1 /*
2 * Copyright (C) 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by appicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "src/tools/proto_merger/allowlist.h"
18
19 #include <google/protobuf/descriptor.pb.h>
20
21 #include "perfetto/ext/base/string_utils.h"
22
23 namespace perfetto {
24 namespace proto_merger {
25 namespace {
26
SplitFieldPath(const std::string & name)27 std::vector<std::string> SplitFieldPath(const std::string& name) {
28 if (name.empty())
29 return {};
30
31 if (name[0] == '.')
32 return base::SplitString(name.substr(1), ".");
33
34 return base::SplitString(name, ".");
35 }
36
ResolveMessageForDescriptor(const google::protobuf::Descriptor & desc,Allowlist & allowlist)37 Allowlist::Message& ResolveMessageForDescriptor(
38 const google::protobuf::Descriptor& desc,
39 Allowlist& allowlist) {
40 std::string name(desc.name());
41 if (!desc.containing_type())
42 return allowlist.messages[name];
43
44 Allowlist::Message& parent =
45 ResolveMessageForDescriptor(*desc.containing_type(), allowlist);
46 return parent.nested_messages[name];
47 }
48
AllowlistEnum(const google::protobuf::EnumDescriptor & desc,Allowlist & allowlist)49 void AllowlistEnum(const google::protobuf::EnumDescriptor& desc,
50 Allowlist& allowlist) {
51 std::string name(desc.name());
52 if (!desc.containing_type()) {
53 allowlist.enums.emplace(name);
54 return;
55 }
56
57 auto& containing =
58 ResolveMessageForDescriptor(*desc.containing_type(), allowlist);
59 containing.enums.emplace(name);
60 }
61
AllowlistField(const google::protobuf::FieldDescriptor & desc,Allowlist & allowlist)62 void AllowlistField(const google::protobuf::FieldDescriptor& desc,
63 Allowlist& allowlist) {
64 auto& containing =
65 ResolveMessageForDescriptor(*desc.containing_type(), allowlist);
66
67 // Check if this field is already allowed and return if so; otherwise add it.
68 // We need to do slightly different things based on whether or not this field
69 // is in a oneof.
70 if (desc.containing_oneof()) {
71 auto& oneof =
72 containing.oneofs[std::string(desc.containing_oneof()->name())];
73 if (!oneof.emplace(desc.number()).second) {
74 return;
75 }
76 } else {
77 if (!containing.fields.emplace(desc.number()).second)
78 return;
79 }
80
81 switch (desc.type()) {
82 case google::protobuf::FieldDescriptor::TYPE_MESSAGE:
83 // For message types, we recursively allow all fields under it including
84 // any types those fields may depend on.
85 for (int i = 0; i < desc.message_type()->field_count(); ++i) {
86 AllowlistField(*desc.message_type()->field(i), allowlist);
87 }
88 break;
89 case google::protobuf::FieldDescriptor::TYPE_ENUM:
90 // For enums, we allow the enum type.
91 AllowlistEnum(*desc.enum_type(), allowlist);
92 break;
93 default:
94 // We don't need to do anything for primitive types.
95 break;
96 }
97 }
98
99 } // namespace
100
AllowlistFromFieldList(const google::protobuf::Descriptor & desc,const std::vector<std::string> & allowed_fields,Allowlist & allowlist)101 base::Status AllowlistFromFieldList(
102 const google::protobuf::Descriptor& desc,
103 const std::vector<std::string>& allowed_fields,
104 Allowlist& allowlist) {
105 for (const auto& field_path : allowed_fields) {
106 std::vector<std::string> pieces = SplitFieldPath(field_path);
107 const auto* current = &desc;
108 for (size_t i = 0; i < pieces.size(); ++i) {
109 const auto* field = current->FindFieldByName(pieces[i]);
110 if (!field) {
111 return base::ErrStatus("Field %s in message %s not found.",
112 pieces[i].c_str(),
113 std::string(current->name()).c_str());
114 }
115 if (i == pieces.size() - 1) {
116 // For the last field, allow the field and any messages it depends on
117 // recursively.
118 AllowlistField(*field, allowlist);
119 break;
120 }
121
122 // All fields before the last should lead to a message type.
123 if (field->type() != google::protobuf::FieldDescriptor::TYPE_MESSAGE) {
124 return base::ErrStatus("Field %s in message %s has a non-message type",
125 std::string(field->name()).c_str(),
126 std::string(desc.name()).c_str());
127 }
128 current = field->message_type();
129 }
130 }
131 return base::OkStatus();
132 }
133
134 } // namespace proto_merger
135 } // namespace perfetto
136