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); } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
