d77521461d
This is a big rewrite to use DBus calls directly instead of going through go-bluetooth first. This is a big change, but I believe it is an improvement. While the go-bluetooth works for many cases, it's a layer in between that I believe hurts more than it helps. Without it, we can just program directly against the BlueZ D-Bus API. The end result is about 10% more code. With this rewrite, I fixed the following issues: * All MapToStruct warnings are gone, like in https://github.com/tinygo-org/bluetooth/issues/193. * Advertisements can be restarted after they were stopped. Previously this resulted in a panic. * Looking at the source code of go-bluetooth, it appears that it includes devices from a different Bluetooth adapter than the one that's currently scanning. This is fixed with the rewrite. * Fix a bug in Adapter.AddService where it would only allow adding a single service. Multiple services can now be added. This was actually the motivating bug that led me down to rewrite the whole thing because I couldn't figure out where the bug was in go-bluetooth (it's many layers deep). * The `WriteEvent` callback in a characteristic now also gets the 'offset' parameter which wasn't provided by go-bluetooth. This rewrite also avoids go-bluetooth specific workarounds like https://github.com/tinygo-org/bluetooth/pull/74 and https://github.com/tinygo-org/bluetooth/pull/121. I have tested all examples in the smoketest-linux Makefile target. They all still work with this rewrite.
71 lines
1.9 KiB
Go
71 lines
1.9 KiB
Go
//go:build !baremetal
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// Some documentation for the BlueZ D-Bus interface:
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// https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc
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package bluetooth
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import (
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"errors"
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"fmt"
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"github.com/godbus/dbus/v5"
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)
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const defaultAdapter = "hci0"
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type Adapter struct {
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id string
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scanCancelChan chan struct{}
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bus *dbus.Conn
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bluez dbus.BusObject // object at /
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adapter dbus.BusObject // object at /org/bluez/hciX
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address string
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defaultAdvertisement *Advertisement
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connectHandler func(device Address, connected bool)
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}
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// DefaultAdapter is the default adapter on the system. On Linux, it is the
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// first adapter available.
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//
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// Make sure to call Enable() before using it to initialize the adapter.
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var DefaultAdapter = &Adapter{
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id: defaultAdapter,
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connectHandler: func(device Address, connected bool) {
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},
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}
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// Enable configures the BLE stack. It must be called before any
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// Bluetooth-related calls (unless otherwise indicated).
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func (a *Adapter) Enable() (err error) {
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bus, err := dbus.SystemBus()
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if err != nil {
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return err
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}
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a.bus = bus
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a.bluez = a.bus.Object("org.bluez", dbus.ObjectPath("/"))
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a.adapter = a.bus.Object("org.bluez", dbus.ObjectPath("/org/bluez/"+a.id))
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addr, err := a.adapter.GetProperty("org.bluez.Adapter1.Address")
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if err != nil {
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if err, ok := err.(dbus.Error); ok && err.Name == "org.freedesktop.DBus.Error.UnknownObject" {
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return fmt.Errorf("bluetooth: adapter %s does not exist", a.adapter.Path())
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}
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return fmt.Errorf("could not activate BlueZ adapter: %w", err)
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}
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addr.Store(&a.address)
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return nil
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}
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func (a *Adapter) Address() (MACAddress, error) {
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if a.address == "" {
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return MACAddress{}, errors.New("adapter not enabled")
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}
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mac, err := ParseMAC(a.address)
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if err != nil {
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return MACAddress{}, err
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}
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return MACAddress{MAC: mac}, nil
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}
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