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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D5AEBC64E75 for ; Thu, 26 Nov 2020 05:58:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C06520770 for ; Thu, 26 Nov 2020 05:58:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387890AbgKZF56 (ORCPT ); Thu, 26 Nov 2020 00:57:58 -0500 Received: from mxout70.expurgate.net ([91.198.224.70]:19219 "EHLO mxout70.expurgate.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387863AbgKZF56 (ORCPT ); Thu, 26 Nov 2020 00:57:58 -0500 Received: from [127.0.0.1] (helo=localhost) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1kiAHv-000AYz-QN; Thu, 26 Nov 2020 06:57:51 +0100 Received: from [195.243.126.94] (helo=securemail.tdt.de) by relay.expurgate.net with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kiAHu-000AYo-VI; Thu, 26 Nov 2020 06:57:50 +0100 Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id A1F9E240041; Thu, 26 Nov 2020 06:57:50 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id 1A759240040; Thu, 26 Nov 2020 06:57:50 +0100 (CET) Received: from mail.dev.tdt.de (localhost [IPv6:::1]) by mail.dev.tdt.de (Postfix) with ESMTP id 77508200F6; Thu, 26 Nov 2020 06:57:44 +0100 (CET) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 26 Nov 2020 06:57:44 +0100 From: Martin Schiller To: Jakub Kicinski Cc: andrew.hendry@gmail.com, davem@davemloft.net, xie.he.0141@gmail.com, linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v6 2/5] net/lapb: support netdev events Organization: TDT AG In-Reply-To: <20201125134925.26d851f7@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> References: <20201124093938.22012-1-ms@dev.tdt.de> <20201124093938.22012-3-ms@dev.tdt.de> <20201125134925.26d851f7@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Message-ID: <82d7a9cb1375a24c8cf26615f71ca99b@dev.tdt.de> X-Sender: ms@dev.tdt.de User-Agent: Roundcube Webmail/1.3.15 X-purgate-type: clean X-purgate: clean X-purgate-ID: 151534::1606370271-00001F6B-90FFE692/0/0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020-11-25 22:49, Jakub Kicinski wrote: > On Tue, 24 Nov 2020 10:39:35 +0100 Martin Schiller wrote: >> This patch allows layer2 (LAPB) to react to netdev events itself and >> avoids the detour via layer3 (X.25). >> >> 1. Establish layer2 on NETDEV_UP events, if the carrier is already up. >> >> 2. Call lapb_disconnect_request() on NETDEV_GOING_DOWN events to >> signal >> the peer that the connection will go down. >> (Only when the carrier is up.) >> >> 3. When a NETDEV_DOWN event occur, clear all queues, enter state >> LAPB_STATE_0 and stop all timers. >> >> 4. The NETDEV_CHANGE event makes it possible to handle carrier loss >> and >> detection. >> >> In case of Carrier Loss, clear all queues, enter state LAPB_STATE_0 >> and stop all timers. >> >> In case of Carrier Detection, we start timer t1 on a DCE interface, >> and on a DTE interface we change to state LAPB_STATE_1 and start >> sending SABM(E). >> >> Signed-off-by: Martin Schiller > >> +/* Handle device status changes. */ >> +static int lapb_device_event(struct notifier_block *this, unsigned >> long event, >> + void *ptr) >> +{ >> + struct net_device *dev = netdev_notifier_info_to_dev(ptr); >> + struct lapb_cb *lapb; >> + >> + if (!net_eq(dev_net(dev), &init_net)) >> + return NOTIFY_DONE; >> + >> + if (dev->type == ARPHRD_X25) { > > Flip condition, save indentation. > > if (dev->type != ARPHRD_X25) > return NOTIFY_DONE; > > You can also pull out of all the cases: > > lapb = lapb_devtostruct(dev); > if (!lapb) > return NOTIFY_DONE; > > right? > >> + switch (event) { >> + case NETDEV_UP: >> + lapb_dbg(0, "(%p) Interface up: %s\n", dev, >> + dev->name); >> + >> + if (netif_carrier_ok(dev)) { >> + lapb = lapb_devtostruct(dev); >> + if (!lapb) >> + break; > >> static int __init lapb_init(void) >> { >> + register_netdevice_notifier(&lapb_dev_notifier); > > This can fail, so: > > return register_netdevice_notifier(&lapb_dev_notifier); > >> return 0; >> } >> >> static void __exit lapb_exit(void) >> { >> WARN_ON(!list_empty(&lapb_list)); >> + >> + unregister_netdevice_notifier(&lapb_dev_notifier); >> } >> >> MODULE_AUTHOR("Jonathan Naylor "); Thanks for your hints! I will send an update.