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