xref: /linux/drivers/net/veth.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2) 
1 /*
2  *  drivers/net/veth.c
3  *
4  *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
5  *
6  * Author: Pavel Emelianov <xemul@openvz.org>
7  * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
8  *
9  */
10 
11 #include <linux/netdevice.h>
12 #include <linux/slab.h>
13 #include <linux/ethtool.h>
14 #include <linux/etherdevice.h>
15 #include <linux/u64_stats_sync.h>
16 
17 #include <net/dst.h>
18 #include <net/xfrm.h>
19 #include <linux/veth.h>
20 #include <linux/module.h>
21 
22 #define DRV_NAME	"veth"
23 #define DRV_VERSION	"1.0"
24 
25 #define MIN_MTU 68		/* Min L3 MTU */
26 #define MAX_MTU 65535		/* Max L3 MTU (arbitrary) */
27 
28 struct veth_net_stats {
29 	u64			rx_packets;
30 	u64			tx_packets;
31 	u64			rx_bytes;
32 	u64			tx_bytes;
33 	u64			rx_dropped;
34 	struct u64_stats_sync	syncp;
35 };
36 
37 struct veth_priv {
38 	struct net_device *peer;
39 	struct veth_net_stats __percpu *stats;
40 };
41 
42 /*
43  * ethtool interface
44  */
45 
46 static struct {
47 	const char string[ETH_GSTRING_LEN];
48 } ethtool_stats_keys[] = {
49 	{ "peer_ifindex" },
50 };
51 
52 static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
53 {
54 	cmd->supported		= 0;
55 	cmd->advertising	= 0;
56 	ethtool_cmd_speed_set(cmd, SPEED_10000);
57 	cmd->duplex		= DUPLEX_FULL;
58 	cmd->port		= PORT_TP;
59 	cmd->phy_address	= 0;
60 	cmd->transceiver	= XCVR_INTERNAL;
61 	cmd->autoneg		= AUTONEG_DISABLE;
62 	cmd->maxtxpkt		= 0;
63 	cmd->maxrxpkt		= 0;
64 	return 0;
65 }
66 
67 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
68 {
69 	strcpy(info->driver, DRV_NAME);
70 	strcpy(info->version, DRV_VERSION);
71 	strcpy(info->fw_version, "N/A");
72 }
73 
74 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
75 {
76 	switch(stringset) {
77 	case ETH_SS_STATS:
78 		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
79 		break;
80 	}
81 }
82 
83 static int veth_get_sset_count(struct net_device *dev, int sset)
84 {
85 	switch (sset) {
86 	case ETH_SS_STATS:
87 		return ARRAY_SIZE(ethtool_stats_keys);
88 	default:
89 		return -EOPNOTSUPP;
90 	}
91 }
92 
93 static void veth_get_ethtool_stats(struct net_device *dev,
94 		struct ethtool_stats *stats, u64 *data)
95 {
96 	struct veth_priv *priv;
97 
98 	priv = netdev_priv(dev);
99 	data[0] = priv->peer->ifindex;
100 }
101 
102 static const struct ethtool_ops veth_ethtool_ops = {
103 	.get_settings		= veth_get_settings,
104 	.get_drvinfo		= veth_get_drvinfo,
105 	.get_link		= ethtool_op_get_link,
106 	.get_strings		= veth_get_strings,
107 	.get_sset_count		= veth_get_sset_count,
108 	.get_ethtool_stats	= veth_get_ethtool_stats,
109 };
110 
111 /*
112  * xmit
113  */
114 
115 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
116 {
117 	struct net_device *rcv = NULL;
118 	struct veth_priv *priv, *rcv_priv;
119 	struct veth_net_stats *stats, *rcv_stats;
120 	int length;
121 
122 	priv = netdev_priv(dev);
123 	rcv = priv->peer;
124 	rcv_priv = netdev_priv(rcv);
125 
126 	stats = this_cpu_ptr(priv->stats);
127 	rcv_stats = this_cpu_ptr(rcv_priv->stats);
128 
129 	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
130 	   will cause bad checksum on forwarded packets */
131 	if (skb->ip_summed == CHECKSUM_NONE &&
132 	    rcv->features & NETIF_F_RXCSUM)
133 		skb->ip_summed = CHECKSUM_UNNECESSARY;
134 
135 	length = skb->len;
136 	if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
137 		goto rx_drop;
138 
139 	u64_stats_update_begin(&stats->syncp);
140 	stats->tx_bytes += length;
141 	stats->tx_packets++;
142 	u64_stats_update_end(&stats->syncp);
143 
144 	u64_stats_update_begin(&rcv_stats->syncp);
145 	rcv_stats->rx_bytes += length;
146 	rcv_stats->rx_packets++;
147 	u64_stats_update_end(&rcv_stats->syncp);
148 
149 	return NETDEV_TX_OK;
150 
151 rx_drop:
152 	u64_stats_update_begin(&rcv_stats->syncp);
153 	rcv_stats->rx_dropped++;
154 	u64_stats_update_end(&rcv_stats->syncp);
155 	return NETDEV_TX_OK;
156 }
157 
158 /*
159  * general routines
160  */
161 
162 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
163 						  struct rtnl_link_stats64 *tot)
164 {
165 	struct veth_priv *priv = netdev_priv(dev);
166 	int cpu;
167 
168 	for_each_possible_cpu(cpu) {
169 		struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
170 		u64 rx_packets, rx_bytes, rx_dropped;
171 		u64 tx_packets, tx_bytes;
172 		unsigned int start;
173 
174 		do {
175 			start = u64_stats_fetch_begin_bh(&stats->syncp);
176 			rx_packets = stats->rx_packets;
177 			tx_packets = stats->tx_packets;
178 			rx_bytes = stats->rx_bytes;
179 			tx_bytes = stats->tx_bytes;
180 			rx_dropped = stats->rx_dropped;
181 		} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
182 		tot->rx_packets += rx_packets;
183 		tot->tx_packets += tx_packets;
184 		tot->rx_bytes   += rx_bytes;
185 		tot->tx_bytes   += tx_bytes;
186 		tot->rx_dropped += rx_dropped;
187 	}
188 
189 	return tot;
190 }
191 
192 static int veth_open(struct net_device *dev)
193 {
194 	struct veth_priv *priv;
195 
196 	priv = netdev_priv(dev);
197 	if (priv->peer == NULL)
198 		return -ENOTCONN;
199 
200 	if (priv->peer->flags & IFF_UP) {
201 		netif_carrier_on(dev);
202 		netif_carrier_on(priv->peer);
203 	}
204 	return 0;
205 }
206 
207 static int veth_close(struct net_device *dev)
208 {
209 	struct veth_priv *priv = netdev_priv(dev);
210 
211 	netif_carrier_off(dev);
212 	netif_carrier_off(priv->peer);
213 
214 	return 0;
215 }
216 
217 static int is_valid_veth_mtu(int new_mtu)
218 {
219 	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
220 }
221 
222 static int veth_change_mtu(struct net_device *dev, int new_mtu)
223 {
224 	if (!is_valid_veth_mtu(new_mtu))
225 		return -EINVAL;
226 	dev->mtu = new_mtu;
227 	return 0;
228 }
229 
230 static int veth_dev_init(struct net_device *dev)
231 {
232 	struct veth_net_stats __percpu *stats;
233 	struct veth_priv *priv;
234 
235 	stats = alloc_percpu(struct veth_net_stats);
236 	if (stats == NULL)
237 		return -ENOMEM;
238 
239 	priv = netdev_priv(dev);
240 	priv->stats = stats;
241 	return 0;
242 }
243 
244 static void veth_dev_free(struct net_device *dev)
245 {
246 	struct veth_priv *priv;
247 
248 	priv = netdev_priv(dev);
249 	free_percpu(priv->stats);
250 	free_netdev(dev);
251 }
252 
253 static const struct net_device_ops veth_netdev_ops = {
254 	.ndo_init            = veth_dev_init,
255 	.ndo_open            = veth_open,
256 	.ndo_stop            = veth_close,
257 	.ndo_start_xmit      = veth_xmit,
258 	.ndo_change_mtu      = veth_change_mtu,
259 	.ndo_get_stats64     = veth_get_stats64,
260 	.ndo_set_mac_address = eth_mac_addr,
261 };
262 
263 static void veth_setup(struct net_device *dev)
264 {
265 	ether_setup(dev);
266 
267 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
268 
269 	dev->netdev_ops = &veth_netdev_ops;
270 	dev->ethtool_ops = &veth_ethtool_ops;
271 	dev->features |= NETIF_F_LLTX;
272 	dev->destructor = veth_dev_free;
273 
274 	dev->hw_features = NETIF_F_NO_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
275 }
276 
277 /*
278  * netlink interface
279  */
280 
281 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
282 {
283 	if (tb[IFLA_ADDRESS]) {
284 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
285 			return -EINVAL;
286 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
287 			return -EADDRNOTAVAIL;
288 	}
289 	if (tb[IFLA_MTU]) {
290 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
291 			return -EINVAL;
292 	}
293 	return 0;
294 }
295 
296 static struct rtnl_link_ops veth_link_ops;
297 
298 static int veth_newlink(struct net *src_net, struct net_device *dev,
299 			 struct nlattr *tb[], struct nlattr *data[])
300 {
301 	int err;
302 	struct net_device *peer;
303 	struct veth_priv *priv;
304 	char ifname[IFNAMSIZ];
305 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
306 	struct ifinfomsg *ifmp;
307 	struct net *net;
308 
309 	/*
310 	 * create and register peer first
311 	 */
312 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
313 		struct nlattr *nla_peer;
314 
315 		nla_peer = data[VETH_INFO_PEER];
316 		ifmp = nla_data(nla_peer);
317 		err = nla_parse(peer_tb, IFLA_MAX,
318 				nla_data(nla_peer) + sizeof(struct ifinfomsg),
319 				nla_len(nla_peer) - sizeof(struct ifinfomsg),
320 				ifla_policy);
321 		if (err < 0)
322 			return err;
323 
324 		err = veth_validate(peer_tb, NULL);
325 		if (err < 0)
326 			return err;
327 
328 		tbp = peer_tb;
329 	} else {
330 		ifmp = NULL;
331 		tbp = tb;
332 	}
333 
334 	if (tbp[IFLA_IFNAME])
335 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
336 	else
337 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
338 
339 	net = rtnl_link_get_net(src_net, tbp);
340 	if (IS_ERR(net))
341 		return PTR_ERR(net);
342 
343 	peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
344 	if (IS_ERR(peer)) {
345 		put_net(net);
346 		return PTR_ERR(peer);
347 	}
348 
349 	if (tbp[IFLA_ADDRESS] == NULL)
350 		random_ether_addr(peer->dev_addr);
351 
352 	err = register_netdevice(peer);
353 	put_net(net);
354 	net = NULL;
355 	if (err < 0)
356 		goto err_register_peer;
357 
358 	netif_carrier_off(peer);
359 
360 	err = rtnl_configure_link(peer, ifmp);
361 	if (err < 0)
362 		goto err_configure_peer;
363 
364 	/*
365 	 * register dev last
366 	 *
367 	 * note, that since we've registered new device the dev's name
368 	 * should be re-allocated
369 	 */
370 
371 	if (tb[IFLA_ADDRESS] == NULL)
372 		random_ether_addr(dev->dev_addr);
373 
374 	if (tb[IFLA_IFNAME])
375 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
376 	else
377 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
378 
379 	if (strchr(dev->name, '%')) {
380 		err = dev_alloc_name(dev, dev->name);
381 		if (err < 0)
382 			goto err_alloc_name;
383 	}
384 
385 	err = register_netdevice(dev);
386 	if (err < 0)
387 		goto err_register_dev;
388 
389 	netif_carrier_off(dev);
390 
391 	/*
392 	 * tie the deviced together
393 	 */
394 
395 	priv = netdev_priv(dev);
396 	priv->peer = peer;
397 
398 	priv = netdev_priv(peer);
399 	priv->peer = dev;
400 	return 0;
401 
402 err_register_dev:
403 	/* nothing to do */
404 err_alloc_name:
405 err_configure_peer:
406 	unregister_netdevice(peer);
407 	return err;
408 
409 err_register_peer:
410 	free_netdev(peer);
411 	return err;
412 }
413 
414 static void veth_dellink(struct net_device *dev, struct list_head *head)
415 {
416 	struct veth_priv *priv;
417 	struct net_device *peer;
418 
419 	priv = netdev_priv(dev);
420 	peer = priv->peer;
421 
422 	unregister_netdevice_queue(dev, head);
423 	unregister_netdevice_queue(peer, head);
424 }
425 
426 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
427 
428 static struct rtnl_link_ops veth_link_ops = {
429 	.kind		= DRV_NAME,
430 	.priv_size	= sizeof(struct veth_priv),
431 	.setup		= veth_setup,
432 	.validate	= veth_validate,
433 	.newlink	= veth_newlink,
434 	.dellink	= veth_dellink,
435 	.policy		= veth_policy,
436 	.maxtype	= VETH_INFO_MAX,
437 };
438 
439 /*
440  * init/fini
441  */
442 
443 static __init int veth_init(void)
444 {
445 	return rtnl_link_register(&veth_link_ops);
446 }
447 
448 static __exit void veth_exit(void)
449 {
450 	rtnl_link_unregister(&veth_link_ops);
451 }
452 
453 module_init(veth_init);
454 module_exit(veth_exit);
455 
456 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
457 MODULE_LICENSE("GPL v2");
458 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
459