[RTNETLINK]: Introduce generic rtnl_create_link().

This routine gets the parsed rtnl attributes and creates a new
link with generic info (IFLA_LINKINFO policy). Its intention
is to help the drivers, that need to create several links at
once (like VETH).

This is nothing but a copy-paste-ed part of rtnl_newlink() function
that is responsible for creation of new device.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 57 insertions, 30 deletions

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 3861c05cdf0f..8218288ab7ee 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -78,6 +78,10 @@ extern void	__rtnl_link_unregister(struct rtnl_link_ops *ops);
 extern int      rtnl_link_register(struct rtnl_link_ops *ops);
 extern void     rtnl_link_unregister(struct rtnl_link_ops *ops);
 
+extern struct net_device *rtnl_create_link(char *ifname,
+                const struct rtnl_link_ops *ops, struct nlattr *tb[]);
+extern const struct nla_policy ifla_policy[IFLA_MAX+1];
+
 #define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
 
 #endif
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2b0b6fac6cef..dca9e80ba574 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -713,7 +713,7 @@ cont:
         return skb->len;
 }
 
-static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
+const struct nla_policy ifla_policy[IFLA_MAX+1] = {
         [IFLA_IFNAME]           = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
         [IFLA_ADDRESS]          = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
         [IFLA_BROADCAST]        = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
@@ -937,6 +937,48 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         return 0;
 }
 
+struct net_device *rtnl_create_link(char *ifname,
+                const struct rtnl_link_ops *ops, struct nlattr *tb[])
+{
+        int err;
+        struct net_device *dev;
+
+        err = -ENOMEM;
+        dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
+        if (!dev)
+                goto err;
+
+        if (strchr(dev->name, '%')) {
+                err = dev_alloc_name(dev, dev->name);
+                if (err < 0)
+                        goto err_free;
+        }
+
+        dev->rtnl_link_ops = ops;
+
+        if (tb[IFLA_MTU])
+                dev->mtu = nla_get_u32(tb[IFLA_MTU]);
+        if (tb[IFLA_ADDRESS])
+                memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
+                                nla_len(tb[IFLA_ADDRESS]));
+        if (tb[IFLA_BROADCAST])
+                memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
+                                nla_len(tb[IFLA_BROADCAST]));
+        if (tb[IFLA_TXQLEN])
+                dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
+        if (tb[IFLA_OPERSTATE])
+                set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
+        if (tb[IFLA_LINKMODE])
+                dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
+
+        return dev;
+
+err_free:
+        free_netdev(dev);
+err:
+        return ERR_PTR(err);
+}
+
 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
         const struct rtnl_link_ops *ops;
@@ -1049,38 +1091,17 @@ replay:
 
                 if (!ifname[0])
                         snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
-                dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
-                if (!dev)
-                        return -ENOMEM;
-
-                if (strchr(dev->name, '%')) {
-                        err = dev_alloc_name(dev, dev->name);
-                        if (err < 0)
-                                goto err_free;
-                }
-                dev->rtnl_link_ops = ops;
-
-                if (tb[IFLA_MTU])
-                        dev->mtu = nla_get_u32(tb[IFLA_MTU]);
-                if (tb[IFLA_ADDRESS])
-                        memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
-                               nla_len(tb[IFLA_ADDRESS]));
-                if (tb[IFLA_BROADCAST])
-                        memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
-                               nla_len(tb[IFLA_BROADCAST]));
-                if (tb[IFLA_TXQLEN])
-                        dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
-                if (tb[IFLA_OPERSTATE])
-                        set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
-                if (tb[IFLA_LINKMODE])
-                        dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
-
-                if (ops->newlink)
+
+                dev = rtnl_create_link(ifname, ops, tb);
+
+                if (IS_ERR(dev))
+                        err = PTR_ERR(dev);
+                else if (ops->newlink)
                         err = ops->newlink(dev, tb, data);
                 else
                         err = register_netdevice(dev);
-err_free:
-                if (err < 0)
+
+                if (err < 0 && !IS_ERR(dev))
                         free_netdev(dev);
                 return err;
         }
@@ -1329,3 +1350,5 @@ EXPORT_SYMBOL(rtnl_unlock);
 EXPORT_SYMBOL(rtnl_unicast);
 EXPORT_SYMBOL(rtnl_notify);
 EXPORT_SYMBOL(rtnl_set_sk_err);
+EXPORT_SYMBOL(rtnl_create_link);
+EXPORT_SYMBOL(ifla_policy);