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>

1 files changed, 48 insertions, 9 deletions

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index fb7d5a7478f..134a2ff6b98 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);
 }
-