From nobody Wed Sep 14 01:08:33 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4MS2Jx4Pxgz4bjhM; Wed, 14 Sep 2022 01:08:33 +0000 (UTC) (envelope-from git@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 4MS2Jx3lBxz3x3L; Wed, 14 Sep 2022 01:08:33 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1663117713; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=oCA0yUpB425Ei7sYc88PLsQHVcYvg2yGLehzOlFMmmw=; b=gpSwjvHLc7E2Aok8NNME9482TAZfHkg3A/jyJ+w932yvPi113JkQAXZq8emxwoEbuY6G5P d0o9kraabGphQwIeO4yB6Bgb2ZH5AhWIMTe/KHU/scCX7j1mdj5oWgyML7kyI3bFveSqjh TAAazEmmdXuiQUN4o2NjJPyYE8qG0Vp0wTIHUwnoPTQEjo0IAdtAWLNmLwUCdYnm3D1bQV EmfhEf2PbKmRWjerLu1PW2SqpegoN3f3i0G66UaDcyflwZ4mpS/P8OLFCp0wfcYu1SiLIT wKEGDttUHv7WPIwmQga1TyYMxp3WHyKbAUjGqG58UA7/iDR3xHOwbLWLvf/zyA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 4MS2Jx2Xg5zWVR; Wed, 14 Sep 2022 01:08:33 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 28E18Xaq007886; Wed, 14 Sep 2022 01:08:33 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 28E18XvQ007885; Wed, 14 Sep 2022 01:08:33 GMT (envelope-from git) Date: Wed, 14 Sep 2022 01:08:33 GMT Message-Id: <202209140108.28E18XvQ007885@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Richard Scheffenegger Subject: git: 3d0b768cc0a0 - stable/13 - tcp: finish SACK loss recovery on sudden lack of SACK blocks List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: rscheff X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 3d0b768cc0a07196aa6167b76b32abb928fb03be Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1663117713; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=oCA0yUpB425Ei7sYc88PLsQHVcYvg2yGLehzOlFMmmw=; b=PCfXu0P2kAm8UUKRof9kA4qUWq7tV+Kc09dkgC4d0xcxsQGr3ihJLAOeC7OWKifPnZwFt3 uQHzk17s5xcawhi78wq5sb/yzmrEqi5UOLQnPGMV5w5JJKp/HbZbddRl7FXc9CyupE+RPF +bNYN5wZ8lCb3W5oqICBAZeABgF55kse7X1IW094WR+jS26U/FHq297YupFTOIOaBJU7JY /Y8agGMbLcUQTXrYApTGTCGilsFbufxXMFBayT7WB6pCTLQshQ8CaZ3q4+Dk8UwGRnVh0u umx31TNdWe+dve8hwSqgScSSvtMz1NJz8V6vxwDjXyOxRhNickrKvBcZnS/6JQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1663117713; a=rsa-sha256; cv=none; b=GIIogNmJvHBf4ojRSbz5G+606y/Nrh0N08nVo+QndDCeTKzl7twwpWGflrADz8u2MBMHwR H3wBhvFyLCVfr8VFELfkhc8nhKjXGVyUd6pjjZaEFW6wFhwMPlxIyMEhPE5vFV3+jAYEZo bTaPaWfjx4t3bCSNy9sJ5vKx7JAgi57DEhiPyOlni4IBH4SC1Cwy7tTlKrDDBOYPqBEhPM XnSaR2fF0ZkwWvX6NTnGKTG66Wc+ahpRPmy73S2lSU1sv/HWZO9aoU9+Fq7R5viBVj6ra9 A4Jip0btEcYq+O7NmE+j38ZFU2dUKHqsGuy9WnXQ533Ju2+oRLd9LkKrBLXeIg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by rscheff: URL: https://cgit.FreeBSD.org/src/commit/?id=3d0b768cc0a07196aa6167b76b32abb928fb03be commit 3d0b768cc0a07196aa6167b76b32abb928fb03be Author: Richard Scheffenegger AuthorDate: 2022-08-31 12:49:25 +0000 Commit: Richard Scheffenegger CommitDate: 2022-09-13 15:14:24 +0000 tcp: finish SACK loss recovery on sudden lack of SACK blocks While a receiver should continue sending SACK blocks for the duration of a SACK loss recovery, if for some reason the TCP options no longer contain these SACK blocks, but we already started maintaining the Scoreboard, keep on handling incoming ACKs (without SACK) as belonging to the SACK recovery. Reported by: thj Reviewed by: tuexen, #transport MFC after: 2 weeks Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D36046 (cherry picked from commit c21b7b55bea2cc2bf3b420c70a9018e703ed6f00) --- sys/netinet/tcp_input.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-) diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 601b4a63716f..557e27721a67 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -287,6 +287,20 @@ kmod_tcpstat_add(int statnum, int val) counter_u64_add(VNET(tcpstat)[statnum], val); } +/* + * Make sure that we only start a SACK loss recovery when + * receiving a duplicate ACK with a SACK block, and also + * complete SACK loss recovery in case the other end + * reneges. + */ +static bool inline +tcp_is_sack_recovery(struct tcpcb *tp, struct tcpopt *to) +{ + return ((tp->t_flags & TF_SACK_PERMIT) && + ((to->to_flags & TOF_SACK) || + (!TAILQ_EMPTY(&tp->snd_holes)))); +} + #ifdef TCP_HHOOK /* * Wrapper for the TCP established input helper hook. @@ -2525,9 +2539,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, TCPSTAT_INC(tcps_rcvacktoomuch); goto dropafterack; } - if ((tp->t_flags & TF_SACK_PERMIT) && - ((to.to_flags & TOF_SACK) || - !TAILQ_EMPTY(&tp->snd_holes))) + if (tcp_is_sack_recovery(tp, &to)) { sack_changed = tcp_sack_doack(tp, &to, th->th_ack); else /* @@ -2597,8 +2609,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, * duplicating packets or a possible DoS attack. */ if (th->th_ack != tp->snd_una || - ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACK) && + (tcp_is_sack_recovery(tp, &to) && !sack_changed)) break; else if (!tcp_timer_active(tp, TT_REXMT)) @@ -2610,8 +2621,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, if (V_tcp_do_prr && IN_FASTRECOVERY(tp->t_flags)) { tcp_do_prr_ack(tp, th, &to); - } else if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACK) && + } else if (tcp_is_sack_recovery(tp, &to) && IN_FASTRECOVERY(tp->t_flags)) { int awnd; @@ -2684,8 +2694,7 @@ enter_recovery: * snd_ssthresh is already updated by * cc_cong_signal. */ - if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACK)) { + if (tcp_is_sack_recovery(tp, &to)) { tp->sackhint.prr_delivered = tp->sackhint.sacked_bytes; } else { @@ -2697,8 +2706,7 @@ enter_recovery: tp->sackhint.recover_fs = max(1, tp->snd_nxt - tp->snd_una); } - if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACK)) { + if (tcp_is_sack_recovery(tp, &to)) { TCPSTAT_INC( tcps_sack_recovery_episode); tp->snd_recover = tp->snd_nxt; @@ -2790,8 +2798,7 @@ enter_recovery: * from the left side. Such partial ACKs should not be * counted as dupacks here. */ - if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACK) && + if (tcp_is_sack_recovery(tp, &to) && sack_changed) { tp->t_dupacks++; /* limit overhead by setting maxseg last */ @@ -3973,8 +3980,7 @@ tcp_do_prr_ack(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to) * (del_data) and an estimate of how many bytes are in the * network. */ - if (((tp->t_flags & TF_SACK_PERMIT) && - (to->to_flags & TOF_SACK)) || + if (tcp_is_sack_recovery(tp, to) || (IN_CONGRECOVERY(tp->t_flags) && !IN_FASTRECOVERY(tp->t_flags))) { del_data = tp->sackhint.delivered_data; @@ -4018,8 +4024,7 @@ tcp_do_prr_ack(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to) * accordingly. */ if (IN_FASTRECOVERY(tp->t_flags)) { - if ((tp->t_flags & TF_SACK_PERMIT) && - (to->to_flags & TOF_SACK)) { + if (tcp_is_sack_recovery(tp, to)) { tp->snd_cwnd = tp->snd_nxt - tp->snd_recover + tp->sackhint.sack_bytes_rexmit + (snd_cnt * maxseg);