From patchwork Thu Feb 22 15:06:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ilya Maximets X-Patchwork-Id: 1902821 X-Patchwork-Delegate: i.maximets@samsung.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org (client-ip=140.211.166.133; helo=smtp2.osuosl.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=patchwork.ozlabs.org) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4Tgc0W4XTyz23d2 for ; Fri, 23 Feb 2024 02:06:02 +1100 (AEDT) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id EC0F041927; Thu, 22 Feb 2024 15:05:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7CnFJMusFzhq; Thu, 22 Feb 2024 15:05:58 +0000 (UTC) X-Comment: SPF check N/A for local connections - client-ip=140.211.9.56; helo=lists.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver= DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 9D50741909 Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id 9D50741909; Thu, 22 Feb 2024 15:05:58 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6D04AC0077; Thu, 22 Feb 2024 15:05:58 +0000 (UTC) X-Original-To: ovs-dev@openvswitch.org Delivered-To: ovs-dev@lists.linuxfoundation.org Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id C57D1C0037 for ; Thu, 22 Feb 2024 15:05:56 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id A870960E62 for ; Thu, 22 Feb 2024 15:05:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Qvrp64JmR_V8 for ; Thu, 22 Feb 2024 15:05:56 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=217.70.183.196; helo=relay4-d.mail.gandi.net; envelope-from=i.maximets@ovn.org; receiver= DMARC-Filter: OpenDMARC Filter v1.4.2 smtp3.osuosl.org BAF9860E36 Authentication-Results: smtp3.osuosl.org; dmarc=none (p=none dis=none) header.from=ovn.org DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org BAF9860E36 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by smtp3.osuosl.org (Postfix) with ESMTPS id BAF9860E36 for ; Thu, 22 Feb 2024 15:05:54 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id E23AEE0008; Thu, 22 Feb 2024 15:05:51 +0000 (UTC) From: Ilya Maximets To: ovs-dev@openvswitch.org Date: Thu, 22 Feb 2024 16:06:32 +0100 Message-ID: <20240222150633.2626722-1-i.maximets@ovn.org> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 X-GND-Sasl: i.maximets@ovn.org Cc: =?utf-8?q?Jaime_Caama=C3=B1o_Ruiz?= , Ilya Maximets Subject: [ovs-dev] [PATCH] ofproto-dpif-trace: Fix infinite recirculation tracing. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ovs-dev-bounces@openvswitch.org Sender: "dev" Trace attempts to process all the recirculations. However, if there is a recirculation loop, i.e. if every recirculation generates another recirculation, this process will never stop. It will grind until the trace fills the system memory. A simple reproducer: make sandbox ovs-vsctl add-br br0 ovs-vsctl add-port br0 p1 ovs-ofctl add-flow br0 "table=0,in_port=p1,ip,actions=ct(table=0)" ovs-appctl ofproto/trace br0 in_port=p1,ip Limit the number of recirculations trace is processing with a fairly arbitrary number - 4096 (loosely based on the resubmit limit, but they are not actually related). Not adding a test for this since it's only for a trace, but also because the test may lead to OOM event in a system if the test fails, which is not nice. Fixes: e6bc8e749381 ("ofproto/trace: Add support for tracing conntrack recirculation") Reported-by: Jaime Caamaño Ruiz Signed-off-by: Ilya Maximets Acked-by: Simon Horman --- ofproto/ofproto-dpif-trace.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/ofproto/ofproto-dpif-trace.c b/ofproto/ofproto-dpif-trace.c index b86e7fe07..87506aa78 100644 --- a/ofproto/ofproto-dpif-trace.c +++ b/ofproto/ofproto-dpif-trace.c @@ -845,17 +845,35 @@ ofproto_trace(struct ofproto_dpif *ofproto, const struct flow *flow, bool names) { struct ovs_list recirc_queue = OVS_LIST_INITIALIZER(&recirc_queue); + int recirculations = 0; + ofproto_trace__(ofproto, flow, packet, &recirc_queue, ofpacts, ofpacts_len, output, names); struct oftrace_recirc_node *recirc_node; LIST_FOR_EACH_POP (recirc_node, node, &recirc_queue) { + if (recirculations++ > 4096) { + ds_put_cstr(output, "\n\n"); + ds_put_char_multiple(output, '=', 79); + ds_put_cstr(output, "\nTrace reached the recirculation limit." + " Sopping the trace here."); + ds_put_format(output, + "\nQueued but not processed: %"PRIuSIZE + " recirculations.", + ovs_list_size(&recirc_queue) + 1); + oftrace_recirc_node_destroy(recirc_node); + break; + } ofproto_trace_recirc_node(recirc_node, next_ct_states, output); ofproto_trace__(ofproto, &recirc_node->flow, recirc_node->packet, &recirc_queue, ofpacts, ofpacts_len, output, names); oftrace_recirc_node_destroy(recirc_node); } + /* Destroy remaining recirculation nodes, if any. */ + LIST_FOR_EACH_POP (recirc_node, node, &recirc_queue) { + oftrace_recirc_node_destroy(recirc_node); + } } void