net: device name allocation cleanups

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index c128af708ebf9911b0152a5b3f78c27231451023..9977288583b88707a8847100fcded81e21b2f7e8 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -893,7 +893,8 @@ static int __dev_alloc_name(struct net *net, const char *name, char *buf)
                free_page((unsigned long) inuse);
        }
 
-       snprintf(buf, IFNAMSIZ, name, i);
+       if (buf != name)
+               snprintf(buf, IFNAMSIZ, name, i);
        if (!__dev_get_by_name(net, buf))
                return i;
 
@@ -933,6 +934,21 @@ int dev_alloc_name(struct net_device *dev, const char *name)
 }
 EXPORT_SYMBOL(dev_alloc_name);
 
+static int dev_get_valid_name(struct net *net, const char *name, char *buf,
+                             bool fmt)
+{
+       if (!dev_valid_name(name))
+               return -EINVAL;
+
+       if (fmt && strchr(name, '%'))
+               return __dev_alloc_name(net, name, buf);
+       else if (__dev_get_by_name(net, name))
+               return -EEXIST;
+       else if (buf != name)
+               strlcpy(buf, name, IFNAMSIZ);
+
+       return 0;
+}
 
 /**
  *     dev_change_name - change name of a device
@@ -956,22 +972,14 @@ int dev_change_name(struct net_device *dev, const char *newname)
        if (dev->flags & IFF_UP)
                return -EBUSY;
 
-       if (!dev_valid_name(newname))
-               return -EINVAL;
-
        if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
                return 0;
 
        memcpy(oldname, dev->name, IFNAMSIZ);
 
-       if (strchr(newname, '%')) {
-               err = dev_alloc_name(dev, newname);
-               if (err < 0)
-                       return err;
-       } else if (__dev_get_by_name(net, newname))
-               return -EEXIST;
-       else
-               strlcpy(dev->name, newname, IFNAMSIZ);
+       err = dev_get_valid_name(net, newname, dev->name, 1);
+       if (err < 0)
+               return err;
 
 rollback:
        /* For now only devices in the initial network namespace
@@ -4883,8 +4891,6 @@ EXPORT_SYMBOL(netdev_fix_features);
 
 int register_netdevice(struct net_device *dev)
 {
-       struct hlist_head *head;
-       struct hlist_node *p;
        int ret;
        struct net *net = dev_net(dev);
 
@@ -4913,26 +4919,14 @@ int register_netdevice(struct net_device *dev)
                }
        }
 
-       if (!dev_valid_name(dev->name)) {
-               ret = -EINVAL;
+       ret = dev_get_valid_name(net, dev->name, dev->name, 0);
+       if (ret)
                goto err_uninit;
-       }
 
        dev->ifindex = dev_new_index(net);
        if (dev->iflink == -1)
                dev->iflink = dev->ifindex;
 
-       /* Check for existence of name */
-       head = dev_name_hash(net, dev->name);
-       hlist_for_each(p, head) {
-               struct net_device *d
-                       = hlist_entry(p, struct net_device, name_hlist);
-               if (!strncmp(d->name, dev->name, IFNAMSIZ)) {
-                       ret = -EEXIST;
-                       goto err_uninit;
-               }
-       }
-
        /* Fix illegal checksum combinations */
        if ((dev->features & NETIF_F_HW_CSUM) &&
            (dev->features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
@@ -5460,8 +5454,6 @@ EXPORT_SYMBOL(unregister_netdev);
 
 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
 {
-       char buf[IFNAMSIZ];
-       const char *destname;
        int err;
 
        ASSERT_RTNL();
@@ -5494,20 +5486,11 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
         * we can use it in the destination network namespace.
         */
        err = -EEXIST;
-       destname = dev->name;
-       if (__dev_get_by_name(net, destname)) {
+       if (__dev_get_by_name(net, dev->name)) {
                /* We get here if we can't use the current device name */
                if (!pat)
                        goto out;
-               if (!dev_valid_name(pat))
-                       goto out;
-               if (strchr(pat, '%')) {
-                       if (__dev_alloc_name(net, pat, buf) < 0)
-                               goto out;
-                       destname = buf;
-               } else
-                       destname = pat;
-               if (__dev_get_by_name(net, destname))
+               if (dev_get_valid_name(net, pat, dev->name, 1))
                        goto out;
        }
 
@@ -5544,10 +5527,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
        /* Actually switch the network namespace */
        dev_net_set(dev, net);
 
-       /* Assign the new device name */
-       if (destname != dev->name)
-               strcpy(dev->name, destname);
-
        /* If there is an ifindex conflict assign a new one */
        if (__dev_get_by_index(net, dev->ifindex)) {
                int iflink = (dev->iflink == dev->ifindex);