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(buffer.size() + sizeof(ChrePigweedNanoappMessage)));
48     if (data == nullptr) {
49       return PW_STATUS_RESOURCE_EXHAUSTED;
50     }
51 
52     data->msgSize = buffer.size();
53     data->msg = &data[1];
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 
ChreChannelOutputBase()66 ChreChannelOutputBase::ChreChannelOutputBase() : ChannelOutput("CHRE") {}
67 
MaximumTransmissionUnit()68 size_t ChreChannelOutputBase::MaximumTransmissionUnit() {
69   return CHRE_MESSAGE_TO_HOST_MAX_SIZE - sizeof(ChrePigweedNanoappMessage);
70 }
71 
setClient(uint32_t nanoappInstanceId)72 void ChreServerNanoappChannelOutput::setClient(uint32_t nanoappInstanceId) {
73   CHRE_ASSERT(nanoappInstanceId <= kRpcNanoappMaxId);
74   if (nanoappInstanceId <= kRpcNanoappMaxId) {
75     mClientInstanceId = static_cast<uint16_t>(nanoappInstanceId);
76   } else {
77     mClientInstanceId = 0;
78   }
79 }
80 
Send(pw::span<const std::byte> buffer)81 pw::Status ChreServerNanoappChannelOutput::Send(
82     pw::span<const std::byte> buffer) {
83   // The permission is not enforced across nanoapps but we still need to
84   // reset the value as it is only applicable to the next message.
85   mPermission.getAndReset();
86 
87   return sendToNanoapp(mClientInstanceId, PW_RPC_CHRE_NAPP_RESPONSE_EVENT_TYPE,
88                        buffer);
89 }
90 
setServer(uint32_t instanceId)91 void ChreClientNanoappChannelOutput::setServer(uint32_t instanceId) {
92   CHRE_ASSERT(instanceId <= kRpcNanoappMaxId);
93   if (instanceId <= kRpcNanoappMaxId) {
94     mServerInstanceId = static_cast<uint16_t>(instanceId);
95   } else {
96     mServerInstanceId = 0;
97   }
98 }
99 
Send(pw::span<const std::byte> buffer)100 pw::Status ChreClientNanoappChannelOutput::Send(
101     pw::span<const std::byte> buffer) {
102   return sendToNanoapp(mServerInstanceId, PW_RPC_CHRE_NAPP_REQUEST_EVENT_TYPE,
103                        buffer);
104 }
105 
setHostEndpoint(uint16_t hostEndpoint)106 void ChreServerHostChannelOutput::setHostEndpoint(uint16_t hostEndpoint) {
107   mEndpointId = hostEndpoint;
108 }
109 
Send(pw::span<const std::byte> buffer)110 pw::Status ChreServerHostChannelOutput::Send(pw::span<const std::byte> buffer) {
111   CHRE_ASSERT(mEndpointId != CHRE_HOST_ENDPOINT_UNSPECIFIED);
112   pw::Status returnCode = PW_STATUS_OK;
113 
114   if (buffer.size() > 0) {
115     uint32_t permission = mPermission.getAndReset();
116     uint8_t *data = static_cast<uint8_t *>(chreHeapAlloc(buffer.size()));
117     if (data == nullptr) {
118       returnCode = PW_STATUS_RESOURCE_EXHAUSTED;
119     } else {
120       memcpy(data, buffer.data(), buffer.size());
121       if (!chreSendMessageWithPermissions(
122               data, buffer.size(), PW_RPC_CHRE_HOST_MESSAGE_TYPE, mEndpointId,
123               permission, heapFreeMessageCallback)) {
124         returnCode = PW_STATUS_INVALID_ARGUMENT;
125       }
126     }
127   }
128 
129   return returnCode;
130 }
131 
132 }  // namespace chre
133