NET: NETROM: Convert NETROM device creation to netlink.HEADax25-bpqether-rework-5.0

Until now, NETROM did create a number of NETROM devices on initialization.
The number could be set by the module parameter nr_ndevs and did default
to 4 while typically only a single one would be used.

With this applied a new version of ip from the iproute2 is required for
NETROM device creation:

  # ip link add type netrom

This will create a NETROM device which will be named netrom0 for the first
device thus consistent with the old naming practice.  Explicit naming
is possible with

  # ip link add name red23 type netrom

which will create a NETROM device named red23.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 107 insertions, 85 deletions

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index cd1dca1f0df7..be99fc7679a2 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -44,8 +44,6 @@
 #include <net/arp.h>
 #include <linux/init.h>
 
-static int nr_ndevs = 4;
-
 int sysctl_netrom_default_path_quality            = NR_DEFAULT_QUAL;
 int sysctl_netrom_obsolescence_count_initialiser  = NR_DEFAULT_OBS;
 int sysctl_netrom_network_ttl_initialiser         = NR_DEFAULT_TTL;
@@ -67,28 +65,6 @@ static DEFINE_SPINLOCK(nr_list_lock);
 static const struct proto_ops nr_proto_ops;
 
 /*
- * NETROM network devices are virtual network devices encapsulating NETROM
- * frames into AX.25 which will be sent through an AX.25 device, so form a
- * special "super class" of normal net devices; split their locks off into a
- * separate class since they always nest.
- */
-static struct lock_class_key nr_netdev_xmit_lock_key;
-static struct lock_class_key nr_netdev_addr_lock_key;
-
-static void nr_set_lockdep_one(struct net_device *dev,
-			       struct netdev_queue *txq,
-			       void *_unused)
-{
-	lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
-}
-
-static void nr_set_lockdep_key(struct net_device *dev)
-{
-	lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
-	netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
-}
-
-/*
  *	Socket removal during an interrupt is now safe.
  */
 static void nr_remove_socket(struct sock *sk)
@@ -1376,8 +1352,6 @@ static struct notifier_block nr_dev_notifier = {
 	.notifier_call	=	nr_device_event,
 };
 
-static struct net_device **dev_nr;
-
 static struct ax25_protocol nr_pid = {
 	.pid	= AX25_P_NETROM,
 	.func	= nr_route_frame
@@ -1389,47 +1363,19 @@ static struct ax25_linkfail nr_linkfail_notifier = {
 
 static int __init nr_proto_init(void)
 {
-	int i;
-	int rc = proto_register(&nr_proto, 0);
+	int err;
 
-	if (rc != 0)
+	err = proto_register(&nr_proto, 0);
+	if (err)
 		goto out;
 
-	if (nr_ndevs > 0x7fffffff/sizeof(struct net_device *)) {
-		printk(KERN_ERR "NET/ROM: nr_proto_init - nr_ndevs parameter to large\n");
-		return -1;
-	}
-
-	dev_nr = kcalloc(nr_ndevs, sizeof(struct net_device *), GFP_KERNEL);
-	if (dev_nr == NULL) {
-		printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device array\n");
-		return -1;
-	}
-
-	for (i = 0; i < nr_ndevs; i++) {
-		char name[IFNAMSIZ];
-		struct net_device *dev;
-
-		sprintf(name, "nr%d", i);
-		dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, nr_setup);
-		if (!dev) {
-			printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device structure\n");
-			goto fail;
-		}
-
-		dev->base_addr = i;
-		if (register_netdev(dev)) {
-			printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register network device\n");
-			free_netdev(dev);
-			goto fail;
-		}
-		nr_set_lockdep_key(dev);
-		dev_nr[i] = dev;
-	}
+	err = rtnl_link_register(&nr_link_ops);
+	if (err)
+		goto out_unregister_proto;
 
 	if (sock_register(&nr_family_ops)) {
 		printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register socket family\n");
-		goto fail;
+		goto out_rtnl_link_unregister;
 	}
 
 	register_netdevice_notifier(&nr_dev_notifier);
@@ -1446,23 +1392,21 @@ static int __init nr_proto_init(void)
 	proc_create_seq("nr", 0444, init_net.proc_net, &nr_info_seqops);
 	proc_create_seq("nr_neigh", 0444, init_net.proc_net, &nr_neigh_seqops);
 	proc_create_seq("nr_nodes", 0444, init_net.proc_net, &nr_node_seqops);
-out:
-	return rc;
-fail:
-	while (--i >= 0) {
-		unregister_netdev(dev_nr[i]);
-		free_netdev(dev_nr[i]);
-	}
-	kfree(dev_nr);
+
+	return 0;
+
+out_rtnl_link_unregister:
+	rtnl_link_unregister(&nr_link_ops);
+
+out_unregister_proto:
 	proto_unregister(&nr_proto);
-	rc = -1;
-	goto out;
+
+out:
+	return err;
 }
 
 static void __exit nr_exit(void)
 {
-	int i;
-
 	remove_proc_entry("nr", init_net.proc_net);
 	remove_proc_entry("nr_neigh", init_net.proc_net);
 	remove_proc_entry("nr_nodes", init_net.proc_net);
@@ -1481,24 +1425,13 @@ static void __exit nr_exit(void)
 
 	sock_unregister(PF_NETROM);
 
-	for (i = 0; i < nr_ndevs; i++) {
-		struct net_device *dev = dev_nr[i];
-		if (dev) {
-			unregister_netdev(dev);
-			free_netdev(dev);
-		}
-	}
-
-	kfree(dev_nr);
+	rtnl_link_unregister(&nr_link_ops);
 	proto_unregister(&nr_proto);
 }
 
 module_init(nr_proto_init);
 module_exit(nr_exit);
 
-module_param(nr_ndevs, int, 0);
-MODULE_PARM_DESC(nr_ndevs, "number of NET/ROM devices");
-
 MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
 MODULE_DESCRIPTION("The amateur radio NET/ROM network and transport layer protocol");
 MODULE_LICENSE("GPL");
diff --git a/net/netrom/nr_dev.c b/net/netrom/nr_dev.c
index 988f542481a8..3dc192317005 100644
--- a/net/netrom/nr_dev.c
+++ b/net/netrom/nr_dev.c
@@ -37,6 +37,28 @@
 #include <net/netrom.h>
 
 /*
+ * NETROM network devices are virtual network devices encapsulating NETROM
+ * frames into AX.25 which will be sent through an AX.25 device, so form a
+ * special "super class" of normal net devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key nr_netdev_xmit_lock_key;
+static struct lock_class_key nr_netdev_addr_lock_key;
+
+static void nr_set_lockdep_one(struct net_device *dev,
+			       struct netdev_queue *txq,
+			       void *_unused)
+{
+	lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
+}
+
+static void nr_set_lockdep_key(struct net_device *dev)
+{
+	lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
+	netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
+}
+
+/*
  *	Only allow IP over NET/ROM frames through if the netrom device is up.
  */
 
@@ -171,6 +193,8 @@ void nr_setup(struct net_device *dev)
 {
 	dev->mtu		= NR_MAX_PACKET_SIZE;
 	dev->netdev_ops		= &nr_netdev_ops;
+	//dev->destructor		= free_netdev;
+
 	dev->header_ops		= &nr_header_ops;
 	dev->hard_header_len	= NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 	dev->addr_len		= AX25_ADDR_LEN;
@@ -179,3 +203,68 @@ void nr_setup(struct net_device *dev)
 	/* New-style flags. */
 	dev->flags		= IFF_NOARP;
 }
+
+static struct device_type nr_type = {
+	.name	= "netrom",
+};
+
+static int nr_validate(struct nlattr *tb[], struct nlattr *data[],
+		       struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != AX25_ADDR_LEN) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid link address");
+			return -EINVAL;
+		}
+
+		if (!ax25_address_is_valid((void *)nla_data(tb[IFLA_ADDRESS]))) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid link address");
+			return -EADDRNOTAVAIL;
+		}
+	}
+
+	return 0;
+}
+
+static int nr_newlink(struct net *src_net, struct net_device *dev,
+		      struct nlattr *tb[], struct nlattr *data[],
+		      struct netlink_ext_ack *extack)
+{
+	int err;
+
+	SET_NETDEV_DEVTYPE(dev, &nr_type);
+
+	err = register_netdevice(dev);
+	if (err)
+		return err;
+
+	nr_set_lockdep_key(dev);
+
+	return 0;
+}
+
+static void nr_dellink(struct net_device *dev, struct list_head *head)
+{
+	unregister_netdevice(dev);
+}
+
+static size_t nr_get_size(const struct net_device *dev)
+{
+	return nla_total_size(AX25_ADDR_LEN) +		/* IFLA_ADDRESS */
+	       0;
+}
+
+struct rtnl_link_ops nr_link_ops __read_mostly = {
+	.kind			= "netrom",
+	.priv_size		= sizeof(struct net_device),
+	.setup			= nr_setup,
+	.maxtype		= 0,
+	.policy			= NULL,
+	.validate		= nr_validate,
+	.newlink		= nr_newlink,
+	.changelink		= NULL,
+	.dellink		= nr_dellink,
+	.get_size		= nr_get_size,
+	.fill_info		= NULL,
+	.get_link_net		= NULL,
+};