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 3192CC433E0 for ; Mon, 25 May 2020 13:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05B972071A for ; Mon, 25 May 2020 13:10:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IB9bPLy6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403795AbgEYNKm (ORCPT ); Mon, 25 May 2020 09:10:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388757AbgEYNKk (ORCPT ); Mon, 25 May 2020 09:10:40 -0400 Received: from mail-qt1-x841.google.com (mail-qt1-x841.google.com [IPv6:2607:f8b0:4864:20::841]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EA85C061A0E; Mon, 25 May 2020 06:10:40 -0700 (PDT) Received: by mail-qt1-x841.google.com with SMTP id v4so13734388qte.3; Mon, 25 May 2020 06:10:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=pjjpr8qpFs8504swd14JpRu7kN7+TUbSTZ7WI8oilL0=; b=IB9bPLy6muADicOnlLhwHsR3Vifxa89T9oZx5wjmguDvgZQNALKnG6AYmI9t3V9rHy +7OzG9uWyBOd5jxOYT4kWJ9WogTPQF/Yi8uVUjlYaglumBZQiROyz9HP5JoKkoThO0uj PbD+PY0fpZxl7FYzkBM5yCPwT7vaoeSSghmMC4HduoNahl7fJnRhae3mp01xsuUMQjHz y51QJKny8DxXmV39cn+FotTuLsXrI4zox+U2sGQYjd3ApyCQXmv+7qx+NbGCxAhOMp5F e1MsCivONYkopFyxTDXvvS2wiwZ1mKg9u8ORpN8HuyAa32BijdkW8rCAc+IIoPY2EfMW cNyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=pjjpr8qpFs8504swd14JpRu7kN7+TUbSTZ7WI8oilL0=; b=E2ASVe7vgCtacNLPaDCVhmIksKH6BidYOjKab/gTeMvF+jZ0oNx0K++NpTwIV3Eo1Q ex1w/lnz8Z1gK6sssc6BESR95zjZlG7s8QhMsJeIlsiokpoKGLx303mVe2HwmEADwSSy Jhc0zOd5eqCTJbeMLWpbR0gwT4lRMd7A+VF6t3ukxjVS63LTj9N95UCnKc6j/TGTkSMM qVk9WoZ7RSl2skqa28P6gZiAiK1Tt6XguYOVzbOcXgoMV8bgNz4kNb9ePTK/DzhXUvmm ItcR32HZGXlzn8viXDb2rowuVmuxKumusFgrOumbEEYZwCCB+48Gsj8jezu4rjP9Umt9 ePAw== X-Gm-Message-State: AOAM53249mTvY9xlym8V8UeLA3SZKaqgmHhiSLt6FOlWa/cY7IPkVYcE Pv+YGpkGd4J5imc/QCm0pBE= X-Google-Smtp-Source: ABdhPJxWSoKK02B/MdhQcba4tNo9m4LQICXKUSz/uLhblty5jVd7id4NuNgmqGr8z118hhbGpOfAKw== X-Received: by 2002:ac8:3f88:: with SMTP id d8mr4157400qtk.164.1590412239591; Mon, 25 May 2020 06:10:39 -0700 (PDT) Received: from localhost.localdomain ([2001:1284:f013:8992:a39b:b6ab:3df8:5b60]) by smtp.gmail.com with ESMTPSA id o31sm15843288qto.64.2020.05.25.06.10.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 May 2020 06:10:38 -0700 (PDT) Received: by localhost.localdomain (Postfix, from userid 1000) id 58805C1A82; Mon, 25 May 2020 10:10:36 -0300 (-03) Date: Mon, 25 May 2020 10:10:36 -0300 From: Marcelo Ricardo Leitner To: Xin Long Cc: Jonas Falkevik , Vlad Yasevich , Neil Horman , "David S. Miller" , Jakub Kicinski , linux-sctp@vger.kernel.org, network dev , LKML Subject: Re: [PATCH] sctp: check assoc before SCTP_ADDR_{MADE_PRIM,ADDED} event Message-ID: <20200525131036.GA2491@localhost.localdomain> References: <20200513160116.GA2491@localhost.localdomain> <20200513213230.GE2491@localhost.localdomain> <20200519204229.GQ2491@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 25, 2020 at 04:42:16PM +0800, Xin Long wrote: > On Sat, May 23, 2020 at 8:04 PM Jonas Falkevik wrote: > > > > 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. Oh, nice finding. > If this is true, as SCTP_COMM_UP event is always followed by state changed > to ESTABLISHED. So I'm thinking to NOT make addr events by checking the > state: > > @@ -343,6 +343,9 @@ void sctp_ulpevent_nofity_peer_addr_change(struct > sctp_transport *transport, > struct sockaddr_storage addr; > struct sctp_ulpevent *event; > > + if (asoc->state < SCTP_STATE_ESTABLISHED) > + return; > + > memset(&addr, 0, sizeof(struct sockaddr_storage)); > memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len); With the above said, yep. Thanks. > > It's not easy to completely do assoc_id change/event reordering/temp check. > As: Temp check should be fine, but agree re the others. Anyhow, the above will be good already. :-) > > 1. sctp_assoc_add_peer() is called in quite a few places where assoc_id is > not set. > 2. it's almost impossible to move SCTP_ADDR_ADDED from sctp_assoc_add_peer() > after SCTP_COMM_UP. > > > > > 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