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>

2 files changed, 49 insertions, 50 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);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 6cc33dc83d1c..20cfc90d5597 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1658,30 +1658,26 @@ int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * f
         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);