xref: /openbmc/linux/drivers/net/ipvlan/ipvtap.c (revision feac8c8b)
1 #include <linux/etherdevice.h>
2 #include "ipvlan.h"
3 #include <linux/if_vlan.h>
4 #include <linux/if_tap.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.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 
26 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
27 		      NETIF_F_TSO6)
28 
29 static dev_t ipvtap_major;
30 static struct cdev ipvtap_cdev;
31 
32 static const void *ipvtap_net_namespace(struct device *d)
33 {
34 	struct net_device *dev = to_net_dev(d->parent);
35 	return dev_net(dev);
36 }
37 
38 static struct class ipvtap_class = {
39 	 .name = "ipvtap",
40 	 .owner = THIS_MODULE,
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 
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 
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 
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 
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 
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 
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 
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, 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 
196 static int 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 
230 static void 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_LICENSE("GPL");
241