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-next>] [day] [month] [year] [list]
Date:	Mon, 11 Aug 2014 14:38:48 -0700
From:	Marcel Holtmann <marcel@...tmann.org>
To:	Daniel Borkmann <dborkman@...hat.com>
Cc:	Network Development <netdev@...r.kernel.org>
Subject: netlink_deliver_tap is broken

Hi Daniel,

the netlink tap functionality is not really usable. At least not from a nlmon perspective. It has three fundamental problems.

a) Multicast netlink messages are not delivered to a registered tap when you do not have any member subscribed to the multicast group

b) Multicast netlink messages are delivered multiple times when you have multiple clients subscribed to that multicast group.

c) Unicast netlink messages are filtered out by the client socket filter meaning they never get to the tap

I think all 3 need to be actually fixed to have nlmon being useful for netlink tracing. I did a simple approach by moving netlink_deliver_tap into the actual right places before the filters. However that does not seems to work since it causes sleeping in wrong context.

You might want to have a look at it to make nlmon actually functional complete and not depending on some external multicast membership or socket filters.

Regards

Marcel

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ