1 /*
2 * Copyright (C) 2024 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 applicable 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/trace_redaction/prune_package_list.h"
18
19 #include <string>
20
21 #include "perfetto/base/logging.h"
22 #include "perfetto/base/status.h"
23 #include "perfetto/protozero/scattered_heap_buffer.h"
24 #include "src/trace_redaction/proto_util.h"
25
26 #include "protos/perfetto/trace/android/packages_list.pbzero.h"
27
28 namespace perfetto::trace_redaction {
29
Transform(const Context & context,std::string * packet) const30 base::Status PrunePackageList::Transform(const Context& context,
31 std::string* packet) const {
32 if (!context.package_uid.has_value()) {
33 return base::ErrStatus("PrunePackageList: missing package uid.");
34 }
35
36 protozero::ProtoDecoder decoder(*packet);
37
38 protos::pbzero::TracePacket::Decoder trace_packet_decoder(*packet);
39
40 auto package_list =
41 decoder.FindField(protos::pbzero::TracePacket::kPackagesListFieldNumber);
42
43 if (!package_list.valid()) {
44 return base::OkStatus();
45 }
46
47 protozero::HeapBuffered<protos::pbzero::TracePacket> packet_message;
48
49 for (auto field = decoder.ReadField(); field.valid();
50 field = decoder.ReadField()) {
51 if (field.id() == protos::pbzero::TracePacket::kPackagesListFieldNumber) {
52 OnPackageList(context, field.as_bytes(),
53 packet_message->set_packages_list());
54 } else {
55 proto_util::AppendField(field, packet_message.get());
56 }
57 }
58
59 packet->assign(packet_message.SerializeAsString());
60
61 return base::OkStatus();
62 }
63
OnPackageList(const Context & context,protozero::ConstBytes bytes,protos::pbzero::PackagesList * message) const64 void PrunePackageList::OnPackageList(
65 const Context& context,
66 protozero::ConstBytes bytes,
67 protos::pbzero::PackagesList* message) const {
68 PERFETTO_DCHECK(message);
69
70 protozero::ProtoDecoder decoder(bytes);
71
72 for (auto field = decoder.ReadField(); field.valid();
73 field = decoder.ReadField()) {
74 if (field.id() == protos::pbzero::PackagesList::kPackagesFieldNumber) {
75 // The package uid should already be normalized (see
76 // find_package_info.cc).
77 //
78 // If there are more than one package entry (see
79 // trace_redaction_framework.h for more details), we need to match all
80 // instances here because retained processes will reference them.
81 protos::pbzero::PackagesList::PackageInfo::Decoder info(field.as_bytes());
82
83 if (info.has_uid() && NormalizeUid(info.uid()) == context.package_uid) {
84 proto_util::AppendField(field, message);
85 }
86 } else {
87 proto_util::AppendField(field, message);
88 }
89 }
90 }
91
92 } // namespace perfetto::trace_redaction
93