r15188: Restore svn rev. 15183, 15184 and 15185, which I inadvertantly clobbered

in r15186. I don't think I should be allowed to use quilt and svn at the
same time any more :(
(This used to be commit e0ca5ead27743c84f5d9310a05d6d718862ead1d)

1 files changed, 47 insertions, 12 deletions

diff --git a/source4/ntvfs/ntvfs_base.c b/source4/ntvfs/ntvfs_base.c
index b1efb44ec7..316a9e9c68 100644
--- a/source4/ntvfs/ntvfs_base.c
+++ b/source4/ntvfs/ntvfs_base.c
@@ -44,11 +44,18 @@ static int num_backends;
 
   The 'type' is used to specify whether this is for a disk, printer or IPC$ share
 */
-_PUBLIC_ NTSTATUS ntvfs_register(const void *_ops)
+_PUBLIC_ NTSTATUS ntvfs_register(const struct ntvfs_ops *ops,
+				 const struct ntvfs_critical_sizes *const sizes)
 {
-	const struct ntvfs_ops *ops = _ops;
 	struct ntvfs_ops *new_ops;
-	
+
+	if (ntvfs_interface_differs(sizes)) {
+		DEBUG(0, ("NTVFS backend '%s' for type %d "
+			  "failed version check\n",
+			  ops->name, (int)ops->type));
+		return NT_STATUS_BAD_FUNCTION_TABLE;
+	}
+
 	if (ntvfs_backend_byname(ops->name, ops->type) != NULL) {
 		/* its already registered! */
 		DEBUG(0,("NTVFS backend '%s' for type %d already registered\n", 
@@ -98,21 +105,49 @@ _PUBLIC_ const struct ntvfs_ops *ntvfs_backend_byname(const char *name, enum ntv
   This can be used by backends to either detect compilation errors, or provide
   multiple implementations for different smbd compilation options in one module
 */
-static const struct ntvfs_critical_sizes critical_sizes = {
-	.interface_version		= NTVFS_INTERFACE_VERSION,
-	.sizeof_ntvfs_critical_sizes	= sizeof(struct ntvfs_critical_sizes),
-	.sizeof_ntvfs_context		= sizeof(struct ntvfs_context),
-	.sizeof_ntvfs_module_context	= sizeof(struct ntvfs_module_context),
-	.sizeof_ntvfs_ops		= sizeof(struct ntvfs_ops),
-	.sizeof_ntvfs_async_state	= sizeof(struct ntvfs_async_state),
-	.sizeof_ntvfs_request		= sizeof(struct ntvfs_request),
-};
+
+static const NTVFS_CURRENT_CRITICAL_SIZES(critical_sizes);
 
 _PUBLIC_ const struct ntvfs_critical_sizes *ntvfs_interface_version(void)
 {
 	return &critical_sizes;
 }
 
+_PUBLIC_ BOOL ntvfs_interface_differs(const struct ntvfs_critical_sizes *const iface)
+{
+	/* The comparison would be easier with memcmp, but compiler-interset
+	 * alignment padding is not guaranteed to be zeroed.
+	 */
+
+#define FIELD_DIFFERS(field) (iface->field != critical_sizes.field)
+
+	if (FIELD_DIFFERS(interface_version))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_critical_sizes))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_context))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_module_context))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_ops))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_async_state))
+		return True;
+
+	if (FIELD_DIFFERS(sizeof_ntvfs_request))
+		return True;
+
+	/* Versions match. */
+	return False;
+
+#undef FIELD_DIFFERS
+}
+
 
 /*
   initialise a connection structure to point at a NTVFS backend