blob: 997ae6ac51ff38f3247cc9e47bc9df43a26b0e47 [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
Antonio Quartulliebf38fb2013-11-03 20:40:48 +010015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Antonio Quartulli785ea112011-11-23 11:35:44 +010016 */
17
18#include <linux/if_ether.h>
19#include <linux/if_arp.h>
Antonio Quartullibe1db4f2013-06-04 12:11:43 +020020#include <linux/if_vlan.h>
Antonio Quartullic384ea32011-06-26 03:37:18 +020021#include <net/arp.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010022
23#include "main.h"
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +020024#include "hash.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010025#include "distributed-arp-table.h"
26#include "hard-interface.h"
27#include "originator.h"
28#include "send.h"
29#include "types.h"
Antonio Quartullic384ea32011-06-26 03:37:18 +020030#include "translation-table.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010031
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020032static void batadv_dat_purge(struct work_struct *work);
33
34/**
35 * batadv_dat_start_timer - initialise the DAT periodic worker
36 * @bat_priv: the bat priv with all the soft interface information
37 */
38static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
39{
40 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
41 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
42 msecs_to_jiffies(10000));
43}
44
45/**
Marek Lindner93178012013-03-10 19:29:15 +080046 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020047 * free it
Marek Lindner93178012013-03-10 19:29:15 +080048 * @dat_entry: the entry to free
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020049 */
50static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
51{
52 if (atomic_dec_and_test(&dat_entry->refcount))
53 kfree_rcu(dat_entry, rcu);
54}
55
56/**
Marek Lindner93178012013-03-10 19:29:15 +080057 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020058 * @dat_entry: the entry to check
59 *
Marek Lindner93178012013-03-10 19:29:15 +080060 * Returns true if the entry has to be purged now, false otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020061 */
62static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
63{
64 return batadv_has_timed_out(dat_entry->last_update,
65 BATADV_DAT_ENTRY_TIMEOUT);
66}
67
68/**
69 * __batadv_dat_purge - delete entries from the DAT local storage
70 * @bat_priv: the bat priv with all the soft interface information
71 * @to_purge: function in charge to decide whether an entry has to be purged or
72 * not. This function takes the dat_entry as argument and has to
73 * returns a boolean value: true is the entry has to be deleted,
74 * false otherwise
75 *
Marek Lindner93178012013-03-10 19:29:15 +080076 * Loops over each entry in the DAT local storage and deletes it if and only if
77 * the to_purge function passed as argument returns true.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020078 */
79static void __batadv_dat_purge(struct batadv_priv *bat_priv,
80 bool (*to_purge)(struct batadv_dat_entry *))
81{
82 spinlock_t *list_lock; /* protects write access to the hash lists */
83 struct batadv_dat_entry *dat_entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -080084 struct hlist_node *node_tmp;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020085 struct hlist_head *head;
86 uint32_t i;
87
88 if (!bat_priv->dat.hash)
89 return;
90
91 for (i = 0; i < bat_priv->dat.hash->size; i++) {
92 head = &bat_priv->dat.hash->table[i];
93 list_lock = &bat_priv->dat.hash->list_locks[i];
94
95 spin_lock_bh(list_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -080096 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020097 hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +080098 /* if a helper function has been passed as parameter,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020099 * ask it if the entry has to be purged or not
100 */
101 if (to_purge && !to_purge(dat_entry))
102 continue;
103
Sasha Levinb67bfe02013-02-27 17:06:00 -0800104 hlist_del_rcu(&dat_entry->hash_entry);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200105 batadv_dat_entry_free_ref(dat_entry);
106 }
107 spin_unlock_bh(list_lock);
108 }
109}
110
111/**
112 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
113 * hash table
114 * @work: kernel work struct
115 */
116static void batadv_dat_purge(struct work_struct *work)
117{
118 struct delayed_work *delayed_work;
119 struct batadv_priv_dat *priv_dat;
120 struct batadv_priv *bat_priv;
121
122 delayed_work = container_of(work, struct delayed_work, work);
123 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
124 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
125
126 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
127 batadv_dat_start_timer(bat_priv);
128}
129
130/**
131 * batadv_compare_dat - comparing function used in the local DAT hash table
132 * @node: node in the local table
133 * @data2: second object to compare the node to
134 *
Marek Lindner93178012013-03-10 19:29:15 +0800135 * Returns 1 if the two entries are the same, 0 otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200136 */
137static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
138{
139 const void *data1 = container_of(node, struct batadv_dat_entry,
140 hash_entry);
141
Antonio Quartulli36484f82013-11-07 08:02:07 +0100142 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200143}
144
Antonio Quartulli785ea112011-11-23 11:35:44 +0100145/**
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200146 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
147 * @skb: ARP packet
148 * @hdr_size: size of the possible header before the ARP packet
149 *
Marek Lindner93178012013-03-10 19:29:15 +0800150 * Returns the value of the hw_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200151 */
152static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
153{
154 uint8_t *addr;
155
156 addr = (uint8_t *)(skb->data + hdr_size);
157 addr += ETH_HLEN + sizeof(struct arphdr);
158
159 return addr;
160}
161
162/**
163 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
164 * @skb: ARP packet
165 * @hdr_size: size of the possible header before the ARP packet
166 *
Marek Lindner93178012013-03-10 19:29:15 +0800167 * Returns the value of the ip_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200168 */
169static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
170{
171 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
172}
173
174/**
175 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
176 * @skb: ARP packet
177 * @hdr_size: size of the possible header before the ARP packet
178 *
Marek Lindner93178012013-03-10 19:29:15 +0800179 * Returns the value of the hw_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200180 */
181static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
182{
183 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
184}
185
186/**
187 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
188 * @skb: ARP packet
189 * @hdr_size: size of the possible header before the ARP packet
190 *
Marek Lindner93178012013-03-10 19:29:15 +0800191 * Returns the value of the ip_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200192 */
193static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
194{
195 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
196}
197
198/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100199 * batadv_hash_dat - compute the hash value for an IP address
200 * @data: data to hash
201 * @size: size of the hash table
202 *
Marek Lindner93178012013-03-10 19:29:15 +0800203 * Returns the selected index in the hash table for the given data.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100204 */
205static uint32_t batadv_hash_dat(const void *data, uint32_t size)
206{
Antonio Quartulli785ea112011-11-23 11:35:44 +0100207 uint32_t hash = 0;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200208 const struct batadv_dat_entry *dat = data;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100209
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200210 hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip));
211 hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid));
Antonio Quartulli785ea112011-11-23 11:35:44 +0100212
213 hash += (hash << 3);
214 hash ^= (hash >> 11);
215 hash += (hash << 15);
216
217 return hash % size;
218}
219
220/**
Marek Lindner93178012013-03-10 19:29:15 +0800221 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200222 * table
223 * @bat_priv: the bat priv with all the soft interface information
224 * @ip: search key
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200225 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200226 *
Marek Lindner93178012013-03-10 19:29:15 +0800227 * Returns the dat_entry if found, NULL otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200228 */
229static struct batadv_dat_entry *
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200230batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
231 unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200232{
233 struct hlist_head *head;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200234 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200235 struct batadv_hashtable *hash = bat_priv->dat.hash;
236 uint32_t index;
237
238 if (!hash)
239 return NULL;
240
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200241 to_find.ip = ip;
242 to_find.vid = vid;
243
244 index = batadv_hash_dat(&to_find, hash->size);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200245 head = &hash->table[index];
246
247 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800248 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200249 if (dat_entry->ip != ip)
250 continue;
251
252 if (!atomic_inc_not_zero(&dat_entry->refcount))
253 continue;
254
255 dat_entry_tmp = dat_entry;
256 break;
257 }
258 rcu_read_unlock();
259
260 return dat_entry_tmp;
261}
262
263/**
264 * batadv_dat_entry_add - add a new dat entry or update it if already exists
265 * @bat_priv: the bat priv with all the soft interface information
266 * @ip: ipv4 to add/edit
267 * @mac_addr: mac address to assign to the given ipv4
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200268 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200269 */
270static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200271 uint8_t *mac_addr, unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200272{
273 struct batadv_dat_entry *dat_entry;
274 int hash_added;
275
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200276 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200277 /* 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,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200283 "Entry updated: %pI4 %pM (vid: %d)\n",
284 &dat_entry->ip, dat_entry->mac_addr,
285 BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200286 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;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200294 dat_entry->vid = vid;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200295 memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
296 dat_entry->last_update = jiffies;
297 atomic_set(&dat_entry->refcount, 2);
298
299 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200300 batadv_hash_dat, dat_entry,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200301 &dat_entry->hash_entry);
302
303 if (unlikely(hash_added != 0)) {
304 /* remove the reference for the hash */
305 batadv_dat_entry_free_ref(dat_entry);
306 goto out;
307 }
308
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200309 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
310 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200311
312out:
313 if (dat_entry)
314 batadv_dat_entry_free_ref(dat_entry);
315}
316
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200317#ifdef CONFIG_BATMAN_ADV_DEBUG
318
319/**
320 * batadv_dbg_arp - print a debug message containing all the ARP packet details
321 * @bat_priv: the bat priv with all the soft interface information
322 * @skb: ARP packet
323 * @type: ARP type
324 * @hdr_size: size of the possible header before the ARP packet
325 * @msg: message to print together with the debugging information
326 */
327static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
328 uint16_t type, int hdr_size, char *msg)
329{
330 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
331 struct batadv_bcast_packet *bcast_pkt;
332 uint8_t *orig_addr;
333 __be32 ip_src, ip_dst;
334
335 if (msg)
336 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
337
338 ip_src = batadv_arp_ip_src(skb, hdr_size);
339 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
340 batadv_dbg(BATADV_DBG_DAT, bat_priv,
341 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
342 batadv_arp_hw_src(skb, hdr_size), &ip_src,
343 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
344
345 if (hdr_size == 0)
346 return;
347
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200348 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
349
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100350 switch (unicast_4addr_packet->u.packet_type) {
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200351 case BATADV_UNICAST:
352 batadv_dbg(BATADV_DBG_DAT, bat_priv,
353 "* encapsulated within a UNICAST packet\n");
354 break;
355 case BATADV_UNICAST_4ADDR:
356 batadv_dbg(BATADV_DBG_DAT, bat_priv,
357 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
358 unicast_4addr_packet->src);
359 switch (unicast_4addr_packet->subtype) {
360 case BATADV_P_DAT_DHT_PUT:
361 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
362 break;
363 case BATADV_P_DAT_DHT_GET:
364 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
365 break;
366 case BATADV_P_DAT_CACHE_REPLY:
367 batadv_dbg(BATADV_DBG_DAT, bat_priv,
368 "* type: DAT_CACHE_REPLY\n");
369 break;
370 case BATADV_P_DATA:
371 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
372 break;
373 default:
374 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100375 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200376 }
377 break;
378 case BATADV_BCAST:
379 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
380 orig_addr = bcast_pkt->orig;
381 batadv_dbg(BATADV_DBG_DAT, bat_priv,
382 "* encapsulated within a BCAST packet (src: %pM)\n",
383 orig_addr);
384 break;
385 default:
386 batadv_dbg(BATADV_DBG_DAT, bat_priv,
387 "* encapsulated within an unknown packet type (0x%x)\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100388 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200389 }
390}
391
392#else
393
394static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
395 uint16_t type, int hdr_size, char *msg)
396{
397}
398
399#endif /* CONFIG_BATMAN_ADV_DEBUG */
400
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200401/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100402 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
403 * @res: the array with the already selected candidates
404 * @select: number of already selected candidates
405 * @tmp_max: address of the currently evaluated node
406 * @max: current round max address
407 * @last_max: address of the last selected candidate
408 * @candidate: orig_node under evaluation
409 * @max_orig_node: last selected candidate
410 *
Marek Lindner93178012013-03-10 19:29:15 +0800411 * Returns true if the node has been elected as next candidate or false
412 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100413 */
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
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800424 /* check if orig node candidate is running DAT */
425 if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
426 goto out;
427
Antonio Quartulli785ea112011-11-23 11:35:44 +0100428 /* Check if this node has already been selected... */
429 for (j = 0; j < select; j++)
430 if (res[j].orig_node == candidate)
431 break;
432 /* ..and possibly skip it */
433 if (j < select)
434 goto out;
435 /* sanity check: has it already been selected? This should not happen */
436 if (tmp_max > last_max)
437 goto out;
438 /* check if during this iteration an originator with a closer dht
439 * address has already been found
440 */
441 if (tmp_max < max)
442 goto out;
443 /* this is an hash collision with the temporary selected node. Choose
444 * the one with the lowest address
445 */
Pau Koning816cd5b2013-02-12 00:18:45 +0000446 if ((tmp_max == max) && max_orig_node &&
Antonio Quartulli785ea112011-11-23 11:35:44 +0100447 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
448 goto out;
449
450 ret = true;
451out:
452 return ret;
453}
454
455/**
456 * batadv_choose_next_candidate - select the next DHT candidate
457 * @bat_priv: the bat priv with all the soft interface information
458 * @cands: candidates array
459 * @select: number of candidates already present in the array
460 * @ip_key: key to look up in the DHT
461 * @last_max: pointer where the address of the selected candidate will be saved
462 */
463static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
464 struct batadv_dat_candidate *cands,
465 int select, batadv_dat_addr_t ip_key,
466 batadv_dat_addr_t *last_max)
467{
468 batadv_dat_addr_t max = 0, tmp_max = 0;
469 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
470 struct batadv_hashtable *hash = bat_priv->orig_hash;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100471 struct hlist_head *head;
472 int i;
473
474 /* if no node is eligible as candidate, leave the candidate type as
475 * NOT_FOUND
476 */
477 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
478
Marek Lindner93178012013-03-10 19:29:15 +0800479 /* iterate over the originator list and find the node with the closest
Antonio Quartulli785ea112011-11-23 11:35:44 +0100480 * dat_address which has not been selected yet
481 */
482 for (i = 0; i < hash->size; i++) {
483 head = &hash->table[i];
484
485 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800486 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800487 /* the dht space is a ring using unsigned addresses */
Antonio Quartulli785ea112011-11-23 11:35:44 +0100488 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
489 ip_key;
490
491 if (!batadv_is_orig_node_eligible(cands, select,
492 tmp_max, max,
493 *last_max, orig_node,
494 max_orig_node))
495 continue;
496
497 if (!atomic_inc_not_zero(&orig_node->refcount))
498 continue;
499
500 max = tmp_max;
501 if (max_orig_node)
502 batadv_orig_node_free_ref(max_orig_node);
503 max_orig_node = orig_node;
504 }
505 rcu_read_unlock();
506 }
507 if (max_orig_node) {
508 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
509 cands[select].orig_node = max_orig_node;
510 batadv_dbg(BATADV_DBG_DAT, bat_priv,
511 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
512 select, max_orig_node->orig, max_orig_node->dat_addr,
513 max);
514 }
515 *last_max = max;
516}
517
518/**
Marek Lindner93178012013-03-10 19:29:15 +0800519 * batadv_dat_select_candidates - select the nodes which the DHT message has to
Antonio Quartulli785ea112011-11-23 11:35:44 +0100520 * be sent to
521 * @bat_priv: the bat priv with all the soft interface information
522 * @ip_dst: ipv4 to look up in the DHT
523 *
524 * An originator O is selected if and only if its DHT_ID value is one of three
525 * closest values (from the LEFT, with wrap around if needed) then the hash
526 * value of the key. ip_dst is the key.
527 *
Marek Lindner93178012013-03-10 19:29:15 +0800528 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100529 */
530static struct batadv_dat_candidate *
531batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
532{
533 int select;
534 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
535 struct batadv_dat_candidate *res;
536
537 if (!bat_priv->orig_hash)
538 return NULL;
539
540 res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC);
541 if (!res)
542 return NULL;
543
544 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
545 BATADV_DAT_ADDR_MAX);
546
547 batadv_dbg(BATADV_DBG_DAT, bat_priv,
548 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
549 ip_key);
550
551 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
552 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
553 &last_max);
554
555 return res;
556}
557
558/**
559 * batadv_dat_send_data - send a payload to the selected candidates
560 * @bat_priv: the bat priv with all the soft interface information
561 * @skb: payload to send
562 * @ip: the DHT key
563 * @packet_subtype: unicast4addr packet subtype to use
564 *
Marek Lindner93178012013-03-10 19:29:15 +0800565 * This function copies the skb with pskb_copy() and is sent as unicast packet
566 * to each of the selected candidates.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100567 *
Marek Lindner93178012013-03-10 19:29:15 +0800568 * Returns true if the packet is sent to at least one candidate, false
569 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100570 */
571static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
572 struct sk_buff *skb, __be32 ip,
573 int packet_subtype)
574{
575 int i;
576 bool ret = false;
577 int send_status;
578 struct batadv_neigh_node *neigh_node = NULL;
579 struct sk_buff *tmp_skb;
580 struct batadv_dat_candidate *cand;
581
582 cand = batadv_dat_select_candidates(bat_priv, ip);
583 if (!cand)
584 goto out;
585
586 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
587
588 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
589 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
590 continue;
591
592 neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
593 if (!neigh_node)
594 goto free_orig;
595
596 tmp_skb = pskb_copy(skb, GFP_ATOMIC);
Martin Hundebøllf097e252013-05-23 16:53:01 +0200597 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
598 cand[i].orig_node,
599 packet_subtype)) {
Antonio Quartulli785ea112011-11-23 11:35:44 +0100600 kfree_skb(tmp_skb);
601 goto free_neigh;
602 }
603
604 send_status = batadv_send_skb_packet(tmp_skb,
605 neigh_node->if_incoming,
606 neigh_node->addr);
Martin Hundebøll4046b242012-04-20 17:02:45 +0200607 if (send_status == NET_XMIT_SUCCESS) {
608 /* count the sent packet */
609 switch (packet_subtype) {
610 case BATADV_P_DAT_DHT_GET:
611 batadv_inc_counter(bat_priv,
612 BATADV_CNT_DAT_GET_TX);
613 break;
614 case BATADV_P_DAT_DHT_PUT:
615 batadv_inc_counter(bat_priv,
616 BATADV_CNT_DAT_PUT_TX);
617 break;
618 }
619
Antonio Quartulli785ea112011-11-23 11:35:44 +0100620 /* packet sent to a candidate: return true */
621 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200622 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100623free_neigh:
624 batadv_neigh_node_free_ref(neigh_node);
625free_orig:
626 batadv_orig_node_free_ref(cand[i].orig_node);
627 }
628
629out:
630 kfree(cand);
631 return ret;
632}
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200633
634/**
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800635 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
636 * setting change
637 * @bat_priv: the bat priv with all the soft interface information
638 */
639static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
640{
641 char dat_mode;
642
643 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
644
645 switch (dat_mode) {
646 case 0:
647 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
648 break;
649 case 1:
650 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
651 NULL, 0);
652 break;
653 }
654}
655
656/**
657 * batadv_dat_status_update - update the dat tvlv container after dat
658 * setting change
659 * @net_dev: the soft interface net device
660 */
661void batadv_dat_status_update(struct net_device *net_dev)
662{
663 struct batadv_priv *bat_priv = netdev_priv(net_dev);
664 batadv_dat_tvlv_container_update(bat_priv);
665}
666
667/**
668 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
669 * @bat_priv: the bat priv with all the soft interface information
670 * @orig: the orig_node of the ogm
671 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
672 * @tvlv_value: tvlv buffer containing the gateway data
673 * @tvlv_value_len: tvlv buffer length
674 */
675static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
676 struct batadv_orig_node *orig,
677 uint8_t flags,
678 void *tvlv_value,
679 uint16_t tvlv_value_len)
680{
681 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
682 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
683 else
684 orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
685}
686
687/**
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200688 * batadv_dat_hash_free - free the local DAT hash table
689 * @bat_priv: the bat priv with all the soft interface information
690 */
691static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
692{
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200693 if (!bat_priv->dat.hash)
694 return;
695
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200696 __batadv_dat_purge(bat_priv, NULL);
697
698 batadv_hash_destroy(bat_priv->dat.hash);
699
700 bat_priv->dat.hash = NULL;
701}
702
703/**
704 * batadv_dat_init - initialise the DAT internals
705 * @bat_priv: the bat priv with all the soft interface information
706 */
707int batadv_dat_init(struct batadv_priv *bat_priv)
708{
709 if (bat_priv->dat.hash)
710 return 0;
711
712 bat_priv->dat.hash = batadv_hash_new(1024);
713
714 if (!bat_priv->dat.hash)
715 return -ENOMEM;
716
717 batadv_dat_start_timer(bat_priv);
718
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800719 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
720 NULL, BATADV_TVLV_DAT, 1,
721 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
722 batadv_dat_tvlv_container_update(bat_priv);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200723 return 0;
724}
725
726/**
727 * batadv_dat_free - free the DAT internals
728 * @bat_priv: the bat priv with all the soft interface information
729 */
730void batadv_dat_free(struct batadv_priv *bat_priv)
731{
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800732 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
733 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
734
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200735 cancel_delayed_work_sync(&bat_priv->dat.work);
736
737 batadv_dat_hash_free(bat_priv);
738}
739
740/**
741 * batadv_dat_cache_seq_print_text - print the local DAT hash table
742 * @seq: seq file to print on
743 * @offset: not used
744 */
745int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
746{
747 struct net_device *net_dev = (struct net_device *)seq->private;
748 struct batadv_priv *bat_priv = netdev_priv(net_dev);
749 struct batadv_hashtable *hash = bat_priv->dat.hash;
750 struct batadv_dat_entry *dat_entry;
751 struct batadv_hard_iface *primary_if;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200752 struct hlist_head *head;
753 unsigned long last_seen_jiffies;
754 int last_seen_msecs, last_seen_secs, last_seen_mins;
755 uint32_t i;
756
757 primary_if = batadv_seq_print_text_primary_if_get(seq);
758 if (!primary_if)
759 goto out;
760
761 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200762 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
763 "MAC", "VID", "last-seen");
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200764
765 for (i = 0; i < hash->size; i++) {
766 head = &hash->table[i];
767
768 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800769 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200770 last_seen_jiffies = jiffies - dat_entry->last_update;
771 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
772 last_seen_mins = last_seen_msecs / 60000;
773 last_seen_msecs = last_seen_msecs % 60000;
774 last_seen_secs = last_seen_msecs / 1000;
775
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200776 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200777 &dat_entry->ip, dat_entry->mac_addr,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200778 BATADV_PRINT_VID(dat_entry->vid),
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200779 last_seen_mins, last_seen_secs);
780 }
781 rcu_read_unlock();
782 }
783
784out:
785 if (primary_if)
786 batadv_hardif_free_ref(primary_if);
787 return 0;
788}
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200789
790/**
791 * batadv_arp_get_type - parse an ARP packet and gets the type
792 * @bat_priv: the bat priv with all the soft interface information
793 * @skb: packet to analyse
794 * @hdr_size: size of the possible header before the ARP packet in the skb
795 *
Marek Lindner93178012013-03-10 19:29:15 +0800796 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200797 */
798static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
799 struct sk_buff *skb, int hdr_size)
800{
801 struct arphdr *arphdr;
802 struct ethhdr *ethhdr;
803 __be32 ip_src, ip_dst;
Matthias Schifferb618ad12013-01-24 18:18:27 +0100804 uint8_t *hw_src, *hw_dst;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200805 uint16_t type = 0;
806
807 /* pull the ethernet header */
808 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
809 goto out;
810
811 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
812
813 if (ethhdr->h_proto != htons(ETH_P_ARP))
814 goto out;
815
816 /* pull the ARP payload */
817 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
818 arp_hdr_len(skb->dev))))
819 goto out;
820
821 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
822
Marek Lindner93178012013-03-10 19:29:15 +0800823 /* check whether the ARP packet carries a valid IP information */
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200824 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
825 goto out;
826
827 if (arphdr->ar_pro != htons(ETH_P_IP))
828 goto out;
829
830 if (arphdr->ar_hln != ETH_ALEN)
831 goto out;
832
833 if (arphdr->ar_pln != 4)
834 goto out;
835
836 /* Check for bad reply/request. If the ARP message is not sane, DAT
837 * will simply ignore it
838 */
839 ip_src = batadv_arp_ip_src(skb, hdr_size);
840 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
841 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
Matthias Schiffer757dd822013-01-24 18:18:26 +0100842 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
843 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
844 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200845 goto out;
846
Matthias Schifferb618ad12013-01-24 18:18:27 +0100847 hw_src = batadv_arp_hw_src(skb, hdr_size);
848 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
849 goto out;
850
Marek Lindner93178012013-03-10 19:29:15 +0800851 /* don't care about the destination MAC address in ARP requests */
Matthias Schifferb618ad12013-01-24 18:18:27 +0100852 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
853 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
854 if (is_zero_ether_addr(hw_dst) ||
855 is_multicast_ether_addr(hw_dst))
856 goto out;
857 }
858
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200859 type = ntohs(arphdr->ar_op);
860out:
861 return type;
862}
Antonio Quartullic384ea32011-06-26 03:37:18 +0200863
864/**
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200865 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
866 * @skb: the buffer containing the packet to extract the VID from
867 * @hdr_size: the size of the batman-adv header encapsulating the packet
868 *
869 * If the packet embedded in the skb is vlan tagged this function returns the
870 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
871 */
872static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
873{
874 unsigned short vid;
875
876 vid = batadv_get_vid(skb, *hdr_size);
877
878 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
879 * If the header contained in the packet is a VLAN one (which is longer)
880 * hdr_size is updated so that the functions will still skip the
881 * correct amount of bytes.
882 */
883 if (vid & BATADV_VLAN_HAS_TAG)
884 *hdr_size += VLAN_HLEN;
885
886 return vid;
887}
888
889/**
Antonio Quartullic384ea32011-06-26 03:37:18 +0200890 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
891 * answer using DAT
892 * @bat_priv: the bat priv with all the soft interface information
893 * @skb: packet to check
894 *
895 * Returns true if the message has been sent to the dht candidates, false
Marek Lindner93178012013-03-10 19:29:15 +0800896 * otherwise. In case of a positive return value the message has to be enqueued
897 * to permit the fallback.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200898 */
899bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
900 struct sk_buff *skb)
901{
902 uint16_t type = 0;
903 __be32 ip_dst, ip_src;
904 uint8_t *hw_src;
905 bool ret = false;
906 struct batadv_dat_entry *dat_entry = NULL;
907 struct sk_buff *skb_new;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200908 int hdr_size = 0;
909 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200910
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200911 if (!atomic_read(&bat_priv->distributed_arp_table))
912 goto out;
913
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200914 vid = batadv_dat_get_vid(skb, &hdr_size);
915
916 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200917 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
918 * message to the selected DHT candidates
919 */
920 if (type != ARPOP_REQUEST)
921 goto out;
922
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200923 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
924 "Parsing outgoing ARP REQUEST");
Antonio Quartullic384ea32011-06-26 03:37:18 +0200925
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200926 ip_src = batadv_arp_ip_src(skb, hdr_size);
927 hw_src = batadv_arp_hw_src(skb, hdr_size);
928 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200929
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200930 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200931
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200932 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200933 if (dat_entry) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200934 /* If the ARP request is destined for a local client the local
935 * client will answer itself. DAT would only generate a
936 * duplicate packet.
937 *
938 * Moreover, if the soft-interface is enslaved into a bridge, an
939 * additional DAT answer may trigger kernel warnings about
940 * a packet coming from the wrong port.
941 */
Antonio Quartullic018ad32013-06-04 12:11:39 +0200942 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr,
943 BATADV_NO_FLAGS)) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200944 ret = true;
945 goto out;
946 }
947
Antonio Quartullic384ea32011-06-26 03:37:18 +0200948 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800949 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200950 dat_entry->mac_addr, hw_src);
951 if (!skb_new)
952 goto out;
953
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200954 if (vid & BATADV_VLAN_HAS_TAG)
955 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
956 vid & VLAN_VID_MASK);
957
Antonio Quartullic384ea32011-06-26 03:37:18 +0200958 skb_reset_mac_header(skb_new);
959 skb_new->protocol = eth_type_trans(skb_new,
Marek Lindner736292c2013-01-12 19:19:06 +0800960 bat_priv->soft_iface);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200961 bat_priv->stats.rx_packets++;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200962 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
Marek Lindner736292c2013-01-12 19:19:06 +0800963 bat_priv->soft_iface->last_rx = jiffies;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200964
965 netif_rx(skb_new);
966 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
967 ret = true;
968 } else {
Marek Lindner93178012013-03-10 19:29:15 +0800969 /* Send the request to the DHT */
Antonio Quartullic384ea32011-06-26 03:37:18 +0200970 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
971 BATADV_P_DAT_DHT_GET);
972 }
973out:
974 if (dat_entry)
975 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200976 return ret;
977}
978
979/**
980 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
981 * answer using the local DAT storage
982 * @bat_priv: the bat priv with all the soft interface information
983 * @skb: packet to check
984 * @hdr_size: size of the encapsulation header
985 *
Marek Lindner93178012013-03-10 19:29:15 +0800986 * Returns true if the request has been answered, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200987 */
988bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
989 struct sk_buff *skb, int hdr_size)
990{
991 uint16_t type;
992 __be32 ip_src, ip_dst;
993 uint8_t *hw_src;
994 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200995 struct batadv_dat_entry *dat_entry = NULL;
996 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200997 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200998 int err;
999
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001000 if (!atomic_read(&bat_priv->distributed_arp_table))
1001 goto out;
1002
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001003 vid = batadv_dat_get_vid(skb, &hdr_size);
1004
Antonio Quartullic384ea32011-06-26 03:37:18 +02001005 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1006 if (type != ARPOP_REQUEST)
1007 goto out;
1008
1009 hw_src = batadv_arp_hw_src(skb, hdr_size);
1010 ip_src = batadv_arp_ip_src(skb, hdr_size);
1011 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1012
1013 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1014 "Parsing incoming ARP REQUEST");
1015
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001016 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001017
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001018 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001019 if (!dat_entry)
1020 goto out;
1021
Antonio Quartullic384ea32011-06-26 03:37:18 +02001022 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +08001023 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +02001024 dat_entry->mac_addr, hw_src);
1025
1026 if (!skb_new)
1027 goto out;
1028
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001029 if (vid & BATADV_VLAN_HAS_TAG)
1030 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1031 vid & VLAN_VID_MASK);
1032
Marek Lindner93178012013-03-10 19:29:15 +08001033 /* To preserve backwards compatibility, the node has choose the outgoing
1034 * format based on the incoming request packet type. The assumption is
1035 * that a node not using the 4addr packet format doesn't support it.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001036 */
1037 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
Linus Lüssinge300d312013-07-03 10:40:00 +02001038 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1039 BATADV_P_DAT_CACHE_REPLY,
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001040 NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001041 else
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001042 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001043
Linus Lüssinge300d312013-07-03 10:40:00 +02001044 if (err != NET_XMIT_DROP) {
Martin Hundebøll4046b242012-04-20 17:02:45 +02001045 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001046 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +02001047 }
Antonio Quartullic384ea32011-06-26 03:37:18 +02001048out:
1049 if (dat_entry)
1050 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001051 if (ret)
1052 kfree_skb(skb);
1053 return ret;
1054}
1055
1056/**
1057 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1058 * @bat_priv: the bat priv with all the soft interface information
1059 * @skb: packet to check
1060 */
1061void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1062 struct sk_buff *skb)
1063{
1064 uint16_t type;
1065 __be32 ip_src, ip_dst;
1066 uint8_t *hw_src, *hw_dst;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001067 int hdr_size = 0;
1068 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001069
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001070 if (!atomic_read(&bat_priv->distributed_arp_table))
1071 return;
1072
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001073 vid = batadv_dat_get_vid(skb, &hdr_size);
1074
1075 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001076 if (type != ARPOP_REPLY)
1077 return;
1078
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001079 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1080 "Parsing outgoing ARP REPLY");
Antonio Quartullic384ea32011-06-26 03:37:18 +02001081
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001082 hw_src = batadv_arp_hw_src(skb, hdr_size);
1083 ip_src = batadv_arp_ip_src(skb, hdr_size);
1084 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1085 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001086
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001087 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1088 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001089
1090 /* Send the ARP reply to the candidates for both the IP addresses that
Marek Lindner93178012013-03-10 19:29:15 +08001091 * the node obtained from the ARP reply
Antonio Quartullic384ea32011-06-26 03:37:18 +02001092 */
1093 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1094 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1095}
1096/**
1097 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1098 * DAT storage only
1099 * @bat_priv: the bat priv with all the soft interface information
1100 * @skb: packet to check
Marek Lindner93178012013-03-10 19:29:15 +08001101 * @hdr_size: size of the encapsulation header
Antonio Quartullic384ea32011-06-26 03:37:18 +02001102 */
1103bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1104 struct sk_buff *skb, int hdr_size)
1105{
1106 uint16_t type;
1107 __be32 ip_src, ip_dst;
1108 uint8_t *hw_src, *hw_dst;
1109 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001110 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001111
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001112 if (!atomic_read(&bat_priv->distributed_arp_table))
1113 goto out;
1114
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001115 vid = batadv_dat_get_vid(skb, &hdr_size);
1116
Antonio Quartullic384ea32011-06-26 03:37:18 +02001117 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1118 if (type != ARPOP_REPLY)
1119 goto out;
1120
1121 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1122 "Parsing incoming ARP REPLY");
1123
1124 hw_src = batadv_arp_hw_src(skb, hdr_size);
1125 ip_src = batadv_arp_ip_src(skb, hdr_size);
1126 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1127 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1128
1129 /* Update our internal cache with both the IP addresses the node got
1130 * within the ARP reply
1131 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001132 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1133 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001134
1135 /* if this REPLY is directed to a client of mine, let's deliver the
1136 * packet to the interface
1137 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001138 ret = !batadv_is_my_client(bat_priv, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001139out:
Matthias Schiffer0d15bec2013-01-23 18:11:53 +01001140 if (ret)
1141 kfree_skb(skb);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001142 /* if ret == false -> packet has to be delivered to the interface */
1143 return ret;
1144}
1145
1146/**
1147 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
Marek Lindner93178012013-03-10 19:29:15 +08001148 * (because the node has already obtained the reply via DAT) or not
Antonio Quartullic384ea32011-06-26 03:37:18 +02001149 * @bat_priv: the bat priv with all the soft interface information
1150 * @forw_packet: the broadcast packet
1151 *
Marek Lindner93178012013-03-10 19:29:15 +08001152 * Returns true if the node can drop the packet, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001153 */
1154bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1155 struct batadv_forw_packet *forw_packet)
1156{
1157 uint16_t type;
1158 __be32 ip_dst;
1159 struct batadv_dat_entry *dat_entry = NULL;
1160 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001161 int hdr_size = sizeof(struct batadv_bcast_packet);
1162 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001163
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001164 if (!atomic_read(&bat_priv->distributed_arp_table))
1165 goto out;
1166
Antonio Quartullic384ea32011-06-26 03:37:18 +02001167 /* If this packet is an ARP_REQUEST and the node already has the
1168 * information that it is going to ask, then the packet can be dropped
1169 */
1170 if (forw_packet->num_packets)
1171 goto out;
1172
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001173 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1174
1175 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001176 if (type != ARPOP_REQUEST)
1177 goto out;
1178
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001179 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1180 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001181 /* check if the node already got this entry */
1182 if (!dat_entry) {
1183 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1184 "ARP Request for %pI4: fallback\n", &ip_dst);
1185 goto out;
1186 }
1187
1188 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1189 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1190 ret = true;
1191
1192out:
1193 if (dat_entry)
1194 batadv_dat_entry_free_ref(dat_entry);
1195 return ret;
1196}