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-rw-r--r--net/batman-adv/distributed-arp-table.c1066
1 files changed, 1066 insertions, 0 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
new file mode 100644
index 000000000000..8e1d89d2b1c1
--- /dev/null
+++ b/net/batman-adv/distributed-arp-table.c
@@ -0,0 +1,1066 @@
1/* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors:
2 *
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>
22#include <net/arp.h>
23
24#include "main.h"
25#include "hash.h"
26#include "distributed-arp-table.h"
27#include "hard-interface.h"
28#include "originator.h"
29#include "send.h"
30#include "types.h"
31#include "translation-table.h"
32#include "unicast.h"
33
34static 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;
86 struct hlist_node *node, *node_tmp;
87 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);
98 hlist_for_each_entry_safe(dat_entry, node, node_tmp, head,
99 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
106 hlist_del_rcu(node);
107 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
147/**
148 * 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/**
201 * 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/**
227 * 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;
238 struct hlist_node *node;
239 struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL;
240 struct batadv_hashtable *hash = bat_priv->dat.hash;
241 uint32_t index;
242
243 if (!hash)
244 return NULL;
245
246 index = batadv_hash_dat(&ip, hash->size);
247 head = &hash->table[index];
248
249 rcu_read_lock();
250 hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) {
251 if (dat_entry->ip != ip)
252 continue;
253
254 if (!atomic_inc_not_zero(&dat_entry->refcount))
255 continue;
256
257 dat_entry_tmp = dat_entry;
258 break;
259 }
260 rcu_read_unlock();
261
262 return dat_entry_tmp;
263}
264
265/**
266 * batadv_dat_entry_add - add a new dat entry or update it if already exists
267 * @bat_priv: the bat priv with all the soft interface information
268 * @ip: ipv4 to add/edit
269 * @mac_addr: mac address to assign to the given ipv4
270 */
271static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
272 uint8_t *mac_addr)
273{
274 struct batadv_dat_entry *dat_entry;
275 int hash_added;
276
277 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip);
278 /* if this entry is already known, just update it */
279 if (dat_entry) {
280 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
281 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
282 dat_entry->last_update = jiffies;
283 batadv_dbg(BATADV_DBG_DAT, bat_priv,
284 "Entry updated: %pI4 %pM\n", &dat_entry->ip,
285 dat_entry->mac_addr);
286 goto out;
287 }
288
289 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
290 if (!dat_entry)
291 goto out;
292
293 dat_entry->ip = ip;
294 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
295 dat_entry->last_update = jiffies;
296 atomic_set(&dat_entry->refcount, 2);
297
298 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
299 batadv_hash_dat, &dat_entry->ip,
300 &dat_entry->hash_entry);
301
302 if (unlikely(hash_added != 0)) {
303 /* remove the reference for the hash */
304 batadv_dat_entry_free_ref(dat_entry);
305 goto out;
306 }
307
308 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM\n",
309 &dat_entry->ip, dat_entry->mac_addr);
310
311out:
312 if (dat_entry)
313 batadv_dat_entry_free_ref(dat_entry);
314}
315
316#ifdef CONFIG_BATMAN_ADV_DEBUG
317
318/**
319 * batadv_dbg_arp - print a debug message containing all the ARP packet details
320 * @bat_priv: the bat priv with all the soft interface information
321 * @skb: ARP packet
322 * @type: ARP type
323 * @hdr_size: size of the possible header before the ARP packet
324 * @msg: message to print together with the debugging information
325 */
326static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
327 uint16_t type, int hdr_size, char *msg)
328{
329 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
330 struct batadv_bcast_packet *bcast_pkt;
331 uint8_t *orig_addr;
332 __be32 ip_src, ip_dst;
333
334 if (msg)
335 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
336
337 ip_src = batadv_arp_ip_src(skb, hdr_size);
338 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
339 batadv_dbg(BATADV_DBG_DAT, bat_priv,
340 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
341 batadv_arp_hw_src(skb, hdr_size), &ip_src,
342 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
343
344 if (hdr_size == 0)
345 return;
346
347 /* if the ARP packet is encapsulated in a batman packet, let's print
348 * some debug messages
349 */
350 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
351
352 switch (unicast_4addr_packet->u.header.packet_type) {
353 case BATADV_UNICAST:
354 batadv_dbg(BATADV_DBG_DAT, bat_priv,
355 "* encapsulated within a UNICAST packet\n");
356 break;
357 case BATADV_UNICAST_4ADDR:
358 batadv_dbg(BATADV_DBG_DAT, bat_priv,
359 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
360 unicast_4addr_packet->src);
361 switch (unicast_4addr_packet->subtype) {
362 case BATADV_P_DAT_DHT_PUT:
363 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
364 break;
365 case BATADV_P_DAT_DHT_GET:
366 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
367 break;
368 case BATADV_P_DAT_CACHE_REPLY:
369 batadv_dbg(BATADV_DBG_DAT, bat_priv,
370 "* type: DAT_CACHE_REPLY\n");
371 break;
372 case BATADV_P_DATA:
373 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
374 break;
375 default:
376 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
377 unicast_4addr_packet->u.header.packet_type);
378 }
379 break;
380 case BATADV_BCAST:
381 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
382 orig_addr = bcast_pkt->orig;
383 batadv_dbg(BATADV_DBG_DAT, bat_priv,
384 "* encapsulated within a BCAST packet (src: %pM)\n",
385 orig_addr);
386 break;
387 default:
388 batadv_dbg(BATADV_DBG_DAT, bat_priv,
389 "* encapsulated within an unknown packet type (0x%x)\n",
390 unicast_4addr_packet->u.header.packet_type);
391 }
392}
393
394#else
395
396static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
397 uint16_t type, int hdr_size, char *msg)
398{
399}
400
401#endif /* CONFIG_BATMAN_ADV_DEBUG */
402
403/**
404 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
405 * @res: the array with the already selected candidates
406 * @select: number of already selected candidates
407 * @tmp_max: address of the currently evaluated node
408 * @max: current round max address
409 * @last_max: address of the last selected candidate
410 * @candidate: orig_node under evaluation
411 * @max_orig_node: last selected candidate
412 *
413 * Returns true if the node has been elected as next candidate or false othrwise
414 */
415static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
416 int select, batadv_dat_addr_t tmp_max,
417 batadv_dat_addr_t max,
418 batadv_dat_addr_t last_max,
419 struct batadv_orig_node *candidate,
420 struct batadv_orig_node *max_orig_node)
421{
422 bool ret = false;
423 int j;
424
425 /* Check if this node has already been selected... */
426 for (j = 0; j < select; j++)
427 if (res[j].orig_node == candidate)
428 break;
429 /* ..and possibly skip it */
430 if (j < select)
431 goto out;
432 /* sanity check: has it already been selected? This should not happen */
433 if (tmp_max > last_max)
434 goto out;
435 /* check if during this iteration an originator with a closer dht
436 * address has already been found
437 */
438 if (tmp_max < max)
439 goto out;
440 /* this is an hash collision with the temporary selected node. Choose
441 * the one with the lowest address
442 */
443 if ((tmp_max == max) &&
444 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
445 goto out;
446
447 ret = true;
448out:
449 return ret;
450}
451
452/**
453 * batadv_choose_next_candidate - select the next DHT candidate
454 * @bat_priv: the bat priv with all the soft interface information
455 * @cands: candidates array
456 * @select: number of candidates already present in the array
457 * @ip_key: key to look up in the DHT
458 * @last_max: pointer where the address of the selected candidate will be saved
459 */
460static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
461 struct batadv_dat_candidate *cands,
462 int select, batadv_dat_addr_t ip_key,
463 batadv_dat_addr_t *last_max)
464{
465 batadv_dat_addr_t max = 0, tmp_max = 0;
466 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
467 struct batadv_hashtable *hash = bat_priv->orig_hash;
468 struct hlist_node *node;
469 struct hlist_head *head;
470 int i;
471
472 /* if no node is eligible as candidate, leave the candidate type as
473 * NOT_FOUND
474 */
475 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
476
477 /* iterate over the originator list and find the node with closest
478 * dat_address which has not been selected yet
479 */
480 for (i = 0; i < hash->size; i++) {
481 head = &hash->table[i];
482
483 rcu_read_lock();
484 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
485 /* the dht space is a ring and addresses are unsigned */
486 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
487 ip_key;
488
489 if (!batadv_is_orig_node_eligible(cands, select,
490 tmp_max, max,
491 *last_max, orig_node,
492 max_orig_node))
493 continue;
494
495 if (!atomic_inc_not_zero(&orig_node->refcount))
496 continue;
497
498 max = tmp_max;
499 if (max_orig_node)
500 batadv_orig_node_free_ref(max_orig_node);
501 max_orig_node = orig_node;
502 }
503 rcu_read_unlock();
504 }
505 if (max_orig_node) {
506 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
507 cands[select].orig_node = max_orig_node;
508 batadv_dbg(BATADV_DBG_DAT, bat_priv,
509 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
510 select, max_orig_node->orig, max_orig_node->dat_addr,
511 max);
512 }
513 *last_max = max;
514}
515
516/**
517 * batadv_dat_select_candidates - selects the nodes which the DHT message has to
518 * be sent to
519 * @bat_priv: the bat priv with all the soft interface information
520 * @ip_dst: ipv4 to look up in the DHT
521 *
522 * An originator O is selected if and only if its DHT_ID value is one of three
523 * closest values (from the LEFT, with wrap around if needed) then the hash
524 * value of the key. ip_dst is the key.
525 *
526 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM
527 */
528static struct batadv_dat_candidate *
529batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
530{
531 int select;
532 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
533 struct batadv_dat_candidate *res;
534
535 if (!bat_priv->orig_hash)
536 return NULL;
537
538 res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC);
539 if (!res)
540 return NULL;
541
542 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
543 BATADV_DAT_ADDR_MAX);
544
545 batadv_dbg(BATADV_DBG_DAT, bat_priv,
546 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
547 ip_key);
548
549 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
550 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
551 &last_max);
552
553 return res;
554}
555
556/**
557 * batadv_dat_send_data - send a payload to the selected candidates
558 * @bat_priv: the bat priv with all the soft interface information
559 * @skb: payload to send
560 * @ip: the DHT key
561 * @packet_subtype: unicast4addr packet subtype to use
562 *
563 * In this function the skb is copied by means of pskb_copy() and is sent as
564 * unicast packet to each of the selected candidates
565 *
566 * Returns true if the packet is sent to at least one candidate, false otherwise
567 */
568static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
569 struct sk_buff *skb, __be32 ip,
570 int packet_subtype)
571{
572 int i;
573 bool ret = false;
574 int send_status;
575 struct batadv_neigh_node *neigh_node = NULL;
576 struct sk_buff *tmp_skb;
577 struct batadv_dat_candidate *cand;
578
579 cand = batadv_dat_select_candidates(bat_priv, ip);
580 if (!cand)
581 goto out;
582
583 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
584
585 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
586 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
587 continue;
588
589 neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
590 if (!neigh_node)
591 goto free_orig;
592
593 tmp_skb = pskb_copy(skb, GFP_ATOMIC);
594 if (!batadv_unicast_4addr_prepare_skb(bat_priv, tmp_skb,
595 cand[i].orig_node,
596 packet_subtype)) {
597 kfree_skb(tmp_skb);
598 goto free_neigh;
599 }
600
601 send_status = batadv_send_skb_packet(tmp_skb,
602 neigh_node->if_incoming,
603 neigh_node->addr);
604 if (send_status == NET_XMIT_SUCCESS) {
605 /* count the sent packet */
606 switch (packet_subtype) {
607 case BATADV_P_DAT_DHT_GET:
608 batadv_inc_counter(bat_priv,
609 BATADV_CNT_DAT_GET_TX);
610 break;
611 case BATADV_P_DAT_DHT_PUT:
612 batadv_inc_counter(bat_priv,
613 BATADV_CNT_DAT_PUT_TX);
614 break;
615 }
616
617 /* packet sent to a candidate: return true */
618 ret = true;
619 }
620free_neigh:
621 batadv_neigh_node_free_ref(neigh_node);
622free_orig:
623 batadv_orig_node_free_ref(cand[i].orig_node);
624 }
625
626out:
627 kfree(cand);
628 return ret;
629}
630
631/**
632 * batadv_dat_hash_free - free the local DAT hash table
633 * @bat_priv: the bat priv with all the soft interface information
634 */
635static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
636{
637 if (!bat_priv->dat.hash)
638 return;
639
640 __batadv_dat_purge(bat_priv, NULL);
641
642 batadv_hash_destroy(bat_priv->dat.hash);
643
644 bat_priv->dat.hash = NULL;
645}
646
647/**
648 * batadv_dat_init - initialise the DAT internals
649 * @bat_priv: the bat priv with all the soft interface information
650 */
651int batadv_dat_init(struct batadv_priv *bat_priv)
652{
653 if (bat_priv->dat.hash)
654 return 0;
655
656 bat_priv->dat.hash = batadv_hash_new(1024);
657
658 if (!bat_priv->dat.hash)
659 return -ENOMEM;
660
661 batadv_dat_start_timer(bat_priv);
662
663 return 0;
664}
665
666/**
667 * batadv_dat_free - free the DAT internals
668 * @bat_priv: the bat priv with all the soft interface information
669 */
670void batadv_dat_free(struct batadv_priv *bat_priv)
671{
672 cancel_delayed_work_sync(&bat_priv->dat.work);
673
674 batadv_dat_hash_free(bat_priv);
675}
676
677/**
678 * batadv_dat_cache_seq_print_text - print the local DAT hash table
679 * @seq: seq file to print on
680 * @offset: not used
681 */
682int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
683{
684 struct net_device *net_dev = (struct net_device *)seq->private;
685 struct batadv_priv *bat_priv = netdev_priv(net_dev);
686 struct batadv_hashtable *hash = bat_priv->dat.hash;
687 struct batadv_dat_entry *dat_entry;
688 struct batadv_hard_iface *primary_if;
689 struct hlist_node *node;
690 struct hlist_head *head;
691 unsigned long last_seen_jiffies;
692 int last_seen_msecs, last_seen_secs, last_seen_mins;
693 uint32_t i;
694
695 primary_if = batadv_seq_print_text_primary_if_get(seq);
696 if (!primary_if)
697 goto out;
698
699 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
700 seq_printf(seq, " %-7s %-13s %5s\n", "IPv4", "MAC",
701 "last-seen");
702
703 for (i = 0; i < hash->size; i++) {
704 head = &hash->table[i];
705
706 rcu_read_lock();
707 hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) {
708 last_seen_jiffies = jiffies - dat_entry->last_update;
709 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
710 last_seen_mins = last_seen_msecs / 60000;
711 last_seen_msecs = last_seen_msecs % 60000;
712 last_seen_secs = last_seen_msecs / 1000;
713
714 seq_printf(seq, " * %15pI4 %14pM %6i:%02i\n",
715 &dat_entry->ip, dat_entry->mac_addr,
716 last_seen_mins, last_seen_secs);
717 }
718 rcu_read_unlock();
719 }
720
721out:
722 if (primary_if)
723 batadv_hardif_free_ref(primary_if);
724 return 0;
725}
726
727/**
728 * batadv_arp_get_type - parse an ARP packet and gets the type
729 * @bat_priv: the bat priv with all the soft interface information
730 * @skb: packet to analyse
731 * @hdr_size: size of the possible header before the ARP packet in the skb
732 *
733 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise
734 */
735static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
736 struct sk_buff *skb, int hdr_size)
737{
738 struct arphdr *arphdr;
739 struct ethhdr *ethhdr;
740 __be32 ip_src, ip_dst;
741 uint16_t type = 0;
742
743 /* pull the ethernet header */
744 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
745 goto out;
746
747 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
748
749 if (ethhdr->h_proto != htons(ETH_P_ARP))
750 goto out;
751
752 /* pull the ARP payload */
753 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
754 arp_hdr_len(skb->dev))))
755 goto out;
756
757 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
758
759 /* Check whether the ARP packet carries a valid
760 * IP information
761 */
762 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
763 goto out;
764
765 if (arphdr->ar_pro != htons(ETH_P_IP))
766 goto out;
767
768 if (arphdr->ar_hln != ETH_ALEN)
769 goto out;
770
771 if (arphdr->ar_pln != 4)
772 goto out;
773
774 /* Check for bad reply/request. If the ARP message is not sane, DAT
775 * will simply ignore it
776 */
777 ip_src = batadv_arp_ip_src(skb, hdr_size);
778 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
779 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
780 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst))
781 goto out;
782
783 type = ntohs(arphdr->ar_op);
784out:
785 return type;
786}
787
788/**
789 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
790 * answer using DAT
791 * @bat_priv: the bat priv with all the soft interface information
792 * @skb: packet to check
793 *
794 * Returns true if the message has been sent to the dht candidates, false
795 * otherwise. In case of true the message has to be enqueued to permit the
796 * fallback
797 */
798bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
799 struct sk_buff *skb)
800{
801 uint16_t type = 0;
802 __be32 ip_dst, ip_src;
803 uint8_t *hw_src;
804 bool ret = false;
805 struct batadv_dat_entry *dat_entry = NULL;
806 struct sk_buff *skb_new;
807 struct batadv_hard_iface *primary_if = NULL;
808
809 if (!atomic_read(&bat_priv->distributed_arp_table))
810 goto out;
811
812 type = batadv_arp_get_type(bat_priv, skb, 0);
813 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
814 * message to the selected DHT candidates
815 */
816 if (type != ARPOP_REQUEST)
817 goto out;
818
819 batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REQUEST");
820
821 ip_src = batadv_arp_ip_src(skb, 0);
822 hw_src = batadv_arp_hw_src(skb, 0);
823 ip_dst = batadv_arp_ip_dst(skb, 0);
824
825 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
826
827 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
828 if (dat_entry) {
829 primary_if = batadv_primary_if_get_selected(bat_priv);
830 if (!primary_if)
831 goto out;
832
833 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
834 primary_if->soft_iface, ip_dst, hw_src,
835 dat_entry->mac_addr, hw_src);
836 if (!skb_new)
837 goto out;
838
839 skb_reset_mac_header(skb_new);
840 skb_new->protocol = eth_type_trans(skb_new,
841 primary_if->soft_iface);
842 bat_priv->stats.rx_packets++;
843 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
844 primary_if->soft_iface->last_rx = jiffies;
845
846 netif_rx(skb_new);
847 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
848 ret = true;
849 } else {
850 /* Send the request on the DHT */
851 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
852 BATADV_P_DAT_DHT_GET);
853 }
854out:
855 if (dat_entry)
856 batadv_dat_entry_free_ref(dat_entry);
857 if (primary_if)
858 batadv_hardif_free_ref(primary_if);
859 return ret;
860}
861
862/**
863 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
864 * answer using the local DAT storage
865 * @bat_priv: the bat priv with all the soft interface information
866 * @skb: packet to check
867 * @hdr_size: size of the encapsulation header
868 *
869 * Returns true if the request has been answered, false otherwise
870 */
871bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
872 struct sk_buff *skb, int hdr_size)
873{
874 uint16_t type;
875 __be32 ip_src, ip_dst;
876 uint8_t *hw_src;
877 struct sk_buff *skb_new;
878 struct batadv_hard_iface *primary_if = NULL;
879 struct batadv_dat_entry *dat_entry = NULL;
880 bool ret = false;
881 int err;
882
883 if (!atomic_read(&bat_priv->distributed_arp_table))
884 goto out;
885
886 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
887 if (type != ARPOP_REQUEST)
888 goto out;
889
890 hw_src = batadv_arp_hw_src(skb, hdr_size);
891 ip_src = batadv_arp_ip_src(skb, hdr_size);
892 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
893
894 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
895 "Parsing incoming ARP REQUEST");
896
897 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
898
899 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
900 if (!dat_entry)
901 goto out;
902
903 primary_if = batadv_primary_if_get_selected(bat_priv);
904 if (!primary_if)
905 goto out;
906
907 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
908 primary_if->soft_iface, ip_dst, hw_src,
909 dat_entry->mac_addr, hw_src);
910
911 if (!skb_new)
912 goto out;
913
914 /* to preserve backwards compatibility, here the node has to answer
915 * using the same packet type it received for the request. This is due
916 * to that if a node is not using the 4addr packet format it may not
917 * support it.
918 */
919 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
920 err = batadv_unicast_4addr_send_skb(bat_priv, skb_new,
921 BATADV_P_DAT_CACHE_REPLY);
922 else
923 err = batadv_unicast_send_skb(bat_priv, skb_new);
924
925 if (!err) {
926 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
927 ret = true;
928 }
929out:
930 if (dat_entry)
931 batadv_dat_entry_free_ref(dat_entry);
932 if (primary_if)
933 batadv_hardif_free_ref(primary_if);
934 if (ret)
935 kfree_skb(skb);
936 return ret;
937}
938
939/**
940 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
941 * @bat_priv: the bat priv with all the soft interface information
942 * @skb: packet to check
943 */
944void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
945 struct sk_buff *skb)
946{
947 uint16_t type;
948 __be32 ip_src, ip_dst;
949 uint8_t *hw_src, *hw_dst;
950
951 if (!atomic_read(&bat_priv->distributed_arp_table))
952 return;
953
954 type = batadv_arp_get_type(bat_priv, skb, 0);
955 if (type != ARPOP_REPLY)
956 return;
957
958 batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REPLY");
959
960 hw_src = batadv_arp_hw_src(skb, 0);
961 ip_src = batadv_arp_ip_src(skb, 0);
962 hw_dst = batadv_arp_hw_dst(skb, 0);
963 ip_dst = batadv_arp_ip_dst(skb, 0);
964
965 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
966 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
967
968 /* Send the ARP reply to the candidates for both the IP addresses that
969 * the node got within the ARP reply
970 */
971 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
972 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
973}
974/**
975 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
976 * DAT storage only
977 * @bat_priv: the bat priv with all the soft interface information
978 * @skb: packet to check
979 * @hdr_size: siaze of the encapsulation header
980 */
981bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
982 struct sk_buff *skb, int hdr_size)
983{
984 uint16_t type;
985 __be32 ip_src, ip_dst;
986 uint8_t *hw_src, *hw_dst;
987 bool ret = false;
988
989 if (!atomic_read(&bat_priv->distributed_arp_table))
990 goto out;
991
992 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
993 if (type != ARPOP_REPLY)
994 goto out;
995
996 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
997 "Parsing incoming ARP REPLY");
998
999 hw_src = batadv_arp_hw_src(skb, hdr_size);
1000 ip_src = batadv_arp_ip_src(skb, hdr_size);
1001 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1002 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1003
1004 /* Update our internal cache with both the IP addresses the node got
1005 * within the ARP reply
1006 */
1007 batadv_dat_entry_add(bat_priv, ip_src, hw_src);
1008 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
1009
1010 /* if this REPLY is directed to a client of mine, let's deliver the
1011 * packet to the interface
1012 */
1013 ret = !batadv_is_my_client(bat_priv, hw_dst);
1014out:
1015 /* if ret == false -> packet has to be delivered to the interface */
1016 return ret;
1017}
1018
1019/**
1020 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1021 * (because the node has already got the reply via DAT) or not
1022 * @bat_priv: the bat priv with all the soft interface information
1023 * @forw_packet: the broadcast packet
1024 *
1025 * Returns true if the node can drop the packet, false otherwise
1026 */
1027bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1028 struct batadv_forw_packet *forw_packet)
1029{
1030 uint16_t type;
1031 __be32 ip_dst;
1032 struct batadv_dat_entry *dat_entry = NULL;
1033 bool ret = false;
1034 const size_t bcast_len = sizeof(struct batadv_bcast_packet);
1035
1036 if (!atomic_read(&bat_priv->distributed_arp_table))
1037 goto out;
1038
1039 /* If this packet is an ARP_REQUEST and the node already has the
1040 * information that it is going to ask, then the packet can be dropped
1041 */
1042 if (forw_packet->num_packets)
1043 goto out;
1044
1045 type = batadv_arp_get_type(bat_priv, forw_packet->skb, bcast_len);
1046 if (type != ARPOP_REQUEST)
1047 goto out;
1048
1049 ip_dst = batadv_arp_ip_dst(forw_packet->skb, bcast_len);
1050 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
1051 /* check if the node already got this entry */
1052 if (!dat_entry) {
1053 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1054 "ARP Request for %pI4: fallback\n", &ip_dst);
1055 goto out;
1056 }
1057
1058 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1059 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1060 ret = true;
1061
1062out:
1063 if (dat_entry)
1064 batadv_dat_entry_free_ref(dat_entry);
1065 return ret;
1066}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-23 14:08:32 -0500