Re: Error loading tcp_bbr kernel module

Hi Michael,

On Sat, May 09, 2020 at 05:42:55PM +0200, Michael Tuexen wrote:
> > On 9. May 2020, at 16:25, Gordon Bergling <gbergling_at_googlemail.com> wrote:
> > I tried tcp_rack and tcp_bbr, since both are separate TCP stacks. I just posted the wrong error message. Both TCP stacks weren’t loadable as a kernel module with just the former mentioned build option.
> > 
> > I currently have build running with both kernel options  you mentioned.
> > 
> > If the build is successful and I can change the default TCP stack to RACK and BBR I let you know.
> That would be great. I have them running on my machines, but I might have missed something.
> > 
> > Further I didn’t find any documentation within tcp(4) regarding RACK and BBR. Since I am about to enhance the manpages, I’ll extent tcp(4) about information about RACK and BBR, but this is a different topic.
> > 
> Yes it is. And I would suggest to use separate man pages, a single one for each stack.
> The the generic man page might refer to them...

My first thoughts on this topic were about to extent tcp(4) and create links to
tcp_rack(4) and tcp_bbr(4), but separate manpages maybe the way to go. I just
have to investigate the respective details. I was once very deep into TCP/IP, 
while building perimeter firewalls with FreeBSD, but this was 20 years ago.

I add you as a reviever for the differential once I have a rough cut 
for the manpages ready.

Best regards,

Gordon

> >> Am 09.05.2020 um 14:37 schrieb Michael Tuexen <tuexen_at_freebsd.org>:
> >>> On 9. May 2020, at 14:18, Gordon Bergling <gbergling_at_googlemail.com> wrote:
> >>> 
> >>> Greetings,
> >>> 
> >>> I build -CURRENT with WITH_EXTRA_TCP_STACKS=1, but I got the following error
> >>> when I try to load for example tcp_bbr.ko.
> >>> z
> >>> kldload: an error occurred while loading module tcp_rack.ko. Please check dmesg(8) for more details.
> >> This indicates that you want to load the RACK stack.
> >> 
> >> Please note that you need for BBR and RACK:
> >> options		TCPHPTS
> >> in the kernel config and in addition to that for RACK
> >> options		RATELIMIT
> >> 
> >>> dmesg shows:
> >>> 
> >>> KLD tcp_bbr.ko: depends on tcphpts - not available or version mismatch
> >>> linker_load_file: /boot/kernel/tcp_bbr.ko - unsupported file type
> >>> 
> >>> Any hints on solving the problem?
> >>> 
> >>> The kernel config is GENERIC.
> >>> 
> >>> Best regards,
> >>> 
> >>> Gordon