ipv4: Remove flowi from struct rtable.
[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 if_list - but not the content */
35 static DEFINE_SPINLOCK(if_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 static void hardif_free_rcu(struct rcu_head *rcu)
44 {
45         struct batman_if *batman_if;
46
47         batman_if = container_of(rcu, struct batman_if, rcu);
48         dev_put(batman_if->net_dev);
49         kref_put(&batman_if->refcount, hardif_free_ref);
50 }
51
52 struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev)
53 {
54         struct batman_if *batman_if;
55
56         rcu_read_lock();
57         list_for_each_entry_rcu(batman_if, &if_list, list) {
58                 if (batman_if->net_dev == net_dev)
59                         goto out;
60         }
61
62         batman_if = NULL;
63
64 out:
65         if (batman_if)
66                 kref_get(&batman_if->refcount);
67
68         rcu_read_unlock();
69         return batman_if;
70 }
71
72 static int is_valid_iface(struct net_device *net_dev)
73 {
74         if (net_dev->flags & IFF_LOOPBACK)
75                 return 0;
76
77         if (net_dev->type != ARPHRD_ETHER)
78                 return 0;
79
80         if (net_dev->addr_len != ETH_ALEN)
81                 return 0;
82
83         /* no batman over batman */
84 #ifdef HAVE_NET_DEVICE_OPS
85         if (net_dev->netdev_ops->ndo_start_xmit == interface_tx)
86                 return 0;
87 #else
88         if (net_dev->hard_start_xmit == interface_tx)
89                 return 0;
90 #endif
91
92         /* Device is being bridged */
93         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
94                 return 0; */
95
96         return 1;
97 }
98
99 static struct batman_if *get_active_batman_if(struct net_device *soft_iface)
100 {
101         struct batman_if *batman_if;
102
103         rcu_read_lock();
104         list_for_each_entry_rcu(batman_if, &if_list, list) {
105                 if (batman_if->soft_iface != soft_iface)
106                         continue;
107
108                 if (batman_if->if_status == IF_ACTIVE)
109                         goto out;
110         }
111
112         batman_if = NULL;
113
114 out:
115         if (batman_if)
116                 kref_get(&batman_if->refcount);
117
118         rcu_read_unlock();
119         return batman_if;
120 }
121
122 static void update_primary_addr(struct bat_priv *bat_priv)
123 {
124         struct vis_packet *vis_packet;
125
126         vis_packet = (struct vis_packet *)
127                                 bat_priv->my_vis_info->skb_packet->data;
128         memcpy(vis_packet->vis_orig,
129                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
130         memcpy(vis_packet->sender_orig,
131                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
132 }
133
134 static void set_primary_if(struct bat_priv *bat_priv,
135                            struct batman_if *batman_if)
136 {
137         struct batman_packet *batman_packet;
138         struct batman_if *old_if;
139
140         if (batman_if)
141                 kref_get(&batman_if->refcount);
142
143         old_if = bat_priv->primary_if;
144         bat_priv->primary_if = batman_if;
145
146         if (old_if)
147                 kref_put(&old_if->refcount, hardif_free_ref);
148
149         if (!bat_priv->primary_if)
150                 return;
151
152         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
153         batman_packet->flags = PRIMARIES_FIRST_HOP;
154         batman_packet->ttl = TTL;
155
156         update_primary_addr(bat_priv);
157
158         /***
159          * hacky trick to make sure that we send the HNA information via
160          * our new primary interface
161          */
162         atomic_set(&bat_priv->hna_local_changed, 1);
163 }
164
165 static bool hardif_is_iface_up(struct batman_if *batman_if)
166 {
167         if (batman_if->net_dev->flags & IFF_UP)
168                 return true;
169
170         return false;
171 }
172
173 static void update_mac_addresses(struct batman_if *batman_if)
174 {
175         memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
176                batman_if->net_dev->dev_addr, ETH_ALEN);
177         memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
178                batman_if->net_dev->dev_addr, ETH_ALEN);
179 }
180
181 static void check_known_mac_addr(struct net_device *net_dev)
182 {
183         struct batman_if *batman_if;
184
185         rcu_read_lock();
186         list_for_each_entry_rcu(batman_if, &if_list, list) {
187                 if ((batman_if->if_status != IF_ACTIVE) &&
188                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
189                         continue;
190
191                 if (batman_if->net_dev == net_dev)
192                         continue;
193
194                 if (!compare_orig(batman_if->net_dev->dev_addr,
195                                   net_dev->dev_addr))
196                         continue;
197
198                 pr_warning("The newly added mac address (%pM) already exists "
199                            "on: %s\n", net_dev->dev_addr,
200                            batman_if->net_dev->name);
201                 pr_warning("It is strongly recommended to keep mac addresses "
202                            "unique to avoid problems!\n");
203         }
204         rcu_read_unlock();
205 }
206
207 int hardif_min_mtu(struct net_device *soft_iface)
208 {
209         struct bat_priv *bat_priv = netdev_priv(soft_iface);
210         struct batman_if *batman_if;
211         /* allow big frames if all devices are capable to do so
212          * (have MTU > 1500 + BAT_HEADER_LEN) */
213         int min_mtu = ETH_DATA_LEN;
214
215         if (atomic_read(&bat_priv->fragmentation))
216                 goto out;
217
218         rcu_read_lock();
219         list_for_each_entry_rcu(batman_if, &if_list, list) {
220                 if ((batman_if->if_status != IF_ACTIVE) &&
221                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
222                         continue;
223
224                 if (batman_if->soft_iface != soft_iface)
225                         continue;
226
227                 min_mtu = min_t(int, batman_if->net_dev->mtu - BAT_HEADER_LEN,
228                                 min_mtu);
229         }
230         rcu_read_unlock();
231 out:
232         return min_mtu;
233 }
234
235 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
236 void update_min_mtu(struct net_device *soft_iface)
237 {
238         int min_mtu;
239
240         min_mtu = hardif_min_mtu(soft_iface);
241         if (soft_iface->mtu != min_mtu)
242                 soft_iface->mtu = min_mtu;
243 }
244
245 static void hardif_activate_interface(struct batman_if *batman_if)
246 {
247         struct bat_priv *bat_priv;
248
249         if (batman_if->if_status != IF_INACTIVE)
250                 return;
251
252         bat_priv = netdev_priv(batman_if->soft_iface);
253
254         update_mac_addresses(batman_if);
255         batman_if->if_status = IF_TO_BE_ACTIVATED;
256
257         /**
258          * the first active interface becomes our primary interface or
259          * the next active interface after the old primay interface was removed
260          */
261         if (!bat_priv->primary_if)
262                 set_primary_if(bat_priv, batman_if);
263
264         bat_info(batman_if->soft_iface, "Interface activated: %s\n",
265                  batman_if->net_dev->name);
266
267         update_min_mtu(batman_if->soft_iface);
268         return;
269 }
270
271 static void hardif_deactivate_interface(struct batman_if *batman_if)
272 {
273         if ((batman_if->if_status != IF_ACTIVE) &&
274            (batman_if->if_status != IF_TO_BE_ACTIVATED))
275                 return;
276
277         batman_if->if_status = IF_INACTIVE;
278
279         bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
280                  batman_if->net_dev->name);
281
282         update_min_mtu(batman_if->soft_iface);
283 }
284
285 int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
286 {
287         struct bat_priv *bat_priv;
288         struct batman_packet *batman_packet;
289
290         if (batman_if->if_status != IF_NOT_IN_USE)
291                 goto out;
292
293         batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
294
295         if (!batman_if->soft_iface) {
296                 batman_if->soft_iface = softif_create(iface_name);
297
298                 if (!batman_if->soft_iface)
299                         goto err;
300
301                 /* dev_get_by_name() increases the reference counter for us */
302                 dev_hold(batman_if->soft_iface);
303         }
304
305         bat_priv = netdev_priv(batman_if->soft_iface);
306         batman_if->packet_len = BAT_PACKET_LEN;
307         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
308
309         if (!batman_if->packet_buff) {
310                 bat_err(batman_if->soft_iface, "Can't add interface packet "
311                         "(%s): out of memory\n", batman_if->net_dev->name);
312                 goto err;
313         }
314
315         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
316         batman_packet->packet_type = BAT_PACKET;
317         batman_packet->version = COMPAT_VERSION;
318         batman_packet->flags = 0;
319         batman_packet->ttl = 2;
320         batman_packet->tq = TQ_MAX_VALUE;
321         batman_packet->num_hna = 0;
322
323         batman_if->if_num = bat_priv->num_ifaces;
324         bat_priv->num_ifaces++;
325         batman_if->if_status = IF_INACTIVE;
326         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
327
328         batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
329         batman_if->batman_adv_ptype.func = batman_skb_recv;
330         batman_if->batman_adv_ptype.dev = batman_if->net_dev;
331         kref_get(&batman_if->refcount);
332         dev_add_pack(&batman_if->batman_adv_ptype);
333
334         atomic_set(&batman_if->seqno, 1);
335         atomic_set(&batman_if->frag_seqno, 1);
336         bat_info(batman_if->soft_iface, "Adding interface: %s\n",
337                  batman_if->net_dev->name);
338
339         if (atomic_read(&bat_priv->fragmentation) && batman_if->net_dev->mtu <
340                 ETH_DATA_LEN + BAT_HEADER_LEN)
341                 bat_info(batman_if->soft_iface,
342                         "The MTU of interface %s is too small (%i) to handle "
343                         "the transport of batman-adv packets. Packets going "
344                         "over this interface will be fragmented on layer2 "
345                         "which could impact the performance. Setting the MTU "
346                         "to %zi would solve the problem.\n",
347                         batman_if->net_dev->name, batman_if->net_dev->mtu,
348                         ETH_DATA_LEN + BAT_HEADER_LEN);
349
350         if (!atomic_read(&bat_priv->fragmentation) && batman_if->net_dev->mtu <
351                 ETH_DATA_LEN + BAT_HEADER_LEN)
352                 bat_info(batman_if->soft_iface,
353                         "The MTU of interface %s is too small (%i) to handle "
354                         "the transport of batman-adv packets. If you experience"
355                         " problems getting traffic through try increasing the "
356                         "MTU to %zi.\n",
357                         batman_if->net_dev->name, batman_if->net_dev->mtu,
358                         ETH_DATA_LEN + BAT_HEADER_LEN);
359
360         if (hardif_is_iface_up(batman_if))
361                 hardif_activate_interface(batman_if);
362         else
363                 bat_err(batman_if->soft_iface, "Not using interface %s "
364                         "(retrying later): interface not active\n",
365                         batman_if->net_dev->name);
366
367         /* begin scheduling originator messages on that interface */
368         schedule_own_packet(batman_if);
369
370 out:
371         return 0;
372
373 err:
374         return -ENOMEM;
375 }
376
377 void hardif_disable_interface(struct batman_if *batman_if)
378 {
379         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
380
381         if (batman_if->if_status == IF_ACTIVE)
382                 hardif_deactivate_interface(batman_if);
383
384         if (batman_if->if_status != IF_INACTIVE)
385                 return;
386
387         bat_info(batman_if->soft_iface, "Removing interface: %s\n",
388                  batman_if->net_dev->name);
389         dev_remove_pack(&batman_if->batman_adv_ptype);
390         kref_put(&batman_if->refcount, hardif_free_ref);
391
392         bat_priv->num_ifaces--;
393         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
394
395         if (batman_if == bat_priv->primary_if) {
396                 struct batman_if *new_if;
397
398                 new_if = get_active_batman_if(batman_if->soft_iface);
399                 set_primary_if(bat_priv, new_if);
400
401                 if (new_if)
402                         kref_put(&new_if->refcount, hardif_free_ref);
403         }
404
405         kfree(batman_if->packet_buff);
406         batman_if->packet_buff = NULL;
407         batman_if->if_status = IF_NOT_IN_USE;
408
409         /* delete all references to this batman_if */
410         purge_orig_ref(bat_priv);
411         purge_outstanding_packets(bat_priv, batman_if);
412         dev_put(batman_if->soft_iface);
413
414         /* nobody uses this interface anymore */
415         if (!bat_priv->num_ifaces)
416                 softif_destroy(batman_if->soft_iface);
417
418         batman_if->soft_iface = NULL;
419 }
420
421 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
422 {
423         struct batman_if *batman_if;
424         int ret;
425
426         ret = is_valid_iface(net_dev);
427         if (ret != 1)
428                 goto out;
429
430         dev_hold(net_dev);
431
432         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
433         if (!batman_if) {
434                 pr_err("Can't add interface (%s): out of memory\n",
435                        net_dev->name);
436                 goto release_dev;
437         }
438
439         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
440         if (ret)
441                 goto free_if;
442
443         batman_if->if_num = -1;
444         batman_if->net_dev = net_dev;
445         batman_if->soft_iface = NULL;
446         batman_if->if_status = IF_NOT_IN_USE;
447         INIT_LIST_HEAD(&batman_if->list);
448         kref_init(&batman_if->refcount);
449
450         check_known_mac_addr(batman_if->net_dev);
451
452         spin_lock(&if_list_lock);
453         list_add_tail_rcu(&batman_if->list, &if_list);
454         spin_unlock(&if_list_lock);
455
456         /* extra reference for return */
457         kref_get(&batman_if->refcount);
458         return batman_if;
459
460 free_if:
461         kfree(batman_if);
462 release_dev:
463         dev_put(net_dev);
464 out:
465         return NULL;
466 }
467
468 static void hardif_remove_interface(struct batman_if *batman_if)
469 {
470         /* first deactivate interface */
471         if (batman_if->if_status != IF_NOT_IN_USE)
472                 hardif_disable_interface(batman_if);
473
474         if (batman_if->if_status != IF_NOT_IN_USE)
475                 return;
476
477         batman_if->if_status = IF_TO_BE_REMOVED;
478         sysfs_del_hardif(&batman_if->hardif_obj);
479         call_rcu(&batman_if->rcu, hardif_free_rcu);
480 }
481
482 void hardif_remove_interfaces(void)
483 {
484         struct batman_if *batman_if, *batman_if_tmp;
485         struct list_head if_queue;
486
487         INIT_LIST_HEAD(&if_queue);
488
489         spin_lock(&if_list_lock);
490         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
491                 list_del_rcu(&batman_if->list);
492                 list_add_tail(&batman_if->list, &if_queue);
493         }
494         spin_unlock(&if_list_lock);
495
496         rtnl_lock();
497         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_queue, list) {
498                 hardif_remove_interface(batman_if);
499         }
500         rtnl_unlock();
501 }
502
503 static int hard_if_event(struct notifier_block *this,
504                          unsigned long event, void *ptr)
505 {
506         struct net_device *net_dev = (struct net_device *)ptr;
507         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
508         struct bat_priv *bat_priv;
509
510         if (!batman_if && event == NETDEV_REGISTER)
511                 batman_if = hardif_add_interface(net_dev);
512
513         if (!batman_if)
514                 goto out;
515
516         switch (event) {
517         case NETDEV_UP:
518                 hardif_activate_interface(batman_if);
519                 break;
520         case NETDEV_GOING_DOWN:
521         case NETDEV_DOWN:
522                 hardif_deactivate_interface(batman_if);
523                 break;
524         case NETDEV_UNREGISTER:
525                 spin_lock(&if_list_lock);
526                 list_del_rcu(&batman_if->list);
527                 spin_unlock(&if_list_lock);
528
529                 hardif_remove_interface(batman_if);
530                 break;
531         case NETDEV_CHANGEMTU:
532                 if (batman_if->soft_iface)
533                         update_min_mtu(batman_if->soft_iface);
534                 break;
535         case NETDEV_CHANGEADDR:
536                 if (batman_if->if_status == IF_NOT_IN_USE)
537                         goto hardif_put;
538
539                 check_known_mac_addr(batman_if->net_dev);
540                 update_mac_addresses(batman_if);
541
542                 bat_priv = netdev_priv(batman_if->soft_iface);
543                 if (batman_if == bat_priv->primary_if)
544                         update_primary_addr(bat_priv);
545                 break;
546         default:
547                 break;
548         };
549
550 hardif_put:
551         kref_put(&batman_if->refcount, hardif_free_ref);
552 out:
553         return NOTIFY_DONE;
554 }
555
556 /* receive a packet with the batman ethertype coming on a hard
557  * interface */
558 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
559                            struct packet_type *ptype,
560                            struct net_device *orig_dev)
561 {
562         struct bat_priv *bat_priv;
563         struct batman_packet *batman_packet;
564         struct batman_if *batman_if;
565         int ret;
566
567         batman_if = container_of(ptype, struct batman_if, batman_adv_ptype);
568         skb = skb_share_check(skb, GFP_ATOMIC);
569
570         /* skb was released by skb_share_check() */
571         if (!skb)
572                 goto err_out;
573
574         /* packet should hold at least type and version */
575         if (unlikely(!pskb_may_pull(skb, 2)))
576                 goto err_free;
577
578         /* expect a valid ethernet header here. */
579         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
580                                 || !skb_mac_header(skb)))
581                 goto err_free;
582
583         if (!batman_if->soft_iface)
584                 goto err_free;
585
586         bat_priv = netdev_priv(batman_if->soft_iface);
587
588         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
589                 goto err_free;
590
591         /* discard frames on not active interfaces */
592         if (batman_if->if_status != IF_ACTIVE)
593                 goto err_free;
594
595         batman_packet = (struct batman_packet *)skb->data;
596
597         if (batman_packet->version != COMPAT_VERSION) {
598                 bat_dbg(DBG_BATMAN, bat_priv,
599                         "Drop packet: incompatible batman version (%i)\n",
600                         batman_packet->version);
601                 goto err_free;
602         }
603
604         /* all receive handlers return whether they received or reused
605          * the supplied skb. if not, we have to free the skb. */
606
607         switch (batman_packet->packet_type) {
608                 /* batman originator packet */
609         case BAT_PACKET:
610                 ret = recv_bat_packet(skb, batman_if);
611                 break;
612
613                 /* batman icmp packet */
614         case BAT_ICMP:
615                 ret = recv_icmp_packet(skb, batman_if);
616                 break;
617
618                 /* unicast packet */
619         case BAT_UNICAST:
620                 ret = recv_unicast_packet(skb, batman_if);
621                 break;
622
623                 /* fragmented unicast packet */
624         case BAT_UNICAST_FRAG:
625                 ret = recv_ucast_frag_packet(skb, batman_if);
626                 break;
627
628                 /* broadcast packet */
629         case BAT_BCAST:
630                 ret = recv_bcast_packet(skb, batman_if);
631                 break;
632
633                 /* vis packet */
634         case BAT_VIS:
635                 ret = recv_vis_packet(skb, batman_if);
636                 break;
637         default:
638                 ret = NET_RX_DROP;
639         }
640
641         if (ret == NET_RX_DROP)
642                 kfree_skb(skb);
643
644         /* return NET_RX_SUCCESS in any case as we
645          * most probably dropped the packet for
646          * routing-logical reasons. */
647
648         return NET_RX_SUCCESS;
649
650 err_free:
651         kfree_skb(skb);
652 err_out:
653         return NET_RX_DROP;
654 }
655
656 struct notifier_block hard_if_notifier = {
657         .notifier_call = hard_if_event,
658 };