From patchwork Mon Jan 13 19:31:41 2025 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: 18775 X-Patchwork-Delegate: a@unstable.cc 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 32EFB84482 for ; Mon, 13 Jan 2025 21:07:52 +0100 (CET) ARC-Seal: i=2; cv=pass; a=rsa-sha256; d=open-mesh.org; s=20121; t=1736798872; b=pzbbmc0oVdTVMfe7aa/HHHL8kUpTuKbamZMndBC8brlZXTi+VQIH1RMx9h6zS7NqKmhTt baWxOJA4ApYi0ibB77PWLCgwTGrMDxjJnKHXa4ohHg8h5bl0Rcor04FQn/w3BySeEo7F9t5 1bqst8Dk2vuFqFfdh63HczUPlYlY/Xo= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1736798872; h=from : sender : reply-to : subject : date : message-id : to : cc : mime-version : content-type : content-transfer-encoding : content-id : content-description : resent-date : resent-from : resent-sender : resent-to : resent-cc : resent-message-id : in-reply-to : references : list-id : list-help : list-unsubscribe : list-subscribe : list-post : list-owner : list-archive; bh=YTTD8vBMWm4+Bv3YLj95Rd2uey28Hj3yN8fA97rY1fM=; b=nWM7swH5RHb/4JkSxtVqnXT1SBk7PLdYm8w6mHS1fj9S71hcJ7x9m8qbhqLlvCe5oFXLk vm+a6cv4t5OIDoQnv+pNazHO1F0sulbVltrkZ8yVST1X9ZWqIleCA1duEhxIb+UvAnIjrA3 7On8N+eBeEVTMapRz+7cHdpxbibeUhs= ARC-Authentication-Results: i=2; open-mesh.org; dkim=fail; arc=pass; dmarc=none Authentication-Results: open-mesh.org; dkim=fail; arc=pass; dmarc=none Received: from mail.aperture-lab.de (mail.aperture-lab.de [IPv6:2a01:4f8:c2c:665b::1]) by diktynna.open-mesh.org (Postfix) with ESMTPS id A3EA781F06 for ; Mon, 13 Jan 2025 21:05:17 +0100 (CET) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1736798718; 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=YTTD8vBMWm4+Bv3YLj95Rd2uey28Hj3yN8fA97rY1fM=; b=mxVgI39vSK0irdV/sA+ezgj89wACI4ZaHcsM6iufHzyHHJbhRx3ahaHA+Q5G6GLMrBK4P7 9jEU8bhQ7kFtB2PZ+rbnlECCcG1SgEKk9dTYOUXLLRTJBYWY6j+kf6Ggw7FiiMtw/MYyX2 cuYTOUdEhoSyPK8MM7xVD+D8eb+60zA= ARC-Authentication-Results: i=1; diktynna.open-mesh.org; dkim=none; spf=pass (diktynna.open-mesh.org: domain of linus.luessing@c0d3.blue designates 2a01:4f8:c2c:665b::1 as permitted sender) smtp.mailfrom=linus.luessing@c0d3.blue; dmarc=none ARC-Seal: i=1; s=20121; d=open-mesh.org; t=1736798718; a=rsa-sha256; cv=none; b=0yHTlUa4x6plt96HORmlM37wHbNAJkNtDC3Zr2v3vGtRgzCfJqSfO0WE/sqi0q5NfQzW1S fqkg8SwUDycly/jBA4hOMBkzgwuQmxn/bqTeIi1dNvGye7SWgo4hqBadWKKNeIhV9s2Iba CGdo1bi4JDp67YfraeNCK1/Y+MlEhpQ= Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5364054CCF7; Mon, 13 Jan 2025 21:05:17 +0100 (CET) From: =?utf-8?q?Linus_L=C3=BCssing?= To: b.a.t.m.a.n@lists.open-mesh.org Cc: =?utf-8?q?Linus_L=C3=BCssing?= Subject: [PATCH v8 3/3] batman-adv: increase DAT DHT timeout Date: Mon, 13 Jan 2025 20:31:41 +0100 Message-ID: <20250113200510.18681-4-linus.luessing@c0d3.blue> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250113200510.18681-1-linus.luessing@c0d3.blue> References: <20250113200510.18681-1-linus.luessing@c0d3.blue> MIME-Version: 1.0 X-Last-TLS-Session-Version: TLSv1.3 Message-ID-Hash: X6M6NNJXRGPPAQHTFDGPARD6D2SQ3UEM X-Message-ID-Hash: X6M6NNJXRGPPAQHTFDGPARD6D2SQ3UEM 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; header-match-b.a.t.m.a.n.lists.open-mesh.org-2; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Currently, the DHT_GET messages of the DAT will likely be left unanswered due to the following issues: When a node has a matching DAT Cache entry for a local ARP Request then this node will answer it directly with the information provided by the cache. This however, will likely lead to missing ARP Replies from the original host. Which in turn leads to the DAT DHT not being updated. Then the local DAT cache entry will time out, triggering a unicasted DHT_GET. However, as the 5min. timeout has passed, the DAT DHT candidates will likely have purged their entry, too. So basically this results in an ARP Request broadcast fallback every five minutes. A second issue is that it is quite common that a host which has long gone offline will be tried to be contacted by another one at some remote period larger than the current 5min. timeout. This too leads to flooded ARP Requests. With this patch the purge timeout for DAT DHT entries is increased to 30min to reduce the number of DAT ARP broadcast fallbacks. Signed-off-by: Linus Lüssing --- net/batman-adv/distributed-arp-table.c | 22 +++++++++++++++++----- net/batman-adv/main.h | 3 ++- 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 8d6d5e338130..7817409bdd44 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -132,15 +132,27 @@ static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) } /** - * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not + * batadv_dat_cache_to_purge() - check if a cache entry has to be purged or not * @dat_entry: the entry to check * * Return: true if the entry has to be purged now, false otherwise. */ -static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) +static bool batadv_dat_cache_to_purge(struct batadv_dat_entry *dat_entry) { return batadv_has_timed_out(dat_entry->last_update, - BATADV_DAT_ENTRY_TIMEOUT); + BATADV_DAT_CACHE_ENTRY_TIMEOUT); +} + +/** + * batadv_dat_dht_to_purge() - check if a DHT entry has to be purged or not + * @dat_entry: the entry to check + * + * Return: true if the entry has to be purged now, false otherwise. + */ +static bool batadv_dat_dht_to_purge(struct batadv_dat_entry *dat_entry) +{ + return batadv_has_timed_out(dat_entry->last_update, + BATADV_DAT_DHT_ENTRY_TIMEOUT); } /** @@ -201,8 +213,8 @@ static void batadv_dat_purge(struct work_struct *work) priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); bat_priv = container_of(priv_dat, struct batadv_priv, dat); - __batadv_dat_purge(bat_priv->dat.cache_hash, batadv_dat_to_purge); - __batadv_dat_purge(bat_priv->dat.dht_hash, batadv_dat_to_purge); + __batadv_dat_purge(bat_priv->dat.cache_hash, batadv_dat_cache_to_purge); + __batadv_dat_purge(bat_priv->dat.dht_hash, batadv_dat_dht_to_purge); batadv_dat_start_timer(bat_priv); } diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 964f3088af5b..4cd4b0e84a6d 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -38,7 +38,8 @@ #define BATADV_TT_WORK_PERIOD 5000 /* 5 seconds */ #define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */ #define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */ -#define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */ +#define BATADV_DAT_CACHE_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */ +#define BATADV_DAT_DHT_ENTRY_TIMEOUT (30 * 60000) /* 30 mins in milliseconds */ /* sliding packet range of received originator messages in sequence numbers * (should be a multiple of our word size) */