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