net ipv6: Convert addrconf 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/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4a839836e59c4d129496c7a2d9d2facdeb94faa4..e3b3421f8dadb036450b2eb54f01ff2193c88e0a 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4365,7 +4365,6 @@ static struct addrconf_sysctl_table
 {
        struct ctl_table_header *sysctl_header;
        ctl_table addrconf_vars[DEVCONF_MAX+1];
-       char *dev_name;
 } addrconf_sysctl __read_mostly = {
        .sysctl_header = NULL,
        .addrconf_vars = {
@@ -4594,17 +4593,7 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 {
        int i;
        struct addrconf_sysctl_table *t;
-
-#define ADDRCONF_CTL_PATH_DEV  3
-
-       struct ctl_path addrconf_ctl_path[] = {
-               { .procname = "net", },
-               { .procname = "ipv6", },
-               { .procname = "conf", },
-               { /* to be set */ },
-               { },
-       };
-
+       char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
 
        t = kmemdup(&addrconf_sysctl, sizeof(*t), GFP_KERNEL);
        if (t == NULL)
@@ -4616,27 +4605,15 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
                t->addrconf_vars[i].extra2 = net;
        }
 
-       /*
-        * Make a copy of dev_name, because '.procname' is regarded as const
-        * by sysctl and we wouldn't want anyone to change it under our feet
-        * (see SIOCSIFNAME).
-        */
-       t->dev_name = kstrdup(dev_name, GFP_KERNEL);
-       if (!t->dev_name)
-               goto free;
+       snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
 
-       addrconf_ctl_path[ADDRCONF_CTL_PATH_DEV].procname = t->dev_name;
-
-       t->sysctl_header = register_net_sysctl_table(net, addrconf_ctl_path,
-                       t->addrconf_vars);
+       t->sysctl_header = register_net_sysctl(net, path, t->addrconf_vars);
        if (t->sysctl_header == NULL)
-               goto free_procname;
+               goto free;
 
        p->sysctl = t;
        return 0;
 
-free_procname:
-       kfree(t->dev_name);
 free:
        kfree(t);
 out:
@@ -4653,7 +4630,6 @@ static void __addrconf_sysctl_unregister(struct ipv6_devconf *p)
        t = p->sysctl;
        p->sysctl = NULL;
        unregister_net_sysctl_table(t->sysctl_header);
-       kfree(t->dev_name);
        kfree(t);
 }