xref: /openbmc/linux/drivers/net/veth.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd) 
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 
16 #include <net/dst.h>
17 #include <net/xfrm.h>
18 #include <linux/veth.h>
19 
20 #define DRV_NAME	"veth"
21 #define DRV_VERSION	"1.0"
22 
23 #define MIN_MTU 68		/* Min L3 MTU */
24 #define MAX_MTU 65535		/* Max L3 MTU (arbitrary) */
25 #define MTU_PAD (ETH_HLEN + 4)  /* Max difference between L2 and L3 size MTU */
26 
27 struct veth_net_stats {
28 	unsigned long	rx_packets;
29 	unsigned long	tx_packets;
30 	unsigned long	rx_bytes;
31 	unsigned long	tx_bytes;
32 	unsigned long	tx_dropped;
33 	unsigned long	rx_dropped;
34 };
35 
36 struct veth_priv {
37 	struct net_device *peer;
38 	struct veth_net_stats __percpu *stats;
39 	unsigned ip_summed;
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 	cmd->speed		= 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 u32 veth_get_rx_csum(struct net_device *dev)
103 {
104 	struct veth_priv *priv;
105 
106 	priv = netdev_priv(dev);
107 	return priv->ip_summed == CHECKSUM_UNNECESSARY;
108 }
109 
110 static int veth_set_rx_csum(struct net_device *dev, u32 data)
111 {
112 	struct veth_priv *priv;
113 
114 	priv = netdev_priv(dev);
115 	priv->ip_summed = data ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
116 	return 0;
117 }
118 
119 static u32 veth_get_tx_csum(struct net_device *dev)
120 {
121 	return (dev->features & NETIF_F_NO_CSUM) != 0;
122 }
123 
124 static int veth_set_tx_csum(struct net_device *dev, u32 data)
125 {
126 	if (data)
127 		dev->features |= NETIF_F_NO_CSUM;
128 	else
129 		dev->features &= ~NETIF_F_NO_CSUM;
130 	return 0;
131 }
132 
133 static const struct ethtool_ops veth_ethtool_ops = {
134 	.get_settings		= veth_get_settings,
135 	.get_drvinfo		= veth_get_drvinfo,
136 	.get_link		= ethtool_op_get_link,
137 	.get_rx_csum		= veth_get_rx_csum,
138 	.set_rx_csum		= veth_set_rx_csum,
139 	.get_tx_csum		= veth_get_tx_csum,
140 	.set_tx_csum		= veth_set_tx_csum,
141 	.get_sg			= ethtool_op_get_sg,
142 	.set_sg			= ethtool_op_set_sg,
143 	.get_strings		= veth_get_strings,
144 	.get_sset_count		= veth_get_sset_count,
145 	.get_ethtool_stats	= veth_get_ethtool_stats,
146 };
147 
148 /*
149  * xmit
150  */
151 
152 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
153 {
154 	struct net_device *rcv = NULL;
155 	struct veth_priv *priv, *rcv_priv;
156 	struct veth_net_stats *stats, *rcv_stats;
157 	int length;
158 
159 	priv = netdev_priv(dev);
160 	rcv = priv->peer;
161 	rcv_priv = netdev_priv(rcv);
162 
163 	stats = this_cpu_ptr(priv->stats);
164 	rcv_stats = this_cpu_ptr(rcv_priv->stats);
165 
166 	if (!(rcv->flags & IFF_UP))
167 		goto tx_drop;
168 
169 	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
170 	   will cause bad checksum on forwarded packets */
171 	if (skb->ip_summed == CHECKSUM_NONE)
172 		skb->ip_summed = rcv_priv->ip_summed;
173 
174 	length = skb->len + ETH_HLEN;
175 	if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
176 		goto rx_drop;
177 
178 	stats->tx_bytes += length;
179 	stats->tx_packets++;
180 
181 	rcv_stats->rx_bytes += length;
182 	rcv_stats->rx_packets++;
183 
184 	return NETDEV_TX_OK;
185 
186 tx_drop:
187 	kfree_skb(skb);
188 	stats->tx_dropped++;
189 	return NETDEV_TX_OK;
190 
191 rx_drop:
192 	rcv_stats->rx_dropped++;
193 	return NETDEV_TX_OK;
194 }
195 
196 /*
197  * general routines
198  */
199 
200 static struct net_device_stats *veth_get_stats(struct net_device *dev)
201 {
202 	struct veth_priv *priv;
203 	int cpu;
204 	struct veth_net_stats *stats, total = {0};
205 
206 	priv = netdev_priv(dev);
207 
208 	for_each_possible_cpu(cpu) {
209 		stats = per_cpu_ptr(priv->stats, cpu);
210 
211 		total.rx_packets += stats->rx_packets;
212 		total.tx_packets += stats->tx_packets;
213 		total.rx_bytes   += stats->rx_bytes;
214 		total.tx_bytes   += stats->tx_bytes;
215 		total.tx_dropped += stats->tx_dropped;
216 		total.rx_dropped += stats->rx_dropped;
217 	}
218 	dev->stats.rx_packets = total.rx_packets;
219 	dev->stats.tx_packets = total.tx_packets;
220 	dev->stats.rx_bytes   = total.rx_bytes;
221 	dev->stats.tx_bytes   = total.tx_bytes;
222 	dev->stats.tx_dropped = total.tx_dropped;
223 	dev->stats.rx_dropped = total.rx_dropped;
224 
225 	return &dev->stats;
226 }
227 
228 static int veth_open(struct net_device *dev)
229 {
230 	struct veth_priv *priv;
231 
232 	priv = netdev_priv(dev);
233 	if (priv->peer == NULL)
234 		return -ENOTCONN;
235 
236 	if (priv->peer->flags & IFF_UP) {
237 		netif_carrier_on(dev);
238 		netif_carrier_on(priv->peer);
239 	}
240 	return 0;
241 }
242 
243 static int veth_close(struct net_device *dev)
244 {
245 	struct veth_priv *priv = netdev_priv(dev);
246 
247 	netif_carrier_off(dev);
248 	netif_carrier_off(priv->peer);
249 
250 	return 0;
251 }
252 
253 static int is_valid_veth_mtu(int new_mtu)
254 {
255 	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
256 }
257 
258 static int veth_change_mtu(struct net_device *dev, int new_mtu)
259 {
260 	if (!is_valid_veth_mtu(new_mtu))
261 		return -EINVAL;
262 	dev->mtu = new_mtu;
263 	return 0;
264 }
265 
266 static int veth_dev_init(struct net_device *dev)
267 {
268 	struct veth_net_stats __percpu *stats;
269 	struct veth_priv *priv;
270 
271 	stats = alloc_percpu(struct veth_net_stats);
272 	if (stats == NULL)
273 		return -ENOMEM;
274 
275 	priv = netdev_priv(dev);
276 	priv->stats = stats;
277 	return 0;
278 }
279 
280 static void veth_dev_free(struct net_device *dev)
281 {
282 	struct veth_priv *priv;
283 
284 	priv = netdev_priv(dev);
285 	free_percpu(priv->stats);
286 	free_netdev(dev);
287 }
288 
289 static const struct net_device_ops veth_netdev_ops = {
290 	.ndo_init            = veth_dev_init,
291 	.ndo_open            = veth_open,
292 	.ndo_stop            = veth_close,
293 	.ndo_start_xmit      = veth_xmit,
294 	.ndo_change_mtu      = veth_change_mtu,
295 	.ndo_get_stats       = veth_get_stats,
296 	.ndo_set_mac_address = eth_mac_addr,
297 };
298 
299 static void veth_setup(struct net_device *dev)
300 {
301 	ether_setup(dev);
302 
303 	dev->netdev_ops = &veth_netdev_ops;
304 	dev->ethtool_ops = &veth_ethtool_ops;
305 	dev->features |= NETIF_F_LLTX;
306 	dev->destructor = veth_dev_free;
307 }
308 
309 /*
310  * netlink interface
311  */
312 
313 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
314 {
315 	if (tb[IFLA_ADDRESS]) {
316 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
317 			return -EINVAL;
318 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
319 			return -EADDRNOTAVAIL;
320 	}
321 	if (tb[IFLA_MTU]) {
322 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
323 			return -EINVAL;
324 	}
325 	return 0;
326 }
327 
328 static struct rtnl_link_ops veth_link_ops;
329 
330 static int veth_newlink(struct net *src_net, struct net_device *dev,
331 			 struct nlattr *tb[], struct nlattr *data[])
332 {
333 	int err;
334 	struct net_device *peer;
335 	struct veth_priv *priv;
336 	char ifname[IFNAMSIZ];
337 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
338 	struct ifinfomsg *ifmp;
339 	struct net *net;
340 
341 	/*
342 	 * create and register peer first
343 	 */
344 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
345 		struct nlattr *nla_peer;
346 
347 		nla_peer = data[VETH_INFO_PEER];
348 		ifmp = nla_data(nla_peer);
349 		err = nla_parse(peer_tb, IFLA_MAX,
350 				nla_data(nla_peer) + sizeof(struct ifinfomsg),
351 				nla_len(nla_peer) - sizeof(struct ifinfomsg),
352 				ifla_policy);
353 		if (err < 0)
354 			return err;
355 
356 		err = veth_validate(peer_tb, NULL);
357 		if (err < 0)
358 			return err;
359 
360 		tbp = peer_tb;
361 	} else {
362 		ifmp = NULL;
363 		tbp = tb;
364 	}
365 
366 	if (tbp[IFLA_IFNAME])
367 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
368 	else
369 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
370 
371 	net = rtnl_link_get_net(src_net, tbp);
372 	if (IS_ERR(net))
373 		return PTR_ERR(net);
374 
375 	peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
376 	if (IS_ERR(peer)) {
377 		put_net(net);
378 		return PTR_ERR(peer);
379 	}
380 
381 	if (tbp[IFLA_ADDRESS] == NULL)
382 		random_ether_addr(peer->dev_addr);
383 
384 	err = register_netdevice(peer);
385 	put_net(net);
386 	net = NULL;
387 	if (err < 0)
388 		goto err_register_peer;
389 
390 	netif_carrier_off(peer);
391 
392 	err = rtnl_configure_link(peer, ifmp);
393 	if (err < 0)
394 		goto err_configure_peer;
395 
396 	/*
397 	 * register dev last
398 	 *
399 	 * note, that since we've registered new device the dev's name
400 	 * should be re-allocated
401 	 */
402 
403 	if (tb[IFLA_ADDRESS] == NULL)
404 		random_ether_addr(dev->dev_addr);
405 
406 	if (tb[IFLA_IFNAME])
407 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
408 	else
409 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
410 
411 	if (strchr(dev->name, '%')) {
412 		err = dev_alloc_name(dev, dev->name);
413 		if (err < 0)
414 			goto err_alloc_name;
415 	}
416 
417 	err = register_netdevice(dev);
418 	if (err < 0)
419 		goto err_register_dev;
420 
421 	netif_carrier_off(dev);
422 
423 	/*
424 	 * tie the deviced together
425 	 */
426 
427 	priv = netdev_priv(dev);
428 	priv->peer = peer;
429 
430 	priv = netdev_priv(peer);
431 	priv->peer = dev;
432 	return 0;
433 
434 err_register_dev:
435 	/* nothing to do */
436 err_alloc_name:
437 err_configure_peer:
438 	unregister_netdevice(peer);
439 	return err;
440 
441 err_register_peer:
442 	free_netdev(peer);
443 	return err;
444 }
445 
446 static void veth_dellink(struct net_device *dev, struct list_head *head)
447 {
448 	struct veth_priv *priv;
449 	struct net_device *peer;
450 
451 	priv = netdev_priv(dev);
452 	peer = priv->peer;
453 
454 	unregister_netdevice_queue(dev, head);
455 	unregister_netdevice_queue(peer, head);
456 }
457 
458 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
459 
460 static struct rtnl_link_ops veth_link_ops = {
461 	.kind		= DRV_NAME,
462 	.priv_size	= sizeof(struct veth_priv),
463 	.setup		= veth_setup,
464 	.validate	= veth_validate,
465 	.newlink	= veth_newlink,
466 	.dellink	= veth_dellink,
467 	.policy		= veth_policy,
468 	.maxtype	= VETH_INFO_MAX,
469 };
470 
471 /*
472  * init/fini
473  */
474 
475 static __init int veth_init(void)
476 {
477 	return rtnl_link_register(&veth_link_ops);
478 }
479 
480 static __exit void veth_exit(void)
481 {
482 	rtnl_link_unregister(&veth_link_ops);
483 }
484 
485 module_init(veth_init);
486 module_exit(veth_exit);
487 
488 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
489 MODULE_LICENSE("GPL v2");
490 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
491