From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73C28C433DF for ; Tue, 18 Aug 2020 22:10:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AF5120658 for ; Tue, 18 Aug 2020 22:10:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726845AbgHRWKt convert rfc822-to-8bit (ORCPT ); Tue, 18 Aug 2020 18:10:49 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:52228 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726617AbgHRWKt (ORCPT ); Tue, 18 Aug 2020 18:10:49 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-191-MOpsCAT6OD-yFq5I57dCzQ-1; Tue, 18 Aug 2020 23:10:45 +0100 X-MC-Unique: MOpsCAT6OD-yFq5I57dCzQ-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 18 Aug 2020 23:10:44 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Tue, 18 Aug 2020 23:10:44 +0100 From: David Laight To: 'Marcelo Ricardo Leitner' CC: "'netdev@vger.kernel.org'" , "'linux-sctp@vger.kernel.org'" Subject: RE: [PATCH] net: sctp: Fix negotiation of the number of data streams. Thread-Topic: [PATCH] net: sctp: Fix negotiation of the number of data streams. Thread-Index: AdZ1bPXrgdZCqbhgQru55h+86tsQbgAM7skAAAJ8QtA= Date: Tue, 18 Aug 2020 22:10:44 +0000 Message-ID: References: <46079a126ad542d380add5f9ba6ffa85@AcuMS.aculab.com> <20200818214648.GJ3399@localhost.localdomain> In-Reply-To: <20200818214648.GJ3399@localhost.localdomain> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: 'Marcelo Ricardo Leitner' > Sent: 18 August 2020 22:47 > > On Tue, Aug 18, 2020 at 02:36:58PM +0000, David Laight wrote: > > The number of streams offered by the remote system was being ignored. > > Any data sent on those streams would get discarded by the remote system. > > That's quite brief and not accurate: it was only ignored if 'Xcnt <= > stream->Xcnt'. The number of streams (esp out ones) received from the remote system in an INIT or INIT_ACK was ignored. So it would always send data chunks using the number of streams requested by the local user. I managed to tweak our M3UA config to get invalid stream numbers sent on both inwards and outwards connections. I only noticed because of testing a (slightly horrid) workaround for no longer being able to use kernel_getsockopt() to retrieve the number of ostreams. The number of ostreams was about the only thing we didn't trace :-( At least my code can now obtain the correct value even for buggy kernels. > Other than this and the Fixes tag, LGTM. Passes the tests here. I'll > ack the v2 then. I wasn't sure whether DM actually wanted a V2 with the fixes tag fixed. I can send one tomorrow. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)