From owner-svn-src-stable@freebsd.org Fri Apr 20 14:21:38 2018 Return-Path: Delivered-To: svn-src-stable@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 0DAFEFA7B68; Fri, 20 Apr 2018 14:21:38 +0000 (UTC) (envelope-from jtl@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 AFC697EE9E; Fri, 20 Apr 2018 14:21:37 +0000 (UTC) (envelope-from jtl@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 AA8401979F; Fri, 20 Apr 2018 14:21:37 +0000 (UTC) (envelope-from jtl@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w3KELbPA053824; Fri, 20 Apr 2018 14:21:37 GMT (envelope-from jtl@FreeBSD.org) Received: (from jtl@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w3KELbAl053823; Fri, 20 Apr 2018 14:21:37 GMT (envelope-from jtl@FreeBSD.org) Message-Id: <201804201421.w3KELbAl053823@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jtl set sender to jtl@FreeBSD.org using -f From: "Jonathan T. Looney" Date: Fri, 20 Apr 2018 14:21:37 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r332819 - stable/11/sys/netinet6 X-SVN-Group: stable-11 X-SVN-Commit-Author: jtl X-SVN-Commit-Paths: stable/11/sys/netinet6 X-SVN-Commit-Revision: 332819 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: 2.1.25 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: Fri, 20 Apr 2018 14:21:38 -0000 Author: jtl Date: Fri Apr 20 14:21:37 2018 New Revision: 332819 URL: https://svnweb.freebsd.org/changeset/base/332819 Log: MFC r331488: This change adds a flag to the DAD entry to indicate whether it is currently on the queue. This prevents accidentally doubly-removing a DAD entry from the queue, while also simplifying some of the logic in nd6_dad_stop(). Sponsored by: Netflix, Inc. Modified: stable/11/sys/netinet6/nd6_nbr.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/netinet6/nd6_nbr.c ============================================================================== --- stable/11/sys/netinet6/nd6_nbr.c Fri Apr 20 14:01:08 2018 (r332818) +++ stable/11/sys/netinet6/nd6_nbr.c Fri Apr 20 14:21:37 2018 (r332819) @@ -1119,6 +1119,7 @@ struct dadq { #define ND_OPT_NONCE_LEN32 \ ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; + bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ }; static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); @@ -1137,6 +1138,7 @@ nd6_dad_add(struct dadq *dp) DADQ_WLOCK(); TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); + dp->dad_ondadq = true; DADQ_WUNLOCK(); } @@ -1145,9 +1147,17 @@ nd6_dad_del(struct dadq *dp) { DADQ_WLOCK(); - TAILQ_REMOVE(&V_dadq, dp, dad_list); - DADQ_WUNLOCK(); - nd6_dad_rele(dp); + if (dp->dad_ondadq) { + /* + * Remove dp from the dadq and release the dadq's + * reference. + */ + TAILQ_REMOVE(&V_dadq, dp, dad_list); + dp->dad_ondadq = false; + DADQ_WUNLOCK(); + nd6_dad_rele(dp); + } else + DADQ_WUNLOCK(); } static struct dadq * @@ -1294,6 +1304,8 @@ nd6_dad_start(struct ifaddr *ifa, int delay) dp->dad_ns_icount = dp->dad_na_icount = 0; dp->dad_ns_ocount = dp->dad_ns_tcount = 0; dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; + + /* Add this to the dadq and add a reference for the dadq. */ refcount_init(&dp->dad_refcnt, 1); nd6_dad_add(dp); nd6_dad_starttimer(dp, delay, 0); @@ -1314,16 +1326,9 @@ nd6_dad_stop(struct ifaddr *ifa) } nd6_dad_stoptimer(dp); - - /* - * The DAD queue entry may have been removed by nd6_dad_timer() while - * we were waiting for it to stop, so re-do the lookup. - */ - nd6_dad_rele(dp); - if (nd6_dad_find(ifa, NULL) == NULL) - return; - nd6_dad_del(dp); + + /* Release this function's reference, acquired by nd6_dad_find(). */ nd6_dad_rele(dp); }