blob: 239992021b1d635382dfcec141723696d7cbf564 [file] [log] [blame]
Antonio Quartulli0b873932013-01-04 03:05:31 +01001/* Copyright (C) 2011-2013 B.A.T.M.A.N. contributors:
Antonio Quartulli785ea112011-11-23 11:35:44 +01002 *
3 * Antonio Quartulli
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
18 */
19
20#include <linux/if_ether.h>
21#include <linux/if_arp.h>
Antonio Quartullic384ea32011-06-26 03:37:18 +020022#include <net/arp.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010023
24#include "main.h"
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +020025#include "hash.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010026#include "distributed-arp-table.h"
27#include "hard-interface.h"
28#include "originator.h"
29#include "send.h"
30#include "types.h"
Antonio Quartullic384ea32011-06-26 03:37:18 +020031#include "translation-table.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010032#include "unicast.h"
33
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020034static void batadv_dat_purge(struct work_struct *work);
35
36/**
37 * batadv_dat_start_timer - initialise the DAT periodic worker
38 * @bat_priv: the bat priv with all the soft interface information
39 */
40static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
41{
42 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
43 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
44 msecs_to_jiffies(10000));
45}
46
47/**
48 * batadv_dat_entry_free_ref - decrements the dat_entry refcounter and possibly
49 * free it
50 * @dat_entry: the oentry to free
51 */
52static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
53{
54 if (atomic_dec_and_test(&dat_entry->refcount))
55 kfree_rcu(dat_entry, rcu);
56}
57
58/**
59 * batadv_dat_to_purge - checks whether a dat_entry has to be purged or not
60 * @dat_entry: the entry to check
61 *
62 * Returns true if the entry has to be purged now, false otherwise
63 */
64static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
65{
66 return batadv_has_timed_out(dat_entry->last_update,
67 BATADV_DAT_ENTRY_TIMEOUT);
68}
69
70/**
71 * __batadv_dat_purge - delete entries from the DAT local storage
72 * @bat_priv: the bat priv with all the soft interface information
73 * @to_purge: function in charge to decide whether an entry has to be purged or
74 * not. This function takes the dat_entry as argument and has to
75 * returns a boolean value: true is the entry has to be deleted,
76 * false otherwise
77 *
78 * Loops over each entry in the DAT local storage and delete it if and only if
79 * the to_purge function passed as argument returns true
80 */
81static void __batadv_dat_purge(struct batadv_priv *bat_priv,
82 bool (*to_purge)(struct batadv_dat_entry *))
83{
84 spinlock_t *list_lock; /* protects write access to the hash lists */
85 struct batadv_dat_entry *dat_entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -080086 struct hlist_node *node_tmp;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020087 struct hlist_head *head;
88 uint32_t i;
89
90 if (!bat_priv->dat.hash)
91 return;
92
93 for (i = 0; i < bat_priv->dat.hash->size; i++) {
94 head = &bat_priv->dat.hash->table[i];
95 list_lock = &bat_priv->dat.hash->list_locks[i];
96
97 spin_lock_bh(list_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -080098 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020099 hash_entry) {
100 /* if an helper function has been passed as parameter,
101 * ask it if the entry has to be purged or not
102 */
103 if (to_purge && !to_purge(dat_entry))
104 continue;
105
Sasha Levinb67bfe02013-02-27 17:06:00 -0800106 hlist_del_rcu(&dat_entry->hash_entry);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200107 batadv_dat_entry_free_ref(dat_entry);
108 }
109 spin_unlock_bh(list_lock);
110 }
111}
112
113/**
114 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
115 * hash table
116 * @work: kernel work struct
117 */
118static void batadv_dat_purge(struct work_struct *work)
119{
120 struct delayed_work *delayed_work;
121 struct batadv_priv_dat *priv_dat;
122 struct batadv_priv *bat_priv;
123
124 delayed_work = container_of(work, struct delayed_work, work);
125 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
126 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
127
128 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
129 batadv_dat_start_timer(bat_priv);
130}
131
132/**
133 * batadv_compare_dat - comparing function used in the local DAT hash table
134 * @node: node in the local table
135 * @data2: second object to compare the node to
136 *
137 * Returns 1 if the two entry are the same, 0 otherwise
138 */
139static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
140{
141 const void *data1 = container_of(node, struct batadv_dat_entry,
142 hash_entry);
143
144 return (memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0);
145}
146
Antonio Quartulli785ea112011-11-23 11:35:44 +0100147/**
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200148 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
149 * @skb: ARP packet
150 * @hdr_size: size of the possible header before the ARP packet
151 *
152 * Returns the value of the hw_src field in the ARP packet
153 */
154static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
155{
156 uint8_t *addr;
157
158 addr = (uint8_t *)(skb->data + hdr_size);
159 addr += ETH_HLEN + sizeof(struct arphdr);
160
161 return addr;
162}
163
164/**
165 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
166 * @skb: ARP packet
167 * @hdr_size: size of the possible header before the ARP packet
168 *
169 * Returns the value of the ip_src field in the ARP packet
170 */
171static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
172{
173 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
174}
175
176/**
177 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
178 * @skb: ARP packet
179 * @hdr_size: size of the possible header before the ARP packet
180 *
181 * Returns the value of the hw_dst field in the ARP packet
182 */
183static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
184{
185 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
186}
187
188/**
189 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
190 * @skb: ARP packet
191 * @hdr_size: size of the possible header before the ARP packet
192 *
193 * Returns the value of the ip_dst field in the ARP packet
194 */
195static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
196{
197 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
198}
199
200/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100201 * batadv_hash_dat - compute the hash value for an IP address
202 * @data: data to hash
203 * @size: size of the hash table
204 *
205 * Returns the selected index in the hash table for the given data
206 */
207static uint32_t batadv_hash_dat(const void *data, uint32_t size)
208{
209 const unsigned char *key = data;
210 uint32_t hash = 0;
211 size_t i;
212
213 for (i = 0; i < 4; i++) {
214 hash += key[i];
215 hash += (hash << 10);
216 hash ^= (hash >> 6);
217 }
218
219 hash += (hash << 3);
220 hash ^= (hash >> 11);
221 hash += (hash << 15);
222
223 return hash % size;
224}
225
226/**
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200227 * batadv_dat_entry_hash_find - looks for a given dat_entry in the local hash
228 * table
229 * @bat_priv: the bat priv with all the soft interface information
230 * @ip: search key
231 *
232 * Returns the dat_entry if found, NULL otherwise
233 */
234static struct batadv_dat_entry *
235batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip)
236{
237 struct hlist_head *head;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200238 struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL;
239 struct batadv_hashtable *hash = bat_priv->dat.hash;
240 uint32_t index;
241
242 if (!hash)
243 return NULL;
244
245 index = batadv_hash_dat(&ip, hash->size);
246 head = &hash->table[index];
247
248 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800249 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200250 if (dat_entry->ip != ip)
251 continue;
252
253 if (!atomic_inc_not_zero(&dat_entry->refcount))
254 continue;
255
256 dat_entry_tmp = dat_entry;
257 break;
258 }
259 rcu_read_unlock();
260
261 return dat_entry_tmp;
262}
263
264/**
265 * batadv_dat_entry_add - add a new dat entry or update it if already exists
266 * @bat_priv: the bat priv with all the soft interface information
267 * @ip: ipv4 to add/edit
268 * @mac_addr: mac address to assign to the given ipv4
269 */
270static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
271 uint8_t *mac_addr)
272{
273 struct batadv_dat_entry *dat_entry;
274 int hash_added;
275
276 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip);
277 /* if this entry is already known, just update it */
278 if (dat_entry) {
279 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
280 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
281 dat_entry->last_update = jiffies;
282 batadv_dbg(BATADV_DBG_DAT, bat_priv,
283 "Entry updated: %pI4 %pM\n", &dat_entry->ip,
284 dat_entry->mac_addr);
285 goto out;
286 }
287
288 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
289 if (!dat_entry)
290 goto out;
291
292 dat_entry->ip = ip;
293 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
294 dat_entry->last_update = jiffies;
295 atomic_set(&dat_entry->refcount, 2);
296
297 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
298 batadv_hash_dat, &dat_entry->ip,
299 &dat_entry->hash_entry);
300
301 if (unlikely(hash_added != 0)) {
302 /* remove the reference for the hash */
303 batadv_dat_entry_free_ref(dat_entry);
304 goto out;
305 }
306
307 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM\n",
308 &dat_entry->ip, dat_entry->mac_addr);
309
310out:
311 if (dat_entry)
312 batadv_dat_entry_free_ref(dat_entry);
313}
314
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200315#ifdef CONFIG_BATMAN_ADV_DEBUG
316
317/**
318 * batadv_dbg_arp - print a debug message containing all the ARP packet details
319 * @bat_priv: the bat priv with all the soft interface information
320 * @skb: ARP packet
321 * @type: ARP type
322 * @hdr_size: size of the possible header before the ARP packet
323 * @msg: message to print together with the debugging information
324 */
325static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
326 uint16_t type, int hdr_size, char *msg)
327{
328 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
329 struct batadv_bcast_packet *bcast_pkt;
330 uint8_t *orig_addr;
331 __be32 ip_src, ip_dst;
332
333 if (msg)
334 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
335
336 ip_src = batadv_arp_ip_src(skb, hdr_size);
337 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
338 batadv_dbg(BATADV_DBG_DAT, bat_priv,
339 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
340 batadv_arp_hw_src(skb, hdr_size), &ip_src,
341 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
342
343 if (hdr_size == 0)
344 return;
345
346 /* if the ARP packet is encapsulated in a batman packet, let's print
347 * some debug messages
348 */
349 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
350
351 switch (unicast_4addr_packet->u.header.packet_type) {
352 case BATADV_UNICAST:
353 batadv_dbg(BATADV_DBG_DAT, bat_priv,
354 "* encapsulated within a UNICAST packet\n");
355 break;
356 case BATADV_UNICAST_4ADDR:
357 batadv_dbg(BATADV_DBG_DAT, bat_priv,
358 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
359 unicast_4addr_packet->src);
360 switch (unicast_4addr_packet->subtype) {
361 case BATADV_P_DAT_DHT_PUT:
362 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
363 break;
364 case BATADV_P_DAT_DHT_GET:
365 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
366 break;
367 case BATADV_P_DAT_CACHE_REPLY:
368 batadv_dbg(BATADV_DBG_DAT, bat_priv,
369 "* type: DAT_CACHE_REPLY\n");
370 break;
371 case BATADV_P_DATA:
372 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
373 break;
374 default:
375 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
376 unicast_4addr_packet->u.header.packet_type);
377 }
378 break;
379 case BATADV_BCAST:
380 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
381 orig_addr = bcast_pkt->orig;
382 batadv_dbg(BATADV_DBG_DAT, bat_priv,
383 "* encapsulated within a BCAST packet (src: %pM)\n",
384 orig_addr);
385 break;
386 default:
387 batadv_dbg(BATADV_DBG_DAT, bat_priv,
388 "* encapsulated within an unknown packet type (0x%x)\n",
389 unicast_4addr_packet->u.header.packet_type);
390 }
391}
392
393#else
394
395static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
396 uint16_t type, int hdr_size, char *msg)
397{
398}
399
400#endif /* CONFIG_BATMAN_ADV_DEBUG */
401
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200402/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100403 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
404 * @res: the array with the already selected candidates
405 * @select: number of already selected candidates
406 * @tmp_max: address of the currently evaluated node
407 * @max: current round max address
408 * @last_max: address of the last selected candidate
409 * @candidate: orig_node under evaluation
410 * @max_orig_node: last selected candidate
411 *
412 * Returns true if the node has been elected as next candidate or false othrwise
413 */
414static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
415 int select, batadv_dat_addr_t tmp_max,
416 batadv_dat_addr_t max,
417 batadv_dat_addr_t last_max,
418 struct batadv_orig_node *candidate,
419 struct batadv_orig_node *max_orig_node)
420{
421 bool ret = false;
422 int j;
423
424 /* Check if this node has already been selected... */
425 for (j = 0; j < select; j++)
426 if (res[j].orig_node == candidate)
427 break;
428 /* ..and possibly skip it */
429 if (j < select)
430 goto out;
431 /* sanity check: has it already been selected? This should not happen */
432 if (tmp_max > last_max)
433 goto out;
434 /* check if during this iteration an originator with a closer dht
435 * address has already been found
436 */
437 if (tmp_max < max)
438 goto out;
439 /* this is an hash collision with the temporary selected node. Choose
440 * the one with the lowest address
441 */
Pau Koning816cd5b2013-02-12 00:18:45 +0000442 if ((tmp_max == max) && max_orig_node &&
Antonio Quartulli785ea112011-11-23 11:35:44 +0100443 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
444 goto out;
445
446 ret = true;
447out:
448 return ret;
449}
450
451/**
452 * batadv_choose_next_candidate - select the next DHT candidate
453 * @bat_priv: the bat priv with all the soft interface information
454 * @cands: candidates array
455 * @select: number of candidates already present in the array
456 * @ip_key: key to look up in the DHT
457 * @last_max: pointer where the address of the selected candidate will be saved
458 */
459static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
460 struct batadv_dat_candidate *cands,
461 int select, batadv_dat_addr_t ip_key,
462 batadv_dat_addr_t *last_max)
463{
464 batadv_dat_addr_t max = 0, tmp_max = 0;
465 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
466 struct batadv_hashtable *hash = bat_priv->orig_hash;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100467 struct hlist_head *head;
468 int i;
469
470 /* if no node is eligible as candidate, leave the candidate type as
471 * NOT_FOUND
472 */
473 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
474
475 /* iterate over the originator list and find the node with closest
476 * dat_address which has not been selected yet
477 */
478 for (i = 0; i < hash->size; i++) {
479 head = &hash->table[i];
480
481 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800482 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Antonio Quartulli785ea112011-11-23 11:35:44 +0100483 /* the dht space is a ring and addresses are unsigned */
484 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
485 ip_key;
486
487 if (!batadv_is_orig_node_eligible(cands, select,
488 tmp_max, max,
489 *last_max, orig_node,
490 max_orig_node))
491 continue;
492
493 if (!atomic_inc_not_zero(&orig_node->refcount))
494 continue;
495
496 max = tmp_max;
497 if (max_orig_node)
498 batadv_orig_node_free_ref(max_orig_node);
499 max_orig_node = orig_node;
500 }
501 rcu_read_unlock();
502 }
503 if (max_orig_node) {
504 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
505 cands[select].orig_node = max_orig_node;
506 batadv_dbg(BATADV_DBG_DAT, bat_priv,
507 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
508 select, max_orig_node->orig, max_orig_node->dat_addr,
509 max);
510 }
511 *last_max = max;
512}
513
514/**
515 * batadv_dat_select_candidates - selects the nodes which the DHT message has to
516 * be sent to
517 * @bat_priv: the bat priv with all the soft interface information
518 * @ip_dst: ipv4 to look up in the DHT
519 *
520 * An originator O is selected if and only if its DHT_ID value is one of three
521 * closest values (from the LEFT, with wrap around if needed) then the hash
522 * value of the key. ip_dst is the key.
523 *
524 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM
525 */
526static struct batadv_dat_candidate *
527batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
528{
529 int select;
530 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
531 struct batadv_dat_candidate *res;
532
533 if (!bat_priv->orig_hash)
534 return NULL;
535
536 res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC);
537 if (!res)
538 return NULL;
539
540 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
541 BATADV_DAT_ADDR_MAX);
542
543 batadv_dbg(BATADV_DBG_DAT, bat_priv,
544 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
545 ip_key);
546
547 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
548 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
549 &last_max);
550
551 return res;
552}
553
554/**
555 * batadv_dat_send_data - send a payload to the selected candidates
556 * @bat_priv: the bat priv with all the soft interface information
557 * @skb: payload to send
558 * @ip: the DHT key
559 * @packet_subtype: unicast4addr packet subtype to use
560 *
561 * In this function the skb is copied by means of pskb_copy() and is sent as
562 * unicast packet to each of the selected candidates
563 *
564 * Returns true if the packet is sent to at least one candidate, false otherwise
565 */
566static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
567 struct sk_buff *skb, __be32 ip,
568 int packet_subtype)
569{
570 int i;
571 bool ret = false;
572 int send_status;
573 struct batadv_neigh_node *neigh_node = NULL;
574 struct sk_buff *tmp_skb;
575 struct batadv_dat_candidate *cand;
576
577 cand = batadv_dat_select_candidates(bat_priv, ip);
578 if (!cand)
579 goto out;
580
581 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
582
583 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
584 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
585 continue;
586
587 neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
588 if (!neigh_node)
589 goto free_orig;
590
591 tmp_skb = pskb_copy(skb, GFP_ATOMIC);
592 if (!batadv_unicast_4addr_prepare_skb(bat_priv, tmp_skb,
593 cand[i].orig_node,
594 packet_subtype)) {
595 kfree_skb(tmp_skb);
596 goto free_neigh;
597 }
598
599 send_status = batadv_send_skb_packet(tmp_skb,
600 neigh_node->if_incoming,
601 neigh_node->addr);
Martin Hundebøll4046b242012-04-20 17:02:45 +0200602 if (send_status == NET_XMIT_SUCCESS) {
603 /* count the sent packet */
604 switch (packet_subtype) {
605 case BATADV_P_DAT_DHT_GET:
606 batadv_inc_counter(bat_priv,
607 BATADV_CNT_DAT_GET_TX);
608 break;
609 case BATADV_P_DAT_DHT_PUT:
610 batadv_inc_counter(bat_priv,
611 BATADV_CNT_DAT_PUT_TX);
612 break;
613 }
614
Antonio Quartulli785ea112011-11-23 11:35:44 +0100615 /* packet sent to a candidate: return true */
616 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200617 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100618free_neigh:
619 batadv_neigh_node_free_ref(neigh_node);
620free_orig:
621 batadv_orig_node_free_ref(cand[i].orig_node);
622 }
623
624out:
625 kfree(cand);
626 return ret;
627}
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200628
629/**
630 * batadv_dat_hash_free - free the local DAT hash table
631 * @bat_priv: the bat priv with all the soft interface information
632 */
633static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
634{
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200635 if (!bat_priv->dat.hash)
636 return;
637
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200638 __batadv_dat_purge(bat_priv, NULL);
639
640 batadv_hash_destroy(bat_priv->dat.hash);
641
642 bat_priv->dat.hash = NULL;
643}
644
645/**
646 * batadv_dat_init - initialise the DAT internals
647 * @bat_priv: the bat priv with all the soft interface information
648 */
649int batadv_dat_init(struct batadv_priv *bat_priv)
650{
651 if (bat_priv->dat.hash)
652 return 0;
653
654 bat_priv->dat.hash = batadv_hash_new(1024);
655
656 if (!bat_priv->dat.hash)
657 return -ENOMEM;
658
659 batadv_dat_start_timer(bat_priv);
660
661 return 0;
662}
663
664/**
665 * batadv_dat_free - free the DAT internals
666 * @bat_priv: the bat priv with all the soft interface information
667 */
668void batadv_dat_free(struct batadv_priv *bat_priv)
669{
670 cancel_delayed_work_sync(&bat_priv->dat.work);
671
672 batadv_dat_hash_free(bat_priv);
673}
674
675/**
676 * batadv_dat_cache_seq_print_text - print the local DAT hash table
677 * @seq: seq file to print on
678 * @offset: not used
679 */
680int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
681{
682 struct net_device *net_dev = (struct net_device *)seq->private;
683 struct batadv_priv *bat_priv = netdev_priv(net_dev);
684 struct batadv_hashtable *hash = bat_priv->dat.hash;
685 struct batadv_dat_entry *dat_entry;
686 struct batadv_hard_iface *primary_if;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200687 struct hlist_head *head;
688 unsigned long last_seen_jiffies;
689 int last_seen_msecs, last_seen_secs, last_seen_mins;
690 uint32_t i;
691
692 primary_if = batadv_seq_print_text_primary_if_get(seq);
693 if (!primary_if)
694 goto out;
695
696 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
697 seq_printf(seq, " %-7s %-13s %5s\n", "IPv4", "MAC",
698 "last-seen");
699
700 for (i = 0; i < hash->size; i++) {
701 head = &hash->table[i];
702
703 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800704 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200705 last_seen_jiffies = jiffies - dat_entry->last_update;
706 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
707 last_seen_mins = last_seen_msecs / 60000;
708 last_seen_msecs = last_seen_msecs % 60000;
709 last_seen_secs = last_seen_msecs / 1000;
710
711 seq_printf(seq, " * %15pI4 %14pM %6i:%02i\n",
712 &dat_entry->ip, dat_entry->mac_addr,
713 last_seen_mins, last_seen_secs);
714 }
715 rcu_read_unlock();
716 }
717
718out:
719 if (primary_if)
720 batadv_hardif_free_ref(primary_if);
721 return 0;
722}
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200723
724/**
725 * batadv_arp_get_type - parse an ARP packet and gets the type
726 * @bat_priv: the bat priv with all the soft interface information
727 * @skb: packet to analyse
728 * @hdr_size: size of the possible header before the ARP packet in the skb
729 *
730 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise
731 */
732static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
733 struct sk_buff *skb, int hdr_size)
734{
735 struct arphdr *arphdr;
736 struct ethhdr *ethhdr;
737 __be32 ip_src, ip_dst;
Matthias Schifferb618ad12013-01-24 18:18:27 +0100738 uint8_t *hw_src, *hw_dst;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200739 uint16_t type = 0;
740
741 /* pull the ethernet header */
742 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
743 goto out;
744
745 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
746
747 if (ethhdr->h_proto != htons(ETH_P_ARP))
748 goto out;
749
750 /* pull the ARP payload */
751 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
752 arp_hdr_len(skb->dev))))
753 goto out;
754
755 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
756
757 /* Check whether the ARP packet carries a valid
758 * IP information
759 */
760 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
761 goto out;
762
763 if (arphdr->ar_pro != htons(ETH_P_IP))
764 goto out;
765
766 if (arphdr->ar_hln != ETH_ALEN)
767 goto out;
768
769 if (arphdr->ar_pln != 4)
770 goto out;
771
772 /* Check for bad reply/request. If the ARP message is not sane, DAT
773 * will simply ignore it
774 */
775 ip_src = batadv_arp_ip_src(skb, hdr_size);
776 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
777 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
Matthias Schiffer757dd822013-01-24 18:18:26 +0100778 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
779 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
780 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200781 goto out;
782
Matthias Schifferb618ad12013-01-24 18:18:27 +0100783 hw_src = batadv_arp_hw_src(skb, hdr_size);
784 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
785 goto out;
786
787 /* we don't care about the destination MAC address in ARP requests */
788 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
789 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
790 if (is_zero_ether_addr(hw_dst) ||
791 is_multicast_ether_addr(hw_dst))
792 goto out;
793 }
794
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200795 type = ntohs(arphdr->ar_op);
796out:
797 return type;
798}
Antonio Quartullic384ea32011-06-26 03:37:18 +0200799
800/**
801 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
802 * answer using DAT
803 * @bat_priv: the bat priv with all the soft interface information
804 * @skb: packet to check
805 *
806 * Returns true if the message has been sent to the dht candidates, false
807 * otherwise. In case of true the message has to be enqueued to permit the
808 * fallback
809 */
810bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
811 struct sk_buff *skb)
812{
813 uint16_t type = 0;
814 __be32 ip_dst, ip_src;
815 uint8_t *hw_src;
816 bool ret = false;
817 struct batadv_dat_entry *dat_entry = NULL;
818 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200819
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200820 if (!atomic_read(&bat_priv->distributed_arp_table))
821 goto out;
822
Antonio Quartullic384ea32011-06-26 03:37:18 +0200823 type = batadv_arp_get_type(bat_priv, skb, 0);
824 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
825 * message to the selected DHT candidates
826 */
827 if (type != ARPOP_REQUEST)
828 goto out;
829
830 batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REQUEST");
831
832 ip_src = batadv_arp_ip_src(skb, 0);
833 hw_src = batadv_arp_hw_src(skb, 0);
834 ip_dst = batadv_arp_ip_dst(skb, 0);
835
836 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
837
838 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
839 if (dat_entry) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200840 /* If the ARP request is destined for a local client the local
841 * client will answer itself. DAT would only generate a
842 * duplicate packet.
843 *
844 * Moreover, if the soft-interface is enslaved into a bridge, an
845 * additional DAT answer may trigger kernel warnings about
846 * a packet coming from the wrong port.
847 */
848 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr)) {
849 ret = true;
850 goto out;
851 }
852
Antonio Quartullic384ea32011-06-26 03:37:18 +0200853 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800854 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200855 dat_entry->mac_addr, hw_src);
856 if (!skb_new)
857 goto out;
858
859 skb_reset_mac_header(skb_new);
860 skb_new->protocol = eth_type_trans(skb_new,
Marek Lindner736292c2013-01-12 19:19:06 +0800861 bat_priv->soft_iface);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200862 bat_priv->stats.rx_packets++;
863 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
Marek Lindner736292c2013-01-12 19:19:06 +0800864 bat_priv->soft_iface->last_rx = jiffies;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200865
866 netif_rx(skb_new);
867 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
868 ret = true;
869 } else {
870 /* Send the request on the DHT */
871 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
872 BATADV_P_DAT_DHT_GET);
873 }
874out:
875 if (dat_entry)
876 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200877 return ret;
878}
879
880/**
881 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
882 * answer using the local DAT storage
883 * @bat_priv: the bat priv with all the soft interface information
884 * @skb: packet to check
885 * @hdr_size: size of the encapsulation header
886 *
887 * Returns true if the request has been answered, false otherwise
888 */
889bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
890 struct sk_buff *skb, int hdr_size)
891{
892 uint16_t type;
893 __be32 ip_src, ip_dst;
894 uint8_t *hw_src;
895 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200896 struct batadv_dat_entry *dat_entry = NULL;
897 bool ret = false;
898 int err;
899
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200900 if (!atomic_read(&bat_priv->distributed_arp_table))
901 goto out;
902
Antonio Quartullic384ea32011-06-26 03:37:18 +0200903 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
904 if (type != ARPOP_REQUEST)
905 goto out;
906
907 hw_src = batadv_arp_hw_src(skb, hdr_size);
908 ip_src = batadv_arp_ip_src(skb, hdr_size);
909 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
910
911 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
912 "Parsing incoming ARP REQUEST");
913
914 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
915
916 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
917 if (!dat_entry)
918 goto out;
919
Antonio Quartullic384ea32011-06-26 03:37:18 +0200920 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800921 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200922 dat_entry->mac_addr, hw_src);
923
924 if (!skb_new)
925 goto out;
926
927 /* to preserve backwards compatibility, here the node has to answer
928 * using the same packet type it received for the request. This is due
929 * to that if a node is not using the 4addr packet format it may not
930 * support it.
931 */
932 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
933 err = batadv_unicast_4addr_send_skb(bat_priv, skb_new,
934 BATADV_P_DAT_CACHE_REPLY);
935 else
936 err = batadv_unicast_send_skb(bat_priv, skb_new);
937
Martin Hundebøll4046b242012-04-20 17:02:45 +0200938 if (!err) {
939 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200940 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200941 }
Antonio Quartullic384ea32011-06-26 03:37:18 +0200942out:
943 if (dat_entry)
944 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200945 if (ret)
946 kfree_skb(skb);
947 return ret;
948}
949
950/**
951 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
952 * @bat_priv: the bat priv with all the soft interface information
953 * @skb: packet to check
954 */
955void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
956 struct sk_buff *skb)
957{
958 uint16_t type;
959 __be32 ip_src, ip_dst;
960 uint8_t *hw_src, *hw_dst;
961
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200962 if (!atomic_read(&bat_priv->distributed_arp_table))
963 return;
964
Antonio Quartullic384ea32011-06-26 03:37:18 +0200965 type = batadv_arp_get_type(bat_priv, skb, 0);
966 if (type != ARPOP_REPLY)
967 return;
968
969 batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REPLY");
970
971 hw_src = batadv_arp_hw_src(skb, 0);
972 ip_src = batadv_arp_ip_src(skb, 0);
973 hw_dst = batadv_arp_hw_dst(skb, 0);
974 ip_dst = batadv_arp_ip_dst(skb, 0);
975
976 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
977 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
978
979 /* Send the ARP reply to the candidates for both the IP addresses that
980 * the node got within the ARP reply
981 */
982 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
983 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
984}
985/**
986 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
987 * DAT storage only
988 * @bat_priv: the bat priv with all the soft interface information
989 * @skb: packet to check
990 * @hdr_size: siaze of the encapsulation header
991 */
992bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
993 struct sk_buff *skb, int hdr_size)
994{
995 uint16_t type;
996 __be32 ip_src, ip_dst;
997 uint8_t *hw_src, *hw_dst;
998 bool ret = false;
999
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001000 if (!atomic_read(&bat_priv->distributed_arp_table))
1001 goto out;
1002
Antonio Quartullic384ea32011-06-26 03:37:18 +02001003 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1004 if (type != ARPOP_REPLY)
1005 goto out;
1006
1007 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1008 "Parsing incoming ARP REPLY");
1009
1010 hw_src = batadv_arp_hw_src(skb, hdr_size);
1011 ip_src = batadv_arp_ip_src(skb, hdr_size);
1012 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1013 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1014
1015 /* Update our internal cache with both the IP addresses the node got
1016 * within the ARP reply
1017 */
1018 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
1019 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
1020
1021 /* if this REPLY is directed to a client of mine, let's deliver the
1022 * packet to the interface
1023 */
1024 ret = !batadv_is_my_client(bat_priv, hw_dst);
1025out:
Matthias Schiffer0d15bec2013-01-23 18:11:53 +01001026 if (ret)
1027 kfree_skb(skb);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001028 /* if ret == false -> packet has to be delivered to the interface */
1029 return ret;
1030}
1031
1032/**
1033 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1034 * (because the node has already got the reply via DAT) or not
1035 * @bat_priv: the bat priv with all the soft interface information
1036 * @forw_packet: the broadcast packet
1037 *
1038 * Returns true if the node can drop the packet, false otherwise
1039 */
1040bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1041 struct batadv_forw_packet *forw_packet)
1042{
1043 uint16_t type;
1044 __be32 ip_dst;
1045 struct batadv_dat_entry *dat_entry = NULL;
1046 bool ret = false;
1047 const size_t bcast_len = sizeof(struct batadv_bcast_packet);
1048
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001049 if (!atomic_read(&bat_priv->distributed_arp_table))
1050 goto out;
1051
Antonio Quartullic384ea32011-06-26 03:37:18 +02001052 /* If this packet is an ARP_REQUEST and the node already has the
1053 * information that it is going to ask, then the packet can be dropped
1054 */
1055 if (forw_packet->num_packets)
1056 goto out;
1057
1058 type = batadv_arp_get_type(bat_priv, forw_packet->skb, bcast_len);
1059 if (type != ARPOP_REQUEST)
1060 goto out;
1061
1062 ip_dst = batadv_arp_ip_dst(forw_packet->skb, bcast_len);
1063 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
1064 /* check if the node already got this entry */
1065 if (!dat_entry) {
1066 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1067 "ARP Request for %pI4: fallback\n", &ip_dst);
1068 goto out;
1069 }
1070
1071 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1072 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1073 ret = true;
1074
1075out:
1076 if (dat_entry)
1077 batadv_dat_entry_free_ref(dat_entry);
1078 return ret;
1079}