From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4400A4F8B5 for ; Sat, 10 Feb 2024 17:09:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707584962; cv=none; b=LmNN6CvpFWRMZ4+LGbNHVOlVdD1JpsIoVajuku7I0I4bffKfcNGYMbppbTNiVzcQnplRnaRZU0uH1zM2ZDgSBSSwExvwg1WSY9o/nuS0Sr25h78jY/ktT2VViMLYGcFU2e5Kxi2GQzVvSRl8UOmh7voarK4fdwvoLD1bWiQDjR0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707584962; c=relaxed/simple; bh=tS85dAHq18M0/E3SEbSnUenMVOVngwQlCarway5FGwQ=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=GN7lk8wP4BPxxsETucroraWE154vsjCvN/MedAC+bQ+THQpmr6BYBgDiuSokOoD17DzvKGDCtni+kz7pyDkAIHdfJx2RdRqnOFlUiwm+Lql3MxDRrqRQL1IKmq52yZ+YlGm/WT3ClSJ88MNexWPMYdmTe/k+CExe1r8VzhhN9Bw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de; spf=pass smtp.mailfrom=posteo.de; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b=rIAG8sg9; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b="rIAG8sg9" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 5F3C0240101 for ; Sat, 10 Feb 2024 18:09:12 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1707584952; bh=tS85dAHq18M0/E3SEbSnUenMVOVngwQlCarway5FGwQ=; h=Message-ID:Subject:From:To:Cc:Date:Autocrypt:Content-Type: Content-Transfer-Encoding:MIME-Version:From; b=rIAG8sg9CKnr+maIyeQmSj8taEPjpgeim/cLy/SxCHQZib5wRcOIJ+35viNZwU05V /MLHlM9cC7qbeXpORTDaR5wsjZZz1FCEekIgM0PFUHkb1zFdODkfZwQCaJgBWXPrE0 7TvWuQXnozuIoUdWMBbRTrsk/oantPxGs+yvVNrXBc4bLwPlYgp6SCQTqp3NZlP6FF Xc8EF1uQRciCqwh58fKAxI2xX5+IKQDhpzjTiK/x6mrHNFr5GGET65ttlZvZiXjgar rJ6etPKeqjZ1WcSbiHgoq04nb6Epm6zhGFPdh+OQqAAX/V5z0O4g8nJQ+bddfThLQh jlu0HgT46YexA== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4TXHJ71MX2z6twP; Sat, 10 Feb 2024 18:09:10 +0100 (CET) Message-ID: <365e312e60de89031d2c816e502f18b4d74b98c7.camel@posteo.de> Subject: Re: Linux SCTP multihoming question From: Philipp Stanner To: David Laight , "'o.evistel@free.fr'" , Marcelo Ricardo Leitner Cc: linux-sctp , 'Andreas Fink' Date: Sat, 10 Feb 2024 17:09:10 +0000 In-Reply-To: <6455bdeb746c4236a1ecc430ba05e707@AcuMS.aculab.com> References: <6f6f11b5c30bce3d6e77d719ef75112dee75250d.profile@marceloleitner.u.sourceforge.net> <1937458162.418765580.1657717120765.JavaMail.zimbra@free.fr> <1024792113.114715673.1707473146836.JavaMail.zimbra@free.fr> <6455bdeb746c4236a1ecc430ba05e707@AcuMS.aculab.com> Autocrypt: addr=stanner@posteo.de; prefer-encrypt=mutual; keydata=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 F7QIFgS2GY4HlfvXRAAgut8lvmafqET/zlEMAp68= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-sctp@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Am Samstag, dem 10.02.2024 um 17:03 +0000 schrieb David Laight: > From: o.evistel@free.fr > > Sent: 09 February 2024 10:06 > >=20 > > I am using linux-sctp as transport for SIGTRAN M3UA on RHEL 8.4 > > with > > multihoming (sctp_bindx(), sctp_connectx() API functions). > > I would like to know, after association setup, if it is possible to > > instruct SCTP to use a specific local address from the list of > > bound > > addresses to reach the peer. >=20 > Unlikely in the extreme. >=20 > If there are 'n' bound local addresses and 'm' remote addresses > (IIRC from the INIT_ACK - but they come from the far end) then > Linux only verifies a route to each local address and picks an > appropriate local address for each one. > So it only sends heartbeats to 'm' addresses, not on 'n * m' > address pairs. >=20 > So if anything of this nature did exist it would limit the > remote addresses used, not the local ones. I've been told once that using the socket option SO_BINDTODEVICE should serve the trick, i.e., it should provoke Linux into choosing the picked device's IP addr as the source IP addr. I've never tested / verified that, though. I'm also not sure if it would have other negative consequences, such as limiting the reachability through non-bound devices. P. >=20 > I think you'll also find that specifying multiple address with > sctp_connectx() only affects where the initial INIT is sent to > (I suspect the addresses get tried in turn). > Once the connection is established the addresses received from > the remote system are almost certainly used instead. >=20 > We don't use connectx(), just try a list of addresses in sequence. > This can then contain the addresses of alternate systems as well > and alternate addresses for a single system. >=20 > If does have to be said that M3UA works a lot better over TCP! > As well as being a far lighter protocol it is much easier to > get multiple M3UA messages into a single ethernet frame with TCP. >=20 > If you've got 10 messages to send, you can use a single send() > to send them (etc). A single recv() can read lots of pending > message and you can cheaply debatch them in userspace. >=20 > This all starts mattering when you are trying to send 10000 > SMS every second (we don't know what they are sending...) >=20 > David >=20 > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, > MK1 1PT, UK > Registration No: 1397386 (Wales)