cloudflared-mirror/connection/quic.go

328 lines
11 KiB
Go

package connection
import (
"context"
"crypto/tls"
"fmt"
"io"
"net"
"net/http"
"strconv"
"strings"
"time"
"github.com/google/uuid"
"github.com/lucas-clemente/quic-go"
"github.com/pkg/errors"
"github.com/rs/zerolog"
"golang.org/x/sync/errgroup"
"github.com/cloudflare/cloudflared/datagramsession"
"github.com/cloudflare/cloudflared/ingress"
quicpogs "github.com/cloudflare/cloudflared/quic"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
)
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"
)
// QUICConnection represents the type that facilitates Proxying via QUIC streams.
type QUICConnection struct {
session quic.Session
logger *zerolog.Logger
httpProxy OriginProxy
sessionManager datagramsession.Manager
}
// NewQUICConnection returns a new instance of QUICConnection.
func NewQUICConnection(
ctx context.Context,
quicConfig *quic.Config,
edgeAddr net.Addr,
tlsConfig *tls.Config,
httpProxy OriginProxy,
connOptions *tunnelpogs.ConnectionOptions,
controlStreamHandler ControlStreamHandler,
observer *Observer,
) (*QUICConnection, error) {
session, err := quic.DialAddr(edgeAddr.String(), tlsConfig, quicConfig)
if err != nil {
return nil, fmt.Errorf("failed to dial to edge: %w", err)
}
registrationStream, err := session.OpenStream()
if err != nil {
return nil, fmt.Errorf("failed to open a registration stream: %w", err)
}
err = controlStreamHandler.ServeControlStream(ctx, registrationStream, connOptions, false)
if err != nil {
// Not wrapping error here to be consistent with the http2 message.
return nil, err
}
datagramMuxer, err := quicpogs.NewDatagramMuxer(session)
if err != nil {
return nil, err
}
sessionManager := datagramsession.NewManager(datagramMuxer, observer.log)
return &QUICConnection{
session: session,
httpProxy: httpProxy,
logger: observer.log,
sessionManager: sessionManager,
}, nil
}
// Serve starts a QUIC session that begins accepting streams.
func (q *QUICConnection) Serve(ctx context.Context) error {
errGroup, ctx := errgroup.WithContext(ctx)
errGroup.Go(func() error {
return q.acceptStream(ctx)
})
errGroup.Go(func() error {
return q.sessionManager.Serve(ctx)
})
return errGroup.Wait()
}
func (q *QUICConnection) acceptStream(ctx context.Context) error {
for {
stream, 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) {
return nil
}
return fmt.Errorf("failed to accept QUIC stream: %w", err)
}
go func() {
defer stream.Close()
if err = q.handleStream(stream); err != nil {
q.logger.Err(err).Msg("Failed to handle QUIC stream")
}
}()
}
}
// Close closes the session with no errors specified.
func (q *QUICConnection) Close() {
q.session.CloseWithError(0, "")
}
func (q *QUICConnection) handleStream(stream quic.Stream) 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 nil
}
return q.handleDataStream(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(stream *quicpogs.RequestServerStream) error {
connectRequest, err := stream.ReadConnectRequestData()
if err != nil {
return err
}
switch connectRequest.Type {
case quicpogs.ConnectionTypeHTTP, quicpogs.ConnectionTypeWebsocket:
req, err := buildHTTPRequest(connectRequest, stream)
if err != nil {
return err
}
w := newHTTPResponseAdapter(stream)
return q.httpProxy.ProxyHTTP(w, req, connectRequest.Type == quicpogs.ConnectionTypeWebsocket)
case quicpogs.ConnectionTypeTCP:
rwa := &streamReadWriteAcker{stream}
return q.httpProxy.ProxyTCP(context.Background(), rwa, &TCPRequest{Dest: connectRequest.Dest})
}
return nil
}
func (q *QUICConnection) handleRPCStream(rpcStream *quicpogs.RPCServerStream) error {
return rpcStream.Serve(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) error {
// 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)
return err
}
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")
return err
}
go q.serveUDPSession(session, closeAfterIdleHint)
q.logger.Debug().Msgf("Registered session %v, %v, %v", sessionID, dstIP, dstPort)
return 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)
}
// 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() error {
return s.WriteConnectResponseData(nil)
}
// httpResponseAdapter translates responses written by the HTTP Proxy into ones that can be used in QUIC.
type httpResponseAdapter struct {
*quicpogs.RequestServerStream
}
func newHTTPResponseAdapter(s *quicpogs.RequestServerStream) httpResponseAdapter {
return httpResponseAdapter{s}
}
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...)
}
func (hrw httpResponseAdapter) WriteErrorResponse(err error) {
hrw.WriteConnectResponseData(err, quicpogs.Metadata{Key: "HttpStatus", Val: strconv.Itoa(http.StatusBadGateway)})
}
func buildHTTPRequest(connectRequest *quicpogs.ConnectRequest, body io.ReadCloser) (*http.Request, error) {
metadata := connectRequest.MetadataMap()
dest := connectRequest.Dest
method := metadata[HTTPMethodKey]
host := metadata[HTTPHostKey]
isWebsocket := connectRequest.Type == quicpogs.ConnectionTypeWebsocket
req, err := http.NewRequest(method, dest, body)
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)
}
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 = nil
}
stripWebsocketUpgradeHeader(req)
return req, err
}
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")
}