Re: [PATCH V11 0/4] BPF: New helper to obtain namespace data from current task

[Carlos Antonio Neira Bustos <cneirabustos@gmail.com>]

On Tue, Sep 24, 2019 at 08:01:17PM +0200, Daniel Borkmann wrote:
> On Tue, Sep 24, 2019 at 12:20:01PM -0300, Carlos Neira wrote:
> > Currently bpf_get_current_pid_tgid(), is used to do pid filtering in bcc's
> > scripts but this helper returns the pid as seen by the root namespace which is
> > fine when a bcc script is not executed inside a container.
> > When the process of interest is inside a container, pid filtering will not work
> > if bpf_get_current_pid_tgid() is used.
> > This helper addresses this limitation returning the pid as it's seen by the current
> > namespace where the script is executing.
> > 
> > In the future different pid_ns files may belong to different devices, according to the
> > discussion between Eric Biederman and Yonghong in 2017 Linux plumbers conference.
> > To address that situation the helper requires inum and dev_t from /proc/self/ns/pid.
> > This helper has the same use cases as bpf_get_current_pid_tgid() as it can be
> > used to do pid filtering even inside a container.
> > 
> > Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
> > 
> > Carlos Neira (4):
> >   fs/nsfs.c: added ns_match
> >   bpf: added new helper bpf_get_ns_current_pid_tgid
> >   tools: Added bpf_get_ns_current_pid_tgid helper
> >   tools/testing/selftests/bpf: Add self-tests for new helper. self tests
> >     added for new helper
> 
> bpf-next is currently closed due to merge window. Please resubmit once back open, thanks.

Thanks, Daniel, I'll do so.

Bests.