| Re: [wakaama-dev] DTLS handshake errors |
Hi Achim, Thanks a lot for your email. The errors occurs on the wakaama client side? >>>>>>>>>>>Yes Are you using a Wakaama server? Or Leshan? >>>>>>>>>>>Leshan If your using Leshan Server and Wakaama client, this may be caused by the DTLS role exchange, >>> OK, I will investigate this, thank you. I’m not sure, if tinyDTLS is aware of that feature. If you could provide a WireShark capture, this would help. >>> On the server it might be possible (I sometimes use tcpdump). On the client (the mbed LPC1768 target) I can only log ad-hoc via USB. I tried analyzing the logs but it’s challenging to understand where it exactly hangs, so I was asking where to look for the DTLS handshake logic if anyone knows and if someone already encountered these issues. Anyway, I’m thinking now of developing some sort of Watchdog in order to avoid the client to be stuck. This would help me solve in stability issues with a quick and dirty reboot (for now) as my application needs to be continuously sending data. Thanks and Kind Regards, Riccardo. By the way, calling “dtls_renegotiate” may not work, it assumes a valid DTLS session. See https://sourceforge.net/p/tinydtls/tickets/12/ From: wakaama-dev-bounces@xxxxxxxxxxx [mailto:wakaama-dev-bounces@xxxxxxxxxxx] On Behalf Of Kraus Achim (INST/ESY1) Hi Riccardo, „epoch 0, seqn 0“: The errors occurs on the wakaama client side? Are you using a Wakaama server? Or Leshan? If your using Leshan Server and Wakaama client, this may be caused by the DTLS role exchange, I’m not sure, if tinyDTLS is aware of that feature. If you could provide a WireShark capture, this would help. By the way, calling “dtls_renegotiate” may not work, it assumes a valid DTLS session. See https://sourceforge.net/p/tinydtls/tickets/12/ Mit freundlichen Grüßen / Best regards Achim Kraus Bosch Software Innovations GmbH Communications (INST/ESY1) Stuttgarter Straße 130 71332 Waiblingen GERMANY Tel. +49 711 811-58139 Registered office: Berlin, Register court: Amtsgericht Charlottenburg, HRB 148411 B Executives: Dr.-Ing. Rainer Kallenbach; Michael Hahn Von: wakaama-dev-bounces@xxxxxxxxxxx [mailto:wakaama-dev-bounces@xxxxxxxxxxx] Im Auftrag von Riccardo Pozza Hi all, I’ve upgraded recently to DTLS communication on my lwm2m client. Sometimes I need to re-handshake with DTLS for re-registration and I rarely get errors, but I do get them during the handshake procedure. Examples thereof: è Error DTLS handling message -552. o The message sequence number is too small, expected XXXX, got 0: è WARN, Wrong epoch, expected X, got 0 Sometimes I just see the initial ClientHello packet sent and no reply whatsoever. The issue in this case is that the client blocks and never gets out unless rebooted, which I’d like to avoid. What is the behaviour on the failed DTLS handshake? Is it possible to render this non-blocking? Thanks and Kind Regards, Riccardo. |