net: add UDP listen, resolver, DNSError, and TCP listener APIs for wasm

dial.go

@@ -87,6 +87,13 @@ type Dialer struct {
 	// If KeepAliveConfig.Enable is false and KeepAlive is negative,
 	// keep-alive probes are disabled.
 	KeepAliveConfig KeepAliveConfig
+
+	// Resolver optionally specifies an alternate resolver to use.
+	//
+	// TINYGO: present for API compatibility; DialContext resolves via the
+	// netdev-backed ResolveTCPAddr/ResolveUDPAddr and does not consult this
+	// field.
+	Resolver *Resolver
 }
 
 // Dial connects to the address on the named network.
@@ -281,3 +288,22 @@ func Listen(network, address string) (Listener, error) {
 
 	return listenTCP(laddr)
 }
+
+// ListenPacket announces on the local network address.
+//
+// TINYGO: only UDP networks are supported, backed by ListenUDP; the
+// returned PacketConn is a *UDPConn.
+func ListenPacket(network, address string) (PacketConn, error) {
+	switch network {
+	case "udp", "udp4":
+	default:
+		return nil, fmt.Errorf("Network %s not supported", network)
+	}
+
+	laddr, err := ResolveUDPAddr(network, address)
+	if err != nil {
+		return nil, err
+	}
+
+	return ListenUDP(network, laddr)
+}

dnserror.go

@@ -0,0 +1,47 @@
+// TINYGO: The following is copied and modified from Go 1.26.2 official implementation.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+// DNSError represents a DNS lookup error.
+type DNSError struct {
+	UnwrapErr   error  // error returned by the [DNSError.Unwrap] method, might be nil
+	Err         string // description of the error
+	Name        string // name looked for
+	Server      string // server used
+	IsTimeout   bool   // if true, timed out; not all timeouts set this
+	IsTemporary bool   // if true, error is temporary; not all errors set this
+
+	// IsNotFound is set to true when the requested name does not
+	// contain any records of the requested type (data not found),
+	// or the name itself was not found (NXDOMAIN).
+	IsNotFound bool
+}
+
+// Unwrap returns e.UnwrapErr.
+func (e *DNSError) Unwrap() error { return e.UnwrapErr }
+
+func (e *DNSError) Error() string {
+	if e == nil {
+		return "<nil>"
+	}
+	s := "lookup " + e.Name
+	if e.Server != "" {
+		s += " on " + e.Server
+	}
+	s += ": " + e.Err
+	return s
+}
+
+// Timeout reports whether the DNS lookup is known to have timed out.
+// This is not always known; a DNS lookup may fail due to a timeout
+// and return a [DNSError] for which Timeout returns false.
+func (e *DNSError) Timeout() bool { return e.IsTimeout }
+
+// Temporary reports whether the DNS error is known to be temporary.
+// This is not always known; a DNS lookup may fail due to a temporary
+// error and return a [DNSError] for which Temporary returns false.
+func (e *DNSError) Temporary() bool { return e.IsTimeout || e.IsTemporary }

http/response.go

@@ -14,6 +14,7 @@ package http
 import (
 	"bufio"
 	"bytes"
+	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -117,6 +118,11 @@ type Response struct {
 	// Request's Body is nil (having already been consumed).
 	// This is only populated for Client requests.
 	Request *Request
+
+	// TLS contains information about the TLS connection on which the response
+	// was received. It is nil for unencrypted responses. TINYGO: populated only
+	// if a caller sets it; the wasm fetch path leaves it nil.
+	TLS *tls.ConnectionState
 }
 
 // Cookies parses and returns the cookies set in the Set-Cookie headers.

http/responsecontroller.go

@@ -0,0 +1,152 @@
+// TINYGO: Copied verbatim from the Go 1.26.2 official implementation to provide
+// the ResponseController API used by net/http/httputil (reverse proxy). The
+// underlying methods degrade to ErrNotSupported when the ResponseWriter does
+// not implement them, which is the standard behavior.
+
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"time"
+)
+
+// A ResponseController is used by an HTTP handler to control the response.
+//
+// A ResponseController may not be used after the [Handler.ServeHTTP] method has returned.
+type ResponseController struct {
+	rw ResponseWriter
+}
+
+// NewResponseController creates a [ResponseController] for a request.
+//
+// The ResponseWriter should be the original value passed to the [Handler.ServeHTTP] method,
+// or have an Unwrap method returning the original ResponseWriter.
+//
+// If the ResponseWriter implements any of the following methods, the ResponseController
+// will call them as appropriate:
+//
+//	Flush()
+//	FlushError() error // alternative Flush returning an error
+//	Hijack() (net.Conn, *bufio.ReadWriter, error)
+//	SetReadDeadline(deadline time.Time) error
+//	SetWriteDeadline(deadline time.Time) error
+//	EnableFullDuplex() error
+//
+// If the ResponseWriter does not support a method, ResponseController returns
+// an error matching [ErrNotSupported].
+func NewResponseController(rw ResponseWriter) *ResponseController {
+	return &ResponseController{rw}
+}
+
+type rwUnwrapper interface {
+	Unwrap() ResponseWriter
+}
+
+// Flush flushes buffered data to the client.
+func (c *ResponseController) Flush() error {
+	rw := c.rw
+	for {
+		switch t := rw.(type) {
+		case interface{ FlushError() error }:
+			return t.FlushError()
+		case Flusher:
+			t.Flush()
+			return nil
+		case rwUnwrapper:
+			rw = t.Unwrap()
+		default:
+			return errNotSupported()
+		}
+	}
+}
+
+// Hijack lets the caller take over the connection.
+// See the [Hijacker] interface for details.
+func (c *ResponseController) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	rw := c.rw
+	for {
+		switch t := rw.(type) {
+		case Hijacker:
+			return t.Hijack()
+		case rwUnwrapper:
+			rw = t.Unwrap()
+		default:
+			return nil, nil, errNotSupported()
+		}
+	}
+}
+
+// SetReadDeadline sets the deadline for reading the entire request, including the body.
+// Reads from the request body after the deadline has been exceeded will return an error.
+// A zero value means no deadline.
+//
+// Setting the read deadline after it has been exceeded will not extend it.
+func (c *ResponseController) SetReadDeadline(deadline time.Time) error {
+	rw := c.rw
+	for {
+		switch t := rw.(type) {
+		case interface{ SetReadDeadline(time.Time) error }:
+			return t.SetReadDeadline(deadline)
+		case rwUnwrapper:
+			rw = t.Unwrap()
+		default:
+			return errNotSupported()
+		}
+	}
+}
+
+// SetWriteDeadline sets the deadline for writing the response.
+// Writes to the response body after the deadline has been exceeded will not block,
+// but may succeed if the data has been buffered.
+// A zero value means no deadline.
+//
+// Setting the write deadline after it has been exceeded will not extend it.
+func (c *ResponseController) SetWriteDeadline(deadline time.Time) error {
+	rw := c.rw
+	for {
+		switch t := rw.(type) {
+		case interface{ SetWriteDeadline(time.Time) error }:
+			return t.SetWriteDeadline(deadline)
+		case rwUnwrapper:
+			rw = t.Unwrap()
+		default:
+			return errNotSupported()
+		}
+	}
+}
+
+// EnableFullDuplex indicates that the request handler will interleave reads from [Request.Body]
+// with writes to the [ResponseWriter].
+//
+// For HTTP/1 requests, the Go HTTP server by default consumes any unread portion of
+// the request body before beginning to write the response, preventing handlers from
+// concurrently reading from the request and writing the response.
+// Calling EnableFullDuplex disables this behavior and permits handlers to continue to read
+// from the request while concurrently writing the response.
+//
+// For HTTP/2 requests, the Go HTTP server always permits concurrent reads and responses.
+func (c *ResponseController) EnableFullDuplex() error {
+	rw := c.rw
+	for {
+		switch t := rw.(type) {
+		case interface{ EnableFullDuplex() error }:
+			return t.EnableFullDuplex()
+		case rwUnwrapper:
+			rw = t.Unwrap()
+		default:
+			return errNotSupported()
+		}
+	}
+}
+
+// errNotSupported returns an error that Is ErrNotSupported,
+// but is not == to it.
+func errNotSupported() error {
+	return fmt.Errorf("%w", ErrNotSupported)
+}

http/server.go

@@ -2779,6 +2779,23 @@ type Server struct {
 	// value.
 	ConnContext func(ctx context.Context, c net.Conn) context.Context
 
+	// TLSNextProto optionally specifies a function to take over
+	// ownership of the provided TLS connection when an ALPN
+	// protocol upgrade has occurred. The map key is the protocol
+	// name negotiated. The Handler argument should be used to
+	// handle HTTP requests and will initialize the Request's TLS
+	// and RemoteAddr if not already set. The connection is
+	// automatically closed when the function returns.
+	// If TLSNextProto is not nil, HTTP/2 support is not enabled
+	// automatically.
+	TLSNextProto map[string]func(*Server, *tls.Conn, Handler)
+
+	// HTTP2 configures HTTP/2 connections.
+	//
+	// This field does not yet have any effect.
+	// See https://go.dev/issue/67813.
+	HTTP2 *HTTP2Config
+
 	inShutdown atomicBool // true when server is in shutdown
 
 	disableKeepAlives int32     // accessed atomically.