1 /* 2 * Copyright (C) 2018 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/tracing/core/packet_stream_validator.h" 18 19 #include <inttypes.h> 20 #include <stddef.h> 21 22 #include "perfetto/base/logging.h" 23 #include "perfetto/protozero/proto_utils.h" 24 #include "perfetto/trace/trusted_packet.pb.h" 25 26 namespace perfetto { 27 28 // static 29 bool PacketStreamValidator::Validate(const Slices& slices) { 30 SlicedProtobufInputStream stream(&slices); 31 size_t size = 0; 32 for (const Slice& slice : slices) 33 size += slice.size; 34 35 protos::TrustedPacket packet; 36 if (!packet.ParseFromBoundedZeroCopyStream(&stream, static_cast<int>(size))) 37 return false; 38 39 // Only the service is allowed to fill in the trusted uid. 40 if (packet.optional_trusted_uid_case() != 41 protos::TrustedPacket::OPTIONAL_TRUSTED_UID_NOT_SET) { 42 return false; 43 } 44 45 // Only the service is allowed to fill in the TraceConfig. 46 if (packet.has_trace_config()) 47 return false; 48 49 // Only the service is allowed to fill in the TraceStats. 50 if (packet.has_trace_stats()) 51 return false; 52 53 // We are deliberately not checking for clock_snapshot for the moment. It's 54 // unclear if we want to allow producers to snapshot their clocks. Ideally we 55 // want a security model where producers can only snapshot their own clocks 56 // and not system ones. However, right now, there isn't a compelling need to 57 // be so prescriptive. 58 59 return true; 60 } 61 62 } // namespace perfetto 63
