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mm/hmm.c: remove superfluous RCU protection around radix tree lookup
[linux/fpc-iii.git] / drivers / net / veth.c
bloba69ad39ee57e7168f2495a56b5b9d208dc9f308e
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/rtnetlink.h>
18 #include <net/dst.h>
19 #include <net/xfrm.h>
20 #include <linux/veth.h>
21 #include <linux/module.h>
22
23 #define DRV_NAME "veth"
24 #define DRV_VERSION "1.0"
25
26 struct pcpu_vstats {
27 u64 packets;
28 u64 bytes;
29 struct u64_stats_sync syncp;
30 };
31
32 struct veth_priv {
33 struct net_device __rcu *peer;
34 atomic64_t dropped;
35 unsigned requested_headroom;
36 };
37
38 /*
39 * ethtool interface
40 */
41
42 static struct {
43 const char string[ETH_GSTRING_LEN];
44 } ethtool_stats_keys[] = {
45 { "peer_ifindex" },
46 };
47
48 static int veth_get_link_ksettings(struct net_device *dev,
49 struct ethtool_link_ksettings *cmd)
50 {
51 cmd->base.speed = SPEED_10000;
52 cmd->base.duplex = DUPLEX_FULL;
53 cmd->base.port = PORT_TP;
54 cmd->base.autoneg = AUTONEG_DISABLE;
55 return 0;
56 }
57
58 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
59 {
60 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
61 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
62 }
63
64 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
65 {
66 switch(stringset) {
67 case ETH_SS_STATS:
68 memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
69 break;
70 }
71 }
72
73 static int veth_get_sset_count(struct net_device *dev, int sset)
74 {
75 switch (sset) {
76 case ETH_SS_STATS:
77 return ARRAY_SIZE(ethtool_stats_keys);
78 default:
79 return -EOPNOTSUPP;
80 }
81 }
82
83 static void veth_get_ethtool_stats(struct net_device *dev,
84 struct ethtool_stats *stats, u64 *data)
85 {
86 struct veth_priv *priv = netdev_priv(dev);
87 struct net_device *peer = rtnl_dereference(priv->peer);
88
89 data[0] = peer ? peer->ifindex : 0;
90 }
91
92 static const struct ethtool_ops veth_ethtool_ops = {
93 .get_drvinfo = veth_get_drvinfo,
94 .get_link = ethtool_op_get_link,
95 .get_strings = veth_get_strings,
96 .get_sset_count = veth_get_sset_count,
97 .get_ethtool_stats = veth_get_ethtool_stats,
98 .get_link_ksettings = veth_get_link_ksettings,
99 };
100
101 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
102 {
103 struct veth_priv *priv = netdev_priv(dev);
104 struct net_device *rcv;
105 int length = skb->len;
106
107 rcu_read_lock();
108 rcv = rcu_dereference(priv->peer);
109 if (unlikely(!rcv)) {
110 kfree_skb(skb);
111 goto drop;
112 }
113
114 if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
115 struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
116
117 u64_stats_update_begin(&stats->syncp);
118 stats->bytes += length;
119 stats->packets++;
120 u64_stats_update_end(&stats->syncp);
121 } else {
122 drop:
123 atomic64_inc(&priv->dropped);
124 }
125 rcu_read_unlock();
126 return NETDEV_TX_OK;
127 }
128
129 /*
130 * general routines
131 */
132
133 static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
134 {
135 struct veth_priv *priv = netdev_priv(dev);
136 int cpu;
137
138 result->packets = 0;
139 result->bytes = 0;
140 for_each_possible_cpu(cpu) {
141 struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
142 u64 packets, bytes;
143 unsigned int start;
144
145 do {
146 start = u64_stats_fetch_begin_irq(&stats->syncp);
147 packets = stats->packets;
148 bytes = stats->bytes;
149 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
150 result->packets += packets;
151 result->bytes += bytes;
152 }
153 return atomic64_read(&priv->dropped);
154 }
155
156 static void veth_get_stats64(struct net_device *dev,
157 struct rtnl_link_stats64 *tot)
158 {
159 struct veth_priv *priv = netdev_priv(dev);
160 struct net_device *peer;
161 struct pcpu_vstats one;
162
163 tot->tx_dropped = veth_stats_one(&one, dev);
164 tot->tx_bytes = one.bytes;
165 tot->tx_packets = one.packets;
166
167 rcu_read_lock();
168 peer = rcu_dereference(priv->peer);
169 if (peer) {
170 tot->rx_dropped = veth_stats_one(&one, peer);
171 tot->rx_bytes = one.bytes;
172 tot->rx_packets = one.packets;
173 }
174 rcu_read_unlock();
175 }
176
177 /* fake multicast ability */
178 static void veth_set_multicast_list(struct net_device *dev)
179 {
180 }
181
182 static int veth_open(struct net_device *dev)
183 {
184 struct veth_priv *priv = netdev_priv(dev);
185 struct net_device *peer = rtnl_dereference(priv->peer);
186
187 if (!peer)
188 return -ENOTCONN;
189
190 if (peer->flags & IFF_UP) {
191 netif_carrier_on(dev);
192 netif_carrier_on(peer);
193 }
194 return 0;
195 }
196
197 static int veth_close(struct net_device *dev)
198 {
199 struct veth_priv *priv = netdev_priv(dev);
200 struct net_device *peer = rtnl_dereference(priv->peer);
201
202 netif_carrier_off(dev);
203 if (peer)
204 netif_carrier_off(peer);
205
206 return 0;
207 }
208
209 static int is_valid_veth_mtu(int mtu)
210 {
211 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
212 }
213
214 static int veth_dev_init(struct net_device *dev)
215 {
216 dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
217 if (!dev->vstats)
218 return -ENOMEM;
219 return 0;
220 }
221
222 static void veth_dev_free(struct net_device *dev)
223 {
224 free_percpu(dev->vstats);
225 }
226
227 #ifdef CONFIG_NET_POLL_CONTROLLER
228 static void veth_poll_controller(struct net_device *dev)
229 {
230 /* veth only receives frames when its peer sends one
231 * Since it's a synchronous operation, we are guaranteed
232 * never to have pending data when we poll for it so
233 * there is nothing to do here.
234 *
235 * We need this though so netpoll recognizes us as an interface that
236 * supports polling, which enables bridge devices in virt setups to
237 * still use netconsole
238 */
239 }
240 #endif /* CONFIG_NET_POLL_CONTROLLER */
241
242 static int veth_get_iflink(const struct net_device *dev)
243 {
244 struct veth_priv *priv = netdev_priv(dev);
245 struct net_device *peer;
246 int iflink;
247
248 rcu_read_lock();
249 peer = rcu_dereference(priv->peer);
250 iflink = peer ? peer->ifindex : 0;
251 rcu_read_unlock();
252
253 return iflink;
254 }
255
256 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
257 {
258 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
259 struct net_device *peer;
260
261 if (new_hr < 0)
262 new_hr = 0;
263
264 rcu_read_lock();
265 peer = rcu_dereference(priv->peer);
266 if (unlikely(!peer))
267 goto out;
268
269 peer_priv = netdev_priv(peer);
270 priv->requested_headroom = new_hr;
271 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
272 dev->needed_headroom = new_hr;
273 peer->needed_headroom = new_hr;
274
275 out:
276 rcu_read_unlock();
277 }
278
279 static const struct net_device_ops veth_netdev_ops = {
280 .ndo_init = veth_dev_init,
281 .ndo_open = veth_open,
282 .ndo_stop = veth_close,
283 .ndo_start_xmit = veth_xmit,
284 .ndo_get_stats64 = veth_get_stats64,
285 .ndo_set_rx_mode = veth_set_multicast_list,
286 .ndo_set_mac_address = eth_mac_addr,
287 #ifdef CONFIG_NET_POLL_CONTROLLER
288 .ndo_poll_controller = veth_poll_controller,
289 #endif
290 .ndo_get_iflink = veth_get_iflink,
291 .ndo_features_check = passthru_features_check,
292 .ndo_set_rx_headroom = veth_set_rx_headroom,
293 };
294
295 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
296 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
297 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
298 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
299 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
300
301 static void veth_setup(struct net_device *dev)
302 {
303 ether_setup(dev);
304
305 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
306 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
307 dev->priv_flags |= IFF_NO_QUEUE;
308 dev->priv_flags |= IFF_PHONY_HEADROOM;
309
310 dev->netdev_ops = &veth_netdev_ops;
311 dev->ethtool_ops = &veth_ethtool_ops;
312 dev->features |= NETIF_F_LLTX;
313 dev->features |= VETH_FEATURES;
314 dev->vlan_features = dev->features &
315 ~(NETIF_F_HW_VLAN_CTAG_TX |
316 NETIF_F_HW_VLAN_STAG_TX |
317 NETIF_F_HW_VLAN_CTAG_RX |
318 NETIF_F_HW_VLAN_STAG_RX);
319 dev->needs_free_netdev = true;
320 dev->priv_destructor = veth_dev_free;
321 dev->max_mtu = ETH_MAX_MTU;
322
323 dev->hw_features = VETH_FEATURES;
324 dev->hw_enc_features = VETH_FEATURES;
325 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
326 }
327
328 /*
329 * netlink interface
330 */
331
332 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
333 struct netlink_ext_ack *extack)
334 {
335 if (tb[IFLA_ADDRESS]) {
336 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
337 return -EINVAL;
338 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
339 return -EADDRNOTAVAIL;
340 }
341 if (tb[IFLA_MTU]) {
342 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
343 return -EINVAL;
344 }
345 return 0;
346 }
347
348 static struct rtnl_link_ops veth_link_ops;
349
350 static int veth_newlink(struct net *src_net, struct net_device *dev,
351 struct nlattr *tb[], struct nlattr *data[],
352 struct netlink_ext_ack *extack)
353 {
354 int err;
355 struct net_device *peer;
356 struct veth_priv *priv;
357 char ifname[IFNAMSIZ];
358 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
359 unsigned char name_assign_type;
360 struct ifinfomsg *ifmp;
361 struct net *net;
362
363 /*
364 * create and register peer first
365 */
366 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
367 struct nlattr *nla_peer;
368
369 nla_peer = data[VETH_INFO_PEER];
370 ifmp = nla_data(nla_peer);
371 err = rtnl_nla_parse_ifla(peer_tb,
372 nla_data(nla_peer) + sizeof(struct ifinfomsg),
373 nla_len(nla_peer) - sizeof(struct ifinfomsg),
374 NULL);
375 if (err < 0)
376 return err;
377
378 err = veth_validate(peer_tb, NULL, extack);
379 if (err < 0)
380 return err;
381
382 tbp = peer_tb;
383 } else {
384 ifmp = NULL;
385 tbp = tb;
386 }
387
388 if (ifmp && tbp[IFLA_IFNAME]) {
389 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
390 name_assign_type = NET_NAME_USER;
391 } else {
392 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
393 name_assign_type = NET_NAME_ENUM;
394 }
395
396 net = rtnl_link_get_net(src_net, tbp);
397 if (IS_ERR(net))
398 return PTR_ERR(net);
399
400 peer = rtnl_create_link(net, ifname, name_assign_type,
401 &veth_link_ops, tbp);
402 if (IS_ERR(peer)) {
403 put_net(net);
404 return PTR_ERR(peer);
405 }
406
407 if (!ifmp || !tbp[IFLA_ADDRESS])
408 eth_hw_addr_random(peer);
409
410 if (ifmp && (dev->ifindex != 0))
411 peer->ifindex = ifmp->ifi_index;
412
413 peer->gso_max_size = dev->gso_max_size;
414 peer->gso_max_segs = dev->gso_max_segs;
415
416 err = register_netdevice(peer);
417 put_net(net);
418 net = NULL;
419 if (err < 0)
420 goto err_register_peer;
421
422 netif_carrier_off(peer);
423
424 err = rtnl_configure_link(peer, ifmp);
425 if (err < 0)
426 goto err_configure_peer;
427
428 /*
429 * register dev last
430 *
431 * note, that since we've registered new device the dev's name
432 * should be re-allocated
433 */
434
435 if (tb[IFLA_ADDRESS] == NULL)
436 eth_hw_addr_random(dev);
437
438 if (tb[IFLA_IFNAME])
439 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
440 else
441 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
442
443 err = register_netdevice(dev);
444 if (err < 0)
445 goto err_register_dev;
446
447 netif_carrier_off(dev);
448
449 /*
450 * tie the deviced together
451 */
452
453 priv = netdev_priv(dev);
454 rcu_assign_pointer(priv->peer, peer);
455
456 priv = netdev_priv(peer);
457 rcu_assign_pointer(priv->peer, dev);
458 return 0;
459
460 err_register_dev:
461 /* nothing to do */
462 err_configure_peer:
463 unregister_netdevice(peer);
464 return err;
465
466 err_register_peer:
467 free_netdev(peer);
468 return err;
469 }
470
471 static void veth_dellink(struct net_device *dev, struct list_head *head)
472 {
473 struct veth_priv *priv;
474 struct net_device *peer;
475
476 priv = netdev_priv(dev);
477 peer = rtnl_dereference(priv->peer);
478
479 /* Note : dellink() is called from default_device_exit_batch(),
480 * before a rcu_synchronize() point. The devices are guaranteed
481 * not being freed before one RCU grace period.
482 */
483 RCU_INIT_POINTER(priv->peer, NULL);
484 unregister_netdevice_queue(dev, head);
485
486 if (peer) {
487 priv = netdev_priv(peer);
488 RCU_INIT_POINTER(priv->peer, NULL);
489 unregister_netdevice_queue(peer, head);
490 }
491 }
492
493 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
494 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
495 };
496
497 static struct net *veth_get_link_net(const struct net_device *dev)
498 {
499 struct veth_priv *priv = netdev_priv(dev);
500 struct net_device *peer = rtnl_dereference(priv->peer);
501
502 return peer ? dev_net(peer) : dev_net(dev);
503 }
504
505 static struct rtnl_link_ops veth_link_ops = {
506 .kind = DRV_NAME,
507 .priv_size = sizeof(struct veth_priv),
508 .setup = veth_setup,
509 .validate = veth_validate,
510 .newlink = veth_newlink,
511 .dellink = veth_dellink,
512 .policy = veth_policy,
513 .maxtype = VETH_INFO_MAX,
514 .get_link_net = veth_get_link_net,
515 };
516
517 /*
518 * init/fini
519 */
520
521 static __init int veth_init(void)
522 {
523 return rtnl_link_register(&veth_link_ops);
524 }
525
526 static __exit void veth_exit(void)
527 {
528 rtnl_link_unregister(&veth_link_ops);
529 }
530
531 module_init(veth_init);
532 module_exit(veth_exit);
533
534 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
535 MODULE_LICENSE("GPL v2");
536 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Linux with added FPC-III support