netdev - Re: [PATCH net-next v2] bonding: add an option to specify a delay between peer notifications

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Thu, 04 Jul 2019 12:31:03 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     vincent@...nat.ch
Cc:     jiri@...nulli.us, j.vosburgh@...il.com, vfalico@...il.com,
        andy@...yhouse.net, netdev@...r.kernel.org
Subject: Re: [PATCH net-next v2] bonding: add an option to specify a delay
 between peer notifications

From: Vincent Bernat <vincent@...nat.ch>
Date: Tue,  2 Jul 2019 19:43:54 +0200

> Currently, gratuitous ARP/ND packets are sent every `miimon'
> milliseconds. This commit allows a user to specify a custom delay
> through a new option, `peer_notif_delay'.
> 
> Like for `updelay' and `downdelay', this delay should be a multiple of
> `miimon' to avoid managing an additional work queue. The configuration
> logic is copied from `updelay' and `downdelay'. However, the default
> value cannot be set using a module parameter: Netlink or sysfs should
> be used to configure this feature.
> 
> When setting `miimon' to 100 and `peer_notif_delay' to 500, we can
> observe the 500 ms delay is respected:
> 
>     20:30:19.354693 ARP, Request who-has 203.0.113.10 tell 203.0.113.10, length 28
>     20:30:19.874892 ARP, Request who-has 203.0.113.10 tell 203.0.113.10, length 28
>     20:30:20.394919 ARP, Request who-has 203.0.113.10 tell 203.0.113.10, length 28
>     20:30:20.914963 ARP, Request who-has 203.0.113.10 tell 203.0.113.10, length 28
> 
> In bond_mii_monitor(), I have tried to keep the lock logic readable.
> The change is due to the fact we cannot rely on a notification to
> lower the value of `bond->send_peer_notif' as `NETDEV_NOTIFY_PEERS' is
> only triggered once every N times, while we need to decrement the
> counter each time.
> 
> iproute2 also needs to be updated to be able to specify this new
> attribute through `ip link'.
> 
> Signed-off-by: Vincent Bernat <vincent@...nat.ch>

Applied, thanks.