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"
"strconv"
"strings"
"github.com/lucas-clemente/quic-go"
"github.com/pkg/errors"
"github.com/rs/zerolog"
quicpogs "github.com/cloudflare/cloudflared/quic"
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"
)
// QUICConnection represents the type that facilitates Proxying via QUIC streams.
type QUICConnection struct {
session quic.Session
logger *zerolog.Logger
httpProxy OriginProxy
gracefulShutdownC <-chan struct{}
stoppedGracefully bool
}
// NewQUICConnection returns a new instance of QUICConnection.
func NewQUICConnection(
ctx context.Context,
quicConfig *quic.Config,
edgeAddr net.Addr,
tlsConfig *tls.Config,
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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
}
return &QUICConnection{
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session: session,
httpProxy: httpProxy,
logger: observer.log,
}, nil
}
// Serve starts a QUIC session that begins accepting streams.
func (q *QUICConnection) Serve(ctx context.Context) error {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
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")
}
}()
}
}
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// Close closes the session with no errors specified.
func (q *QUICConnection) Close() {
q.session.CloseWithError(0, "")
}
func (q *QUICConnection) handleStream(stream quic.Stream) error {
connectRequest, err := quicpogs.ReadConnectRequestData(stream)
if err != nil {
return err
}
switch connectRequest.Type {
case quicpogs.ConnectionTypeHTTP, quicpogs.ConnectionTypeWebsocket:
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req, err := buildHTTPRequest(connectRequest, stream)
if err != nil {
return err
}
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w := newHTTPResponseAdapter(stream)
return q.httpProxy.ProxyHTTP(w, req, connectRequest.Type == quicpogs.ConnectionTypeWebsocket)
case quicpogs.ConnectionTypeTCP:
rwa := &streamReadWriteAcker{
ReadWriter: stream,
}
return q.httpProxy.ProxyTCP(context.Background(), rwa, &TCPRequest{Dest: connectRequest.Dest})
}
return nil
}
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// streamReadWriteAcker is a light wrapper over QUIC streams with a callback to send response back to
// the client.
type streamReadWriteAcker struct {
io.ReadWriter
}
// AckConnection acks response back to the proxy.
func (s *streamReadWriteAcker) AckConnection() error {
return quicpogs.WriteConnectResponseData(s, nil)
}
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// httpResponseAdapter translates responses written by the HTTP Proxy into ones that can be used in QUIC.
type httpResponseAdapter struct {
io.Writer
}
func newHTTPResponseAdapter(w io.Writer) httpResponseAdapter {
return httpResponseAdapter{w}
}
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 quicpogs.WriteConnectResponseData(hrw, nil, metadata...)
}
func (hrw httpResponseAdapter) WriteErrorResponse(err error) {
quicpogs.WriteConnectResponseData(hrw, err, quicpogs.Metadata{Key: "HttpStatus", Val: strconv.Itoa(http.StatusBadGateway)})
}
func buildHTTPRequest(connectRequest *quicpogs.ConnectRequest, body io.ReadCloser) (*http.Request, 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.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
}
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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")
}