1 /*
2  * Copyright (C) 2020 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 "chpp/services/timesync.h"
18 
19 #include <stdbool.h>
20 #include <stddef.h>
21 #include <stdint.h>
22 
23 #include "chpp/app.h"
24 #include "chpp/common/timesync.h"
25 #include "chpp/log.h"
26 #include "chpp/macros.h"
27 #include "chpp/services.h"
28 #include "chpp/time.h"
29 #include "chpp/transport.h"
30 
31 /**
32  * Processes the GetTime (0x0001) request and responds with the time as on the
33  * service. This should be the same clock used to timestamp any data samples
34  * provided to CHPP.
35  *
36  * @param context Maintains status for each app layer instance.
37  * @param buf Input data. Cannot be null.
38  * @param len Length of input data in bytes.
39  */
40 static void chppTimesyncGetTime(struct ChppAppState *context,
41                                 const uint8_t *buf, size_t len) {
42   UNUSED_VAR(len);
43   const struct ChppAppHeader *requestHeader = (const struct ChppAppHeader *)buf;
44 
45   struct ChppTimesyncResponse *response =
46       chppAllocServiceResponseFixed(requestHeader, struct ChppTimesyncResponse);
47   size_t responseLen = sizeof(*response);
48 
49   if (response == NULL) {
50     CHPP_LOG_OOM();
51     CHPP_DEBUG_ASSERT(false);
52 
53   } else {
54     response->timeNs = chppGetCurrentTimeNs();
55     CHPP_LOGD("chppTimesyncGetTime returning %" PRIuSIZE
56               " bytes at time=%" PRIu64,
57               responseLen, response->timeNs / CHPP_NSEC_PER_MSEC);
58 
59     chppEnqueueTxDatagramOrFail(context->transportContext, response,
60                                 responseLen);
61   }
62 }
63 
64 /************************************************
65  *  Public Functions
66  ***********************************************/
67 
68 bool chppDispatchTimesyncClientRequest(struct ChppAppState *context,
69                                        const uint8_t *buf, size_t len) {
70   UNUSED_VAR(len);
71   const struct ChppAppHeader *rxHeader = (const struct ChppAppHeader *)buf;
72   bool success = true;
73 
74   switch (rxHeader->command) {
75     case CHPP_TIMESYNC_COMMAND_GETTIME: {
76       chppTimesyncGetTime(context, buf, len);
77       break;
78     }
79     default: {
80       success = false;
81     }
82   }
83   return success;
84 }
85