1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/etherdevice.h>
3 #include "ipvlan.h"
4 #include <linux/if_vlan.h>
5 #include <linux/if_tap.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.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
27 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
28 NETIF_F_TSO6)
29
30 static dev_t ipvtap_major;
31 static struct cdev ipvtap_cdev;
32
ipvtap_net_namespace(const struct device * d)33 static const void *ipvtap_net_namespace(const struct device *d)
34 {
35 const struct net_device *dev = to_net_dev(d->parent);
36 return dev_net(dev);
37 }
38
39 static struct class ipvtap_class = {
40 .name = "ipvtap",
41 .ns_type = &net_ns_type_operations,
42 .namespace = ipvtap_net_namespace,
43 };
44
45 struct ipvtap_dev {
46 struct ipvl_dev vlan;
47 struct tap_dev tap;
48 };
49
ipvtap_count_tx_dropped(struct tap_dev * tap)50 static void ipvtap_count_tx_dropped(struct tap_dev *tap)
51 {
52 struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
53 struct ipvl_dev *vlan = &vlantap->vlan;
54
55 this_cpu_inc(vlan->pcpu_stats->tx_drps);
56 }
57
ipvtap_count_rx_dropped(struct tap_dev * tap)58 static void ipvtap_count_rx_dropped(struct tap_dev *tap)
59 {
60 struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
61 struct ipvl_dev *vlan = &vlantap->vlan;
62
63 ipvlan_count_rx(vlan, 0, 0, 0);
64 }
65
ipvtap_update_features(struct tap_dev * tap,netdev_features_t features)66 static void ipvtap_update_features(struct tap_dev *tap,
67 netdev_features_t features)
68 {
69 struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
70 struct ipvl_dev *vlan = &vlantap->vlan;
71
72 vlan->sfeatures = features;
73 netdev_update_features(vlan->dev);
74 }
75
ipvtap_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)76 static int ipvtap_newlink(struct net *src_net, struct net_device *dev,
77 struct nlattr *tb[], struct nlattr *data[],
78 struct netlink_ext_ack *extack)
79 {
80 struct ipvtap_dev *vlantap = netdev_priv(dev);
81 int err;
82
83 INIT_LIST_HEAD(&vlantap->tap.queue_list);
84
85 /* Since macvlan supports all offloads by default, make
86 * tap support all offloads also.
87 */
88 vlantap->tap.tap_features = TUN_OFFLOADS;
89 vlantap->tap.count_tx_dropped = ipvtap_count_tx_dropped;
90 vlantap->tap.update_features = ipvtap_update_features;
91 vlantap->tap.count_rx_dropped = ipvtap_count_rx_dropped;
92
93 err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
94 if (err)
95 return err;
96
97 /* Don't put anything that may fail after macvlan_common_newlink
98 * because we can't undo what it does.
99 */
100 err = ipvlan_link_new(src_net, dev, tb, data, extack);
101 if (err) {
102 netdev_rx_handler_unregister(dev);
103 return err;
104 }
105
106 vlantap->tap.dev = vlantap->vlan.dev;
107
108 return err;
109 }
110
ipvtap_dellink(struct net_device * dev,struct list_head * head)111 static void ipvtap_dellink(struct net_device *dev,
112 struct list_head *head)
113 {
114 struct ipvtap_dev *vlan = netdev_priv(dev);
115
116 netdev_rx_handler_unregister(dev);
117 tap_del_queues(&vlan->tap);
118 ipvlan_link_delete(dev, head);
119 }
120
ipvtap_setup(struct net_device * dev)121 static void ipvtap_setup(struct net_device *dev)
122 {
123 ipvlan_link_setup(dev);
124 dev->tx_queue_len = TUN_READQ_SIZE;
125 dev->priv_flags &= ~IFF_NO_QUEUE;
126 }
127
128 static struct rtnl_link_ops ipvtap_link_ops __read_mostly = {
129 .kind = "ipvtap",
130 .setup = ipvtap_setup,
131 .newlink = ipvtap_newlink,
132 .dellink = ipvtap_dellink,
133 .priv_size = sizeof(struct ipvtap_dev),
134 };
135
ipvtap_device_event(struct notifier_block * unused,unsigned long event,void * ptr)136 static int ipvtap_device_event(struct notifier_block *unused,
137 unsigned long event, void *ptr)
138 {
139 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
140 struct ipvtap_dev *vlantap;
141 struct device *classdev;
142 dev_t devt;
143 int err;
144 char tap_name[IFNAMSIZ];
145
146 if (dev->rtnl_link_ops != &ipvtap_link_ops)
147 return NOTIFY_DONE;
148
149 snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
150 vlantap = netdev_priv(dev);
151
152 switch (event) {
153 case NETDEV_REGISTER:
154 /* Create the device node here after the network device has
155 * been registered but before register_netdevice has
156 * finished running.
157 */
158 err = tap_get_minor(ipvtap_major, &vlantap->tap);
159 if (err)
160 return notifier_from_errno(err);
161
162 devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
163 classdev = device_create(&ipvtap_class, &dev->dev, devt,
164 dev, "%s", tap_name);
165 if (IS_ERR(classdev)) {
166 tap_free_minor(ipvtap_major, &vlantap->tap);
167 return notifier_from_errno(PTR_ERR(classdev));
168 }
169 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
170 tap_name);
171 if (err)
172 return notifier_from_errno(err);
173 break;
174 case NETDEV_UNREGISTER:
175 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
176 if (vlantap->tap.minor == 0)
177 break;
178 sysfs_remove_link(&dev->dev.kobj, tap_name);
179 devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
180 device_destroy(&ipvtap_class, devt);
181 tap_free_minor(ipvtap_major, &vlantap->tap);
182 break;
183 case NETDEV_CHANGE_TX_QUEUE_LEN:
184 if (tap_queue_resize(&vlantap->tap))
185 return NOTIFY_BAD;
186 break;
187 }
188
189 return NOTIFY_DONE;
190 }
191
192 static struct notifier_block ipvtap_notifier_block __read_mostly = {
193 .notifier_call = ipvtap_device_event,
194 };
195
ipvtap_init(void)196 static int __init ipvtap_init(void)
197 {
198 int err;
199
200 err = tap_create_cdev(&ipvtap_cdev, &ipvtap_major, "ipvtap",
201 THIS_MODULE);
202 if (err)
203 goto out1;
204
205 err = class_register(&ipvtap_class);
206 if (err)
207 goto out2;
208
209 err = register_netdevice_notifier(&ipvtap_notifier_block);
210 if (err)
211 goto out3;
212
213 err = ipvlan_link_register(&ipvtap_link_ops);
214 if (err)
215 goto out4;
216
217 return 0;
218
219 out4:
220 unregister_netdevice_notifier(&ipvtap_notifier_block);
221 out3:
222 class_unregister(&ipvtap_class);
223 out2:
224 tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
225 out1:
226 return err;
227 }
228 module_init(ipvtap_init);
229
ipvtap_exit(void)230 static void __exit ipvtap_exit(void)
231 {
232 rtnl_link_unregister(&ipvtap_link_ops);
233 unregister_netdevice_notifier(&ipvtap_notifier_block);
234 class_unregister(&ipvtap_class);
235 tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
236 }
237 module_exit(ipvtap_exit);
238 MODULE_ALIAS_RTNL_LINK("ipvtap");
239 MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>");
240 MODULE_DESCRIPTION("IP-VLAN based tap driver");
241 MODULE_LICENSE("GPL");
242