Document struct nd_ifinfo protection, remove obsolete .initialized member

All access to struct ifnet's member *if_nd is read-only, with the one
write exception being nd6_slowtimo() updating ND information.

IPv6 Neighbour Discovery information is fully protected by the net lock.
---
nd6_ifattach() allocates and unconditionally initialises struct ifnet's
*if_nd member, so early in if_attachsetup() that there is no way to query
unitialised Neighour Unreachable Detection bits.

Only SIOCGIFINFO_IN6 through ndp(8) used the .initialized member:
Added/set since 2002 sys/netinet6/nd6.c r1.42
    attach nd_ifinfo structure to if_afdata.
    split IPv6 MTU (advertised by RA) from real link MTU.
    sync with kame

Read      since 2002 usr.sbin/ndp/ndp.c r1.16
    use new SIOCGIFINFO_IN6.  random other cleanups.  sync w/kame.

Obsolete  since 2017 sys/netinet6/nd6.c r1.217
                     usr.sbin/ndp/ndp.c r1.85
    Remove knob and always do neighbor unreachable detection.

Feedback OK bluhm

1 files changed, 1 insertions, 4 deletions

diff --git a/usr.sbin/ndp/ndp.c b/usr.sbin/ndp/ndp.c
index 8b3cfeeb300..80cca743bc4 100644
--- a/usr.sbin/ndp/ndp.c
+++ b/usr.sbin/ndp/ndp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ndp.c,v 1.104 2022/11/09 18:00:02 kn Exp $	*/
+/*	$OpenBSD: ndp.c,v 1.105 2022/11/28 19:13:36 kn Exp $	*/
 /*	$KAME: ndp.c,v 1.101 2002/07/17 08:46:33 itojun Exp $	*/
 
 /*
@@ -888,9 +888,6 @@ ifinfo(const char *ifname)
 	if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) == -1)
 		err(1, "ioctl(SIOCGIFINFO_IN6)");
 
-	if (!nd.ndi.initialized)
-		errx(1, "%s: not initialized yet", ifname);
-
 	printf("basereachable=%ds%dms",
 	    nd.ndi.basereachable / 1000, nd.ndi.basereachable % 1000);
 	printf(", reachable=%ds", nd.ndi.reachable);