[linux-block.git] / drivers / net / macvtap.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/etherdevice.h>
#include <linux/if_macvlan.h>
#include <linux/if_tap.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
#include <linux/compat.h>
#include <linux/if_tun.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/cache.h>
#include <linux/sched/signal.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/fs.h>
#include <linux/uio.h>

#include <net/net_namespace.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <linux/virtio_net.h>
#include <linux/skb_array.h>

struct macvtap_dev {
	struct macvlan_dev vlan;
	struct tap_dev    tap;
};

/*
 * Variables for dealing with macvtaps device numbers.
 */
static dev_t macvtap_major;

static const void *macvtap_net_namespace(const struct device *d)
{
	const struct net_device *dev = to_net_dev(d->parent);
	return dev_net(dev);
}

static struct class macvtap_class = {
	.name = "macvtap",
	.owner = THIS_MODULE,
	.ns_type = &net_ns_type_operations,
	.namespace = macvtap_net_namespace,
};
static struct cdev macvtap_cdev;

#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
		      NETIF_F_TSO6)

static void macvtap_count_tx_dropped(struct tap_dev *tap)
{
	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	struct macvlan_dev *vlan = &vlantap->vlan;

	this_cpu_inc(vlan->pcpu_stats->tx_dropped);
}

static void macvtap_count_rx_dropped(struct tap_dev *tap)
{
	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	struct macvlan_dev *vlan = &vlantap->vlan;

	macvlan_count_rx(vlan, 0, 0, 0);
}

static void macvtap_update_features(struct tap_dev *tap,
				    netdev_features_t features)
{
	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	struct macvlan_dev *vlan = &vlantap->vlan;

	vlan->set_features = features;
	netdev_update_features(vlan->dev);
}

static int macvtap_newlink(struct net *src_net, struct net_device *dev,
			   struct nlattr *tb[], struct nlattr *data[],
			   struct netlink_ext_ack *extack)
{
	struct macvtap_dev *vlantap = netdev_priv(dev);
	int err;

	INIT_LIST_HEAD(&vlantap->tap.queue_list);

	/* Since macvlan supports all offloads by default, make
	 * tap support all offloads also.
	 */
	vlantap->tap.tap_features = TUN_OFFLOADS;

	/* Register callbacks for rx/tx drops accounting and updating
	 * net_device features
	 */
	vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped;
	vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped;
	vlantap->tap.update_features  = macvtap_update_features;

	err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
	if (err)
		return err;

	/* Don't put anything that may fail after macvlan_common_newlink
	 * because we can't undo what it does.
	 */
	err = macvlan_common_newlink(src_net, dev, tb, data, extack);
	if (err) {
		netdev_rx_handler_unregister(dev);
		return err;
	}

	vlantap->tap.dev = vlantap->vlan.dev;

	return 0;
}

static void macvtap_dellink(struct net_device *dev,
			    struct list_head *head)
{
	struct macvtap_dev *vlantap = netdev_priv(dev);

	netdev_rx_handler_unregister(dev);
	tap_del_queues(&vlantap->tap);
	macvlan_dellink(dev, head);
}

static void macvtap_setup(struct net_device *dev)
{
	macvlan_common_setup(dev);
	dev->tx_queue_len = TUN_READQ_SIZE;
}

static struct net *macvtap_link_net(const struct net_device *dev)
{
	return dev_net(macvlan_dev_real_dev(dev));
}

static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
	.kind		= "macvtap",
	.setup		= macvtap_setup,
	.newlink	= macvtap_newlink,
	.dellink	= macvtap_dellink,
	.get_link_net	= macvtap_link_net,
	.priv_size      = sizeof(struct macvtap_dev),
};

static int macvtap_device_event(struct notifier_block *unused,
				unsigned long event, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	struct macvtap_dev *vlantap;
	struct device *classdev;
	dev_t devt;
	int err;
	char tap_name[IFNAMSIZ];

	if (dev->rtnl_link_ops != &macvtap_link_ops)
		return NOTIFY_DONE;

	snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
	vlantap = netdev_priv(dev);

	switch (event) {
	case NETDEV_REGISTER:
		/* Create the device node here after the network device has
		 * been registered but before register_netdevice has
		 * finished running.
		 */
		err = tap_get_minor(macvtap_major, &vlantap->tap);
		if (err)
			return notifier_from_errno(err);

		devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
		classdev = device_create(&macvtap_class, &dev->dev, devt,
					 dev, "%s", tap_name);
		if (IS_ERR(classdev)) {
			tap_free_minor(macvtap_major, &vlantap->tap);
			return notifier_from_errno(PTR_ERR(classdev));
		}
		err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
					tap_name);
		if (err)
			return notifier_from_errno(err);
		break;
	case NETDEV_UNREGISTER:
		/* vlan->minor == 0 if NETDEV_REGISTER above failed */
		if (vlantap->tap.minor == 0)
			break;
		sysfs_remove_link(&dev->dev.kobj, tap_name);
		devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
		device_destroy(&macvtap_class, devt);
		tap_free_minor(macvtap_major, &vlantap->tap);
		break;
	case NETDEV_CHANGE_TX_QUEUE_LEN:
		if (tap_queue_resize(&vlantap->tap))
			return NOTIFY_BAD;
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block macvtap_notifier_block __read_mostly = {
	.notifier_call	= macvtap_device_event,
};

static int __init macvtap_init(void)
{
	int err;

	err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
			      THIS_MODULE);
	if (err)
		goto out1;

	err = class_register(&macvtap_class);
	if (err)
		goto out2;

	err = register_netdevice_notifier(&macvtap_notifier_block);
	if (err)
		goto out3;

	err = macvlan_link_register(&macvtap_link_ops);
	if (err)
		goto out4;

	return 0;

out4:
	unregister_netdevice_notifier(&macvtap_notifier_block);
out3:
	class_unregister(&macvtap_class);
out2:
	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
out1:
	return err;
}
module_init(macvtap_init);

static void __exit macvtap_exit(void)
{
	rtnl_link_unregister(&macvtap_link_ops);
	unregister_netdevice_notifier(&macvtap_notifier_block);
	class_unregister(&macvtap_class);
	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
}
module_exit(macvtap_exit);

MODULE_ALIAS_RTNL_LINK("macvtap");
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
a8e04698 SG	2	#include <linux/etherdevice.h>
a8e04698 SG	3	#include <linux/if_macvlan.h>
635b8c8e	4	#include <linux/if_tap.h>
a8e04698 SG	5	#include <linux/if_vlan.h>
	6	#include <linux/interrupt.h>
	7	#include <linux/nsproxy.h>
	8	#include <linux/compat.h>
	9	#include <linux/if_tun.h>
	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
	12	#include <linux/cache.h>
174cd4b1	13	#include <linux/sched/signal.h>
a8e04698 SG	14	#include <linux/types.h>
	15	#include <linux/slab.h>
	16	#include <linux/wait.h>
	17	#include <linux/cdev.h>
	18	#include <linux/idr.h>
	19	#include <linux/fs.h>
	20	#include <linux/uio.h>
	21
	22	#include <net/net_namespace.h>
	23	#include <net/rtnetlink.h>
	24	#include <net/sock.h>
	25	#include <linux/virtio_net.h>
	26	#include <linux/skb_array.h>
	27
6fe3faf8 SG	28	struct macvtap_dev {
	29	struct macvlan_dev vlan;
	30	struct tap_dev tap;
	31	};
	32
a8e04698 SG	33	/*
	34	* Variables for dealing with macvtaps device numbers.
	35	*/
	36	static dev_t macvtap_major;
a8e04698	37
fa627348	38	static const void macvtap_net_namespace(const struct device d)
a8e04698	39	{
fa627348	40	const struct net_device *dev = to_net_dev(d->parent);
a8e04698 SG	41	return dev_net(dev);
	42	}
	43
	44	static struct class macvtap_class = {
	45	.name = "macvtap",
	46	.owner = THIS_MODULE,
	47	.ns_type = &net_ns_type_operations,
	48	.namespace = macvtap_net_namespace,
	49	};
	50	static struct cdev macvtap_cdev;
	51
	52	#define TUN_OFFLOADS (NETIF_F_HW_CSUM \| NETIF_F_TSO_ECN \| NETIF_F_TSO \| \
fb652fdf	53	NETIF_F_TSO6)
a8e04698	54
6fe3faf8 SG	55	static void macvtap_count_tx_dropped(struct tap_dev *tap)
	56	{
	57	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	58	struct macvlan_dev *vlan = &vlantap->vlan;
	59
	60	this_cpu_inc(vlan->pcpu_stats->tx_dropped);
	61	}
	62
	63	static void macvtap_count_rx_dropped(struct tap_dev *tap)
	64	{
	65	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	66	struct macvlan_dev *vlan = &vlantap->vlan;
	67
	68	macvlan_count_rx(vlan, 0, 0, 0);
	69	}
	70
	71	static void macvtap_update_features(struct tap_dev *tap,
	72	netdev_features_t features)
	73	{
	74	struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
	75	struct macvlan_dev *vlan = &vlantap->vlan;
	76
	77	vlan->set_features = features;
	78	netdev_update_features(vlan->dev);
	79	}
	80
7a3f4a18 MS	81	static int macvtap_newlink(struct net src_net, struct net_device dev,
	82	struct nlattr tb[], struct nlattr data[],
	83	struct netlink_ext_ack *extack)
a8e04698	84	{
6fe3faf8	85	struct macvtap_dev *vlantap = netdev_priv(dev);
a8e04698 SG	86	int err;
a8e04698 SG	87
6fe3faf8	88	INIT_LIST_HEAD(&vlantap->tap.queue_list);
a8e04698 SG	89
	90	/* Since macvlan supports all offloads by default, make
	91	* tap support all offloads also.
	92	*/
6fe3faf8	93	vlantap->tap.tap_features = TUN_OFFLOADS;
a8e04698	94
6fe3faf8 SG	95	/* Register callbacks for rx/tx drops accounting and updating
	96	* net_device features
	97	*/
	98	vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped;
	99	vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped;
	100	vlantap->tap.update_features = macvtap_update_features;
	101
	102	err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
a8e04698 SG	103	if (err)
	104	return err;
	105
	106	/* Don't put anything that may fail after macvlan_common_newlink
	107	* because we can't undo what it does.
	108	*/
42ab19ee	109	err = macvlan_common_newlink(src_net, dev, tb, data, extack);
a8e04698 SG	110	if (err) {
	111	netdev_rx_handler_unregister(dev);
	112	return err;
	113	}
	114
6fe3faf8 SG	115	vlantap->tap.dev = vlantap->vlan.dev;
6fe3faf8 SG	116
a8e04698 SG	117	return 0;
	118	}
	119
	120	static void macvtap_dellink(struct net_device *dev,
	121	struct list_head *head)
	122	{
6fe3faf8 SG	123	struct macvtap_dev *vlantap = netdev_priv(dev);
6fe3faf8 SG	124
a8e04698	125	netdev_rx_handler_unregister(dev);
6fe3faf8	126	tap_del_queues(&vlantap->tap);
a8e04698 SG	127	macvlan_dellink(dev, head);
	128	}
	129
	130	static void macvtap_setup(struct net_device *dev)
	131	{
	132	macvlan_common_setup(dev);
	133	dev->tx_queue_len = TUN_READQ_SIZE;
	134	}
	135
a0219215 SE	136	static struct net macvtap_link_net(const struct net_device dev)
	137	{
	138	return dev_net(macvlan_dev_real_dev(dev));
	139	}
	140
a8e04698 SG	141	static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
	142	.kind = "macvtap",
	143	.setup = macvtap_setup,
	144	.newlink = macvtap_newlink,
	145	.dellink = macvtap_dellink,
a0219215	146	.get_link_net = macvtap_link_net,
6fe3faf8	147	.priv_size = sizeof(struct macvtap_dev),
a8e04698 SG	148	};
	149
	150	static int macvtap_device_event(struct notifier_block *unused,
	151	unsigned long event, void *ptr)
	152	{
	153	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6fe3faf8	154	struct macvtap_dev *vlantap;
a8e04698 SG	155	struct device *classdev;
	156	dev_t devt;
	157	int err;
	158	char tap_name[IFNAMSIZ];
	159
	160	if (dev->rtnl_link_ops != &macvtap_link_ops)
	161	return NOTIFY_DONE;
	162
	163	snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
6fe3faf8	164	vlantap = netdev_priv(dev);
a8e04698 SG	165
	166	switch (event) {
	167	case NETDEV_REGISTER:
	168	/* Create the device node here after the network device has
	169	* been registered but before register_netdevice has
	170	* finished running.
	171	*/
d9f1f61c	172	err = tap_get_minor(macvtap_major, &vlantap->tap);
a8e04698 SG	173	if (err)
	174	return notifier_from_errno(err);
	175
6fe3faf8	176	devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
a8e04698	177	classdev = device_create(&macvtap_class, &dev->dev, devt,
1c5b5b3f	178	dev, "%s", tap_name);
a8e04698	179	if (IS_ERR(classdev)) {
d9f1f61c	180	tap_free_minor(macvtap_major, &vlantap->tap);
a8e04698 SG	181	return notifier_from_errno(PTR_ERR(classdev));
	182	}
	183	err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
	184	tap_name);
	185	if (err)
	186	return notifier_from_errno(err);
	187	break;
	188	case NETDEV_UNREGISTER:
	189	/* vlan->minor == 0 if NETDEV_REGISTER above failed */
6fe3faf8	190	if (vlantap->tap.minor == 0)
a8e04698 SG	191	break;
a8e04698 SG	192	sysfs_remove_link(&dev->dev.kobj, tap_name);
6fe3faf8	193	devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
a8e04698	194	device_destroy(&macvtap_class, devt);
d9f1f61c	195	tap_free_minor(macvtap_major, &vlantap->tap);
a8e04698 SG	196	break;
a8e04698 SG	197	case NETDEV_CHANGE_TX_QUEUE_LEN:
6fe3faf8	198	if (tap_queue_resize(&vlantap->tap))
a8e04698 SG	199	return NOTIFY_BAD;
	200	break;
	201	}
	202
	203	return NOTIFY_DONE;
	204	}
	205
	206	static struct notifier_block macvtap_notifier_block __read_mostly = {
	207	.notifier_call = macvtap_device_event,
	208	};
	209
d57aae2e	210	static int __init macvtap_init(void)
a8e04698 SG	211	{
	212	int err;
	213
dea6e19f GM	214	err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
dea6e19f GM	215	THIS_MODULE);
a8e04698	216	if (err)
ebc05ba7	217	goto out1;
a8e04698 SG	218
	219	err = class_register(&macvtap_class);
	220	if (err)
ebc05ba7	221	goto out2;
a8e04698 SG	222
	223	err = register_netdevice_notifier(&macvtap_notifier_block);
	224	if (err)
ebc05ba7	225	goto out3;
a8e04698 SG	226
	227	err = macvlan_link_register(&macvtap_link_ops);
	228	if (err)
ebc05ba7	229	goto out4;
a8e04698 SG	230
	231	return 0;
	232
a8e04698	233	out4:
ebc05ba7	234	unregister_netdevice_notifier(&macvtap_notifier_block);
a8e04698	235	out3:
ebc05ba7	236	class_unregister(&macvtap_class);
a8e04698	237	out2:
ebc05ba7	238	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
a8e04698 SG	239	out1:
	240	return err;
	241	}
	242	module_init(macvtap_init);
	243
d57aae2e	244	static void __exit macvtap_exit(void)
a8e04698 SG	245	{
	246	rtnl_link_unregister(&macvtap_link_ops);
	247	unregister_netdevice_notifier(&macvtap_notifier_block);
	248	class_unregister(&macvtap_class);
ebc05ba7	249	tap_destroy_cdev(macvtap_major, &macvtap_cdev);
a8e04698 SG	250	}
	251	module_exit(macvtap_exit);
	252
	253	MODULE_ALIAS_RTNL_LINK("macvtap");
	254	MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
	255	MODULE_LICENSE("GPL");