cloudflared-mirror/connection/connection.go

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package connection
import (
"context"
"crypto/tls"
"net"
"sync"
"time"
"github.com/cloudflare/cloudflared/h2mux"
"github.com/cloudflare/cloudflared/tunnelrpc"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
rpc "zombiezen.com/go/capnproto2/rpc"
)
const (
dialTimeout = 5 * time.Second
openStreamTimeout = 30 * time.Second
)
type dialError struct {
cause error
}
func (e dialError) Error() string {
return e.cause.Error()
}
type muxerShutdownError struct{}
func (e muxerShutdownError) Error() string {
return "muxer shutdown"
}
type ConnectionConfig struct {
TLSConfig *tls.Config
HeartbeatInterval time.Duration
MaxHeartbeats uint64
Logger *logrus.Entry
}
type connectionHandler interface {
serve(ctx context.Context) error
connect(ctx context.Context, parameters *tunnelpogs.ConnectParameters) (*tunnelpogs.ConnectResult, error)
shutdown()
}
type h2muxHandler struct {
muxer *h2mux.Muxer
logger *logrus.Entry
}
type muxedStreamHandler struct {
}
// Implements MuxedStreamHandler interface
func (h *muxedStreamHandler) ServeStream(stream *h2mux.MuxedStream) error {
return nil
}
func (h *h2muxHandler) serve(ctx context.Context) error {
// Serve doesn't return until h2mux is shutdown
if err := h.muxer.Serve(ctx); err != nil {
return err
}
return muxerShutdownError{}
}
// Connect is used to establish connections with cloudflare's edge network
func (h *h2muxHandler) connect(ctx context.Context, parameters *tunnelpogs.ConnectParameters) (*tunnelpogs.ConnectResult, error) {
openStreamCtx, cancel := context.WithTimeout(ctx, openStreamTimeout)
defer cancel()
conn, err := h.newRPConn(openStreamCtx)
if err != nil {
return nil, errors.Wrap(err, "Failed to create new RPC connection")
}
defer conn.Close()
tsClient := tunnelpogs.TunnelServer_PogsClient{Client: conn.Bootstrap(ctx)}
return tsClient.Connect(ctx, parameters)
}
func (h *h2muxHandler) shutdown() {
h.muxer.Shutdown()
}
func (h *h2muxHandler) newRPConn(ctx context.Context) (*rpc.Conn, error) {
stream, err := h.muxer.OpenStream(ctx, []h2mux.Header{
{Name: ":method", Value: "RPC"},
{Name: ":scheme", Value: "capnp"},
{Name: ":path", Value: "*"},
}, nil)
if err != nil {
return nil, err
}
return rpc.NewConn(
tunnelrpc.NewTransportLogger(h.logger.WithField("subsystem", "rpc-register"), rpc.StreamTransport(stream)),
tunnelrpc.ConnLog(h.logger.WithField("subsystem", "rpc-transport")),
), nil
}
// NewConnectionHandler returns a connectionHandler, wrapping h2mux to make RPC calls
func newH2MuxHandler(ctx context.Context,
config *ConnectionConfig,
edgeIP *net.TCPAddr,
) (connectionHandler, error) {
// Inherit from parent context so we can cancel (Ctrl-C) while dialing
dialCtx, dialCancel := context.WithTimeout(ctx, dialTimeout)
defer dialCancel()
dialer := net.Dialer{DualStack: true}
plaintextEdgeConn, err := dialer.DialContext(dialCtx, "tcp", edgeIP.String())
if err != nil {
return nil, dialError{cause: errors.Wrap(err, "DialContext error")}
}
edgeConn := tls.Client(plaintextEdgeConn, config.TLSConfig)
edgeConn.SetDeadline(time.Now().Add(dialTimeout))
err = edgeConn.Handshake()
if err != nil {
return nil, dialError{cause: errors.Wrap(err, "Handshake with edge error")}
}
// clear the deadline on the conn; h2mux has its own timeouts
edgeConn.SetDeadline(time.Time{})
// Establish a muxed connection with the edge
// Client mux handshake with agent server
muxer, err := h2mux.Handshake(edgeConn, edgeConn, h2mux.MuxerConfig{
Timeout: dialTimeout,
Handler: &muxedStreamHandler{},
IsClient: true,
HeartbeatInterval: config.HeartbeatInterval,
MaxHeartbeats: config.MaxHeartbeats,
Logger: config.Logger,
})
if err != nil {
return nil, err
}
return &h2muxHandler{
muxer: muxer,
logger: config.Logger,
}, nil
}
// connectionPool is a pool of connection handlers
type connectionPool struct {
sync.Mutex
connectionHandlers []connectionHandler
}
func (cp *connectionPool) put(h connectionHandler) {
cp.Lock()
defer cp.Unlock()
cp.connectionHandlers = append(cp.connectionHandlers, h)
}
func (cp *connectionPool) close() {
cp.Lock()
defer cp.Unlock()
for _, h := range cp.connectionHandlers {
h.shutdown()
}
}