// 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 struct ns_common *macvtap_net_namespace(const struct device *d){	const struct net_device *dev = to_net_dev(d->parent); 	return to_ns_common(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_device *dev,			   struct rtnl_newlink_params *params,			   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(dev, params, 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_DESCRIPTION("MAC-VLAN based tap driver");MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");MODULE_LICENSE("GPL");