loop.h

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/*
 * include/linux/loop.h
 *
 * Written by Theodore Ts'o, 3/29/93.
 *
 * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
 * permitted under the GNU General Public License.
 */
#ifndef _UAPI_LINUX_LOOP_H
#define _UAPI_LINUX_LOOP_H


#define LO_NAME_SIZE    64
#define LO_KEY_SIZE 32


/*
 * Loop flags
 */
enum {
    LO_FLAGS_READ_ONLY  = 1,
    LO_FLAGS_AUTOCLEAR  = 4,
    LO_FLAGS_PARTSCAN   = 8,
};

#include <asm/posix_types.h>    /* for __kernel_old_dev_t */
#include <linux/types.h>    /* for __u64 */

/* Backwards compatibility version */
struct loop_info {
    int        lo_number;       /* ioctl r/o */
    __kernel_old_dev_t lo_device;       /* ioctl r/o */
    unsigned long      lo_inode;        /* ioctl r/o */
    __kernel_old_dev_t lo_rdevice;      /* ioctl r/o */
    int        lo_offset;
    int        lo_encrypt_type;
    int        lo_encrypt_key_size;     /* ioctl w/o */
    int        lo_flags;            /* ioctl r/o */
    char           lo_name[LO_NAME_SIZE];
    unsigned char      lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
    unsigned long      lo_init[2];
    char           reserved[4];
};

struct loop_info64 {
    __u64          lo_device;           /* ioctl r/o */
    __u64          lo_inode;            /* ioctl r/o */
    __u64          lo_rdevice;          /* ioctl r/o */
    __u64          lo_offset;
    __u64          lo_sizelimit;/* bytes, 0 == max available */
    __u32          lo_number;           /* ioctl r/o */
    __u32          lo_encrypt_type;
    __u32          lo_encrypt_key_size;     /* ioctl w/o */
    __u32          lo_flags;            /* ioctl r/o */
    __u8           lo_file_name[LO_NAME_SIZE];
    __u8           lo_crypt_name[LO_NAME_SIZE];
    __u8           lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
    __u64          lo_init[2];
};

/*
 * Loop filter types
 */

#define LO_CRYPT_NONE       0
#define LO_CRYPT_XOR        1
#define LO_CRYPT_DES        2
#define LO_CRYPT_FISH2      3    /* Twofish encryption */
#define LO_CRYPT_BLOW       4
#define LO_CRYPT_CAST128    5
#define LO_CRYPT_IDEA       6
#define LO_CRYPT_DUMMY      9
#define LO_CRYPT_SKIPJACK   10
#define LO_CRYPT_CRYPTOAPI  18
#define MAX_LO_CRYPT        20

/*
 * IOCTL commands --- we will commandeer 0x4C ('L')
 */

#define LOOP_SET_FD     0x4C00
#define LOOP_CLR_FD     0x4C01
#define LOOP_SET_STATUS     0x4C02
#define LOOP_GET_STATUS     0x4C03
#define LOOP_SET_STATUS64   0x4C04
#define LOOP_GET_STATUS64   0x4C05
#define LOOP_CHANGE_FD      0x4C06
#define LOOP_SET_CAPACITY   0x4C07

/* /dev/loop-control interface */
#define LOOP_CTL_ADD        0x4C80
#define LOOP_CTL_REMOVE     0x4C81
#define LOOP_CTL_GET_FREE   0x4C82
#endif /* _UAPI_LINUX_LOOP_H */