filesystem

Documentation

Index

• func CheckFLockedPID(filepath string) error
• func CopyFile(sourcePath, destPath string, overwrite bool) (bool, error)
• func HaveReadAccessTo(path string) bool
• func MakeFLockedPID(filepath string) (*os.File, error)
• func MoveFile(sourcePath, destPath string, overwrite bool) (bool, error)
• func OpenFileOverridingUmask(name string, flag int, perm os.FileMode) (*os.File, error)
• func SplitFileName(file string) (string, string)
• func UpdateMountInfo() error
• type DeviceNumber
  • func (num DeviceNumber) String() string
• type ErrAlreadySetup
  • func (err *ErrAlreadySetup) Error() string
• type ErrCorruptMetadata
  • func (err *ErrCorruptMetadata) Error() string
• type ErrFollowLink
  • func (err *ErrFollowLink) Error() string
• type ErrMakeLink
  • func (err *ErrMakeLink) Error() string
• type ErrNotAMountpoint
  • func (err *ErrNotAMountpoint) Error() string
• type ErrNotSetup
  • func (err *ErrNotSetup) Error() string
• type ErrPolicyNotFound
  • func (err *ErrPolicyNotFound) Error() string
• type ErrProtectorNotFound
  • func (err *ErrProtectorNotFound) Error() string
• type Mount
  • func AllFilesystems() ([]*Mount, error)
  • func FindMount(path string) (*Mount, error)
  • func GetMount(mountpoint string) (*Mount, error)
• type PathSorter
  • func (p PathSorter) Len() int
  • func (p PathSorter) Less(i, j int) bool
  • func (p PathSorter) Swap(i, j int)

Functions

func CheckFLockedPID

func CheckFLockedPID(filepath string) error

*

• 파일이 잠겨있는지 확인한다.

func CopyFile

func CopyFile(sourcePath, destPath string, overwrite bool) (bool, error)

GoLang: os.Rename() give error "invalid cross-device link" for Docker container with Volumes. MoveFile(source, destination) will work moving file between folders

func HaveReadAccessTo

func HaveReadAccessTo(path string) bool

HaveReadAccessTo returns true if the process has read access to a file or directory, without actually opening it.

func MakeFLockedPID

func MakeFLockedPID(filepath string) (*os.File, error)

*

• 파일을 잠그고 PID를 기록한다.

func MoveFile

func MoveFile(sourcePath, destPath string, overwrite bool) (bool, error)

GoLang: os.Rename() give error "invalid cross-device link" for Docker container with Volumes. MoveFile(source, destination) will work moving file between folders

func OpenFileOverridingUmask

func OpenFileOverridingUmask(name string, flag int, perm os.FileMode) (*os.File, error)

OpenFileOverridingUmask calls os.OpenFile but with the umask overridden so that no permission bits are masked out if the file is created.

func SplitFileName

func SplitFileName(file string) (string, string)

func UpdateMountInfo

func UpdateMountInfo() error

UpdateMountInfo updates the filesystem mountpoint maps with the current state of the filesystem mountpoints. Returns error if the initialization fails.

Types

type DeviceNumber

type DeviceNumber uint64

DeviceNumber represents a combined major:minor device number.

func (DeviceNumber) String

func (num DeviceNumber) String() string

type ErrAlreadySetup

type ErrAlreadySetup struct {
	Mount *Mount
}

ErrAlreadySetup indicates that a filesystem is already setup for fscrypt.

func (*ErrAlreadySetup) Error

func (err *ErrAlreadySetup) Error() string

type ErrCorruptMetadata

type ErrCorruptMetadata struct {
	Path            string
	UnderlyingError error
}

ErrCorruptMetadata indicates that an fscrypt metadata file is corrupt.

func (*ErrCorruptMetadata) Error

func (err *ErrCorruptMetadata) Error() string

type ErrFollowLink

type ErrFollowLink struct {
	Link            string
	UnderlyingError error
}

ErrFollowLink indicates that a protector link can't be followed.

func (*ErrFollowLink) Error

func (err *ErrFollowLink) Error() string

type ErrMakeLink

type ErrMakeLink struct {
	Target          *Mount
	UnderlyingError error
}

ErrMakeLink indicates that a protector link can't be created.

func (*ErrMakeLink) Error

func (err *ErrMakeLink) Error() string

type ErrNotAMountpoint

type ErrNotAMountpoint struct {
	Path string
}

ErrNotAMountpoint indicates that a path is not a mountpoint.

func (*ErrNotAMountpoint) Error

func (err *ErrNotAMountpoint) Error() string

type ErrNotSetup

type ErrNotSetup struct {
	Mount *Mount
}

ErrNotSetup indicates that a filesystem is not setup for fscrypt.

func (*ErrNotSetup) Error

func (err *ErrNotSetup) Error() string

type ErrPolicyNotFound

type ErrPolicyNotFound struct {
	Descriptor string
	Mount      *Mount
}

ErrPolicyNotFound indicates that the policy metadata was not found.

func (*ErrPolicyNotFound) Error

func (err *ErrPolicyNotFound) Error() string

type ErrProtectorNotFound

type ErrProtectorNotFound struct {
	Descriptor string
	Mount      *Mount
}

ErrProtectorNotFound indicates that the protector metadata was not found.

func (*ErrProtectorNotFound) Error

func (err *ErrProtectorNotFound) Error() string

type Mount

type Mount struct {
	Path           string
	FilesystemType string
	Device         string
	DeviceNumber   DeviceNumber
	Subtree        string
	ReadOnly       bool
}

Mount contains information for a specific mounted filesystem.

Path           - Absolute path where the directory is mounted
FilesystemType - Type of the mounted filesystem, e.g. "ext4"
Device         - Device for filesystem (empty string if we cannot find one)
DeviceNumber   - Device number of the filesystem.  This is set even if
		 Device isn't, since all filesystems have a device
		 number assigned by the kernel, even pseudo-filesystems.
Subtree        - The mounted subtree of the filesystem.  This is usually
		 "/", meaning that the entire filesystem is mounted, but
		 it can differ for bind mounts.
ReadOnly       - True if this is a read-only mount

In order to use a Mount to store fscrypt metadata, some directories must be setup first. Specifically, the directories created look like: <mountpoint> └── .fscrypt

├── policies
└── protectors

These "policies" and "protectors" directories will contain files that are the corresponding metadata structures for policies and protectors. The public interface includes functions for setting up these directories and Adding, Getting, and Removing these files.

There is also the ability to reference another filesystem's metadata. This is used when a Policy on filesystem A is protected with Protector on filesystem B. In this scenario, we store a "link file" in the protectors directory whose contents look like "UUID=3a6d9a76-47f0-4f13-81bf-3332fbe984fb".

We also allow ".fscrypt" to be a symlink which was previously created. This allows login protectors to be created when the root filesystem is read-only, provided that "/.fscrypt" is a symlink pointing to a writable location.

func AllFilesystems

func AllFilesystems() ([]*Mount, error)

AllFilesystems lists all mounted filesystems ordered by path to their "main" Mount. Use CheckSetup() to see if they are set up for use with fscrypt.

func FindMount

func FindMount(path string) (*Mount, error)

FindMount returns the main Mount object for the filesystem which contains the file at the specified path. An error is returned if the path is invalid or if we cannot load the required mount data. If a mount has been updated since the last call to one of the mount functions, run UpdateMountInfo to see changes.

func GetMount

func GetMount(mountpoint string) (*Mount, error)

GetMount is like FindMount, except GetMount also returns an error if the path doesn't name the same file as the filesystem's "main" Mount. For example, if a filesystem is fully mounted at "/mnt" and if "/mnt/a" exists, then FindMount("/mnt/a") will succeed whereas GetMount("/mnt/a") will fail. This is true even if "/mnt/a" is a bind mount of part of the same filesystem.

type PathSorter

type PathSorter []*Mount

PathSorter allows mounts to be sorted by Path.

func (PathSorter) Len

func (p PathSorter) Len() int

func (PathSorter) Less

func (p PathSorter) Less(i, j int) bool

func (PathSorter) Swap

func (p PathSorter) Swap(i, j int)