From: Cyrill Gorcunov <gorcu...@gmail.com>
Date: Thu, 10 Mar 2016 23:01:34 +0300
> On Thu, Mar 10, 2016 at 02:55:43PM -0500, David Miller wrote:
>> >
>> > Hmm, but inetdev_destroy() is only called when NETDEV_UNREGISTER
>> > is happening and masq already registers a netdev notifier...
>>
>> Indeed, good catch. Therefore:
>>
>> 1) Keep the masq netdev notifier. That will flush the conntrack table
>> for the inetdev_destroy event.
>>
>> 2) Make the inetdev notifier only do something if inetdev->dead is
>> false. (ie. we are flushing an individual address)
>>
>> And then we don't need the NETDEV_UNREGISTER thing at all:
>>
>> diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
>> b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
>> index c6eb421..f71841a 100644
>> --- a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
>> +++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
>> @@ -108,10 +108,20 @@ static int masq_inet_event(struct notifier_block *this,
>> unsigned long event,
>> void *ptr)
>> {
>> - struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev;
>> struct netdev_notifier_info info;
>> + struct in_ifaddr *ifa = ptr;
>> + struct in_device *idev;
>>
>> - netdev_notifier_info_init(&info, dev);
>> + /* The masq_dev_notifier will catch the case of the device going
>> + * down. So if the inetdev is dead and being destroyed we have
>> + * no work to do. Otherwise this is an individual address removal
>> + * and we have to perform the flush.
>> + */
>> + idev = ifa->ifa_dev;
>> + if (idev->dead)
>> + return NOTIFY_DONE;
>> +
>> + netdev_notifier_info_init(&info, idev->dev);
>> return masq_device_event(this, event, &info);
>> }
>
> Guys, I'm lost. Currently masq_device_event calls for conntrack
> cleanup with device index, so that once device is going down, the
> appropriate conntracks gonna be dropped off. Now if device is dead
> nobody will cleanup the conntracks?
Both notifiers are run in the inetdev_destroy() case.
Maybe that's what you are missing.
