From owner-freebsd-bugs@freebsd.org Mon Aug 12 11:36:15 2019 Return-Path: Delivered-To: freebsd-bugs@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 DC560B0183 for ; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 466YhH5XrZz4F2n for ; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id BC793B0181; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) Delivered-To: bugs@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 BC3A1B017F for ; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) (envelope-from bugzilla-noreply@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) server-signature RSA-PSS (4096 bits) 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 466YhH4Xt8z4F2m for ; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 79ABC25F70 for ; Mon, 12 Aug 2019 11:36:15 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x7CBaFE0003307 for ; Mon, 12 Aug 2019 11:36:15 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x7CBaFEH003306 for bugs@FreeBSD.org; Mon, 12 Aug 2019 11:36:15 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 239799] IP_MINTTL broken Date: Mon, 12 Aug 2019 11:36:15 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 12.0-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: vincent@bernat.ch X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Aug 2019 11:36:15 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D239799 Bug ID: 239799 Summary: IP_MINTTL broken Product: Base System Version: 12.0-STABLE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: vincent@bernat.ch Hey! Use of IP_MINTTL to ensure a minimum TTL on input TCP packets is broken. Wh= en this option is enabled for a socket, all incoming packets are dropped. When= it comes to compare the TTL in `tcp_input.c`, the reported TTL is 0: ```c if (inp->inp_ip_minttl !=3D 0) { #ifdef INET6 if (isipv6) { if (inp->inp_ip_minttl > ip6->ip6_hlim) goto dropunlock; } else #endif if (inp->inp_ip_minttl > ip->ip_ttl) goto dropunlock; } ``` A few lines earlier, we have: ```c struct ipovly *ipov =3D (struct ipovly *)ip; /* * Checksum extended TCP header and data. */ len =3D off0 + tlen; bzero(ipov->ih_x1, sizeof(ipov->ih_x1)); ipov->ih_len =3D htons(tlen); th->th_sum =3D in_cksum(m, len); /* Reset length for SDT probes. */ ip->ip_len =3D htons(len); /* Reset TOS bits */ ip->ip_tos =3D iptos; /* Re-initialization for later version check */ ip->ip_v =3D IPVERSION; ip->ip_hl =3D off0 >> 2; ``` `ip->ip_ttl` also needs to be restored after this code. --=20 You are receiving this mail because: You are the assignee for the bug.=