Add health check support for http-based v2ray transport

transport/v2raygrpc/client.go

@@ -18,6 +18,7 @@ import (
 	"google.golang.org/grpc/backoff"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/keepalive"
 )
 
 var _ adapter.V2RayClientTransport = (*Client)(nil)
@@ -40,6 +41,13 @@ func NewClient(ctx context.Context, dialer N.Dialer, serverAddr M.Socksaddr, opt
 	} else {
 		dialOptions = append(dialOptions, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	}
+	if options.IdleTimeout > 0 {
+		dialOptions = append(dialOptions, grpc.WithKeepaliveParams(keepalive.ClientParameters{
+			Time:                time.Duration(options.IdleTimeout),
+			Timeout:             time.Duration(options.PingTimeout),
+			PermitWithoutStream: options.PermitWithoutStream,
+		}))
+	}
 	dialOptions = append(dialOptions, grpc.WithConnectParams(grpc.ConnectParams{
 		Backoff: backoff.Config{
 			BaseDelay:  500 * time.Millisecond,