Add ping proxy implementation

icmp.go

@@ -0,0 +1,29 @@
+package tun
+
+import (
+	"context"
+	"net"
+	"net/netip"
+	"os"
+	"runtime"
+
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+
+	"golang.org/x/sys/unix"
+)
+
+func NewICMPDestination(ctx context.Context, logger logger.Logger, dialer net.Dialer, network string, address netip.Addr, routeContext DirectRouteContext) (DirectRouteDestination, error) {
+	if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
+		return NewUnprivilegedICMPDestination(ctx, logger, dialer, network, address, routeContext)
+	} else {
+		destination, err := NewPrivilegedICMPDestination(ctx, logger, dialer, network, address, routeContext)
+		if err != nil {
+			if E.IsMulti(err, os.ErrPermission, unix.EPERM) {
+				return NewUnprivilegedICMPDestination(ctx, logger, dialer, network, address, routeContext)
+			}
+			return nil, err
+		}
+		return destination, nil
+	}
+}