chore: proxyDialer can limited support old dial function

constant/adapters.go

@@ -2,6 +2,7 @@ package constant
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
 	"net/netip"
@@ -44,6 +45,8 @@ const (
 	DefaultTLSTimeout = DefaultTCPTimeout
 )
 
+var ErrNotSupport = errors.New("no support")
+
 type Connection interface {
 	Chains() Chain
 	AppendToChains(adapter ProxyAdapter)
@@ -117,7 +120,7 @@ type ProxyAdapter interface {
 	// SupportUOT return UDP over TCP support
 	SupportUOT() bool
 
-	SupportWithDialer() bool
+	SupportWithDialer() NetWork
 	DialContextWithDialer(ctx context.Context, dialer Dialer, metadata *Metadata) (Conn, error)
 	ListenPacketWithDialer(ctx context.Context, dialer Dialer, metadata *Metadata) (PacketConn, error)
 

constant/metadata.go

@@ -15,7 +15,10 @@ const (
 	TCP NetWork = iota
 	UDP
 	ALLNet
+	InvalidNet = 0xff
+)
 
+const (
 	HTTP Type = iota
 	HTTPS
 	SOCKS4
@@ -33,12 +36,16 @@ const (
 type NetWork int
 
 func (n NetWork) String() string {
-	if n == TCP {
+	switch n {
+	case TCP:
 		return "tcp"
-	} else if n == UDP {
+	case UDP:
 		return "udp"
+	case ALLNet:
+		return "all"
+	default:
+		return "invalid"
 	}
-	return "all"
 }
 
 func (n NetWork) MarshalJSON() ([]byte, error) {