badtls: Support uTLS and TLS ECH for read waiter

common/badtls/read_wait_ech.go

@@ -0,0 +1,31 @@
+//go:build go1.21 && !without_badtls && with_ech
+
+package badtls
+
+import (
+	"net"
+	_ "unsafe"
+
+	"github.com/sagernet/cloudflare-tls"
+	"github.com/sagernet/sing/common"
+)
+
+func init() {
+	tlsRegistry = append(tlsRegistry, func(conn net.Conn) (loaded bool, tlsReadRecord func() error, tlsHandlePostHandshakeMessage func() error) {
+		tlsConn, loaded := common.Cast[*tls.Conn](conn)
+		if !loaded {
+			return
+		}
+		return true, func() error {
+				return echReadRecord(tlsConn)
+			}, func() error {
+				return echHandlePostHandshakeMessage(tlsConn)
+			}
+	})
+}
+
+//go:linkname echReadRecord github.com/sagernet/cloudflare-tls.(*Conn).readRecord
+func echReadRecord(c *tls.Conn) error
+
+//go:linkname echHandlePostHandshakeMessage github.com/sagernet/cloudflare-tls.(*Conn).handlePostHandshakeMessage
+func echHandlePostHandshakeMessage(c *tls.Conn) error