Re: [PATCH bpf-next 5/7] selftests: bpf: add test for sk_assign

On Tue, Mar 17, 2020 at 12:31 AM Martin KaFai Lau [off-list ref] wrote:

On Thu, Mar 12, 2020 at 04:36:46PM -0700, Joe Stringer wrote:

quoted

From: Lorenz Bauer <redacted>

Attach a tc direct-action classifier to lo in a fresh network
namespace, and rewrite all connection attempts to localhost:4321
to localhost:1234.

Keep in mind that both client to server and server to client traffic
passes the classifier.

Signed-off-by: Lorenz Bauer <redacted>
Signed-off-by: Joe Stringer <redacted>
---
 tools/testing/selftests/bpf/.gitignore        |   1 +
 tools/testing/selftests/bpf/Makefile          |   3 +-
 .../selftests/bpf/progs/test_sk_assign.c      | 127 +++++++++++++
 tools/testing/selftests/bpf/test_sk_assign.c  | 176 ++++++++++++++++++

Can this test be put under the test_progs.c framework?

I'm not sure, how does the test_progs.c framework handle the logic in
"tools/testing/selftests/bpf/test_sk_assign.sh"?

Specifically I'm looking for:
* Unique netns to avoid messing with host networking stack configuration
* Control over routes
* Attaching loaded bpf programs to ingress qdisc of a device

These are each trivial one-liners in the supplied shell script
(admittedly building on existing shell infrastructure in the tests dir
and iproute2 package). Seems like maybe the netns parts aren't so bad
looking at flow_dissector_reattach.c but anything involving netlink
configuration would either require pulling in a netlink library
dependency somewhere or shelling out to the existing binaries. At that
point I wonder if we're trying to achieve integration of this test
into some automated prog runner, is there a simpler way like a place I
can just add a one-liner to run the test_sk_assign.sh script?

quoted

 tools/testing/selftests/bpf/test_sk_assign.sh |  19 ++