netbird/signal/signal.go
2021-06-10 17:08:40 +02:00

99 lines
3.0 KiB
Go

package signal
import (
"context"
"fmt"
log "github.com/sirupsen/logrus"
"github.com/wiretrustee/wiretrustee/signal/peer"
"github.com/wiretrustee/wiretrustee/signal/proto"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/status"
"io"
)
// SignalExchangeServer an instance of a Signal server
type SignalExchangeServer struct {
registry *peer.Registry
}
// NewServer creates a new Signal server
func NewServer() *SignalExchangeServer {
return &SignalExchangeServer{
registry: peer.NewRegistry(),
}
}
// Send forwards a message to the signal peer
func (s *SignalExchangeServer) Send(ctx context.Context, msg *proto.EncryptedMessage) (*proto.EncryptedMessage, error) {
if !s.registry.IsPeerRegistered(msg.Key) {
return nil, fmt.Errorf("unknown peer %s", msg.Key)
}
if dstPeer, found := s.registry.Get(msg.RemoteKey); found {
//forward the message to the target peer
err := dstPeer.Stream.Send(msg)
if err != nil {
log.Errorf("error while forwarding message from peer [%s] to peer [%s]", msg.Key, msg.RemoteKey)
//todo respond to the sender?
}
} else {
log.Warnf("message from peer [%s] can't be forwarded to peer [%s] because destination peer is not connected", msg.Key, msg.RemoteKey)
//todo respond to the sender?
}
return &proto.EncryptedMessage{}, nil
}
// ConnectStream connects to the exchange stream
func (s *SignalExchangeServer) ConnectStream(stream proto.SignalExchange_ConnectStreamServer) error {
p, err := s.connectPeer(stream)
if err != nil {
return err
}
log.Infof("peer [%s] has successfully connected", p.Id)
for {
msg, err := stream.Recv()
if err == io.EOF {
break
} else if err != nil {
return err
}
log.Debugf("received a new message from peer [%s] to peer [%s]", p.Id, msg.RemoteKey)
// lookup the target peer where the message is going to
if dstPeer, found := s.registry.Get(msg.RemoteKey); found {
//forward the message to the target peer
err := dstPeer.Stream.Send(msg)
if err != nil {
log.Errorf("error while forwarding message from peer [%s] to peer [%s]", p.Id, msg.RemoteKey)
//todo respond to the sender?
}
} else {
log.Warnf("message from peer [%s] can't be forwarded to peer [%s] because destination peer is not connected", p.Id, msg.RemoteKey)
//todo respond to the sender?
}
}
<-stream.Context().Done()
return stream.Context().Err()
}
// Handles initial Peer connection.
// Each connection must provide an ID header.
// At this moment the connecting Peer will be registered in the peer.Registry
func (s SignalExchangeServer) connectPeer(stream proto.SignalExchange_ConnectStreamServer) (*peer.Peer, error) {
if meta, hasMeta := metadata.FromIncomingContext(stream.Context()); hasMeta {
if id, found := meta[proto.HeaderId]; found {
p := peer.NewPeer(id[0], stream)
s.registry.Register(p)
return p, nil
} else {
return nil, status.Errorf(codes.FailedPrecondition, "missing connection header: "+proto.HeaderId)
}
} else {
return nil, status.Errorf(codes.FailedPrecondition, "missing connection stream meta")
}
}