macvlan: remove one synchronize_rcu() call
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / net / macvlan.c
1 /*
2  * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of
7  * the License, or (at your option) any later version.
8  *
9  * The code this is based on carried the following copyright notice:
10  * ---
11  * (C) Copyright 2001-2006
12  * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
13  * Re-worked by Ben Greear <greearb@candelatech.com>
14  * ---
15  */
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/errno.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/rculist.h>
24 #include <linux/notifier.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/ethtool.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_link.h>
30 #include <linux/if_macvlan.h>
31 #include <net/rtnetlink.h>
32 #include <net/xfrm.h>
33
34 #define MACVLAN_HASH_SIZE       (1 << BITS_PER_BYTE)
35
36 struct macvlan_port {
37         struct net_device       *dev;
38         struct hlist_head       vlan_hash[MACVLAN_HASH_SIZE];
39         struct list_head        vlans;
40         struct rcu_head         rcu;
41         bool                    passthru;
42         int                     count;
43 };
44
45 static void macvlan_port_destroy(struct net_device *dev);
46
47 #define macvlan_port_get_rcu(dev) \
48         ((struct macvlan_port *) rcu_dereference(dev->rx_handler_data))
49 #define macvlan_port_get(dev) ((struct macvlan_port *) dev->rx_handler_data)
50 #define macvlan_port_exists(dev) (dev->priv_flags & IFF_MACVLAN_PORT)
51
52 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
53                                                const unsigned char *addr)
54 {
55         struct macvlan_dev *vlan;
56         struct hlist_node *n;
57
58         hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
59                 if (!compare_ether_addr_64bits(vlan->dev->dev_addr, addr))
60                         return vlan;
61         }
62         return NULL;
63 }
64
65 static void macvlan_hash_add(struct macvlan_dev *vlan)
66 {
67         struct macvlan_port *port = vlan->port;
68         const unsigned char *addr = vlan->dev->dev_addr;
69
70         hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
71 }
72
73 static void macvlan_hash_del(struct macvlan_dev *vlan, bool sync)
74 {
75         hlist_del_rcu(&vlan->hlist);
76         if (sync)
77                 synchronize_rcu();
78 }
79
80 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
81                                         const unsigned char *addr)
82 {
83         macvlan_hash_del(vlan, true);
84         /* Now that we are unhashed it is safe to change the device
85          * address without confusing packet delivery.
86          */
87         memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
88         macvlan_hash_add(vlan);
89 }
90
91 static int macvlan_addr_busy(const struct macvlan_port *port,
92                                 const unsigned char *addr)
93 {
94         /* Test to see if the specified multicast address is
95          * currently in use by the underlying device or
96          * another macvlan.
97          */
98         if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
99                 return 1;
100
101         if (macvlan_hash_lookup(port, addr))
102                 return 1;
103
104         return 0;
105 }
106
107
108 static int macvlan_broadcast_one(struct sk_buff *skb,
109                                  const struct macvlan_dev *vlan,
110                                  const struct ethhdr *eth, bool local)
111 {
112         struct net_device *dev = vlan->dev;
113         if (!skb)
114                 return NET_RX_DROP;
115
116         if (local)
117                 return vlan->forward(dev, skb);
118
119         skb->dev = dev;
120         if (!compare_ether_addr_64bits(eth->h_dest,
121                                        dev->broadcast))
122                 skb->pkt_type = PACKET_BROADCAST;
123         else
124                 skb->pkt_type = PACKET_MULTICAST;
125
126         return vlan->receive(skb);
127 }
128
129 static void macvlan_broadcast(struct sk_buff *skb,
130                               const struct macvlan_port *port,
131                               struct net_device *src,
132                               enum macvlan_mode mode)
133 {
134         const struct ethhdr *eth = eth_hdr(skb);
135         const struct macvlan_dev *vlan;
136         struct hlist_node *n;
137         struct sk_buff *nskb;
138         unsigned int i;
139         int err;
140
141         if (skb->protocol == htons(ETH_P_PAUSE))
142                 return;
143
144         for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
145                 hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
146                         if (vlan->dev == src || !(vlan->mode & mode))
147                                 continue;
148
149                         nskb = skb_clone(skb, GFP_ATOMIC);
150                         err = macvlan_broadcast_one(nskb, vlan, eth,
151                                          mode == MACVLAN_MODE_BRIDGE);
152                         macvlan_count_rx(vlan, skb->len + ETH_HLEN,
153                                          err == NET_RX_SUCCESS, 1);
154                 }
155         }
156 }
157
158 /* called under rcu_read_lock() from netif_receive_skb */
159 static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
160 {
161         struct macvlan_port *port;
162         struct sk_buff *skb = *pskb;
163         const struct ethhdr *eth = eth_hdr(skb);
164         const struct macvlan_dev *vlan;
165         const struct macvlan_dev *src;
166         struct net_device *dev;
167         unsigned int len = 0;
168         int ret = NET_RX_DROP;
169
170         port = macvlan_port_get_rcu(skb->dev);
171         if (is_multicast_ether_addr(eth->h_dest)) {
172                 src = macvlan_hash_lookup(port, eth->h_source);
173                 if (!src)
174                         /* frame comes from an external address */
175                         macvlan_broadcast(skb, port, NULL,
176                                           MACVLAN_MODE_PRIVATE |
177                                           MACVLAN_MODE_VEPA    |
178                                           MACVLAN_MODE_PASSTHRU|
179                                           MACVLAN_MODE_BRIDGE);
180                 else if (src->mode == MACVLAN_MODE_VEPA)
181                         /* flood to everyone except source */
182                         macvlan_broadcast(skb, port, src->dev,
183                                           MACVLAN_MODE_VEPA |
184                                           MACVLAN_MODE_BRIDGE);
185                 else if (src->mode == MACVLAN_MODE_BRIDGE)
186                         /*
187                          * flood only to VEPA ports, bridge ports
188                          * already saw the frame on the way out.
189                          */
190                         macvlan_broadcast(skb, port, src->dev,
191                                           MACVLAN_MODE_VEPA);
192                 return RX_HANDLER_PASS;
193         }
194
195         if (port->passthru)
196                 vlan = list_first_entry(&port->vlans, struct macvlan_dev, list);
197         else
198                 vlan = macvlan_hash_lookup(port, eth->h_dest);
199         if (vlan == NULL)
200                 return RX_HANDLER_PASS;
201
202         dev = vlan->dev;
203         if (unlikely(!(dev->flags & IFF_UP))) {
204                 kfree_skb(skb);
205                 return RX_HANDLER_CONSUMED;
206         }
207         len = skb->len + ETH_HLEN;
208         skb = skb_share_check(skb, GFP_ATOMIC);
209         if (!skb)
210                 goto out;
211
212         skb->dev = dev;
213         skb->pkt_type = PACKET_HOST;
214
215         ret = vlan->receive(skb);
216
217 out:
218         macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);
219         return RX_HANDLER_CONSUMED;
220 }
221
222 static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
223 {
224         const struct macvlan_dev *vlan = netdev_priv(dev);
225         const struct macvlan_port *port = vlan->port;
226         const struct macvlan_dev *dest;
227         __u8 ip_summed = skb->ip_summed;
228
229         if (vlan->mode == MACVLAN_MODE_BRIDGE) {
230                 const struct ethhdr *eth = (void *)skb->data;
231                 skb->ip_summed = CHECKSUM_UNNECESSARY;
232
233                 /* send to other bridge ports directly */
234                 if (is_multicast_ether_addr(eth->h_dest)) {
235                         macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
236                         goto xmit_world;
237                 }
238
239                 dest = macvlan_hash_lookup(port, eth->h_dest);
240                 if (dest && dest->mode == MACVLAN_MODE_BRIDGE) {
241                         unsigned int length = skb->len + ETH_HLEN;
242                         int ret = dest->forward(dest->dev, skb);
243                         macvlan_count_rx(dest, length,
244                                          ret == NET_RX_SUCCESS, 0);
245
246                         return NET_XMIT_SUCCESS;
247                 }
248         }
249
250 xmit_world:
251         skb->ip_summed = ip_summed;
252         skb_set_dev(skb, vlan->lowerdev);
253         return dev_queue_xmit(skb);
254 }
255
256 netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
257                                struct net_device *dev)
258 {
259         unsigned int len = skb->len;
260         int ret;
261         const struct macvlan_dev *vlan = netdev_priv(dev);
262
263         ret = macvlan_queue_xmit(skb, dev);
264         if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
265                 struct macvlan_pcpu_stats *pcpu_stats;
266
267                 pcpu_stats = this_cpu_ptr(vlan->pcpu_stats);
268                 u64_stats_update_begin(&pcpu_stats->syncp);
269                 pcpu_stats->tx_packets++;
270                 pcpu_stats->tx_bytes += len;
271                 u64_stats_update_end(&pcpu_stats->syncp);
272         } else {
273                 this_cpu_inc(vlan->pcpu_stats->tx_dropped);
274         }
275         return ret;
276 }
277 EXPORT_SYMBOL_GPL(macvlan_start_xmit);
278
279 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
280                                unsigned short type, const void *daddr,
281                                const void *saddr, unsigned len)
282 {
283         const struct macvlan_dev *vlan = netdev_priv(dev);
284         struct net_device *lowerdev = vlan->lowerdev;
285
286         return dev_hard_header(skb, lowerdev, type, daddr,
287                                saddr ? : dev->dev_addr, len);
288 }
289
290 static const struct header_ops macvlan_hard_header_ops = {
291         .create         = macvlan_hard_header,
292         .rebuild        = eth_rebuild_header,
293         .parse          = eth_header_parse,
294         .cache          = eth_header_cache,
295         .cache_update   = eth_header_cache_update,
296 };
297
298 static int macvlan_open(struct net_device *dev)
299 {
300         struct macvlan_dev *vlan = netdev_priv(dev);
301         struct net_device *lowerdev = vlan->lowerdev;
302         int err;
303
304         if (vlan->port->passthru) {
305                 dev_set_promiscuity(lowerdev, 1);
306                 goto hash_add;
307         }
308
309         err = -EBUSY;
310         if (macvlan_addr_busy(vlan->port, dev->dev_addr))
311                 goto out;
312
313         err = dev_uc_add(lowerdev, dev->dev_addr);
314         if (err < 0)
315                 goto out;
316         if (dev->flags & IFF_ALLMULTI) {
317                 err = dev_set_allmulti(lowerdev, 1);
318                 if (err < 0)
319                         goto del_unicast;
320         }
321
322 hash_add:
323         macvlan_hash_add(vlan);
324         return 0;
325
326 del_unicast:
327         dev_uc_del(lowerdev, dev->dev_addr);
328 out:
329         return err;
330 }
331
332 static int macvlan_stop(struct net_device *dev)
333 {
334         struct macvlan_dev *vlan = netdev_priv(dev);
335         struct net_device *lowerdev = vlan->lowerdev;
336
337         if (vlan->port->passthru) {
338                 dev_set_promiscuity(lowerdev, -1);
339                 goto hash_del;
340         }
341
342         dev_mc_unsync(lowerdev, dev);
343         if (dev->flags & IFF_ALLMULTI)
344                 dev_set_allmulti(lowerdev, -1);
345
346         dev_uc_del(lowerdev, dev->dev_addr);
347
348 hash_del:
349         macvlan_hash_del(vlan, !dev->dismantle);
350         return 0;
351 }
352
353 static int macvlan_set_mac_address(struct net_device *dev, void *p)
354 {
355         struct macvlan_dev *vlan = netdev_priv(dev);
356         struct net_device *lowerdev = vlan->lowerdev;
357         struct sockaddr *addr = p;
358         int err;
359
360         if (!is_valid_ether_addr(addr->sa_data))
361                 return -EADDRNOTAVAIL;
362
363         if (!(dev->flags & IFF_UP)) {
364                 /* Just copy in the new address */
365                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
366         } else {
367                 /* Rehash and update the device filters */
368                 if (macvlan_addr_busy(vlan->port, addr->sa_data))
369                         return -EBUSY;
370
371                 err = dev_uc_add(lowerdev, addr->sa_data);
372                 if (err)
373                         return err;
374
375                 dev_uc_del(lowerdev, dev->dev_addr);
376
377                 macvlan_hash_change_addr(vlan, addr->sa_data);
378         }
379         return 0;
380 }
381
382 static void macvlan_change_rx_flags(struct net_device *dev, int change)
383 {
384         struct macvlan_dev *vlan = netdev_priv(dev);
385         struct net_device *lowerdev = vlan->lowerdev;
386
387         if (change & IFF_ALLMULTI)
388                 dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
389 }
390
391 static void macvlan_set_multicast_list(struct net_device *dev)
392 {
393         struct macvlan_dev *vlan = netdev_priv(dev);
394
395         dev_mc_sync(vlan->lowerdev, dev);
396 }
397
398 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
399 {
400         struct macvlan_dev *vlan = netdev_priv(dev);
401
402         if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
403                 return -EINVAL;
404         dev->mtu = new_mtu;
405         return 0;
406 }
407
408 /*
409  * macvlan network devices have devices nesting below it and are a special
410  * "super class" of normal network devices; split their locks off into a
411  * separate class since they always nest.
412  */
413 static struct lock_class_key macvlan_netdev_xmit_lock_key;
414 static struct lock_class_key macvlan_netdev_addr_lock_key;
415
416 #define MACVLAN_FEATURES \
417         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
418          NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
419          NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO | NETIF_F_RXCSUM)
420
421 #define MACVLAN_STATE_MASK \
422         ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
423
424 static void macvlan_set_lockdep_class_one(struct net_device *dev,
425                                           struct netdev_queue *txq,
426                                           void *_unused)
427 {
428         lockdep_set_class(&txq->_xmit_lock,
429                           &macvlan_netdev_xmit_lock_key);
430 }
431
432 static void macvlan_set_lockdep_class(struct net_device *dev)
433 {
434         lockdep_set_class(&dev->addr_list_lock,
435                           &macvlan_netdev_addr_lock_key);
436         netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
437 }
438
439 static int macvlan_init(struct net_device *dev)
440 {
441         struct macvlan_dev *vlan = netdev_priv(dev);
442         const struct net_device *lowerdev = vlan->lowerdev;
443
444         dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
445                                   (lowerdev->state & MACVLAN_STATE_MASK);
446         dev->features           = lowerdev->features & MACVLAN_FEATURES;
447         dev->features           |= NETIF_F_LLTX;
448         dev->gso_max_size       = lowerdev->gso_max_size;
449         dev->iflink             = lowerdev->ifindex;
450         dev->hard_header_len    = lowerdev->hard_header_len;
451
452         macvlan_set_lockdep_class(dev);
453
454         vlan->pcpu_stats = alloc_percpu(struct macvlan_pcpu_stats);
455         if (!vlan->pcpu_stats)
456                 return -ENOMEM;
457
458         return 0;
459 }
460
461 static void macvlan_uninit(struct net_device *dev)
462 {
463         struct macvlan_dev *vlan = netdev_priv(dev);
464         struct macvlan_port *port = vlan->port;
465
466         free_percpu(vlan->pcpu_stats);
467
468         port->count -= 1;
469         if (!port->count)
470                 macvlan_port_destroy(port->dev);
471 }
472
473 static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
474                                                          struct rtnl_link_stats64 *stats)
475 {
476         struct macvlan_dev *vlan = netdev_priv(dev);
477
478         if (vlan->pcpu_stats) {
479                 struct macvlan_pcpu_stats *p;
480                 u64 rx_packets, rx_bytes, rx_multicast, tx_packets, tx_bytes;
481                 u32 rx_errors = 0, tx_dropped = 0;
482                 unsigned int start;
483                 int i;
484
485                 for_each_possible_cpu(i) {
486                         p = per_cpu_ptr(vlan->pcpu_stats, i);
487                         do {
488                                 start = u64_stats_fetch_begin_bh(&p->syncp);
489                                 rx_packets      = p->rx_packets;
490                                 rx_bytes        = p->rx_bytes;
491                                 rx_multicast    = p->rx_multicast;
492                                 tx_packets      = p->tx_packets;
493                                 tx_bytes        = p->tx_bytes;
494                         } while (u64_stats_fetch_retry_bh(&p->syncp, start));
495
496                         stats->rx_packets       += rx_packets;
497                         stats->rx_bytes         += rx_bytes;
498                         stats->multicast        += rx_multicast;
499                         stats->tx_packets       += tx_packets;
500                         stats->tx_bytes         += tx_bytes;
501                         /* rx_errors & tx_dropped are u32, updated
502                          * without syncp protection.
503                          */
504                         rx_errors       += p->rx_errors;
505                         tx_dropped      += p->tx_dropped;
506                 }
507                 stats->rx_errors        = rx_errors;
508                 stats->rx_dropped       = rx_errors;
509                 stats->tx_dropped       = tx_dropped;
510         }
511         return stats;
512 }
513
514 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
515                                         struct ethtool_drvinfo *drvinfo)
516 {
517         snprintf(drvinfo->driver, 32, "macvlan");
518         snprintf(drvinfo->version, 32, "0.1");
519 }
520
521 static int macvlan_ethtool_get_settings(struct net_device *dev,
522                                         struct ethtool_cmd *cmd)
523 {
524         const struct macvlan_dev *vlan = netdev_priv(dev);
525         return dev_ethtool_get_settings(vlan->lowerdev, cmd);
526 }
527
528 static const struct ethtool_ops macvlan_ethtool_ops = {
529         .get_link               = ethtool_op_get_link,
530         .get_settings           = macvlan_ethtool_get_settings,
531         .get_drvinfo            = macvlan_ethtool_get_drvinfo,
532 };
533
534 static const struct net_device_ops macvlan_netdev_ops = {
535         .ndo_init               = macvlan_init,
536         .ndo_uninit             = macvlan_uninit,
537         .ndo_open               = macvlan_open,
538         .ndo_stop               = macvlan_stop,
539         .ndo_start_xmit         = macvlan_start_xmit,
540         .ndo_change_mtu         = macvlan_change_mtu,
541         .ndo_change_rx_flags    = macvlan_change_rx_flags,
542         .ndo_set_mac_address    = macvlan_set_mac_address,
543         .ndo_set_multicast_list = macvlan_set_multicast_list,
544         .ndo_get_stats64        = macvlan_dev_get_stats64,
545         .ndo_validate_addr      = eth_validate_addr,
546 };
547
548 void macvlan_common_setup(struct net_device *dev)
549 {
550         ether_setup(dev);
551
552         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
553         dev->netdev_ops         = &macvlan_netdev_ops;
554         dev->destructor         = free_netdev;
555         dev->header_ops         = &macvlan_hard_header_ops,
556         dev->ethtool_ops        = &macvlan_ethtool_ops;
557 }
558 EXPORT_SYMBOL_GPL(macvlan_common_setup);
559
560 static void macvlan_setup(struct net_device *dev)
561 {
562         macvlan_common_setup(dev);
563         dev->tx_queue_len       = 0;
564 }
565
566 static int macvlan_port_create(struct net_device *dev)
567 {
568         struct macvlan_port *port;
569         unsigned int i;
570         int err;
571
572         if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
573                 return -EINVAL;
574
575         port = kzalloc(sizeof(*port), GFP_KERNEL);
576         if (port == NULL)
577                 return -ENOMEM;
578
579         port->passthru = false;
580         port->dev = dev;
581         INIT_LIST_HEAD(&port->vlans);
582         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
583                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
584
585         err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
586         if (err)
587                 kfree(port);
588
589         dev->priv_flags |= IFF_MACVLAN_PORT;
590         return err;
591 }
592
593 static void macvlan_port_rcu_free(struct rcu_head *head)
594 {
595         struct macvlan_port *port;
596
597         port = container_of(head, struct macvlan_port, rcu);
598         kfree(port);
599 }
600
601 static void macvlan_port_destroy(struct net_device *dev)
602 {
603         struct macvlan_port *port = macvlan_port_get(dev);
604
605         dev->priv_flags &= ~IFF_MACVLAN_PORT;
606         netdev_rx_handler_unregister(dev);
607         call_rcu(&port->rcu, macvlan_port_rcu_free);
608 }
609
610 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
611 {
612         if (tb[IFLA_ADDRESS]) {
613                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
614                         return -EINVAL;
615                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
616                         return -EADDRNOTAVAIL;
617         }
618
619         if (data && data[IFLA_MACVLAN_MODE]) {
620                 switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
621                 case MACVLAN_MODE_PRIVATE:
622                 case MACVLAN_MODE_VEPA:
623                 case MACVLAN_MODE_BRIDGE:
624                 case MACVLAN_MODE_PASSTHRU:
625                         break;
626                 default:
627                         return -EINVAL;
628                 }
629         }
630         return 0;
631 }
632
633 int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
634                            struct nlattr *tb[], struct nlattr *data[],
635                            int (*receive)(struct sk_buff *skb),
636                            int (*forward)(struct net_device *dev,
637                                           struct sk_buff *skb))
638 {
639         struct macvlan_dev *vlan = netdev_priv(dev);
640         struct macvlan_port *port;
641         struct net_device *lowerdev;
642         int err;
643
644         if (!tb[IFLA_LINK])
645                 return -EINVAL;
646
647         lowerdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
648         if (lowerdev == NULL)
649                 return -ENODEV;
650
651         /* When creating macvlans on top of other macvlans - use
652          * the real device as the lowerdev.
653          */
654         if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
655                 struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
656                 lowerdev = lowervlan->lowerdev;
657         }
658
659         if (!tb[IFLA_MTU])
660                 dev->mtu = lowerdev->mtu;
661         else if (dev->mtu > lowerdev->mtu)
662                 return -EINVAL;
663
664         if (!tb[IFLA_ADDRESS])
665                 random_ether_addr(dev->dev_addr);
666
667         if (!macvlan_port_exists(lowerdev)) {
668                 err = macvlan_port_create(lowerdev);
669                 if (err < 0)
670                         return err;
671         }
672         port = macvlan_port_get(lowerdev);
673
674         /* Only 1 macvlan device can be created in passthru mode */
675         if (port->passthru)
676                 return -EINVAL;
677
678         vlan->lowerdev = lowerdev;
679         vlan->dev      = dev;
680         vlan->port     = port;
681         vlan->receive  = receive;
682         vlan->forward  = forward;
683
684         vlan->mode     = MACVLAN_MODE_VEPA;
685         if (data && data[IFLA_MACVLAN_MODE])
686                 vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
687
688         if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
689                 if (port->count)
690                         return -EINVAL;
691                 port->passthru = true;
692                 memcpy(dev->dev_addr, lowerdev->dev_addr, ETH_ALEN);
693         }
694
695         port->count += 1;
696         err = register_netdevice(dev);
697         if (err < 0)
698                 goto destroy_port;
699
700         list_add_tail(&vlan->list, &port->vlans);
701         netif_stacked_transfer_operstate(lowerdev, dev);
702
703         return 0;
704
705 destroy_port:
706         port->count -= 1;
707         if (!port->count)
708                 macvlan_port_destroy(lowerdev);
709
710         return err;
711 }
712 EXPORT_SYMBOL_GPL(macvlan_common_newlink);
713
714 static int macvlan_newlink(struct net *src_net, struct net_device *dev,
715                            struct nlattr *tb[], struct nlattr *data[])
716 {
717         return macvlan_common_newlink(src_net, dev, tb, data,
718                                       netif_rx,
719                                       dev_forward_skb);
720 }
721
722 void macvlan_dellink(struct net_device *dev, struct list_head *head)
723 {
724         struct macvlan_dev *vlan = netdev_priv(dev);
725
726         list_del(&vlan->list);
727         unregister_netdevice_queue(dev, head);
728 }
729 EXPORT_SYMBOL_GPL(macvlan_dellink);
730
731 static int macvlan_changelink(struct net_device *dev,
732                 struct nlattr *tb[], struct nlattr *data[])
733 {
734         struct macvlan_dev *vlan = netdev_priv(dev);
735         if (data && data[IFLA_MACVLAN_MODE])
736                 vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
737         return 0;
738 }
739
740 static size_t macvlan_get_size(const struct net_device *dev)
741 {
742         return nla_total_size(4);
743 }
744
745 static int macvlan_fill_info(struct sk_buff *skb,
746                                 const struct net_device *dev)
747 {
748         struct macvlan_dev *vlan = netdev_priv(dev);
749
750         NLA_PUT_U32(skb, IFLA_MACVLAN_MODE, vlan->mode);
751         return 0;
752
753 nla_put_failure:
754         return -EMSGSIZE;
755 }
756
757 static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
758         [IFLA_MACVLAN_MODE] = { .type = NLA_U32 },
759 };
760
761 int macvlan_link_register(struct rtnl_link_ops *ops)
762 {
763         /* common fields */
764         ops->priv_size          = sizeof(struct macvlan_dev);
765         ops->validate           = macvlan_validate;
766         ops->maxtype            = IFLA_MACVLAN_MAX;
767         ops->policy             = macvlan_policy;
768         ops->changelink         = macvlan_changelink;
769         ops->get_size           = macvlan_get_size;
770         ops->fill_info          = macvlan_fill_info;
771
772         return rtnl_link_register(ops);
773 };
774 EXPORT_SYMBOL_GPL(macvlan_link_register);
775
776 static struct rtnl_link_ops macvlan_link_ops = {
777         .kind           = "macvlan",
778         .setup          = macvlan_setup,
779         .newlink        = macvlan_newlink,
780         .dellink        = macvlan_dellink,
781 };
782
783 static int macvlan_device_event(struct notifier_block *unused,
784                                 unsigned long event, void *ptr)
785 {
786         struct net_device *dev = ptr;
787         struct macvlan_dev *vlan, *next;
788         struct macvlan_port *port;
789         LIST_HEAD(list_kill);
790
791         if (!macvlan_port_exists(dev))
792                 return NOTIFY_DONE;
793
794         port = macvlan_port_get(dev);
795
796         switch (event) {
797         case NETDEV_CHANGE:
798                 list_for_each_entry(vlan, &port->vlans, list)
799                         netif_stacked_transfer_operstate(vlan->lowerdev,
800                                                          vlan->dev);
801                 break;
802         case NETDEV_FEAT_CHANGE:
803                 list_for_each_entry(vlan, &port->vlans, list) {
804                         vlan->dev->features = dev->features & MACVLAN_FEATURES;
805                         vlan->dev->gso_max_size = dev->gso_max_size;
806                         netdev_features_change(vlan->dev);
807                 }
808                 break;
809         case NETDEV_UNREGISTER:
810                 /* twiddle thumbs on netns device moves */
811                 if (dev->reg_state != NETREG_UNREGISTERING)
812                         break;
813
814                 list_for_each_entry_safe(vlan, next, &port->vlans, list)
815                         vlan->dev->rtnl_link_ops->dellink(vlan->dev, &list_kill);
816                 unregister_netdevice_many(&list_kill);
817                 list_del(&list_kill);
818                 break;
819         case NETDEV_PRE_TYPE_CHANGE:
820                 /* Forbid underlaying device to change its type. */
821                 return NOTIFY_BAD;
822         }
823         return NOTIFY_DONE;
824 }
825
826 static struct notifier_block macvlan_notifier_block __read_mostly = {
827         .notifier_call  = macvlan_device_event,
828 };
829
830 static int __init macvlan_init_module(void)
831 {
832         int err;
833
834         register_netdevice_notifier(&macvlan_notifier_block);
835
836         err = macvlan_link_register(&macvlan_link_ops);
837         if (err < 0)
838                 goto err1;
839         return 0;
840 err1:
841         unregister_netdevice_notifier(&macvlan_notifier_block);
842         return err;
843 }
844
845 static void __exit macvlan_cleanup_module(void)
846 {
847         rtnl_link_unregister(&macvlan_link_ops);
848         unregister_netdevice_notifier(&macvlan_notifier_block);
849 }
850
851 module_init(macvlan_init_module);
852 module_exit(macvlan_cleanup_module);
853
854 MODULE_LICENSE("GPL");
855 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
856 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
857 MODULE_ALIAS_RTNL_LINK("macvlan");