Commit fa63d353 authored by Pedro Tammela's avatar Pedro Tammela Committed by David S. Miller
Browse files

selftests: tc-testing: rework namespaces and devices setup 



As mentioned in the TC Workshop 0x17, our recent changes to tdc broke
downstream CI systems like tuxsuite. The issue is the classic problem
with rcu/workqueue objects where you can miss them if not enough wall time
has passed. The latter is subjective to the system and kernel config,
in my machine could be nanoseconds while in another could be microseconds
or more.

In order to make the suite deterministic, poll for the existence
of the objects in a reasonable manner. Talking netlink directly is the
the best solution in order to avoid paying the cost of multiple
'fork()' calls, so introduce a netlink based setup routine using
pyroute2. We leave the iproute2 one as a fallback when pyroute2 is not
available.

Also rework the iproute2 side to mimic the netlink routine where it
creates DEV0 as the peer of DEV1 and moves DEV1 into the net namespace.
This way when the namespace is deleted DEV0 is also deleted
automatically, leaving no margin for resource leaks.

Another bonus of this change is that our setup time sped up by a factor
of 2 when using netlink.

Signed-off-by: default avatarPedro Tammela <pctammela@mojatatu.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9ffa01ca

tools/testing/selftests/tc-testing/plugin-lib/nsPlugin.py

+49 −20
Original line number Diff line number Diff line
@@ -9,6 +9,14 @@ from TdcPlugin import TdcPlugin 


from tdc_config import *



try:

    from pyroute2 import netns

    from pyroute2 import IPRoute

    netlink = True

except ImportError:

    netlink = False

    print("!!! Consider installing pyroute2 !!!")



def prepare_suite(obj, test):

    original = obj.args.NAMES
@@ -28,6 +36,9 @@ def prepare_suite(obj, test): 
    shadow['DEV2'] = original['DEV2']

    obj.args.NAMES = shadow



    if netlink == True:

        obj._nl_ns_create()

    else:

        obj._ns_create()



    # Make sure the netns is visible in the fs
@@ -67,7 +78,6 @@ class SubPlugin(TdcPlugin): 
        if test_skip:

            return





    def post_case(self):

        if self.args.verbose:

            print('{}.post_case'.format(self.sub_class))
@@ -119,23 +129,41 @@ class SubPlugin(TdcPlugin): 
            print('adjust_command:  return command [{}]'.format(command))

        return command



    def _ports_create_cmds(self):

        cmds = []



        cmds.append(self._replace_keywords('link add $DEV0 type veth peer name $DEV1'))

        cmds.append(self._replace_keywords('link set $DEV0 up'))

        cmds.append(self._replace_keywords('link add $DUMMY type dummy'))

    def _nl_ns_create(self):

        ns = self.args.NAMES["NS"];

        dev0 = self.args.NAMES["DEV0"];

        dev1 = self.args.NAMES["DEV1"];

        dummy = self.args.NAMES["DUMMY"];



        return cmds



    def _ports_create(self):

        self._exec_cmd_batched('pre', self._ports_create_cmds())

        if self.args.verbose:

            print('{}._nl_ns_create'.format(self.sub_class))



    def _ports_destroy_cmd(self):

        return self._replace_keywords('link del $DEV0')

        netns.create(ns)

        netns.pushns(newns=ns)

        with IPRoute() as ip:

            ip.link('add', ifname=dev1, kind='veth', peer={'ifname': dev0, 'net_ns_fd':'/proc/1/ns/net'})

            ip.link('add', ifname=dummy, kind='dummy')

            while True:

                try:

                    dev1_idx = ip.link_lookup(ifname=dev1)[0]

                    dummy_idx = ip.link_lookup(ifname=dummy)[0]

                    ip.link('set', index=dev1_idx, state='up')

                    ip.link('set', index=dummy_idx, state='up')

                    break

                except:

                    time.sleep(0.1)

                    continue

        netns.popns()



    def _ports_destroy(self):

        self._exec_cmd('post', self._ports_destroy_cmd())

        with IPRoute() as ip:

            while True:

                try:

                    dev0_idx = ip.link_lookup(ifname=dev0)[0]

                    ip.link('set', index=dev0_idx, state='up')

                    break

                except:

                    time.sleep(0.1)

                    continue



    def _ns_create_cmds(self):

        cmds = []
@@ -143,10 +171,13 @@ class SubPlugin(TdcPlugin): 
        ns = self.args.NAMES['NS']



        cmds.append(self._replace_keywords('netns add {}'.format(ns)))

        cmds.append(self._replace_keywords('link add $DEV1 type veth peer name $DEV0'))

        cmds.append(self._replace_keywords('link set $DEV1 netns {}'.format(ns)))

        cmds.append(self._replace_keywords('link add $DUMMY type dummy'.format(ns)))

        cmds.append(self._replace_keywords('link set $DUMMY netns {}'.format(ns)))

        cmds.append(self._replace_keywords('netns exec {} $IP link set $DEV1 up'.format(ns)))

        cmds.append(self._replace_keywords('netns exec {} $IP link set $DUMMY up'.format(ns)))

        cmds.append(self._replace_keywords('link set $DEV0 up'.format(ns)))



        if self.args.device:

            cmds.append(self._replace_keywords('link set $DEV2 netns {}'.format(ns)))
@@ -159,7 +190,6 @@ class SubPlugin(TdcPlugin): 
        Create the network namespace in which the tests will be run and set up

        the required network devices for it.

        '''

        self._ports_create()

        self._exec_cmd_batched('pre', self._ns_create_cmds())



    def _ns_destroy_cmd(self):
@@ -171,7 +201,6 @@ class SubPlugin(TdcPlugin): 
        devices as well)

        '''

        self._exec_cmd('post', self._ns_destroy_cmd())

        self._ports_destroy()



    @cached_property

    def _proc(self):