From patchwork Thu Nov 26 06:35:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Schiller X-Patchwork-Id: 334116 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 A0E71C64E7B for ; Thu, 26 Nov 2020 06:36:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7320A2173E for ; Thu, 26 Nov 2020 06:36:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388149AbgKZGg2 (ORCPT ); Thu, 26 Nov 2020 01:36:28 -0500 Received: from mxout70.expurgate.net ([91.198.224.70]:45683 "EHLO mxout70.expurgate.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731734AbgKZGg2 (ORCPT ); Thu, 26 Nov 2020 01:36:28 -0500 Received: from [127.0.0.1] (helo=localhost) by relay.expurgate.net with smtp (Exim 4.92) (envelope-from ) id 1kiAtE-0001ZO-7q; Thu, 26 Nov 2020 07:36:24 +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 1kiAtD-000SA3-JF; Thu, 26 Nov 2020 07:36:23 +0100 Received: from securemail.tdt.de (localhost [127.0.0.1]) by securemail.tdt.de (Postfix) with ESMTP id 483EB240041; Thu, 26 Nov 2020 07:36:23 +0100 (CET) Received: from mail.dev.tdt.de (unknown [10.2.4.42]) by securemail.tdt.de (Postfix) with ESMTP id BA8A0240040; Thu, 26 Nov 2020 07:36:22 +0100 (CET) Received: from mschiller01.dev.tdt.de (unknown [10.2.3.20]) by mail.dev.tdt.de (Postfix) with ESMTPSA id 3A24D200F6; Thu, 26 Nov 2020 07:36:17 +0100 (CET) From: Martin Schiller To: andrew.hendry@gmail.com, davem@davemloft.net, kuba@kernel.org, xie.he.0141@gmail.com Cc: linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Schiller Subject: [PATCH net-next v7 2/5] net/lapb: support netdev events Date: Thu, 26 Nov 2020 07:35:54 +0100 Message-ID: <20201126063557.1283-3-ms@dev.tdt.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201126063557.1283-1-ms@dev.tdt.de> References: <20201126063557.1283-1-ms@dev.tdt.de> MIME-Version: 1.0 X-purgate-type: clean X-purgate: clean X-purgate-ID: 151534::1606372584-000040F5-AE428DF6/0/0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- net/lapb/lapb_iface.c | 82 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c index 3c03f6512c5f..213ea7abc9ab 100644 --- a/net/lapb/lapb_iface.c +++ b/net/lapb/lapb_iface.c @@ -418,14 +418,94 @@ int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) return used; } +/* 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) + return NOTIFY_DONE; + + lapb = lapb_devtostruct(dev); + if (!lapb) + return NOTIFY_DONE; + + switch (event) { + case NETDEV_UP: + lapb_dbg(0, "(%p) Interface up: %s\n", dev, dev->name); + + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier is already up: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } + break; + case NETDEV_GOING_DOWN: + if (netif_carrier_ok(dev)) + lapb_disconnect_request(dev); + break; + case NETDEV_DOWN: + lapb_dbg(0, "(%p) Interface down: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + break; + case NETDEV_CHANGE: + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier detected: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } else { + lapb_dbg(0, "(%p) Carrier lost: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + } + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block lapb_dev_notifier = { + .notifier_call = lapb_device_event, +}; + static int __init lapb_init(void) { - return 0; + return register_netdevice_notifier(&lapb_dev_notifier); } static void __exit lapb_exit(void) { WARN_ON(!list_empty(&lapb_list)); + + unregister_netdevice_notifier(&lapb_dev_notifier); } MODULE_AUTHOR("Jonathan Naylor ");