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/*
* Copyright (C) 2024 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "src/trace_redaction/scrub_process_trees.h"
#include "perfetto/base/status.h"
#include "perfetto/protozero/field.h"
#include "perfetto/protozero/scattered_heap_buffer.h"
#include "src/trace_redaction/proto_util.h"
#include "src/trace_redaction/trace_redaction_framework.h"
#include "protos/perfetto/trace/ps/process_tree.pbzero.h"
#include "protos/perfetto/trace/trace_packet.pbzero.h"
namespace perfetto::trace_redaction {
namespace {
// Appends a value to the message if (and only if) the pid belongs to the target
// package.
void TryAppendPid(const Context& context,
const protozero::Field& timestamp,
const protozero::Field& pid,
const protozero::Field& value,
protozero::Message* message) {
// All valid processes with have a time and pid/tid values. However, if
// they're missing values, the trace is corrupt. To avoid making this work by
// dropping too much data, drop the cmdline for all processes.
if (!timestamp.valid() || !pid.valid()) {
return;
}
if (context.timeline->PidConnectsToUid(timestamp.as_uint64(), pid.as_int32(),
*context.package_uid)) {
proto_util::AppendField(value, message);
}
}
} // namespace
base::Status ScrubProcessTrees::VerifyContext(const Context& context) const {
if (!context.package_uid.has_value()) {
return base::ErrStatus("ScrubProcessTrees: missing package uid.");
}
if (!context.timeline) {
return base::ErrStatus("ScrubProcessTrees: missing timeline.");
}
return base::OkStatus();
}
void ScrubProcessTrees::TransformProcess(
const Context& context,
const protozero::Field& timestamp,
const protozero::Field& process,
protos::pbzero::ProcessTree* process_tree) const {
protozero::ProtoDecoder decoder(process.as_bytes());
auto pid =
decoder.FindField(protos::pbzero::ProcessTree::Process::kPidFieldNumber);
auto* process_message = process_tree->add_processes();
for (auto field = decoder.ReadField(); field.valid();
field = decoder.ReadField()) {
if (field.id() ==
protos::pbzero::ProcessTree::Process::kCmdlineFieldNumber) {
TryAppendPid(context, timestamp, pid, field, process_message);
} else {
proto_util::AppendField(field, process_message);
}
}
}
void ScrubProcessTrees::TransformThread(
const Context& context,
const protozero::Field& timestamp,
const protozero::Field& thread,
protos::pbzero::ProcessTree* process_tree) const {
protozero::ProtoDecoder decoder(thread.as_bytes());
auto tid =
decoder.FindField(protos::pbzero::ProcessTree::Thread::kTidFieldNumber);
auto* thread_message = process_tree->add_threads();
for (auto field = decoder.ReadField(); field.valid();
field = decoder.ReadField()) {
if (field.id() == protos::pbzero::ProcessTree::Thread::kNameFieldNumber) {
TryAppendPid(context, timestamp, tid, field, thread_message);
} else {
proto_util::AppendField(field, thread_message);
}
}
}
} // namespace perfetto::trace_redaction