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 | .ns_type = &net_ns_type_operations, |
47 | .namespace = macvtap_net_namespace, |
48 | }; |
49 | static 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 | |
54 | static 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 | |
62 | static 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, len: 0, success: 0, multicast: 0); |
68 | } |
69 | |
70 | static 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(dev: vlan->dev); |
78 | } |
79 | |
80 | static 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(list: &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, rx_handler: tap_handle_frame, rx_handler_data: &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 | |
119 | static 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(tap: &vlantap->tap); |
126 | macvlan_dellink(dev, head); |
127 | } |
128 | |
129 | static void macvtap_setup(struct net_device *dev) |
130 | { |
131 | macvlan_common_setup(dev); |
132 | dev->tx_queue_len = TUN_READQ_SIZE; |
133 | } |
134 | |
135 | static struct net *macvtap_link_net(const struct net_device *dev) |
136 | { |
137 | return dev_net(dev: macvlan_dev_real_dev(dev)); |
138 | } |
139 | |
140 | static 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 | |
149 | static 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(info: 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(buf: tap_name, IFNAMSIZ, fmt: "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 has |
168 | * been registered but before register_netdevice has |
169 | * finished running. |
170 | */ |
171 | err = tap_get_minor(major: macvtap_major, tap: &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(cls: &macvtap_class, parent: &dev->dev, devt, |
177 | drvdata: dev, fmt: "%s" , tap_name); |
178 | if (IS_ERR(ptr: classdev)) { |
179 | tap_free_minor(major: macvtap_major, tap: &vlantap->tap); |
180 | return notifier_from_errno(err: PTR_ERR(ptr: classdev)); |
181 | } |
182 | err = sysfs_create_link(kobj: &dev->dev.kobj, target: &classdev->kobj, |
183 | name: 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(kobj: &dev->dev.kobj, name: tap_name); |
192 | devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor); |
193 | device_destroy(cls: &macvtap_class, devt); |
194 | tap_free_minor(major: macvtap_major, tap: &vlantap->tap); |
195 | break; |
196 | case NETDEV_CHANGE_TX_QUEUE_LEN: |
197 | if (tap_queue_resize(tap: &vlantap->tap)) |
198 | return NOTIFY_BAD; |
199 | break; |
200 | } |
201 | |
202 | return NOTIFY_DONE; |
203 | } |
204 | |
205 | static struct notifier_block macvtap_notifier_block __read_mostly = { |
206 | .notifier_call = macvtap_device_event, |
207 | }; |
208 | |
209 | static int __init macvtap_init(void) |
210 | { |
211 | int err; |
212 | |
213 | err = tap_create_cdev(tap_cdev: &macvtap_cdev, tap_major: &macvtap_major, device_name: "macvtap" , |
214 | THIS_MODULE); |
215 | if (err) |
216 | goto out1; |
217 | |
218 | err = class_register(class: &macvtap_class); |
219 | if (err) |
220 | goto out2; |
221 | |
222 | err = register_netdevice_notifier(nb: &macvtap_notifier_block); |
223 | if (err) |
224 | goto out3; |
225 | |
226 | err = macvlan_link_register(ops: &macvtap_link_ops); |
227 | if (err) |
228 | goto out4; |
229 | |
230 | return 0; |
231 | |
232 | out4: |
233 | unregister_netdevice_notifier(nb: &macvtap_notifier_block); |
234 | out3: |
235 | class_unregister(class: &macvtap_class); |
236 | out2: |
237 | tap_destroy_cdev(major: macvtap_major, tap_cdev: &macvtap_cdev); |
238 | out1: |
239 | return err; |
240 | } |
241 | module_init(macvtap_init); |
242 | |
243 | static void __exit macvtap_exit(void) |
244 | { |
245 | rtnl_link_unregister(ops: &macvtap_link_ops); |
246 | unregister_netdevice_notifier(nb: &macvtap_notifier_block); |
247 | class_unregister(class: &macvtap_class); |
248 | tap_destroy_cdev(major: macvtap_major, tap_cdev: &macvtap_cdev); |
249 | } |
250 | module_exit(macvtap_exit); |
251 | |
252 | MODULE_ALIAS_RTNL_LINK("macvtap" ); |
253 | MODULE_DESCRIPTION("MAC-VLAN based tap driver" ); |
254 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>" ); |
255 | MODULE_LICENSE("GPL" ); |
256 | |