veth.c revision 237114384ab22c174ec4641e809f8e6cbcfce774 
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
28struct 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
37struct veth_priv {
38	struct net_device *peer;
39	struct veth_net_stats __percpu *stats;
40};
41
42/*
43 * ethtool interface
44 */
45
46static struct {
47	const char string[ETH_GSTRING_LEN];
48} ethtool_stats_keys[] = {
49	{ "peer_ifindex" },
50};
51
52static 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
67static 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
73static 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
82static 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
92static 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
101static 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
114static 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
150rx_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
161static 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
191static 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
206static 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
216static int is_valid_veth_mtu(int new_mtu)
217{
218	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
219}
220
221static 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
229static 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
243static 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
252static 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
262static void veth_setup(struct net_device *dev)
263{
264	ether_setup(dev);
265
266	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
267
268	dev->netdev_ops = &veth_netdev_ops;
269	dev->ethtool_ops = &veth_ethtool_ops;
270	dev->features |= NETIF_F_LLTX;
271	dev->destructor = veth_dev_free;
272
273	dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
274}
275
276/*
277 * netlink interface
278 */
279
280static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
281{
282	if (tb[IFLA_ADDRESS]) {
283		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
284			return -EINVAL;
285		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
286			return -EADDRNOTAVAIL;
287	}
288	if (tb[IFLA_MTU]) {
289		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
290			return -EINVAL;
291	}
292	return 0;
293}
294
295static struct rtnl_link_ops veth_link_ops;
296
297static int veth_newlink(struct net *src_net, struct net_device *dev,
298			 struct nlattr *tb[], struct nlattr *data[])
299{
300	int err;
301	struct net_device *peer;
302	struct veth_priv *priv;
303	char ifname[IFNAMSIZ];
304	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
305	struct ifinfomsg *ifmp;
306	struct net *net;
307
308	/*
309	 * create and register peer first
310	 */
311	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
312		struct nlattr *nla_peer;
313
314		nla_peer = data[VETH_INFO_PEER];
315		ifmp = nla_data(nla_peer);
316		err = nla_parse(peer_tb, IFLA_MAX,
317				nla_data(nla_peer) + sizeof(struct ifinfomsg),
318				nla_len(nla_peer) - sizeof(struct ifinfomsg),
319				ifla_policy);
320		if (err < 0)
321			return err;
322
323		err = veth_validate(peer_tb, NULL);
324		if (err < 0)
325			return err;
326
327		tbp = peer_tb;
328	} else {
329		ifmp = NULL;
330		tbp = tb;
331	}
332
333	if (tbp[IFLA_IFNAME])
334		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
335	else
336		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
337
338	net = rtnl_link_get_net(src_net, tbp);
339	if (IS_ERR(net))
340		return PTR_ERR(net);
341
342	peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
343	if (IS_ERR(peer)) {
344		put_net(net);
345		return PTR_ERR(peer);
346	}
347
348	if (tbp[IFLA_ADDRESS] == NULL)
349		random_ether_addr(peer->dev_addr);
350
351	err = register_netdevice(peer);
352	put_net(net);
353	net = NULL;
354	if (err < 0)
355		goto err_register_peer;
356
357	netif_carrier_off(peer);
358
359	err = rtnl_configure_link(peer, ifmp);
360	if (err < 0)
361		goto err_configure_peer;
362
363	/*
364	 * register dev last
365	 *
366	 * note, that since we've registered new device the dev's name
367	 * should be re-allocated
368	 */
369
370	if (tb[IFLA_ADDRESS] == NULL)
371		random_ether_addr(dev->dev_addr);
372
373	if (tb[IFLA_IFNAME])
374		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
375	else
376		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
377
378	if (strchr(dev->name, '%')) {
379		err = dev_alloc_name(dev, dev->name);
380		if (err < 0)
381			goto err_alloc_name;
382	}
383
384	err = register_netdevice(dev);
385	if (err < 0)
386		goto err_register_dev;
387
388	netif_carrier_off(dev);
389
390	/*
391	 * tie the deviced together
392	 */
393
394	priv = netdev_priv(dev);
395	priv->peer = peer;
396
397	priv = netdev_priv(peer);
398	priv->peer = dev;
399	return 0;
400
401err_register_dev:
402	/* nothing to do */
403err_alloc_name:
404err_configure_peer:
405	unregister_netdevice(peer);
406	return err;
407
408err_register_peer:
409	free_netdev(peer);
410	return err;
411}
412
413static void veth_dellink(struct net_device *dev, struct list_head *head)
414{
415	struct veth_priv *priv;
416	struct net_device *peer;
417
418	priv = netdev_priv(dev);
419	peer = priv->peer;
420
421	unregister_netdevice_queue(dev, head);
422	unregister_netdevice_queue(peer, head);
423}
424
425static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
426	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
427};
428
429static struct rtnl_link_ops veth_link_ops = {
430	.kind		= DRV_NAME,
431	.priv_size	= sizeof(struct veth_priv),
432	.setup		= veth_setup,
433	.validate	= veth_validate,
434	.newlink	= veth_newlink,
435	.dellink	= veth_dellink,
436	.policy		= veth_policy,
437	.maxtype	= VETH_INFO_MAX,
438};
439
440/*
441 * init/fini
442 */
443
444static __init int veth_init(void)
445{
446	return rtnl_link_register(&veth_link_ops);
447}
448
449static __exit void veth_exit(void)
450{
451	rtnl_link_unregister(&veth_link_ops);
452}
453
454module_init(veth_init);
455module_exit(veth_exit);
456
457MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
458MODULE_LICENSE("GPL v2");
459MODULE_ALIAS_RTNL_LINK(DRV_NAME);
460