1 //
2 // Copyright 2017 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 "h4_protocol.h"
18 
19 #define LOG_TAG "android.hardware.bluetooth-hci-h4"
20 
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <log/log.h>
24 #include <sys/uio.h>
25 #include <unistd.h>
26 
27 namespace android {
28 namespace hardware {
29 namespace bluetooth {
30 namespace hci {
31 
Send(uint8_t type,const uint8_t * data,size_t length)32 size_t H4Protocol::Send(uint8_t type, const uint8_t* data, size_t length) {
33   struct iovec iov[] = {{&type, sizeof(type)},
34                         {const_cast<uint8_t*>(data), length}};
35   ssize_t ret = 0;
36   do {
37     ret = TEMP_FAILURE_RETRY(writev(uart_fd_, iov, sizeof(iov) / sizeof(iov[0])));
38   } while (-1 == ret && EAGAIN == errno);
39 
40   if (ret == -1) {
41     ALOGE("%s error writing to UART (%s)", __func__, strerror(errno));
42   } else if (ret < static_cast<ssize_t>(length + 1)) {
43     ALOGE("%s: %d / %d bytes written - something went wrong...", __func__,
44           static_cast<int>(ret), static_cast<int>(length + 1));
45   }
46   return ret;
47 }
48 
OnPacketReady()49 void H4Protocol::OnPacketReady() {
50   switch (hci_packet_type_) {
51     case HCI_PACKET_TYPE_EVENT:
52       event_cb_(hci_packetizer_.GetPacket());
53       break;
54     case HCI_PACKET_TYPE_ACL_DATA:
55       acl_cb_(hci_packetizer_.GetPacket());
56       break;
57     case HCI_PACKET_TYPE_SCO_DATA:
58       sco_cb_(hci_packetizer_.GetPacket());
59       break;
60     default:
61       LOG_ALWAYS_FATAL("%s: Unimplemented packet type %d", __func__,
62                        static_cast<int>(hci_packet_type_));
63   }
64   // Get ready for the next type byte.
65   hci_packet_type_ = HCI_PACKET_TYPE_UNKNOWN;
66 }
67 
OnDataReady(int fd)68 void H4Protocol::OnDataReady(int fd) {
69   if (hci_packet_type_ == HCI_PACKET_TYPE_UNKNOWN) {
70     uint8_t buffer[1] = {0};
71     ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, 1));
72     if (bytes_read != 1) {
73       if (bytes_read == 0) {
74         // This is only expected if the UART got closed when shutting down.
75         ALOGE("%s: Unexpected EOF reading the packet type!", __func__);
76         sleep(5);  // Expect to be shut down within 5 seconds.
77         return;
78       } else if (bytes_read < 0) {
79         LOG_ALWAYS_FATAL("%s: Read packet type error: %s", __func__,
80                          strerror(errno));
81       } else {
82         LOG_ALWAYS_FATAL("%s: More bytes read than expected (%u)!", __func__,
83                          static_cast<unsigned int>(bytes_read));
84       }
85     }
86     hci_packet_type_ = static_cast<HciPacketType>(buffer[0]);
87     if (hci_packet_type_ != HCI_PACKET_TYPE_ACL_DATA &&
88         hci_packet_type_ != HCI_PACKET_TYPE_SCO_DATA &&
89         hci_packet_type_ != HCI_PACKET_TYPE_EVENT) {
90       LOG_ALWAYS_FATAL("%s: Unimplemented packet type %d", __func__,
91                        static_cast<int>(hci_packet_type_));
92     }
93   } else {
94     hci_packetizer_.OnDataReady(fd, hci_packet_type_);
95   }
96 }
97 
98 }  // namespace hci
99 }  // namespace bluetooth
100 }  // namespace hardware
101 }  // namespace android
102