From owner-svn-src-all@freebsd.org Thu May 21 23:31:59 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 66D132F80F0; Thu, 21 May 2020 23:31:59 +0000 (UTC) (envelope-from freebsd@gndrsh.dnsmgr.net) Received: from gndrsh.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 49Sm9W0dnyz4VZQ; Thu, 21 May 2020 23:31:58 +0000 (UTC) (envelope-from freebsd@gndrsh.dnsmgr.net) Received: from gndrsh.dnsmgr.net (localhost [127.0.0.1]) by gndrsh.dnsmgr.net (8.13.3/8.13.3) with ESMTP id 04LNVv9C018958; Thu, 21 May 2020 16:31:57 -0700 (PDT) (envelope-from freebsd@gndrsh.dnsmgr.net) Received: (from freebsd@localhost) by gndrsh.dnsmgr.net (8.13.3/8.13.3/Submit) id 04LNVvac018957; Thu, 21 May 2020 16:31:57 -0700 (PDT) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <202005212331.04LNVvac018957@gndrsh.dnsmgr.net> Subject: Re: svn commit: r361340 - in stable/12/sys/netinet: . tcp_stacks In-Reply-To: <202005211941.04LJfPQ0023810@repo.freebsd.org> To: Richard Scheffenegger Date: Thu, 21 May 2020 16:31:57 -0700 (PDT) CC: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Reply-To: rgrimes@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: 49Sm9W0dnyz4VZQ X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:13868, ipnet:69.59.192.0/19, country:US] 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: Thu, 21 May 2020 23:31:59 -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. There should of been a note here: This does NOT contain the merge of the change to bbrv1 since at this time that code does not exist in stable/12, and there is no plan to merge that code to stable/12. > 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 > -- Rod Grimes rgrimes@freebsd.org