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  */
16 enum {
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 */
37 struct 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 
52 struct 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  */
77 struct 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