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>

1 files changed, 39 insertions, 36 deletions

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index cd3af59b38a1..67ba9914e52e 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2496,7 +2496,6 @@ static struct neigh_sysctl_table {
 			.proc_handler	= &proc_dointvec,
 		},
 		{
-			.ctl_name	= NET_NEIGH_RETRANS_TIME,
 			.procname	= "retrans_time",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
@@ -2541,27 +2540,40 @@ static struct neigh_sysctl_table {
 			.proc_handler	= &proc_dointvec,
 		},
 		{
-			.ctl_name	= NET_NEIGH_ANYCAST_DELAY,
 			.procname	= "anycast_delay",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
 			.proc_handler	= &proc_dointvec_userhz_jiffies,
 		},
 		{
-			.ctl_name	= NET_NEIGH_PROXY_DELAY,
 			.procname	= "proxy_delay",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
 			.proc_handler	= &proc_dointvec_userhz_jiffies,
 		},
 		{
-			.ctl_name	= NET_NEIGH_LOCKTIME,
 			.procname	= "locktime",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
 			.proc_handler	= &proc_dointvec_userhz_jiffies,
 		},
 		{
+			.ctl_name	= NET_NEIGH_RETRANS_TIME_MS,
+			.procname	= "retrans_time_ms",
+			.maxlen		= sizeof(int),
+			.mode		= 0644,
+			.proc_handler	= &proc_dointvec_ms_jiffies,
+			.strategy	= &sysctl_ms_jiffies,
+		},
+		{
+			.ctl_name	= NET_NEIGH_REACHABLE_TIME_MS,
+			.procname	= "base_reachable_time_ms",
+			.maxlen		= sizeof(int),
+			.mode		= 0644,
+			.proc_handler	= &proc_dointvec_ms_jiffies,
+			.strategy	= &sysctl_ms_jiffies,
+		},
+		{
 			.ctl_name	= NET_NEIGH_GC_INTERVAL,
 			.procname	= "gc_interval",
 			.maxlen		= sizeof(int),
@@ -2590,22 +2602,7 @@ static struct neigh_sysctl_table {
 			.mode		= 0644,
 			.proc_handler	= &proc_dointvec,
 		},
-		{
-			.ctl_name	= NET_NEIGH_RETRANS_TIME_MS,
-			.procname	= "retrans_time_ms",
-			.maxlen		= sizeof(int),
-			.mode		= 0644,
-			.proc_handler	= &proc_dointvec_ms_jiffies,
-			.strategy	= &sysctl_ms_jiffies,
-		},
-		{
-			.ctl_name	= NET_NEIGH_REACHABLE_TIME_MS,
-			.procname	= "base_reachable_time_ms",
-			.maxlen		= sizeof(int),
-			.mode		= 0644,
-			.proc_handler	= &proc_dointvec_ms_jiffies,
-			.strategy	= &sysctl_ms_jiffies,
-		},
+		{}
 	},
 	.neigh_dev = {
 		{
@@ -2658,42 +2655,48 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 	t->neigh_vars[9].data  = &p->anycast_delay;
 	t->neigh_vars[10].data = &p->proxy_delay;
 	t->neigh_vars[11].data = &p->locktime;
+	t->neigh_vars[12].data  = &p->retrans_time;
+	t->neigh_vars[13].data  = &p->base_reachable_time;
 
 	if (dev) {
 		dev_name_source = dev->name;
 		t->neigh_dev[0].ctl_name = dev->ifindex;
-		t->neigh_vars[12].procname = NULL;
-		t->neigh_vars[13].procname = NULL;
-		t->neigh_vars[14].procname = NULL;
-		t->neigh_vars[15].procname = NULL;
+		/* Terminate the table early */
+		memset(&t->neigh_vars[14], 0, sizeof(t->neigh_vars[14]));
 	} else {
 		dev_name_source = t->neigh_dev[0].procname;
-		t->neigh_vars[12].data = (int *)(p + 1);
-		t->neigh_vars[13].data = (int *)(p + 1) + 1;
-		t->neigh_vars[14].data = (int *)(p + 1) + 2;
-		t->neigh_vars[15].data = (int *)(p + 1) + 3;
+		t->neigh_vars[14].data = (int *)(p + 1);
+		t->neigh_vars[15].data = (int *)(p + 1) + 1;
+		t->neigh_vars[16].data = (int *)(p + 1) + 2;
+		t->neigh_vars[17].data = (int *)(p + 1) + 3;
 	}
 
-	t->neigh_vars[16].data  = &p->retrans_time;
-	t->neigh_vars[17].data  = &p->base_reachable_time;
 
 	if (handler || strategy) {
 		/* RetransTime */
 		t->neigh_vars[3].proc_handler = handler;
 		t->neigh_vars[3].strategy = strategy;
 		t->neigh_vars[3].extra1 = dev;
+		if (!strategy)
+			t->neigh_vars[3].ctl_name = CTL_UNNUMBERED;
 		/* ReachableTime */
 		t->neigh_vars[4].proc_handler = handler;
 		t->neigh_vars[4].strategy = strategy;
 		t->neigh_vars[4].extra1 = dev;
+		if (!strategy)
+			t->neigh_vars[4].ctl_name = CTL_UNNUMBERED;
 		/* RetransTime (in milliseconds)*/
-		t->neigh_vars[16].proc_handler = handler;
-		t->neigh_vars[16].strategy = strategy;
-		t->neigh_vars[16].extra1 = dev;
+		t->neigh_vars[12].proc_handler = handler;
+		t->neigh_vars[12].strategy = strategy;
+		t->neigh_vars[12].extra1 = dev;
+		if (!strategy)
+			t->neigh_vars[12].ctl_name = CTL_UNNUMBERED;
 		/* ReachableTime (in milliseconds) */
-		t->neigh_vars[17].proc_handler = handler;
-		t->neigh_vars[17].strategy = strategy;
-		t->neigh_vars[17].extra1 = dev;
+		t->neigh_vars[13].proc_handler = handler;
+		t->neigh_vars[13].strategy = strategy;
+		t->neigh_vars[13].extra1 = dev;
+		if (!strategy)
+			t->neigh_vars[13].ctl_name = CTL_UNNUMBERED;
 	}
 
 	dev_name = kstrdup(dev_name_source, GFP_KERNEL);