1#include <linux/etherdevice.h>
2#include <linux/if_macvlan.h>
3#include <linux/if_tap.h>
4#include <linux/if_vlan.h>
5#include <linux/interrupt.h>
6#include <linux/nsproxy.h>
7#include <linux/compat.h>
8#include <linux/if_tun.h>
9#include <linux/module.h>
10#include <linux/skbuff.h>
11#include <linux/cache.h>
12#include <linux/sched/signal.h>
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/wait.h>
16#include <linux/cdev.h>
17#include <linux/idr.h>
18#include <linux/fs.h>
19#include <linux/uio.h>
20
21#include <net/net_namespace.h>
22#include <net/rtnetlink.h>
23#include <net/sock.h>
24#include <linux/virtio_net.h>
25#include <linux/skb_array.h>
26
27struct macvtap_dev {
28 struct macvlan_dev vlan;
29 struct tap_dev tap;
30};
31
32/*
33 * Variables for dealing with macvtaps device numbers.
34 */
35static dev_t macvtap_major;
36
37static const void *macvtap_net_namespace(struct device *d)
38{
39 struct net_device *dev = to_net_dev(d->parent);
40 return dev_net(dev);
41}
42
43static struct class macvtap_class = {
44 .name = "macvtap",
45 .owner = THIS_MODULE,
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, make
90 * tap support all offloads also.
91 */
92 vlantap->tap.tap_features = TUN_OFFLOADS;
93
94 /* Register callbacks for rx/tx drops accounting and updating
95 * net_device features
96 */
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_newlink
106 * 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 rtnl_link_ops macvtap_link_ops __read_mostly = {
136 .kind = "macvtap",
137 .setup = macvtap_setup,
138 .newlink = macvtap_newlink,
139 .dellink = macvtap_dellink,
140 .priv_size = sizeof(struct macvtap_dev),
141};
142
143static int macvtap_device_event(struct notifier_block *unused,
144 unsigned long event, void *ptr)
145{
146 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
147 struct macvtap_dev *vlantap;
148 struct device *classdev;
149 dev_t devt;
150 int err;
151 char tap_name[IFNAMSIZ];
152
153 if (dev->rtnl_link_ops != &macvtap_link_ops)
154 return NOTIFY_DONE;
155
156 snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
157 vlantap = netdev_priv(dev);
158
159 switch (event) {
160 case NETDEV_REGISTER:
161 /* Create the device node here after the network device has
162 * been registered but before register_netdevice has
163 * finished running.
164 */
165 err = tap_get_minor(macvtap_major, &vlantap->tap);
166 if (err)
167 return notifier_from_errno(err);
168
169 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
170 classdev = device_create(&macvtap_class, &dev->dev, devt,
171 dev, tap_name);
172 if (IS_ERR(classdev)) {
173 tap_free_minor(macvtap_major, &vlantap->tap);
174 return notifier_from_errno(PTR_ERR(classdev));
175 }
176 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
177 tap_name);
178 if (err)
179 return notifier_from_errno(err);
180 break;
181 case NETDEV_UNREGISTER:
182 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
183 if (vlantap->tap.minor == 0)
184 break;
185 sysfs_remove_link(&dev->dev.kobj, tap_name);
186 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
187 device_destroy(&macvtap_class, devt);
188 tap_free_minor(macvtap_major, &vlantap->tap);
189 break;
190 case NETDEV_CHANGE_TX_QUEUE_LEN:
191 if (tap_queue_resize(&vlantap->tap))
192 return NOTIFY_BAD;
193 break;
194 }
195
196 return NOTIFY_DONE;
197}
198
199static struct notifier_block macvtap_notifier_block __read_mostly = {
200 .notifier_call = macvtap_device_event,
201};
202
203static int macvtap_init(void)
204{
205 int err;
206
207 err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
208 THIS_MODULE);
209 if (err)
210 goto out1;
211
212 err = class_register(&macvtap_class);
213 if (err)
214 goto out2;
215
216 err = register_netdevice_notifier(&macvtap_notifier_block);
217 if (err)
218 goto out3;
219
220 err = macvlan_link_register(&macvtap_link_ops);
221 if (err)
222 goto out4;
223
224 return 0;
225
226out4:
227 unregister_netdevice_notifier(&macvtap_notifier_block);
228out3:
229 class_unregister(&macvtap_class);
230out2:
231 tap_destroy_cdev(macvtap_major, &macvtap_cdev);
232out1:
233 return err;
234}
235module_init(macvtap_init);
236
237static void macvtap_exit(void)
238{
239 rtnl_link_unregister(&macvtap_link_ops);
240 unregister_netdevice_notifier(&macvtap_notifier_block);
241 class_unregister(&macvtap_class);
242 tap_destroy_cdev(macvtap_major, &macvtap_cdev);
243}
244module_exit(macvtap_exit);
245
246MODULE_ALIAS_RTNL_LINK("macvtap");
247MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
248MODULE_LICENSE("GPL");
249