netdev - Re: twice past the taps, thence out to net?

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]

Message-ID: <1323975277.2769.20.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC>
Date:	Thu, 15 Dec 2011 19:54:37 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Rick Jones <rick.jones2@...com>
Cc:	Vijay Subramanian <subramanian.vijay@...il.com>,
	tcpdump-workers@...ts.tcpdump.org, netdev@...r.kernel.org
Subject: Re: twice past the taps, thence out to net?

Le jeudi 15 décembre 2011 à 10:32 -0800, Rick Jones a écrit :
> > More exactly, we call dev_queue_xmit_nit() from dev_hard_start_xmit()
> > _before_ giving skb to device driver.
> >
> > If device driver returns NETDEV_TX_BUSY, and a qdisc was setup on the
> > device, packet is requeued.
> >
> > Later, when queue is allowed to send again packets, packet is
> > retransmitted (and traced a second time in dev_queue_xmit_nit())
> 
> Is this then an unintended consequence bug, or a known feature?
> 

Its a well known feature, some people attempted to remove it ;)

http://answers.softpicks.net/answers/topic/-PATCH-tcpdump-may-trace-some-outbound-packets-twice--2204640-1.htm



--
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