sysctl: fix neighbour table sysctls.

- In ipv6 ndisc_ifinfo_syctl_change so it doesn't depend on binary
  sysctl names for a function that works with proc.

- In neighbour.c reorder the table to put the possibly unused entries
  at the end so we can remove them by terminating the table early.

- In neighbour.c kill the entries with questionable binary sysctl
  handling behavior.

- In neighbour.c if we don't have a strategy routine remove the
  binary path.  So we don't the default sysctl strategy routine
  on data that is not ready for it.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 6cc33dc..20cfc90 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1658,30 +1658,26 @@
 	struct inet6_dev *idev;
 	int ret;
 
-	if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
-	    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
+	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
+	    (strcmp(ctl->procname, "base_reachable_time") == 0))
 		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
 
-	switch (ctl->ctl_name) {
-	case NET_NEIGH_RETRANS_TIME:
+	if (strcmp(ctl->procname, "retrans_time") == 0)
 		ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
-		break;
-	case NET_NEIGH_REACHABLE_TIME:
+
+	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
 		ret = proc_dointvec_jiffies(ctl, write,
 					    filp, buffer, lenp, ppos);
-		break;
-	case NET_NEIGH_RETRANS_TIME_MS:
-	case NET_NEIGH_REACHABLE_TIME_MS:
+
+	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
+		 (strcmp(ctl->procname, "base_reacable_time_ms") == 0))
 		ret = proc_dointvec_ms_jiffies(ctl, write,
 					       filp, buffer, lenp, ppos);
-		break;
-	default:
+	else
 		ret = -1;
-	}
 
 	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
-		if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
-		    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
+		if (ctl->data == &idev->nd_parms->base_reachable_time)
 			idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
 		idev->tstamp = jiffies;
 		inet6_ifinfo_notify(RTM_NEWLINK, idev);