fix android dns query

When a rewrite rule has both match and rewriter set, the body is only
sent to the rewriter plugin if it matches the pattern. A nil pattern
(non-empty match) means unconditional rewrite via the plugin.

Coincidence: fix indentation drift in the previous commit's rewrite
condition blocks (tab alignment was off by one level).

auth/auth_test.go

@@ -4,11 +4,13 @@ import (
 	"context"
 	"errors"
 	"io"
+	"net"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/go-gost/core/auth"
+	xctx "github.com/go-gost/x/ctx"
 	"github.com/go-gost/x/internal/loader"
 	xlogger "github.com/go-gost/x/logger"
 )
@@ -1003,3 +1005,96 @@ type staticAuther struct {
 func (s *staticAuther) Authenticate(ctx context.Context, user, password string, opts ...auth.Option) (string, bool) {
 	return s.id, s.ok
 }
+
+// --- whitelist tests ---
+
+func TestWhitelistedAuthenticator_IPMatch(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"192.168.1.100"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 54321})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "" || !ok {
+		t.Fatalf("expected (\"\", true) for matched IP, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_IPNoMatch(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"192.168.1.100"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("10.0.0.1"), Port: 12345})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "test" || !ok {
+		t.Fatalf("expected (\"test\", true) for non-matched IP, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_CIDRMatch(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"10.0.0.0/8"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("10.1.2.3"), Port: 9999})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "" || !ok {
+		t.Fatalf("expected (\"\", true) for matched CIDR, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_CIDRNoMatch(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"10.0.0.0/8"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.1"), Port: 8080})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "test" || !ok {
+		t.Fatalf("expected (\"test\", true) for non-matched CIDR, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_EmptyPatterns(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 54321})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "test" || !ok {
+		t.Fatalf("expected (\"test\", true) for empty patterns, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_NoSrcAddr(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"192.168.1.100"})
+	id, ok := w.Authenticate(context.Background(), "user", "pass")
+	if id != "test" || !ok {
+		t.Fatalf("expected (\"test\", true) with no src addr in context, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_NilAuther(t *testing.T) {
+	// When IP matches, the whitelist returns OK regardless of nil auther.
+	w := WhitelistedAuthenticator(nil, []string{"192.168.1.100"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 54321})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "" || !ok {
+		t.Fatalf("expected (\"\", true) for matched whitelist even with nil auther, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_NilAutherNoMatch(t *testing.T) {
+	// When IP does not match and auther is nil, it falls through to ("", false).
+	w := WhitelistedAuthenticator(nil, []string{"192.168.1.100"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("10.0.0.1"), Port: 54321})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "" || ok {
+		t.Fatalf("expected (\"\", false) for nil auther with non-matching IP, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_UnderlyingDenies(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: false}, []string{"10.0.0.0/8"})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.1"), Port: 8080})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "test" || ok {
+		t.Fatalf("expected (\"test\", false) when underlying auther denies, got (%q, %v)", id, ok)
+	}
+}
+
+func TestWhitelistedAuthenticator_InvalidPatterns(t *testing.T) {
+	w := WhitelistedAuthenticator(&staticAuther{id: "test", ok: true}, []string{"not-an-ip", "also-not-cidr/", ""})
+	ctx := xctx.ContextWithSrcAddr(context.Background(), &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 54321})
+	id, ok := w.Authenticate(ctx, "user", "pass")
+	if id != "test" || !ok {
+		t.Fatalf("expected (\"test\", true) for all-invalid patterns, got (%q, %v)", id, ok)
+	}
+}

auth/whitelist.go

@@ -0,0 +1,61 @@
+package auth
+
+import (
+	"context"
+	"net"
+	"strings"
+
+	"github.com/go-gost/core/auth"
+	xctx "github.com/go-gost/x/ctx"
+	"github.com/go-gost/x/internal/matcher"
+)
+
+// whitelistedAuthenticator wraps an Authenticator to skip authentication
+// for client IPs matching the configured whitelist patterns.
+type whitelistedAuthenticator struct {
+	auther      auth.Authenticator
+	ipMatcher   matcher.Matcher
+	cidrMatcher matcher.Matcher
+}
+
+// WhitelistedAuthenticator returns an Authenticator that skips the underlying
+// auther when the client's IP address matches one of the given patterns.
+// Patterns may be IP addresses (e.g. "192.168.1.1") or CIDR ranges
+// (e.g. "10.0.0.0/8"). Invalid patterns are silently ignored.
+func WhitelistedAuthenticator(auther auth.Authenticator, patterns []string) auth.Authenticator {
+	var ips []net.IP
+	var inets []*net.IPNet
+	for _, pattern := range patterns {
+		pattern = strings.TrimSpace(pattern)
+		if pattern == "" {
+			continue
+		}
+		if ip := net.ParseIP(pattern); ip != nil {
+			ips = append(ips, ip)
+			continue
+		}
+		if _, inet, err := net.ParseCIDR(pattern); err == nil {
+			inets = append(inets, inet)
+		}
+	}
+	return &whitelistedAuthenticator{
+		auther:      auther,
+		ipMatcher:   matcher.IPMatcher(ips),
+		cidrMatcher: matcher.CIDRMatcher(inets),
+	}
+}
+
+func (w *whitelistedAuthenticator) Authenticate(ctx context.Context, user, password string, opts ...auth.Option) (string, bool) {
+	if srcAddr := xctx.SrcAddrFromContext(ctx); srcAddr != nil {
+		host, _, err := net.SplitHostPort(srcAddr.String())
+		if err == nil && host != "" {
+			if w.ipMatcher.Match(host) || w.cidrMatcher.Match(host) {
+				return "", true
+			}
+		}
+	}
+	if w.auther != nil {
+		return w.auther.Authenticate(ctx, user, password, opts...)
+	}
+	return "", false
+}

config/config.go

@@ -316,6 +316,11 @@ type RecorderObject struct {
 	Metadata map[string]any `yaml:",omitempty" json:"metadata,omitempty"`
 }
 
+type RewriterConfig struct {
+	Name   string        `json:"name"`
+	Plugin *PluginConfig `yaml:",omitempty" json:"plugin,omitempty"`
+}
+
 type LimiterConfig struct {
 	Name   string        `json:"name"`
 	Limits []string      `yaml:",omitempty" json:"limits,omitempty"`
@@ -397,6 +402,8 @@ type HTTPBodyRewriteConfig struct {
 	Type        string
 	Match       string
 	Replacement string
+	// name of the rewriter plugin (via registry)
+	Rewriter string
 }
 
 type NodeFilterConfig struct {
@@ -405,6 +412,15 @@ type NodeFilterConfig struct {
 	Path     string `yaml:",omitempty" json:"path,omitempty"`
 }
 
+// NodeMatcherConfig defines a routing-rule matcher for a hop node.
+//
+// Priority controls election among multiple matching nodes:
+//   - 0 (default): auto-computed from the rule string length — longer rules
+//     (more specific) get higher priority.
+//   - negative: the node participates in matching but priority short-circuit
+//     is disabled; the selector (round-robin, random, hash, etc.) always applies.
+//   - positive: explicit priority; when a single node has strictly higher
+//     priority than all others, it wins directly, bypassing the selector.
 type NodeMatcherConfig struct {
 	Rule     string `yaml:",omitempty" json:"rule,omitempty"`
 	Priority int    `yaml:",omitempty" json:"priority,omitempty"`
@@ -478,8 +494,9 @@ type ServiceConfig struct {
 	Logger     string            `yaml:",omitempty" json:"logger,omitempty"`
 	Loggers    []string          `yaml:",omitempty" json:"loggers,omitempty"`
 	Observer   string            `yaml:",omitempty" json:"observer,omitempty"`
-	Recorders  []*RecorderObject `yaml:",omitempty" json:"recorders,omitempty"`
+	Rewriter  string            `yaml:",omitempty" json:"rewriter,omitempty"`
-	Handler    *HandlerConfig    `yaml:",omitempty" json:"handler,omitempty"`
+	Recorders []*RecorderObject `yaml:",omitempty" json:"recorders,omitempty"`
+	Handler   *HandlerConfig    `yaml:",omitempty" json:"handler,omitempty"`
 	Listener   *ListenerConfig   `yaml:",omitempty" json:"listener,omitempty"`
 	Forwarder  *ForwarderConfig  `yaml:",omitempty" json:"forwarder,omitempty"`
 	Metadata   map[string]any    `yaml:",omitempty" json:"metadata,omitempty"`
@@ -628,6 +645,7 @@ type Config struct {
 	Routers    []*RouterConfig    `yaml:",omitempty" json:"routers,omitempty"`
 	SDs        []*SDConfig        `yaml:"sds,omitempty" json:"sds,omitempty"`
 	Recorders  []*RecorderConfig  `yaml:",omitempty" json:"recorders,omitempty"`
+	Rewriters  []*RewriterConfig  `yaml:",omitempty" json:"rewriters,omitempty"`
 	Limiters   []*LimiterConfig   `yaml:",omitempty" json:"limiters,omitempty"`
 	Quotas     []*QuotaConfig     `yaml:",omitempty" json:"quotas,omitempty"`
 	CLimiters  []*LimiterConfig   `yaml:"climiters,omitempty" json:"climiters,omitempty"`

config/loader/loader.go

@@ -22,6 +22,7 @@ import (
 	reg "github.com/go-gost/core/registry"
 	"github.com/go-gost/core/resolver"
 	"github.com/go-gost/core/router"
+	"github.com/go-gost/core/rewriter"
 	"github.com/go-gost/core/sd"
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/config/parsing"
@@ -38,6 +39,7 @@ import (
 	quota_parser "github.com/go-gost/x/config/parsing/quota"
 	recorder_parser "github.com/go-gost/x/config/parsing/recorder"
 	resolver_parser "github.com/go-gost/x/config/parsing/resolver"
+	rewriter_parser "github.com/go-gost/x/config/parsing/rewriter"
 	router_parser "github.com/go-gost/x/config/parsing/router"
 	sd_parser "github.com/go-gost/x/config/parsing/sd"
 	service_parser "github.com/go-gost/x/config/parsing/service"
@@ -244,6 +246,16 @@ func register(cfg *config.Config) error {
 		}
 	}
 
+	{
+		var entries []named[rewriter.Rewriter]
+		for _, c := range cfg.Rewriters {
+			entries = append(entries, named[rewriter.Rewriter]{c.Name, rewriter_parser.ParseRewriter(c)})
+		}
+		if err := registerGroup(entries, registry.RewriterRegistry()); err != nil {
+			return err
+		}
+	}
+
 	{
 		var entries []named[traffic.TrafficLimiter]
 		for _, c := range cfg.Limiters {

config/parsing/node/parse.go

@@ -29,6 +29,29 @@ import (
 // metadata-driven options (so_mark, interface, netns, proxy protocol), sets up
 // bypass rules, node filters, HTTP settings, and TLS node settings. The hop
 // parameter is used only for logging context.
+
+func parseBodyRewrites(vs []config.HTTPBodyRewriteConfig, log logger.Logger) []chain.HTTPBodyRewriteSettings {
+	var out []chain.HTTPBodyRewriteSettings
+	for _, v := range vs {
+		pattern, _ := regexp.Compile(v.Match)
+		rw := chain.HTTPBodyRewriteSettings{
+			Type:        v.Type,
+			Pattern:     pattern,
+			Replacement: []byte(v.Replacement),
+		}
+		if v.Rewriter != "" {
+			if !registry.RewriterRegistry().IsRegistered(v.Rewriter) {
+				log.Warnf("rewriter %q not found in registry for rewrite rule", v.Rewriter)
+			}
+			rw.Rewriter = registry.RewriterRegistry().Get(v.Rewriter)
+		}
+		if pattern != nil || rw.Rewriter != nil {
+			out = append(out, rw)
+		}
+	}
+	return out
+}
+
 func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.Node, error) {
 	if cfg == nil {
 		return nil, nil
@@ -176,6 +199,10 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 		if rule := strings.TrimSpace(cfg.Matcher.Rule); rule != "" {
 			if matcher, err := routing.NewMatcher(rule); err == nil {
 				log.Debugf("new matcher for node %s with rule %s", cfg.Name, cfg.Matcher.Rule)
+				// Priority 0 means "use default": automatically set to the
+				// rule length so longer (more specific) rules outrank shorter
+				// ones. Use a negative priority to opt out of this behavior
+				// and always go through the selector.
 				if priority == 0 {
 					priority = len(cfg.Matcher.Rule)
 				}
@@ -222,33 +249,9 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 				})
 			}
 		}
-		for _, v := range cfg.HTTP.RewriteBody {
+		settings.RewriteResponseBody = append(settings.RewriteResponseBody, parseBodyRewrites(cfg.HTTP.RewriteBody, log)...)
-			if pattern, _ := regexp.Compile(v.Match); pattern != nil {
+		settings.RewriteResponseBody = append(settings.RewriteResponseBody, parseBodyRewrites(cfg.HTTP.RewriteResponseBody, log)...)
-				settings.RewriteResponseBody = append(settings.RewriteResponseBody, chain.HTTPBodyRewriteSettings{
+		settings.RewriteRequestBody = append(settings.RewriteRequestBody, parseBodyRewrites(cfg.HTTP.RewriteRequestBody, log)...)
-					Type:        v.Type,
-					Pattern:     pattern,
-					Replacement: []byte(v.Replacement),
-				})
-			}
-		}
-		for _, v := range cfg.HTTP.RewriteResponseBody {
-			if pattern, _ := regexp.Compile(v.Match); pattern != nil {
-				settings.RewriteResponseBody = append(settings.RewriteResponseBody, chain.HTTPBodyRewriteSettings{
-					Type:        v.Type,
-					Pattern:     pattern,
-					Replacement: []byte(v.Replacement),
-				})
-			}
-		}
-		for _, v := range cfg.HTTP.RewriteRequestBody {
-			if pattern, _ := regexp.Compile(v.Match); pattern != nil {
-				settings.RewriteRequestBody = append(settings.RewriteRequestBody, chain.HTTPBodyRewriteSettings{
-					Type:        v.Type,
-					Pattern:     pattern,
-					Replacement: []byte(v.Replacement),
-				})
-			}
-		}
 		opts = append(opts, chain.HTTPNodeOption(settings))
 	}
 

config/parsing/rewriter/parse.go

@@ -0,0 +1,48 @@
+package rewriter
+
+import (
+	"crypto/tls"
+	"strings"
+
+	"github.com/go-gost/core/rewriter"
+	"github.com/go-gost/x/config"
+	"github.com/go-gost/x/internal/plugin"
+	rewriter_plugin "github.com/go-gost/x/rewriter/plugin"
+)
+
+// ParseRewriter converts a RewriterConfig into a rewriter.Rewriter.
+// It currently supports plugin backends only (HTTP or gRPC).
+// Returns nil when cfg is nil or no backend is configured.
+func ParseRewriter(cfg *config.RewriterConfig) rewriter.Rewriter {
+	if cfg == nil {
+		return nil
+	}
+
+	if cfg.Plugin != nil {
+		var tlsCfg *tls.Config
+		if cfg.Plugin.TLS != nil {
+			tlsCfg = &tls.Config{
+				ServerName:         cfg.Plugin.TLS.ServerName,
+				InsecureSkipVerify: !cfg.Plugin.TLS.Secure,
+			}
+		}
+		switch strings.ToLower(cfg.Plugin.Type) {
+		case "http":
+			return rewriter_plugin.NewHTTPPlugin(
+				cfg.Name, cfg.Plugin.Addr,
+				plugin.TokenOption(cfg.Plugin.Token),
+				plugin.TLSConfigOption(tlsCfg),
+				plugin.TimeoutOption(cfg.Plugin.Timeout),
+			)
+		default:
+			return rewriter_plugin.NewGRPCPlugin(
+				cfg.Name, cfg.Plugin.Addr,
+				plugin.TokenOption(cfg.Plugin.Token),
+				plugin.TLSConfigOption(tlsCfg),
+				plugin.TimeoutOption(cfg.Plugin.Timeout),
+			)
+		}
+	}
+
+	return nil
+}

config/parsing/service/parse.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-gost/core/handler"
 	"github.com/go-gost/core/hop"
 	"github.com/go-gost/core/listener"
+	"github.com/go-gost/core/rewriter"
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/observer/stats"
 	"github.com/go-gost/core/recorder"
@@ -303,6 +304,32 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 		auther = xauth.AuthenticatorGroup(authers...)
 	}
 
+	// Parse skipauth from handler metadata to whitelist client IPs that
+	// should bypass authentication. Accepts both YAML arrays
+	// (skipauth: ["10.0.0.0/8"]) and comma-separated URL query values
+	// (?skipauth=10.0.0.0/8,192.168.1.1).
+	if cfg.Handler.Metadata != nil {
+		hmd := metadata.NewMetadata(cfg.Handler.Metadata)
+		skipauth := mdutil.GetStrings(hmd, "skipauth")
+		if len(skipauth) == 0 {
+			if s := mdutil.GetString(hmd, "skipauth"); s != "" {
+				for _, p := range strings.Split(s, ",") {
+					if p = strings.TrimSpace(p); p != "" {
+						skipauth = append(skipauth, p)
+					}
+				}
+			}
+		}
+		if len(skipauth) > 0 {
+			if auther != nil {
+				auther = xauth.WhitelistedAuthenticator(auther, skipauth)
+				handlerLogger.Debugf("skipauth whitelist applied: %v", skipauth)
+			} else {
+				handlerLogger.Warnf("skipauth configured but no auther set — authentication is already disabled for all clients")
+			}
+		}
+	}
+
 	var recorders []recorder.RecorderObject
 	for _, r := range cfg.Recorders {
 		md := metadata.NewMetadata(r.Metadata)
@@ -327,6 +354,14 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 		})
 	}
 
+	var rew rewriter.Rewriter
+	if cfg.Rewriter != "" {
+		if !registry.RewriterRegistry().IsRegistered(cfg.Rewriter) {
+			serviceLogger.Warnf("rewriter %q not found in registry", cfg.Rewriter)
+		}
+		rew = registry.RewriterRegistry().Get(cfg.Rewriter)
+	}
+
 	routerOpts = []chain.RouterOption{
 		chain.RetriesRouterOption(cfg.Handler.Retries),
 		chain.TimeoutRouterOption(dialTimeout),
@@ -356,6 +391,7 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 			handler.TrafficLimiterOption(registry.TrafficLimiterRegistry().Get(cfg.Handler.Limiter)),
 			handler.ObserverOption(registry.ObserverRegistry().Get(cfg.Handler.Observer)),
 			handler.RecordersOption(recorders...),
+			handler.RewriterOption(rew),
 			handler.LoggerOption(handlerLogger),
 			handler.ServiceOption(cfg.Name),
 			handler.NetnsOption(netnsIn),

connector/http/connector.go

@@ -2,9 +2,12 @@ package http
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	"encoding/base64"
+	"encoding/binary"
 	"fmt"
+	"hash/crc32"
 	"net"
 	"net/http"
 	"net/http/httputil"
@@ -53,10 +56,16 @@ func (c *httpConnector) Connect(ctx context.Context, conn net.Conn, network, add
 	})
 	log.Debugf("connect %s/%s", address, network)
 
+	connectHost := address
+	if c.md.host != "" {
+		// 伪装的地址
+		connectHost = c.md.host
+	}
+
 	req := &http.Request{
 		Method:     http.MethodConnect,
-		URL:        &url.URL{Host: address},
+		URL:        &url.URL{Host: connectHost},
-		Host:       address,
+		Host:       connectHost,
 		ProtoMajor: 1,
 		ProtoMinor: 1,
 		Header:     c.md.header,
@@ -67,6 +76,12 @@ func (c *httpConnector) Connect(ctx context.Context, conn net.Conn, network, add
 	}
 	req.Header.Set("Proxy-Connection", "keep-alive")
 
+	// 真实连接的地址
+	if c.md.host != "" {
+		targetAddr := encodeServerName(address)
+		req.Header.Set("Gost-Target", targetAddr)
+	}
+
 	if user := c.options.Auth; user != nil {
 		u := user.Username()
 		p, _ := user.Password()
@@ -129,3 +144,10 @@ func (c *httpConnector) Connect(ctx context.Context, conn net.Conn, network, add
 
 	return conn, nil
 }
+
+func encodeServerName(name string) string {
+	buf := &bytes.Buffer{}
+	binary.Write(buf, binary.BigEndian, crc32.ChecksumIEEE([]byte(name)))
+	buf.WriteString(base64.RawURLEncoding.EncodeToString([]byte(name)))
+	return base64.RawURLEncoding.EncodeToString(buf.Bytes())
+}

connector/http/metadata.go

@@ -11,15 +11,19 @@ import (
 type metadata struct {
 	connectTimeout time.Duration
 	header         http.Header
+	//伪装混淆用host
+	host string
 }
 
 func (c *httpConnector) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		connectTimeout = "timeout"
 		header         = "header"
+		host           = "host"
 	)
 
 	c.md.connectTimeout = mdutil.GetDuration(md, connectTimeout)
+	c.md.host = mdutil.GetString(md, host)
 
 	if mm := mdutil.GetStringMapString(md, header); len(mm) > 0 {
 		hd := http.Header{}

dialer/mtls/dialer.go

@@ -2,7 +2,6 @@ package mtls
 
 import (
 	"context"
-	"crypto/tls"
 	"errors"
 	"net"
 	"sync"
@@ -16,6 +15,7 @@ import (
 	"github.com/go-gost/x/internal/net/proxyproto"
 	"github.com/go-gost/x/internal/util/mux"
 	"github.com/go-gost/x/registry"
+	"github.com/go-gost/x/util"
 )
 
 func init() {
@@ -141,7 +141,7 @@ func (d *mtlsDialer) Handshake(ctx context.Context, conn net.Conn, options ...di
 }
 
 func (d *mtlsDialer) initSession(ctx context.Context, conn net.Conn) (*muxSession, error) {
-	tlsConn := tls.Client(conn, d.options.TLSConfig)
+	tlsConn := util.NewUTLSChromeClient(conn, d.options.TLSConfig)
 	if err := tlsConn.HandshakeContext(ctx); err != nil {
 		return nil, err
 	}

dialer/mws/dialer.go

@@ -17,6 +17,7 @@ import (
 	"github.com/go-gost/x/internal/util/mux"
 	ws_util "github.com/go-gost/x/internal/util/ws"
 	"github.com/go-gost/x/registry"
+	"github.com/go-gost/x/util"
 	"github.com/gorilla/websocket"
 )
 
@@ -172,17 +173,30 @@ func (d *mwsDialer) initSession(ctx context.Context, host string, conn net.Conn,
 		},
 	}
 
-	url := url.URL{Scheme: "ws", Host: host, Path: d.md.path}
+	urlObj := url.URL{Scheme: "ws", Host: host, Path: d.md.path}
 	if d.tlsEnabled {
-		url.Scheme = "wss"
+		urlObj.Scheme = "wss"
 		dialer.TLSClientConfig = d.options.TLSConfig
+		dialer.NetDialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+			client, err := util.NewUTLSWebSocketClient(conn, d.options.TLSConfig, d.md.useH2)
+			if err != nil {
+				return nil, err
+			}
+			if err := client.Handshake(); err != nil {
+				return nil, err
+			}
+			return client, nil
+		}
 	}
 
 	if d.md.handshakeTimeout > 0 {
 		conn.SetReadDeadline(time.Now().Add(d.md.handshakeTimeout))
 	}
-
+	urlStr, errUnescape := url.QueryUnescape(urlObj.String())
-	c, resp, err := dialer.DialContext(ctx, url.String(), d.md.header)
+	if errUnescape != nil {
+		d.options.Logger.Debugf("[mws] URL QueryUnescape Error URL.String() -> %s", urlObj.String())
+	}
+	c, resp, err := dialer.DialContext(ctx, urlStr, d.md.header)
 	if err != nil {
 		return nil, err
 	}

dialer/mws/metadata.go

@@ -5,8 +5,8 @@ import (
 	"time"
 
 	mdata "github.com/go-gost/core/metadata"
-	mdutil "github.com/go-gost/x/metadata/util"
 	"github.com/go-gost/x/internal/util/mux"
+	mdutil "github.com/go-gost/x/metadata/util"
 )
 
 const (
@@ -18,6 +18,8 @@ type metadata struct {
 	host string
 	path string
 
+	useH2 bool
+
 	handshakeTimeout  time.Duration
 	readHeaderTimeout time.Duration
 	readBufferSize    int
@@ -77,5 +79,7 @@ func (d *mwsDialer) parseMetadata(md mdata.Metadata) (err error) {
 	d.md.tcpKeepaliveInterval = mdutil.GetDuration(md, "tcp.keepalive.interval")
 	d.md.tcpKeepaliveCount = mdutil.GetInt(md, "tcp.keepalive.count")
 
+	d.md.useH2 = mdutil.GetBool(md, "h2")
+
 	return
 }

dialer/tls/dialer.go

@@ -2,7 +2,6 @@ package tls
 
 import (
 	"context"
-	"crypto/tls"
 	"net"
 	"time"
 
@@ -13,6 +12,7 @@ import (
 	xnet "github.com/go-gost/x/internal/net"
 	"github.com/go-gost/x/internal/net/proxyproto"
 	"github.com/go-gost/x/registry"
+	"github.com/go-gost/x/util"
 )
 
 func init() {
@@ -77,7 +77,7 @@ func (d *tlsDialer) Handshake(ctx context.Context, conn net.Conn, options ...dia
 		defer conn.SetDeadline(time.Time{})
 	}
 
-	tlsConn := tls.Client(conn, d.options.TLSConfig)
+	tlsConn := util.NewUTLSChromeClient(conn, d.options.TLSConfig)
 	if err := tlsConn.HandshakeContext(ctx); err != nil {
 		conn.Close()
 		return nil, err

dialer/utls/dialer.go

@@ -5,7 +5,6 @@ import (
 	"crypto/tls"
 	"net"
 	"time"
-	"unsafe"
 
 	"github.com/go-gost/core/dialer"
 	"github.com/go-gost/core/logger"
@@ -14,6 +13,7 @@ import (
 	xnet "github.com/go-gost/x/internal/net"
 	"github.com/go-gost/x/internal/net/proxyproto"
 	"github.com/go-gost/x/registry"
+	"github.com/go-gost/x/util"
 	utls "github.com/refraction-networking/utls"
 )
 
@@ -82,7 +82,7 @@ func (d *utlsDialer) Handshake(ctx context.Context, conn net.Conn, options ...di
 	clientHelloID, ok := GetClientHelloID(d.md.fingerprint)
 	if ok {
 		d.log.Debugf("utls handshake with fingerprint: %s", d.md.fingerprint)
-		utlsCfg := (*utls.Config)(unsafe.Pointer(d.options.TLSConfig))
+		utlsCfg := util.NewUTLSConfig(d.options.TLSConfig)
 		uconn := utls.UClient(conn, utlsCfg, clientHelloID)
 		if err := uconn.HandshakeContext(ctx); err != nil {
 			conn.Close()

dialer/ws/dialer.go

@@ -13,6 +13,7 @@ import (
 	"github.com/go-gost/x/internal/net/proxyproto"
 	ws_util "github.com/go-gost/x/internal/util/ws"
 	"github.com/go-gost/x/registry"
+	"github.com/go-gost/x/util"
 	"github.com/gorilla/websocket"
 )
 
@@ -110,13 +111,26 @@ func (d *wsDialer) Handshake(ctx context.Context, conn net.Conn, options ...dial
 		},
 	}
 
-	url := url.URL{Scheme: "ws", Host: host, Path: d.md.path}
+	urlObj := url.URL{Scheme: "ws", Host: host, Path: d.md.path}
 	if d.tlsEnabled {
-		url.Scheme = "wss"
+		urlObj.Scheme = "wss"
 		dialer.TLSClientConfig = d.options.TLSConfig
+		dialer.NetDialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+			client, err := util.NewUTLSWebSocketClient(conn, d.options.TLSConfig, d.md.useH2)
+			if err != nil {
+				return nil, err
+			}
+			if err := client.Handshake(); err != nil {
+				return nil, err
+			}
+			return client, nil
+		}
 	}
-
+	urlStr, errUnescape := url.QueryUnescape(urlObj.String())
-	c, resp, err := dialer.DialContext(ctx, url.String(), d.md.header)
+	if errUnescape != nil {
+		d.options.Logger.Debugf("[ws] URL QueryUnescape Error URL.String() -> %s", urlObj.String())
+	}
+	c, resp, err := dialer.DialContext(ctx, urlStr, d.md.header)
 	if err != nil {
 		return nil, err
 	}

dialer/ws/metadata.go

@@ -14,8 +14,9 @@ const (
 )
 
 type metadata struct {
-	host string
+	host  string
-	path string
+	path  string
+	useH2 bool
 
 	handshakeTimeout  time.Duration
 	readHeaderTimeout time.Duration
@@ -66,5 +67,6 @@ func (d *wsDialer) parseMetadata(md mdata.Metadata) (err error) {
 	d.md.tcpKeepaliveInterval = mdutil.GetDuration(md, "tcp.keepalive.interval")
 	d.md.tcpKeepaliveCount = mdutil.GetInt(md, "tcp.keepalive.count")
 
+	d.md.useH2 = mdutil.GetBool(md, "h2")
 	return
 }

go.mod

@@ -7,11 +7,11 @@ require (
 	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d
 	github.com/gin-contrib/cors v1.7.2
 	github.com/gin-gonic/gin v1.10.1
-	github.com/go-gost/core v0.4.3
+	github.com/go-gost/core v0.5.1
 	github.com/go-gost/go-shadowsocks2 v0.1.3
 	github.com/go-gost/gosocks4 v0.1.0
 	github.com/go-gost/gosocks5 v0.5.0
-	github.com/go-gost/plugin v0.3.0
+	github.com/go-gost/plugin v0.4.0
 	github.com/go-gost/relay v0.6.1
 	github.com/go-gost/tls-dissector v0.2.0
 	github.com/go-redis/redis/v8 v8.11.5

go.sum

@@ -51,16 +51,18 @@ github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE
 github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
 github.com/gin-gonic/gin v1.10.1 h1:T0ujvqyCSqRopADpgPgiTT63DUQVSfojyME59Ei63pQ=
 github.com/gin-gonic/gin v1.10.1/go.mod h1:4PMNQiOhvDRa013RKVbsiNwoyezlm2rm0uX/T7kzp5Y=
-github.com/go-gost/core v0.4.3 h1:9VEHRzuSq/MVdDZYrp/TtVG0+0r6NVGUQDXsJozrvJs=
+github.com/go-gost/core v0.5.0 h1:3SkPojjqw2Av9l5OSyRVlBpRvWhaXgU5BWMXB9aR4SM=
-github.com/go-gost/core v0.4.3/go.mod h1:WGI43jOka7FAsSAwi/fSMaqxdR+E339ycb4NBGlFr6A=
+github.com/go-gost/core v0.5.0/go.mod h1:WGI43jOka7FAsSAwi/fSMaqxdR+E339ycb4NBGlFr6A=
+github.com/go-gost/core v0.5.1 h1:HbIn3naEOC661Z4SwzaSYUzffWSRbU0P6gkxiHmuG0I=
+github.com/go-gost/core v0.5.1/go.mod h1:WGI43jOka7FAsSAwi/fSMaqxdR+E339ycb4NBGlFr6A=
 github.com/go-gost/go-shadowsocks2 v0.1.3 h1:6CUZLp+mTWXnKP2aK8/Z9ZP+ERMX9gSbywmPu4kGX/A=
 github.com/go-gost/go-shadowsocks2 v0.1.3/go.mod h1:866zFNNI3He6Wef1M/IvAjTal74WhcfKfBgRpTlkKys=
 github.com/go-gost/gosocks4 v0.1.0 h1:eAzev6qw4fzkFQKC9uCHLVNnnPdHyqCggbnfNN80Pmk=
 github.com/go-gost/gosocks4 v0.1.0/go.mod h1:hzVjwijJuZR1pp3GqpTj+AKcSGrx68RlWTrQMFMYBP0=
 github.com/go-gost/gosocks5 v0.5.0 h1:YE37l1MJwde8diIQdynStqogMotG5enoTdborhA5yic=
 github.com/go-gost/gosocks5 v0.5.0/go.mod h1:1G6I7HP7VFVxveGkoK8mnprnJqSqJjdcASKsdUn4Pp4=
-github.com/go-gost/plugin v0.3.0 h1:pmll8nNd9PX92BWMB5+b2y2SEkBAWJLxD2ANfX+WHuw=
+github.com/go-gost/plugin v0.4.0 h1:M7MR5PL7QAFCrdWfcXVX+5iLNTVIZlhl8FfdV/K8dZY=
-github.com/go-gost/plugin v0.3.0/go.mod h1:oN23l+yGDCIP9G3KnDl/I/0zVGOobZUDCB2Z5yYYXts=
+github.com/go-gost/plugin v0.4.0/go.mod h1:oN23l+yGDCIP9G3KnDl/I/0zVGOobZUDCB2Z5yYYXts=
 github.com/go-gost/relay v0.6.1 h1:7SqnHFbY8x/DzvjpK03a5zcVH9+TbJAcnW/RT6s1ecc=
 github.com/go-gost/relay v0.6.1/go.mod h1:Dku0f5sfjOClrZFiDmQUrYYJ4uof7rnkCUBfsl0PSAI=
 github.com/go-gost/tls-dissector v0.2.0 h1:9tE6WOzzpurATTBWn60DU4R8gibpGNY8/qVcc1SicVg=

handler/socks/v5/udp.go

@@ -93,6 +93,21 @@ func (h *socks5Handler) handleUDP(ctx context.Context, conn net.Conn, network st
 		return err
 	}
 
+	// A direct (no-chain) UDP association yields a raw *net.UDPConn, which
+	// cannot consume the domainAddr returned by udpConn.ReadFrom for
+	// ATYP=DOMAINNAME datagrams. Wrap it so domains are resolved through the
+	// configured resolver (hostMapper → resolver → system DNS) instead of the
+	// previous hardcoded net.ResolveUDPAddr in the SOCKS5 decode path.
+	// Chain-backed PacketConns (udpTunConn, udpRelayConn, ...) encode domains
+	// as ATYP=Domain themselves and are left untouched.
+	if _, isDirect := pc.(*net.UDPConn); isDirect {
+		pc = &resolvePacketConn{
+			PacketConn:  pc,
+			resolver:    h.options.Router.Options().Resolver,
+			hostMapper:  h.options.Router.Options().HostMapper,
+		}
+	}
+
 	saddr := gosocks5.Addr{}
 	saddr.ParseFrom(cc.LocalAddr().String())
 
@@ -203,6 +218,55 @@ func (f *filteredPacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error
 	}
 }
 
+// resolvePacketConn wraps the upstream net.PacketConn for a direct (no-chain)
+// UDP association and resolves domain addresses to IPs in WriteTo calls.
+//
+// udpConn.ReadFrom now returns a domainAddr for ATYP=DOMAINNAME datagrams so
+// the domain survives to the chain; a raw *net.UDPConn cannot consume a
+// domainAddr (WriteTo needs *net.UDPAddr), so direct connections are wrapped
+// here. Resolution order is hostMapper → configured resolver → system DNS, so a
+// configured resolver (e.g. resolver=1.1.1.1) is honored instead of leaking
+// through the system resolver.
+type resolvePacketConn struct {
+	net.PacketConn
+	resolver   resolver.Resolver
+	hostMapper hosts.HostMapper
+}
+
+func (c *resolvePacketConn) WriteTo(b []byte, addr net.Addr) (int, error) {
+	host, portStr, err := net.SplitHostPort(addr.String())
+	if err != nil {
+		return c.PacketConn.WriteTo(b, addr)
+	}
+	if net.ParseIP(host) != nil {
+		return c.PacketConn.WriteTo(b, addr)
+	}
+
+	var ips []net.IP
+	if c.hostMapper != nil {
+		ips, _ = c.hostMapper.Lookup(context.Background(), "ip", host)
+	}
+	if len(ips) == 0 && c.resolver != nil {
+		ips, _ = c.resolver.Resolve(context.Background(), "ip", host)
+	}
+	if len(ips) == 0 {
+		ips, _ = net.LookupIP(host)
+	}
+	if len(ips) == 0 {
+		return 0, fmt.Errorf("socks5 udp: cannot resolve %s", host)
+	}
+
+	ip := ips[0]
+	for _, candidate := range ips {
+		if candidate.To4() != nil {
+			ip = candidate
+			break
+		}
+	}
+	port, _ := strconv.Atoi(portStr)
+	return c.PacketConn.WriteTo(b, &net.UDPAddr{IP: ip, Port: port})
+}
+
 // domainResolvePacketConn wraps a net.PacketConn and resolves domain
 // addresses to IPs in WriteTo calls. This guarantees that SOCKS5 UDP
 // response datagrams never carry ATYP=Domain (0x03), which some clients

hop/hop.go

@@ -208,13 +208,17 @@ func (p *chainHop) Select(ctx context.Context, opts ...hop.SelectOption) *chain.
 	})
 
 	if nodes[0].Options().Priority > 0 &&
-		!anyBackupNode(nodes) {
+		!anyBackupNode(nodes) &&
+		nodes[0].Options().Priority > nodes[1].Options().Priority {
 		// Priority short-circuit: highest-priority non-backup node wins.
 		// Conditions: (1) top priority > 0 means a matcher indicated routing
 		// specificity, so the top node is authoritative for this request;
 		// (2) no backup node is present, otherwise BackupFilter would be
-		// silently bypassed. When both hold the selector (FailFilter,
+		// silently bypassed; (3) the top priority is strictly higher than
-		// BackupFilter, strategy) is skipped and the best node wins directly.
+		// the second-highest — when multiple nodes share the same matcher
+		// rule they have equal priority and the selector (FailFilter,
+		// BackupFilter, strategy) should still apply for load balancing.
+		// When all three hold the selector is skipped and the best node wins directly.
 		p.logger.Debugf("priority shortcut: node %s selected", nodes[0].Name)
 		return nodes[0]
 	}

hop/hop_test.go

@@ -522,6 +522,31 @@ func TestSelect_WithSelector(t *testing.T) {
 	}
 }
 
+func TestSelect_EqualPriorityDoesNotShortcut(t *testing.T) {
+	// Two nodes with identical matchers get the same default priority.
+	// The priority shortcut must NOT trigger when multiple nodes share
+	// the highest priority — the selector should still apply.
+	n1 := chain.NewNode("n1", "127.0.0.1:8080",
+		chain.MatcherNodeOption(&testMatcher{match: true}),
+		chain.PriorityNodeOption(50),
+	)
+	n2 := chain.NewNode("n2", "127.0.0.1:9090",
+		chain.MatcherNodeOption(&testMatcher{match: true}),
+		chain.PriorityNodeOption(50),
+	)
+	sel := &testNodeSelector{selectedIdx: 1} // picks n2
+	h := newTestHop(NodeOption(n1, n2), SelectorOption(sel))
+	defer h.Close()
+
+	node := h.Select(context.Background())
+	if node == nil {
+		t.Fatal("expected node, got nil")
+	}
+	if node.Name != "n2" {
+		t.Errorf("expected 'n2' (selected by selector, not shortcut), got %q", node.Name)
+	}
+}
+
 func TestSelect_NilNodesSkipped(t *testing.T) {
 	h := newTestHop()
 	defer h.Close()

internal/net/dialer/dialer.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"runtime"
 	"strings"
 	"syscall"
 	"time"
@@ -145,8 +146,12 @@ func (d *Dialer) dialOnce(ctx context.Context, network, addr, ifceName string, i
 	default:
 		return nil, fmt.Errorf("dial: unsupported network %s", network)
 	}
+	var resolver *net.Resolver
+	if runtime.GOOS != "android" {
+		resolver = &net.Resolver{PreferGo: true}
+	}
 	netd := net.Dialer{
-		Resolver:  &net.Resolver{PreferGo: true},
+		Resolver:  resolver,
 		LocalAddr: ifAddr,
 		Control: func(network, address string, c syscall.RawConn) error {
 			return c.Control(func(fd uintptr) {

internal/util/forwarder/sniffer_http.go

@@ -356,6 +356,7 @@ func (h *Sniffer) httpRoundTrip(ctx context.Context, rw, cc io.ReadWriteCloser,
 			if re.Pattern.MatchString(req.URL.Path) {
 				if s := re.Pattern.ReplaceAllString(req.URL.Path, re.Replacement); s != "" {
 					req.URL.Path = s
+					ro.HTTP.URI = req.URL.RequestURI()
 					break
 				}
 			}
@@ -368,7 +369,7 @@ func (h *Sniffer) httpRoundTrip(ctx context.Context, rw, cc io.ReadWriteCloser,
 
 	// Rewrite request body before wrapping for recording,
 	// so the recorder sees the rewritten content.
-	if err = rewriteReqBody(req, reqBodyRewrites...); err != nil {
+	if err = rewriteReqBody(ctx, req, reqBodyRewrites...); err != nil {
 		log.Errorf("rewrite request body: %v", err)
 		return
 	}
@@ -445,7 +446,7 @@ func (h *Sniffer) httpRoundTrip(ctx context.Context, rw, cc io.ReadWriteCloser,
 		resp.Header.Set("Connection", "close")
 	}
 
-	if err = rewriteRespBody(resp, respBodyRewrites...); err != nil {
+	if err = rewriteRespBody(ctx, resp, respBodyRewrites...); err != nil {
 		log.Errorf("rewrite body: %v", err)
 		return
 	}

internal/util/forwarder/sniffer_rewrite.go

@@ -41,7 +41,7 @@ func (h *Sniffer) handleUpgradeResponse(ctx context.Context, rw, cc io.ReadWrite
 	return xnet.Pipe(ctx, rw, cc)
 }
 
-func rewriteRespBody(resp *http.Response, rewrites ...chain.HTTPBodyRewriteSettings) error {
+func rewriteRespBody(ctx context.Context, resp *http.Response, rewrites ...chain.HTTPBodyRewriteSettings) error {
 	if resp == nil || len(rewrites) == 0 || resp.ContentLength <= 0 {
 		return nil
 	}
@@ -65,7 +65,14 @@ func rewriteRespBody(resp *http.Response, rewrites ...chain.HTTPBodyRewriteSetti
 			continue
 		}
 
-		if rewrite.Pattern != nil {
+			if rewrite.Rewriter != nil {
+				if rewrite.Pattern == nil || rewrite.Pattern.Match(body) {
+					body, err = rewrite.Rewriter.Rewrite(ctx, body)
+					if err != nil {
+						return err
+					}
+				}
+			} else if rewrite.Pattern != nil {
 			body = rewrite.Pattern.ReplaceAll(body, rewrite.Replacement)
 		}
 	}
@@ -90,7 +97,7 @@ func drainBody(b io.ReadCloser) (body []byte, err error) {
 	return buf.Bytes(), nil
 }
 
-func rewriteReqBody(req *http.Request, rewrites ...chain.HTTPBodyRewriteSettings) error {
+func rewriteReqBody(ctx context.Context, req *http.Request, rewrites ...chain.HTTPBodyRewriteSettings) error {
 	if req == nil || len(rewrites) == 0 || req.Body == nil || req.ContentLength <= 0 {
 		return nil
 	}
@@ -114,7 +121,14 @@ func rewriteReqBody(req *http.Request, rewrites ...chain.HTTPBodyRewriteSettings
 			continue
 		}
 
-		if rewrite.Pattern != nil {
+			if rewrite.Rewriter != nil {
+				if rewrite.Pattern == nil || rewrite.Pattern.Match(body) {
+					body, err = rewrite.Rewriter.Rewrite(ctx, body)
+					if err != nil {
+						return err
+					}
+				}
+			} else if rewrite.Pattern != nil {
 			body = rewrite.Pattern.ReplaceAll(body, rewrite.Replacement)
 		}
 	}

internal/util/forwarder/sniffer_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/go-gost/core/chain"
 	"github.com/go-gost/core/hop"
 	"github.com/go-gost/core/recorder"
+	"github.com/go-gost/core/rewriter"
 	xlogger "github.com/go-gost/x/logger"
 	xrecorder "github.com/go-gost/x/recorder"
 )
@@ -164,7 +165,7 @@ func TestRewriteReqBody(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			if tt.req != nil {
-				_ = rewriteReqBody(tt.req, tt.rewrites...)
+				_ = rewriteReqBody(context.Background(), tt.req, tt.rewrites...)
 				if tt.req.Body != nil {
 					body, _ := io.ReadAll(tt.req.Body)
 					tt.req.Body.Close()
@@ -178,7 +179,7 @@ func TestRewriteReqBody(t *testing.T) {
 					t.Errorf("ContentLength = %d, want %d", tt.req.ContentLength, tt.wantCL)
 				}
 			} else {
-				_ = rewriteReqBody(nil) // should not panic
+				_ = rewriteReqBody(context.Background(), nil) // should not panic
 			}
 		})
 	}
@@ -344,8 +345,8 @@ func TestDrainBody(t *testing.T) {
 
 func TestRewriteRespBody(t *testing.T) {
 	t.Run("nil response", func(t *testing.T) {
-		if err := rewriteRespBody(nil); err != nil {
+		if err := rewriteRespBody(context.Background(), nil); err != nil {
-			t.Errorf("rewriteRespBody(nil) = %v, want nil", err)
+			t.Errorf("rewriteRespBody(context.Background(), nil) = %v, want nil", err)
 		}
 	})
 
@@ -354,7 +355,7 @@ func TestRewriteRespBody(t *testing.T) {
 			ContentLength: 100,
 			Body:          io.NopCloser(strings.NewReader("original")),
 		}
-		_ = rewriteRespBody(resp)
+		_ = rewriteRespBody(context.Background(), resp)
 		// Body unchanged
 		got, _ := io.ReadAll(resp.Body)
 		if string(got) != "original" {
@@ -367,7 +368,7 @@ func TestRewriteRespBody(t *testing.T) {
 			ContentLength: 0,
 			Body:          io.NopCloser(strings.NewReader("original")),
 		}
-		_ = rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+		_ = rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 			Pattern:     regexp.MustCompile("."),
 			Type:        "*",
 			Replacement: []byte("replaced"),
@@ -385,7 +386,7 @@ func TestRewriteRespBody(t *testing.T) {
 			ContentLength: 100,
 			Body:          io.NopCloser(strings.NewReader("original")),
 		}
-		_ = rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+		_ = rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 			Type:        "*",
 			Replacement: []byte("replaced"),
 		})
@@ -413,7 +414,7 @@ func TestRewriteRespBodyContentTypeFilter(t *testing.T) {
 			ContentLength: 100,
 			Body:          io.NopCloser(strings.NewReader("original")),
 		}
-		_ = rewriteRespBody(resp, makeRewrite("text/html", "replaced"))
+		_ = rewriteRespBody(context.Background(), resp, makeRewrite("text/html", "replaced"))
 		got, _ := io.ReadAll(resp.Body)
 		if string(got) != "replaced" {
 			t.Errorf("body = %q, want %q", string(got), "replaced")
@@ -426,7 +427,7 @@ func TestRewriteRespBodyContentTypeFilter(t *testing.T) {
 			ContentLength: 100,
 			Body:          io.NopCloser(strings.NewReader("hello")),
 		}
-		_ = rewriteRespBody(resp, makeRewrite("*", "world"))
+		_ = rewriteRespBody(context.Background(), resp, makeRewrite("*", "world"))
 		got, _ := io.ReadAll(resp.Body)
 		if string(got) != "world" {
 			t.Errorf("body = %q, want %q", string(got), "world")
@@ -439,7 +440,7 @@ func TestRewriteRespBodyContentTypeFilter(t *testing.T) {
 			ContentLength: 100,
 			Body:          io.NopCloser(strings.NewReader("original")),
 		}
-		_ = rewriteRespBody(resp, makeRewrite("text/html", "replaced"))
+		_ = rewriteRespBody(context.Background(), resp, makeRewrite("text/html", "replaced"))
 		got, _ := io.ReadAll(resp.Body)
 		if string(got) != "original" {
 			t.Errorf("body = %q, want %q (unchanged)", string(got), "original")
@@ -454,7 +455,7 @@ func TestRewriteRespBodyContentTypeFilter(t *testing.T) {
 		}
 		// Empty type defaults to "text/html", and response has no Content-Type -> "" containing "text/html"? No.
 		// strings.Contains("text/html", "") is always true, so rewrite should happen.
-		_ = rewriteRespBody(resp, makeRewrite("", "replaced"))
+		_ = rewriteRespBody(context.Background(), resp, makeRewrite("", "replaced"))
 		got, _ := io.ReadAll(resp.Body)
 		if string(got) != "replaced" {
 			t.Errorf("body = %q, want %q (should be rewritten)", string(got), "replaced")
@@ -1146,7 +1147,7 @@ func TestRewriteRespBody_PatternReplacement(t *testing.T) {
 		ContentLength: 100,
 		Body:          io.NopCloser(strings.NewReader("<title>Old Title</title>")),
 	}
-	err := rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 		Pattern:     regexp.MustCompile("Old"),
 		Type:        "text/html",
 		Replacement: []byte("New"),
@@ -1169,7 +1170,7 @@ func TestRewriteRespBody_MultipleRewrites(t *testing.T) {
 		ContentLength: 100,
 		Body:          io.NopCloser(strings.NewReader("hello")),
 	}
-	err := rewriteRespBody(resp,
+	err := rewriteRespBody(context.Background(), resp,
 		chain.HTTPBodyRewriteSettings{
 			Pattern:     regexp.MustCompile("h.*o"),
 			Type:        "text/html",
@@ -1196,7 +1197,7 @@ func TestRewriteRespBody_NilPattern(t *testing.T) {
 		ContentLength: 100,
 		Body:          io.NopCloser(strings.NewReader("original")),
 	}
-	err := rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 		Pattern:     nil,
 		Type:        "*",
 		Replacement: []byte("replaced"),
@@ -1215,7 +1216,7 @@ func TestRewriteRespBody_EmptyContentTypeUsesDefault(t *testing.T) {
 		ContentLength: 100,
 		Body:          io.NopCloser(strings.NewReader("original")),
 	}
-	err := rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 		Pattern:     regexp.MustCompile(".*"),
 		Type:        "",
 		Replacement: []byte("rewritten"),
@@ -1235,7 +1236,7 @@ func TestRewriteRespBody_NegativeContentLength(t *testing.T) {
 		ContentLength: -1,
 		Body:          io.NopCloser(strings.NewReader("original")),
 	}
-	err := rewriteRespBody(resp, chain.HTTPBodyRewriteSettings{
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
 		Pattern:     regexp.MustCompile(".*"),
 		Type:        "*",
 		Replacement: []byte("replaced"),
@@ -1250,9 +1251,209 @@ func TestRewriteRespBody_NegativeContentLength(t *testing.T) {
 }
 
 // =============================================================================
-// copyWebsocketFrame Additional Tests
+// Rewriter Plugin Tests
 // =============================================================================
 
+// mockRewriter is a simple rewriter.Rewriter for testing.
+type mockRewriter struct {
+	cb     func(b []byte) []byte
+	called bool
+}
+
+func (m *mockRewriter) Rewrite(_ context.Context, b []byte, _ ...rewriter.RewriteOption) ([]byte, error) {
+	m.called = true
+	if m.cb != nil {
+		return m.cb(b), nil
+	}
+	return b, nil
+}
+
+func TestRewriteRespBody_RewriterNilPattern(t *testing.T) {
+	rw := &mockRewriter{}
+	resp := &http.Response{
+		Header:        http.Header{"Content-Type": {"text/html"}},
+		ContentLength: 100,
+		Body:          io.NopCloser(strings.NewReader("hello")),
+	}
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
+		Type:     "*",
+		Rewriter: rw,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !rw.called {
+		t.Error("rewriter was not called")
+	}
+}
+
+func TestRewriteRespBody_RewriterMatchPass(t *testing.T) {
+	rw := &mockRewriter{
+		cb: func(b []byte) []byte {
+			return []byte("rewritten")
+		},
+	}
+	resp := &http.Response{
+		Header:        http.Header{"Content-Type": {"text/html"}},
+		ContentLength: 100,
+		Body:          io.NopCloser(strings.NewReader("hello world")),
+	}
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
+		Type:     "*",
+		Pattern:  regexp.MustCompile("hello"),
+		Rewriter: rw,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !rw.called {
+		t.Fatal("rewriter was not called")
+	}
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != "rewritten" {
+		t.Errorf("body = %q, want %q", string(body), "rewritten")
+	}
+	if resp.ContentLength != int64(len("rewritten")) {
+		t.Errorf("ContentLength = %d, want %d", resp.ContentLength, len("rewritten"))
+	}
+}
+
+func TestRewriteRespBody_RewriterMatchSkip(t *testing.T) {
+	rw := &mockRewriter{}
+	resp := &http.Response{
+		Header:        http.Header{"Content-Type": {"text/html"}},
+		ContentLength: 100,
+		Body:          io.NopCloser(strings.NewReader("hello world")),
+	}
+	err := rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
+		Type:     "*",
+		Pattern:  regexp.MustCompile("xyz"),
+		Rewriter: rw,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rw.called {
+		t.Fatal("rewriter should not have been called: body did not match pattern")
+	}
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != "hello world" {
+		t.Errorf("body = %q, want %q (unchanged)", string(body), "hello world")
+	}
+}
+
+func TestRewriteRespBody_RewriterContentTypeFilter(t *testing.T) {
+	rw := &mockRewriter{
+		cb: func(b []byte) []byte { return []byte("rewritten") },
+	}
+
+	t.Run("type matches calls rewriter", func(t *testing.T) {
+		rw.called = false
+		resp := &http.Response{
+			Header:        http.Header{"Content-Type": {"application/json"}},
+			ContentLength: 100,
+			Body:          io.NopCloser(strings.NewReader(`{"key":"value"}`)),
+		}
+		_ = rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
+			Type:     "application/json",
+			Rewriter: rw,
+		})
+		if !rw.called {
+			t.Error("rewriter should have been called")
+		}
+	})
+
+	t.Run("type mismatch skips rewriter", func(t *testing.T) {
+		rw.called = false
+		resp := &http.Response{
+			Header:        http.Header{"Content-Type": {"text/plain"}},
+			ContentLength: 100,
+			Body:          io.NopCloser(strings.NewReader("hello")),
+		}
+		_ = rewriteRespBody(context.Background(), resp, chain.HTTPBodyRewriteSettings{
+			Type:     "application/json",
+			Rewriter: rw,
+		})
+		if rw.called {
+			t.Error("rewriter should not have been called: content type mismatch")
+		}
+		body, _ := io.ReadAll(resp.Body)
+		if string(body) != "hello" {
+			t.Errorf("body = %q, want %q (unchanged)", string(body), "hello")
+		}
+	})
+}
+
+func TestRewriteReqBody_Rewriter(t *testing.T) {
+	rw := &mockRewriter{
+		cb: func(b []byte) []byte {
+			return []byte("rewritten")
+		},
+	}
+
+	t.Run("nil pattern calls rewriter", func(t *testing.T) {
+		rw.called = false
+		req := &http.Request{
+			Body:          io.NopCloser(strings.NewReader("hello")),
+			ContentLength: 5,
+			Header:        http.Header{"Content-Type": {"text/plain"}},
+		}
+		_ = rewriteReqBody(context.Background(), req, chain.HTTPBodyRewriteSettings{
+			Type:     "*",
+			Rewriter: rw,
+		})
+		if !rw.called {
+			t.Fatal("rewriter was not called")
+		}
+		body, _ := io.ReadAll(req.Body)
+		if string(body) != "rewritten" {
+			t.Errorf("body = %q, want %q", string(body), "rewritten")
+		}
+	})
+
+	t.Run("match passes through to rewriter", func(t *testing.T) {
+		rw.called = false
+		req := &http.Request{
+			Body:          io.NopCloser(strings.NewReader("hello world")),
+			ContentLength: 11,
+			Header:        http.Header{"Content-Type": {"text/html"}},
+		}
+		_ = rewriteReqBody(context.Background(), req, chain.HTTPBodyRewriteSettings{
+			Type:     "text/html",
+			Pattern:  regexp.MustCompile("hello"),
+			Rewriter: rw,
+		})
+		if !rw.called {
+			t.Fatal("rewriter was not called")
+		}
+		body, _ := io.ReadAll(req.Body)
+		if string(body) != "rewritten" {
+			t.Errorf("body = %q, want %q", string(body), "rewritten")
+		}
+	})
+
+	t.Run("non-match skips rewriter", func(t *testing.T) {
+		rw.called = false
+		req := &http.Request{
+			Body:          io.NopCloser(strings.NewReader("hello world")),
+			ContentLength: 11,
+			Header:        http.Header{"Content-Type": {"text/html"}},
+		}
+		_ = rewriteReqBody(context.Background(), req, chain.HTTPBodyRewriteSettings{
+			Type:     "text/html",
+			Pattern:  regexp.MustCompile("xyz"),
+			Rewriter: rw,
+		})
+		if rw.called {
+			t.Fatal("rewriter should not have been called: body did not match pattern")
+		}
+		body, _ := io.ReadAll(req.Body)
+		if string(body) != "hello world" {
+			t.Errorf("body = %q, want %q (unchanged)", string(body), "hello world")
+		}
+	})
+}
+
 func TestCopyWebsocketFrame_EmptyPayload(t *testing.T) {
 	h := &Sniffer{
 		Recorder:        &noopRecorder{},

internal/util/socks/conn.go

@@ -3,6 +3,7 @@ package socks
 import (
 	"bytes"
 	"net"
+	"strconv"
 
 	"github.com/go-gost/core/common/bufpool"
 	"github.com/go-gost/gosocks5"
@@ -106,6 +107,20 @@ func UDPConn(c net.PacketConn, bufferSize int) net.PacketConn {
 	}
 }
 
+// domainAddr is a net.Addr that preserves a domain name without resolving it.
+// Returned by udpConn.ReadFrom when a SOCKS5 UDP datagram carries
+// ATYP=DOMAINNAME, so that downstream consumers (e.g. relay-chain WriteTo) can
+// forward the domain verbatim instead of forcing a local DNS lookup that would
+// leak the query through the system resolver and bypass any configured resolver.
+type domainAddr struct {
+	network string
+	host    string
+	port    int
+}
+
+func (a *domainAddr) Network() string { return a.network }
+func (a *domainAddr) String() string  { return net.JoinHostPort(a.host, strconv.Itoa(a.port)) }
+
 // ReadFrom reads an UDP datagram.
 // NOTE: for server side,
 // the returned addr is the target address the client want to relay to.
@@ -128,7 +143,11 @@ func (c *udpConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
 	}
 	n = copy(b, buf[hlen:n])
 
-	addr, err = net.ResolveUDPAddr("udp", socksAddr.String())
+	if net.ParseIP(socksAddr.Host) != nil {
+		addr, err = net.ResolveUDPAddr("udp", socksAddr.String())
+	} else {
+		addr = &domainAddr{network: "udp", host: socksAddr.Host, port: int(socksAddr.Port)}
+	}
 	return
 }
 

registry/registry.go

@@ -21,6 +21,7 @@ import (
 	reg "github.com/go-gost/core/registry"
 	"github.com/go-gost/core/resolver"
 	"github.com/go-gost/core/router"
+	"github.com/go-gost/core/rewriter"
 	"github.com/go-gost/core/sd"
 	"github.com/go-gost/core/service"
 	"github.com/go-gost/x/limiter/quota"
@@ -46,6 +47,7 @@ var (
 	resolverReg  reg.Registry[resolver.Resolver]   = new(resolverRegistry)
 	hostsReg     reg.Registry[hosts.HostMapper]    = new(hostsRegistry)
 	recorderReg  reg.Registry[recorder.Recorder]   = new(recorderRegistry)
+	rewriterReg  reg.Registry[rewriter.Rewriter]   = new(rewriterRegistry)
 
 	trafficLimiterReg reg.Registry[traffic.TrafficLimiter] = new(trafficLimiterRegistry)
 	connLimiterReg    reg.Registry[conn.ConnLimiter]       = new(connLimiterRegistry)
@@ -187,6 +189,11 @@ func RecorderRegistry() reg.Registry[recorder.Recorder] {
 	return recorderReg
 }
 
+// RewriterRegistry returns the global registry of rewriter instances.
+func RewriterRegistry() reg.Registry[rewriter.Rewriter] {
+	return rewriterReg
+}
+
 // TrafficLimiterRegistry returns the global registry of traffic limiter instances.
 func TrafficLimiterRegistry() reg.Registry[traffic.TrafficLimiter] {
 	return trafficLimiterReg

registry/rewriter.go

@@ -0,0 +1,43 @@
+package registry
+
+import (
+	"context"
+
+	"github.com/go-gost/core/rewriter"
+)
+
+// rewriterRegistry implements a hot-reload-safe registry for rewriter.Rewriter.
+type rewriterRegistry struct {
+	registry[rewriter.Rewriter]
+}
+
+// Register stores a Rewriter under the given name.
+func (r *rewriterRegistry) Register(name string, v rewriter.Rewriter) error {
+	return r.registry.Register(name, v)
+}
+
+// Get returns a wrapper that delegates to the currently registered Rewriter.
+// Returns nil if name is empty.
+func (r *rewriterRegistry) Get(name string) rewriter.Rewriter {
+	if name != "" {
+		return &rewriterWrapper{name: name, r: r}
+	}
+	return nil
+}
+
+func (r *rewriterRegistry) get(name string) rewriter.Rewriter {
+	return r.registry.Get(name)
+}
+
+type rewriterWrapper struct {
+	name string
+	r    *rewriterRegistry
+}
+
+func (w *rewriterWrapper) Rewrite(ctx context.Context, b []byte, opts ...rewriter.RewriteOption) ([]byte, error) {
+	v := w.r.get(w.name)
+	if v == nil {
+		return b, nil
+	}
+	return v.Rewrite(ctx, b, opts...)
+}

rewriter/plugin/grpc.go

@@ -0,0 +1,90 @@
+package rewriter
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/rewriter"
+	"github.com/go-gost/plugin/rewriter/proto"
+	"github.com/go-gost/x/internal/plugin"
+	"google.golang.org/grpc"
+)
+
+type grpcPlugin struct {
+	conn   grpc.ClientConnInterface
+	client proto.RewriterClient
+	log    logger.Logger
+}
+
+// NewGRPCPlugin creates a Rewriter plugin based on gRPC.
+func NewGRPCPlugin(name string, addr string, opts ...plugin.Option) rewriter.Rewriter {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	log := logger.Default().WithFields(map[string]any{
+		"kind":     "rewriter",
+		"rewriter": name,
+	})
+	conn, err := plugin.NewGRPCConn(addr, &options)
+	if err != nil {
+		log.Error(err)
+	}
+	if conn == nil {
+		return nil
+	}
+
+	p := &grpcPlugin{
+		conn: conn,
+		log:  log,
+	}
+	p.client = proto.NewRewriterClient(conn)
+	return p
+}
+
+func (p *grpcPlugin) Rewrite(ctx context.Context, b []byte, opts ...rewriter.RewriteOption) ([]byte, error) {
+	if p.client == nil {
+		return b, nil
+	}
+
+	var options rewriter.RewriteOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	md, err := json.Marshal(options.Metadata)
+	if err != nil {
+		return b, err
+	}
+
+	reply, err := p.client.Rewrite(ctx,
+		&proto.RewriteRequest{
+			Data:     b,
+			Metadata: md,
+		})
+	if err != nil {
+		p.log.Error(err)
+		return b, err
+	}
+	if reply == nil || !reply.Ok {
+		return b, nil
+	}
+	if reply.Data != nil {
+		return reply.Data, nil
+	}
+	return b, nil
+}
+
+func (p *grpcPlugin) Close() error {
+	if p.conn == nil {
+		return nil
+	}
+
+	if closer, ok := p.conn.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}

rewriter/plugin/http.go

@@ -0,0 +1,106 @@
+package rewriter
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/rewriter"
+	"github.com/go-gost/x/internal/plugin"
+)
+
+type httpPluginRequest struct {
+	Data     []byte `json:"data"`
+	Metadata []byte `json:"metadata"`
+}
+
+type httpPluginResponse struct {
+	OK   bool   `json:"ok"`
+	Data []byte `json:"data"`
+}
+
+type httpPlugin struct {
+	url    string
+	client *http.Client
+	header http.Header
+	log    logger.Logger
+}
+
+// NewHTTPPlugin creates a Rewriter plugin based on HTTP.
+func NewHTTPPlugin(name string, url string, opts ...plugin.Option) rewriter.Rewriter {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &httpPlugin{
+		url:    url,
+		client: plugin.NewHTTPClient(&options),
+		header: options.Header,
+		log: logger.Default().WithFields(map[string]any{
+			"kind":     "rewriter",
+			"rewriter": name,
+		}),
+	}
+}
+
+func (p *httpPlugin) Rewrite(ctx context.Context, b []byte, opts ...rewriter.RewriteOption) ([]byte, error) {
+	if p.client == nil {
+		return b, nil
+	}
+
+	var options rewriter.RewriteOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	md, err := json.Marshal(options.Metadata)
+	if err != nil {
+		return b, err
+	}
+
+	rb := httpPluginRequest{
+		Data:     b,
+		Metadata: md,
+	}
+	v, err := json.Marshal(&rb)
+	if err != nil {
+		return b, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.url, bytes.NewReader(v))
+	if err != nil {
+		return b, err
+	}
+
+	if p.header != nil {
+		req.Header = p.header.Clone()
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return b, err
+	}
+	defer resp.Body.Close()
+	defer io.Copy(io.Discard, resp.Body)
+
+	if resp.StatusCode != http.StatusOK {
+		return b, nil
+	}
+
+	res := httpPluginResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return b, err
+	}
+
+	if !res.OK {
+		return b, nil
+	}
+	if res.Data != nil {
+		return res.Data, nil
+	}
+	return b, nil
+}

util/utls.go

@@ -0,0 +1,145 @@
+package util
+
+import (
+	stdtls "crypto/tls"
+	"encoding/hex"
+	"net"
+
+	tls "github.com/refraction-networking/utls"
+)
+
+func NewUTLSClient(conn net.Conn, config *stdtls.Config, clientHelloID tls.ClientHelloID) *tls.UConn {
+	return tls.UClient(conn, NewUTLSConfig(config), clientHelloID)
+}
+
+func NewUTLSChromeClient(conn net.Conn, config *stdtls.Config) *tls.UConn {
+	return NewUTLSClient(conn, config, tls.HelloChrome_Auto)
+}
+
+func NewUTLSWebSocketClient(conn net.Conn, config *stdtls.Config, useH2 bool) (*tls.UConn, error) {
+	utlsConfig := NewLegacyUTLSConfig(config)
+	if useH2 {
+		return tls.UClient(conn, utlsConfig, tls.HelloChrome_Auto), nil
+	}
+
+	client := tls.UClient(conn, utlsConfig, tls.HelloCustom)
+	spec, err := NewWebSocketClientHelloSpec()
+	if err != nil {
+		return nil, err
+	}
+	if err := client.ApplyPreset(spec); err != nil {
+		return nil, err
+	}
+	return client, nil
+}
+
+func NewLegacyUTLSConfig(config *stdtls.Config) *tls.Config {
+	if config == nil {
+		return &tls.Config{}
+	}
+
+	cfg := &tls.Config{
+		InsecureSkipVerify: config.InsecureSkipVerify,
+		ServerName:         config.ServerName,
+		ClientAuth:         tls.ClientAuthType(config.ClientAuth),
+		ClientCAs:          config.ClientCAs,
+		RootCAs:            config.RootCAs,
+	}
+
+	cfg.Certificates = make([]tls.Certificate, 0, len(config.Certificates))
+	for _, cert := range config.Certificates {
+		cfg.Certificates = append(cfg.Certificates, tls.Certificate{
+			Certificate:                 cert.Certificate,
+			PrivateKey:                  cert.PrivateKey,
+			OCSPStaple:                  cert.OCSPStaple,
+			SignedCertificateTimestamps: cert.SignedCertificateTimestamps,
+			Leaf:                        cert.Leaf,
+		})
+	}
+
+	return cfg
+}
+
+func NewUTLSConfig(config *stdtls.Config) *tls.Config {
+	if config == nil {
+		return &tls.Config{}
+	}
+
+	cfg := &tls.Config{
+		Rand:                        config.Rand,
+		Time:                        config.Time,
+		RootCAs:                     config.RootCAs,
+		NextProtos:                  append([]string(nil), config.NextProtos...),
+		ServerName:                  config.ServerName,
+		ClientAuth:                  tls.ClientAuthType(config.ClientAuth),
+		ClientCAs:                   config.ClientCAs,
+		InsecureSkipVerify:          config.InsecureSkipVerify,
+		CipherSuites:                append([]uint16(nil), config.CipherSuites...),
+		SessionTicketsDisabled:      config.SessionTicketsDisabled,
+		MinVersion:                  config.MinVersion,
+		MaxVersion:                  config.MaxVersion,
+		DynamicRecordSizingDisabled: config.DynamicRecordSizingDisabled,
+		Renegotiation:               tls.RenegotiationSupport(config.Renegotiation),
+		KeyLogWriter:                config.KeyLogWriter,
+		VerifyPeerCertificate:       config.VerifyPeerCertificate,
+	}
+
+	cfg.Certificates = make([]tls.Certificate, 0, len(config.Certificates))
+	for _, cert := range config.Certificates {
+		cfg.Certificates = append(cfg.Certificates, toUTLSCertificate(cert))
+	}
+
+	cfg.CurvePreferences = make([]tls.CurveID, 0, len(config.CurvePreferences))
+	for _, curve := range config.CurvePreferences {
+		cfg.CurvePreferences = append(cfg.CurvePreferences, tls.CurveID(curve))
+	}
+
+	if config.VerifyConnection != nil {
+		cfg.VerifyConnection = func(state tls.ConnectionState) error {
+			return config.VerifyConnection(toStdTLSConnectionState(state))
+		}
+	}
+
+	return cfg
+}
+
+func toUTLSCertificate(cert stdtls.Certificate) tls.Certificate {
+	signatureAlgorithms := make([]tls.SignatureScheme, 0, len(cert.SupportedSignatureAlgorithms))
+	for _, sig := range cert.SupportedSignatureAlgorithms {
+		signatureAlgorithms = append(signatureAlgorithms, tls.SignatureScheme(sig))
+	}
+
+	return tls.Certificate{
+		Certificate:                  cert.Certificate,
+		PrivateKey:                   cert.PrivateKey,
+		SupportedSignatureAlgorithms: signatureAlgorithms,
+		OCSPStaple:                   cert.OCSPStaple,
+		SignedCertificateTimestamps:  cert.SignedCertificateTimestamps,
+		Leaf:                         cert.Leaf,
+	}
+}
+
+func toStdTLSConnectionState(state tls.ConnectionState) stdtls.ConnectionState {
+	return stdtls.ConnectionState{
+		Version:                     state.Version,
+		HandshakeComplete:           state.HandshakeComplete,
+		DidResume:                   state.DidResume,
+		CipherSuite:                 state.CipherSuite,
+		NegotiatedProtocol:          state.NegotiatedProtocol,
+		NegotiatedProtocolIsMutual:  state.NegotiatedProtocolIsMutual,
+		ServerName:                  state.ServerName,
+		PeerCertificates:            state.PeerCertificates,
+		VerifiedChains:              state.VerifiedChains,
+		SignedCertificateTimestamps: state.SignedCertificateTimestamps,
+		OCSPResponse:                state.OCSPResponse,
+		TLSUnique:                   state.TLSUnique,
+		ECHAccepted:                 state.ECHAccepted,
+	}
+}
+
+func NewWebSocketClientHelloSpec() (*tls.ClientHelloSpec, error) {
+	fingerprinter := &tls.Fingerprinter{}
+	rawCapturedClientHelloBytes, _ := hex.DecodeString("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")
+	spec, err := fingerprinter.FingerprintClientHello(rawCapturedClientHelloBytes)
+	return spec, err
+}

util/utls_test.go

@@ -0,0 +1,109 @@
+package util
+
+import (
+	stdtls "crypto/tls"
+	"net"
+	"testing"
+
+	tls "github.com/refraction-networking/utls"
+)
+
+func TestNewUTLSConfigPreservesClientSettings(t *testing.T) {
+	called := false
+	cfg := NewUTLSConfig(&stdtls.Config{
+		ServerName:                  "example.com",
+		InsecureSkipVerify:          true,
+		NextProtos:                  []string{"h2", "http/1.1"},
+		MinVersion:                  stdtls.VersionTLS12,
+		MaxVersion:                  stdtls.VersionTLS13,
+		CipherSuites:                []uint16{stdtls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
+		CurvePreferences:            []stdtls.CurveID{stdtls.X25519, stdtls.CurveP256},
+		DynamicRecordSizingDisabled: true,
+		Renegotiation:               stdtls.RenegotiateOnceAsClient,
+		VerifyConnection: func(state stdtls.ConnectionState) error {
+			called = true
+			if state.ServerName != "example.com" {
+				t.Fatalf("ServerName = %q, want example.com", state.ServerName)
+			}
+			return nil
+		},
+	})
+
+	if cfg.ServerName != "example.com" {
+		t.Fatalf("ServerName = %q, want example.com", cfg.ServerName)
+	}
+	if !cfg.InsecureSkipVerify {
+		t.Fatal("InsecureSkipVerify was not preserved")
+	}
+	if len(cfg.NextProtos) != 2 || cfg.NextProtos[0] != "h2" || cfg.NextProtos[1] != "http/1.1" {
+		t.Fatalf("NextProtos = %v", cfg.NextProtos)
+	}
+	if cfg.MinVersion != tls.VersionTLS12 || cfg.MaxVersion != tls.VersionTLS13 {
+		t.Fatalf("version range = %x-%x", cfg.MinVersion, cfg.MaxVersion)
+	}
+	if len(cfg.CipherSuites) != 1 || cfg.CipherSuites[0] != tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 {
+		t.Fatalf("CipherSuites = %v", cfg.CipherSuites)
+	}
+	if len(cfg.CurvePreferences) != 2 || cfg.CurvePreferences[0] != tls.X25519 || cfg.CurvePreferences[1] != tls.CurveP256 {
+		t.Fatalf("CurvePreferences = %v", cfg.CurvePreferences)
+	}
+	if !cfg.DynamicRecordSizingDisabled {
+		t.Fatal("DynamicRecordSizingDisabled was not preserved")
+	}
+	if cfg.Renegotiation != tls.RenegotiateOnceAsClient {
+		t.Fatalf("Renegotiation = %v", cfg.Renegotiation)
+	}
+	if cfg.VerifyConnection == nil {
+		t.Fatal("VerifyConnection was not preserved")
+	}
+	if err := cfg.VerifyConnection(tls.ConnectionState{ServerName: "example.com"}); err != nil {
+		t.Fatal(err)
+	}
+	if !called {
+		t.Fatal("VerifyConnection wrapper was not called")
+	}
+}
+
+func TestNewUTLSChromeClientBuildsChromeHello(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c1.Close()
+	defer c2.Close()
+
+	client := NewUTLSChromeClient(c1, &stdtls.Config{ServerName: "example.com"})
+	if client.ClientHelloID != tls.HelloChrome_Auto {
+		t.Fatalf("ClientHelloID = %+v, want %+v", client.ClientHelloID, tls.HelloChrome_Auto)
+	}
+	if err := client.BuildHandshakeStateWithoutSession(); err != nil {
+		t.Fatal(err)
+	}
+	if len(client.Extensions) == 0 {
+		t.Fatal("Chrome ClientHello has no extensions")
+	}
+}
+
+func TestNewUTLSWebSocketClientAppliesCustomSpec(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c1.Close()
+	defer c2.Close()
+
+	client, err := NewUTLSWebSocketClient(c1, &stdtls.Config{
+		ServerName: "example.com",
+		NextProtos: []string{"h2"},
+		MinVersion: stdtls.VersionTLS13,
+	}, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if client.ClientHelloID != tls.HelloCustom {
+		t.Fatalf("ClientHelloID = %+v, want %+v", client.ClientHelloID, tls.HelloCustom)
+	}
+	if len(client.Extensions) == 0 {
+		t.Fatal("custom WebSocket ClientHello preset has no extensions")
+	}
+	if err := client.BuildHandshakeStateWithoutSession(); err != nil {
+		t.Fatal(err)
+	}
+	if len(client.HandshakeState.Hello.AlpnProtocols) != 1 || client.HandshakeState.Hello.AlpnProtocols[0] != "http/1.1" {
+		t.Fatalf("ALPN = %v, want [http/1.1]", client.HandshakeState.Hello.AlpnProtocols)
+	}
+}