1 
2 /*
3  * Copyright (C) 2017 The Android Open Source Project
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *      http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #ifndef CHRE_HOST_HOST_PROTOCOL_HOST_H_
19 #define CHRE_HOST_HOST_PROTOCOL_HOST_H_
20 
21 #include <stdint.h>
22 
23 #include "chre/platform/shared/host_protocol_common.h"
24 #include "chre_host/fragmented_load_transaction.h"
25 #include "chre_host/generated/host_messages_generated.h"
26 #include "flatbuffers/flatbuffers.h"
27 
28 #include <vector>
29 
30 namespace android {
31 namespace chre {
32 
33 /**
34  * Checks that a string encapsulated as a byte vector is null-terminated, and
35  * if it is, returns a pointer to the vector's data. Otherwise returns null.
36  *
37  * This is similar to getStringFromByteVector in host_protocol_chre.h. Ensure
38  * that method's implementation is kept in sync with this.
39  *
40  * @param vec Target vector, can be null
41  *
42  * @return Pointer to the vector's data, or null
43  */
44 const char *getStringFromByteVector(const std::vector<int8_t> &vec);
45 
46 /**
47  * Calling code should provide an implementation of this interface to handle
48  * parsed results from decodeMessageFromChre().
49  */
50 class IChreMessageHandlers {
51  public:
52   virtual ~IChreMessageHandlers() = default;
53 
handleNanoappMessage(const::chre::fbs::NanoappMessageT &)54   virtual void handleNanoappMessage(
55       const ::chre::fbs::NanoappMessageT & /*message*/){};
56 
handleHubInfoResponse(const::chre::fbs::HubInfoResponseT &)57   virtual void handleHubInfoResponse(
58       const ::chre::fbs::HubInfoResponseT & /*response*/){};
59 
handleNanoappListResponse(const::chre::fbs::NanoappListResponseT &)60   virtual void handleNanoappListResponse(
61       const ::chre::fbs::NanoappListResponseT & /*response*/){};
62 
handleLoadNanoappResponse(const::chre::fbs::LoadNanoappResponseT &)63   virtual void handleLoadNanoappResponse(
64       const ::chre::fbs::LoadNanoappResponseT & /*response*/){};
65 
handleUnloadNanoappResponse(const::chre::fbs::UnloadNanoappResponseT &)66   virtual void handleUnloadNanoappResponse(
67       const ::chre::fbs::UnloadNanoappResponseT & /*response*/){};
68 
handleDebugDumpData(const::chre::fbs::DebugDumpDataT &)69   virtual void handleDebugDumpData(
70       const ::chre::fbs::DebugDumpDataT & /*data*/){};
71 
handleDebugDumpResponse(const::chre::fbs::DebugDumpResponseT &)72   virtual void handleDebugDumpResponse(
73       const ::chre::fbs::DebugDumpResponseT & /*response*/){};
74 
handleSelfTestResponse(const::chre::fbs::SelfTestResponseT &)75   virtual void handleSelfTestResponse(
76       const ::chre::fbs::SelfTestResponseT & /*response*/){};
77 };
78 
79 /**
80  * A set of helper methods that simplify the encode/decode of FlatBuffers
81  * messages used in communication with CHRE from the host.
82  */
83 class HostProtocolHost : public ::chre::HostProtocolCommon {
84  public:
85   /**
86    * Decodes a message sent from CHRE and invokes the appropriate handler
87    * function in the provided interface implementation to handle the parsed
88    * result.
89    *
90    * @param message Buffer containing a complete FlatBuffers CHRE message
91    * @param messageLen Size of the message, in bytes
92    * @param handlers Set of callbacks to handle the parsed message. If this
93    *        function returns success, then exactly one of these functions was
94    *        called.
95    *
96    * @return true if the message was parsed successfully and passed to a handler
97    */
98   static bool decodeMessageFromChre(const void *message, size_t messageLen,
99                                     IChreMessageHandlers &handlers);
100 
101   /**
102    * Encodes a message requesting hub information from CHRE
103    *
104    * @param builder A newly constructed FlatBufferBuilder that will be used to
105    *        construct the message
106    */
107   static void encodeHubInfoRequest(flatbuffers::FlatBufferBuilder &builder);
108 
109   /**
110    * Encodes a message requesting to load a nanoapp specified by the included
111    * (possibly fragmented) binary payload and metadata.
112    *
113    * @param builder A newly constructed FlatBufferBuilder that will be used to
114    *        construct the message
115    * @param request The FragmentedLoadRequest object with the binary and the
116    *        metadata
117    * @param respondBeforeStart See LoadNanoappRequest.respond_before_start in
118    *        flatbuffers message.
119    */
120   static void encodeFragmentedLoadNanoappRequest(
121       flatbuffers::FlatBufferBuilder &builder,
122       const FragmentedLoadRequest &request, bool respondBeforeStart = false);
123 
124   /**
125    * Encodes a message requesting the list of loaded nanoapps from CHRE
126    *
127    * @param builder A newly constructed FlatBufferBuilder that will be used to
128    *        construct the message
129    */
130   static void encodeNanoappListRequest(flatbuffers::FlatBufferBuilder &builder);
131 
132   /**
133    * Encodes a message requesting to unload a nanoapp specified by app ID.
134    *
135    * @param builder A newly constructed FlatBufferBuilder that will be used to
136    *        construct the message
137    * @param transactionId A transaction identifier to tie the subsequent
138    *        response to this request
139    * @param appId Identifier for the app to unload
140    * @param allowSystemNanoappUnload Whether this request should be allowed to
141    *        result in unloading a system nanoapp (e.g. requests from the context
142    *        hub HAL should have set this to false, as system nanoapps are not
143    *        expected to be managed through that HAL)
144    */
145   static void encodeUnloadNanoappRequest(
146       flatbuffers::FlatBufferBuilder &builder, uint32_t transactionId,
147       uint64_t appId, bool allowSystemNanoappUnload);
148 
149   /**
150    * Encodes a message to send the AP timestamp to CHRE
151    *
152    * @param builder A newly constructed FlatBufferBuilder that will be used to
153    *        construct the message
154    * @param offset The AP to SLPI offset in nanoseconds
155    */
156   static void encodeTimeSyncMessage(flatbuffers::FlatBufferBuilder &builder,
157                                     int64_t offset);
158 
159   /**
160    * Encodes a message requesting debugging information from CHRE
161    *
162    * @param builder A newly constructed FlatBufferBuilder that will be used to
163    *        construct the message
164    */
165   static void encodeDebugDumpRequest(flatbuffers::FlatBufferBuilder &builder);
166 
167   /**
168    * Decodes the host client ID included in the message container
169    *
170    * @param message Buffer containing a complete FlatBuffers CHRE message
171    * @param messageLen Size of the message, in bytes
172    * @param hostClientId Output parameter that will be populated with the client
173    *        ID included in the message on success
174    *
175    * @return true if the host client ID was successfully decoded from the
176    *         message
177    */
178   static bool extractHostClientIdAndType(const void *message, size_t messageLen,
179                                          uint16_t *hostClientId,
180                                          ::chre::fbs::ChreMessage *messageType);
181 
182   /**
183    * Update the host client ID field in the MessageContainer.
184    *
185    * @param message Buffer containing a complete FlatBuffers CHRE message
186    * @param messageLen Size of the message, in bytes
187    * @param hostClientId The value to set the host client ID to
188    *
189    * @return true if the message was verified successfully, and we were able to
190    *         modify the host client ID field
191    */
192   static bool mutateHostClientId(void *message, size_t messageLen,
193                                  uint16_t hostClientId);
194 
195   /**
196    * Encodes a message requesting to load a nanoapp specified by the included
197    * binary payload and metadata.
198    *
199    * @param builder A newly constructed FlatBufferBuilder that will be used to
200    *        construct the message
201    */
202   static void encodeLoadNanoappRequestForBinary(
203       flatbuffers::FlatBufferBuilder &builder, uint32_t transactionId,
204       uint64_t appId, uint32_t appVersion, uint32_t appFlags,
205       uint32_t targetApiVersion, const std::vector<uint8_t> &nanoappBinary,
206       uint32_t fragmentId, size_t appTotalSizeBytes, bool respondBeforeStart);
207 
208   /**
209    * Encodes a message requesting to load a nanoapp specified by the included
210    * binary filename and metadata.
211    *
212    * @param builder A newly constructed FlatBufferBuilder that will be used to
213    *        construct the message
214    */
215   static void encodeLoadNanoappRequestForFile(
216       flatbuffers::FlatBufferBuilder &builder, uint32_t transactionId,
217       uint64_t appId, uint32_t appVersion, uint32_t targetApiVersion,
218       const char *nanoappBinaryName);
219 
220   /**
221    * Encodes a message notifying CHRE of a user setting change.
222    *
223    * @param builder A newly constructed FlatBufferBuilder that will be used to
224    *        construct the message
225    * @param setting The setting value that the user changed
226    * @param newState The state that the user change the setting to.
227    */
228   static void encodeSettingChangeNotification(
229       flatbuffers::FlatBufferBuilder &builder, ::chre::fbs::Setting setting,
230       ::chre::fbs::SettingState newState);
231 
232   /**
233    * Encodes a message to request CHRE to perform a self test.
234    */
235   static void encodeSelfTestRequest(flatbuffers::FlatBufferBuilder &builder);
236 };
237 
238 }  // namespace chre
239 }  // namespace android
240 
241 #endif  // CHRE_HOST_HOST_PROTOCOL_HOST_H_
242