net neighbour: Convert to use register_net_sysctl

Using an ascii path to register_net_sysctl as opposed to the slightly
awkward ctl_path allows for much simpler code.

We no longer need to malloc dev_name to keep it alive the length of our
sysctl register instead we can use a small temporary buffer on the
stack.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 27 deletions

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0c2df3d3cfbf..fadaa819b854 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2799,7 +2799,6 @@ enum {
 static struct neigh_sysctl_table {
         struct ctl_table_header *sysctl_header;
         struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
-        char *dev_name;
 } neigh_sysctl_template __read_mostly = {
         .neigh_vars = {
                 [NEIGH_VAR_MCAST_PROBE] = {
@@ -2925,19 +2924,7 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 {
         struct neigh_sysctl_table *t;
         const char *dev_name_source = NULL;
-
-#define NEIGH_CTL_PATH_ROOT     0
-#define NEIGH_CTL_PATH_PROTO    1
-#define NEIGH_CTL_PATH_NEIGH    2
-#define NEIGH_CTL_PATH_DEV      3
-
-        struct ctl_path neigh_path[] = {
-                { .procname = "net",     },
-                { .procname = "proto",   },
-                { .procname = "neigh",   },
-                { .procname = "default", },
-                { },
-        };
+        char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
 
         t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
         if (!t)
@@ -2965,7 +2952,7 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
                 memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
                        sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
         } else {
-                dev_name_source = neigh_path[NEIGH_CTL_PATH_DEV].procname;
+                dev_name_source = "default";
                 t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1);
                 t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1;
                 t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2;
@@ -2988,23 +2975,16 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].extra1 = dev;
         }
 
-        t->dev_name = kstrdup(dev_name_source, GFP_KERNEL);
-        if (!t->dev_name)
-                goto free;
-
-        neigh_path[NEIGH_CTL_PATH_DEV].procname = t->dev_name;
-        neigh_path[NEIGH_CTL_PATH_PROTO].procname = p_name;
-
+        snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
+                p_name, dev_name_source);
         t->sysctl_header =
-                register_net_sysctl_table(neigh_parms_net(p), neigh_path, t->neigh_vars);
+                register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
         if (!t->sysctl_header)
-                goto free_procname;
+                goto free;
 
         p->sysctl_table = t;
         return 0;
 
-free_procname:
-        kfree(t->dev_name);
 free:
         kfree(t);
 err:
@@ -3018,7 +2998,6 @@ void neigh_sysctl_unregister(struct neigh_parms *p)
                 struct neigh_sysctl_table *t = p->sysctl_table;
                 p->sysctl_table = NULL;
                 unregister_net_sysctl_table(t->sysctl_header);
-                kfree(t->dev_name);
                 kfree(t);
         }
 }