Merge branch 'batman-adv/next' of git://git.open-mesh.org/ecsv/linux-merge
[linux-3.10.git] / net / batman-adv / hard-interface.c
1 /*
2  * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner, Simon Wunderlich
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA
19  *
20  */
21
22 #include "main.h"
23 #include "hard-interface.h"
24 #include "soft-interface.h"
25 #include "send.h"
26 #include "translation-table.h"
27 #include "routing.h"
28 #include "bat_sysfs.h"
29 #include "originator.h"
30 #include "hash.h"
31
32 #include <linux/if_arp.h>
33
34 /* protect update critical side of hardif_list - but not the content */
35 static DEFINE_SPINLOCK(hardif_list_lock);
36
37
38 static int batman_skb_recv(struct sk_buff *skb,
39                            struct net_device *dev,
40                            struct packet_type *ptype,
41                            struct net_device *orig_dev);
42
43 void hardif_free_rcu(struct rcu_head *rcu)
44 {
45         struct hard_iface *hard_iface;
46
47         hard_iface = container_of(rcu, struct hard_iface, rcu);
48         dev_put(hard_iface->net_dev);
49         kfree(hard_iface);
50 }
51
52 struct hard_iface *hardif_get_by_netdev(struct net_device *net_dev)
53 {
54         struct hard_iface *hard_iface;
55
56         rcu_read_lock();
57         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
58                 if (hard_iface->net_dev == net_dev &&
59                     atomic_inc_not_zero(&hard_iface->refcount))
60                         goto out;
61         }
62
63         hard_iface = NULL;
64
65 out:
66         rcu_read_unlock();
67         return hard_iface;
68 }
69
70 static int is_valid_iface(struct net_device *net_dev)
71 {
72         if (net_dev->flags & IFF_LOOPBACK)
73                 return 0;
74
75         if (net_dev->type != ARPHRD_ETHER)
76                 return 0;
77
78         if (net_dev->addr_len != ETH_ALEN)
79                 return 0;
80
81         /* no batman over batman */
82         if (softif_is_valid(net_dev))
83                 return 0;
84
85         /* Device is being bridged */
86         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
87                 return 0; */
88
89         return 1;
90 }
91
92 static struct hard_iface *hardif_get_active(struct net_device *soft_iface)
93 {
94         struct hard_iface *hard_iface;
95
96         rcu_read_lock();
97         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
98                 if (hard_iface->soft_iface != soft_iface)
99                         continue;
100
101                 if (hard_iface->if_status == IF_ACTIVE &&
102                     atomic_inc_not_zero(&hard_iface->refcount))
103                         goto out;
104         }
105
106         hard_iface = NULL;
107
108 out:
109         rcu_read_unlock();
110         return hard_iface;
111 }
112
113 static void update_primary_addr(struct bat_priv *bat_priv)
114 {
115         struct vis_packet *vis_packet;
116
117         vis_packet = (struct vis_packet *)
118                                 bat_priv->my_vis_info->skb_packet->data;
119         memcpy(vis_packet->vis_orig,
120                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
121         memcpy(vis_packet->sender_orig,
122                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
123 }
124
125 static void set_primary_if(struct bat_priv *bat_priv,
126                            struct hard_iface *hard_iface)
127 {
128         struct batman_packet *batman_packet;
129         struct hard_iface *old_if;
130
131         if (hard_iface && !atomic_inc_not_zero(&hard_iface->refcount))
132                 hard_iface = NULL;
133
134         old_if = bat_priv->primary_if;
135         bat_priv->primary_if = hard_iface;
136
137         if (old_if)
138                 hardif_free_ref(old_if);
139
140         if (!bat_priv->primary_if)
141                 return;
142
143         batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
144         batman_packet->flags = PRIMARIES_FIRST_HOP;
145         batman_packet->ttl = TTL;
146
147         update_primary_addr(bat_priv);
148
149         /***
150          * hacky trick to make sure that we send the HNA information via
151          * our new primary interface
152          */
153         atomic_set(&bat_priv->hna_local_changed, 1);
154 }
155
156 static bool hardif_is_iface_up(struct hard_iface *hard_iface)
157 {
158         if (hard_iface->net_dev->flags & IFF_UP)
159                 return true;
160
161         return false;
162 }
163
164 static void update_mac_addresses(struct hard_iface *hard_iface)
165 {
166         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->orig,
167                hard_iface->net_dev->dev_addr, ETH_ALEN);
168         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->prev_sender,
169                hard_iface->net_dev->dev_addr, ETH_ALEN);
170 }
171
172 static void check_known_mac_addr(struct net_device *net_dev)
173 {
174         struct hard_iface *hard_iface;
175
176         rcu_read_lock();
177         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
178                 if ((hard_iface->if_status != IF_ACTIVE) &&
179                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
180                         continue;
181
182                 if (hard_iface->net_dev == net_dev)
183                         continue;
184
185                 if (!compare_eth(hard_iface->net_dev->dev_addr,
186                                  net_dev->dev_addr))
187                         continue;
188
189                 pr_warning("The newly added mac address (%pM) already exists "
190                            "on: %s\n", net_dev->dev_addr,
191                            hard_iface->net_dev->name);
192                 pr_warning("It is strongly recommended to keep mac addresses "
193                            "unique to avoid problems!\n");
194         }
195         rcu_read_unlock();
196 }
197
198 int hardif_min_mtu(struct net_device *soft_iface)
199 {
200         struct bat_priv *bat_priv = netdev_priv(soft_iface);
201         struct hard_iface *hard_iface;
202         /* allow big frames if all devices are capable to do so
203          * (have MTU > 1500 + BAT_HEADER_LEN) */
204         int min_mtu = ETH_DATA_LEN;
205
206         if (atomic_read(&bat_priv->fragmentation))
207                 goto out;
208
209         rcu_read_lock();
210         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
211                 if ((hard_iface->if_status != IF_ACTIVE) &&
212                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
213                         continue;
214
215                 if (hard_iface->soft_iface != soft_iface)
216                         continue;
217
218                 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
219                                 min_mtu);
220         }
221         rcu_read_unlock();
222 out:
223         return min_mtu;
224 }
225
226 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
227 void update_min_mtu(struct net_device *soft_iface)
228 {
229         int min_mtu;
230
231         min_mtu = hardif_min_mtu(soft_iface);
232         if (soft_iface->mtu != min_mtu)
233                 soft_iface->mtu = min_mtu;
234 }
235
236 static void hardif_activate_interface(struct hard_iface *hard_iface)
237 {
238         struct bat_priv *bat_priv;
239
240         if (hard_iface->if_status != IF_INACTIVE)
241                 return;
242
243         bat_priv = netdev_priv(hard_iface->soft_iface);
244
245         update_mac_addresses(hard_iface);
246         hard_iface->if_status = IF_TO_BE_ACTIVATED;
247
248         /**
249          * the first active interface becomes our primary interface or
250          * the next active interface after the old primay interface was removed
251          */
252         if (!bat_priv->primary_if)
253                 set_primary_if(bat_priv, hard_iface);
254
255         bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
256                  hard_iface->net_dev->name);
257
258         update_min_mtu(hard_iface->soft_iface);
259         return;
260 }
261
262 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
263 {
264         if ((hard_iface->if_status != IF_ACTIVE) &&
265             (hard_iface->if_status != IF_TO_BE_ACTIVATED))
266                 return;
267
268         hard_iface->if_status = IF_INACTIVE;
269
270         bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
271                  hard_iface->net_dev->name);
272
273         update_min_mtu(hard_iface->soft_iface);
274 }
275
276 int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
277 {
278         struct bat_priv *bat_priv;
279         struct batman_packet *batman_packet;
280         struct net_device *soft_iface;
281         int ret;
282
283         if (hard_iface->if_status != IF_NOT_IN_USE)
284                 goto out;
285
286         if (!atomic_inc_not_zero(&hard_iface->refcount))
287                 goto out;
288
289         soft_iface = dev_get_by_name(&init_net, iface_name);
290
291         if (!soft_iface) {
292                 soft_iface = softif_create(iface_name);
293
294                 if (!soft_iface) {
295                         ret = -ENOMEM;
296                         goto err;
297                 }
298
299                 /* dev_get_by_name() increases the reference counter for us */
300                 dev_hold(soft_iface);
301         }
302
303         if (!softif_is_valid(soft_iface)) {
304                 pr_err("Can't create batman mesh interface %s: "
305                        "already exists as regular interface\n",
306                        soft_iface->name);
307                 dev_put(soft_iface);
308                 ret = -EINVAL;
309                 goto err;
310         }
311
312         hard_iface->soft_iface = soft_iface;
313         bat_priv = netdev_priv(hard_iface->soft_iface);
314         hard_iface->packet_len = BAT_PACKET_LEN;
315         hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC);
316
317         if (!hard_iface->packet_buff) {
318                 bat_err(hard_iface->soft_iface, "Can't add interface packet "
319                         "(%s): out of memory\n", hard_iface->net_dev->name);
320                 ret = -ENOMEM;
321                 goto err;
322         }
323
324         batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
325         batman_packet->packet_type = BAT_PACKET;
326         batman_packet->version = COMPAT_VERSION;
327         batman_packet->flags = 0;
328         batman_packet->ttl = 2;
329         batman_packet->tq = TQ_MAX_VALUE;
330         batman_packet->num_hna = 0;
331
332         hard_iface->if_num = bat_priv->num_ifaces;
333         bat_priv->num_ifaces++;
334         hard_iface->if_status = IF_INACTIVE;
335         orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
336
337         hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
338         hard_iface->batman_adv_ptype.func = batman_skb_recv;
339         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
340         dev_add_pack(&hard_iface->batman_adv_ptype);
341
342         atomic_set(&hard_iface->seqno, 1);
343         atomic_set(&hard_iface->frag_seqno, 1);
344         bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
345                  hard_iface->net_dev->name);
346
347         if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
348                 ETH_DATA_LEN + BAT_HEADER_LEN)
349                 bat_info(hard_iface->soft_iface,
350                         "The MTU of interface %s is too small (%i) to handle "
351                         "the transport of batman-adv packets. Packets going "
352                         "over this interface will be fragmented on layer2 "
353                         "which could impact the performance. Setting the MTU "
354                         "to %zi would solve the problem.\n",
355                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
356                         ETH_DATA_LEN + BAT_HEADER_LEN);
357
358         if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
359                 ETH_DATA_LEN + BAT_HEADER_LEN)
360                 bat_info(hard_iface->soft_iface,
361                         "The MTU of interface %s is too small (%i) to handle "
362                         "the transport of batman-adv packets. If you experience"
363                         " problems getting traffic through try increasing the "
364                         "MTU to %zi.\n",
365                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
366                         ETH_DATA_LEN + BAT_HEADER_LEN);
367
368         if (hardif_is_iface_up(hard_iface))
369                 hardif_activate_interface(hard_iface);
370         else
371                 bat_err(hard_iface->soft_iface, "Not using interface %s "
372                         "(retrying later): interface not active\n",
373                         hard_iface->net_dev->name);
374
375         /* begin scheduling originator messages on that interface */
376         schedule_own_packet(hard_iface);
377
378 out:
379         return 0;
380
381 err:
382         hardif_free_ref(hard_iface);
383         return ret;
384 }
385
386 void hardif_disable_interface(struct hard_iface *hard_iface)
387 {
388         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
389
390         if (hard_iface->if_status == IF_ACTIVE)
391                 hardif_deactivate_interface(hard_iface);
392
393         if (hard_iface->if_status != IF_INACTIVE)
394                 return;
395
396         bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
397                  hard_iface->net_dev->name);
398         dev_remove_pack(&hard_iface->batman_adv_ptype);
399
400         bat_priv->num_ifaces--;
401         orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
402
403         if (hard_iface == bat_priv->primary_if) {
404                 struct hard_iface *new_if;
405
406                 new_if = hardif_get_active(hard_iface->soft_iface);
407                 set_primary_if(bat_priv, new_if);
408
409                 if (new_if)
410                         hardif_free_ref(new_if);
411         }
412
413         kfree(hard_iface->packet_buff);
414         hard_iface->packet_buff = NULL;
415         hard_iface->if_status = IF_NOT_IN_USE;
416
417         /* delete all references to this hard_iface */
418         purge_orig_ref(bat_priv);
419         purge_outstanding_packets(bat_priv, hard_iface);
420         dev_put(hard_iface->soft_iface);
421
422         /* nobody uses this interface anymore */
423         if (!bat_priv->num_ifaces)
424                 softif_destroy(hard_iface->soft_iface);
425
426         hard_iface->soft_iface = NULL;
427         hardif_free_ref(hard_iface);
428 }
429
430 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
431 {
432         struct hard_iface *hard_iface;
433         int ret;
434
435         ret = is_valid_iface(net_dev);
436         if (ret != 1)
437                 goto out;
438
439         dev_hold(net_dev);
440
441         hard_iface = kmalloc(sizeof(struct hard_iface), GFP_ATOMIC);
442         if (!hard_iface) {
443                 pr_err("Can't add interface (%s): out of memory\n",
444                        net_dev->name);
445                 goto release_dev;
446         }
447
448         ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
449         if (ret)
450                 goto free_if;
451
452         hard_iface->if_num = -1;
453         hard_iface->net_dev = net_dev;
454         hard_iface->soft_iface = NULL;
455         hard_iface->if_status = IF_NOT_IN_USE;
456         INIT_LIST_HEAD(&hard_iface->list);
457         /* extra reference for return */
458         atomic_set(&hard_iface->refcount, 2);
459
460         check_known_mac_addr(hard_iface->net_dev);
461
462         spin_lock(&hardif_list_lock);
463         list_add_tail_rcu(&hard_iface->list, &hardif_list);
464         spin_unlock(&hardif_list_lock);
465
466         return hard_iface;
467
468 free_if:
469         kfree(hard_iface);
470 release_dev:
471         dev_put(net_dev);
472 out:
473         return NULL;
474 }
475
476 static void hardif_remove_interface(struct hard_iface *hard_iface)
477 {
478         /* first deactivate interface */
479         if (hard_iface->if_status != IF_NOT_IN_USE)
480                 hardif_disable_interface(hard_iface);
481
482         if (hard_iface->if_status != IF_NOT_IN_USE)
483                 return;
484
485         hard_iface->if_status = IF_TO_BE_REMOVED;
486         sysfs_del_hardif(&hard_iface->hardif_obj);
487         hardif_free_ref(hard_iface);
488 }
489
490 void hardif_remove_interfaces(void)
491 {
492         struct hard_iface *hard_iface, *hard_iface_tmp;
493         struct list_head if_queue;
494
495         INIT_LIST_HEAD(&if_queue);
496
497         spin_lock(&hardif_list_lock);
498         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
499                                  &hardif_list, list) {
500                 list_del_rcu(&hard_iface->list);
501                 list_add_tail(&hard_iface->list, &if_queue);
502         }
503         spin_unlock(&hardif_list_lock);
504
505         rtnl_lock();
506         list_for_each_entry_safe(hard_iface, hard_iface_tmp, &if_queue, list) {
507                 hardif_remove_interface(hard_iface);
508         }
509         rtnl_unlock();
510 }
511
512 static int hard_if_event(struct notifier_block *this,
513                          unsigned long event, void *ptr)
514 {
515         struct net_device *net_dev = (struct net_device *)ptr;
516         struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
517         struct bat_priv *bat_priv;
518
519         if (!hard_iface && event == NETDEV_REGISTER)
520                 hard_iface = hardif_add_interface(net_dev);
521
522         if (!hard_iface)
523                 goto out;
524
525         switch (event) {
526         case NETDEV_UP:
527                 hardif_activate_interface(hard_iface);
528                 break;
529         case NETDEV_GOING_DOWN:
530         case NETDEV_DOWN:
531                 hardif_deactivate_interface(hard_iface);
532                 break;
533         case NETDEV_UNREGISTER:
534                 spin_lock(&hardif_list_lock);
535                 list_del_rcu(&hard_iface->list);
536                 spin_unlock(&hardif_list_lock);
537
538                 hardif_remove_interface(hard_iface);
539                 break;
540         case NETDEV_CHANGEMTU:
541                 if (hard_iface->soft_iface)
542                         update_min_mtu(hard_iface->soft_iface);
543                 break;
544         case NETDEV_CHANGEADDR:
545                 if (hard_iface->if_status == IF_NOT_IN_USE)
546                         goto hardif_put;
547
548                 check_known_mac_addr(hard_iface->net_dev);
549                 update_mac_addresses(hard_iface);
550
551                 bat_priv = netdev_priv(hard_iface->soft_iface);
552                 if (hard_iface == bat_priv->primary_if)
553                         update_primary_addr(bat_priv);
554                 break;
555         default:
556                 break;
557         };
558
559 hardif_put:
560         hardif_free_ref(hard_iface);
561 out:
562         return NOTIFY_DONE;
563 }
564
565 /* receive a packet with the batman ethertype coming on a hard
566  * interface */
567 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
568                            struct packet_type *ptype,
569                            struct net_device *orig_dev)
570 {
571         struct bat_priv *bat_priv;
572         struct batman_packet *batman_packet;
573         struct hard_iface *hard_iface;
574         int ret;
575
576         hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
577         skb = skb_share_check(skb, GFP_ATOMIC);
578
579         /* skb was released by skb_share_check() */
580         if (!skb)
581                 goto err_out;
582
583         /* packet should hold at least type and version */
584         if (unlikely(!pskb_may_pull(skb, 2)))
585                 goto err_free;
586
587         /* expect a valid ethernet header here. */
588         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
589                                 || !skb_mac_header(skb)))
590                 goto err_free;
591
592         if (!hard_iface->soft_iface)
593                 goto err_free;
594
595         bat_priv = netdev_priv(hard_iface->soft_iface);
596
597         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
598                 goto err_free;
599
600         /* discard frames on not active interfaces */
601         if (hard_iface->if_status != IF_ACTIVE)
602                 goto err_free;
603
604         batman_packet = (struct batman_packet *)skb->data;
605
606         if (batman_packet->version != COMPAT_VERSION) {
607                 bat_dbg(DBG_BATMAN, bat_priv,
608                         "Drop packet: incompatible batman version (%i)\n",
609                         batman_packet->version);
610                 goto err_free;
611         }
612
613         /* all receive handlers return whether they received or reused
614          * the supplied skb. if not, we have to free the skb. */
615
616         switch (batman_packet->packet_type) {
617                 /* batman originator packet */
618         case BAT_PACKET:
619                 ret = recv_bat_packet(skb, hard_iface);
620                 break;
621
622                 /* batman icmp packet */
623         case BAT_ICMP:
624                 ret = recv_icmp_packet(skb, hard_iface);
625                 break;
626
627                 /* unicast packet */
628         case BAT_UNICAST:
629                 ret = recv_unicast_packet(skb, hard_iface);
630                 break;
631
632                 /* fragmented unicast packet */
633         case BAT_UNICAST_FRAG:
634                 ret = recv_ucast_frag_packet(skb, hard_iface);
635                 break;
636
637                 /* broadcast packet */
638         case BAT_BCAST:
639                 ret = recv_bcast_packet(skb, hard_iface);
640                 break;
641
642                 /* vis packet */
643         case BAT_VIS:
644                 ret = recv_vis_packet(skb, hard_iface);
645                 break;
646         default:
647                 ret = NET_RX_DROP;
648         }
649
650         if (ret == NET_RX_DROP)
651                 kfree_skb(skb);
652
653         /* return NET_RX_SUCCESS in any case as we
654          * most probably dropped the packet for
655          * routing-logical reasons. */
656
657         return NET_RX_SUCCESS;
658
659 err_free:
660         kfree_skb(skb);
661 err_out:
662         return NET_RX_DROP;
663 }
664
665 struct notifier_block hard_if_notifier = {
666         .notifier_call = hard_if_event,
667 };