xref: /openbmc/linux/drivers/net/veth.c (revision 37cf4d1a) 
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 
21 #define DRV_NAME	"veth"
22 #define DRV_VERSION	"1.0"
23 
24 #define MIN_MTU 68		/* Min L3 MTU */
25 #define MAX_MTU 65535		/* Max L3 MTU (arbitrary) */
26 
27 struct veth_net_stats {
28 	u64			rx_packets;
29 	u64			tx_packets;
30 	u64			rx_bytes;
31 	u64			tx_bytes;
32 	u64			rx_dropped;
33 	u64			tx_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 tx_drop:
152 	kfree_skb(skb);
153 	u64_stats_update_begin(&stats->syncp);
154 	stats->tx_dropped++;
155 	u64_stats_update_end(&stats->syncp);
156 	return NETDEV_TX_OK;
157 
158 rx_drop:
159 	u64_stats_update_begin(&rcv_stats->syncp);
160 	rcv_stats->rx_dropped++;
161 	u64_stats_update_end(&rcv_stats->syncp);
162 	return NETDEV_TX_OK;
163 }
164 
165 /*
166  * general routines
167  */
168 
169 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
170 						  struct rtnl_link_stats64 *tot)
171 {
172 	struct veth_priv *priv = netdev_priv(dev);
173 	int cpu;
174 
175 	for_each_possible_cpu(cpu) {
176 		struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
177 		u64 rx_packets, rx_bytes, rx_dropped;
178 		u64 tx_packets, tx_bytes, tx_dropped;
179 		unsigned int start;
180 
181 		do {
182 			start = u64_stats_fetch_begin_bh(&stats->syncp);
183 			rx_packets = stats->rx_packets;
184 			tx_packets = stats->tx_packets;
185 			rx_bytes = stats->rx_bytes;
186 			tx_bytes = stats->tx_bytes;
187 			rx_dropped = stats->rx_dropped;
188 			tx_dropped = stats->tx_dropped;
189 		} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
190 		tot->rx_packets += rx_packets;
191 		tot->tx_packets += tx_packets;
192 		tot->rx_bytes   += rx_bytes;
193 		tot->tx_bytes   += tx_bytes;
194 		tot->rx_dropped += rx_dropped;
195 		tot->tx_dropped += tx_dropped;
196 	}
197 
198 	return tot;
199 }
200 
201 static int veth_open(struct net_device *dev)
202 {
203 	struct veth_priv *priv;
204 
205 	priv = netdev_priv(dev);
206 	if (priv->peer == NULL)
207 		return -ENOTCONN;
208 
209 	if (priv->peer->flags & IFF_UP) {
210 		netif_carrier_on(dev);
211 		netif_carrier_on(priv->peer);
212 	}
213 	return 0;
214 }
215 
216 static int veth_close(struct net_device *dev)
217 {
218 	struct veth_priv *priv = netdev_priv(dev);
219 
220 	netif_carrier_off(dev);
221 	netif_carrier_off(priv->peer);
222 
223 	return 0;
224 }
225 
226 static int is_valid_veth_mtu(int new_mtu)
227 {
228 	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
229 }
230 
231 static int veth_change_mtu(struct net_device *dev, int new_mtu)
232 {
233 	if (!is_valid_veth_mtu(new_mtu))
234 		return -EINVAL;
235 	dev->mtu = new_mtu;
236 	return 0;
237 }
238 
239 static int veth_dev_init(struct net_device *dev)
240 {
241 	struct veth_net_stats __percpu *stats;
242 	struct veth_priv *priv;
243 
244 	stats = alloc_percpu(struct veth_net_stats);
245 	if (stats == NULL)
246 		return -ENOMEM;
247 
248 	priv = netdev_priv(dev);
249 	priv->stats = stats;
250 	return 0;
251 }
252 
253 static void veth_dev_free(struct net_device *dev)
254 {
255 	struct veth_priv *priv;
256 
257 	priv = netdev_priv(dev);
258 	free_percpu(priv->stats);
259 	free_netdev(dev);
260 }
261 
262 static const struct net_device_ops veth_netdev_ops = {
263 	.ndo_init            = veth_dev_init,
264 	.ndo_open            = veth_open,
265 	.ndo_stop            = veth_close,
266 	.ndo_start_xmit      = veth_xmit,
267 	.ndo_change_mtu      = veth_change_mtu,
268 	.ndo_get_stats64     = veth_get_stats64,
269 	.ndo_set_mac_address = eth_mac_addr,
270 };
271 
272 static void veth_setup(struct net_device *dev)
273 {
274 	ether_setup(dev);
275 
276 	dev->netdev_ops = &veth_netdev_ops;
277 	dev->ethtool_ops = &veth_ethtool_ops;
278 	dev->features |= NETIF_F_LLTX;
279 	dev->destructor = veth_dev_free;
280 
281 	dev->hw_features = NETIF_F_NO_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
282 }
283 
284 /*
285  * netlink interface
286  */
287 
288 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
289 {
290 	if (tb[IFLA_ADDRESS]) {
291 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
292 			return -EINVAL;
293 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
294 			return -EADDRNOTAVAIL;
295 	}
296 	if (tb[IFLA_MTU]) {
297 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
298 			return -EINVAL;
299 	}
300 	return 0;
301 }
302 
303 static struct rtnl_link_ops veth_link_ops;
304 
305 static int veth_newlink(struct net *src_net, struct net_device *dev,
306 			 struct nlattr *tb[], struct nlattr *data[])
307 {
308 	int err;
309 	struct net_device *peer;
310 	struct veth_priv *priv;
311 	char ifname[IFNAMSIZ];
312 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
313 	struct ifinfomsg *ifmp;
314 	struct net *net;
315 
316 	/*
317 	 * create and register peer first
318 	 */
319 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
320 		struct nlattr *nla_peer;
321 
322 		nla_peer = data[VETH_INFO_PEER];
323 		ifmp = nla_data(nla_peer);
324 		err = nla_parse(peer_tb, IFLA_MAX,
325 				nla_data(nla_peer) + sizeof(struct ifinfomsg),
326 				nla_len(nla_peer) - sizeof(struct ifinfomsg),
327 				ifla_policy);
328 		if (err < 0)
329 			return err;
330 
331 		err = veth_validate(peer_tb, NULL);
332 		if (err < 0)
333 			return err;
334 
335 		tbp = peer_tb;
336 	} else {
337 		ifmp = NULL;
338 		tbp = tb;
339 	}
340 
341 	if (tbp[IFLA_IFNAME])
342 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
343 	else
344 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
345 
346 	net = rtnl_link_get_net(src_net, tbp);
347 	if (IS_ERR(net))
348 		return PTR_ERR(net);
349 
350 	peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
351 	if (IS_ERR(peer)) {
352 		put_net(net);
353 		return PTR_ERR(peer);
354 	}
355 
356 	if (tbp[IFLA_ADDRESS] == NULL)
357 		random_ether_addr(peer->dev_addr);
358 
359 	err = register_netdevice(peer);
360 	put_net(net);
361 	net = NULL;
362 	if (err < 0)
363 		goto err_register_peer;
364 
365 	netif_carrier_off(peer);
366 
367 	err = rtnl_configure_link(peer, ifmp);
368 	if (err < 0)
369 		goto err_configure_peer;
370 
371 	/*
372 	 * register dev last
373 	 *
374 	 * note, that since we've registered new device the dev's name
375 	 * should be re-allocated
376 	 */
377 
378 	if (tb[IFLA_ADDRESS] == NULL)
379 		random_ether_addr(dev->dev_addr);
380 
381 	if (tb[IFLA_IFNAME])
382 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
383 	else
384 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
385 
386 	if (strchr(dev->name, '%')) {
387 		err = dev_alloc_name(dev, dev->name);
388 		if (err < 0)
389 			goto err_alloc_name;
390 	}
391 
392 	err = register_netdevice(dev);
393 	if (err < 0)
394 		goto err_register_dev;
395 
396 	netif_carrier_off(dev);
397 
398 	/*
399 	 * tie the deviced together
400 	 */
401 
402 	priv = netdev_priv(dev);
403 	priv->peer = peer;
404 
405 	priv = netdev_priv(peer);
406 	priv->peer = dev;
407 	return 0;
408 
409 err_register_dev:
410 	/* nothing to do */
411 err_alloc_name:
412 err_configure_peer:
413 	unregister_netdevice(peer);
414 	return err;
415 
416 err_register_peer:
417 	free_netdev(peer);
418 	return err;
419 }
420 
421 static void veth_dellink(struct net_device *dev, struct list_head *head)
422 {
423 	struct veth_priv *priv;
424 	struct net_device *peer;
425 
426 	priv = netdev_priv(dev);
427 	peer = priv->peer;
428 
429 	unregister_netdevice_queue(dev, head);
430 	unregister_netdevice_queue(peer, head);
431 }
432 
433 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
434 
435 static struct rtnl_link_ops veth_link_ops = {
436 	.kind		= DRV_NAME,
437 	.priv_size	= sizeof(struct veth_priv),
438 	.setup		= veth_setup,
439 	.validate	= veth_validate,
440 	.newlink	= veth_newlink,
441 	.dellink	= veth_dellink,
442 	.policy		= veth_policy,
443 	.maxtype	= VETH_INFO_MAX,
444 };
445 
446 /*
447  * init/fini
448  */
449 
450 static __init int veth_init(void)
451 {
452 	return rtnl_link_register(&veth_link_ops);
453 }
454 
455 static __exit void veth_exit(void)
456 {
457 	rtnl_link_unregister(&veth_link_ops);
458 }
459 
460 module_init(veth_init);
461 module_exit(veth_exit);
462 
463 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
464 MODULE_LICENSE("GPL v2");
465 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
466