Add option to select hci adapter

cmd/tesla-control/main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/teslamotors/vehicle-command/internal/log"
 	"github.com/teslamotors/vehicle-command/pkg/account"
 	"github.com/teslamotors/vehicle-command/pkg/cli"
+	"github.com/teslamotors/vehicle-command/pkg/connector/ble"
 	"github.com/teslamotors/vehicle-command/pkg/protocol"
 	"github.com/teslamotors/vehicle-command/pkg/vehicle"
 )
@@ -163,12 +164,10 @@ func main() {
 
 	acct, car, err := config.Connect(ctx)
 	if err != nil {
-		writeErr("Error: %s", err)
-		// Error isn't wrapped so we have to check for a substring explicitly.
-		if strings.Contains(err.Error(), "operation not permitted") {
-			// The underlying BLE package calls HCIDEVDOWN on the BLE device, presumably as a
-			// heavy-handed way of dealing with devices that are in a bad state.
-			writeErr("\nTry again after granting this application CAP_NET_ADMIN:\n\n\tsudo setcap 'cap_net_admin=eip' \"$(which %s)\"\n", os.Args[0])
+		if ble.IsAdapterError(err) {
+			writeErr("%s", ble.AdapterErrorHelpMessage(err))
+		} else {
+			writeErr("Error: %s", err)
 		}
 		return
 	}

examples/ble/doc.go

@@ -5,6 +5,12 @@ your car and turns on the AC.
 For more fleshed out examples of other commands, see
 [github.com/tesla/vehicle-command/pkg/cmd/tesla-control].
 
+# Scanning for vehicles
+
+To scan for vehicles, use the -scan-only flag:
+
+	./ble -scan-only -vin YOUR_VIN
+
 # Pairing with the vehicle
 
 To generate a key pair with OpenSSL:
@@ -26,5 +32,9 @@ Sending commands to the vehicle requires the private key you generated above:
 	./ble -vin YOUR_VIN -key private.pem
 
 You can add the -debug flag to inspect the bytes sent over BLE.
+
+You can also specify the Bluetooth adapter to use on Linux with the -bt-adapter flag:
+
+	./ble -vin YOUR_VIN -key private.pem -bt-adapter hci0
 */
 package main

examples/ble/main.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/signal"
+	"runtime"
 	"time"
 
 	debugger "github.com/teslamotors/vehicle-command/internal/log"
@@ -27,29 +29,74 @@ func main() {
 
 	// Provided through command line options
 	var (
+		scanOnly       bool
+		btAdapter      string
 		privateKeyFile string
 		vin            string
 	)
+	flag.BoolVar(&scanOnly, "scan-only", false, "Scan for vehicles and exit")
 	flag.StringVar(&privateKeyFile, "key", "", "Private key `file` for authorizing commands (PEM PKCS8 NIST-P256)")
 	flag.StringVar(&vin, "vin", "", "Vehicle Identification Number (`VIN`) of the car")
 	flag.BoolVar(&debug, "debug", false, "Enable debugging of TX/RX BLE packets")
+	if runtime.GOOS == "linux" {
+		flag.StringVar(&btAdapter, "bt-adapter", "", "Optional ID of Bluetooth adapter to use")
+	}
+
 	flag.Parse()
 
 	if debug {
 		debugger.SetLevel(debugger.LevelDebug)
 	}
 
-	// For simplcity, allow 30 seconds to wake up the vehicle, connect to it,
-	// and unlock. In practice you'd want a fresh timeout for each command.
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-	defer cancel()
+	err := ble.InitAdapterWithID(btAdapter)
+	if err != nil {
+		if ble.IsAdapterError(err) {
+			logger.Print(ble.AdapterErrorHelpMessage(err))
+		} else {
+			logger.Printf("Failed to initialize BLE adapter: %s", err)
+		}
+		return
+	}
 
 	if vin == "" {
 		logger.Printf("Must specify VIN")
 		return
 	}
 
-	var err error
+	if scanOnly {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		doneChan := make(chan struct{})
+		go func() {
+			_, err := ble.ScanVehicleBeacon(ctx, vin)
+			if err != nil && ctx.Err() == nil {
+				logger.Printf("Scan failed: %s", err)
+			} else if ctx.Err() == nil {
+				logger.Printf("Found vehicle")
+				status = 0
+			}
+			close(doneChan)
+		}()
+		logger.Printf("Scanning for BLE devices until interrupted")
+
+		signalChan := make(chan os.Signal, 1)
+		signal.Notify(signalChan, os.Interrupt)
+		select {
+		case <-doneChan:
+		case <-signalChan:
+			logger.Printf("Stopping scan")
+			cancel()
+			<-doneChan
+			status = 130 // Script terminated by SIGINT
+		}
+		return
+	}
+
+	// For simplicity, allow 30 seconds to wake up the vehicle, connect to it,
+	// and unlock. In practice you'd want a fresh timeout for each command.
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
 	var privateKey protocol.ECDHPrivateKey
 	if privateKeyFile != "" {
 		if privateKey, err = protocol.LoadPrivateKey(privateKeyFile); err != nil {
@@ -58,7 +105,14 @@ func main() {
 		}
 	}
 
-	conn, err := ble.NewConnection(ctx, vin)
+	scan, err := ble.ScanVehicleBeacon(ctx, vin)
+	if err != nil {
+		logger.Println(err)
+		return
+	}
+	logger.Printf("Found vehicle: %s (%s) %ddBm", scan.LocalName, scan.Address, scan.RSSI)
+
+	conn, err := ble.NewConnectionFromScanResult(ctx, vin, scan)
 	if err != nil {
 		logger.Printf("Failed to connect to vehicle: %s", err)
 		return

pkg/cli/config.go

@@ -144,6 +144,7 @@ type Config struct {
 	KeyringKeyName   string // Username for private key in system keyring
 	KeyringTokenName string // Username for OAuth token in system keyring
 	VIN              string
+	BtAdapterID      string // ID of Bluetooth adapter to use (Linux only)
 	TokenFilename    string
 	KeyFilename      string
 	CacheFilename    string
@@ -207,6 +208,7 @@ func (c *Config) RegisterCommandLineFlags() {
 		flag.StringVar(&c.Backend.FileDir, "keyring-file-dir", keyringDirectory, "keyring `directory` for file-backed keyring types")
 		flag.BoolVar(&c.Debug, "keyring-debug", false, "Enable keyring debug logging")
 	}
+	c.registerCommandLineFlagsOsSpecific()
 }
 
 // LoadCredentials attempts to open a keyring, prompting for a password if not needed. Call this
@@ -469,6 +471,11 @@ func (c *Config) ConnectRemote(ctx context.Context, skey protocol.ECDHPrivateKey
 
 // ConnectLocal connects to a vehicle over BLE.
 func (c *Config) ConnectLocal(ctx context.Context, skey protocol.ECDHPrivateKey) (car *vehicle.Vehicle, err error) {
+	err = ble.InitAdapterWithID(c.BtAdapterID)
+	if err != nil {
+		return nil, err
+	}
+
 	conn, err := ble.NewConnection(ctx, c.VIN)
 	if err != nil {
 		return nil, err

pkg/cli/config_darwin.go

@@ -0,0 +1,5 @@
+package cli
+
+func (c *Config) registerCommandLineFlagsOsSpecific() {
+	// Nothing yet
+}

pkg/cli/config_linux.go

@@ -0,0 +1,9 @@
+package cli
+
+import "flag"
+
+func (c *Config) registerCommandLineFlagsOsSpecific() {
+	if c.Flags.isSet(FlagBLE) {
+		flag.StringVar(&c.BtAdapterID, "bt-adapter", "", "ID of the Bluetooth adapter to use. Defaults to hci0.")
+	}
+}

pkg/cli/config_windows.go

@@ -0,0 +1,5 @@
+package cli
+
+func (c *Config) registerCommandLineFlagsOsSpecific() {
+	// Nothing yet
+}