bridge: allow creating bridge devices with netlink

Add netlink device ops to allow creating bridge device via netlink.
This works in a manner similar to vlan, macvlan and bonding.

Example:
  # ip link add link dev br0 type bridge
  # ip link del dev br0

The change required rearranging initializtion code to deal with
being called by create link. Most of the initialization happens
in br_dev_setup, but allocation of stats is done in ndo_init callback
to deal with allocation failure. Sysfs setup has to wait until
after the network device kobject is registered.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 101 insertions, 87 deletions

diff --git a/net/bridge/br.c b/net/bridge/br.c
index 84bbb82599b2..f20c4fd915a8 100644
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -104,3 +104,4 @@ module_init(br_init)
 module_exit(br_deinit)
 MODULE_LICENSE("GPL");
 MODULE_VERSION(BR_VERSION);
+MODULE_ALIAS_RTNL_LINK("bridge");
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 21e5901186ea..45cfd54b06d3 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -74,6 +74,17 @@ out:
         return NETDEV_TX_OK;
 }
 
+static int br_dev_init(struct net_device *dev)
+{
+        struct net_bridge *br = netdev_priv(dev);
+
+        br->stats = alloc_percpu(struct br_cpu_netstats);
+        if (!br->stats)
+                return -ENOMEM;
+
+        return 0;
+}
+
 static int br_dev_open(struct net_device *dev)
 {
         struct net_bridge *br = netdev_priv(dev);
@@ -334,6 +345,7 @@ static const struct ethtool_ops br_ethtool_ops = {
 static const struct net_device_ops br_netdev_ops = {
         .ndo_open                = br_dev_open,
         .ndo_stop                = br_dev_stop,
+        .ndo_init                = br_dev_init,
         .ndo_start_xmit          = br_dev_xmit,
         .ndo_get_stats64         = br_get_stats64,
         .ndo_set_mac_address     = br_set_mac_address,
@@ -357,18 +369,47 @@ static void br_dev_free(struct net_device *dev)
         free_netdev(dev);
 }
 
+static struct device_type br_type = {
+        .name   = "bridge",
+};
+
 void br_dev_setup(struct net_device *dev)
 {
+        struct net_bridge *br = netdev_priv(dev);
+
         random_ether_addr(dev->dev_addr);
         ether_setup(dev);
 
         dev->netdev_ops = &br_netdev_ops;
         dev->destructor = br_dev_free;
         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
+        SET_NETDEV_DEVTYPE(dev, &br_type);
         dev->tx_queue_len = 0;
         dev->priv_flags = IFF_EBRIDGE;
 
         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO | NETIF_F_HW_VLAN_TX;
+
+        br->dev = dev;
+        spin_lock_init(&br->lock);
+        INIT_LIST_HEAD(&br->port_list);
+        spin_lock_init(&br->hash_lock);
+
+        br->bridge_id.prio[0] = 0x80;
+        br->bridge_id.prio[1] = 0x00;
+
+        memcpy(br->group_addr, br_group_address, ETH_ALEN);
+
+        br->feature_mask = dev->features;
+        br->stp_enabled = BR_NO_STP;
+        br->designated_root = br->bridge_id;
+        br->bridge_max_age = br->max_age = 20 * HZ;
+        br->bridge_hello_time = br->hello_time = 2 * HZ;
+        br->bridge_forward_delay = br->forward_delay = 15 * HZ;
+        br->ageing_time = 300 * HZ;
+
+        br_netfilter_rtable_init(br);
+        br_stp_timer_init(br);
+        br_multicast_init(br);
 }
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 718b60366dfe..7f5379c593d9 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -175,56 +175,6 @@ static void del_br(struct net_bridge *br, struct list_head *head)
         unregister_netdevice_queue(br->dev, head);
 }
 
-static struct net_device *new_bridge_dev(struct net *net, const char *name)
-{
-        struct net_bridge *br;
-        struct net_device *dev;
-
-        dev = alloc_netdev(sizeof(struct net_bridge), name,
-                           br_dev_setup);
-
-        if (!dev)
-                return NULL;
-        dev_net_set(dev, net);
-
-        br = netdev_priv(dev);
-        br->dev = dev;
-
-        br->stats = alloc_percpu(struct br_cpu_netstats);
-        if (!br->stats) {
-                free_netdev(dev);
-                return NULL;
-        }
-
-        spin_lock_init(&br->lock);
-        INIT_LIST_HEAD(&br->port_list);
-        spin_lock_init(&br->hash_lock);
-
-        br->bridge_id.prio[0] = 0x80;
-        br->bridge_id.prio[1] = 0x00;
-
-        memcpy(br->group_addr, br_group_address, ETH_ALEN);
-
-        br->feature_mask = dev->features;
-        br->stp_enabled = BR_NO_STP;
-        br->designated_root = br->bridge_id;
-        br->root_path_cost = 0;
-        br->root_port = 0;
-        br->bridge_max_age = br->max_age = 20 * HZ;
-        br->bridge_hello_time = br->hello_time = 2 * HZ;
-        br->bridge_forward_delay = br->forward_delay = 15 * HZ;
-        br->topology_change = 0;
-        br->topology_change_detected = 0;
-        br->ageing_time = 300 * HZ;
-
-        br_netfilter_rtable_init(br);
-
-        br_stp_timer_init(br);
-        br_multicast_init(br);
-
-        return dev;
-}
-
 /* find an available port number */
 static int find_portno(struct net_bridge *br)
 {
@@ -277,42 +227,19 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br,
         return p;
 }
 
-static struct device_type br_type = {
-        .name   = "bridge",
-};
-
 int br_add_bridge(struct net *net, const char *name)
 {
         struct net_device *dev;
-        int ret;
 
-        dev = new_bridge_dev(net, name);
+        dev = alloc_netdev(sizeof(struct net_bridge), name,
+                           br_dev_setup);
+
         if (!dev)
                 return -ENOMEM;
 
-        rtnl_lock();
-        if (strchr(dev->name, '%')) {
-                ret = dev_alloc_name(dev, dev->name);
-                if (ret < 0)
-                        goto out_free;
-        }
-
-        SET_NETDEV_DEVTYPE(dev, &br_type);
-
-        ret = register_netdevice(dev);
-        if (ret)
-                goto out_free;
-
-        ret = br_sysfs_addbr(dev);
-        if (ret)
-                unregister_netdevice(dev);
- out:
-        rtnl_unlock();
-        return ret;
+        dev_net_set(dev, net);
 
-out_free:
-        free_netdev(dev);
-        goto out;
+        return register_netdev(dev);
 }
 
 int br_del_bridge(struct net *net, const char *name)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index fb7d5a7478fe..134a2ff6b98b 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -12,9 +12,11 @@
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
+#include <linux/etherdevice.h>
 #include <net/rtnetlink.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
+
 #include "br_private.h"
 
 static inline size_t br_nlmsg_size(void)
@@ -188,24 +190,61 @@ static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
         return 0;
 }
 
+static int br_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+        if (tb[IFLA_ADDRESS]) {
+                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+                        return -EINVAL;
+                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+                        return -EADDRNOTAVAIL;
+        }
+
+        return 0;
+}
+
+static struct rtnl_link_ops br_link_ops __read_mostly = {
+        .kind           = "bridge",
+        .priv_size      = sizeof(struct net_bridge),
+        .setup          = br_dev_setup,
+        .validate       = br_validate,
+};
 
 int __init br_netlink_init(void)
 {
-        if (__rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo))
-                return -ENOBUFS;
-
-        /* Only the first call to __rtnl_register can fail */
-        __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL);
+        int err;
 
-        __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, br_fdb_add, NULL);
-        __rtnl_register(PF_BRIDGE, RTM_DELNEIGH, br_fdb_delete, NULL);
-        __rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, br_fdb_dump);
+        err = rtnl_link_register(&br_link_ops);
+        if (err < 0)
+                goto err1;
+
+        err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo);
+        if (err)
+                goto err2;
+        err = __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL);
+        if (err)
+                goto err3;
+        err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, br_fdb_add, NULL);
+        if (err)
+                goto err3;
+        err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH, br_fdb_delete, NULL);
+        if (err)
+                goto err3;
+        err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, br_fdb_dump);
+        if (err)
+                goto err3;
 
         return 0;
+
+err3:
+        rtnl_unregister_all(PF_BRIDGE);
+err2:
+        rtnl_link_unregister(&br_link_ops);
+err1:
+        return err;
 }
 
 void __exit br_netlink_fini(void)
 {
+        rtnl_link_unregister(&br_link_ops);
         rtnl_unregister_all(PF_BRIDGE);
 }
-
diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 7d337c9b6082..7a03bb975375 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -36,6 +36,12 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
         struct net_bridge *br;
         int err;
 
+        /* register of bridge completed, add sysfs entries */
+        if ((dev->priv_flags && IFF_EBRIDGE) && event == NETDEV_REGISTER) {
+                br_sysfs_addbr(dev);
+                return NOTIFY_DONE;
+        }
+
         /* not a port of a bridge */
         p = br_port_get_rtnl(dev);
         if (!p)