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e19f9759 | 1 | /* Copyright (C) 2011-2014 B.A.T.M.A.N. contributors: |
785ea114 AQ |
2 | * |
3 | * Antonio Quartulli | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
785ea114 AQ |
16 | */ |
17 | ||
18 | #include <linux/if_ether.h> | |
19 | #include <linux/if_arp.h> | |
be1db4f6 | 20 | #include <linux/if_vlan.h> |
c384ea3e | 21 | #include <net/arp.h> |
785ea114 AQ |
22 | |
23 | #include "main.h" | |
5c3a0e55 | 24 | #include "hash.h" |
785ea114 AQ |
25 | #include "distributed-arp-table.h" |
26 | #include "hard-interface.h" | |
27 | #include "originator.h" | |
28 | #include "send.h" | |
29 | #include "types.h" | |
c384ea3e | 30 | #include "translation-table.h" |
785ea114 | 31 | |
2f1dfbe1 AQ |
32 | static 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 | */ | |
38 | static 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 | /** | |
93178018 | 46 | * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly |
2f1dfbe1 | 47 | * free it |
93178018 | 48 | * @dat_entry: the entry to free |
2f1dfbe1 AQ |
49 | */ |
50 | static 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 | /** | |
93178018 | 57 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
58 | * @dat_entry: the entry to check |
59 | * | |
93178018 | 60 | * Returns true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
61 | */ |
62 | static 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 | * | |
93178018 ML |
76 | * 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. | |
2f1dfbe1 AQ |
78 | */ |
79 | static 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; | |
b67bfe0d | 84 | struct hlist_node *node_tmp; |
2f1dfbe1 AQ |
85 | 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); | |
b67bfe0d | 96 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 97 | hash_entry) { |
93178018 | 98 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
99 | * ask it if the entry has to be purged or not |
100 | */ | |
101 | if (to_purge && !to_purge(dat_entry)) | |
102 | continue; | |
103 | ||
b67bfe0d | 104 | hlist_del_rcu(&dat_entry->hash_entry); |
2f1dfbe1 AQ |
105 | 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 | */ | |
116 | static 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 | * | |
93178018 | 135 | * Returns 1 if the two entries are the same, 0 otherwise. |
2f1dfbe1 AQ |
136 | */ |
137 | static 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 | ||
36484f84 | 142 | return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0; |
2f1dfbe1 AQ |
143 | } |
144 | ||
5c3a0e55 AQ |
145 | /** |
146 | * 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 | * | |
93178018 | 150 | * Returns the value of the hw_src field in the ARP packet. |
5c3a0e55 AQ |
151 | */ |
152 | static 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 | * | |
93178018 | 167 | * Returns the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
168 | */ |
169 | static __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 | * | |
93178018 | 179 | * Returns the value of the hw_dst field in the ARP packet. |
5c3a0e55 AQ |
180 | */ |
181 | static 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 | * | |
93178018 | 191 | * Returns the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
192 | */ |
193 | static __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 | ||
785ea114 AQ |
198 | /** |
199 | * batadv_hash_dat - compute the hash value for an IP address | |
200 | * @data: data to hash | |
201 | * @size: size of the hash table | |
202 | * | |
93178018 | 203 | * Returns the selected index in the hash table for the given data. |
785ea114 AQ |
204 | */ |
205 | static uint32_t batadv_hash_dat(const void *data, uint32_t size) | |
206 | { | |
785ea114 | 207 | uint32_t hash = 0; |
be1db4f6 | 208 | const struct batadv_dat_entry *dat = data; |
785ea114 | 209 | |
be1db4f6 AQ |
210 | hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip)); |
211 | hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid)); | |
785ea114 AQ |
212 | |
213 | hash += (hash << 3); | |
214 | hash ^= (hash >> 11); | |
215 | hash += (hash << 15); | |
216 | ||
217 | return hash % size; | |
218 | } | |
219 | ||
2f1dfbe1 | 220 | /** |
93178018 | 221 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
222 | * table |
223 | * @bat_priv: the bat priv with all the soft interface information | |
224 | * @ip: search key | |
be1db4f6 | 225 | * @vid: VLAN identifier |
2f1dfbe1 | 226 | * |
93178018 | 227 | * Returns the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
228 | */ |
229 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
230 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
231 | unsigned short vid) | |
2f1dfbe1 AQ |
232 | { |
233 | struct hlist_head *head; | |
be1db4f6 | 234 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 AQ |
235 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
236 | uint32_t index; | |
237 | ||
238 | if (!hash) | |
239 | return NULL; | |
240 | ||
be1db4f6 AQ |
241 | to_find.ip = ip; |
242 | to_find.vid = vid; | |
243 | ||
244 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
245 | head = &hash->table[index]; |
246 | ||
247 | rcu_read_lock(); | |
b67bfe0d | 248 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
249 | 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 | |
be1db4f6 | 268 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
269 | */ |
270 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
be1db4f6 | 271 | uint8_t *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
272 | { |
273 | struct batadv_dat_entry *dat_entry; | |
274 | int hash_added; | |
275 | ||
be1db4f6 | 276 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
277 | /* if this entry is already known, just update it */ |
278 | if (dat_entry) { | |
279 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 280 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
281 | dat_entry->last_update = jiffies; |
282 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
283 | "Entry updated: %pI4 %pM (vid: %d)\n", |
284 | &dat_entry->ip, dat_entry->mac_addr, | |
285 | BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
286 | goto out; |
287 | } | |
288 | ||
289 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
290 | if (!dat_entry) | |
291 | goto out; | |
292 | ||
293 | dat_entry->ip = ip; | |
be1db4f6 | 294 | dat_entry->vid = vid; |
8fdd0153 | 295 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
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, | |
be1db4f6 | 300 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
301 | &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 | ||
be1db4f6 AQ |
309 | 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)); | |
2f1dfbe1 AQ |
311 | |
312 | out: | |
313 | if (dat_entry) | |
314 | batadv_dat_entry_free_ref(dat_entry); | |
315 | } | |
316 | ||
5c3a0e55 AQ |
317 | #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 | */ | |
327 | static 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 | ||
5c3a0e55 AQ |
348 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
349 | ||
a40d9b07 | 350 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
351 | 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", | |
a40d9b07 | 375 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
376 | } |
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", | |
a40d9b07 | 388 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
389 | } |
390 | } | |
391 | ||
392 | #else | |
393 | ||
394 | static 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 | ||
785ea114 AQ |
401 | /** |
402 | * 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 | * | |
93178018 ML |
411 | * Returns true if the node has been elected as next candidate or false |
412 | * otherwise. | |
785ea114 AQ |
413 | */ |
414 | static 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 | ||
17cf0ea4 ML |
424 | /* check if orig node candidate is running DAT */ |
425 | if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT)) | |
426 | goto out; | |
427 | ||
785ea114 AQ |
428 | /* 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 | */ | |
816cd5b8 | 446 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
447 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
448 | goto out; | |
449 | ||
450 | ret = true; | |
451 | out: | |
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 | */ | |
463 | static 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; | |
785ea114 AQ |
471 | 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 | ||
93178018 | 479 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
480 | * 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(); | |
b67bfe0d | 486 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 487 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
488 | 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 | /** | |
93178018 | 519 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
520 | * 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 | * | |
93178018 | 528 | * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
529 | */ |
530 | static struct batadv_dat_candidate * | |
531 | batadv_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 | ||
0185dda6 AQ |
540 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
541 | GFP_ATOMIC); | |
785ea114 AQ |
542 | if (!res) |
543 | return NULL; | |
544 | ||
545 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst, | |
546 | BATADV_DAT_ADDR_MAX); | |
547 | ||
548 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
549 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
550 | ip_key); | |
551 | ||
552 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
553 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
554 | &last_max); | |
555 | ||
556 | return res; | |
557 | } | |
558 | ||
559 | /** | |
560 | * batadv_dat_send_data - send a payload to the selected candidates | |
561 | * @bat_priv: the bat priv with all the soft interface information | |
562 | * @skb: payload to send | |
563 | * @ip: the DHT key | |
564 | * @packet_subtype: unicast4addr packet subtype to use | |
565 | * | |
93178018 ML |
566 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
567 | * to each of the selected candidates. | |
785ea114 | 568 | * |
93178018 ML |
569 | * Returns true if the packet is sent to at least one candidate, false |
570 | * otherwise. | |
785ea114 AQ |
571 | */ |
572 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
573 | struct sk_buff *skb, __be32 ip, | |
574 | int packet_subtype) | |
575 | { | |
576 | int i; | |
577 | bool ret = false; | |
578 | int send_status; | |
579 | struct batadv_neigh_node *neigh_node = NULL; | |
580 | struct sk_buff *tmp_skb; | |
581 | struct batadv_dat_candidate *cand; | |
582 | ||
583 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
584 | if (!cand) | |
585 | goto out; | |
586 | ||
587 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
588 | ||
589 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
590 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
591 | continue; | |
592 | ||
7351a482 SW |
593 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
594 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
595 | if (!neigh_node) |
596 | goto free_orig; | |
597 | ||
bad93e9d | 598 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
599 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
600 | cand[i].orig_node, | |
601 | packet_subtype)) { | |
785ea114 AQ |
602 | kfree_skb(tmp_skb); |
603 | goto free_neigh; | |
604 | } | |
605 | ||
606 | send_status = batadv_send_skb_packet(tmp_skb, | |
607 | neigh_node->if_incoming, | |
608 | neigh_node->addr); | |
4046b24a MH |
609 | if (send_status == NET_XMIT_SUCCESS) { |
610 | /* count the sent packet */ | |
611 | switch (packet_subtype) { | |
612 | case BATADV_P_DAT_DHT_GET: | |
613 | batadv_inc_counter(bat_priv, | |
614 | BATADV_CNT_DAT_GET_TX); | |
615 | break; | |
616 | case BATADV_P_DAT_DHT_PUT: | |
617 | batadv_inc_counter(bat_priv, | |
618 | BATADV_CNT_DAT_PUT_TX); | |
619 | break; | |
620 | } | |
621 | ||
785ea114 AQ |
622 | /* packet sent to a candidate: return true */ |
623 | ret = true; | |
4046b24a | 624 | } |
785ea114 AQ |
625 | free_neigh: |
626 | batadv_neigh_node_free_ref(neigh_node); | |
627 | free_orig: | |
628 | batadv_orig_node_free_ref(cand[i].orig_node); | |
629 | } | |
630 | ||
631 | out: | |
632 | kfree(cand); | |
633 | return ret; | |
634 | } | |
2f1dfbe1 | 635 | |
17cf0ea4 ML |
636 | /** |
637 | * batadv_dat_tvlv_container_update - update the dat tvlv container after dat | |
638 | * setting change | |
639 | * @bat_priv: the bat priv with all the soft interface information | |
640 | */ | |
641 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
642 | { | |
643 | char dat_mode; | |
644 | ||
645 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
646 | ||
647 | switch (dat_mode) { | |
648 | case 0: | |
649 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
650 | break; | |
651 | case 1: | |
652 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
653 | NULL, 0); | |
654 | break; | |
655 | } | |
656 | } | |
657 | ||
658 | /** | |
659 | * batadv_dat_status_update - update the dat tvlv container after dat | |
660 | * setting change | |
661 | * @net_dev: the soft interface net device | |
662 | */ | |
663 | void batadv_dat_status_update(struct net_device *net_dev) | |
664 | { | |
665 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 666 | |
17cf0ea4 ML |
667 | batadv_dat_tvlv_container_update(bat_priv); |
668 | } | |
669 | ||
670 | /** | |
671 | * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container | |
672 | * @bat_priv: the bat priv with all the soft interface information | |
673 | * @orig: the orig_node of the ogm | |
674 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
675 | * @tvlv_value: tvlv buffer containing the gateway data | |
676 | * @tvlv_value_len: tvlv buffer length | |
677 | */ | |
678 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
679 | struct batadv_orig_node *orig, | |
680 | uint8_t flags, | |
681 | void *tvlv_value, | |
682 | uint16_t tvlv_value_len) | |
683 | { | |
684 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
685 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT; | |
686 | else | |
687 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT; | |
688 | } | |
689 | ||
2f1dfbe1 AQ |
690 | /** |
691 | * batadv_dat_hash_free - free the local DAT hash table | |
692 | * @bat_priv: the bat priv with all the soft interface information | |
693 | */ | |
694 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
695 | { | |
33af49ad AQ |
696 | if (!bat_priv->dat.hash) |
697 | return; | |
698 | ||
2f1dfbe1 AQ |
699 | __batadv_dat_purge(bat_priv, NULL); |
700 | ||
701 | batadv_hash_destroy(bat_priv->dat.hash); | |
702 | ||
703 | bat_priv->dat.hash = NULL; | |
704 | } | |
705 | ||
706 | /** | |
707 | * batadv_dat_init - initialise the DAT internals | |
708 | * @bat_priv: the bat priv with all the soft interface information | |
709 | */ | |
710 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
711 | { | |
712 | if (bat_priv->dat.hash) | |
713 | return 0; | |
714 | ||
715 | bat_priv->dat.hash = batadv_hash_new(1024); | |
716 | ||
717 | if (!bat_priv->dat.hash) | |
718 | return -ENOMEM; | |
719 | ||
720 | batadv_dat_start_timer(bat_priv); | |
721 | ||
17cf0ea4 ML |
722 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
723 | NULL, BATADV_TVLV_DAT, 1, | |
724 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
725 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
726 | return 0; |
727 | } | |
728 | ||
729 | /** | |
730 | * batadv_dat_free - free the DAT internals | |
731 | * @bat_priv: the bat priv with all the soft interface information | |
732 | */ | |
733 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
734 | { | |
17cf0ea4 ML |
735 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
736 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
737 | ||
2f1dfbe1 AQ |
738 | cancel_delayed_work_sync(&bat_priv->dat.work); |
739 | ||
740 | batadv_dat_hash_free(bat_priv); | |
741 | } | |
742 | ||
743 | /** | |
744 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
745 | * @seq: seq file to print on | |
746 | * @offset: not used | |
747 | */ | |
748 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
749 | { | |
750 | struct net_device *net_dev = (struct net_device *)seq->private; | |
751 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
752 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
753 | struct batadv_dat_entry *dat_entry; | |
754 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
755 | struct hlist_head *head; |
756 | unsigned long last_seen_jiffies; | |
757 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
758 | uint32_t i; | |
759 | ||
760 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
761 | if (!primary_if) | |
762 | goto out; | |
763 | ||
764 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
be1db4f6 AQ |
765 | seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4", |
766 | "MAC", "VID", "last-seen"); | |
2f1dfbe1 AQ |
767 | |
768 | for (i = 0; i < hash->size; i++) { | |
769 | head = &hash->table[i]; | |
770 | ||
771 | rcu_read_lock(); | |
b67bfe0d | 772 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
773 | last_seen_jiffies = jiffies - dat_entry->last_update; |
774 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
775 | last_seen_mins = last_seen_msecs / 60000; | |
776 | last_seen_msecs = last_seen_msecs % 60000; | |
777 | last_seen_secs = last_seen_msecs / 1000; | |
778 | ||
be1db4f6 | 779 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 780 | &dat_entry->ip, dat_entry->mac_addr, |
be1db4f6 | 781 | BATADV_PRINT_VID(dat_entry->vid), |
2f1dfbe1 AQ |
782 | last_seen_mins, last_seen_secs); |
783 | } | |
784 | rcu_read_unlock(); | |
785 | } | |
786 | ||
787 | out: | |
788 | if (primary_if) | |
789 | batadv_hardif_free_ref(primary_if); | |
790 | return 0; | |
791 | } | |
5c3a0e55 AQ |
792 | |
793 | /** | |
794 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
795 | * @bat_priv: the bat priv with all the soft interface information | |
796 | * @skb: packet to analyse | |
797 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
798 | * | |
93178018 | 799 | * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 AQ |
800 | */ |
801 | static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv, | |
802 | struct sk_buff *skb, int hdr_size) | |
803 | { | |
804 | struct arphdr *arphdr; | |
805 | struct ethhdr *ethhdr; | |
806 | __be32 ip_src, ip_dst; | |
b618ad11 | 807 | uint8_t *hw_src, *hw_dst; |
5c3a0e55 AQ |
808 | uint16_t type = 0; |
809 | ||
810 | /* pull the ethernet header */ | |
811 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
812 | goto out; | |
813 | ||
814 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
815 | ||
816 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
817 | goto out; | |
818 | ||
819 | /* pull the ARP payload */ | |
820 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
821 | arp_hdr_len(skb->dev)))) | |
822 | goto out; | |
823 | ||
824 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
825 | ||
93178018 | 826 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
827 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
828 | goto out; | |
829 | ||
830 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
831 | goto out; | |
832 | ||
833 | if (arphdr->ar_hln != ETH_ALEN) | |
834 | goto out; | |
835 | ||
836 | if (arphdr->ar_pln != 4) | |
837 | goto out; | |
838 | ||
839 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
840 | * will simply ignore it | |
841 | */ | |
842 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
843 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
844 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
845 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
846 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
847 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
848 | goto out; |
849 | ||
b618ad11 MS |
850 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
851 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
852 | goto out; | |
853 | ||
93178018 | 854 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
855 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
856 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
857 | if (is_zero_ether_addr(hw_dst) || | |
858 | is_multicast_ether_addr(hw_dst)) | |
859 | goto out; | |
860 | } | |
861 | ||
5c3a0e55 AQ |
862 | type = ntohs(arphdr->ar_op); |
863 | out: | |
864 | return type; | |
865 | } | |
c384ea3e | 866 | |
be1db4f6 AQ |
867 | /** |
868 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
869 | * @skb: the buffer containing the packet to extract the VID from | |
870 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
871 | * | |
872 | * If the packet embedded in the skb is vlan tagged this function returns the | |
873 | * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned. | |
874 | */ | |
875 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
876 | { | |
877 | unsigned short vid; | |
878 | ||
879 | vid = batadv_get_vid(skb, *hdr_size); | |
880 | ||
881 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
882 | * If the header contained in the packet is a VLAN one (which is longer) | |
883 | * hdr_size is updated so that the functions will still skip the | |
884 | * correct amount of bytes. | |
885 | */ | |
886 | if (vid & BATADV_VLAN_HAS_TAG) | |
887 | *hdr_size += VLAN_HLEN; | |
888 | ||
889 | return vid; | |
890 | } | |
891 | ||
c384ea3e AQ |
892 | /** |
893 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
894 | * answer using DAT | |
895 | * @bat_priv: the bat priv with all the soft interface information | |
896 | * @skb: packet to check | |
897 | * | |
898 | * Returns true if the message has been sent to the dht candidates, false | |
93178018 ML |
899 | * otherwise. In case of a positive return value the message has to be enqueued |
900 | * to permit the fallback. | |
c384ea3e AQ |
901 | */ |
902 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
903 | struct sk_buff *skb) | |
904 | { | |
905 | uint16_t type = 0; | |
906 | __be32 ip_dst, ip_src; | |
907 | uint8_t *hw_src; | |
908 | bool ret = false; | |
909 | struct batadv_dat_entry *dat_entry = NULL; | |
910 | struct sk_buff *skb_new; | |
be1db4f6 AQ |
911 | int hdr_size = 0; |
912 | unsigned short vid; | |
c384ea3e | 913 | |
33af49ad AQ |
914 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
915 | goto out; | |
916 | ||
be1db4f6 AQ |
917 | vid = batadv_dat_get_vid(skb, &hdr_size); |
918 | ||
919 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
920 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
921 | * message to the selected DHT candidates | |
922 | */ | |
923 | if (type != ARPOP_REQUEST) | |
924 | goto out; | |
925 | ||
be1db4f6 AQ |
926 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
927 | "Parsing outgoing ARP REQUEST"); | |
c384ea3e | 928 | |
be1db4f6 AQ |
929 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
930 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
931 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 932 | |
be1db4f6 | 933 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 934 | |
be1db4f6 | 935 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 936 | if (dat_entry) { |
88e48d7b AQ |
937 | /* If the ARP request is destined for a local client the local |
938 | * client will answer itself. DAT would only generate a | |
939 | * duplicate packet. | |
940 | * | |
941 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
942 | * additional DAT answer may trigger kernel warnings about | |
943 | * a packet coming from the wrong port. | |
944 | */ | |
cc2f3386 | 945 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
946 | ret = true; |
947 | goto out; | |
948 | } | |
949 | ||
c384ea3e | 950 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 951 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
952 | dat_entry->mac_addr, hw_src); |
953 | if (!skb_new) | |
954 | goto out; | |
955 | ||
be1db4f6 AQ |
956 | if (vid & BATADV_VLAN_HAS_TAG) |
957 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
958 | vid & VLAN_VID_MASK); | |
959 | ||
c384ea3e AQ |
960 | skb_reset_mac_header(skb_new); |
961 | skb_new->protocol = eth_type_trans(skb_new, | |
736292c2 | 962 | bat_priv->soft_iface); |
c384ea3e | 963 | bat_priv->stats.rx_packets++; |
be1db4f6 | 964 | bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size; |
736292c2 | 965 | bat_priv->soft_iface->last_rx = jiffies; |
c384ea3e AQ |
966 | |
967 | netif_rx(skb_new); | |
968 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
969 | ret = true; | |
970 | } else { | |
93178018 | 971 | /* Send the request to the DHT */ |
c384ea3e AQ |
972 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, |
973 | BATADV_P_DAT_DHT_GET); | |
974 | } | |
975 | out: | |
976 | if (dat_entry) | |
977 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
978 | return ret; |
979 | } | |
980 | ||
981 | /** | |
982 | * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to | |
983 | * answer using the local DAT storage | |
984 | * @bat_priv: the bat priv with all the soft interface information | |
985 | * @skb: packet to check | |
986 | * @hdr_size: size of the encapsulation header | |
987 | * | |
93178018 | 988 | * Returns true if the request has been answered, false otherwise. |
c384ea3e AQ |
989 | */ |
990 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
991 | struct sk_buff *skb, int hdr_size) | |
992 | { | |
993 | uint16_t type; | |
994 | __be32 ip_src, ip_dst; | |
995 | uint8_t *hw_src; | |
996 | struct sk_buff *skb_new; | |
c384ea3e AQ |
997 | struct batadv_dat_entry *dat_entry = NULL; |
998 | bool ret = false; | |
be1db4f6 | 999 | unsigned short vid; |
c384ea3e AQ |
1000 | int err; |
1001 | ||
33af49ad AQ |
1002 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1003 | goto out; | |
1004 | ||
be1db4f6 AQ |
1005 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1006 | ||
c384ea3e AQ |
1007 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1008 | if (type != ARPOP_REQUEST) | |
1009 | goto out; | |
1010 | ||
1011 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1012 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1013 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1014 | ||
1015 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1016 | "Parsing incoming ARP REQUEST"); | |
1017 | ||
be1db4f6 | 1018 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1019 | |
be1db4f6 | 1020 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1021 | if (!dat_entry) |
1022 | goto out; | |
1023 | ||
c384ea3e | 1024 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 1025 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
1026 | dat_entry->mac_addr, hw_src); |
1027 | ||
1028 | if (!skb_new) | |
1029 | goto out; | |
1030 | ||
927c2ed7 LL |
1031 | /* the rest of the TX path assumes that the mac_header offset pointing |
1032 | * to the inner Ethernet header has been set, therefore reset it now. | |
1033 | */ | |
1034 | skb_reset_mac_header(skb_new); | |
1035 | ||
be1db4f6 AQ |
1036 | if (vid & BATADV_VLAN_HAS_TAG) |
1037 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1038 | vid & VLAN_VID_MASK); | |
1039 | ||
93178018 ML |
1040 | /* To preserve backwards compatibility, the node has choose the outgoing |
1041 | * format based on the incoming request packet type. The assumption is | |
1042 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1043 | */ |
1044 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1045 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1046 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1047 | NULL, vid); |
c384ea3e | 1048 | else |
6c413b1c | 1049 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1050 | |
e300d314 | 1051 | if (err != NET_XMIT_DROP) { |
4046b24a | 1052 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1053 | ret = true; |
4046b24a | 1054 | } |
c384ea3e AQ |
1055 | out: |
1056 | if (dat_entry) | |
1057 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1058 | if (ret) |
1059 | kfree_skb(skb); | |
1060 | return ret; | |
1061 | } | |
1062 | ||
1063 | /** | |
1064 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1065 | * @bat_priv: the bat priv with all the soft interface information | |
1066 | * @skb: packet to check | |
1067 | */ | |
1068 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1069 | struct sk_buff *skb) | |
1070 | { | |
1071 | uint16_t type; | |
1072 | __be32 ip_src, ip_dst; | |
1073 | uint8_t *hw_src, *hw_dst; | |
be1db4f6 AQ |
1074 | int hdr_size = 0; |
1075 | unsigned short vid; | |
c384ea3e | 1076 | |
33af49ad AQ |
1077 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1078 | return; | |
1079 | ||
be1db4f6 AQ |
1080 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1081 | ||
1082 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1083 | if (type != ARPOP_REPLY) |
1084 | return; | |
1085 | ||
be1db4f6 AQ |
1086 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
1087 | "Parsing outgoing ARP REPLY"); | |
c384ea3e | 1088 | |
be1db4f6 AQ |
1089 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1090 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1091 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1092 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1093 | |
be1db4f6 AQ |
1094 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1095 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1096 | |
1097 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1098 | * the node obtained from the ARP reply |
c384ea3e AQ |
1099 | */ |
1100 | batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT); | |
1101 | batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT); | |
1102 | } | |
1103 | /** | |
1104 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1105 | * DAT storage only | |
1106 | * @bat_priv: the bat priv with all the soft interface information | |
1107 | * @skb: packet to check | |
93178018 | 1108 | * @hdr_size: size of the encapsulation header |
c384ea3e AQ |
1109 | */ |
1110 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1111 | struct sk_buff *skb, int hdr_size) | |
1112 | { | |
1113 | uint16_t type; | |
1114 | __be32 ip_src, ip_dst; | |
1115 | uint8_t *hw_src, *hw_dst; | |
1116 | bool ret = false; | |
be1db4f6 | 1117 | unsigned short vid; |
c384ea3e | 1118 | |
33af49ad AQ |
1119 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1120 | goto out; | |
1121 | ||
be1db4f6 AQ |
1122 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1123 | ||
c384ea3e AQ |
1124 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1125 | if (type != ARPOP_REPLY) | |
1126 | goto out; | |
1127 | ||
1128 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1129 | "Parsing incoming ARP REPLY"); | |
1130 | ||
1131 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1132 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1133 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1134 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1135 | ||
1136 | /* Update our internal cache with both the IP addresses the node got | |
1137 | * within the ARP reply | |
1138 | */ | |
be1db4f6 AQ |
1139 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1140 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1141 | |
1142 | /* if this REPLY is directed to a client of mine, let's deliver the | |
1143 | * packet to the interface | |
1144 | */ | |
be1db4f6 | 1145 | ret = !batadv_is_my_client(bat_priv, hw_dst, vid); |
c384ea3e | 1146 | out: |
0d15bece MS |
1147 | if (ret) |
1148 | kfree_skb(skb); | |
c384ea3e AQ |
1149 | /* if ret == false -> packet has to be delivered to the interface */ |
1150 | return ret; | |
1151 | } | |
1152 | ||
1153 | /** | |
1154 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1155 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1156 | * @bat_priv: the bat priv with all the soft interface information |
1157 | * @forw_packet: the broadcast packet | |
1158 | * | |
93178018 | 1159 | * Returns true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1160 | */ |
1161 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1162 | struct batadv_forw_packet *forw_packet) | |
1163 | { | |
1164 | uint16_t type; | |
1165 | __be32 ip_dst; | |
1166 | struct batadv_dat_entry *dat_entry = NULL; | |
1167 | bool ret = false; | |
be1db4f6 AQ |
1168 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1169 | unsigned short vid; | |
c384ea3e | 1170 | |
33af49ad AQ |
1171 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1172 | goto out; | |
1173 | ||
c384ea3e AQ |
1174 | /* If this packet is an ARP_REQUEST and the node already has the |
1175 | * information that it is going to ask, then the packet can be dropped | |
1176 | */ | |
1177 | if (forw_packet->num_packets) | |
1178 | goto out; | |
1179 | ||
be1db4f6 AQ |
1180 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1181 | ||
1182 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1183 | if (type != ARPOP_REQUEST) |
1184 | goto out; | |
1185 | ||
be1db4f6 AQ |
1186 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1187 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1188 | /* check if the node already got this entry */ |
1189 | if (!dat_entry) { | |
1190 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1191 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1192 | goto out; | |
1193 | } | |
1194 | ||
1195 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1196 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1197 | ret = true; | |
1198 | ||
1199 | out: | |
1200 | if (dat_entry) | |
1201 | batadv_dat_entry_free_ref(dat_entry); | |
1202 | return ret; | |
1203 | } |