From owner-svn-src-all@freebsd.org Sat Mar 24 13:18:09 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 C3E05F6CF44; Sat, 24 Mar 2018 13:18:09 +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 748766B7F0; Sat, 24 Mar 2018 13:18:09 +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 6F5C37AD7; Sat, 24 Mar 2018 13:18:09 +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 w2ODI9J3028765; Sat, 24 Mar 2018 13:18:09 GMT (envelope-from jtl@FreeBSD.org) Received: (from jtl@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w2ODI9qT028764; Sat, 24 Mar 2018 13:18:09 GMT (envelope-from jtl@FreeBSD.org) Message-Id: <201803241318.w2ODI9qT028764@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jtl set sender to jtl@FreeBSD.org using -f From: "Jonathan T. Looney" Date: Sat, 24 Mar 2018 13:18:09 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r331488 - head/sys/netinet6 X-SVN-Group: head X-SVN-Commit-Author: jtl X-SVN-Commit-Paths: head/sys/netinet6 X-SVN-Commit-Revision: 331488 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 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: Sat, 24 Mar 2018 13:18:10 -0000 Author: jtl Date: Sat Mar 24 13:18:09 2018 New Revision: 331488 URL: https://svnweb.freebsd.org/changeset/base/331488 Log: 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(). Reviewed by: ae, hrs, vangyzen MFC after: 2 weeks Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D10943 Modified: head/sys/netinet6/nd6_nbr.c Modified: head/sys/netinet6/nd6_nbr.c ============================================================================== --- head/sys/netinet6/nd6_nbr.c Sat Mar 24 13:13:52 2018 (r331487) +++ head/sys/netinet6/nd6_nbr.c Sat Mar 24 13:18:09 2018 (r331488) @@ -1120,6 +1120,7 @@ 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); @@ -1138,6 +1139,7 @@ nd6_dad_add(struct dadq *dp) DADQ_WLOCK(); TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); + dp->dad_ondadq = true; DADQ_WUNLOCK(); } @@ -1146,9 +1148,17 @@ 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 * @@ -1281,6 +1291,8 @@ 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); @@ -1301,17 +1313,9 @@ 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); - dp = nd6_dad_find(ifa, NULL); - if (dp == NULL) - return; - nd6_dad_del(dp); + + /* Release this function's reference, acquired by nd6_dad_find(). */ nd6_dad_rele(dp); }