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/*
* 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: 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 256 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[256];
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
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