net: create generic bridge ops

The PF_BRIDGE:RTM_{GET|SET}LINK nlmsg family and type are
currently embedded in the ./net/bridge module. This prohibits
them from being used by other bridging devices. One example
of this being hardware that has embedded bridging components.

In order to use these nlmsg types more generically this patch
adds two net_device_ops hooks. One to set link bridge attributes
and another to dump the current bride attributes.

	ndo_bridge_setlink()
	ndo_bridge_getlink()

CC: Lennert Buytenhek <buytenh@wantstofly.org>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 80 insertions, 0 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 64fe3cca2a4e..a068666b322f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2252,6 +2252,83 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
+static int rtnl_bridge_getlink(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct net_device *dev;
+	int idx = 0;
+	u32 portid = NETLINK_CB(cb->skb).portid;
+	u32 seq = cb->nlh->nlmsg_seq;
+
+	rcu_read_lock();
+	for_each_netdev_rcu(net, dev) {
+		const struct net_device_ops *ops = dev->netdev_ops;
+		struct net_device *master = dev->master;
+
+		if (idx < cb->args[0])
+			continue;
+
+		if (master && master->netdev_ops->ndo_bridge_getlink) {
+			const struct net_device_ops *bops = master->netdev_ops;
+			int err = bops->ndo_bridge_getlink(skb, portid,
+							   seq, dev);
+
+			if (err < 0)
+				break;
+			else
+				idx++;
+		}
+
+		if (ops->ndo_bridge_getlink) {
+			int err = ops->ndo_bridge_getlink(skb, portid,
+							  seq, dev);
+
+			if (err < 0)
+				break;
+			else
+				idx++;
+		}
+	}
+	rcu_read_unlock();
+	cb->args[0] = idx;
+
+	return skb->len;
+}
+
+static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ifinfomsg *ifm;
+	struct net_device *dev;
+	int err = -EINVAL;
+
+	if (nlmsg_len(nlh) < sizeof(*ifm))
+		return -EINVAL;
+
+	ifm = nlmsg_data(nlh);
+	if (ifm->ifi_family != AF_BRIDGE)
+		return -EPFNOSUPPORT;
+
+	dev = __dev_get_by_index(net, ifm->ifi_index);
+	if (!dev) {
+		pr_info("PF_BRIDGE: RTM_SETLINK with unknown ifindex\n");
+		return -ENODEV;
+	}
+
+	if (dev->master && dev->master->netdev_ops->ndo_bridge_setlink) {
+		err = dev->master->netdev_ops->ndo_bridge_setlink(dev, nlh);
+		if (err)
+			goto out;
+	}
+
+	if (dev->netdev_ops->ndo_bridge_setlink)
+		err = dev->netdev_ops->ndo_bridge_setlink(dev, nlh);
+
+out:
+	return err;
+}
+
 /* Protected by RTNL sempahore.  */
 static struct rtattr **rta_buf;
 static int rtattr_max;
@@ -2433,5 +2510,8 @@ void __init rtnetlink_init(void)
 	rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, rtnl_fdb_add, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_DELNEIGH, rtnl_fdb_del, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, rtnl_fdb_dump, NULL);
+
+	rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, rtnl_bridge_getlink, NULL);
+	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
 }