Merge tag 'media/v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[linux-2.6-microblaze.git] / drivers / net / macvtap.c
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(struct device *d)
39 {
40         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 rtnl_link_ops macvtap_link_ops __read_mostly = {
137         .kind           = "macvtap",
138         .setup          = macvtap_setup,
139         .newlink        = macvtap_newlink,
140         .dellink        = macvtap_dellink,
141         .priv_size      = sizeof(struct macvtap_dev),
142 };
143
144 static int macvtap_device_event(struct notifier_block *unused,
145                                 unsigned long event, void *ptr)
146 {
147         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
148         struct macvtap_dev *vlantap;
149         struct device *classdev;
150         dev_t devt;
151         int err;
152         char tap_name[IFNAMSIZ];
153
154         if (dev->rtnl_link_ops != &macvtap_link_ops)
155                 return NOTIFY_DONE;
156
157         snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
158         vlantap = netdev_priv(dev);
159
160         switch (event) {
161         case NETDEV_REGISTER:
162                 /* Create the device node here after the network device has
163                  * been registered but before register_netdevice has
164                  * finished running.
165                  */
166                 err = tap_get_minor(macvtap_major, &vlantap->tap);
167                 if (err)
168                         return notifier_from_errno(err);
169
170                 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
171                 classdev = device_create(&macvtap_class, &dev->dev, devt,
172                                          dev, tap_name);
173                 if (IS_ERR(classdev)) {
174                         tap_free_minor(macvtap_major, &vlantap->tap);
175                         return notifier_from_errno(PTR_ERR(classdev));
176                 }
177                 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
178                                         tap_name);
179                 if (err)
180                         return notifier_from_errno(err);
181                 break;
182         case NETDEV_UNREGISTER:
183                 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
184                 if (vlantap->tap.minor == 0)
185                         break;
186                 sysfs_remove_link(&dev->dev.kobj, tap_name);
187                 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
188                 device_destroy(&macvtap_class, devt);
189                 tap_free_minor(macvtap_major, &vlantap->tap);
190                 break;
191         case NETDEV_CHANGE_TX_QUEUE_LEN:
192                 if (tap_queue_resize(&vlantap->tap))
193                         return NOTIFY_BAD;
194                 break;
195         }
196
197         return NOTIFY_DONE;
198 }
199
200 static struct notifier_block macvtap_notifier_block __read_mostly = {
201         .notifier_call  = macvtap_device_event,
202 };
203
204 static int macvtap_init(void)
205 {
206         int err;
207
208         err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
209                               THIS_MODULE);
210         if (err)
211                 goto out1;
212
213         err = class_register(&macvtap_class);
214         if (err)
215                 goto out2;
216
217         err = register_netdevice_notifier(&macvtap_notifier_block);
218         if (err)
219                 goto out3;
220
221         err = macvlan_link_register(&macvtap_link_ops);
222         if (err)
223                 goto out4;
224
225         return 0;
226
227 out4:
228         unregister_netdevice_notifier(&macvtap_notifier_block);
229 out3:
230         class_unregister(&macvtap_class);
231 out2:
232         tap_destroy_cdev(macvtap_major, &macvtap_cdev);
233 out1:
234         return err;
235 }
236 module_init(macvtap_init);
237
238 static void macvtap_exit(void)
239 {
240         rtnl_link_unregister(&macvtap_link_ops);
241         unregister_netdevice_notifier(&macvtap_notifier_block);
242         class_unregister(&macvtap_class);
243         tap_destroy_cdev(macvtap_major, &macvtap_cdev);
244 }
245 module_exit(macvtap_exit);
246
247 MODULE_ALIAS_RTNL_LINK("macvtap");
248 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
249 MODULE_LICENSE("GPL");