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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 D7E79C47080 for ; Mon, 31 May 2021 16:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBC6D61027 for ; Mon, 31 May 2021 16:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234082AbhEaQ0p (ORCPT ); Mon, 31 May 2021 12:26:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:40254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234111AbhEaOog (ORCPT ); Mon, 31 May 2021 10:44:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8C38B613F4; Mon, 31 May 2021 13:54:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622469295; bh=gmvVBqqMIOOkqbraOZbqVPVvvHeqcqt6NIdqQ2Izlrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cFR2RqWjNx89EEHlVpCi7sTwcZ2k61l9ewyCulRDhWlFjB2HlJwQTxTfH1MjlXYne hL3styfTfdPbaUbLgbd+RCbWCQ9V43U+/zVSRoqapLoTs5XzYV9IIrWoiegLV6lrWV no5XobjeAJbTzOVdCmoJukAlZMhzS9/D/ol/M6mk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Oltean , "David S. Miller" Subject: [PATCH 5.12 144/296] net: dsa: sja1105: use 4095 as the private VLAN for untagged traffic Date: Mon, 31 May 2021 15:13:19 +0200 Message-Id: <20210531130708.712352125@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130703.762129381@linuxfoundation.org> References: <20210531130703.762129381@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vladimir Oltean commit ed040abca4c1db72dfd3b8483b6ed6bfb7c2571e upstream. One thing became visible when writing the blamed commit, and that was that STP and PTP frames injected by net/dsa/tag_sja1105.c using the deferred xmit mechanism are always classified to the pvid of the CPU port, regardless of whatever VLAN there might be in these packets. So a decision needed to be taken regarding the mechanism through which we should ensure that delivery of STP and PTP traffic is possible when we are in a VLAN awareness mode that involves tag_8021q. This is because tag_8021q is not concerned with managing the pvid of the CPU port, since as far as tag_8021q is concerned, no traffic should be sent as untagged from the CPU port. So we end up not actually having a pvid on the CPU port if we only listen to tag_8021q, and unless we do something about it. The decision taken at the time was to keep VLAN 1 in the list of priv->dsa_8021q_vlans, and make it a pvid of the CPU port. This ensures that STP and PTP frames can always be sent to the outside world. However there is a problem. If we do the following while we are in the best_effort_vlan_filtering=true mode: ip link add br0 type bridge vlan_filtering 1 ip link set swp2 master br0 bridge vlan del dev swp2 vid 1 Then untagged and pvid-tagged frames should be dropped. But we observe that they aren't, and this is because of the precaution we took that VID 1 is always installed on all ports. So clearly VLAN 1 is not good for this purpose. What about VLAN 0? Well, VLAN 0 is managed by the 8021q module, and that module wants to ensure that 802.1p tagged frames are always received by a port, and are always transmitted as VLAN-tagged (with VLAN ID 0). Whereas we want our STP and PTP frames to be untagged if the stack sent them as untagged - we don't want the driver to just decide out of the blue that it adds VID 0 to some packets. So what to do? Well, there is one other VLAN that is reserved, and that is 4095: $ ip link add link swp2 name swp2.4095 type vlan id 4095 Error: 8021q: Invalid VLAN id. $ bridge vlan add dev swp2 vid 4095 Error: bridge: Vlan id is invalid. After we made this change, VLAN 1 is indeed forwarded and/or dropped according to the bridge VLAN table, there are no further alterations done by the sja1105 driver. Fixes: ec5ae61076d0 ("net: dsa: sja1105: save/restore VLANs using a delta commit method") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/dsa/sja1105/sja1105_main.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -26,6 +26,7 @@ #include "sja1105_tas.h" #define SJA1105_UNKNOWN_MULTICAST 0x010000000000ull +#define SJA1105_DEFAULT_VLAN (VLAN_N_VID - 1) static const struct dsa_switch_ops sja1105_switch_ops; @@ -321,6 +322,13 @@ static int sja1105_init_l2_lookup_params return 0; } +/* Set up a default VLAN for untagged traffic injected from the CPU + * using management routes (e.g. STP, PTP) as opposed to tag_8021q. + * All DT-defined ports are members of this VLAN, and there are no + * restrictions on forwarding (since the CPU selects the destination). + * Frames from this VLAN will always be transmitted as untagged, and + * neither the bridge nor the 8021q module cannot create this VLAN ID. + */ static int sja1105_init_static_vlan(struct sja1105_private *priv) { struct sja1105_table *table; @@ -330,17 +338,13 @@ static int sja1105_init_static_vlan(stru .vmemb_port = 0, .vlan_bc = 0, .tag_port = 0, - .vlanid = 1, + .vlanid = SJA1105_DEFAULT_VLAN, }; struct dsa_switch *ds = priv->ds; int port; table = &priv->static_config.tables[BLK_IDX_VLAN_LOOKUP]; - /* The static VLAN table will only contain the initial pvid of 1. - * All other VLANs are to be configured through dynamic entries, - * and kept in the static configuration table as backing memory. - */ if (table->entry_count) { kfree(table->entries); table->entry_count = 0; @@ -353,9 +357,6 @@ static int sja1105_init_static_vlan(stru table->entry_count = 1; - /* VLAN 1: all DT-defined ports are members; no restrictions on - * forwarding; always transmit as untagged. - */ for (port = 0; port < ds->num_ports; port++) { struct sja1105_bridge_vlan *v; @@ -366,15 +367,12 @@ static int sja1105_init_static_vlan(stru pvid.vlan_bc |= BIT(port); pvid.tag_port &= ~BIT(port); - /* Let traffic that don't need dsa_8021q (e.g. STP, PTP) be - * transmitted as untagged. - */ v = kzalloc(sizeof(*v), GFP_KERNEL); if (!v) return -ENOMEM; v->port = port; - v->vid = 1; + v->vid = SJA1105_DEFAULT_VLAN; v->untagged = true; if (dsa_is_cpu_port(ds, port)) v->pvid = true;