xref: /openbmc/linux/drivers/net/veth.c (revision d0b73b48) 
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			rx_bytes;
31 	u64			tx_packets;
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 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
70 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
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 const struct ethtool_ops veth_ethtool_ops = {
102 	.get_settings		= veth_get_settings,
103 	.get_drvinfo		= veth_get_drvinfo,
104 	.get_link		= ethtool_op_get_link,
105 	.get_strings		= veth_get_strings,
106 	.get_sset_count		= veth_get_sset_count,
107 	.get_ethtool_stats	= veth_get_ethtool_stats,
108 };
109 
110 /*
111  * xmit
112  */
113 
114 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
115 {
116 	struct net_device *rcv = NULL;
117 	struct veth_priv *priv, *rcv_priv;
118 	struct veth_net_stats *stats, *rcv_stats;
119 	int length;
120 
121 	priv = netdev_priv(dev);
122 	rcv = priv->peer;
123 	rcv_priv = netdev_priv(rcv);
124 
125 	stats = this_cpu_ptr(priv->stats);
126 	rcv_stats = this_cpu_ptr(rcv_priv->stats);
127 
128 	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
129 	   will cause bad checksum on forwarded packets */
130 	if (skb->ip_summed == CHECKSUM_NONE &&
131 	    rcv->features & NETIF_F_RXCSUM)
132 		skb->ip_summed = CHECKSUM_UNNECESSARY;
133 
134 	length = skb->len;
135 	if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
136 		goto rx_drop;
137 
138 	u64_stats_update_begin(&stats->syncp);
139 	stats->tx_bytes += length;
140 	stats->tx_packets++;
141 	u64_stats_update_end(&stats->syncp);
142 
143 	u64_stats_update_begin(&rcv_stats->syncp);
144 	rcv_stats->rx_bytes += length;
145 	rcv_stats->rx_packets++;
146 	u64_stats_update_end(&rcv_stats->syncp);
147 
148 	return NETDEV_TX_OK;
149 
150 rx_drop:
151 	u64_stats_update_begin(&rcv_stats->syncp);
152 	rcv_stats->rx_dropped++;
153 	u64_stats_update_end(&rcv_stats->syncp);
154 	return NETDEV_TX_OK;
155 }
156 
157 /*
158  * general routines
159  */
160 
161 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
162 						  struct rtnl_link_stats64 *tot)
163 {
164 	struct veth_priv *priv = netdev_priv(dev);
165 	int cpu;
166 
167 	for_each_possible_cpu(cpu) {
168 		struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
169 		u64 rx_packets, rx_bytes, rx_dropped;
170 		u64 tx_packets, tx_bytes;
171 		unsigned int start;
172 
173 		do {
174 			start = u64_stats_fetch_begin_bh(&stats->syncp);
175 			rx_packets = stats->rx_packets;
176 			tx_packets = stats->tx_packets;
177 			rx_bytes = stats->rx_bytes;
178 			tx_bytes = stats->tx_bytes;
179 			rx_dropped = stats->rx_dropped;
180 		} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
181 		tot->rx_packets += rx_packets;
182 		tot->tx_packets += tx_packets;
183 		tot->rx_bytes   += rx_bytes;
184 		tot->tx_bytes   += tx_bytes;
185 		tot->rx_dropped += rx_dropped;
186 	}
187 
188 	return tot;
189 }
190 
191 static int veth_open(struct net_device *dev)
192 {
193 	struct veth_priv *priv;
194 
195 	priv = netdev_priv(dev);
196 	if (priv->peer == NULL)
197 		return -ENOTCONN;
198 
199 	if (priv->peer->flags & IFF_UP) {
200 		netif_carrier_on(dev);
201 		netif_carrier_on(priv->peer);
202 	}
203 	return 0;
204 }
205 
206 static int veth_close(struct net_device *dev)
207 {
208 	struct veth_priv *priv = netdev_priv(dev);
209 
210 	netif_carrier_off(dev);
211 	netif_carrier_off(priv->peer);
212 
213 	return 0;
214 }
215 
216 static int is_valid_veth_mtu(int new_mtu)
217 {
218 	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
219 }
220 
221 static int veth_change_mtu(struct net_device *dev, int new_mtu)
222 {
223 	if (!is_valid_veth_mtu(new_mtu))
224 		return -EINVAL;
225 	dev->mtu = new_mtu;
226 	return 0;
227 }
228 
229 static int veth_dev_init(struct net_device *dev)
230 {
231 	struct veth_net_stats __percpu *stats;
232 	struct veth_priv *priv;
233 
234 	stats = alloc_percpu(struct veth_net_stats);
235 	if (stats == NULL)
236 		return -ENOMEM;
237 
238 	priv = netdev_priv(dev);
239 	priv->stats = stats;
240 	return 0;
241 }
242 
243 static void veth_dev_free(struct net_device *dev)
244 {
245 	struct veth_priv *priv;
246 
247 	priv = netdev_priv(dev);
248 	free_percpu(priv->stats);
249 	free_netdev(dev);
250 }
251 
252 static const struct net_device_ops veth_netdev_ops = {
253 	.ndo_init            = veth_dev_init,
254 	.ndo_open            = veth_open,
255 	.ndo_stop            = veth_close,
256 	.ndo_start_xmit      = veth_xmit,
257 	.ndo_change_mtu      = veth_change_mtu,
258 	.ndo_get_stats64     = veth_get_stats64,
259 	.ndo_set_mac_address = eth_mac_addr,
260 };
261 
262 static void veth_setup(struct net_device *dev)
263 {
264 	ether_setup(dev);
265 
266 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
267 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
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_HW_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(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 		eth_hw_addr_random(peer);
351 
352 	if (ifmp && (dev->ifindex != 0))
353 		peer->ifindex = ifmp->ifi_index;
354 
355 	err = register_netdevice(peer);
356 	put_net(net);
357 	net = NULL;
358 	if (err < 0)
359 		goto err_register_peer;
360 
361 	netif_carrier_off(peer);
362 
363 	err = rtnl_configure_link(peer, ifmp);
364 	if (err < 0)
365 		goto err_configure_peer;
366 
367 	/*
368 	 * register dev last
369 	 *
370 	 * note, that since we've registered new device the dev's name
371 	 * should be re-allocated
372 	 */
373 
374 	if (tb[IFLA_ADDRESS] == NULL)
375 		eth_hw_addr_random(dev);
376 
377 	if (tb[IFLA_IFNAME])
378 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
379 	else
380 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
381 
382 	if (strchr(dev->name, '%')) {
383 		err = dev_alloc_name(dev, dev->name);
384 		if (err < 0)
385 			goto err_alloc_name;
386 	}
387 
388 	err = register_netdevice(dev);
389 	if (err < 0)
390 		goto err_register_dev;
391 
392 	netif_carrier_off(dev);
393 
394 	/*
395 	 * tie the deviced together
396 	 */
397 
398 	priv = netdev_priv(dev);
399 	priv->peer = peer;
400 
401 	priv = netdev_priv(peer);
402 	priv->peer = dev;
403 	return 0;
404 
405 err_register_dev:
406 	/* nothing to do */
407 err_alloc_name:
408 err_configure_peer:
409 	unregister_netdevice(peer);
410 	return err;
411 
412 err_register_peer:
413 	free_netdev(peer);
414 	return err;
415 }
416 
417 static void veth_dellink(struct net_device *dev, struct list_head *head)
418 {
419 	struct veth_priv *priv;
420 	struct net_device *peer;
421 
422 	priv = netdev_priv(dev);
423 	peer = priv->peer;
424 
425 	unregister_netdevice_queue(dev, head);
426 	unregister_netdevice_queue(peer, head);
427 }
428 
429 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
430 	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
431 };
432 
433 static struct rtnl_link_ops veth_link_ops = {
434 	.kind		= DRV_NAME,
435 	.priv_size	= sizeof(struct veth_priv),
436 	.setup		= veth_setup,
437 	.validate	= veth_validate,
438 	.newlink	= veth_newlink,
439 	.dellink	= veth_dellink,
440 	.policy		= veth_policy,
441 	.maxtype	= VETH_INFO_MAX,
442 };
443 
444 /*
445  * init/fini
446  */
447 
448 static __init int veth_init(void)
449 {
450 	return rtnl_link_register(&veth_link_ops);
451 }
452 
453 static __exit void veth_exit(void)
454 {
455 	rtnl_link_unregister(&veth_link_ops);
456 }
457 
458 module_init(veth_init);
459 module_exit(veth_exit);
460 
461 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
462 MODULE_LICENSE("GPL v2");
463 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
464