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0b873931 | 1 | /* Copyright (C) 2011-2013 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 | |
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> | |
be1db4f6 | 22 | #include <linux/if_vlan.h> |
c384ea3e | 23 | #include <net/arp.h> |
785ea114 AQ |
24 | |
25 | #include "main.h" | |
5c3a0e55 | 26 | #include "hash.h" |
785ea114 AQ |
27 | #include "distributed-arp-table.h" |
28 | #include "hard-interface.h" | |
29 | #include "originator.h" | |
30 | #include "send.h" | |
31 | #include "types.h" | |
c384ea3e | 32 | #include "translation-table.h" |
785ea114 | 33 | |
2f1dfbe1 AQ |
34 | static void batadv_dat_purge(struct work_struct *work); |
35 | ||
36 | /** | |
37 | * batadv_dat_start_timer - initialise the DAT periodic worker | |
38 | * @bat_priv: the bat priv with all the soft interface information | |
39 | */ | |
40 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
41 | { | |
42 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
43 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
44 | msecs_to_jiffies(10000)); | |
45 | } | |
46 | ||
47 | /** | |
93178018 | 48 | * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly |
2f1dfbe1 | 49 | * free it |
93178018 | 50 | * @dat_entry: the entry to free |
2f1dfbe1 AQ |
51 | */ |
52 | static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry) | |
53 | { | |
54 | if (atomic_dec_and_test(&dat_entry->refcount)) | |
55 | kfree_rcu(dat_entry, rcu); | |
56 | } | |
57 | ||
58 | /** | |
93178018 | 59 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
60 | * @dat_entry: the entry to check |
61 | * | |
93178018 | 62 | * Returns true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
63 | */ |
64 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
65 | { | |
66 | return batadv_has_timed_out(dat_entry->last_update, | |
67 | BATADV_DAT_ENTRY_TIMEOUT); | |
68 | } | |
69 | ||
70 | /** | |
71 | * __batadv_dat_purge - delete entries from the DAT local storage | |
72 | * @bat_priv: the bat priv with all the soft interface information | |
73 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
74 | * not. This function takes the dat_entry as argument and has to | |
75 | * returns a boolean value: true is the entry has to be deleted, | |
76 | * false otherwise | |
77 | * | |
93178018 ML |
78 | * Loops over each entry in the DAT local storage and deletes it if and only if |
79 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
80 | */ |
81 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
82 | bool (*to_purge)(struct batadv_dat_entry *)) | |
83 | { | |
84 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
85 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 86 | struct hlist_node *node_tmp; |
2f1dfbe1 AQ |
87 | struct hlist_head *head; |
88 | uint32_t i; | |
89 | ||
90 | if (!bat_priv->dat.hash) | |
91 | return; | |
92 | ||
93 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
94 | head = &bat_priv->dat.hash->table[i]; | |
95 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
96 | ||
97 | spin_lock_bh(list_lock); | |
b67bfe0d | 98 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 99 | hash_entry) { |
93178018 | 100 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
101 | * ask it if the entry has to be purged or not |
102 | */ | |
103 | if (to_purge && !to_purge(dat_entry)) | |
104 | continue; | |
105 | ||
b67bfe0d | 106 | hlist_del_rcu(&dat_entry->hash_entry); |
2f1dfbe1 AQ |
107 | batadv_dat_entry_free_ref(dat_entry); |
108 | } | |
109 | spin_unlock_bh(list_lock); | |
110 | } | |
111 | } | |
112 | ||
113 | /** | |
114 | * batadv_dat_purge - periodic task that deletes old entries from the local DAT | |
115 | * hash table | |
116 | * @work: kernel work struct | |
117 | */ | |
118 | static void batadv_dat_purge(struct work_struct *work) | |
119 | { | |
120 | struct delayed_work *delayed_work; | |
121 | struct batadv_priv_dat *priv_dat; | |
122 | struct batadv_priv *bat_priv; | |
123 | ||
124 | delayed_work = container_of(work, struct delayed_work, work); | |
125 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); | |
126 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
127 | ||
128 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
129 | batadv_dat_start_timer(bat_priv); | |
130 | } | |
131 | ||
132 | /** | |
133 | * batadv_compare_dat - comparing function used in the local DAT hash table | |
134 | * @node: node in the local table | |
135 | * @data2: second object to compare the node to | |
136 | * | |
93178018 | 137 | * Returns 1 if the two entries are the same, 0 otherwise. |
2f1dfbe1 AQ |
138 | */ |
139 | static int batadv_compare_dat(const struct hlist_node *node, const void *data2) | |
140 | { | |
141 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
142 | hash_entry); | |
143 | ||
144 | return (memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0); | |
145 | } | |
146 | ||
5c3a0e55 AQ |
147 | /** |
148 | * batadv_arp_hw_src - extract the hw_src field from an ARP packet | |
149 | * @skb: ARP packet | |
150 | * @hdr_size: size of the possible header before the ARP packet | |
151 | * | |
93178018 | 152 | * Returns the value of the hw_src field in the ARP packet. |
5c3a0e55 AQ |
153 | */ |
154 | static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) | |
155 | { | |
156 | uint8_t *addr; | |
157 | ||
158 | addr = (uint8_t *)(skb->data + hdr_size); | |
159 | addr += ETH_HLEN + sizeof(struct arphdr); | |
160 | ||
161 | return addr; | |
162 | } | |
163 | ||
164 | /** | |
165 | * batadv_arp_ip_src - extract the ip_src field from an ARP packet | |
166 | * @skb: ARP packet | |
167 | * @hdr_size: size of the possible header before the ARP packet | |
168 | * | |
93178018 | 169 | * Returns the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
170 | */ |
171 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
172 | { | |
173 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
174 | } | |
175 | ||
176 | /** | |
177 | * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet | |
178 | * @skb: ARP packet | |
179 | * @hdr_size: size of the possible header before the ARP packet | |
180 | * | |
93178018 | 181 | * Returns the value of the hw_dst field in the ARP packet. |
5c3a0e55 AQ |
182 | */ |
183 | static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) | |
184 | { | |
185 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
186 | } | |
187 | ||
188 | /** | |
189 | * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet | |
190 | * @skb: ARP packet | |
191 | * @hdr_size: size of the possible header before the ARP packet | |
192 | * | |
93178018 | 193 | * Returns the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
194 | */ |
195 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
196 | { | |
197 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
198 | } | |
199 | ||
785ea114 AQ |
200 | /** |
201 | * batadv_hash_dat - compute the hash value for an IP address | |
202 | * @data: data to hash | |
203 | * @size: size of the hash table | |
204 | * | |
93178018 | 205 | * Returns the selected index in the hash table for the given data. |
785ea114 AQ |
206 | */ |
207 | static uint32_t batadv_hash_dat(const void *data, uint32_t size) | |
208 | { | |
785ea114 | 209 | uint32_t hash = 0; |
be1db4f6 | 210 | const struct batadv_dat_entry *dat = data; |
785ea114 | 211 | |
be1db4f6 AQ |
212 | hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip)); |
213 | hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid)); | |
785ea114 AQ |
214 | |
215 | hash += (hash << 3); | |
216 | hash ^= (hash >> 11); | |
217 | hash += (hash << 15); | |
218 | ||
219 | return hash % size; | |
220 | } | |
221 | ||
2f1dfbe1 | 222 | /** |
93178018 | 223 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
224 | * table |
225 | * @bat_priv: the bat priv with all the soft interface information | |
226 | * @ip: search key | |
be1db4f6 | 227 | * @vid: VLAN identifier |
2f1dfbe1 | 228 | * |
93178018 | 229 | * Returns the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
230 | */ |
231 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
232 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
233 | unsigned short vid) | |
2f1dfbe1 AQ |
234 | { |
235 | struct hlist_head *head; | |
be1db4f6 | 236 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 AQ |
237 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
238 | uint32_t index; | |
239 | ||
240 | if (!hash) | |
241 | return NULL; | |
242 | ||
be1db4f6 AQ |
243 | to_find.ip = ip; |
244 | to_find.vid = vid; | |
245 | ||
246 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
247 | head = &hash->table[index]; |
248 | ||
249 | rcu_read_lock(); | |
b67bfe0d | 250 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
251 | if (dat_entry->ip != ip) |
252 | continue; | |
253 | ||
254 | if (!atomic_inc_not_zero(&dat_entry->refcount)) | |
255 | continue; | |
256 | ||
257 | dat_entry_tmp = dat_entry; | |
258 | break; | |
259 | } | |
260 | rcu_read_unlock(); | |
261 | ||
262 | return dat_entry_tmp; | |
263 | } | |
264 | ||
265 | /** | |
266 | * batadv_dat_entry_add - add a new dat entry or update it if already exists | |
267 | * @bat_priv: the bat priv with all the soft interface information | |
268 | * @ip: ipv4 to add/edit | |
269 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 270 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
271 | */ |
272 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
be1db4f6 | 273 | uint8_t *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
274 | { |
275 | struct batadv_dat_entry *dat_entry; | |
276 | int hash_added; | |
277 | ||
be1db4f6 | 278 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
279 | /* if this entry is already known, just update it */ |
280 | if (dat_entry) { | |
281 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
282 | memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN); | |
283 | dat_entry->last_update = jiffies; | |
284 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
285 | "Entry updated: %pI4 %pM (vid: %d)\n", |
286 | &dat_entry->ip, dat_entry->mac_addr, | |
287 | BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
288 | goto out; |
289 | } | |
290 | ||
291 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
292 | if (!dat_entry) | |
293 | goto out; | |
294 | ||
295 | dat_entry->ip = ip; | |
be1db4f6 | 296 | dat_entry->vid = vid; |
2f1dfbe1 AQ |
297 | memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN); |
298 | dat_entry->last_update = jiffies; | |
299 | atomic_set(&dat_entry->refcount, 2); | |
300 | ||
301 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, | |
be1db4f6 | 302 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
303 | &dat_entry->hash_entry); |
304 | ||
305 | if (unlikely(hash_added != 0)) { | |
306 | /* remove the reference for the hash */ | |
307 | batadv_dat_entry_free_ref(dat_entry); | |
308 | goto out; | |
309 | } | |
310 | ||
be1db4f6 AQ |
311 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
312 | &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
313 | |
314 | out: | |
315 | if (dat_entry) | |
316 | batadv_dat_entry_free_ref(dat_entry); | |
317 | } | |
318 | ||
5c3a0e55 AQ |
319 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
320 | ||
321 | /** | |
322 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
323 | * @bat_priv: the bat priv with all the soft interface information | |
324 | * @skb: ARP packet | |
325 | * @type: ARP type | |
326 | * @hdr_size: size of the possible header before the ARP packet | |
327 | * @msg: message to print together with the debugging information | |
328 | */ | |
329 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
330 | uint16_t type, int hdr_size, char *msg) | |
331 | { | |
332 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
333 | struct batadv_bcast_packet *bcast_pkt; | |
334 | uint8_t *orig_addr; | |
335 | __be32 ip_src, ip_dst; | |
336 | ||
337 | if (msg) | |
338 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
339 | ||
340 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
341 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
342 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
343 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
344 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
345 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
346 | ||
347 | if (hdr_size == 0) | |
348 | return; | |
349 | ||
5c3a0e55 AQ |
350 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
351 | ||
a40d9b07 | 352 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
353 | case BATADV_UNICAST: |
354 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
355 | "* encapsulated within a UNICAST packet\n"); | |
356 | break; | |
357 | case BATADV_UNICAST_4ADDR: | |
358 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
359 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
360 | unicast_4addr_packet->src); | |
361 | switch (unicast_4addr_packet->subtype) { | |
362 | case BATADV_P_DAT_DHT_PUT: | |
363 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
364 | break; | |
365 | case BATADV_P_DAT_DHT_GET: | |
366 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
367 | break; | |
368 | case BATADV_P_DAT_CACHE_REPLY: | |
369 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
370 | "* type: DAT_CACHE_REPLY\n"); | |
371 | break; | |
372 | case BATADV_P_DATA: | |
373 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
374 | break; | |
375 | default: | |
376 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 377 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
378 | } |
379 | break; | |
380 | case BATADV_BCAST: | |
381 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
382 | orig_addr = bcast_pkt->orig; | |
383 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
384 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
385 | orig_addr); | |
386 | break; | |
387 | default: | |
388 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
389 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 390 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
391 | } |
392 | } | |
393 | ||
394 | #else | |
395 | ||
396 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
397 | uint16_t type, int hdr_size, char *msg) | |
398 | { | |
399 | } | |
400 | ||
401 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
402 | ||
785ea114 AQ |
403 | /** |
404 | * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate | |
405 | * @res: the array with the already selected candidates | |
406 | * @select: number of already selected candidates | |
407 | * @tmp_max: address of the currently evaluated node | |
408 | * @max: current round max address | |
409 | * @last_max: address of the last selected candidate | |
410 | * @candidate: orig_node under evaluation | |
411 | * @max_orig_node: last selected candidate | |
412 | * | |
93178018 ML |
413 | * Returns true if the node has been elected as next candidate or false |
414 | * otherwise. | |
785ea114 AQ |
415 | */ |
416 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
417 | int select, batadv_dat_addr_t tmp_max, | |
418 | batadv_dat_addr_t max, | |
419 | batadv_dat_addr_t last_max, | |
420 | struct batadv_orig_node *candidate, | |
421 | struct batadv_orig_node *max_orig_node) | |
422 | { | |
423 | bool ret = false; | |
424 | int j; | |
425 | ||
17cf0ea4 ML |
426 | /* check if orig node candidate is running DAT */ |
427 | if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT)) | |
428 | goto out; | |
429 | ||
785ea114 AQ |
430 | /* Check if this node has already been selected... */ |
431 | for (j = 0; j < select; j++) | |
432 | if (res[j].orig_node == candidate) | |
433 | break; | |
434 | /* ..and possibly skip it */ | |
435 | if (j < select) | |
436 | goto out; | |
437 | /* sanity check: has it already been selected? This should not happen */ | |
438 | if (tmp_max > last_max) | |
439 | goto out; | |
440 | /* check if during this iteration an originator with a closer dht | |
441 | * address has already been found | |
442 | */ | |
443 | if (tmp_max < max) | |
444 | goto out; | |
445 | /* this is an hash collision with the temporary selected node. Choose | |
446 | * the one with the lowest address | |
447 | */ | |
816cd5b8 | 448 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
449 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
450 | goto out; | |
451 | ||
452 | ret = true; | |
453 | out: | |
454 | return ret; | |
455 | } | |
456 | ||
457 | /** | |
458 | * batadv_choose_next_candidate - select the next DHT candidate | |
459 | * @bat_priv: the bat priv with all the soft interface information | |
460 | * @cands: candidates array | |
461 | * @select: number of candidates already present in the array | |
462 | * @ip_key: key to look up in the DHT | |
463 | * @last_max: pointer where the address of the selected candidate will be saved | |
464 | */ | |
465 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
466 | struct batadv_dat_candidate *cands, | |
467 | int select, batadv_dat_addr_t ip_key, | |
468 | batadv_dat_addr_t *last_max) | |
469 | { | |
470 | batadv_dat_addr_t max = 0, tmp_max = 0; | |
471 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; | |
472 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
473 | struct hlist_head *head; |
474 | int i; | |
475 | ||
476 | /* if no node is eligible as candidate, leave the candidate type as | |
477 | * NOT_FOUND | |
478 | */ | |
479 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
480 | ||
93178018 | 481 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
482 | * dat_address which has not been selected yet |
483 | */ | |
484 | for (i = 0; i < hash->size; i++) { | |
485 | head = &hash->table[i]; | |
486 | ||
487 | rcu_read_lock(); | |
b67bfe0d | 488 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 489 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
490 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
491 | ip_key; | |
492 | ||
493 | if (!batadv_is_orig_node_eligible(cands, select, | |
494 | tmp_max, max, | |
495 | *last_max, orig_node, | |
496 | max_orig_node)) | |
497 | continue; | |
498 | ||
499 | if (!atomic_inc_not_zero(&orig_node->refcount)) | |
500 | continue; | |
501 | ||
502 | max = tmp_max; | |
503 | if (max_orig_node) | |
504 | batadv_orig_node_free_ref(max_orig_node); | |
505 | max_orig_node = orig_node; | |
506 | } | |
507 | rcu_read_unlock(); | |
508 | } | |
509 | if (max_orig_node) { | |
510 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
511 | cands[select].orig_node = max_orig_node; | |
512 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
513 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
514 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
515 | max); | |
516 | } | |
517 | *last_max = max; | |
518 | } | |
519 | ||
520 | /** | |
93178018 | 521 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
522 | * be sent to |
523 | * @bat_priv: the bat priv with all the soft interface information | |
524 | * @ip_dst: ipv4 to look up in the DHT | |
525 | * | |
526 | * An originator O is selected if and only if its DHT_ID value is one of three | |
527 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
528 | * value of the key. ip_dst is the key. | |
529 | * | |
93178018 | 530 | * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
531 | */ |
532 | static struct batadv_dat_candidate * | |
533 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst) | |
534 | { | |
535 | int select; | |
536 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
537 | struct batadv_dat_candidate *res; | |
538 | ||
539 | if (!bat_priv->orig_hash) | |
540 | return NULL; | |
541 | ||
542 | res = kmalloc(BATADV_DAT_CANDIDATES_NUM * sizeof(*res), GFP_ATOMIC); | |
543 | if (!res) | |
544 | return NULL; | |
545 | ||
546 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst, | |
547 | BATADV_DAT_ADDR_MAX); | |
548 | ||
549 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
550 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
551 | ip_key); | |
552 | ||
553 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
554 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
555 | &last_max); | |
556 | ||
557 | return res; | |
558 | } | |
559 | ||
560 | /** | |
561 | * batadv_dat_send_data - send a payload to the selected candidates | |
562 | * @bat_priv: the bat priv with all the soft interface information | |
563 | * @skb: payload to send | |
564 | * @ip: the DHT key | |
565 | * @packet_subtype: unicast4addr packet subtype to use | |
566 | * | |
93178018 ML |
567 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
568 | * to each of the selected candidates. | |
785ea114 | 569 | * |
93178018 ML |
570 | * Returns true if the packet is sent to at least one candidate, false |
571 | * otherwise. | |
785ea114 AQ |
572 | */ |
573 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
574 | struct sk_buff *skb, __be32 ip, | |
575 | int packet_subtype) | |
576 | { | |
577 | int i; | |
578 | bool ret = false; | |
579 | int send_status; | |
580 | struct batadv_neigh_node *neigh_node = NULL; | |
581 | struct sk_buff *tmp_skb; | |
582 | struct batadv_dat_candidate *cand; | |
583 | ||
584 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
585 | if (!cand) | |
586 | goto out; | |
587 | ||
588 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
589 | ||
590 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
591 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
592 | continue; | |
593 | ||
594 | neigh_node = batadv_orig_node_get_router(cand[i].orig_node); | |
595 | if (!neigh_node) | |
596 | goto free_orig; | |
597 | ||
598 | tmp_skb = pskb_copy(skb, GFP_ATOMIC); | |
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); | |
666 | batadv_dat_tvlv_container_update(bat_priv); | |
667 | } | |
668 | ||
669 | /** | |
670 | * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container | |
671 | * @bat_priv: the bat priv with all the soft interface information | |
672 | * @orig: the orig_node of the ogm | |
673 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
674 | * @tvlv_value: tvlv buffer containing the gateway data | |
675 | * @tvlv_value_len: tvlv buffer length | |
676 | */ | |
677 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
678 | struct batadv_orig_node *orig, | |
679 | uint8_t flags, | |
680 | void *tvlv_value, | |
681 | uint16_t tvlv_value_len) | |
682 | { | |
683 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
684 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT; | |
685 | else | |
686 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT; | |
687 | } | |
688 | ||
2f1dfbe1 AQ |
689 | /** |
690 | * batadv_dat_hash_free - free the local DAT hash table | |
691 | * @bat_priv: the bat priv with all the soft interface information | |
692 | */ | |
693 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
694 | { | |
33af49ad AQ |
695 | if (!bat_priv->dat.hash) |
696 | return; | |
697 | ||
2f1dfbe1 AQ |
698 | __batadv_dat_purge(bat_priv, NULL); |
699 | ||
700 | batadv_hash_destroy(bat_priv->dat.hash); | |
701 | ||
702 | bat_priv->dat.hash = NULL; | |
703 | } | |
704 | ||
705 | /** | |
706 | * batadv_dat_init - initialise the DAT internals | |
707 | * @bat_priv: the bat priv with all the soft interface information | |
708 | */ | |
709 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
710 | { | |
711 | if (bat_priv->dat.hash) | |
712 | return 0; | |
713 | ||
714 | bat_priv->dat.hash = batadv_hash_new(1024); | |
715 | ||
716 | if (!bat_priv->dat.hash) | |
717 | return -ENOMEM; | |
718 | ||
719 | batadv_dat_start_timer(bat_priv); | |
720 | ||
17cf0ea4 ML |
721 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
722 | NULL, BATADV_TVLV_DAT, 1, | |
723 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
724 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
725 | return 0; |
726 | } | |
727 | ||
728 | /** | |
729 | * batadv_dat_free - free the DAT internals | |
730 | * @bat_priv: the bat priv with all the soft interface information | |
731 | */ | |
732 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
733 | { | |
17cf0ea4 ML |
734 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
735 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
736 | ||
2f1dfbe1 AQ |
737 | cancel_delayed_work_sync(&bat_priv->dat.work); |
738 | ||
739 | batadv_dat_hash_free(bat_priv); | |
740 | } | |
741 | ||
742 | /** | |
743 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
744 | * @seq: seq file to print on | |
745 | * @offset: not used | |
746 | */ | |
747 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
748 | { | |
749 | struct net_device *net_dev = (struct net_device *)seq->private; | |
750 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
751 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
752 | struct batadv_dat_entry *dat_entry; | |
753 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
754 | struct hlist_head *head; |
755 | unsigned long last_seen_jiffies; | |
756 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
757 | uint32_t i; | |
758 | ||
759 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
760 | if (!primary_if) | |
761 | goto out; | |
762 | ||
763 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
be1db4f6 AQ |
764 | seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4", |
765 | "MAC", "VID", "last-seen"); | |
2f1dfbe1 AQ |
766 | |
767 | for (i = 0; i < hash->size; i++) { | |
768 | head = &hash->table[i]; | |
769 | ||
770 | rcu_read_lock(); | |
b67bfe0d | 771 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
772 | last_seen_jiffies = jiffies - dat_entry->last_update; |
773 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
774 | last_seen_mins = last_seen_msecs / 60000; | |
775 | last_seen_msecs = last_seen_msecs % 60000; | |
776 | last_seen_secs = last_seen_msecs / 1000; | |
777 | ||
be1db4f6 | 778 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 779 | &dat_entry->ip, dat_entry->mac_addr, |
be1db4f6 | 780 | BATADV_PRINT_VID(dat_entry->vid), |
2f1dfbe1 AQ |
781 | last_seen_mins, last_seen_secs); |
782 | } | |
783 | rcu_read_unlock(); | |
784 | } | |
785 | ||
786 | out: | |
787 | if (primary_if) | |
788 | batadv_hardif_free_ref(primary_if); | |
789 | return 0; | |
790 | } | |
5c3a0e55 AQ |
791 | |
792 | /** | |
793 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
794 | * @bat_priv: the bat priv with all the soft interface information | |
795 | * @skb: packet to analyse | |
796 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
797 | * | |
93178018 | 798 | * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 AQ |
799 | */ |
800 | static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv, | |
801 | struct sk_buff *skb, int hdr_size) | |
802 | { | |
803 | struct arphdr *arphdr; | |
804 | struct ethhdr *ethhdr; | |
805 | __be32 ip_src, ip_dst; | |
b618ad11 | 806 | uint8_t *hw_src, *hw_dst; |
5c3a0e55 AQ |
807 | uint16_t type = 0; |
808 | ||
809 | /* pull the ethernet header */ | |
810 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
811 | goto out; | |
812 | ||
813 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
814 | ||
815 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
816 | goto out; | |
817 | ||
818 | /* pull the ARP payload */ | |
819 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
820 | arp_hdr_len(skb->dev)))) | |
821 | goto out; | |
822 | ||
823 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
824 | ||
93178018 | 825 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
826 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
827 | goto out; | |
828 | ||
829 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
830 | goto out; | |
831 | ||
832 | if (arphdr->ar_hln != ETH_ALEN) | |
833 | goto out; | |
834 | ||
835 | if (arphdr->ar_pln != 4) | |
836 | goto out; | |
837 | ||
838 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
839 | * will simply ignore it | |
840 | */ | |
841 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
842 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
843 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
844 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
845 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
846 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
847 | goto out; |
848 | ||
b618ad11 MS |
849 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
850 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
851 | goto out; | |
852 | ||
93178018 | 853 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
854 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
855 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
856 | if (is_zero_ether_addr(hw_dst) || | |
857 | is_multicast_ether_addr(hw_dst)) | |
858 | goto out; | |
859 | } | |
860 | ||
5c3a0e55 AQ |
861 | type = ntohs(arphdr->ar_op); |
862 | out: | |
863 | return type; | |
864 | } | |
c384ea3e | 865 | |
be1db4f6 AQ |
866 | /** |
867 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
868 | * @skb: the buffer containing the packet to extract the VID from | |
869 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
870 | * | |
871 | * If the packet embedded in the skb is vlan tagged this function returns the | |
872 | * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned. | |
873 | */ | |
874 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
875 | { | |
876 | unsigned short vid; | |
877 | ||
878 | vid = batadv_get_vid(skb, *hdr_size); | |
879 | ||
880 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
881 | * If the header contained in the packet is a VLAN one (which is longer) | |
882 | * hdr_size is updated so that the functions will still skip the | |
883 | * correct amount of bytes. | |
884 | */ | |
885 | if (vid & BATADV_VLAN_HAS_TAG) | |
886 | *hdr_size += VLAN_HLEN; | |
887 | ||
888 | return vid; | |
889 | } | |
890 | ||
c384ea3e AQ |
891 | /** |
892 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
893 | * answer using DAT | |
894 | * @bat_priv: the bat priv with all the soft interface information | |
895 | * @skb: packet to check | |
896 | * | |
897 | * Returns true if the message has been sent to the dht candidates, false | |
93178018 ML |
898 | * otherwise. In case of a positive return value the message has to be enqueued |
899 | * to permit the fallback. | |
c384ea3e AQ |
900 | */ |
901 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
902 | struct sk_buff *skb) | |
903 | { | |
904 | uint16_t type = 0; | |
905 | __be32 ip_dst, ip_src; | |
906 | uint8_t *hw_src; | |
907 | bool ret = false; | |
908 | struct batadv_dat_entry *dat_entry = NULL; | |
909 | struct sk_buff *skb_new; | |
be1db4f6 AQ |
910 | int hdr_size = 0; |
911 | unsigned short vid; | |
c384ea3e | 912 | |
33af49ad AQ |
913 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
914 | goto out; | |
915 | ||
be1db4f6 AQ |
916 | vid = batadv_dat_get_vid(skb, &hdr_size); |
917 | ||
918 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
919 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
920 | * message to the selected DHT candidates | |
921 | */ | |
922 | if (type != ARPOP_REQUEST) | |
923 | goto out; | |
924 | ||
be1db4f6 AQ |
925 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
926 | "Parsing outgoing ARP REQUEST"); | |
c384ea3e | 927 | |
be1db4f6 AQ |
928 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
929 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
930 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 931 | |
be1db4f6 | 932 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 933 | |
be1db4f6 | 934 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 935 | if (dat_entry) { |
88e48d7b AQ |
936 | /* If the ARP request is destined for a local client the local |
937 | * client will answer itself. DAT would only generate a | |
938 | * duplicate packet. | |
939 | * | |
940 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
941 | * additional DAT answer may trigger kernel warnings about | |
942 | * a packet coming from the wrong port. | |
943 | */ | |
c018ad3d AQ |
944 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, |
945 | BATADV_NO_FLAGS)) { | |
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 | ||
be1db4f6 AQ |
1031 | if (vid & BATADV_VLAN_HAS_TAG) |
1032 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1033 | vid & VLAN_VID_MASK); | |
1034 | ||
93178018 ML |
1035 | /* To preserve backwards compatibility, the node has choose the outgoing |
1036 | * format based on the incoming request packet type. The assumption is | |
1037 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1038 | */ |
1039 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1040 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1041 | BATADV_P_DAT_CACHE_REPLY, | |
1042 | vid); | |
c384ea3e | 1043 | else |
e300d314 | 1044 | err = batadv_send_skb_via_tt(bat_priv, skb_new, vid); |
c384ea3e | 1045 | |
e300d314 | 1046 | if (err != NET_XMIT_DROP) { |
4046b24a | 1047 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1048 | ret = true; |
4046b24a | 1049 | } |
c384ea3e AQ |
1050 | out: |
1051 | if (dat_entry) | |
1052 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1053 | if (ret) |
1054 | kfree_skb(skb); | |
1055 | return ret; | |
1056 | } | |
1057 | ||
1058 | /** | |
1059 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1060 | * @bat_priv: the bat priv with all the soft interface information | |
1061 | * @skb: packet to check | |
1062 | */ | |
1063 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1064 | struct sk_buff *skb) | |
1065 | { | |
1066 | uint16_t type; | |
1067 | __be32 ip_src, ip_dst; | |
1068 | uint8_t *hw_src, *hw_dst; | |
be1db4f6 AQ |
1069 | int hdr_size = 0; |
1070 | unsigned short vid; | |
c384ea3e | 1071 | |
33af49ad AQ |
1072 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1073 | return; | |
1074 | ||
be1db4f6 AQ |
1075 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1076 | ||
1077 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1078 | if (type != ARPOP_REPLY) |
1079 | return; | |
1080 | ||
be1db4f6 AQ |
1081 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
1082 | "Parsing outgoing ARP REPLY"); | |
c384ea3e | 1083 | |
be1db4f6 AQ |
1084 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1085 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1086 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1087 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1088 | |
be1db4f6 AQ |
1089 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1090 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1091 | |
1092 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1093 | * the node obtained from the ARP reply |
c384ea3e AQ |
1094 | */ |
1095 | batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT); | |
1096 | batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT); | |
1097 | } | |
1098 | /** | |
1099 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1100 | * DAT storage only | |
1101 | * @bat_priv: the bat priv with all the soft interface information | |
1102 | * @skb: packet to check | |
93178018 | 1103 | * @hdr_size: size of the encapsulation header |
c384ea3e AQ |
1104 | */ |
1105 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1106 | struct sk_buff *skb, int hdr_size) | |
1107 | { | |
1108 | uint16_t type; | |
1109 | __be32 ip_src, ip_dst; | |
1110 | uint8_t *hw_src, *hw_dst; | |
1111 | bool ret = false; | |
be1db4f6 | 1112 | unsigned short vid; |
c384ea3e | 1113 | |
33af49ad AQ |
1114 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1115 | goto out; | |
1116 | ||
be1db4f6 AQ |
1117 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1118 | ||
c384ea3e AQ |
1119 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1120 | if (type != ARPOP_REPLY) | |
1121 | goto out; | |
1122 | ||
1123 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1124 | "Parsing incoming ARP REPLY"); | |
1125 | ||
1126 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1127 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1128 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1129 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1130 | ||
1131 | /* Update our internal cache with both the IP addresses the node got | |
1132 | * within the ARP reply | |
1133 | */ | |
be1db4f6 AQ |
1134 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1135 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1136 | |
1137 | /* if this REPLY is directed to a client of mine, let's deliver the | |
1138 | * packet to the interface | |
1139 | */ | |
be1db4f6 | 1140 | ret = !batadv_is_my_client(bat_priv, hw_dst, vid); |
c384ea3e | 1141 | out: |
0d15bece MS |
1142 | if (ret) |
1143 | kfree_skb(skb); | |
c384ea3e AQ |
1144 | /* if ret == false -> packet has to be delivered to the interface */ |
1145 | return ret; | |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1150 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1151 | * @bat_priv: the bat priv with all the soft interface information |
1152 | * @forw_packet: the broadcast packet | |
1153 | * | |
93178018 | 1154 | * Returns true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1155 | */ |
1156 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1157 | struct batadv_forw_packet *forw_packet) | |
1158 | { | |
1159 | uint16_t type; | |
1160 | __be32 ip_dst; | |
1161 | struct batadv_dat_entry *dat_entry = NULL; | |
1162 | bool ret = false; | |
be1db4f6 AQ |
1163 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1164 | unsigned short vid; | |
c384ea3e | 1165 | |
33af49ad AQ |
1166 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1167 | goto out; | |
1168 | ||
c384ea3e AQ |
1169 | /* If this packet is an ARP_REQUEST and the node already has the |
1170 | * information that it is going to ask, then the packet can be dropped | |
1171 | */ | |
1172 | if (forw_packet->num_packets) | |
1173 | goto out; | |
1174 | ||
be1db4f6 AQ |
1175 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1176 | ||
1177 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1178 | if (type != ARPOP_REQUEST) |
1179 | goto out; | |
1180 | ||
be1db4f6 AQ |
1181 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1182 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1183 | /* check if the node already got this entry */ |
1184 | if (!dat_entry) { | |
1185 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1186 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1187 | goto out; | |
1188 | } | |
1189 | ||
1190 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1191 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1192 | ret = true; | |
1193 | ||
1194 | out: | |
1195 | if (dat_entry) | |
1196 | batadv_dat_entry_free_ref(dat_entry); | |
1197 | return ret; | |
1198 | } |