forked from tinygo-org/bluetooth
-
Notifications
You must be signed in to change notification settings - Fork 0
/
gap_windows.go
249 lines (216 loc) · 7.73 KB
/
gap_windows.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
package bluetooth
import (
"fmt"
"unsafe"
"github.com/go-ole/go-ole"
"github.com/saltosystems/winrt-go"
"github.com/saltosystems/winrt-go/windows/devices/bluetooth"
"github.com/saltosystems/winrt-go/windows/devices/bluetooth/advertisement"
"github.com/saltosystems/winrt-go/windows/devices/bluetooth/genericattributeprofile"
"github.com/saltosystems/winrt-go/windows/foundation"
"github.com/saltosystems/winrt-go/windows/storage/streams"
)
// Address contains a Bluetooth MAC address.
type Address struct {
MACAddress
}
// Scan starts a BLE scan. It is stopped by a call to StopScan. A common pattern
// is to cancel the scan when a particular device has been found.
func (a *Adapter) Scan(callback func(*Adapter, ScanResult)) (err error) {
if a.watcher != nil {
// Cannot scan more than once: which one should ScanStop()
// stop?
return errScanning
}
a.watcher, err = advertisement.NewBluetoothLEAdvertisementWatcher()
if err != nil {
return
}
defer func() {
_ = a.watcher.Release()
a.watcher = nil
}()
// Set scanning mode to active so we receive scan responses
// from devices in advertising mode
err = a.watcher.SetScanningMode(advertisement.BluetoothLEScanningModeActive)
if err != nil {
return
}
// Listen for incoming BLE advertisement packets.
// We need a TypedEventHandler<TSender, TResult> to listen to events, but since this is a parameterized delegate
// its GUID depends on the classes used as sender and result, so we need to compute it:
// TypedEventHandler<BluetoothLEAdvertisementWatcher, BluetoothLEAdvertisementReceivedEventArgs>
eventReceivedGuid := winrt.ParameterizedInstanceGUID(
foundation.GUIDTypedEventHandler,
advertisement.SignatureBluetoothLEAdvertisementWatcher,
advertisement.SignatureBluetoothLEAdvertisementReceivedEventArgs,
)
handler := foundation.NewTypedEventHandler(ole.NewGUID(eventReceivedGuid), func(instance *foundation.TypedEventHandler, sender, arg unsafe.Pointer) {
args := (*advertisement.BluetoothLEAdvertisementReceivedEventArgs)(arg)
result := getScanResultFromArgs(args)
callback(a, result)
})
defer handler.Release()
token, err := a.watcher.AddReceived(handler)
if err != nil {
return
}
defer a.watcher.RemoveReceived(token)
// Wait for when advertisement has stopped by a call to StopScan().
// Advertisement doesn't seem to stop right away, there is an
// intermediate Stopping state.
stoppingChan := make(chan struct{})
// TypedEventHandler<BluetoothLEAdvertisementWatcher, BluetoothLEAdvertisementWatcherStoppedEventArgs>
eventStoppedGuid := winrt.ParameterizedInstanceGUID(
foundation.GUIDTypedEventHandler,
advertisement.SignatureBluetoothLEAdvertisementWatcher,
advertisement.SignatureBluetoothLEAdvertisementWatcherStoppedEventArgs,
)
stoppedHandler := foundation.NewTypedEventHandler(ole.NewGUID(eventStoppedGuid), func(_ *foundation.TypedEventHandler, _, _ unsafe.Pointer) {
// Note: the args parameter has an Error property that should
// probably be checked, but I'm not sure when stopping the
// advertisement watcher could ever result in an error (except
// for bugs).
close(stoppingChan)
})
defer stoppedHandler.Release()
token, err = a.watcher.AddStopped(stoppedHandler)
if err != nil {
return
}
defer a.watcher.RemoveStopped(token)
err = a.watcher.Start()
if err != nil {
return err
}
// Wait until advertisement has stopped, and finish.
<-stoppingChan
return nil
}
func getScanResultFromArgs(args *advertisement.BluetoothLEAdvertisementReceivedEventArgs) ScanResult {
// parse bluetooth address
addr, _ := args.GetBluetoothAddress()
adr := Address{}
for i := range adr.MAC {
adr.MAC[i] = byte(addr)
addr >>= 8
}
sigStrength, _ := args.GetRawSignalStrengthInDBm()
result := ScanResult{
RSSI: sigStrength,
Address: adr,
}
var manufacturerData map[uint16][]byte = make(map[uint16][]byte)
if winAdv, err := args.GetAdvertisement(); err == nil && winAdv != nil {
vector, _ := winAdv.GetManufacturerData()
size, _ := vector.GetSize()
for i := uint32(0); i < size; i++ {
element, _ := vector.GetAt(i)
manData := (*advertisement.BluetoothLEManufacturerData)(element)
companyID, _ := manData.GetCompanyId()
buffer, _ := manData.GetData()
manufacturerData[companyID] = bufferToSlice(buffer)
}
}
// Note: the IsRandom bit is never set.
advertisement, _ := args.GetAdvertisement()
localName, _ := advertisement.GetLocalName()
result.AdvertisementPayload = &advertisementFields{
AdvertisementFields{
LocalName: localName,
ManufacturerData: manufacturerData,
},
}
return result
}
func bufferToSlice(buffer *streams.IBuffer) []byte {
dataReader, _ := streams.FromBuffer(buffer)
defer dataReader.Release()
bufferSize, _ := buffer.GetLength()
if bufferSize == 0 {
return nil
}
data, _ := dataReader.ReadBytes(bufferSize)
return data
}
// StopScan stops any in-progress scan. It can be called from within a Scan
// callback to stop the current scan. If no scan is in progress, an error will
// be returned.
func (a *Adapter) StopScan() error {
if a.watcher == nil {
return errNotScanning
}
return a.watcher.Stop()
}
// Device is a connection to a remote peripheral.
type Device struct {
device *bluetooth.BluetoothLEDevice
session *genericattributeprofile.GattSession
}
// Connect starts a connection attempt to the given peripheral device address.
//
// On Linux and Windows, the IsRandom part of the address is ignored.
func (a *Adapter) Connect(address Address, params ConnectionParams) (*Device, error) {
var winAddr uint64
for i := range address.MAC {
winAddr += uint64(address.MAC[i]) << (8 * i)
}
// IAsyncOperation<BluetoothLEDevice>
bleDeviceOp, err := bluetooth.FromBluetoothAddressAsync(winAddr)
if err != nil {
return nil, err
}
// We need to pass the signature of the parameter returned by the async operation:
// IAsyncOperation<BluetoothLEDevice>
if err := awaitAsyncOperation(bleDeviceOp, bluetooth.SignatureBluetoothLEDevice); err != nil {
return nil, fmt.Errorf("error connecting to device: %w", err)
}
res, err := bleDeviceOp.GetResults()
if err != nil {
return nil, err
}
// The returned BluetoothLEDevice is set to null if FromBluetoothAddressAsync can't find the device identified by bluetoothAddress
if uintptr(res) == 0x0 {
return nil, fmt.Errorf("device with the given address was not found")
}
bleDevice := (*bluetooth.BluetoothLEDevice)(res)
// Creating a BluetoothLEDevice object by calling this method alone doesn't (necessarily) initiate a connection.
// To initiate a connection, we need to set GattSession.MaintainConnection to true.
dID, err := bleDevice.GetBluetoothDeviceId()
if err != nil {
return nil, err
}
// Windows does not support explicitly connecting to a device.
// Instead it has the concept of a GATT session that is owned
// by the calling program.
gattSessionOp, err := genericattributeprofile.FromDeviceIdAsync(dID) // IAsyncOperation<GattSession>
if err != nil {
return nil, err
}
if err := awaitAsyncOperation(gattSessionOp, genericattributeprofile.SignatureGattSession); err != nil {
return nil, fmt.Errorf("error getting gatt session: %w", err)
}
gattRes, err := gattSessionOp.GetResults()
if err != nil {
return nil, err
}
newSession := (*genericattributeprofile.GattSession)(gattRes)
// This keeps the device connected until we set maintain_connection = False.
if err := newSession.SetMaintainConnection(true); err != nil {
return nil, err
}
return &Device{bleDevice, newSession}, nil
}
// Disconnect from the BLE device. This method is non-blocking and does not
// wait until the connection is fully gone.
func (d *Device) Disconnect() error {
defer d.device.Release()
defer d.session.Release()
if err := d.session.Close(); err != nil {
return err
}
if err := d.device.Close(); err != nil {
return err
}
return nil
}