netdev - pppoe.ko intercepts PADT frames and leaves pppd ignorant

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Message-ID: <1383163753.21123.22.camel@dcbw.foobar.com>
Date:	Wed, 30 Oct 2013 15:09:13 -0500
From:	Dan Williams <dcbw@...hat.com>
To:	netdev@...r.kernel.org
Subject: pppoe.ko intercepts PADT frames and leaves pppd ignorant

Hi,

I noticed that pppd is completely ignorant of kernel handling of PADT
frames; they will cause the kernel to terminate the PPPoE connection,
but pppd continues blissfully on until the LCP echo timeout.  Ideally
pppd/rp-pppoe would notice that a PADT was received, and could then
clean up immediately.  This apparently happens fine with usermode PPPoE,
but not with kernel PPPoE.

pppoe_disc_rcv() intercepts PADT and verifies it, and then drops it on
the floor.  How is userland supposed to know that the PPPoE session is
now a zombie and the PPP session should be cleaned up?

Thanks,
Dan

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