Real MTU problems with BIO pair

Detlef Vollmann dv at
Fri Aug 21 18:32:55 UTC 2020

On 2020-08-21 19:48, Benjamin Kaduk wrote:
> On Fri, Aug 21, 2020 at 05:05:51PM +0200, Detlef Vollmann wrote:
>> On 2020-08-20 21:44, Detlef Vollmann wrote:
>>> Is there any way to set the maximum fragment size for
>>> DTLS handshake with a BIO pair?
>> One solution is to set the MTU and the int_bio size to
>> exactly the same value.
>> Another option would be to use BIO_set_callback_ex() and send
>> the data to the socket after each BIO_write() into int_bio,
>> but the problem here is that BIO_set_data() cannot be used
>> as the ptr is already used for the peer address.
> There's always EX_DATA...
Thanks for the pointer. Using my own hash table would also be
an option.

But in the meantime I found that I can define my own BIO_METHOD,
so this is probably my preferred option.


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