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>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0c2df3d3cfbf4e40c468c796f11d1e8ca3d76619..fadaa819b854fe100d242ff2231e1a47905328ea 100644 (file)
--- 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);
        }
 }