cloudflared-mirror/connection/quic.go

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package connection
import (
"context"
"crypto/tls"
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"fmt"
"io"
"net"
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"net/http"
"net/netip"
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"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"github.com/google/uuid"
"github.com/lucas-clemente/quic-go"
"github.com/pkg/errors"
"github.com/rs/zerolog"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
"golang.org/x/sync/errgroup"
"github.com/cloudflare/cloudflared/datagramsession"
"github.com/cloudflare/cloudflared/ingress"
"github.com/cloudflare/cloudflared/packet"
quicpogs "github.com/cloudflare/cloudflared/quic"
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"github.com/cloudflare/cloudflared/tracing"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
)
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const (
// HTTPHeaderKey is used to get or set http headers in QUIC ALPN if the underlying proxy connection type is HTTP.
HTTPHeaderKey = "HttpHeader"
// HTTPMethodKey is used to get or set http method in QUIC ALPN if the underlying proxy connection type is HTTP.
HTTPMethodKey = "HttpMethod"
// HTTPHostKey is used to get or set http Method in QUIC ALPN if the underlying proxy connection type is HTTP.
HTTPHostKey = "HttpHost"
QUICMetadataFlowID = "FlowID"
// emperically this capacity has been working well
demuxChanCapacity = 16
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)
var (
portForConnIndex = make(map[uint8]int, 0)
portMapMutex sync.Mutex
)
// QUICConnection represents the type that facilitates Proxying via QUIC streams.
type QUICConnection struct {
session quic.Connection
logger *zerolog.Logger
orchestrator Orchestrator
// sessionManager tracks active sessions. It receives datagrams from quic connection via datagramMuxer
sessionManager datagramsession.Manager
// datagramMuxer mux/demux datagrams from quic connection
datagramMuxer *quicpogs.DatagramMuxerV2
packetRouter *ingress.PacketRouter
controlStreamHandler ControlStreamHandler
connOptions *tunnelpogs.ConnectionOptions
}
// NewQUICConnection returns a new instance of QUICConnection.
func NewQUICConnection(
quicConfig *quic.Config,
edgeAddr net.Addr,
connIndex uint8,
tlsConfig *tls.Config,
orchestrator Orchestrator,
connOptions *tunnelpogs.ConnectionOptions,
controlStreamHandler ControlStreamHandler,
logger *zerolog.Logger,
packetRouterConfig *ingress.GlobalRouterConfig,
) (*QUICConnection, error) {
udpConn, err := createUDPConnForConnIndex(connIndex, logger)
if err != nil {
return nil, err
}
session, err := quic.Dial(udpConn, edgeAddr, edgeAddr.String(), tlsConfig, quicConfig)
if err != nil {
// close the udp server socket in case of error connecting to the edge
udpConn.Close()
return nil, &EdgeQuicDialError{Cause: err}
}
// wrap the session, so that the UDPConn is closed after session is closed.
session = &wrapCloseableConnQuicConnection{
session,
udpConn,
}
sessionDemuxChan := make(chan *packet.Session, demuxChanCapacity)
datagramMuxer := quicpogs.NewDatagramMuxerV2(session, logger, sessionDemuxChan)
sessionManager := datagramsession.NewManager(logger, datagramMuxer.SendToSession, sessionDemuxChan)
packetRouter := ingress.NewPacketRouter(packetRouterConfig, datagramMuxer, logger, orchestrator.WarpRoutingEnabled)
return &QUICConnection{
session: session,
orchestrator: orchestrator,
logger: logger,
sessionManager: sessionManager,
datagramMuxer: datagramMuxer,
packetRouter: packetRouter,
controlStreamHandler: controlStreamHandler,
connOptions: connOptions,
}, nil
}
// Serve starts a QUIC session that begins accepting streams.
func (q *QUICConnection) Serve(ctx context.Context) error {
// origintunneld assumes the first stream is used for the control plane
controlStream, err := q.session.OpenStream()
if err != nil {
return fmt.Errorf("failed to open a registration control stream: %w", err)
}
// If either goroutine returns nil error, we rely on this cancellation to make sure the other goroutine exits
// as fast as possible as well. Nil error means we want to exit for good (caller code won't retry serving this
// connection).
// If either goroutine returns a non nil error, then the error group cancels the context, thus also canceling the
// other goroutine as fast as possible.
ctx, cancel := context.WithCancel(ctx)
errGroup, ctx := errgroup.WithContext(ctx)
// In the future, if cloudflared can autonomously push traffic to the edge, we have to make sure the control
// stream is already fully registered before the other goroutines can proceed.
errGroup.Go(func() error {
defer cancel()
return q.serveControlStream(ctx, controlStream)
})
errGroup.Go(func() error {
defer cancel()
return q.acceptStream(ctx)
})
errGroup.Go(func() error {
defer cancel()
return q.sessionManager.Serve(ctx)
})
errGroup.Go(func() error {
defer cancel()
return q.datagramMuxer.ServeReceive(ctx)
})
errGroup.Go(func() error {
defer cancel()
return q.packetRouter.Serve(ctx)
})
return errGroup.Wait()
}
func (q *QUICConnection) serveControlStream(ctx context.Context, controlStream quic.Stream) error {
// This blocks until the control plane is done.
err := q.controlStreamHandler.ServeControlStream(ctx, controlStream, q.connOptions, q.orchestrator)
if err != nil {
// Not wrapping error here to be consistent with the http2 message.
return err
}
return nil
}
// Close closes the session with no errors specified.
func (q *QUICConnection) Close() {
q.session.CloseWithError(0, "")
}
func (q *QUICConnection) acceptStream(ctx context.Context) error {
defer q.Close()
for {
quicStream, err := q.session.AcceptStream(ctx)
if err != nil {
// context.Canceled is usually a user ctrl+c. We don't want to log an error here as it's intentional.
if errors.Is(err, context.Canceled) || q.controlStreamHandler.IsStopped() {
return nil
}
return fmt.Errorf("failed to accept QUIC stream: %w", err)
}
go q.runStream(quicStream)
}
}
func (q *QUICConnection) runStream(quicStream quic.Stream) {
ctx := quicStream.Context()
stream := quicpogs.NewSafeStreamCloser(quicStream)
defer stream.Close()
// we are going to fuse readers/writers from stream <- cloudflared -> origin, and we want to guarantee that
// code executed in the code path of handleStream don't trigger an earlier close to the downstream write stream.
// So, we wrap the stream with a no-op write closer and only this method can actually close write side of the stream.
// A call to close will simulate a close to the read-side, which will fail subsequent reads.
noCloseStream := &nopCloserReadWriter{ReadWriteCloser: stream}
if err := q.handleStream(ctx, noCloseStream); err != nil {
q.logger.Err(err).Msg("Failed to handle QUIC stream")
}
}
func (q *QUICConnection) handleStream(ctx context.Context, stream io.ReadWriteCloser) error {
signature, err := quicpogs.DetermineProtocol(stream)
if err != nil {
return err
}
switch signature {
case quicpogs.DataStreamProtocolSignature:
reqServerStream, err := quicpogs.NewRequestServerStream(stream, signature)
if err != nil {
return err
}
return q.handleDataStream(ctx, reqServerStream)
case quicpogs.RPCStreamProtocolSignature:
rpcStream, err := quicpogs.NewRPCServerStream(stream, signature)
if err != nil {
return err
}
return q.handleRPCStream(rpcStream)
default:
return fmt.Errorf("unknown protocol %v", signature)
}
}
func (q *QUICConnection) handleDataStream(ctx context.Context, stream *quicpogs.RequestServerStream) error {
request, err := stream.ReadConnectRequestData()
if err != nil {
return err
}
if err := q.dispatchRequest(ctx, stream, err, request); err != nil {
_ = stream.WriteConnectResponseData(err)
q.logger.Err(err).Str("type", request.Type.String()).Str("dest", request.Dest).Msg("Request failed")
}
return nil
}
func (q *QUICConnection) dispatchRequest(ctx context.Context, stream *quicpogs.RequestServerStream, err error, request *quicpogs.ConnectRequest) error {
originProxy, err := q.orchestrator.GetOriginProxy()
if err != nil {
return err
}
switch request.Type {
case quicpogs.ConnectionTypeHTTP, quicpogs.ConnectionTypeWebsocket:
tracedReq, err := buildHTTPRequest(ctx, request, stream, q.logger)
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if err != nil {
return err
}
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w := newHTTPResponseAdapter(stream)
return originProxy.ProxyHTTP(w, tracedReq, request.Type == quicpogs.ConnectionTypeWebsocket)
case quicpogs.ConnectionTypeTCP:
rwa := &streamReadWriteAcker{stream}
metadata := request.MetadataMap()
return originProxy.ProxyTCP(ctx, rwa, &TCPRequest{
Dest: request.Dest,
FlowID: metadata[QUICMetadataFlowID],
CfTraceID: metadata[tracing.TracerContextName],
})
}
return nil
}
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func (q *QUICConnection) handleRPCStream(rpcStream *quicpogs.RPCServerStream) error {
return rpcStream.Serve(q, q, q.logger)
}
// RegisterUdpSession is the RPC method invoked by edge to register and run a session
func (q *QUICConnection) RegisterUdpSession(ctx context.Context, sessionID uuid.UUID, dstIP net.IP, dstPort uint16, closeAfterIdleHint time.Duration, traceContext string) (*tunnelpogs.RegisterUdpSessionResponse, error) {
traceCtx := tracing.NewTracedContext(ctx, traceContext, q.logger)
ctx, registerSpan := traceCtx.Tracer().Start(traceCtx, "register-session", trace.WithAttributes(
attribute.String("session-id", sessionID.String()),
attribute.String("dst", fmt.Sprintf("%s:%d", dstIP, dstPort)),
))
// Each session is a series of datagram from an eyeball to a dstIP:dstPort.
// (src port, dst IP, dst port) uniquely identifies a session, so it needs a dedicated connected socket.
originProxy, err := ingress.DialUDP(dstIP, dstPort)
if err != nil {
q.logger.Err(err).Msgf("Failed to create udp proxy to %s:%d", dstIP, dstPort)
tracing.EndWithErrorStatus(registerSpan, err)
return nil, err
}
registerSpan.SetAttributes(
attribute.Bool("socket-bind-success", true),
attribute.String("src", originProxy.LocalAddr().String()),
)
session, err := q.sessionManager.RegisterSession(ctx, sessionID, originProxy)
if err != nil {
q.logger.Err(err).Str("sessionID", sessionID.String()).Msgf("Failed to register udp session")
tracing.EndWithErrorStatus(registerSpan, err)
return nil, err
}
go q.serveUDPSession(session, closeAfterIdleHint)
q.logger.Debug().Str("sessionID", sessionID.String()).Str("src", originProxy.LocalAddr().String()).Str("dst", fmt.Sprintf("%s:%d", dstIP, dstPort)).Msgf("Registered session")
tracing.End(registerSpan)
resp := tunnelpogs.RegisterUdpSessionResponse{
Spans: traceCtx.GetProtoSpans(),
}
return &resp, nil
}
func (q *QUICConnection) serveUDPSession(session *datagramsession.Session, closeAfterIdleHint time.Duration) {
ctx := q.session.Context()
closedByRemote, err := session.Serve(ctx, closeAfterIdleHint)
// If session is terminated by remote, then we know it has been unregistered from session manager and edge
if !closedByRemote {
if err != nil {
q.closeUDPSession(ctx, session.ID, err.Error())
} else {
q.closeUDPSession(ctx, session.ID, "terminated without error")
}
}
q.logger.Debug().Err(err).Str("sessionID", session.ID.String()).Msg("Session terminated")
}
// closeUDPSession first unregisters the session from session manager, then it tries to unregister from edge
func (q *QUICConnection) closeUDPSession(ctx context.Context, sessionID uuid.UUID, message string) {
q.sessionManager.UnregisterSession(ctx, sessionID, message, false)
stream, err := q.session.OpenStream()
if err != nil {
// Log this at debug because this is not an error if session was closed due to lost connection
// with edge
q.logger.Debug().Err(err).Str("sessionID", sessionID.String()).
Msgf("Failed to open quic stream to unregister udp session with edge")
return
}
rpcClientStream, err := quicpogs.NewRPCClientStream(ctx, stream, q.logger)
if err != nil {
// Log this at debug because this is not an error if session was closed due to lost connection
// with edge
q.logger.Err(err).Str("sessionID", sessionID.String()).
Msgf("Failed to open rpc stream to unregister udp session with edge")
return
}
if err := rpcClientStream.UnregisterUdpSession(ctx, sessionID, message); err != nil {
q.logger.Err(err).Str("sessionID", sessionID.String()).
Msgf("Failed to unregister udp session with edge")
}
}
// UnregisterUdpSession is the RPC method invoked by edge to unregister and terminate a sesssion
func (q *QUICConnection) UnregisterUdpSession(ctx context.Context, sessionID uuid.UUID, message string) error {
return q.sessionManager.UnregisterSession(ctx, sessionID, message, true)
}
// UpdateConfiguration is the RPC method invoked by edge when there is a new configuration
func (q *QUICConnection) UpdateConfiguration(ctx context.Context, version int32, config []byte) *tunnelpogs.UpdateConfigurationResponse {
return q.orchestrator.UpdateConfig(version, config)
}
// streamReadWriteAcker is a light wrapper over QUIC streams with a callback to send response back to
// the client.
type streamReadWriteAcker struct {
*quicpogs.RequestServerStream
}
// AckConnection acks response back to the proxy.
func (s *streamReadWriteAcker) AckConnection(tracePropagation string) error {
metadata := quicpogs.Metadata{
Key: tracing.CanonicalCloudflaredTracingHeader,
Val: tracePropagation,
}
return s.WriteConnectResponseData(nil, metadata)
}
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// httpResponseAdapter translates responses written by the HTTP Proxy into ones that can be used in QUIC.
type httpResponseAdapter struct {
*quicpogs.RequestServerStream
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}
func newHTTPResponseAdapter(s *quicpogs.RequestServerStream) httpResponseAdapter {
return httpResponseAdapter{s}
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}
func (hrw httpResponseAdapter) AddTrailer(trailerName, trailerValue string) {
// we do not support trailers over QUIC
}
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func (hrw httpResponseAdapter) WriteRespHeaders(status int, header http.Header) error {
metadata := make([]quicpogs.Metadata, 0)
metadata = append(metadata, quicpogs.Metadata{Key: "HttpStatus", Val: strconv.Itoa(status)})
for k, vv := range header {
for _, v := range vv {
httpHeaderKey := fmt.Sprintf("%s:%s", HTTPHeaderKey, k)
metadata = append(metadata, quicpogs.Metadata{Key: httpHeaderKey, Val: v})
}
}
return hrw.WriteConnectResponseData(nil, metadata...)
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}
func (hrw httpResponseAdapter) WriteErrorResponse(err error) {
hrw.WriteConnectResponseData(err, quicpogs.Metadata{Key: "HttpStatus", Val: strconv.Itoa(http.StatusBadGateway)})
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}
func buildHTTPRequest(
ctx context.Context,
connectRequest *quicpogs.ConnectRequest,
body io.ReadCloser,
log *zerolog.Logger,
) (*tracing.TracedHTTPRequest, error) {
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metadata := connectRequest.MetadataMap()
dest := connectRequest.Dest
method := metadata[HTTPMethodKey]
host := metadata[HTTPHostKey]
isWebsocket := connectRequest.Type == quicpogs.ConnectionTypeWebsocket
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req, err := http.NewRequestWithContext(ctx, method, dest, body)
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if err != nil {
return nil, err
}
req.Host = host
for _, metadata := range connectRequest.Metadata {
if strings.Contains(metadata.Key, HTTPHeaderKey) {
// metadata.Key is off the format httpHeaderKey:<HTTPHeader>
httpHeaderKey := strings.Split(metadata.Key, ":")
if len(httpHeaderKey) != 2 {
return nil, fmt.Errorf("header Key: %s malformed", metadata.Key)
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}
req.Header.Add(httpHeaderKey[1], metadata.Val)
}
}
// Go's http.Client automatically sends chunked request body if this value is not set on the
// *http.Request struct regardless of header:
// https://go.googlesource.com/go/+/go1.8rc2/src/net/http/transfer.go#154.
if err := setContentLength(req); err != nil {
return nil, fmt.Errorf("Error setting content-length: %w", err)
}
// Go's client defaults to chunked encoding after a 200ms delay if the following cases are true:
// * the request body blocks
// * the content length is not set (or set to -1)
// * the method doesn't usually have a body (GET, HEAD, DELETE, ...)
// * there is no transfer-encoding=chunked already set.
// So, if transfer cannot be chunked and content length is 0, we dont set a request body.
if !isWebsocket && !isTransferEncodingChunked(req) && req.ContentLength == 0 {
req.Body = http.NoBody
}
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stripWebsocketUpgradeHeader(req)
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// Check for tracing on request
tracedReq := tracing.NewTracedHTTPRequest(req, log)
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return tracedReq, err
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}
func setContentLength(req *http.Request) error {
var err error
if contentLengthStr := req.Header.Get("Content-Length"); contentLengthStr != "" {
req.ContentLength, err = strconv.ParseInt(contentLengthStr, 10, 64)
}
return err
}
func isTransferEncodingChunked(req *http.Request) bool {
transferEncodingVal := req.Header.Get("Transfer-Encoding")
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Transfer-Encoding suggests that this can be a comma
// separated value as well.
return strings.Contains(strings.ToLower(transferEncodingVal), "chunked")
}
// A helper struct that guarantees a call to close only affects read side, but not write side.
type nopCloserReadWriter struct {
io.ReadWriteCloser
// for use by Read only
// we don't need a memory barrier here because there is an implicit assumption that
// Read calls can't happen concurrently by different go-routines.
sawEOF bool
// should be updated and read using atomic primitives.
// value is read in Read method and written in Close method, which could be done by different
// go-routines.
closed uint32
}
func (np *nopCloserReadWriter) Read(p []byte) (n int, err error) {
if np.sawEOF {
return 0, io.EOF
}
if atomic.LoadUint32(&np.closed) > 0 {
return 0, fmt.Errorf("closed by handler")
}
n, err = np.ReadWriteCloser.Read(p)
if err == io.EOF {
np.sawEOF = true
}
return
}
func (np *nopCloserReadWriter) Close() error {
atomic.StoreUint32(&np.closed, 1)
return nil
}
// muxerWrapper wraps DatagramMuxerV2 to satisfy the packet.FunnelUniPipe interface
type muxerWrapper struct {
muxer *quicpogs.DatagramMuxerV2
}
func (rp *muxerWrapper) SendPacket(dst netip.Addr, pk packet.RawPacket) error {
return rp.muxer.SendPacket(quicpogs.RawPacket(pk))
}
func (rp *muxerWrapper) ReceivePacket(ctx context.Context) (packet.RawPacket, error) {
pk, err := rp.muxer.ReceivePacket(ctx)
if err != nil {
return packet.RawPacket{}, err
}
rawPacket, ok := pk.(quicpogs.RawPacket)
if ok {
return packet.RawPacket(rawPacket), nil
}
return packet.RawPacket{}, fmt.Errorf("unexpected packet type %+v", pk)
}
func (rp *muxerWrapper) Close() error {
return nil
}
func createUDPConnForConnIndex(connIndex uint8, logger *zerolog.Logger) (*net.UDPConn, error) {
portMapMutex.Lock()
defer portMapMutex.Unlock()
// if port was not set yet, it will be zero, so bind will randomly allocate one.
if port, ok := portForConnIndex[connIndex]; ok {
udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: port})
// if there wasn't an error, or if port was 0 (independently of error or not, just return)
if err == nil {
return udpConn, nil
} else {
logger.Debug().Err(err).Msgf("Unable to reuse port %d for connIndex %d. Falling back to random allocation.", port, connIndex)
}
}
// if we reached here, then there was an error or port as not been allocated it.
udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
if err == nil {
udpAddr, ok := (udpConn.LocalAddr()).(*net.UDPAddr)
if !ok {
return nil, fmt.Errorf("unable to cast to udpConn")
}
portForConnIndex[connIndex] = udpAddr.Port
} else {
delete(portForConnIndex, connIndex)
}
return udpConn, err
}
type wrapCloseableConnQuicConnection struct {
quic.Connection
udpConn *net.UDPConn
}
func (w *wrapCloseableConnQuicConnection) CloseWithError(errorCode quic.ApplicationErrorCode, reason string) error {
err := w.Connection.CloseWithError(errorCode, reason)
w.udpConn.Close()
return err
}