From owner-svn-src-all@freebsd.org Tue Dec 4 22:10:10 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 56A5913231FA; Tue, 4 Dec 2018 22:10:10 +0000 (UTC) (envelope-from tuexen@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id EEC2074CEF; Tue, 4 Dec 2018 22:10:09 +0000 (UTC) (envelope-from tuexen@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 CE5B53306; Tue, 4 Dec 2018 22:10:09 +0000 (UTC) (envelope-from tuexen@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id wB4MA9Mw093451; Tue, 4 Dec 2018 22:10:09 GMT (envelope-from tuexen@FreeBSD.org) Received: (from tuexen@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id wB4MA9rk093449; Tue, 4 Dec 2018 22:10:09 GMT (envelope-from tuexen@FreeBSD.org) Message-Id: <201812042210.wB4MA9rk093449@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: tuexen set sender to tuexen@FreeBSD.org using -f From: Michael Tuexen Date: Tue, 4 Dec 2018 22:10:09 +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: r341498 - in stable/12/sys/netinet: . tcp_stacks X-SVN-Group: stable-12 X-SVN-Commit-Author: tuexen X-SVN-Commit-Paths: in stable/12/sys/netinet: . tcp_stacks X-SVN-Commit-Revision: 341498 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: EEC2074CEF X-Spamd-Result: default: False [-0.02 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-0.48)[-0.475,0]; NEURAL_SPAM_SHORT(0.50)[0.496,0]; NEURAL_HAM_LONG(-0.05)[-0.046,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-Rspamd-Server: mx1.freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 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: Tue, 04 Dec 2018 22:10:10 -0000 Author: tuexen Date: Tue Dec 4 22:10:09 2018 New Revision: 341498 URL: https://svnweb.freebsd.org/changeset/base/341498 Log: MFC r340774: Ensure that TCP RST-segments announce consistently a receiver window of zero. This was already done when sending them via tcp_respond(). Reviewed by: rrs@ Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D17949 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 Tue Dec 4 22:05:36 2018 (r341497) +++ stable/12/sys/netinet/tcp_output.c Tue Dec 4 22:10:09 2018 (r341498) @@ -1171,14 +1171,18 @@ send: /* * Calculate receive window. Don't shrink window, * but avoid silly window syndrome. + * If a RST segment is sent, advertise a window of zero. */ - if (recwin < (so->so_rcv.sb_hiwat / 4) && - recwin < tp->t_maxseg) + if (flags & TH_RST) { recwin = 0; - if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && - recwin < (tp->rcv_adv - tp->rcv_nxt)) - recwin = (tp->rcv_adv - tp->rcv_nxt); - + } else { + if (recwin < (so->so_rcv.sb_hiwat / 4) && + recwin < tp->t_maxseg) + recwin = 0; + if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && + recwin < (tp->rcv_adv - tp->rcv_nxt)) + recwin = (tp->rcv_adv - tp->rcv_nxt); + } /* * According to RFC1323 the window field in a SYN (i.e., a * or ) segment itself is never scaled. The Modified: stable/12/sys/netinet/tcp_stacks/rack.c ============================================================================== --- stable/12/sys/netinet/tcp_stacks/rack.c Tue Dec 4 22:05:36 2018 (r341497) +++ stable/12/sys/netinet/tcp_stacks/rack.c Tue Dec 4 22:10:09 2018 (r341498) @@ -8189,15 +8189,20 @@ send: /* * Calculate receive window. Don't shrink window, but avoid silly * window syndrome. + * If a RST segment is sent, advertise a window of zero. */ - if (recwin < (long)(so->so_rcv.sb_hiwat / 4) && - recwin < (long)tp->t_maxseg) + if (flags & TH_RST) { recwin = 0; - if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && - recwin < (long)(tp->rcv_adv - tp->rcv_nxt)) - recwin = (long)(tp->rcv_adv - tp->rcv_nxt); - if (recwin > (long)TCP_MAXWIN << tp->rcv_scale) - recwin = (long)TCP_MAXWIN << tp->rcv_scale; + } else { + if (recwin < (long)(so->so_rcv.sb_hiwat / 4) && + recwin < (long)tp->t_maxseg) + recwin = 0; + if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) && + recwin < (long)(tp->rcv_adv - tp->rcv_nxt)) + recwin = (long)(tp->rcv_adv - tp->rcv_nxt); + if (recwin > (long)TCP_MAXWIN << tp->rcv_scale) + recwin = (long)TCP_MAXWIN << tp->rcv_scale; + } /* * According to RFC1323 the window field in a SYN (i.e., a or