On 10/20/22 18:33, Ilya Maximets wrote: > On 10/20/22 17:32, Aaron Conole wrote: >> Hi Ilya, >> >> Ilya Maximets <i.maximets@xxxxxxx> writes: >> >>> On 10/19/22 20:30, Aaron Conole wrote: >>>> Previous commit resolves a WARN splat that can be difficult to reproduce, >>>> but with the ovs-dpctl.py utility, it can be trivial. Introduce a test >>>> case which creates a DP, and then downgrades the feature set. This will >>>> include a utility 'ovs-dpctl.py' that can be extended to do additional >>>> work. >>>> >>>> Signed-off-by: Aaron Conole <aconole@xxxxxxxxxx> >>>> Signed-off-by: Kevin Sprague <ksprague0711@xxxxxxxxx> >>>> --- >>>> MAINTAINERS | 1 + >>>> tools/testing/selftests/Makefile | 1 + >>>> .../selftests/net/openvswitch/Makefile | 13 + >>>> .../selftests/net/openvswitch/openvswitch.sh | 216 +++++++++ >>>> .../selftests/net/openvswitch/ovs-dpctl.py | 411 ++++++++++++++++++ >>>> 5 files changed, 642 insertions(+) >>>> create mode 100644 tools/testing/selftests/net/openvswitch/Makefile >>>> create mode 100755 tools/testing/selftests/net/openvswitch/openvswitch.sh >>>> create mode 100644 tools/testing/selftests/net/openvswitch/ovs-dpctl.py >>>> >>>> diff --git a/MAINTAINERS b/MAINTAINERS >>>> index abbe88e1c50b..295a6b0fbe26 100644 >>>> --- a/MAINTAINERS >>>> +++ b/MAINTAINERS >>>> @@ -15434,6 +15434,7 @@ S: Maintained >>>> W: http://openvswitch.org >>>> F: include/uapi/linux/openvswitch.h >>>> F: net/openvswitch/ >>>> +F: tools/testing/selftests/net/openvswitch/ >>>> >>>> OPERATING PERFORMANCE POINTS (OPP) >>>> M: Viresh Kumar <vireshk@xxxxxxxxxx> >>> >>> ... >>> >>>> +exit ${exitcode} >>>> diff --git a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py >>>> b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py >>>> new file mode 100644 >>>> index 000000000000..791d76b7adcd >>>> --- /dev/null >>>> +++ b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py >>>> @@ -0,0 +1,411 @@ >>>> +#!/usr/bin/env python3 >>>> +# SPDX-License-Identifier: GPL-2.0 >>>> + >>>> +# Controls the openvswitch module. Part of the kselftest suite, but >>>> +# can be used for some diagnostic purpose as well. >>>> + >>>> +import logging >>>> +import multiprocessing >>>> +import socket >>>> +import struct >>>> +import sys >>>> + >>>> +try: >>>> + from libnl.attr import NLA_NESTED, NLA_STRING, NLA_U32, NLA_UNSPEC >>>> + from libnl.attr import nla_get_string, nla_get_u32 >>>> + from libnl.attr import nla_put, nla_put_string, nla_put_u32 >>>> + from libnl.attr import nla_policy >>>> + >>>> + from libnl.error import errmsg >>>> + >>>> + from libnl.genl.ctrl import genl_ctrl_resolve >>>> + from libnl.genl.genl import genl_connect, genlmsg_parse, genlmsg_put >>>> + >>>> + from libnl.handlers import nl_cb_alloc, nl_cb_set >>>> + from libnl.handlers import NL_CB_CUSTOM, NL_CB_MSG_IN, NL_CB_VALID >>>> + from libnl.handlers import NL_OK, NL_STOP >>>> + >>>> + from libnl.linux_private.netlink import NLM_F_ACK, NLM_F_DUMP >>>> + from libnl.linux_private.netlink import NLM_F_REQUEST, NLMSG_DONE >>>> + >>>> + from libnl.msg import NL_AUTO_SEQ, nlmsg_alloc, nlmsg_hdr >>>> + >>>> + from libnl.nl import NLMSG_ERROR, nl_recvmsgs_default, nl_send_auto >>>> + from libnl.socket_ import nl_socket_alloc, nl_socket_set_cb >>>> + from libnl.socket_ import nl_socket_get_local_port >>>> +except ModuleNotFoundError: >>>> + print("Need to install the python libnl3 library.") >>> >>> >>> Hey, Aaron and Kevin. Selftests sounds like a very important and >>> long overdue thing to add. Thanks for working on this! >>> >>> I have some worries about the libnl3 library though. It doesn't >>> seem to be maintained well. It it maintained by a single person, >>> it it was at least 3 different single persons over the last 7 >>> years via forks. It didn't get any significant development done >>> since 2015 as well and no commits at all for a last 1.5 years. >>> It is not packaged by any major distributions. >> >> :-/ On my fedora: >> >> 11:12:24 aconole@RHTPC1VM0NT ~$ dnf search python3-libnl3 >> Last metadata expiration check: 1 day, 0:25:11 ago on Wed 19 Oct 2022 10:47:21 AM EDT. >> ===================== Name Exactly Matched: python3-libnl3 ===================== >> python3-libnl3.x86_64 : libnl3 binding for Python 3 >> >> >> And I can use it: >> >> 11:18:39 aconole@RHTPC1VM0NT {(6a5c83bdd991...)} ~/git/linux/tools/testing/selftests/net/openvswitch$ sudo python3 ./ovs-dpctl.py show >> foop >> Lookups: Hit: 0 Missed: 0 Lost: 0 >> Flows: 0 >> Masks: Hit: 0 Total: 0 >> Cache: Hit: 0 >> Caches: >> Masks-cache: size: 256 >> Port 0: foop (internal) >> 11:18:43 aconole@RHTPC1VM0NT {(6a5c83bdd991...)} ~/git/linux/tools/testing/selftests/net/openvswitch$ rpm -qa | grep python3-libnl3 >> python3-libnl3-3.5.0-6.fc34.x86_64 >> 11:19:01 aconole@RHTPC1VM0NT {(6a5c83bdd991...)} ~/git/linux/tools/testing/selftests/net/openvswitch$ >> >> Was there some place you did not find it? > > You're right, I missed that somehow. But this is not an > https://github.com/coolshou/libnl3 project. :) > These are python bindings for the C libnl library: > > $ dnf info python3-libnl3 > Available Packages > Name : python3-libnl3 > Version : 3.7.0 > Release : 1.fc36 > Architecture : x86_64 > Size : 153 k > Source : libnl3-3.7.0-1.fc36.src.rpm > Repository : updates > Summary : libnl3 binding for Python 3 > URL : http://www.infradead.org/~tgr/libnl/ > License : LGPLv2 > Description : Python 3 bindings for libnl3 Actually, I can't find an equivalent package for Ubuntu 22.04. And since pip is not an option (pip install libnl3 is a different package), there is no way to install it there beside building from sources. Am I still missing something? > >> >>> I'm talking about https://github.com/coolshou/libnl3 . Please, >>> correct me if that is not the right one. There are too many >>> libraies with the name libnl out there... That is also not a great >>> sign. >> >> Yes, this is the project. > > Doensn't look like it... > >> We did look at some of the ones you >> mentioned, but didn't find much. >> >> It is a sparse landscape of projects that provide netlink support in >> python. >> >>> The C library libnl (https://github.com/thom311/libnl) seems to >>> be well maintained in general. It has experimental python >>> bindings which are not really supported much. Python bindings >>> received only 2 actual code-changing commits in the last 7 years. >>> Both of them are just python 2/3 compatibility changes. >>> Maybe that is not that big of a deal since it's not really a >>> real python library, but a wrapper on top of a main C library. >>> However, I didn't find these python bindings to be packaged in >>> distributions. And they seem to be not available in pip as well. >>> So, building them is kind of a pain. >> >> Well, the python libnl3 should be installable via pip3. Ex: >> >> 11:27:15 aconole@RHTPC1VM0NT ~$ pip3 install libnl3 >> Defaulting to user installation because normal site-packages is not writeable >> Collecting libnl3 >> Using cached libnl3-0.3.0-py3-none-any.whl (89 kB) >> Installing collected packages: libnl3 >> Successfully installed libnl3-0.3.0 > > And this is https://pypi.org/project/libnl3/, which is the > https://github.com/coolshou/libnl3 project. So, by installing > libnl3 via pip and installing python3-libnl3 from the fedora > you're getting two completely different libraries. > > So, which one users should use? > > I can't find python bindings for the C libnl (which is the > python3-libnl3 package) in pypi, so it can't be installed > with pip. > > >> >> So I guess that is worth something. >> >> At least on Fedora it is installable from distribution as well. >> >>> There is another option which is pyroute2. It positions itself >>> primarily as a netlink library and it does include an >>> pyroute2.netlink module indeed: >>> https://github.com/svinota/pyroute2/tree/master/pyroute2/netlink >>> See the __init__.py for usage examples. >>> >>> This one looks to me like the most trustworthy. It is actively >>> used by everyone in the python networking world, e.g. by OpenStack. >>> And it is actively developed and maintained unlike other >>> netlink-related python projects. It is also packaged in most of the >>> main distributions, so it's easy to install and use. Many people >>> already have it installed for other purposes. >>> >>> TBH, I didn't compare the functionality, but I'd expect that most >>> of the things we need are implemented. >>> >>> What do you think? >> >> We can certainly look at switching, but having a quick glance, it seems >> pyroute2 expects to provide the genl commands as well, so they would >> want us to create an ovs module in pyroute2 that includes all of the ovs >> family support. Of course, we can always do this just in our module, >> but I think it isn't the way pyroute2 project wants to be structured. >> More like a library that provides all the command functionality. > > What I was thinking is to import pyroute2.netlink and the > pyroute2.netlink.generic and go from there. But I didn't > look too deep on how to actually implement the functionality. > > The python bindings for the C libnl (python3-libnl3) sounds > like a fine option since they are actually packaged in > distributions (missed that in my initial reply). However, > the fact that you can not install them via pip and actually > you will install something but completely different is kind > of weird. This has to be at least better documented, so > users will know what to install and they will not try to use > pip for that. > >> >>> On the other note, I'm not a real python developer, but the code >>> looks more like a C than a python even for me. Firstly, I'd say >>> that it would be great to maintain some coding style, e.g. by >>> checking with flake8 and/or black. See some issues/suggestions >>> provided by these tools below. >> >> Agreed. BTW, on the rhel8 system I developed on: >> >> [root@wsfd-netdev60 openvswitch]# flake8 ./ovs-dpctl.py >> [root@wsfd-netdev60 openvswitch]# >> >> So, I guess it is probably that I should have used a different system to >> do the flake8 checks. > > Maybe the python version is different... I was running on f36 > with python 3.10. Also, the list of defaults might be different. > flake8 doesn't use default ignore list if one is explicitly provided. > >> >>> Secondly, we shouldd at least use argparse for argument parsing. >>> It's part of the standard library since python 3.2, so doens't >>> require any special dependencies to be installed. >> >> Okay - I can switch to argparse. TBH, I haven't kept up with python >> standard library for some time. > > Well, 3.2 was released 11 years ago. :) > >> >>> Some parts of the code can probably be re-written to be more >>> "pythonic" as well, but I won't dive into that for now. I didn't >>> review the code deep enough for that. >> >> I have difficulty sometimes understanding what it means to be "Real >> Python (tm)" - I don't plan to change things too much. I can certainly >> switch to using argparse, but unless you give something you want to >> change, I would not change anything. > > I breifly looked through code and though I don't fully > understand what this piece supposed to do: > > + segment = hdrval.find(":") > + if segment == -1: > + segment = len(hdrval) > + hdrver = int(hdrval[:segment], 0) > + if len(hdrval[:segment]): > + userfeatures = int(hdrval[:segment], 0) > > but I have a strong feeling that this part can benefit > from use of hdrval.split(':'). > > I won't insist on that too much. :) > > Best regards, Ilya Maximets.
