Add proxy support for ICMP echo request

adapter/outbound.go

@@ -3,9 +3,11 @@ package adapter
 import (
 	"context"
 	"net/netip"
+	"time"
 
 	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing-tun"
 	N "github.com/sagernet/sing/common/network"
 )
 
@@ -20,10 +22,16 @@ type Outbound interface {
 }
 
 type OutboundWithPreferredRoutes interface {
+	Outbound
 	PreferredDomain(domain string) bool
 	PreferredAddress(address netip.Addr) bool
 }
 
+type DirectRouteOutbound interface {
+	Outbound
+	NewDirectRouteConnection(metadata InboundContext, routeContext tun.DirectRouteContext, timeout time.Duration) (tun.DirectRouteDestination, error)
+}
+
 type OutboundRegistry interface {
 	option.OutboundOptionsRegistry
 	CreateOutbound(ctx context.Context, router Router, logger log.ContextLogger, tag string, outboundType string, options any) (Outbound, error)

adapter/router.go

@@ -6,8 +6,10 @@ import (
 	"net"
 	"net/http"
 	"sync"
+	"time"
 
 	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-tun"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
 	"github.com/sagernet/sing/common/ntp"
@@ -19,7 +21,7 @@ import (
 type Router interface {
 	Lifecycle
 	ConnectionRouter
-	PreMatch(metadata InboundContext) error
+	PreMatch(metadata InboundContext, context tun.DirectRouteContext, timeout time.Duration) (tun.DirectRouteDestination, error)
 	ConnectionRouterEx
 	RuleSet(tag string) (RuleSet, bool)
 	NeedWIFIState() bool