Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Petr Machata


Willem de Bruijn  writes:

> 1. Cleaning up remote state in all conditions, including timeout/kill.
>
>Some tests require a setup phase before the test, and a matching
>cleanup phase. If any of the configured state is variable (even
>just a randomized filepath) this needs to be communicated to the
>cleanup phase. The remote filepath is handled well here. But if
>a test needs per-test setup? Say, change MTU or an Ethtool feature.
>Multiple related tests may want to share a setup/cleanup.

Personally I like to wrap responsibilities of this sort in context
managers, e.g. something along these lines:

class changed_mtu:
def __init__(self, dev, mtu):
self.dev = dev
self.mtu = mtu

def __enter__(self):
js = cmd(f"ip -j link show dev {self.dev}", json=True)
self.orig_mtu = something_something(js)
cmd(f"ip link set dev {self.dev} mtu {self.mtu}")

def __exit__(self, type, value, traceback):
cmd(f"ip link set dev {self.dev} mtu {self.orig_mtu}")

with changed_mtu(swp1, 1):
   # MTU is 10K here
# and back to 1500

A lot of this can be made generic, where some object is given a setup /
cleanup commands and just invokes those. But things like MTU, ethtool
speed, sysctls and what have you that need to save a previous state and
revert back to it will probably need a custom handler. Like we have them
in lib.sh as well.



Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Paolo Abeni
On Mon, 2024-04-15 at 07:19 -0700, Jakub Kicinski wrote:
> On Mon, 15 Apr 2024 10:57:31 +0200 Paolo Abeni wrote:
> > If I read correctly the above will do a full ssh handshake for each
> > command. If the test script/setup is complex, I think/fear the overhead
> > could become a bit cumbersome.
> 
> Connection reuse. I wasn't sure if I should add a hint to the README,
> let me do so.

I'm sorry for the multiple, incremental feedback. I think such hinto
the readme will be definitely useful, thanks!

Paolo




Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Paolo Abeni
On Mon, 2024-04-15 at 07:19 -0700, Jakub Kicinski wrote:
> On Mon, 15 Apr 2024 10:57:31 +0200 Paolo Abeni wrote:
> > If I read correctly the above will do a full ssh handshake for each
> > command. If the test script/setup is complex, I think/fear the overhead
> > could become a bit cumbersome.
> 
> Connection reuse. I wasn't sure if I should add a hint to the README,
> let me do so.
> 
> > Would using something alike Fabric to create a single connection at
> > endpoint instantiation time and re-using it for all the command be too
> > much? 
> 
> IDK what "Fabric" is, if its commonly used we can add the option
> in tree. If less commonly - I hope the dynamic loading scheme
> will allow users to very easily drop in their own class that 
> integrates with Fabric, without dirtying the tree? :)

I'm really a python-expert. 'Fabric' a python library to execute
commands over ssh:

https://www.fabfile.org/
> 
No idea how much commont it is.

I'm fine with ssh connection sharing.

Thanks,

Paolo 




Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Willem de Bruijn
Jakub Kicinski wrote:
> On Sun, 14 Apr 2024 13:04:46 -0400 Willem de Bruijn wrote:
> > 1. Cleaning up remote state in all conditions, including timeout/kill.
> > 
> >Some tests require a setup phase before the test, and a matching
> >cleanup phase. If any of the configured state is variable (even
> >just a randomized filepath) this needs to be communicated to the
> >cleanup phase. The remote filepath is handled well here. But if
> >a test needs per-test setup? Say, change MTU or an Ethtool feature.
> >Multiple related tests may want to share a setup/cleanup.
> > 
> >Related: some tests may need benefit from a lightweight stateless
> >check phase to detect preconditions before committing to any setup.
> >Again, say an Ethtool feature like rx-gro-hw, or AF_XDP metadata rx.
> 
> I think this falls into the "frameworking debate" we were having with
> Petr. The consensus seems to be to keep things as simple as possible.

Makes sense. We can find the sticking points as we go along.

tools/testing/selftests/net already has a couple of hardware feature
tests, that probably see little use now that they require manual
testing (csum, gro, toeplitz, ..). Really excited to include them in
this infra to hopefully see more regular testing across more hardware.

> If we see that tests are poorly written and would benefit from extra
> structure we should try impose some, but every local custom is
> something people will have to learn.

The above were just observations from embedding tests like those
mentioned in our internal custom test framework. Especially with
heterogenous hardware, a lot of it is "can we run this test on this
platform", or "disable this feature as it interacts with the tested
feature" (e.g., HW-GRO and csum.c).

> timeout/kill is provided to us already by the kselftest harness.
> 
> > 2. Synchronizing peers. Often both peers need to be started at the
> >same time, but then the client may need to wait until the server
> >is listening. Paolo added a nice local script to detect a listening
> >socket with sockstat. Less of a problem with TCP tests than UDP or
> >raw packet tests.
> 
> Yes, definitely. We should probably add that with the first test that
> needs it.





Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Jakub Kicinski
On Mon, 15 Apr 2024 10:57:31 +0200 Paolo Abeni wrote:
> If I read correctly the above will do a full ssh handshake for each
> command. If the test script/setup is complex, I think/fear the overhead
> could become a bit cumbersome.

Connection reuse. I wasn't sure if I should add a hint to the README,
let me do so.

> Would using something alike Fabric to create a single connection at
> endpoint instantiation time and re-using it for all the command be too
> much? 

IDK what "Fabric" is, if its commonly used we can add the option
in tree. If less commonly - I hope the dynamic loading scheme
will allow users to very easily drop in their own class that 
integrates with Fabric, without dirtying the tree? :)



Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Jakub Kicinski
On Sun, 14 Apr 2024 13:04:46 -0400 Willem de Bruijn wrote:
> 1. Cleaning up remote state in all conditions, including timeout/kill.
> 
>Some tests require a setup phase before the test, and a matching
>cleanup phase. If any of the configured state is variable (even
>just a randomized filepath) this needs to be communicated to the
>cleanup phase. The remote filepath is handled well here. But if
>a test needs per-test setup? Say, change MTU or an Ethtool feature.
>Multiple related tests may want to share a setup/cleanup.
> 
>Related: some tests may need benefit from a lightweight stateless
>check phase to detect preconditions before committing to any setup.
>Again, say an Ethtool feature like rx-gro-hw, or AF_XDP metadata rx.

I think this falls into the "frameworking debate" we were having with
Petr. The consensus seems to be to keep things as simple as possible.
If we see that tests are poorly written and would benefit from extra
structure we should try impose some, but every local custom is
something people will have to learn.

timeout/kill is provided to us already by the kselftest harness.

> 2. Synchronizing peers. Often both peers need to be started at the
>same time, but then the client may need to wait until the server
>is listening. Paolo added a nice local script to detect a listening
>socket with sockstat. Less of a problem with TCP tests than UDP or
>raw packet tests.

Yes, definitely. We should probably add that with the first test that
needs it.



Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-15 Thread Paolo Abeni
On Fri, 2024-04-12 at 16:37 -0700, Jakub Kicinski wrote:
> +class Endpoint:
> +def __init__(self, name):
> +self.name = name
> +self._tmpdir = None
> +
> +def __del__(self):
> +if self._tmpdir:
> +self.cmd("rm -rf " + self._tmpdir)
> +self._tmpdir = None
> +
> +def cmd(self, comm, *args):
> +c = cmd("ssh " + self.name + " " + shlex.quote(comm), *args)
> +return c.stdout, c.stderr, c.ret

If I read correctly the above will do a full ssh handshake for each
command. If the test script/setup is complex, I think/fear the overhead
could become a bit cumbersome.

Would using something alike Fabric to create a single connection at
endpoint instantiation time and re-using it for all the command be too
much? 


Thanks,

Paolo




Re: [PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-14 Thread Willem de Bruijn
Jakub Kicinski wrote:
> Define the endpoint "model". To execute most meaningful device
> driver tests we need to be able to communicate with a remote system,
> and have it send traffic to the device under test.
> 
> Various test environments will have different requirements.
> 
> 0) "Local" netdevsim-based testing can simply use net namespaces.
> netdevsim supports connecting two devices now, to form a veth-like
> construct.
> 
> 1) Similarly on hosts with multiple NICs, the NICs may be connected
> together with a loopback cable or internal device loopback.
> One interface may be placed into separate netns, and tests
> would proceed much like in the netdevsim case. Note that
> the loopback config or the moving of one interface
> into a netns is not expected to be part of selftest code.
> 
> 2) Some systems may need to communicate with the endpoint via SSH.
> 
> 3) Last but not least environment may have its own custom communication
> method.
> 
> Fundamentally we only need two operations:
>  - run a command remotely
>  - deploy a binary (if some tool we need is built as part of kselftests)
> 
> Wrap these two in a class. Use dynamic loading to load the Endpoint
> class. This will allow very easy definition of other communication
> methods without bothering upstream code base.
> 
> Stick to the "simple" / "no unnecessary abstractions" model for
> referring to the endpoints. The host / endpoint object are passed
> as an argument to the usual cmd() or ip() invocation. For example:
> 
>  ip("link show", json=True, host=endpoint)
> 
> Signed-off-by: Jakub Kicinski 
> ---
>  .../selftests/drivers/net/lib/py/__init__.py  |  1 +
>  .../selftests/drivers/net/lib/py/endpoint.py  | 13 +++
>  .../selftests/drivers/net/lib/py/ep_netns.py  | 15 
>  .../selftests/drivers/net/lib/py/ep_ssh.py| 34 +++
>  tools/testing/selftests/net/lib/py/utils.py   | 19 ++-
>  5 files changed, 73 insertions(+), 9 deletions(-)
>  create mode 100644 tools/testing/selftests/drivers/net/lib/py/endpoint.py
>  create mode 100644 tools/testing/selftests/drivers/net/lib/py/ep_netns.py
>  create mode 100644 tools/testing/selftests/drivers/net/lib/py/ep_ssh.py
> 
> diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py 
> b/tools/testing/selftests/drivers/net/lib/py/__init__.py
> index 4653dffcd962..0d71ec83135b 100644
> --- a/tools/testing/selftests/drivers/net/lib/py/__init__.py
> +++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py
> @@ -15,3 +15,4 @@ KSFT_DIR = (Path(__file__).parent / "../../../..").resolve()
>  sys.exit(4)
>  
>  from .env import *
> +from .endpoint import Endpoint
> diff --git a/tools/testing/selftests/drivers/net/lib/py/endpoint.py 
> b/tools/testing/selftests/drivers/net/lib/py/endpoint.py
> new file mode 100644
> index ..9272fdc47a06
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/lib/py/endpoint.py
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +import importlib
> +
> +_modules = {}
> +
> +def Endpoint(ep_type, ep_args):
> +global _modules
> +
> +if ep_type not in _modules:
> +_modules[ep_type] = importlib.import_module("..ep_" + ep_type, 
> __name__)
> +
> +return getattr(_modules[ep_type], "Endpoint")(ep_args)
> diff --git a/tools/testing/selftests/drivers/net/lib/py/ep_netns.py 
> b/tools/testing/selftests/drivers/net/lib/py/ep_netns.py
> new file mode 100644
> index ..f5c588bb31f0
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/lib/py/ep_netns.py
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +from lib.py import cmd
> +
> +
> +class Endpoint:
> +def __init__(self, name):
> +self.name = name
> +
> +def cmd(self, *args):
> +c = cmd(*args, ns=self.name)
> +return c.stdout, c.stderr, c.ret
> +
> +def deploy(self, what):
> +return what
> diff --git a/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py 
> b/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py
> new file mode 100644
> index ..620df0dd8c07
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py
> @@ -0,0 +1,34 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +import os
> +import shlex
> +import string
> +import random
> +
> +from lib.py import cmd
> +
> +
> +class Endpoint:
> +def __init__(self, name):
> +self.name = name
> +self._tmpdir = None
> +
> +def __del__(self):
> +if self._tmpdir:
> +self.cmd("rm -rf " + self._tmpdir)
> +self._tmpdir = None
> +
> +def cmd(self, comm, *args):
> +c = cmd("ssh " + self.name + " " + shlex.quote(comm), *args)
> +return c.stdout, c.stderr, c.ret
> +
> +def _mktmp(self):
> +return ''.join(random.choice(string.ascii_lowercase) for _ in 
> range(8))
> +
> +def deploy(self, what):
> +if not self._tmpdir:
> +self._tmpdir = "/tmp/" + self._mktmp()
> +self.cmd("mkdir " 

[PATCH net-next 1/5] selftests: drv-net: define endpoint structures

2024-04-12 Thread Jakub Kicinski
Define the endpoint "model". To execute most meaningful device
driver tests we need to be able to communicate with a remote system,
and have it send traffic to the device under test.

Various test environments will have different requirements.

0) "Local" netdevsim-based testing can simply use net namespaces.
netdevsim supports connecting two devices now, to form a veth-like
construct.

1) Similarly on hosts with multiple NICs, the NICs may be connected
together with a loopback cable or internal device loopback.
One interface may be placed into separate netns, and tests
would proceed much like in the netdevsim case. Note that
the loopback config or the moving of one interface
into a netns is not expected to be part of selftest code.

2) Some systems may need to communicate with the endpoint via SSH.

3) Last but not least environment may have its own custom communication
method.

Fundamentally we only need two operations:
 - run a command remotely
 - deploy a binary (if some tool we need is built as part of kselftests)

Wrap these two in a class. Use dynamic loading to load the Endpoint
class. This will allow very easy definition of other communication
methods without bothering upstream code base.

Stick to the "simple" / "no unnecessary abstractions" model for
referring to the endpoints. The host / endpoint object are passed
as an argument to the usual cmd() or ip() invocation. For example:

 ip("link show", json=True, host=endpoint)

Signed-off-by: Jakub Kicinski 
---
 .../selftests/drivers/net/lib/py/__init__.py  |  1 +
 .../selftests/drivers/net/lib/py/endpoint.py  | 13 +++
 .../selftests/drivers/net/lib/py/ep_netns.py  | 15 
 .../selftests/drivers/net/lib/py/ep_ssh.py| 34 +++
 tools/testing/selftests/net/lib/py/utils.py   | 19 ++-
 5 files changed, 73 insertions(+), 9 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/endpoint.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/ep_netns.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/ep_ssh.py

diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py 
b/tools/testing/selftests/drivers/net/lib/py/__init__.py
index 4653dffcd962..0d71ec83135b 100644
--- a/tools/testing/selftests/drivers/net/lib/py/__init__.py
+++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py
@@ -15,3 +15,4 @@ KSFT_DIR = (Path(__file__).parent / "../../../..").resolve()
 sys.exit(4)
 
 from .env import *
+from .endpoint import Endpoint
diff --git a/tools/testing/selftests/drivers/net/lib/py/endpoint.py 
b/tools/testing/selftests/drivers/net/lib/py/endpoint.py
new file mode 100644
index ..9272fdc47a06
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/lib/py/endpoint.py
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import importlib
+
+_modules = {}
+
+def Endpoint(ep_type, ep_args):
+global _modules
+
+if ep_type not in _modules:
+_modules[ep_type] = importlib.import_module("..ep_" + ep_type, 
__name__)
+
+return getattr(_modules[ep_type], "Endpoint")(ep_args)
diff --git a/tools/testing/selftests/drivers/net/lib/py/ep_netns.py 
b/tools/testing/selftests/drivers/net/lib/py/ep_netns.py
new file mode 100644
index ..f5c588bb31f0
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/lib/py/ep_netns.py
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+
+from lib.py import cmd
+
+
+class Endpoint:
+def __init__(self, name):
+self.name = name
+
+def cmd(self, *args):
+c = cmd(*args, ns=self.name)
+return c.stdout, c.stderr, c.ret
+
+def deploy(self, what):
+return what
diff --git a/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py 
b/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py
new file mode 100644
index ..620df0dd8c07
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/lib/py/ep_ssh.py
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import os
+import shlex
+import string
+import random
+
+from lib.py import cmd
+
+
+class Endpoint:
+def __init__(self, name):
+self.name = name
+self._tmpdir = None
+
+def __del__(self):
+if self._tmpdir:
+self.cmd("rm -rf " + self._tmpdir)
+self._tmpdir = None
+
+def cmd(self, comm, *args):
+c = cmd("ssh " + self.name + " " + shlex.quote(comm), *args)
+return c.stdout, c.stderr, c.ret
+
+def _mktmp(self):
+return ''.join(random.choice(string.ascii_lowercase) for _ in range(8))
+
+def deploy(self, what):
+if not self._tmpdir:
+self._tmpdir = "/tmp/" + self._mktmp()
+self.cmd("mkdir " + self._tmpdir)
+file_name = self._tmpdir + "/" + self._mktmp() + os.path.basename(what)
+cmd(f"scp {what} {self.name}:{file_name}")
+return file_name
diff --git a/tools/testing/selftests/net/lib/py/utils.py 
b/tools/testing/selftests/net/lib/py/utils.py
index