From patchwork Tue Sep 29 11:00:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 262899 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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 2E278C4727C for ; Tue, 29 Sep 2020 12:42:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C323B20725 for ; Tue, 29 Sep 2020 12:42:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601383345; bh=4Fn02eDFZtPlnUl7ObLXShx518WzLqboPIdEWn/Q9T8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hL5sRQcQKbZPvvKnRU9PZreMHURqa03Me6RlyDp/zHcsx6O3dOMkpTrlVYfIuTuEz f90xmtMCaS63nri0f3ZqFIIb+R9vjbktrk5+Xfb/Xg5Vy0WVb+q+4TMmFQ0c1tPbuf ZTT6dmPYxfQe1lbQGP3H4Wxn1CD5bry3eltJYeHY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730432AbgI2MmY (ORCPT ); Tue, 29 Sep 2020 08:42:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:53240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729272AbgI2LLt (ORCPT ); Tue, 29 Sep 2020 07:11:49 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 66BC420848; Tue, 29 Sep 2020 11:11:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377908; bh=4Fn02eDFZtPlnUl7ObLXShx518WzLqboPIdEWn/Q9T8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vtYTLdirjQ7+LtqjEOYkYuad4NcSlKoy8WbdKQm2YoByOziTorPvnHBpUa+zEx/4K 9A9nz7/JG4QRQaXMqy6dhc/vXvcly6nbuNTWCyStF3u2SMRuOQRiZwNg6eSBD8SsDq hwg3l5C1GGtDszNj0R73rmchBQ+ZbiCR3RdacNxU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?q?Linus_L=C3=BCssing?= , Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH 4.9 114/121] batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh Date: Tue, 29 Sep 2020 13:00:58 +0200 Message-Id: <20200929105935.831093423@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105930.172747117@linuxfoundation.org> References: <20200929105930.172747117@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Linus Lüssing [ Upstream commit 74c09b7275126da1b642b90c9cdc3ae8b729ad4b ] Scenario: * Multicast frame send from mesh to a BLA backbone (multiple nodes with their bat0 bridged together, with BLA enabled) Issue: * BLA backbone nodes receive the frame multiple times on bat0, once from mesh->bat0 and once from each backbone_gw from LAN For unicast, a node will send only to the best backbone gateway according to the TQ. However for multicast we currently cannot determine if multiple destination nodes share the same backbone if they don't share the same backbone with us. So we need to keep sending the unicasts to all backbone gateways and let the backbone gateways decide which one will forward the frame. We can use the CLAIM mechanism to make this decision. One catch: The batman-adv gateway feature for DHCP packets potentially sends multicast packets in the same batman-adv unicast header as the multicast optimizations code. And we are not allowed to drop those even if we did not claim the source address of the sender, as for such packets there is only this one multicast-in-unicast packet. How can we distinguish the two cases? The gateway feature uses a batman-adv unicast 4 address header. While the multicast-to-unicasts feature uses a simple, 3 address batman-adv unicast header. So let's use this to distinguish. Fixes: fe2da6ff27c7 ("batman-adv: check incoming packet type for bla") Signed-off-by: Linus Lüssing Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin --- net/batman-adv/bridge_loop_avoidance.c | 34 +++++++++++++++++++------- net/batman-adv/bridge_loop_avoidance.h | 4 +-- net/batman-adv/soft-interface.c | 6 ++--- 3 files changed, 30 insertions(+), 14 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index f24b1cee4993f..516c45771d59b 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1822,7 +1822,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame - * @is_bcast: the packet came in a broadcast packet type. + * @packet_type: the batman packet type this frame came in * * batadv_bla_rx avoidance checks if: * * we have to race for a claim @@ -1834,7 +1834,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, * further process the skb. */ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, - unsigned short vid, bool is_bcast) + unsigned short vid, int packet_type) { struct batadv_bla_backbone_gw *backbone_gw; struct ethhdr *ethhdr; @@ -1856,9 +1856,24 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, goto handled; if (unlikely(atomic_read(&bat_priv->bla.num_requests))) - /* don't allow broadcasts while requests are in flight */ - if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) - goto handled; + /* don't allow multicast packets while requests are in flight */ + if (is_multicast_ether_addr(ethhdr->h_dest)) + /* Both broadcast flooding or multicast-via-unicasts + * delivery might send to multiple backbone gateways + * sharing the same LAN and therefore need to coordinate + * which backbone gateway forwards into the LAN, + * by claiming the payload source address. + * + * Broadcast flooding and multicast-via-unicasts + * delivery use the following two batman packet types. + * Note: explicitly exclude BATADV_UNICAST_4ADDR, + * as the DHCP gateway feature will send explicitly + * to only one BLA gateway, so the claiming process + * should be avoided there. + */ + if (packet_type == BATADV_BCAST || + packet_type == BATADV_UNICAST) + goto handled; ether_addr_copy(search_claim.addr, ethhdr->h_source); search_claim.vid = vid; @@ -1886,13 +1901,14 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, goto allow; } - /* if it is a broadcast ... */ - if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { + /* if it is a multicast ... */ + if (is_multicast_ether_addr(ethhdr->h_dest) && + (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) { /* ... drop it. the responsible gateway is in charge. * - * We need to check is_bcast because with the gateway + * We need to check packet type because with the gateway * feature, broadcasts (like DHCP requests) may be sent - * using a unicast packet type. + * using a unicast 4 address packet type. See comment above. */ goto handled; } else { diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h index 1ae93e46fb984..40b8ec9d4b1b5 100644 --- a/net/batman-adv/bridge_loop_avoidance.h +++ b/net/batman-adv/bridge_loop_avoidance.h @@ -29,7 +29,7 @@ struct sk_buff; #ifdef CONFIG_BATMAN_ADV_BLA bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, - unsigned short vid, bool is_bcast); + unsigned short vid, int packet_type); bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid); bool batadv_bla_is_backbone_gw(struct sk_buff *skb, @@ -56,7 +56,7 @@ int batadv_bla_claim_dump(struct sk_buff *msg, struct netlink_callback *cb); static inline bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, - bool is_bcast) + int packet_type) { return false; } diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 99d2c453c8722..af0a8439cf08a 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -415,10 +415,10 @@ void batadv_interface_rx(struct net_device *soft_iface, struct vlan_ethhdr *vhdr; struct ethhdr *ethhdr; unsigned short vid; - bool is_bcast; + int packet_type; batadv_bcast_packet = (struct batadv_bcast_packet *)skb->data; - is_bcast = (batadv_bcast_packet->packet_type == BATADV_BCAST); + packet_type = batadv_bcast_packet->packet_type; skb_pull_rcsum(skb, hdr_size); skb_reset_mac_header(skb); @@ -463,7 +463,7 @@ void batadv_interface_rx(struct net_device *soft_iface, /* Let the bridge loop avoidance check the packet. If will * not handle it, we can safely push it up. */ - if (batadv_bla_rx(bat_priv, skb, vid, is_bcast)) + if (batadv_bla_rx(bat_priv, skb, vid, packet_type)) goto out; if (orig_node)