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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> | |
65d7d460 | 22 | #include <linux/bitops.h> |
1e2c2a4f SE |
23 | #include <linux/byteorder/generic.h> |
24 | #include <linux/errno.h> | |
25 | #include <linux/etherdevice.h> | |
26 | #include <linux/fs.h> | |
785ea114 | 27 | #include <linux/if_arp.h> |
1e2c2a4f | 28 | #include <linux/if_ether.h> |
be1db4f6 | 29 | #include <linux/if_vlan.h> |
1e2c2a4f SE |
30 | #include <linux/in.h> |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/list.h> | |
34 | #include <linux/rculist.h> | |
35 | #include <linux/rcupdate.h> | |
36 | #include <linux/seq_file.h> | |
37 | #include <linux/skbuff.h> | |
38 | #include <linux/slab.h> | |
39 | #include <linux/spinlock.h> | |
40 | #include <linux/stddef.h> | |
41 | #include <linux/string.h> | |
42 | #include <linux/workqueue.h> | |
c384ea3e | 43 | #include <net/arp.h> |
785ea114 | 44 | |
785ea114 | 45 | #include "hard-interface.h" |
1e2c2a4f | 46 | #include "hash.h" |
785ea114 AQ |
47 | #include "originator.h" |
48 | #include "send.h" | |
c384ea3e | 49 | #include "translation-table.h" |
785ea114 | 50 | |
2f1dfbe1 AQ |
51 | static void batadv_dat_purge(struct work_struct *work); |
52 | ||
53 | /** | |
54 | * batadv_dat_start_timer - initialise the DAT periodic worker | |
55 | * @bat_priv: the bat priv with all the soft interface information | |
56 | */ | |
57 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
58 | { | |
59 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
60 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
61 | msecs_to_jiffies(10000)); | |
62 | } | |
63 | ||
64 | /** | |
93178018 | 65 | * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly |
2f1dfbe1 | 66 | * free it |
93178018 | 67 | * @dat_entry: the entry to free |
2f1dfbe1 AQ |
68 | */ |
69 | static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry) | |
70 | { | |
71 | if (atomic_dec_and_test(&dat_entry->refcount)) | |
72 | kfree_rcu(dat_entry, rcu); | |
73 | } | |
74 | ||
75 | /** | |
93178018 | 76 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
77 | * @dat_entry: the entry to check |
78 | * | |
93178018 | 79 | * Returns true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
80 | */ |
81 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
82 | { | |
83 | return batadv_has_timed_out(dat_entry->last_update, | |
84 | BATADV_DAT_ENTRY_TIMEOUT); | |
85 | } | |
86 | ||
87 | /** | |
88 | * __batadv_dat_purge - delete entries from the DAT local storage | |
89 | * @bat_priv: the bat priv with all the soft interface information | |
90 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
91 | * not. This function takes the dat_entry as argument and has to | |
92 | * returns a boolean value: true is the entry has to be deleted, | |
93 | * false otherwise | |
94 | * | |
93178018 ML |
95 | * Loops over each entry in the DAT local storage and deletes it if and only if |
96 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
97 | */ |
98 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
99 | bool (*to_purge)(struct batadv_dat_entry *)) | |
100 | { | |
101 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
102 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 103 | struct hlist_node *node_tmp; |
2f1dfbe1 | 104 | struct hlist_head *head; |
6b5e971a | 105 | u32 i; |
2f1dfbe1 AQ |
106 | |
107 | if (!bat_priv->dat.hash) | |
108 | return; | |
109 | ||
110 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
111 | head = &bat_priv->dat.hash->table[i]; | |
112 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
113 | ||
114 | spin_lock_bh(list_lock); | |
b67bfe0d | 115 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 116 | hash_entry) { |
93178018 | 117 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
118 | * ask it if the entry has to be purged or not |
119 | */ | |
120 | if (to_purge && !to_purge(dat_entry)) | |
121 | continue; | |
122 | ||
b67bfe0d | 123 | hlist_del_rcu(&dat_entry->hash_entry); |
2f1dfbe1 AQ |
124 | batadv_dat_entry_free_ref(dat_entry); |
125 | } | |
126 | spin_unlock_bh(list_lock); | |
127 | } | |
128 | } | |
129 | ||
130 | /** | |
131 | * batadv_dat_purge - periodic task that deletes old entries from the local DAT | |
132 | * hash table | |
133 | * @work: kernel work struct | |
134 | */ | |
135 | static void batadv_dat_purge(struct work_struct *work) | |
136 | { | |
137 | struct delayed_work *delayed_work; | |
138 | struct batadv_priv_dat *priv_dat; | |
139 | struct batadv_priv *bat_priv; | |
140 | ||
141 | delayed_work = container_of(work, struct delayed_work, work); | |
142 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); | |
143 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
144 | ||
145 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
146 | batadv_dat_start_timer(bat_priv); | |
147 | } | |
148 | ||
149 | /** | |
150 | * batadv_compare_dat - comparing function used in the local DAT hash table | |
151 | * @node: node in the local table | |
152 | * @data2: second object to compare the node to | |
153 | * | |
93178018 | 154 | * Returns 1 if the two entries are the same, 0 otherwise. |
2f1dfbe1 AQ |
155 | */ |
156 | static int batadv_compare_dat(const struct hlist_node *node, const void *data2) | |
157 | { | |
158 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
159 | hash_entry); | |
160 | ||
36484f84 | 161 | return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0; |
2f1dfbe1 AQ |
162 | } |
163 | ||
5c3a0e55 AQ |
164 | /** |
165 | * batadv_arp_hw_src - extract the hw_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 hw_src field in the ARP packet. |
5c3a0e55 | 170 | */ |
6b5e971a | 171 | static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) |
5c3a0e55 | 172 | { |
6b5e971a | 173 | u8 *addr; |
5c3a0e55 | 174 | |
6b5e971a | 175 | addr = (u8 *)(skb->data + hdr_size); |
5c3a0e55 AQ |
176 | addr += ETH_HLEN + sizeof(struct arphdr); |
177 | ||
178 | return addr; | |
179 | } | |
180 | ||
181 | /** | |
182 | * batadv_arp_ip_src - extract the ip_src field from an ARP packet | |
183 | * @skb: ARP packet | |
184 | * @hdr_size: size of the possible header before the ARP packet | |
185 | * | |
93178018 | 186 | * Returns the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
187 | */ |
188 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
189 | { | |
190 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
191 | } | |
192 | ||
193 | /** | |
194 | * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet | |
195 | * @skb: ARP packet | |
196 | * @hdr_size: size of the possible header before the ARP packet | |
197 | * | |
93178018 | 198 | * Returns the value of the hw_dst field in the ARP packet. |
5c3a0e55 | 199 | */ |
6b5e971a | 200 | static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) |
5c3a0e55 AQ |
201 | { |
202 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
203 | } | |
204 | ||
205 | /** | |
206 | * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet | |
207 | * @skb: ARP packet | |
208 | * @hdr_size: size of the possible header before the ARP packet | |
209 | * | |
93178018 | 210 | * Returns the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
211 | */ |
212 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
213 | { | |
214 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
215 | } | |
216 | ||
785ea114 AQ |
217 | /** |
218 | * batadv_hash_dat - compute the hash value for an IP address | |
219 | * @data: data to hash | |
220 | * @size: size of the hash table | |
221 | * | |
93178018 | 222 | * Returns the selected index in the hash table for the given data. |
785ea114 | 223 | */ |
6b5e971a | 224 | static u32 batadv_hash_dat(const void *data, u32 size) |
785ea114 | 225 | { |
6b5e971a | 226 | u32 hash = 0; |
be1db4f6 | 227 | const struct batadv_dat_entry *dat = data; |
36fd61cb | 228 | const unsigned char *key; |
6b5e971a | 229 | u32 i; |
36fd61cb SE |
230 | |
231 | key = (const unsigned char *)&dat->ip; | |
232 | for (i = 0; i < sizeof(dat->ip); i++) { | |
233 | hash += key[i]; | |
234 | hash += (hash << 10); | |
235 | hash ^= (hash >> 6); | |
236 | } | |
785ea114 | 237 | |
36fd61cb SE |
238 | key = (const unsigned char *)&dat->vid; |
239 | for (i = 0; i < sizeof(dat->vid); i++) { | |
240 | hash += key[i]; | |
241 | hash += (hash << 10); | |
242 | hash ^= (hash >> 6); | |
243 | } | |
785ea114 AQ |
244 | |
245 | hash += (hash << 3); | |
246 | hash ^= (hash >> 11); | |
247 | hash += (hash << 15); | |
248 | ||
249 | return hash % size; | |
250 | } | |
251 | ||
2f1dfbe1 | 252 | /** |
93178018 | 253 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
254 | * table |
255 | * @bat_priv: the bat priv with all the soft interface information | |
256 | * @ip: search key | |
be1db4f6 | 257 | * @vid: VLAN identifier |
2f1dfbe1 | 258 | * |
93178018 | 259 | * Returns the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
260 | */ |
261 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
262 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
263 | unsigned short vid) | |
2f1dfbe1 AQ |
264 | { |
265 | struct hlist_head *head; | |
be1db4f6 | 266 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 | 267 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
6b5e971a | 268 | u32 index; |
2f1dfbe1 AQ |
269 | |
270 | if (!hash) | |
271 | return NULL; | |
272 | ||
be1db4f6 AQ |
273 | to_find.ip = ip; |
274 | to_find.vid = vid; | |
275 | ||
276 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
277 | head = &hash->table[index]; |
278 | ||
279 | rcu_read_lock(); | |
b67bfe0d | 280 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
281 | if (dat_entry->ip != ip) |
282 | continue; | |
283 | ||
284 | if (!atomic_inc_not_zero(&dat_entry->refcount)) | |
285 | continue; | |
286 | ||
287 | dat_entry_tmp = dat_entry; | |
288 | break; | |
289 | } | |
290 | rcu_read_unlock(); | |
291 | ||
292 | return dat_entry_tmp; | |
293 | } | |
294 | ||
295 | /** | |
296 | * batadv_dat_entry_add - add a new dat entry or update it if already exists | |
297 | * @bat_priv: the bat priv with all the soft interface information | |
298 | * @ip: ipv4 to add/edit | |
299 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 300 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
301 | */ |
302 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
6b5e971a | 303 | u8 *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
304 | { |
305 | struct batadv_dat_entry *dat_entry; | |
306 | int hash_added; | |
307 | ||
be1db4f6 | 308 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
309 | /* if this entry is already known, just update it */ |
310 | if (dat_entry) { | |
311 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 312 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
313 | dat_entry->last_update = jiffies; |
314 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
315 | "Entry updated: %pI4 %pM (vid: %d)\n", |
316 | &dat_entry->ip, dat_entry->mac_addr, | |
317 | BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
318 | goto out; |
319 | } | |
320 | ||
321 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
322 | if (!dat_entry) | |
323 | goto out; | |
324 | ||
325 | dat_entry->ip = ip; | |
be1db4f6 | 326 | dat_entry->vid = vid; |
8fdd0153 | 327 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
328 | dat_entry->last_update = jiffies; |
329 | atomic_set(&dat_entry->refcount, 2); | |
330 | ||
331 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, | |
be1db4f6 | 332 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
333 | &dat_entry->hash_entry); |
334 | ||
335 | if (unlikely(hash_added != 0)) { | |
336 | /* remove the reference for the hash */ | |
337 | batadv_dat_entry_free_ref(dat_entry); | |
338 | goto out; | |
339 | } | |
340 | ||
be1db4f6 AQ |
341 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
342 | &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
343 | |
344 | out: | |
345 | if (dat_entry) | |
346 | batadv_dat_entry_free_ref(dat_entry); | |
347 | } | |
348 | ||
5c3a0e55 AQ |
349 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
350 | ||
351 | /** | |
352 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
353 | * @bat_priv: the bat priv with all the soft interface information | |
354 | * @skb: ARP packet | |
355 | * @type: ARP type | |
356 | * @hdr_size: size of the possible header before the ARP packet | |
357 | * @msg: message to print together with the debugging information | |
358 | */ | |
359 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
6b5e971a | 360 | u16 type, int hdr_size, char *msg) |
5c3a0e55 AQ |
361 | { |
362 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
363 | struct batadv_bcast_packet *bcast_pkt; | |
6b5e971a | 364 | u8 *orig_addr; |
5c3a0e55 AQ |
365 | __be32 ip_src, ip_dst; |
366 | ||
367 | if (msg) | |
368 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
369 | ||
370 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
371 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
372 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
373 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
374 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
375 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
376 | ||
377 | if (hdr_size == 0) | |
378 | return; | |
379 | ||
5c3a0e55 AQ |
380 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
381 | ||
a40d9b07 | 382 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
383 | case BATADV_UNICAST: |
384 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
385 | "* encapsulated within a UNICAST packet\n"); | |
386 | break; | |
387 | case BATADV_UNICAST_4ADDR: | |
388 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
389 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
390 | unicast_4addr_packet->src); | |
391 | switch (unicast_4addr_packet->subtype) { | |
392 | case BATADV_P_DAT_DHT_PUT: | |
393 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
394 | break; | |
395 | case BATADV_P_DAT_DHT_GET: | |
396 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
397 | break; | |
398 | case BATADV_P_DAT_CACHE_REPLY: | |
399 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
400 | "* type: DAT_CACHE_REPLY\n"); | |
401 | break; | |
402 | case BATADV_P_DATA: | |
403 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
404 | break; | |
405 | default: | |
406 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 407 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
408 | } |
409 | break; | |
410 | case BATADV_BCAST: | |
411 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
412 | orig_addr = bcast_pkt->orig; | |
413 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
414 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
415 | orig_addr); | |
416 | break; | |
417 | default: | |
418 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
419 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 420 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
421 | } |
422 | } | |
423 | ||
424 | #else | |
425 | ||
426 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
6b5e971a | 427 | u16 type, int hdr_size, char *msg) |
5c3a0e55 AQ |
428 | { |
429 | } | |
430 | ||
431 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
432 | ||
785ea114 AQ |
433 | /** |
434 | * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate | |
435 | * @res: the array with the already selected candidates | |
436 | * @select: number of already selected candidates | |
437 | * @tmp_max: address of the currently evaluated node | |
438 | * @max: current round max address | |
439 | * @last_max: address of the last selected candidate | |
440 | * @candidate: orig_node under evaluation | |
441 | * @max_orig_node: last selected candidate | |
442 | * | |
93178018 ML |
443 | * Returns true if the node has been elected as next candidate or false |
444 | * otherwise. | |
785ea114 AQ |
445 | */ |
446 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
447 | int select, batadv_dat_addr_t tmp_max, | |
448 | batadv_dat_addr_t max, | |
449 | batadv_dat_addr_t last_max, | |
450 | struct batadv_orig_node *candidate, | |
451 | struct batadv_orig_node *max_orig_node) | |
452 | { | |
453 | bool ret = false; | |
454 | int j; | |
455 | ||
17cf0ea4 | 456 | /* check if orig node candidate is running DAT */ |
65d7d460 | 457 | if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities)) |
17cf0ea4 ML |
458 | goto out; |
459 | ||
785ea114 AQ |
460 | /* Check if this node has already been selected... */ |
461 | for (j = 0; j < select; j++) | |
462 | if (res[j].orig_node == candidate) | |
463 | break; | |
464 | /* ..and possibly skip it */ | |
465 | if (j < select) | |
466 | goto out; | |
467 | /* sanity check: has it already been selected? This should not happen */ | |
468 | if (tmp_max > last_max) | |
469 | goto out; | |
470 | /* check if during this iteration an originator with a closer dht | |
471 | * address has already been found | |
472 | */ | |
473 | if (tmp_max < max) | |
474 | goto out; | |
475 | /* this is an hash collision with the temporary selected node. Choose | |
476 | * the one with the lowest address | |
477 | */ | |
816cd5b8 | 478 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
479 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
480 | goto out; | |
481 | ||
482 | ret = true; | |
483 | out: | |
484 | return ret; | |
485 | } | |
486 | ||
487 | /** | |
488 | * batadv_choose_next_candidate - select the next DHT candidate | |
489 | * @bat_priv: the bat priv with all the soft interface information | |
490 | * @cands: candidates array | |
491 | * @select: number of candidates already present in the array | |
492 | * @ip_key: key to look up in the DHT | |
493 | * @last_max: pointer where the address of the selected candidate will be saved | |
494 | */ | |
495 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
496 | struct batadv_dat_candidate *cands, | |
497 | int select, batadv_dat_addr_t ip_key, | |
498 | batadv_dat_addr_t *last_max) | |
499 | { | |
4f248cff SE |
500 | batadv_dat_addr_t max = 0; |
501 | batadv_dat_addr_t tmp_max = 0; | |
785ea114 AQ |
502 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; |
503 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
504 | struct hlist_head *head; |
505 | int i; | |
506 | ||
507 | /* if no node is eligible as candidate, leave the candidate type as | |
508 | * NOT_FOUND | |
509 | */ | |
510 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
511 | ||
93178018 | 512 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
513 | * dat_address which has not been selected yet |
514 | */ | |
515 | for (i = 0; i < hash->size; i++) { | |
516 | head = &hash->table[i]; | |
517 | ||
518 | rcu_read_lock(); | |
b67bfe0d | 519 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 520 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
521 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
522 | ip_key; | |
523 | ||
524 | if (!batadv_is_orig_node_eligible(cands, select, | |
525 | tmp_max, max, | |
526 | *last_max, orig_node, | |
527 | max_orig_node)) | |
528 | continue; | |
529 | ||
530 | if (!atomic_inc_not_zero(&orig_node->refcount)) | |
531 | continue; | |
532 | ||
533 | max = tmp_max; | |
534 | if (max_orig_node) | |
535 | batadv_orig_node_free_ref(max_orig_node); | |
536 | max_orig_node = orig_node; | |
537 | } | |
538 | rcu_read_unlock(); | |
539 | } | |
540 | if (max_orig_node) { | |
541 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
542 | cands[select].orig_node = max_orig_node; | |
543 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
544 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
545 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
546 | max); | |
547 | } | |
548 | *last_max = max; | |
549 | } | |
550 | ||
551 | /** | |
93178018 | 552 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
553 | * be sent to |
554 | * @bat_priv: the bat priv with all the soft interface information | |
555 | * @ip_dst: ipv4 to look up in the DHT | |
556 | * | |
557 | * An originator O is selected if and only if its DHT_ID value is one of three | |
558 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
559 | * value of the key. ip_dst is the key. | |
560 | * | |
93178018 | 561 | * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
562 | */ |
563 | static struct batadv_dat_candidate * | |
564 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst) | |
565 | { | |
566 | int select; | |
567 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
568 | struct batadv_dat_candidate *res; | |
b7fe3d4f | 569 | struct batadv_dat_entry dat; |
785ea114 AQ |
570 | |
571 | if (!bat_priv->orig_hash) | |
572 | return NULL; | |
573 | ||
0185dda6 AQ |
574 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
575 | GFP_ATOMIC); | |
785ea114 AQ |
576 | if (!res) |
577 | return NULL; | |
578 | ||
b7fe3d4f SE |
579 | dat.ip = ip_dst; |
580 | dat.vid = 0; | |
581 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat, | |
785ea114 AQ |
582 | BATADV_DAT_ADDR_MAX); |
583 | ||
584 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
585 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
586 | ip_key); | |
587 | ||
588 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
589 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
590 | &last_max); | |
591 | ||
592 | return res; | |
593 | } | |
594 | ||
595 | /** | |
596 | * batadv_dat_send_data - send a payload to the selected candidates | |
597 | * @bat_priv: the bat priv with all the soft interface information | |
598 | * @skb: payload to send | |
599 | * @ip: the DHT key | |
600 | * @packet_subtype: unicast4addr packet subtype to use | |
601 | * | |
93178018 ML |
602 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
603 | * to each of the selected candidates. | |
785ea114 | 604 | * |
93178018 ML |
605 | * Returns true if the packet is sent to at least one candidate, false |
606 | * otherwise. | |
785ea114 AQ |
607 | */ |
608 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
609 | struct sk_buff *skb, __be32 ip, | |
610 | int packet_subtype) | |
611 | { | |
612 | int i; | |
613 | bool ret = false; | |
614 | int send_status; | |
615 | struct batadv_neigh_node *neigh_node = NULL; | |
616 | struct sk_buff *tmp_skb; | |
617 | struct batadv_dat_candidate *cand; | |
618 | ||
619 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
620 | if (!cand) | |
621 | goto out; | |
622 | ||
623 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
624 | ||
625 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
626 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
627 | continue; | |
628 | ||
7351a482 SW |
629 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
630 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
631 | if (!neigh_node) |
632 | goto free_orig; | |
633 | ||
bad93e9d | 634 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
635 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
636 | cand[i].orig_node, | |
637 | packet_subtype)) { | |
785ea114 AQ |
638 | kfree_skb(tmp_skb); |
639 | goto free_neigh; | |
640 | } | |
641 | ||
642 | send_status = batadv_send_skb_packet(tmp_skb, | |
643 | neigh_node->if_incoming, | |
644 | neigh_node->addr); | |
4046b24a MH |
645 | if (send_status == NET_XMIT_SUCCESS) { |
646 | /* count the sent packet */ | |
647 | switch (packet_subtype) { | |
648 | case BATADV_P_DAT_DHT_GET: | |
649 | batadv_inc_counter(bat_priv, | |
650 | BATADV_CNT_DAT_GET_TX); | |
651 | break; | |
652 | case BATADV_P_DAT_DHT_PUT: | |
653 | batadv_inc_counter(bat_priv, | |
654 | BATADV_CNT_DAT_PUT_TX); | |
655 | break; | |
656 | } | |
657 | ||
785ea114 AQ |
658 | /* packet sent to a candidate: return true */ |
659 | ret = true; | |
4046b24a | 660 | } |
785ea114 AQ |
661 | free_neigh: |
662 | batadv_neigh_node_free_ref(neigh_node); | |
663 | free_orig: | |
664 | batadv_orig_node_free_ref(cand[i].orig_node); | |
665 | } | |
666 | ||
667 | out: | |
668 | kfree(cand); | |
669 | return ret; | |
670 | } | |
2f1dfbe1 | 671 | |
17cf0ea4 ML |
672 | /** |
673 | * batadv_dat_tvlv_container_update - update the dat tvlv container after dat | |
674 | * setting change | |
675 | * @bat_priv: the bat priv with all the soft interface information | |
676 | */ | |
677 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
678 | { | |
679 | char dat_mode; | |
680 | ||
681 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
682 | ||
683 | switch (dat_mode) { | |
684 | case 0: | |
685 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
686 | break; | |
687 | case 1: | |
688 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
689 | NULL, 0); | |
690 | break; | |
691 | } | |
692 | } | |
693 | ||
694 | /** | |
695 | * batadv_dat_status_update - update the dat tvlv container after dat | |
696 | * setting change | |
697 | * @net_dev: the soft interface net device | |
698 | */ | |
699 | void batadv_dat_status_update(struct net_device *net_dev) | |
700 | { | |
701 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 702 | |
17cf0ea4 ML |
703 | batadv_dat_tvlv_container_update(bat_priv); |
704 | } | |
705 | ||
706 | /** | |
707 | * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container | |
708 | * @bat_priv: the bat priv with all the soft interface information | |
709 | * @orig: the orig_node of the ogm | |
710 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
711 | * @tvlv_value: tvlv buffer containing the gateway data | |
712 | * @tvlv_value_len: tvlv buffer length | |
713 | */ | |
714 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
715 | struct batadv_orig_node *orig, | |
6b5e971a SE |
716 | u8 flags, |
717 | void *tvlv_value, u16 tvlv_value_len) | |
17cf0ea4 ML |
718 | { |
719 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
65d7d460 | 720 | clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 | 721 | else |
65d7d460 | 722 | set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 ML |
723 | } |
724 | ||
2f1dfbe1 AQ |
725 | /** |
726 | * batadv_dat_hash_free - free the local DAT hash table | |
727 | * @bat_priv: the bat priv with all the soft interface information | |
728 | */ | |
729 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
730 | { | |
33af49ad AQ |
731 | if (!bat_priv->dat.hash) |
732 | return; | |
733 | ||
2f1dfbe1 AQ |
734 | __batadv_dat_purge(bat_priv, NULL); |
735 | ||
736 | batadv_hash_destroy(bat_priv->dat.hash); | |
737 | ||
738 | bat_priv->dat.hash = NULL; | |
739 | } | |
740 | ||
741 | /** | |
742 | * batadv_dat_init - initialise the DAT internals | |
743 | * @bat_priv: the bat priv with all the soft interface information | |
744 | */ | |
745 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
746 | { | |
747 | if (bat_priv->dat.hash) | |
748 | return 0; | |
749 | ||
750 | bat_priv->dat.hash = batadv_hash_new(1024); | |
751 | ||
752 | if (!bat_priv->dat.hash) | |
753 | return -ENOMEM; | |
754 | ||
755 | batadv_dat_start_timer(bat_priv); | |
756 | ||
17cf0ea4 ML |
757 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
758 | NULL, BATADV_TVLV_DAT, 1, | |
759 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
760 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
761 | return 0; |
762 | } | |
763 | ||
764 | /** | |
765 | * batadv_dat_free - free the DAT internals | |
766 | * @bat_priv: the bat priv with all the soft interface information | |
767 | */ | |
768 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
769 | { | |
17cf0ea4 ML |
770 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
771 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
772 | ||
2f1dfbe1 AQ |
773 | cancel_delayed_work_sync(&bat_priv->dat.work); |
774 | ||
775 | batadv_dat_hash_free(bat_priv); | |
776 | } | |
777 | ||
778 | /** | |
779 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
780 | * @seq: seq file to print on | |
781 | * @offset: not used | |
782 | */ | |
783 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
784 | { | |
785 | struct net_device *net_dev = (struct net_device *)seq->private; | |
786 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
787 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
788 | struct batadv_dat_entry *dat_entry; | |
789 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
790 | struct hlist_head *head; |
791 | unsigned long last_seen_jiffies; | |
792 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
6b5e971a | 793 | u32 i; |
2f1dfbe1 AQ |
794 | |
795 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
796 | if (!primary_if) | |
797 | goto out; | |
798 | ||
799 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
be1db4f6 AQ |
800 | seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4", |
801 | "MAC", "VID", "last-seen"); | |
2f1dfbe1 AQ |
802 | |
803 | for (i = 0; i < hash->size; i++) { | |
804 | head = &hash->table[i]; | |
805 | ||
806 | rcu_read_lock(); | |
b67bfe0d | 807 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
808 | last_seen_jiffies = jiffies - dat_entry->last_update; |
809 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
810 | last_seen_mins = last_seen_msecs / 60000; | |
811 | last_seen_msecs = last_seen_msecs % 60000; | |
812 | last_seen_secs = last_seen_msecs / 1000; | |
813 | ||
be1db4f6 | 814 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 815 | &dat_entry->ip, dat_entry->mac_addr, |
be1db4f6 | 816 | BATADV_PRINT_VID(dat_entry->vid), |
2f1dfbe1 AQ |
817 | last_seen_mins, last_seen_secs); |
818 | } | |
819 | rcu_read_unlock(); | |
820 | } | |
821 | ||
822 | out: | |
823 | if (primary_if) | |
824 | batadv_hardif_free_ref(primary_if); | |
825 | return 0; | |
826 | } | |
5c3a0e55 AQ |
827 | |
828 | /** | |
829 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
830 | * @bat_priv: the bat priv with all the soft interface information | |
831 | * @skb: packet to analyse | |
832 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
833 | * | |
93178018 | 834 | * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 | 835 | */ |
6b5e971a SE |
836 | static u16 batadv_arp_get_type(struct batadv_priv *bat_priv, |
837 | struct sk_buff *skb, int hdr_size) | |
5c3a0e55 AQ |
838 | { |
839 | struct arphdr *arphdr; | |
840 | struct ethhdr *ethhdr; | |
841 | __be32 ip_src, ip_dst; | |
6b5e971a SE |
842 | u8 *hw_src, *hw_dst; |
843 | u16 type = 0; | |
5c3a0e55 AQ |
844 | |
845 | /* pull the ethernet header */ | |
846 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
847 | goto out; | |
848 | ||
849 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
850 | ||
851 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
852 | goto out; | |
853 | ||
854 | /* pull the ARP payload */ | |
855 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
856 | arp_hdr_len(skb->dev)))) | |
857 | goto out; | |
858 | ||
859 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
860 | ||
93178018 | 861 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
862 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
863 | goto out; | |
864 | ||
865 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
866 | goto out; | |
867 | ||
868 | if (arphdr->ar_hln != ETH_ALEN) | |
869 | goto out; | |
870 | ||
871 | if (arphdr->ar_pln != 4) | |
872 | goto out; | |
873 | ||
874 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
875 | * will simply ignore it | |
876 | */ | |
877 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
878 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
879 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
880 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
881 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
882 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
883 | goto out; |
884 | ||
b618ad11 MS |
885 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
886 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
887 | goto out; | |
888 | ||
93178018 | 889 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
890 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
891 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
892 | if (is_zero_ether_addr(hw_dst) || | |
893 | is_multicast_ether_addr(hw_dst)) | |
894 | goto out; | |
895 | } | |
896 | ||
5c3a0e55 AQ |
897 | type = ntohs(arphdr->ar_op); |
898 | out: | |
899 | return type; | |
900 | } | |
c384ea3e | 901 | |
be1db4f6 AQ |
902 | /** |
903 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
904 | * @skb: the buffer containing the packet to extract the VID from | |
905 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
906 | * | |
907 | * If the packet embedded in the skb is vlan tagged this function returns the | |
908 | * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned. | |
909 | */ | |
910 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
911 | { | |
912 | unsigned short vid; | |
913 | ||
914 | vid = batadv_get_vid(skb, *hdr_size); | |
915 | ||
916 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
917 | * If the header contained in the packet is a VLAN one (which is longer) | |
918 | * hdr_size is updated so that the functions will still skip the | |
919 | * correct amount of bytes. | |
920 | */ | |
921 | if (vid & BATADV_VLAN_HAS_TAG) | |
922 | *hdr_size += VLAN_HLEN; | |
923 | ||
924 | return vid; | |
925 | } | |
926 | ||
c384ea3e AQ |
927 | /** |
928 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
929 | * answer using DAT | |
930 | * @bat_priv: the bat priv with all the soft interface information | |
931 | * @skb: packet to check | |
932 | * | |
933 | * Returns true if the message has been sent to the dht candidates, false | |
93178018 ML |
934 | * otherwise. In case of a positive return value the message has to be enqueued |
935 | * to permit the fallback. | |
c384ea3e AQ |
936 | */ |
937 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
938 | struct sk_buff *skb) | |
939 | { | |
6b5e971a | 940 | u16 type = 0; |
c384ea3e | 941 | __be32 ip_dst, ip_src; |
6b5e971a | 942 | u8 *hw_src; |
c384ea3e AQ |
943 | bool ret = false; |
944 | struct batadv_dat_entry *dat_entry = NULL; | |
945 | struct sk_buff *skb_new; | |
be1db4f6 AQ |
946 | int hdr_size = 0; |
947 | unsigned short vid; | |
c384ea3e | 948 | |
33af49ad AQ |
949 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
950 | goto out; | |
951 | ||
be1db4f6 AQ |
952 | vid = batadv_dat_get_vid(skb, &hdr_size); |
953 | ||
954 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
955 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
956 | * message to the selected DHT candidates | |
957 | */ | |
958 | if (type != ARPOP_REQUEST) | |
959 | goto out; | |
960 | ||
be1db4f6 AQ |
961 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
962 | "Parsing outgoing ARP REQUEST"); | |
c384ea3e | 963 | |
be1db4f6 AQ |
964 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
965 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
966 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 967 | |
be1db4f6 | 968 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 969 | |
be1db4f6 | 970 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 971 | if (dat_entry) { |
88e48d7b AQ |
972 | /* If the ARP request is destined for a local client the local |
973 | * client will answer itself. DAT would only generate a | |
974 | * duplicate packet. | |
975 | * | |
976 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
977 | * additional DAT answer may trigger kernel warnings about | |
978 | * a packet coming from the wrong port. | |
979 | */ | |
cc2f3386 | 980 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
981 | ret = true; |
982 | goto out; | |
983 | } | |
984 | ||
c384ea3e | 985 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 986 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
987 | dat_entry->mac_addr, hw_src); |
988 | if (!skb_new) | |
989 | goto out; | |
990 | ||
be1db4f6 AQ |
991 | if (vid & BATADV_VLAN_HAS_TAG) |
992 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
993 | vid & VLAN_VID_MASK); | |
994 | ||
c384ea3e AQ |
995 | skb_reset_mac_header(skb_new); |
996 | skb_new->protocol = eth_type_trans(skb_new, | |
736292c2 | 997 | bat_priv->soft_iface); |
c384ea3e | 998 | bat_priv->stats.rx_packets++; |
be1db4f6 | 999 | bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size; |
736292c2 | 1000 | bat_priv->soft_iface->last_rx = jiffies; |
c384ea3e AQ |
1001 | |
1002 | netif_rx(skb_new); | |
1003 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
1004 | ret = true; | |
1005 | } else { | |
93178018 | 1006 | /* Send the request to the DHT */ |
c384ea3e AQ |
1007 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, |
1008 | BATADV_P_DAT_DHT_GET); | |
1009 | } | |
1010 | out: | |
1011 | if (dat_entry) | |
1012 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1013 | return ret; |
1014 | } | |
1015 | ||
1016 | /** | |
1017 | * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to | |
1018 | * answer using the local DAT storage | |
1019 | * @bat_priv: the bat priv with all the soft interface information | |
1020 | * @skb: packet to check | |
1021 | * @hdr_size: size of the encapsulation header | |
1022 | * | |
93178018 | 1023 | * Returns true if the request has been answered, false otherwise. |
c384ea3e AQ |
1024 | */ |
1025 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
1026 | struct sk_buff *skb, int hdr_size) | |
1027 | { | |
6b5e971a | 1028 | u16 type; |
c384ea3e | 1029 | __be32 ip_src, ip_dst; |
6b5e971a | 1030 | u8 *hw_src; |
c384ea3e | 1031 | struct sk_buff *skb_new; |
c384ea3e AQ |
1032 | struct batadv_dat_entry *dat_entry = NULL; |
1033 | bool ret = false; | |
be1db4f6 | 1034 | unsigned short vid; |
c384ea3e AQ |
1035 | int err; |
1036 | ||
33af49ad AQ |
1037 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1038 | goto out; | |
1039 | ||
be1db4f6 AQ |
1040 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1041 | ||
c384ea3e AQ |
1042 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1043 | if (type != ARPOP_REQUEST) | |
1044 | goto out; | |
1045 | ||
1046 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1047 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1048 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1049 | ||
1050 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1051 | "Parsing incoming ARP REQUEST"); | |
1052 | ||
be1db4f6 | 1053 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1054 | |
be1db4f6 | 1055 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1056 | if (!dat_entry) |
1057 | goto out; | |
1058 | ||
c384ea3e | 1059 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 1060 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
1061 | dat_entry->mac_addr, hw_src); |
1062 | ||
1063 | if (!skb_new) | |
1064 | goto out; | |
1065 | ||
927c2ed7 LL |
1066 | /* the rest of the TX path assumes that the mac_header offset pointing |
1067 | * to the inner Ethernet header has been set, therefore reset it now. | |
1068 | */ | |
1069 | skb_reset_mac_header(skb_new); | |
1070 | ||
be1db4f6 AQ |
1071 | if (vid & BATADV_VLAN_HAS_TAG) |
1072 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1073 | vid & VLAN_VID_MASK); | |
1074 | ||
93178018 ML |
1075 | /* To preserve backwards compatibility, the node has choose the outgoing |
1076 | * format based on the incoming request packet type. The assumption is | |
1077 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1078 | */ |
1079 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1080 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1081 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1082 | NULL, vid); |
c384ea3e | 1083 | else |
6c413b1c | 1084 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1085 | |
e300d314 | 1086 | if (err != NET_XMIT_DROP) { |
4046b24a | 1087 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1088 | ret = true; |
4046b24a | 1089 | } |
c384ea3e AQ |
1090 | out: |
1091 | if (dat_entry) | |
1092 | batadv_dat_entry_free_ref(dat_entry); | |
c384ea3e AQ |
1093 | if (ret) |
1094 | kfree_skb(skb); | |
1095 | return ret; | |
1096 | } | |
1097 | ||
1098 | /** | |
1099 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1100 | * @bat_priv: the bat priv with all the soft interface information | |
1101 | * @skb: packet to check | |
1102 | */ | |
1103 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1104 | struct sk_buff *skb) | |
1105 | { | |
6b5e971a | 1106 | u16 type; |
c384ea3e | 1107 | __be32 ip_src, ip_dst; |
6b5e971a | 1108 | u8 *hw_src, *hw_dst; |
be1db4f6 AQ |
1109 | int hdr_size = 0; |
1110 | unsigned short vid; | |
c384ea3e | 1111 | |
33af49ad AQ |
1112 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1113 | return; | |
1114 | ||
be1db4f6 AQ |
1115 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1116 | ||
1117 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1118 | if (type != ARPOP_REPLY) |
1119 | return; | |
1120 | ||
be1db4f6 AQ |
1121 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
1122 | "Parsing outgoing ARP REPLY"); | |
c384ea3e | 1123 | |
be1db4f6 AQ |
1124 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1125 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1126 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1127 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1128 | |
be1db4f6 AQ |
1129 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1130 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1131 | |
1132 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1133 | * the node obtained from the ARP reply |
c384ea3e AQ |
1134 | */ |
1135 | batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT); | |
1136 | batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT); | |
1137 | } | |
aa143d28 | 1138 | |
c384ea3e AQ |
1139 | /** |
1140 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1141 | * DAT storage only | |
1142 | * @bat_priv: the bat priv with all the soft interface information | |
1143 | * @skb: packet to check | |
93178018 | 1144 | * @hdr_size: size of the encapsulation header |
f202a666 AQ |
1145 | * |
1146 | * Returns true if the packet was snooped and consumed by DAT. False if the | |
1147 | * packet has to be delivered to the interface | |
c384ea3e AQ |
1148 | */ |
1149 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1150 | struct sk_buff *skb, int hdr_size) | |
1151 | { | |
6b5e971a | 1152 | u16 type; |
c384ea3e | 1153 | __be32 ip_src, ip_dst; |
6b5e971a | 1154 | u8 *hw_src, *hw_dst; |
f202a666 | 1155 | bool dropped = false; |
be1db4f6 | 1156 | unsigned short vid; |
c384ea3e | 1157 | |
33af49ad AQ |
1158 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1159 | goto out; | |
1160 | ||
be1db4f6 AQ |
1161 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1162 | ||
c384ea3e AQ |
1163 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1164 | if (type != ARPOP_REPLY) | |
1165 | goto out; | |
1166 | ||
1167 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1168 | "Parsing incoming ARP REPLY"); | |
1169 | ||
1170 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1171 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1172 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1173 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1174 | ||
1175 | /* Update our internal cache with both the IP addresses the node got | |
1176 | * within the ARP reply | |
1177 | */ | |
be1db4f6 AQ |
1178 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1179 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1180 | |
1181 | /* if this REPLY is directed to a client of mine, let's deliver the | |
1182 | * packet to the interface | |
1183 | */ | |
f202a666 AQ |
1184 | dropped = !batadv_is_my_client(bat_priv, hw_dst, vid); |
1185 | ||
1186 | /* if this REPLY is sent on behalf of a client of mine, let's drop the | |
1187 | * packet because the client will reply by itself | |
1188 | */ | |
1189 | dropped |= batadv_is_my_client(bat_priv, hw_src, vid); | |
c384ea3e | 1190 | out: |
f202a666 | 1191 | if (dropped) |
0d15bece | 1192 | kfree_skb(skb); |
f202a666 AQ |
1193 | /* if dropped == false -> deliver to the interface */ |
1194 | return dropped; | |
c384ea3e AQ |
1195 | } |
1196 | ||
1197 | /** | |
1198 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1199 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1200 | * @bat_priv: the bat priv with all the soft interface information |
1201 | * @forw_packet: the broadcast packet | |
1202 | * | |
93178018 | 1203 | * Returns true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1204 | */ |
1205 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1206 | struct batadv_forw_packet *forw_packet) | |
1207 | { | |
6b5e971a | 1208 | u16 type; |
c384ea3e AQ |
1209 | __be32 ip_dst; |
1210 | struct batadv_dat_entry *dat_entry = NULL; | |
1211 | bool ret = false; | |
be1db4f6 AQ |
1212 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1213 | unsigned short vid; | |
c384ea3e | 1214 | |
33af49ad AQ |
1215 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1216 | goto out; | |
1217 | ||
c384ea3e AQ |
1218 | /* If this packet is an ARP_REQUEST and the node already has the |
1219 | * information that it is going to ask, then the packet can be dropped | |
1220 | */ | |
1221 | if (forw_packet->num_packets) | |
1222 | goto out; | |
1223 | ||
be1db4f6 AQ |
1224 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1225 | ||
1226 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1227 | if (type != ARPOP_REQUEST) |
1228 | goto out; | |
1229 | ||
be1db4f6 AQ |
1230 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1231 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1232 | /* check if the node already got this entry */ |
1233 | if (!dat_entry) { | |
1234 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1235 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1236 | goto out; | |
1237 | } | |
1238 | ||
1239 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1240 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1241 | ret = true; | |
1242 | ||
1243 | out: | |
1244 | if (dat_entry) | |
1245 | batadv_dat_entry_free_ref(dat_entry); | |
1246 | return ret; | |
1247 | } |