Re: [PATCH v2 1/4] test-runner: Support running hostapd in namespaces

[James Prestwood <prestwoj@gmail.com>]

Hi Andrew,

On Thu, 2022-07-07 at 22:03 +0200, Andrew Zaborowski wrote:
> The kernel will not let us test some scenarios of communication
> between
> two hwsim radios (e.g. STA and AP) if they're in the same net
> namespace.
> For example, when connected, you can't add normal IPv4 subnet routes
> for
> the same subnet on two different interfaces in one namespace (you'd
> either get an EEXIST or you'd replace the other route), you can set
> different metrics on the routes but that won't fix IP routing.  For
> testNetconfig the result is that communication works for DHCP before
> we
> get the inital lease but renewals won't work because they're unicast.
> Allow hostapd to run on a radio that has been moved to a different
> namespace in hw.conf so we don't have to work around these issues.
> ---
> changes in v2:
>  - ensure at least one hostapd session starts if the [HOSTAPD]
> section
>    is present to mimic original behaviour and fix testEAD
> 
>  tools/run-tests | 82 ++++++++++++++++++++++++++++++++---------------
> --
>  tools/utils.py  |  2 +-
>  2 files changed, 54 insertions(+), 30 deletions(-)
> 
> diff --git a/tools/run-tests b/tools/run-tests
> index 565847df..c0f230cb 100755
> --- a/tools/run-tests
> +++ b/tools/run-tests
> @@ -58,16 +58,19 @@ def exit_vm():
>         runner.stop()
>  
>  class Interface:
> -       def __init__(self, name, config):
> +       def __init__(self, name, config, ns=None):
>                 self.name = name
>                 self.ctrl_interface = '/var/run/hostapd/' + name
>                 self.config = config
> +               self.ns = ns
>  
>         def __del__(self):
> -               Process(['iw', 'dev', self.name, 'del']).wait()
> +               Process(['iw', 'dev', self.name, 'del'],
> +                               namespace=self.ns.name if self.ns
> else None).wait()
>  
>         def set_interface_state(self, state):
> -               Process(['ip', 'link', 'set', self.name,
> state]).wait()
> +               Process(['ip', 'link', 'set', self.name, state],
> +                               namespace=self.ns.name if self.ns
> else None).wait()
>  

So rather than this "self.ns.name if self.ns else None" thing, you
could either store the namespace name directly (since self.ns is only
used for the name), or store the namespace object like you do and
replace Process(...) with self.ns.start_process(...).

>  class Radio:
>         def __init__(self, name):
> @@ -75,11 +78,16 @@ class Radio:
>                 # hostapd will reset this if this radio is used by it
>                 self.use = 'iwd'
>                 self.interface = None
> +               self.ns = None
>  
>         def __del__(self):
>                 print("Removing radio %s" % self.name)
>                 self.interface = None
>  
> +       def set_namespace(self, ns):
> +               self.ns = ns
> +               Process(['iw', 'phy', self.name, 'set', 'netns',
> 'name', ns.name]).wait()
> +
>         def create_interface(self, config, use):
>                 global intf_id
>  
> @@ -87,19 +95,21 @@ class Radio:
>  
>                 intf_id += 1
>  
> -               self.interface = Interface(ifname, config)
> +               self.interface = Interface(ifname, config,
> ns=self.ns)
>                 self.use = use
>  
>                 Process(['iw', 'phy', self.name, 'interface', 'add',
> ifname,
> -                               'type', 'managed']).wait()
> +                               'type', 'managed'],
> namespace=self.ns.name if self.ns else None).wait()
>  
>                 return self.interface

Since create_interface() is the only function that needs the namespace
couldn't we remove set_namespace entirely and just pass the namespace
name into create_interface?

>  
>         def __str__(self):
>                 ret = self.name + ':\n'
> -               ret += '\tUsed By: %s ' % self.use
> +               ret += '\tUsed By: %s' % self.use
>                 if self.interface:
> -                       ret += '(%s)' % self.interface.name
> +                       ret += ' (%s)' % self.interface.name
> +               if self.ns is not None:
> +                       ret += ' (ns=%s)' % self.ns.name
>  
>                 ret += '\n'
>  
> @@ -188,7 +198,7 @@ class Hostapd:
>                 A set of running hostapd instances. This is really
> just a single
>                 process since hostapd can be started with multiple
> config files.
>         '''
> -       def __init__(self, radios, configs, radius):
> +       def __init__(self, ns, radios, configs, radius):
>                 if len(configs) != len(radios):
>                         raise Exception("Config (%d) and radio (%d)
> list length not equal" % \
>                                                 (len(configs),
> len(radios)))
> @@ -198,8 +208,8 @@ class Hostapd:
>                 Process(['ip', 'link', 'set', 'eth0', 'up']).wait()
>                 Process(['ip', 'link', 'set', 'eth1', 'up']).wait()
>  
> -               self.global_ctrl_iface = '/var/run/hostapd/ctrl'
> -
> +               self.ns = ns
> +               self.global_ctrl_iface = '/var/run/hostapd/ctrl' +
> (str(ns.name) if ns.name else 'main')
>                 self.instances = [HostapdInstance(c, r) for c, r in
> zip(configs, radios)]
>  
>                 ifaces = [rad.interface.name for rad in radios]
> @@ -227,7 +237,7 @@ class Hostapd:
>                 if Process.is_verbose('hostapd'):
>                         args.append('-d')
>  
> -               self.process = Process(args)
> +               self.process = Process(args, namespace=ns.name)
>  
>                 self.process.wait_for_socket(self.global_ctrl_iface,
> 30)
>  
> @@ -397,32 +407,44 @@ class TestContext(Namespace):
>                         #          tests. In this case you would not
> care what
>                         #          was using each radio, just that
> there was
>                         #          enough to run all tests.
> -                       nradios = 0
> -                       for k, _ in settings.items():
> -                               if k == 'radius_server':
> -                                       continue
> -                               nradios += 1
> -
> -                       hapd_radios = self.radios[:nradios]
> -
> +                       hapd_configs = [conf for rad, conf in
> settings.items() if rad != 'radius_server']
> +                       hapd_processes = [(self,
> self.radios[:len(hapd_configs)], hapd_configs)]
>                 else:
> -                       hapd_radios = [rad for rad in self.radios if
> rad.name in settings]
> -
> -               hapd_configs = [conf for rad, conf in
> settings.items() if rad != 'radius_server']
> +                       hapd_processes = []
> +                       for ns in [self] + self.namespaces:
> +                               ns_radios = [rad for rad in ns.radios
> if rad.name in settings]
> +                               if len(ns_radios):
> +                                       ns_configs =
> [settings[rad.name] for rad in ns_radios]
> +                                       hapd_processes.append((ns,
> ns_radios, ns_configs))
> +                       if not hapd_processes:
> +                               hapd_processes.append((self, [], []))
>  
>                 radius_config = settings.get('radius_server', None)
>  
> -               self.hostapd = Hostapd(hapd_radios, hapd_configs,
> radius_config)
> -               self.hostapd.attach_cli()
> +               self.hostapd = [Hostapd(ns, radios, configs,
> radius_config)
> +                               for ns, radios, configs in
> hapd_processes]
> +
> +               for hapd in self.hostapd:
> +                       hapd.attach_cli()
>  
>         def get_frequencies(self):
>                 frequencies = []
>  
> -               for hapd in self.hostapd.instances:
> -                       frequencies.append(hapd.cli.frequency)
> +               for hapd in self.hostapd:
> +                       frequencies += [instance.cli.frequency for
> instance in hapd.instances]
>  
>                 return frequencies
>  
> +       def get_hapd_instance(self, config=None):
> +               instances = [i for hapd in self.hostapd for i in
> hapd.instances]
> +
> +               if config is None:
> +                       return instances[0]
> +
> +               for hapd in instances:
> +                       if hapd.config == config:
> +                               return hapd
> +

Looks like this got carried over from that dropped patch?

>         def start_wpas_interfaces(self):
>                 if 'WPA_SUPPLICANT' not in self.hw_config:
>                         return
> @@ -543,11 +565,13 @@ class TestContext(Namespace):
>                 for arg in vars(self.args):
>                         ret += '\t --%s %s\n' % (arg,
> str(getattr(self.args, arg)))
>  
> -               ret += 'Hostapd:\n'
>                 if self.hostapd:
> -                       for h in self.hostapd.instances:
> -                               ret += '\t%s\n' % str(h)
> +                       for hapd in self.hostapd:
> +                               ret += 'Hostapd (ns=%s):\n' %
> (hapd.ns.name,)
> +                               for h in hapd.instances:
> +                                       ret += '\t%s\n' % (str(h),)
>                 else:
> +                       ret += 'Hostapd:\n'
>                         ret += '\tNo Hostapd instances\n'
>  
>                 info = self.meminfo_to_dict()
> diff --git a/tools/utils.py b/tools/utils.py
> index f3e12a85..bc030230 100644
> --- a/tools/utils.py
> +++ b/tools/utils.py
> @@ -324,7 +324,7 @@ class Namespace:
>  
>                 Process(['ip', 'netns', 'add', name]).wait()
>                 for r in radios:
> -                       Process(['iw', 'phy', r.name, 'set', 'netns',
> 'name', name]).wait()
> +                       r.set_namespace(self)
>  
>                 self.start_dbus()
>