fix: race condition, tunnel relay, error handling

internal/proxy/proxy.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"sync/atomic"
 	"time"
 
 	"github.com/kreatoo/ihtc/internal/log"
@@ -12,7 +13,7 @@ import (
 )
 
 type Proxy struct {
-	listenAddr   string
+	listenAddr   atomic.Pointer[string]
 	obfuscateCfg obfuscate.Config
 	logger       *log.Logger
 	srv          *http.Server
@@ -20,10 +21,10 @@ type Proxy struct {
 
 func New(addr string, cfg obfuscate.Config, logger *log.Logger) *Proxy {
 	p := &Proxy{
-		listenAddr:   addr,
 		obfuscateCfg: cfg,
 		logger:       logger,
 	}
+	p.listenAddr.Store(&addr)
 	p.srv = &http.Server{
 		Addr:    addr,
 		Handler: http.HandlerFunc(p.handle),
@@ -32,16 +33,17 @@ func New(addr string, cfg obfuscate.Config, logger *log.Logger) *Proxy {
 }
 
 func (p *Proxy) ListenAddr() string {
-	return p.listenAddr
+	return *p.listenAddr.Load()
 }
 
 func (p *Proxy) Start() error {
-	l, err := net.Listen("tcp", p.listenAddr)
+	l, err := net.Listen("tcp", *p.listenAddr.Load())
 	if err != nil {
 		return err
 	}
-	p.listenAddr = l.Addr().String()
-	p.logger.Info("listening on %s", p.listenAddr)
+	resolved := l.Addr().String()
+	p.listenAddr.Store(&resolved)
+	p.logger.Info("listening on %s", resolved)
 	return p.srv.Serve(l)
 }
 
@@ -85,15 +87,18 @@ func (p *Proxy) handleConnect(w http.ResponseWriter, r *http.Request) {
 	defer clientConn.Close()
 
 	if _, err := bufrw.WriteString("HTTP/1.1 200 Connection Established\r\n\r\n"); err != nil {
+		p.logger.Debug("write CONNECT response: %v", err)
 		return
 	}
 	if err := bufrw.Flush(); err != nil {
+		p.logger.Debug("flush CONNECT response: %v", err)
 		return
 	}
 
 	n, err := obfuscate.HandleClientHello(dest, clientConn, p.obfuscateCfg)
-	if err != nil && err != io.EOF {
-		p.logger.Debug("ClientHello frag: wrote %d bytes, err: %v", n, err)
+	if err != nil {
+		p.logger.Debug("ClientHello frag failed: %v", err)
+		return
 	}
 
 	p.logger.Debug("tunnel %s established (%d byte ClientHello fragmented)", target, n)
@@ -108,6 +113,7 @@ func (p *Proxy) handleConnect(w http.ResponseWriter, r *http.Request) {
 		done <- struct{}{}
 	}()
 	<-done
+	<-done
 }
 
 func (p *Proxy) handleHTTP(w http.ResponseWriter, r *http.Request) {