From patchwork Thu Mar 19 13:03:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229086 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 C8AA2C4332D for ; Thu, 19 Mar 2020 13:18:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9FFAE206D7 for ; Thu, 19 Mar 2020 13:18:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623935; bh=UVIq3kfmmMt4OxRi/iwoPRHANQQVObbhqUMTpEQTYOo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Uc+xWl9NWRqg29HJPmNQhYJPm0qzB698BlpG7Of9DHy8yBEry0JLuq0gUiqpmiNFK 6+wTYHpzbKl8afmOlnlA8UohXWG5TIC8ZhcUPi7ghYQ39CYRAPCwtNnJ7ynxS82kmq VoWST7ECcGvVRmMtUwc/92TJrJGcqbwnPbLcHWp8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727749AbgCSNSy (ORCPT ); Thu, 19 Mar 2020 09:18:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:41642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728696AbgCSNSw (ORCPT ); Thu, 19 Mar 2020 09:18:52 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 19D2C214D8; Thu, 19 Mar 2020 13:18:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623931; bh=UVIq3kfmmMt4OxRi/iwoPRHANQQVObbhqUMTpEQTYOo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qduhFeHIhiUHTwo1frGI8+IRuQM/eBYQaiW2bNUUMLRKi0jl9UCaKo/EI8jYsOv7k +xvOq1iENFlIkyE6TDNr7pZbQiM6zuREMh76WI1ZYPYExPYyoQmgZ8PsqQ7yEYpgnE Oqz1XIrChCfrJvd1oTa3V9eUm8v2jxwetXeFvvsw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Marek Lindner , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 4.14 75/99] batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs Date: Thu, 19 Mar 2020 14:03:53 +0100 Message-Id: <20200319124003.828460399@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123941.630731708@linuxfoundation.org> References: <20200319123941.630731708@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marek Lindner commit 16116dac23396e73c01eeee97b102e4833a4b205 upstream. A translation table TVLV changset sent with an OGM consists of a number of headers (one per VLAN) plus the changeset itself (addition and/or deletion of entries). The per-VLAN headers are used by OGM recipients for consistency checks. Said consistency check might determine that a full translation table request is needed to restore consistency. If the TT sender adds per-VLAN headers of empty VLANs into the OGM, recipients are led to believe to have reached an inconsistent state and thus request a full table update. The full table does not contain empty VLANs (due to missing entries) the cycle restarts when the next OGM is issued. Consequently, when the translation table TVLV headers are composed, empty VLANs are to be excluded. Fixes: 21a57f6e7a3b ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Marek Lindner Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/translation-table.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -941,15 +941,20 @@ batadv_tt_prepare_tvlv_local_data(struct struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_softif_vlan *vlan; u16 num_vlan = 0; - u16 num_entries = 0; + u16 vlan_entries = 0; + u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; int change_offset; spin_lock_bh(&bat_priv->softif_vlan_list_lock); hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + num_vlan++; - num_entries += atomic_read(&vlan->tt.num_entries); + total_entries += vlan_entries; } change_offset = sizeof(**tt_data); @@ -957,7 +962,7 @@ batadv_tt_prepare_tvlv_local_data(struct /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) - *tt_len = batadv_tt_len(num_entries); + *tt_len = batadv_tt_len(total_entries); tvlv_len = *tt_len; tvlv_len += change_offset; @@ -974,6 +979,10 @@ batadv_tt_prepare_tvlv_local_data(struct tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc);