviewed-by: Adam Jackson <ajax@redhat.com>

2 files changed, 22 insertions, 9 deletions

diff --git a/glx/glxcmds.c b/glx/glxcmds.c
index 5d633dfc5..9b4bc9ec3 100644
--- a/glx/glxcmds.c
+++ b/glx/glxcmds.c
@@ -1132,7 +1132,8 @@ int __glXDisp_GetFBConfigsSGIX(__GLXclientState *cl, GLbyte *pc)
 {
     ClientPtr client = cl->client;
     xGLXGetFBConfigsSGIXReq *req = (xGLXGetFBConfigsSGIXReq *) pc;
-    REQUEST_SIZE_MATCH(xGLXGetFBConfigsSGIXReq);
+    /* work around mesa bug, don't use REQUEST_SIZE_MATCH */
+    REQUEST_AT_LEAST_SIZE(xGLXGetFBConfigsSGIXReq);
     return DoGetFBConfigs(cl, req->screen);
 }
 
@@ -1356,7 +1357,9 @@ int __glXDisp_DestroyPixmap(__GLXclientState *cl, GLbyte *pc)
     ClientPtr client = cl->client;
     xGLXDestroyPixmapReq *req = (xGLXDestroyPixmapReq *) pc;
 
-    REQUEST_SIZE_MATCH(xGLXDestroyPixmapReq);
+    /* should be REQUEST_SIZE_MATCH, but mesa's glXDestroyPixmap used to set
+     * length to 3 instead of 2 */
+    REQUEST_AT_LEAST_SIZE(xGLXDestroyPixmapReq);
 
     return DoDestroyDrawable(cl, req->glxpixmap, GLX_DRAWABLE_PIXMAP);
 }
@@ -1498,7 +1501,13 @@ int __glXDisp_ChangeDrawableAttributes(__GLXclientState *cl, GLbyte *pc)
 	client->errorValue = req->numAttribs;
 	return BadValue;
     }
+#if 0
+    /* mesa sends an additional 8 bytes */
     REQUEST_FIXED_SIZE(xGLXChangeDrawableAttributesReq, req->numAttribs << 3);
+#else
+    if (((sizeof(xGLXChangeDrawableAttributesReq) + (req->numAttribs << 3)) >> 2) < client->req_len)
+	    return BadLength;
+#endif
 
     return DoChangeDrawableAttributes(cl->client, req->drawable,
 				      req->numAttribs, (CARD32 *) (req + 1));
@@ -1563,7 +1572,8 @@ int __glXDisp_DestroyWindow(__GLXclientState *cl, GLbyte *pc)
     ClientPtr client = cl->client;
     xGLXDestroyWindowReq *req = (xGLXDestroyWindowReq *) pc;
 
-    REQUEST_SIZE_MATCH(xGLXDestroyWindowReq);
+    /* mesa's glXDestroyWindow used to set length to 3 instead of 2 */
+    REQUEST_AT_LEAST_SIZE(xGLXDestroyWindowReq);
 
     return DoDestroyDrawable(cl, req->glxwindow, GLX_DRAWABLE_WINDOW);
 }
@@ -1872,7 +1882,8 @@ int __glXDisp_GetDrawableAttributes(__GLXclientState *cl, GLbyte *pc)
     ClientPtr client = cl->client;
     xGLXGetDrawableAttributesReq *req = (xGLXGetDrawableAttributesReq *)pc;
 
-    REQUEST_SIZE_MATCH(xGLXGetDrawableAttributesReq);
+    /* this should be REQUEST_SIZE_MATCH, but mesa sends an additional 4 bytes */
+    REQUEST_AT_LEAST_SIZE(xGLXGetDrawableAttributesReq);
 
     return DoGetDrawableAttributes(cl, req->drawable);
 }
diff --git a/glx/glxcmdsswap.c b/glx/glxcmdsswap.c
index d58de6299..76e6fb629 100644
--- a/glx/glxcmdsswap.c
+++ b/glx/glxcmdsswap.c
@@ -279,7 +279,7 @@ int __glXDispSwap_GetFBConfigsSGIX(__GLXclientState *cl, GLbyte *pc)
     xGLXGetFBConfigsSGIXReq *req = (xGLXGetFBConfigsSGIXReq *) pc;
     __GLX_DECLARE_SWAP_VARIABLES;
 
-    REQUEST_SIZE_MATCH(xGLXGetFBConfigsSGIXReq);
+    REQUEST_AT_LEAST_SIZE(xGLXGetFBConfigsSGIXReq);
 
     __GLX_SWAP_INT(&req->screen);
     return __glXDisp_GetFBConfigsSGIX(cl, pc);
@@ -368,7 +368,7 @@ int __glXDispSwap_DestroyPixmap(__GLXclientState *cl, GLbyte *pc)
     xGLXDestroyGLXPixmapReq *req = (xGLXDestroyGLXPixmapReq *) pc;
     __GLX_DECLARE_SWAP_VARIABLES;
 
-    REQUEST_SIZE_MATCH(xGLXDestroyGLXPixmapReq);
+    REQUEST_AT_LEAST_SIZE(xGLXDestroyGLXPixmapReq);
 
     __GLX_SWAP_SHORT(&req->length);
     __GLX_SWAP_INT(&req->glxpixmap);
@@ -476,7 +476,9 @@ int __glXDispSwap_ChangeDrawableAttributes(__GLXclientState *cl, GLbyte *pc)
 	client->errorValue = req->numAttribs;
 	return BadValue;
     }
-    REQUEST_FIXED_SIZE(xGLXChangeDrawableAttributesReq, req->numAttribs << 3);
+    if (((sizeof(xGLXChangeDrawableAttributesReq) + (req->numAttribs << 3)) >> 2) < client->req_len)
+	return BadLength;
+
     attribs = (CARD32*)(req + 1);
     __GLX_SWAP_INT_ARRAY(attribs, req->numAttribs << 1);
 
@@ -542,7 +544,7 @@ int __glXDispSwap_DestroyWindow(__GLXclientState *cl, GLbyte *pc)
     xGLXDestroyWindowReq *req = (xGLXDestroyWindowReq *) pc;
     __GLX_DECLARE_SWAP_VARIABLES;
 
-    REQUEST_SIZE_MATCH(xGLXDestroyWindowReq);
+    REQUEST_AT_LEAST_SIZE(xGLXDestroyWindowReq);
 
     __GLX_SWAP_INT(&req->glxwindow);
 
@@ -742,7 +744,7 @@ int __glXDispSwap_GetDrawableAttributes(__GLXclientState *cl, GLbyte *pc)
     xGLXGetDrawableAttributesReq *req = (xGLXGetDrawableAttributesReq *)pc;
     __GLX_DECLARE_SWAP_VARIABLES;
 
-    REQUEST_SIZE_MATCH(xGLXGetDrawableAttributesReq);
+    REQUEST_AT_LEAST_SIZE(xGLXGetDrawableAttributesReq);
 
     __GLX_SWAP_SHORT(&req->length);
     __GLX_SWAP_INT(&req->drawable);