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9f6446c7 | 1 | /* Copyright (C) 2011-2015 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 | ||
1e2c2a4f SE |
18 | #include "distributed-arp-table.h" |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/atomic.h> | |
22 | #include <linux/byteorder/generic.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/etherdevice.h> | |
25 | #include <linux/fs.h> | |
785ea114 | 26 | #include <linux/if_arp.h> |
1e2c2a4f | 27 | #include <linux/if_ether.h> |
be1db4f6 | 28 | #include <linux/if_vlan.h> |
1e2c2a4f SE |
29 | #include <linux/in.h> |
30 | #include <linux/jiffies.h> | |
31 | #include <linux/kernel.h> | |
32 | #include <linux/list.h> | |
33 | #include <linux/rculist.h> | |
34 | #include <linux/rcupdate.h> | |
35 | #include <linux/seq_file.h> | |
36 | #include <linux/skbuff.h> | |
37 | #include <linux/slab.h> | |
38 | #include <linux/spinlock.h> | |
39 | #include <linux/stddef.h> | |
40 | #include <linux/string.h> | |
41 | #include <linux/workqueue.h> | |
c384ea3e | 42 | #include <net/arp.h> |
785ea114 | 43 | |
785ea114 | 44 | #include "hard-interface.h" |
1e2c2a4f | 45 | #include "hash.h" |
785ea114 AQ |
46 | #include "originator.h" |
47 | #include "send.h" | |
c384ea3e | 48 | #include "translation-table.h" |
785ea114 | 49 | |
2f1dfbe1 AQ |
50 | static void batadv_dat_purge(struct work_struct *work); |
51 | ||
52 | /** | |
53 | * batadv_dat_start_timer - initialise the DAT periodic worker | |
54 | * @bat_priv: the bat priv with all the soft interface information | |
55 | */ | |
56 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
57 | { | |
58 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
59 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
60 | msecs_to_jiffies(10000)); | |
61 | } | |
62 | ||
63 | /** | |
93178018 | 64 | * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly |
2f1dfbe1 | 65 | * free it |
93178018 | 66 | * @dat_entry: the entry to free |
2f1dfbe1 AQ |
67 | */ |
68 | static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry) | |
69 | { | |
70 | if (atomic_dec_and_test(&dat_entry->refcount)) | |
71 | kfree_rcu(dat_entry, rcu); | |
72 | } | |
73 | ||
74 | /** | |
93178018 | 75 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
76 | * @dat_entry: the entry to check |
77 | * | |
93178018 | 78 | * Returns true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
79 | */ |
80 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
81 | { | |
82 | return batadv_has_timed_out(dat_entry->last_update, | |
83 | BATADV_DAT_ENTRY_TIMEOUT); | |
84 | } | |
85 | ||
86 | /** | |
87 | * __batadv_dat_purge - delete entries from the DAT local storage | |
88 | * @bat_priv: the bat priv with all the soft interface information | |
89 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
90 | * not. This function takes the dat_entry as argument and has to | |
91 | * returns a boolean value: true is the entry has to be deleted, | |
92 | * false otherwise | |
93 | * | |
93178018 ML |
94 | * Loops over each entry in the DAT local storage and deletes it if and only if |
95 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
96 | */ |
97 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
98 | bool (*to_purge)(struct batadv_dat_entry *)) | |
99 | { | |
100 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
101 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 102 | struct hlist_node *node_tmp; |
2f1dfbe1 AQ |
103 | struct hlist_head *head; |
104 | uint32_t i; | |
105 | ||
106 | if (!bat_priv->dat.hash) | |
107 | return; | |
108 | ||
109 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
110 | head = &bat_priv->dat.hash->table[i]; | |
111 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
112 | ||
113 | spin_lock_bh(list_lock); | |
b67bfe0d | 114 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 115 | hash_entry) { |
93178018 | 116 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
117 | * ask it if the entry has to be purged or not |
118 | */ | |
119 | if (to_purge && !to_purge(dat_entry)) | |
120 | continue; | |
121 | ||
b67bfe0d | 122 | hlist_del_rcu(&dat_entry->hash_entry); |
2f1dfbe1 AQ |
123 | batadv_dat_entry_free_ref(dat_entry); |
124 | } | |
125 | spin_unlock_bh(list_lock); | |
126 | } | |
127 | } | |
128 | ||
129 | /** | |
130 | * batadv_dat_purge - periodic task that deletes old entries from the local DAT | |
131 | * hash table | |
132 | * @work: kernel work struct | |
133 | */ | |
134 | static void batadv_dat_purge(struct work_struct *work) | |
135 | { | |
136 | struct delayed_work *delayed_work; | |
137 | struct batadv_priv_dat *priv_dat; | |
138 | struct batadv_priv *bat_priv; | |
139 | ||
140 | delayed_work = container_of(work, struct delayed_work, work); | |
141 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); | |
142 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
143 | ||
144 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
145 | batadv_dat_start_timer(bat_priv); | |
146 | } | |
147 | ||
148 | /** | |
149 | * batadv_compare_dat - comparing function used in the local DAT hash table | |
150 | * @node: node in the local table | |
151 | * @data2: second object to compare the node to | |
152 | * | |
93178018 | 153 | * Returns 1 if the two entries are the same, 0 otherwise. |
2f1dfbe1 AQ |
154 | */ |
155 | static int batadv_compare_dat(const struct hlist_node *node, const void *data2) | |
156 | { | |
157 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
158 | hash_entry); | |
159 | ||
36484f84 | 160 | return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0; |
2f1dfbe1 AQ |
161 | } |
162 | ||
5c3a0e55 AQ |
163 | /** |
164 | * batadv_arp_hw_src - extract the hw_src field from an ARP packet | |
165 | * @skb: ARP packet | |
166 | * @hdr_size: size of the possible header before the ARP packet | |
167 | * | |
93178018 | 168 | * Returns the value of the hw_src field in the ARP packet. |
5c3a0e55 AQ |
169 | */ |
170 | static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) | |
171 | { | |
172 | uint8_t *addr; | |
173 | ||
174 | addr = (uint8_t *)(skb->data + hdr_size); | |
175 | addr += ETH_HLEN + sizeof(struct arphdr); | |
176 | ||
177 | return addr; | |
178 | } | |
179 | ||
180 | /** | |
181 | * batadv_arp_ip_src - extract the ip_src field from an ARP packet | |
182 | * @skb: ARP packet | |
183 | * @hdr_size: size of the possible header before the ARP packet | |
184 | * | |
93178018 | 185 | * Returns the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
186 | */ |
187 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
188 | { | |
189 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
190 | } | |
191 | ||
192 | /** | |
193 | * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet | |
194 | * @skb: ARP packet | |
195 | * @hdr_size: size of the possible header before the ARP packet | |
196 | * | |
93178018 | 197 | * Returns the value of the hw_dst field in the ARP packet. |
5c3a0e55 AQ |
198 | */ |
199 | static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) | |
200 | { | |
201 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
202 | } | |
203 | ||
204 | /** | |
205 | * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet | |
206 | * @skb: ARP packet | |
207 | * @hdr_size: size of the possible header before the ARP packet | |
208 | * | |
93178018 | 209 | * Returns the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
210 | */ |
211 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
212 | { | |
213 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
214 | } | |
215 | ||
785ea114 AQ |
216 | /** |
217 | * batadv_hash_dat - compute the hash value for an IP address | |
218 | * @data: data to hash | |
219 | * @size: size of the hash table | |
220 | * | |
93178018 | 221 | * Returns the selected index in the hash table for the given data. |
785ea114 AQ |
222 | */ |
223 | static uint32_t batadv_hash_dat(const void *data, uint32_t size) | |
224 | { | |
785ea114 | 225 | uint32_t hash = 0; |
be1db4f6 | 226 | const struct batadv_dat_entry *dat = data; |
36fd61cb SE |
227 | const unsigned char *key; |
228 | uint32_t i; | |
229 | ||
230 | key = (const unsigned char *)&dat->ip; | |
231 | for (i = 0; i < sizeof(dat->ip); i++) { | |
232 | hash += key[i]; | |
233 | hash += (hash << 10); | |
234 | hash ^= (hash >> 6); | |
235 | } | |
785ea114 | 236 | |
36fd61cb SE |
237 | key = (const unsigned char *)&dat->vid; |
238 | for (i = 0; i < sizeof(dat->vid); i++) { | |
239 | hash += key[i]; | |
240 | hash += (hash << 10); | |
241 | hash ^= (hash >> 6); | |
242 | } | |
785ea114 AQ |
243 | |
244 | hash += (hash << 3); | |
245 | hash ^= (hash >> 11); | |
246 | hash += (hash << 15); | |
247 | ||
248 | return hash % size; | |
249 | } | |
250 | ||
2f1dfbe1 | 251 | /** |
93178018 | 252 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
253 | * table |
254 | * @bat_priv: the bat priv with all the soft interface information | |
255 | * @ip: search key | |
be1db4f6 | 256 | * @vid: VLAN identifier |
2f1dfbe1 | 257 | * |
93178018 | 258 | * Returns the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
259 | */ |
260 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
261 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
262 | unsigned short vid) | |
2f1dfbe1 AQ |
263 | { |
264 | struct hlist_head *head; | |
be1db4f6 | 265 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 AQ |
266 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
267 | uint32_t index; | |
268 | ||
269 | if (!hash) | |
270 | return NULL; | |
271 | ||
be1db4f6 AQ |
272 | to_find.ip = ip; |
273 | to_find.vid = vid; | |
274 | ||
275 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
276 | head = &hash->table[index]; |
277 | ||
278 | rcu_read_lock(); | |
b67bfe0d | 279 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
280 | if (dat_entry->ip != ip) |
281 | continue; | |
282 | ||
283 | if (!atomic_inc_not_zero(&dat_entry->refcount)) | |
284 | continue; | |
285 | ||
286 | dat_entry_tmp = dat_entry; | |
287 | break; | |
288 | } | |
289 | rcu_read_unlock(); | |
290 | ||
291 | return dat_entry_tmp; | |
292 | } | |
293 | ||
294 | /** | |
295 | * batadv_dat_entry_add - add a new dat entry or update it if already exists | |
296 | * @bat_priv: the bat priv with all the soft interface information | |
297 | * @ip: ipv4 to add/edit | |
298 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 299 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
300 | */ |
301 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
be1db4f6 | 302 | uint8_t *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
303 | { |
304 | struct batadv_dat_entry *dat_entry; | |
305 | int hash_added; | |
306 | ||
be1db4f6 | 307 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
308 | /* if this entry is already known, just update it */ |
309 | if (dat_entry) { | |
310 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 311 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
312 | dat_entry->last_update = jiffies; |
313 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
314 | "Entry updated: %pI4 %pM (vid: %d)\n", |
315 | &dat_entry->ip, dat_entry->mac_addr, | |
316 | BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
317 | goto out; |
318 | } | |
319 | ||
320 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
321 | if (!dat_entry) | |
322 | goto out; | |
323 | ||
324 | dat_entry->ip = ip; | |
be1db4f6 | 325 | dat_entry->vid = vid; |
8fdd0153 | 326 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
327 | dat_entry->last_update = jiffies; |
328 | atomic_set(&dat_entry->refcount, 2); | |
329 | ||
330 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, | |
be1db4f6 | 331 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
332 | &dat_entry->hash_entry); |
333 | ||
334 | if (unlikely(hash_added != 0)) { | |
335 | /* remove the reference for the hash */ | |
336 | batadv_dat_entry_free_ref(dat_entry); | |
337 | goto out; | |
338 | } | |
339 | ||
be1db4f6 AQ |
340 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
341 | &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
342 | |
343 | out: | |
344 | if (dat_entry) | |
345 | batadv_dat_entry_free_ref(dat_entry); | |
346 | } | |
347 | ||
5c3a0e55 AQ |
348 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
349 | ||
350 | /** | |
351 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
352 | * @bat_priv: the bat priv with all the soft interface information | |
353 | * @skb: ARP packet | |
354 | * @type: ARP type | |
355 | * @hdr_size: size of the possible header before the ARP packet | |
356 | * @msg: message to print together with the debugging information | |
357 | */ | |
358 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
359 | uint16_t type, int hdr_size, char *msg) | |
360 | { | |
361 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
362 | struct batadv_bcast_packet *bcast_pkt; | |
363 | uint8_t *orig_addr; | |
364 | __be32 ip_src, ip_dst; | |
365 | ||
366 | if (msg) | |
367 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
368 | ||
369 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
370 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
371 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
372 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
373 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
374 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
375 | ||
376 | if (hdr_size == 0) | |
377 | return; | |
378 | ||
5c3a0e55 AQ |
379 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
380 | ||
a40d9b07 | 381 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
382 | case BATADV_UNICAST: |
383 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
384 | "* encapsulated within a UNICAST packet\n"); | |
385 | break; | |
386 | case BATADV_UNICAST_4ADDR: | |
387 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
388 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
389 | unicast_4addr_packet->src); | |
390 | switch (unicast_4addr_packet->subtype) { | |
391 | case BATADV_P_DAT_DHT_PUT: | |
392 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
393 | break; | |
394 | case BATADV_P_DAT_DHT_GET: | |
395 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
396 | break; | |
397 | case BATADV_P_DAT_CACHE_REPLY: | |
398 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
399 | "* type: DAT_CACHE_REPLY\n"); | |
400 | break; | |
401 | case BATADV_P_DATA: | |
402 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
403 | break; | |
404 | default: | |
405 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 406 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
407 | } |
408 | break; | |
409 | case BATADV_BCAST: | |
410 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
411 | orig_addr = bcast_pkt->orig; | |
412 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
413 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
414 | orig_addr); | |
415 | break; | |
416 | default: | |
417 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
418 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 419 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
420 | } |
421 | } | |
422 | ||
423 | #else | |
424 | ||
425 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
426 | uint16_t type, int hdr_size, char *msg) | |
427 | { | |
428 | } | |
429 | ||
430 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
431 | ||
785ea114 AQ |
432 | /** |
433 | * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate | |
434 | * @res: the array with the already selected candidates | |
435 | * @select: number of already selected candidates | |
436 | * @tmp_max: address of the currently evaluated node | |
437 | * @max: current round max address | |
438 | * @last_max: address of the last selected candidate | |
439 | * @candidate: orig_node under evaluation | |
440 | * @max_orig_node: last selected candidate | |
441 | * | |
93178018 ML |
442 | * Returns true if the node has been elected as next candidate or false |
443 | * otherwise. | |
785ea114 AQ |
444 | */ |
445 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
446 | int select, batadv_dat_addr_t tmp_max, | |
447 | batadv_dat_addr_t max, | |
448 | batadv_dat_addr_t last_max, | |
449 | struct batadv_orig_node *candidate, | |
450 | struct batadv_orig_node *max_orig_node) | |
451 | { | |
452 | bool ret = false; | |
453 | int j; | |
454 | ||
17cf0ea4 ML |
455 | /* check if orig node candidate is running DAT */ |
456 | if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT)) | |
457 | goto out; | |
458 | ||
785ea114 AQ |
459 | /* Check if this node has already been selected... */ |
460 | for (j = 0; j < select; j++) | |
461 | if (res[j].orig_node == candidate) | |
462 | break; | |
463 | /* ..and possibly skip it */ | |
464 | if (j < select) | |
465 | goto out; | |
466 | /* sanity check: has it already been selected? This should not happen */ | |
467 | if (tmp_max > last_max) | |
468 | goto out; | |
469 | /* check if during this iteration an originator with a closer dht | |
470 | * address has already been found | |
471 | */ | |
472 | if (tmp_max < max) | |
473 | goto out; | |
474 | /* this is an hash collision with the temporary selected node. Choose | |
475 | * the one with the lowest address | |
476 | */ | |
816cd5b8 | 477 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
478 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
479 | goto out; | |
480 | ||
481 | ret = true; | |
482 | out: | |
483 | return ret; | |
484 | } | |
485 | ||
486 | /** | |
487 | * batadv_choose_next_candidate - select the next DHT candidate | |
488 | * @bat_priv: the bat priv with all the soft interface information | |
489 | * @cands: candidates array | |
490 | * @select: number of candidates already present in the array | |
491 | * @ip_key: key to look up in the DHT | |
492 | * @last_max: pointer where the address of the selected candidate will be saved | |
493 | */ | |
494 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
495 | struct batadv_dat_candidate *cands, | |
496 | int select, batadv_dat_addr_t ip_key, | |
497 | batadv_dat_addr_t *last_max) | |
498 | { | |
499 | batadv_dat_addr_t max = 0, tmp_max = 0; | |
500 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; | |
501 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
502 | struct hlist_head *head; |
503 | int i; | |
504 | ||
505 | /* if no node is eligible as candidate, leave the candidate type as | |
506 | * NOT_FOUND | |
507 | */ | |
508 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
509 | ||
93178018 | 510 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
511 | * dat_address which has not been selected yet |
512 | */ | |
513 | for (i = 0; i < hash->size; i++) { | |
514 | head = &hash->table[i]; | |
515 | ||
516 | rcu_read_lock(); | |
b67bfe0d | 517 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 518 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
519 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
520 | ip_key; | |
521 | ||
522 | if (!batadv_is_orig_node_eligible(cands, select, | |
523 | tmp_max, max, | |
524 | *last_max, orig_node, | |
525 | max_orig_node)) | |
526 | continue; | |
527 | ||
528 | if (!atomic_inc_not_zero(&orig_node->refcount)) | |
529 | continue; | |
530 | ||
531 | max = tmp_max; | |
532 | if (max_orig_node) | |
533 | batadv_orig_node_free_ref(max_orig_node); | |
534 | max_orig_node = orig_node; | |
535 | } | |
536 | rcu_read_unlock(); | |
537 | } | |
538 | if (max_orig_node) { | |
539 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
540 | cands[select].orig_node = max_orig_node; | |
541 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
542 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
543 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
544 | max); | |
545 | } | |
546 | *last_max = max; | |
547 | } | |
548 | ||
549 | /** | |
93178018 | 550 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
551 | * be sent to |
552 | * @bat_priv: the bat priv with all the soft interface information | |
553 | * @ip_dst: ipv4 to look up in the DHT | |
554 | * | |
555 | * An originator O is selected if and only if its DHT_ID value is one of three | |
556 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
557 | * value of the key. ip_dst is the key. | |
558 | * | |
93178018 | 559 | * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
560 | */ |
561 | static struct batadv_dat_candidate * | |
562 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst) | |
563 | { | |
564 | int select; | |
565 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
566 | struct batadv_dat_candidate *res; | |
567 | ||
568 | if (!bat_priv->orig_hash) | |
569 | return NULL; | |
570 | ||
0185dda6 AQ |
571 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
572 | GFP_ATOMIC); | |
785ea114 AQ |
573 | if (!res) |
574 | return NULL; | |
575 | ||
576 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst, | |
577 | BATADV_DAT_ADDR_MAX); | |
578 | ||
579 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
580 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
581 | ip_key); | |
582 | ||
583 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
584 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
585 | &last_max); | |
586 | ||
587 | return res; | |
588 | } | |
589 | ||
590 | /** | |
591 | * batadv_dat_send_data - send a payload to the selected candidates | |
592 | * @bat_priv: the bat priv with all the soft interface information | |
593 | * @skb: payload to send | |
594 | * @ip: the DHT key | |
595 | * @packet_subtype: unicast4addr packet subtype to use | |
596 | * | |
93178018 ML |
597 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
598 | * to each of the selected candidates. | |
785ea114 | 599 | * |
93178018 ML |
600 | * Returns true if the packet is sent to at least one candidate, false |
601 | * otherwise. | |
785ea114 AQ |
602 | */ |
603 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
604 | struct sk_buff *skb, __be32 ip, | |
605 | int packet_subtype) | |
606 | { | |
607 | int i; | |
608 | bool ret = false; | |
609 | int send_status; | |
610 | struct batadv_neigh_node *neigh_node = NULL; | |
611 | struct sk_buff *tmp_skb; | |
612 | struct batadv_dat_candidate *cand; | |
613 | ||
614 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
615 | if (!cand) | |
616 | goto out; | |
617 | ||
618 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
619 | ||
620 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
621 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
622 | continue; | |
623 | ||
7351a482 SW |
624 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
625 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
626 | if (!neigh_node) |
627 | goto free_orig; | |
628 | ||
bad93e9d | 629 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
630 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
631 | cand[i].orig_node, | |
632 | packet_subtype)) { | |
785ea114 AQ |
633 | kfree_skb(tmp_skb); |
634 | goto free_neigh; | |
635 | } | |
636 | ||
637 | send_status = batadv_send_skb_packet(tmp_skb, | |
638 | neigh_node->if_incoming, | |
639 | neigh_node->addr); | |
4046b24a MH |
640 | if (send_status == NET_XMIT_SUCCESS) { |
641 | /* count the sent packet */ | |
642 | switch (packet_subtype) { | |
643 | case BATADV_P_DAT_DHT_GET: | |
644 | batadv_inc_counter(bat_priv, | |
645 | BATADV_CNT_DAT_GET_TX); | |
646 | break; | |
647 | case BATADV_P_DAT_DHT_PUT: | |
648 | batadv_inc_counter(bat_priv, | |
649 | BATADV_CNT_DAT_PUT_TX); | |
650 | break; | |
651 | } | |
652 | ||
785ea114 AQ |
653 | /* packet sent to a candidate: return true */ |
654 | ret = true; | |
4046b24a | 655 | } |
785ea114 AQ |
656 | free_neigh: |
657 | batadv_neigh_node_free_ref(neigh_node); | |
658 | free_orig: | |
659 | batadv_orig_node_free_ref(cand[i].orig_node); | |
660 | } | |
661 | ||
662 | out: | |
663 | kfree(cand); | |
664 | return ret; | |
665 | } | |
2f1dfbe1 | 666 | |
17cf0ea4 ML |
667 | /** |
668 | * batadv_dat_tvlv_container_update - update the dat tvlv container after dat | |
669 | * setting change | |
670 | * @bat_priv: the bat priv with all the soft interface information | |
671 | */ | |
672 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
673 | { | |
674 | char dat_mode; | |
675 | ||
676 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
677 | ||
678 | switch (dat_mode) { | |
679 | case 0: | |
680 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
681 | break; | |
682 | case 1: | |
683 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
684 | NULL, 0); | |
685 | break; | |
686 | } | |
687 | } | |
688 | ||
689 | /** | |
690 | * batadv_dat_status_update - update the dat tvlv container after dat | |
691 | * setting change | |
692 | * @net_dev: the soft interface net device | |
693 | */ | |
694 | void batadv_dat_status_update(struct net_device *net_dev) | |
695 | { | |
696 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 697 | |
17cf0ea4 ML |
698 | batadv_dat_tvlv_container_update(bat_priv); |
699 | } | |
700 | ||
701 | /** | |
702 | * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container | |
703 | * @bat_priv: the bat priv with all the soft interface information | |
704 | * @orig: the orig_node of the ogm | |
705 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
706 | * @tvlv_value: tvlv buffer containing the gateway data | |
707 | * @tvlv_value_len: tvlv buffer length | |
708 | */ | |
709 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
710 | struct batadv_orig_node *orig, | |
711 | uint8_t flags, | |
712 | void *tvlv_value, | |
713 | uint16_t tvlv_value_len) | |
714 | { | |
715 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
716 | orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT; | |
717 | else | |
718 | orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT; | |
719 | } | |
720 | ||
2f1dfbe1 AQ |
721 | /** |
722 | * batadv_dat_hash_free - free the local DAT hash table | |
723 | * @bat_priv: the bat priv with all the soft interface information | |
724 | */ | |
725 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
726 | { | |
33af49ad AQ |
727 | if (!bat_priv->dat.hash) |
728 | return; | |
729 | ||
2f1dfbe1 AQ |
730 | __batadv_dat_purge(bat_priv, NULL); |
731 | ||
732 | batadv_hash_destroy(bat_priv->dat.hash); | |
733 | ||
734 | bat_priv->dat.hash = NULL; | |
735 | } | |
736 | ||
737 | /** | |
738 | * batadv_dat_init - initialise the DAT internals | |
739 | * @bat_priv: the bat priv with all the soft interface information | |
740 | */ | |
741 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
742 | { | |
743 | if (bat_priv->dat.hash) | |
744 | return 0; | |
745 | ||
746 | bat_priv->dat.hash = batadv_hash_new(1024); | |
747 | ||
748 | if (!bat_priv->dat.hash) | |
749 | return -ENOMEM; | |
750 | ||
751 | batadv_dat_start_timer(bat_priv); | |
752 | ||
17cf0ea4 ML |
753 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
754 | NULL, BATADV_TVLV_DAT, 1, | |
755 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
756 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
757 | return 0; |
758 | } | |
759 | ||
760 | /** | |
761 | * batadv_dat_free - free the DAT internals | |
762 | * @bat_priv: the bat priv with all the soft interface information | |
763 | */ | |
764 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
765 | { | |
17cf0ea4 ML |
766 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
767 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
768 | ||
2f1dfbe1 AQ |
769 | cancel_delayed_work_sync(&bat_priv->dat.work); |
770 | ||
771 | batadv_dat_hash_free(bat_priv); | |
772 | } | |
773 | ||
774 | /** | |
775 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
776 | * @seq: seq file to print on | |
777 | * @offset: not used | |
778 | */ | |
779 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
780 | { | |
781 | struct net_device *net_dev = (struct net_device *)seq->private; | |
782 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
783 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
784 | struct batadv_dat_entry *dat_entry; | |
785 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
786 | struct hlist_head *head; |
787 | unsigned long last_seen_jiffies; | |
788 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
789 | uint32_t i; | |
790 | ||
791 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
792 | if (!primary_if) | |
793 | goto out; | |
794 | ||
795 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
be1db4f6 AQ |
796 | seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4", |
797 | "MAC", "VID", "last-seen"); | |
2f1dfbe1 AQ |
798 | |
799 | for (i = 0; i < hash->size; i++) { | |
800 | head = &hash->table[i]; | |
801 | ||
802 | rcu_read_lock(); | |
b67bfe0d | 803 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
804 | last_seen_jiffies = jiffies - dat_entry->last_update; |
805 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
806 | last_seen_mins = last_seen_msecs / 60000; | |
807 | last_seen_msecs = last_seen_msecs % 60000; | |
808 | last_seen_secs = last_seen_msecs / 1000; | |
809 | ||
be1db4f6 | 810 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 811 | &dat_entry->ip, dat_entry->mac_addr, |
be1db4f6 | 812 | BATADV_PRINT_VID(dat_entry->vid), |
2f1dfbe1 AQ |
813 | last_seen_mins, last_seen_secs); |
814 | } | |
815 | rcu_read_unlock(); | |
816 | } | |
817 | ||
818 | out: | |
819 | if (primary_if) | |
820 | batadv_hardif_free_ref(primary_if); | |
821 | return 0; | |
822 | } | |
5c3a0e55 AQ |
823 | |
824 | /** | |
825 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
826 | * @bat_priv: the bat priv with all the soft interface information | |
827 | * @skb: packet to analyse | |
828 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
829 | * | |
93178018 | 830 | * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 AQ |
831 | */ |
832 | static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv, | |
833 | struct sk_buff *skb, int hdr_size) | |
834 | { | |
835 | struct arphdr *arphdr; | |
836 | struct ethhdr *ethhdr; | |
837 | __be32 ip_src, ip_dst; | |
b618ad11 | 838 | uint8_t *hw_src, *hw_dst; |
5c3a0e55 AQ |
839 | uint16_t type = 0; |
840 | ||
841 | /* pull the ethernet header */ | |
842 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
843 | goto out; | |
844 | ||
845 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
846 | ||
847 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
848 | goto out; | |
849 | ||
850 | /* pull the ARP payload */ | |
851 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
852 | arp_hdr_len(skb->dev)))) | |
853 | goto out; | |
854 | ||
855 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
856 | ||
93178018 | 857 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
858 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
859 | goto out; | |
860 | ||
861 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
862 | goto out; | |
863 | ||
864 | if (arphdr->ar_hln != ETH_ALEN) | |
865 | goto out; | |
866 | ||
867 | if (arphdr->ar_pln != 4) | |
868 | goto out; | |
869 | ||
870 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
871 | * will simply ignore it | |
872 | */ | |
873 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
874 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
875 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
876 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
877 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
878 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
879 | goto out; |
880 | ||
b618ad11 MS |
881 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
882 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
883 | goto out; | |
884 | ||
93178018 | 885 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
886 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
887 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
888 | if (is_zero_ether_addr(hw_dst) || | |
889 | is_multicast_ether_addr(hw_dst)) | |
890 | goto out; | |
891 | } | |
892 | ||
5c3a0e55 AQ |
893 | type = ntohs(arphdr->ar_op); |
894 | out: | |
895 | return type; | |
896 | } | |
c384ea3e | 897 | |
be1db4f6 AQ |
898 | /** |
899 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
900 | * @skb: the buffer containing the packet to extract the VID from | |
901 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
902 | * | |
903 | * If the packet embedded in the skb is vlan tagged this function returns the | |
904 | * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned. | |
905 | */ | |
906 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
907 | { | |
908 | unsigned short vid; | |
909 | ||
910 | vid = batadv_get_vid(skb, *hdr_size); | |
911 | ||
912 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
913 | * If the header contained in the packet is a VLAN one (which is longer) | |
914 | * hdr_size is updated so that the functions will still skip the | |
915 | * correct amount of bytes. | |
916 | */ | |
917 | if (vid & BATADV_VLAN_HAS_TAG) | |
918 | *hdr_size += VLAN_HLEN; | |
919 | ||
920 | return vid; | |
921 | } | |
922 | ||
c384ea3e AQ |
923 | /** |
924 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
925 | * answer using DAT | |
926 | * @bat_priv: the bat priv with all the soft interface information | |
927 | * @skb: packet to check | |
928 | * | |
929 | * Returns true if the message has been sent to the dht candidates, false | |
93178018 ML |
930 | * otherwise. In case of a positive return value the message has to be enqueued |
931 | * to permit the fallback. | |
c384ea3e AQ |
932 | */ |
933 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
934 | struct sk_buff *skb) | |
935 | { | |
936 | uint16_t type = 0; | |
937 | __be32 ip_dst, ip_src; | |
938 | uint8_t *hw_src; | |
939 | bool ret = false; | |
940 | struct batadv_dat_entry *dat_entry = NULL; | |
941 | struct sk_buff *skb_new; | |
be1db4f6 AQ |
942 | int hdr_size = 0; |
943 | unsigned short vid; | |
c384ea3e | 944 | |
33af49ad AQ |
945 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
946 | goto out; | |
947 | ||
be1db4f6 AQ |
948 | vid = batadv_dat_get_vid(skb, &hdr_size); |
949 | ||
950 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
951 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
952 | * message to the selected DHT candidates | |
953 | */ | |
954 | if (type != ARPOP_REQUEST) | |
955 | goto out; | |
956 | ||
be1db4f6 AQ |
957 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
958 | "Parsing outgoing ARP REQUEST"); | |
c384ea3e | 959 | |
be1db4f6 AQ |
960 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
961 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
962 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 963 | |
be1db4f6 | 964 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 965 | |
be1db4f6 | 966 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 967 | if (dat_entry) { |
88e48d7b AQ |
968 | /* If the ARP request is destined for a local client the local |
969 | * client will answer itself. DAT would only generate a | |
970 | * duplicate packet. | |
971 | * | |
972 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
973 | * additional DAT answer may trigger kernel warnings about | |
974 | * a packet coming from the wrong port. | |
975 | */ | |
cc2f3386 | 976 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
977 | ret = true; |
978 | goto out; | |
979 | } | |
980 | ||
c384ea3e | 981 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 982 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
983 | dat_entry->mac_addr, hw_src); |
984 | if (!skb_new) | |
985 | goto out; | |
986 | ||
be1db4f6 AQ |
987 | if (vid & BATADV_VLAN_HAS_TAG) |
988 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
989 | vid & VLAN_VID_MASK); | |
990 | ||
c384ea3e AQ |
991 | skb_reset_mac_header(skb_new); |
992 | skb_new->protocol = eth_type_trans(skb_new, | |
736292c2 | 993 | bat_priv->soft_iface); |
c384ea3e | 994 | bat_priv->stats.rx_packets++; |
be1db4f6 | 995 | bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size; |
736292c2 | 996 | bat_priv->soft_iface->last_rx = jiffies; |
c384ea3e AQ |
997 | |
998 | netif_rx(skb_new); | |
999 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
1000 | ret = true; | |
1001 | } else { | |
93178018 | 1002 | /* Send the request to the DHT */ |
c384ea3e AQ |
1003 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, |
1004 | BATADV_P_DAT_DHT_GET); | |
1005 | } | |
1006 | out: | |
1007 | if (dat_entry) | |
1008 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1009 | return ret; |
1010 | } | |
1011 | ||
1012 | /** | |
1013 | * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to | |
1014 | * answer using the local DAT storage | |
1015 | * @bat_priv: the bat priv with all the soft interface information | |
1016 | * @skb: packet to check | |
1017 | * @hdr_size: size of the encapsulation header | |
1018 | * | |
93178018 | 1019 | * Returns true if the request has been answered, false otherwise. |
c384ea3e AQ |
1020 | */ |
1021 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
1022 | struct sk_buff *skb, int hdr_size) | |
1023 | { | |
1024 | uint16_t type; | |
1025 | __be32 ip_src, ip_dst; | |
1026 | uint8_t *hw_src; | |
1027 | struct sk_buff *skb_new; | |
c384ea3e AQ |
1028 | struct batadv_dat_entry *dat_entry = NULL; |
1029 | bool ret = false; | |
be1db4f6 | 1030 | unsigned short vid; |
c384ea3e AQ |
1031 | int err; |
1032 | ||
33af49ad AQ |
1033 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1034 | goto out; | |
1035 | ||
be1db4f6 AQ |
1036 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1037 | ||
c384ea3e AQ |
1038 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1039 | if (type != ARPOP_REQUEST) | |
1040 | goto out; | |
1041 | ||
1042 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1043 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1044 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1045 | ||
1046 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1047 | "Parsing incoming ARP REQUEST"); | |
1048 | ||
be1db4f6 | 1049 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1050 | |
be1db4f6 | 1051 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1052 | if (!dat_entry) |
1053 | goto out; | |
1054 | ||
c384ea3e | 1055 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 1056 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
1057 | dat_entry->mac_addr, hw_src); |
1058 | ||
1059 | if (!skb_new) | |
1060 | goto out; | |
1061 | ||
927c2ed7 LL |
1062 | /* the rest of the TX path assumes that the mac_header offset pointing |
1063 | * to the inner Ethernet header has been set, therefore reset it now. | |
1064 | */ | |
1065 | skb_reset_mac_header(skb_new); | |
1066 | ||
be1db4f6 AQ |
1067 | if (vid & BATADV_VLAN_HAS_TAG) |
1068 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1069 | vid & VLAN_VID_MASK); | |
1070 | ||
93178018 ML |
1071 | /* To preserve backwards compatibility, the node has choose the outgoing |
1072 | * format based on the incoming request packet type. The assumption is | |
1073 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1074 | */ |
1075 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1076 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1077 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1078 | NULL, vid); |
c384ea3e | 1079 | else |
6c413b1c | 1080 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1081 | |
e300d314 | 1082 | if (err != NET_XMIT_DROP) { |
4046b24a | 1083 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1084 | ret = true; |
4046b24a | 1085 | } |
c384ea3e AQ |
1086 | out: |
1087 | if (dat_entry) | |
1088 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1089 | if (ret) |
1090 | kfree_skb(skb); | |
1091 | return ret; | |
1092 | } | |
1093 | ||
1094 | /** | |
1095 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1096 | * @bat_priv: the bat priv with all the soft interface information | |
1097 | * @skb: packet to check | |
1098 | */ | |
1099 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1100 | struct sk_buff *skb) | |
1101 | { | |
1102 | uint16_t type; | |
1103 | __be32 ip_src, ip_dst; | |
1104 | uint8_t *hw_src, *hw_dst; | |
be1db4f6 AQ |
1105 | int hdr_size = 0; |
1106 | unsigned short vid; | |
c384ea3e | 1107 | |
33af49ad AQ |
1108 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1109 | return; | |
1110 | ||
be1db4f6 AQ |
1111 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1112 | ||
1113 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1114 | if (type != ARPOP_REPLY) |
1115 | return; | |
1116 | ||
be1db4f6 AQ |
1117 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
1118 | "Parsing outgoing ARP REPLY"); | |
c384ea3e | 1119 | |
be1db4f6 AQ |
1120 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1121 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1122 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1123 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1124 | |
be1db4f6 AQ |
1125 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1126 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1127 | |
1128 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1129 | * the node obtained from the ARP reply |
c384ea3e AQ |
1130 | */ |
1131 | batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT); | |
1132 | batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT); | |
1133 | } | |
aa143d28 | 1134 | |
c384ea3e AQ |
1135 | /** |
1136 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1137 | * DAT storage only | |
1138 | * @bat_priv: the bat priv with all the soft interface information | |
1139 | * @skb: packet to check | |
93178018 | 1140 | * @hdr_size: size of the encapsulation header |
c384ea3e AQ |
1141 | */ |
1142 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1143 | struct sk_buff *skb, int hdr_size) | |
1144 | { | |
1145 | uint16_t type; | |
1146 | __be32 ip_src, ip_dst; | |
1147 | uint8_t *hw_src, *hw_dst; | |
1148 | bool ret = false; | |
be1db4f6 | 1149 | unsigned short vid; |
c384ea3e | 1150 | |
33af49ad AQ |
1151 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1152 | goto out; | |
1153 | ||
be1db4f6 AQ |
1154 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1155 | ||
c384ea3e AQ |
1156 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1157 | if (type != ARPOP_REPLY) | |
1158 | goto out; | |
1159 | ||
1160 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1161 | "Parsing incoming ARP REPLY"); | |
1162 | ||
1163 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1164 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1165 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1166 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1167 | ||
1168 | /* Update our internal cache with both the IP addresses the node got | |
1169 | * within the ARP reply | |
1170 | */ | |
be1db4f6 AQ |
1171 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1172 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1173 | |
1174 | /* if this REPLY is directed to a client of mine, let's deliver the | |
1175 | * packet to the interface | |
1176 | */ | |
be1db4f6 | 1177 | ret = !batadv_is_my_client(bat_priv, hw_dst, vid); |
c384ea3e | 1178 | out: |
0d15bece MS |
1179 | if (ret) |
1180 | kfree_skb(skb); | |
c384ea3e AQ |
1181 | /* if ret == false -> packet has to be delivered to the interface */ |
1182 | return ret; | |
1183 | } | |
1184 | ||
1185 | /** | |
1186 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1187 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1188 | * @bat_priv: the bat priv with all the soft interface information |
1189 | * @forw_packet: the broadcast packet | |
1190 | * | |
93178018 | 1191 | * Returns true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1192 | */ |
1193 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1194 | struct batadv_forw_packet *forw_packet) | |
1195 | { | |
1196 | uint16_t type; | |
1197 | __be32 ip_dst; | |
1198 | struct batadv_dat_entry *dat_entry = NULL; | |
1199 | bool ret = false; | |
be1db4f6 AQ |
1200 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1201 | unsigned short vid; | |
c384ea3e | 1202 | |
33af49ad AQ |
1203 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1204 | goto out; | |
1205 | ||
c384ea3e AQ |
1206 | /* If this packet is an ARP_REQUEST and the node already has the |
1207 | * information that it is going to ask, then the packet can be dropped | |
1208 | */ | |
1209 | if (forw_packet->num_packets) | |
1210 | goto out; | |
1211 | ||
be1db4f6 AQ |
1212 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1213 | ||
1214 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1215 | if (type != ARPOP_REQUEST) |
1216 | goto out; | |
1217 | ||
be1db4f6 AQ |
1218 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1219 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1220 | /* check if the node already got this entry */ |
1221 | if (!dat_entry) { | |
1222 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1223 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1224 | goto out; | |
1225 | } | |
1226 | ||
1227 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1228 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1229 | ret = true; | |
1230 | ||
1231 | out: | |
1232 | if (dat_entry) | |
1233 | batadv_dat_entry_free_ref(dat_entry); | |
1234 | return ret; | |
1235 | } |