OpenSSL server - FreeBSD/Ubuntu

[gorhas]

Yes... I am a little bit vague - since I don't fully understand what is 
going on.

I have a OpenSSL-server and a OpenSSL-client. The client are sending 
"binary" data to the server with SSL_write and the server is receiving 
with SSL_read. I am using a function call like

no_bytes = SSL_read(ssl, ssl_buffer, SSL_BUFFER_SIZE);

This works suprisingly good. I always get a full buffer. If I run the 
application on the local network between two machines, i get exteemly 
good performance. If I run from our IoT devicd I get not so good 
performance. This is expected since this is connected by a BG95 (mobile 
module). But the problem is that sometimes the packet rate slows down 
and sometimes it comes to a halt.

Since I am using high level calls like SSL_read/write I have not mutch 
use of tools like tcpdump, strace et.al. since I can't influence the 
packet flow from the high level api:s.

Since the data I am transfereing is about 5MB (a sound file) I belive 
that the network provider (Telenor) have som kind of "trafic shaping" in 
action. And I don't understand how I can investigate this.

This is a rather important application for me (commercial) and if some  
wants to cut in and investigate the problem please let me know.

// GH

Den 2021-02-03 kl. 11:35, skrev Niklas Hallqvist via BUS:
> It's a rather open question you are posing, your problem could be almost anything.
> Please provide more input.  Does this happen even in the simplest localhost scenario?
> When you say thee server "stops", what does that a mean?  Does it crash, spin, block on network input,
> Block on anything else (like on getting some resource it needs to deal with the client provided data, like an output pipe)?
>
> You just have to give a lot more information.
> t
> Otherwise tcpdump, various system call tracers (like Astrid hinted about), potential libcall tracers (like ltrace) and
> Since you are writing your own server, a debugger like gdb, are your friend.
>
> /Niklas
>
>
>> On 2 Feb 2021, at 21:32, G Hasse via BUS <bus at stacken.kth.se> wrote:
>>
>> Hi!
>>
>> I don't know if this is a BUS question - but if not - forgive me!
>>
>> I am trying to write an openssl server, and have som problem.
>>
>> A client is sending binary packets with SSL_write, and a server is reveiving with
>> SSL_read. Everyting is OK until about 1500000 bytes are sent. Then the server
>> just stops...
>>
>> Is there any ideas how to investigate this?
>>
>> // GH
>>
>> -- 
>> Göran Hasse
>> Raditex Control AB
>> Boo 229, 715 91 ODENSBACKEN
>> tel: 070 5530148
>> mail: gorhas at raditex.nu
>> _________________________________________________
>> BSD Users Sweden -- BUS at stacken.kth.se
>> https://lists.stacken.kth.se/mailman/listinfo/bus
>>
> _________________________________________________
> BSD Users Sweden -- BUS at stacken.kth.se
> https://lists.stacken.kth.se/mailman/listinfo/bus

-- 
Göran Hasse
Raditex Control AB, Boo 229, 715 91  ODENSBACKEN
email: gorhas at raditex.nu  mobile: +46 70 5530148