1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_ACCESSIBILITY_AX_TREE_FUZZER_UTIL_H_
#define UI_ACCESSIBILITY_AX_TREE_FUZZER_UTIL_H_
#include "ui/accessibility/ax_tree.h"
#include "ui/accessibility/ax_tree_data.h"
#include "ui/accessibility/ax_tree_id.h"
#include "ui/accessibility/ax_tree_update.h"
#include "ui/accessibility/test_single_ax_tree_manager.h"
// TODO(janewman): Replace usage with ...FuzzedDataProvider...
class FuzzerData {
public:
FuzzerData(const unsigned char* data, size_t size);
size_t RemainingBytes();
unsigned char NextByte();
const unsigned char* NextBytes(size_t amount);
private:
const unsigned char* data_;
const size_t data_size_;
size_t data_index_;
};
class AXTreeFuzzerGenerator {
public:
AXTreeFuzzerGenerator() = default;
~AXTreeFuzzerGenerator() = default;
ui::AXTree* GetTree();
void GenerateInitialUpdate(FuzzerData& fuzz_data, int node_count);
bool GenerateTreeUpdate(FuzzerData& fuzz_data, size_t node_count);
ui::AXNodeID GetMaxAssignedID() const;
// This must be kept in sync with the minimum amount of data needed to create
// any node. Any optional node data should check to ensure there is space.
static constexpr size_t kMinimumNewNodeFuzzDataSize = 5;
static constexpr size_t kMinTextFuzzDataSize = 10;
static constexpr size_t kMaxTextFuzzDataSize = 200;
// When creating a node, we allow for the next node to be a sibling of an
// ancestor, this constant determines the maximum nodes we will pop when
// building the tree.
static constexpr size_t kMaxAncestorPopCount = 3;
private:
enum NextNodeRelationship {
// Next node is a child of this node. (This node is a parent.)
kChild,
// Next node is sibling to this node. (This node is a leaf.)
kSibling,
// Next node is sibling to an ancestor. (This node is a leaf.)
kSiblingToAncestor,
};
enum TreeUpdateOperation {
kAddChild,
kRemoveNode,
kTextChange,
kNoOperation
};
void RecursiveGenerateUpdate(const ui::AXNode* node,
ui::AXTreeUpdate& tree_update,
FuzzerData& fuzz_data,
std::set<ui::AXNodeID>& updated_nodes);
// TODO(janewman): Many of these can be made static.
ui::AXNodeData CreateChildNodeData(ui::AXNodeData& parent,
ui::AXNodeID new_node_id);
NextNodeRelationship DetermineNextNodeRelationship(ax::mojom::Role role,
unsigned char byte);
TreeUpdateOperation DetermineTreeUpdateOperation(const ui::AXNode* node,
unsigned char byte);
void AddRoleSpecificProperties(FuzzerData& fuzz_data,
ui::AXNodeData& node,
const std::string& parentName,
size_t extra_data_size);
ax::mojom::Role GetInterestingRole(unsigned char byte,
ax::mojom::Role parent_role);
bool CanHaveChildren(ax::mojom::Role role);
bool CanHaveText(ax::mojom::Role role);
std::u16string GenerateInterestingText(const unsigned char* data,
size_t size);
ui::AXNodeID max_assigned_node_id_;
ui::TestSingleAXTreeManager tree_manager_;
};
#endif // UI_ACCESSIBILITY_AX_TREE_FUZZER_UTIL_H_
|
