/*
    FUSE: Filesystem in Userspace
    Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>

    This program can be distributed under the terms of the GNU GPL.
    See the file COPYING.
*/

/*
 * This file defines the kernel interface of FUSE
 *
 * Protocol changelog:
 *
 * 7.9:
 *  - new fuse_getattr_in input argument of GETATTR
 *  - add lk_flags in fuse_lk_in
 *  - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
 *  - add blksize field to fuse_attr
 *  - add file flags field to fuse_read_in and fuse_write_in
 *
 * 7.10
 *  - add nonseekable open flag
 *
 * 7.11
 *  - add IOCTL message
 *  - add unsolicited notification support
 *  - add POLL message and NOTIFY_POLL notification
 *
 * 7.12
 *  - add umask flag to input argument of open, mknod and mkdir
 *  - add notification messages for invalidation of inodes and
 *    directory entries
 *
 * 7.13
 *  - make max number of background requests and congestion threshold
 *    tunables
 */

#ifndef _LINUX_FUSE_H
#define _LINUX_FUSE_H

#include <linux/types.h>

/*
 * Version negotiation:
 *
 * Both the kernel and userspace send the version they support in the
 * INIT request and reply respectively.
 *
 * If the major versions match then both shall use the smallest
 * of the two minor versions for communication.
 *
 * If the kernel supports a larger major version, then userspace shall
 * reply with the major version it supports, ignore the rest of the
 * INIT message and expect a new INIT message from the kernel with a
 * matching major version.
 *
 * If the library supports a larger major version, then it shall fall
 * back to the major protocol version sent by the kernel for
 * communication and reply with that major version (and an arbitrary
 * supported minor version).
 */

/** Version number of this interface */
#define FUSE_KERNEL_VERSION 7

/** Minor version number of this interface */
#define FUSE_KERNEL_MINOR_VERSION 13

/** The node ID of the root inode */
#define FUSE_ROOT_ID 1

/* Make sure all structures are padded to 64bit boundary, so 32bit
   userspace works under 64bit kernels */

struct fuse_attr {
        __u64        ino;
        __u64        size;
        __u64        blocks;
        __u64        atime;
        __u64        mtime;
        __u64        ctime;
        __u32        atimensec;
        __u32        mtimensec;
        __u32        ctimensec;
        __u32        mode;
        __u32        nlink;
        __u32        uid;
        __u32        gid;
        __u32        rdev;
        __u32        blksize;
        __u32        padding;
};

struct fuse_kstatfs {
        __u64        blocks;
        __u64        bfree;
        __u64        bavail;
        __u64        files;
        __u64        ffree;
        __u32        bsize;
        __u32        namelen;
        __u32        frsize;
        __u32        padding;
        __u32        spare[6];
};

struct fuse_file_lock {
        __u64        start;
        __u64        end;
        __u32        type;
        __u32        pid; /* tgid */
};

/**
 * Bitmasks for fuse_setattr_in.valid
 */
#define FATTR_MODE        (1 << 0)
#define FATTR_UID        (1 << 1)
#define FATTR_GID        (1 << 2)
#define FATTR_SIZE        (1 << 3)
#define FATTR_ATIME        (1 << 4)
#define FATTR_MTIME        (1 << 5)
#define FATTR_FH        (1 << 6)
#define FATTR_ATIME_NOW        (1 << 7)
#define FATTR_MTIME_NOW        (1 << 8)
#define FATTR_LOCKOWNER        (1 << 9)

/**
 * Flags returned by the OPEN request
 *
 * FOPEN_DIRECT_IO: bypass page cache for this open file
 * FOPEN_KEEP_CACHE: don't invalidate the data cache on open
 * FOPEN_NONSEEKABLE: the file is not seekable
 */
#define FOPEN_DIRECT_IO                (1 << 0)
#define FOPEN_KEEP_CACHE        (1 << 1)
#define FOPEN_NONSEEKABLE        (1 << 2)

/**
 * INIT request/reply flags
 *
 * FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
 * FUSE_DONT_MASK: don't apply umask to file mode on create operations
 */
#define FUSE_ASYNC_READ                (1 << 0)
#define FUSE_POSIX_LOCKS        (1 << 1)
#define FUSE_FILE_OPS                (1 << 2)
#define FUSE_ATOMIC_O_TRUNC        (1 << 3)
#define FUSE_EXPORT_SUPPORT        (1 << 4)
#define FUSE_BIG_WRITES                (1 << 5)
#define FUSE_DONT_MASK                (1 << 6)

/**
 * CUSE INIT request/reply flags
 *
 * CUSE_UNRESTRICTED_IOCTL:  use unrestricted ioctl
 */
#define CUSE_UNRESTRICTED_IOCTL        (1 << 0)

/**
 * Release flags
 */
#define FUSE_RELEASE_FLUSH        (1 << 0)

/**
 * Getattr flags
 */
#define FUSE_GETATTR_FH                (1 << 0)

/**
 * Lock flags
 */
#define FUSE_LK_FLOCK                (1 << 0)

/**
 * WRITE flags
 *
 * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
 * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
 */
#define FUSE_WRITE_CACHE        (1 << 0)
#define FUSE_WRITE_LOCKOWNER        (1 << 1)

/**
 * Read flags
 */
#define FUSE_READ_LOCKOWNER        (1 << 1)

/**
 * Ioctl flags
 *
 * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
 * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
 * FUSE_IOCTL_RETRY: retry with new iovecs
 *
 * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
 */
#define FUSE_IOCTL_COMPAT        (1 << 0)
#define FUSE_IOCTL_UNRESTRICTED        (1 << 1)
#define FUSE_IOCTL_RETRY        (1 << 2)

#define FUSE_IOCTL_MAX_IOV        256

/**
 * Poll flags
 *
 * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
 */
#define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)

enum fuse_opcode {
        FUSE_LOOKUP           = 1,
        FUSE_FORGET           = 2,  /* no reply */
        FUSE_GETATTR           = 3,
        FUSE_SETATTR           = 4,
        FUSE_READLINK           = 5,
        FUSE_SYMLINK           = 6,
        FUSE_MKNOD           = 8,
        FUSE_MKDIR           = 9,
        FUSE_UNLINK           = 10,
        FUSE_RMDIR           = 11,
        FUSE_RENAME           = 12,
        FUSE_LINK           = 13,
        FUSE_OPEN           = 14,
        FUSE_READ           = 15,
        FUSE_WRITE           = 16,
        FUSE_STATFS           = 17,
        FUSE_RELEASE       = 18,
        FUSE_FSYNC         = 20,
        FUSE_SETXATTR      = 21,
        FUSE_GETXATTR      = 22,
        FUSE_LISTXATTR     = 23,
        FUSE_REMOVEXATTR   = 24,
        FUSE_FLUSH         = 25,
        FUSE_INIT          = 26,
        FUSE_OPENDIR       = 27,
        FUSE_READDIR       = 28,
        FUSE_RELEASEDIR    = 29,
        FUSE_FSYNCDIR      = 30,
        FUSE_GETLK         = 31,
        FUSE_SETLK         = 32,
        FUSE_SETLKW        = 33,
        FUSE_ACCESS        = 34,
        FUSE_CREATE        = 35,
        FUSE_INTERRUPT     = 36,
        FUSE_BMAP          = 37,
        FUSE_DESTROY       = 38,
        FUSE_IOCTL         = 39,
        FUSE_POLL          = 40,

        /* CUSE specific operations */
        CUSE_INIT          = 4096,
};

enum fuse_notify_code {
        FUSE_NOTIFY_POLL   = 1,
        FUSE_NOTIFY_INVAL_INODE = 2,
        FUSE_NOTIFY_INVAL_ENTRY = 3,
        FUSE_NOTIFY_CODE_MAX,
};

/* The read buffer is required to be at least 8k, but may be much larger */
#define FUSE_MIN_READ_BUFFER 8192

#define FUSE_COMPAT_ENTRY_OUT_SIZE 120

struct fuse_entry_out {
        __u64        nodeid;                /* Inode ID */
        __u64        generation;        /* Inode generation: nodeid:gen must
                                   be unique for the fs's lifetime */
        __u64        entry_valid;        /* Cache timeout for the name */
        __u64        attr_valid;        /* Cache timeout for the attributes */
        __u32        entry_valid_nsec;
        __u32        attr_valid_nsec;
        struct fuse_attr attr;
};

struct fuse_forget_in {
        __u64        nlookup;
};

struct fuse_getattr_in {
        __u32        getattr_flags;
        __u32        dummy;
        __u64        fh;
};

#define FUSE_COMPAT_ATTR_OUT_SIZE 96

struct fuse_attr_out {
        __u64        attr_valid;        /* Cache timeout for the attributes */
        __u32        attr_valid_nsec;
        __u32        dummy;
        struct fuse_attr attr;
};

#define FUSE_COMPAT_MKNOD_IN_SIZE 8

struct fuse_mknod_in {
        __u32        mode;
        __u32        rdev;
        __u32        umask;
        __u32        padding;
};

struct fuse_mkdir_in {
        __u32        mode;
        __u32        umask;
};

struct fuse_rename_in {
        __u64        newdir;
};

struct fuse_link_in {
        __u64        oldnodeid;
};

struct fuse_setattr_in {
        __u32        valid;
        __u32        padding;
        __u64        fh;
        __u64        size;
        __u64        lock_owner;
        __u64        atime;
        __u64        mtime;
        __u64        unused2;
        __u32        atimensec;
        __u32        mtimensec;
        __u32        unused3;
        __u32        mode;
        __u32        unused4;
        __u32        uid;
        __u32        gid;
        __u32        unused5;
};

struct fuse_open_in {
        __u32        flags;
        __u32        unused;
};

struct fuse_create_in {
        __u32        flags;
        __u32        mode;
        __u32        umask;
        __u32        padding;
};

struct fuse_open_out {
        __u64        fh;
        __u32        open_flags;
        __u32        padding;
};

struct fuse_release_in {
        __u64        fh;
        __u32        flags;
        __u32        release_flags;
        __u64        lock_owner;
};

struct fuse_flush_in {
        __u64        fh;
        __u32        unused;
        __u32        padding;
        __u64        lock_owner;
};

struct fuse_read_in {
        __u64        fh;
        __u64        offset;
        __u32        size;
        __u32        read_flags;
        __u64        lock_owner;
        __u32        flags;
        __u32        padding;
};

#define FUSE_COMPAT_WRITE_IN_SIZE 24

struct fuse_write_in {
        __u64        fh;
        __u64        offset;
        __u32        size;
        __u32        write_flags;
        __u64        lock_owner;
        __u32        flags;
        __u32        padding;
};

struct fuse_write_out {
        __u32        size;
        __u32        padding;
};

#define FUSE_COMPAT_STATFS_SIZE 48

struct fuse_statfs_out {
        struct fuse_kstatfs st;
};

struct fuse_fsync_in {
        __u64        fh;
        __u32        fsync_flags;
        __u32        padding;
};

struct fuse_setxattr_in {
        __u32        size;
        __u32        flags;
};

struct fuse_getxattr_in {
        __u32        size;
        __u32        padding;
};

struct fuse_getxattr_out {
        __u32        size;
        __u32        padding;
};

struct fuse_lk_in {
        __u64        fh;
        __u64        owner;
        struct fuse_file_lock lk;
        __u32        lk_flags;
        __u32        padding;
};

struct fuse_lk_out {
        struct fuse_file_lock lk;
};

struct fuse_access_in {
        __u32        mask;
        __u32        padding;
};

struct fuse_init_in {
        __u32        major;
        __u32        minor;
        __u32        max_readahead;
        __u32        flags;
};

struct fuse_init_out {
        __u32        major;
        __u32        minor;
        __u32        max_readahead;
        __u32        flags;
        __u16   max_background;
        __u16   congestion_threshold;
        __u32        max_write;
};

#define CUSE_INIT_INFO_MAX 4096

struct cuse_init_in {
        __u32        major;
        __u32        minor;
        __u32        unused;
        __u32        flags;
};

struct cuse_init_out {
        __u32        major;
        __u32        minor;
        __u32        unused;
        __u32        flags;
        __u32        max_read;
        __u32        max_write;
        __u32        dev_major;                /* chardev major */
        __u32        dev_minor;                /* chardev minor */
        __u32        spare[10];
};

struct fuse_interrupt_in {
        __u64        unique;
};

struct fuse_bmap_in {
        __u64        block;
        __u32        blocksize;
        __u32        padding;
};

struct fuse_bmap_out {
        __u64        block;
};

struct fuse_ioctl_in {
        __u64        fh;
        __u32        flags;
        __u32        cmd;
        __u64        arg;
        __u32        in_size;
        __u32        out_size;
};

struct fuse_ioctl_out {
        __s32        result;
        __u32        flags;
        __u32        in_iovs;
        __u32        out_iovs;
};

struct fuse_poll_in {
        __u64        fh;
        __u64        kh;
        __u32        flags;
        __u32   padding;
};

struct fuse_poll_out {
        __u32        revents;
        __u32        padding;
};

struct fuse_notify_poll_wakeup_out {
        __u64        kh;
};

struct fuse_in_header {
        __u32        len;
        __u32        opcode;
        __u64        unique;
        __u64        nodeid;
        __u32        uid;
        __u32        gid;
        __u32        pid;
        __u32        padding;
};

struct fuse_out_header {
        __u32        len;
        __s32        error;
        __u64        unique;
};

struct fuse_dirent {
        __u64        ino;
        __u64        off;
        __u32        namelen;
        __u32        type;
        char name[0];
};

#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
#define FUSE_DIRENT_ALIGN(x) (((x) + sizeof(__u64) - 1) & ~(sizeof(__u64) - 1))
#define FUSE_DIRENT_SIZE(d) \
        FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)

struct fuse_notify_inval_inode_out {
        __u64        ino;
        __s64        off;
        __s64        len;
};

struct fuse_notify_inval_entry_out {
        __u64        parent;
        __u32        namelen;
        __u32        padding;
};

#endif /* _LINUX_FUSE_H */