Files
BLE_emulator/internal/ble/agent.go
2026-02-08 03:35:43 +01:00

140 lines
4.5 KiB
Go

package ble
import (
"context"
"fmt"
"os/exec"
"time"
"github.com/godbus/dbus/v5"
)
const (
agentPath = "/org/bluez/agent/noinputnooutput"
agentInterface = "org.bluez.Agent1"
agentManager = "org.bluez.AgentManager1"
bluezService = "org.bluez"
bluezPath = "/org/bluez"
)
// NoInputNoOutputAgent implements org.bluez.Agent1 with NoInputNoOutput capability.
// This disables pairing prompts and allows "Just Works" pairing.
type NoInputNoOutputAgent struct{}
// Release is called when the agent is unregistered.
func (a *NoInputNoOutputAgent) Release() *dbus.Error {
return nil
}
// RequestPinCode returns an error as PIN codes are not supported with NoInputNoOutput.
func (a *NoInputNoOutputAgent) RequestPinCode(device dbus.ObjectPath) (string, *dbus.Error) {
return "", dbus.NewError("org.bluez.Error.Rejected", []any{"NoInputNoOutput agent"})
}
// DisplayPinCode does nothing as we have no display.
func (a *NoInputNoOutputAgent) DisplayPinCode(device dbus.ObjectPath, pincode string) *dbus.Error {
return nil
}
// RequestPasskey returns an error as passkeys are not supported with NoInputNoOutput.
func (a *NoInputNoOutputAgent) RequestPasskey(device dbus.ObjectPath) (uint32, *dbus.Error) {
return 0, dbus.NewError("org.bluez.Error.Rejected", []any{"NoInputNoOutput agent"})
}
// DisplayPasskey does nothing as we have no display.
func (a *NoInputNoOutputAgent) DisplayPasskey(device dbus.ObjectPath, passkey uint32, entered uint16) *dbus.Error {
return nil
}
// RequestConfirmation auto-accepts pairing for "Just Works" mode.
func (a *NoInputNoOutputAgent) RequestConfirmation(device dbus.ObjectPath, passkey uint32) *dbus.Error {
return nil // Accept pairing silently
}
// RequestAuthorization auto-accepts authorization for "Just Works" mode.
func (a *NoInputNoOutputAgent) RequestAuthorization(device dbus.ObjectPath) *dbus.Error {
return nil // Accept authorization silently
}
// AuthorizeService auto-accepts service authorization.
func (a *NoInputNoOutputAgent) AuthorizeService(device dbus.ObjectPath, uuid string) *dbus.Error {
return nil // Accept service authorization silently
}
// Cancel is called when an operation is canceled.
func (a *NoInputNoOutputAgent) Cancel() *dbus.Error {
return nil
}
// RegisterNoInputNoOutputAgent connects to system DBus and registers a NoInputNoOutput
// agent with BlueZ. This disables pairing prompts for BLE connections.
func RegisterNoInputNoOutputAgent() error {
conn, err := dbus.SystemBus()
if err != nil {
return fmt.Errorf("failed to connect to system DBus: %w", err)
}
agent := &NoInputNoOutputAgent{}
// Export the agent object on DBus
err = conn.Export(agent, agentPath, agentInterface)
if err != nil {
return fmt.Errorf("failed to export agent: %w", err)
}
// Get the AgentManager interface
agentMgr := conn.Object(bluezService, bluezPath)
// Register our agent with NoInputNoOutput capability
call := agentMgr.Call(agentManager+".RegisterAgent", 0, dbus.ObjectPath(agentPath), "NoInputNoOutput")
if call.Err != nil {
return fmt.Errorf("failed to register agent: %w", call.Err)
}
// Request to be the default agent
call = agentMgr.Call(agentManager+".RequestDefaultAgent", 0, dbus.ObjectPath(agentPath))
if call.Err != nil {
return fmt.Errorf("failed to set default agent: %w", call.Err)
}
return nil
}
// SetAdapterNotPairable sets the Pairable property to false on the default adapter.
// This is optional and prevents the adapter from initiating pairing.
func SetAdapterNotPairable() error {
conn, err := dbus.SystemBus()
if err != nil {
return fmt.Errorf("failed to connect to system DBus: %w", err)
}
// Get the default adapter (hci0)
adapter := conn.Object(bluezService, "/org/bluez/hci0")
// Set Pairable to false using org.freedesktop.DBus.Properties interface
call := adapter.Call("org.freedesktop.DBus.Properties.Set", 0,
"org.bluez.Adapter1", "Pairable", dbus.MakeVariant(false))
if call.Err != nil {
return fmt.Errorf("failed to set Pairable: %w", call.Err)
}
return nil
}
// DisableBonding runs btmgmt to disable bonding on the default adapter.
// This prevents phones from initiating pairing requests.
func DisableBonding() error {
ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
defer cancel()
cmd := exec.CommandContext(ctx, "btmgmt", "-i", "0", "bondable", "off")
output, err := cmd.CombinedOutput()
if ctx.Err() == context.DeadlineExceeded {
return fmt.Errorf("btmgmt timed out")
}
if err != nil {
return fmt.Errorf("failed to disable bonding: %w (output: %s)", err, output)
}
return nil
}