genetlink: Introduce genl_register_family_with_ops()

This introduces genl_register_family_with_ops() that registers a genetlink
family along with operations from a table. This is used to kill copy'n'paste
occurrences in following patches.
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/genetlink.h

@@ -88,6 +88,8 @@ struct genl_ops
 };
 
 extern int genl_register_family(struct genl_family *family);
+extern int genl_register_family_with_ops(struct genl_family *family,
+	struct genl_ops *ops, size_t n_ops);
 extern int genl_unregister_family(struct genl_family *family);
 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);

net/netlink/genetlink.c

@@ -383,6 +383,52 @@ int genl_register_family(struct genl_family *family)
 	return err;
 }
 
+/**
+ * genl_register_family_with_ops - register a generic netlink family
+ * @family: generic netlink family
+ * @ops: operations to be registered
+ * @n_ops: number of elements to register
+ *
+ * Registers the specified family and operations from the specified table.
+ * Only one family may be registered with the same family name or identifier.
+ *
+ * The family id may equal GENL_ID_GENERATE causing an unique id to
+ * be automatically generated and assigned.
+ *
+ * Either a doit or dumpit callback must be specified for every registered
+ * operation or the function will fail. Only one operation structure per
+ * command identifier may be registered.
+ *
+ * See include/net/genetlink.h for more documenation on the operations
+ * structure.
+ *
+ * This is equivalent to calling genl_register_family() followed by
+ * genl_register_ops() for every operation entry in the table taking
+ * care to unregister the family on error path.
+ *
+ * Return 0 on success or a negative error code.
+ */
+int genl_register_family_with_ops(struct genl_family *family,
+	struct genl_ops *ops, size_t n_ops)
+{
+	int err, i;
+
+	err = genl_register_family(family);
+	if (err)
+		return err;
+
+	for (i = 0; i < n_ops; ++i, ++ops) {
+		err = genl_register_ops(family, ops);
+		if (err)
+			goto err_out;
+	}
+	return 0;
+err_out:
+	genl_unregister_family(family);
+	return err;
+}
+EXPORT_SYMBOL(genl_register_family_with_ops);
+
 /**
  * genl_unregister_family - unregister generic netlink family
  * @family: generic netlink family