From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202502 header.b=gluhPl3p; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 5B64A5A0275 for ; Tue, 18 Mar 2025 06:22:09 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202502; t=1742275325; bh=Ggc/cxATY7DFpiijcXn54tTSrNFZykYqj9IsVuC3Il4=; h=Date:From:To:Cc:Subject:From; b=gluhPl3puA/k92OHXmubUWtNSKxbymvhdd7cQmn/MDtYzAe15uq1Ma+Sqa8QGElFK vUqkN4s0IW+pk42fTa1yKv17ntYBkXRQnBbFNkR7pnvGrgNcsj3nQx4GGLV/9Rx9TO ZsX8NqSjPSjiZvo9UL3/JkCgMTToUgkURHE3tKfPPhiA3gab0n1nV6ogvJ2WVR1I3p Xe0Sd/kdN6da0GoPSd2UQFuWj9taL5PxsIdOcz+aiDhKU6gLEoAOtU4Afudeb5Zq6Q 6EnQqh7cEmkrKA8Ql2XKu5OJO580RRrQL/Pegxh6+sufmacmzCH26KyOz/V02tT18m etKPBLuZhP6cA== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4ZH0Zj2blMz4xFb; Tue, 18 Mar 2025 16:22:05 +1100 (AEDT) Date: Tue, 18 Mar 2025 16:21:58 +1100 From: David Gibson To: Stefano Brivio Subject: Migration failure across bridge Message-ID: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dpOajtsNxbXk3yqM" Content-Disposition: inline Message-ID-Hash: DUTWZPL54IRU2K6FNVOBBLL2S2WOU7EG X-Message-ID-Hash: DUTWZPL54IRU2K6FNVOBBLL2S2WOU7EG X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --dpOajtsNxbXk3yqM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Continued investigating the problem with migration failing across a bridge. Good news is I've found the problem... or at least one problem. Bad news is we'll have to change the migration stream format to fix it. The packets are being dropped in tcp_validate_incoming() due to a failed PAWS check (skb drop reason "TCP_RFC7323_PAWS"). That in turn looks to be because we don't preserve TCP timestamp state across the migration. We preserve _whether_ TCP timestamps are active on the connection (TCPOPT_TIMESTAMP entry in TCP_REPAIR_OPTIONS), but we don't preserve the current timestamp values (TCP_TIMESTAMP socket option). The equivalent CRIU code is https://github.com/checkpoint-restore/criu/blob/d18912fc88f3dc7bde5fdfa3575= 691977eb21753/soccr/soccr.c#L266 and https://github.com/checkpoint-restore/criu/blob/d18912fc88f3dc7bde5fdfa3575= 691977eb21753/soccr/soccr.c#L572 I'll work on writing a fix tomorrow. Not yet sure why we didn't hit this with a local migration. I'm guessing some part of being a local connection means we're bypassing the PAWS check. --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --dpOajtsNxbXk3yqM Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmfZAuQACgkQzQJF27ox 2GeX4BAAhWFq2xjHpGcnS+7+PT63uVSJlwJHyJiBwiyqvj0s0sBWFTQLDRNVBIUM WBlhwIjBZ+hxYuVKaqL6ca9tWRTiwYDygB+e+O6sOx8+zXeNfVgbj/o6hSiOBVfa CdxXl75T/Z9I/MoO3iD+E7gqgrYaPglL2X4tQwxGsVwkP7UjvWic9COgvItajEuJ CXwJDI0tAqeMe51PG1tDcL5CgxrmSXK1HweNyJuGfmBt6LI35eaZqOYQAxQSwyCq o9JECgnUVQ6mlz3NQDwroTOfV+5O8m9TCrT9IcrcOYujC885bx4CXVWufRFZAJKf OQgOzSiA815JQVCFfh1RqWrihKACnDDc+OjXDfLitYqiKKdvGc3j0329HALvcdkY 13sKHTMrSjJMla+ctFjP6bGkYb3eJreyTEYn7CYCx5qXdDgr6AiZKwF2vAL3D5VU 5jDOwYh5qCCPiRJ01TpBbXJV1uo8fBCWGqs7BDhZQpW4z3ST+cPs2GskJBa50sSZ ti+ig0MXac+hJVGMuNsf1wPH+2mhQW8zD3+E3ZeK1gZs1uvHU3FDJc8r2G5sxhhY mG+JQ4gulF/oEXC6QsDAtRI2svuPrTBip6GHDuADqeADZTkX11/kT+/4830w1yZb nwehFXKxL6b7oV7yTxVZA8oYyGoUkKTQ9oRUH9pLsDXZPQzLI+U= =M6bN -----END PGP SIGNATURE----- --dpOajtsNxbXk3yqM--