Can't set outgoing ttl

[internelp]

On macOS , we can use -m ttl to set this variable, like this:

ping google.com -m 1

On Windows, we can use -i ttl to set this variable, like this:

ping google.com -i 1

[zuvola]

I added the ttl option. Please check it out.

[internelp]

Hi zuvola, I think there are still some problems.

This is my code:

    try {
      debugPrint(DateTime.now().toIso8601String());
      final ping = Ping(
        'www.google.com',
        count: 1,
        timeout: 10,
        interval: 1,
        ipv6: false,
        ttl: 1,
      );
      ping.stream.listen((PingData event) {
        print(">>>>>>>${DateTime.now().toIso8601String()}");
        print("response:  ${event.response.toString()}");
        print("response time:  ${event.response?.time}");
        print("response ip:  ${event.response?.ip}");
        print("error: ${event.error}");
        print("summary: ${event.summary.toString()}");
        print("<<<<<<<");
      });
    } catch (e) {
      print('error $e');
    }

And this is the output:

flutter: 2022-04-12T16:39:37.860499
start:131873042
flutter: >>>>>>>2022-04-12T16:39:47.950086
flutter: response:  PingResponse(seq:0, ip:199.59.148.229, ttl:1, time:0.0 ms)
flutter: response time:  0:00:00.000000
flutter: response ip:  199.59.148.229
flutter: error: PingError.requestTimedOut
flutter: summary: null
flutter: <<<<<<<
flutter: >>>>>>>2022-04-12T16:39:47.954159
flutter: response:  null
flutter: response time:  null
flutter: response ip:  null
flutter: error: null
flutter: summary: PingSummary(transmitted:1, received:0, time:10001 ms)
flutter: <<<<<<<

This is macos ping output:

feng@Fengs-iMac ~ % ping www.google.com -m 1 -t 2 
PING www.google.com (199.59.148.229): 56 data bytes
36 bytes from 10.0.54.254: Time to live exceeded
Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst
 4  5  00 5400 f96c   0 0000  01  01 235f 10.0.54.189  199.59.148.229 

Request timeout for icmp_seq 0
36 bytes from 10.0.54.254: Time to live exceeded
Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst
 4  5  00 5400 60fc   0 0000  01  01 bbcf 10.0.54.189  199.59.148.229 

--- www.google.com ping statistics ---
2 packets transmitted, 0 packets received, 100.0% packet loss

My ip is 10.0.54.2; My network gateway ip is 10.0.54.254; My ping destination domin is www.google.com and it's ip is 199.59.148.229;

The route map is like below: 10.0.54.2 <--> 10.0.54.254(first router) <--> 22.33.44.55(second router) <--> Several routers <--> 199.59.148.229(google.com's ip)

When I set the outgoing ttl is 1, my gateway (10.0.54.254) will reponse me the Time to live exceeded error, and the reponse ip will be 10.0.54.254.

If I set the ttl is 2, the reponse will be 22.33.44.55(second router).

Only if the TTL value is greater than the number of routers I sent to google.com will google.com return it directly.

But flutter_icmp_ping's reponse is not like this.

My guess is that you may have overlooked reponses from non-target addresses.

Please check, thanks.

[internelp]

The correct response would be something like this

flutter: >>>>>>>2022-04-12T16:39:47.950086
flutter: response:  PingResponse(seq:0, ip:199.59.148.229, ttl:1, time:0.0 ms)
flutter: response time:  0:00:00.012000
flutter: response ip:  `10.0.54.254`
flutter: error: `PingError.timeToLiveExceeded`
flutter: summary: null
flutter: <<<<<<<

[zuvola]

Thank you for your report. I am using a library called GBPing internally, and it seems to be the problem here. This library is out of development, so it looks like I'll have to fix it myself. I will take a look at it when I have time. Of course, PR is very welcome.

[internelp]

https://developer.apple.com/library/archive/samplecode/SimplePing/Introduction/Intro.html

Apple have samplecode named "SimplePing", but I'm not good at using OC for development. Maybe you can refer to or replace GBPing.

Adding ICMP Protocol to flutter is a great work. Thank you for your efforts.

[zuvola]

Thanks for the information. It would certainly be best if we could replace the library.

[Vasilisk7]

Any updates?