From owner-freebsd-net@FreeBSD.ORG Thu Mar 15 19:50:31 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 32DBF106566B for ; Thu, 15 Mar 2012 19:50:31 +0000 (UTC) (envelope-from seyit.ozgur@istanbul.net) Received: from spamtrap.istanbul.net (spamtrap.istanbul.net [85.111.12.34]) by mx1.freebsd.org (Postfix) with ESMTP id A6BED8FC0A for ; Thu, 15 Mar 2012 19:50:30 +0000 (UTC) X-ASG-Debug-ID: 1331841018-0426ae630318e630001-QdxwpM Received: from GAMMA.magnetdigital.local (gamma.magnetdigital.local [192.168.131.244]) by spamtrap.istanbul.net with ESMTP id SGQnubMqWQOibB7P for ; Thu, 15 Mar 2012 21:50:18 +0200 (EET) X-Barracuda-Envelope-From: seyit.ozgur@istanbul.net X-Barracuda-RBL-Trusted-Forwarder: 192.168.131.244 Received: from YUHANNA.magnetdigital.local ([fe80::1058:3088:f9b1:1346]) by GAMMA.magnetdigital.local ([fe80::3cca:d6ef:febb:fafb%17]) with mapi id 14.01.0218.012; Thu, 15 Mar 2012 21:49:29 +0200 From: =?iso-8859-1?Q?Seyit_=D6zg=FCr?= X-Barracuda-Apparent-Source-IP: fe80::1058:3088:f9b1:1346 To: "freebsd-net@freebsd.org" Thread-Topic: Malformed syn packet cause %100 cpu and interrupts FreeBSD 9.0 release X-ASG-Orig-Subj: Malformed syn packet cause %100 cpu and interrupts FreeBSD 9.0 release Thread-Index: Ac0C5Fxpv2wbk7REQXGSXBWgiq7+JA== Date: Thu, 15 Mar 2012 19:49:28 +0000 Message-ID: <3807CE6F3BF4B04EB897F4EBF2D258CE5C05F221@yuhanna.magnetdigital.local> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.28.11.161] MIME-Version: 1.0 X-Barracuda-Connect: gamma.magnetdigital.local[192.168.131.244] X-Barracuda-Start-Time: 1331841018 X-Barracuda-URL: http://10.10.140.221:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests=HTML_MESSAGE, NORMAL_HTTP_TO_IP X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.91306 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- 0.00 NORMAL_HTTP_TO_IP URI: Uses a dotted-decimal IP address in URL 0.00 HTML_MESSAGE BODY: HTML included in message Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Malformed syn packet cause %100 cpu and interrupts FreeBSD 9.0 release X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Mar 2012 19:50:31 -0000 Hi, Today we tried to see what happens Malformed syn packets on FreeBSD 9.0 rel= ease.. Those packets rise to CPU %100 and stucks.. listening on ix0, link-type EN10MB (Ethernet), capture size 65535 bytes 18:33:30.010215 IP vgn44-1-88-123-89-40.fbx.proxad.net > 85.xxx.xxx.90: tcp 18:33:30.010242 IP 225.74.196.88.sta.estpak.ee > 85.xxx.xxx.90: tcp 18:33:30.010269 IP Nnov-Prospekt.71.quantum.rn > 85.xxx.xxx.90: tcp 18:33:30.010296 IP host52-108-static.49-88-b.business.telecomitalia.it > 85= .xxx.xxx.90: tcp 18:33:30.010325 IP 125.Red-88-1-75.dynamicIP.rima-tde.net > 85.xxx.xxx.90: = tcp i dont know which tool generate those packets.. but as we see i dont see se= q, flag, lenth etc.. just this ouput on tcpdump... Is there any kernel feature for do NOT process malformed syn packets ??