Re: [libmicrohttpd] Problem send large trunk of data over upgraded connection with epoll and https enabled

[Nguyen Xuan Viet]

Dear Christian,

I'm sorry but this bug still happen on latest version of this library.
The "test_upgrade_large_tls" still hangs with very large data send over the upgraded connection.
We can reproduce this issue by increase "LARGE_STRING" and/or "LARGE_REPLY_STRING" size to a huge string, for example duplicate current "Hello..." string to 41 lines or more.

This issue only happens with EPOLL + HTTPS, for other cases, it works normally.
Could you please check this issue for me?

Thanks,
Viet

On 7/30/19 11:00 PM, Việt Nguyễn Xuân wrote:

Dear Christian,

Thanks for your reply.
I'm very happy to hear your information. I will continue to work with your latest source in the future.

Best regards,
Viet

On 30/07/2019 01:04, Christian Grothoff wrote:

Dear Viet,

Thanks for the additional details.  With your report, I was able to
reproduce the issue (test_upgrade_large.c added) and fix it in
bafd078984be5f846287107824eca99e6c6c42cc.

Happy hacking!

Christian

On 6/24/19 7:16 PM, Việt Nguyễn Xuân wrote:

Hi all,

Sorry, I cannot reply your email, so I reply it here.
I'm sorry, for the moment I cannot provide the code for you. But you can
reproduce the issue by modify the src/microhttpd/test_upgrade.c, set the
connection memory limit to a very low value, for example 512, this
change should be made for HTTPS section. In the function "run_usock" and
"run_usock_client", please replace the test string "Hello World" by a
real larger string with length about 160 - 170 bytes. After that do a
make check and you will see the test_upgrade_tls test hang forever.

Thanks,
Best regards,
Viet

------------------------------------------------------------------------
*From:* Việt Nguyễn Xuân
*Sent:* Sunday, June 23, 2019 11:28 AM
*To:* libmicrohttpd@gnu.org
*Subject:* [libmicrohttpd]Problem send large trunk of data over upgraded
connection with epoll and https enabled
 
Hi All,

I'm using libmicrohttpd to implement a WebSocket server based on HTTP
Upgrade connection.
I'm using latest git revision of this library for my work.
Everything works well for small message passes over upgraded connection,
I tested with Chrome and Firefox browsers and they are all Ok.
But I have a trouble when sending large trunk of message to the server,
if the size of message is larger than 1/3 connection buffer size, it's
very often that this message will be queued for next send or is not sent
at all. For smaller messages, they will be sent and received immediately.

This issue  only happens when I enable HTTPs combine with EPOLL internal
thread, for other combination it seems that this issue does not happen.
For example I can send large message normally with HTTPS + POLL internal
thread or with HTTP + EPOLL internal thread.

Could you please check this issue for me?
Thanks a lot.

Viet