host_protocol_host.h revision 2f6b50aa8e01717948efd3024f6ab4f4825c0a18 
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/host_messages_generated.h"
25#include "flatbuffers/flatbuffers.h"
26
27namespace android {
28namespace chre {
29
30/**
31 * Calling code should provide an implementation of this interface to handle
32 * parsed results from decodeMessageFromChre().
33 */
34class IChreMessageHandlers {
35 public:
36  virtual ~IChreMessageHandlers() = default;
37
38  virtual void handleNanoappMessage(
39      uint64_t appId, uint32_t messageType, uint16_t hostEndpoint,
40      const void *messageData, size_t messageDataLen) = 0;
41
42  virtual void handleHubInfoResponse(
43      const char *name, const char *vendor,
44      const char *toolchain, uint32_t legacyPlatformVersion,
45      uint32_t legacyToolchainVersion, float peakMips, float stoppedPower,
46      float sleepPower, float peakPower, uint32_t maxMessageLen,
47      uint64_t platformId, uint32_t version) = 0;
48
49  virtual void handleNanoappListResponse(
50      const ::chre::fbs::NanoappListResponseT& response) = 0;
51
52  virtual void handleLoadNanoappResponse(
53      const ::chre::fbs::LoadNanoappResponseT& response) = 0;
54
55  virtual void handleUnloadNanoappResponse(
56      const ::chre::fbs::UnloadNanoappResponseT& response) = 0;
57};
58
59/**
60 * A set of helper methods that simplify the encode/decode of FlatBuffers
61 * messages used in communication with CHRE from the host.
62 */
63class HostProtocolHost : public ::chre::HostProtocolCommon {
64 public:
65  /**
66   * Decodes a message sent from CHRE and invokes the appropriate handler
67   * function in the provided interface implementation to handle the parsed
68   * result.
69   *
70   * @param message Buffer containing a complete FlatBuffers CHRE message
71   * @param messageLen Size of the message, in bytes
72   * @param handlers Set of callbacks to handle the parsed message. If this
73   *        function returns success, then exactly one of these functions was
74   *        called.
75   *
76   * @return true if the message was parsed successfully and passed to a handler
77   */
78  static bool decodeMessageFromChre(const void *message, size_t messageLen,
79                                    IChreMessageHandlers& handlers);
80
81  /**
82   * Encodes a message requesting hub information from CHRE
83   *
84   * @param builder A newly constructed FlatBufferBuilder that will be used to
85   *        construct the message
86   */
87  static void encodeHubInfoRequest(flatbuffers::FlatBufferBuilder& builder);
88
89  /**
90   * Encodes a message requesting to load a nanoapp specified by the included
91   * binary payload and metadata.
92   *
93   * @param builder A newly constructed FlatBufferBuilder that will be used to
94   *        construct the message
95   */
96  static void encodeLoadNanoappRequest(
97      flatbuffers::FlatBufferBuilder& builder, uint32_t transactionId,
98      uint64_t appId, uint32_t appVersion, uint32_t targetApiVersion,
99      const std::vector<uint8_t>& nanoappBinary);
100
101  /**
102   * Encodes a message requesting the list of loaded nanoapps from CHRE
103   *
104   * @param builder A newly constructed FlatBufferBuilder that will be used to
105   *        construct the message
106   */
107  static void encodeNanoappListRequest(flatbuffers::FlatBufferBuilder& builder);
108
109  /**
110   * Encodes a message requesting to unload a nanoapp specified by app ID.
111   *
112   * @param builder A newly constructed FlatBufferBuilder that will be used to
113   *        construct the message
114   * @param transactionId A transaction identifier to tie the subsequent
115   *        response to this request
116   * @param appId Identifier for the app to unload
117   * @param allowSystemNanoappUnload Whether this request should be allowed to
118   *        result in unloading a system nanoapp (e.g. requests from the context
119   *        hub HAL should have set this to false, as system nanoapps are not
120   *        expected to be managed through that HAL)
121   */
122  static void encodeUnloadNanoappRequest(
123      flatbuffers::FlatBufferBuilder& builder, uint32_t transactionId,
124      uint64_t appId, bool allowSystemNanoappUnload);
125
126  /**
127   * Decodes the host client ID included in the message container
128   *
129   * @param message Buffer containing a complete FlatBuffers CHRE message
130   * @param messageLen Size of the message, in bytes
131   * @param hostClientId Output parameter that will be populated with the client
132   *        ID included in the message on success
133   *
134   * @return true if the host client ID was successfully decoded from the
135   *         message
136   */
137  static bool extractHostClientIdAndType(
138      const void *message, size_t messageLen, uint16_t *hostClientId,
139      ::chre::fbs::ChreMessage *messageType);
140
141  /**
142   * Update the host client ID field in the MessageContainer.
143   *
144   * @param message Buffer containing a complete FlatBuffers CHRE message
145   * @param messageLen Size of the message, in bytes
146   * @param hostClientId The value to set the host client ID to
147   *
148   * @return true if the message was verified successfully, and we were able to
149   *         modify the host client ID field
150   */
151  static bool mutateHostClientId(void *message, size_t messageLen,
152                                 uint16_t hostClientId);
153};
154
155}  // namespace chre
156}  // namespace android
157
158#endif  // CHRE_HOST_HOST_PROTOCOL_HOST_H_
159