Initial import

1 files changed, 103 insertions, 0 deletions

diff --git a/ipc/kdbus/handle.h b/ipc/kdbus/handle.h
new file mode 100644
index 000000000..8a36c0595
--- /dev/null
+++ b/ipc/kdbus/handle.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_HANDLE_H
+#define __KDBUS_HANDLE_H
+
+#include <linux/fs.h>
+#include <uapi/linux/kdbus.h>
+
+extern const struct file_operations kdbus_handle_ops;
+
+/**
+ * kdbus_arg - information and state of a single ioctl command item
+ * @type:		item type
+ * @item:		set by the parser to the first found item of this type
+ * @multiple:		whether multiple items of this type are allowed
+ * @mandatory:		whether at least one item of this type is required
+ *
+ * This structure describes a single item in an ioctl command payload. The
+ * caller has to pre-fill the type and flags, the parser will then use this
+ * information to verify the ioctl payload. @item is set by the parser to point
+ * to the first occurrence of the item.
+ */
+struct kdbus_arg {
+	u64 type;
+	struct kdbus_item *item;
+	bool multiple : 1;
+	bool mandatory : 1;
+};
+
+/**
+ * kdbus_args - information and state of ioctl command parser
+ * @allowed_flags:	set of flags this command supports
+ * @argc:		number of items in @argv
+ * @argv:		array of items this command supports
+ * @user:		set by parser to user-space location of current command
+ * @cmd:		set by parser to kernel copy of command payload
+ * @cmd_buf:		512 bytes inline buf to avoid kmalloc() on small cmds
+ * @items:		points to item array in @cmd
+ * @items_size:		size of @items in bytes
+ * @is_cmd:		whether this is a command-payload or msg-payload
+ *
+ * This structure is used to parse ioctl command payloads on each invocation.
+ * The ioctl handler has to pre-fill the flags and allowed items before passing
+ * the object to kdbus_args_parse(). The parser will copy the command payload
+ * into kernel-space and verify the correctness of the data.
+ *
+ * We use a 512 bytes buffer for small command payloads, to be allocated on
+ * stack on syscall entrance.
+ */
+struct kdbus_args {
+	u64 allowed_flags;
+	size_t argc;
+	struct kdbus_arg *argv;
+
+	struct kdbus_cmd __user *user;
+	struct kdbus_cmd *cmd;
+	u8 cmd_buf[512];
+
+	struct kdbus_item *items;
+	size_t items_size;
+	bool is_cmd : 1;
+};
+
+int __kdbus_args_parse(struct kdbus_args *args, bool is_cmd, void __user *argp,
+		       size_t type_size, size_t items_offset, void **out);
+int kdbus_args_clear(struct kdbus_args *args, int ret);
+
+#define kdbus_args_parse(_args, _argp, _v)                              \
+	({                                                              \
+		BUILD_BUG_ON(offsetof(typeof(**(_v)), size) !=          \
+			     offsetof(struct kdbus_cmd, size));         \
+		BUILD_BUG_ON(offsetof(typeof(**(_v)), flags) !=         \
+			     offsetof(struct kdbus_cmd, flags));        \
+		BUILD_BUG_ON(offsetof(typeof(**(_v)), return_flags) !=  \
+			     offsetof(struct kdbus_cmd, return_flags)); \
+		__kdbus_args_parse((_args), 1, (_argp), sizeof(**(_v)), \
+				   offsetof(typeof(**(_v)), items),     \
+				   (void **)(_v));                      \
+	})
+
+#define kdbus_args_parse_msg(_args, _argp, _v)                          \
+	({                                                              \
+		BUILD_BUG_ON(offsetof(typeof(**(_v)), size) !=          \
+			     offsetof(struct kdbus_cmd, size));         \
+		BUILD_BUG_ON(offsetof(typeof(**(_v)), flags) !=         \
+			     offsetof(struct kdbus_cmd, flags));        \
+		__kdbus_args_parse((_args), 0, (_argp), sizeof(**(_v)), \
+				   offsetof(typeof(**(_v)), items),     \
+				   (void **)(_v));                      \
+	})
+
+#endif