Source file src/internal/syscall/windows/reparse_windows.go

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package windows
     6  
     7  import (
     8  	"syscall"
     9  	"unsafe"
    10  )
    11  
    12  const (
    13  	FSCTL_SET_REPARSE_POINT    = 0x000900A4
    14  	IO_REPARSE_TAG_MOUNT_POINT = 0xA0000003
    15  	IO_REPARSE_TAG_DEDUP       = 0x80000013
    16  
    17  	SYMLINK_FLAG_RELATIVE = 1
    18  )
    19  
    20  // These structures are described
    21  // in https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/ca069dad-ed16-42aa-b057-b6b207f447cc
    22  // and https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/b41f1cbf-10df-4a47-98d4-1c52a833d913.
    23  
    24  type REPARSE_DATA_BUFFER struct {
    25  	ReparseTag        uint32
    26  	ReparseDataLength uint16
    27  	Reserved          uint16
    28  	DUMMYUNIONNAME    byte
    29  }
    30  
    31  // REPARSE_DATA_BUFFER_HEADER is a common part of REPARSE_DATA_BUFFER structure.
    32  type REPARSE_DATA_BUFFER_HEADER struct {
    33  	ReparseTag uint32
    34  	// The size, in bytes, of the reparse data that follows
    35  	// the common portion of the REPARSE_DATA_BUFFER element.
    36  	// This value is the length of the data starting at the
    37  	// SubstituteNameOffset field.
    38  	ReparseDataLength uint16
    39  	Reserved          uint16
    40  }
    41  
    42  type SymbolicLinkReparseBuffer struct {
    43  	// The integer that contains the offset, in bytes,
    44  	// of the substitute name string in the PathBuffer array,
    45  	// computed as an offset from byte 0 of PathBuffer. Note that
    46  	// this offset must be divided by 2 to get the array index.
    47  	SubstituteNameOffset uint16
    48  	// The integer that contains the length, in bytes, of the
    49  	// substitute name string. If this string is null-terminated,
    50  	// SubstituteNameLength does not include the Unicode null character.
    51  	SubstituteNameLength uint16
    52  	// PrintNameOffset is similar to SubstituteNameOffset.
    53  	PrintNameOffset uint16
    54  	// PrintNameLength is similar to SubstituteNameLength.
    55  	PrintNameLength uint16
    56  	// Flags specifies whether the substitute name is a full path name or
    57  	// a path name relative to the directory containing the symbolic link.
    58  	Flags      uint32
    59  	PathBuffer [1]uint16
    60  }
    61  
    62  // Path returns path stored in rb.
    63  func (rb *SymbolicLinkReparseBuffer) Path() string {
    64  	n1 := rb.SubstituteNameOffset / 2
    65  	n2 := (rb.SubstituteNameOffset + rb.SubstituteNameLength) / 2
    66  	return syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(&rb.PathBuffer[0]))[n1:n2:n2])
    67  }
    68  
    69  type MountPointReparseBuffer struct {
    70  	// The integer that contains the offset, in bytes,
    71  	// of the substitute name string in the PathBuffer array,
    72  	// computed as an offset from byte 0 of PathBuffer. Note that
    73  	// this offset must be divided by 2 to get the array index.
    74  	SubstituteNameOffset uint16
    75  	// The integer that contains the length, in bytes, of the
    76  	// substitute name string. If this string is null-terminated,
    77  	// SubstituteNameLength does not include the Unicode null character.
    78  	SubstituteNameLength uint16
    79  	// PrintNameOffset is similar to SubstituteNameOffset.
    80  	PrintNameOffset uint16
    81  	// PrintNameLength is similar to SubstituteNameLength.
    82  	PrintNameLength uint16
    83  	PathBuffer      [1]uint16
    84  }
    85  
    86  // Path returns path stored in rb.
    87  func (rb *MountPointReparseBuffer) Path() string {
    88  	n1 := rb.SubstituteNameOffset / 2
    89  	n2 := (rb.SubstituteNameOffset + rb.SubstituteNameLength) / 2
    90  	return syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(&rb.PathBuffer[0]))[n1:n2:n2])
    91  }
    92  

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