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 Received: from diktynna.open-mesh.org (diktynna.open-mesh.org [136.243.236.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4A985CA5FDD for ; Sat, 3 Oct 2026 07:28:06 +0000 (UTC) Received: from diktynna.open-mesh.org (localhost [IPv6:::1]) by diktynna.open-mesh.org (Postfix) with ESMTP id DCA7F84270 for ; Sat, 03 Oct 2026 09:28:04 +0200 (CEST) ARC-Seal: i=2; cv=pass; a=rsa-sha256; d=open-mesh.org; s=20121; t=1791012484; b=ik+k1ZrwQGuDLNuWWVAwyhtTUVUNFz0VlXF8Hrn7Q38zsjP+ew8+cL86diNkjqkZFngAY W4vvYO/UpWO6y55JHu/sMFzhwiSnaQHtidBM3wHtLI+mhjMLC5Rgr8vGhu3cUxuBLly63k6 1SaeYvJdTCaKI0jL2k8PYOvInaxvRS4= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1791012484; 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=s2GXkNO8bDuIXGHmR1GWNh0JRuDikJzowvcUK2EbCtw=; b=qdQ8gI+KQKrD0ekCqPT4hmDqxqISJxgu3Mmw5WKc0KMAFYo0oXh5iZJ2Gy9hC9k8v2I75 PKEmtaDJvlS9fm3KMeHFxSltS+KIQgaNZ9WRophw75Jf6+b467sJWIxCV/DfB4G5ORzSuLL tYIZ6JsKQVFo0PH3WT6H1MfrypztuFM= 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 [116.203.183.178]) by diktynna.open-mesh.org (Postfix) with ESMTPS id B1D2382C2E for ; Sat, 03 Oct 2026 09:26:40 +0200 (CEST) ARC-Seal: i=1; a=rsa-sha256; d=open-mesh.org; s=20121; cv=none; t=1791012410; b=iOCnjMq7quoBEATzH4izCZ9DGJTcb8vKUP1gTysXLAzPpcoFOZBApm8vKQ2e+CNh2qz/ne lA38b9WMHGIewp7wB9Nc0RXK/0i6RwN+Y7r7KOUpU5UhVB0gV8tYmwS1iBH+SqMexuAR8+ mfWhT/m91Esu4SoqbvN8PstPodqQo80= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1791012410; 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=s2GXkNO8bDuIXGHmR1GWNh0JRuDikJzowvcUK2EbCtw=; b=jT9ze9B8MgUYA7OXzc+5a2pjnu4PK0Maec5nEMK2hp2yBrVZ+n1pFRzie1QfKQ8IBJVWFE ASXWIJQGfnj1p5HaKqMFILZ4QN2gD3e8M1bWTpizEe/cRq2A8eB4dbIN09DH4UNkXQG2CH +z0B+jadNuWU5vJgAEodEaiYCU/bEZA= ARC-Authentication-Results: i=1; diktynna.open-mesh.org; dkim=none; dmarc=none; spf=pass (diktynna.open-mesh.org: domain of linus.luessing@c0d3.blue designates 116.203.183.178 as permitted sender) smtp.mailfrom=linus.luessing@c0d3.blue Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 2A41F2334A; Sat, 03 Oct 2026 09:26:40 +0200 (CEST) From: =?UTF-8?q?Linus=20L=C3=BCssing?= To: b.a.t.m.a.n@lists.open-mesh.org Cc: =?UTF-8?q?Linus=20L=C3=BCssing?= Subject: [batadv,v12 3/5] batman-adv: increase DAT DHT timeout Date: Sat, 3 Oct 2026 09:26:26 +0200 Message-ID: <20261003072628.28052-4-linus.luessing@c0d3.blue> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261003072628.28052-1-linus.luessing@c0d3.blue> References: <20261003072628.28052-1-linus.luessing@c0d3.blue> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Message-ID-Hash: OHGZDEOP3ZIYUXCNYVMCVITHQUY74BNC X-Message-ID-Hash: OHGZDEOP3ZIYUXCNYVMCVITHQUY74BNC X-MailFrom: linus.luessing@c0d3.blue X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; 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; header-match-b.a.t.m.a.n.lists.open-mesh.org-3; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 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 af08812c7ecd..321df338fb8d 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -199,15 +199,27 @@ 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); } /** @@ -268,8 +280,8 @@ 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 e738758ee4a7..17af6322e157 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -36,7 +36,8 @@ #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) */ -- 2.55.0