path: root/vendor/bazil.org/fuse/fuse_kernel.go

// See the file LICENSE for copyright and licensing information.

// Derived from FUSE's fuse_kernel.h, which carries this notice:
/*
   This file defines the kernel interface of FUSE
   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>


   This -- and only this -- header file may also be distributed under
   the terms of the BSD Licence as follows:

   Copyright (C) 2001-2007 Miklos Szeredi. All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:
   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGE.
*/

package fuse

import (
    "fmt"
    "syscall"
    "unsafe"
)

// The FUSE version implemented by the package.
const (
    protoVersionMinMajor = 7
    protoVersionMinMinor = 8
    protoVersionMaxMajor = 7
    protoVersionMaxMinor = 12
)

const (
    rootID = 1
)

type kstatfs struct {
    Blocks  uint64
    Bfree   uint64
    Bavail  uint64
    Files   uint64
    Ffree   uint64
    Bsize   uint32
    Namelen uint32
    Frsize  uint32
    _       uint32
    Spare   [6]uint32
}

type fileLock struct {
    Start uint64
    End   uint64
    Type  uint32
    Pid   uint32
}

// GetattrFlags are bit flags that can be seen in GetattrRequest.
type GetattrFlags uint32

const (
    // Indicates the handle is valid.
    GetattrFh GetattrFlags = 1 << 0
)

var getattrFlagsNames = []flagName{
    {uint32(GetattrFh), "GetattrFh"},
}

func (fl GetattrFlags) String() string {
    return flagString(uint32(fl), getattrFlagsNames)
}

// The SetattrValid are bit flags describing which fields in the SetattrRequest
// are included in the change.
type SetattrValid uint32

const (
    SetattrMode   SetattrValid = 1 << 0
    SetattrUid    SetattrValid = 1 << 1
    SetattrGid    SetattrValid = 1 << 2
    SetattrSize   SetattrValid = 1 << 3
    SetattrAtime  SetattrValid = 1 << 4
    SetattrMtime  SetattrValid = 1 << 5
    SetattrHandle SetattrValid = 1 << 6

    // Linux only(?)
    SetattrAtimeNow  SetattrValid = 1 << 7
    SetattrMtimeNow  SetattrValid = 1 << 8
    SetattrLockOwner SetattrValid = 1 << 9 // http://www.mail-archive.com/git-commits-head@vger.kernel.org/msg27852.html

    // OS X only
    SetattrCrtime   SetattrValid = 1 << 28
    SetattrChgtime  SetattrValid = 1 << 29
    SetattrBkuptime SetattrValid = 1 << 30
    SetattrFlags    SetattrValid = 1 << 31
)

func (fl SetattrValid) Mode() bool      { return fl&SetattrMode != 0 }
func (fl SetattrValid) Uid() bool       { return fl&SetattrUid != 0 }
func (fl SetattrValid) Gid() bool       { return fl&SetattrGid != 0 }
func (fl SetattrValid) Size() bool      { return fl&SetattrSize != 0 }
func (fl SetattrValid) Atime() bool     { return fl&SetattrAtime != 0 }
func (fl SetattrValid) Mtime() bool     { return fl&SetattrMtime != 0 }
func (fl SetattrValid) Handle() bool    { return fl&SetattrHandle != 0 }
func (fl SetattrValid) AtimeNow() bool  { return fl&SetattrAtimeNow != 0 }
func (fl SetattrValid) MtimeNow() bool  { return fl&SetattrMtimeNow != 0 }
func (fl SetattrValid) LockOwner() bool { return fl&SetattrLockOwner != 0 }
func (fl SetattrValid) Crtime() bool    { return fl&SetattrCrtime != 0 }
func (fl SetattrValid) Chgtime() bool   { return fl&SetattrChgtime != 0 }
func (fl SetattrValid) Bkuptime() bool  { return fl&SetattrBkuptime != 0 }
func (fl SetattrValid) Flags() bool     { return fl&SetattrFlags != 0 }

func (fl SetattrValid) String() string {
    return flagString(uint32(fl), setattrValidNames)
}

var setattrValidNames = []flagName{
    {uint32(SetattrMode), "SetattrMode"},
    {uint32(SetattrUid), "SetattrUid"},
    {uint32(SetattrGid), "SetattrGid"},
    {uint32(SetattrSize), "SetattrSize"},
    {uint32(SetattrAtime), "SetattrAtime"},
    {uint32(SetattrMtime), "SetattrMtime"},
    {uint32(SetattrHandle), "SetattrHandle"},
    {uint32(SetattrAtimeNow), "SetattrAtimeNow"},
    {uint32(SetattrMtimeNow), "SetattrMtimeNow"},
    {uint32(SetattrLockOwner), "SetattrLockOwner"},
    {uint32(SetattrCrtime), "SetattrCrtime"},
    {uint32(SetattrChgtime), "SetattrChgtime"},
    {uint32(SetattrBkuptime), "SetattrBkuptime"},
    {uint32(SetattrFlags), "SetattrFlags"},
}

// Flags that can be seen in OpenRequest.Flags.
const (
    // Access modes. These are not 1-bit flags, but alternatives where
    // only one can be chosen. See the IsReadOnly etc convenience
    // methods.
    OpenReadOnly  OpenFlags = syscall.O_RDONLY
    OpenWriteOnly OpenFlags = syscall.O_WRONLY
    OpenReadWrite OpenFlags = syscall.O_RDWR

    // File was opened in append-only mode, all writes will go to end
    // of file. OS X does not provide this information.
    OpenAppend    OpenFlags = syscall.O_APPEND
    OpenCreate    OpenFlags = syscall.O_CREAT
    OpenDirectory OpenFlags = syscall.O_DIRECTORY
    OpenExclusive OpenFlags = syscall.O_EXCL
    OpenNonblock  OpenFlags = syscall.O_NONBLOCK
    OpenSync      OpenFlags = syscall.O_SYNC
    OpenTruncate  OpenFlags = syscall.O_TRUNC
)

// OpenAccessModeMask is a bitmask that separates the access mode
// from the other flags in OpenFlags.
const OpenAccessModeMask OpenFlags = syscall.O_ACCMODE

// OpenFlags are the O_FOO flags passed to open/create/etc calls. For
// example, os.O_WRONLY | os.O_APPEND.
type OpenFlags uint32

func (fl OpenFlags) String() string {
    // O_RDONLY, O_RWONLY, O_RDWR are not flags
    s := accModeName(fl & OpenAccessModeMask)
    flags := uint32(fl &^ OpenAccessModeMask)
    if flags != 0 {
        s = s + "+" + flagString(flags, openFlagNames)
    }
    return s
}

// Return true if OpenReadOnly is set.
func (fl OpenFlags) IsReadOnly() bool {
    return fl&OpenAccessModeMask == OpenReadOnly
}

// Return true if OpenWriteOnly is set.
func (fl OpenFlags) IsWriteOnly() bool {
    return fl&OpenAccessModeMask == OpenWriteOnly
}

// Return true if OpenReadWrite is set.
func (fl OpenFlags) IsReadWrite() bool {
    return fl&OpenAccessModeMask == OpenReadWrite
}

func accModeName(flags OpenFlags) string {
    switch flags {
    case OpenReadOnly:
        return "OpenReadOnly"
    case OpenWriteOnly:
        return "OpenWriteOnly"
    case OpenReadWrite:
        return "OpenReadWrite"
    default:
        return ""
    }
}

var openFlagNames = []flagName{
    {uint32(OpenAppend), "OpenAppend"},
    {uint32(OpenCreate), "OpenCreate"},
    {uint32(OpenDirectory), "OpenDirectory"},
    {uint32(OpenExclusive), "OpenExclusive"},
    {uint32(OpenNonblock), "OpenNonblock"},
    {uint32(OpenSync), "OpenSync"},
    {uint32(OpenTruncate), "OpenTruncate"},
}

// The OpenResponseFlags are returned in the OpenResponse.
type OpenResponseFlags uint32

const (
    OpenDirectIO    OpenResponseFlags = 1 << 0 // bypass page cache for this open file
    OpenKeepCache   OpenResponseFlags = 1 << 1 // don't invalidate the data cache on open
    OpenNonSeekable OpenResponseFlags = 1 << 2 // mark the file as non-seekable (not supported on OS X)

    OpenPurgeAttr OpenResponseFlags = 1 << 30 // OS X
    OpenPurgeUBC  OpenResponseFlags = 1 << 31 // OS X
)

func (fl OpenResponseFlags) String() string {
    return flagString(uint32(fl), openResponseFlagNames)
}

var openResponseFlagNames = []flagName{
    {uint32(OpenDirectIO), "OpenDirectIO"},
    {uint32(OpenKeepCache), "OpenKeepCache"},
    {uint32(OpenNonSeekable), "OpenNonSeekable"},
    {uint32(OpenPurgeAttr), "OpenPurgeAttr"},
    {uint32(OpenPurgeUBC), "OpenPurgeUBC"},
}

// The InitFlags are used in the Init exchange.
type InitFlags uint32

const (
    InitAsyncRead     InitFlags = 1 << 0
    InitPosixLocks    InitFlags = 1 << 1
    InitFileOps       InitFlags = 1 << 2
    InitAtomicTrunc   InitFlags = 1 << 3
    InitExportSupport InitFlags = 1 << 4
    InitBigWrites     InitFlags = 1 << 5
    // Do not mask file access modes with umask. Not supported on OS X.
    InitDontMask        InitFlags = 1 << 6
    InitSpliceWrite     InitFlags = 1 << 7
    InitSpliceMove      InitFlags = 1 << 8
    InitSpliceRead      InitFlags = 1 << 9
    InitFlockLocks      InitFlags = 1 << 10
    InitHasIoctlDir     InitFlags = 1 << 11
    InitAutoInvalData   InitFlags = 1 << 12
    InitDoReaddirplus   InitFlags = 1 << 13
    InitReaddirplusAuto InitFlags = 1 << 14
    InitAsyncDIO        InitFlags = 1 << 15
    InitWritebackCache  InitFlags = 1 << 16
    InitNoOpenSupport   InitFlags = 1 << 17

    InitCaseSensitive InitFlags = 1 << 29 // OS X only
    InitVolRename     InitFlags = 1 << 30 // OS X only
    InitXtimes        InitFlags = 1 << 31 // OS X only
)

type flagName struct {
    bit  uint32
    name string
}

var initFlagNames = []flagName{
    {uint32(InitAsyncRead), "InitAsyncRead"},
    {uint32(InitPosixLocks), "InitPosixLocks"},
    {uint32(InitFileOps), "InitFileOps"},
    {uint32(InitAtomicTrunc), "InitAtomicTrunc"},
    {uint32(InitExportSupport), "InitExportSupport"},
    {uint32(InitBigWrites), "InitBigWrites"},
    {uint32(InitDontMask), "InitDontMask"},
    {uint32(InitSpliceWrite), "InitSpliceWrite"},
    {uint32(InitSpliceMove), "InitSpliceMove"},
    {uint32(InitSpliceRead), "InitSpliceRead"},
    {uint32(InitFlockLocks), "InitFlockLocks"},
    {uint32(InitHasIoctlDir), "InitHasIoctlDir"},
    {uint32(InitAutoInvalData), "InitAutoInvalData"},
    {uint32(InitDoReaddirplus), "InitDoReaddirplus"},
    {uint32(InitReaddirplusAuto), "InitReaddirplusAuto"},
    {uint32(InitAsyncDIO), "InitAsyncDIO"},
    {uint32(InitWritebackCache), "InitWritebackCache"},
    {uint32(InitNoOpenSupport), "InitNoOpenSupport"},

    {uint32(InitCaseSensitive), "InitCaseSensitive"},
    {uint32(InitVolRename), "InitVolRename"},
    {uint32(InitXtimes), "InitXtimes"},
}

func (fl InitFlags) String() string {
    return flagString(uint32(fl), initFlagNames)
}

func flagString(f uint32, names []flagName) string {
    var s string

    if f == 0 {
        return "0"
    }

    for _, n := range names {
        if f&n.bit != 0 {
            s += "+" + n.name
            f &^= n.bit
        }
    }
    if f != 0 {
        s += fmt.Sprintf("%+#x", f)
    }
    return s[1:]
}

// The ReleaseFlags are used in the Release exchange.
type ReleaseFlags uint32

const (
    ReleaseFlush ReleaseFlags = 1 << 0
)

func (fl ReleaseFlags) String() string {
    return flagString(uint32(fl), releaseFlagNames)
}

var releaseFlagNames = []flagName{
    {uint32(ReleaseFlush), "ReleaseFlush"},
}

// Opcodes
const (
    opLookup      = 1
    opForget      = 2 // no reply
    opGetattr     = 3
    opSetattr     = 4
    opReadlink    = 5
    opSymlink     = 6
    opMknod       = 8
    opMkdir       = 9
    opUnlink      = 10
    opRmdir       = 11
    opRename      = 12
    opLink        = 13
    opOpen        = 14
    opRead        = 15
    opWrite       = 16
    opStatfs      = 17
    opRelease     = 18
    opFsync       = 20
    opSetxattr    = 21
    opGetxattr    = 22
    opListxattr   = 23
    opRemovexattr = 24
    opFlush       = 25
    opInit        = 26
    opOpendir     = 27
    opReaddir     = 28
    opReleasedir  = 29
    opFsyncdir    = 30
    opGetlk       = 31
    opSetlk       = 32
    opSetlkw      = 33
    opAccess      = 34
    opCreate      = 35
    opInterrupt   = 36
    opBmap        = 37
    opDestroy     = 38
    opIoctl       = 39 // Linux?
    opPoll        = 40 // Linux?

    // OS X
    opSetvolname = 61
    opGetxtimes  = 62
    opExchange   = 63
)

type entryOut struct {
    Nodeid         uint64 // Inode ID
    Generation     uint64 // Inode generation
    EntryValid     uint64 // Cache timeout for the name
    AttrValid      uint64 // Cache timeout for the attributes
    EntryValidNsec uint32
    AttrValidNsec  uint32
    Attr           attr
}

func entryOutSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 9}):
        return unsafe.Offsetof(entryOut{}.Attr) + unsafe.Offsetof(entryOut{}.Attr.Blksize)
    default:
        return unsafe.Sizeof(entryOut{})
    }
}

type forgetIn struct {
    Nlookup uint64
}

type getattrIn struct {
    GetattrFlags uint32
    _            uint32
    Fh           uint64
}

type attrOut struct {
    AttrValid     uint64 // Cache timeout for the attributes
    AttrValidNsec uint32
    _             uint32
    Attr          attr
}

func attrOutSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 9}):
        return unsafe.Offsetof(attrOut{}.Attr) + unsafe.Offsetof(attrOut{}.Attr.Blksize)
    default:
        return unsafe.Sizeof(attrOut{})
    }
}

// OS X
type getxtimesOut struct {
    Bkuptime     uint64
    Crtime       uint64
    BkuptimeNsec uint32
    CrtimeNsec   uint32
}

type mknodIn struct {
    Mode  uint32
    Rdev  uint32
    Umask uint32
    _     uint32
    // "filename\x00" follows.
}

func mknodInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 12}):
        return unsafe.Offsetof(mknodIn{}.Umask)
    default:
        return unsafe.Sizeof(mknodIn{})
    }
}

type mkdirIn struct {
    Mode  uint32
    Umask uint32
    // filename follows
}

func mkdirInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 12}):
        return unsafe.Offsetof(mkdirIn{}.Umask) + 4
    default:
        return unsafe.Sizeof(mkdirIn{})
    }
}

type renameIn struct {
    Newdir uint64
    // "oldname\x00newname\x00" follows
}

// OS X
type exchangeIn struct {
    Olddir  uint64
    Newdir  uint64
    Options uint64
    // "oldname\x00newname\x00" follows
}

type linkIn struct {
    Oldnodeid uint64
}

type setattrInCommon struct {
    Valid     uint32
    _         uint32
    Fh        uint64
    Size      uint64
    LockOwner uint64 // unused on OS X?
    Atime     uint64
    Mtime     uint64
    Unused2   uint64
    AtimeNsec uint32
    MtimeNsec uint32
    Unused3   uint32
    Mode      uint32
    Unused4   uint32
    Uid       uint32
    Gid       uint32
    Unused5   uint32
}

type openIn struct {
    Flags  uint32
    Unused uint32
}

type openOut struct {
    Fh        uint64
    OpenFlags uint32
    _         uint32
}

type createIn struct {
    Flags uint32
    Mode  uint32
    Umask uint32
    _     uint32
}

func createInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 12}):
        return unsafe.Offsetof(createIn{}.Umask)
    default:
        return unsafe.Sizeof(createIn{})
    }
}

type releaseIn struct {
    Fh           uint64
    Flags        uint32
    ReleaseFlags uint32
    LockOwner    uint32
}

type flushIn struct {
    Fh         uint64
    FlushFlags uint32
    _          uint32
    LockOwner  uint64
}

type readIn struct {
    Fh        uint64
    Offset    uint64
    Size      uint32
    ReadFlags uint32
    LockOwner uint64
    Flags     uint32
    _         uint32
}

func readInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 9}):
        return unsafe.Offsetof(readIn{}.ReadFlags) + 4
    default:
        return unsafe.Sizeof(readIn{})
    }
}

// The ReadFlags are passed in ReadRequest.
type ReadFlags uint32

const (
    // LockOwner field is valid.
    ReadLockOwner ReadFlags = 1 << 1
)

var readFlagNames = []flagName{
    {uint32(ReadLockOwner), "ReadLockOwner"},
}

func (fl ReadFlags) String() string {
    return flagString(uint32(fl), readFlagNames)
}

type writeIn struct {
    Fh         uint64
    Offset     uint64
    Size       uint32
    WriteFlags uint32
    LockOwner  uint64
    Flags      uint32
    _          uint32
}

func writeInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 9}):
        return unsafe.Offsetof(writeIn{}.LockOwner)
    default:
        return unsafe.Sizeof(writeIn{})
    }
}

type writeOut struct {
    Size uint32
    _    uint32
}

// The WriteFlags are passed in WriteRequest.
type WriteFlags uint32

const (
    WriteCache WriteFlags = 1 << 0
    // LockOwner field is valid.
    WriteLockOwner WriteFlags = 1 << 1
)

var writeFlagNames = []flagName{
    {uint32(WriteCache), "WriteCache"},
    {uint32(WriteLockOwner), "WriteLockOwner"},
}

func (fl WriteFlags) String() string {
    return flagString(uint32(fl), writeFlagNames)
}

const compatStatfsSize = 48

type statfsOut struct {
    St kstatfs
}

type fsyncIn struct {
    Fh         uint64
    FsyncFlags uint32
    _          uint32
}

type setxattrInCommon struct {
    Size  uint32
    Flags uint32
}

func (setxattrInCommon) position() uint32 {
    return 0
}

type getxattrInCommon struct {
    Size uint32
    _    uint32
}

func (getxattrInCommon) position() uint32 {
    return 0
}

type getxattrOut struct {
    Size uint32
    _    uint32
}

type lkIn struct {
    Fh      uint64
    Owner   uint64
    Lk      fileLock
    LkFlags uint32
    _       uint32
}

func lkInSize(p Protocol) uintptr {
    switch {
    case p.LT(Protocol{7, 9}):
        return unsafe.Offsetof(lkIn{}.LkFlags)
    default:
        return unsafe.Sizeof(lkIn{})
    }
}

type lkOut struct {
    Lk fileLock
}

type accessIn struct {
    Mask uint32
    _    uint32
}

type initIn struct {
    Major        uint32
    Minor        uint32
    MaxReadahead uint32
    Flags        uint32
}

const initInSize = int(unsafe.Sizeof(initIn{}))

type initOut struct {
    Major        uint32
    Minor        uint32
    MaxReadahead uint32
    Flags        uint32
    Unused       uint32
    MaxWrite     uint32
}

type interruptIn struct {
    Unique uint64
}

type bmapIn struct {
    Block     uint64
    BlockSize uint32
    _         uint32
}

type bmapOut struct {
    Block uint64
}

type inHeader struct {
    Len    uint32
    Opcode uint32
    Unique uint64
    Nodeid uint64
    Uid    uint32
    Gid    uint32
    Pid    uint32
    _      uint32
}

const inHeaderSize = int(unsafe.Sizeof(inHeader{}))

type outHeader struct {
    Len    uint32
    Error  int32
    Unique uint64
}

type dirent struct {
    Ino     uint64
    Off     uint64
    Namelen uint32
    Type    uint32
    Name    [0]byte
}

const direntSize = 8 + 8 + 4 + 4

const (
    notifyCodePoll       int32 = 1
    notifyCodeInvalInode int32 = 2
    notifyCodeInvalEntry int32 = 3
)

type notifyInvalInodeOut struct {
    Ino uint64
    Off int64
    Len int64
}

type notifyInvalEntryOut struct {
    Parent  uint64
    Namelen uint32
    _       uint32
}