From owner-svn-src-head@freebsd.org Wed Sep 30 03:37:38 2015 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 56E78A0CAB3; Wed, 30 Sep 2015 03:37:38 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2E09A1335; Wed, 30 Sep 2015 03:37:38 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.70]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id t8U3bclQ046893; Wed, 30 Sep 2015 03:37:38 GMT (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id t8U3bcoD046892; Wed, 30 Sep 2015 03:37:38 GMT (envelope-from glebius@FreeBSD.org) Message-Id: <201509300337.t8U3bcoD046892@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: glebius set sender to glebius@FreeBSD.org using -f From: Gleb Smirnoff Date: Wed, 30 Sep 2015 03:37:38 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r288412 - head/sys/netinet X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Sep 2015 03:37:38 -0000 Author: glebius Date: Wed Sep 30 03:37:37 2015 New Revision: 288412 URL: https://svnweb.freebsd.org/changeset/base/288412 Log: When processing ICMP need frag message, ignore the suggested MTU unless it is smaller than the current one for this connection. This is behavior specified by RFC 1191, and this is how original BSD stack behaved, but this was unintentionally regressed in r182851. Reported & tested by: Richard Russo Differential Revision: D3567 Sponsored by: Nginx, Inc. Modified: head/sys/netinet/tcp_subr.c Modified: head/sys/netinet/tcp_subr.c ============================================================================== --- head/sys/netinet/tcp_subr.c Wed Sep 30 03:36:41 2015 (r288411) +++ head/sys/netinet/tcp_subr.c Wed Sep 30 03:37:37 2015 (r288412) @@ -1541,11 +1541,6 @@ tcp_ctlinput(int cmd, struct sockaddr *s * in the route to the suggested new * value (if given) and then notify. */ - bzero(&inc, sizeof(inc)); - inc.inc_faddr = faddr; - inc.inc_fibnum = - inp->inp_inc.inc_fibnum; - mtu = ntohs(icp->icmp_nextmtu); /* * If no alternative MTU was @@ -1560,14 +1555,18 @@ tcp_ctlinput(int cmd, struct sockaddr *s mtu = V_tcp_minmss + sizeof(struct tcpiphdr); /* - * Only cache the MTU if it - * is smaller than the interface - * or route MTU. tcp_mtudisc() - * will do right thing by itself. + * Only process the offered MTU if it + * is smaller than the current one. */ - if (mtu <= tcp_maxmtu(&inc, NULL)) + if (mtu < tp->t_maxopd + + sizeof(struct tcpiphdr)) { + bzero(&inc, sizeof(inc)); + inc.inc_faddr = faddr; + inc.inc_fibnum = + inp->inp_inc.inc_fibnum; tcp_hc_updatemtu(&inc, mtu); - tcp_mtudisc(inp, mtu); + tcp_mtudisc(inp, mtu); + } } else inp = (*notify)(inp, inetctlerrmap[cmd]);