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(const struct device *d)
34{
35	const 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	 .ns_type = &net_ns_type_operations,
42	 .namespace = ipvtap_net_namespace,
43};
44
45struct ipvtap_dev {
46	struct ipvl_dev vlan;
47	struct tap_dev	  tap;
48};
49
50static 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
58static 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
66static 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
76static 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
111static 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
121static 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
128static 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
136static 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
192static struct notifier_block ipvtap_notifier_block __read_mostly = {
193	.notifier_call	= ipvtap_device_event,
194};
195
196static 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
219out4:
220	unregister_netdevice_notifier(&ipvtap_notifier_block);
221out3:
222	class_unregister(&ipvtap_class);
223out2:
224	tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
225out1:
226	return err;
227}
228module_init(ipvtap_init);
229
230static 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}
237module_exit(ipvtap_exit);
238MODULE_ALIAS_RTNL_LINK("ipvtap");
239MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>");
240MODULE_DESCRIPTION("IP-VLAN based tap driver");
241MODULE_LICENSE("GPL");
242