From owner-cvs-src@FreeBSD.ORG Thu Apr 21 14:29:34 2005 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B9B5216A4CE; Thu, 21 Apr 2005 14:29:34 +0000 (GMT) Received: from repoman.freebsd.org (repoman.freebsd.org [216.136.204.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id 99CD443D1D; Thu, 21 Apr 2005 14:29:34 +0000 (GMT) (envelope-from andre@FreeBSD.org) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.13.1/8.13.1) with ESMTP id j3LETYp3018409; Thu, 21 Apr 2005 14:29:34 GMT (envelope-from andre@repoman.freebsd.org) Received: (from andre@localhost) by repoman.freebsd.org (8.13.1/8.13.1/Submit) id j3LETYoT018408; Thu, 21 Apr 2005 14:29:34 GMT (envelope-from andre) Message-Id: <200504211429.j3LETYoT018408@repoman.freebsd.org> From: Andre Oppermann Date: Thu, 21 Apr 2005 14:29:34 +0000 (UTC) To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org X-FreeBSD-CVS-Branch: HEAD Subject: cvs commit: src/sys/netinet ip_icmp.c ip_icmp.h tcp_subr.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Apr 2005 14:29:35 -0000 andre 2005-04-21 14:29:34 UTC FreeBSD src repository Modified files: sys/netinet ip_icmp.c ip_icmp.h tcp_subr.c Log: Move Path MTU discovery ICMP processing from icmp_input() to tcp_ctlinput() and subject it to active tcpcb and sequence number checking. Previously any ICMP unreachable/needfrag message would cause an update to the TCP hostcache. Now only ICMP PMTU messages belonging to an active TCP session with the correct src/dst/port and sequence number will update the hostcache and complete the path MTU discovery process. Note that we don't entirely implement the recommended counter measures of Section 7.2 of the paper. However we close down the possible degradation vector from trivially easy to really complex and resource intensive. In addition we have limited the smallest acceptable MTU with net.inet.tcp.minmss sysctl for some time already, further reducing the effect of any degradation due to an attack. Security: draft-gont-tcpm-icmp-attacks-03.txt Section 7.2 MFC after: 3 days Revision Changes Path 1.99 +1 -45 src/sys/netinet/ip_icmp.c 1.24 +1 -0 src/sys/netinet/ip_icmp.h 1.223 +36 -7 src/sys/netinet/tcp_subr.c