[INET]: Merge sys.net.ipv4.ip_forward and sys.net.ipv4.conf.all.forwarding

AFAIS these two entries should do the same thing - change the
forwarding state on ipv4_devconf and on all the devices.

I propose to merge the handlers together using ctl paths.

The inet_forward_change() is static after this and I move
it higher to be closer to other "propagation" helpers and
to avoid diff making patches based on { and } matching :)
i.e. - make them easier to read.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 44 insertions, 88 deletions

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index d83fee2dc643..dd093ea4c489 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -135,7 +135,6 @@ extern struct in_device	*inetdev_by_index(int);
 extern __be32           inet_select_addr(const struct net_device *dev, __be32 dst, int scope);
 extern __be32           inet_confirm_addr(const struct net_device *dev, __be32 dst, __be32 local, int scope);
 extern struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix, __be32 mask);
-extern void             inet_forward_change(void);
 
 static __inline__ int inet_ifa_match(__be32 addr, struct in_ifaddr *ifa)
 {
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 9e2747aab252..d1dc0150647d 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1263,6 +1263,28 @@ static void devinet_copy_dflt_conf(int i)
         read_unlock(&dev_base_lock);
 }
 
+static void inet_forward_change(void)
+{
+        struct net_device *dev;
+        int on = IPV4_DEVCONF_ALL(FORWARDING);
+
+        IPV4_DEVCONF_ALL(ACCEPT_REDIRECTS) = !on;
+        IPV4_DEVCONF_DFLT(FORWARDING) = on;
+
+        read_lock(&dev_base_lock);
+        for_each_netdev(&init_net, dev) {
+                struct in_device *in_dev;
+                rcu_read_lock();
+                in_dev = __in_dev_get_rcu(dev);
+                if (in_dev)
+                        IN_DEV_CONF_SET(in_dev, FORWARDING, on);
+                rcu_read_unlock();
+        }
+        read_unlock(&dev_base_lock);
+
+        rt_cache_flush(0);
+}
+
 static int devinet_conf_proc(ctl_table *ctl, int write,
                              struct file* filp, void __user *buffer,
                              size_t *lenp, loff_t *ppos)
@@ -1332,28 +1354,6 @@ static int devinet_conf_sysctl(ctl_table *table, int __user *name, int nlen,
         return 1;
 }
 
-void inet_forward_change(void)
-{
-        struct net_device *dev;
-        int on = IPV4_DEVCONF_ALL(FORWARDING);
-
-        IPV4_DEVCONF_ALL(ACCEPT_REDIRECTS) = !on;
-        IPV4_DEVCONF_DFLT(FORWARDING) = on;
-
-        read_lock(&dev_base_lock);
-        for_each_netdev(&init_net, dev) {
-                struct in_device *in_dev;
-                rcu_read_lock();
-                in_dev = __in_dev_get_rcu(dev);
-                if (in_dev)
-                        IN_DEV_CONF_SET(in_dev, FORWARDING, on);
-                rcu_read_unlock();
-        }
-        read_unlock(&dev_base_lock);
-
-        rt_cache_flush(0);
-}
-
 static int devinet_sysctl_forward(ctl_table *ctl, int write,
                                   struct file* filp, void __user *buffer,
                                   size_t *lenp, loff_t *ppos)
@@ -1536,6 +1536,27 @@ static void devinet_sysctl_unregister(struct ipv4_devconf *p)
 }
 #endif
 
+static struct ctl_table ctl_forward_entry[] = {
+        {
+                .ctl_name       = NET_IPV4_FORWARD,
+                .procname       = "ip_forward",
+                .data           = &ipv4_devconf.data[
+                                        NET_IPV4_CONF_FORWARDING - 1],
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = devinet_sysctl_forward,
+                .strategy       = devinet_conf_sysctl,
+                .extra1         = &ipv4_devconf,
+        },
+        { },
+};
+
+static __initdata struct ctl_path net_ipv4_path[] = {
+        { .procname = "net", .ctl_name = CTL_NET, },
+        { .procname = "ipv4", .ctl_name = NET_IPV4, },
+        { },
+};
+
 void __init devinet_init(void)
 {
         register_gifconf(PF_INET, inet_gifconf);
@@ -1549,6 +1570,7 @@ void __init devinet_init(void)
                         &ipv4_devconf);
         __devinet_sysctl_register("default", NET_PROTO_CONF_DEFAULT,
                         &ipv4_devconf_dflt);
+        register_sysctl_paths(net_ipv4_path, ctl_forward_entry);
 #endif
 }
 
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index bfd0dec6238d..844f26fab06f 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -27,62 +27,6 @@ static int tcp_retr1_max = 255;
 static int ip_local_port_range_min[] = { 1, 1 };
 static int ip_local_port_range_max[] = { 65535, 65535 };
 
-static
-int ipv4_sysctl_forward(ctl_table *ctl, int write, struct file * filp,
-                        void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-        int val = IPV4_DEVCONF_ALL(FORWARDING);
-        int ret;
-
-        ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
-
-        if (write && IPV4_DEVCONF_ALL(FORWARDING) != val)
-                inet_forward_change();
-
-        return ret;
-}
-
-static int ipv4_sysctl_forward_strategy(ctl_table *table,
-                         int __user *name, int nlen,
-                         void __user *oldval, size_t __user *oldlenp,
-                         void __user *newval, size_t newlen)
-{
-        int *valp = table->data;
-        int new;
-
-        if (!newval || !newlen)
-                return 0;
-
-        if (newlen != sizeof(int))
-                return -EINVAL;
-
-        if (get_user(new, (int __user *)newval))
-                return -EFAULT;
-
-        if (new == *valp)
-                return 0;
-
-        if (oldval && oldlenp) {
-                size_t len;
-
-                if (get_user(len, oldlenp))
-                        return -EFAULT;
-
-                if (len) {
-                        if (len > table->maxlen)
-                                len = table->maxlen;
-                        if (copy_to_user(oldval, valp, len))
-                                return -EFAULT;
-                        if (put_user(len, oldlenp))
-                                return -EFAULT;
-                }
-        }
-
-        *valp = new;
-        inet_forward_change();
-        return 1;
-}
-
 extern seqlock_t sysctl_port_range_lock;
 extern int sysctl_local_port_range[2];
 
@@ -282,15 +226,6 @@ static struct ctl_table ipv4_table[] = {
                 .proc_handler   = &proc_dointvec
         },
         {
-                .ctl_name       = NET_IPV4_FORWARD,
-                .procname       = "ip_forward",
-                .data           = &IPV4_DEVCONF_ALL(FORWARDING),
-                .maxlen         = sizeof(int),
-                .mode           = 0644,
-                .proc_handler   = &ipv4_sysctl_forward,
-                .strategy       = &ipv4_sysctl_forward_strategy
-        },
-        {
                 .ctl_name       = NET_IPV4_DEFAULT_TTL,
                 .procname       = "ip_default_ttl",
                 .data           = &sysctl_ip_default_ttl,