From owner-freebsd-net@freebsd.org Fri Jan 29 12:54:27 2021 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 070204EB69A for ; Fri, 29 Jan 2021 12:54:27 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 4DRy366dWSz4s0d for ; Fri, 29 Jan 2021 12:54:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id E3AB14EB699; Fri, 29 Jan 2021 12:54:26 +0000 (UTC) Delivered-To: net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E371D4EB65D for ; Fri, 29 Jan 2021 12:54:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DRy3663KQz4rZj for ; Fri, 29 Jan 2021 12:54:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id C2F7322FC6 for ; Fri, 29 Jan 2021 12:54:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 10TCsQEO047911 for ; Fri, 29 Jan 2021 12:54:26 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 10TCsQ9W047910 for net@FreeBSD.org; Fri, 29 Jan 2021 12:54:26 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 252913] [tcp] Using RACK leaks mbufs Date: Fri, 29 Jan 2021 12:54:27 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 12.2-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: iron.udjin@gmail.com X-Bugzilla-Status: In Progress X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: tuexen@freebsd.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Jan 2021 12:54:27 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D252913 --- Comment #24 from iron.udjin@gmail.com --- (In reply to Michael Tuexen from comment #23) 1. For such looping TCP connections at Nov 16 2020 I wrote script which che= cks if SENDQ greater 1700000 and drop them use tcpdrop: netstat -p tcp -n | awk '{print $3" "$5" "$6}' | egrep "^[0-9]" | grep -v '= ^0\ ' | while read line; do SENDQ=3D`echo $line | awk '{print $1}'` if [ "$SENDQ" -gt "1700000" ]; then echo $line | awk '{print $2}' | awk -F\. '{print $1"."$2"."$3"."$4" "$5}' | xargs tcpdrop XXX.XXX.XXX.XXX 443 > /dev/null echo -n "`date`: " >> /root/check_drop.log echo "$line - DROPPED" >> /root/check_drop.log fi done # cat /root/check_drop.log | wc -l 460 Sometimes the script kills 5-10 connections/hour. Sometimes nothing in a da= y. I'll disable this script and when I catch such connection, I'll post sysctl net.inet.tcp.rack output. >So could you start without enabling RACK, start capturing traffic with tcp= dump, enable RACK, ensure that some connection hit the bug, and stop the ca= pturing. 2. It's impossible because very low percent of connections hit such looping state. And that's happening not right after enabling RACK. On the picture I wanted to show how looping connections increases traffic volume. I assume t= he connection should hit a few conditions to start looping. I can write script which with a certain frequency will collect network vaia= bles and write output to the log file. Tell me please frequency and variables wh= ich you need to see and I'll share logs via private link by webserver (will ema= il you credentials). --=20 You are receiving this mail because: You are on the CC list for the bug.=