From owner-svn-src-stable@freebsd.org Thu May 21 19:41:25 2020 Return-Path: Delivered-To: svn-src-stable@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 DB4782F28F4; Thu, 21 May 2020 19:41:25 +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 49Sg3T5Y5lz4CTT; Thu, 21 May 2020 19:41:25 +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 B98EB12AE1; Thu, 21 May 2020 19:41:25 +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 04LJfPJJ023813; Thu, 21 May 2020 19:41:25 GMT (envelope-from rscheff@FreeBSD.org) Received: (from rscheff@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 04LJfPQ0023810; Thu, 21 May 2020 19:41:25 GMT (envelope-from rscheff@FreeBSD.org) Message-Id: <202005211941.04LJfPQ0023810@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rscheff set sender to rscheff@FreeBSD.org using -f From: Richard Scheffenegger Date: Thu, 21 May 2020 19:41:25 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r361340 - in stable/12/sys/netinet: . tcp_stacks X-SVN-Group: stable-12 X-SVN-Commit-Author: rscheff X-SVN-Commit-Paths: in stable/12/sys/netinet: . tcp_stacks X-SVN-Commit-Revision: 361340 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 May 2020 19:41:25 -0000 Author: rscheff Date: Thu May 21 19:41:25 2020 New Revision: 361340 URL: https://svnweb.freebsd.org/changeset/base/361340 Log: MFC r360479: Prevent premature shrinking of the scaled receive window which can cause a TCP client to use invalid or stale TCP sequence numbers for ACK packets. Packets with old sequence numbers are ignored and not used to update the send window size. This might cause the TCP session to hang indefinitely under some circumstances. Reported by: Cui Cheng Reviewed by: tuexen (mentor), rgrimes (mentor, blanket) Approved by: tuexen (mentor), rgrimes (mentor, blanket) MFC after: 3 weeks Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D24515 Modified: stable/12/sys/netinet/tcp_output.c stable/12/sys/netinet/tcp_stacks/rack.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/tcp_output.c ============================================================================== --- stable/12/sys/netinet/tcp_output.c Thu May 21 18:50:05 2020 (r361339) +++ stable/12/sys/netinet/tcp_output.c Thu May 21 19:41:25 2020 (r361340) @@ -1206,8 +1206,11 @@ send: if (flags & TH_SYN) th->th_win = htons((u_short) (min(sbspace(&so->so_rcv), TCP_MAXWIN))); - else + else { + /* Avoid shrinking window with window scaling. */ + recwin = roundup2(recwin, 1 << tp->rcv_scale); th->th_win = htons((u_short)(recwin >> tp->rcv_scale)); + } /* * Adjust the RXWIN0SENT flag - indicate that we have advertised Modified: stable/12/sys/netinet/tcp_stacks/rack.c ============================================================================== --- stable/12/sys/netinet/tcp_stacks/rack.c Thu May 21 18:50:05 2020 (r361339) +++ stable/12/sys/netinet/tcp_stacks/rack.c Thu May 21 19:41:25 2020 (r361340) @@ -8355,8 +8355,11 @@ send: if (flags & TH_SYN) th->th_win = htons((u_short) (min(sbspace(&so->so_rcv), TCP_MAXWIN))); - else + else { + /* Avoid shrinking window with window scaling. */ + recwin = roundup2(recwin, 1 << tp->rcv_scale); th->th_win = htons((u_short)(recwin >> tp->rcv_scale)); + } /* * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0 * window. This may cause the remote transmitter to stall. This