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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 8AF59C433DF for ; Sat, 23 May 2020 12:04:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6390A207FB for ; Sat, 23 May 2020 12:04:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ichpuJ0g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387828AbgEWMEh (ORCPT ); Sat, 23 May 2020 08:04:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387741AbgEWMEh (ORCPT ); Sat, 23 May 2020 08:04:37 -0400 Received: from mail-yb1-xb42.google.com (mail-yb1-xb42.google.com [IPv6:2607:f8b0:4864:20::b42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB0DDC061A0E; Sat, 23 May 2020 05:04:36 -0700 (PDT) Received: by mail-yb1-xb42.google.com with SMTP id l67so2385788ybl.4; Sat, 23 May 2020 05:04:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DhGzYuZdmCs4q+4fA867qJiX3xyRHjIKtnyYfMLs02I=; b=ichpuJ0gIuSQ2VCmkBvKBIr/6XI99zmSJr9dAZG4GCI8TclCluamytMNS1M3w6wlJN uoCQNqrD9uMHmlZ0MYZJ8ZA1KW4+ljvi6LB6xjNMK4o6QoH8ZabLGUzAHeLTrzCIClUY Iw2f5OTCJdY4tMaSSXNDCOKOqx/Hq8zvTNNjmEUS61uniS5ZSb/bHiFZ1h74b9d1p6ts +GAnIGQNVyjGooMjx69E4svYmMo+9G3IiSCnBqt64Guxbvg5SnsgCiqSP6kouOmQ6SuT sAUvZaH7PeXdfYkCDA9LBtKPdSNC1Cd+jf4Uj0h5cf8HT4ZRwfIwGma1byxZ9ktmAqnq msjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DhGzYuZdmCs4q+4fA867qJiX3xyRHjIKtnyYfMLs02I=; b=h4JqYkaGYVJ1saMxK9avGOhd1XZRYscxquKpFppeC+04dmaFBIZ5gM1ggt+evIFgmY od/aHzTbSDEMRUGKMMq+R0PYA6wuITDzUppSSJGpzDEcUxN/lS/NoPWZZWT12wMdRNuY /aw78+oYL4UwMlc6glL8VaAVw84Ko8GJKacDJVEidtiQGHnSGZknpWZt2o9TqrOrM25m W7iQkz0zFV1MVIWow5/cYb6A9T3pSSVung5fy4FFtkXvxAKgZXrz+ADDyAk6yl7XeJVN TRmT4PKH3mIKN9DZ0Zg2y8dkWoNouLxFQ6XPYnChvEqUmc3Iku52d68gn51lqgRo6RhU SOjQ== X-Gm-Message-State: AOAM533Xi0iUnLfFQzij25910ZfwsGAF5E7l6s5z6xM2Bq4TKosEtEZ+ dF739i8mc+ySxiKMLVb6g3jA3iUMsi0buUZNMjg= X-Google-Smtp-Source: ABdhPJzpQfFvhmqh+ffL0lGGfCUKTAYxpl53Gwm9m7DeCkDOiysK4rwSC54fee+1LsCqH6/NLesyFQ9pe+KO4fg5PNc= X-Received: by 2002:a5b:811:: with SMTP id x17mr29774810ybp.27.1590235476111; Sat, 23 May 2020 05:04:36 -0700 (PDT) MIME-Version: 1.0 References: <20200513160116.GA2491@localhost.localdomain> <20200513213230.GE2491@localhost.localdomain> <20200519204229.GQ2491@localhost.localdomain> In-Reply-To: <20200519204229.GQ2491@localhost.localdomain> From: Jonas Falkevik Date: Sat, 23 May 2020 14:04:24 +0200 Message-ID: Subject: Re: [PATCH] sctp: check assoc before SCTP_ADDR_{MADE_PRIM,ADDED} event To: Marcelo Ricardo Leitner Cc: Vlad Yasevich , Neil Horman , "David S. Miller" , Jakub Kicinski , linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Xin Long Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, May 19, 2020 at 10:42 PM Marcelo Ricardo Leitner wrote: > > On Fri, May 15, 2020 at 10:30:29AM +0200, Jonas Falkevik wrote: > > On Wed, May 13, 2020 at 11:32 PM Marcelo Ricardo Leitner > > wrote: > > > > > > On Wed, May 13, 2020 at 10:11:05PM +0200, Jonas Falkevik wrote: > > > > On Wed, May 13, 2020 at 6:01 PM Marcelo Ricardo Leitner > > > > wrote: > > > > > > > > > > On Wed, May 13, 2020 at 04:52:16PM +0200, Jonas Falkevik wrote: > > > > > > Do not generate SCTP_ADDR_{MADE_PRIM,ADDED} events for SCTP_FUTURE_ASSOC assocs. > > > > > > > > > > How did you get them? > > > > > > > > > > > > > I think one case is when receiving INIT chunk in sctp_sf_do_5_1B_init(). > > > > Here a closed association is created, sctp_make_temp_assoc(). > > > > Which is later used when calling sctp_process_init(). > > > > In sctp_process_init() one of the first things are to call > > > > sctp_assoc_add_peer() > > > > on the closed / temp assoc. > > > > > > > > sctp_assoc_add_peer() are generating the SCTP_ADDR_ADDED event on the socket > > > > for the potentially new association. > > > > > > I see, thanks. The SCTP_FUTURE_ASSOC means something different. It is > > > for setting/getting socket options that will be used for new asocs. In > > > this case, it is just a coincidence that asoc_id is not set (but > > > initialized to 0) and SCTP_FUTURE_ASSOC is also 0. > > > > yes, you are right, I overlooked that. > > > > > Moreso, if I didn't > > > miss anything, it would block valid events, such as those from > > > sctp_sf_do_5_1D_ce > > > sctp_process_init > > > because sctp_process_init will only call sctp_assoc_set_id() by its > > > end. > > > > Do we want these events at this stage? > > Since the association is a newly established one, have the peer address changed? > > Should we enqueue these messages with sm commands instead? > > And drop them if we don't have state SCTP_STATE_ESTABLISHED? > > > > > > > > I can't see a good reason for generating any event on temp assocs. So > > > I'm thinking the checks on this patch should be on whether the asoc is > > > a temporary one instead. WDYT? > > > > > > > Agree, we shouldn't rely on coincidence. > > Either check temp instead or the above mentioned state? > > > > > Then, considering the socket is locked, both code points should be > > > allocating the IDR earlier. It's expensive, yes (point being, it could > > > be avoided in case of other failures), but it should be generating > > > events with the right assoc id. Are you interested in pursuing this > > > fix as well? > > > > Sure. > > > > If we check temp status instead, we would need to allocate IDR earlier, > > as you mention. So that we send the notification with correct assoc id. > > > > But shouldn't the SCTP_COMM_UP, for a newly established association, be the > > first notification event sent? > > The SCTP_COMM_UP notification is enqueued later in sctp_sf_do_5_1D_ce(). > > The RFC doesn't mention any specific ordering for them, but it would > make sense. Reading the FreeBSD code now (which I consider a reference > implementation), it doesn't raise these notifications from > INIT_ACK/COOKIE_ECHO at all. The only trigger for SCTP_ADDR_ADDED > event is ASCONF ADD command itself. So these are extra in Linux, and > I'm afraid we got to stick with them. > > Considering the error handling it already has, looks like the > reordering is feasible and welcomed. I'm thinking the temp check and > reordering is the best way forward here. > > Thoughts? Neil? Xin? The assoc_id change might be considered an UAPI > breakage. Some order is mentioned in RFC 6458 Chapter 6.1.1. SCTP_COMM_UP: A new association is now ready, and data may be exchanged with this peer. When an association has been established successfully, this notification should be the first one. I can make a patch with a check on temp and make COMM_UP event first. Currently the COMM_UP event is enqueued via commands while the SCTP_ADDR_ADDED event is enqueued directly. sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); vs. asoc->stream.si->enqueue_event(&asoc->ulpq, event); Do you want me to change to use commands instead of enqueing? Or should we enqueue the COMM_UP event directly? -Jonas