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0046b040 | 1 | /* Copyright (C) 2011-2016 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> | |
68a6722c | 33 | #include <linux/kref.h> |
1e2c2a4f SE |
34 | #include <linux/list.h> |
35 | #include <linux/rculist.h> | |
36 | #include <linux/rcupdate.h> | |
37 | #include <linux/seq_file.h> | |
38 | #include <linux/skbuff.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/spinlock.h> | |
41 | #include <linux/stddef.h> | |
42 | #include <linux/string.h> | |
43 | #include <linux/workqueue.h> | |
c384ea3e | 44 | #include <net/arp.h> |
785ea114 | 45 | |
785ea114 | 46 | #include "hard-interface.h" |
1e2c2a4f | 47 | #include "hash.h" |
785ea114 AQ |
48 | #include "originator.h" |
49 | #include "send.h" | |
c384ea3e | 50 | #include "translation-table.h" |
785ea114 | 51 | |
2f1dfbe1 AQ |
52 | static void batadv_dat_purge(struct work_struct *work); |
53 | ||
54 | /** | |
55 | * batadv_dat_start_timer - initialise the DAT periodic worker | |
56 | * @bat_priv: the bat priv with all the soft interface information | |
57 | */ | |
58 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
59 | { | |
60 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
61 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
62 | msecs_to_jiffies(10000)); | |
63 | } | |
64 | ||
68a6722c SE |
65 | /** |
66 | * batadv_dat_entry_release - release dat_entry from lists and queue for free | |
67 | * after rcu grace period | |
68 | * @ref: kref pointer of the dat_entry | |
69 | */ | |
70 | static void batadv_dat_entry_release(struct kref *ref) | |
71 | { | |
72 | struct batadv_dat_entry *dat_entry; | |
73 | ||
74 | dat_entry = container_of(ref, struct batadv_dat_entry, refcount); | |
75 | ||
76 | kfree_rcu(dat_entry, rcu); | |
77 | } | |
78 | ||
2f1dfbe1 | 79 | /** |
a6416f9f | 80 | * batadv_dat_entry_put - decrement the dat_entry refcounter and possibly |
68a6722c SE |
81 | * release it |
82 | * @dat_entry: dat_entry to be free'd | |
2f1dfbe1 | 83 | */ |
a6416f9f | 84 | static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) |
2f1dfbe1 | 85 | { |
68a6722c | 86 | kref_put(&dat_entry->refcount, batadv_dat_entry_release); |
2f1dfbe1 AQ |
87 | } |
88 | ||
89 | /** | |
93178018 | 90 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
91 | * @dat_entry: the entry to check |
92 | * | |
62fe710f | 93 | * Return: true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
94 | */ |
95 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
96 | { | |
97 | return batadv_has_timed_out(dat_entry->last_update, | |
98 | BATADV_DAT_ENTRY_TIMEOUT); | |
99 | } | |
100 | ||
101 | /** | |
102 | * __batadv_dat_purge - delete entries from the DAT local storage | |
103 | * @bat_priv: the bat priv with all the soft interface information | |
104 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
105 | * not. This function takes the dat_entry as argument and has to | |
106 | * returns a boolean value: true is the entry has to be deleted, | |
107 | * false otherwise | |
108 | * | |
93178018 ML |
109 | * Loops over each entry in the DAT local storage and deletes it if and only if |
110 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
111 | */ |
112 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
113 | bool (*to_purge)(struct batadv_dat_entry *)) | |
114 | { | |
115 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
116 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 117 | struct hlist_node *node_tmp; |
2f1dfbe1 | 118 | struct hlist_head *head; |
6b5e971a | 119 | u32 i; |
2f1dfbe1 AQ |
120 | |
121 | if (!bat_priv->dat.hash) | |
122 | return; | |
123 | ||
124 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
125 | head = &bat_priv->dat.hash->table[i]; | |
126 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
127 | ||
128 | spin_lock_bh(list_lock); | |
b67bfe0d | 129 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 130 | hash_entry) { |
93178018 | 131 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
132 | * ask it if the entry has to be purged or not |
133 | */ | |
134 | if (to_purge && !to_purge(dat_entry)) | |
135 | continue; | |
136 | ||
b67bfe0d | 137 | hlist_del_rcu(&dat_entry->hash_entry); |
a6416f9f | 138 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
139 | } |
140 | spin_unlock_bh(list_lock); | |
141 | } | |
142 | } | |
143 | ||
144 | /** | |
145 | * batadv_dat_purge - periodic task that deletes old entries from the local DAT | |
146 | * hash table | |
147 | * @work: kernel work struct | |
148 | */ | |
149 | static void batadv_dat_purge(struct work_struct *work) | |
150 | { | |
151 | struct delayed_work *delayed_work; | |
152 | struct batadv_priv_dat *priv_dat; | |
153 | struct batadv_priv *bat_priv; | |
154 | ||
155 | delayed_work = container_of(work, struct delayed_work, work); | |
156 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); | |
157 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
158 | ||
159 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
160 | batadv_dat_start_timer(bat_priv); | |
161 | } | |
162 | ||
163 | /** | |
164 | * batadv_compare_dat - comparing function used in the local DAT hash table | |
165 | * @node: node in the local table | |
166 | * @data2: second object to compare the node to | |
167 | * | |
62fe710f | 168 | * Return: 1 if the two entries are the same, 0 otherwise. |
2f1dfbe1 AQ |
169 | */ |
170 | static int batadv_compare_dat(const struct hlist_node *node, const void *data2) | |
171 | { | |
172 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
173 | hash_entry); | |
174 | ||
36484f84 | 175 | return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0; |
2f1dfbe1 AQ |
176 | } |
177 | ||
5c3a0e55 AQ |
178 | /** |
179 | * batadv_arp_hw_src - extract the hw_src field from an ARP packet | |
180 | * @skb: ARP packet | |
181 | * @hdr_size: size of the possible header before the ARP packet | |
182 | * | |
62fe710f | 183 | * Return: the value of the hw_src field in the ARP packet. |
5c3a0e55 | 184 | */ |
6b5e971a | 185 | static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) |
5c3a0e55 | 186 | { |
6b5e971a | 187 | u8 *addr; |
5c3a0e55 | 188 | |
6b5e971a | 189 | addr = (u8 *)(skb->data + hdr_size); |
5c3a0e55 AQ |
190 | addr += ETH_HLEN + sizeof(struct arphdr); |
191 | ||
192 | return addr; | |
193 | } | |
194 | ||
195 | /** | |
196 | * batadv_arp_ip_src - extract the ip_src field from an ARP packet | |
197 | * @skb: ARP packet | |
198 | * @hdr_size: size of the possible header before the ARP packet | |
199 | * | |
62fe710f | 200 | * Return: the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
201 | */ |
202 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
203 | { | |
204 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
205 | } | |
206 | ||
207 | /** | |
208 | * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet | |
209 | * @skb: ARP packet | |
210 | * @hdr_size: size of the possible header before the ARP packet | |
211 | * | |
62fe710f | 212 | * Return: the value of the hw_dst field in the ARP packet. |
5c3a0e55 | 213 | */ |
6b5e971a | 214 | static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) |
5c3a0e55 AQ |
215 | { |
216 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
217 | } | |
218 | ||
219 | /** | |
220 | * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet | |
221 | * @skb: ARP packet | |
222 | * @hdr_size: size of the possible header before the ARP packet | |
223 | * | |
62fe710f | 224 | * Return: the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
225 | */ |
226 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
227 | { | |
228 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
229 | } | |
230 | ||
785ea114 AQ |
231 | /** |
232 | * batadv_hash_dat - compute the hash value for an IP address | |
233 | * @data: data to hash | |
234 | * @size: size of the hash table | |
235 | * | |
62fe710f | 236 | * Return: the selected index in the hash table for the given data. |
785ea114 | 237 | */ |
6b5e971a | 238 | static u32 batadv_hash_dat(const void *data, u32 size) |
785ea114 | 239 | { |
6b5e971a | 240 | u32 hash = 0; |
be1db4f6 | 241 | const struct batadv_dat_entry *dat = data; |
36fd61cb | 242 | const unsigned char *key; |
6b5e971a | 243 | u32 i; |
36fd61cb SE |
244 | |
245 | key = (const unsigned char *)&dat->ip; | |
246 | for (i = 0; i < sizeof(dat->ip); i++) { | |
247 | hash += key[i]; | |
248 | hash += (hash << 10); | |
249 | hash ^= (hash >> 6); | |
250 | } | |
785ea114 | 251 | |
36fd61cb SE |
252 | key = (const unsigned char *)&dat->vid; |
253 | for (i = 0; i < sizeof(dat->vid); i++) { | |
254 | hash += key[i]; | |
255 | hash += (hash << 10); | |
256 | hash ^= (hash >> 6); | |
257 | } | |
785ea114 AQ |
258 | |
259 | hash += (hash << 3); | |
260 | hash ^= (hash >> 11); | |
261 | hash += (hash << 15); | |
262 | ||
263 | return hash % size; | |
264 | } | |
265 | ||
2f1dfbe1 | 266 | /** |
93178018 | 267 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
268 | * table |
269 | * @bat_priv: the bat priv with all the soft interface information | |
270 | * @ip: search key | |
be1db4f6 | 271 | * @vid: VLAN identifier |
2f1dfbe1 | 272 | * |
62fe710f | 273 | * Return: the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
274 | */ |
275 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
276 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
277 | unsigned short vid) | |
2f1dfbe1 AQ |
278 | { |
279 | struct hlist_head *head; | |
be1db4f6 | 280 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 | 281 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
6b5e971a | 282 | u32 index; |
2f1dfbe1 AQ |
283 | |
284 | if (!hash) | |
285 | return NULL; | |
286 | ||
be1db4f6 AQ |
287 | to_find.ip = ip; |
288 | to_find.vid = vid; | |
289 | ||
290 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
291 | head = &hash->table[index]; |
292 | ||
293 | rcu_read_lock(); | |
b67bfe0d | 294 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
295 | if (dat_entry->ip != ip) |
296 | continue; | |
297 | ||
68a6722c | 298 | if (!kref_get_unless_zero(&dat_entry->refcount)) |
2f1dfbe1 AQ |
299 | continue; |
300 | ||
301 | dat_entry_tmp = dat_entry; | |
302 | break; | |
303 | } | |
304 | rcu_read_unlock(); | |
305 | ||
306 | return dat_entry_tmp; | |
307 | } | |
308 | ||
309 | /** | |
310 | * batadv_dat_entry_add - add a new dat entry or update it if already exists | |
311 | * @bat_priv: the bat priv with all the soft interface information | |
312 | * @ip: ipv4 to add/edit | |
313 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 314 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
315 | */ |
316 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
6b5e971a | 317 | u8 *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
318 | { |
319 | struct batadv_dat_entry *dat_entry; | |
320 | int hash_added; | |
321 | ||
be1db4f6 | 322 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
323 | /* if this entry is already known, just update it */ |
324 | if (dat_entry) { | |
325 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 326 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
327 | dat_entry->last_update = jiffies; |
328 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
329 | "Entry updated: %pI4 %pM (vid: %d)\n", |
330 | &dat_entry->ip, dat_entry->mac_addr, | |
331 | BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
332 | goto out; |
333 | } | |
334 | ||
335 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
336 | if (!dat_entry) | |
337 | goto out; | |
338 | ||
339 | dat_entry->ip = ip; | |
be1db4f6 | 340 | dat_entry->vid = vid; |
8fdd0153 | 341 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 | 342 | dat_entry->last_update = jiffies; |
68a6722c SE |
343 | kref_init(&dat_entry->refcount); |
344 | kref_get(&dat_entry->refcount); | |
2f1dfbe1 AQ |
345 | |
346 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, | |
be1db4f6 | 347 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
348 | &dat_entry->hash_entry); |
349 | ||
350 | if (unlikely(hash_added != 0)) { | |
351 | /* remove the reference for the hash */ | |
a6416f9f | 352 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
353 | goto out; |
354 | } | |
355 | ||
be1db4f6 AQ |
356 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
357 | &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid)); | |
2f1dfbe1 AQ |
358 | |
359 | out: | |
360 | if (dat_entry) | |
a6416f9f | 361 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
362 | } |
363 | ||
5c3a0e55 AQ |
364 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
365 | ||
366 | /** | |
367 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
368 | * @bat_priv: the bat priv with all the soft interface information | |
369 | * @skb: ARP packet | |
370 | * @type: ARP type | |
371 | * @hdr_size: size of the possible header before the ARP packet | |
372 | * @msg: message to print together with the debugging information | |
373 | */ | |
374 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
6b5e971a | 375 | u16 type, int hdr_size, char *msg) |
5c3a0e55 AQ |
376 | { |
377 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
378 | struct batadv_bcast_packet *bcast_pkt; | |
6b5e971a | 379 | u8 *orig_addr; |
5c3a0e55 AQ |
380 | __be32 ip_src, ip_dst; |
381 | ||
382 | if (msg) | |
383 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
384 | ||
385 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
386 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
387 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
388 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
389 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
390 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
391 | ||
392 | if (hdr_size == 0) | |
393 | return; | |
394 | ||
5c3a0e55 AQ |
395 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
396 | ||
a40d9b07 | 397 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
398 | case BATADV_UNICAST: |
399 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
400 | "* encapsulated within a UNICAST packet\n"); | |
401 | break; | |
402 | case BATADV_UNICAST_4ADDR: | |
403 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
404 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
405 | unicast_4addr_packet->src); | |
406 | switch (unicast_4addr_packet->subtype) { | |
407 | case BATADV_P_DAT_DHT_PUT: | |
408 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
409 | break; | |
410 | case BATADV_P_DAT_DHT_GET: | |
411 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
412 | break; | |
413 | case BATADV_P_DAT_CACHE_REPLY: | |
414 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
415 | "* type: DAT_CACHE_REPLY\n"); | |
416 | break; | |
417 | case BATADV_P_DATA: | |
418 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
419 | break; | |
420 | default: | |
421 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 422 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
423 | } |
424 | break; | |
425 | case BATADV_BCAST: | |
426 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
427 | orig_addr = bcast_pkt->orig; | |
428 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
429 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
430 | orig_addr); | |
431 | break; | |
432 | default: | |
433 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
434 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 435 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
436 | } |
437 | } | |
438 | ||
439 | #else | |
440 | ||
441 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
6b5e971a | 442 | u16 type, int hdr_size, char *msg) |
5c3a0e55 AQ |
443 | { |
444 | } | |
445 | ||
446 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
447 | ||
785ea114 AQ |
448 | /** |
449 | * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate | |
450 | * @res: the array with the already selected candidates | |
451 | * @select: number of already selected candidates | |
452 | * @tmp_max: address of the currently evaluated node | |
453 | * @max: current round max address | |
454 | * @last_max: address of the last selected candidate | |
455 | * @candidate: orig_node under evaluation | |
456 | * @max_orig_node: last selected candidate | |
457 | * | |
62fe710f | 458 | * Return: true if the node has been elected as next candidate or false |
93178018 | 459 | * otherwise. |
785ea114 AQ |
460 | */ |
461 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
462 | int select, batadv_dat_addr_t tmp_max, | |
463 | batadv_dat_addr_t max, | |
464 | batadv_dat_addr_t last_max, | |
465 | struct batadv_orig_node *candidate, | |
466 | struct batadv_orig_node *max_orig_node) | |
467 | { | |
468 | bool ret = false; | |
469 | int j; | |
470 | ||
17cf0ea4 | 471 | /* check if orig node candidate is running DAT */ |
65d7d460 | 472 | if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities)) |
17cf0ea4 ML |
473 | goto out; |
474 | ||
785ea114 AQ |
475 | /* Check if this node has already been selected... */ |
476 | for (j = 0; j < select; j++) | |
477 | if (res[j].orig_node == candidate) | |
478 | break; | |
479 | /* ..and possibly skip it */ | |
480 | if (j < select) | |
481 | goto out; | |
482 | /* sanity check: has it already been selected? This should not happen */ | |
483 | if (tmp_max > last_max) | |
484 | goto out; | |
485 | /* check if during this iteration an originator with a closer dht | |
486 | * address has already been found | |
487 | */ | |
488 | if (tmp_max < max) | |
489 | goto out; | |
490 | /* this is an hash collision with the temporary selected node. Choose | |
491 | * the one with the lowest address | |
492 | */ | |
816cd5b8 | 493 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
494 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
495 | goto out; | |
496 | ||
497 | ret = true; | |
498 | out: | |
499 | return ret; | |
500 | } | |
501 | ||
502 | /** | |
503 | * batadv_choose_next_candidate - select the next DHT candidate | |
504 | * @bat_priv: the bat priv with all the soft interface information | |
505 | * @cands: candidates array | |
506 | * @select: number of candidates already present in the array | |
507 | * @ip_key: key to look up in the DHT | |
508 | * @last_max: pointer where the address of the selected candidate will be saved | |
509 | */ | |
510 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
511 | struct batadv_dat_candidate *cands, | |
512 | int select, batadv_dat_addr_t ip_key, | |
513 | batadv_dat_addr_t *last_max) | |
514 | { | |
4f248cff SE |
515 | batadv_dat_addr_t max = 0; |
516 | batadv_dat_addr_t tmp_max = 0; | |
785ea114 AQ |
517 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; |
518 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
519 | struct hlist_head *head; |
520 | int i; | |
521 | ||
522 | /* if no node is eligible as candidate, leave the candidate type as | |
523 | * NOT_FOUND | |
524 | */ | |
525 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
526 | ||
93178018 | 527 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
528 | * dat_address which has not been selected yet |
529 | */ | |
530 | for (i = 0; i < hash->size; i++) { | |
531 | head = &hash->table[i]; | |
532 | ||
533 | rcu_read_lock(); | |
b67bfe0d | 534 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 535 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
536 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
537 | ip_key; | |
538 | ||
539 | if (!batadv_is_orig_node_eligible(cands, select, | |
540 | tmp_max, max, | |
541 | *last_max, orig_node, | |
542 | max_orig_node)) | |
543 | continue; | |
544 | ||
7c124391 | 545 | if (!kref_get_unless_zero(&orig_node->refcount)) |
785ea114 AQ |
546 | continue; |
547 | ||
548 | max = tmp_max; | |
549 | if (max_orig_node) | |
5d967310 | 550 | batadv_orig_node_put(max_orig_node); |
785ea114 AQ |
551 | max_orig_node = orig_node; |
552 | } | |
553 | rcu_read_unlock(); | |
554 | } | |
555 | if (max_orig_node) { | |
556 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
557 | cands[select].orig_node = max_orig_node; | |
558 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
559 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
560 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
561 | max); | |
562 | } | |
563 | *last_max = max; | |
564 | } | |
565 | ||
566 | /** | |
93178018 | 567 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
568 | * be sent to |
569 | * @bat_priv: the bat priv with all the soft interface information | |
570 | * @ip_dst: ipv4 to look up in the DHT | |
571 | * | |
572 | * An originator O is selected if and only if its DHT_ID value is one of three | |
573 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
574 | * value of the key. ip_dst is the key. | |
575 | * | |
62fe710f | 576 | * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
577 | */ |
578 | static struct batadv_dat_candidate * | |
579 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst) | |
580 | { | |
581 | int select; | |
582 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
583 | struct batadv_dat_candidate *res; | |
b7fe3d4f | 584 | struct batadv_dat_entry dat; |
785ea114 AQ |
585 | |
586 | if (!bat_priv->orig_hash) | |
587 | return NULL; | |
588 | ||
0185dda6 AQ |
589 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
590 | GFP_ATOMIC); | |
785ea114 AQ |
591 | if (!res) |
592 | return NULL; | |
593 | ||
b7fe3d4f SE |
594 | dat.ip = ip_dst; |
595 | dat.vid = 0; | |
596 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat, | |
785ea114 AQ |
597 | BATADV_DAT_ADDR_MAX); |
598 | ||
599 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
600 | "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst, | |
601 | ip_key); | |
602 | ||
603 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
604 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
605 | &last_max); | |
606 | ||
607 | return res; | |
608 | } | |
609 | ||
610 | /** | |
611 | * batadv_dat_send_data - send a payload to the selected candidates | |
612 | * @bat_priv: the bat priv with all the soft interface information | |
613 | * @skb: payload to send | |
614 | * @ip: the DHT key | |
615 | * @packet_subtype: unicast4addr packet subtype to use | |
616 | * | |
93178018 ML |
617 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
618 | * to each of the selected candidates. | |
785ea114 | 619 | * |
62fe710f | 620 | * Return: true if the packet is sent to at least one candidate, false |
93178018 | 621 | * otherwise. |
785ea114 AQ |
622 | */ |
623 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
624 | struct sk_buff *skb, __be32 ip, | |
625 | int packet_subtype) | |
626 | { | |
627 | int i; | |
628 | bool ret = false; | |
629 | int send_status; | |
630 | struct batadv_neigh_node *neigh_node = NULL; | |
631 | struct sk_buff *tmp_skb; | |
632 | struct batadv_dat_candidate *cand; | |
633 | ||
634 | cand = batadv_dat_select_candidates(bat_priv, ip); | |
635 | if (!cand) | |
636 | goto out; | |
637 | ||
638 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
639 | ||
640 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
641 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
642 | continue; | |
643 | ||
7351a482 SW |
644 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
645 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
646 | if (!neigh_node) |
647 | goto free_orig; | |
648 | ||
bad93e9d | 649 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
650 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
651 | cand[i].orig_node, | |
652 | packet_subtype)) { | |
785ea114 AQ |
653 | kfree_skb(tmp_skb); |
654 | goto free_neigh; | |
655 | } | |
656 | ||
95d39278 | 657 | send_status = batadv_send_unicast_skb(tmp_skb, neigh_node); |
4046b24a MH |
658 | if (send_status == NET_XMIT_SUCCESS) { |
659 | /* count the sent packet */ | |
660 | switch (packet_subtype) { | |
661 | case BATADV_P_DAT_DHT_GET: | |
662 | batadv_inc_counter(bat_priv, | |
663 | BATADV_CNT_DAT_GET_TX); | |
664 | break; | |
665 | case BATADV_P_DAT_DHT_PUT: | |
666 | batadv_inc_counter(bat_priv, | |
667 | BATADV_CNT_DAT_PUT_TX); | |
668 | break; | |
669 | } | |
670 | ||
785ea114 AQ |
671 | /* packet sent to a candidate: return true */ |
672 | ret = true; | |
4046b24a | 673 | } |
785ea114 | 674 | free_neigh: |
25bb2509 | 675 | batadv_neigh_node_put(neigh_node); |
785ea114 | 676 | free_orig: |
5d967310 | 677 | batadv_orig_node_put(cand[i].orig_node); |
785ea114 AQ |
678 | } |
679 | ||
680 | out: | |
681 | kfree(cand); | |
682 | return ret; | |
683 | } | |
2f1dfbe1 | 684 | |
17cf0ea4 ML |
685 | /** |
686 | * batadv_dat_tvlv_container_update - update the dat tvlv container after dat | |
687 | * setting change | |
688 | * @bat_priv: the bat priv with all the soft interface information | |
689 | */ | |
690 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
691 | { | |
692 | char dat_mode; | |
693 | ||
694 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
695 | ||
696 | switch (dat_mode) { | |
697 | case 0: | |
698 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
699 | break; | |
700 | case 1: | |
701 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
702 | NULL, 0); | |
703 | break; | |
704 | } | |
705 | } | |
706 | ||
707 | /** | |
708 | * batadv_dat_status_update - update the dat tvlv container after dat | |
709 | * setting change | |
710 | * @net_dev: the soft interface net device | |
711 | */ | |
712 | void batadv_dat_status_update(struct net_device *net_dev) | |
713 | { | |
714 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 715 | |
17cf0ea4 ML |
716 | batadv_dat_tvlv_container_update(bat_priv); |
717 | } | |
718 | ||
719 | /** | |
720 | * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container | |
721 | * @bat_priv: the bat priv with all the soft interface information | |
722 | * @orig: the orig_node of the ogm | |
723 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
724 | * @tvlv_value: tvlv buffer containing the gateway data | |
725 | * @tvlv_value_len: tvlv buffer length | |
726 | */ | |
727 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
728 | struct batadv_orig_node *orig, | |
6b5e971a SE |
729 | u8 flags, |
730 | void *tvlv_value, u16 tvlv_value_len) | |
17cf0ea4 ML |
731 | { |
732 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
65d7d460 | 733 | clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 | 734 | else |
65d7d460 | 735 | set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 ML |
736 | } |
737 | ||
2f1dfbe1 AQ |
738 | /** |
739 | * batadv_dat_hash_free - free the local DAT hash table | |
740 | * @bat_priv: the bat priv with all the soft interface information | |
741 | */ | |
742 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
743 | { | |
33af49ad AQ |
744 | if (!bat_priv->dat.hash) |
745 | return; | |
746 | ||
2f1dfbe1 AQ |
747 | __batadv_dat_purge(bat_priv, NULL); |
748 | ||
749 | batadv_hash_destroy(bat_priv->dat.hash); | |
750 | ||
751 | bat_priv->dat.hash = NULL; | |
752 | } | |
753 | ||
754 | /** | |
755 | * batadv_dat_init - initialise the DAT internals | |
756 | * @bat_priv: the bat priv with all the soft interface information | |
fe13c2aa AQ |
757 | * |
758 | * Return: 0 in case of success, a negative error code otherwise | |
2f1dfbe1 AQ |
759 | */ |
760 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
761 | { | |
762 | if (bat_priv->dat.hash) | |
763 | return 0; | |
764 | ||
765 | bat_priv->dat.hash = batadv_hash_new(1024); | |
766 | ||
767 | if (!bat_priv->dat.hash) | |
768 | return -ENOMEM; | |
769 | ||
770 | batadv_dat_start_timer(bat_priv); | |
771 | ||
17cf0ea4 ML |
772 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
773 | NULL, BATADV_TVLV_DAT, 1, | |
774 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
775 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
776 | return 0; |
777 | } | |
778 | ||
779 | /** | |
780 | * batadv_dat_free - free the DAT internals | |
781 | * @bat_priv: the bat priv with all the soft interface information | |
782 | */ | |
783 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
784 | { | |
17cf0ea4 ML |
785 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
786 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
787 | ||
2f1dfbe1 AQ |
788 | cancel_delayed_work_sync(&bat_priv->dat.work); |
789 | ||
790 | batadv_dat_hash_free(bat_priv); | |
791 | } | |
792 | ||
793 | /** | |
794 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
795 | * @seq: seq file to print on | |
796 | * @offset: not used | |
fe13c2aa AQ |
797 | * |
798 | * Return: always 0 | |
2f1dfbe1 AQ |
799 | */ |
800 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
801 | { | |
802 | struct net_device *net_dev = (struct net_device *)seq->private; | |
803 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
804 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
805 | struct batadv_dat_entry *dat_entry; | |
806 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
807 | struct hlist_head *head; |
808 | unsigned long last_seen_jiffies; | |
809 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
6b5e971a | 810 | u32 i; |
2f1dfbe1 AQ |
811 | |
812 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
813 | if (!primary_if) | |
814 | goto out; | |
815 | ||
816 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
be1db4f6 AQ |
817 | seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4", |
818 | "MAC", "VID", "last-seen"); | |
2f1dfbe1 AQ |
819 | |
820 | for (i = 0; i < hash->size; i++) { | |
821 | head = &hash->table[i]; | |
822 | ||
823 | rcu_read_lock(); | |
b67bfe0d | 824 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
825 | last_seen_jiffies = jiffies - dat_entry->last_update; |
826 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
827 | last_seen_mins = last_seen_msecs / 60000; | |
828 | last_seen_msecs = last_seen_msecs % 60000; | |
829 | last_seen_secs = last_seen_msecs / 1000; | |
830 | ||
be1db4f6 | 831 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 832 | &dat_entry->ip, dat_entry->mac_addr, |
be1db4f6 | 833 | BATADV_PRINT_VID(dat_entry->vid), |
2f1dfbe1 AQ |
834 | last_seen_mins, last_seen_secs); |
835 | } | |
836 | rcu_read_unlock(); | |
837 | } | |
838 | ||
839 | out: | |
840 | if (primary_if) | |
82047ad7 | 841 | batadv_hardif_put(primary_if); |
2f1dfbe1 AQ |
842 | return 0; |
843 | } | |
5c3a0e55 AQ |
844 | |
845 | /** | |
846 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
847 | * @bat_priv: the bat priv with all the soft interface information | |
848 | * @skb: packet to analyse | |
849 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
850 | * | |
62fe710f | 851 | * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 | 852 | */ |
6b5e971a SE |
853 | static u16 batadv_arp_get_type(struct batadv_priv *bat_priv, |
854 | struct sk_buff *skb, int hdr_size) | |
5c3a0e55 AQ |
855 | { |
856 | struct arphdr *arphdr; | |
857 | struct ethhdr *ethhdr; | |
858 | __be32 ip_src, ip_dst; | |
6b5e971a SE |
859 | u8 *hw_src, *hw_dst; |
860 | u16 type = 0; | |
5c3a0e55 AQ |
861 | |
862 | /* pull the ethernet header */ | |
863 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
864 | goto out; | |
865 | ||
866 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
867 | ||
868 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
869 | goto out; | |
870 | ||
871 | /* pull the ARP payload */ | |
872 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
873 | arp_hdr_len(skb->dev)))) | |
874 | goto out; | |
875 | ||
876 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
877 | ||
93178018 | 878 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
879 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
880 | goto out; | |
881 | ||
882 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
883 | goto out; | |
884 | ||
885 | if (arphdr->ar_hln != ETH_ALEN) | |
886 | goto out; | |
887 | ||
888 | if (arphdr->ar_pln != 4) | |
889 | goto out; | |
890 | ||
891 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
892 | * will simply ignore it | |
893 | */ | |
894 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
895 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
896 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
897 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
898 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
899 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
900 | goto out; |
901 | ||
b618ad11 MS |
902 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
903 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
904 | goto out; | |
905 | ||
93178018 | 906 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
907 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
908 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
909 | if (is_zero_ether_addr(hw_dst) || | |
910 | is_multicast_ether_addr(hw_dst)) | |
911 | goto out; | |
912 | } | |
913 | ||
5c3a0e55 AQ |
914 | type = ntohs(arphdr->ar_op); |
915 | out: | |
916 | return type; | |
917 | } | |
c384ea3e | 918 | |
be1db4f6 AQ |
919 | /** |
920 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
921 | * @skb: the buffer containing the packet to extract the VID from | |
922 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
923 | * | |
62fe710f SE |
924 | * Return: If the packet embedded in the skb is vlan tagged this function |
925 | * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS | |
926 | * is returned. | |
be1db4f6 AQ |
927 | */ |
928 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
929 | { | |
930 | unsigned short vid; | |
931 | ||
932 | vid = batadv_get_vid(skb, *hdr_size); | |
933 | ||
934 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
935 | * If the header contained in the packet is a VLAN one (which is longer) | |
936 | * hdr_size is updated so that the functions will still skip the | |
937 | * correct amount of bytes. | |
938 | */ | |
939 | if (vid & BATADV_VLAN_HAS_TAG) | |
940 | *hdr_size += VLAN_HLEN; | |
941 | ||
942 | return vid; | |
943 | } | |
944 | ||
c384ea3e AQ |
945 | /** |
946 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
947 | * answer using DAT | |
948 | * @bat_priv: the bat priv with all the soft interface information | |
949 | * @skb: packet to check | |
950 | * | |
62fe710f | 951 | * Return: true if the message has been sent to the dht candidates, false |
93178018 ML |
952 | * otherwise. In case of a positive return value the message has to be enqueued |
953 | * to permit the fallback. | |
c384ea3e AQ |
954 | */ |
955 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
956 | struct sk_buff *skb) | |
957 | { | |
6b5e971a | 958 | u16 type = 0; |
c384ea3e | 959 | __be32 ip_dst, ip_src; |
6b5e971a | 960 | u8 *hw_src; |
c384ea3e AQ |
961 | bool ret = false; |
962 | struct batadv_dat_entry *dat_entry = NULL; | |
963 | struct sk_buff *skb_new; | |
be1db4f6 AQ |
964 | int hdr_size = 0; |
965 | unsigned short vid; | |
c384ea3e | 966 | |
33af49ad AQ |
967 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
968 | goto out; | |
969 | ||
be1db4f6 AQ |
970 | vid = batadv_dat_get_vid(skb, &hdr_size); |
971 | ||
972 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
973 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
974 | * message to the selected DHT candidates | |
975 | */ | |
976 | if (type != ARPOP_REQUEST) | |
977 | goto out; | |
978 | ||
be1db4f6 AQ |
979 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
980 | "Parsing outgoing ARP REQUEST"); | |
c384ea3e | 981 | |
be1db4f6 AQ |
982 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
983 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
984 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 985 | |
be1db4f6 | 986 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 987 | |
be1db4f6 | 988 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 989 | if (dat_entry) { |
88e48d7b AQ |
990 | /* If the ARP request is destined for a local client the local |
991 | * client will answer itself. DAT would only generate a | |
992 | * duplicate packet. | |
993 | * | |
994 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
995 | * additional DAT answer may trigger kernel warnings about | |
996 | * a packet coming from the wrong port. | |
997 | */ | |
cc2f3386 | 998 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
999 | ret = true; |
1000 | goto out; | |
1001 | } | |
1002 | ||
c384ea3e | 1003 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 1004 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
1005 | dat_entry->mac_addr, hw_src); |
1006 | if (!skb_new) | |
1007 | goto out; | |
1008 | ||
be1db4f6 AQ |
1009 | if (vid & BATADV_VLAN_HAS_TAG) |
1010 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1011 | vid & VLAN_VID_MASK); | |
1012 | ||
c384ea3e AQ |
1013 | skb_reset_mac_header(skb_new); |
1014 | skb_new->protocol = eth_type_trans(skb_new, | |
736292c2 | 1015 | bat_priv->soft_iface); |
c384ea3e | 1016 | bat_priv->stats.rx_packets++; |
be1db4f6 | 1017 | bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size; |
736292c2 | 1018 | bat_priv->soft_iface->last_rx = jiffies; |
c384ea3e AQ |
1019 | |
1020 | netif_rx(skb_new); | |
1021 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
1022 | ret = true; | |
1023 | } else { | |
93178018 | 1024 | /* Send the request to the DHT */ |
c384ea3e AQ |
1025 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, |
1026 | BATADV_P_DAT_DHT_GET); | |
1027 | } | |
1028 | out: | |
1029 | if (dat_entry) | |
a6416f9f | 1030 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1031 | return ret; |
1032 | } | |
1033 | ||
1034 | /** | |
1035 | * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to | |
1036 | * answer using the local DAT storage | |
1037 | * @bat_priv: the bat priv with all the soft interface information | |
1038 | * @skb: packet to check | |
1039 | * @hdr_size: size of the encapsulation header | |
1040 | * | |
62fe710f | 1041 | * Return: true if the request has been answered, false otherwise. |
c384ea3e AQ |
1042 | */ |
1043 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
1044 | struct sk_buff *skb, int hdr_size) | |
1045 | { | |
6b5e971a | 1046 | u16 type; |
c384ea3e | 1047 | __be32 ip_src, ip_dst; |
6b5e971a | 1048 | u8 *hw_src; |
c384ea3e | 1049 | struct sk_buff *skb_new; |
c384ea3e AQ |
1050 | struct batadv_dat_entry *dat_entry = NULL; |
1051 | bool ret = false; | |
be1db4f6 | 1052 | unsigned short vid; |
c384ea3e AQ |
1053 | int err; |
1054 | ||
33af49ad AQ |
1055 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1056 | goto out; | |
1057 | ||
be1db4f6 AQ |
1058 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1059 | ||
c384ea3e AQ |
1060 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1061 | if (type != ARPOP_REQUEST) | |
1062 | goto out; | |
1063 | ||
1064 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1065 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1066 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1067 | ||
1068 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1069 | "Parsing incoming ARP REQUEST"); | |
1070 | ||
be1db4f6 | 1071 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1072 | |
be1db4f6 | 1073 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1074 | if (!dat_entry) |
1075 | goto out; | |
1076 | ||
c384ea3e | 1077 | skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, |
736292c2 | 1078 | bat_priv->soft_iface, ip_dst, hw_src, |
c384ea3e AQ |
1079 | dat_entry->mac_addr, hw_src); |
1080 | ||
1081 | if (!skb_new) | |
1082 | goto out; | |
1083 | ||
927c2ed7 LL |
1084 | /* the rest of the TX path assumes that the mac_header offset pointing |
1085 | * to the inner Ethernet header has been set, therefore reset it now. | |
1086 | */ | |
1087 | skb_reset_mac_header(skb_new); | |
1088 | ||
be1db4f6 AQ |
1089 | if (vid & BATADV_VLAN_HAS_TAG) |
1090 | skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), | |
1091 | vid & VLAN_VID_MASK); | |
1092 | ||
93178018 ML |
1093 | /* To preserve backwards compatibility, the node has choose the outgoing |
1094 | * format based on the incoming request packet type. The assumption is | |
1095 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1096 | */ |
1097 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1098 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1099 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1100 | NULL, vid); |
c384ea3e | 1101 | else |
6c413b1c | 1102 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1103 | |
e300d314 | 1104 | if (err != NET_XMIT_DROP) { |
4046b24a | 1105 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1106 | ret = true; |
4046b24a | 1107 | } |
c384ea3e AQ |
1108 | out: |
1109 | if (dat_entry) | |
a6416f9f | 1110 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1111 | if (ret) |
1112 | kfree_skb(skb); | |
1113 | return ret; | |
1114 | } | |
1115 | ||
1116 | /** | |
1117 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1118 | * @bat_priv: the bat priv with all the soft interface information | |
1119 | * @skb: packet to check | |
1120 | */ | |
1121 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1122 | struct sk_buff *skb) | |
1123 | { | |
6b5e971a | 1124 | u16 type; |
c384ea3e | 1125 | __be32 ip_src, ip_dst; |
6b5e971a | 1126 | u8 *hw_src, *hw_dst; |
be1db4f6 AQ |
1127 | int hdr_size = 0; |
1128 | unsigned short vid; | |
c384ea3e | 1129 | |
33af49ad AQ |
1130 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1131 | return; | |
1132 | ||
be1db4f6 AQ |
1133 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1134 | ||
1135 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1136 | if (type != ARPOP_REPLY) |
1137 | return; | |
1138 | ||
be1db4f6 AQ |
1139 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, |
1140 | "Parsing outgoing ARP REPLY"); | |
c384ea3e | 1141 | |
be1db4f6 AQ |
1142 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1143 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1144 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1145 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1146 | |
be1db4f6 AQ |
1147 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1148 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1149 | |
1150 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1151 | * the node obtained from the ARP reply |
c384ea3e AQ |
1152 | */ |
1153 | batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT); | |
1154 | batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT); | |
1155 | } | |
aa143d28 | 1156 | |
c384ea3e AQ |
1157 | /** |
1158 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1159 | * DAT storage only | |
1160 | * @bat_priv: the bat priv with all the soft interface information | |
1161 | * @skb: packet to check | |
93178018 | 1162 | * @hdr_size: size of the encapsulation header |
f202a666 | 1163 | * |
62fe710f | 1164 | * Return: true if the packet was snooped and consumed by DAT. False if the |
f202a666 | 1165 | * packet has to be delivered to the interface |
c384ea3e AQ |
1166 | */ |
1167 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1168 | struct sk_buff *skb, int hdr_size) | |
1169 | { | |
6b5e971a | 1170 | u16 type; |
c384ea3e | 1171 | __be32 ip_src, ip_dst; |
6b5e971a | 1172 | u8 *hw_src, *hw_dst; |
f202a666 | 1173 | bool dropped = false; |
be1db4f6 | 1174 | unsigned short vid; |
c384ea3e | 1175 | |
33af49ad AQ |
1176 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1177 | goto out; | |
1178 | ||
be1db4f6 AQ |
1179 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1180 | ||
c384ea3e AQ |
1181 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1182 | if (type != ARPOP_REPLY) | |
1183 | goto out; | |
1184 | ||
1185 | batadv_dbg_arp(bat_priv, skb, type, hdr_size, | |
1186 | "Parsing incoming ARP REPLY"); | |
1187 | ||
1188 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1189 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1190 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1191 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1192 | ||
1193 | /* Update our internal cache with both the IP addresses the node got | |
1194 | * within the ARP reply | |
1195 | */ | |
be1db4f6 AQ |
1196 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1197 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1198 | |
1199 | /* if this REPLY is directed to a client of mine, let's deliver the | |
1200 | * packet to the interface | |
1201 | */ | |
f202a666 AQ |
1202 | dropped = !batadv_is_my_client(bat_priv, hw_dst, vid); |
1203 | ||
1204 | /* if this REPLY is sent on behalf of a client of mine, let's drop the | |
1205 | * packet because the client will reply by itself | |
1206 | */ | |
1207 | dropped |= batadv_is_my_client(bat_priv, hw_src, vid); | |
c384ea3e | 1208 | out: |
f202a666 | 1209 | if (dropped) |
0d15bece | 1210 | kfree_skb(skb); |
f202a666 AQ |
1211 | /* if dropped == false -> deliver to the interface */ |
1212 | return dropped; | |
c384ea3e AQ |
1213 | } |
1214 | ||
1215 | /** | |
1216 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1217 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1218 | * @bat_priv: the bat priv with all the soft interface information |
1219 | * @forw_packet: the broadcast packet | |
1220 | * | |
62fe710f | 1221 | * Return: true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1222 | */ |
1223 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1224 | struct batadv_forw_packet *forw_packet) | |
1225 | { | |
6b5e971a | 1226 | u16 type; |
c384ea3e AQ |
1227 | __be32 ip_dst; |
1228 | struct batadv_dat_entry *dat_entry = NULL; | |
1229 | bool ret = false; | |
be1db4f6 AQ |
1230 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1231 | unsigned short vid; | |
c384ea3e | 1232 | |
33af49ad AQ |
1233 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1234 | goto out; | |
1235 | ||
c384ea3e AQ |
1236 | /* If this packet is an ARP_REQUEST and the node already has the |
1237 | * information that it is going to ask, then the packet can be dropped | |
1238 | */ | |
1239 | if (forw_packet->num_packets) | |
1240 | goto out; | |
1241 | ||
be1db4f6 AQ |
1242 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1243 | ||
1244 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1245 | if (type != ARPOP_REQUEST) |
1246 | goto out; | |
1247 | ||
be1db4f6 AQ |
1248 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1249 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1250 | /* check if the node already got this entry */ |
1251 | if (!dat_entry) { | |
1252 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1253 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1254 | goto out; | |
1255 | } | |
1256 | ||
1257 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1258 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1259 | ret = true; | |
1260 | ||
1261 | out: | |
1262 | if (dat_entry) | |
a6416f9f | 1263 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1264 | return ret; |
1265 | } |