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785ea114 AQ |
1 | /* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors: |
2 | * | |
3 | * Antonio Quartulli | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
17 | * 02110-1301, USA | |
18 | */ | |
19 | ||
20 | #include <linux/if_ether.h> | |
21 | #include <linux/if_arp.h> | |
22 | ||
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" | |
30 | #include "unicast.h" | |
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 | /** | |
46 | * batadv_dat_entry_free_ref - decrements the dat_entry refcounter and possibly | |
47 | * free it | |
48 | * @dat_entry: the oentry to free | |
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 | /** | |
57 | * batadv_dat_to_purge - checks whether a dat_entry has to be purged or not | |
58 | * @dat_entry: the entry to check | |
59 | * | |
60 | * Returns true if the entry has to be purged now, false otherwise | |
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 | * | |
76 | * Loops over each entry in the DAT local storage and delete it if and only if | |
77 | * the to_purge function passed as argument returns true | |
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; | |
84 | struct hlist_node *node, *node_tmp; | |
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); | |
96 | hlist_for_each_entry_safe(dat_entry, node, node_tmp, head, | |
97 | hash_entry) { | |
98 | /* if an helper function has been passed as parameter, | |
99 | * ask it if the entry has to be purged or not | |
100 | */ | |
101 | if (to_purge && !to_purge(dat_entry)) | |
102 | continue; | |
103 | ||
104 | hlist_del_rcu(node); | |
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 | * | |
135 | * Returns 1 if the two entry are the same, 0 otherwise | |
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 | ||
142 | return (memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0); | |
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 | * | |
150 | * Returns the value of the hw_src field in the ARP packet | |
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 | * | |
167 | * Returns the value of the ip_src field in the ARP packet | |
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 | * | |
179 | * Returns the value of the hw_dst field in the ARP packet | |
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 | * | |
191 | * Returns the value of the ip_dst field in the ARP packet | |
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 | * | |
203 | * Returns the selected index in the hash table for the given data | |
204 | */ | |
205 | static uint32_t batadv_hash_dat(const void *data, uint32_t size) | |
206 | { | |
207 | const unsigned char *key = data; | |
208 | uint32_t hash = 0; | |
209 | size_t i; | |
210 | ||
211 | for (i = 0; i < 4; i++) { | |
212 | hash += key[i]; | |
213 | hash += (hash << 10); | |
214 | hash ^= (hash >> 6); | |
215 | } | |
216 | ||
217 | hash += (hash << 3); | |
218 | hash ^= (hash >> 11); | |
219 | hash += (hash << 15); | |
220 | ||
221 | return hash % size; | |
222 | } | |
223 | ||
2f1dfbe1 AQ |
224 | /** |
225 | * batadv_dat_entry_hash_find - looks for a given dat_entry in the local hash | |
226 | * table | |
227 | * @bat_priv: the bat priv with all the soft interface information | |
228 | * @ip: search key | |
229 | * | |
230 | * Returns the dat_entry if found, NULL otherwise | |
231 | */ | |
232 | static struct batadv_dat_entry * | |
233 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip) | |
234 | { | |
235 | struct hlist_head *head; | |
236 | struct hlist_node *node; | |
237 | struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL; | |
238 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
239 | uint32_t index; | |
240 | ||
241 | if (!hash) | |
242 | return NULL; | |
243 | ||
244 | index = batadv_hash_dat(&ip, hash->size); | |
245 | head = &hash->table[index]; | |
246 | ||
247 | rcu_read_lock(); | |
248 | hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) { | |
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 | |
268 | */ | |
269 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
270 | uint8_t *mac_addr) | |
271 | { | |
272 | struct batadv_dat_entry *dat_entry; | |
273 | int hash_added; | |
274 | ||
275 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip); | |
276 | /* if this entry is already known, just update it */ | |
277 | if (dat_entry) { | |
278 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
279 | memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN); | |
280 | dat_entry->last_update = jiffies; | |
281 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
282 | "Entry updated: %pI4 %pM\n", &dat_entry->ip, | |
283 | dat_entry->mac_addr); | |
284 | goto out; | |
285 | } | |
286 | ||
287 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
288 | if (!dat_entry) | |
289 | goto out; | |
290 | ||
291 | dat_entry->ip = ip; | |
292 | memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN); | |
293 | dat_entry->last_update = jiffies; | |
294 | atomic_set(&dat_entry->refcount, 2); | |
295 | ||
296 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, | |
297 | batadv_hash_dat, &dat_entry->ip, | |
298 | &dat_entry->hash_entry); | |
299 | ||
300 | if (unlikely(hash_added != 0)) { | |
301 | /* remove the reference for the hash */ | |
302 | batadv_dat_entry_free_ref(dat_entry); | |
303 | goto out; | |
304 | } | |
305 | ||
306 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM\n", | |
307 | &dat_entry->ip, dat_entry->mac_addr); | |
308 | ||
309 | out: | |
310 | if (dat_entry) | |
311 | batadv_dat_entry_free_ref(dat_entry); | |
312 | } | |
313 | ||
5c3a0e55 AQ |
314 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
315 | ||
316 | /** | |
317 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
318 | * @bat_priv: the bat priv with all the soft interface information | |
319 | * @skb: ARP packet | |
320 | * @type: ARP type | |
321 | * @hdr_size: size of the possible header before the ARP packet | |
322 | * @msg: message to print together with the debugging information | |
323 | */ | |
324 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
325 | uint16_t type, int hdr_size, char *msg) | |
326 | { | |
327 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
328 | struct batadv_bcast_packet *bcast_pkt; | |
329 | uint8_t *orig_addr; | |
330 | __be32 ip_src, ip_dst; | |
331 | ||
332 | if (msg) | |
333 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
334 | ||
335 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
336 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
337 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
338 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
339 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
340 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
341 | ||
342 | if (hdr_size == 0) | |
343 | return; | |
344 | ||
345 | /* if the ARP packet is encapsulated in a batman packet, let's print | |
346 | * some debug messages | |
347 | */ | |
348 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; | |
349 | ||
350 | switch (unicast_4addr_packet->u.header.packet_type) { | |
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", | |
375 | unicast_4addr_packet->u.header.packet_type); | |
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", | |
388 | unicast_4addr_packet->u.header.packet_type); | |
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 | * | |
411 | * Returns true if the node has been elected as next candidate or false othrwise | |
412 | */ | |
413 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
414 | int select, batadv_dat_addr_t tmp_max, | |
415 | batadv_dat_addr_t max, | |
416 | batadv_dat_addr_t last_max, | |
417 | struct batadv_orig_node *candidate, | |
418 | struct batadv_orig_node *max_orig_node) | |
419 | { | |
420 | bool ret = false; | |
421 | int j; | |
422 | ||
423 | /* Check if this node has already been selected... */ | |
424 | for (j = 0; j < select; j++) | |
425 | if (res[j].orig_node == candidate) | |
426 | break; | |
427 | /* ..and possibly skip it */ | |
428 | if (j < select) | |
429 | goto out; | |
430 | /* sanity check: has it already been selected? This should not happen */ | |
431 | if (tmp_max > last_max) | |
432 | goto out; | |
433 | /* check if during this iteration an originator with a closer dht | |
434 | * address has already been found | |
435 | */ | |
436 | if (tmp_max < max) | |
437 | goto out; | |
438 | /* this is an hash collision with the temporary selected node. Choose | |
439 | * the one with the lowest address | |
440 | */ | |
441 | if ((tmp_max == max) && | |
442 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) | |
443 | goto out; | |
444 | ||
445 | ret = true; | |
446 | out: | |
447 | return ret; | |
448 | } | |
449 | ||
450 | /** | |
451 | * batadv_choose_next_candidate - select the next DHT candidate | |
452 | * @bat_priv: the bat priv with all the soft interface information | |
453 | * @cands: candidates array | |
454 | * @select: number of candidates already present in the array | |
455 | * @ip_key: key to look up in the DHT | |
456 | * @last_max: pointer where the address of the selected candidate will be saved | |
457 | */ | |
458 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
459 | struct batadv_dat_candidate *cands, | |
460 | int select, batadv_dat_addr_t ip_key, | |
461 | batadv_dat_addr_t *last_max) | |
462 | { | |
463 | batadv_dat_addr_t max = 0, tmp_max = 0; | |
464 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; | |
465 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
466 | struct hlist_node *node; | |
467 | struct hlist_head *head; | |
468 | int i; | |
469 | ||
470 | /* if no node is eligible as candidate, leave the candidate type as | |
471 | * NOT_FOUND | |
472 | */ | |
473 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
474 | ||
475 | /* iterate over the originator list and find the node with closest | |
476 | * dat_address which has not been selected yet | |
477 | */ | |
478 | for (i = 0; i < hash->size; i++) { | |
479 | head = &hash->table[i]; | |
480 | ||
481 | rcu_read_lock(); | |
482 | hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) { | |
483 | /* the dht space is a ring and addresses are unsigned */ | |
484 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + | |
485 | ip_key; | |
486 | ||
487 | if (!batadv_is_orig_node_eligible(cands, select, | |
488 | tmp_max, max, | |
489 | *last_max, orig_node, | |
490 | max_orig_node)) | |
491 | continue; | |
492 | ||
493 | if (!atomic_inc_not_zero(&orig_node->refcount)) | |
494 | continue; | |
495 | ||
496 | max = tmp_max; | |
497 | if (max_orig_node) | |
498 | batadv_orig_node_free_ref(max_orig_node); | |
499 | max_orig_node = orig_node; | |
500 | } | |
501 | rcu_read_unlock(); | |
502 | } | |
503 | if (max_orig_node) { | |
504 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
505 | cands[select].orig_node = max_orig_node; | |
506 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
507 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
508 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
509 | max); | |
510 | } | |
511 | *last_max = max; | |
512 | } | |
513 | ||
514 | /** | |
515 | * batadv_dat_select_candidates - selects the nodes which the DHT message has to | |
516 | * be sent to | |
517 | * @bat_priv: the bat priv with all the soft interface information | |
518 | * @ip_dst: ipv4 to look up in the DHT | |
519 | * | |
520 | * An originator O is selected if and only if its DHT_ID value is one of three | |
521 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
522 | * value of the key. ip_dst is the key. | |
523 | * | |
524 | * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM | |
525 | */ | |
526 | static struct batadv_dat_candidate * | |
527 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst) | |
528 | { | |
529 | int select; | |
530 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
531 | struct batadv_dat_candidate *res; | |
532 | ||
533 | if (!bat_priv->orig_hash) | |
534 | return NULL; | |
535 | ||
536 | res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC); | |
537 | if (!res) | |
538 | return NULL; | |
539 | ||
540 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst, | |
541 | BATADV_DAT_ADDR_MAX); | |
542 | ||
543 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
544 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
545 | ip_key); | |
546 | ||
547 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
548 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
549 | &last_max); | |
550 | ||
551 | return res; | |
552 | } | |
553 | ||
554 | /** | |
555 | * batadv_dat_send_data - send a payload to the selected candidates | |
556 | * @bat_priv: the bat priv with all the soft interface information | |
557 | * @skb: payload to send | |
558 | * @ip: the DHT key | |
559 | * @packet_subtype: unicast4addr packet subtype to use | |
560 | * | |
561 | * In this function the skb is copied by means of pskb_copy() and is sent as | |
562 | * unicast packet to each of the selected candidates | |
563 | * | |
564 | * Returns true if the packet is sent to at least one candidate, false otherwise | |
565 | */ | |
566 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
567 | struct sk_buff *skb, __be32 ip, | |
568 | int packet_subtype) | |
569 | { | |
570 | int i; | |
571 | bool ret = false; | |
572 | int send_status; | |
573 | struct batadv_neigh_node *neigh_node = NULL; | |
574 | struct sk_buff *tmp_skb; | |
575 | struct batadv_dat_candidate *cand; | |
576 | ||
577 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
578 | if (!cand) | |
579 | goto out; | |
580 | ||
581 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
582 | ||
583 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
584 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
585 | continue; | |
586 | ||
587 | neigh_node = batadv_orig_node_get_router(cand[i].orig_node); | |
588 | if (!neigh_node) | |
589 | goto free_orig; | |
590 | ||
591 | tmp_skb = pskb_copy(skb, GFP_ATOMIC); | |
592 | if (!batadv_unicast_4addr_prepare_skb(bat_priv, tmp_skb, | |
593 | cand[i].orig_node, | |
594 | packet_subtype)) { | |
595 | kfree_skb(tmp_skb); | |
596 | goto free_neigh; | |
597 | } | |
598 | ||
599 | send_status = batadv_send_skb_packet(tmp_skb, | |
600 | neigh_node->if_incoming, | |
601 | neigh_node->addr); | |
602 | if (send_status == NET_XMIT_SUCCESS) | |
603 | /* packet sent to a candidate: return true */ | |
604 | ret = true; | |
605 | free_neigh: | |
606 | batadv_neigh_node_free_ref(neigh_node); | |
607 | free_orig: | |
608 | batadv_orig_node_free_ref(cand[i].orig_node); | |
609 | } | |
610 | ||
611 | out: | |
612 | kfree(cand); | |
613 | return ret; | |
614 | } | |
2f1dfbe1 AQ |
615 | |
616 | /** | |
617 | * batadv_dat_hash_free - free the local DAT hash table | |
618 | * @bat_priv: the bat priv with all the soft interface information | |
619 | */ | |
620 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
621 | { | |
622 | __batadv_dat_purge(bat_priv, NULL); | |
623 | ||
624 | batadv_hash_destroy(bat_priv->dat.hash); | |
625 | ||
626 | bat_priv->dat.hash = NULL; | |
627 | } | |
628 | ||
629 | /** | |
630 | * batadv_dat_init - initialise the DAT internals | |
631 | * @bat_priv: the bat priv with all the soft interface information | |
632 | */ | |
633 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
634 | { | |
635 | if (bat_priv->dat.hash) | |
636 | return 0; | |
637 | ||
638 | bat_priv->dat.hash = batadv_hash_new(1024); | |
639 | ||
640 | if (!bat_priv->dat.hash) | |
641 | return -ENOMEM; | |
642 | ||
643 | batadv_dat_start_timer(bat_priv); | |
644 | ||
645 | return 0; | |
646 | } | |
647 | ||
648 | /** | |
649 | * batadv_dat_free - free the DAT internals | |
650 | * @bat_priv: the bat priv with all the soft interface information | |
651 | */ | |
652 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
653 | { | |
654 | cancel_delayed_work_sync(&bat_priv->dat.work); | |
655 | ||
656 | batadv_dat_hash_free(bat_priv); | |
657 | } | |
658 | ||
659 | /** | |
660 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
661 | * @seq: seq file to print on | |
662 | * @offset: not used | |
663 | */ | |
664 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
665 | { | |
666 | struct net_device *net_dev = (struct net_device *)seq->private; | |
667 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
668 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
669 | struct batadv_dat_entry *dat_entry; | |
670 | struct batadv_hard_iface *primary_if; | |
671 | struct hlist_node *node; | |
672 | struct hlist_head *head; | |
673 | unsigned long last_seen_jiffies; | |
674 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
675 | uint32_t i; | |
676 | ||
677 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
678 | if (!primary_if) | |
679 | goto out; | |
680 | ||
681 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
682 | seq_printf(seq, " %-7s %-13s %5s\n", "IPv4", "MAC", | |
683 | "last-seen"); | |
684 | ||
685 | for (i = 0; i < hash->size; i++) { | |
686 | head = &hash->table[i]; | |
687 | ||
688 | rcu_read_lock(); | |
689 | hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) { | |
690 | last_seen_jiffies = jiffies - dat_entry->last_update; | |
691 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
692 | last_seen_mins = last_seen_msecs / 60000; | |
693 | last_seen_msecs = last_seen_msecs % 60000; | |
694 | last_seen_secs = last_seen_msecs / 1000; | |
695 | ||
696 | seq_printf(seq, " * %15pI4 %14pM %6i:%02i\n", | |
697 | &dat_entry->ip, dat_entry->mac_addr, | |
698 | last_seen_mins, last_seen_secs); | |
699 | } | |
700 | rcu_read_unlock(); | |
701 | } | |
702 | ||
703 | out: | |
704 | if (primary_if) | |
705 | batadv_hardif_free_ref(primary_if); | |
706 | return 0; | |
707 | } | |
5c3a0e55 AQ |
708 | |
709 | /** | |
710 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
711 | * @bat_priv: the bat priv with all the soft interface information | |
712 | * @skb: packet to analyse | |
713 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
714 | * | |
715 | * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise | |
716 | */ | |
717 | static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv, | |
718 | struct sk_buff *skb, int hdr_size) | |
719 | { | |
720 | struct arphdr *arphdr; | |
721 | struct ethhdr *ethhdr; | |
722 | __be32 ip_src, ip_dst; | |
723 | uint16_t type = 0; | |
724 | ||
725 | /* pull the ethernet header */ | |
726 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
727 | goto out; | |
728 | ||
729 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
730 | ||
731 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
732 | goto out; | |
733 | ||
734 | /* pull the ARP payload */ | |
735 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
736 | arp_hdr_len(skb->dev)))) | |
737 | goto out; | |
738 | ||
739 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
740 | ||
741 | /* Check whether the ARP packet carries a valid | |
742 | * IP information | |
743 | */ | |
744 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) | |
745 | goto out; | |
746 | ||
747 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
748 | goto out; | |
749 | ||
750 | if (arphdr->ar_hln != ETH_ALEN) | |
751 | goto out; | |
752 | ||
753 | if (arphdr->ar_pln != 4) | |
754 | goto out; | |
755 | ||
756 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
757 | * will simply ignore it | |
758 | */ | |
759 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
760 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
761 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
762 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst)) | |
763 | goto out; | |
764 | ||
765 | type = ntohs(arphdr->ar_op); | |
766 | out: | |
767 | return type; | |
768 | } |