xref: /openbmc/linux/drivers/net/veth.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076) 
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/ethtool.h>
13 #include <linux/etherdevice.h>
14 
15 #include <net/dst.h>
16 #include <net/xfrm.h>
17 #include <linux/veth.h>
18 
19 #define DRV_NAME	"veth"
20 #define DRV_VERSION	"1.0"
21 
22 #define MIN_MTU 68		/* Min L3 MTU */
23 #define MAX_MTU 65535		/* Max L3 MTU (arbitrary) */
24 #define MTU_PAD (ETH_HLEN + 4)  /* Max difference between L2 and L3 size MTU */
25 
26 struct veth_net_stats {
27 	unsigned long	rx_packets;
28 	unsigned long	tx_packets;
29 	unsigned long	rx_bytes;
30 	unsigned long	tx_bytes;
31 	unsigned long	tx_dropped;
32 	unsigned long	rx_dropped;
33 };
34 
35 struct veth_priv {
36 	struct net_device *peer;
37 	struct veth_net_stats *stats;
38 	unsigned ip_summed;
39 };
40 
41 /*
42  * ethtool interface
43  */
44 
45 static struct {
46 	const char string[ETH_GSTRING_LEN];
47 } ethtool_stats_keys[] = {
48 	{ "peer_ifindex" },
49 };
50 
51 static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
52 {
53 	cmd->supported		= 0;
54 	cmd->advertising	= 0;
55 	cmd->speed		= SPEED_10000;
56 	cmd->duplex		= DUPLEX_FULL;
57 	cmd->port		= PORT_TP;
58 	cmd->phy_address	= 0;
59 	cmd->transceiver	= XCVR_INTERNAL;
60 	cmd->autoneg		= AUTONEG_DISABLE;
61 	cmd->maxtxpkt		= 0;
62 	cmd->maxrxpkt		= 0;
63 	return 0;
64 }
65 
66 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
67 {
68 	strcpy(info->driver, DRV_NAME);
69 	strcpy(info->version, DRV_VERSION);
70 	strcpy(info->fw_version, "N/A");
71 }
72 
73 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
74 {
75 	switch(stringset) {
76 	case ETH_SS_STATS:
77 		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
78 		break;
79 	}
80 }
81 
82 static int veth_get_sset_count(struct net_device *dev, int sset)
83 {
84 	switch (sset) {
85 	case ETH_SS_STATS:
86 		return ARRAY_SIZE(ethtool_stats_keys);
87 	default:
88 		return -EOPNOTSUPP;
89 	}
90 }
91 
92 static void veth_get_ethtool_stats(struct net_device *dev,
93 		struct ethtool_stats *stats, u64 *data)
94 {
95 	struct veth_priv *priv;
96 
97 	priv = netdev_priv(dev);
98 	data[0] = priv->peer->ifindex;
99 }
100 
101 static u32 veth_get_rx_csum(struct net_device *dev)
102 {
103 	struct veth_priv *priv;
104 
105 	priv = netdev_priv(dev);
106 	return priv->ip_summed == CHECKSUM_UNNECESSARY;
107 }
108 
109 static int veth_set_rx_csum(struct net_device *dev, u32 data)
110 {
111 	struct veth_priv *priv;
112 
113 	priv = netdev_priv(dev);
114 	priv->ip_summed = data ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
115 	return 0;
116 }
117 
118 static u32 veth_get_tx_csum(struct net_device *dev)
119 {
120 	return (dev->features & NETIF_F_NO_CSUM) != 0;
121 }
122 
123 static int veth_set_tx_csum(struct net_device *dev, u32 data)
124 {
125 	if (data)
126 		dev->features |= NETIF_F_NO_CSUM;
127 	else
128 		dev->features &= ~NETIF_F_NO_CSUM;
129 	return 0;
130 }
131 
132 static struct ethtool_ops veth_ethtool_ops = {
133 	.get_settings		= veth_get_settings,
134 	.get_drvinfo		= veth_get_drvinfo,
135 	.get_link		= ethtool_op_get_link,
136 	.get_rx_csum		= veth_get_rx_csum,
137 	.set_rx_csum		= veth_set_rx_csum,
138 	.get_tx_csum		= veth_get_tx_csum,
139 	.set_tx_csum		= veth_set_tx_csum,
140 	.get_sg			= ethtool_op_get_sg,
141 	.set_sg			= ethtool_op_set_sg,
142 	.get_strings		= veth_get_strings,
143 	.get_sset_count		= veth_get_sset_count,
144 	.get_ethtool_stats	= veth_get_ethtool_stats,
145 };
146 
147 /*
148  * xmit
149  */
150 
151 static int veth_xmit(struct sk_buff *skb, struct net_device *dev)
152 {
153 	struct net_device *rcv = NULL;
154 	struct veth_priv *priv, *rcv_priv;
155 	struct veth_net_stats *stats, *rcv_stats;
156 	int length, cpu;
157 
158 	skb_orphan(skb);
159 
160 	priv = netdev_priv(dev);
161 	rcv = priv->peer;
162 	rcv_priv = netdev_priv(rcv);
163 
164 	cpu = smp_processor_id();
165 	stats = per_cpu_ptr(priv->stats, cpu);
166 	rcv_stats = per_cpu_ptr(rcv_priv->stats, cpu);
167 
168 	if (!(rcv->flags & IFF_UP))
169 		goto tx_drop;
170 
171 	if (skb->len > (rcv->mtu + MTU_PAD))
172 		goto rx_drop;
173 
174 	skb->pkt_type = PACKET_HOST;
175 	skb->protocol = eth_type_trans(skb, rcv);
176 	if (dev->features & NETIF_F_NO_CSUM)
177 		skb->ip_summed = rcv_priv->ip_summed;
178 
179 	dst_release(skb->dst);
180 	skb->dst = NULL;
181 	skb->mark = 0;
182 	secpath_reset(skb);
183 	nf_reset(skb);
184 
185 	length = skb->len;
186 
187 	stats->tx_bytes += length;
188 	stats->tx_packets++;
189 
190 	rcv_stats->rx_bytes += length;
191 	rcv_stats->rx_packets++;
192 
193 	netif_rx(skb);
194 	return 0;
195 
196 tx_drop:
197 	kfree_skb(skb);
198 	stats->tx_dropped++;
199 	return 0;
200 
201 rx_drop:
202 	kfree_skb(skb);
203 	rcv_stats->rx_dropped++;
204 	return 0;
205 }
206 
207 /*
208  * general routines
209  */
210 
211 static struct net_device_stats *veth_get_stats(struct net_device *dev)
212 {
213 	struct veth_priv *priv;
214 	struct net_device_stats *dev_stats;
215 	int cpu;
216 	struct veth_net_stats *stats;
217 
218 	priv = netdev_priv(dev);
219 	dev_stats = &dev->stats;
220 
221 	dev_stats->rx_packets = 0;
222 	dev_stats->tx_packets = 0;
223 	dev_stats->rx_bytes = 0;
224 	dev_stats->tx_bytes = 0;
225 	dev_stats->tx_dropped = 0;
226 	dev_stats->rx_dropped = 0;
227 
228 	for_each_online_cpu(cpu) {
229 		stats = per_cpu_ptr(priv->stats, cpu);
230 
231 		dev_stats->rx_packets += stats->rx_packets;
232 		dev_stats->tx_packets += stats->tx_packets;
233 		dev_stats->rx_bytes += stats->rx_bytes;
234 		dev_stats->tx_bytes += stats->tx_bytes;
235 		dev_stats->tx_dropped += stats->tx_dropped;
236 		dev_stats->rx_dropped += stats->rx_dropped;
237 	}
238 
239 	return dev_stats;
240 }
241 
242 static int veth_open(struct net_device *dev)
243 {
244 	struct veth_priv *priv;
245 
246 	priv = netdev_priv(dev);
247 	if (priv->peer == NULL)
248 		return -ENOTCONN;
249 
250 	if (priv->peer->flags & IFF_UP) {
251 		netif_carrier_on(dev);
252 		netif_carrier_on(priv->peer);
253 	}
254 	return 0;
255 }
256 
257 static int veth_close(struct net_device *dev)
258 {
259 	struct veth_priv *priv = netdev_priv(dev);
260 
261 	netif_carrier_off(dev);
262 	netif_carrier_off(priv->peer);
263 
264 	return 0;
265 }
266 
267 static int is_valid_veth_mtu(int new_mtu)
268 {
269 	return (new_mtu >= MIN_MTU && new_mtu <= MAX_MTU);
270 }
271 
272 static int veth_change_mtu(struct net_device *dev, int new_mtu)
273 {
274 	if (!is_valid_veth_mtu(new_mtu))
275 		return -EINVAL;
276 	dev->mtu = new_mtu;
277 	return 0;
278 }
279 
280 static int veth_dev_init(struct net_device *dev)
281 {
282 	struct veth_net_stats *stats;
283 	struct veth_priv *priv;
284 
285 	stats = alloc_percpu(struct veth_net_stats);
286 	if (stats == NULL)
287 		return -ENOMEM;
288 
289 	priv = netdev_priv(dev);
290 	priv->stats = stats;
291 	return 0;
292 }
293 
294 static void veth_dev_free(struct net_device *dev)
295 {
296 	struct veth_priv *priv;
297 
298 	priv = netdev_priv(dev);
299 	free_percpu(priv->stats);
300 	free_netdev(dev);
301 }
302 
303 static const struct net_device_ops veth_netdev_ops = {
304 	.ndo_init            = veth_dev_init,
305 	.ndo_open            = veth_open,
306 	.ndo_stop            = veth_close,
307 	.ndo_start_xmit      = veth_xmit,
308 	.ndo_change_mtu      = veth_change_mtu,
309 	.ndo_get_stats       = veth_get_stats,
310 	.ndo_set_mac_address = eth_mac_addr,
311 };
312 
313 static void veth_setup(struct net_device *dev)
314 {
315 	ether_setup(dev);
316 
317 	dev->netdev_ops = &veth_netdev_ops;
318 	dev->ethtool_ops = &veth_ethtool_ops;
319 	dev->features |= NETIF_F_LLTX;
320 	dev->destructor = veth_dev_free;
321 }
322 
323 /*
324  * netlink interface
325  */
326 
327 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
328 {
329 	if (tb[IFLA_ADDRESS]) {
330 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
331 			return -EINVAL;
332 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
333 			return -EADDRNOTAVAIL;
334 	}
335 	if (tb[IFLA_MTU]) {
336 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
337 			return -EINVAL;
338 	}
339 	return 0;
340 }
341 
342 static struct rtnl_link_ops veth_link_ops;
343 
344 static int veth_newlink(struct net_device *dev,
345 			 struct nlattr *tb[], struct nlattr *data[])
346 {
347 	int err;
348 	struct net_device *peer;
349 	struct veth_priv *priv;
350 	char ifname[IFNAMSIZ];
351 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
352 
353 	/*
354 	 * create and register peer first
355 	 *
356 	 * struct ifinfomsg is at the head of VETH_INFO_PEER, but we
357 	 * skip it since no info from it is useful yet
358 	 */
359 
360 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
361 		struct nlattr *nla_peer;
362 
363 		nla_peer = data[VETH_INFO_PEER];
364 		err = nla_parse(peer_tb, IFLA_MAX,
365 				nla_data(nla_peer) + sizeof(struct ifinfomsg),
366 				nla_len(nla_peer) - sizeof(struct ifinfomsg),
367 				ifla_policy);
368 		if (err < 0)
369 			return err;
370 
371 		err = veth_validate(peer_tb, NULL);
372 		if (err < 0)
373 			return err;
374 
375 		tbp = peer_tb;
376 	} else
377 		tbp = tb;
378 
379 	if (tbp[IFLA_IFNAME])
380 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
381 	else
382 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
383 
384 	peer = rtnl_create_link(dev_net(dev), ifname, &veth_link_ops, tbp);
385 	if (IS_ERR(peer))
386 		return PTR_ERR(peer);
387 
388 	if (tbp[IFLA_ADDRESS] == NULL)
389 		random_ether_addr(peer->dev_addr);
390 
391 	err = register_netdevice(peer);
392 	if (err < 0)
393 		goto err_register_peer;
394 
395 	netif_carrier_off(peer);
396 
397 	/*
398 	 * register dev last
399 	 *
400 	 * note, that since we've registered new device the dev's name
401 	 * should be re-allocated
402 	 */
403 
404 	if (tb[IFLA_ADDRESS] == NULL)
405 		random_ether_addr(dev->dev_addr);
406 
407 	if (tb[IFLA_IFNAME])
408 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
409 	else
410 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
411 
412 	if (strchr(dev->name, '%')) {
413 		err = dev_alloc_name(dev, dev->name);
414 		if (err < 0)
415 			goto err_alloc_name;
416 	}
417 
418 	err = register_netdevice(dev);
419 	if (err < 0)
420 		goto err_register_dev;
421 
422 	netif_carrier_off(dev);
423 
424 	/*
425 	 * tie the deviced together
426 	 */
427 
428 	priv = netdev_priv(dev);
429 	priv->peer = peer;
430 
431 	priv = netdev_priv(peer);
432 	priv->peer = dev;
433 	return 0;
434 
435 err_register_dev:
436 	/* nothing to do */
437 err_alloc_name:
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)
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(dev);
455 	unregister_netdevice(peer);
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