[openssl-users] Issue with select after SSL_get_wfd

[Grace Priscilla Jero]

Thankyou Hugh,
I know that it is datagram and we are not acknowledged. I just was looking
for a way if SSL will be aware whether the packet is consumed or not.
or anyway we can get the status from SSL on the packet consumption.

Thanks,
Grace

On Fri, Feb 16, 2018 at 4:13 PM, Hugh Maaskant <hugh.maaskant at gmail.com>
wrote:

> Hi Grace,
>
> UDP is a datagram service - think of it as “fire and forget”. So the
> sending socket will not know if or when the packet has been delivered to
> the receiver, let alone that it has been consumed. You could, of course,
> create your own application level acks and retries etcetera, but before you
> know it you are rebuilding TCP.
>
> See e.g. https://www.diffen.com/difference/TCP_vs_UDP for a comparison
> between UDP and TCP.
>
> rgds,
>
> Hugh
>
> On 16 Feb 2018, at 04:35, Grace Priscilla Jero <grace.priscilla at gmail.com>
> wrote:
>
> Hi All,
>
> I want to know the status of the SSL_WRITE for DTLS on UDP on a
> non-blocking socket. Only if the other end does the recvfrom I want to
> continue with subsequent SSL_WRITE.
>
> Below is what I have tried.
>
> //Making the socket blocking - if I dont do below then select call hangs
>
> if (wfd = SSL_get_wfd(ssl))
>     {
>             flags = fcntl(wfd, F_GETFL);
>             flags &= ~O_NONBLOCK;
>             fcntl(a_wfd, F_SETFL, flags);
>
>                 FD_SET(wfd, &write_fds);
>     }
> len = SSL_write(          ssl,
>                                      buf,
>                                      elen);
>
> i = select(wfd+1, NULL, &write_fds, 0, 0);
>
> The other side has not yet done the SSL_read but i is "1".
> Is their something wrong with this?
>
> Thanks,
> Grace
>
> --
> openssl-users mailing list
> To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
>
>
>
> --
> openssl-users mailing list
> To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20180216/e9f7961b/attachment.html>