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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 Quartullibe1db4f2013-06-04 12:11:43 +020022#include <linux/if_vlan.h>
Antonio Quartullic384ea32011-06-26 03:37:18 +020023#include <net/arp.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010024
25#include "main.h"
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +020026#include "hash.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010027#include "distributed-arp-table.h"
28#include "hard-interface.h"
29#include "originator.h"
30#include "send.h"
31#include "types.h"
Antonio Quartullic384ea32011-06-26 03:37:18 +020032#include "translation-table.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010033
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/**
Marek Lindner93178012013-03-10 19:29:15 +080048 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020049 * free it
Marek Lindner93178012013-03-10 19:29:15 +080050 * @dat_entry: the entry to free
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020051 */
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/**
Marek Lindner93178012013-03-10 19:29:15 +080059 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020060 * @dat_entry: the entry to check
61 *
Marek Lindner93178012013-03-10 19:29:15 +080062 * Returns true if the entry has to be purged now, false otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020063 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +080078 * Loops over each entry in the DAT local storage and deletes it if and only if
79 * the to_purge function passed as argument returns true.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020080 */
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) {
Marek Lindner93178012013-03-10 19:29:15 +0800100 /* if a helper function has been passed as parameter,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200101 * 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 *
Marek Lindner93178012013-03-10 19:29:15 +0800137 * Returns 1 if the two entries are the same, 0 otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200138 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +0800152 * Returns the value of the hw_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200153 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +0800169 * Returns the value of the ip_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200170 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +0800181 * Returns the value of the hw_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200182 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +0800193 * Returns the value of the ip_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200194 */
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 *
Marek Lindner93178012013-03-10 19:29:15 +0800205 * Returns the selected index in the hash table for the given data.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100206 */
207static uint32_t batadv_hash_dat(const void *data, uint32_t size)
208{
Antonio Quartulli785ea112011-11-23 11:35:44 +0100209 uint32_t hash = 0;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200210 const struct batadv_dat_entry *dat = data;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100211
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200212 hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip));
213 hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid));
Antonio Quartulli785ea112011-11-23 11:35:44 +0100214
215 hash += (hash << 3);
216 hash ^= (hash >> 11);
217 hash += (hash << 15);
218
219 return hash % size;
220}
221
222/**
Marek Lindner93178012013-03-10 19:29:15 +0800223 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200224 * table
225 * @bat_priv: the bat priv with all the soft interface information
226 * @ip: search key
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200227 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200228 *
Marek Lindner93178012013-03-10 19:29:15 +0800229 * Returns the dat_entry if found, NULL otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200230 */
231static struct batadv_dat_entry *
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200232batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
233 unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200234{
235 struct hlist_head *head;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200236 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200237 struct batadv_hashtable *hash = bat_priv->dat.hash;
238 uint32_t index;
239
240 if (!hash)
241 return NULL;
242
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200243 to_find.ip = ip;
244 to_find.vid = vid;
245
246 index = batadv_hash_dat(&to_find, hash->size);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200247 head = &hash->table[index];
248
249 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800250 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200251 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
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200270 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200271 */
272static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200273 uint8_t *mac_addr, unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200274{
275 struct batadv_dat_entry *dat_entry;
276 int hash_added;
277
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200278 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200279 /* if this entry is already known, just update it */
280 if (dat_entry) {
281 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
282 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
283 dat_entry->last_update = jiffies;
284 batadv_dbg(BATADV_DBG_DAT, bat_priv,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200285 "Entry updated: %pI4 %pM (vid: %d)\n",
286 &dat_entry->ip, dat_entry->mac_addr,
287 BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200288 goto out;
289 }
290
291 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
292 if (!dat_entry)
293 goto out;
294
295 dat_entry->ip = ip;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200296 dat_entry->vid = vid;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200297 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
298 dat_entry->last_update = jiffies;
299 atomic_set(&dat_entry->refcount, 2);
300
301 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200302 batadv_hash_dat, dat_entry,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200303 &dat_entry->hash_entry);
304
305 if (unlikely(hash_added != 0)) {
306 /* remove the reference for the hash */
307 batadv_dat_entry_free_ref(dat_entry);
308 goto out;
309 }
310
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200311 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
312 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200313
314out:
315 if (dat_entry)
316 batadv_dat_entry_free_ref(dat_entry);
317}
318
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200319#ifdef CONFIG_BATMAN_ADV_DEBUG
320
321/**
322 * batadv_dbg_arp - print a debug message containing all the ARP packet details
323 * @bat_priv: the bat priv with all the soft interface information
324 * @skb: ARP packet
325 * @type: ARP type
326 * @hdr_size: size of the possible header before the ARP packet
327 * @msg: message to print together with the debugging information
328 */
329static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
330 uint16_t type, int hdr_size, char *msg)
331{
332 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
333 struct batadv_bcast_packet *bcast_pkt;
334 uint8_t *orig_addr;
335 __be32 ip_src, ip_dst;
336
337 if (msg)
338 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
339
340 ip_src = batadv_arp_ip_src(skb, hdr_size);
341 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
342 batadv_dbg(BATADV_DBG_DAT, bat_priv,
343 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
344 batadv_arp_hw_src(skb, hdr_size), &ip_src,
345 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
346
347 if (hdr_size == 0)
348 return;
349
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200350 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
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200403/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100404 * 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 *
Marek Lindner93178012013-03-10 19:29:15 +0800413 * Returns true if the node has been elected as next candidate or false
414 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100415 */
416static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
417 int select, batadv_dat_addr_t tmp_max,
418 batadv_dat_addr_t max,
419 batadv_dat_addr_t last_max,
420 struct batadv_orig_node *candidate,
421 struct batadv_orig_node *max_orig_node)
422{
423 bool ret = false;
424 int j;
425
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800426 /* check if orig node candidate is running DAT */
427 if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
428 goto out;
429
Antonio Quartulli785ea112011-11-23 11:35:44 +0100430 /* Check if this node has already been selected... */
431 for (j = 0; j < select; j++)
432 if (res[j].orig_node == candidate)
433 break;
434 /* ..and possibly skip it */
435 if (j < select)
436 goto out;
437 /* sanity check: has it already been selected? This should not happen */
438 if (tmp_max > last_max)
439 goto out;
440 /* check if during this iteration an originator with a closer dht
441 * address has already been found
442 */
443 if (tmp_max < max)
444 goto out;
445 /* this is an hash collision with the temporary selected node. Choose
446 * the one with the lowest address
447 */
Pau Koning816cd5b2013-02-12 00:18:45 +0000448 if ((tmp_max == max) && max_orig_node &&
Antonio Quartulli785ea112011-11-23 11:35:44 +0100449 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
450 goto out;
451
452 ret = true;
453out:
454 return ret;
455}
456
457/**
458 * batadv_choose_next_candidate - select the next DHT candidate
459 * @bat_priv: the bat priv with all the soft interface information
460 * @cands: candidates array
461 * @select: number of candidates already present in the array
462 * @ip_key: key to look up in the DHT
463 * @last_max: pointer where the address of the selected candidate will be saved
464 */
465static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
466 struct batadv_dat_candidate *cands,
467 int select, batadv_dat_addr_t ip_key,
468 batadv_dat_addr_t *last_max)
469{
470 batadv_dat_addr_t max = 0, tmp_max = 0;
471 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
472 struct batadv_hashtable *hash = bat_priv->orig_hash;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100473 struct hlist_head *head;
474 int i;
475
476 /* if no node is eligible as candidate, leave the candidate type as
477 * NOT_FOUND
478 */
479 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
480
Marek Lindner93178012013-03-10 19:29:15 +0800481 /* iterate over the originator list and find the node with the closest
Antonio Quartulli785ea112011-11-23 11:35:44 +0100482 * dat_address which has not been selected yet
483 */
484 for (i = 0; i < hash->size; i++) {
485 head = &hash->table[i];
486
487 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800488 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800489 /* the dht space is a ring using unsigned addresses */
Antonio Quartulli785ea112011-11-23 11:35:44 +0100490 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
491 ip_key;
492
493 if (!batadv_is_orig_node_eligible(cands, select,
494 tmp_max, max,
495 *last_max, orig_node,
496 max_orig_node))
497 continue;
498
499 if (!atomic_inc_not_zero(&orig_node->refcount))
500 continue;
501
502 max = tmp_max;
503 if (max_orig_node)
504 batadv_orig_node_free_ref(max_orig_node);
505 max_orig_node = orig_node;
506 }
507 rcu_read_unlock();
508 }
509 if (max_orig_node) {
510 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
511 cands[select].orig_node = max_orig_node;
512 batadv_dbg(BATADV_DBG_DAT, bat_priv,
513 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
514 select, max_orig_node->orig, max_orig_node->dat_addr,
515 max);
516 }
517 *last_max = max;
518}
519
520/**
Marek Lindner93178012013-03-10 19:29:15 +0800521 * batadv_dat_select_candidates - select the nodes which the DHT message has to
Antonio Quartulli785ea112011-11-23 11:35:44 +0100522 * be sent to
523 * @bat_priv: the bat priv with all the soft interface information
524 * @ip_dst: ipv4 to look up in the DHT
525 *
526 * An originator O is selected if and only if its DHT_ID value is one of three
527 * closest values (from the LEFT, with wrap around if needed) then the hash
528 * value of the key. ip_dst is the key.
529 *
Marek Lindner93178012013-03-10 19:29:15 +0800530 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100531 */
532static struct batadv_dat_candidate *
533batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
534{
535 int select;
536 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
537 struct batadv_dat_candidate *res;
538
539 if (!bat_priv->orig_hash)
540 return NULL;
541
542 res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC);
543 if (!res)
544 return NULL;
545
546 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
547 BATADV_DAT_ADDR_MAX);
548
549 batadv_dbg(BATADV_DBG_DAT, bat_priv,
550 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
551 ip_key);
552
553 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
554 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
555 &last_max);
556
557 return res;
558}
559
560/**
561 * batadv_dat_send_data - send a payload to the selected candidates
562 * @bat_priv: the bat priv with all the soft interface information
563 * @skb: payload to send
564 * @ip: the DHT key
565 * @packet_subtype: unicast4addr packet subtype to use
566 *
Marek Lindner93178012013-03-10 19:29:15 +0800567 * This function copies the skb with pskb_copy() and is sent as unicast packet
568 * to each of the selected candidates.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100569 *
Marek Lindner93178012013-03-10 19:29:15 +0800570 * Returns true if the packet is sent to at least one candidate, false
571 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100572 */
573static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
574 struct sk_buff *skb, __be32 ip,
575 int packet_subtype)
576{
577 int i;
578 bool ret = false;
579 int send_status;
580 struct batadv_neigh_node *neigh_node = NULL;
581 struct sk_buff *tmp_skb;
582 struct batadv_dat_candidate *cand;
583
584 cand = batadv_dat_select_candidates(bat_priv, ip);
585 if (!cand)
586 goto out;
587
588 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
589
590 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
591 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
592 continue;
593
594 neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
595 if (!neigh_node)
596 goto free_orig;
597
598 tmp_skb = pskb_copy(skb, GFP_ATOMIC);
Martin Hundebøllf097e252013-05-23 16:53:01 +0200599 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
600 cand[i].orig_node,
601 packet_subtype)) {
Antonio Quartulli785ea112011-11-23 11:35:44 +0100602 kfree_skb(tmp_skb);
603 goto free_neigh;
604 }
605
606 send_status = batadv_send_skb_packet(tmp_skb,
607 neigh_node->if_incoming,
608 neigh_node->addr);
Martin Hundebøll4046b242012-04-20 17:02:45 +0200609 if (send_status == NET_XMIT_SUCCESS) {
610 /* count the sent packet */
611 switch (packet_subtype) {
612 case BATADV_P_DAT_DHT_GET:
613 batadv_inc_counter(bat_priv,
614 BATADV_CNT_DAT_GET_TX);
615 break;
616 case BATADV_P_DAT_DHT_PUT:
617 batadv_inc_counter(bat_priv,
618 BATADV_CNT_DAT_PUT_TX);
619 break;
620 }
621
Antonio Quartulli785ea112011-11-23 11:35:44 +0100622 /* packet sent to a candidate: return true */
623 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200624 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100625free_neigh:
626 batadv_neigh_node_free_ref(neigh_node);
627free_orig:
628 batadv_orig_node_free_ref(cand[i].orig_node);
629 }
630
631out:
632 kfree(cand);
633 return ret;
634}
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200635
636/**
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800637 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
638 * setting change
639 * @bat_priv: the bat priv with all the soft interface information
640 */
641static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
642{
643 char dat_mode;
644
645 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
646
647 switch (dat_mode) {
648 case 0:
649 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
650 break;
651 case 1:
652 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
653 NULL, 0);
654 break;
655 }
656}
657
658/**
659 * batadv_dat_status_update - update the dat tvlv container after dat
660 * setting change
661 * @net_dev: the soft interface net device
662 */
663void batadv_dat_status_update(struct net_device *net_dev)
664{
665 struct batadv_priv *bat_priv = netdev_priv(net_dev);
666 batadv_dat_tvlv_container_update(bat_priv);
667}
668
669/**
670 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
671 * @bat_priv: the bat priv with all the soft interface information
672 * @orig: the orig_node of the ogm
673 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
674 * @tvlv_value: tvlv buffer containing the gateway data
675 * @tvlv_value_len: tvlv buffer length
676 */
677static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
678 struct batadv_orig_node *orig,
679 uint8_t flags,
680 void *tvlv_value,
681 uint16_t tvlv_value_len)
682{
683 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
684 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
685 else
686 orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
687}
688
689/**
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200690 * batadv_dat_hash_free - free the local DAT hash table
691 * @bat_priv: the bat priv with all the soft interface information
692 */
693static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
694{
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200695 if (!bat_priv->dat.hash)
696 return;
697
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200698 __batadv_dat_purge(bat_priv, NULL);
699
700 batadv_hash_destroy(bat_priv->dat.hash);
701
702 bat_priv->dat.hash = NULL;
703}
704
705/**
706 * batadv_dat_init - initialise the DAT internals
707 * @bat_priv: the bat priv with all the soft interface information
708 */
709int batadv_dat_init(struct batadv_priv *bat_priv)
710{
711 if (bat_priv->dat.hash)
712 return 0;
713
714 bat_priv->dat.hash = batadv_hash_new(1024);
715
716 if (!bat_priv->dat.hash)
717 return -ENOMEM;
718
719 batadv_dat_start_timer(bat_priv);
720
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800721 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
722 NULL, BATADV_TVLV_DAT, 1,
723 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
724 batadv_dat_tvlv_container_update(bat_priv);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200725 return 0;
726}
727
728/**
729 * batadv_dat_free - free the DAT internals
730 * @bat_priv: the bat priv with all the soft interface information
731 */
732void batadv_dat_free(struct batadv_priv *bat_priv)
733{
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800734 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
735 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
736
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200737 cancel_delayed_work_sync(&bat_priv->dat.work);
738
739 batadv_dat_hash_free(bat_priv);
740}
741
742/**
743 * batadv_dat_cache_seq_print_text - print the local DAT hash table
744 * @seq: seq file to print on
745 * @offset: not used
746 */
747int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
748{
749 struct net_device *net_dev = (struct net_device *)seq->private;
750 struct batadv_priv *bat_priv = netdev_priv(net_dev);
751 struct batadv_hashtable *hash = bat_priv->dat.hash;
752 struct batadv_dat_entry *dat_entry;
753 struct batadv_hard_iface *primary_if;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200754 struct hlist_head *head;
755 unsigned long last_seen_jiffies;
756 int last_seen_msecs, last_seen_secs, last_seen_mins;
757 uint32_t i;
758
759 primary_if = batadv_seq_print_text_primary_if_get(seq);
760 if (!primary_if)
761 goto out;
762
763 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200764 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
765 "MAC", "VID", "last-seen");
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200766
767 for (i = 0; i < hash->size; i++) {
768 head = &hash->table[i];
769
770 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800771 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200772 last_seen_jiffies = jiffies - dat_entry->last_update;
773 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
774 last_seen_mins = last_seen_msecs / 60000;
775 last_seen_msecs = last_seen_msecs % 60000;
776 last_seen_secs = last_seen_msecs / 1000;
777
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200778 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200779 &dat_entry->ip, dat_entry->mac_addr,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200780 BATADV_PRINT_VID(dat_entry->vid),
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200781 last_seen_mins, last_seen_secs);
782 }
783 rcu_read_unlock();
784 }
785
786out:
787 if (primary_if)
788 batadv_hardif_free_ref(primary_if);
789 return 0;
790}
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200791
792/**
793 * batadv_arp_get_type - parse an ARP packet and gets the type
794 * @bat_priv: the bat priv with all the soft interface information
795 * @skb: packet to analyse
796 * @hdr_size: size of the possible header before the ARP packet in the skb
797 *
Marek Lindner93178012013-03-10 19:29:15 +0800798 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200799 */
800static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
801 struct sk_buff *skb, int hdr_size)
802{
803 struct arphdr *arphdr;
804 struct ethhdr *ethhdr;
805 __be32 ip_src, ip_dst;
Matthias Schifferb618ad12013-01-24 18:18:27 +0100806 uint8_t *hw_src, *hw_dst;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200807 uint16_t type = 0;
808
809 /* pull the ethernet header */
810 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
811 goto out;
812
813 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
814
815 if (ethhdr->h_proto != htons(ETH_P_ARP))
816 goto out;
817
818 /* pull the ARP payload */
819 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
820 arp_hdr_len(skb->dev))))
821 goto out;
822
823 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
824
Marek Lindner93178012013-03-10 19:29:15 +0800825 /* check whether the ARP packet carries a valid IP information */
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200826 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
827 goto out;
828
829 if (arphdr->ar_pro != htons(ETH_P_IP))
830 goto out;
831
832 if (arphdr->ar_hln != ETH_ALEN)
833 goto out;
834
835 if (arphdr->ar_pln != 4)
836 goto out;
837
838 /* Check for bad reply/request. If the ARP message is not sane, DAT
839 * will simply ignore it
840 */
841 ip_src = batadv_arp_ip_src(skb, hdr_size);
842 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
843 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
Matthias Schiffer757dd822013-01-24 18:18:26 +0100844 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
845 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
846 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200847 goto out;
848
Matthias Schifferb618ad12013-01-24 18:18:27 +0100849 hw_src = batadv_arp_hw_src(skb, hdr_size);
850 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
851 goto out;
852
Marek Lindner93178012013-03-10 19:29:15 +0800853 /* don't care about the destination MAC address in ARP requests */
Matthias Schifferb618ad12013-01-24 18:18:27 +0100854 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
855 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
856 if (is_zero_ether_addr(hw_dst) ||
857 is_multicast_ether_addr(hw_dst))
858 goto out;
859 }
860
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200861 type = ntohs(arphdr->ar_op);
862out:
863 return type;
864}
Antonio Quartullic384ea32011-06-26 03:37:18 +0200865
866/**
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200867 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
868 * @skb: the buffer containing the packet to extract the VID from
869 * @hdr_size: the size of the batman-adv header encapsulating the packet
870 *
871 * If the packet embedded in the skb is vlan tagged this function returns the
872 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
873 */
874static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
875{
876 unsigned short vid;
877
878 vid = batadv_get_vid(skb, *hdr_size);
879
880 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
881 * If the header contained in the packet is a VLAN one (which is longer)
882 * hdr_size is updated so that the functions will still skip the
883 * correct amount of bytes.
884 */
885 if (vid & BATADV_VLAN_HAS_TAG)
886 *hdr_size += VLAN_HLEN;
887
888 return vid;
889}
890
891/**
Antonio Quartullic384ea32011-06-26 03:37:18 +0200892 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
893 * answer using DAT
894 * @bat_priv: the bat priv with all the soft interface information
895 * @skb: packet to check
896 *
897 * Returns true if the message has been sent to the dht candidates, false
Marek Lindner93178012013-03-10 19:29:15 +0800898 * otherwise. In case of a positive return value the message has to be enqueued
899 * to permit the fallback.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200900 */
901bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
902 struct sk_buff *skb)
903{
904 uint16_t type = 0;
905 __be32 ip_dst, ip_src;
906 uint8_t *hw_src;
907 bool ret = false;
908 struct batadv_dat_entry *dat_entry = NULL;
909 struct sk_buff *skb_new;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200910 int hdr_size = 0;
911 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200912
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200913 if (!atomic_read(&bat_priv->distributed_arp_table))
914 goto out;
915
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200916 vid = batadv_dat_get_vid(skb, &hdr_size);
917
918 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200919 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
920 * message to the selected DHT candidates
921 */
922 if (type != ARPOP_REQUEST)
923 goto out;
924
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200925 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
926 "Parsing outgoing ARP REQUEST");
Antonio Quartullic384ea32011-06-26 03:37:18 +0200927
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200928 ip_src = batadv_arp_ip_src(skb, hdr_size);
929 hw_src = batadv_arp_hw_src(skb, hdr_size);
930 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200931
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200932 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200933
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200934 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200935 if (dat_entry) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200936 /* If the ARP request is destined for a local client the local
937 * client will answer itself. DAT would only generate a
938 * duplicate packet.
939 *
940 * Moreover, if the soft-interface is enslaved into a bridge, an
941 * additional DAT answer may trigger kernel warnings about
942 * a packet coming from the wrong port.
943 */
Antonio Quartullic018ad32013-06-04 12:11:39 +0200944 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr,
945 BATADV_NO_FLAGS)) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200946 ret = true;
947 goto out;
948 }
949
Antonio Quartullic384ea32011-06-26 03:37:18 +0200950 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800951 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200952 dat_entry->mac_addr, hw_src);
953 if (!skb_new)
954 goto out;
955
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200956 if (vid & BATADV_VLAN_HAS_TAG)
957 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
958 vid & VLAN_VID_MASK);
959
Antonio Quartullic384ea32011-06-26 03:37:18 +0200960 skb_reset_mac_header(skb_new);
961 skb_new->protocol = eth_type_trans(skb_new,
Marek Lindner736292c2013-01-12 19:19:06 +0800962 bat_priv->soft_iface);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200963 bat_priv->stats.rx_packets++;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200964 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
Marek Lindner736292c2013-01-12 19:19:06 +0800965 bat_priv->soft_iface->last_rx = jiffies;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200966
967 netif_rx(skb_new);
968 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
969 ret = true;
970 } else {
Marek Lindner93178012013-03-10 19:29:15 +0800971 /* Send the request to the DHT */
Antonio Quartullic384ea32011-06-26 03:37:18 +0200972 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
973 BATADV_P_DAT_DHT_GET);
974 }
975out:
976 if (dat_entry)
977 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200978 return ret;
979}
980
981/**
982 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
983 * answer using the local DAT storage
984 * @bat_priv: the bat priv with all the soft interface information
985 * @skb: packet to check
986 * @hdr_size: size of the encapsulation header
987 *
Marek Lindner93178012013-03-10 19:29:15 +0800988 * Returns true if the request has been answered, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200989 */
990bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
991 struct sk_buff *skb, int hdr_size)
992{
993 uint16_t type;
994 __be32 ip_src, ip_dst;
995 uint8_t *hw_src;
996 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200997 struct batadv_dat_entry *dat_entry = NULL;
998 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200999 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001000 int err;
1001
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001002 if (!atomic_read(&bat_priv->distributed_arp_table))
1003 goto out;
1004
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001005 vid = batadv_dat_get_vid(skb, &hdr_size);
1006
Antonio Quartullic384ea32011-06-26 03:37:18 +02001007 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1008 if (type != ARPOP_REQUEST)
1009 goto out;
1010
1011 hw_src = batadv_arp_hw_src(skb, hdr_size);
1012 ip_src = batadv_arp_ip_src(skb, hdr_size);
1013 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1014
1015 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1016 "Parsing incoming ARP REQUEST");
1017
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001018 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001019
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001020 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001021 if (!dat_entry)
1022 goto out;
1023
Antonio Quartullic384ea32011-06-26 03:37:18 +02001024 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +08001025 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +02001026 dat_entry->mac_addr, hw_src);
1027
1028 if (!skb_new)
1029 goto out;
1030
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001031 if (vid & BATADV_VLAN_HAS_TAG)
1032 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1033 vid & VLAN_VID_MASK);
1034
Marek Lindner93178012013-03-10 19:29:15 +08001035 /* To preserve backwards compatibility, the node has choose the outgoing
1036 * format based on the incoming request packet type. The assumption is
1037 * that a node not using the 4addr packet format doesn't support it.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001038 */
1039 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
Linus Lüssinge300d312013-07-03 10:40:00 +02001040 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1041 BATADV_P_DAT_CACHE_REPLY,
1042 vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001043 else
Linus Lüssinge300d312013-07-03 10:40:00 +02001044 err = batadv_send_skb_via_tt(bat_priv, skb_new, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001045
Linus Lüssinge300d312013-07-03 10:40:00 +02001046 if (err != NET_XMIT_DROP) {
Martin Hundebøll4046b242012-04-20 17:02:45 +02001047 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001048 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +02001049 }
Antonio Quartullic384ea32011-06-26 03:37:18 +02001050out:
1051 if (dat_entry)
1052 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001053 if (ret)
1054 kfree_skb(skb);
1055 return ret;
1056}
1057
1058/**
1059 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1060 * @bat_priv: the bat priv with all the soft interface information
1061 * @skb: packet to check
1062 */
1063void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1064 struct sk_buff *skb)
1065{
1066 uint16_t type;
1067 __be32 ip_src, ip_dst;
1068 uint8_t *hw_src, *hw_dst;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001069 int hdr_size = 0;
1070 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001071
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001072 if (!atomic_read(&bat_priv->distributed_arp_table))
1073 return;
1074
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001075 vid = batadv_dat_get_vid(skb, &hdr_size);
1076
1077 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001078 if (type != ARPOP_REPLY)
1079 return;
1080
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001081 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1082 "Parsing outgoing ARP REPLY");
Antonio Quartullic384ea32011-06-26 03:37:18 +02001083
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001084 hw_src = batadv_arp_hw_src(skb, hdr_size);
1085 ip_src = batadv_arp_ip_src(skb, hdr_size);
1086 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1087 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001088
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001089 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1090 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001091
1092 /* Send the ARP reply to the candidates for both the IP addresses that
Marek Lindner93178012013-03-10 19:29:15 +08001093 * the node obtained from the ARP reply
Antonio Quartullic384ea32011-06-26 03:37:18 +02001094 */
1095 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1096 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1097}
1098/**
1099 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1100 * DAT storage only
1101 * @bat_priv: the bat priv with all the soft interface information
1102 * @skb: packet to check
Marek Lindner93178012013-03-10 19:29:15 +08001103 * @hdr_size: size of the encapsulation header
Antonio Quartullic384ea32011-06-26 03:37:18 +02001104 */
1105bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1106 struct sk_buff *skb, int hdr_size)
1107{
1108 uint16_t type;
1109 __be32 ip_src, ip_dst;
1110 uint8_t *hw_src, *hw_dst;
1111 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001112 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001113
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001114 if (!atomic_read(&bat_priv->distributed_arp_table))
1115 goto out;
1116
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001117 vid = batadv_dat_get_vid(skb, &hdr_size);
1118
Antonio Quartullic384ea32011-06-26 03:37:18 +02001119 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1120 if (type != ARPOP_REPLY)
1121 goto out;
1122
1123 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1124 "Parsing incoming ARP REPLY");
1125
1126 hw_src = batadv_arp_hw_src(skb, hdr_size);
1127 ip_src = batadv_arp_ip_src(skb, hdr_size);
1128 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1129 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1130
1131 /* Update our internal cache with both the IP addresses the node got
1132 * within the ARP reply
1133 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001134 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1135 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001136
1137 /* if this REPLY is directed to a client of mine, let's deliver the
1138 * packet to the interface
1139 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001140 ret = !batadv_is_my_client(bat_priv, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001141out:
Matthias Schiffer0d15bec2013-01-23 18:11:53 +01001142 if (ret)
1143 kfree_skb(skb);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001144 /* if ret == false -> packet has to be delivered to the interface */
1145 return ret;
1146}
1147
1148/**
1149 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
Marek Lindner93178012013-03-10 19:29:15 +08001150 * (because the node has already obtained the reply via DAT) or not
Antonio Quartullic384ea32011-06-26 03:37:18 +02001151 * @bat_priv: the bat priv with all the soft interface information
1152 * @forw_packet: the broadcast packet
1153 *
Marek Lindner93178012013-03-10 19:29:15 +08001154 * Returns true if the node can drop the packet, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001155 */
1156bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1157 struct batadv_forw_packet *forw_packet)
1158{
1159 uint16_t type;
1160 __be32 ip_dst;
1161 struct batadv_dat_entry *dat_entry = NULL;
1162 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001163 int hdr_size = sizeof(struct batadv_bcast_packet);
1164 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001165
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001166 if (!atomic_read(&bat_priv->distributed_arp_table))
1167 goto out;
1168
Antonio Quartullic384ea32011-06-26 03:37:18 +02001169 /* If this packet is an ARP_REQUEST and the node already has the
1170 * information that it is going to ask, then the packet can be dropped
1171 */
1172 if (forw_packet->num_packets)
1173 goto out;
1174
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001175 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1176
1177 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001178 if (type != ARPOP_REQUEST)
1179 goto out;
1180
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001181 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1182 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001183 /* check if the node already got this entry */
1184 if (!dat_entry) {
1185 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1186 "ARP Request for %pI4: fallback\n", &ip_dst);
1187 goto out;
1188 }
1189
1190 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1191 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1192 ret = true;
1193
1194out:
1195 if (dat_entry)
1196 batadv_dat_entry_free_ref(dat_entry);
1197 return ret;
1198}