[BUG] bsb-lan fails to close http connection after delivering home page

[DE-cr]

BSB-LAN Version 3.0.3-202212094171550 (github head version from 2022-12-19 07:51)

Architecture ESP32 NodeMCU

Bus system BSB

Describe the bug On my system, the http connection is not closed properly after completely delivering the home page (http://bsb-lan/) contents (including the final \</html\>\r\n\r\n). After a while, the client then complains (Firefox: "Fehler: Verbindung unterbrochen [...]") or just hangs (wget). This only seems to happen when "check for updates" is enabled!

[fredlcore]

Can you try and change line 110 in print_webpage.h from flushToWebClient(); to forcedflushToWebClient(); and see if the problem persists?

[DE-cr]

Thank you for the quick reply - even with this less-than-substantial bug! I've changed what you've suggested: The problem persists.

[dukess]

Can you run Wireshark (windows) or tcpdump (*nix) for packets capturing? It would help to understanding where is bug appears. tcpdump -A -i eth0 host 0.0.0.0 and tcp port 80

[DE-cr]

Here's the WireShark (Linux) protocol: 2022-12-1918-27-cr_wireshark.zip

[dukess]

BSB-LAN flush all bytes to client browser but doesn't connection closing after ~1000 msec. May it rebooted in this time for some reason?

[DE-cr]

Yes, that's it! Uptime in /C shows that it does reboot after delivering / contents. But why?

[fredlcore]

What does SerMo log say? Is there a crash?

[DE-cr]

There's no SerMo: The unit sits inside the boiler casing. Should I try telnet monitoring?

[fredlcore]

No point. In case there is a crash, how should the crash message be sent to the telnet client?

[DE-cr]

@fredlcore, could you please remove the bogus 9 from http://bsb-lan.de/bsb-version.h and let me see if the problem persists?

[fredlcore]

Why should this have anything to do with it and why don't you remove it yourself locally and test it then?

[DE-cr]

The problem could be writing beyond the end of version_number[15] in include/print_webpage.h: webPrintSite(). The version check in calling bsb-lan's root page reads http://bsb-lan.de/bsb-version.h, not my local copy.

[DE-cr]

I've included a fix in my still open PR https://github.com/fredlcore/BSB-LAN/pull/499 P.S. ...which I have successfully tested on my system, of course.

[DE-cr]

Btw, this also explains a slightly different phenomenon I had been experiencing lately: Instead of memorizing /K, /DG, etc. (OK, I've got these two memorized now), I usually start my http sessions with my bsb-lan unit via http://bsb-lan, and then use the menus. For the last couple of weeks, (quickly) selecting one of the menu entries after loading http://bsb-lan lead to a "server cannot be reached" message - which I hadn't worried much about, as a subsequent F5=refresh loaded the desired page alright. I did not open a bug report for that because I thought that it could have been due to a weak WLAN connection in my network. Now I know that the server could not be reached because it was rebooting at those times. Of course this only happens upon loading the bsb-lan http root page if the "newer version available?" check is activated - and COMPILETIME in http://bsb-lan.de/bsb-version.h contains one digit too many.

[fredlcore]

Thanks for spotting this, I wouldn't have thought about this if I had had time to start bugfixing now. No need for a fix as this number will be overwritten with a correct COMPILETIME value once I push the next version number (which I might do before the holidays, as soon as I have confirmation on some other matter).