[IPV4]: Add default config support after inetdev_init

Previously once inetdev_init has been called on a device any changes
made to ipv4_devconf_dflt would have no effect on that device's
configuration.

This creates a problem since we have moved the point where
inetdev_init is called from when an address is added to where the
device is registered.

This patch is the first half of a set that tries to mimic the old
behaviour while still calling inetdev_init.

It propagates any changes to ipv4_devconf_dflt to those devices that
have not had the corresponding attribute set.

The next patch will forcibly set all values at the point where
inetdev_init was previously called.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 1ef174d83e09de8783d4e5016e7d588a07d687e8..40adefdfe5d13646106153523690bf1e322d29db 100644 (file)
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -3,6 +3,7 @@
 
 #ifdef __KERNEL__
 
+#include <linux/bitmap.h>
 #include <linux/if.h>
 #include <linux/netdevice.h>
 #include <linux/rcupdate.h>
@@ -12,6 +13,7 @@ struct ipv4_devconf
 {
        void    *sysctl;
        int     data[__NET_IPV4_CONF_MAX - 1];
+       DECLARE_BITMAP(state, __NET_IPV4_CONF_MAX - 1);
 };
 
 extern struct ipv4_devconf ipv4_devconf;
@@ -53,6 +55,7 @@ static inline void ipv4_devconf_set(struct in_device *in_dev, int index,
                                    int val)
 {
        index--;
+       set_bit(index, in_dev->cnf.state);
        in_dev->cnf.data[index] = val;
 }
 

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 00940660739fc8897c592289fedc8840f3394aa0..e19734795a7b7cb69dbbaba7ead4f3b1a2dd303f 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1244,6 +1244,91 @@ errout:
 
 #ifdef CONFIG_SYSCTL
 
+static void devinet_copy_dflt_conf(int i)
+{
+       struct net_device *dev;
+
+       read_lock(&dev_base_lock);
+       for_each_netdev(dev) {
+               struct in_device *in_dev;
+               rcu_read_lock();
+               in_dev = __in_dev_get_rcu(dev);
+               if (in_dev && !test_bit(i, in_dev->cnf.state))
+                       in_dev->cnf.data[i] = ipv4_devconf_dflt.data[i];
+               rcu_read_unlock();
+       }
+       read_unlock(&dev_base_lock);
+}
+
+static int devinet_conf_proc(ctl_table *ctl, int write,
+                            struct file* filp, void __user *buffer,
+                            size_t *lenp, loff_t *ppos)
+{
+       int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+
+       if (write) {
+               struct ipv4_devconf *cnf = ctl->extra1;
+               int i = (int *)ctl->data - cnf->data;
+
+               set_bit(i, cnf->state);
+
+               if (cnf == &ipv4_devconf_dflt)
+                       devinet_copy_dflt_conf(i);
+       }
+
+       return ret;
+}
+
+static int devinet_conf_sysctl(ctl_table *table, int __user *name, int nlen,
+                              void __user *oldval, size_t __user *oldlenp,
+                              void __user *newval, size_t newlen)
+{
+       struct ipv4_devconf *cnf;
+       int *valp = table->data;
+       int new;
+       int i;
+
+       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;
+
+       cnf = table->extra1;
+       i = (int *)table->data - cnf->data;
+
+       set_bit(i, cnf->state);
+
+       if (cnf == &ipv4_devconf_dflt)
+               devinet_copy_dflt_conf(i);
+
+       return 1;
+}
+
 void inet_forward_change(void)
 {
        struct net_device *dev;
@@ -1302,40 +1387,13 @@ int ipv4_doint_and_flush_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;
+       int ret = devinet_conf_sysctl(table, name, nlen, oldval, oldlenp,
+                                     newval, newlen);
 
-       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;
-               }
-       }
+       if (ret == 1)
+               rt_cache_flush(0);
 
-       *valp = new;
-       rt_cache_flush(0);
-       return 1;
+       return ret;
 }
 
 
@@ -1349,13 +1407,16 @@ int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
                .mode           = mval, \
                .proc_handler   = proc, \
                .strategy       = sysctl, \
+               .extra1         = &ipv4_devconf, \
        }
 
 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
-       DEVINET_SYSCTL_ENTRY(attr, name, 0644, &proc_dointvec, NULL)
+       DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc, \
+                            devinet_conf_sysctl)
 
 #define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
-       DEVINET_SYSCTL_ENTRY(attr, name, 0444, &proc_dointvec, NULL)
+       DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc, \
+                            devinet_conf_sysctl)
 
 #define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc, sysctl) \
        DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc, sysctl)
@@ -1374,7 +1435,8 @@ static struct devinet_sysctl_table {
 } devinet_sysctl = {
        .devinet_vars = {
                DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
-                                            devinet_sysctl_forward, NULL),
+                                            devinet_sysctl_forward,
+                                            devinet_conf_sysctl),
                DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
 
                DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
@@ -1448,6 +1510,7 @@ static void devinet_sysctl_register(struct in_device *in_dev,
                return;
        for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
                t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
+               t->devinet_vars[i].extra1 = p;
        }
 
        if (dev) {