github.com/tumi8/quic-go@v0.37.4-tum/http3/server.go (about)

     1  package http3
     2  
     3  import (
     4  	"context"
     5  	"crypto/tls"
     6  	"errors"
     7  	"fmt"
     8  	"io"
     9  	"net"
    10  	"net/http"
    11  	"runtime"
    12  	"strings"
    13  	"sync"
    14  	"time"
    15  
    16  	"github.com/tumi8/quic-go"
    17  	"github.com/tumi8/quic-go/noninternal/protocol"
    18  	"github.com/tumi8/quic-go/noninternal/utils"
    19  	"github.com/tumi8/quic-go/quicvarint"
    20  	"github.com/quic-go/qpack"
    21  )
    22  
    23  // allows mocking of quic.Listen and quic.ListenAddr
    24  var (
    25  	quicListen = func(conn net.PacketConn, tlsConf *tls.Config, config *quic.Config) (QUICEarlyListener, error) {
    26  		return quic.ListenEarly(conn, tlsConf, config)
    27  	}
    28  	quicListenAddr = func(addr string, tlsConf *tls.Config, config *quic.Config) (QUICEarlyListener, error) {
    29  		return quic.ListenAddrEarly(addr, tlsConf, config)
    30  	}
    31  )
    32  
    33  const (
    34  	// NextProtoH3Draft29 is the ALPN protocol negotiated during the TLS handshake, for QUIC draft 29.
    35  	NextProtoH3Draft29 = "h3-29"
    36  	// NextProtoH3 is the ALPN protocol negotiated during the TLS handshake, for QUIC v1 and v2.
    37  	NextProtoH3 = "h3"
    38  )
    39  
    40  // StreamType is the stream type of a unidirectional stream.
    41  type StreamType uint64
    42  
    43  const (
    44  	streamTypeControlStream      = 0
    45  	streamTypePushStream         = 1
    46  	streamTypeQPACKEncoderStream = 2
    47  	streamTypeQPACKDecoderStream = 3
    48  )
    49  
    50  // A QUICEarlyListener listens for incoming QUIC connections.
    51  type QUICEarlyListener interface {
    52  	Accept(context.Context) (quic.EarlyConnection, error)
    53  	Addr() net.Addr
    54  	io.Closer
    55  }
    56  
    57  var _ QUICEarlyListener = &quic.EarlyListener{}
    58  
    59  func versionToALPN(v protocol.VersionNumber) string {
    60  	//nolint:exhaustive // These are all the versions we care about.
    61  	switch v {
    62  	case protocol.Version1, protocol.Version2:
    63  		return NextProtoH3
    64  	default:
    65  		return ""
    66  	}
    67  }
    68  
    69  // ConfigureTLSConfig creates a new tls.Config which can be used
    70  // to create a quic.Listener meant for serving http3. The created
    71  // tls.Config adds the functionality of detecting the used QUIC version
    72  // in order to set the correct ALPN value for the http3 connection.
    73  func ConfigureTLSConfig(tlsConf *tls.Config) *tls.Config {
    74  	// The tls.Config used to setup the quic.Listener needs to have the GetConfigForClient callback set.
    75  	// That way, we can get the QUIC version and set the correct ALPN value.
    76  	return &tls.Config{
    77  		GetConfigForClient: func(ch *tls.ClientHelloInfo) (*tls.Config, error) {
    78  			// determine the ALPN from the QUIC version used
    79  			proto := NextProtoH3
    80  			val := ch.Context().Value(quic.QUICVersionContextKey)
    81  			if v, ok := val.(quic.VersionNumber); ok {
    82  				proto = versionToALPN(v)
    83  			}
    84  			config := tlsConf
    85  			if tlsConf.GetConfigForClient != nil {
    86  				getConfigForClient := tlsConf.GetConfigForClient
    87  				var err error
    88  				conf, err := getConfigForClient(ch)
    89  				if err != nil {
    90  					return nil, err
    91  				}
    92  				if conf != nil {
    93  					config = conf
    94  				}
    95  			}
    96  			if config == nil {
    97  				return nil, nil
    98  			}
    99  			config = config.Clone()
   100  			config.NextProtos = []string{proto}
   101  			return config, nil
   102  		},
   103  	}
   104  }
   105  
   106  // contextKey is a value for use with context.WithValue. It's used as
   107  // a pointer so it fits in an interface{} without allocation.
   108  type contextKey struct {
   109  	name string
   110  }
   111  
   112  func (k *contextKey) String() string { return "quic-go/http3 context value " + k.name }
   113  
   114  // ServerContextKey is a context key. It can be used in HTTP
   115  // handlers with Context.Value to access the server that
   116  // started the handler. The associated value will be of
   117  // type *http3.Server.
   118  var ServerContextKey = &contextKey{"http3-server"}
   119  
   120  type requestError struct {
   121  	err       error
   122  	streamErr ErrCode
   123  	connErr   ErrCode
   124  }
   125  
   126  func newStreamError(code ErrCode, err error) requestError {
   127  	return requestError{err: err, streamErr: code}
   128  }
   129  
   130  func newConnError(code ErrCode, err error) requestError {
   131  	return requestError{err: err, connErr: code}
   132  }
   133  
   134  // listenerInfo contains info about specific listener added with addListener
   135  type listenerInfo struct {
   136  	port int // 0 means that no info about port is available
   137  }
   138  
   139  // Server is a HTTP/3 server.
   140  type Server struct {
   141  	// Addr optionally specifies the UDP address for the server to listen on,
   142  	// in the form "host:port".
   143  	//
   144  	// When used by ListenAndServe and ListenAndServeTLS methods, if empty,
   145  	// ":https" (port 443) is used. See net.Dial for details of the address
   146  	// format.
   147  	//
   148  	// Otherwise, if Port is not set and underlying QUIC listeners do not
   149  	// have valid port numbers, the port part is used in Alt-Svc headers set
   150  	// with SetQuicHeaders.
   151  	Addr string
   152  
   153  	// Port is used in Alt-Svc response headers set with SetQuicHeaders. If
   154  	// needed Port can be manually set when the Server is created.
   155  	//
   156  	// This is useful when a Layer 4 firewall is redirecting UDP traffic and
   157  	// clients must use a port different from the port the Server is
   158  	// listening on.
   159  	Port int
   160  
   161  	// TLSConfig provides a TLS configuration for use by server. It must be
   162  	// set for ListenAndServe and Serve methods.
   163  	TLSConfig *tls.Config
   164  
   165  	// QuicConfig provides the parameters for QUIC connection created with
   166  	// Serve. If nil, it uses reasonable default values.
   167  	//
   168  	// Configured versions are also used in Alt-Svc response header set with
   169  	// SetQuicHeaders.
   170  	QuicConfig *quic.Config
   171  
   172  	// Handler is the HTTP request handler to use. If not set, defaults to
   173  	// http.NotFound.
   174  	Handler http.Handler
   175  
   176  	// EnableDatagrams enables support for HTTP/3 datagrams.
   177  	// If set to true, QuicConfig.EnableDatagram will be set.
   178  	// See https://datatracker.ietf.org/doc/html/draft-ietf-masque-h3-datagram-07.
   179  	EnableDatagrams bool
   180  
   181  	// MaxHeaderBytes controls the maximum number of bytes the server will
   182  	// read parsing the request HEADERS frame. It does not limit the size of
   183  	// the request body. If zero or negative, http.DefaultMaxHeaderBytes is
   184  	// used.
   185  	MaxHeaderBytes int
   186  
   187  	// AdditionalSettings specifies additional HTTP/3 settings.
   188  	// It is invalid to specify any settings defined by the HTTP/3 draft and the datagram draft.
   189  	AdditionalSettings map[uint64]uint64
   190  
   191  	// StreamHijacker, when set, is called for the first unknown frame parsed on a bidirectional stream.
   192  	// It is called right after parsing the frame type.
   193  	// If parsing the frame type fails, the error is passed to the callback.
   194  	// In that case, the frame type will not be set.
   195  	// Callers can either ignore the frame and return control of the stream back to HTTP/3
   196  	// (by returning hijacked false).
   197  	// Alternatively, callers can take over the QUIC stream (by returning hijacked true).
   198  	StreamHijacker func(FrameType, quic.Connection, quic.Stream, error) (hijacked bool, err error)
   199  
   200  	// UniStreamHijacker, when set, is called for unknown unidirectional stream of unknown stream type.
   201  	// If parsing the stream type fails, the error is passed to the callback.
   202  	// In that case, the stream type will not be set.
   203  	UniStreamHijacker func(StreamType, quic.Connection, quic.ReceiveStream, error) (hijacked bool)
   204  
   205  	mutex     sync.RWMutex
   206  	listeners map[*QUICEarlyListener]listenerInfo
   207  
   208  	closed bool
   209  
   210  	altSvcHeader string
   211  
   212  	logger utils.Logger
   213  }
   214  
   215  // ListenAndServe listens on the UDP address s.Addr and calls s.Handler to handle HTTP/3 requests on incoming connections.
   216  //
   217  // If s.Addr is blank, ":https" is used.
   218  func (s *Server) ListenAndServe() error {
   219  	return s.serveConn(s.TLSConfig, nil)
   220  }
   221  
   222  // ListenAndServeTLS listens on the UDP address s.Addr and calls s.Handler to handle HTTP/3 requests on incoming connections.
   223  //
   224  // If s.Addr is blank, ":https" is used.
   225  func (s *Server) ListenAndServeTLS(certFile, keyFile string) error {
   226  	var err error
   227  	certs := make([]tls.Certificate, 1)
   228  	certs[0], err = tls.LoadX509KeyPair(certFile, keyFile)
   229  	if err != nil {
   230  		return err
   231  	}
   232  	// We currently only use the cert-related stuff from tls.Config,
   233  	// so we don't need to make a full copy.
   234  	config := &tls.Config{
   235  		Certificates: certs,
   236  	}
   237  	return s.serveConn(config, nil)
   238  }
   239  
   240  // Serve an existing UDP connection.
   241  // It is possible to reuse the same connection for outgoing connections.
   242  // Closing the server does not close the connection.
   243  func (s *Server) Serve(conn net.PacketConn) error {
   244  	return s.serveConn(s.TLSConfig, conn)
   245  }
   246  
   247  // ServeQUICConn serves a single QUIC connection.
   248  func (s *Server) ServeQUICConn(conn quic.Connection) error {
   249  	s.mutex.Lock()
   250  	if s.logger == nil {
   251  		s.logger = utils.DefaultLogger.WithPrefix("server")
   252  	}
   253  	s.mutex.Unlock()
   254  
   255  	return s.handleConn(conn)
   256  }
   257  
   258  // ServeListener serves an existing QUIC listener.
   259  // Make sure you use http3.ConfigureTLSConfig to configure a tls.Config
   260  // and use it to construct a http3-friendly QUIC listener.
   261  // Closing the server does close the listener.
   262  // ServeListener always returns a non-nil error. After Shutdown or Close, the returned error is http.ErrServerClosed.
   263  func (s *Server) ServeListener(ln QUICEarlyListener) error {
   264  	if err := s.addListener(&ln); err != nil {
   265  		return err
   266  	}
   267  	defer s.removeListener(&ln)
   268  	for {
   269  		conn, err := ln.Accept(context.Background())
   270  		if err == quic.ErrServerClosed {
   271  			return http.ErrServerClosed
   272  		}
   273  		if err != nil {
   274  			return err
   275  		}
   276  		go func() {
   277  			if err := s.handleConn(conn); err != nil {
   278  				s.logger.Debugf(err.Error())
   279  			}
   280  		}()
   281  	}
   282  }
   283  
   284  var errServerWithoutTLSConfig = errors.New("use of http3.Server without TLSConfig")
   285  
   286  func (s *Server) serveConn(tlsConf *tls.Config, conn net.PacketConn) error {
   287  	if tlsConf == nil {
   288  		return errServerWithoutTLSConfig
   289  	}
   290  
   291  	s.mutex.Lock()
   292  	closed := s.closed
   293  	s.mutex.Unlock()
   294  	if closed {
   295  		return http.ErrServerClosed
   296  	}
   297  
   298  	baseConf := ConfigureTLSConfig(tlsConf)
   299  	quicConf := s.QuicConfig
   300  	if quicConf == nil {
   301  		quicConf = &quic.Config{Allow0RTT: true}
   302  	} else {
   303  		quicConf = s.QuicConfig.Clone()
   304  	}
   305  	if s.EnableDatagrams {
   306  		quicConf.EnableDatagrams = true
   307  	}
   308  
   309  	var ln QUICEarlyListener
   310  	var err error
   311  	if conn == nil {
   312  		addr := s.Addr
   313  		if addr == "" {
   314  			addr = ":https"
   315  		}
   316  		ln, err = quicListenAddr(addr, baseConf, quicConf)
   317  	} else {
   318  		ln, err = quicListen(conn, baseConf, quicConf)
   319  	}
   320  	if err != nil {
   321  		return err
   322  	}
   323  	return s.ServeListener(ln)
   324  }
   325  
   326  func extractPort(addr string) (int, error) {
   327  	_, portStr, err := net.SplitHostPort(addr)
   328  	if err != nil {
   329  		return 0, err
   330  	}
   331  
   332  	portInt, err := net.LookupPort("tcp", portStr)
   333  	if err != nil {
   334  		return 0, err
   335  	}
   336  	return portInt, nil
   337  }
   338  
   339  func (s *Server) generateAltSvcHeader() {
   340  	if len(s.listeners) == 0 {
   341  		// Don't announce any ports since no one is listening for connections
   342  		s.altSvcHeader = ""
   343  		return
   344  	}
   345  
   346  	// This code assumes that we will use protocol.SupportedVersions if no quic.Config is passed.
   347  	supportedVersions := protocol.SupportedVersions
   348  	if s.QuicConfig != nil && len(s.QuicConfig.Versions) > 0 {
   349  		supportedVersions = s.QuicConfig.Versions
   350  	}
   351  
   352  	// keep track of which have been seen so we don't yield duplicate values
   353  	seen := make(map[string]struct{}, len(supportedVersions))
   354  	var versionStrings []string
   355  	for _, version := range supportedVersions {
   356  		if v := versionToALPN(version); len(v) > 0 {
   357  			if _, ok := seen[v]; !ok {
   358  				versionStrings = append(versionStrings, v)
   359  				seen[v] = struct{}{}
   360  			}
   361  		}
   362  	}
   363  
   364  	var altSvc []string
   365  	addPort := func(port int) {
   366  		for _, v := range versionStrings {
   367  			altSvc = append(altSvc, fmt.Sprintf(`%s=":%d"; ma=2592000`, v, port))
   368  		}
   369  	}
   370  
   371  	if s.Port != 0 {
   372  		// if Port is specified, we must use it instead of the
   373  		// listener addresses since there's a reason it's specified.
   374  		addPort(s.Port)
   375  	} else {
   376  		// if we have some listeners assigned, try to find ports
   377  		// which we can announce, otherwise nothing should be announced
   378  		validPortsFound := false
   379  		for _, info := range s.listeners {
   380  			if info.port != 0 {
   381  				addPort(info.port)
   382  				validPortsFound = true
   383  			}
   384  		}
   385  		if !validPortsFound {
   386  			if port, err := extractPort(s.Addr); err == nil {
   387  				addPort(port)
   388  			}
   389  		}
   390  	}
   391  
   392  	s.altSvcHeader = strings.Join(altSvc, ",")
   393  }
   394  
   395  // We store a pointer to interface in the map set. This is safe because we only
   396  // call trackListener via Serve and can track+defer untrack the same pointer to
   397  // local variable there. We never need to compare a Listener from another caller.
   398  func (s *Server) addListener(l *QUICEarlyListener) error {
   399  	s.mutex.Lock()
   400  	defer s.mutex.Unlock()
   401  
   402  	if s.closed {
   403  		return http.ErrServerClosed
   404  	}
   405  	if s.logger == nil {
   406  		s.logger = utils.DefaultLogger.WithPrefix("server")
   407  	}
   408  	if s.listeners == nil {
   409  		s.listeners = make(map[*QUICEarlyListener]listenerInfo)
   410  	}
   411  
   412  	if port, err := extractPort((*l).Addr().String()); err == nil {
   413  		s.listeners[l] = listenerInfo{port}
   414  	} else {
   415  		s.logger.Errorf("Unable to extract port from listener %+v, will not be announced using SetQuicHeaders: %s", err)
   416  		s.listeners[l] = listenerInfo{}
   417  	}
   418  	s.generateAltSvcHeader()
   419  	return nil
   420  }
   421  
   422  func (s *Server) removeListener(l *QUICEarlyListener) {
   423  	s.mutex.Lock()
   424  	defer s.mutex.Unlock()
   425  	delete(s.listeners, l)
   426  	s.generateAltSvcHeader()
   427  }
   428  
   429  func (s *Server) handleConn(conn quic.Connection) error {
   430  	decoder := qpack.NewDecoder(nil)
   431  
   432  	// send a SETTINGS frame
   433  	str, err := conn.OpenUniStream()
   434  	if err != nil {
   435  		return fmt.Errorf("opening the control stream failed: %w", err)
   436  	}
   437  	b := make([]byte, 0, 64)
   438  	b = quicvarint.Append(b, streamTypeControlStream) // stream type
   439  	b = (&settingsFrame{Datagram: s.EnableDatagrams, Other: s.AdditionalSettings}).Append(b)
   440  	str.Write(b)
   441  
   442  	go s.handleUnidirectionalStreams(conn)
   443  
   444  	// Process all requests immediately.
   445  	// It's the client's responsibility to decide which requests are eligible for 0-RTT.
   446  	for {
   447  		str, err := conn.AcceptStream(context.Background())
   448  		if err != nil {
   449  			var appErr *quic.ApplicationError
   450  			if errors.As(err, &appErr) && appErr.ErrorCode == quic.ApplicationErrorCode(ErrCodeNoError) {
   451  				return nil
   452  			}
   453  			return fmt.Errorf("accepting stream failed: %w", err)
   454  		}
   455  		go func() {
   456  			rerr := s.handleRequest(conn, str, decoder, func() {
   457  				conn.CloseWithError(quic.ApplicationErrorCode(ErrCodeFrameUnexpected), "")
   458  			})
   459  			if rerr.err == errHijacked {
   460  				return
   461  			}
   462  			if rerr.err != nil || rerr.streamErr != 0 || rerr.connErr != 0 {
   463  				s.logger.Debugf("Handling request failed: %s", err)
   464  				if rerr.streamErr != 0 {
   465  					str.CancelWrite(quic.StreamErrorCode(rerr.streamErr))
   466  				}
   467  				if rerr.connErr != 0 {
   468  					var reason string
   469  					if rerr.err != nil {
   470  						reason = rerr.err.Error()
   471  					}
   472  					conn.CloseWithError(quic.ApplicationErrorCode(rerr.connErr), reason)
   473  				}
   474  				return
   475  			}
   476  			str.Close()
   477  		}()
   478  	}
   479  }
   480  
   481  func (s *Server) handleUnidirectionalStreams(conn quic.Connection) {
   482  	for {
   483  		str, err := conn.AcceptUniStream(context.Background())
   484  		if err != nil {
   485  			s.logger.Debugf("accepting unidirectional stream failed: %s", err)
   486  			return
   487  		}
   488  
   489  		go func(str quic.ReceiveStream) {
   490  			streamType, err := quicvarint.Read(quicvarint.NewReader(str))
   491  			if err != nil {
   492  				if s.UniStreamHijacker != nil && s.UniStreamHijacker(StreamType(streamType), conn, str, err) {
   493  					return
   494  				}
   495  				s.logger.Debugf("reading stream type on stream %d failed: %s", str.StreamID(), err)
   496  				return
   497  			}
   498  			// We're only interested in the control stream here.
   499  			switch streamType {
   500  			case streamTypeControlStream:
   501  			case streamTypeQPACKEncoderStream, streamTypeQPACKDecoderStream:
   502  				// Our QPACK implementation doesn't use the dynamic table yet.
   503  				// TODO: check that only one stream of each type is opened.
   504  				return
   505  			case streamTypePushStream: // only the server can push
   506  				conn.CloseWithError(quic.ApplicationErrorCode(ErrCodeStreamCreationError), "")
   507  				return
   508  			default:
   509  				if s.UniStreamHijacker != nil && s.UniStreamHijacker(StreamType(streamType), conn, str, nil) {
   510  					return
   511  				}
   512  				str.CancelRead(quic.StreamErrorCode(ErrCodeStreamCreationError))
   513  				return
   514  			}
   515  			f, err := parseNextFrame(str, nil)
   516  			if err != nil {
   517  				conn.CloseWithError(quic.ApplicationErrorCode(ErrCodeFrameError), "")
   518  				return
   519  			}
   520  			sf, ok := f.(*settingsFrame)
   521  			if !ok {
   522  				conn.CloseWithError(quic.ApplicationErrorCode(ErrCodeMissingSettings), "")
   523  				return
   524  			}
   525  			if !sf.Datagram {
   526  				return
   527  			}
   528  			// If datagram support was enabled on our side as well as on the client side,
   529  			// we can expect it to have been negotiated both on the transport and on the HTTP/3 layer.
   530  			// Note: ConnectionState() will block until the handshake is complete (relevant when using 0-RTT).
   531  			if s.EnableDatagrams && !conn.ConnectionState().SupportsDatagrams {
   532  				conn.CloseWithError(quic.ApplicationErrorCode(ErrCodeSettingsError), "missing QUIC Datagram support")
   533  			}
   534  		}(str)
   535  	}
   536  }
   537  
   538  func (s *Server) maxHeaderBytes() uint64 {
   539  	if s.MaxHeaderBytes <= 0 {
   540  		return http.DefaultMaxHeaderBytes
   541  	}
   542  	return uint64(s.MaxHeaderBytes)
   543  }
   544  
   545  func (s *Server) handleRequest(conn quic.Connection, str quic.Stream, decoder *qpack.Decoder, onFrameError func()) requestError {
   546  	var ufh unknownFrameHandlerFunc
   547  	if s.StreamHijacker != nil {
   548  		ufh = func(ft FrameType, e error) (processed bool, err error) { return s.StreamHijacker(ft, conn, str, e) }
   549  	}
   550  	frame, err := parseNextFrame(str, ufh)
   551  	if err != nil {
   552  		if err == errHijacked {
   553  			return requestError{err: errHijacked}
   554  		}
   555  		return newStreamError(ErrCodeRequestIncomplete, err)
   556  	}
   557  	hf, ok := frame.(*headersFrame)
   558  	if !ok {
   559  		return newConnError(ErrCodeFrameUnexpected, errors.New("expected first frame to be a HEADERS frame"))
   560  	}
   561  	if hf.Length > s.maxHeaderBytes() {
   562  		return newStreamError(ErrCodeFrameError, fmt.Errorf("HEADERS frame too large: %d bytes (max: %d)", hf.Length, s.maxHeaderBytes()))
   563  	}
   564  	headerBlock := make([]byte, hf.Length)
   565  	if _, err := io.ReadFull(str, headerBlock); err != nil {
   566  		return newStreamError(ErrCodeRequestIncomplete, err)
   567  	}
   568  	hfs, err := decoder.DecodeFull(headerBlock)
   569  	if err != nil {
   570  		// TODO: use the right error code
   571  		return newConnError(ErrCodeGeneralProtocolError, err)
   572  	}
   573  	req, err := requestFromHeaders(hfs)
   574  	if err != nil {
   575  		return newStreamError(ErrCodeMessageError, err)
   576  	}
   577  
   578  	connState := conn.ConnectionState().TLS
   579  	req.TLS = &connState
   580  	req.RemoteAddr = conn.RemoteAddr().String()
   581  
   582  	// Check that the client doesn't send more data in DATA frames than indicated by the Content-Length header (if set).
   583  	// See section 4.1.2 of RFC 9114.
   584  	var httpStr Stream
   585  	if _, ok := req.Header["Content-Length"]; ok && req.ContentLength >= 0 {
   586  		httpStr = newLengthLimitedStream(newStream(str, onFrameError), req.ContentLength)
   587  	} else {
   588  		httpStr = newStream(str, onFrameError)
   589  	}
   590  	body := newRequestBody(httpStr)
   591  	req.Body = body
   592  
   593  	if s.logger.Debug() {
   594  		s.logger.Infof("%s %s%s, on stream %d", req.Method, req.Host, req.RequestURI, str.StreamID())
   595  	} else {
   596  		s.logger.Infof("%s %s%s", req.Method, req.Host, req.RequestURI)
   597  	}
   598  
   599  	ctx := str.Context()
   600  	ctx = context.WithValue(ctx, ServerContextKey, s)
   601  	ctx = context.WithValue(ctx, http.LocalAddrContextKey, conn.LocalAddr())
   602  	req = req.WithContext(ctx)
   603  	r := newResponseWriter(str, conn, s.logger)
   604  	handler := s.Handler
   605  	if handler == nil {
   606  		handler = http.DefaultServeMux
   607  	}
   608  
   609  	var panicked bool
   610  	func() {
   611  		defer func() {
   612  			if p := recover(); p != nil {
   613  				panicked = true
   614  				if p == http.ErrAbortHandler {
   615  					return
   616  				}
   617  				// Copied from net/http/server.go
   618  				const size = 64 << 10
   619  				buf := make([]byte, size)
   620  				buf = buf[:runtime.Stack(buf, false)]
   621  				s.logger.Errorf("http: panic serving: %v\n%s", p, buf)
   622  			}
   623  		}()
   624  		handler.ServeHTTP(r, req)
   625  	}()
   626  
   627  	if body.wasStreamHijacked() {
   628  		return requestError{err: errHijacked}
   629  	}
   630  
   631  	// only write response when there is no panic
   632  	if !panicked {
   633  		r.WriteHeader(http.StatusOK)
   634  		r.Flush()
   635  	}
   636  	// If the EOF was read by the handler, CancelRead() is a no-op.
   637  	str.CancelRead(quic.StreamErrorCode(ErrCodeNoError))
   638  	return requestError{}
   639  }
   640  
   641  // Close the server immediately, aborting requests and sending CONNECTION_CLOSE frames to connected clients.
   642  // Close in combination with ListenAndServe() (instead of Serve()) may race if it is called before a UDP socket is established.
   643  func (s *Server) Close() error {
   644  	s.mutex.Lock()
   645  	defer s.mutex.Unlock()
   646  
   647  	s.closed = true
   648  
   649  	var err error
   650  	for ln := range s.listeners {
   651  		if cerr := (*ln).Close(); cerr != nil && err == nil {
   652  			err = cerr
   653  		}
   654  	}
   655  	return err
   656  }
   657  
   658  // CloseGracefully shuts down the server gracefully. The server sends a GOAWAY frame first, then waits for either timeout to trigger, or for all running requests to complete.
   659  // CloseGracefully in combination with ListenAndServe() (instead of Serve()) may race if it is called before a UDP socket is established.
   660  func (s *Server) CloseGracefully(timeout time.Duration) error {
   661  	// TODO: implement
   662  	return nil
   663  }
   664  
   665  // ErrNoAltSvcPort is the error returned by SetQuicHeaders when no port was found
   666  // for Alt-Svc to announce. This can happen if listening on a PacketConn without a port
   667  // (UNIX socket, for example) and no port is specified in Server.Port or Server.Addr.
   668  var ErrNoAltSvcPort = errors.New("no port can be announced, specify it explicitly using Server.Port or Server.Addr")
   669  
   670  // SetQuicHeaders can be used to set the proper headers that announce that this server supports HTTP/3.
   671  // The values set by default advertise all of the ports the server is listening on, but can be
   672  // changed to a specific port by setting Server.Port before launching the serverr.
   673  // If no listener's Addr().String() returns an address with a valid port, Server.Addr will be used
   674  // to extract the port, if specified.
   675  // For example, a server launched using ListenAndServe on an address with port 443 would set:
   676  //
   677  //	Alt-Svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
   678  func (s *Server) SetQuicHeaders(hdr http.Header) error {
   679  	s.mutex.RLock()
   680  	defer s.mutex.RUnlock()
   681  
   682  	if s.altSvcHeader == "" {
   683  		return ErrNoAltSvcPort
   684  	}
   685  	// use the map directly to avoid constant canonicalization
   686  	// since the key is already canonicalized
   687  	hdr["Alt-Svc"] = append(hdr["Alt-Svc"], s.altSvcHeader)
   688  	return nil
   689  }
   690  
   691  // ListenAndServeQUIC listens on the UDP network address addr and calls the
   692  // handler for HTTP/3 requests on incoming connections. http.DefaultServeMux is
   693  // used when handler is nil.
   694  func ListenAndServeQUIC(addr, certFile, keyFile string, handler http.Handler) error {
   695  	server := &Server{
   696  		Addr:    addr,
   697  		Handler: handler,
   698  	}
   699  	return server.ListenAndServeTLS(certFile, keyFile)
   700  }
   701  
   702  // ListenAndServe listens on the given network address for both, TLS and QUIC
   703  // connections in parallel. It returns if one of the two returns an error.
   704  // http.DefaultServeMux is used when handler is nil.
   705  // The correct Alt-Svc headers for QUIC are set.
   706  func ListenAndServe(addr, certFile, keyFile string, handler http.Handler) error {
   707  	// Load certs
   708  	var err error
   709  	certs := make([]tls.Certificate, 1)
   710  	certs[0], err = tls.LoadX509KeyPair(certFile, keyFile)
   711  	if err != nil {
   712  		return err
   713  	}
   714  	// We currently only use the cert-related stuff from tls.Config,
   715  	// so we don't need to make a full copy.
   716  	config := &tls.Config{
   717  		Certificates: certs,
   718  	}
   719  
   720  	if addr == "" {
   721  		addr = ":https"
   722  	}
   723  
   724  	// Open the listeners
   725  	udpAddr, err := net.ResolveUDPAddr("udp", addr)
   726  	if err != nil {
   727  		return err
   728  	}
   729  	udpConn, err := net.ListenUDP("udp", udpAddr)
   730  	if err != nil {
   731  		return err
   732  	}
   733  	defer udpConn.Close()
   734  
   735  	if handler == nil {
   736  		handler = http.DefaultServeMux
   737  	}
   738  	// Start the servers
   739  	quicServer := &Server{
   740  		TLSConfig: config,
   741  		Handler:   handler,
   742  	}
   743  
   744  	hErr := make(chan error)
   745  	qErr := make(chan error)
   746  	go func() {
   747  		hErr <- http.ListenAndServeTLS(addr, certFile, keyFile, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
   748  			quicServer.SetQuicHeaders(w.Header())
   749  			handler.ServeHTTP(w, r)
   750  		}))
   751  	}()
   752  	go func() {
   753  		qErr <- quicServer.Serve(udpConn)
   754  	}()
   755  
   756  	select {
   757  	case err := <-hErr:
   758  		quicServer.Close()
   759  		return err
   760  	case err := <-qErr:
   761  		// Cannot close the HTTP server or wait for requests to complete properly :/
   762  		return err
   763  	}
   764  }