From owner-svn-src-all@freebsd.org Thu Nov 22 19:49:54 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 0E67811052D4; Thu, 22 Nov 2018 19:49:54 +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 A8B8D83589; Thu, 22 Nov 2018 19:49:53 +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 89A2A14486; Thu, 22 Nov 2018 19:49:53 +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 wAMJnrh3078977; Thu, 22 Nov 2018 19:49:53 GMT (envelope-from tuexen@FreeBSD.org) Received: (from tuexen@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id wAMJnrm0078975; Thu, 22 Nov 2018 19:49:53 GMT (envelope-from tuexen@FreeBSD.org) Message-Id: <201811221949.wAMJnrm0078975@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: tuexen set sender to tuexen@FreeBSD.org using -f From: Michael Tuexen Date: Thu, 22 Nov 2018 19:49:53 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340774 - in head/sys/netinet: . tcp_stacks X-SVN-Group: head X-SVN-Commit-Author: tuexen X-SVN-Commit-Paths: in head/sys/netinet: . tcp_stacks X-SVN-Commit-Revision: 340774 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: A8B8D83589 X-Spamd-Result: default: False [1.32 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_SPAM_LONG(0.42)[0.420,0]; NEURAL_SPAM_MEDIUM(0.74)[0.738,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_SPAM_SHORT(0.16)[0.158,0] 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: Thu, 22 Nov 2018 19:49:54 -0000 Author: tuexen Date: Thu Nov 22 19:49:52 2018 New Revision: 340774 URL: https://svnweb.freebsd.org/changeset/base/340774 Log: 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@ MFC after: 1 week Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D17949 Modified: head/sys/netinet/tcp_output.c head/sys/netinet/tcp_stacks/rack.c Modified: head/sys/netinet/tcp_output.c ============================================================================== --- head/sys/netinet/tcp_output.c Thu Nov 22 18:59:05 2018 (r340773) +++ head/sys/netinet/tcp_output.c Thu Nov 22 19:49:52 2018 (r340774) @@ -1172,14 +1172,18 @@ 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: head/sys/netinet/tcp_stacks/rack.c ============================================================================== --- head/sys/netinet/tcp_stacks/rack.c Thu Nov 22 18:59:05 2018 (r340773) +++ head/sys/netinet/tcp_stacks/rack.c Thu Nov 22 19:49:52 2018 (r340774) @@ -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