> Am 30.10.2025 um 15:05 schrieb Patrick Schlangen via curl-library
> <[email protected]>:
>
> Hi,
>
> I've been looking for a way to have something like
> CURLMOPT_MAX_HOST_CONNECTIONS - but instead of limiting by hostname:port,
> limit by peer / IP address.
>
> It seems it's not straightforward to add this in a way similar to
> CURLMOPT_MAX_HOST_CONNECTIONS since that limit seem to be checked before the
> address resolution has been done.
>
> Another idea I had was trying to use CURLOPT_OPENSOCKETFUNCTION and introduce
> some kind of special return value (like CURL_SOCKET_BAD) which causes the
> connection to be put in pending state, and have libcurl retry the socket
> creation later. That could also be useful for implementing other custom ways
> of limiting connections, or to retry socket creation if the system (or
> application) runs out of sockets.
>
> Any thoughts on this? Maybe I'm missing some way in which this can already be
> implemented right now without changes to libcurl?
You are correct that there is no obvious place in libcurl where to add that.
Connection are chosen/reused based on the url authority (and config parameters)
and once a connection is created, it counts and is used.
Limiting on IP address has another tricky issue: a hostname can resolve to many
IP addresses. Which one will eventually be used depends on the IP Eyeballing
and what it succeeds with. For a new connection with a previous host name, that
might be a different address.
This also should show that intercepting somehow at socket creation is also
tricky. Sockets are created for IP eyeballing, maybe many per connection (until
one succeeds, then the rest is closed).
Maybe it would be good to take a step back and describe what you actually want
to achieve? Is this for a private setup only or should it work on the public
internet? etc.
Kind Regards,
Stefan
>
> Thanks,
>
> Patrick
> --
> Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library
> Etiquette: https://curl.se/mail/etiquette.html
--
Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library
Etiquette: https://curl.se/mail/etiquette.html
