1/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
2/*
3 * Copyright 1993 by Theodore Ts'o.
4 */
5#ifndef _UAPI_LINUX_LOOP_H
6#define _UAPI_LINUX_LOOP_H
7
8
9#define LO_NAME_SIZE	64
10#define LO_KEY_SIZE	32
11
12
13/*
14 * Loop flags
15 */
16enum {
17	LO_FLAGS_READ_ONLY	= 1,
18	LO_FLAGS_AUTOCLEAR	= 4,
19	LO_FLAGS_PARTSCAN	= 8,
20	LO_FLAGS_DIRECT_IO	= 16,
21};
22
23/* LO_FLAGS that can be set using LOOP_SET_STATUS(64) */
24#define LOOP_SET_STATUS_SETTABLE_FLAGS (LO_FLAGS_AUTOCLEAR | LO_FLAGS_PARTSCAN)
25
26/* LO_FLAGS that can be cleared using LOOP_SET_STATUS(64) */
27#define LOOP_SET_STATUS_CLEARABLE_FLAGS (LO_FLAGS_AUTOCLEAR)
28
29/* LO_FLAGS that can be set using LOOP_CONFIGURE */
30#define LOOP_CONFIGURE_SETTABLE_FLAGS (LO_FLAGS_READ_ONLY | LO_FLAGS_AUTOCLEAR \
31				       | LO_FLAGS_PARTSCAN | LO_FLAGS_DIRECT_IO)
32
33#include <asm/posix_types.h>	/* for __kernel_old_dev_t */
34#include <linux/types.h>	/* for __u64 */
35
36/* Backwards compatibility version */
37struct loop_info {
38	int		   lo_number;		/* ioctl r/o */
39	__kernel_old_dev_t lo_device; 		/* ioctl r/o */
40	unsigned long	   lo_inode; 		/* ioctl r/o */
41	__kernel_old_dev_t lo_rdevice; 		/* ioctl r/o */
42	int		   lo_offset;
43	int		   lo_encrypt_type;		/* obsolete, ignored */
44	int		   lo_encrypt_key_size; 	/* ioctl w/o */
45	int		   lo_flags;
46	char		   lo_name[LO_NAME_SIZE];
47	unsigned char	   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
48	unsigned long	   lo_init[2];
49	char		   reserved[4];
50};
51
52struct loop_info64 {
53	__u64		   lo_device;			/* ioctl r/o */
54	__u64		   lo_inode;			/* ioctl r/o */
55	__u64		   lo_rdevice;			/* ioctl r/o */
56	__u64		   lo_offset;
57	__u64		   lo_sizelimit;/* bytes, 0 == max available */
58	__u32		   lo_number;			/* ioctl r/o */
59	__u32		   lo_encrypt_type;		/* obsolete, ignored */
60	__u32		   lo_encrypt_key_size;		/* ioctl w/o */
61	__u32		   lo_flags;
62	__u8		   lo_file_name[LO_NAME_SIZE];
63	__u8		   lo_crypt_name[LO_NAME_SIZE];
64	__u8		   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
65	__u64		   lo_init[2];
66};
67
68/**
69 * struct loop_config - Complete configuration for a loop device.
70 * @fd: fd of the file to be used as a backing file for the loop device.
71 * @block_size: block size to use; ignored if 0.
72 * @info: struct loop_info64 to configure the loop device with.
73 *
74 * This structure is used with the LOOP_CONFIGURE ioctl, and can be used to
75 * atomically setup and configure all loop device parameters at once.
76 */
77struct loop_config {
78	__u32			fd;
79	__u32                   block_size;
80	struct loop_info64	info;
81	__u64			__reserved[8];
82};
83
84/*
85 * Loop filter types
86 */
87
88#define LO_CRYPT_NONE		0
89#define LO_CRYPT_XOR		1
90#define LO_CRYPT_DES		2
91#define LO_CRYPT_FISH2		3    /* Twofish encryption */
92#define LO_CRYPT_BLOW		4
93#define LO_CRYPT_CAST128	5
94#define LO_CRYPT_IDEA		6
95#define LO_CRYPT_DUMMY		9
96#define LO_CRYPT_SKIPJACK	10
97#define LO_CRYPT_CRYPTOAPI	18
98#define MAX_LO_CRYPT		20
99
100/*
101 * IOCTL commands --- we will commandeer 0x4C ('L')
102 */
103
104#define LOOP_SET_FD		0x4C00
105#define LOOP_CLR_FD		0x4C01
106#define LOOP_SET_STATUS		0x4C02
107#define LOOP_GET_STATUS		0x4C03
108#define LOOP_SET_STATUS64	0x4C04
109#define LOOP_GET_STATUS64	0x4C05
110#define LOOP_CHANGE_FD		0x4C06
111#define LOOP_SET_CAPACITY	0x4C07
112#define LOOP_SET_DIRECT_IO	0x4C08
113#define LOOP_SET_BLOCK_SIZE	0x4C09
114#define LOOP_CONFIGURE		0x4C0A
115
116/* /dev/loop-control interface */
117#define LOOP_CTL_ADD		0x4C80
118#define LOOP_CTL_REMOVE		0x4C81
119#define LOOP_CTL_GET_FREE	0x4C82
120#endif /* _UAPI_LINUX_LOOP_H */
121