Xi: check for Use permission on the device in SetClientPointer().

Presumably, some intelligent, XI2-aware management app will be calling
XISetClientPointer on behalf of other clients; this check makes sure
the target client has permission on the device.

Requires changing the prototype to return status code instead of Bool.

Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>

Xi/xisetclientpointer.c

@@ -98,10 +98,11 @@ ProcXISetClientPointer(ClientPtr client)
     } else
         targetClient = client;
 
-    if (!SetClientPointer(targetClient, pDev))
+    rc = SetClientPointer(targetClient, pDev);
+    if (rc != Success)
     {
         client->errorValue = stuff->deviceid;
-        return BadDevice;
+        return rc;
     }
 
     return Success;

dix/events.c

@@ -5699,21 +5699,25 @@ WriteEventsToClient(ClientPtr pClient, int count, xEvent *events)
  * PickPointer()).
  * If a keyboard is needed, the first keyboard paired with the CP is used.
  */
-Bool
+int
 SetClientPointer(ClientPtr client, DeviceIntPtr device)
 {
+    int rc = XaceHook(XACE_DEVICE_ACCESS, client, device, DixUseAccess);
+    if (rc != Success)
+	return rc;
+
     if (!IsMaster(device))
     {
         ErrorF("[dix] Need master device for ClientPointer. This is a bug.\n");
-        return FALSE;
+        return BadDevice;
     } else if (!device->spriteInfo->spriteOwner)
     {
         ErrorF("[dix] Device %d does not have a sprite. "
                 "Cannot be ClientPointer\n", device->id);
-        return FALSE;
+        return BadDevice;
     }
     client->clientPtr = device;
-    return TRUE;
+    return Success;
 }
 
 /* PickPointer will pick an appropriate pointer for the given client.

include/dix.h

@@ -485,7 +485,7 @@ extern _X_EXPORT int TryClientEvents(
 
 extern _X_EXPORT void WindowsRestructured(void);
 
-extern Bool SetClientPointer(
+extern int SetClientPointer(
         ClientPtr /* client */,
         DeviceIntPtr /* device */);