xref: /aosp_15_r20/system/chre/util/pigweed/chre_channel_output.cc (revision 84e339476a462649f82315436d70fd732297a399)
1 /*
2  * Copyright (C) 2022 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/util/pigweed/chre_channel_output.h"
18 
19 #include <cstdint>
20 
21 #include "chre/util/nanoapp/callbacks.h"
22 #include "chre/util/pigweed/rpc_helper.h"
23 
24 namespace chre {
25 namespace {
26 
nappMessageFreeCb(uint16_t,void * eventData)27 void nappMessageFreeCb(uint16_t /* eventType */, void *eventData) {
28   chreHeapFree(eventData);
29 }
30 
31 /**
32  * Sends the buffer to the nanoapp.
33  *
34  * The buffer is first wrapped into a ChrePigweedNanoappMessage struct.
35  *
36  * @param targetInstanceId The nanoapp to send the message to
37  * @param eventType The event to send to the nanoapp
38  * @param buffer The buffer to send
39  * @return The status of the operation
40  */
sendToNanoapp(uint32_t targetInstanceId,uint16_t eventType,pw::span<const std::byte> buffer)41 pw::Status sendToNanoapp(uint32_t targetInstanceId, uint16_t eventType,
42                          pw::span<const std::byte> buffer) {
43   CHRE_ASSERT(targetInstanceId != 0);
44 
45   if (buffer.size() > 0) {
46     auto *data = static_cast<ChrePigweedNanoappMessage *>(
47         chreHeapAlloc(static_cast<uint32_t>(
48             buffer.size() + sizeof(ChrePigweedNanoappMessage))));
49     if (data == nullptr) {
50       return PW_STATUS_RESOURCE_EXHAUSTED;
51     }
52 
53     data->msgSize = buffer.size();
54     memcpy(data->msg, buffer.data(), buffer.size());
55 
56     if (!chreSendEvent(eventType, data, nappMessageFreeCb, targetInstanceId)) {
57       return PW_STATUS_INVALID_ARGUMENT;
58     }
59   }
60 
61   return PW_STATUS_OK;
62 }
63 
64 }  // namespace
65 
setClient(uint32_t nanoappInstanceId)66 void ChreServerNanoappChannelOutput::setClient(uint32_t nanoappInstanceId) {
67   CHRE_ASSERT(nanoappInstanceId <= kRpcNanoappMaxId);
68   if (nanoappInstanceId <= kRpcNanoappMaxId) {
69     mClientInstanceId = static_cast<uint16_t>(nanoappInstanceId);
70   } else {
71     mClientInstanceId = 0;
72   }
73 }
74 
MaximumTransmissionUnit()75 size_t ChreServerNanoappChannelOutput::MaximumTransmissionUnit() {
76   return CHRE_MESSAGE_TO_HOST_MAX_SIZE - sizeof(ChrePigweedNanoappMessage);
77 }
78 
Send(pw::span<const std::byte> buffer)79 pw::Status ChreServerNanoappChannelOutput::Send(
80     pw::span<const std::byte> buffer) {
81   // The permission is not enforced across nanoapps but we still need to
82   // reset the value as it is only applicable to the next message.
83   mPermission.getAndReset();
84 
85   return sendToNanoapp(mClientInstanceId, CHRE_EVENT_RPC_RESPONSE, buffer);
86 }
87 
setServer(uint32_t instanceId)88 void ChreClientNanoappChannelOutput::setServer(uint32_t instanceId) {
89   CHRE_ASSERT(instanceId <= kRpcNanoappMaxId);
90   if (instanceId <= kRpcNanoappMaxId) {
91     mServerInstanceId = static_cast<uint16_t>(instanceId);
92   } else {
93     mServerInstanceId = 0;
94   }
95 }
96 
MaximumTransmissionUnit()97 size_t ChreClientNanoappChannelOutput::MaximumTransmissionUnit() {
98   return CHRE_MESSAGE_TO_HOST_MAX_SIZE - sizeof(ChrePigweedNanoappMessage);
99 }
100 
Send(pw::span<const std::byte> buffer)101 pw::Status ChreClientNanoappChannelOutput::Send(
102     pw::span<const std::byte> buffer) {
103   return sendToNanoapp(mServerInstanceId, CHRE_EVENT_RPC_REQUEST, buffer);
104 }
105 
setHostEndpoint(uint16_t hostEndpoint)106 void ChreServerHostChannelOutput::setHostEndpoint(uint16_t hostEndpoint) {
107   mEndpointId = hostEndpoint;
108 }
109 
MaximumTransmissionUnit()110 size_t ChreServerHostChannelOutput::MaximumTransmissionUnit() {
111   return CHRE_MESSAGE_TO_HOST_MAX_SIZE - sizeof(ChrePigweedNanoappMessage);
112 }
113 
Send(pw::span<const std::byte> buffer)114 pw::Status ChreServerHostChannelOutput::Send(pw::span<const std::byte> buffer) {
115   CHRE_ASSERT(mEndpointId != CHRE_HOST_ENDPOINT_UNSPECIFIED);
116   pw::Status returnCode = PW_STATUS_OK;
117 
118   if (buffer.size() > 0) {
119     uint32_t permission = mPermission.getAndReset();
120     uint8_t *data = static_cast<uint8_t *>(
121         chreHeapAlloc(static_cast<uint32_t>(buffer.size())));
122     if (data == nullptr) {
123       returnCode = PW_STATUS_RESOURCE_EXHAUSTED;
124     } else {
125       memcpy(data, buffer.data(), buffer.size());
126       if (!chreSendMessageWithPermissions(
127               data, buffer.size(), CHRE_MESSAGE_TYPE_RPC, mEndpointId,
128               permission, heapFreeMessageCallback)) {
129         returnCode = PW_STATUS_INVALID_ARGUMENT;
130       }
131     }
132   }
133 
134   return returnCode;
135 }
136 
137 }  // namespace chre
138