From: "Daniel P. Berrangé" <berrange@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: pbonzini@redhat.com, thuth@redhat.com, qemu-devel@nongnu.org,
vgoyal@redhat.com
Subject: Re: libcap vs libcap-ng mess
Date: Fri, 29 Nov 2019 09:34:09 +0000 [thread overview]
Message-ID: <20191129093409.GB2260471@redhat.com> (raw)
In-Reply-To: <20191128190408.GC3294@work-vm>
On Thu, Nov 28, 2019 at 07:04:08PM +0000, Dr. David Alan Gilbert wrote:
> Hi,
> We seem to have a bit of a mess with libcap and libcap-ng; and I'm not
> sure if we should try and untangle it.
>
> a) Our configure script has tests for both libcap and libcap-ng
> for libcap it says $cap, for libcap-ng it says $cap_ng (ok)
> If $cap is set - nothing happens?
> If $cap_ng is set - we define CONFIG_LIBCAP (!)
Wow, confusing to the max.
> b) We use both
> 1) pr-helper and bridge-helper use CONFIG_LIBCAP and use cap-ng
> 2) 9p's virtfs-proxy-helper uses libcap - it's got a check in
> configure to make sure you have libcap if you've asked for 9p
>
> c) Our gitlab-ci.yml installs libcap-dev to get the 9p stuff tested
> but never installes libcap-ng-dev
Opps.
>
> I hit this because we're using libcap in virtiofsd at the moment.
>
> So hmm how to fix?
> I'm tempted to:
> x) Replace CONFIG_LIBCAP by CONFIG_LIBCAPNG to make it clear
Definitely
> y) Should we flip over to only using one or the other - what
> are the advantages?
In libvirt we use libcap-ng. We picked this originally as its API
design allows you do write simpler code than libcap in some cases
You can see some docs & examples here:
https://people.redhat.com/sgrubb/libcap-ng/
So I vote for changing the 9p code to use libcap-ng.
> z) We should probably add the other one to the ci.
Yep.
Regards,
Daniel
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next prev parent reply other threads:[~2019-11-29 9:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 19:04 libcap vs libcap-ng mess Dr. David Alan Gilbert
2019-11-29 9:34 ` Daniel P. Berrangé [this message]
2019-11-29 10:46 ` Paolo Bonzini
2019-11-29 10:51 ` Dr. David Alan Gilbert
2019-11-29 18:01 ` Dr. David Alan Gilbert
2019-11-29 18:12 ` Paolo Bonzini
2019-11-29 18:20 ` Dr. David Alan Gilbert
2019-11-29 18:27 ` Paolo Bonzini
2019-11-29 18:54 ` Dr. David Alan Gilbert
2019-11-29 23:19 ` Paolo Bonzini
2019-12-02 10:07 ` Dr. David Alan Gilbert
2019-12-02 10:33 ` Paolo Bonzini
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