Check bytesSent at every invocation of _maintainOutgoing() and if 0 throw Network Unreachable

Question

Check bytesSent at every invocation of _maintainOutgoing() and if 0 throw Network Unreachable

Ifilehk opened this issue a year ago · comments

Hello Jan

Back again with an issue. Getting a network unreachable unhandled exception during a _dtlsClient._socket.send in dtls_client.dart _maintainOutgoing() line 559.

I suppose that every _maintainOutgoing() invocation has to be checked on the number of sent bytes and throw Network unreachable consequently.

Server side might need the same ...

Jan Romann · Answer 1 · Tue Apr 18 2023 16:50:17 GMT+0800 (China Standard Time)

Hi @Ifilehk, welcome back and thank you for reporting this issue!

I suppose that every _maintainOutgoing() invocation has to be checked on the number of sent bytes and throw Network unreachable consequently.

So would you suggest that a SocketException should be thrown if the number of bytes sent is equal to 0? Or would another behavior be better here?

Ifilehk · Answer 2 · Tue Apr 18 2023 17:11:35 GMT+0800 (China Standard Time)

I think that the answer should be an exception + connection close and cleanings because for what ever reason the network adapter has been deactivated. So no reason to continue with the current connection.

Jan Romann · Answer 3 · Sun Apr 23 2023 18:47:37 GMT+0800 (China Standard Time)

Hi @Ifilehk, sorry for the delay! I tried to come up with a fix in #75, could you try out if that resolves the issue?

Ifilehk · Answer 4 · Wed Apr 26 2023 18:23:15 GMT+0800 (China Standard Time)

No problem !!!

Will give a try and let you know

Ifilehk · Answer 5 · Thu Apr 27 2023 01:51:33 GMT+0800 (China Standard Time)

Here my comments:

On client side:
A Exception: DtlsException: Sending failed: Not connected is thrown. I would expect a SocketException Network unreachable. Otherwise behavior seems to be OK.

On server side:
On Ubuntu, unfortunately the invocation of _dtlsServer._socket.send doesn't return 0 on Network unreachable. The app crashes with the system exception Network unreachable without possibility to catch it.

Will open an issue there to have at least the same behavior seen on Android.

Jan Romann · Answer 6 · Thu Apr 27 2023 01:54:04 GMT+0800 (China Standard Time)

Thank you for your feedback!

On client side:
A Exception: DtlsException: Sending failed: Not connected is thrown. I would expect a SocketException > Network unreachable. Otherwise behavior seems to be OK.

I will update #75 accordingly :)

On server side:
On Ubuntu, unfortunately the invocation of _dtlsServer._socket.send doesn't return 0 on Network unreachable. The app crashes with the system exception Network unreachable without possibility to catch it.

Will open an issue there to have at least the same behavior seen on Android.

Hmm, okay, so there is no potential to fix it here, right?

Ifilehk · Answer 7 · Thu Apr 27 2023 03:12:28 GMT+0800 (China Standard Time)

Your fix is already there and you can not make more at this point. Let's see if the flutter team will do something.

…

On Apr 26, 2023, 18:54, at 18:54, Jan Romann ***@***.***> wrote: Thank you for your feedback! > On client side: > A Exception: DtlsException: Sending failed: Not connected is thrown. I would expect a SocketException > Network unreachable. Otherwise behavior seems to be OK. I will update #75 accordingly :) > On server side: > On Ubuntu, unfortunately the invocation of _dtlsServer._socket.send doesn't return 0 on Network unreachable. The app crashes with the system exception Network unreachable without possibility to catch it. > > Will open an issue there to have at least the same behavior seen on Android. Hmm, okay, so there is no potential to fix it here, right? -- Reply to this email directly or view it on GitHub: #74 (comment) You are receiving this because you were mentioned. Message ID: ***@***.***>

Ifilehk · Answer 8 · Thu Apr 27 2023 03:13:05 GMT+0800 (China Standard Time)

Will let you know

…

On Apr 23, 2023, 11:47, at 11:47, Jan Romann ***@***.***> wrote: Hi @Ifilehk, sorry for the delay! I tried to come up with a fix in #75, could you try out if that resolves the issue? -- Reply to this email directly or view it on GitHub: #74 (comment) You are receiving this because you were mentioned. Message ID: ***@***.***>

Jan Romann · Answer 9 · Thu Apr 27 2023 03:57:50 GMT+0800 (China Standard Time)

A Exception: DtlsException: Sending failed: Not connected is thrown. I would expect a SocketException Network unreachable. Otherwise behavior seems to be OK.

Hmm, on second thought, for this exception, I think the current behavior does make sense since this exception is only thrown if the connection has not been established or has been closed. Or would you say that there should be a further differentiation?