From patchwork Tue Sep 1 01:26:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Linus_L=C3=BCssing?= X-Patchwork-Id: 18159 X-Patchwork-Delegate: sw@simonwunderlich.de Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from diktynna.open-mesh.org (localhost [IPv6:::1]) by diktynna.open-mesh.org (Postfix) with ESMTP id C4C5D8068C; Tue, 1 Sep 2020 03:26:32 +0200 (CEST) Received: from mail.aperture-lab.de (mail.aperture-lab.de [138.201.29.205]) by diktynna.open-mesh.org (Postfix) with ESMTPS id E3A72803C8 for ; Tue, 1 Sep 2020 03:26:24 +0200 (CEST) From: =?utf-8?q?Linus_L=C3=BCssing?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c0d3.blue; s=2018; t=1598923584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SeMUIimmvd1BomBIMWzE0E6mR9shlrNZ5783ITgqvvM=; b=FqFDH1PwHdu2sZz1BX+NPGEC3cey/ZqJLFp4Wt2HCWC5moXwQoY711kkqK0fwaH4egcqE1 Ac7VjdCVdUnTJCMiUMH6/Z0Cjl0hAEJA8xWs8wL/E/IO/+NMgBsvWeOrL84kW0JyfBm+kI CHnVgrDTFcZJx2yoz/Ao8s+q+zFVx5Vqmp9gxqCDVSJKz10nXa3/u/s58WtsYF//qh07X1 A1yuhG4ot27mOtVMR8wObWdBYPO4xt+/xAM90vUq0XjtOdEmW+blZos/5CKwnsy3YK6+Nw xP4mmU7vDZbVqds3fTnw1NgxCZfB+b7859bilV1lWcco9IPF/AJ+nyevS6J6Eg== To: b.a.t.m.a.n@lists.open-mesh.org Cc: =?utf-8?q?Linus_L=C3=BCssing?= Subject: [PATCH maint 4/4] batman-adv: mcast: fix duplicate mcast packets from BLA backbone to mesh Date: Tue, 1 Sep 2020 03:26:06 +0200 Message-Id: <20200901012606.7620-4-linus.luessing@c0d3.blue> In-Reply-To: <20200901012606.7620-1-linus.luessing@c0d3.blue> References: <20200901012606.7620-1-linus.luessing@c0d3.blue> MIME-Version: 1.0 Authentication-Results: ORIGINATING; auth=pass smtp.auth=linus.luessing@c0d3.blue smtp.mailfrom=linus.luessing@c0d3.blue ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1598923584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SeMUIimmvd1BomBIMWzE0E6mR9shlrNZ5783ITgqvvM=; b=XUfgF5IWzHswNjEMteZSXah2jhFRyo5c7cgXrl9M7ntClsNIfOOyzElqPRt/w6AEON8UFm J1E23D7xLMRFmEmpdWVmgL9Kqu2HEbaV57bDtRoZfavkrBtYPHVWY2xEUhwYdAZaOhsGp7 H55Fewfemn68BwO3dcsOaglx+18HTXI= ARC-Seal: i=1; s=20121; d=open-mesh.org; t=1598923584; a=rsa-sha256; cv=none; b=pa7R+Y0+85G5ixGyOXEPxtKUw+5JGq93weaVSNATblyGra0n31QDCrgz12HA/F0tTEGsgd Bp4YEZtb6PhpmZn4ZWi3YvplXLo5Z5CwAE+OCrnlbQaoMhn/fB5ar/r/zWXC6r5kziWgAZ 47mKK5avFfobHX9ljFj2vnXuloh5Esg= ARC-Authentication-Results: i=1; diktynna.open-mesh.org; dkim=none (invalid DKIM record) header.d=c0d3.blue header.s=2018 header.b=FqFDH1Pw; spf=none (diktynna.open-mesh.org: domain of linus.luessing@c0d3.blue has no SPF policy when checking 138.201.29.205) smtp.mailfrom=linus.luessing@c0d3.blue Message-ID-Hash: EB3THLQ67GSMH5HPEVYXZV7UWVVY6C7P X-Message-ID-Hash: EB3THLQ67GSMH5HPEVYXZV7UWVVY6C7P X-MailFrom: linus.luessing@c0d3.blue X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-b.a.t.m.a.n.lists.open-mesh.org-0; header-match-b.a.t.m.a.n.lists.open-mesh.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header X-Mailman-Version: 3.2.1 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Scenario: * Multicast frame send from BLA backbone gateways (multiple nodes with their bat0 bridged together, with BLA enabled) sharing the same LAN to nodes in the mesh Issue: * Nodes receive the frame multiple times on bat0 from the mesh, once from each foreign BLA backbone gateway which shares the same LAN with another For multicast frames via batman-adv broadcast packets coming from the same BLA backbone but from different backbone gateways duplicates are currently detected via a CRC history of previously received packets. However this CRC so far was not performed for multicast frames received via batman-adv unicast packets. Fixing this by appyling the same check for such packets, too. Room for improvements in the future: Ideally we would introduce the possibility to not only claim a client, but a complete originator, too. This would allow us to only send a multicast-in-unicast packet from a BLA backbone gateway claiming the node and by that avoid potential redundant transmissions in the first place. Signed-off-by: Linus Lüssing --- net/batman-adv/bridge_loop_avoidance.c | 86 +++++++++++++++++++++----- 1 file changed, 70 insertions(+), 16 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 9603a6d0..c509a83d 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1580,14 +1580,16 @@ int batadv_bla_init(struct batadv_priv *bat_priv) } /** - * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup. + * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the soft interface information - * @skb: contains the bcast_packet to be checked - * - * check if it is on our broadcast list. Another gateway might - * have sent the same packet because it is connected to the same backbone, - * so we have to remove this duplicate. + * @skb: contains the multicast packet to be checked + * @payload_ptr: pointer to position inside the head buffer of the skb + * marking the start of the data to be CRC'ed * + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. + * This is performed by checking the CRC, which will tell us * with a good chance that it is the same packet. If it is furthermore * sent by another host, drop it. We allow equal packets from @@ -1595,19 +1597,17 @@ int batadv_bla_init(struct batadv_priv *bat_priv) * * Return: true if a packet is in the duplicate list, false otherwise. */ -bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, - struct sk_buff *skb) +static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb, u8 *payload_ptr, + const u8 *orig) { + struct batadv_bcast_duplist_entry *entry; + bool ret = false; int i, curr; __be32 crc; - struct batadv_bcast_packet *bcast_packet; - struct batadv_bcast_duplist_entry *entry; - bool ret = false; - - bcast_packet = (struct batadv_bcast_packet *)skb->data; /* calculate the crc ... */ - crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1)); + crc = batadv_skb_crc32(skb, payload_ptr); spin_lock_bh(&bat_priv->bla.bcast_duplist_lock); @@ -1626,7 +1626,8 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, if (entry->crc != crc) continue; - if (batadv_compare_eth(entry->orig, bcast_packet->orig)) + if (!is_zero_ether_addr(entry->orig) && + batadv_compare_eth(entry->orig, orig)) continue; /* this entry seems to match: same crc, not too old, @@ -1643,7 +1644,7 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, entry = &bat_priv->bla.bcast_duplist[curr]; entry->crc = crc; entry->entrytime = jiffies; - ether_addr_copy(entry->orig, bcast_packet->orig); + ether_addr_copy(entry->orig, orig); bat_priv->bla.bcast_duplist_curr = curr; out: @@ -1652,6 +1653,52 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, return ret; } +/** + * batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup. + * @bat_priv: the bat priv with all the soft interface information + * @skb: contains the multicast packet to be checked, decapsulated from a + * unicast_packet + * + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. + * + * Return: true if a packet is in the duplicate list, false otherwise. + */ +static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + u8 orig[ETH_ALEN]; + + eth_zero_addr(orig); + + return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, orig); +} + +/** + * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup. + * @bat_priv: the bat priv with all the soft interface information + * @skb: contains the bcast_packet to be checked + * + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. + * + * Return: true if a packet is in the duplicate list, false otherwise. + */ +bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct batadv_bcast_packet *bcast_packet; + u8 *payload_ptr; + + bcast_packet = (struct batadv_bcast_packet *)skb->data; + payload_ptr = (u8 *)(bcast_packet + 1); + + return batadv_bla_check_duplist(bat_priv, skb, payload_ptr, + bcast_packet->orig); +} + /** * batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for * the VLAN identified by vid. @@ -1852,6 +1899,13 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, (!is_broadcast_ether_addr(ethhdr->h_dest) || is_bcast)) goto handled; + /* potential duplicates from foreign BLA backbone gateways via + * multicast-in-unicast packets + */ + if (is_multicast_ether_addr(ethhdr->h_dest) && !is_bcast && + batadv_bla_check_ucast_duplist(bat_priv, skb)) + goto handled; + ether_addr_copy(search_claim.addr, ethhdr->h_source); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim);