netdev - Re: [PATCH net-next v2] ipv4: fib: Replay events when registering FIB notifier

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

Date:   Mon, 31 Oct 2016 14:24:06 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     idosch@...sch.org
Cc:     netdev@...r.kernel.org, davem@...emloft.net, jiri@...lanox.com,
        mlxsw@...lanox.com, roopa@...ulusnetworks.com,
        dsa@...ulusnetworks.com, nikolay@...ulusnetworks.com,
        andy@...yhouse.net, vivien.didelot@...oirfairelinux.com,
        andrew@...n.ch, f.fainelli@...il.com, alexander.h.duyck@...el.com,
        kuznet@....inr.ac.ru, jmorris@...ei.org, yoshfuji@...ux-ipv6.org,
        kaber@...sh.net, Ido Schimmel <idosch@...lanox.com>
Subject: Re: [PATCH net-next v2] ipv4: fib: Replay events when registering
 FIB notifier

On Mon, 2016-10-31 at 23:13 +0200, idosch@...sch.org wrote:
> From: Ido Schimmel <idosch@...lanox.com>
> 
> When registering a FIB notifier block we should notify the caller of
> already existing FIB entries and rules, as it would otherwise have an
> incomplete view of the FIB tables. This is especially important for
> switchdev drivers that support FIB offloads. Failing to notify them of
> existing entries may lead to packet loss.
> 
> Upon registration, walk the leafs of all the routing tables and for each
> leaf send notification of existing FIB aliases. Similarly, when
> unregistering the notifier synthesize a deletion event, thereby
> relieving potential callers from the need to perform cleanup.
> 
> The above is consistent with the netdevice notification chain, where
> "registration and up events are replayed to the new notifier" upon
> registration.
> 
> Signed-off-by: Ido Schimmel <idosch@...lanox.com>
> Reviewed-by: Jiri Pirko <jiri@...lanox.com>



How well will this work for large FIB tables ?

Holding rtnl while sending thousands of skb will prevent consumers to
make progress ?