Add support for ech retry configs

common/tls/client.go

@@ -2,6 +2,8 @@ package tls
 
 import (
 	"context"
+	"crypto/tls"
+	"errors"
 	"net"
 	"os"
 
@@ -41,6 +43,13 @@ func ClientHandshake(ctx context.Context, conn net.Conn, config Config) (Conn, e
 	ctx, cancel := context.WithTimeout(ctx, C.TCPTimeout)
 	defer cancel()
 	tlsConn, err := aTLS.ClientHandshake(ctx, conn, config)
+	var echErr *tls.ECHRejectionError
+	if errors.As(err, &echErr) && len(echErr.RetryConfigList) > 0 {
+		if echConfig, isECH := config.(ECHCapableConfig); isECH {
+			echConfig.SetECHConfigList(echErr.RetryConfigList)
+			tlsConn, err = aTLS.ClientHandshake(ctx, conn, config)
+		}
+	}
 	if err != nil {
 		return nil, err
 	}

experimental/clashapi/cache.go

@@ -14,6 +14,7 @@ import (
 func cacheRouter(ctx context.Context) http.Handler {
 	r := chi.NewRouter()
 	r.Post("/fakeip/flush", flushFakeip(ctx))
+	r.Post("/dns/flush", flushDNS(ctx))
 	return r
 }
 
@@ -31,3 +32,13 @@ func flushFakeip(ctx context.Context) func(w http.ResponseWriter, r *http.Reques
 		render.NoContent(w, r)
 	}
 }
+
+func flushDNS(ctx context.Context) func(w http.ResponseWriter, r *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		dnsRouter := service.FromContext[adapter.DNSRouter](ctx)
+		if dnsRouter != nil {
+			dnsRouter.ClearCache()
+		}
+		render.NoContent(w, r)
+	}
+}