opt: add router only option

Author: BugenZhao

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "flashroute_rs"
-version = "0.2.0"
+version = "0.2.1"
 authors = [
     "Bugen Zhao <[email protected]>",
     "Zhengdong Wang <[email protected]>",

Cargo.toml

@@ -23,6 +23,8 @@ pub struct Opt {
     pub probing_rate: u64,
     #[structopt(short = "2", help = "Send at least 2 probes to each target")]
     pub two: bool,
+    #[structopt(long)]
+    pub router_only: bool,
 
     // Connection
     #[structopt(long, parse(try_from_str = utils::get_interface), default_value = "")]

src/opt.rs

@@ -410,7 +410,9 @@ impl Tracerouter {
                 }
             } else {
                 // from destination
-                backward_stop_set.insert(result.responder);
+                if !OPT.router_only {
+                    backward_stop_set.insert(result.responder);
+                }
                 dcb.stop_forward();
             }
         }