From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Carlson Date: Wed, 06 May 2020 15:15:46 +0000 Subject: Re: PPPoE Modem hangup after random time - how to debug? Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-ppp@vger.kernel.org On 2020-05-06 10:26, Guillaume Nault wrote: > On Wed, May 06, 2020 at 11:52:48AM +0200, David Bala=C5=BEic wrote: >> (the last line is from my fix, the connection is now not dropped when >> the PADT is not for us; works fine, my connection stays up and >> working) >> > Looks like a more fundamental issue. This frame shouldn't have been > accepted in the first place. Can you also print the packet class > ("... pkt_type %u", ..., skb->pkt_type)? >=20 > Testing the destination MAC here is likely to just paper over the > problem. Having either sketchy (e.g., CRC hash filter based) or just absent hardware filtering of unicast addresses isn't an unknown property for some Ethernet devices. Relying on exact match from the underlying hardware seems like a bad idea. (Some, for instance, can either receive "all multicast" or can filter using the low N bits of the CRC to index into a 2^N-bit hash table, but can't really exclude a unicast packet that happens to match the low N bits of a selectively enabled multicast address. See, for example, the PowerQUICC implementation. But there are quite a few that work like this. It wouldn't surprise me in the least that 'ar71xx' [Atheros/Qualcomm?] is like this.) I agree that having to test the MAC address right here is a bit lame and that the driver itself ought to assist the hardware in doing the Right Thing. --=20 James Carlson 42.703N 71.076W