blob: 6d0b471eede8639f55b33c5c4d434c8fddef6ee5 [file] [log] [blame]
Sven Eckelmann9f6446c2015-04-23 13:16:35 +02001/* Copyright (C) 2011-2015 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
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020018#include "distributed-arp-table.h"
19#include "main.h"
20
21#include <linux/atomic.h>
22#include <linux/byteorder/generic.h>
23#include <linux/errno.h>
24#include <linux/etherdevice.h>
25#include <linux/fs.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010026#include <linux/if_arp.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020027#include <linux/if_ether.h>
Antonio Quartullibe1db4f2013-06-04 12:11:43 +020028#include <linux/if_vlan.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020029#include <linux/in.h>
30#include <linux/jiffies.h>
31#include <linux/kernel.h>
32#include <linux/list.h>
33#include <linux/rculist.h>
34#include <linux/rcupdate.h>
35#include <linux/seq_file.h>
36#include <linux/skbuff.h>
37#include <linux/slab.h>
38#include <linux/spinlock.h>
39#include <linux/stddef.h>
40#include <linux/string.h>
41#include <linux/workqueue.h>
Antonio Quartullic384ea32011-06-26 03:37:18 +020042#include <net/arp.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010043
Antonio Quartulli785ea112011-11-23 11:35:44 +010044#include "hard-interface.h"
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020045#include "hash.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010046#include "originator.h"
47#include "send.h"
Antonio Quartullic384ea32011-06-26 03:37:18 +020048#include "translation-table.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010049
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020050static void batadv_dat_purge(struct work_struct *work);
51
52/**
53 * batadv_dat_start_timer - initialise the DAT periodic worker
54 * @bat_priv: the bat priv with all the soft interface information
55 */
56static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
57{
58 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
59 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
60 msecs_to_jiffies(10000));
61}
62
63/**
Marek Lindner93178012013-03-10 19:29:15 +080064 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020065 * free it
Marek Lindner93178012013-03-10 19:29:15 +080066 * @dat_entry: the entry to free
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020067 */
68static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
69{
70 if (atomic_dec_and_test(&dat_entry->refcount))
71 kfree_rcu(dat_entry, rcu);
72}
73
74/**
Marek Lindner93178012013-03-10 19:29:15 +080075 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020076 * @dat_entry: the entry to check
77 *
Marek Lindner93178012013-03-10 19:29:15 +080078 * Returns true if the entry has to be purged now, false otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020079 */
80static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
81{
82 return batadv_has_timed_out(dat_entry->last_update,
83 BATADV_DAT_ENTRY_TIMEOUT);
84}
85
86/**
87 * __batadv_dat_purge - delete entries from the DAT local storage
88 * @bat_priv: the bat priv with all the soft interface information
89 * @to_purge: function in charge to decide whether an entry has to be purged or
90 * not. This function takes the dat_entry as argument and has to
91 * returns a boolean value: true is the entry has to be deleted,
92 * false otherwise
93 *
Marek Lindner93178012013-03-10 19:29:15 +080094 * Loops over each entry in the DAT local storage and deletes it if and only if
95 * the to_purge function passed as argument returns true.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020096 */
97static void __batadv_dat_purge(struct batadv_priv *bat_priv,
98 bool (*to_purge)(struct batadv_dat_entry *))
99{
100 spinlock_t *list_lock; /* protects write access to the hash lists */
101 struct batadv_dat_entry *dat_entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800102 struct hlist_node *node_tmp;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200103 struct hlist_head *head;
104 uint32_t i;
105
106 if (!bat_priv->dat.hash)
107 return;
108
109 for (i = 0; i < bat_priv->dat.hash->size; i++) {
110 head = &bat_priv->dat.hash->table[i];
111 list_lock = &bat_priv->dat.hash->list_locks[i];
112
113 spin_lock_bh(list_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -0800114 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200115 hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800116 /* if a helper function has been passed as parameter,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200117 * ask it if the entry has to be purged or not
118 */
119 if (to_purge && !to_purge(dat_entry))
120 continue;
121
Sasha Levinb67bfe02013-02-27 17:06:00 -0800122 hlist_del_rcu(&dat_entry->hash_entry);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200123 batadv_dat_entry_free_ref(dat_entry);
124 }
125 spin_unlock_bh(list_lock);
126 }
127}
128
129/**
130 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
131 * hash table
132 * @work: kernel work struct
133 */
134static void batadv_dat_purge(struct work_struct *work)
135{
136 struct delayed_work *delayed_work;
137 struct batadv_priv_dat *priv_dat;
138 struct batadv_priv *bat_priv;
139
140 delayed_work = container_of(work, struct delayed_work, work);
141 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
142 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
143
144 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
145 batadv_dat_start_timer(bat_priv);
146}
147
148/**
149 * batadv_compare_dat - comparing function used in the local DAT hash table
150 * @node: node in the local table
151 * @data2: second object to compare the node to
152 *
Marek Lindner93178012013-03-10 19:29:15 +0800153 * Returns 1 if the two entries are the same, 0 otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200154 */
155static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
156{
157 const void *data1 = container_of(node, struct batadv_dat_entry,
158 hash_entry);
159
Antonio Quartulli36484f82013-11-07 08:02:07 +0100160 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200161}
162
Antonio Quartulli785ea112011-11-23 11:35:44 +0100163/**
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200164 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
165 * @skb: ARP packet
166 * @hdr_size: size of the possible header before the ARP packet
167 *
Marek Lindner93178012013-03-10 19:29:15 +0800168 * Returns the value of the hw_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200169 */
170static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
171{
172 uint8_t *addr;
173
174 addr = (uint8_t *)(skb->data + hdr_size);
175 addr += ETH_HLEN + sizeof(struct arphdr);
176
177 return addr;
178}
179
180/**
181 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
182 * @skb: ARP packet
183 * @hdr_size: size of the possible header before the ARP packet
184 *
Marek Lindner93178012013-03-10 19:29:15 +0800185 * Returns the value of the ip_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200186 */
187static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
188{
189 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
190}
191
192/**
193 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
194 * @skb: ARP packet
195 * @hdr_size: size of the possible header before the ARP packet
196 *
Marek Lindner93178012013-03-10 19:29:15 +0800197 * Returns the value of the hw_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200198 */
199static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
200{
201 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
202}
203
204/**
205 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
206 * @skb: ARP packet
207 * @hdr_size: size of the possible header before the ARP packet
208 *
Marek Lindner93178012013-03-10 19:29:15 +0800209 * Returns the value of the ip_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200210 */
211static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
212{
213 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
214}
215
216/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100217 * batadv_hash_dat - compute the hash value for an IP address
218 * @data: data to hash
219 * @size: size of the hash table
220 *
Marek Lindner93178012013-03-10 19:29:15 +0800221 * Returns the selected index in the hash table for the given data.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100222 */
223static uint32_t batadv_hash_dat(const void *data, uint32_t size)
224{
Antonio Quartulli785ea112011-11-23 11:35:44 +0100225 uint32_t hash = 0;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200226 const struct batadv_dat_entry *dat = data;
Sven Eckelmann36fd61c2015-03-01 09:46:18 +0100227 const unsigned char *key;
228 uint32_t i;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100229
Sven Eckelmann36fd61c2015-03-01 09:46:18 +0100230 key = (const unsigned char *)&dat->ip;
231 for (i = 0; i < sizeof(dat->ip); i++) {
232 hash += key[i];
233 hash += (hash << 10);
234 hash ^= (hash >> 6);
235 }
236
237 key = (const unsigned char *)&dat->vid;
238 for (i = 0; i < sizeof(dat->vid); i++) {
239 hash += key[i];
240 hash += (hash << 10);
241 hash ^= (hash >> 6);
242 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100243
244 hash += (hash << 3);
245 hash ^= (hash >> 11);
246 hash += (hash << 15);
247
248 return hash % size;
249}
250
251/**
Marek Lindner93178012013-03-10 19:29:15 +0800252 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200253 * table
254 * @bat_priv: the bat priv with all the soft interface information
255 * @ip: search key
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200256 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200257 *
Marek Lindner93178012013-03-10 19:29:15 +0800258 * Returns the dat_entry if found, NULL otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200259 */
260static struct batadv_dat_entry *
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200261batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
262 unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200263{
264 struct hlist_head *head;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200265 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200266 struct batadv_hashtable *hash = bat_priv->dat.hash;
267 uint32_t index;
268
269 if (!hash)
270 return NULL;
271
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200272 to_find.ip = ip;
273 to_find.vid = vid;
274
275 index = batadv_hash_dat(&to_find, hash->size);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200276 head = &hash->table[index];
277
278 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800279 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200280 if (dat_entry->ip != ip)
281 continue;
282
283 if (!atomic_inc_not_zero(&dat_entry->refcount))
284 continue;
285
286 dat_entry_tmp = dat_entry;
287 break;
288 }
289 rcu_read_unlock();
290
291 return dat_entry_tmp;
292}
293
294/**
295 * batadv_dat_entry_add - add a new dat entry or update it if already exists
296 * @bat_priv: the bat priv with all the soft interface information
297 * @ip: ipv4 to add/edit
298 * @mac_addr: mac address to assign to the given ipv4
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200299 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200300 */
301static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200302 uint8_t *mac_addr, unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200303{
304 struct batadv_dat_entry *dat_entry;
305 int hash_added;
306
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200307 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200308 /* if this entry is already known, just update it */
309 if (dat_entry) {
310 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
Antonio Quartulli8fdd0152014-01-22 00:42:11 +0100311 ether_addr_copy(dat_entry->mac_addr, mac_addr);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200312 dat_entry->last_update = jiffies;
313 batadv_dbg(BATADV_DBG_DAT, bat_priv,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200314 "Entry updated: %pI4 %pM (vid: %d)\n",
315 &dat_entry->ip, dat_entry->mac_addr,
316 BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200317 goto out;
318 }
319
320 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
321 if (!dat_entry)
322 goto out;
323
324 dat_entry->ip = ip;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200325 dat_entry->vid = vid;
Antonio Quartulli8fdd0152014-01-22 00:42:11 +0100326 ether_addr_copy(dat_entry->mac_addr, mac_addr);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200327 dat_entry->last_update = jiffies;
328 atomic_set(&dat_entry->refcount, 2);
329
330 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200331 batadv_hash_dat, dat_entry,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200332 &dat_entry->hash_entry);
333
334 if (unlikely(hash_added != 0)) {
335 /* remove the reference for the hash */
336 batadv_dat_entry_free_ref(dat_entry);
337 goto out;
338 }
339
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200340 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
341 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200342
343out:
344 if (dat_entry)
345 batadv_dat_entry_free_ref(dat_entry);
346}
347
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200348#ifdef CONFIG_BATMAN_ADV_DEBUG
349
350/**
351 * batadv_dbg_arp - print a debug message containing all the ARP packet details
352 * @bat_priv: the bat priv with all the soft interface information
353 * @skb: ARP packet
354 * @type: ARP type
355 * @hdr_size: size of the possible header before the ARP packet
356 * @msg: message to print together with the debugging information
357 */
358static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
359 uint16_t type, int hdr_size, char *msg)
360{
361 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
362 struct batadv_bcast_packet *bcast_pkt;
363 uint8_t *orig_addr;
364 __be32 ip_src, ip_dst;
365
366 if (msg)
367 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
368
369 ip_src = batadv_arp_ip_src(skb, hdr_size);
370 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
371 batadv_dbg(BATADV_DBG_DAT, bat_priv,
372 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
373 batadv_arp_hw_src(skb, hdr_size), &ip_src,
374 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
375
376 if (hdr_size == 0)
377 return;
378
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200379 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
380
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100381 switch (unicast_4addr_packet->u.packet_type) {
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200382 case BATADV_UNICAST:
383 batadv_dbg(BATADV_DBG_DAT, bat_priv,
384 "* encapsulated within a UNICAST packet\n");
385 break;
386 case BATADV_UNICAST_4ADDR:
387 batadv_dbg(BATADV_DBG_DAT, bat_priv,
388 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
389 unicast_4addr_packet->src);
390 switch (unicast_4addr_packet->subtype) {
391 case BATADV_P_DAT_DHT_PUT:
392 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
393 break;
394 case BATADV_P_DAT_DHT_GET:
395 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
396 break;
397 case BATADV_P_DAT_CACHE_REPLY:
398 batadv_dbg(BATADV_DBG_DAT, bat_priv,
399 "* type: DAT_CACHE_REPLY\n");
400 break;
401 case BATADV_P_DATA:
402 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
403 break;
404 default:
405 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100406 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200407 }
408 break;
409 case BATADV_BCAST:
410 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
411 orig_addr = bcast_pkt->orig;
412 batadv_dbg(BATADV_DBG_DAT, bat_priv,
413 "* encapsulated within a BCAST packet (src: %pM)\n",
414 orig_addr);
415 break;
416 default:
417 batadv_dbg(BATADV_DBG_DAT, bat_priv,
418 "* encapsulated within an unknown packet type (0x%x)\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100419 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200420 }
421}
422
423#else
424
425static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
426 uint16_t type, int hdr_size, char *msg)
427{
428}
429
430#endif /* CONFIG_BATMAN_ADV_DEBUG */
431
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200432/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100433 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
434 * @res: the array with the already selected candidates
435 * @select: number of already selected candidates
436 * @tmp_max: address of the currently evaluated node
437 * @max: current round max address
438 * @last_max: address of the last selected candidate
439 * @candidate: orig_node under evaluation
440 * @max_orig_node: last selected candidate
441 *
Marek Lindner93178012013-03-10 19:29:15 +0800442 * Returns true if the node has been elected as next candidate or false
443 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100444 */
445static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
446 int select, batadv_dat_addr_t tmp_max,
447 batadv_dat_addr_t max,
448 batadv_dat_addr_t last_max,
449 struct batadv_orig_node *candidate,
450 struct batadv_orig_node *max_orig_node)
451{
452 bool ret = false;
453 int j;
454
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800455 /* check if orig node candidate is running DAT */
456 if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
457 goto out;
458
Antonio Quartulli785ea112011-11-23 11:35:44 +0100459 /* Check if this node has already been selected... */
460 for (j = 0; j < select; j++)
461 if (res[j].orig_node == candidate)
462 break;
463 /* ..and possibly skip it */
464 if (j < select)
465 goto out;
466 /* sanity check: has it already been selected? This should not happen */
467 if (tmp_max > last_max)
468 goto out;
469 /* check if during this iteration an originator with a closer dht
470 * address has already been found
471 */
472 if (tmp_max < max)
473 goto out;
474 /* this is an hash collision with the temporary selected node. Choose
475 * the one with the lowest address
476 */
Pau Koning816cd5b2013-02-12 00:18:45 +0000477 if ((tmp_max == max) && max_orig_node &&
Antonio Quartulli785ea112011-11-23 11:35:44 +0100478 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
479 goto out;
480
481 ret = true;
482out:
483 return ret;
484}
485
486/**
487 * batadv_choose_next_candidate - select the next DHT candidate
488 * @bat_priv: the bat priv with all the soft interface information
489 * @cands: candidates array
490 * @select: number of candidates already present in the array
491 * @ip_key: key to look up in the DHT
492 * @last_max: pointer where the address of the selected candidate will be saved
493 */
494static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
495 struct batadv_dat_candidate *cands,
496 int select, batadv_dat_addr_t ip_key,
497 batadv_dat_addr_t *last_max)
498{
499 batadv_dat_addr_t max = 0, tmp_max = 0;
500 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
501 struct batadv_hashtable *hash = bat_priv->orig_hash;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100502 struct hlist_head *head;
503 int i;
504
505 /* if no node is eligible as candidate, leave the candidate type as
506 * NOT_FOUND
507 */
508 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
509
Marek Lindner93178012013-03-10 19:29:15 +0800510 /* iterate over the originator list and find the node with the closest
Antonio Quartulli785ea112011-11-23 11:35:44 +0100511 * dat_address which has not been selected yet
512 */
513 for (i = 0; i < hash->size; i++) {
514 head = &hash->table[i];
515
516 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800517 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800518 /* the dht space is a ring using unsigned addresses */
Antonio Quartulli785ea112011-11-23 11:35:44 +0100519 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
520 ip_key;
521
522 if (!batadv_is_orig_node_eligible(cands, select,
523 tmp_max, max,
524 *last_max, orig_node,
525 max_orig_node))
526 continue;
527
528 if (!atomic_inc_not_zero(&orig_node->refcount))
529 continue;
530
531 max = tmp_max;
532 if (max_orig_node)
533 batadv_orig_node_free_ref(max_orig_node);
534 max_orig_node = orig_node;
535 }
536 rcu_read_unlock();
537 }
538 if (max_orig_node) {
539 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
540 cands[select].orig_node = max_orig_node;
541 batadv_dbg(BATADV_DBG_DAT, bat_priv,
542 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
543 select, max_orig_node->orig, max_orig_node->dat_addr,
544 max);
545 }
546 *last_max = max;
547}
548
549/**
Marek Lindner93178012013-03-10 19:29:15 +0800550 * batadv_dat_select_candidates - select the nodes which the DHT message has to
Antonio Quartulli785ea112011-11-23 11:35:44 +0100551 * be sent to
552 * @bat_priv: the bat priv with all the soft interface information
553 * @ip_dst: ipv4 to look up in the DHT
554 *
555 * An originator O is selected if and only if its DHT_ID value is one of three
556 * closest values (from the LEFT, with wrap around if needed) then the hash
557 * value of the key. ip_dst is the key.
558 *
Marek Lindner93178012013-03-10 19:29:15 +0800559 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100560 */
561static struct batadv_dat_candidate *
562batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
563{
564 int select;
565 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
566 struct batadv_dat_candidate *res;
567
568 if (!bat_priv->orig_hash)
569 return NULL;
570
Antonio Quartulli0185dda2014-05-24 06:43:47 +0200571 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
572 GFP_ATOMIC);
Antonio Quartulli785ea112011-11-23 11:35:44 +0100573 if (!res)
574 return NULL;
575
576 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
577 BATADV_DAT_ADDR_MAX);
578
579 batadv_dbg(BATADV_DBG_DAT, bat_priv,
580 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
581 ip_key);
582
583 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
584 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
585 &last_max);
586
587 return res;
588}
589
590/**
591 * batadv_dat_send_data - send a payload to the selected candidates
592 * @bat_priv: the bat priv with all the soft interface information
593 * @skb: payload to send
594 * @ip: the DHT key
595 * @packet_subtype: unicast4addr packet subtype to use
596 *
Marek Lindner93178012013-03-10 19:29:15 +0800597 * This function copies the skb with pskb_copy() and is sent as unicast packet
598 * to each of the selected candidates.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100599 *
Marek Lindner93178012013-03-10 19:29:15 +0800600 * Returns true if the packet is sent to at least one candidate, false
601 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100602 */
603static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
604 struct sk_buff *skb, __be32 ip,
605 int packet_subtype)
606{
607 int i;
608 bool ret = false;
609 int send_status;
610 struct batadv_neigh_node *neigh_node = NULL;
611 struct sk_buff *tmp_skb;
612 struct batadv_dat_candidate *cand;
613
614 cand = batadv_dat_select_candidates(bat_priv, ip);
615 if (!cand)
616 goto out;
617
618 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
619
620 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
621 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
622 continue;
623
Simon Wunderlich7351a4822013-11-13 19:14:47 +0100624 neigh_node = batadv_orig_router_get(cand[i].orig_node,
625 BATADV_IF_DEFAULT);
Antonio Quartulli785ea112011-11-23 11:35:44 +0100626 if (!neigh_node)
627 goto free_orig;
628
Octavian Purdilabad93e92014-06-12 01:36:26 +0300629 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
Martin Hundebøllf097e252013-05-23 16:53:01 +0200630 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
631 cand[i].orig_node,
632 packet_subtype)) {
Antonio Quartulli785ea112011-11-23 11:35:44 +0100633 kfree_skb(tmp_skb);
634 goto free_neigh;
635 }
636
637 send_status = batadv_send_skb_packet(tmp_skb,
638 neigh_node->if_incoming,
639 neigh_node->addr);
Martin Hundebøll4046b242012-04-20 17:02:45 +0200640 if (send_status == NET_XMIT_SUCCESS) {
641 /* count the sent packet */
642 switch (packet_subtype) {
643 case BATADV_P_DAT_DHT_GET:
644 batadv_inc_counter(bat_priv,
645 BATADV_CNT_DAT_GET_TX);
646 break;
647 case BATADV_P_DAT_DHT_PUT:
648 batadv_inc_counter(bat_priv,
649 BATADV_CNT_DAT_PUT_TX);
650 break;
651 }
652
Antonio Quartulli785ea112011-11-23 11:35:44 +0100653 /* packet sent to a candidate: return true */
654 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200655 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100656free_neigh:
657 batadv_neigh_node_free_ref(neigh_node);
658free_orig:
659 batadv_orig_node_free_ref(cand[i].orig_node);
660 }
661
662out:
663 kfree(cand);
664 return ret;
665}
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200666
667/**
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800668 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
669 * setting change
670 * @bat_priv: the bat priv with all the soft interface information
671 */
672static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
673{
674 char dat_mode;
675
676 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
677
678 switch (dat_mode) {
679 case 0:
680 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
681 break;
682 case 1:
683 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
684 NULL, 0);
685 break;
686 }
687}
688
689/**
690 * batadv_dat_status_update - update the dat tvlv container after dat
691 * setting change
692 * @net_dev: the soft interface net device
693 */
694void batadv_dat_status_update(struct net_device *net_dev)
695{
696 struct batadv_priv *bat_priv = netdev_priv(net_dev);
Antonio Quartullif1386942014-05-10 18:56:37 +0200697
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800698 batadv_dat_tvlv_container_update(bat_priv);
699}
700
701/**
702 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
703 * @bat_priv: the bat priv with all the soft interface information
704 * @orig: the orig_node of the ogm
705 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
706 * @tvlv_value: tvlv buffer containing the gateway data
707 * @tvlv_value_len: tvlv buffer length
708 */
709static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
710 struct batadv_orig_node *orig,
711 uint8_t flags,
712 void *tvlv_value,
713 uint16_t tvlv_value_len)
714{
715 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
716 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
717 else
718 orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
719}
720
721/**
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200722 * batadv_dat_hash_free - free the local DAT hash table
723 * @bat_priv: the bat priv with all the soft interface information
724 */
725static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
726{
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200727 if (!bat_priv->dat.hash)
728 return;
729
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200730 __batadv_dat_purge(bat_priv, NULL);
731
732 batadv_hash_destroy(bat_priv->dat.hash);
733
734 bat_priv->dat.hash = NULL;
735}
736
737/**
738 * batadv_dat_init - initialise the DAT internals
739 * @bat_priv: the bat priv with all the soft interface information
740 */
741int batadv_dat_init(struct batadv_priv *bat_priv)
742{
743 if (bat_priv->dat.hash)
744 return 0;
745
746 bat_priv->dat.hash = batadv_hash_new(1024);
747
748 if (!bat_priv->dat.hash)
749 return -ENOMEM;
750
751 batadv_dat_start_timer(bat_priv);
752
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800753 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
754 NULL, BATADV_TVLV_DAT, 1,
755 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
756 batadv_dat_tvlv_container_update(bat_priv);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200757 return 0;
758}
759
760/**
761 * batadv_dat_free - free the DAT internals
762 * @bat_priv: the bat priv with all the soft interface information
763 */
764void batadv_dat_free(struct batadv_priv *bat_priv)
765{
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800766 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
767 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
768
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200769 cancel_delayed_work_sync(&bat_priv->dat.work);
770
771 batadv_dat_hash_free(bat_priv);
772}
773
774/**
775 * batadv_dat_cache_seq_print_text - print the local DAT hash table
776 * @seq: seq file to print on
777 * @offset: not used
778 */
779int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
780{
781 struct net_device *net_dev = (struct net_device *)seq->private;
782 struct batadv_priv *bat_priv = netdev_priv(net_dev);
783 struct batadv_hashtable *hash = bat_priv->dat.hash;
784 struct batadv_dat_entry *dat_entry;
785 struct batadv_hard_iface *primary_if;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200786 struct hlist_head *head;
787 unsigned long last_seen_jiffies;
788 int last_seen_msecs, last_seen_secs, last_seen_mins;
789 uint32_t i;
790
791 primary_if = batadv_seq_print_text_primary_if_get(seq);
792 if (!primary_if)
793 goto out;
794
795 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200796 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
797 "MAC", "VID", "last-seen");
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200798
799 for (i = 0; i < hash->size; i++) {
800 head = &hash->table[i];
801
802 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800803 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200804 last_seen_jiffies = jiffies - dat_entry->last_update;
805 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
806 last_seen_mins = last_seen_msecs / 60000;
807 last_seen_msecs = last_seen_msecs % 60000;
808 last_seen_secs = last_seen_msecs / 1000;
809
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200810 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200811 &dat_entry->ip, dat_entry->mac_addr,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200812 BATADV_PRINT_VID(dat_entry->vid),
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200813 last_seen_mins, last_seen_secs);
814 }
815 rcu_read_unlock();
816 }
817
818out:
819 if (primary_if)
820 batadv_hardif_free_ref(primary_if);
821 return 0;
822}
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200823
824/**
825 * batadv_arp_get_type - parse an ARP packet and gets the type
826 * @bat_priv: the bat priv with all the soft interface information
827 * @skb: packet to analyse
828 * @hdr_size: size of the possible header before the ARP packet in the skb
829 *
Marek Lindner93178012013-03-10 19:29:15 +0800830 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200831 */
832static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
833 struct sk_buff *skb, int hdr_size)
834{
835 struct arphdr *arphdr;
836 struct ethhdr *ethhdr;
837 __be32 ip_src, ip_dst;
Matthias Schifferb618ad12013-01-24 18:18:27 +0100838 uint8_t *hw_src, *hw_dst;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200839 uint16_t type = 0;
840
841 /* pull the ethernet header */
842 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
843 goto out;
844
845 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
846
847 if (ethhdr->h_proto != htons(ETH_P_ARP))
848 goto out;
849
850 /* pull the ARP payload */
851 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
852 arp_hdr_len(skb->dev))))
853 goto out;
854
855 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
856
Marek Lindner93178012013-03-10 19:29:15 +0800857 /* check whether the ARP packet carries a valid IP information */
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200858 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
859 goto out;
860
861 if (arphdr->ar_pro != htons(ETH_P_IP))
862 goto out;
863
864 if (arphdr->ar_hln != ETH_ALEN)
865 goto out;
866
867 if (arphdr->ar_pln != 4)
868 goto out;
869
870 /* Check for bad reply/request. If the ARP message is not sane, DAT
871 * will simply ignore it
872 */
873 ip_src = batadv_arp_ip_src(skb, hdr_size);
874 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
875 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
Matthias Schiffer757dd822013-01-24 18:18:26 +0100876 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
877 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
878 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200879 goto out;
880
Matthias Schifferb618ad12013-01-24 18:18:27 +0100881 hw_src = batadv_arp_hw_src(skb, hdr_size);
882 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
883 goto out;
884
Marek Lindner93178012013-03-10 19:29:15 +0800885 /* don't care about the destination MAC address in ARP requests */
Matthias Schifferb618ad12013-01-24 18:18:27 +0100886 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
887 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
888 if (is_zero_ether_addr(hw_dst) ||
889 is_multicast_ether_addr(hw_dst))
890 goto out;
891 }
892
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200893 type = ntohs(arphdr->ar_op);
894out:
895 return type;
896}
Antonio Quartullic384ea32011-06-26 03:37:18 +0200897
898/**
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200899 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
900 * @skb: the buffer containing the packet to extract the VID from
901 * @hdr_size: the size of the batman-adv header encapsulating the packet
902 *
903 * If the packet embedded in the skb is vlan tagged this function returns the
904 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
905 */
906static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
907{
908 unsigned short vid;
909
910 vid = batadv_get_vid(skb, *hdr_size);
911
912 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
913 * If the header contained in the packet is a VLAN one (which is longer)
914 * hdr_size is updated so that the functions will still skip the
915 * correct amount of bytes.
916 */
917 if (vid & BATADV_VLAN_HAS_TAG)
918 *hdr_size += VLAN_HLEN;
919
920 return vid;
921}
922
923/**
Antonio Quartullic384ea32011-06-26 03:37:18 +0200924 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
925 * answer using DAT
926 * @bat_priv: the bat priv with all the soft interface information
927 * @skb: packet to check
928 *
929 * Returns true if the message has been sent to the dht candidates, false
Marek Lindner93178012013-03-10 19:29:15 +0800930 * otherwise. In case of a positive return value the message has to be enqueued
931 * to permit the fallback.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200932 */
933bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
934 struct sk_buff *skb)
935{
936 uint16_t type = 0;
937 __be32 ip_dst, ip_src;
938 uint8_t *hw_src;
939 bool ret = false;
940 struct batadv_dat_entry *dat_entry = NULL;
941 struct sk_buff *skb_new;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200942 int hdr_size = 0;
943 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200944
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200945 if (!atomic_read(&bat_priv->distributed_arp_table))
946 goto out;
947
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200948 vid = batadv_dat_get_vid(skb, &hdr_size);
949
950 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200951 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
952 * message to the selected DHT candidates
953 */
954 if (type != ARPOP_REQUEST)
955 goto out;
956
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200957 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
958 "Parsing outgoing ARP REQUEST");
Antonio Quartullic384ea32011-06-26 03:37:18 +0200959
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200960 ip_src = batadv_arp_ip_src(skb, hdr_size);
961 hw_src = batadv_arp_hw_src(skb, hdr_size);
962 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200963
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200964 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200965
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200966 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200967 if (dat_entry) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200968 /* If the ARP request is destined for a local client the local
969 * client will answer itself. DAT would only generate a
970 * duplicate packet.
971 *
972 * Moreover, if the soft-interface is enslaved into a bridge, an
973 * additional DAT answer may trigger kernel warnings about
974 * a packet coming from the wrong port.
975 */
Antonio Quartullicc2f3382014-03-29 17:27:38 +0100976 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200977 ret = true;
978 goto out;
979 }
980
Antonio Quartullic384ea32011-06-26 03:37:18 +0200981 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800982 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200983 dat_entry->mac_addr, hw_src);
984 if (!skb_new)
985 goto out;
986
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200987 if (vid & BATADV_VLAN_HAS_TAG)
988 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
989 vid & VLAN_VID_MASK);
990
Antonio Quartullic384ea32011-06-26 03:37:18 +0200991 skb_reset_mac_header(skb_new);
992 skb_new->protocol = eth_type_trans(skb_new,
Marek Lindner736292c2013-01-12 19:19:06 +0800993 bat_priv->soft_iface);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200994 bat_priv->stats.rx_packets++;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200995 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
Marek Lindner736292c2013-01-12 19:19:06 +0800996 bat_priv->soft_iface->last_rx = jiffies;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200997
998 netif_rx(skb_new);
999 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1000 ret = true;
1001 } else {
Marek Lindner93178012013-03-10 19:29:15 +08001002 /* Send the request to the DHT */
Antonio Quartullic384ea32011-06-26 03:37:18 +02001003 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
1004 BATADV_P_DAT_DHT_GET);
1005 }
1006out:
1007 if (dat_entry)
1008 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001009 return ret;
1010}
1011
1012/**
1013 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1014 * answer using the local DAT storage
1015 * @bat_priv: the bat priv with all the soft interface information
1016 * @skb: packet to check
1017 * @hdr_size: size of the encapsulation header
1018 *
Marek Lindner93178012013-03-10 19:29:15 +08001019 * Returns true if the request has been answered, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001020 */
1021bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1022 struct sk_buff *skb, int hdr_size)
1023{
1024 uint16_t type;
1025 __be32 ip_src, ip_dst;
1026 uint8_t *hw_src;
1027 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001028 struct batadv_dat_entry *dat_entry = NULL;
1029 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001030 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001031 int err;
1032
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001033 if (!atomic_read(&bat_priv->distributed_arp_table))
1034 goto out;
1035
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001036 vid = batadv_dat_get_vid(skb, &hdr_size);
1037
Antonio Quartullic384ea32011-06-26 03:37:18 +02001038 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1039 if (type != ARPOP_REQUEST)
1040 goto out;
1041
1042 hw_src = batadv_arp_hw_src(skb, hdr_size);
1043 ip_src = batadv_arp_ip_src(skb, hdr_size);
1044 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1045
1046 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1047 "Parsing incoming ARP REQUEST");
1048
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001049 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001050
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001051 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001052 if (!dat_entry)
1053 goto out;
1054
Antonio Quartullic384ea32011-06-26 03:37:18 +02001055 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +08001056 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +02001057 dat_entry->mac_addr, hw_src);
1058
1059 if (!skb_new)
1060 goto out;
1061
Linus Lüssing927c2ed2014-01-19 22:22:45 +01001062 /* the rest of the TX path assumes that the mac_header offset pointing
1063 * to the inner Ethernet header has been set, therefore reset it now.
1064 */
1065 skb_reset_mac_header(skb_new);
1066
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001067 if (vid & BATADV_VLAN_HAS_TAG)
1068 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1069 vid & VLAN_VID_MASK);
1070
Marek Lindner93178012013-03-10 19:29:15 +08001071 /* To preserve backwards compatibility, the node has choose the outgoing
1072 * format based on the incoming request packet type. The assumption is
1073 * that a node not using the 4addr packet format doesn't support it.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001074 */
1075 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
Linus Lüssinge300d312013-07-03 10:40:00 +02001076 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1077 BATADV_P_DAT_CACHE_REPLY,
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001078 NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001079 else
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001080 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001081
Linus Lüssinge300d312013-07-03 10:40:00 +02001082 if (err != NET_XMIT_DROP) {
Martin Hundebøll4046b242012-04-20 17:02:45 +02001083 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001084 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +02001085 }
Antonio Quartullic384ea32011-06-26 03:37:18 +02001086out:
1087 if (dat_entry)
1088 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001089 if (ret)
1090 kfree_skb(skb);
1091 return ret;
1092}
1093
1094/**
1095 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1096 * @bat_priv: the bat priv with all the soft interface information
1097 * @skb: packet to check
1098 */
1099void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1100 struct sk_buff *skb)
1101{
1102 uint16_t type;
1103 __be32 ip_src, ip_dst;
1104 uint8_t *hw_src, *hw_dst;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001105 int hdr_size = 0;
1106 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001107
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001108 if (!atomic_read(&bat_priv->distributed_arp_table))
1109 return;
1110
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001111 vid = batadv_dat_get_vid(skb, &hdr_size);
1112
1113 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001114 if (type != ARPOP_REPLY)
1115 return;
1116
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001117 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1118 "Parsing outgoing ARP REPLY");
Antonio Quartullic384ea32011-06-26 03:37:18 +02001119
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001120 hw_src = batadv_arp_hw_src(skb, hdr_size);
1121 ip_src = batadv_arp_ip_src(skb, hdr_size);
1122 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1123 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001124
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001125 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1126 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001127
1128 /* Send the ARP reply to the candidates for both the IP addresses that
Marek Lindner93178012013-03-10 19:29:15 +08001129 * the node obtained from the ARP reply
Antonio Quartullic384ea32011-06-26 03:37:18 +02001130 */
1131 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1132 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1133}
Antonio Quartulliaa143d22014-09-01 14:37:27 +02001134
Antonio Quartullic384ea32011-06-26 03:37:18 +02001135/**
1136 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1137 * DAT storage only
1138 * @bat_priv: the bat priv with all the soft interface information
1139 * @skb: packet to check
Marek Lindner93178012013-03-10 19:29:15 +08001140 * @hdr_size: size of the encapsulation header
Antonio Quartullif202a662015-06-16 21:06:24 +02001141 *
1142 * Returns true if the packet was snooped and consumed by DAT. False if the
1143 * packet has to be delivered to the interface
Antonio Quartullic384ea32011-06-26 03:37:18 +02001144 */
1145bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1146 struct sk_buff *skb, int hdr_size)
1147{
1148 uint16_t type;
1149 __be32 ip_src, ip_dst;
1150 uint8_t *hw_src, *hw_dst;
Antonio Quartullif202a662015-06-16 21:06:24 +02001151 bool dropped = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001152 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001153
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001154 if (!atomic_read(&bat_priv->distributed_arp_table))
1155 goto out;
1156
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001157 vid = batadv_dat_get_vid(skb, &hdr_size);
1158
Antonio Quartullic384ea32011-06-26 03:37:18 +02001159 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1160 if (type != ARPOP_REPLY)
1161 goto out;
1162
1163 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1164 "Parsing incoming ARP REPLY");
1165
1166 hw_src = batadv_arp_hw_src(skb, hdr_size);
1167 ip_src = batadv_arp_ip_src(skb, hdr_size);
1168 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1169 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1170
1171 /* Update our internal cache with both the IP addresses the node got
1172 * within the ARP reply
1173 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001174 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1175 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001176
1177 /* if this REPLY is directed to a client of mine, let's deliver the
1178 * packet to the interface
1179 */
Antonio Quartullif202a662015-06-16 21:06:24 +02001180 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1181
1182 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1183 * packet because the client will reply by itself
1184 */
1185 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001186out:
Antonio Quartullif202a662015-06-16 21:06:24 +02001187 if (dropped)
Matthias Schiffer0d15bec2013-01-23 18:11:53 +01001188 kfree_skb(skb);
Antonio Quartullif202a662015-06-16 21:06:24 +02001189 /* if dropped == false -> deliver to the interface */
1190 return dropped;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001191}
1192
1193/**
1194 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
Marek Lindner93178012013-03-10 19:29:15 +08001195 * (because the node has already obtained the reply via DAT) or not
Antonio Quartullic384ea32011-06-26 03:37:18 +02001196 * @bat_priv: the bat priv with all the soft interface information
1197 * @forw_packet: the broadcast packet
1198 *
Marek Lindner93178012013-03-10 19:29:15 +08001199 * Returns true if the node can drop the packet, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001200 */
1201bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1202 struct batadv_forw_packet *forw_packet)
1203{
1204 uint16_t type;
1205 __be32 ip_dst;
1206 struct batadv_dat_entry *dat_entry = NULL;
1207 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001208 int hdr_size = sizeof(struct batadv_bcast_packet);
1209 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001210
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001211 if (!atomic_read(&bat_priv->distributed_arp_table))
1212 goto out;
1213
Antonio Quartullic384ea32011-06-26 03:37:18 +02001214 /* If this packet is an ARP_REQUEST and the node already has the
1215 * information that it is going to ask, then the packet can be dropped
1216 */
1217 if (forw_packet->num_packets)
1218 goto out;
1219
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001220 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1221
1222 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001223 if (type != ARPOP_REQUEST)
1224 goto out;
1225
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001226 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1227 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001228 /* check if the node already got this entry */
1229 if (!dat_entry) {
1230 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1231 "ARP Request for %pI4: fallback\n", &ip_dst);
1232 goto out;
1233 }
1234
1235 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1236 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1237 ret = true;
1238
1239out:
1240 if (dat_entry)
1241 batadv_dat_entry_free_ref(dat_entry);
1242 return ret;
1243}