1 // SPDX-License-Identifier: GPL-2.0-only 2 #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 28 struct macvtap_dev { 29 struct macvlan_dev vlan; 30 struct tap_dev tap; 31 }; 32 33 /* 34 * Variables for dealing with macvtaps device numbers. 35 */ 36 static dev_t macvtap_major; 37 38 static 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 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 | \ 53 NETIF_F_TSO6) 54 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 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) 84 { 85 struct macvtap_dev *vlantap = netdev_priv(dev); 86 int err; 87 88 INIT_LIST_HEAD(&vlantap->tap.queue_list); 89 90 /* Since macvlan supports all offloads by default, make 91 * tap support all offloads also. 92 */ 93 vlantap->tap.tap_features = TUN_OFFLOADS; 94 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); 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 */ 109 err = macvlan_common_newlink(src_net, dev, tb, data, extack); 110 if (err) { 111 netdev_rx_handler_unregister(dev); 112 return err; 113 } 114 115 vlantap->tap.dev = vlantap->vlan.dev; 116 117 return 0; 118 } 119 120 static void macvtap_dellink(struct net_device *dev, 121 struct list_head *head) 122 { 123 struct macvtap_dev *vlantap = netdev_priv(dev); 124 125 netdev_rx_handler_unregister(dev); 126 tap_del_queues(&vlantap->tap); 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 } 135 136 static struct net *macvtap_link_net(const struct net_device *dev) 137 { 138 return dev_net(macvlan_dev_real_dev(dev)); 139 } 140 141 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, 146 .get_link_net = macvtap_link_net, 147 .priv_size = sizeof(struct macvtap_dev), 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); 154 struct macvtap_dev *vlantap; 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); 164 vlantap = netdev_priv(dev); 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 */ 172 err = tap_get_minor(macvtap_major, &vlantap->tap); 173 if (err) 174 return notifier_from_errno(err); 175 176 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor); 177 classdev = device_create(&macvtap_class, &dev->dev, devt, 178 dev, "%s", tap_name); 179 if (IS_ERR(classdev)) { 180 tap_free_minor(macvtap_major, &vlantap->tap); 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 */ 190 if (vlantap->tap.minor == 0) 191 break; 192 sysfs_remove_link(&dev->dev.kobj, tap_name); 193 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor); 194 device_destroy(&macvtap_class, devt); 195 tap_free_minor(macvtap_major, &vlantap->tap); 196 break; 197 case NETDEV_CHANGE_TX_QUEUE_LEN: 198 if (tap_queue_resize(&vlantap->tap)) 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 }; 209 210 static int __init macvtap_init(void) 211 { 212 int err; 213 214 err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap", 215 THIS_MODULE); 216 if (err) 217 goto out1; 218 219 err = class_register(&macvtap_class); 220 if (err) 221 goto out2; 222 223 err = register_netdevice_notifier(&macvtap_notifier_block); 224 if (err) 225 goto out3; 226 227 err = macvlan_link_register(&macvtap_link_ops); 228 if (err) 229 goto out4; 230 231 return 0; 232 233 out4: 234 unregister_netdevice_notifier(&macvtap_notifier_block); 235 out3: 236 class_unregister(&macvtap_class); 237 out2: 238 tap_destroy_cdev(macvtap_major, &macvtap_cdev); 239 out1: 240 return err; 241 } 242 module_init(macvtap_init); 243 244 static void __exit macvtap_exit(void) 245 { 246 rtnl_link_unregister(&macvtap_link_ops); 247 unregister_netdevice_notifier(&macvtap_notifier_block); 248 class_unregister(&macvtap_class); 249 tap_destroy_cdev(macvtap_major, &macvtap_cdev); 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"); 256