[Devel] [PATCH vz10] selftests: drv-net: avoid host firewall interference

[Konstantin Khorenko]

Please check hci-tests.vhistrg repo for the following commit:
https://bitbucket.org/virtuozzocore/hci-tests.vhistrg/commits/00e524341ea1e55a11d9de5cb2ab03cb21118208

commit 00e524341ea1e55a11d9de5cb2ab03cb21118208
Author: Aleksei Oladko <aleksey.oladko at virtuozzo.com>
Date:   Wed Feb 18 09:33:35 2026 +0000

    hci-kselftests: stop firewalld to prevent test hangs

    Some net/forwarding kselftests disable the default timeout and wait
    for generated packets to be received. If firewall rules are active,
    the packets may be dropped and the test can hang indefinitely.

    The hci-kselftest previously attempted to clear firewall rules
    with "nft flush ruleset", but firewalld restored them, causing the
    tests to hang.

    Stop firewalld instead to ensure the rules are not reinstalled
    during test execution.

    vstorage-ui-agent service monitors availability of firewalld and
    restores it if needed => need to disable it as well.

    /etc/firewalld/firewalld.conf CleanupOnExit option might cause
    firewalld not to clear rules on a service stop =>
    clean up rules additionally just in case.

    https://virtuozzo.atlassian.net/browse/VSTOR-125054

    Signed-off-by: Aleksei Oladko <aleksey.oladko at virtuozzo.com>


It should already disable all iptables and Co.

And taking this into account - do we still need this patch?
If yes - why?


--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

On 6/25/26 00:33, Eva Kurchatova wrote:
> The NetDrvEpEnv test environment creates a netdevsim device in
> init_net and a peer in a separate network namespace. Tests such as
> ping.py's test_tcp start a socat listener in init_net and expect the
> remote namespace to connect to it via random port.
> 
> When a host firewall (e.g. firewalld with nftables backend) is active,
> its INPUT chain rejects inbound TCP connections to ports not in its
> allow-list. ICMP is explicitly permitted, so ping tests pass, but
> TCP-based tests hang indefinitely: the socat listener never receives a
> connection, and bkg(exit_wait=True) waits forever for it to exit,
> resulting in a timeout failure.
> 
> Fix this by adding the local netdevsim interface to the firewalld
> trusted zone after creating the test topology in create_local().
> The trusted zone accepts all traffic unconditionally, bypassing any
> filtering rules. The interface is removed from the zone during
> cleanup in __del__(). Both operations use fail=False so they are
> silently skipped on systems without firewalld.
> 
> Signed-off-by: Eva Kurchatova <eva.kurchatova at virtuozzo.com>
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-135793
> Feature: fix selftests
> 
> ---
>  tools/testing/selftests/drivers/net/lib/py/env.py | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
> index 1ea9bb695e94..b3d4c1accb25 100644
> --- a/tools/testing/selftests/drivers/net/lib/py/env.py
> +++ b/tools/testing/selftests/drivers/net/lib/py/env.py
> @@ -92,6 +92,7 @@ class NetDrvEpEnv:
>          self._netns = None
>          self._ns = None
>          self._ns_peer = None
> +        self._fw_ifname = None
>  
>          if "NETIF" in self.env:
>              if nsim_test is True:
> @@ -156,6 +157,13 @@ class NetDrvEpEnv:
>          ip(f"-6 addr add dev {self._ns_peer.nsims[0].ifname} {self.nsim_v6_pfx}2/64 nodad", ns=self._netns)
>          ip(f"   link set dev {self._ns_peer.nsims[0].ifname} up", ns=self._netns)
>  
> +        # Allow all inbound traffic on the local test interface.
> +        # A host firewall (e.g. firewalld) may reject connections to
> +        # random test ports, causing TCP-based tests to time out.
> +        self._fw_ifname = self._ns.nsims[0].ifname
> +        cmd(f"firewall-cmd --zone=trusted --add-interface={self._fw_ifname}",
> +            fail=False)
> +
>      def _check_env(self):
>          vars_needed = [
>              ["LOCAL_V4", "LOCAL_V6"],
> @@ -190,6 +198,11 @@ class NetDrvEpEnv:
>          self.__del__()
>  
>      def __del__(self):
> +        if self._fw_ifname:
> +            cmd(f"firewall-cmd --zone=trusted "
> +                f"--remove-interface={self._fw_ifname}",
> +                fail=False)
> +            self._fw_ifname = None
>          if self._ns:
>              self._ns.remove()
>              self._ns = None