[net-next,v5,0/7] selftests: drv-net: support testing with a remote system

Hi!

Implement support for tests which require access to a remote system /
endpoint which can generate traffic.
This series concludes the "groundwork" for upstream driver tests.

I wanted to support the three models which came up in discussions:
 - SW testing with netdevsim
 - "local" testing with two ports on the same system in a loopback
 - "remote" testing via SSH
so there is a tiny bit of an abstraction which wraps up how "remote"
commands are executed. Otherwise hopefully there's nothing surprising.

I'm only adding a ping test. I had a bigger one written but I was
worried we'll get into discussing the details of the test itself
and how I chose to hack up netdevsim, instead of the test infra...
So that test will be a follow up :)

v5:
 - fix rand port generation, and wrap it in a helper in case
   the random thing proves to be flaky
 - reuseaddr
 - explicitly select the address family
v4: https://lore.kernel.org/all/20240418233844.2762396-1-kuba@kernel.org
 - improve coding style of patch 5
 - switch from netcat to socat (patch 6)
 - support exit_wait for bkg() in context manager
 - add require_XYZ() helpers (patch 7)
 - increase timeouts a little (1,3 -> 5 sec)
v3: https://lore.kernel.org/all/20240417231146.2435572-1-kuba@kernel.org
 - first two patches are new
 - make Remote::cmd() return Popen() object (patch 3)
 - always operate on absolute paths (patch 3)
 - last two patches are new
v2: https://lore.kernel.org/all/20240416004556.1618804-1-kuba@kernel.org
 - rename endpoint -> remote
 - use 2001:db8:: v6 prefix
 - add a note about persistent SSH connections
 - add the kernel config
v1: https://lore.kernel.org/all/20240412233705.1066444-1-kuba@kernel.org

Jakub Kicinski (7):
  selftests: drv-net: define endpoint structures
  selftests: drv-net: factor out parsing of the env
  selftests: drv-net: construct environment for running tests which
    require an endpoint
  selftests: drv-net: add a trivial ping test
  selftests: net: support matching cases by name prefix
  selftests: drv-net: add a TCP ping test case (and useful helpers)
  selftests: drv-net: add require_XYZ() helpers for validating env

 tools/testing/selftests/drivers/net/Makefile  |   5 +-
 .../testing/selftests/drivers/net/README.rst  |  33 ++++
 .../selftests/drivers/net/lib/py/__init__.py  |   1 +
 .../selftests/drivers/net/lib/py/env.py       | 175 ++++++++++++++++--
 .../selftests/drivers/net/lib/py/remote.py    |  15 ++
 .../drivers/net/lib/py/remote_netns.py        |  21 +++
 .../drivers/net/lib/py/remote_ssh.py          |  39 ++++
 tools/testing/selftests/drivers/net/ping.py   |  51 +++++
 .../testing/selftests/net/lib/py/__init__.py  |   1 +
 tools/testing/selftests/net/lib/py/ksft.py    |  13 +-
 tools/testing/selftests/net/lib/py/netns.py   |  31 ++++
 tools/testing/selftests/net/lib/py/utils.py   |  60 +++++-
 12 files changed, 416 insertions(+), 29 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/remote.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/remote_netns.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/remote_ssh.py
 create mode 100755 tools/testing/selftests/drivers/net/ping.py
 create mode 100644 tools/testing/selftests/net/lib/py/netns.py