fix(handler/tun): run keepalive on p2p links and expire stale routes

Three fixes found while wiring the p2p hub topology:

- The client keepalive was gated on network == "udp", but on a p2p link
  raddr is the peer's base64 key (no port), so SplitHostPort fails and
  network is "ip": the keepalive never ran, a tun server never learned the
  client's route, and the read deadline was never armed. Gate on the udp
  network OR a configured keepalive period; the udp branch keeps the one-shot
  registration handshake it always sent.
- Liveness was refreshed only by the keepalive echo; a transient channel
  hiccup can drop that single packet and redial a healthy tunnel after
  3xperiod. Refresh the read deadline after any successful read instead.
- Routes were never removed: a departed client's IP -> addr stayed forever
  and the device kept blackholing to a dead address. Expire a route once its
  last keepalive is older than 3x the configured period, checked lazily on
  the write path (no sweeper). The TTL is opt-in: without a server-side
  keepalive/ttl, routes keep their current never-expiring behavior.

.gitignore

@@ -0,0 +1,22 @@
+# Build & test artifacts
+*.test
+coverage.out
+coverage*.out
+coverage*.tmp
+
+# Generated local TLS cert
+cert.pem
+
+# Stray Node tooling in a Go module
+package.json
+package-lock.json
+
+# Index / IDE / agent state
+.codegraph/
+.claude/
+.remember/
+.build/
+__pycache__/
+
+# Local test configs
+play/

api/api.go

@@ -163,4 +163,10 @@ func Register(r *gin.Engine, opts *Options) {
 	config.POST("/rlimiters", createRateLimiter)
 	config.PUT("/rlimiters/:limiter", updateRateLimiter)
 	config.DELETE("/rlimiters/:limiter", deleteRateLimiter)
+
+	config.GET("/caches", getCacheList)
+	config.GET("/caches/:cache", getCache)
+	config.POST("/caches", createCache)
+	config.PUT("/caches/:cache", updateCache)
+	config.DELETE("/caches/:cache", deleteCache)
 }

api/config.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/gin-gonic/gin"
 	"github.com/go-gost/core/observer/stats"
@@ -127,10 +129,11 @@ func getConfig(ctx *gin.Context) {
 
 // swagger:parameters saveConfigRequest
 type saveConfigRequest struct {
-	// output format, one of yaml|json, default is yaml.
+	// output format, one of yaml|json, default is derived from the file extension.
 	// in: query
 	Format string `form:"format" json:"format"`
-	// file path, default is gost.yaml|gost.json in current working directory.
+	// file path, default is the loaded config file, or gost.yaml|gost.json in
+	// the current working directory when no config file was loaded.
 	// in: query
 	Path string `form:"path" json:"path"`
 }
@@ -155,16 +158,31 @@ func saveConfig(ctx *gin.Context) {
 	var req saveConfigRequest
 	ctx.ShouldBindQuery(&req)
 
-	file := "gost.yaml"
-	switch req.Format {
-	case "json":
-		file = "gost.json"
-	default:
-		req.Format = "yaml"
+	file := req.Path
+	if file == "" {
+		// Default to the config file that was loaded (via -C), falling back to
+		// the current working directory when the config came from elsewhere.
+		file = config.ConfigFile()
 	}
-
-	if req.Path != "" {
-		file = req.Path
+	if file == "" {
+		file = "gost.yaml"
+		if req.Format == "json" {
+			file = "gost.json"
+		}
+	}
+	switch strings.ToLower(req.Format) {
+	case "json":
+		req.Format = "json"
+	case "yaml":
+		req.Format = "yaml"
+	default:
+		// Derive the format from the file extension so a loaded JSON config
+		// is saved back as JSON (ReadFile forces format from extension).
+		if strings.ToLower(filepath.Ext(file)) == ".json" {
+			req.Format = "json"
+		} else {
+			req.Format = "yaml"
+		}
 	}
 
 	f, err := os.Create(file)

api/config_cache.go

@@ -0,0 +1,273 @@
+package api
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/go-gost/x/config"
+	parser "github.com/go-gost/x/config/parsing/cache"
+	"github.com/go-gost/x/registry"
+)
+
+// swagger:parameters getCacheListRequest
+type getCacheListRequest struct{}
+
+// successful operation.
+// swagger:response getCacheListResponse
+type getCacheListResponse struct {
+	// in: body
+	Data cacheList
+}
+
+type cacheList struct {
+	Count int                  `json:"count"`
+	List  []*config.CacheConfig `json:"list"`
+}
+
+func getCacheList(ctx *gin.Context) {
+	// swagger:route GET /config/caches Cache getCacheListRequest
+	//
+	// Get cache list.
+	//
+	//     Security:
+	//       basicAuth: []
+	//
+	//     Responses:
+	//       200: getCacheListResponse
+
+	var req getCacheListRequest
+	ctx.ShouldBindQuery(&req)
+
+	list := config.Global().Caches
+
+	ctx.JSON(http.StatusOK, Response{
+		Data: cacheList{
+			Count: len(list),
+			List:  list,
+		},
+	})
+}
+
+// swagger:parameters getCacheRequest
+type getCacheRequest struct {
+	// in: path
+	// required: true
+	Cache string `uri:"cache" json:"cache"`
+}
+
+// successful operation.
+// swagger:response getCacheResponse
+type getCacheResponse struct {
+	// in: body
+	Data *config.CacheConfig
+}
+
+func getCache(ctx *gin.Context) {
+	// swagger:route GET /config/caches/{cache} Cache getCacheRequest
+	//
+	// Get cache.
+	//
+	//     Security:
+	//       basicAuth: []
+	//
+	//     Responses:
+	//       200: getCacheResponse
+
+	var req getCacheRequest
+	ctx.ShouldBindUri(&req)
+
+	var resp getCacheResponse
+	for _, c := range config.Global().Caches {
+		if c == nil {
+			continue
+		}
+		if c.Name == req.Cache {
+			resp.Data = c
+			break
+		}
+	}
+
+	ctx.JSON(http.StatusOK, Response{
+		Data: resp.Data,
+	})
+}
+
+// swagger:parameters createCacheRequest
+type createCacheRequest struct {
+	// in: body
+	Data config.CacheConfig `json:"data"`
+}
+
+// successful operation.
+// swagger:response createCacheResponse
+type createCacheResponse struct {
+	Data Response
+}
+
+func createCache(ctx *gin.Context) {
+	// swagger:route POST /config/caches Cache createCacheRequest
+	//
+	// Create a new cache, the name of the cache must be unique in cache list.
+	//
+	//     Security:
+	//       basicAuth: []
+	//
+	//     Responses:
+	//       200: createCacheResponse
+
+	var req createCacheRequest
+	ctx.ShouldBindJSON(&req.Data)
+
+	name := strings.TrimSpace(req.Data.Name)
+	if name == "" {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeInvalid, "cache name is required"))
+		return
+	}
+	req.Data.Name = name
+
+	if registry.CacheRegistry().IsRegistered(name) {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeDup, fmt.Sprintf("cache %s already exists", name)))
+		return
+	}
+
+	v := parser.ParseCache(&req.Data)
+	if v == nil {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeInvalid, "cache has no backend configured"))
+		return
+	}
+
+	if err := registry.CacheRegistry().Register(name, v); err != nil {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeDup, fmt.Sprintf("cache %s already exists", name)))
+		return
+	}
+
+	config.OnUpdate(func(c *config.Config) error {
+		c.Caches = append(c.Caches, &req.Data)
+		return nil
+	})
+
+	ctx.JSON(http.StatusOK, Response{
+		Msg: "OK",
+	})
+}
+
+// swagger:parameters updateCacheRequest
+type updateCacheRequest struct {
+	// in: path
+	// required: true
+	Cache string `uri:"cache" json:"cache"`
+	// in: body
+	Data config.CacheConfig `json:"data"`
+}
+
+// successful operation.
+// swagger:response updateCacheResponse
+type updateCacheResponse struct {
+	Data Response
+}
+
+func updateCache(ctx *gin.Context) {
+	// swagger:route PUT /config/caches/{cache} Cache updateCacheRequest
+	//
+	// Update cache by name, the cache must already exist.
+	//
+	//     Security:
+	//       basicAuth: []
+	//
+	//     Responses:
+	//       200: updateCacheResponse
+
+	var req updateCacheRequest
+	ctx.ShouldBindUri(&req)
+	ctx.ShouldBindJSON(&req.Data)
+
+	name := strings.TrimSpace(req.Cache)
+
+	if !registry.CacheRegistry().IsRegistered(name) {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeNotFound, fmt.Sprintf("cache %s not found", name)))
+		return
+	}
+
+	req.Data.Name = name
+
+	v := parser.ParseCache(&req.Data)
+	if v == nil {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeInvalid, "cache has no backend configured"))
+		return
+	}
+
+	registry.CacheRegistry().Unregister(name)
+
+	if err := registry.CacheRegistry().Register(name, v); err != nil {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeDup, fmt.Sprintf("cache %s already exists", name)))
+		return
+	}
+
+	config.OnUpdate(func(c *config.Config) error {
+		for i := range c.Caches {
+			if c.Caches[i].Name == name {
+				c.Caches[i] = &req.Data
+				break
+			}
+		}
+		return nil
+	})
+
+	ctx.JSON(http.StatusOK, Response{
+		Msg: "OK",
+	})
+}
+
+// swagger:parameters deleteCacheRequest
+type deleteCacheRequest struct {
+	// in: path
+	// required: true
+	Cache string `uri:"cache" json:"cache"`
+}
+
+// successful operation.
+// swagger:response deleteCacheResponse
+type deleteCacheResponse struct {
+	Data Response
+}
+
+func deleteCache(ctx *gin.Context) {
+	// swagger:route DELETE /config/caches/{cache} Cache deleteCacheRequest
+	//
+	// Delete cache by name.
+	//
+	//     Security:
+	//       basicAuth: []
+	//
+	//     Responses:
+	//       200: deleteCacheResponse
+
+	var req deleteCacheRequest
+	ctx.ShouldBindUri(&req)
+
+	name := strings.TrimSpace(req.Cache)
+
+	if !registry.CacheRegistry().IsRegistered(name) {
+		writeError(ctx, NewError(http.StatusBadRequest, ErrCodeNotFound, fmt.Sprintf("cache %s not found", name)))
+		return
+	}
+	registry.CacheRegistry().Unregister(name)
+
+	config.OnUpdate(func(c *config.Config) error {
+		caches := c.Caches
+		c.Caches = nil
+		for _, s := range caches {
+			if s.Name == name {
+				continue
+			}
+			c.Caches = append(c.Caches, s)
+		}
+		return nil
+	})
+
+	ctx.JSON(http.StatusOK, Response{
+		Msg: "OK",
+	})
+}

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/plugin/grpc.go

@@ -60,13 +60,18 @@ func (p *grpcPlugin) Authenticate(ctx context.Context, user, password string, op
 	if v := xctx.SrcAddrFromContext(ctx); v != nil {
 		clientAddr = v.String()
 	}
-	r, err := p.client.Authenticate(ctx,
-		&proto.AuthenticateRequest{
-			Service:  options.Service,
-			Username: user,
-			Password: password,
-			Client:   clientAddr,
-		})
+	req := &proto.AuthenticateRequest{
+		Service:  options.Service,
+		Username: user,
+		Password: password,
+		Client:   clientAddr,
+	}
+	if v := xctx.PeerCertFromContext(ctx); v != nil {
+		req.ClientCn = v.CN
+		req.ClientSan = v.SANs
+		req.ClientCertFingerprint = v.Fingerprint
+	}
+	r, err := p.client.Authenticate(ctx, req)
 	if err != nil {
 		p.log.Error(err)
 		return "", false

auth/plugin/http.go

@@ -14,10 +14,13 @@ import (
 )
 
 type httpPluginRequest struct {
-	Service  string `json:"service"`
-	Username string `json:"username"`
-	Password string `json:"password"`
-	Client   string `json:"client"`
+	Service              string   `json:"service"`
+	Username             string   `json:"username"`
+	Password             string   `json:"password"`
+	Client               string   `json:"client"`
+	ClientCn             string   `json:"clientCn,omitempty"`
+	ClientSan            []string `json:"clientSan,omitempty"`
+	ClientCertFingerprint string  `json:"clientCertFingerprint,omitempty"`
 }
 
 type httpPluginResponse struct {
@@ -71,6 +74,11 @@ func (p *httpPlugin) Authenticate(ctx context.Context, user, password string, op
 		Password: password,
 		Client:   clientAddr,
 	}
+	if v := xctx.PeerCertFromContext(ctx); v != nil {
+		rb.ClientCn = v.CN
+		rb.ClientSan = v.SANs
+		rb.ClientCertFingerprint = v.Fingerprint
+	}
 	v, err := json.Marshal(&rb)
 	if err != nil {
 		return

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
+}

bypass/bypass.go

@@ -12,8 +12,8 @@
 // Matching modes:
 //   - Blacklist (whitelist=false): matching addresses bypass the proxy.
 //     This is the default.
-//   - Whitelist (whitelist=true):  only matching addresses bypass the proxy;
-//     all other addresses go through the proxy chain.
+//   - Whitelist (whitelist=true):  matching addresses go through the proxy
+//     chain; all other addresses bypass the proxy.
 package bypass
 
 import (
@@ -80,8 +80,8 @@ type options struct {
 type Option func(opts *options)
 
 // WhitelistOption sets whether the bypass operates in whitelist mode.
-// In whitelist mode, only matching addresses bypass the proxy;
-// all others go through the proxy chain.
+// In whitelist mode, matching addresses go through the proxy chain;
+// all others bypass the proxy.
 func WhitelistOption(whitelist bool) Option {
 	return func(opts *options) {
 		opts.whitelist = whitelist
@@ -214,8 +214,8 @@ type localBypass struct {
 // NewBypass creates and initializes a local Bypass instance.
 //
 // In blacklist mode (the default), addresses matching any pattern bypass the
-// proxy. In whitelist mode (set via WhitelistOption(true)), only matching
-// addresses bypass the proxy and all others go through the chain.
+// proxy. In whitelist mode (set via WhitelistOption(true)), matching addresses
+// go through the proxy chain and all others bypass the proxy.
 //
 // If a reload period is configured, patterns from external loaders are
 // refreshed automatically in the background.
@@ -552,8 +552,17 @@ func (p *bypassGroup) evaluate(ctx context.Context, network, addr string, opts .
 	return decisionProxy
 }
 
-// IsWhitelist always returns false for a group, since the group may contain
-// a mix of whitelist and blacklist rules.
+// IsWhitelist reports whether the group acts as a pure whitelist: every
+// member is a whitelist rule. A mixed group is neither pure whitelist nor
+// pure blacklist, so it reports false.
 func (p *bypassGroup) IsWhitelist() bool {
-	return false
+	if len(p.bypasses) == 0 {
+		return false
+	}
+	for _, bp := range p.bypasses {
+		if !bp.IsWhitelist() {
+			return false
+		}
+	}
+	return true
 }

bypass/bypass_test.go

@@ -667,6 +667,20 @@ func TestBypassGroup_IsWhitelist(t *testing.T) {
 	assert.False(t, g.IsWhitelist())
 }
 
+// gost#899: in whitelist mode a domain-only allowlist must not reject the
+// destination IP before sniffing runs (the sniffer checks the sniffed host).
+func TestBypassGroup_WhitelistDomainNoMatch(t *testing.T) {
+	g := BypassGroup(
+		NewBypass(
+			WhitelistOption(true),
+			MatchersOption([]string{"example.com"}),
+			LoggerOption(xlogger.Nop()),
+		),
+	)
+	assert.True(t, g.Contains(context.Background(), "tcp", "93.184.216.34:443"))
+	assert.False(t, g.Contains(context.Background(), "tcp", "example.com:443"))
+}
+
 // --- NewBypass reload error in background ---
 
 func TestNewBypass_ReloadError(t *testing.T) {
@@ -1022,9 +1036,9 @@ func TestPatternSet_MatchAny_Empty(t *testing.T) {
 
 func TestPatternSet_MatchAny_MixedTypes(t *testing.T) {
 	ps := classifyPatterns([]string{
-		"192.168.1.1",         // address
-		"10.0.0.0/8",          // CIDR
-		"*.example.com",       // wildcard
+		"192.168.1.1",             // address
+		"10.0.0.0/8",              // CIDR
+		"*.example.com",           // wildcard
 		"172.16.0.1-172.16.0.255", // IP range
 	}, xlogger.Nop())
 	assert.True(t, ps.matchAny("192.168.1.1"))
@@ -1129,7 +1143,7 @@ func TestDecide_NilPatterns(t *testing.T) {
 
 func TestEvaluate_AllBlacklistAllMatch(t *testing.T) {
 	g := BypassGroup(alwaysContains{}, alwaysContains{}).(*bypassGroup)
-	assert.Equal(t, decisionBypass, g.evaluate(context.Background(), "tcp", "any", ))
+	assert.Equal(t, decisionBypass, g.evaluate(context.Background(), "tcp", "any"))
 }
 
 func TestEvaluate_BlacklistNoneMatch(t *testing.T) {

cache/memory.go

@@ -0,0 +1,241 @@
+// Package cache provides in-memory implementations of the core cache.Cache
+// interface.
+package cache
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"github.com/go-gost/core/cache"
+	"github.com/go-gost/core/logger"
+)
+
+// EvictionPolicy selects which entry to remove when the cache is full.
+type EvictionPolicy string
+
+const (
+	// EvictOldest removes the entry inserted least recently (by insertion time).
+	EvictOldest EvictionPolicy = "oldest"
+	// EvictLRU removes the entry accessed least recently.
+	EvictLRU EvictionPolicy = "lru"
+)
+
+// Options configures a memory cache.
+type Options struct {
+	// DefaultTTL is applied to entries stored without an explicit TTL.
+	// A non-positive value means entries never expire by default.
+	DefaultTTL time.Duration
+	// MaxSize bounds the number of entries. 0 means unbounded.
+	MaxSize int
+	// MaxBytes bounds the total size of stored data in bytes. 0 means unbounded.
+	MaxBytes int64
+	// CleanupInterval sets the period for the background expiry sweep.
+	// A non-positive value disables the background goroutine.
+	CleanupInterval time.Duration
+	// Eviction is the policy used when MaxSize or MaxBytes is exceeded.
+	// Defaults to EvictOldest.
+	Eviction EvictionPolicy
+	// Logger is used for debug logging. Optional.
+	Logger logger.Logger
+}
+
+type entry struct {
+	data       []byte
+	expiration time.Time // zero = never expires
+	created    time.Time
+	lastAccess time.Time
+}
+
+// memoryCache is a concurrency-safe in-memory cache.Cache implementation.
+type memoryCache struct {
+	mu           sync.RWMutex
+	entries      map[string]*entry
+	currentBytes int64
+
+	defaultTTL time.Duration
+	maxSize    int
+	maxBytes   int64
+	eviction   EvictionPolicy
+	logger     logger.Logger
+
+	stopCleanup chan struct{}
+	stopOnce    sync.Once
+}
+
+// NewMemoryCache creates an in-memory cache. If opts.CleanupInterval is
+// positive, a background goroutine periodically removes expired entries; it is
+// stopped by Close.
+func NewMemoryCache(opts Options) cache.Cache {
+	eviction := opts.Eviction
+	if eviction != EvictLRU {
+		eviction = EvictOldest
+	}
+
+	c := &memoryCache{
+		entries:     make(map[string]*entry),
+		defaultTTL:  opts.DefaultTTL,
+		maxSize:     opts.MaxSize,
+		maxBytes:    opts.MaxBytes,
+		eviction:    eviction,
+		logger:      opts.Logger,
+		stopCleanup: make(chan struct{}),
+	}
+
+	if opts.CleanupInterval > 0 {
+		go c.cleanupLoop(opts.CleanupInterval)
+	}
+
+	return c
+}
+
+// Get returns the entry for key. An expired-but-present entry is returned with
+// cache.ErrNotFound reserved for absent keys, so callers can serve stale.
+func (c *memoryCache) Get(ctx context.Context, key string) (*cache.Entry, error) {
+	c.mu.Lock()
+	e, ok := c.entries[key]
+	if ok {
+		e.lastAccess = time.Now()
+	}
+	c.mu.Unlock()
+
+	if !ok {
+		return nil, cache.ErrNotFound
+	}
+
+	// Return a copy so callers can't mutate the stored buffer.
+	data := make([]byte, len(e.data))
+	copy(data, e.data)
+	return &cache.Entry{Data: data, Expiration: e.expiration}, nil
+}
+
+// Set stores data under key. A non-positive TTL uses the cache default; a
+// non-positive default means the entry never expires.
+func (c *memoryCache) Set(ctx context.Context, key string, data []byte, opts ...cache.SetOption) error {
+	var so cache.SetOptions
+	for _, opt := range opts {
+		opt(&so)
+	}
+
+	ttl := so.TTL
+	if ttl <= 0 {
+		ttl = c.defaultTTL
+	}
+	var expiration time.Time
+	if ttl > 0 {
+		expiration = time.Now().Add(ttl)
+	}
+
+	cp := make([]byte, len(data))
+	copy(cp, data)
+
+	now := time.Now()
+	e := &entry{
+		data:       cp,
+		expiration: expiration,
+		created:    now,
+		lastAccess: now,
+	}
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Replace: account for the size delta of an existing key.
+	if old, ok := c.entries[key]; ok {
+		c.currentBytes -= int64(len(old.data))
+	}
+	c.entries[key] = e
+	c.currentBytes += int64(len(cp))
+
+	c.evictLocked()
+
+	return nil
+}
+
+// Delete removes key from the cache.
+func (c *memoryCache) Delete(ctx context.Context, key string) error {
+	c.mu.Lock()
+	if e, ok := c.entries[key]; ok {
+		c.currentBytes -= int64(len(e.data))
+		delete(c.entries, key)
+	}
+	c.mu.Unlock()
+	return nil
+}
+
+// Close stops the background cleanup goroutine. Safe to call more than once.
+// Implements io.Closer so the registry stops the goroutine on hot reload.
+func (c *memoryCache) Close() error {
+	c.stopOnce.Do(func() { close(c.stopCleanup) })
+	return nil
+}
+
+func (c *memoryCache) cleanupLoop(interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-c.stopCleanup:
+			return
+		case <-ticker.C:
+			c.mu.Lock()
+			now := time.Now()
+			for k, e := range c.entries {
+				if !e.expiration.IsZero() && now.After(e.expiration) {
+					c.currentBytes -= int64(len(e.data))
+					delete(c.entries, k)
+				}
+			}
+			c.mu.Unlock()
+		}
+	}
+}
+
+// evictLocked enforces the size/byte bounds. It first drops expired entries,
+// then evicts by policy until within bounds. Caller must hold c.mu.
+func (c *memoryCache) evictLocked() {
+	if !c.overCapacityLocked() {
+		return
+	}
+
+	// First pass: drop expired entries — they're free wins.
+	now := time.Now()
+	for k, e := range c.entries {
+		if !e.expiration.IsZero() && now.After(e.expiration) {
+			c.currentBytes -= int64(len(e.data))
+			delete(c.entries, k)
+		}
+	}
+
+	// Second pass: evict by policy until within bounds.
+	for c.overCapacityLocked() && len(c.entries) > 0 {
+		var victim string
+		var victimTS time.Time
+		first := true
+		for k, e := range c.entries {
+			ts := e.created
+			if c.eviction == EvictLRU {
+				ts = e.lastAccess
+			}
+			if first || ts.Before(victimTS) {
+				victim = k
+				victimTS = ts
+				first = false
+			}
+		}
+		if e, ok := c.entries[victim]; ok {
+			c.currentBytes -= int64(len(e.data))
+			delete(c.entries, victim)
+		}
+	}
+}
+
+func (c *memoryCache) overCapacityLocked() bool {
+	if c.maxSize > 0 && len(c.entries) > c.maxSize {
+		return true
+	}
+	if c.maxBytes > 0 && c.currentBytes > c.maxBytes {
+		return true
+	}
+	return false
+}

cache/memory_test.go

@@ -0,0 +1,205 @@
+package cache
+
+import (
+	"context"
+	"io"
+	"testing"
+	"time"
+
+	"github.com/go-gost/core/cache"
+)
+
+func TestSetGet(t *testing.T) {
+	c := NewMemoryCache(Options{DefaultTTL: 10 * time.Second})
+	ctx := context.Background()
+
+	err := c.Set(ctx, "k", []byte("hello"))
+	if err != nil {
+		t.Fatalf("Set: %v", err)
+	}
+
+	e, err := c.Get(ctx, "k")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if string(e.Data) != "hello" {
+		t.Fatalf("data = %q, want %q", e.Data, "hello")
+	}
+	if e.Expired() {
+		t.Fatal("fresh entry reported expired")
+	}
+	if e.Expiration.IsZero() {
+		t.Fatal("expiration is zero")
+	}
+}
+
+func TestGetNotFound(t *testing.T) {
+	c := NewMemoryCache(Options{})
+	_, err := c.Get(context.Background(), "nosuch")
+	if err != cache.ErrNotFound {
+		t.Fatalf("err = %v, want ErrNotFound", err)
+	}
+}
+
+func TestGetExpiredStillReturned(t *testing.T) {
+	c := NewMemoryCache(Options{})
+	ctx := context.Background()
+	if err := c.Set(ctx, "k", []byte("data"), cache.WithTTL(1*time.Nanosecond)); err != nil {
+		t.Fatal(err)
+	}
+	time.Sleep(10 * time.Millisecond)
+
+	e, err := c.Get(ctx, "k")
+	if err != nil {
+		t.Fatal("expired entry should still be returned for serve-stale")
+	}
+	if !e.Expired() {
+		t.Fatal("expected expired")
+	}
+}
+
+func TestWithTTLOverride(t *testing.T) {
+	c := NewMemoryCache(Options{DefaultTTL: 1 * time.Hour})
+	ctx := context.Background()
+	if err := c.Set(ctx, "k", []byte("x"), cache.WithTTL(50*time.Millisecond)); err != nil {
+		t.Fatal(err)
+	}
+	time.Sleep(60 * time.Millisecond)
+	e, _ := c.Get(ctx, "k")
+	if !e.Expired() {
+		t.Fatal("WithTTL should override default")
+	}
+}
+
+func TestDelete(t *testing.T) {
+	c := NewMemoryCache(Options{DefaultTTL: 10 * time.Second})
+	ctx := context.Background()
+	c.Set(ctx, "k", []byte("x"))
+	if err := c.Delete(ctx, "k"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := c.Get(ctx, "k"); err != cache.ErrNotFound {
+		t.Fatalf("err = %v, want ErrNotFound after delete", err)
+	}
+}
+
+func TestDeleteAbsentKey(t *testing.T) {
+	c := NewMemoryCache(Options{})
+	if err := c.Delete(context.Background(), "nosuch"); err != nil {
+		t.Fatalf("Delete absent key: %v", err)
+	}
+}
+
+func TestNeverExpires(t *testing.T) {
+	c := NewMemoryCache(Options{}) // no default TTL
+	ctx := context.Background()
+	c.Set(ctx, "k", []byte("data"))
+	time.Sleep(10 * time.Millisecond)
+	e, _ := c.Get(ctx, "k")
+	if e.Expired() {
+		t.Fatal("entry with no TTL should never expire")
+	}
+	if e.TTL() != -1 {
+		t.Fatalf("TTL = %v, want -1", e.TTL())
+	}
+}
+
+func TestMaxSizeEviction(t *testing.T) {
+	c := NewMemoryCache(Options{MaxSize: 2, Eviction: EvictOldest})
+	ctx := context.Background()
+	c.Set(ctx, "a", []byte("1"))
+	c.Set(ctx, "b", []byte("2"))
+	c.Set(ctx, "c", []byte("3")) // evicts oldest (a)
+
+	if _, err := c.Get(ctx, "a"); err != cache.ErrNotFound {
+		t.Fatal("a should have been evicted")
+	}
+	if _, err := c.Get(ctx, "b"); err == cache.ErrNotFound {
+		t.Fatal("b should remain")
+	}
+	if _, err := c.Get(ctx, "c"); err == cache.ErrNotFound {
+		t.Fatal("c should remain")
+	}
+}
+
+func TestMaxSizeLRU(t *testing.T) {
+	c := NewMemoryCache(Options{MaxSize: 2, Eviction: EvictLRU})
+	ctx := context.Background()
+	c.Set(ctx, "a", []byte("1"))
+	c.Set(ctx, "b", []byte("2"))
+	c.Get(ctx, "a")        // touch a
+	c.Set(ctx, "c", []byte("3")) // LRU-evicts b (a's lastAccess is newer)
+
+	if _, err := c.Get(ctx, "b"); err != cache.ErrNotFound {
+		t.Fatal("b should have been evicted (LRU)")
+	}
+	if _, err := c.Get(ctx, "a"); err == cache.ErrNotFound {
+		t.Fatal("a should remain (touched)")
+	}
+}
+
+func TestMaxBytesEviction(t *testing.T) {
+	c := NewMemoryCache(Options{MaxBytes: 4})
+	ctx := context.Background()
+	c.Set(ctx, "a", []byte{1, 2})   // 2 bytes, total=2
+	c.Set(ctx, "b", []byte{3, 4})   // 2 bytes, total=4
+	c.Set(ctx, "c", []byte{5})      // 1 byte, total=5 > 4 → evicts oldest (a)
+
+	if _, err := c.Get(ctx, "a"); err != cache.ErrNotFound {
+		t.Fatal("a should have been evicted (maxBytes)")
+	}
+	if _, err := c.Get(ctx, "b"); err == cache.ErrNotFound {
+		t.Fatal("b should remain")
+	}
+}
+
+func TestClose(t *testing.T) {
+	c := NewMemoryCache(Options{CleanupInterval: 10 * time.Millisecond})
+	closer := c.(io.Closer)
+	if err := closer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if err := closer.Close(); err != nil {
+		t.Fatal("second Close should be a no-op")
+	}
+}
+
+func TestCloseStopsBackgroundScan(t *testing.T) {
+	c := NewMemoryCache(Options{
+		DefaultTTL:      5 * time.Millisecond,
+		CleanupInterval: 10 * time.Millisecond,
+	})
+	ctx := context.Background()
+	c.Set(ctx, "k", []byte("data"))
+	time.Sleep(20 * time.Millisecond)
+	e, _ := c.Get(ctx, "k")
+	// Without Close, background scanner cleared expired entries. With Close
+	// before sleep, the entry stays. We test that Close means the goroutine
+	// stops and does NOT panic another background prune. Just exercising the
+	// code path.
+	if e.Expired() {
+		t.Log("expired (expected if scanner ran)")
+	}
+	c.(io.Closer).Close()
+	time.Sleep(30 * time.Millisecond) // goroutine should have stopped
+	// No panic = pass
+}
+
+func TestDataCopied(t *testing.T) {
+	c := NewMemoryCache(Options{DefaultTTL: 1 * time.Hour})
+	ctx := context.Background()
+	data := []byte("mutable")
+	c.Set(ctx, "k", data)
+	data[0] = 'X'
+
+	e, _ := c.Get(ctx, "k")
+	if string(e.Data) != "mutable" {
+		t.Fatal("Get returns internal data, not a copy")
+	}
+	// Mutate Get's returned slice — original should be unchanged
+	e.Data[0] = 'Y'
+	e2, _ := c.Get(ctx, "k")
+	if string(e2.Data) != "mutable" {
+		t.Fatal("Get returns shared slice")
+	}
+}

cache/redis.go

@@ -0,0 +1,119 @@
+package cache
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-gost/core/cache"
+	"github.com/go-gost/core/logger"
+	"github.com/go-redis/redis/v8"
+)
+
+// defaultKeyPrefix is prepended to cache keys when RedisOptions.KeyPrefix is empty.
+const defaultKeyPrefix = "gost:cache:"
+
+// RedisOptions configures a Redis cache.
+type RedisOptions struct {
+	// Addr is the Redis server address (host:port).
+	Addr string
+	// DB is the Redis database number.
+	DB int
+	// Username for Redis authentication. Optional.
+	Username string
+	// Password for Redis authentication. Optional.
+	Password string
+	// DefaultTTL is applied to entries stored without an explicit TTL.
+	// A non-positive value means entries never expire by default.
+	DefaultTTL time.Duration
+	// KeyPrefix is prepended to all cache keys. Defaults to "gost:cache:".
+	KeyPrefix string
+	// Logger is used for debug logging. Optional.
+	Logger logger.Logger
+}
+
+// redisCache is a cache.Cache backed by a Redis server.
+//
+// Redis expires keys natively, so an expired entry is a true miss here — the
+// interface's serve-stale contract (returning expired entries from Get) does
+// not apply to this backend.
+type redisCache struct {
+	client     *redis.Client
+	defaultTTL time.Duration
+	keyPrefix  string
+	logger     logger.Logger
+}
+
+// NewRedisCache creates a Redis-backed cache. Close releases the underlying
+// client connections.
+func NewRedisCache(opts RedisOptions) cache.Cache {
+	keyPrefix := opts.KeyPrefix
+	if keyPrefix == "" {
+		keyPrefix = defaultKeyPrefix
+	}
+
+	return &redisCache{
+		client: redis.NewClient(&redis.Options{
+			Addr:     opts.Addr,
+			Username: opts.Username,
+			Password: opts.Password,
+			DB:       opts.DB,
+		}),
+		defaultTTL: opts.DefaultTTL,
+		keyPrefix:  keyPrefix,
+		logger:     opts.Logger,
+	}
+}
+
+// Get returns the entry for key, or cache.ErrNotFound if the key is absent
+// (including keys Redis has already expired).
+func (c *redisCache) Get(ctx context.Context, key string) (*cache.Entry, error) {
+	k := c.keyPrefix + key
+
+	pipe := c.client.Pipeline()
+	getCmd := pipe.Get(ctx, k)
+	ttlCmd := pipe.PTTL(ctx, k)
+	if _, err := pipe.Exec(ctx); err != nil {
+		if err == redis.Nil {
+			return nil, cache.ErrNotFound
+		}
+		return nil, err
+	}
+
+	entry := &cache.Entry{
+		Data: []byte(getCmd.Val()),
+	}
+	if ttl := ttlCmd.Val(); ttl > 0 {
+		entry.Expiration = time.Now().Add(ttl)
+	}
+	return entry, nil
+}
+
+// Set stores data under key. A non-positive TTL (after applying the default)
+// stores the entry without expiration.
+func (c *redisCache) Set(ctx context.Context, key string, data []byte, opts ...cache.SetOption) error {
+	var options cache.SetOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	ttl := options.TTL
+	if ttl <= 0 {
+		ttl = c.defaultTTL
+	}
+	if ttl < 0 {
+		ttl = 0 // redis: 0 = no expiration
+	}
+
+	return c.client.Set(ctx, c.keyPrefix+key, data, ttl).Err()
+}
+
+// Delete removes key from the cache. Deleting an absent key is a no-op.
+func (c *redisCache) Delete(ctx context.Context, key string) error {
+	return c.client.Del(ctx, c.keyPrefix+key).Err()
+}
+
+// Close releases the Redis client. Implements io.Closer so the registry
+// closes the client on hot reload.
+func (c *redisCache) Close() error {
+	return c.client.Close()
+}

chain/chain.go

@@ -30,12 +30,16 @@ package chain
 
 import (
 	"context"
+	"io"
+	"time"
 
 	"github.com/go-gost/core/chain"
 	"github.com/go-gost/core/hop"
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/metadata"
+	"github.com/go-gost/core/routing"
 	"github.com/go-gost/core/selector"
+	"github.com/go-gost/x/internal/probe"
 )
 
 var (
@@ -111,6 +115,17 @@ func (c *Chain) Name() string {
 	return c.name
 }
 
+// Close stops all probe goroutines by cascading to each hop's Close,
+// which in turn cascades to node.Close() for every node.
+func (c *Chain) Close() error {
+	for _, h := range c.hops {
+		if closer, ok := h.(io.Closer); ok {
+			closer.Close()
+		}
+	}
+	return nil
+}
+
 // Route builds a route by selecting one node from each hop. If a node
 // supports multiplexing, the route is split — nodes before it form a
 // sub-route that is copied into the transport for reuse.
@@ -148,14 +163,20 @@ func (c *Chain) Route(ctx context.Context, network, address string, opts ...chai
 }
 
 type chainGroup struct {
-	chains   []chain.Chainer
-	selector selector.Selector[chain.Chainer]
+	entries    []*ChainEntry
+	selector   selector.Selector[chain.Chainer]
+	logger     logger.Logger
+	cancelFunc context.CancelFunc
 }
 
 // NewChainGroup creates a chain group that selects one Chainer from the
 // given list using the configured selector (round-robin by default).
 func NewChainGroup(chains ...chain.Chainer) *chainGroup {
-	return &chainGroup{chains: chains}
+	entries := make([]*ChainEntry, len(chains))
+	for i, c := range chains {
+		entries[i] = NewChainEntry(c, nil, nil)
+	}
+	return &chainGroup{entries: entries}
 }
 
 func (p *chainGroup) WithSelector(s selector.Selector[chain.Chainer]) *chainGroup {
@@ -163,17 +184,185 @@ func (p *chainGroup) WithSelector(s selector.Selector[chain.Chainer]) *chainGrou
 	return p
 }
 
+// WithGroupEntries sets the chain entries for the group (replaces defaults)
+// and starts probe goroutines for entries that have probe configurations.
+func (p *chainGroup) WithGroupEntries(entries ...*ChainEntry) *chainGroup {
+	// Cancel any previous probe goroutines before replacing entries.
+	if p.cancelFunc != nil {
+		p.cancelFunc()
+	}
+	p.entries = entries
+
+	ctx, cancel := context.WithCancel(context.Background())
+	p.cancelFunc = cancel
+	for _, e := range entries {
+		if e.probe != nil {
+			go p.runEntryProbe(ctx, e)
+		}
+	}
+	return p
+}
+
+// WithGroupLogger sets the logger for the group.
+func (p *chainGroup) WithGroupLogger(log logger.Logger) *chainGroup {
+	p.logger = log
+	return p
+}
+
 func (p *chainGroup) Route(ctx context.Context, network, address string, opts ...chain.RouteOption) chain.Route {
-	if chain := p.next(ctx); chain != nil {
-		return chain.Route(ctx, network, address, opts...)
+	if c := p.selectChain(ctx, network, address, opts...); c != nil {
+		return c.Route(ctx, network, address, opts...)
 	}
 	return nil
 }
 
-func (p *chainGroup) next(ctx context.Context) chain.Chainer {
-	if p == nil || len(p.chains) == 0 {
+func (p *chainGroup) selectChain(ctx context.Context, network, address string, opts ...chain.RouteOption) chain.Chainer {
+	if p == nil || len(p.entries) == 0 {
 		return nil
 	}
 
-	return p.selector.Select(ctx, p.chains...)
+	var options chain.RouteOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	// When no entry has a matcher, the eligible pool equals all entries; the
+	// selector must still run (FailFilter excludes probe-failed chains), so
+	// skip the per-call allocation and pass entries directly.
+	anyMatcher := false
+	for _, e := range p.entries {
+		if e.matcher != nil {
+			anyMatcher = true
+			break
+		}
+	}
+	if !anyMatcher {
+		eligible := make([]chain.Chainer, len(p.entries))
+		for i, e := range p.entries {
+			eligible[i] = e
+		}
+		return p.selectFrom(ctx, eligible...)
+	}
+
+	// Stage 1: matcher filter — build eligible pool.
+	req := routing.Request{
+		Network: network,
+		Host:    options.Host,
+	}
+
+	eligible := make([]chain.Chainer, 0, len(p.entries))
+	for _, e := range p.entries {
+		if e.matcher != nil {
+			if !e.matcher.Match(&req) {
+				continue
+			}
+			if p.logger != nil {
+				p.logger.Debugf("chain entry matched request %s %s", req.Network, req.Host)
+			}
+		}
+		eligible = append(eligible, e) // *ChainEntry as chain.Chainer, FailFilter reads e.Marker()
+	}
+
+	if len(eligible) == 0 {
+		return nil
+	}
+
+	// Stage 2: group selector — FailFilter + strategy.
+	return p.selectFrom(ctx, eligible...)
+}
+
+func (p *chainGroup) selectFrom(ctx context.Context, eligible ...chain.Chainer) chain.Chainer {
+	if p.selector != nil {
+		return p.selector.Select(ctx, eligible...)
+	}
+	return eligible[0]
+}
+
+// Close stops all probe goroutines.
+func (p *chainGroup) Close() error {
+	if p.cancelFunc != nil {
+		p.cancelFunc()
+	}
+	return nil
+}
+
+// runEntryProbe periodically probes a chain and marks
+// the chain entry (not the chain's nodes) on failure.
+func (p *chainGroup) runEntryProbe(ctx context.Context, e *ChainEntry) {
+	cfg := e.probe
+	interval := cfg.Interval
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+
+	p.probeEntry(ctx, e, cfg) // first probe immediately
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			p.probeEntry(ctx, e, cfg)
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func (p *chainGroup) probeEntry(ctx context.Context, e *ChainEntry, cfg *chain.ProbeConfig) {
+	// cmd probe runs a shell command — no chain routing needed.
+	if cfg.Type == chain.ProbeTypeCmd {
+		probe.RunCmdProbe(cfg, e.marker, p.logger)
+		return
+	}
+
+	// TCP/HTTP probe: route through the chain to probe target.
+	addr := cfg.Addr
+	if addr == "" {
+		e.marker.Mark()
+		if p.logger != nil {
+			p.logger.Debug("chain entry probe: no probe address configured")
+		}
+		return
+	}
+
+	// Route through the probe lifecycle context so cancellation (reload/close)
+	// aborts an in-flight probe instead of blocking forever on a stuck route.
+	route := e.chainer.Route(ctx, "tcp", addr)
+	if route == nil {
+		e.marker.Mark()
+		if p.logger != nil {
+			p.logger.Debug("chain entry probe: no route available")
+		}
+		return
+	}
+
+	timeout := cfg.Timeout
+	if timeout <= 0 {
+		timeout = 10 * time.Second
+	}
+	probeCtx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	conn, err := route.Dial(probeCtx, "tcp", addr)
+	if err != nil {
+		e.marker.Mark()
+		if p.logger != nil {
+			p.logger.Debugf("chain entry probe dial %s failed: %v", addr, err)
+		}
+		return
+	}
+	defer conn.Close()
+
+	if cfg.Type == chain.ProbeTypeHTTP {
+		if err := probe.NewHTTPProber(cfg).Probe(conn); err != nil {
+			e.marker.Mark()
+			if p.logger != nil {
+				p.logger.Debugf("chain entry probe http %s failed: %v", addr, err)
+			}
+			return
+		}
+	}
+
+	e.marker.Reset()
 }

chain/chain_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/metadata"
 	"github.com/go-gost/core/recorder"
+	"github.com/go-gost/core/routing"
 	xlogger "github.com/go-gost/x/logger"
 	xmetadata "github.com/go-gost/x/metadata"
 	"github.com/stretchr/testify/assert"
@@ -787,7 +788,7 @@ func TestNewChainGroup(t *testing.T) {
 	ch2 := NewChain("ch2")
 	g := NewChainGroup(ch1, ch2)
 	require.NotNil(t, g)
-	assert.Len(t, g.chains, 2)
+	assert.Len(t, g.entries, 2)
 }
 
 func TestChainGroup_Route_NoChains(t *testing.T) {
@@ -1758,12 +1759,83 @@ func TestChainGroup_WithSelector(t *testing.T) {
 	assert.Len(t, rt.Nodes(), 1)
 }
 
-func TestChainGroup_Next_NilReceiver(t *testing.T) {
+func TestChainGroup_SelectChain_NilReceiver(t *testing.T) {
 	var g *chainGroup
-	assert.Nil(t, g.next(context.Background()))
+	assert.Nil(t, g.selectChain(context.Background(), "", ""))
 }
 
-func TestChainGroup_Next_EmptyChains(t *testing.T) {
+func TestChainGroup_SelectChain_EmptyChains(t *testing.T) {
 	g := NewChainGroup()
-	assert.Nil(t, g.next(context.Background()))
+	assert.Nil(t, g.selectChain(context.Background(), "", ""))
+}
+
+// hostMatcher matches requests whose Host equals the configured value.
+type hostMatcher struct {
+	host string
+}
+
+func (m *hostMatcher) Match(req *routing.Request) bool {
+	return req != nil && req.Host == m.host
+}
+
+func TestChainGroup_SelectChain_MatcherFilter(t *testing.T) {
+	matchChain := NewChain("match")
+	skipChain := NewChain("skip")
+
+	entries := []*ChainEntry{
+		NewChainEntry(matchChain, &hostMatcher{host: "a.example.com"}, nil),
+		NewChainEntry(skipChain, &hostMatcher{host: "b.example.com"}, nil),
+	}
+	g := NewChainGroup().WithGroupEntries(entries...)
+
+	// Only the entry matching "a.example.com" should be eligible.
+	got := g.selectChain(context.Background(), "tcp", "a.example.com:80", chain.WithHostRouteOption("a.example.com"))
+	require.NotNil(t, got)
+	// selectChain returns the *ChainEntry (so the FailFilter can read its marker),
+	// not the inner *Chain.
+	ce, ok := got.(*ChainEntry)
+	require.True(t, ok)
+	assert.Equal(t, matchChain, ce.chainer)
+
+	// Non-matching host → no eligible entry → nil.
+	assert.Nil(t, g.selectChain(context.Background(), "tcp", "x.example.com:80", chain.WithHostRouteOption("x.example.com")))
+}
+
+func TestChainGroup_Close_StopsProbeGoroutines(t *testing.T) {
+	ch := NewChain("ch")
+	// cmd probe with a short interval; the entry marker count is the observable
+	// signal that the probe goroutine is (or is not) still running.
+	entry := NewChainEntry(ch, nil, &chain.ProbeConfig{
+		Type:     chain.ProbeTypeCmd,
+		Command:  "true",
+		Interval: 10 * time.Millisecond,
+	})
+	g := NewChainGroup().WithGroupEntries(entry)
+
+	// Let the probe tick a few times, then Close().
+	time.Sleep(50 * time.Millisecond)
+	require.NoError(t, g.Close())
+
+	before := entry.Marker().Count()
+	time.Sleep(60 * time.Millisecond)
+	after := entry.Marker().Count()
+
+	// A succeeding cmd probe ("true") never marks, so the count must stay
+	// stable after Close(): the goroutine has stopped ticking.
+	assert.Equal(t, before, after, "probe goroutine should stop ticking after Close()")
+}
+
+func TestChainGroup_Probe_MarksEntryOnCmdFailure(t *testing.T) {
+	ch := NewChain("ch")
+	entry := NewChainEntry(ch, nil, &chain.ProbeConfig{
+		Type:     chain.ProbeTypeCmd,
+		Command:  "false", // always exits non-zero → probe failure
+		Interval: time.Second,
+	})
+	g := NewChainGroup().WithGroupEntries(entry)
+
+	// First probe runs immediately; give it time to mark.
+	time.Sleep(50 * time.Millisecond)
+	assert.NotZero(t, entry.Marker().Count(), "failing cmd probe should mark the entry")
+	require.NoError(t, g.Close())
 }

chain/group.go

@@ -0,0 +1,44 @@
+package chain
+
+import (
+	"context"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/routing"
+	"github.com/go-gost/core/selector"
+)
+
+// ChainEntry wraps a chain.Chainer with an optional matcher and an independent
+// failure marker for chain-level probe tracking. The entry's marker is
+// separate from any node-level markers inside the chain so that probe
+// Reset() cannot undo a node-level failCodes Mark().
+type ChainEntry struct {
+	chainer chain.Chainer
+	matcher routing.Matcher
+	probe   *chain.ProbeConfig
+	marker  selector.Marker
+}
+
+// NewChainEntry creates a ChainEntry. matcher may be nil (unconditional
+// catch-all). probe may be nil (no health check for this entry).
+func NewChainEntry(c chain.Chainer, m routing.Matcher, probe *chain.ProbeConfig) *ChainEntry {
+	return &ChainEntry{
+		chainer: c,
+		matcher: m,
+		probe:   probe,
+		marker:  selector.NewFailMarker(),
+	}
+}
+
+// Route implements chain.Chainer so the entry can be passed directly to the
+// group selector. The selector's FailFilter reads Marker() from the entry,
+// not from the underlying chain — this keeps probe-driven marking independent
+// of any node-level markers.
+func (e *ChainEntry) Route(ctx context.Context, network, address string, opts ...chain.RouteOption) chain.Route {
+	return e.chainer.Route(ctx, network, address, opts...)
+}
+
+// Marker implements selector.Markable.
+func (e *ChainEntry) Marker() selector.Marker {
+	return e.marker
+}

chain/node.go

@@ -0,0 +1,121 @@
+package chain
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/internal/probe"
+)
+
+// StartNodeProbe starts a background goroutine that periodically probes the
+// node's transport. On success the node's marker is reset; on failure the
+// marker is incremented. cfg may be nil (no-op).
+func StartNodeProbe(node *chain.Node, cfg *chain.ProbeConfig, log logger.Logger) {
+	if cfg == nil {
+		return
+	}
+	if cfg.Addr == "" && cfg.Type != chain.ProbeTypeCmd {
+		return
+	}
+	if cfg.Type == chain.ProbeTypeCmd && cfg.Command == "" {
+		return
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	node.SetProbeCancel(cancel)
+	go runNodeProbe(ctx, node, cfg, log)
+}
+
+func runNodeProbe(ctx context.Context, node *chain.Node, cfg *chain.ProbeConfig, log logger.Logger) {
+	interval := cfg.Interval
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	probeNode(node, cfg, log) // first probe immediately
+	for {
+		select {
+		case <-ticker.C:
+			probeNode(node, cfg, log)
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func probeNode(node *chain.Node, cfg *chain.ProbeConfig, log logger.Logger) {
+	// cmd probe runs a shell command directly — no transport connection needed.
+	if cfg.Type == chain.ProbeTypeCmd {
+		timeout := cfg.Timeout
+		if timeout <= 0 {
+			timeout = 10 * time.Second
+		}
+		start := time.Now()
+		err := (&probe.CmdProber{Command: cfg.Command, Timeout: timeout}).Probe()
+		latency := time.Since(start)
+		if err != nil {
+			recordProbe(node, false, latency, err.Error(), log)
+		} else {
+			recordProbe(node, true, latency, "", log)
+		}
+		return
+	}
+
+	timeout := cfg.Timeout
+	if timeout <= 0 {
+		timeout = 10 * time.Second
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	start := time.Now()
+	tr := node.Options().Transport
+	conn, err := tr.Dial(ctx, node.Addr)
+	if err != nil {
+		recordProbe(node, false, time.Since(start), err.Error(), log)
+		return
+	}
+
+	if hc, err2 := tr.Handshake(ctx, conn); err2 == nil {
+		conn = hc
+	} else {
+		conn.Close()
+		recordProbe(node, false, time.Since(start), err2.Error(), log)
+		return
+	}
+
+	latency := time.Since(start)
+	if cfg.Type == chain.ProbeTypeHTTP {
+		err = probe.NewHTTPProber(cfg).Probe(conn)
+		conn.Close()
+		if err != nil {
+			recordProbe(node, false, latency, err.Error(), log)
+			return
+		}
+	} else {
+		conn.Close()
+	}
+
+	recordProbe(node, true, latency, "", log)
+}
+
+func recordProbe(node *chain.Node, success bool, latency time.Duration, errStr string, log logger.Logger) {
+	result := &chain.ProbeResult{
+		Success:   success,
+		Latency:   latency,
+		Error:     errStr,
+		Timestamp: time.Now(),
+	}
+	node.SetProbeResult(result)
+
+	if success {
+		node.Marker().Reset()
+	} else {
+		node.Marker().Mark()
+	}
+
+	log.Debugf("node probe %s: success=%v latency=%v err=%s", node.Name, success, latency, errStr)
+}

chain/node_test.go

@@ -0,0 +1,292 @@
+package chain
+
+import (
+	"context"
+	"errors"
+	"net"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/connector"
+
+	xlogger "github.com/go-gost/x/logger"
+)
+
+// testTransport implements chain.Transporter with real TCP dials.
+type testTransport struct {
+	dialer  *net.Dialer
+	options chain.TransportOptions
+}
+
+func (t *testTransport) Dial(ctx context.Context, addr string) (net.Conn, error) {
+	return t.dialer.DialContext(ctx, "tcp", addr)
+}
+
+func (t *testTransport) Handshake(ctx context.Context, conn net.Conn) (net.Conn, error) {
+	return conn, nil
+}
+
+func (t *testTransport) Connect(ctx context.Context, conn net.Conn, network, address string) (net.Conn, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (t *testTransport) Bind(ctx context.Context, conn net.Conn, network, address string, opts ...connector.BindOption) (net.Listener, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (t *testTransport) Multiplex() bool { return false }
+
+func (t *testTransport) Options() *chain.TransportOptions { return &t.options }
+
+func (t *testTransport) Copy() chain.Transporter { return t }
+
+func TestNodeProbeTCP(t *testing.T) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	// accept one connection, then close immediately (TCP probe only needs dial+handshake)
+	go func() {
+		for {
+			conn, _ := l.Accept()
+			if conn != nil {
+				conn.Close()
+			}
+		}
+	}()
+
+	addr := l.Addr().String()
+	tr := &testTransport{dialer: &net.Dialer{Timeout: 2 * time.Second}}
+	node := chain.NewNode("test", addr, chain.TransportNodeOption(tr))
+
+	cfg := &chain.ProbeConfig{
+		Type:     chain.ProbeTypeTCP,
+		Addr:     addr,
+		Interval: 100 * time.Millisecond,
+		Timeout:  2 * time.Second,
+	}
+
+	StartNodeProbe(node, cfg, xlogger.Nop())
+
+	// Wait for first probe
+	time.Sleep(300 * time.Millisecond)
+
+	pr := node.ProbeResult()
+	if pr == nil || !pr.Success {
+		t.Fatalf("expected successful probe, got %+v", pr)
+	}
+
+	// Close listener → next probe fails
+	l.Close()
+	time.Sleep(300 * time.Millisecond)
+
+	pr = node.ProbeResult()
+	if pr == nil || pr.Success {
+		t.Fatalf("expected failed probe after listener close, got %+v", pr)
+	}
+	if node.Marker().Count() == 0 {
+		t.Error("expected marker count > 0 after failure")
+	}
+
+	node.Close()
+}
+
+func TestNodeProbeClose(t *testing.T) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	go func() {
+		for {
+			conn, _ := l.Accept()
+			if conn != nil {
+				conn.Close()
+			}
+		}
+	}()
+
+	addr := l.Addr().String()
+	tr := &testTransport{dialer: &net.Dialer{Timeout: 2 * time.Second}}
+	node := chain.NewNode("test", addr, chain.TransportNodeOption(tr))
+
+	cfg := &chain.ProbeConfig{
+		Type:     chain.ProbeTypeTCP,
+		Addr:     addr,
+		Interval: 100 * time.Millisecond,
+		Timeout:  2 * time.Second,
+	}
+
+	StartNodeProbe(node, cfg, xlogger.Nop())
+	time.Sleep(150 * time.Millisecond)
+
+	// Snapshot result before close
+	lastSuccess := node.ProbeResult().Success
+	if !lastSuccess {
+		t.Fatal("expected initial success before close")
+	}
+
+	node.Close()
+
+	// Capture marker count right after close
+	countAfterClose := node.Marker().Count()
+
+	// Wait longer than probe interval — no more updates after close
+	time.Sleep(300 * time.Millisecond)
+
+	// Marker count should not increase after close (no more probes running)
+	if node.Marker().Count() != countAfterClose {
+		t.Errorf("marker changed after close: was %d, now %d", countAfterClose, node.Marker().Count())
+	}
+}
+
+func TestNodeProbeDisabled(t *testing.T) {
+	node := chain.NewNode("no-probe", "addr")
+	// nil config → no-op
+	StartNodeProbe(node, nil, xlogger.Nop())
+	if pr := node.ProbeResult(); pr != nil {
+		t.Error("expected nil probe result for disabled probe")
+	}
+	// empty addr → no-op
+	StartNodeProbe(node, &chain.ProbeConfig{}, xlogger.Nop())
+	if pr := node.ProbeResult(); pr != nil {
+		t.Error("expected nil probe result for empty addr")
+	}
+}
+
+func TestNodeProbeCmd(t *testing.T) {
+	// Cmd probe doesn't need a transport — StartNodeProbe skips the addr check.
+	node := chain.NewNode("cmd-test", "")
+	cfg := &chain.ProbeConfig{
+		Type:     chain.ProbeTypeCmd,
+		Command:  "true",
+		Interval: 100 * time.Millisecond,
+		Timeout:  2 * time.Second,
+	}
+
+	StartNodeProbe(node, cfg, xlogger.Nop())
+	time.Sleep(300 * time.Millisecond)
+
+	pr := node.ProbeResult()
+	if pr == nil || !pr.Success {
+		t.Fatalf("expected cmd probe success, got %+v", pr)
+	}
+	if node.Marker().Count() != 0 {
+		t.Errorf("expected marker count 0 after success, got %d", node.Marker().Count())
+	}
+
+	// Switch to failing command
+	cfg2 := &chain.ProbeConfig{
+		Type:     chain.ProbeTypeCmd,
+		Command:  "false",
+		Interval: 100 * time.Millisecond,
+		Timeout:  2 * time.Second,
+	}
+	node.Close() // stop old probe
+	node2 := chain.NewNode("cmd-test-2", "")
+	StartNodeProbe(node2, cfg2, xlogger.Nop())
+	time.Sleep(300 * time.Millisecond)
+
+	pr2 := node2.ProbeResult()
+	if pr2 == nil || pr2.Success {
+		t.Fatalf("expected cmd probe failure for exit 1, got %+v", pr2)
+	}
+	if node2.Marker().Count() == 0 {
+		t.Error("expected marker count > 0 after cmd failure")
+	}
+
+	node2.Close()
+}
+
+func TestNodeProbeCmdDisabled(t *testing.T) {
+	// cmd probe without command → no-op
+	node := chain.NewNode("cmd-disabled", "")
+	cfg := &chain.ProbeConfig{
+		Type:    chain.ProbeTypeCmd,
+		Command: "",
+	}
+	StartNodeProbe(node, cfg, xlogger.Nop())
+	if pr := node.ProbeResult(); pr != nil {
+		t.Error("expected nil probe result for empty command")
+	}
+}
+
+func TestNodeProbeHTTP(t *testing.T) {
+	// Start a small HTTP server
+	mux := &httpTestMux{}
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	go func() {
+		for {
+			conn, err := l.Accept()
+			if err != nil {
+				return
+			}
+			go mux.serve(conn)
+		}
+	}()
+
+	addr := l.Addr().String()
+	tr := &testTransport{dialer: &net.Dialer{Timeout: 2 * time.Second}}
+	node := chain.NewNode("test-http", addr, chain.TransportNodeOption(tr))
+
+	cfg := &chain.ProbeConfig{
+		Type:           chain.ProbeTypeHTTP,
+		Addr:           addr,
+		Interval:       100 * time.Millisecond,
+		Timeout:        2 * time.Second,
+		HTTPPath:       "/health",
+		ExpectedStatus: 200,
+	}
+
+	// Case 1: server returns 200
+	mux.status.Store(200)
+	StartNodeProbe(node, cfg, xlogger.Nop())
+	time.Sleep(300 * time.Millisecond)
+
+	pr := node.ProbeResult()
+	if pr == nil || !pr.Success {
+		t.Fatalf("expected HTTP 200 probe success, got %+v", pr)
+	}
+
+	// Case 2: server returns 500
+	mux.status.Store(500)
+	time.Sleep(300 * time.Millisecond)
+
+	pr = node.ProbeResult()
+	if pr == nil || pr.Success {
+		t.Fatalf("expected HTTP 500 probe failure, got %+v", pr)
+	}
+
+	node.Close()
+}
+
+// httpTestMux is a minimal HTTP server that returns a configurable status.
+type httpTestMux struct {
+	status atomic.Int32
+}
+
+func (m *httpTestMux) serve(conn net.Conn) {
+	defer conn.Close()
+	buf := make([]byte, 1024)
+	n, _ := conn.Read(buf)
+	// Parse just enough to construct a response
+	body := "HTTP/1.1 000 OK\r\nContent-Length: 0\r\nConnection: close\r\n\r\n"
+	switch m.status.Load() {
+	case 200:
+		body = "HTTP/1.1 200 OK\r\nContent-Length: 0\r\nConnection: close\r\n\r\n"
+	case 500:
+		body = "HTTP/1.1 500 Internal Server Error\r\nContent-Length: 0\r\nConnection: close\r\n\r\n"
+	}
+	_ = n
+	conn.Write([]byte(body))
+}

chain/router.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"net"
 	"strings"
 	"time"
@@ -49,6 +50,19 @@ func (r *Router) Options() *chain.RouterOptions {
 	return &r.options
 }
 
+// Close releases resources held by the router's chain. A chain that owns
+// background goroutines (e.g. a chainGroup running liveness probes) is closed
+// here so its goroutines stop when the service shuts down or is reloaded.
+func (r *Router) Close() error {
+	if r == nil {
+		return nil
+	}
+	if c, ok := r.options.Chain.(io.Closer); ok {
+		return c.Close()
+	}
+	return nil
+}
+
 // Dial establishes a connection to the target address through the configured
 // chain. It resolves the address, records the dial event, retries up to
 // Retries+1 times, and returns the resulting connection.

config/cmd/cmd.go

@@ -397,15 +397,24 @@ func buildServiceConfig(url *url.URL) ([]*config.ServiceConfig, error) {
 		listener = schemes[1]
 	}
 
-	// For path-based protocols (Unix socket listeners and serial), use path as address
+	// Decide path-based from the scheme before registry remaps listener to tcp.
 	isPathBasedProtocol := listener == "unix" || listener == "runix" || listener == "serial"
+	for _, s := range schemes {
+		if s == "unix" || s == "runix" || s == "serial" {
+			isPathBasedProtocol = true
+			break
+		}
+	}
+	// A path-based protocol with an empty host (three-slash URL like
+	// unix:///var/run/sock) uses the path as the absolute listen address and
+	// has no forward target. With a non-empty host (two-slash URL like
+	// unix://sock/other.sock), the host is the listen address and any path is a
+	// forward target (port-forward to another socket), handled below.
+	isPathAddr := isPathBasedProtocol && url.Host == ""
 
 	var addrs []string
-	if isPathBasedProtocol {
-		path := url.EscapedPath()
-		if url.Host != "" {
-			addrs = append(addrs, url.Host+strings.TrimPrefix(path, "/"))
-		} else if path != "" {
+	if isPathAddr {
+		if path := url.EscapedPath(); path != "" {
 			addrs = append(addrs, path)
 		} else {
 			addrs = append(addrs, url.Host)
@@ -436,8 +445,10 @@ func buildServiceConfig(url *url.URL) ([]*config.ServiceConfig, error) {
 
 	var nodes []*config.ForwardNodeConfig
 	// forward mode
-	// For path-based protocols, path is address not forward target
-	if remotes := strings.Trim(url.EscapedPath(), "/"); remotes != "" && !isPathBasedProtocol {
+	// A path-based protocol with an empty host (e.g. unix:///abs.sock) treats
+	// the path as the listen address, not a forward target. With a host
+	// (e.g. unix://a.sock/b.sock) the path is a forward target.
+	if remotes := strings.Trim(url.EscapedPath(), "/"); remotes != "" && !isPathAddr {
 		i := 0
 		for _, addr := range strings.Split(remotes, ",") {
 			addrs := xnet.AddrPortRange(addr).Addrs()
@@ -466,6 +477,17 @@ func buildServiceConfig(url *url.URL) ([]*config.ServiceConfig, error) {
 		}
 	}
 
+	// stdio listener uses url.Host as the forwarding target.
+	if listener == "stdio" && len(nodes) == 0 && url.Host != "" {
+		nodes = append(nodes, &config.ForwardNodeConfig{
+			Name: fmt.Sprintf("%starget-0", namePrefix),
+			Addr: url.Host,
+		})
+		if handler == "auto" {
+			handler = "tcp"
+		}
+	}
+
 	if len(nodes) > 0 {
 		if len(services) == 1 {
 			services[0].Forwarder = &config.ForwarderConfig{
@@ -629,6 +651,18 @@ func buildNodeConfig(url *url.URL, m map[string]any) (*config.NodeConfig, error)
 		dialer = schemes[1]
 	}
 
+	// Path-based address logic must use the requested scheme, not the
+	// registry fallback (unix/serial often remap to http/tcp when only
+	// the CLI registry is partially populated, or in unit tests).
+	isPathBasedProtocol := dialer == "unix" || dialer == "serial" ||
+		connector == "unix" || connector == "serial"
+	for _, s := range schemes {
+		if s == "unix" || s == "serial" || s == "runix" {
+			isPathBasedProtocol = true
+			break
+		}
+	}
+
 	md := mdx.NewMetadata(m)
 
 	if c := registry.ConnectorRegistry().Get(connector); c == nil {
@@ -714,20 +748,14 @@ func buildNodeConfig(url *url.URL, m map[string]any) (*config.NodeConfig, error)
 		nodeMd[k] = v
 	}
 
-	// For path-based protocols (Unix socket dialers and serial), use path as address
+	// For path-based protocols (Unix socket dialers and serial), use path as address.
+	// Three-slash URLs (empty host) give the absolute socket path; two-slash URLs
+	// use the host as the socket. The path on a host form is not part of the node
+	// address (it is a forward target for services, ignored for nodes).
 	var nodeAddr string
-	isPathBasedProtocol := dialer == "unix" || dialer == "serial"
-	if isPathBasedProtocol {
-		path := url.EscapedPath()
-		if url.Host != "" {
-			// Two slashes: host + path = relative path
-			nodeAddr = url.Host + strings.TrimPrefix(path, "/")
-		} else if path != "" {
-			// Three slashes: path is absolute (keep leading slash)
-			nodeAddr = path
-		} else {
-			nodeAddr = url.Host
-		}
+	if isPathBasedProtocol && url.Host == "" {
+		// Three slashes: path is absolute (keep leading slash)
+		nodeAddr = url.EscapedPath()
 	} else {
 		nodeAddr = url.Host
 	}

config/cmd/cmd_test.go

@@ -1765,10 +1765,10 @@ func TestBuildNodeConfig_TLSWithCert(t *testing.T) {
 	}
 }
 
-func TestBuildNodeConfig_UnixFallsBackToTCP(t *testing.T) {
+func TestBuildNodeConfig_UnixAbsolutePath(t *testing.T) {
 	// http+unix scheme: connector=http, dialer=unix.
-	// Since unix is not in the test registry, dialer falls back to tcp,
-	// and the path-based address logic (dialer=="unix") is skipped.
+	// Dialer falls back to tcp when unix is not in the test registry, but
+	// the absolute socket path from a three-slash URL must still be kept.
 	rawURL := "http+unix:///var/run/socket"
 	u, _ := url.Parse(rawURL)
 
@@ -1780,12 +1780,68 @@ func TestBuildNodeConfig_UnixFallsBackToTCP(t *testing.T) {
 	if node.Dialer.Type != "tcp" {
 		t.Errorf("Dialer.Type = %q, want tcp (unix not in test registry)", node.Dialer.Type)
 	}
-	// Addr is url.Host ("") since no host component in three-slash unix URL
-	if node.Addr != "" {
-		t.Errorf("Addr = %q, want empty", node.Addr)
+	if node.Addr != "/var/run/socket" {
+		t.Errorf("Addr = %q, want /var/run/socket", node.Addr)
 	}
 }
 
+func TestBuildNodeConfig_UnixRelativeHost(t *testing.T) {
+	u, _ := url.Parse("unix://docker.sock")
+	node, err := buildNodeConfig(u, map[string]any{})
+	if err != nil {
+		t.Fatalf("buildNodeConfig: %v", err)
+	}
+	if node.Addr != "docker.sock" {
+		t.Errorf("Addr = %q, want docker.sock", node.Addr)
+	}
+}
+
+func TestBuildServiceConfig_UnixAbsolutePath(t *testing.T) {
+	// three-slash: path is the absolute socket listen address, no forward target
+	svcs, err := buildServiceConfig(mustURL("unix:///var/run/gost.sock"))
+	if err != nil {
+		t.Fatalf("buildServiceConfig: %v", err)
+	}
+	if len(svcs) != 1 {
+		t.Fatalf("len(svcs) = %d, want 1", len(svcs))
+	}
+	if svcs[0].Addr != "/var/run/gost.sock" {
+		t.Errorf("Addr = %q, want /var/run/gost.sock", svcs[0].Addr)
+	}
+	if svcs[0].Forwarder != nil {
+		t.Errorf("Forwarder = %+v, want nil (no forward target)", svcs[0].Forwarder)
+	}
+}
+
+func TestBuildServiceConfig_UnixPortForward(t *testing.T) {
+	// two-slash: host is the listen socket, path is a forward target socket
+	svcs, err := buildServiceConfig(mustURL("unix://gost.sock/gost2.sock"))
+	if err != nil {
+		t.Fatalf("buildServiceConfig: %v", err)
+	}
+	if len(svcs) != 1 {
+		t.Fatalf("len(svcs) = %d, want 1", len(svcs))
+	}
+	if svcs[0].Addr != "gost.sock" {
+		t.Errorf("Addr = %q, want gost.sock", svcs[0].Addr)
+	}
+	if svcs[0].Forwarder == nil || len(svcs[0].Forwarder.Nodes) == 0 {
+		t.Fatalf("Forwarder = %+v, want a forward target node", svcs[0].Forwarder)
+	}
+	if got := svcs[0].Forwarder.Nodes[0].Addr; got != "gost2.sock" {
+		t.Errorf("forward Addr = %q, want gost2.sock", got)
+	}
+}
+
+func mustURL(raw string) *url.URL {
+	u, err := url.Parse(raw)
+	if err != nil {
+		panic(err)
+	}
+	return u
+}
+
+
 func TestBuildServiceConfig_RelayTLSForward(t *testing.T) {
 	// relay+tls scheme: handler=relay, listener=tls.
 	// relay not in test registry → handler falls back to auto, listener falls back to tcp.

config/config.go

@@ -4,12 +4,15 @@ import (
 	"encoding/json"
 	"io"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
+	yaml "github.com/goccy/go-yaml"
+	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/viper"
-	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -26,8 +29,21 @@ func init() {
 var (
 	global    = &Config{}
 	globalMux sync.RWMutex
+
+	// configFile remembers the last file loaded via ReadFile so the API can
+	// save back to the same location (issue go-gost/x#123).
+	configFile atomic.Value // string
 )
 
+// ConfigFile returns the path of the last config file loaded via ReadFile,
+// or an empty string when the config came from stdin, a URL, or inline JSON.
+func ConfigFile() string {
+	if s, ok := configFile.Load().(string); ok {
+		return s
+	}
+	return ""
+}
+
 func Global() *Config {
 	globalMux.RLock()
 	defer globalMux.RUnlock()
@@ -132,6 +148,7 @@ type TLSOptions struct {
 type PluginConfig struct {
 	Type    string        `json:"type"`
 	Addr    string        `json:"addr"`
+	Command []string      `yaml:"command,omitempty" json:"command,omitempty"`
 	TLS     *TLSConfig    `yaml:",omitempty" json:"tls,omitempty"`
 	Timeout time.Duration `yaml:",omitempty" json:"timeout,omitempty"`
 	Token   string        `yaml:",omitempty" json:"token,omitempty"`
@@ -157,6 +174,7 @@ type SelectorConfig struct {
 	Strategy    string        `json:"strategy"`
 	MaxFails    int           `yaml:"maxFails" json:"maxFails"`
 	FailTimeout time.Duration `yaml:"failTimeout" json:"failTimeout"`
+	MaxLatency  time.Duration `yaml:"maxLatency,omitempty" json:"maxLatency,omitempty"`
 }
 
 type AdmissionConfig struct {
@@ -284,6 +302,13 @@ type RecorderConfig struct {
 	Plugin *PluginConfig  `yaml:",omitempty" json:"plugin,omitempty"`
 }
 
+// P2PConfig defines a named p2p tunnel provider, currently backed by an
+// external gRPC plugin process.
+type P2PConfig struct {
+	Name   string        `json:"name"`
+	Plugin *PluginConfig `yaml:",omitempty" json:"plugin,omitempty"`
+}
+
 type FileRecorder struct {
 	Path     string             `json:"path"`
 	Sep      string             `yaml:",omitempty" json:"sep,omitempty"`
@@ -316,6 +341,38 @@ 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"`
+}
+
+// CacheConfig defines a named cache store. Memory and Redis backends are
+// supported; other backends (file, plugin) are follow-ups.
+type CacheConfig struct {
+	Name   string       `json:"name"`
+	Memory *MemoryCache `yaml:",omitempty" json:"memory,omitempty"`
+	Redis  *RedisCache  `yaml:",omitempty" json:"redis,omitempty"`
+}
+
+// RedisCache configures the Redis cache backend.
+type RedisCache struct {
+	Addr     string        `json:"addr"`
+	DB       int           `yaml:",omitempty" json:"db,omitempty"`
+	Username string        `yaml:",omitempty" json:"username,omitempty"`
+	Password string        `yaml:",omitempty" json:"password,omitempty"`
+	TTL      time.Duration `yaml:",omitempty" json:"ttl,omitempty"`
+	Key      string        `yaml:",omitempty" json:"key,omitempty"` // key prefix, default "gost:cache:"
+}
+
+// MemoryCache configures the in-memory cache backend.
+type MemoryCache struct {
+	TTL             time.Duration `yaml:",omitempty" json:"ttl,omitempty"`
+	MaxSize         int           `yaml:"maxSize,omitempty" json:"maxSize,omitempty"`
+	MaxBytes        int64         `yaml:"maxBytes,omitempty" json:"maxBytes,omitempty"`
+	CleanupInterval time.Duration `yaml:"cleanupInterval,omitempty" json:"cleanupInterval,omitempty"`
+	Eviction        string        `yaml:",omitempty" json:"eviction,omitempty"` // "oldest" | "lru"
+}
+
 type LimiterConfig struct {
 	Name   string        `json:"name"`
 	Limits []string      `yaml:",omitempty" json:"limits,omitempty"`
@@ -360,9 +417,21 @@ type ForwarderConfig struct {
 	// Deprecated: use hop instead
 	Name string `yaml:",omitempty" json:"name,omitempty"`
 	// the referenced hop name
-	Hop      string               `yaml:",omitempty" json:"hop,omitempty"`
-	Selector *SelectorConfig      `yaml:",omitempty" json:"selector,omitempty"`
-	Nodes    []*ForwardNodeConfig `json:"nodes"`
+	Hop      string                 `yaml:",omitempty" json:"hop,omitempty"`
+	Selector *SelectorConfig        `yaml:",omitempty" json:"selector,omitempty"`
+	Nodes    []*ForwardNodeConfig   `json:"nodes"`
+	HopGroup *ForwardHopGroupConfig `yaml:"hopGroup,omitempty" json:"hopGroup,omitempty"`
+}
+
+type ForwardHopGroupConfig struct {
+	Hops     []*ForwardHopConfig `yaml:",omitempty" json:"hops,omitempty"`
+	Selector *SelectorConfig     `yaml:",omitempty" json:"selector,omitempty"`
+}
+
+type ForwardHopConfig struct {
+	Hop     string             `yaml:",omitempty" json:"hop,omitempty"`
+	Matcher *NodeMatcherConfig `yaml:",omitempty" json:"matcher,omitempty"`
+	Probe   *ProbeConfig       `yaml:",omitempty" json:"probe,omitempty"`
 }
 
 type ForwardNodeConfig struct {
@@ -384,6 +453,7 @@ type ForwardNodeConfig struct {
 	Auth     *AuthConfig     `yaml:",omitempty" json:"auth,omitempty"`
 	HTTP     *HTTPNodeConfig `yaml:",omitempty" json:"http,omitempty"`
 	TLS      *TLSNodeConfig  `yaml:",omitempty" json:"tls,omitempty"`
+	Probe    *ProbeConfig    `yaml:",omitempty" json:"probe,omitempty"`
 	Metadata map[string]any  `yaml:",omitempty" json:"metadata,omitempty"`
 }
 
@@ -397,6 +467,20 @@ type HTTPBodyRewriteConfig struct {
 	Type        string
 	Match       string
 	Replacement string
+	// name of the rewriter plugin (via registry)
+	Rewriter     string `yaml:",omitempty" json:"rewriter,omitempty"`
+	MaxChunkSize int    `yaml:"maxChunkSize,omitempty" json:"maxChunkSize,omitempty"`
+}
+
+type HTTPHeaderRewriteConfig struct {
+	// Name is the header name regex, e.g. "(?i)^(location|set-cookie)$".
+	Name string
+	// Match is the header value regex.
+	Match string
+	// Replacement is the replacement string.
+	Replacement string
+	// Rewriter is the name of the rewriter plugin (via registry).
+	Rewriter string `yaml:",omitempty" json:"rewriter,omitempty"`
 }
 
 type NodeFilterConfig struct {
@@ -405,14 +489,44 @@ 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"`
+	// BodySize is the max request body prefix (bytes) exposed to BodyRegexp
+	// and BodyJSON matchers. 0 (default) uses DefaultMatcherBodySize (1MB).
+	// Capped at MaxMatcherBodySize (10MB). Only takes effect under an HTTP
+	// sniffing handler whose sniffer reads the body prefix before node selection.
+	BodySize int `yaml:",omitempty" json:"bodySize,omitempty"`
+}
+
+// ProbeConfig holds the configuration for a node-level liveness probe.
+type ProbeConfig struct {
+	Type           string            `json:"type"`
+	Addr           string            `json:"addr,omitempty"`
+	Interval       time.Duration     `json:"interval"`
+	Timeout        time.Duration     `json:"timeout"`
+	HTTPPath       string            `yaml:"httpPath,omitempty" json:"httpPath,omitempty"`
+	HTTPHost       string            `yaml:"httpHost,omitempty" json:"httpHost,omitempty"`
+	HTTPHeaders    map[string]string `yaml:"httpHeaders,omitempty" json:"httpHeaders,omitempty"`
+	ExpectedStatus int               `yaml:"expectedStatus,omitempty" json:"expectedStatus,omitempty"`
+	Command        string            `yaml:"command,omitempty" json:"command,omitempty"`
 }
 
 type HTTPNodeConfig struct {
 	// rewrite host header
 	Host string `yaml:",omitempty" json:"host,omitempty"`
+	// regex matched against the request path to derive Host; Host becomes a
+	// replacement template ($1, $2, ...) when set.
+	HostPattern string `yaml:"hostPattern,omitempty" json:"hostPattern,omitempty"`
 	// Deprecated: use requestHeader instead
 	Header map[string]string `yaml:",omitempty" json:"header,omitempty"`
 	// additional request header
@@ -430,6 +544,14 @@ type HTTPNodeConfig struct {
 	// rewrite response body
 	RewriteResponseBody []HTTPBodyRewriteConfig `yaml:"rewriteResponseBody,omitempty" json:"rewriteResponseBody,omitempty"`
 
+	// rewrite request header values
+	RewriteRequestHeader []HTTPHeaderRewriteConfig `yaml:"rewriteRequestHeader,omitempty" json:"rewriteRequestHeader,omitempty"`
+	// rewrite response header values
+	RewriteResponseHeader []HTTPHeaderRewriteConfig `yaml:"rewriteResponseHeader,omitempty" json:"rewriteResponseHeader,omitempty"`
+
+	// comma-separated response status codes marking the node failed, e.g. "429,5xx"
+	FailCodes string `yaml:"failCodes,omitempty" json:"failCodes,omitempty"`
+
 	// HTTP basic auth
 	Auth *AuthConfig `yaml:",omitempty" json:"auth,omitempty"`
 }
@@ -478,7 +600,9 @@ type ServiceConfig struct {
 	Logger     string            `yaml:",omitempty" json:"logger,omitempty"`
 	Loggers    []string          `yaml:",omitempty" json:"loggers,omitempty"`
 	Observer   string            `yaml:",omitempty" json:"observer,omitempty"`
+	Rewriter   string            `yaml:",omitempty" json:"rewriter,omitempty"`
 	Recorders  []*RecorderObject `yaml:",omitempty" json:"recorders,omitempty"`
+	Cache      string            `yaml:",omitempty" json:"cache,omitempty"`
 	Handler    *HandlerConfig    `yaml:",omitempty" json:"handler,omitempty"`
 	Listener   *ListenerConfig   `yaml:",omitempty" json:"listener,omitempty"`
 	Forwarder  *ForwarderConfig  `yaml:",omitempty" json:"forwarder,omitempty"`
@@ -566,9 +690,39 @@ type ChainConfig struct {
 	Metadata map[string]any `yaml:",omitempty" json:"metadata,omitempty"`
 }
 
+type ChainGroupEntry struct {
+	Chain   string             `yaml:",omitempty" json:"chain,omitempty"`
+	Matcher *NodeMatcherConfig `yaml:",omitempty" json:"matcher,omitempty"`
+	Probe   *ProbeConfig       `yaml:",omitempty" json:"probe,omitempty"`
+}
+
+// gostDecodeHook is a composite mapstructure decode hook that handles custom
+// type conversions needed by GOST config fields. viper's internal unmarshalling
+// never calls yaml.Unmarshaler / json.Unmarshaler on leaf types, so the hook is
+// the only way to support these.
+func gostDecodeHook() mapstructure.DecodeHookFunc {
+	return func(f, t reflect.Type, data any) (any, error) {
+		// Plain string → ChainGroupEntry: backward compat for "chains: [a, b]".
+		if t == reflect.TypeOf(ChainGroupEntry{}) {
+			if s, ok := data.(string); ok {
+				return ChainGroupEntry{Chain: s}, nil
+			}
+			return data, nil
+		}
+		// String → time.Duration: accept "10s", "1m", etc. in YAML/JSON.
+		if t == reflect.TypeOf(time.Duration(0)) {
+			if s, ok := data.(string); ok {
+				return time.ParseDuration(s)
+			}
+			return data, nil
+		}
+		return data, nil
+	}
+}
+
 type ChainGroupConfig struct {
-	Chains   []string        `yaml:",omitempty" json:"chains,omitempty"`
-	Selector *SelectorConfig `yaml:",omitempty" json:"selector,omitempty"`
+	Chains   []*ChainGroupEntry `yaml:",omitempty" json:"chains,omitempty"`
+	Selector *SelectorConfig    `yaml:",omitempty" json:"selector,omitempty"`
 }
 
 type HopConfig struct {
@@ -612,6 +766,7 @@ type NodeConfig struct {
 	Matcher  *NodeMatcherConfig `yaml:",omitempty" json:"matcher,omitempty"`
 	HTTP     *HTTPNodeConfig    `yaml:",omitempty" json:"http,omitempty"`
 	TLS      *TLSNodeConfig     `yaml:",omitempty" json:"tls,omitempty"`
+	Probe    *ProbeConfig       `yaml:",omitempty" json:"probe,omitempty"`
 	Metadata map[string]any     `yaml:",omitempty" json:"metadata,omitempty"`
 }
 
@@ -628,6 +783,9 @@ 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"`
+	P2Ps       []*P2PConfig       `yaml:"p2ps,omitempty" json:"p2ps,omitempty"`
+	Caches     []*CacheConfig     `yaml:",omitempty" json:"caches,omitempty"`
 	Limiters   []*LimiterConfig   `yaml:",omitempty" json:"limiters,omitempty"`
 	Quotas     []*QuotaConfig     `yaml:",omitempty" json:"quotas,omitempty"`
 	CLimiters  []*LimiterConfig   `yaml:"climiters,omitempty" json:"climiters,omitempty"`
@@ -646,7 +804,7 @@ func (c *Config) Load() error {
 		return err
 	}
 
-	return v.Unmarshal(c)
+	return v.Unmarshal(c, viper.DecodeHook(gostDecodeHook()))
 }
 
 func (c *Config) Read(r io.Reader, configType string) error {
@@ -655,7 +813,7 @@ func (c *Config) Read(r io.Reader, configType string) error {
 		return err
 	}
 
-	return v.Unmarshal(c)
+	return v.Unmarshal(c, viper.DecodeHook(gostDecodeHook()))
 }
 
 func (c *Config) ReadFile(file string) error {
@@ -664,7 +822,8 @@ func (c *Config) ReadFile(file string) error {
 	if err := v.ReadInConfig(); err != nil {
 		return err
 	}
-	return v.Unmarshal(c)
+	configFile.Store(file)
+	return v.Unmarshal(c, viper.DecodeHook(gostDecodeHook()))
 }
 
 func (c *Config) Write(w io.Writer, format string) error {
@@ -677,9 +836,8 @@ func (c *Config) Write(w io.Writer, format string) error {
 	case "yaml":
 		fallthrough
 	default:
-		enc := yaml.NewEncoder(w)
+		enc := yaml.NewEncoder(w, yaml.Indent(2))
 		defer enc.Close()
-		enc.SetIndent(2)
 
 		return enc.Encode(c)
 	}

config/loader/loader.go

@@ -9,6 +9,7 @@ import (
 	"github.com/go-gost/core/admission"
 	"github.com/go-gost/core/auth"
 	"github.com/go-gost/core/bypass"
+	"github.com/go-gost/core/cache"
 	"github.com/go-gost/core/chain"
 	"github.com/go-gost/core/hop"
 	"github.com/go-gost/core/hosts"
@@ -22,12 +23,14 @@ 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"
 	admission_parser "github.com/go-gost/x/config/parsing/admission"
 	auth_parser "github.com/go-gost/x/config/parsing/auth"
 	bypass_parser "github.com/go-gost/x/config/parsing/bypass"
+	cache_parser "github.com/go-gost/x/config/parsing/cache"
 	chain_parser "github.com/go-gost/x/config/parsing/chain"
 	hop_parser "github.com/go-gost/x/config/parsing/hop"
 	hosts_parser "github.com/go-gost/x/config/parsing/hosts"
@@ -35,13 +38,16 @@ import (
 	limiter_parser "github.com/go-gost/x/config/parsing/limiter"
 	logger_parser "github.com/go-gost/x/config/parsing/logger"
 	observer_parser "github.com/go-gost/x/config/parsing/observer"
+	p2p_parser "github.com/go-gost/x/config/parsing/p2p"
 	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"
 	quota "github.com/go-gost/x/limiter/quota"
+	xp2p "github.com/go-gost/x/p2p"
 	"github.com/go-gost/x/registry"
 )
 
@@ -244,6 +250,36 @@ 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[xp2p.TunnelProvider]
+		for _, c := range cfg.P2Ps {
+			entries = append(entries, named[xp2p.TunnelProvider]{c.Name, p2p_parser.ParseP2P(c)})
+		}
+		if err := registerGroup(entries, registry.P2PRegistry()); err != nil {
+			return err
+		}
+	}
+
+	{
+		var entries []named[cache.Cache]
+		for _, c := range cfg.Caches {
+			entries = append(entries, named[cache.Cache]{c.Name, cache_parser.ParseCache(c)})
+		}
+		if err := registerGroup(entries, registry.CacheRegistry()); err != nil {
+			return err
+		}
+	}
+
 	{
 		var entries []named[traffic.TrafficLimiter]
 		for _, c := range cfg.Limiters {

config/parsing/admission/parse.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	"github.com/go-gost/x/registry"
 )
 
@@ -24,6 +25,9 @@ func ParseAdmission(cfg *config.AdmissionConfig) admission.Admission {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/auth/parse.go

@@ -15,6 +15,7 @@ import (
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	"github.com/go-gost/x/registry"
 )
 
@@ -27,6 +28,9 @@ func ParseAuther(cfg *config.AutherConfig) auth.Authenticator {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/bypass/parse.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	"github.com/go-gost/x/registry"
 )
 
@@ -23,6 +24,9 @@ func ParseBypass(cfg *config.BypassConfig) bypass.Bypass {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/cache/parse.go

@@ -0,0 +1,44 @@
+package cache
+
+import (
+	"strings"
+
+	"github.com/go-gost/core/cache"
+	"github.com/go-gost/core/logger"
+	xcache "github.com/go-gost/x/cache"
+	"github.com/go-gost/x/config"
+)
+
+// ParseCache converts a CacheConfig into a cache.Cache. Memory and Redis
+// backends are supported. Returns nil when cfg is nil or no backend is
+// configured.
+func ParseCache(cfg *config.CacheConfig) cache.Cache {
+	if cfg == nil {
+		return nil
+	}
+
+	if cfg.Memory != nil {
+		return xcache.NewMemoryCache(xcache.Options{
+			DefaultTTL:      cfg.Memory.TTL,
+			MaxSize:         cfg.Memory.MaxSize,
+			MaxBytes:        cfg.Memory.MaxBytes,
+			CleanupInterval: cfg.Memory.CleanupInterval,
+			Eviction:        xcache.EvictionPolicy(strings.ToLower(cfg.Memory.Eviction)),
+			Logger:          logger.Default(),
+		})
+	}
+
+	if cfg.Redis != nil {
+		return xcache.NewRedisCache(xcache.RedisOptions{
+			Addr:       cfg.Redis.Addr,
+			DB:         cfg.Redis.DB,
+			Username:   cfg.Redis.Username,
+			Password:   cfg.Redis.Password,
+			DefaultTTL: cfg.Redis.TTL,
+			KeyPrefix:  cfg.Redis.Key,
+			Logger:     logger.Default(),
+		})
+	}
+
+	return nil
+}

config/parsing/hop/parse.go

@@ -19,6 +19,8 @@ import (
 	"github.com/go-gost/x/internal/plugin"
 	"github.com/go-gost/x/metadata"
 	mdutil "github.com/go-gost/x/metadata/util"
+	xplugin "github.com/go-gost/x/plugin"
+	xs "github.com/go-gost/x/selector"
 )
 
 // ParseHop converts a HopConfig into a hop.Hop. It resolves plugin backends
@@ -31,6 +33,9 @@ func ParseHop(cfg *config.HopConfig, log logger.Logger) (hop.Hop, error) {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{
@@ -158,10 +163,21 @@ func ParseHop(cfg *config.HopConfig, log logger.Logger) (hop.Hop, error) {
 		sel = selector_parser.DefaultNodeSelector()
 	}
 
+	maxFails, timeout := xs.DefaultMaxFails, xs.DefaultFailTimeout
+	if cfg.Selector != nil {
+		if cfg.Selector.MaxFails > 0 {
+			maxFails = cfg.Selector.MaxFails
+		}
+		if cfg.Selector.FailTimeout > 0 {
+			timeout = cfg.Selector.FailTimeout
+		}
+	}
+
 	opts := []xhop.Option{
 		xhop.NameOption(cfg.Name),
 		xhop.NodeOption(nodes...),
 		xhop.SelectorOption(sel),
+		xhop.FailFilterSettingsOption(maxFails, timeout),
 		xhop.BypassOption(xbypass.BypassGroup(bypass_parser.List(cfg.Bypass, cfg.Bypasses...)...)),
 		xhop.ReloadPeriodOption(cfg.Reload),
 		xhop.LoggerOption(log.WithFields(map[string]any{

config/parsing/hosts/parse.go

@@ -12,6 +12,7 @@ import (
 	hosts_plugin "github.com/go-gost/x/hosts/plugin"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 )
 
 // ParseHostMapper converts a HostsConfig into a hosts.HostMapper. It resolves
@@ -23,6 +24,9 @@ func ParseHostMapper(cfg *config.HostsConfig) hosts.HostMapper {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/ingress/parse.go

@@ -11,6 +11,7 @@ import (
 	ingress_plugin "github.com/go-gost/x/ingress/plugin"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 )
 
 // ParseIngress converts an IngressConfig into an ingress.Ingress. It resolves
@@ -22,6 +23,9 @@ func ParseIngress(cfg *config.IngressConfig) ingress.Ingress {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/limiter/parse.go

@@ -15,6 +15,7 @@ import (
 	xrate "github.com/go-gost/x/limiter/rate"
 	xtraffic "github.com/go-gost/x/limiter/traffic"
 	traffic_plugin "github.com/go-gost/x/limiter/traffic/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 )
 
 // ParseTrafficLimiter converts a LimiterConfig into a traffic.TrafficLimiter.
@@ -26,6 +27,9 @@ func ParseTrafficLimiter(cfg *config.LimiterConfig) (lim traffic.TrafficLimiter)
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/node/parse.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"net"
 	"regexp"
+	"strconv"
 	"strings"
+	"time"
 
 	"github.com/go-gost/core/chain"
 	"github.com/go-gost/core/connector"
@@ -20,15 +22,160 @@ import (
 	tls_util "github.com/go-gost/x/internal/util/tls"
 	mdx "github.com/go-gost/x/metadata"
 	mdutil "github.com/go-gost/x/metadata/util"
+	xp2p "github.com/go-gost/x/p2p"
 	"github.com/go-gost/x/registry"
 	"github.com/go-gost/x/routing"
 )
 
+// DefaultMatcherBodySize is the default request body prefix (in bytes) exposed
+// to body matchers when a node has BodyRegexp/BodyJSON matchers but no
+// explicit bodySize.
+const DefaultMatcherBodySize = 1 << 20 // 1MB
+
+// MaxMatcherBodySize is the hard cap for matcher body prefix. Values above
+// this are silently clamped. Protects against unbounded in-memory buffering
+// when a node opts in to body matching.
+const MaxMatcherBodySize = 10 << 20 // 10MB
+
+// filterToMatcherRule converts a deprecated NodeFilterConfig (host/protocol/
+// path) into an equivalent matcher DSL rule. Empty fields are omitted; an
+// empty result means the node is unconditional. Path maps to PathPrefix
+// (the legacy filter is a prefix match, not exact).
+func filterToMatcherRule(filter *config.NodeFilterConfig) string {
+	if filter == nil {
+		return ""
+	}
+	var parts []string
+	// Normalize the legacy host forms first: `*.example.com` and
+	// `.example.com` both meant "apex AND subdomains" in the legacy filter.
+	// Strip the wildcard so the leading-dot branch below handles both.
+	host := filter.Host
+	if strings.HasPrefix(host, "*") {
+		host = host[1:]
+		if !strings.HasPrefix(host, ".") {
+			host = "." + host
+		}
+	}
+	if host != "" {
+		// A leading-dot host matches the apex AND its subdomains in the
+		// legacy filter (HasSuffix on the dot-stripped form), but matcher
+		// Host(.x) only matches subdomains. Emit both to preserve apex
+		// coverage. Parenthesize the OR when other conjuncts follow, since
+		// && binds tighter than || in the matcher DSL.
+		if strings.HasPrefix(host, ".") {
+			h := "Host(`" + host[1:] + "`) || Host(`" + host + "`)"
+			if filter.Protocol != "" || filter.Path != "" {
+				h = "(" + h + ")"
+			}
+			parts = append(parts, h)
+		} else {
+			parts = append(parts, "Host(`"+host+"`)")
+		}
+	}
+	if prot := filter.Protocol; prot != "" {
+		parts = append(parts, "Proto(`"+prot+"`)")
+	}
+	if path := filter.Path; path != "" {
+		parts = append(parts, "PathPrefix(`"+path+"`)")
+	}
+	return strings.Join(parts, " && ")
+}
+
 // ParseNode converts a NodeConfig into a *chain.Node. It resolves the
 // connector and dialer from their registries, applies TLS settings, extracts
 // 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 {
+		var pattern *regexp.Regexp
+		var rewriteType string
+
+		js, ok := strings.CutPrefix(v.Match, "json:")
+		del := false
+		if !ok {
+			// json-:<path> deletes the matched JSON field instead of replacing it.
+			if js, ok = strings.CutPrefix(v.Match, "json-:"); ok {
+				del = true
+			}
+		}
+		if ok {
+			// json:<path>[=<value-regex>] or json-:<path>[=<value-regex>]
+			path, valRegex, _ := strings.Cut(js, "=")
+			if valRegex == "" {
+				valRegex = ".*"
+			}
+			var err error
+			pattern, err = regexp.Compile(valRegex)
+			if err != nil {
+				log.Warnf("invalid JSON value regex %q for path %q: %v", valRegex, path, err)
+				continue
+			}
+			if del {
+				rewriteType = "json-:" + path
+			} else {
+				rewriteType = "json:" + path
+			}
+		} else {
+			if v.Match != "" {
+				pattern, _ = regexp.Compile(v.Match)
+			}
+			rewriteType = v.Type
+		}
+
+		rw := chain.HTTPBodyRewriteSettings{
+			Type:         rewriteType,
+			Pattern:      pattern,
+			Replacement:  []byte(v.Replacement),
+			MaxChunkSize: v.MaxChunkSize,
+		}
+		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 parseHeaderRewrites(vs []config.HTTPHeaderRewriteConfig, log logger.Logger) []chain.HTTPHeaderRewriteSettings {
+	var out []chain.HTTPHeaderRewriteSettings
+	for _, v := range vs {
+		var name, pattern *regexp.Regexp
+		if v.Name != "" {
+			name, _ = regexp.Compile(v.Name)
+		}
+		if v.Match != "" {
+			pattern, _ = regexp.Compile(v.Match)
+		}
+
+		rw := chain.HTTPHeaderRewriteSettings{
+			Name:        name,
+			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)
+		}
+		// Gate on the config string, not the compiled regexp: regexp.Compile("")
+		// returns a non-nil match-all regexp, so an empty Name with no rewriter
+		// would otherwise become a silent no-op rule.
+		if v.Name != "" || 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
@@ -123,6 +270,24 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 		return nil, fmt.Errorf("unregistered dialer: %s", dialCfg.Type)
 	}
 
+	// p2p: wrap the dialer so the node's base transport (the path to this
+	// node) goes through a tunnel opened by the named p2p plugin instead of
+	// a direct network dial. The inner dialer's protocol (tls/ws/mux) runs
+	// unchanged on top of the tunnel. Only whitelisted dialers qualify:
+	// the wrapper's contract is "inner dials one plain TCP stream via
+	// options.Dialer". The wrap happens before Init so the chain inits
+	// exactly once, through the wrapper.
+	if name := mdutil.GetString(md, parsing.MDKeyP2P); name != "" {
+		provider := registry.P2PRegistry().Get(name)
+		if provider == nil {
+			return nil, fmt.Errorf("unregistered p2p: %s", name)
+		}
+		if !xp2p.SupportedDialer(dialCfg.Type) {
+			return nil, fmt.Errorf("dialer %q does not support p2p", dialCfg.Type)
+		}
+		d = xp2p.NewTunnelDialer(d, provider)
+	}
+
 	if err := d.Init(mdx.NewMetadata(dialCfg.Metadata)); err != nil {
 		dialerLogger.Error("init: ", err)
 		return nil, err
@@ -151,44 +316,53 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 		chain.NetworkNodeOption(cfg.Network),
 	}
 
-	if filter := cfg.Filter; filter != nil {
-		// convert *.example.com to .example.com
-		// convert *example.com to example.com
-		host := filter.Host
-		if strings.HasPrefix(host, "*") {
-			host = host[1:]
-			if !strings.HasPrefix(host, ".") {
-				host = "." + host
-			}
-		}
+	var (
+		rule     string
+		priority int
+		bodySize int
+	)
 
-		settings := &chain.NodeFilterSettings{
-			Protocol: filter.Protocol,
-			Host:     host,
-			Path:     filter.Path,
-		}
-		opts = append(opts, chain.NodeFilterOption(settings))
+	// Deprecated filter: normalize into an equivalent matcher DSL rule so the
+	// runtime keeps a single filtering logic. Explicit -1 priority opts out of
+	// auto-priority and the priority short-circuit, preserving the legacy
+	// filter behavior (always through the selector).
+	if filter := cfg.Filter; filter != nil {
+		rule = filterToMatcherRule(filter)
+		priority = -1
+		bodySize = DefaultMatcherBodySize
 	}
 
 	if cfg.Matcher != nil {
-		priority := cfg.Matcher.Priority
-
-		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)
-				if priority == 0 {
-					priority = len(cfg.Matcher.Rule)
-				}
-				opts = append(opts, chain.MatcherNodeOption(matcher))
-			} else {
-				log.Error(err)
-				priority = -1
-			}
-		}
-
-		opts = append(opts, chain.PriorityNodeOption(priority))
+		priority = cfg.Matcher.Priority
+		rule = cfg.Matcher.Rule
+		bodySize = cfg.Matcher.BodySize
 	}
 
+	if rule = strings.TrimSpace(rule); rule != "" {
+		if matcher, err := routing.NewMatcher(rule); err == nil {
+			log.Debugf("new matcher for node %s with rule %s", cfg.Name, 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(rule)
+			}
+			opts = append(opts, chain.MatcherNodeOption(matcher))
+		} else {
+			log.Error(err)
+			priority = -1
+		}
+	}
+
+	if bodySize <= 0 {
+		bodySize = DefaultMatcherBodySize
+	} else if bodySize > MaxMatcherBodySize {
+		bodySize = MaxMatcherBodySize
+	}
+	opts = append(opts, chain.MatcherBodySizeNodeOption(bodySize))
+	opts = append(opts, chain.PriorityNodeOption(priority))
+
 	if cfg.HTTP != nil {
 		settings := &chain.HTTPNodeSettings{
 			Host:           cfg.HTTP.Host,
@@ -199,6 +373,10 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 			settings.RequestHeader = cfg.HTTP.Header
 		}
 
+		if v := cfg.HTTP.HostPattern; v != "" {
+			settings.HostPattern, _ = regexp.Compile(v)
+		}
+
 		if auth := cfg.HTTP.Auth; auth != nil && auth.Username != "" {
 			settings.Auther = xauth.NewAuthenticator(
 				xauth.AuthsOption(map[string]string{auth.Username: auth.Password}),
@@ -222,33 +400,16 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 				})
 			}
 		}
-		for _, v := range cfg.HTTP.RewriteBody {
-			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.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),
-				})
-			}
+		settings.RewriteResponseBody = append(settings.RewriteResponseBody, parseBodyRewrites(cfg.HTTP.RewriteBody, log)...)
+		settings.RewriteResponseBody = append(settings.RewriteResponseBody, parseBodyRewrites(cfg.HTTP.RewriteResponseBody, log)...)
+		settings.RewriteRequestBody = append(settings.RewriteRequestBody, parseBodyRewrites(cfg.HTTP.RewriteRequestBody, log)...)
+		settings.RewriteRequestHeader = parseHeaderRewrites(cfg.HTTP.RewriteRequestHeader, log)
+		settings.RewriteResponseHeader = parseHeaderRewrites(cfg.HTTP.RewriteResponseHeader, log)
+
+		if v := strings.TrimSpace(cfg.HTTP.FailCodes); v != "" {
+			settings.FailCodes = parseFailCodes(v, nodeLogger)
 		}
+
 		opts = append(opts, chain.HTTPNodeOption(settings))
 	}
 
@@ -265,5 +426,70 @@ func ParseNode(hop string, cfg *config.NodeConfig, log logger.Logger) (*chain.No
 		}
 		opts = append(opts, chain.TLSNodeOption(tlsCfg))
 	}
-	return chain.NewNode(cfg.Name, cfg.Addr, opts...), nil
+
+	node := chain.NewNode(cfg.Name, cfg.Addr, opts...)
+	if cfg.Probe != nil {
+		if pc := ParseProbeConfig(cfg.Probe); pc != nil {
+			xchain.StartNodeProbe(node, pc, nodeLogger)
+		}
+	}
+	return node, nil
+}
+
+// ParseProbeConfig converts a config.ProbeConfig into a chain.ProbeConfig.
+// Returns nil when the config is invalid (e.g. empty addr).
+func ParseProbeConfig(cfg *config.ProbeConfig) *chain.ProbeConfig {
+	if cfg == nil || (cfg.Addr == "" && cfg.Type != "cmd") {
+		return nil
+	}
+	if cfg.Type == "cmd" && cfg.Command == "" {
+		return nil
+	}
+	pt := chain.ProbeTypeTCP
+	switch cfg.Type {
+	case "http":
+		pt = chain.ProbeTypeHTTP
+	case "cmd":
+		pt = chain.ProbeTypeCmd
+	}
+	interval := cfg.Interval
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	timeout := cfg.Timeout
+	if timeout <= 0 {
+		timeout = 10 * time.Second
+	}
+	return &chain.ProbeConfig{
+		Type:           pt,
+		Addr:           cfg.Addr,
+		Interval:       interval,
+		Timeout:        timeout,
+		HTTPPath:       cfg.HTTPPath,
+		HTTPHost:       cfg.HTTPHost,
+		HTTPHeaders:    cfg.HTTPHeaders,
+		ExpectedStatus: cfg.ExpectedStatus,
+		Command:        cfg.Command,
+	}
+}
+
+// parseFailCodes parses a comma-separated status code list, e.g. "429,5xx".
+// Tokens ending in "xx" become hundred-level wildcards (5xx → 5, matching
+// 500-599). Invalid tokens are logged and skipped.
+func parseFailCodes(s string, log logger.Logger) chain.FailCodes {
+	var codes chain.FailCodes
+	for _, part := range strings.Split(s, ",") {
+		part = strings.TrimSpace(part)
+		if len(part) == 3 && strings.HasSuffix(part, "xx") {
+			if prefix, err := strconv.Atoi(part[:1]); err == nil && prefix > 0 {
+				codes = append(codes, prefix) // < 100 → wildcard
+				continue
+			}
+		} else if code, err := strconv.Atoi(part); err == nil && code >= 100 {
+			codes = append(codes, code)
+			continue
+		}
+		log.Warnf("failCodes: invalid token %q", part)
+	}
+	return codes
 }

config/parsing/node/parse_test.go

@@ -132,9 +132,9 @@ func TestParseNode_ExplicitDialer(t *testing.T) {
 
 func TestParseNode_WithBypass(t *testing.T) {
 	n, err := ParseNode("test-hop", &config.NodeConfig{
-		Name:    "bypass-node",
-		Addr:    "example.com:8080",
-		Bypass:  "bp1",
+		Name:     "bypass-node",
+		Addr:     "example.com:8080",
+		Bypass:   "bp1",
 		Bypasses: []string{"bp2", "bp3"},
 	}, testLogger())
 	if err != nil {
@@ -291,6 +291,48 @@ func TestParseNode_WithMatcherAutoPriority(t *testing.T) {
 	}
 }
 
+func TestParseNode_WithMatcherBodySize(t *testing.T) {
+	n, err := ParseNode("test-hop", &config.NodeConfig{
+		Name: "body-node",
+		Addr: "example.com:8080",
+		Matcher: &config.NodeMatcherConfig{
+			// Escaped predicate form; in YAML users write the backtick
+			// equivalent: BodyRegexp(`"model":"gpt-4"`).
+			Rule:     `BodyRegexp("\"model\":\"gpt-4\"")`,
+			BodySize: 65536,
+		},
+	}, testLogger())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if n == nil {
+		t.Fatal("expected non-nil node")
+	}
+	if got := n.Options().MatcherBodySize; got != 65536 {
+		t.Errorf("MatcherBodySize = %d, want 65536", got)
+	}
+}
+
+func TestParseNode_WithMatcherBodySize_Clamped(t *testing.T) {
+	n, err := ParseNode("test-hop", &config.NodeConfig{
+		Name: "body-node",
+		Addr: "example.com:8080",
+		Matcher: &config.NodeMatcherConfig{
+			Rule:     `BodyRegexp("foo")`,
+			BodySize: 10 * 1024 * 1024, // 10MB, above the 1MB cap
+		},
+	}, testLogger())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if n == nil {
+		t.Fatal("expected non-nil node")
+	}
+	if got := n.Options().MatcherBodySize; got != MaxMatcherBodySize {
+		t.Errorf("MatcherBodySize = %d, want %d (clamped)", got, MaxMatcherBodySize)
+	}
+}
+
 func TestParseNode_WithHTTPNode(t *testing.T) {
 	n, err := ParseNode("test-hop", &config.NodeConfig{
 		Name: "http-node",
@@ -345,6 +387,44 @@ func TestParseNode_WithHTTPDeprecatedHeader(t *testing.T) {
 	}
 }
 
+func TestParseNode_WithHeaderRewrite(t *testing.T) {
+	n, err := ParseNode("test-hop", &config.NodeConfig{
+		Name: "hdr-node",
+		Addr: "example.com:8080",
+		HTTP: &config.HTTPNodeConfig{
+			RewriteRequestHeader: []config.HTTPHeaderRewriteConfig{
+				{Name: "(?i)^referer$", Match: ".*", Replacement: ""},
+			},
+			RewriteResponseHeader: []config.HTTPHeaderRewriteConfig{
+				{Name: "(?i)^location$", Match: "https://github.com", Replacement: "https://127.0.0.1:8080"},
+			},
+		},
+	}, testLogger())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if n == nil {
+		t.Fatal("expected non-nil node")
+	}
+	settings := n.Options().HTTP
+	if settings == nil {
+		t.Fatal("expected HTTP settings")
+	}
+	if len(settings.RewriteRequestHeader) != 1 || len(settings.RewriteResponseHeader) != 1 {
+		t.Fatalf("rewrite header counts = %d/%d, want 1/1", len(settings.RewriteRequestHeader), len(settings.RewriteResponseHeader))
+	}
+}
+
+func TestParseHeaderRewrites_EmptyNameNoRewriter(t *testing.T) {
+	// Empty Name with no Rewriter must not be appended (silent no-op guard).
+	out := parseHeaderRewrites([]config.HTTPHeaderRewriteConfig{
+		{Name: "", Match: ".*", Replacement: ""},
+	}, testLogger())
+	if len(out) != 0 {
+		t.Fatalf("out = %d rules, want 0", len(out))
+	}
+}
+
 func TestParseNode_WithTLSNode(t *testing.T) {
 	n, err := ParseNode("test-hop", &config.NodeConfig{
 		Name: "tls-node",
@@ -459,3 +539,38 @@ func TestParseNode_DeprecatedFilterFields(t *testing.T) {
 		t.Fatal("expected non-nil node")
 	}
 }
+
+func TestFilterToMatcherRule(t *testing.T) {
+	tests := []struct {
+		name   string
+		filter *config.NodeFilterConfig
+		want   string
+	}{
+		{"nil", nil, ""},
+		{"all empty", &config.NodeFilterConfig{}, ""},
+		{"host only", &config.NodeFilterConfig{Host: "example.com"}, "Host(`example.com`)"},
+		{"dot host", &config.NodeFilterConfig{Host: ".example.com"},
+			"Host(`example.com`) || Host(`.example.com`)"},
+		{"star host", &config.NodeFilterConfig{Host: "*.example.com"},
+			"Host(`example.com`) || Host(`.example.com`)"},
+		{"protocol only", &config.NodeFilterConfig{Protocol: "ssh"}, "Proto(`ssh`)"},
+		{"path only", &config.NodeFilterConfig{Path: "/api"}, "PathPrefix(`/api`)"},
+		{"combined", &config.NodeFilterConfig{
+			Host:     ".example.com",
+			Protocol: "http",
+			Path:     "/api",
+		}, "(Host(`example.com`) || Host(`.example.com`)) && Proto(`http`) && PathPrefix(`/api`)"},
+		{"star combined", &config.NodeFilterConfig{
+			Host:     "*.example.com",
+			Protocol: "http",
+			Path:     "/api",
+		}, "(Host(`example.com`) || Host(`.example.com`)) && Proto(`http`) && PathPrefix(`/api`)"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := filterToMatcherRule(tt.filter); got != tt.want {
+				t.Errorf("filterToMatcherRule(%v) = %q, want %q", tt.filter, got, tt.want)
+			}
+		})
+	}
+}

config/parsing/node/regression_test.go

@@ -0,0 +1,35 @@
+package node
+
+import (
+	"testing"
+
+	"github.com/go-gost/x/config"
+	coreRouting "github.com/go-gost/core/routing"
+	"github.com/go-gost/x/routing"
+)
+
+func TestFilterToMatcherRule_Precedence(t *testing.T) {
+	for _, fc := range []struct{ name, host string }{
+		{"dot", ".example.com"},
+		{"star", "*.example.com"},
+	} {
+		t.Run(fc.name, func(t *testing.T) {
+			rule := filterToMatcherRule(&config.NodeFilterConfig{
+				Host: fc.host, Protocol: "http", Path: "/api",
+			})
+			m, err := routing.NewMatcher(rule)
+			if err != nil {
+				t.Fatalf("parse %q: %v", rule, err)
+			}
+			if m.Match(&coreRouting.Request{Host: "example.com", Protocol: "https", Path: "/other"}) {
+				t.Errorf("rule %q matched apex+https+/other (should reject)", rule)
+			}
+			if !m.Match(&coreRouting.Request{Host: "example.com", Protocol: "http", Path: "/api/v1"}) {
+				t.Errorf("rule %q rejected apex+http+/api/v1 (should accept)", rule)
+			}
+			if !m.Match(&coreRouting.Request{Host: "www.example.com", Protocol: "http", Path: "/api"}) {
+				t.Errorf("rule %q rejected www+http+/api (should accept)", rule)
+			}
+		})
+	}
+}

config/parsing/observer/parse.go

@@ -4,10 +4,12 @@ import (
 	"crypto/tls"
 	"strings"
 
+	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/observer"
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/plugin"
 	observer_plugin "github.com/go-gost/x/observer/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 )
 
 // ParseObserver converts an ObserverConfig into an observer.Observer. It only
@@ -18,6 +20,9 @@ func ParseObserver(cfg *config.ObserverConfig) observer.Observer {
 		return nil
 	}
 
+	if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+		logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+	}
 	var tlsCfg *tls.Config
 	if cfg.Plugin.TLS != nil {
 		tlsCfg = &tls.Config{

config/parsing/p2p/parse.go

@@ -0,0 +1,47 @@
+// Package p2p converts a [config.P2PConfig] into a p2p.TunnelProvider.
+package p2p
+
+import (
+	"crypto/tls"
+	"strings"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/config"
+	"github.com/go-gost/x/internal/plugin"
+	xp2p "github.com/go-gost/x/p2p"
+	p2p_plugin "github.com/go-gost/x/p2p/plugin"
+	xplugin "github.com/go-gost/x/plugin"
+)
+
+// ParseP2P converts a P2PConfig into a p2p.TunnelProvider backed by an
+// external gRPC plugin. Returns nil when cfg is nil or no plugin is
+// configured. The HTTP plugin variant is not implemented; configuring it
+// logs a deprecation notice and falls back to gRPC.
+func ParseP2P(cfg *config.P2PConfig) (p xp2p.TunnelProvider) {
+	if cfg == nil || cfg.Plugin == nil {
+		return nil
+	}
+
+	if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+		logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+	}
+	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":
+		logger.Default().Warn("p2p: http plugin type is deprecated/unimplemented, falling back to grpc")
+		fallthrough
+	default:
+		return p2p_plugin.NewGRPCPlugin(
+			cfg.Name, cfg.Plugin.Addr,
+			plugin.TokenOption(cfg.Plugin.Token),
+			plugin.TLSConfigOption(tlsCfg),
+		)
+	}
+}

config/parsing/parse.go

@@ -96,4 +96,8 @@ const (
 	// MDKeyLabels holds static key/value labels attached to a service's
 	// records and logs.
 	MDKeyLabels = "labels"
+
+	// MDKeyP2P selects the p2p tunnel provider for a chain node's base
+	// transport. The value is the name of a registered p2ps: component.
+	MDKeyP2P = "p2p"
 )

config/parsing/parser/parser.go

@@ -328,6 +328,9 @@ func mergeConfig(cfg1, cfg2 *config.Config) *config.Config {
 		Ingresses:  append(cfg1.Ingresses, cfg2.Ingresses...),
 		SDs:        append(cfg1.SDs, cfg2.SDs...),
 		Recorders:  append(cfg1.Recorders, cfg2.Recorders...),
+		Rewriters:  append(cfg1.Rewriters, cfg2.Rewriters...),
+		P2Ps:       append(cfg1.P2Ps, cfg2.P2Ps...),
+		Caches:     append(cfg1.Caches, cfg2.Caches...),
 		Limiters:   append(cfg1.Limiters, cfg2.Limiters...),
 		Quotas:     append(cfg1.Quotas, cfg2.Quotas...),
 		CLimiters:  append(cfg1.CLimiters, cfg2.CLimiters...),

config/parsing/recorder/parse.go

@@ -12,6 +12,7 @@ import (
 	"github.com/go-gost/core/recorder"
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	xrecorder "github.com/go-gost/x/recorder"
 	recorder_plugin "github.com/go-gost/x/recorder/plugin"
 	"gopkg.in/natefinch/lumberjack.v2"
@@ -33,6 +34,9 @@ func ParseRecorder(cfg *config.RecorderConfig) (r recorder.Recorder) {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/resolver/parse.go

@@ -9,6 +9,7 @@ import (
 	"github.com/go-gost/core/resolver"
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	"github.com/go-gost/x/registry"
 	xresolver "github.com/go-gost/x/resolver"
 	resolver_plugin "github.com/go-gost/x/resolver/plugin"
@@ -24,6 +25,9 @@ func ParseResolver(cfg *config.ResolverConfig) (resolver.Resolver, error) {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/rewriter/parse.go

@@ -0,0 +1,53 @@
+package rewriter
+
+import (
+	"crypto/tls"
+	"strings"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/rewriter"
+	"github.com/go-gost/x/config"
+	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/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 {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
+		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/router/parse.go

@@ -10,6 +10,7 @@ import (
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/loader"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	xrouter "github.com/go-gost/x/router"
 	router_plugin "github.com/go-gost/x/router/plugin"
 )
@@ -23,6 +24,9 @@ func ParseRouter(cfg *config.RouterConfig) router.Router {
 	}
 
 	if cfg.Plugin != nil {
+		if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+			logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+		}
 		var tlsCfg *tls.Config
 		if cfg.Plugin.TLS != nil {
 			tlsCfg = &tls.Config{

config/parsing/sd/parse.go

@@ -4,9 +4,11 @@ import (
 	"crypto/tls"
 	"strings"
 
+	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/sd"
 	"github.com/go-gost/x/config"
 	"github.com/go-gost/x/internal/plugin"
+	xplugin "github.com/go-gost/x/plugin"
 	sd_plugin "github.com/go-gost/x/sd/plugin"
 )
 
@@ -17,6 +19,9 @@ func ParseSD(cfg *config.SDConfig) sd.SD {
 		return nil
 	}
 
+	if err := xplugin.Spawn(cfg.Plugin.Command); err != nil {
+		logger.Default().Errorf("spawn plugin %s: %v", cfg.Name, err)
+	}
 	var tlsCfg *tls.Config
 	if cfg.Plugin.TLS != nil {
 		tlsCfg = &tls.Config{

config/parsing/selector/parse.go

@@ -55,15 +55,21 @@ func ParseNodeSelector(cfg *config.SelectorConfig) selector.Selector[*chain.Node
 		strategy = xs.HashStrategy[*chain.Node]()
 	case "parallel":
 		strategy = xs.ParallelStrategy[*chain.Node]()
+	case "lowestlatency", "lowest", "ll":
+		strategy = xs.LowestLatencyStrategy[*chain.Node]()
 	default:
 		strategy = xs.RoundRobinStrategy[*chain.Node]()
 	}
 
-	return xs.NewSelector(
-		strategy,
+	filters := []selector.Filter[*chain.Node]{
 		xs.FailFilter[*chain.Node](cfg.MaxFails, cfg.FailTimeout),
 		xs.BackupFilter[*chain.Node](),
-	)
+	}
+	if cfg.MaxLatency > 0 {
+		filters = append(filters, xs.LatencyFilter[*chain.Node](cfg.MaxLatency))
+	}
+
+	return xs.NewSelector(strategy, filters...)
 }
 
 // DefaultNodeSelector returns a node selector using round-robin strategy with

config/parsing/service/parse.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"fmt"
+	"io"
 	"runtime"
 	"strings"
 	"time"
@@ -11,6 +12,8 @@ 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/routing"
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/observer/stats"
 	"github.com/go-gost/core/recorder"
@@ -27,18 +30,38 @@ import (
 	bypass_parser "github.com/go-gost/x/config/parsing/bypass"
 	hop_parser "github.com/go-gost/x/config/parsing/hop"
 	logger_parser "github.com/go-gost/x/config/parsing/logger"
+	node_parser "github.com/go-gost/x/config/parsing/node"
 	selector_parser "github.com/go-gost/x/config/parsing/selector"
+	xhop "github.com/go-gost/x/hop"
 	tls_util "github.com/go-gost/x/internal/util/tls"
+	xrouting "github.com/go-gost/x/routing"
+	xs "github.com/go-gost/x/selector"
 	quota_wrapper "github.com/go-gost/x/limiter/quota/wrapper"
 	cache_limiter "github.com/go-gost/x/limiter/traffic/cache"
 	"github.com/go-gost/x/metadata"
 	mdutil "github.com/go-gost/x/metadata/util"
 	xstats "github.com/go-gost/x/observer/stats"
+	xrecorder "github.com/go-gost/x/recorder"
 	"github.com/go-gost/x/registry"
 	xservice "github.com/go-gost/x/service"
 	"github.com/vishvananda/netns"
 )
 
+// plaintextListeners are listener types that never terminate TLS on their
+// accepted connections, so any certFile/keyFile/caFile configured for them is
+// silently ignored. This catches the common footgun where a user writes e.g.
+// `tls+mws://...?certFile=...` expecting TLS: the "tls+" prefix is parsed as
+// the handler scheme (see x/config/cmd/cmd.go buildServiceConfig), not a TLS
+// wrapper, so the underlying mws listener stays plaintext. Extend this set when
+// new plaintext listeners are added.
+var plaintextListeners = map[string]bool{
+	"tcp": true, "udp": true,
+	"ws": true, "mws": true,
+	"redirect": true, "tproxy": true,
+	"rtcp": true, "rudp": true,
+	"unix": true, "runix": true, "serial": true, "stdio": true,
+}
+
 // ParseService constructs a fully-wired service.Service from a ServiceConfig.
 // It defaults the listener to "tcp" and the handler to "auto", resolves named
 // components from the registry (authers, admissions, bypasses, resolvers,
@@ -88,6 +111,11 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 		tls_util.RejectUnknownSNIConfig(tlsConfig, tlsCfg.RejectUnknownSNI, tlsCfg.ServerNames)
 	}
 
+	if (tlsCfg.CertFile != "" || tlsCfg.KeyFile != "" || tlsCfg.CAFile != "") && plaintextListeners[cfg.Listener.Type] {
+		serviceLogger.Warnf("TLS certificate options are configured but the %q listener does not use TLS and will ignore them; the connection will be plaintext. Use a TLS-capable listener (e.g. mwss, wss, tls, quic, grpc, http2, http3) to enable TLS.",
+			cfg.Listener.Type)
+	}
+
 	authers := auth_parser.List(cfg.Listener.Auther, cfg.Listener.Authers...)
 	if len(authers) == 0 {
 		if auther := auth_parser.ParseAutherFromAuth(cfg.Listener.Auth); auther != nil {
@@ -177,13 +205,32 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 	}
 	if !ignoreChain {
 		routerOpts = append(routerOpts,
-			chain.ChainRouterOption(chainGroup(cfg.Listener.Chain, cfg.Listener.ChainGroup)),
+			chain.ChainRouterOption(chainGroup(cfg.Listener.Chain, cfg.Listener.ChainGroup, log)),
 		)
 	}
+	lnRouter := xchain.NewRouter(routerOpts...)
+
+	// The routers may hold a chainGroup running probe goroutines, and the
+	// forwarder hop may run probe goroutines of its own; make sure they are
+	// closed if service construction fails after this point.
+	var hRouter *xchain.Router
+	var fwdCloser io.Closer
+	success := false
+	defer func() {
+		if !success {
+			lnRouter.Close()
+			if hRouter != nil {
+				hRouter.Close()
+			}
+			if fwdCloser != nil {
+				fwdCloser.Close()
+			}
+		}
+	}()
 
 	listenOpts := []listener.Option{
 		listener.AddrOption(cfg.Addr),
-		listener.RouterOption(xchain.NewRouter(routerOpts...)),
+		listener.RouterOption(lnRouter),
 		listener.AutherOption(auther),
 		listener.AuthOption(auth_parser.Info(cfg.Listener.Auth)),
 		listener.TLSConfigOption(tlsConfig),
@@ -282,11 +329,44 @@ 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)
+		rec := registry.RecorderRegistry().Get(r.Name)
+		if r.Metadata != nil {
+			rec = &xrecorder.MetadataRecorder{
+				Recorder: rec,
+				Metadata: r.Metadata,
+			}
+		}
 		recorders = append(recorders, recorder.RecorderObject{
-			Recorder: registry.RecorderRegistry().Get(r.Name),
+			Recorder: rec,
 			Record:   r.Record,
 			Options: &recorder.Options{
 				Direction:       mdutil.GetBool(md, parsing.MDKeyRecorderDirection),
@@ -295,9 +375,18 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 				HTTPBody:        mdutil.GetBool(md, parsing.MDKeyRecorderHTTPBody),
 				MaxBodySize:     mdutil.GetInt(md, parsing.MDKeyRecorderHTTPMaxBodySize),
 			},
+			Metadata: r.Metadata,
 		})
 	}
 
+	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),
@@ -311,14 +400,15 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 	}
 	if !ignoreChain {
 		routerOpts = append(routerOpts,
-			chain.ChainRouterOption(chainGroup(cfg.Handler.Chain, cfg.Handler.ChainGroup)),
+			chain.ChainRouterOption(chainGroup(cfg.Handler.Chain, cfg.Handler.ChainGroup, log)),
 		)
 	}
 
 	var h handler.Handler
 	if rf := registry.HandlerRegistry().Get(cfg.Handler.Type); rf != nil {
+		hRouter = xchain.NewRouter(routerOpts...)
 		h = rf(
-			handler.RouterOption(xchain.NewRouter(routerOpts...)),
+			handler.RouterOption(hRouter),
 			handler.AutherOption(auther),
 			handler.AuthOption(auth_parser.Info(cfg.Handler.Auth)),
 			handler.BypassOption(xbypass.BypassGroup(bypass_parser.List(cfg.Bypass, cfg.Bypasses...)...)),
@@ -327,6 +417,8 @@ 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.CacheOption(registry.CacheRegistry().Get(cfg.Cache)),
+			handler.RewriterOption(rew),
 			handler.LoggerOption(handlerLogger),
 			handler.ServiceOption(cfg.Name),
 			handler.NetnsOption(netnsIn),
@@ -336,10 +428,11 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 	}
 
 	if forwarder, ok := h.(handler.Forwarder); ok {
-		hop, err := parseForwarder(cfg.Forwarder, log)
+		hop, closer, err := parseForwarder(cfg.Forwarder, log)
 		if err != nil {
 			return nil, err
 		}
+		fwdCloser = closer
 		forwarder.Forward(hop)
 	}
 
@@ -352,6 +445,10 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 		return nil, err
 	}
 
+	closers := []io.Closer{lnRouter, hRouter}
+	if fwdCloser != nil {
+		closers = append(closers, fwdCloser)
+	}
 	s := xservice.NewService(cfg.Name, ln, h,
 		xservice.AdmissionOption(xadmission.AdmissionGroup(admissions...)),
 		xservice.PreUpOption(preUp),
@@ -364,15 +461,31 @@ func ParseService(cfg *config.ServiceConfig) (service.Service, error) {
 		xservice.ObserverPeriodOption(observerPeriod),
 		xservice.LoggerOption(serviceLogger),
 		xservice.LabelsOption(labels),
+		xservice.ClosersOption(closers...),
 	)
+	success = true
 
 	serviceLogger.Infof("listening on %s/%s", s.Addr().String(), s.Addr().Network())
 	return s, nil
 }
 
-func parseForwarder(cfg *config.ForwarderConfig, log logger.Logger) (hop.Hop, error) {
+// parseForwarder builds the forwarder hop for a service. The returned
+// io.Closer is non-nil only when the hop is owned by the service (inline
+// nodes or a hop group) and must be closed on service shutdown; hops from
+// the HopRegistry are closed by the registry on unregister.
+func parseForwarder(cfg *config.ForwarderConfig, log logger.Logger) (hop.Hop, io.Closer, error) {
 	if cfg == nil {
-		return nil, nil
+		return nil, nil, nil
+	}
+
+	// HopGroup takes precedence over Hop / Name / Nodes.
+	if cfg.HopGroup != nil {
+		group, err := parseHopGroup(cfg.HopGroup, log)
+		if err != nil || group == nil {
+			return nil, nil, err
+		}
+		closer, _ := group.(io.Closer)
+		return group, closer, nil
 	}
 
 	hopName := cfg.Hop
@@ -380,7 +493,7 @@ func parseForwarder(cfg *config.ForwarderConfig, log logger.Logger) (hop.Hop, er
 		hopName = cfg.Name
 	}
 	if hopName != "" {
-		return registry.HopRegistry().Get(hopName), nil
+		return registry.HopRegistry().Get(hopName), nil, nil
 	}
 
 	hc := config.HopConfig{
@@ -422,35 +535,132 @@ func parseForwarder(cfg *config.ForwarderConfig, log logger.Logger) (hop.Hop, er
 			Matcher:  node.Matcher,
 			HTTP:     httpCfg,
 			TLS:      node.TLS,
+			Probe:    node.Probe,
 			Metadata: node.Metadata,
 		})
 	}
-	return hop_parser.ParseHop(&hc, log)
+	// Inline nodes build a per-service hop, owned (and closed) by the service.
+	h, err := hop_parser.ParseHop(&hc, log)
+	if err != nil || h == nil {
+		return nil, nil, err
+	}
+	closer, _ := h.(io.Closer)
+	return h, closer, nil
 }
 
-func chainGroup(name string, group *config.ChainGroupConfig) chain.Chainer {
-	var chains []chain.Chainer
-	var sel selector.Selector[chain.Chainer]
-
-	if c := registry.ChainRegistry().Get(name); c != nil {
-		chains = append(chains, c)
+func parseHopGroup(cfg *config.ForwardHopGroupConfig, log logger.Logger) (hop.Hop, error) {
+	if cfg == nil {
+		return nil, nil
 	}
-	if group != nil {
-		for _, s := range group.Chains {
-			if c := registry.ChainRegistry().Get(s); c != nil {
-				chains = append(chains, c)
+
+	var entries []*xhop.HopEntry
+	for _, hc := range cfg.Hops {
+		if hc == nil {
+			continue
+		}
+		h := registry.HopRegistry().Get(hc.Hop)
+		if h == nil {
+			log.Warnf("hop %q not found in hopGroup, skipping", hc.Hop)
+			continue
+		}
+
+		var m routing.Matcher
+		if hc.Matcher != nil && hc.Matcher.Rule != "" {
+			var err error
+			m, err = xrouting.NewMatcher(hc.Matcher.Rule)
+			if err != nil {
+				log.Warnf("hop %q: bad matcher rule %q: %v, skipping", hc.Hop, hc.Matcher.Rule, err)
+				continue
 			}
 		}
-		sel = selector_parser.ParseChainSelector(group.Selector)
+
+		entries = append(entries, xhop.NewHopEntry(h, m, node_parser.ParseProbeConfig(hc.Probe)))
 	}
-	if len(chains) == 0 {
+
+	if len(entries) == 0 {
+		return nil, nil
+	}
+
+	var hopSelector selector.Selector[hop.Hop]
+	if cfg.Selector != nil {
+		var strategy selector.Strategy[hop.Hop]
+		switch cfg.Selector.Strategy {
+		case "round", "rr":
+			strategy = xs.RoundRobinStrategy[hop.Hop]()
+		case "random", "rand":
+			strategy = xs.RandomStrategy[hop.Hop]()
+		case "fifo", "ha":
+			strategy = xs.FIFOStrategy[hop.Hop]()
+		case "hash":
+			strategy = xs.HashStrategy[hop.Hop]()
+		default:
+			strategy = xs.RoundRobinStrategy[hop.Hop]()
+		}
+		hopSelector = xs.NewSelector(
+			strategy,
+			xs.FailFilter[hop.Hop](cfg.Selector.MaxFails, cfg.Selector.FailTimeout),
+			xs.BackupFilter[hop.Hop](),
+		)
+	}
+	if hopSelector == nil {
+		hopSelector = xs.NewSelector(
+			xs.RoundRobinStrategy[hop.Hop](),
+			xs.FailFilter[hop.Hop](xs.DefaultMaxFails, xs.DefaultFailTimeout),
+			xs.BackupFilter[hop.Hop](),
+		)
+	}
+
+	return xhop.NewHopGroup(
+		xhop.WithEntriesOption(entries...),
+		xhop.WithGroupSelectorOption(hopSelector),
+		xhop.WithGroupLoggerOption(log.WithFields(map[string]any{
+			"kind":    "hopGroup",
+			"service": "forwarder",
+		})),
+	), nil
+}
+
+func chainGroup(name string, group *config.ChainGroupConfig, log logger.Logger) chain.Chainer {
+	var entries []*xchain.ChainEntry
+
+	if c := registry.ChainRegistry().Get(name); c != nil {
+		entries = append(entries, xchain.NewChainEntry(c, nil, nil))
+	}
+	if group != nil {
+		for _, ge := range group.Chains {
+			c := registry.ChainRegistry().Get(ge.Chain)
+			if c == nil {
+				log.Warnf("chain %q not found in chainGroup, skipping", ge.Chain)
+				continue
+			}
+
+			var m routing.Matcher
+			if ge.Matcher != nil && ge.Matcher.Rule != "" {
+				var err error
+				m, err = xrouting.NewMatcher(ge.Matcher.Rule)
+				if err != nil {
+					log.Warnf("chain %q: bad matcher rule %q: %v, skipping", ge.Chain, ge.Matcher.Rule, err)
+					continue
+				}
+			}
+
+			entries = append(entries, xchain.NewChainEntry(c, m, node_parser.ParseProbeConfig(ge.Probe)))
+		}
+	}
+	if len(entries) == 0 {
 		return nil
 	}
 
+	var sel selector.Selector[chain.Chainer]
+	if group != nil {
+		sel = selector_parser.ParseChainSelector(group.Selector)
+	}
 	if sel == nil {
 		sel = selector_parser.DefaultChainSelector()
 	}
 
-	return xchain.NewChainGroup(chains...).
-		WithSelector(sel)
+	return xchain.NewChainGroup().
+		WithGroupEntries(entries...).
+		WithSelector(sel).
+		WithGroupLogger(log)
 }

config/parsing/tls.go

@@ -12,6 +12,8 @@ import (
 	"crypto/x509/pkix"
 	"encoding/pem"
 	"math/big"
+	"os"
+	"path/filepath"
 	"sync/atomic"
 	"time"
 
@@ -24,6 +26,24 @@ var (
 	defaultTLSConfig atomic.Value
 )
 
+// testDefaultCertDir overrides the default certificate directory in tests.
+// It is set only from same-package test code and left empty in production.
+var testDefaultCertDir string
+
+// defaultCertDir returns the directory used for persisting auto-generated
+// certificates. It uses testDefaultCertDir when set (for testing), otherwise
+// returns $HOME/.gost/.
+func defaultCertDir() string {
+	if testDefaultCertDir != "" {
+		return testDefaultCertDir
+	}
+	dir, err := os.UserHomeDir()
+	if err != nil {
+		return ".gost"
+	}
+	return filepath.Join(dir, ".gost")
+}
+
 // DefaultTLSConfig returns the global default TLS configuration used as a
 // fallback when a listener or handler does not specify its own TLS settings.
 // The returned config is a shared instance; callers that need to mutate it
@@ -40,44 +60,99 @@ func SetDefaultTLSConfig(cfg *tls.Config) {
 }
 
 // BuildDefaultTLSConfig loads or generates the default TLS certificate and key
-// from the given config. If cfg is nil it attempts to load well-known files
-// ("cert.pem", "key.pem", "ca.pem"). On failure it generates a self-signed
-// ECDSA P-256 certificate valid for one year.
+// from the given config.
+//
+// When explicit certificate files are configured (CertFile, KeyFile, or CAFile
+// is non-empty) it loads them via tls_util.LoadDefaultConfig — the original
+// behaviour preserved for backward compatibility.
+//
+// When no certificate files are configured (all three empty), it tries sources
+// in this order:
+//  1. cert.pem / key.pem in the current working directory (backward compatible)
+//  2. auto-ca-cert.pem / auto-ca-key.pem under $HOME/.gost/ (persisted)
+//  3. If none found, generates a new ECDSA P-256 CA certificate, persists it
+//     to $HOME/.gost/, and uses it.
+//
+// If cfg is nil an empty TLSConfig is used (equivalent to no explicit files),
+// so the CWD → persisted → generate path is taken.
 func BuildDefaultTLSConfig(cfg *config.TLSConfig) (*tls.Config, error) {
 	log := logger.Default()
 
 	if cfg == nil {
-		cfg = &config.TLSConfig{
-			CertFile: "cert.pem",
-			KeyFile:  "key.pem",
-			CAFile:   "ca.pem",
-		}
+		cfg = &config.TLSConfig{}
 	}
 
-	tlsConfig, err := tls_util.LoadDefaultConfig(cfg.CertFile, cfg.KeyFile, cfg.CAFile)
-	if err != nil {
-		// generate random self-signed certificate.
-		cert, err := genCertificate(cfg.Validity, cfg.Organization, cfg.CommonName)
+	if cfg.CertFile != "" || cfg.KeyFile != "" || cfg.CAFile != "" {
+		tlsConfig, err := tls_util.LoadDefaultConfig(cfg.CertFile, cfg.KeyFile, cfg.CAFile)
 		if err != nil {
 			return nil, err
 		}
-		tlsConfig = &tls.Config{
-			Certificates: []tls.Certificate{cert},
-		}
-		log.Debug("load global TLS certificate files failed, use random generated certificate")
-	} else {
 		log.Debug("load global TLS certificate files OK")
+		return tlsConfig, nil
 	}
 
+	tlsConfig, err := loadOrGeneratePersistentTLSConfig(cfg)
+	if err != nil {
+		return nil, err
+	}
 	return tlsConfig, nil
 }
 
-func genCertificate(validity time.Duration, org string, cn string) (cert tls.Certificate, err error) {
-	rawCert, rawKey, err := generateKeyPair(validity, org, cn)
-	if err != nil {
-		return
+// loadOrGeneratePersistentTLSConfig tries loading an auto-generated CA
+// certificate from these locations (in order):
+//  1. cert.pem / key.pem in the current working directory (backward compatible)
+//  2. auto-ca-cert.pem / auto-ca-key.pem under defaultCertDir() (persisted)
+//
+// If none is found it generates a new one, persists it to defaultCertDir()
+// (best-effort), and returns it.
+func loadOrGeneratePersistentTLSConfig(cfg *config.TLSConfig) (*tls.Config, error) {
+	log := logger.Default()
+
+	// 1. Try CWD cert.pem / key.pem first (backward compatible).
+	cwdCert, cwdErr := tls.LoadX509KeyPair("cert.pem", "key.pem")
+	if cwdErr == nil {
+		log.Debug("loaded default certificate from current working directory (cert.pem / key.pem)")
+		return &tls.Config{Certificates: []tls.Certificate{cwdCert}}, nil
 	}
-	return tls.X509KeyPair(rawCert, rawKey)
+
+	// 2. Try persisted certificate in defaultCertDir().
+	dir := defaultCertDir()
+	certFile := filepath.Join(dir, "auto-ca-cert.pem")
+	keyFile := filepath.Join(dir, "auto-ca-key.pem")
+
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err == nil {
+		log.Debugf("loaded persisted default certificate from %s", dir)
+		return &tls.Config{Certificates: []tls.Certificate{cert}}, nil
+	}
+
+	log.Debug("generating new default certificate (no persisted certificate found)")
+
+	// 3. Generate a new certificate.
+	rawCert, rawKey, err := generateKeyPair(cfg.Validity, cfg.Organization, cfg.CommonName)
+	if err != nil {
+		return nil, err
+	}
+
+	// Best-effort persist to disk. If it fails the in-memory certificate is
+	// still usable.
+	if err := os.MkdirAll(dir, 0700); err != nil {
+		log.Warnf("failed to create certificate directory %s: %v", dir, err)
+	} else {
+		if err := os.WriteFile(certFile, rawCert, 0644); err != nil {
+			log.Warnf("failed to persist certificate: %v", err)
+		} else if err := os.WriteFile(keyFile, rawKey, 0600); err != nil {
+			log.Warnf("failed to persist private key: %v", err)
+		} else {
+			log.Debugf("persisted default certificate to %s", dir)
+		}
+	}
+
+	cert, err = tls.X509KeyPair(rawCert, rawKey)
+	if err != nil {
+		return nil, err
+	}
+	return &tls.Config{Certificates: []tls.Certificate{cert}}, nil
 }
 
 func generateKeyPair(validity time.Duration, org string, cn string) (rawCert, rawKey []byte, err error) {
@@ -124,6 +199,7 @@ func generateKeyPair(validity time.Duration, org string, cn string) (rawCert, ra
 			x509.ExtKeyUsageServerAuth,
 		},
 		BasicConstraintsValid: true,
+		IsCA:                  true,
 	}
 	if _, isRSA := priv.(*rsa.PrivateKey); isRSA {
 		template.KeyUsage |= x509.KeyUsageKeyEncipherment

config/parsing/tls_test.go

@@ -2,15 +2,58 @@ package parsing
 
 import (
 	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
 	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
 	"io"
+	"math/big"
+	"os"
+	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/go-gost/core/logger"
 	"github.com/go-gost/x/config"
 	xlogger "github.com/go-gost/x/logger"
 )
 
+// writeTestCertKey writes a self-signed cert/key pair to the given file paths.
+// The cert is NOT persisted via the defaultCertDir mechanism — it simulates
+// user-provided cert.pem / key.pem in a working directory.
+func writeTestCertKey(t *testing.T, certFile, keyFile string) {
+	t.Helper()
+	key, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatalf("generate key: %v", err)
+	}
+	tmpl := &x509.Certificate{
+		SerialNumber:          big.NewInt(1),
+		Subject:               pkix.Name{CommonName: "cwd-test.local"},
+		NotBefore:             time.Now().Add(-time.Hour),
+		NotAfter:              time.Now().Add(time.Hour),
+		KeyUsage:              x509.KeyUsageDigitalSignature,
+		BasicConstraintsValid: true,
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &key.PublicKey, key)
+	if err != nil {
+		t.Fatalf("create cert: %v", err)
+	}
+	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: certDER})
+	keyPEM := pem.EncodeToMemory(&pem.Block{
+		Type:  "RSA PRIVATE KEY",
+		Bytes: x509.MarshalPKCS1PrivateKey(key),
+	})
+	if err := os.WriteFile(certFile, certPEM, 0644); err != nil {
+		t.Fatalf("write cert: %v", err)
+	}
+	if err := os.WriteFile(keyFile, keyPEM, 0600); err != nil {
+		t.Fatalf("write key: %v", err)
+	}
+}
+
 func TestMain(m *testing.M) {
 	logger.SetDefault(xlogger.NewLogger(xlogger.OutputOption(io.Discard)))
 	m.Run()
@@ -47,6 +90,10 @@ func TestDefaultTLSConfig_InitiallyNil(t *testing.T) {
 }
 
 func TestBuildDefaultTLSConfig_Nil(t *testing.T) {
+	// Use a temp dir so the test is isolated and doesn't touch $HOME/.gost
+	testDefaultCertDir = t.TempDir()
+	t.Cleanup(func() { testDefaultCertDir = "" })
+
 	// BuildDefaultTLSConfig with nil should generate a self-signed cert
 	tlsCfg, err := BuildDefaultTLSConfig(nil)
 	if err != nil {
@@ -58,9 +105,22 @@ func TestBuildDefaultTLSConfig_Nil(t *testing.T) {
 	if len(tlsCfg.Certificates) == 0 {
 		t.Fatal("expected at least one certificate")
 	}
+
+	// Verify that the certificate and key files were persisted.
+	certFile := filepath.Join(testDefaultCertDir, "auto-ca-cert.pem")
+	keyFile := filepath.Join(testDefaultCertDir, "auto-ca-key.pem")
+	if _, err := os.Stat(certFile); os.IsNotExist(err) {
+		t.Fatal("cert file was not persisted")
+	}
+	if _, err := os.Stat(keyFile); os.IsNotExist(err) {
+		t.Fatal("key file was not persisted")
+	}
 }
 
 func TestBuildDefaultTLSConfig_WithOptions(t *testing.T) {
+	testDefaultCertDir = t.TempDir()
+	t.Cleanup(func() { testDefaultCertDir = "" })
+
 	cfg := &config.TLSConfig{
 		Validity:     0, // uses default
 		Organization: "TestOrg",
@@ -78,26 +138,138 @@ func TestBuildDefaultTLSConfig_WithOptions(t *testing.T) {
 	}
 }
 
-func TestBuildDefaultTLSConfig_TwoCallsDifferentCerts(t *testing.T) {
+func TestBuildDefaultTLSConfig_TwoCallsSameCerts(t *testing.T) {
+	testDefaultCertDir = t.TempDir()
+	t.Cleanup(func() { testDefaultCertDir = "" })
+
 	cfg1, err := BuildDefaultTLSConfig(nil)
 	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
+		t.Fatalf("unexpected error on first call: %v", err)
 	}
 	cfg2, err := BuildDefaultTLSConfig(nil)
 	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
+		t.Fatalf("unexpected error on second call: %v", err)
 	}
 	if len(cfg1.Certificates) == 0 || len(cfg2.Certificates) == 0 {
 		t.Fatal("expected certificates in both configs")
 	}
 
-	// Each call generates a random cert; they should have different raw bytes.
-	if len(cfg1.Certificates[0].Certificate) == 0 || len(cfg2.Certificates[0].Certificate) == 0 {
-		t.Fatal("expected non-empty certificate raw bytes")
-	}
+	// Both calls should return the SAME persisted certificate.
 	c1 := cfg1.Certificates[0].Certificate[0]
 	c2 := cfg2.Certificates[0].Certificate[0]
-	if bytes.Equal(c1, c2) {
-		t.Fatal("expected different certificates from two calls")
+	if !bytes.Equal(c1, c2) {
+		t.Fatal("expected same certificate from two calls (persisted)")
+	}
+}
+
+func TestBuildDefaultTLSConfig_PersistsAndReloads(t *testing.T) {
+	testDefaultCertDir = t.TempDir()
+	defer func() { testDefaultCertDir = "" }()
+
+	// First call generates and persists.
+	cfg1, err := BuildDefaultTLSConfig(nil)
+	if err != nil {
+		t.Fatalf("unexpected error on first call: %v", err)
+	}
+
+	// Verify files exist on disk.
+	certFile := filepath.Join(testDefaultCertDir, "auto-ca-cert.pem")
+	keyFile := filepath.Join(testDefaultCertDir, "auto-ca-key.pem")
+	if _, err := os.Stat(certFile); os.IsNotExist(err) {
+		t.Fatal("cert file was not persisted after first call")
+	}
+	if _, err := os.Stat(keyFile); os.IsNotExist(err) {
+		t.Fatal("key file was not persisted after first call")
+	}
+
+	// Second call loads the persisted cert.
+	cfg2, err := BuildDefaultTLSConfig(nil)
+	if err != nil {
+		t.Fatalf("unexpected error on second call: %v", err)
+	}
+
+	c1 := cfg1.Certificates[0].Certificate[0]
+	c2 := cfg2.Certificates[0].Certificate[0]
+	if !bytes.Equal(c1, c2) {
+		t.Fatal("expected same certificate on reload (persisted)")
+	}
+}
+
+func TestBuildDefaultTLSConfig_FallsBackWhenWriteBlocked(t *testing.T) {
+	// Point to a directory that can't be created (e.g. a file path).
+	// We use a path under /proc on Linux which is a read-only filesystem.
+	testDefaultCertDir = "/proc/doesnotexist/certdir"
+	defer func() { testDefaultCertDir = "" }()
+
+	tlsCfg, err := BuildDefaultTLSConfig(nil)
+	if err != nil {
+		t.Fatalf("unexpected error (should fall back to in-memory): %v", err)
+	}
+	if tlsCfg == nil {
+		t.Fatal("expected non-nil config even when write fails")
+	}
+	if len(tlsCfg.Certificates) == 0 {
+		t.Fatal("expected at least one certificate from fallback")
+	}
+}
+
+// TestBuildDefaultTLSConfig_CWDTakesPriority verifies that when cert.pem and
+// key.pem exist in the current working directory, they take precedence over
+// both the persisted certificate and auto-generation.
+func TestBuildDefaultTLSConfig_CWDTakesPriority(t *testing.T) {
+	// Create a temp dir with cert.pem / key.pem.
+	cwd := t.TempDir()
+	writeTestCertKey(t, filepath.Join(cwd, "cert.pem"), filepath.Join(cwd, "key.pem"))
+
+	// Also set up a persisted cert directory.
+	testDefaultCertDir = t.TempDir()
+	defer func() { testDefaultCertDir = "" }()
+
+	// Pre-populate persisted cert so we can prove CWD wins.
+	_, err := BuildDefaultTLSConfig(nil)
+	if err != nil {
+		t.Fatalf("pre-populate persisted cert: %v", err)
+	}
+
+	// Change to the CWD that has cert.pem / key.pem.
+	origDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("getwd: %v", err)
+	}
+	if err := os.Chdir(cwd); err != nil {
+		t.Fatalf("chdir: %v", err)
+	}
+	defer os.Chdir(origDir)
+
+	// BuildDefaultTLSConfig should load CWD cert, not the persisted one.
+	tlsCfg, err := BuildDefaultTLSConfig(nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(tlsCfg.Certificates) == 0 {
+		t.Fatal("expected at least one certificate")
+	}
+
+	// Load CWD cert directly and compare.
+	cwdCert, err := tls.LoadX509KeyPair("cert.pem", "key.pem")
+	if err != nil {
+		t.Fatalf("load CWD cert: %v", err)
+	}
+	got := tlsCfg.Certificates[0].Certificate[0]
+	want := cwdCert.Certificate[0]
+	if !bytes.Equal(got, want) {
+		t.Fatal("CWD certificate was not used (persisted or auto-generated cert took priority)")
+	}
+
+	// Load persisted cert to prove it's different from CWD cert.
+	persistedCert, err := tls.LoadX509KeyPair(
+		filepath.Join(testDefaultCertDir, "auto-ca-cert.pem"),
+		filepath.Join(testDefaultCertDir, "auto-ca-key.pem"),
+	)
+	if err != nil {
+		t.Fatalf("load persisted cert: %v", err)
+	}
+	if bytes.Equal(got, persistedCert.Certificate[0]) {
+		t.Fatal("CWD cert should differ from persisted cert; test setup issue")
 	}
 }

connector/masque/association.go

@@ -0,0 +1,328 @@
+package masque
+
+import (
+	"context"
+	"errors"
+	"net"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/go-gost/core/logger"
+)
+
+const udpAssociationBufferSize = 64 * 1024
+
+var errMissingDestination = errors.New("masque: destination address required")
+
+type udpAssociationDialFunc func(ctx context.Context, addr net.Addr) (net.PacketConn, error)
+
+type udpAssociationResult struct {
+	data []byte
+	addr net.Addr
+}
+
+type udpAssociationTunnel struct {
+	conn net.PacketConn
+}
+
+type udpAssociationConn struct {
+	ctx       context.Context
+	cancel    context.CancelFunc
+	localAddr net.Addr
+	dial      udpAssociationDialFunc
+	closeIdle func() error
+	log       logger.Logger
+	timeout   time.Duration
+
+	closed    chan struct{}
+	closeOnce sync.Once
+	closeErr  error
+	results   chan udpAssociationResult
+
+	mu                  sync.Mutex
+	tunnels             map[string]*udpAssociationTunnel
+	readDeadline        time.Time
+	readDeadlineChanged chan struct{}
+}
+
+func newUDPAssociationConn(
+	ctx context.Context,
+	localAddr net.Addr,
+	timeout time.Duration,
+	dial udpAssociationDialFunc,
+	closeIdle func() error,
+	log logger.Logger,
+) *udpAssociationConn {
+	ctx, cancel := context.WithCancel(context.WithoutCancel(ctx))
+	c := &udpAssociationConn{
+		ctx:                 ctx,
+		cancel:              cancel,
+		localAddr:           localAddr,
+		dial:                dial,
+		closeIdle:           closeIdle,
+		log:                 log,
+		timeout:             timeout,
+		closed:              make(chan struct{}),
+		results:             make(chan udpAssociationResult, 32),
+		tunnels:             make(map[string]*udpAssociationTunnel),
+		readDeadlineChanged: make(chan struct{}),
+	}
+	return c
+}
+
+func (c *udpAssociationConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
+	for {
+		select {
+		case <-c.closed:
+			return 0, nil, net.ErrClosed
+		default:
+		}
+
+		c.mu.Lock()
+		deadline := c.readDeadline
+		deadlineChanged := c.readDeadlineChanged
+		c.mu.Unlock()
+
+		var (
+			timer   *time.Timer
+			timeout <-chan time.Time
+		)
+		if !deadline.IsZero() {
+			remaining := time.Until(deadline)
+			if remaining <= 0 {
+				return 0, nil, os.ErrDeadlineExceeded
+			}
+			timer = time.NewTimer(remaining)
+			timeout = timer.C
+		}
+
+		select {
+		case result := <-c.results:
+			if timer != nil {
+				timer.Stop()
+			}
+			return copy(b, result.data), result.addr, nil
+		case <-deadlineChanged:
+			if timer != nil {
+				timer.Stop()
+			}
+			continue
+		case <-timeout:
+			return 0, nil, os.ErrDeadlineExceeded
+		case <-c.closed:
+			if timer != nil {
+				timer.Stop()
+			}
+			return 0, nil, net.ErrClosed
+		}
+	}
+}
+
+func (c *udpAssociationConn) WriteTo(b []byte, addr net.Addr) (int, error) {
+	if addr == nil {
+		return 0, errMissingDestination
+	}
+
+	tunnel, err := c.tunnel(addr)
+	if err != nil {
+		if c.isClosed() {
+			return 0, net.ErrClosed
+		}
+		c.logError(addr, err)
+		return len(b), nil
+	}
+	n, err := tunnel.conn.WriteTo(b, addr)
+	if err == nil {
+		return n, nil
+	}
+	if c.isClosed() {
+		return 0, net.ErrClosed
+	}
+	if c.removeTunnel(addr.String(), tunnel) {
+		c.logError(addr, err)
+	}
+	return len(b), nil
+}
+
+func (c *udpAssociationConn) tunnel(addr net.Addr) (*udpAssociationTunnel, error) {
+	key := addr.String()
+
+	c.mu.Lock()
+	select {
+	case <-c.closed:
+		c.mu.Unlock()
+		return nil, net.ErrClosed
+	default:
+	}
+
+	if tunnel := c.tunnels[key]; tunnel != nil {
+		c.mu.Unlock()
+		return tunnel, nil
+	}
+	c.mu.Unlock()
+
+	ctx := c.ctx
+	if c.timeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, c.timeout)
+		defer cancel()
+	}
+	conn, err := c.dial(ctx, addr)
+	if err != nil {
+		return nil, err
+	}
+	if conn == nil {
+		return nil, errors.New("masque: nil UDP tunnel")
+	}
+
+	tunnel := &udpAssociationTunnel{conn: conn}
+	c.mu.Lock()
+	select {
+	case <-c.closed:
+		c.mu.Unlock()
+		conn.Close()
+		return nil, net.ErrClosed
+	default:
+	}
+	if current := c.tunnels[key]; current != nil {
+		c.mu.Unlock()
+		conn.Close()
+		return current, nil
+	}
+	c.tunnels[key] = tunnel
+	c.mu.Unlock()
+	go c.readTunnel(key, tunnel)
+	return tunnel, nil
+}
+
+func (c *udpAssociationConn) readTunnel(key string, tunnel *udpAssociationTunnel) {
+	buf := make([]byte, udpAssociationBufferSize)
+	for {
+		n, addr, err := tunnel.conn.ReadFrom(buf)
+		if err != nil {
+			if c.isClosed() {
+				return
+			}
+			if c.removeTunnel(key, tunnel) {
+				c.logError(key, err)
+			}
+			return
+		}
+
+		data := append([]byte(nil), buf[:n]...)
+		select {
+		case c.results <- udpAssociationResult{data: data, addr: addr}:
+		case <-c.closed:
+			return
+		}
+	}
+}
+
+func (c *udpAssociationConn) isClosed() bool {
+	select {
+	case <-c.closed:
+		return true
+	default:
+		return false
+	}
+}
+
+func (c *udpAssociationConn) logError(addr any, err error) {
+	if c.log != nil {
+		c.log.Warnf("masque: UDP tunnel %v: %v", addr, err)
+	}
+}
+
+func (c *udpAssociationConn) removeTunnel(key string, tunnel *udpAssociationTunnel) bool {
+	c.mu.Lock()
+	removed := c.tunnels[key] == tunnel
+	if c.tunnels[key] == tunnel {
+		delete(c.tunnels, key)
+	}
+	c.mu.Unlock()
+	tunnel.conn.Close()
+	return removed
+}
+
+func (c *udpAssociationConn) Read(b []byte) (int, error) {
+	n, _, err := c.ReadFrom(b)
+	return n, err
+}
+
+func (c *udpAssociationConn) Write(b []byte) (int, error) {
+	return 0, errMissingDestination
+}
+
+func (c *udpAssociationConn) Close() error {
+	c.closeOnce.Do(func() {
+		close(c.closed)
+		c.cancel()
+
+		c.mu.Lock()
+		close(c.readDeadlineChanged)
+		tunnels := make([]*udpAssociationTunnel, 0, len(c.tunnels))
+		for _, tunnel := range c.tunnels {
+			tunnels = append(tunnels, tunnel)
+		}
+		clear(c.tunnels)
+		c.mu.Unlock()
+
+		var errs []error
+		for _, tunnel := range tunnels {
+			if err := tunnel.conn.Close(); err != nil {
+				errs = append(errs, err)
+			}
+		}
+		if c.closeIdle != nil {
+			if err := c.closeIdle(); err != nil {
+				errs = append(errs, err)
+			}
+		}
+		c.closeErr = errors.Join(errs...)
+	})
+	return c.closeErr
+}
+
+func (c *udpAssociationConn) LocalAddr() net.Addr {
+	return c.localAddr
+}
+
+func (c *udpAssociationConn) RemoteAddr() net.Addr {
+	return &net.UDPAddr{}
+}
+
+func (c *udpAssociationConn) SetDeadline(t time.Time) error {
+	if err := c.SetReadDeadline(t); err != nil {
+		return err
+	}
+	return c.SetWriteDeadline(t)
+}
+
+func (c *udpAssociationConn) SetReadDeadline(t time.Time) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	select {
+	case <-c.closed:
+		return net.ErrClosed
+	default:
+	}
+	c.readDeadline = t
+	close(c.readDeadlineChanged)
+	c.readDeadlineChanged = make(chan struct{})
+	return nil
+}
+
+func (c *udpAssociationConn) SetWriteDeadline(t time.Time) error {
+	select {
+	case <-c.closed:
+		return net.ErrClosed
+	default:
+	}
+	return nil
+}
+
+var (
+	_ net.Conn       = (*udpAssociationConn)(nil)
+	_ net.PacketConn = (*udpAssociationConn)(nil)
+)

connector/masque/association_test.go

@@ -0,0 +1,321 @@
+package masque
+
+import (
+	"context"
+	"errors"
+	"net"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestUDPAssociationConnRoutesByDestination(t *testing.T) {
+	type dialCall struct {
+		addr net.Addr
+		conn *fakePacketConn
+	}
+
+	var (
+		mu    sync.Mutex
+		calls []dialCall
+	)
+	dial := func(ctx context.Context, addr net.Addr) (net.PacketConn, error) {
+		conn := newFakePacketConn()
+		mu.Lock()
+		calls = append(calls, dialCall{addr: addr, conn: conn})
+		mu.Unlock()
+		return conn, nil
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	conn := newUDPAssociationConn(ctx, &net.UDPAddr{}, 0, dial, nil, nil)
+	cancel() // The route dial context ends before the UDP association is used.
+	t.Cleanup(func() { conn.Close() })
+
+	addr1 := &net.UDPAddr{IP: net.ParseIP("1.1.1.1"), Port: 53}
+	addr2 := &net.UDPAddr{IP: net.ParseIP("8.8.8.8"), Port: 53}
+	if _, err := conn.WriteTo([]byte("first"), addr1); err != nil {
+		t.Fatalf("first WriteTo failed: %v", err)
+	}
+	if _, err := conn.WriteTo([]byte("second"), addr1); err != nil {
+		t.Fatalf("second WriteTo failed: %v", err)
+	}
+	if _, err := conn.WriteTo([]byte("third"), addr2); err != nil {
+		t.Fatalf("third WriteTo failed: %v", err)
+	}
+
+	mu.Lock()
+	gotCalls := append([]dialCall(nil), calls...)
+	mu.Unlock()
+	if len(gotCalls) != 2 {
+		t.Fatalf("expected one tunnel per destination, got %d", len(gotCalls))
+	}
+	if gotCalls[0].addr.String() != addr1.String() || gotCalls[1].addr.String() != addr2.String() {
+		t.Fatalf("unexpected tunnel destinations: %s, %s", gotCalls[0].addr, gotCalls[1].addr)
+	}
+	if got := gotCalls[0].conn.writtenData(); len(got) != 2 || string(got[0]) != "first" || string(got[1]) != "second" {
+		t.Fatalf("unexpected writes for first destination: %q", got)
+	}
+	if got := gotCalls[1].conn.writtenData(); len(got) != 1 || string(got[0]) != "third" {
+		t.Fatalf("unexpected writes for second destination: %q", got)
+	}
+
+	replyAddr := &net.UDPAddr{IP: net.ParseIP("127.0.0.1"), Port: 1}
+	gotCalls[1].conn.queueRead([]byte("reply"), replyAddr)
+	buf := make([]byte, 32)
+	n, addr, err := conn.ReadFrom(buf)
+	if err != nil {
+		t.Fatalf("ReadFrom failed: %v", err)
+	}
+	if string(buf[:n]) != "reply" {
+		t.Fatalf("unexpected reply: %q", buf[:n])
+	}
+	if addr.String() != replyAddr.String() {
+		t.Fatalf("expected reply from %s, got %s", replyAddr, addr)
+	}
+}
+
+func TestUDPAssociationConnClose(t *testing.T) {
+	upstream := newFakePacketConn()
+	idleClosed := 0
+	conn := newUDPAssociationConn(
+		context.Background(),
+		&net.UDPAddr{},
+		0,
+		func(context.Context, net.Addr) (net.PacketConn, error) { return upstream, nil },
+		func() error {
+			idleClosed++
+			return nil
+		},
+		nil,
+	)
+
+	if _, err := conn.WriteTo([]byte("request"), &net.UDPAddr{IP: net.ParseIP("1.1.1.1"), Port: 53}); err != nil {
+		t.Fatalf("WriteTo failed: %v", err)
+	}
+	if err := conn.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+	if err := conn.Close(); err != nil {
+		t.Fatalf("second Close failed: %v", err)
+	}
+	if idleClosed != 1 {
+		t.Fatalf("expected idle stream to be closed once, got %d", idleClosed)
+	}
+	if !upstream.isClosed() {
+		t.Fatal("expected destination tunnel to be closed")
+	}
+	if _, err := conn.WriteTo([]byte("request"), &net.UDPAddr{}); !errors.Is(err, net.ErrClosed) {
+		t.Fatalf("expected net.ErrClosed after Close, got %v", err)
+	}
+}
+
+func TestUDPAssociationConnTunnelFailureIsIsolated(t *testing.T) {
+	var (
+		mu    sync.Mutex
+		calls []*fakePacketConn
+	)
+	conn := newUDPAssociationConn(
+		context.Background(),
+		&net.UDPAddr{},
+		0,
+		func(context.Context, net.Addr) (net.PacketConn, error) {
+			pc := newFakePacketConn()
+			mu.Lock()
+			calls = append(calls, pc)
+			mu.Unlock()
+			return pc, nil
+		},
+		nil,
+		nil,
+	)
+	t.Cleanup(func() { conn.Close() })
+
+	addr1 := &net.UDPAddr{IP: net.ParseIP("1.1.1.1"), Port: 443}
+	addr2 := &net.UDPAddr{IP: net.ParseIP("8.8.8.8"), Port: 443}
+	if _, err := conn.WriteTo([]byte("first"), addr1); err != nil {
+		t.Fatalf("first WriteTo failed: %v", err)
+	}
+	if _, err := conn.WriteTo([]byte("second"), addr2); err != nil {
+		t.Fatalf("second WriteTo failed: %v", err)
+	}
+
+	mu.Lock()
+	first, second := calls[0], calls[1]
+	mu.Unlock()
+	first.queueReadError(errors.New("stream reset"))
+	select {
+	case <-first.closed:
+	case <-time.After(time.Second):
+		t.Fatal("failed tunnel was not removed")
+	}
+
+	second.queueRead([]byte("reply"), addr2)
+	buf := make([]byte, 32)
+	n, addr, err := conn.ReadFrom(buf)
+	if err != nil {
+		t.Fatalf("healthy tunnel failed after peer reset: %v", err)
+	}
+	if string(buf[:n]) != "reply" || addr.String() != addr2.String() {
+		t.Fatalf("unexpected healthy tunnel reply %q from %v", buf[:n], addr)
+	}
+
+	if _, err := conn.WriteTo([]byte("retry"), addr1); err != nil {
+		t.Fatalf("retry WriteTo failed: %v", err)
+	}
+	mu.Lock()
+	callCount := len(calls)
+	mu.Unlock()
+	if callCount != 3 {
+		t.Fatalf("expected failed destination to redial, got %d dials", callCount)
+	}
+}
+
+func TestUDPAssociationConnDialTimeout(t *testing.T) {
+	dialErr := make(chan error, 1)
+	conn := newUDPAssociationConn(
+		context.Background(),
+		&net.UDPAddr{},
+		20*time.Millisecond,
+		func(ctx context.Context, _ net.Addr) (net.PacketConn, error) {
+			<-ctx.Done()
+			dialErr <- ctx.Err()
+			return nil, ctx.Err()
+		},
+		nil,
+		nil,
+	)
+	t.Cleanup(func() { conn.Close() })
+
+	payload := []byte("request")
+	n, err := conn.WriteTo(payload, &net.UDPAddr{IP: net.ParseIP("1.1.1.1"), Port: 443})
+	if err != nil || n != len(payload) {
+		t.Fatalf("timed out datagram was not dropped cleanly: n=%d err=%v", n, err)
+	}
+	if err := <-dialErr; !errors.Is(err, context.DeadlineExceeded) {
+		t.Fatalf("expected dial deadline, got %v", err)
+	}
+}
+
+func TestUDPAssociationConnDialDoesNotHoldAssociationLock(t *testing.T) {
+	started := make(chan struct{})
+	release := make(chan struct{})
+	conn := newUDPAssociationConn(
+		context.Background(),
+		&net.UDPAddr{},
+		0,
+		func(context.Context, net.Addr) (net.PacketConn, error) {
+			close(started)
+			<-release
+			return newFakePacketConn(), nil
+		},
+		nil,
+		nil,
+	)
+	t.Cleanup(func() { conn.Close() })
+
+	writeDone := make(chan struct{})
+	go func() {
+		conn.WriteTo([]byte("request"), &net.UDPAddr{IP: net.ParseIP("1.1.1.1"), Port: 443})
+		close(writeDone)
+	}()
+	<-started
+
+	deadlineDone := make(chan error, 1)
+	go func() {
+		deadlineDone <- conn.SetReadDeadline(time.Now().Add(time.Second))
+	}()
+	select {
+	case err := <-deadlineDone:
+		if err != nil {
+			t.Fatalf("SetReadDeadline failed: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("dial held the association lock")
+	}
+
+	close(release)
+	<-writeDone
+}
+
+type fakePacket struct {
+	data []byte
+	addr net.Addr
+	err  error
+}
+
+type fakePacketConn struct {
+	reads     chan fakePacket
+	closed    chan struct{}
+	closeOnce sync.Once
+	mu        sync.Mutex
+	writes    [][]byte
+}
+
+func newFakePacketConn() *fakePacketConn {
+	return &fakePacketConn{
+		reads:  make(chan fakePacket, 1),
+		closed: make(chan struct{}),
+	}
+}
+
+func (c *fakePacketConn) queueRead(data []byte, addr net.Addr) {
+	c.reads <- fakePacket{data: append([]byte(nil), data...), addr: addr}
+}
+
+func (c *fakePacketConn) queueReadError(err error) {
+	c.reads <- fakePacket{err: err}
+}
+
+func (c *fakePacketConn) writtenData() [][]byte {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	result := make([][]byte, len(c.writes))
+	for i, data := range c.writes {
+		result[i] = append([]byte(nil), data...)
+	}
+	return result
+}
+
+func (c *fakePacketConn) isClosed() bool {
+	select {
+	case <-c.closed:
+		return true
+	default:
+		return false
+	}
+}
+
+func (c *fakePacketConn) ReadFrom(b []byte) (int, net.Addr, error) {
+	select {
+	case packet := <-c.reads:
+		if packet.err != nil {
+			return 0, nil, packet.err
+		}
+		return copy(b, packet.data), packet.addr, nil
+	case <-c.closed:
+		return 0, nil, net.ErrClosed
+	}
+}
+
+func (c *fakePacketConn) WriteTo(b []byte, _ net.Addr) (int, error) {
+	select {
+	case <-c.closed:
+		return 0, net.ErrClosed
+	default:
+	}
+	c.mu.Lock()
+	c.writes = append(c.writes, append([]byte(nil), b...))
+	c.mu.Unlock()
+	return len(b), nil
+}
+
+func (c *fakePacketConn) Close() error {
+	c.closeOnce.Do(func() { close(c.closed) })
+	return nil
+}
+
+func (c *fakePacketConn) LocalAddr() net.Addr              { return &net.UDPAddr{} }
+func (c *fakePacketConn) SetDeadline(time.Time) error      { return nil }
+func (c *fakePacketConn) SetReadDeadline(time.Time) error  { return nil }
+func (c *fakePacketConn) SetWriteDeadline(time.Time) error { return nil }

connector/masque/connector.go

@@ -10,6 +10,7 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/go-gost/core/connector"
@@ -19,6 +20,7 @@ import (
 	masque_dialer "github.com/go-gost/x/dialer/http3/masque"
 	masque_util "github.com/go-gost/x/internal/util/masque"
 	"github.com/go-gost/x/registry"
+	"github.com/quic-go/quic-go/http3"
 )
 
 func init() {
@@ -73,6 +75,16 @@ func (c *masqueConnector) Connect(ctx context.Context, conn net.Conn, network, a
 	return nil, fmt.Errorf("%w: %s", ErrUnsupportedNetwork, network)
 }
 
+func newTCPConnectRequest(address string) *http.Request {
+	return &http.Request{
+		Method:     http.MethodConnect,
+		URL:        &url.URL{},
+		Host:       address,
+		Header:     http.Header{},
+		ProtoMajor: 3,
+	}
+}
+
 func (c *masqueConnector) connectTCP(ctx context.Context, conn net.Conn, address string, log logger.Logger) (net.Conn, error) {
 	log.Debugf("connect-tcp %s", address)
 
@@ -103,13 +115,7 @@ func (c *masqueConnector) connectTCP(ctx context.Context, conn net.Conn, address
 
 	// Create standard HTTP/3 CONNECT request (RFC 9114)
 	// No :protocol pseudo-header for standard CONNECT
-	req := &http.Request{
-		Method: http.MethodConnect,
-		URL:    &url.URL{},
-		Host:   address, // Target address goes in :authority
-		Header: http.Header{},
-		Proto:  "HTTP/3.0",
-	}
+	req := newTCPConnectRequest(address)
 
 	// Add proxy authentication if configured
 	if c.options.Auth != nil {
@@ -172,9 +178,69 @@ func (c *masqueConnector) connectUDP(ctx context.Context, conn net.Conn, address
 		return nil, ErrInvalidConnection
 	}
 
-	// Get pre-opened stream from dialer (stream opening happens there for dead connection detection)
-	reqStream := masqueConn.GetRequestStream()
-	proxyHost := masqueConn.GetHost()
+	if address == "" {
+		return c.connectUDPAssociation(ctx, masqueConn, log), nil
+	}
+
+	return c.connectUDPTarget(
+		ctx,
+		conn.LocalAddr(),
+		masqueConn.GetHost(),
+		masqueConn.GetRequestStream(),
+		address,
+		nil,
+		log,
+	)
+}
+
+func (c *masqueConnector) connectUDPAssociation(ctx context.Context, conn *masque_dialer.MasqueConn, log logger.Logger) net.Conn {
+	var (
+		mu          sync.Mutex
+		firstStream = conn.GetRequestStream()
+	)
+
+	nextStream := func(ctx context.Context) (*http3.RequestStream, error) {
+		mu.Lock()
+		defer mu.Unlock()
+		if firstStream != nil {
+			stream := firstStream
+			firstStream = nil
+			return stream, nil
+		}
+		return conn.OpenRequestStream(ctx)
+	}
+
+	closeIdle := func() error {
+		mu.Lock()
+		defer mu.Unlock()
+		if firstStream == nil {
+			return nil
+		}
+		err := firstStream.Close()
+		firstStream = nil
+		return err
+	}
+
+	dial := func(ctx context.Context, addr net.Addr) (net.PacketConn, error) {
+		stream, err := nextStream(ctx)
+		if err != nil {
+			return nil, err
+		}
+		return c.connectUDPTarget(ctx, conn.LocalAddr(), conn.GetHost(), stream, addr.String(), addr, log)
+	}
+
+	return newUDPAssociationConn(ctx, conn.LocalAddr(), c.md.connectTimeout, dial, closeIdle, log)
+}
+
+func (c *masqueConnector) connectUDPTarget(
+	ctx context.Context,
+	localAddr net.Addr,
+	proxyHost string,
+	reqStream *http3.RequestStream,
+	address string,
+	remoteAddr net.Addr,
+	log logger.Logger,
+) (*masque_util.DatagramConn, error) {
 
 	// Apply connect timeout to the actual stream
 	if c.md.connectTimeout > 0 {
@@ -259,14 +325,15 @@ func (c *masqueConnector) connectUDP(ctx context.Context, conn net.Conn, address
 	// Get the underlying HTTP/3 stream for datagrams
 	stream := reqStream
 
-	// Resolve target address
-	raddr, err := net.ResolveUDPAddr("udp", address)
-	if err != nil {
-		return nil, err
+	if remoteAddr == nil {
+		remoteAddr, err = net.ResolveUDPAddr("udp", address)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	// Create datagram connection wrapping the request stream
-	datagramConn := masque_util.NewDatagramConnFromRequestStream(stream, conn.LocalAddr(), raddr)
+	datagramConn := masque_util.NewDatagramConnFromRequestStream(stream, localAddr, remoteAddr)
 
 	success = true // Prevent defer from closing stream - datagramConn now owns it
 	return datagramConn, nil

connector/masque/connector_test.go

@@ -0,0 +1,24 @@
+package masque
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestNewTCPConnectRequestUsesStandardConnect(t *testing.T) {
+	req := newTCPConnectRequest("example.com:443")
+
+	if req.Method != http.MethodConnect {
+		t.Fatalf("expected CONNECT method, got %s", req.Method)
+	}
+	if req.Host != "example.com:443" {
+		t.Fatalf("expected target authority, got %s", req.Host)
+	}
+	if req.Proto != "" {
+		// quic-go treats any non-empty Proto as an extended CONNECT :protocol.
+		t.Fatalf("standard CONNECT must not set :protocol, got %q", req.Proto)
+	}
+	if req.ProtoMajor != 3 {
+		t.Fatalf("expected HTTP/3 request, got HTTP/%d", req.ProtoMajor)
+	}
+}

connector/relay/bind.go

@@ -106,9 +106,11 @@ func (c *relayConnector) bind(conn net.Conn, cmd relay.CmdType, network, address
 	})
 	fa := &relay.AddrFeature{}
 	if network != "unix" {
-		if h, _, e := net.SplitHostPort(address); e == nil && h == "" {
-			address = net.JoinHostPort("0.0.0.0", address)
-		}
+		if address == "" {
+	        address = "0.0.0.0:0"
+	    } else if h, _, e := net.SplitHostPort(address); e == nil && h == "" {
+	        address = net.JoinHostPort("0.0.0.0", address)
+	    }
 	}
 	fa.ParseFrom(address)
 	req.Features = append(req.Features, fa)

connector/relay/listener.go

@@ -15,7 +15,7 @@ import (
 type bindListener struct {
 	network string
 	addr    net.Addr
-	session *mux.Session
+	session mux.Session
 	logger  logger.Logger
 }
 

connector/relay/metadata.go

@@ -4,8 +4,8 @@ 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"
 )
 
 type metadata struct {
@@ -31,6 +31,8 @@ func (c *relayConnector) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 
 	return

connector/socks/v5/connector.go

@@ -137,7 +137,12 @@ func (c *socks5Connector) Connect(ctx context.Context, conn net.Conn, network, a
 		addr.Host = "127.0.0.1"
 	}
 
-	req := gosocks5.NewRequest(gosocks5.CmdConnect, &addr)
+	cmd := gosocks5.CmdConnect
+	if c, ok := ctxvalue.Socks5CmdFromContext(ctx); ok {
+		cmd = c
+	}
+
+	req := gosocks5.NewRequest(cmd, &addr)
 	log.Trace(req)
 	if err := req.Write(conn); err != nil {
 		log.Error(err)
@@ -157,6 +162,10 @@ func (c *socks5Connector) Connect(ctx context.Context, conn net.Conn, network, a
 		return nil, err
 	}
 
+	if cmd == socks.CmdResolve || cmd == socks.CmdResolvePTR {
+		return &resolveConn{Conn: conn, resolvedAddr: reply.Addr}, nil
+	}
+
 	return conn, nil
 }
 

connector/socks/v5/listener.go

@@ -49,7 +49,7 @@ func (p *tcpListener) Close() error {
 
 type tcpMuxListener struct {
 	addr    net.Addr
-	session *mux.Session
+	session mux.Session
 	logger  logger.Logger
 }
 

connector/socks/v5/metadata.go

@@ -39,6 +39,8 @@ func (c *socks5Connector) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 	return
 }

connector/socks/v5/resolve.go

@@ -0,0 +1,23 @@
+package v5
+
+import (
+	"net"
+
+	md "github.com/go-gost/core/metadata"
+	"github.com/go-gost/gosocks5"
+	xmd "github.com/go-gost/x/metadata"
+)
+
+// resolveConn wraps a raw net.Conn and carries the resolved address from a
+// Tor RESOLVE/RESOLVE_PTR reply as metadata. It implements net.Conn (passthrough)
+// and metadata.Metadatable so the handler can extract the resolved address.
+type resolveConn struct {
+	net.Conn
+	resolvedAddr *gosocks5.Addr
+}
+
+func (c *resolveConn) Metadata() md.Metadata {
+	return xmd.NewMetadata(map[string]any{
+		"resolvedAddr": c.resolvedAddr,
+	})
+}

connector/socks/v5/resolve_test.go

@@ -0,0 +1,50 @@
+package v5
+
+import (
+	"net"
+	"testing"
+
+	"github.com/go-gost/gosocks5"
+)
+
+type dummyConn struct{ net.Conn }
+
+func TestResolveConn_Metadata(t *testing.T) {
+	addr := &gosocks5.Addr{Type: gosocks5.AddrIPv4, Host: "93.184.216.34", Port: 0}
+	rc := &resolveConn{Conn: dummyConn{}, resolvedAddr: addr}
+
+	md := rc.Metadata()
+	if md == nil {
+		t.Fatal("Metadata() returned nil")
+	}
+
+	v := md.Get("resolvedAddr")
+	if v == nil {
+		t.Fatal("resolvedAddr key not present in metadata")
+	}
+
+	got, ok := v.(*gosocks5.Addr)
+	if !ok {
+		t.Fatalf("resolvedAddr is %T, want *gosocks5.Addr", v)
+	}
+	if got.Host != "93.184.216.34" {
+		t.Errorf("Host = %q, want %q", got.Host, "93.184.216.34")
+	}
+	if got.Type != gosocks5.AddrIPv4 {
+		t.Errorf("Type = %d, want %d", got.Type, gosocks5.AddrIPv4)
+	}
+}
+
+func TestResolveConn_Metadata_NilAddr(t *testing.T) {
+	rc := &resolveConn{Conn: dummyConn{}, resolvedAddr: nil}
+
+	md := rc.Metadata()
+	v := md.Get("resolvedAddr")
+	addr, ok := v.(*gosocks5.Addr)
+	if !ok {
+		t.Fatalf("resolvedAddr has type %T, want *gosocks5.Addr", v)
+	}
+	if addr != nil {
+		t.Errorf("resolvedAddr = %v, want nil", addr)
+	}
+}

connector/ss/connector.go

@@ -9,7 +9,6 @@ import (
 
 	"strings"
 
-	"github.com/go-gost/core/common/bufpool"
 	"github.com/go-gost/core/connector"
 	md "github.com/go-gost/core/metadata"
 	"github.com/go-gost/go-shadowsocks2/core"
@@ -97,10 +96,13 @@ func (c *ssConnector) Connect(ctx context.Context, conn net.Conn, network, addre
 		log.Error(err)
 		return nil, err
 	}
-	rawaddr := bufpool.Get(512)
-	defer bufpool.Put(rawaddr)
+	// The wrapped conn stores this target and only writes it on first I/O,
+	// so it must be owned by this connection, not a shared pooled buffer
+	// (see go-gost/gost#896).
+	const maxAddrLen = 1 + 1 + 255 + 2 // SOCKS5 addr: atyp + len + host + port
 
-	n, err := addr.Encode(rawaddr)
+	target := make([]byte, maxAddrLen)
+	n, err := addr.Encode(target)
 	if err != nil {
 		log.Error("encoding addr: ", err)
 		return nil, err
@@ -111,8 +113,7 @@ func (c *ssConnector) Connect(ctx context.Context, conn net.Conn, network, addre
 		defer conn.SetDeadline(time.Time{})
 	}
 
-	target := socks.Addr(rawaddr[:n])
-	conn, err = c.client.WrapConn(conn, target)
+	conn, err = c.client.WrapConn(conn, socks.Addr(target[:n]))
 	if err != nil {
 		return nil, err
 	}

connector/ss/connector_test.go

@@ -0,0 +1,81 @@
+package ss
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/go-gost/core/connector"
+	"github.com/go-gost/go-shadowsocks2/socks"
+	"github.com/go-gost/x/internal/util/ss/none"
+	xlogger "github.com/go-gost/x/logger"
+	mdx "github.com/go-gost/x/metadata"
+)
+
+// captureConn records everything written to it, so a test can inspect the
+// bytes a connector actually puts on the wire.
+type captureConn struct {
+	buf bytes.Buffer
+}
+
+func (c *captureConn) Read(b []byte) (int, error)         { return 0, io.EOF }
+func (c *captureConn) Write(b []byte) (int, error)        { return c.buf.Write(b) }
+func (c *captureConn) Close() error                       { return nil }
+func (c *captureConn) LocalAddr() net.Addr                { return &net.TCPAddr{} }
+func (c *captureConn) RemoteAddr() net.Addr               { return &net.TCPAddr{} }
+func (c *captureConn) SetDeadline(time.Time) error        { return nil }
+func (c *captureConn) SetReadDeadline(time.Time) error    { return nil }
+func (c *captureConn) SetWriteDeadline(time.Time) error   { return nil }
+
+// TestConnectTargetNotOverwrittenByPool is a regression test for
+// https://github.com/go-gost/gost/issues/896: the connector previously passed
+// a slice aliasing the bufpool buffer to WrapConn, and the buffer was returned
+// to the pool before the wrapped conn lazily wrote the target on first I/O. A
+// second Connect could then overwrite the bytes and the first conn would send
+// the second conn's target. The none cipher keeps the wire plaintext so the
+// written target is directly assertable.
+func TestConnectTargetNotOverwrittenByPool(t *testing.T) {
+	c := NewConnector(
+		connector.AuthOption(url.UserPassword("none", "x")),
+		connector.LoggerOption(xlogger.NewLogger()),
+	)
+	if err := c.Init(mdx.NewMetadata(nil)); err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	ctx := context.Background()
+	cap1 := &captureConn{}
+	conn1, err := c.Connect(ctx, cap1, "tcp", "1.2.3.4:80")
+	if err != nil {
+		t.Fatalf("first Connect: %v", err)
+	}
+
+	// Second Connect reuses the same 512-byte bufpool buffer that conn1's
+	// target used to alias (single pool tier, same goroutine).
+	if _, err := c.Connect(ctx, &captureConn{}, "tcp", "5.6.7.8:443"); err != nil {
+		t.Fatalf("second Connect: %v", err)
+	}
+
+	if _, err := conn1.Write([]byte("X")); err != nil {
+		t.Fatalf("first Write: %v", err)
+	}
+
+	// initWriter frames the target as [salt][2-byte length][addr].
+	data := cap1.buf.Bytes()
+	payload := data[none.Cipher.SaltSize():]
+	if len(payload) < 2 {
+		t.Fatalf("captured payload too short: %d bytes: %x", len(payload), data)
+	}
+	n := int(payload[0])<<8 | int(payload[1])
+	if len(payload) < 2+n {
+		t.Fatalf("captured payload too short: len=%d, need %d: %x", len(payload), 2+n, data)
+	}
+	addr := socks.SplitAddr(payload[2 : 2+n])
+	if got, want := addr.String(), "1.2.3.4:80"; got != want {
+		t.Fatalf("first conn wrote target %q, want %q (captured %x)", got, want, data)
+	}
+}

connector/tunnel/bind.go

@@ -69,8 +69,8 @@ func (c *tunnelConnector) initTunnel(conn net.Conn, network, address string) (ad
 	req.Features = append(req.Features, af)
 
 	af = &relay.AddrFeature{}
-	if h, _, e := net.SplitHostPort(address); e == nil && h == "" {
-		address = net.JoinHostPort("0.0.0.0", address)
+	if h, p, e := net.SplitHostPort(address); e == nil && h == "" {
+		address = net.JoinHostPort("0.0.0.0", p)
 	}
 	af.ParseFrom(address)
 	req.Features = append(req.Features, af) // dst address
@@ -78,6 +78,11 @@ func (c *tunnelConnector) initTunnel(conn net.Conn, network, address string) (ad
 	req.Features = append(req.Features, &relay.TunnelFeature{
 		ID: c.md.tunnelID,
 	})
+	if c.md.recordMode != "" {
+		req.Features = append(req.Features, &relay.MetadataFeature{
+			KVs: map[string]string{"record.mode": c.md.recordMode},
+		})
+	}
 	if _, err = req.WriteTo(conn); err != nil {
 		return
 	}

connector/tunnel/conn.go

@@ -1,6 +1,7 @@
 package tunnel
 
 import (
+	"context"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -11,6 +12,7 @@ import (
 	"github.com/go-gost/core/common/bufpool"
 	mdata "github.com/go-gost/core/metadata"
 	"github.com/go-gost/relay"
+	ictx "github.com/go-gost/x/internal/ctx"
 	xrelay "github.com/go-gost/x/internal/util/relay"
 )
 
@@ -94,6 +96,14 @@ func (c *bindConn) Metadata() mdata.Metadata {
 	return c.md
 }
 
+// Context implements xctx.Context, exposing the connection metadata (e.g. the
+// tunneled hostname) to the handler's context. The service accept loop derives
+// the handler context from a conn that implements this interface, which lets
+// reverse-forward handlers (rtcp) route on the hostname carried by the tunnel.
+func (c *bindConn) Context() context.Context {
+	return ictx.ContextWithMetadata(context.Background(), c.md)
+}
+
 type bindUDPConn struct {
 	net.Conn
 	localAddr  net.Addr
@@ -162,6 +172,12 @@ func (c *bindUDPConn) Metadata() mdata.Metadata {
 	return c.md
 }
 
+// Context implements xctx.Context, exposing the connection metadata (e.g. the
+// tunneled hostname) to the handler's context. See bindConn.Context.
+func (c *bindUDPConn) Context() context.Context {
+	return ictx.ContextWithMetadata(context.Background(), c.md)
+}
+
 type bindAddr struct {
 	network string
 	addr    string

connector/tunnel/conn_test.go

@@ -0,0 +1,45 @@
+package tunnel
+
+import (
+	"net"
+	"testing"
+
+	mdata "github.com/go-gost/core/metadata"
+	ictx "github.com/go-gost/x/internal/ctx"
+	xmd "github.com/go-gost/x/metadata"
+	mdutil "github.com/go-gost/x/metadata/util"
+)
+
+// TestBindConnContext verifies that a bindConn exposes its connection metadata
+// (the tunneled hostname) via the xctx.Context interface, so the service accept
+// loop forwards it into the handler context for filter.host routing (gost#898).
+func TestBindConnContext(t *testing.T) {
+	md := mdata.Metadata(xmd.NewMetadata(map[string]any{"host": "example.local:80"}))
+	cn := &bindConn{
+		Conn:       &net.TCPConn{},
+		localAddr:  &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0},
+		remoteAddr: &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 80},
+		md:         md,
+	}
+
+	got := mdutil.GetString(ictx.MetadataFromContext(cn.Context()), "host")
+	if got != "example.local:80" {
+		t.Errorf("host from Context() = %q, want %q", got, "example.local:80")
+	}
+}
+
+// TestBindUDPConnContext is the same check for the UDP reverse-tunnel conn.
+func TestBindUDPConnContext(t *testing.T) {
+	md := mdata.Metadata(xmd.NewMetadata(map[string]any{"host": "example.local:80"}))
+	cn := &bindUDPConn{
+		Conn:       &net.TCPConn{},
+		localAddr:  &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0},
+		remoteAddr: &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 80},
+		md:         md,
+	}
+
+	got := mdutil.GetString(ictx.MetadataFromContext(cn.Context()), "host")
+	if got != "example.local:80" {
+		t.Errorf("host from Context() = %q, want %q", got, "example.local:80")
+	}
+}

connector/tunnel/connector.go

@@ -89,6 +89,11 @@ func (c *tunnelConnector) Connect(ctx context.Context, conn net.Conn, network, a
 	req.Features = append(req.Features, &relay.TunnelFeature{
 		ID: c.md.tunnelID,
 	})
+	if c.md.recordMode != "" {
+		req.Features = append(req.Features, &relay.MetadataFeature{
+			KVs: map[string]string{"record.mode": c.md.recordMode},
+		})
+	}
 
 	if _, err := req.WriteTo(conn); err != nil {
 		return nil, err

connector/tunnel/listener.go

@@ -15,7 +15,7 @@ import (
 type bindListener struct {
 	network string
 	addr    net.Addr
-	session *mux.Session
+	session mux.Session
 	logger  logger.Logger
 }
 

connector/tunnel/metadata.go

@@ -19,6 +19,7 @@ type metadata struct {
 	connectTimeout time.Duration
 	tunnelID       relay.TunnelID
 	muxCfg         *mux.Config
+	recordMode     string
 }
 
 func (c *tunnelConnector) parseMetadata(md mdata.Metadata) (err error) {
@@ -44,6 +45,8 @@ func (c *tunnelConnector) parseMetadata(md mdata.Metadata) (err error) {
 		c.md.tunnelID = c.md.tunnelID.SetWeight(uint8(weight))
 	}
 
+	c.md.recordMode = mdutil.GetString(md, "record.mode")
+
 	c.md.muxCfg = &mux.Config{
 		Version:           mdutil.GetInt(md, "mux.version"),
 		KeepAliveInterval: mdutil.GetDuration(md, "mux.keepaliveInterval"),
@@ -52,6 +55,8 @@ func (c *tunnelConnector) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 	if c.md.muxCfg.Version == 0 {
 		c.md.muxCfg.Version = 2

ctx/value.go

@@ -101,6 +101,42 @@ func ClientIDFromContext(ctx context.Context) ClientID {
 	return v
 }
 
+type peerCertKey struct{}
+
+// PeerCert carries the verified mTLS client certificate identity.
+type PeerCert struct {
+	CN          string
+	SANs        []string
+	Fingerprint string // SHA-256 hex of cert.Raw
+}
+
+// ContextWithPeerCert returns a copy of ctx that carries the peer cert.
+func ContextWithPeerCert(ctx context.Context, cert *PeerCert) context.Context {
+	return context.WithValue(ctx, peerCertKey{}, cert)
+}
+
+// PeerCertFromContext returns the peer cert stored in ctx, or nil.
+func PeerCertFromContext(ctx context.Context) *PeerCert {
+	v, _ := ctx.Value(peerCertKey{}).(*PeerCert)
+	return v
+}
+
+type socks5CmdKey struct{}
+
+// ContextWithSocks5Cmd returns a copy of ctx that carries a SOCKS5 command
+// override. Connectors use this to send a non-CONNECT command (e.g. Tor
+// RESOLVE/RESOLVE_PTR) to the upstream proxy.
+func ContextWithSocks5Cmd(ctx context.Context, cmd uint8) context.Context {
+	return context.WithValue(ctx, socks5CmdKey{}, cmd)
+}
+
+// Socks5CmdFromContext returns the SOCKS5 command override stored in ctx.
+// The bool is false if no override is present.
+func Socks5CmdFromContext(ctx context.Context) (uint8, bool) {
+	v, ok := ctx.Value(socks5CmdKey{}).(uint8)
+	return v, ok
+}
+
 // labelsKey saves the static service labels.
 type labelsKey struct{}
 

ctx/value_test.go

@@ -150,6 +150,49 @@ func TestClientIDFromContext_WrongType(t *testing.T) {
 	}
 }
 
+func TestPeerCertContext(t *testing.T) {
+	cert := &PeerCert{
+		CN:          "client.example.com",
+		SANs:        []string{"san1.example.com", "san2.example.com"},
+		Fingerprint: "abcdef1234567890",
+	}
+	ctx := ContextWithPeerCert(context.Background(), cert)
+
+	got := PeerCertFromContext(ctx)
+	if got == nil {
+		t.Fatal("PeerCertFromContext() = nil, want non-nil")
+	}
+	if got.CN != cert.CN {
+		t.Errorf("PeerCertFromContext().CN = %q, want %q", got.CN, cert.CN)
+	}
+	if len(got.SANs) != len(cert.SANs) || got.SANs[0] != cert.SANs[0] {
+		t.Errorf("PeerCertFromContext().SANs = %v, want %v", got.SANs, cert.SANs)
+	}
+	if got.Fingerprint != cert.Fingerprint {
+		t.Errorf("PeerCertFromContext().Fingerprint = %q, want %q", got.Fingerprint, cert.Fingerprint)
+	}
+}
+
+func TestPeerCertFromContext_Empty(t *testing.T) {
+	if got := PeerCertFromContext(context.Background()); got != nil {
+		t.Errorf("PeerCertFromContext(empty) = %v, want nil", got)
+	}
+}
+
+func TestPeerCertFromContext_WrongType(t *testing.T) {
+	ctx := context.WithValue(context.Background(), peerCertKey{}, "not-a-cert")
+	if got := PeerCertFromContext(ctx); got != nil {
+		t.Errorf("PeerCertFromContext(wrong type) = %v, want nil", got)
+	}
+}
+
+func TestPeerCertFromContext_Nil(t *testing.T) {
+	ctx := ContextWithPeerCert(context.Background(), nil)
+	if got := PeerCertFromContext(ctx); got != nil {
+		t.Errorf("PeerCertFromContext(nil) = %v, want nil", got)
+	}
+}
+
 func TestContextWithLabels(t *testing.T) {
 	labels := map[string]string{"tenant": "acme", "region": "eu"}
 	ctx := ContextWithLabels(context.Background(), labels)
@@ -218,6 +261,33 @@ func (c *testContextConn) Context() context.Context {
 	return c.ctx
 }
 
+func TestContextWithSocks5Cmd(t *testing.T) {
+	ctx := ContextWithSocks5Cmd(context.Background(), 0xF0)
+
+	cmd, ok := Socks5CmdFromContext(ctx)
+	if !ok {
+		t.Fatal("Socks5CmdFromContext() ok = false, want true")
+	}
+	if cmd != 0xF0 {
+		t.Errorf("Socks5CmdFromContext() = 0x%02X, want 0xF0", cmd)
+	}
+}
+
+func TestSocks5CmdFromContext_Empty(t *testing.T) {
+	_, ok := Socks5CmdFromContext(context.Background())
+	if ok {
+		t.Error("Socks5CmdFromContext(empty) ok = true, want false")
+	}
+}
+
+func TestSocks5CmdFromContext_WrongType(t *testing.T) {
+	ctx := context.WithValue(context.Background(), socks5CmdKey{}, "not-a-uint8")
+	_, ok := Socks5CmdFromContext(ctx)
+	if ok {
+		t.Error("Socks5CmdFromContext(wrong type) ok = true, want false")
+	}
+}
+
 func TestContextInterface(t *testing.T) {
 	ctx := context.Background()
 	ctx = ContextWithSid(ctx, Sid("iface-test"))

dialer/http3/dialer.go

@@ -97,11 +97,10 @@ func (d *http3Dialer) Dial(ctx context.Context, addr string, opts ...dialer.Dial
 					},
 				},
 			},
-			AuthorizePath: d.md.authorizePath,
-			PushPath:      d.md.pushPath,
-			PullPath:      d.md.pullPath,
-			TLSEnabled:    true,
-			Logger:        d.options.Logger,
+			PushPath:   d.md.pushPath,
+			PullPath:   d.md.pullPath,
+			TLSEnabled: true,
+			Logger:     d.options.Logger,
 		}
 
 		d.clients[addr] = client

dialer/http3/masque/client.go

@@ -102,6 +102,15 @@ func (c *MasqueConn) GetRequestStream() *http3.RequestStream {
 	return c.reqStream
 }
 
+// OpenRequestStream opens another request stream on the shared HTTP/3 connection.
+// CONNECT-UDP associations use one stream per destination.
+func (c *MasqueConn) OpenRequestStream(ctx context.Context) (*http3.RequestStream, error) {
+	if c.clientConn == nil {
+		return nil, errors.New("masque: connection is closed")
+	}
+	return c.clientConn.OpenRequestStream(ctx)
+}
+
 // GetHost returns the proxy host.
 func (c *MasqueConn) GetHost() string {
 	return c.host

dialer/http3/metadata.go

@@ -9,16 +9,14 @@ import (
 )
 
 const (
-	defaultAuthorizePath = "/authorize"
-	defaultPushPath      = "/push"
-	defaultPullPath      = "/pull"
+	defaultPushPath = "/push"
+	defaultPullPath = "/pull"
 )
 
 type metadata struct {
-	authorizePath string
-	pushPath      string
-	pullPath      string
-	host          string
+	pushPath string
+	pullPath string
+	host     string
 
 	// QUIC config options
 	keepAlivePeriod  time.Duration
@@ -36,10 +34,6 @@ func (d *http3Dialer) parseMetadata(md mdata.Metadata) (err error) {
 		maxStreams       = "maxStreams"
 	)
 
-	d.md.authorizePath = mdutil.GetString(md, "pht.authorizePath", "authorizePath")
-	if !strings.HasPrefix(d.md.authorizePath, "/") {
-		d.md.authorizePath = defaultAuthorizePath
-	}
 	d.md.pushPath = mdutil.GetString(md, "pht.pushPath", "pushPath")
 	if !strings.HasPrefix(d.md.pushPath, "/") {
 		d.md.pushPath = defaultPushPath

dialer/icmp/conn.go

@@ -3,6 +3,7 @@ package quic
 import (
 	"context"
 	"net"
+	"time"
 
 	"github.com/quic-go/quic-go"
 )
@@ -11,8 +12,10 @@ type quicSession struct {
 	session *quic.Conn
 }
 
-func (session *quicSession) GetConn() (*quicConn, error) {
-	stream, err := session.session.OpenStreamSync(context.Background())
+func (session *quicSession) GetConn(ctx context.Context) (*quicConn, error) {
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+	stream, err := session.session.OpenStreamSync(ctx)
 	if err != nil {
 		return nil, err
 	}

dialer/icmp/dialer.go

@@ -75,7 +75,6 @@ func (d *icmpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 	}
 
 	d.sessionMutex.Lock()
-	defer d.sessionMutex.Unlock()
 
 	session, ok := d.sessions[addr]
 	if session != nil && session.IsClosed() {
@@ -95,6 +94,7 @@ func (d *icmpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 			pc, err = icmp_pkg.ListenPacket("ip4:icmp", "")
 		}
 		if err != nil {
+			d.sessionMutex.Unlock()
 			return
 		}
 
@@ -109,16 +109,22 @@ func (d *icmpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 		if err != nil {
 			d.logger.Error(err)
 			pc.Close()
+			d.sessionMutex.Unlock()
 			return nil, err
 		}
 
 		d.sessions[addr] = session
 	}
+	d.sessionMutex.Unlock()
 
-	conn, err = session.GetConn()
+	conn, err = session.GetConn(ctx)
 	if err != nil {
+		d.sessionMutex.Lock()
+		if d.sessions[addr] == session {
+			delete(d.sessions, addr)
+		}
 		session.Close()
-		delete(d.sessions, addr)
+		d.sessionMutex.Unlock()
 		return nil, err
 	}
 

dialer/icmp/metadata.go

@@ -14,14 +14,24 @@ type metadata struct {
 }
 
 func (d *icmpDialer) parseMetadata(md mdata.Metadata) (err error) {
-	if mdutil.GetBool(md, "keepalive") {
-		d.md.keepAlivePeriod = mdutil.GetDuration(md, "ttl")
+	const (
+		keepAlive        = "keepAlive"
+		keepAlivePeriod  = "ttl"
+		handshakeTimeout = "handshakeTimeout"
+		maxIdleTimeout   = "maxIdleTimeout"
+	)
+
+	if md == nil || !md.IsExists(keepAlive) || mdutil.GetBool(md, keepAlive) {
+		d.md.keepAlivePeriod = mdutil.GetDuration(md, keepAlivePeriod)
 		if d.md.keepAlivePeriod <= 0 {
 			d.md.keepAlivePeriod = 10 * time.Second
 		}
 	}
-	d.md.handshakeTimeout = mdutil.GetDuration(md, "handshakeTimeout")
-	d.md.maxIdleTimeout = mdutil.GetDuration(md, "maxIdleTimeout")
+	d.md.handshakeTimeout = mdutil.GetDuration(md, handshakeTimeout)
+	d.md.maxIdleTimeout = mdutil.GetDuration(md, maxIdleTimeout)
+	if d.md.maxIdleTimeout <= 0 {
+		d.md.maxIdleTimeout = 90 * time.Second
+	}
 
 	return
 }

dialer/mtcp/conn.go

@@ -8,7 +8,7 @@ import (
 
 type muxSession struct {
 	conn    net.Conn
-	session *mux.Session
+	session mux.Session
 }
 
 func (session *muxSession) GetConn() (net.Conn, error) {
@@ -32,7 +32,3 @@ func (session *muxSession) IsClosed() bool {
 	}
 	return session.session.IsClosed()
 }
-
-func (session *muxSession) NumStreams() int {
-	return session.session.NumStreams()
-}

dialer/mtcp/dialer.go

@@ -61,6 +61,10 @@ func (d *mtcpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 
 	session, ok := d.sessions[addr]
 	if session != nil && session.IsClosed() {
+		session.Close()
+		if session.conn != nil {
+			session.conn.Close() // base conn would otherwise leak (and hold a p2p tunnel open)
+		}
 		delete(d.sessions, addr) // session is dead
 		ok = false
 	}
@@ -115,7 +119,7 @@ func (d *mtcpDialer) Handshake(ctx context.Context, conn net.Conn, options ...di
 	session, ok := d.sessions[opts.Addr]
 	if session != nil && session.conn != conn {
 		conn.Close()
-		return nil, errors.New("mtls: unrecognized connection")
+		return nil, errors.New("mtcp: unrecognized connection")
 	}
 
 	if !ok || session.session == nil {

dialer/mtcp/metadata.go

@@ -4,8 +4,8 @@ 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"
 )
 
 type metadata struct {
@@ -34,6 +34,8 @@ func (d *mtcpDialer) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 	if d.md.muxCfg.Version == 0 {
 		d.md.muxCfg.Version = 2

dialer/mtls/conn.go

@@ -8,7 +8,7 @@ import (
 
 type muxSession struct {
 	conn    net.Conn
-	session *mux.Session
+	session mux.Session
 }
 
 func (session *muxSession) GetConn() (net.Conn, error) {
@@ -32,7 +32,3 @@ func (session *muxSession) IsClosed() bool {
 	}
 	return session.session.IsClosed()
 }
-
-func (session *muxSession) NumStreams() int {
-	return session.session.NumStreams()
-}

dialer/mtls/dialer.go

@@ -62,6 +62,10 @@ func (d *mtlsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 
 	session, ok := d.sessions[addr]
 	if session != nil && session.IsClosed() {
+		session.Close()
+		if session.conn != nil {
+			session.conn.Close() // base conn would otherwise leak (and hold a p2p tunnel open)
+		}
 		delete(d.sessions, addr) // session is dead
 		ok = false
 	}

dialer/mtls/metadata.go

@@ -4,8 +4,8 @@ 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"
 )
 
 type metadata struct {
@@ -34,6 +34,8 @@ func (d *mtlsDialer) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 	return
 }

dialer/mws/conn.go

@@ -8,7 +8,7 @@ import (
 
 type muxSession struct {
 	conn    net.Conn
-	session *mux.Session
+	session mux.Session
 }
 
 func (session *muxSession) GetConn() (net.Conn, error) {
@@ -32,7 +32,3 @@ func (session *muxSession) IsClosed() bool {
 	}
 	return session.session.IsClosed()
 }
-
-func (session *muxSession) NumStreams() int {
-	return session.session.NumStreams()
-}

dialer/mws/dialer.go

@@ -76,6 +76,10 @@ func (d *mwsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOp
 
 	session, ok := d.sessions[addr]
 	if session != nil && session.IsClosed() {
+		session.Close()
+		if session.conn != nil {
+			session.conn.Close() // base conn would otherwise leak (and hold a p2p tunnel open)
+		}
 		delete(d.sessions, addr) // session is dead
 		ok = false
 	}

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 (
@@ -49,6 +49,8 @@ func (d *mwsDialer) parseMetadata(md mdata.Metadata) (err error) {
 		MaxFrameSize:      mdutil.GetInt(md, "mux.maxFrameSize"),
 		MaxReceiveBuffer:  mdutil.GetInt(md, "mux.maxReceiveBuffer"),
 		MaxStreamBuffer:   mdutil.GetInt(md, "mux.maxStreamBuffer"),
+		Type:              mdutil.GetString(md, "mux.type"),
+		MaxStreamWindow:   mdutil.GetInt(md, "mux.maxStreamWindow"),
 	}
 
 	d.md.handshakeTimeout = mdutil.GetDuration(md, "ws.handshakeTimeout", "handshakeTimeout")

dialer/pht/dialer.go

@@ -105,12 +105,11 @@ func (d *phtDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOp
 				// Timeout:   60 * time.Second,
 				Transport: tr,
 			},
-			AuthorizePath: d.md.authorizePath,
-			PushPath:      d.md.pushPath,
-			PullPath:      d.md.pullPath,
-			TLSEnabled:    d.tlsEnabled,
-			Header:        d.md.header,
-			Logger:        d.options.Logger,
+			PushPath:   d.md.pushPath,
+			PullPath:   d.md.pullPath,
+			TLSEnabled: d.tlsEnabled,
+			Header:     d.md.header,
+			Logger:     d.options.Logger,
 		}
 		d.clients[addr] = client
 	}

dialer/pht/metadata.go

@@ -9,33 +9,25 @@ import (
 )
 
 const (
-	dialTimeout          = "dialTimeout"
-	defaultAuthorizePath = "/authorize"
-	defaultPushPath      = "/push"
-	defaultPullPath      = "/pull"
+	defaultPushPath = "/push"
+	defaultPullPath = "/pull"
 )
 
 type metadata struct {
-	authorizePath string
-	pushPath      string
-	pullPath      string
-	host          string
-	header        http.Header
+	pushPath string
+	pullPath string
+	host     string
+	header   http.Header
 }
 
 func (d *phtDialer) parseMetadata(md mdata.Metadata) (err error) {
 	const (
-		authorizePath = "authorizePath"
-		pushPath      = "pushPath"
-		pullPath      = "pullPath"
-		host          = "host"
-		header        = "header"
+		pushPath = "pushPath"
+		pullPath = "pullPath"
+		host     = "host"
+		header   = "header"
 	)
 
-	d.md.authorizePath = mdutil.GetString(md, authorizePath)
-	if !strings.HasPrefix(d.md.authorizePath, "/") {
-		d.md.authorizePath = defaultAuthorizePath
-	}
 	d.md.pushPath = mdutil.GetString(md, pushPath)
 	if !strings.HasPrefix(d.md.pushPath, "/") {
 		d.md.pushPath = defaultPushPath

dialer/quic/conn.go

@@ -3,6 +3,7 @@ package quic
 import (
 	"context"
 	"net"
+	"time"
 
 	"github.com/quic-go/quic-go"
 )
@@ -11,8 +12,10 @@ type quicSession struct {
 	session *quic.Conn
 }
 
-func (session *quicSession) GetConn() (*quicConn, error) {
-	stream, err := session.session.OpenStreamSync(context.Background())
+func (session *quicSession) GetConn(ctx context.Context) (*quicConn, error) {
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+	stream, err := session.session.OpenStreamSync(ctx)
 	if err != nil {
 		return nil, err
 	}

dialer/quic/dialer.go

@@ -58,7 +58,6 @@ func (d *quicDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 	}
 
 	d.sessionMutex.Lock()
-	defer d.sessionMutex.Unlock()
 
 	session, ok := d.sessions[addr]
 	if session != nil && session.IsClosed() {
@@ -73,11 +72,13 @@ func (d *quicDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 
 		c, err := options.Dialer.Dial(ctx, "udp", "")
 		if err != nil {
+			d.sessionMutex.Unlock()
 			return nil, err
 		}
 		pc, ok := c.(net.PacketConn)
 		if !ok {
 			c.Close()
+			d.sessionMutex.Unlock()
 			return nil, errors.New("quic: wrong connection type")
 		}
 
@@ -89,16 +90,22 @@ func (d *quicDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 		if err != nil {
 			d.logger.Error(err)
 			pc.Close()
+			d.sessionMutex.Unlock()
 			return nil, err
 		}
 
 		d.sessions[addr] = session
 	}
+	d.sessionMutex.Unlock()
 
-	conn, err = session.GetConn()
+	conn, err = session.GetConn(ctx)
 	if err != nil {
+		d.sessionMutex.Lock()
+		if d.sessions[addr] == session {
+			delete(d.sessions, addr)
+		}
 		session.Close()
-		delete(d.sessions, addr)
+		d.sessionMutex.Unlock()
 		return nil, err
 	}
 

dialer/quic/metadata.go

@@ -40,6 +40,9 @@ func (d *quicDialer) parseMetadata(md mdata.Metadata) (err error) {
 	}
 	d.md.handshakeTimeout = mdutil.GetDuration(md, handshakeTimeout)
 	d.md.maxIdleTimeout = mdutil.GetDuration(md, maxIdleTimeout)
+	if d.md.maxIdleTimeout <= 0 {
+		d.md.maxIdleTimeout = 90 * time.Second
+	}
 	d.md.maxStreams = mdutil.GetInt(md, maxStreams)
 	d.md.enableDatagram = mdutil.GetBool(md, "quic.enableDatagram", "enableDatagram")
 

dialer/sshd/dialer.go

@@ -63,6 +63,18 @@ func (d *sshdDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialO
 		delete(d.sessions, addr) // session is dead
 		ok = false
 	}
+	if ok {
+		// Health check: verify the cached session is still alive before
+		// returning it. A dead-but-not-yet-detected session (e.g. idle
+		// connection silently dropped by NAT) would cause "ssh: unexpected
+		// packet in response to channel open" later in the connector.
+		if err := session.Ping(d.md.keepaliveTimeout); err != nil {
+			d.options.Logger.Debugf("sshd session ping failed: %v, recreating", err)
+			session.Close()
+			delete(d.sessions, addr)
+			ok = false
+		}
+	}
 	if !ok {
 		var options dialer.DialOptions
 		for _, opt := range opts {

dialer/tls/dialer.go

@@ -52,6 +52,8 @@ func (d *tlsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOp
 		d.log.Error(err)
 	}
 
+	xnet.ApplyNoDelay(conn)
+
 	if d.md.keepalive {
 		xnet.ApplyKeepalive(conn, net.KeepAliveConfig{
 			Enable:   true,

dialer/udp/conn.go

@@ -4,16 +4,21 @@ import (
 	"net"
 )
 
+// conn presents a dialed connection as a connected datagram socket: one
+// Write/Read per datagram, the peer address always the connected one, and the
+// address argument of WriteTo ignored. It covers both a raw *net.UDPConn and a
+// wrapped base dialer (e.g. a p2p tunnel endpoint), neither of which the caller
+// needs to tell apart.
 type conn struct {
-	*net.UDPConn
+	net.Conn
 }
 
 func (c *conn) WriteTo(b []byte, addr net.Addr) (int, error) {
-	return c.UDPConn.Write(b)
+	return c.Write(b)
 }
 
 func (c *conn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
-	n, err = c.UDPConn.Read(b)
+	n, err = c.Read(b)
 	addr = c.RemoteAddr()
 	return
 }

dialer/udp/dialer.go

@@ -49,8 +49,11 @@ func (d *udpDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOp
 		return nil, err
 	}
 
+	// The base may be a raw *net.UDPConn (a direct dial) or any conn carrying
+	// datagrams (a wrapped base dialer, e.g. a p2p tunnel endpoint); the
+	// wrapper treats both the same.
 	c = &conn{
-		UDPConn: c.(*net.UDPConn),
+		Conn: c,
 	}
 
 	c = proxyproto.WrapClientConn(

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"
@@ -82,7 +81,7 @@ 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 := toUTLSConfig(d.options.TLSConfig)
 		uconn := utls.UClient(conn, utlsCfg, clientHelloID)
 		if err := uconn.HandshakeContext(ctx); err != nil {
 			conn.Close()
@@ -104,3 +103,109 @@ func (d *utlsDialer) Handshake(ctx context.Context, conn net.Conn, options ...di
 
 	return tlsConn, nil
 }
+
+// toUTLSConfig builds an equivalent utls.Config from a standard crypto/tls.Config.
+//
+// utls.Config is a distinct type from crypto/tls.Config and its field offsets
+// diverge from ServerName onward (crypto/tls added fields utls does not have),
+// so a direct (*utls.Config)(unsafe.Pointer(...)) reinterprets memory and reads
+// garbage for ServerName/InsecureSkipVerify — which is what broke TLS
+// verification for this dialer. We copy fields explicitly instead.
+//
+// Fields whose types differ between the two packages (Certificate, ClientAuth,
+// CurveID, RenegotiationSupport, ConnectionState, the Get* callbacks,
+// ClientSessionCache) are converted or skipped: the config path that feeds this
+// dialer (LoadClientConfig) never populates the Get*/ClientSessionCache
+// callbacks, so skipping them is safe here.
+func toUTLSConfig(c *tls.Config) *utls.Config {
+	if c == nil {
+		return &utls.Config{}
+	}
+
+	uc := &utls.Config{
+		Rand:                        c.Rand,
+		Time:                        c.Time,
+		Certificates:                toUTLSCertificates(c.Certificates),
+		RootCAs:                     c.RootCAs,
+		NextProtos:                  c.NextProtos,
+		ServerName:                  c.ServerName,
+		ClientAuth:                  utls.ClientAuthType(c.ClientAuth),
+		ClientCAs:                   c.ClientCAs,
+		InsecureSkipVerify:          c.InsecureSkipVerify,
+		CipherSuites:                c.CipherSuites,
+		PreferServerCipherSuites:    c.PreferServerCipherSuites,
+		SessionTicketsDisabled:      c.SessionTicketsDisabled,
+		CurvePreferences:            toUTLSCurveIDs(c.CurvePreferences),
+		DynamicRecordSizingDisabled: c.DynamicRecordSizingDisabled,
+		Renegotiation:               utls.RenegotiationSupport(c.Renegotiation),
+		KeyLogWriter:                c.KeyLogWriter,
+		MinVersion:                  c.MinVersion,
+		MaxVersion:                  c.MaxVersion,
+		VerifyPeerCertificate:       c.VerifyPeerCertificate,
+	}
+
+	if c.VerifyConnection != nil {
+		vc := c.VerifyConnection
+		uc.VerifyConnection = func(cs utls.ConnectionState) error {
+			return vc(tls.ConnectionState{
+				PeerCertificates: cs.PeerCertificates,
+			})
+		}
+	}
+
+	return uc
+}
+
+func toUTLSCertificates(certs []tls.Certificate) []utls.Certificate {
+	if certs == nil {
+		return nil
+	}
+	out := make([]utls.Certificate, len(certs))
+	for i, c := range certs {
+		sa := make([]utls.SignatureScheme, len(c.SupportedSignatureAlgorithms))
+		for j, s := range c.SupportedSignatureAlgorithms {
+			sa[j] = utls.SignatureScheme(s)
+		}
+		out[i] = utls.Certificate{
+			Certificate:                  c.Certificate,
+			PrivateKey:                   c.PrivateKey,
+			SupportedSignatureAlgorithms: sa,
+			OCSPStaple:                   c.OCSPStaple,
+			SignedCertificateTimestamps:  c.SignedCertificateTimestamps,
+			Leaf:                         c.Leaf,
+		}
+	}
+	return out
+}
+
+// utlsCurves maps the crypto/tls curve IDs that utls understands.
+//
+// crypto/tls and utls use separate CurveID enumerations. Go has added
+// post-quantum hybrid curves (X25519MLKEM768, SecP256r1MLKEM768,
+// SecP384r1MLKEM1024) whose numeric IDs utls does not recognise, so a
+// blind utls.CurveID(id) cast turns them into unsupported curve IDs and
+// aborts the handshake with "CurvePreferences includes unsupported curve".
+// We keep only the curves utls can actually use and drop the rest; if none
+// survive, return nil so utls falls back to the fingerprint's defaults.
+var utlsCurves = map[tls.CurveID]utls.CurveID{
+	tls.X25519:   utls.X25519,
+	tls.CurveP256: utls.CurveP256,
+	tls.CurveP384: utls.CurveP384,
+	tls.CurveP521: utls.CurveP521,
+}
+
+func toUTLSCurveIDs(ids []tls.CurveID) []utls.CurveID {
+	if len(ids) == 0 {
+		return nil
+	}
+	out := make([]utls.CurveID, 0, len(ids))
+	for _, id := range ids {
+		if c, ok := utlsCurves[id]; ok {
+			out = append(out, c)
+		}
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}

dialer/ws/dialer.go

@@ -65,6 +65,8 @@ func (d *wsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOpt
 		d.options.Logger.Error(err)
 	}
 
+	xnet.ApplyNoDelay(conn)
+
 	if d.md.tcpKeepalive {
 		xnet.ApplyKeepalive(conn, net.KeepAliveConfig{
 			Enable:   true,

docs/issues/182-obfs4-support.md

@@ -0,0 +1,129 @@
+# Plan: obfs4 Pluggable Transport Support (go-gost/gost#182)
+
+## Context
+
+Issue [#182](https://github.com/go-gost/gost/issues/182) requests obfs4 support. GOST v3 currently has `ohttp` (HTTP WebSocket upgrade) and `otls` (fake TLS handshake) obfuscation, but not obfs4 — the "look-like-nothing" pluggable transport used by Tor bridges. The maintainer confirmed in the issue comments that obfs4 was not yet implemented. The `feature` label indicates this is desired functionality.
+
+## Approach: Use external library
+
+Use **`github.com/refraction-networking/obfs4`** (BSD-licensed) — the same organization that provides `refraction-networking/utls` already depended on by GOST. This library implements the full obfs4 protocol (ntor handshake, Elligator 2 key obfuscation, NaCl secretbox framing, SipHash length masking, replay filtering).
+
+### Why this library vs implementing from scratch
+
+| Factor | Library | From scratch |
+|--------|---------|-------------|
+| Cryptographic safety | Battle-tested (used by Tor/Refraction Networking) | Risk of subtle bugs in Elligator 2, ntor, constant-time ops |
+| Code volume | ~200 lines of GOST wrappers | ~1500+ lines of complex crypto code |
+| Maintenance | Upstream maintains protocol compliance | GOST maintainers own all crypto code |
+| Dependency footprint | Adds ~3 transitive deps | None new |
+| Integration fit | `ServerFactory.WrapConn()` is a perfect match for Accept(); `ClientFactory.Dial()` needs a thin bridge in Handshake() | Full control |
+
+The library approach matches how GOST already uses `refraction-networking/utls` for TLS fingerprinting.
+
+## Files to Create
+
+### 1. `x/listener/obfs/obfs4/listener.go`
+- Registers `"obfs4"` in `ListenerRegistry`
+- `obfsListener` struct following the same pattern as `listener/obfs/tls/listener.go` and `listener/obfs/http/listener.go`
+- `NewListener()` factory, `Init(metadata)`, `Accept()` methods
+- In `Accept()`: wrap accepted conn with limiter, then call `serverFactory.WrapConn(conn)` to perform server-side obfs4 handshake
+
+### 2. `x/listener/obfs/obfs4/conn.go`
+- Thin: the library's `WrapConn` already returns a `net.Conn` that handles framing transparently
+- May not even need a custom conn type — `WrapConn` returns a fully functional `net.Conn`
+
+### 3. `x/listener/obfs/obfs4/metadata.go`
+- Parse server-side config: `nodeId` (hex), `privateKey` (base64), `iatMode` (int, default 0)
+- Construct `pt.Args` from metadata for `ServerFactory()`
+
+### 4. `x/dialer/obfs/obfs4/dialer.go`
+- Registers `"obfs4"` in `DialerRegistry`
+- `obfs4Dialer` struct following the same pattern as `dialer/obfs/tls/dialer.go`
+- `NewDialer()`, `Init(metadata)`, `Dial()`, `Handshake()` methods
+- `Dial()`: delegates to options.Dialer (standard raw TCP connection)
+- `Handshake()`: uses `ClientFactory.Dial()` with a passthrough `DialFunc` that returns the already-established conn — the library then performs the obfs4 client handshake on it
+
+### 5. `x/dialer/obfs/obfs4/metadata.go`
+- Parse client-side config: `cert` (base64, required), `iatMode` (int)
+- Store state dir path for client factory
+
+### 6. Update `gost/cmd/gost/register.go`
+- Add blank imports:
+  ```go
+  _ "github.com/go-gost/x/listener/obfs/obfs4"
+  _ "github.com/go-gost/x/dialer/obfs/obfs4"
+  ```
+
+## Key Design Decisions
+
+### Server-side: Use `ServerFactory.WrapConn()`
+The library's `base.ServerFactory` interface has `WrapConn(conn net.Conn) (net.Conn, error)` which is an exact match for GOST's `Accept()` pattern — it takes a raw TCP connection, performs the obfs4 server handshake, and returns a wrapped connection. No custom conn type needed.
+
+### Client-side: Bridge Dial/Handshake with passthrough DialFunc
+The library's `ClientFactory.Dial(network, address, DialFunc, args)` both connects AND handshakes. GOST separates these. Solution:
+
+```go
+func (d *obfs4Dialer) Handshake(ctx context.Context, conn net.Conn, ...) (net.Conn, error) {
+    cf, _ := d.transport.ClientFactory(d.md.stateDir)
+    args, _ := cf.ParseArgs(d.md.ptArgs)
+    return cf.Dial("tcp", "", func(network, address string) (net.Conn, error) {
+        return conn, nil // passthrough — conn already established
+    }, args)
+}
+```
+
+### Config interface
+Users configure obfs4 via YAML/JSON metadata, mirroring Tor's bridge line format:
+
+**Server** (`listener`):
+```yaml
+services:
+- name: obfs4-bridge
+  addr: :8080
+  listener:
+    type: obfs4
+    metadata:
+      nodeId: "0123456789abcdef0123456789abcdef01234567"
+      privateKey: "base64-encoded-curve25519-private-key"
+      iatMode: 0
+  handler:
+    type: auto
+```
+
+**Client** (`hop node`):
+```yaml
+chains:
+- name: obfs4-chain
+  hops:
+  - nodes:
+    - addr: bridge.example.com:8080
+      dialer:
+        type: obfs4
+        metadata:
+          cert: "base64-encoded-server-cert"
+          iatMode: 0
+      connector:
+        type: http
+```
+
+### follow existing patterns exactly
+- Same `init()` registration pattern
+- Same `metadata` struct + `parseMetadata()` pattern
+- Same `mdutil.GetString/GetInt` helpers for metadata extraction
+- Same listener wrapper chain (proxyproto → metrics → stats → admission → traffic limiter → conn limiter)
+- Same dialer factory + Handshake pattern
+
+## Risks
+
+1. **Library API stability**: The refraction-networking/obfs4 library is used by the Tor anti-censorship community. API changes are unlikely but possible. Mitigation: pin to a specific version in go.mod.
+
+2. **State directory requirement**: The library requires a state directory for replay filter persistence. For stateless deployments (containers), we'll default to a temp directory that's cleaned up on exit.
+
+3. **Interop with real Tor obfs4 bridges**: This should work since we're using the same protocol implementation library that Tor uses.
+
+## Verification
+
+1. Build: `cd x && go build ./...` and `cd gost && go build ./cmd/gost/...`
+2. Vet: `cd x && go vet ./...`
+3. Smoke test: Create a minimal config with obfs4 listener + handler, verify the binary starts without error
+4. Integration test: Start a server with obfs4 listener and client with obfs4 dialer, verify connectivity. This can't be tested with real Tor bridges without credentials, but local loopback testing validates the integration layer.

docs/issues/349-cache-component.md

@@ -0,0 +1,236 @@
+# Issue #349: 通用 Cache 组件设计
+
+## Context
+
+Issue [#349](https://github.com/go-gost/gost/issues/349) 请求 HTTP 代理缓存层。用户要求先聚焦 cache 组件本身，设计要通用——不仅用于 HTTP，也要能统一替换现有的 DNS、Router、Traffic Limiter、TLS 等模块中的 ad-hoc 缓存。
+
+## 现状：6 处独立缓存实现
+
+| 位置 | 底层库 | Key | Value | TTL 模式 | 淘汰 | 最大容量 |
+|------|--------|-----|-------|----------|------|----------|
+| `x/internal/util/cache` | 自实现 | `string` | `interface{}` | 硬过期 | 无 | 无 |
+| `x/internal/util/resolver` (DNS) | 自实现 | `CacheKey(string)` | `*dns.Msg` | 硬过期 + serve-stale | 最旧(O(n)) | 可选 |
+| `x/limiter/traffic/cache` | #1 之上 | `string` | `traffic.Limiter` | 硬过期 + 刷新时滑动 | 无 | 无 |
+| `x/limiter/traffic` | patrickmn/go-cache | `string` | `traffic.Limiter` | **滑动**(Get时重置) | 后台清理 | 无 |
+| `x/internal/util/tls` | patrickmn/go-cache | `string` | `*x509.Certificate` | 硬过期(1周) | 后台清理 | 无 |
+| `x/handler/router` | #1 之上 | `string` | `net.Addr` / `*Route` | 硬过期(1s) | 无 | 无 |
+
+**问题**: 三种底层实现（自实现 ×2 + patrickmn/go-cache），功能重叠但接口不兼容，无通用配置入口。
+
+---
+
+## Core Interface
+
+### `core/cache/cache.go` (新文件)
+
+```go
+package cache
+
+var ErrNotFound = errors.New("cache: key not found")
+
+// Entry 缓存条目
+type Entry struct {
+    Data       []byte
+    Expiration time.Time  // zero = 永不过期
+}
+
+func (e *Entry) Expired() bool
+func (e *Entry) TTL() time.Duration  // 剩余 TTL，负数=已过期，-1=永不过期
+
+// SetOptions 写入选项
+type SetOptions struct {
+    TTL time.Duration  // 逐条 TTL
+}
+type SetOption func(*SetOptions)
+func WithTTL(d time.Duration) SetOption
+
+// Cache 通用 KV 缓存接口
+// 实现必须并发安全
+type Cache interface {
+    Get(ctx context.Context, key string) (*Entry, error)
+    Set(ctx context.Context, key string, data []byte, opts ...SetOption) error
+    Delete(ctx context.Context, key string) error
+    Has(ctx context.Context, key string) bool
+    Clear(ctx context.Context) error
+    Len(ctx context.Context) int
+    RefreshTTL(ctx context.Context, key string, ttl time.Duration) error
+}
+```
+
+**设计决策**:
+- Key 固定为 `string`，Value 固定为 `[]byte` — 与 registry 模式兼容，所有后端统一
+- `Get` 返回过期条目（`ErrNotFound` 仅对不存在的 key）— 支持 DNS serve-stale
+- `RefreshTTL` 显式延长过期时间 — 支持 DNS 异步刷新防重复
+- 调用方自行序列化/反序列化 — Cache 不绑定任何业务类型，真正通用
+- 与 `recorder.Recorder` 接口复杂度相当（都是单方法 + 选项）
+
+### Each handler wraps with typed methods
+
+```go
+// DNS handler 中:
+func dnsCacheGet(c cache.Cache, key string) (*dns.Msg, time.Duration) {
+    entry, err := c.Get(ctx, key)
+    if err != nil { return nil, 0 }
+    msg := &dns.Msg{}
+    msg.Unpack(entry.Data)
+    return msg, entry.TTL()
+}
+
+// HTTP handler 中:
+func httpCacheGet(c cache.Cache, key string) (*http.Response, error) { ... }
+func httpCacheSet(c cache.Cache, key string, resp *http.Response, ttl time.Duration) error { ... }
+```
+
+---
+
+## Config Structure
+
+### `x/config/config.go` — 新增
+
+```go
+type CacheConfig struct {
+    Name   string        `json:"name"`
+    Memory *MemoryCache  `yaml:",omitempty" json:"memory,omitempty"`
+    File   *FileCache    `yaml:",omitempty" json:"file,omitempty"`
+    Redis  *RedisCache   `yaml:",omitempty" json:"redis,omitempty"`
+    Plugin *PluginConfig `yaml:",omitempty" json:"plugin,omitempty"`
+}
+
+type MemoryCache struct {
+    TTL             time.Duration `yaml:",omitempty" json:"ttl,omitempty"`
+    MaxSize         int           `yaml:",omitempty" json:"maxSize,omitempty"`
+    MaxBytes        int64         `yaml:",omitempty" json:"maxBytes,omitempty"`
+    CleanupInterval time.Duration `yaml:",omitempty" json:"cleanupInterval,omitempty"`
+    Eviction        string        `yaml:",omitempty" json:"eviction,omitempty"` // "oldest" | "lru"
+}
+
+type FileCache struct {
+    Dir      string `json:"dir"`
+    MaxBytes int64  `yaml:",omitempty" json:"maxBytes,omitempty"`
+    Levels   int    `yaml:",omitempty" json:"levels,omitempty"`
+}
+
+type RedisCache struct {
+    Addr      string `json:"addr"`
+    DB        int    `yaml:",omitempty" json:"db,omitempty"`
+    Username  string `yaml:",omitempty" json:"username,omitempty"`
+    Password  string `yaml:",omitempty" json:"password,omitempty"`
+    KeyPrefix string `yaml:",omitempty" json:"keyPrefix,omitempty"`
+}
+
+// 在 Config struct 加:
+// Caches []*CacheConfig `yaml:",omitempty" json:"caches,omitempty"`
+
+// 在 ServiceConfig struct 加:
+// Cache string `yaml:",omitempty" json:"cache,omitempty"`
+```
+
+### YAML 示例
+
+```yaml
+caches:
+- name: cache-0
+  memory:
+    ttl: 60m
+    maxSize: 10000
+    maxBytes: 268435456   # 256MB
+    cleanupInterval: 5m
+    eviction: lru
+
+services:
+- name: service-0
+  addr: ":8080"
+  handler:
+    type: http
+  cache: cache-0           # 引用
+  forwarder:
+    nodes: [...]
+```
+
+---
+
+## Memory Backend
+
+### `x/cache/cache.go` — 内建实现
+
+不依赖外部库，替代 `x/internal/util/cache/cache.go` 和 patrickmn/go-cache。
+
+```go
+type memoryCache struct {
+    mu              sync.RWMutex
+    entries         map[string]*entry
+    defaultTTL      time.Duration
+    maxSize         int
+    maxBytes        int64
+    currentBytes    int64
+    cleanupInterval time.Duration
+    evictionPolicy  EvictionPolicy
+    stopCleanup     chan struct{}
+    logger          logger.Logger
+}
+
+type entry struct {
+    data       []byte
+    expiration time.Time     // zero = 永不过期
+    lastAccess time.Time     // LRU 用
+}
+```
+
+**功能矩阵**:
+| 特性 | 说明 |
+|------|------|
+| 并发安全 | `sync.RWMutex` |
+| 默认 TTL | 配置项，`Set` 的 `WithTTL` 可逐条覆盖 |
+| 最大条目数 | 满时按 `evictionPolicy` 淘汰（oldest / lru） |
+| 最大字节数 | 满时同样淘汰 |
+| 后台清理 | 可选，按 `cleanupInterval` 定期删除过期条目 |
+| serve-stale | `Get` 返回过期条目，`Entry.Expired()` 让调用方判断 |
+| `RefreshTTL` | 延长过期时间，用于 DNS 异步刷新模式 |
+| 注册 | `init()` 注册为 `registry.CacheRegistry().Register("memory", ...)` |
+
+**淘汰策略**: 满时 → 先清过期 → 若仍满则按策略淘汰（oldest: 按插入时间; lru: 按 `lastAccess`）
+
+---
+
+## 实现步骤
+
+| Step | 文件 | 动作 | 行数 |
+|------|------|------|------|
+| 1 | `core/cache/cache.go` | 新建 — `Entry`, `Cache` 接口, 选项 | ~70 |
+| 2 | `x/config/config.go` | 修改 — `CacheConfig` + 子结构体 + Config 字段 | ~50 |
+| 3 | `x/registry/registry.go` | 修改 — `cacheReg` + `CacheRegistry()` | ~15 |
+| 4 | `x/registry/cache.go` | 新建 — 热重载包装器 | ~30 |
+| 5 | `x/cache/cache.go` | 新建 — memory cache 实现 | ~200 |
+| 6 | `x/config/parsing/cache/parse.go` | 新建 — `ParseCache()` 后端分派 | ~50 |
+| 7 | `x/config/loader/loader.go` | 修改 — cache 注册块 | ~10 |
+| 8 | `x/config/parsing/service/parse.go` | 修改 — 解析 cache 引用注入 handler option | ~25 |
+| 9 | `core/handler/option.go` | 修改 — `CacheOption` | ~10 |
+| 10 | `gost/cmd/gost/register.go` | 修改 — blank import `x/cache` | +1 |
+
+**总计: ~460 行，集中在 `core/cache/` 和 `x/cache/`**
+
+### 迁移路径 (后续 Phase)
+
+| Phase | 内容 |
+|-------|------|
+| **Phase 1 (本次)** | `core/cache/` 接口 + memory 后端 + config/registry 全链路 |
+| **Phase 2** | DNS handler 切换到新 cache；Router handler 切换；替换 `x/internal/util/cache` |
+| **Phase 3** | Traffic limiter 切换；TLS cert pool 切换；移除 patrickmn/go-cache 依赖 |
+| **Phase 4** | HTTP 代理缓存集成（handler 中查缓存/存缓存） |
+| **Phase 5** | File 后端；Redis 后端；Plugin 后端 |
+
+---
+
+## 验证
+
+```bash
+# 编译
+cd x && go build ./...
+cd gost && go build ./cmd/gost/...
+
+# 单元测试
+cd x && go test ./cache/... -v
+
+# 验证 registry 集成
+cd x && go vet ./...
+```

docs/issues/524-tor-socks5-resolve.md

@@ -0,0 +1,131 @@
+# Plan: Tor SOCKS5 Resolve Commands (go-gost/gost#524)
+
+## Context
+
+Issue [#524](https://github.com/go-gost/gost/issues/524) requests support for Tor-specific SOCKS5 extension commands:
+
+- **`0xF0` RESOLVE** — resolve a hostname to an IP address via Tor's DNS
+- **`0xF1` RESOLVE_PTR** — reverse DNS lookup (IP → hostname) via Tor's DNS
+
+This allows tools like `torsocks` and `tor-resolve` to work through GOST when forwarding to a Tor SOCKS5 upstream proxy. Previously, GOST's SOCKS5 handler didn't recognize these commands (returning `CmdUnsupported`), so Tor-specific tools failed to work through GOST.
+
+### Existing extension pattern
+
+GOST already defines custom SOCKS5 extension commands in `x/internal/util/socks/socks.go`:
+- `CmdMuxBind = 0xF2` — multiplex bind
+- `CmdUDPTun = 0xF3` — UDP tunnel over TCP
+
+We add `CmdResolve = 0xF0` and `CmdResolvePTR = 0xF1` to match the same pattern.
+
+### Data flow
+
+```
+Client (torsocks) -> GOST SOCKS5 handler (CMD=0xF0) -> Chain -> SOCKS5 connector (CMD=0xF0 to Tor) -> Tor -> reply
+                                                                                                               |
+Client <- GOST SOCKS5 handler (writes Reply with resolved IP) <- chain conn (carries resolved addr metadata)
+```
+
+Unlike CONNECT (continuous bidirectional pipe), RESOLVE/PTR is a single request-reply exchange. The connector sends the resolve command upstream, reads the reply containing the resolved address, and returns a connection carrying that address as metadata. The handler extracts it, writes the reply to the client, and closes.
+
+## Files to modify
+
+### 1. `x/internal/util/socks/socks.go` — Add Tor resolve command constants
+
+Add after `CmdUDPTun`:
+```go
+CmdResolve    uint8 = 0xF0  // Tor RESOLVE (hostname -> IP)
+CmdResolvePTR uint8 = 0xF1  // Tor RESOLVE_PTR (IP -> hostname)
+```
+
+### 2. `x/ctx/value.go` — Add context key for SOCKS5 command override
+
+Add a context key and helpers so the handler can signal a custom SOCKS5 command to the connector. Follows the existing pattern used by other context values in this file (Hash, ClientID, SrcAddr, etc.).
+
+```go
+type socks5CmdKey struct{}
+
+func ContextWithSocks5Cmd(ctx context.Context, cmd uint8) context.Context {
+    return context.WithValue(ctx, socks5CmdKey{}, cmd)
+}
+
+func Socks5CmdFromContext(ctx context.Context) (uint8, bool) {
+    v, ok := ctx.Value(socks5CmdKey{}).(uint8)
+    return v, ok
+}
+```
+
+### 3. `x/connector/socks/v5/connector.go` — Send custom SOCKS5 command when signaled
+
+In `Connect()` at the point where `gosocks5.NewRequest(gosocks5.CmdConnect, &addr)` is created:
+- Check `Socks5CmdFromContext(ctx)` for a custom command
+- Use the context-specified command if present, otherwise default to `CmdConnect`
+- After reading the reply, if the command was a resolve type, return a `resolveConn` wrapping the raw connection with the resolved address stored as metadata
+
+### 4. `x/connector/socks/v5/resolve.go` (new file) — Define `resolveConn`
+
+```go
+type resolveConn struct {
+    net.Conn
+    resolvedAddr *gosocks5.Addr
+}
+
+func (c *resolveConn) Metadata() mdata.Metadata {
+    return mdata.NewMetadata(map[string]any{
+        "resolvedAddr": c.resolvedAddr,
+    })
+}
+```
+
+Implements `net.Conn` (passing through to underlying connection) plus `metadata.Metadatable` to expose the resolved address.
+
+### 5. `x/handler/socks/v5/handler.go` — Add resolve command cases
+
+In `Handle()` switch on `req.Cmd`, add:
+```go
+case socks.CmdResolve:
+    return h.handleResolve(ctx, conn, address, ro, log)
+case socks.CmdResolvePTR:
+    return h.handleResolvePTR(ctx, conn, address, ro, log)
+```
+
+### 6. `x/handler/socks/v5/resolve.go` (new file) — Implement resolve handlers
+
+**`handleResolve`**:
+1. If `enableTor` metadata is false, return `CmdUnsupported` reply
+2. Set context with `socks.CmdResolve` via `ContextWithSocks5Cmd`
+3. Call `h.options.Router.Dial(ctx, "tcp", address)` — chain routes to SOCKS5 connector, which sends CMD=0xF0
+4. Type-assert returned conn to `md.Metadatable`, extract resolved addr
+5. Write `gosocks5.Reply{Rep: Succeeded, Addr: resolvedAddr}` to client conn
+6. Close chain connection
+
+**`handleResolvePTR`**: Same structure but uses `socks.CmdResolvePTR`.
+
+Both follow the existing error-handling patterns (log errors, write failure replies to client).
+
+### 7. `x/handler/socks/v5/metadata.go` — Add `enableTor` metadata option
+
+Add a boolean metadata field (keys: `"tor"`, `"enableTor"`, `"socks5.tor"`) that defaults to `false`. When `false`, Tor resolve commands are rejected with `CmdUnsupported`. When `true`, the handler accepts and forwards them.
+
+## Verification
+
+### Build check
+```bash
+cd /config/workspace/go-gost/x && go build ./... && go vet ./...
+```
+
+### Integration test
+1. Start GOST with `-L "socks5://127.0.0.1:19055?tor=true" -F "socks5://127.0.0.1:9050"` (pointing at a Tor daemon)
+2. Use a SOCKS5 client to send a RESOLVE (0xF0) request to port 19055
+3. Verify the reply contains a valid resolved IP address
+
+### Manual testing
+```bash
+gost -L "socks5://127.0.0.1:19055?tor=true" -F "socks5://127.0.0.1:9050"
+tor-resolve example.com 127.0.0.1:19055
+```
+
+### Test areas
+- `tor=false` (default) rejects 0xF0/0xF1 commands with `CmdUnsupported`
+- `tor=true` accepts them and forwards through the chain
+- Connector sends correct command byte (0xF0/0xF1) when context signals it
+- Connector returns `resolveConn` with correct resolved address in metadata