Remove constant basereachable and retrans members from struct nd_ifinfo

Both are initalised with compile-time constants and never written to.

They are part of the Neighbour Discovery machinery and only surface
through the single-user SIOCGIFINFO_IN6:
	$ ndp -i lo0
	basereachable=30s0ms, reachable=39s, retrans=1s0ms

These values are read-only since 2017
sys/netinet6/nd6.c r1.217
usr.sbin/ndp/ndp.c r1.85
    Remove knob and always do neighbor unreachable detection

Inline the macros (to keep meaningful names), shrink the per-interface
allocated struct nd_ifinfo to what is actually needed and inline
nd6_dad_starttimer()'s constant `msec' argument.

Nothing else in base, incl. regress, uses SIOCGIFINFO_IN6 or `ndp -i'.

OK bluhm

3 files changed, 15 insertions, 23 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 8cedafd1d35..e51b11fc04e 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.256 2022/11/28 19:13:36 kn Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.257 2022/12/02 15:35:35 kn Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -124,9 +124,7 @@ nd6_ifattach(struct ifnet *ifp)
 
 	nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
 
-	nd->basereachable = REACHABLE_TIME;
-	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
-	nd->retrans = RETRANS_TIMER;
+	nd->reachable = ND_COMPUTE_RTIME(REACHABLE_TIME);
 
 	ifp->if_nd = nd;
 }
@@ -356,7 +354,7 @@ nd6_llinfo_timer(struct rtentry *rt)
 	case ND6_LLINFO_INCOMPLETE:
 		if (ln->ln_asked < nd6_mmaxtries) {
 			ln->ln_asked++;
-			nd6_llinfo_settimer(ln, ifp->if_nd->retrans / 1000);
+			nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000);
 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
 		} else {
 			struct mbuf *m = ln->ln_hold;
@@ -403,13 +401,13 @@ nd6_llinfo_timer(struct rtentry *rt)
 		/* We need NUD */
 		ln->ln_asked = 1;
 		ln->ln_state = ND6_LLINFO_PROBE;
-		nd6_llinfo_settimer(ln, ifp->if_nd->retrans / 1000);
+		nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000);
 		nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0);
 		break;
 	case ND6_LLINFO_PROBE:
 		if (ln->ln_asked < nd6_umaxtries) {
 			ln->ln_asked++;
-			nd6_llinfo_settimer(ln, ifp->if_nd->retrans / 1000);
+			nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000);
 			nd6_ns_output(ifp, &dst->sin6_addr,
 			    &dst->sin6_addr, ln, 0);
 		} else {
@@ -1285,8 +1283,7 @@ nd6_slowtimo(void *ignored_arg)
 
 	TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
 		nd6if = ifp->if_nd;
-		if (nd6if->basereachable && /* already initialized */
-		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
+		if ((nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
 			/*
 			 * Since reachable time rarely changes by router
 			 * advertisements, we SHOULD insure that a new random
@@ -1294,7 +1291,7 @@ nd6_slowtimo(void *ignored_arg)
 			 * (RFC 2461, 6.3.4)
 			 */
 			nd6if->recalctm = ND6_RECALC_REACHTM_INTERVAL;
-			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
+			nd6if->reachable = ND_COMPUTE_RTIME(REACHABLE_TIME);
 		}
 	}
 	NET_UNLOCK();
@@ -1403,7 +1400,7 @@ nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
 	 */
 	if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) {
 		ln->ln_asked++;
-		nd6_llinfo_settimer(ln, ifp->if_nd->retrans / 1000);
+		nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000);
 		nd6_ns_output(ifp, NULL, &satosin6(dst)->sin6_addr, ln, 0);
 	}
 	return (EAGAIN);
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 6f29de0fe72..d096ccd4fb8 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.h,v 1.90 2022/11/28 19:13:36 kn Exp $	*/
+/*	$OpenBSD: nd6.h,v 1.91 2022/12/02 15:35:35 kn Exp $	*/
 /*	$KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $	*/
 
 /*
@@ -45,14 +45,11 @@
 
 /*
  *  Locks used to protect struct members in this file:
- *	I	immutable after creation
  *	N	net lock
  */
 
 struct nd_ifinfo {
-	u_int32_t basereachable;	/* [I] BaseReachableTime */
 	u_int32_t reachable;		/* [N] Reachable Time */
-	u_int32_t retrans;		/* [I] Retrans Timer */
 	int recalctm;			/* [N] BaseReachable recalc timer */
 };
 
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index d3c627484f5..09a9e5e4e95 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6_nbr.c,v 1.137 2022/12/02 12:58:37 kn Exp $	*/
+/*	$OpenBSD: nd6_nbr.c,v 1.138 2022/12/02 15:35:35 kn Exp $	*/
 /*	$KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei Exp $	*/
 
 /*
@@ -76,7 +76,7 @@ struct dadq {
 };
 
 struct dadq *nd6_dad_find(struct ifaddr *);
-void nd6_dad_starttimer(struct dadq *, int);
+void nd6_dad_starttimer(struct dadq *);
 void nd6_dad_stoptimer(struct dadq *);
 void nd6_dad_timer(void *);
 void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
@@ -1050,17 +1050,15 @@ nd6_dad_find(struct ifaddr *ifa)
 }
 
 void
-nd6_dad_starttimer(struct dadq *dp, int msec)
+nd6_dad_starttimer(struct dadq *dp)
 {
-
 	timeout_set_proc(&dp->dad_timer_ch, nd6_dad_timer, dp->dad_ifa);
-	timeout_add_msec(&dp->dad_timer_ch, msec);
+	timeout_add_msec(&dp->dad_timer_ch, RETRANS_TIMER);
 }
 
 void
 nd6_dad_stoptimer(struct dadq *dp)
 {
-
 	timeout_del(&dp->dad_timer_ch);
 }
 
@@ -1122,7 +1120,7 @@ nd6_dad_start(struct ifaddr *ifa)
 	dp->dad_ns_icount = dp->dad_na_icount = 0;
 	dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 	nd6_dad_ns_output(dp, ifa);
-	nd6_dad_starttimer(dp, ifa->ifa_ifp->if_nd->retrans);
+	nd6_dad_starttimer(dp);
 }
 
 /*
@@ -1202,7 +1200,7 @@ nd6_dad_timer(void *xifa)
 		 * We have more NS to go.  Send NS packet for DAD.
 		 */
 		nd6_dad_ns_output(dp, ifa);
-		nd6_dad_starttimer(dp, ifa->ifa_ifp->if_nd->retrans);
+		nd6_dad_starttimer(dp);
 	} else {
 		/*
 		 * We have transmitted sufficient number of DAD packets.