From owner-svn-src-all@freebsd.org Wed May 27 22:34:47 2020 Return-Path: Delivered-To: svn-src-all@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 6FD642F1DE6; Wed, 27 May 2020 22:34:47 +0000 (UTC) (envelope-from rscheff@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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49XQcl2Pg6z4Hs7; Wed, 27 May 2020 22:34:47 +0000 (UTC) (envelope-from rscheff@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4DBFC1BEF5; Wed, 27 May 2020 22:34:47 +0000 (UTC) (envelope-from rscheff@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 04RMYlFk016808; Wed, 27 May 2020 22:34:47 GMT (envelope-from rscheff@FreeBSD.org) Received: (from rscheff@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 04RMYkuZ016806; Wed, 27 May 2020 22:34:46 GMT (envelope-from rscheff@FreeBSD.org) Message-Id: <202005272234.04RMYkuZ016806@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rscheff set sender to rscheff@FreeBSD.org using -f From: Richard Scheffenegger Date: Wed, 27 May 2020 22:34:46 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-releng@freebsd.org Subject: svn commit: r361565 - releng/11.4/sys/netinet X-SVN-Group: releng X-SVN-Commit-Author: rscheff X-SVN-Commit-Paths: releng/11.4/sys/netinet X-SVN-Commit-Revision: 361565 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 May 2020 22:34:47 -0000 Author: rscheff Date: Wed May 27 22:34:46 2020 New Revision: 361565 URL: https://svnweb.freebsd.org/changeset/base/361565 Log: MFS r361436: MFC r361347: With RFC3168 ECN, CWR SHOULD only be sent with new data. Overly conservative data receivers may ignore the CWR flag on other packets, and keep ECE latched. This can result in continuous reduction of the congestion window, and very poor performance when ECN is enabled. This does NOT contain the merge of the change to RACK since at this time that code does not exist in stable/11, and there is no plan to merge RACK to stable/11. PR: 243590 Reviewed by: rgrimes (mentor), rrs Approved by: re(gjb) Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D23364 Modified: releng/11.4/sys/netinet/tcp_input.c releng/11.4/sys/netinet/tcp_output.c Directory Properties: releng/11.4/ (props changed) Modified: releng/11.4/sys/netinet/tcp_input.c ============================================================================== --- releng/11.4/sys/netinet/tcp_input.c Wed May 27 21:56:45 2020 (r361564) +++ releng/11.4/sys/netinet/tcp_input.c Wed May 27 22:34:46 2020 (r361565) @@ -417,9 +417,15 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, ui } break; case CC_ECN: - if (!IN_CONGRECOVERY(tp->t_flags)) { + if (!IN_CONGRECOVERY(tp->t_flags) || + /* + * Allow ECN reaction on ACK to CWR, if + * that data segment was also CE marked. + */ + SEQ_GEQ(th->th_ack, tp->snd_recover)) { + EXIT_CONGRECOVERY(tp->t_flags); TCPSTAT_INC(tcps_ecn_rcwnd); - tp->snd_recover = tp->snd_max; + tp->snd_recover = tp->snd_max + 1; if (tp->t_flags & TF_ECN_PERMIT) tp->t_flags |= TF_ECN_SND_CWR; } Modified: releng/11.4/sys/netinet/tcp_output.c ============================================================================== --- releng/11.4/sys/netinet/tcp_output.c Wed May 27 21:56:45 2020 (r361564) +++ releng/11.4/sys/netinet/tcp_output.c Wed May 27 22:34:46 2020 (r361565) @@ -1161,7 +1161,8 @@ send: * Ignore pure ack packets, retransmissions and window probes. */ if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) && - !((tp->t_flags & TF_FORCEDATA) && len == 1)) { + !((tp->t_flags & TF_FORCEDATA) && len == 1 && + SEQ_LT(tp->snd_una, tp->snd_max))) { #ifdef INET6 if (isipv6) ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20); @@ -1169,15 +1170,15 @@ send: #endif ip->ip_tos |= IPTOS_ECN_ECT0; TCPSTAT_INC(tcps_ecn_ect0); + /* + * Reply with proper ECN notifications. + * Only set CWR on new data segments. + */ + if (tp->t_flags & TF_ECN_SND_CWR) { + flags |= TH_CWR; + tp->t_flags &= ~TF_ECN_SND_CWR; + } } - - /* - * Reply with proper ECN notifications. - */ - if (tp->t_flags & TF_ECN_SND_CWR) { - flags |= TH_CWR; - tp->t_flags &= ~TF_ECN_SND_CWR; - } if (tp->t_flags & TF_ECN_SND_ECE) flags |= TH_ECE; }