dissect.target.filesystems.nfs

Module Contents

Classes

NfsFilesystem	Filesystem implementation of a NFS share
NfsDirEntry	Directory entry base class. Closely models os.DirEntry.
NfsFilesystemEntry	Base class for filesystem entries.
NfsStream	Basic buffered stream that provides aligned reads.

Attributes

ConCredentials
ConVerifier
ClientFactory
AuthSetter

dissect.target.filesystems.nfs.ConCredentials

dissect.target.filesystems.nfs.ConVerifier

dissect.target.filesystems.nfs.ClientFactory

dissect.target.filesystems.nfs.AuthSetter

exception dissect.target.filesystems.nfs.AuthFlavorNotSupported(supported_flavors: list[int], provided_flavor: int)

Bases: Exception

Common base class for all non-exit exceptions.

supported

provided

__str__() → str

Return str(self).

class dissect.target.filesystems.nfs.NfsFilesystem(client_factory: ClientFactory, root_handle: dissect.target.helpers.nfs.nfs3.FileHandle)

Bases: dissect.target.filesystem.Filesystem

Filesystem implementation of a NFS share

The connection is lazily established to not waste resources. Use the connect method to conveniently create a new instance.

__type__ = 'nfs'

A short string identifying the type of filesystem.

classmethod connect(address: str, exported_dir: str, auth: dissect.target.helpers.sunrpc.client.AuthScheme[ConCredentials, ConVerifier] | AuthSetter, local_port: int | dissect.target.helpers.sunrpc.client.LocalPortPolicy = 0, timeout_in_seconds: float | None = 5.0) → Self

Utility function to setup a connection to a NFS share.

Parameters:

• hostname – The remote hostname.

• port – The remote port.

• auth – The authentication scheme.

• local_port – The local port to bind to. If equal to LocalPortPolicy.PRIVILEGED or -1, bind to the first free privileged port. If equal to LocalPortPolicy.ANY or 0, bind to any free port. Otherwise, bind to the specified port.

• timeout_in_seconds – The timeout for making the connection.

static detect(_: BinaryIO) → bool

Detect whether the fh file-handle is supported by this Filesystem implementation.

The position of fh will be restored before returning.

Parameters:

fh – A file-like object, usually a disk or partition.

Returns:

True if fh is supported, False otherwise.

get(path: str, relentry: NfsFilesystemEntry | None = None) → NfsFilesystemEntry

Get a filesystem entry.

Parameters:

• path – The path to the entry. The path is relative to relentry, if provided.

• relentry – The relative entry to start from. If not provided, the root entry is used.

class dissect.target.filesystems.nfs.NfsDirEntry(fs: Filesystem, path: str, name: str, entry: Any)

Bases: dissect.target.filesystem.DirEntry

Directory entry base class. Closely models os.DirEntry.

Filesystem implementations are encouraged to subclass this class to provide efficient implementations of the various methods.

Parameters:

• fs – The filesystem the entry belongs to.

• path – The path of the parent directory.

• name – The name of the entry.

• entry – The raw entry backing this directory entry.

fs: NfsFilesystem

The filesystem the entry belongs to.

entry: dissect.target.helpers.nfs.nfs3.EntryPlus

The raw entry backing this directory entry.

get() → NfsFilesystemEntry

Retrieve the FilesystemEntry this directory entry points to.

Subclasses should override this method to provide an efficient implementation.

stat(*, follow_symlinks: bool = True) → dissect.target.helpers.fsutil.stat_result

class dissect.target.filesystems.nfs.NfsFilesystemEntry(fs: NfsFilesystem, path: str, file_handle: dissect.target.helpers.nfs.nfs3.FileHandle, attributes: dissect.target.helpers.nfs.nfs3.FileAttributes | None = None)

Bases: dissect.target.filesystem.FilesystemEntry

Base class for filesystem entries.

fs: NfsFilesystem

entry: dissect.target.helpers.nfs.nfs3.FileHandle

get(path: str) → NfsFilesystemEntry

Get a new filesystem entry relative to this entry

is_file(follow_symlinks: bool = True) → bool

Determine if this entry is a file.

Parameters:

follow_symlinks – Whether to resolve the entry if it is a symbolic link.

Returns:

True if the entry is a file or a symbolic link to a file, return False otherwise. If follow_symlinks is False, return True only if the entry is a file (without following symlinks).

is_dir(follow_symlinks: bool = True) → bool

Determine if this entry is a directory.

Parameters:

follow_symlinks – Whether to resolve the entry if it is a symbolic link.

Returns:

True if the entry is a directory or a symbolic link to a directory, return False otherwise. If follow_symlinks is False, return True only if the entry is a directory (without following symlinks).

is_symlink() → bool

Determine whether this entry is a symlink.

Returns:

True if the entry is a symbolic link, False otherwise.

readlink() → str

Read the link where this entry points to, return the resulting path as string.

If it is a symlink and returns the entry that corresponds to that path. This means it follows the path a link points to, it tries to do it recursively.

Returns:

The path the link points to.

readlink_ext() → NfsFilesystemEntry

Read the link where this entry points to, return the resulting path as FilesystemEntry.

If it is a symlink and returns the string that corresponds to that path. This means it follows the path a link points to, it tries to do it recursively.

Returns:

The filesystem entry the link points to.

scandir() → collections.abc.Iterator[NfsDirEntry]

Iterate over the contents of a directory, yields FilesystemEntry.

Returns:

An iterator of FilesystemEntry.

open() → NfsStream

Open this filesystem entry.

Returns:

A file-like object. Resolves symlinks when possible

stat(follow_symlinks: bool = True) → dissect.target.helpers.fsutil.stat_result

Determine the stat information of this entry.

If the entry is a symlink and follow_symlinks is True, it gets resolved, attempting to stat the path where it points to.

Parameters:

follow_symlinks – Whether to resolve the symbolic link if this entry is a symbolic link.

Returns:

The stat information of this entry.

lstat() → dissect.target.helpers.fsutil.stat_result

Determine the stat information of this entry, without resolving the symlinks.

When it detects a symlink, it will stat the information of the symlink, not the path it points to.

Returns:

The stat information of this entry.

class dissect.target.filesystems.nfs.NfsStream(client: dissect.target.helpers.nfs.client.nfs.Client, file_handle: dissect.target.helpers.nfs.nfs3.FileHandle, size: int | None)

Bases: dissect.util.stream.AlignedStream

Basic buffered stream that provides aligned reads.

Must be subclassed for various stream implementations. Subclasses can implement:

• _read()

• _seek()

The offset and length for _read are guaranteed to be aligned for streams of a known size. If your stream has an unknown size (i.e. size == None), reads of length -1 (i.e. read until EOF) will be passed through to your implementation of _read. The only time that overriding _seek would make sense is if there’s no known size of your stream, but still want to provide SEEK_END functionality.

Most subclasses of AlignedStream take one or more file-like objects as source. Operations on these subclasses, like reading, will modify the source file-like object as a side effect.

Parameters:

• size – The size of the stream. This is used in read and seek operations. None if unknown.

• align – The alignment size. Read operations are aligned on this boundary. Also determines buffer size.

_read(offset: int, size: int) → bytes

Read method that backs this aligned stream.

_seek(pos: int, whence: int = 0) → int

Calculate and return the new stream position after a seek.