diff options
Diffstat (limited to 'drivers/net/macvtap.c')
| -rw-r--r-- | drivers/net/macvtap.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c new file mode 100644 index 000000000..d1f435788 --- /dev/null +++ b/drivers/net/macvtap.c @@ -0,0 +1,255 @@ +// 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(struct device *d) +{ + 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"); |