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>] [day] [month] [year] [list]
Message-ID: <be47cd18bbf0b90a602c58a4aea746a8@oktetlabs.ru>
Date:	Mon, 09 Aug 2010 16:33:35 +0400
From:	Nikita Rastegaev <Nikita.Rastegaev@...etlabs.ru>
To:	<linux-kernel@...r.kernel.org>
Subject: Multicast MAC when sending via gateway

I observe some strange behavior when sending multicast datagrams 
via gateway. It appears that destination MAC in UDP packets differs 
when using connected and connectionless socket. In case of 
connectionless socket destination MAC field of UDP header is filled 
with MAC address of gateway, but in case we use connect()
with multicast address, destination MAC is set to multicast MAC. 
I don't know, which behavior is right, but different behavior seems 
strange.

I run the attached test on thorin1 machine and use thorin2 as a gateway.
thorin1 is running 2.6.26-2-686 kernel, thorin2 is 2.6.26-2-amd64.
I also attach ifconfig and route output for this machines and tcpdump 
output on thorin2 when running test. There we can see the following:

16:02:30.567909 00:27:0e:09:01:2a > 00:27:0e:09:02:2a, ethertype IPv4
(0x0800), length 58: 10.54.10.1.40074 > 237.92.130.210.51721: UDP, length
16
16:02:30.567984 00:27:0e:09:01:2a > 01:00:5e:5c:82:d2, ethertype IPv4
(0x0800), length 74: 10.54.10.1.43360 > 237.92.130.210.51721: UDP, length
32

Is it a bug or is this kind of behavior expected?

I wish to be personally CC'ed the answers/comments posted to the list in
response to this posting.

Nikita Rastegaev <Nikita.Rastegaev@...etlabs.ru>
Content of type "text/plain" skipped

Content of type "text/plain" skipped

Content of type "text/plain" skipped

Content of type "text/plain" skipped

Content of type "text/plain" skipped

Content of type "text/plain" skipped

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ