104 lines
2.2 KiB
Go
104 lines
2.2 KiB
Go
package peers
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import (
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"crypto/rand"
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"fmt"
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"time"
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"github.com/golang/protobuf/proto"
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udpp2p "github.com/schollz/peerdiscovery"
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"go.uber.org/zap"
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)
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const (
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pingInterval = 500 * time.Millisecond
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searchLimit = 2 * time.Minute
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)
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type NotifyHandler func(*LocalPairingPeerHello)
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type UDPNotifier struct {
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logger *zap.Logger
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id []byte
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notifyOutput NotifyHandler
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}
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func NewUDPNotifier(logger *zap.Logger, outputFunc NotifyHandler) (*UDPNotifier, error) {
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randID := make([]byte, 32)
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_, err := rand.Read(randID)
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if err != nil {
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return nil, err
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}
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n := new(UDPNotifier)
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n.logger = logger
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n.id = randID
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n.notifyOutput = outputFunc
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return n, nil
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}
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func (u *UDPNotifier) makePayload(deviceName, deviceType string) (*LocalPairingPeerHello, error) {
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return NewLocalPairingPeerHello(u.id, deviceName, deviceType, k)
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}
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func (u *UDPNotifier) notify(d udpp2p.Discovered) {
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h := new(LocalPairingPeerHello)
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err := proto.Unmarshal(d.Payload, &h.LocalPairingPeerHello)
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if err != nil {
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u.logger.Error("notify unmarshalling of payload failed", zap.Error(err))
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return
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}
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ok := h.verify(&k.PublicKey)
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if !ok {
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u.logger.Error("verification of unmarshalled payload failed", zap.Any("LocalPairingPeerHello", h))
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return
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}
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h.Discovered = d
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u.notifyOutput(h)
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}
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func (u *UDPNotifier) MakeUDPP2PSettings(deviceName, deviceType string) (*udpp2p.Settings, error) {
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if u.notifyOutput == nil {
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return nil, fmt.Errorf("UDPNotifier has no notiftOutput function defined")
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}
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h, err := u.makePayload(deviceName, deviceType)
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if err != nil {
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return nil, err
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}
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mh, err := proto.Marshal(&h.LocalPairingPeerHello)
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if err != nil {
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return nil, err
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}
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return &udpp2p.Settings{
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Notify: u.notify,
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Payload: mh,
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}, nil
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}
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func Search(deviceName, deviceType string, notify NotifyHandler, stop chan struct{}, logger *zap.Logger) error {
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un, err := NewUDPNotifier(logger, notify)
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if err != nil {
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return err
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}
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settings, err := un.MakeUDPP2PSettings(deviceName, deviceType)
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if err != nil {
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return err
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}
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settings.Delay = pingInterval
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settings.TimeLimit = searchLimit
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settings.StopChan = stop
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go func() {
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_, err = udpp2p.Discover(*settings)
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logger.Error("error while discovering udp peers", zap.Error(err))
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}()
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return nil
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}
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