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1// SPDX-License-Identifier: GPL-2.0-only2#include <linux/etherdevice.h>3#include <linux/if_macvlan.h>4#include <linux/if_tap.h>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>13#include <linux/sched/signal.h>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 28struct macvtap_dev {29 struct macvlan_dev vlan;30 struct tap_dev tap;31};32 33/*34 * Variables for dealing with macvtaps device numbers.35 */36static dev_t macvtap_major;37 38static const void *macvtap_net_namespace(const struct device *d)39{40 const struct net_device *dev = to_net_dev(d->parent);41 return dev_net(dev);42}43 44static struct class macvtap_class = {45 .name = "macvtap",46 .ns_type = &net_ns_type_operations,47 .namespace = macvtap_net_namespace,48};49static struct cdev macvtap_cdev;50 51#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \52 NETIF_F_TSO6)53 54static 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 62static 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 70static 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 80static int macvtap_newlink(struct net *src_net, struct net_device *dev,81 struct nlattr *tb[], struct nlattr *data[],82 struct netlink_ext_ack *extack)83{84 struct macvtap_dev *vlantap = netdev_priv(dev);85 int err;86 87 INIT_LIST_HEAD(&vlantap->tap.queue_list);88 89 /* Since macvlan supports all offloads by default, make90 * tap support all offloads also.91 */92 vlantap->tap.tap_features = TUN_OFFLOADS;93 94 /* Register callbacks for rx/tx drops accounting and updating95 * net_device features96 */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);102 if (err)103 return err;104 105 /* Don't put anything that may fail after macvlan_common_newlink106 * because we can't undo what it does.107 */108 err = macvlan_common_newlink(src_net, dev, tb, data, extack);109 if (err) {110 netdev_rx_handler_unregister(dev);111 return err;112 }113 114 vlantap->tap.dev = vlantap->vlan.dev;115 116 return 0;117}118 119static void macvtap_dellink(struct net_device *dev,120 struct list_head *head)121{122 struct macvtap_dev *vlantap = netdev_priv(dev);123 124 netdev_rx_handler_unregister(dev);125 tap_del_queues(&vlantap->tap);126 macvlan_dellink(dev, head);127}128 129static void macvtap_setup(struct net_device *dev)130{131 macvlan_common_setup(dev);132 dev->tx_queue_len = TUN_READQ_SIZE;133}134 135static struct net *macvtap_link_net(const struct net_device *dev)136{137 return dev_net(macvlan_dev_real_dev(dev));138}139 140static struct rtnl_link_ops macvtap_link_ops __read_mostly = {141 .kind = "macvtap",142 .setup = macvtap_setup,143 .newlink = macvtap_newlink,144 .dellink = macvtap_dellink,145 .get_link_net = macvtap_link_net,146 .priv_size = sizeof(struct macvtap_dev),147};148 149static 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);153 struct macvtap_dev *vlantap;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);163 vlantap = netdev_priv(dev);164 165 switch (event) {166 case NETDEV_REGISTER:167 /* Create the device node here after the network device has168 * been registered but before register_netdevice has169 * finished running.170 */171 err = tap_get_minor(macvtap_major, &vlantap->tap);172 if (err)173 return notifier_from_errno(err);174 175 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);176 classdev = device_create(&macvtap_class, &dev->dev, devt,177 dev, "%s", tap_name);178 if (IS_ERR(classdev)) {179 tap_free_minor(macvtap_major, &vlantap->tap);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 */189 if (vlantap->tap.minor == 0)190 break;191 sysfs_remove_link(&dev->dev.kobj, tap_name);192 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);193 device_destroy(&macvtap_class, devt);194 tap_free_minor(macvtap_major, &vlantap->tap);195 break;196 case NETDEV_CHANGE_TX_QUEUE_LEN:197 if (tap_queue_resize(&vlantap->tap))198 return NOTIFY_BAD;199 break;200 }201 202 return NOTIFY_DONE;203}204 205static struct notifier_block macvtap_notifier_block __read_mostly = {206 .notifier_call = macvtap_device_event,207};208 209static int __init macvtap_init(void)210{211 int err;212 213 err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",214 THIS_MODULE);215 if (err)216 goto out1;217 218 err = class_register(&macvtap_class);219 if (err)220 goto out2;221 222 err = register_netdevice_notifier(&macvtap_notifier_block);223 if (err)224 goto out3;225 226 err = macvlan_link_register(&macvtap_link_ops);227 if (err)228 goto out4;229 230 return 0;231 232out4:233 unregister_netdevice_notifier(&macvtap_notifier_block);234out3:235 class_unregister(&macvtap_class);236out2:237 tap_destroy_cdev(macvtap_major, &macvtap_cdev);238out1:239 return err;240}241module_init(macvtap_init);242 243static void __exit macvtap_exit(void)244{245 rtnl_link_unregister(&macvtap_link_ops);246 unregister_netdevice_notifier(&macvtap_notifier_block);247 class_unregister(&macvtap_class);248 tap_destroy_cdev(macvtap_major, &macvtap_cdev);249}250module_exit(macvtap_exit);251 252MODULE_ALIAS_RTNL_LINK("macvtap");253MODULE_DESCRIPTION("MAC-VLAN based tap driver");254MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");255MODULE_LICENSE("GPL");256