1 /*
2  * Copyright (C) 2017 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 "chre/platform/shared/host_protocol_common.h"
18 
19 #include <string.h>
20 
21 #include "chre/platform/shared/host_messages_generated.h"
22 
23 using flatbuffers::FlatBufferBuilder;
24 using flatbuffers::Offset;
25 using flatbuffers::Vector;
26 
27 namespace chre {
28 
encodeNanoappMessage(FlatBufferBuilder & builder,uint64_t appId,uint32_t messageType,uint16_t hostEndpoint,const void * messageData,size_t messageDataLen)29 void HostProtocolCommon::encodeNanoappMessage(
30     FlatBufferBuilder& builder, uint64_t appId, uint32_t messageType,
31     uint16_t hostEndpoint, const void *messageData, size_t messageDataLen) {
32   auto messageDataOffset = builder.CreateVector(
33       static_cast<const uint8_t *>(messageData), messageDataLen);
34 
35   auto nanoappMessage = fbs::CreateNanoappMessage(
36       builder, appId, messageType, hostEndpoint, messageDataOffset);
37   finalize(builder, fbs::ChreMessage::NanoappMessage, nanoappMessage.Union());
38 }
39 
addStringAsByteVector(FlatBufferBuilder & builder,const char * str)40 Offset<Vector<int8_t>> HostProtocolCommon::addStringAsByteVector(
41     FlatBufferBuilder& builder, const char *str) {
42   return builder.CreateVector(reinterpret_cast<const int8_t *>(str),
43                               strlen(str) + 1);
44 }
45 
finalize(FlatBufferBuilder & builder,fbs::ChreMessage messageType,flatbuffers::Offset<void> message,uint16_t hostClientId)46 void HostProtocolCommon::finalize(
47     FlatBufferBuilder& builder, fbs::ChreMessage messageType,
48     flatbuffers::Offset<void> message, uint16_t hostClientId) {
49   fbs::HostAddress hostAddr(hostClientId);
50   auto container = fbs::CreateMessageContainer(
51       builder, messageType, message, &hostAddr);
52   builder.Finish(container);
53 }
54 
verifyMessage(const void * message,size_t messageLen)55 bool HostProtocolCommon::verifyMessage(const void *message, size_t messageLen) {
56   bool valid = false;
57 
58   if (message != nullptr) {
59     flatbuffers::Verifier verifier(static_cast<const uint8_t *>(message),
60                                    messageLen);
61 
62     valid = fbs::VerifyMessageContainerBuffer(verifier);
63   }
64 
65   return valid;
66 }
67 
68 
69 }  // namespace chre
70