xref: /openbmc/linux/drivers/net/veth.c (revision 23289a37e2b127dfc4de1313fba15bb4c9f0cd5b) 
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 const 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 netdev_tx_t 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->tstamp.tv64 = 0;
175 	skb->pkt_type = PACKET_HOST;
176 	skb->protocol = eth_type_trans(skb, rcv);
177 	if (dev->features & NETIF_F_NO_CSUM)
178 		skb->ip_summed = rcv_priv->ip_summed;
179 
180 	skb->mark = 0;
181 	secpath_reset(skb);
182 	nf_reset(skb);
183 
184 	length = skb->len;
185 
186 	stats->tx_bytes += length;
187 	stats->tx_packets++;
188 
189 	rcv_stats->rx_bytes += length;
190 	rcv_stats->rx_packets++;
191 
192 	netif_rx(skb);
193 	return NETDEV_TX_OK;
194 
195 tx_drop:
196 	kfree_skb(skb);
197 	stats->tx_dropped++;
198 	return NETDEV_TX_OK;
199 
200 rx_drop:
201 	kfree_skb(skb);
202 	rcv_stats->rx_dropped++;
203 	return NETDEV_TX_OK;
204 }
205 
206 /*
207  * general routines
208  */
209 
210 static struct net_device_stats *veth_get_stats(struct net_device *dev)
211 {
212 	struct veth_priv *priv;
213 	struct net_device_stats *dev_stats;
214 	int cpu;
215 	struct veth_net_stats *stats;
216 
217 	priv = netdev_priv(dev);
218 	dev_stats = &dev->stats;
219 
220 	dev_stats->rx_packets = 0;
221 	dev_stats->tx_packets = 0;
222 	dev_stats->rx_bytes = 0;
223 	dev_stats->tx_bytes = 0;
224 	dev_stats->tx_dropped = 0;
225 	dev_stats->rx_dropped = 0;
226 
227 	for_each_online_cpu(cpu) {
228 		stats = per_cpu_ptr(priv->stats, cpu);
229 
230 		dev_stats->rx_packets += stats->rx_packets;
231 		dev_stats->tx_packets += stats->tx_packets;
232 		dev_stats->rx_bytes += stats->rx_bytes;
233 		dev_stats->tx_bytes += stats->tx_bytes;
234 		dev_stats->tx_dropped += stats->tx_dropped;
235 		dev_stats->rx_dropped += stats->rx_dropped;
236 	}
237 
238 	return dev_stats;
239 }
240 
241 static int veth_open(struct net_device *dev)
242 {
243 	struct veth_priv *priv;
244 
245 	priv = netdev_priv(dev);
246 	if (priv->peer == NULL)
247 		return -ENOTCONN;
248 
249 	if (priv->peer->flags & IFF_UP) {
250 		netif_carrier_on(dev);
251 		netif_carrier_on(priv->peer);
252 	}
253 	return 0;
254 }
255 
256 static int veth_close(struct net_device *dev)
257 {
258 	struct veth_priv *priv = netdev_priv(dev);
259 
260 	netif_carrier_off(dev);
261 	netif_carrier_off(priv->peer);
262 
263 	return 0;
264 }
265 
266 static int is_valid_veth_mtu(int new_mtu)
267 {
268 	return (new_mtu >= MIN_MTU && new_mtu <= MAX_MTU);
269 }
270 
271 static int veth_change_mtu(struct net_device *dev, int new_mtu)
272 {
273 	if (!is_valid_veth_mtu(new_mtu))
274 		return -EINVAL;
275 	dev->mtu = new_mtu;
276 	return 0;
277 }
278 
279 static int veth_dev_init(struct net_device *dev)
280 {
281 	struct veth_net_stats *stats;
282 	struct veth_priv *priv;
283 
284 	stats = alloc_percpu(struct veth_net_stats);
285 	if (stats == NULL)
286 		return -ENOMEM;
287 
288 	priv = netdev_priv(dev);
289 	priv->stats = stats;
290 	return 0;
291 }
292 
293 static void veth_dev_free(struct net_device *dev)
294 {
295 	struct veth_priv *priv;
296 
297 	priv = netdev_priv(dev);
298 	free_percpu(priv->stats);
299 	free_netdev(dev);
300 }
301 
302 static const struct net_device_ops veth_netdev_ops = {
303 	.ndo_init            = veth_dev_init,
304 	.ndo_open            = veth_open,
305 	.ndo_stop            = veth_close,
306 	.ndo_start_xmit      = veth_xmit,
307 	.ndo_change_mtu      = veth_change_mtu,
308 	.ndo_get_stats       = veth_get_stats,
309 	.ndo_set_mac_address = eth_mac_addr,
310 };
311 
312 static void veth_setup(struct net_device *dev)
313 {
314 	ether_setup(dev);
315 
316 	dev->netdev_ops = &veth_netdev_ops;
317 	dev->ethtool_ops = &veth_ethtool_ops;
318 	dev->features |= NETIF_F_LLTX;
319 	dev->destructor = veth_dev_free;
320 }
321 
322 /*
323  * netlink interface
324  */
325 
326 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
327 {
328 	if (tb[IFLA_ADDRESS]) {
329 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
330 			return -EINVAL;
331 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
332 			return -EADDRNOTAVAIL;
333 	}
334 	if (tb[IFLA_MTU]) {
335 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
336 			return -EINVAL;
337 	}
338 	return 0;
339 }
340 
341 static struct rtnl_link_ops veth_link_ops;
342 
343 static int veth_newlink(struct net_device *dev,
344 			 struct nlattr *tb[], struct nlattr *data[])
345 {
346 	int err;
347 	struct net_device *peer;
348 	struct veth_priv *priv;
349 	char ifname[IFNAMSIZ];
350 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
351 
352 	/*
353 	 * create and register peer first
354 	 *
355 	 * struct ifinfomsg is at the head of VETH_INFO_PEER, but we
356 	 * skip it since no info from it is useful yet
357 	 */
358 
359 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
360 		struct nlattr *nla_peer;
361 
362 		nla_peer = data[VETH_INFO_PEER];
363 		err = nla_parse(peer_tb, IFLA_MAX,
364 				nla_data(nla_peer) + sizeof(struct ifinfomsg),
365 				nla_len(nla_peer) - sizeof(struct ifinfomsg),
366 				ifla_policy);
367 		if (err < 0)
368 			return err;
369 
370 		err = veth_validate(peer_tb, NULL);
371 		if (err < 0)
372 			return err;
373 
374 		tbp = peer_tb;
375 	} else
376 		tbp = tb;
377 
378 	if (tbp[IFLA_IFNAME])
379 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
380 	else
381 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
382 
383 	peer = rtnl_create_link(dev_net(dev), ifname, &veth_link_ops, tbp);
384 	if (IS_ERR(peer))
385 		return PTR_ERR(peer);
386 
387 	if (tbp[IFLA_ADDRESS] == NULL)
388 		random_ether_addr(peer->dev_addr);
389 
390 	err = register_netdevice(peer);
391 	if (err < 0)
392 		goto err_register_peer;
393 
394 	netif_carrier_off(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 	unregister_netdevice(peer);
438 	return err;
439 
440 err_register_peer:
441 	free_netdev(peer);
442 	return err;
443 }
444 
445 static void veth_dellink(struct net_device *dev, struct list_head *head)
446 {
447 	struct veth_priv *priv;
448 	struct net_device *peer;
449 
450 	priv = netdev_priv(dev);
451 	peer = priv->peer;
452 
453 	unregister_netdevice(dev);
454 	unregister_netdevice(peer);
455 }
456 
457 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
458 
459 static struct rtnl_link_ops veth_link_ops = {
460 	.kind		= DRV_NAME,
461 	.priv_size	= sizeof(struct veth_priv),
462 	.setup		= veth_setup,
463 	.validate	= veth_validate,
464 	.newlink	= veth_newlink,
465 	.dellink	= veth_dellink,
466 	.policy		= veth_policy,
467 	.maxtype	= VETH_INFO_MAX,
468 };
469 
470 /*
471  * init/fini
472  */
473 
474 static __init int veth_init(void)
475 {
476 	return rtnl_link_register(&veth_link_ops);
477 }
478 
479 static __exit void veth_exit(void)
480 {
481 	rtnl_link_unregister(&veth_link_ops);
482 }
483 
484 module_init(veth_init);
485 module_exit(veth_exit);
486 
487 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
488 MODULE_LICENSE("GPL v2");
489 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
490