# This file is Copyright 2019 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#
"""All plugins output a TreeGrid object which must then be rendered (either by a
GUI, or as text output, html output or in some other form.
This module defines both the output format (:class:`TreeGrid`) and the
renderer interface which can interact with a TreeGrid to produce
suitable output.
"""
import datetime
from abc import abstractmethod, ABCMeta
from collections import abc
from typing import Any, Callable, ClassVar, Generator, List, NamedTuple, Optional, TypeVar, Type, Tuple, Union
Column = NamedTuple('Column', [('name', str), ('type', Any)])
RenderOption = Any
[docs]class Renderer(metaclass = ABCMeta):
"""Class that defines the interface that all output renderers must
support."""
def __init__(self, options: Optional[List[RenderOption]] = None) -> None:
"""Accepts an options object to configure the renderers."""
# FIXME: Once the config option objects are in place, put the _type_check in place
[docs] @abstractmethod
def get_render_options(self) -> List[RenderOption]:
"""Returns a list of rendering options."""
[docs] @abstractmethod
def render(self, grid: 'TreeGrid') -> None:
"""Takes a grid object and renders it based on the object's
preferences."""
[docs]class ColumnSortKey(metaclass = ABCMeta):
ascending: bool = True
@abstractmethod
def __call__(self, values: List[Any]) -> Any:
"""The key function passed as a sort key to the TreeGrid's visit
function."""
[docs]class TreeNode(abc.Sequence, metaclass = ABCMeta):
def __init__(self, path, treegrid, parent, values):
"""Initializes the TreeNode."""
@property
@abstractmethod
def values(self) -> List['BaseTypes']:
"""Returns the list of values from the particular node, based on column
index."""
@property
@abstractmethod
def path(self) -> str:
"""Returns a path identifying string.
This should be seen as opaque by external classes, Parsing of
path locations based on this string are not guaranteed to remain
stable.
"""
@property
@abstractmethod
def parent(self) -> Optional['TreeNode']:
"""Returns the parent node of this node or None."""
@property
@abstractmethod
def path_depth(self) -> int:
"""Return the path depth of the current node."""
[docs] @abstractmethod
def path_changed(self, path: str, added: bool = False) -> None:
"""Updates the path based on the addition or removal of a node higher
up in the tree.
This should only be called by the containing TreeGrid and
expects to only be called for affected nodes.
"""
[docs]class BaseAbsentValue(object):
"""Class that represents values which are not present for some reason."""
[docs]class Disassembly(object):
"""A class to indicate that the bytes provided should be disassembled
(based on the architecture)"""
possible_architectures = ['intel', 'intel64', 'arm', 'arm64']
def __init__(self, data: bytes, offset: int = 0, architecture: str = 'intel64') -> None:
self.data = data
self.architecture = None
if architecture in self.possible_architectures:
self.architecture = architecture
if not isinstance(offset, int):
raise TypeError("Offset must be an integer type")
self.offset = offset
# We don't class these off a shared base, because the BaseTypes must only
# contain the types that the validator will accept (which would not include the base)
_Type = TypeVar("_Type")
BaseTypes = Union[Type[int], Type[str], Type[float], Type[bytes], Type[datetime.datetime], Type[BaseAbsentValue],
Type[Disassembly]]
ColumnsType = List[Tuple[str, BaseTypes]]
VisitorSignature = Callable[[TreeNode, _Type], _Type]
[docs]class TreeGrid(object, metaclass = ABCMeta):
"""Class providing the interface for a TreeGrid (which contains TreeNodes)
The structure of a TreeGrid is designed to maintain the structure of the tree in a single object.
For this reason each TreeNode does not hold its children, they are managed by the top level object.
This leaves the Nodes as simple data carries and prevents them being used to manipulate the tree as a whole.
This is a data structure, and is not expected to be modified much once created.
Carrying the children under the parent makes recursion easier, but then every node is its own little tree
and must have all the supporting tree functions. It also allows for a node to be present in several different trees,
and to create cycles.
"""
base_types: ClassVar[Tuple] = (int, str, float, bytes, datetime.datetime, Disassembly)
def __init__(self, columns: ColumnsType, generator: Generator) -> None:
"""Constructs a TreeGrid object using a specific set of columns.
The TreeGrid itself is a root element, that can have children but no values.
The TreeGrid does *not* contain any information about formatting,
these are up to the renderers and plugins.
Args:
columns: A list of column tuples made up of (name, type).
generator: An iterable containing row for a tree grid, each row contains a indent level followed by the values for each column in order.
"""
[docs] @staticmethod
@abstractmethod
def sanitize_name(text: str) -> str:
"""Method used to sanitize column names for TreeNodes."""
[docs] @abstractmethod
def populate(self,
function: VisitorSignature = None,
initial_accumulator: Any = None,
fail_on_errors: bool = True) -> Optional[Exception]:
"""Populates the tree by consuming the TreeGrid's construction
generator Func is called on every node, so can be used to create output
on demand.
This is equivalent to a one-time visit.
"""
@property
@abstractmethod
def populated(self) -> bool:
"""Indicates that population has completed and the tree may now be
manipulated separately."""
@property
@abstractmethod
def columns(self) -> List[Column]:
"""Returns the available columns and their ordering and types."""
[docs] @abstractmethod
def children(self, node: TreeNode) -> List[TreeNode]:
"""Returns the subnodes of a particular node in order."""
[docs] @abstractmethod
def values(self, node: TreeNode) -> Tuple[BaseTypes, ...]:
"""Returns the values for a particular node.
The values returned are mutable,
"""
[docs] @abstractmethod
def is_ancestor(self, node: TreeNode, descendant: TreeNode) -> bool:
"""Returns true if descendent is a child, grandchild, etc of node."""
[docs] @abstractmethod
def max_depth(self) -> int:
"""Returns the maximum depth of the tree."""
[docs] @staticmethod
def path_depth(node: TreeNode) -> int:
"""Returns the path depth of a particular node."""
return node.path_depth
[docs] @abstractmethod
def visit(self,
node: Optional[TreeNode],
function: VisitorSignature,
initial_accumulator: _Type,
sort_key: ColumnSortKey = None) -> None:
"""Visits all the nodes in a tree, calling function on each one.
function should have the signature function(node, accumulator) and return new_accumulator
If accumulators are not needed, the function must still accept a second parameter.
The order of that the nodes are visited is always depth first, however, the order children are traversed can
be set based on a sort_key function which should accept a node's values and return something that can be
sorted to receive the desired order (similar to the sort/sorted key).
If node is None, then the root node is used.
Args:
node: The initial node to be visited
function: The visitor to apply to the nodes under the initial node
initial_accumulator: An accumulator that allows data to be transferred between one visitor call to the next
sort_key: Information about the sort order of columns in order to determine the ordering of results
"""