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7db7d9f3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
ac79cbb9 | 2 | /* Copyright (C) 2011-2017 B.A.T.M.A.N. contributors: |
785ea114 AQ |
3 | * |
4 | * Antonio Quartulli | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of version 2 of the GNU General Public | |
8 | * License as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
ebf38fb7 | 16 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
785ea114 AQ |
17 | */ |
18 | ||
1e2c2a4f SE |
19 | #include "distributed-arp-table.h" |
20 | #include "main.h" | |
21 | ||
22 | #include <linux/atomic.h> | |
65d7d460 | 23 | #include <linux/bitops.h> |
1e2c2a4f SE |
24 | #include <linux/byteorder/generic.h> |
25 | #include <linux/errno.h> | |
26 | #include <linux/etherdevice.h> | |
b92b94ac | 27 | #include <linux/gfp.h> |
785ea114 | 28 | #include <linux/if_arp.h> |
1e2c2a4f | 29 | #include <linux/if_ether.h> |
be1db4f6 | 30 | #include <linux/if_vlan.h> |
1e2c2a4f SE |
31 | #include <linux/in.h> |
32 | #include <linux/jiffies.h> | |
33 | #include <linux/kernel.h> | |
68a6722c | 34 | #include <linux/kref.h> |
1e2c2a4f SE |
35 | #include <linux/list.h> |
36 | #include <linux/rculist.h> | |
37 | #include <linux/rcupdate.h> | |
38 | #include <linux/seq_file.h> | |
39 | #include <linux/skbuff.h> | |
40 | #include <linux/slab.h> | |
41 | #include <linux/spinlock.h> | |
42 | #include <linux/stddef.h> | |
43 | #include <linux/string.h> | |
44 | #include <linux/workqueue.h> | |
c384ea3e | 45 | #include <net/arp.h> |
785ea114 | 46 | |
00311de5 | 47 | #include "bridge_loop_avoidance.h" |
785ea114 | 48 | #include "hard-interface.h" |
1e2c2a4f | 49 | #include "hash.h" |
ba412080 | 50 | #include "log.h" |
785ea114 AQ |
51 | #include "originator.h" |
52 | #include "send.h" | |
c384ea3e | 53 | #include "translation-table.h" |
1f8dce49 | 54 | #include "tvlv.h" |
785ea114 | 55 | |
2f1dfbe1 AQ |
56 | static void batadv_dat_purge(struct work_struct *work); |
57 | ||
58 | /** | |
7e9a8c2c | 59 | * batadv_dat_start_timer() - initialise the DAT periodic worker |
2f1dfbe1 AQ |
60 | * @bat_priv: the bat priv with all the soft interface information |
61 | */ | |
62 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
63 | { | |
64 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
65 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
66 | msecs_to_jiffies(10000)); | |
67 | } | |
68 | ||
68a6722c | 69 | /** |
7e9a8c2c | 70 | * batadv_dat_entry_release() - release dat_entry from lists and queue for free |
68a6722c SE |
71 | * after rcu grace period |
72 | * @ref: kref pointer of the dat_entry | |
73 | */ | |
74 | static void batadv_dat_entry_release(struct kref *ref) | |
75 | { | |
76 | struct batadv_dat_entry *dat_entry; | |
77 | ||
78 | dat_entry = container_of(ref, struct batadv_dat_entry, refcount); | |
79 | ||
80 | kfree_rcu(dat_entry, rcu); | |
81 | } | |
82 | ||
2f1dfbe1 | 83 | /** |
7e9a8c2c | 84 | * batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly |
68a6722c SE |
85 | * release it |
86 | * @dat_entry: dat_entry to be free'd | |
2f1dfbe1 | 87 | */ |
a6416f9f | 88 | static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) |
2f1dfbe1 | 89 | { |
68a6722c | 90 | kref_put(&dat_entry->refcount, batadv_dat_entry_release); |
2f1dfbe1 AQ |
91 | } |
92 | ||
93 | /** | |
7e9a8c2c | 94 | * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
95 | * @dat_entry: the entry to check |
96 | * | |
62fe710f | 97 | * Return: true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
98 | */ |
99 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
100 | { | |
101 | return batadv_has_timed_out(dat_entry->last_update, | |
102 | BATADV_DAT_ENTRY_TIMEOUT); | |
103 | } | |
104 | ||
105 | /** | |
7e9a8c2c | 106 | * __batadv_dat_purge() - delete entries from the DAT local storage |
2f1dfbe1 AQ |
107 | * @bat_priv: the bat priv with all the soft interface information |
108 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
109 | * not. This function takes the dat_entry as argument and has to | |
110 | * returns a boolean value: true is the entry has to be deleted, | |
111 | * false otherwise | |
112 | * | |
93178018 ML |
113 | * Loops over each entry in the DAT local storage and deletes it if and only if |
114 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
115 | */ |
116 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
117 | bool (*to_purge)(struct batadv_dat_entry *)) | |
118 | { | |
119 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
120 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 121 | struct hlist_node *node_tmp; |
2f1dfbe1 | 122 | struct hlist_head *head; |
6b5e971a | 123 | u32 i; |
2f1dfbe1 AQ |
124 | |
125 | if (!bat_priv->dat.hash) | |
126 | return; | |
127 | ||
128 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
129 | head = &bat_priv->dat.hash->table[i]; | |
130 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
131 | ||
132 | spin_lock_bh(list_lock); | |
b67bfe0d | 133 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 134 | hash_entry) { |
93178018 | 135 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
136 | * ask it if the entry has to be purged or not |
137 | */ | |
138 | if (to_purge && !to_purge(dat_entry)) | |
139 | continue; | |
140 | ||
b67bfe0d | 141 | hlist_del_rcu(&dat_entry->hash_entry); |
a6416f9f | 142 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
143 | } |
144 | spin_unlock_bh(list_lock); | |
145 | } | |
146 | } | |
147 | ||
148 | /** | |
7e9a8c2c SE |
149 | * batadv_dat_purge() - periodic task that deletes old entries from the local |
150 | * DAT hash table | |
2f1dfbe1 AQ |
151 | * @work: kernel work struct |
152 | */ | |
153 | static void batadv_dat_purge(struct work_struct *work) | |
154 | { | |
155 | struct delayed_work *delayed_work; | |
156 | struct batadv_priv_dat *priv_dat; | |
157 | struct batadv_priv *bat_priv; | |
158 | ||
4ba4bc0f | 159 | delayed_work = to_delayed_work(work); |
2f1dfbe1 AQ |
160 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); |
161 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
162 | ||
163 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
164 | batadv_dat_start_timer(bat_priv); | |
165 | } | |
166 | ||
167 | /** | |
7e9a8c2c | 168 | * batadv_compare_dat() - comparing function used in the local DAT hash table |
2f1dfbe1 AQ |
169 | * @node: node in the local table |
170 | * @data2: second object to compare the node to | |
171 | * | |
4b426b10 | 172 | * Return: true if the two entries are the same, false otherwise. |
2f1dfbe1 | 173 | */ |
4b426b10 | 174 | static bool batadv_compare_dat(const struct hlist_node *node, const void *data2) |
2f1dfbe1 AQ |
175 | { |
176 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
177 | hash_entry); | |
178 | ||
4b426b10 | 179 | return memcmp(data1, data2, sizeof(__be32)) == 0; |
2f1dfbe1 AQ |
180 | } |
181 | ||
5c3a0e55 | 182 | /** |
7e9a8c2c | 183 | * batadv_arp_hw_src() - extract the hw_src field from an ARP packet |
5c3a0e55 AQ |
184 | * @skb: ARP packet |
185 | * @hdr_size: size of the possible header before the ARP packet | |
186 | * | |
62fe710f | 187 | * Return: the value of the hw_src field in the ARP packet. |
5c3a0e55 | 188 | */ |
6b5e971a | 189 | static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) |
5c3a0e55 | 190 | { |
6b5e971a | 191 | u8 *addr; |
5c3a0e55 | 192 | |
6b5e971a | 193 | addr = (u8 *)(skb->data + hdr_size); |
5c3a0e55 AQ |
194 | addr += ETH_HLEN + sizeof(struct arphdr); |
195 | ||
196 | return addr; | |
197 | } | |
198 | ||
199 | /** | |
7e9a8c2c | 200 | * batadv_arp_ip_src() - extract the ip_src field from an ARP packet |
5c3a0e55 AQ |
201 | * @skb: ARP packet |
202 | * @hdr_size: size of the possible header before the ARP packet | |
203 | * | |
62fe710f | 204 | * Return: the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
205 | */ |
206 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
207 | { | |
208 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
209 | } | |
210 | ||
211 | /** | |
7e9a8c2c | 212 | * batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet |
5c3a0e55 AQ |
213 | * @skb: ARP packet |
214 | * @hdr_size: size of the possible header before the ARP packet | |
215 | * | |
62fe710f | 216 | * Return: the value of the hw_dst field in the ARP packet. |
5c3a0e55 | 217 | */ |
6b5e971a | 218 | static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) |
5c3a0e55 AQ |
219 | { |
220 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
221 | } | |
222 | ||
223 | /** | |
7e9a8c2c | 224 | * batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet |
5c3a0e55 AQ |
225 | * @skb: ARP packet |
226 | * @hdr_size: size of the possible header before the ARP packet | |
227 | * | |
62fe710f | 228 | * Return: the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
229 | */ |
230 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
231 | { | |
232 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
233 | } | |
234 | ||
785ea114 | 235 | /** |
7e9a8c2c | 236 | * batadv_hash_dat() - compute the hash value for an IP address |
785ea114 AQ |
237 | * @data: data to hash |
238 | * @size: size of the hash table | |
239 | * | |
62fe710f | 240 | * Return: the selected index in the hash table for the given data. |
785ea114 | 241 | */ |
6b5e971a | 242 | static u32 batadv_hash_dat(const void *data, u32 size) |
785ea114 | 243 | { |
6b5e971a | 244 | u32 hash = 0; |
be1db4f6 | 245 | const struct batadv_dat_entry *dat = data; |
36fd61cb | 246 | const unsigned char *key; |
6b5e971a | 247 | u32 i; |
36fd61cb SE |
248 | |
249 | key = (const unsigned char *)&dat->ip; | |
250 | for (i = 0; i < sizeof(dat->ip); i++) { | |
251 | hash += key[i]; | |
252 | hash += (hash << 10); | |
253 | hash ^= (hash >> 6); | |
254 | } | |
785ea114 | 255 | |
36fd61cb SE |
256 | key = (const unsigned char *)&dat->vid; |
257 | for (i = 0; i < sizeof(dat->vid); i++) { | |
258 | hash += key[i]; | |
259 | hash += (hash << 10); | |
260 | hash ^= (hash >> 6); | |
261 | } | |
785ea114 AQ |
262 | |
263 | hash += (hash << 3); | |
264 | hash ^= (hash >> 11); | |
265 | hash += (hash << 15); | |
266 | ||
267 | return hash % size; | |
268 | } | |
269 | ||
2f1dfbe1 | 270 | /** |
7e9a8c2c | 271 | * batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
272 | * table |
273 | * @bat_priv: the bat priv with all the soft interface information | |
274 | * @ip: search key | |
be1db4f6 | 275 | * @vid: VLAN identifier |
2f1dfbe1 | 276 | * |
62fe710f | 277 | * Return: the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
278 | */ |
279 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
280 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
281 | unsigned short vid) | |
2f1dfbe1 AQ |
282 | { |
283 | struct hlist_head *head; | |
be1db4f6 | 284 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 | 285 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
6b5e971a | 286 | u32 index; |
2f1dfbe1 AQ |
287 | |
288 | if (!hash) | |
289 | return NULL; | |
290 | ||
be1db4f6 AQ |
291 | to_find.ip = ip; |
292 | to_find.vid = vid; | |
293 | ||
294 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
295 | head = &hash->table[index]; |
296 | ||
297 | rcu_read_lock(); | |
b67bfe0d | 298 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
299 | if (dat_entry->ip != ip) |
300 | continue; | |
301 | ||
68a6722c | 302 | if (!kref_get_unless_zero(&dat_entry->refcount)) |
2f1dfbe1 AQ |
303 | continue; |
304 | ||
305 | dat_entry_tmp = dat_entry; | |
306 | break; | |
307 | } | |
308 | rcu_read_unlock(); | |
309 | ||
310 | return dat_entry_tmp; | |
311 | } | |
312 | ||
313 | /** | |
7e9a8c2c | 314 | * batadv_dat_entry_add() - add a new dat entry or update it if already exists |
2f1dfbe1 AQ |
315 | * @bat_priv: the bat priv with all the soft interface information |
316 | * @ip: ipv4 to add/edit | |
317 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 318 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
319 | */ |
320 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
6b5e971a | 321 | u8 *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
322 | { |
323 | struct batadv_dat_entry *dat_entry; | |
324 | int hash_added; | |
325 | ||
be1db4f6 | 326 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
327 | /* if this entry is already known, just update it */ |
328 | if (dat_entry) { | |
329 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 330 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
331 | dat_entry->last_update = jiffies; |
332 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
333 | "Entry updated: %pI4 %pM (vid: %d)\n", |
334 | &dat_entry->ip, dat_entry->mac_addr, | |
f7a2bd65 | 335 | batadv_print_vid(vid)); |
2f1dfbe1 AQ |
336 | goto out; |
337 | } | |
338 | ||
339 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
340 | if (!dat_entry) | |
341 | goto out; | |
342 | ||
343 | dat_entry->ip = ip; | |
be1db4f6 | 344 | dat_entry->vid = vid; |
8fdd0153 | 345 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 | 346 | dat_entry->last_update = jiffies; |
68a6722c | 347 | kref_init(&dat_entry->refcount); |
2f1dfbe1 | 348 | |
6a51e09d | 349 | kref_get(&dat_entry->refcount); |
2f1dfbe1 | 350 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, |
be1db4f6 | 351 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
352 | &dat_entry->hash_entry); |
353 | ||
354 | if (unlikely(hash_added != 0)) { | |
355 | /* remove the reference for the hash */ | |
a6416f9f | 356 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
357 | goto out; |
358 | } | |
359 | ||
be1db4f6 | 360 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
f7a2bd65 | 361 | &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid)); |
2f1dfbe1 AQ |
362 | |
363 | out: | |
364 | if (dat_entry) | |
a6416f9f | 365 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
366 | } |
367 | ||
5c3a0e55 AQ |
368 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
369 | ||
370 | /** | |
7e9a8c2c SE |
371 | * batadv_dbg_arp() - print a debug message containing all the ARP packet |
372 | * details | |
5c3a0e55 AQ |
373 | * @bat_priv: the bat priv with all the soft interface information |
374 | * @skb: ARP packet | |
5c3a0e55 AQ |
375 | * @hdr_size: size of the possible header before the ARP packet |
376 | * @msg: message to print together with the debugging information | |
377 | */ | |
378 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
843314c9 | 379 | int hdr_size, char *msg) |
5c3a0e55 AQ |
380 | { |
381 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
382 | struct batadv_bcast_packet *bcast_pkt; | |
6b5e971a | 383 | u8 *orig_addr; |
5c3a0e55 AQ |
384 | __be32 ip_src, ip_dst; |
385 | ||
386 | if (msg) | |
387 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
388 | ||
389 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
390 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
391 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
392 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
393 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
394 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
395 | ||
396 | if (hdr_size == 0) | |
397 | return; | |
398 | ||
5c3a0e55 AQ |
399 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
400 | ||
a40d9b07 | 401 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
402 | case BATADV_UNICAST: |
403 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
404 | "* encapsulated within a UNICAST packet\n"); | |
405 | break; | |
406 | case BATADV_UNICAST_4ADDR: | |
407 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
408 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
409 | unicast_4addr_packet->src); | |
410 | switch (unicast_4addr_packet->subtype) { | |
411 | case BATADV_P_DAT_DHT_PUT: | |
412 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
413 | break; | |
414 | case BATADV_P_DAT_DHT_GET: | |
415 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
416 | break; | |
417 | case BATADV_P_DAT_CACHE_REPLY: | |
418 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
419 | "* type: DAT_CACHE_REPLY\n"); | |
420 | break; | |
421 | case BATADV_P_DATA: | |
422 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
423 | break; | |
424 | default: | |
425 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 426 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
427 | } |
428 | break; | |
429 | case BATADV_BCAST: | |
430 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
431 | orig_addr = bcast_pkt->orig; | |
432 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
433 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
434 | orig_addr); | |
435 | break; | |
436 | default: | |
437 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
438 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 439 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
440 | } |
441 | } | |
442 | ||
443 | #else | |
444 | ||
445 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
843314c9 | 446 | int hdr_size, char *msg) |
5c3a0e55 AQ |
447 | { |
448 | } | |
449 | ||
450 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
451 | ||
785ea114 | 452 | /** |
7e9a8c2c | 453 | * batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate |
785ea114 AQ |
454 | * @res: the array with the already selected candidates |
455 | * @select: number of already selected candidates | |
456 | * @tmp_max: address of the currently evaluated node | |
457 | * @max: current round max address | |
458 | * @last_max: address of the last selected candidate | |
459 | * @candidate: orig_node under evaluation | |
460 | * @max_orig_node: last selected candidate | |
461 | * | |
62fe710f | 462 | * Return: true if the node has been elected as next candidate or false |
93178018 | 463 | * otherwise. |
785ea114 AQ |
464 | */ |
465 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
466 | int select, batadv_dat_addr_t tmp_max, | |
467 | batadv_dat_addr_t max, | |
468 | batadv_dat_addr_t last_max, | |
469 | struct batadv_orig_node *candidate, | |
470 | struct batadv_orig_node *max_orig_node) | |
471 | { | |
472 | bool ret = false; | |
473 | int j; | |
474 | ||
17cf0ea4 | 475 | /* check if orig node candidate is running DAT */ |
65d7d460 | 476 | if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities)) |
17cf0ea4 ML |
477 | goto out; |
478 | ||
785ea114 AQ |
479 | /* Check if this node has already been selected... */ |
480 | for (j = 0; j < select; j++) | |
481 | if (res[j].orig_node == candidate) | |
482 | break; | |
483 | /* ..and possibly skip it */ | |
484 | if (j < select) | |
485 | goto out; | |
486 | /* sanity check: has it already been selected? This should not happen */ | |
487 | if (tmp_max > last_max) | |
488 | goto out; | |
489 | /* check if during this iteration an originator with a closer dht | |
490 | * address has already been found | |
491 | */ | |
492 | if (tmp_max < max) | |
493 | goto out; | |
494 | /* this is an hash collision with the temporary selected node. Choose | |
495 | * the one with the lowest address | |
496 | */ | |
825ffe1f SE |
497 | if (tmp_max == max && max_orig_node && |
498 | batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0) | |
785ea114 AQ |
499 | goto out; |
500 | ||
501 | ret = true; | |
502 | out: | |
503 | return ret; | |
504 | } | |
505 | ||
506 | /** | |
7e9a8c2c | 507 | * batadv_choose_next_candidate() - select the next DHT candidate |
785ea114 AQ |
508 | * @bat_priv: the bat priv with all the soft interface information |
509 | * @cands: candidates array | |
510 | * @select: number of candidates already present in the array | |
511 | * @ip_key: key to look up in the DHT | |
512 | * @last_max: pointer where the address of the selected candidate will be saved | |
513 | */ | |
514 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
515 | struct batadv_dat_candidate *cands, | |
516 | int select, batadv_dat_addr_t ip_key, | |
517 | batadv_dat_addr_t *last_max) | |
518 | { | |
4f248cff SE |
519 | batadv_dat_addr_t max = 0; |
520 | batadv_dat_addr_t tmp_max = 0; | |
785ea114 AQ |
521 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; |
522 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
523 | struct hlist_head *head; |
524 | int i; | |
525 | ||
526 | /* if no node is eligible as candidate, leave the candidate type as | |
527 | * NOT_FOUND | |
528 | */ | |
529 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
530 | ||
93178018 | 531 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
532 | * dat_address which has not been selected yet |
533 | */ | |
534 | for (i = 0; i < hash->size; i++) { | |
535 | head = &hash->table[i]; | |
536 | ||
537 | rcu_read_lock(); | |
b67bfe0d | 538 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 539 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
540 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
541 | ip_key; | |
542 | ||
543 | if (!batadv_is_orig_node_eligible(cands, select, | |
544 | tmp_max, max, | |
545 | *last_max, orig_node, | |
546 | max_orig_node)) | |
547 | continue; | |
548 | ||
7c124391 | 549 | if (!kref_get_unless_zero(&orig_node->refcount)) |
785ea114 AQ |
550 | continue; |
551 | ||
552 | max = tmp_max; | |
553 | if (max_orig_node) | |
5d967310 | 554 | batadv_orig_node_put(max_orig_node); |
785ea114 AQ |
555 | max_orig_node = orig_node; |
556 | } | |
557 | rcu_read_unlock(); | |
558 | } | |
559 | if (max_orig_node) { | |
560 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
561 | cands[select].orig_node = max_orig_node; | |
562 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
563 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
564 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
565 | max); | |
566 | } | |
567 | *last_max = max; | |
568 | } | |
569 | ||
570 | /** | |
7e9a8c2c SE |
571 | * batadv_dat_select_candidates() - select the nodes which the DHT message has |
572 | * to be sent to | |
785ea114 AQ |
573 | * @bat_priv: the bat priv with all the soft interface information |
574 | * @ip_dst: ipv4 to look up in the DHT | |
2871734e | 575 | * @vid: VLAN identifier |
785ea114 AQ |
576 | * |
577 | * An originator O is selected if and only if its DHT_ID value is one of three | |
578 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
579 | * value of the key. ip_dst is the key. | |
580 | * | |
62fe710f | 581 | * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
582 | */ |
583 | static struct batadv_dat_candidate * | |
2871734e AQ |
584 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst, |
585 | unsigned short vid) | |
785ea114 AQ |
586 | { |
587 | int select; | |
588 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
589 | struct batadv_dat_candidate *res; | |
b7fe3d4f | 590 | struct batadv_dat_entry dat; |
785ea114 AQ |
591 | |
592 | if (!bat_priv->orig_hash) | |
593 | return NULL; | |
594 | ||
0185dda6 AQ |
595 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
596 | GFP_ATOMIC); | |
785ea114 AQ |
597 | if (!res) |
598 | return NULL; | |
599 | ||
b7fe3d4f | 600 | dat.ip = ip_dst; |
2871734e | 601 | dat.vid = vid; |
b7fe3d4f | 602 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat, |
785ea114 AQ |
603 | BATADV_DAT_ADDR_MAX); |
604 | ||
605 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
22f0502e | 606 | "%s(): IP=%pI4 hash(IP)=%u\n", __func__, &ip_dst, |
785ea114 AQ |
607 | ip_key); |
608 | ||
609 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
610 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
611 | &last_max); | |
612 | ||
613 | return res; | |
614 | } | |
615 | ||
616 | /** | |
7e9a8c2c | 617 | * batadv_dat_send_data() - send a payload to the selected candidates |
785ea114 AQ |
618 | * @bat_priv: the bat priv with all the soft interface information |
619 | * @skb: payload to send | |
620 | * @ip: the DHT key | |
2871734e | 621 | * @vid: VLAN identifier |
785ea114 AQ |
622 | * @packet_subtype: unicast4addr packet subtype to use |
623 | * | |
93178018 ML |
624 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
625 | * to each of the selected candidates. | |
785ea114 | 626 | * |
62fe710f | 627 | * Return: true if the packet is sent to at least one candidate, false |
93178018 | 628 | * otherwise. |
785ea114 AQ |
629 | */ |
630 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
631 | struct sk_buff *skb, __be32 ip, | |
2871734e | 632 | unsigned short vid, int packet_subtype) |
785ea114 AQ |
633 | { |
634 | int i; | |
635 | bool ret = false; | |
636 | int send_status; | |
637 | struct batadv_neigh_node *neigh_node = NULL; | |
638 | struct sk_buff *tmp_skb; | |
639 | struct batadv_dat_candidate *cand; | |
640 | ||
2871734e | 641 | cand = batadv_dat_select_candidates(bat_priv, ip, vid); |
785ea114 AQ |
642 | if (!cand) |
643 | goto out; | |
644 | ||
645 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
646 | ||
647 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
648 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
649 | continue; | |
650 | ||
7351a482 SW |
651 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
652 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
653 | if (!neigh_node) |
654 | goto free_orig; | |
655 | ||
bad93e9d | 656 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
657 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
658 | cand[i].orig_node, | |
659 | packet_subtype)) { | |
785ea114 AQ |
660 | kfree_skb(tmp_skb); |
661 | goto free_neigh; | |
662 | } | |
663 | ||
95d39278 | 664 | send_status = batadv_send_unicast_skb(tmp_skb, neigh_node); |
4046b24a MH |
665 | if (send_status == NET_XMIT_SUCCESS) { |
666 | /* count the sent packet */ | |
667 | switch (packet_subtype) { | |
668 | case BATADV_P_DAT_DHT_GET: | |
669 | batadv_inc_counter(bat_priv, | |
670 | BATADV_CNT_DAT_GET_TX); | |
671 | break; | |
672 | case BATADV_P_DAT_DHT_PUT: | |
673 | batadv_inc_counter(bat_priv, | |
674 | BATADV_CNT_DAT_PUT_TX); | |
675 | break; | |
676 | } | |
677 | ||
785ea114 AQ |
678 | /* packet sent to a candidate: return true */ |
679 | ret = true; | |
4046b24a | 680 | } |
785ea114 | 681 | free_neigh: |
25bb2509 | 682 | batadv_neigh_node_put(neigh_node); |
785ea114 | 683 | free_orig: |
5d967310 | 684 | batadv_orig_node_put(cand[i].orig_node); |
785ea114 AQ |
685 | } |
686 | ||
687 | out: | |
688 | kfree(cand); | |
689 | return ret; | |
690 | } | |
2f1dfbe1 | 691 | |
17cf0ea4 | 692 | /** |
7e9a8c2c | 693 | * batadv_dat_tvlv_container_update() - update the dat tvlv container after dat |
17cf0ea4 ML |
694 | * setting change |
695 | * @bat_priv: the bat priv with all the soft interface information | |
696 | */ | |
697 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
698 | { | |
699 | char dat_mode; | |
700 | ||
701 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
702 | ||
703 | switch (dat_mode) { | |
704 | case 0: | |
705 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
706 | break; | |
707 | case 1: | |
708 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
709 | NULL, 0); | |
710 | break; | |
711 | } | |
712 | } | |
713 | ||
714 | /** | |
7e9a8c2c | 715 | * batadv_dat_status_update() - update the dat tvlv container after dat |
17cf0ea4 ML |
716 | * setting change |
717 | * @net_dev: the soft interface net device | |
718 | */ | |
719 | void batadv_dat_status_update(struct net_device *net_dev) | |
720 | { | |
721 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 722 | |
17cf0ea4 ML |
723 | batadv_dat_tvlv_container_update(bat_priv); |
724 | } | |
725 | ||
726 | /** | |
7e9a8c2c | 727 | * batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container |
17cf0ea4 ML |
728 | * @bat_priv: the bat priv with all the soft interface information |
729 | * @orig: the orig_node of the ogm | |
730 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
731 | * @tvlv_value: tvlv buffer containing the gateway data | |
732 | * @tvlv_value_len: tvlv buffer length | |
733 | */ | |
734 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
735 | struct batadv_orig_node *orig, | |
6b5e971a SE |
736 | u8 flags, |
737 | void *tvlv_value, u16 tvlv_value_len) | |
17cf0ea4 ML |
738 | { |
739 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
65d7d460 | 740 | clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 | 741 | else |
65d7d460 | 742 | set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 ML |
743 | } |
744 | ||
2f1dfbe1 | 745 | /** |
7e9a8c2c | 746 | * batadv_dat_hash_free() - free the local DAT hash table |
2f1dfbe1 AQ |
747 | * @bat_priv: the bat priv with all the soft interface information |
748 | */ | |
749 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
750 | { | |
33af49ad AQ |
751 | if (!bat_priv->dat.hash) |
752 | return; | |
753 | ||
2f1dfbe1 AQ |
754 | __batadv_dat_purge(bat_priv, NULL); |
755 | ||
756 | batadv_hash_destroy(bat_priv->dat.hash); | |
757 | ||
758 | bat_priv->dat.hash = NULL; | |
759 | } | |
760 | ||
761 | /** | |
7e9a8c2c | 762 | * batadv_dat_init() - initialise the DAT internals |
2f1dfbe1 | 763 | * @bat_priv: the bat priv with all the soft interface information |
fe13c2aa AQ |
764 | * |
765 | * Return: 0 in case of success, a negative error code otherwise | |
2f1dfbe1 AQ |
766 | */ |
767 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
768 | { | |
769 | if (bat_priv->dat.hash) | |
770 | return 0; | |
771 | ||
772 | bat_priv->dat.hash = batadv_hash_new(1024); | |
773 | ||
774 | if (!bat_priv->dat.hash) | |
775 | return -ENOMEM; | |
776 | ||
777 | batadv_dat_start_timer(bat_priv); | |
778 | ||
17cf0ea4 ML |
779 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
780 | NULL, BATADV_TVLV_DAT, 1, | |
781 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
782 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
783 | return 0; |
784 | } | |
785 | ||
786 | /** | |
7e9a8c2c | 787 | * batadv_dat_free() - free the DAT internals |
2f1dfbe1 AQ |
788 | * @bat_priv: the bat priv with all the soft interface information |
789 | */ | |
790 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
791 | { | |
17cf0ea4 ML |
792 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
793 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
794 | ||
2f1dfbe1 AQ |
795 | cancel_delayed_work_sync(&bat_priv->dat.work); |
796 | ||
797 | batadv_dat_hash_free(bat_priv); | |
798 | } | |
799 | ||
dc1cbd14 | 800 | #ifdef CONFIG_BATMAN_ADV_DEBUGFS |
2f1dfbe1 | 801 | /** |
7e9a8c2c | 802 | * batadv_dat_cache_seq_print_text() - print the local DAT hash table |
2f1dfbe1 AQ |
803 | * @seq: seq file to print on |
804 | * @offset: not used | |
fe13c2aa AQ |
805 | * |
806 | * Return: always 0 | |
2f1dfbe1 AQ |
807 | */ |
808 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
809 | { | |
810 | struct net_device *net_dev = (struct net_device *)seq->private; | |
811 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
812 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
813 | struct batadv_dat_entry *dat_entry; | |
814 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
815 | struct hlist_head *head; |
816 | unsigned long last_seen_jiffies; | |
817 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
6b5e971a | 818 | u32 i; |
2f1dfbe1 AQ |
819 | |
820 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
821 | if (!primary_if) | |
822 | goto out; | |
823 | ||
824 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
925a6f37 AQ |
825 | seq_puts(seq, |
826 | " IPv4 MAC VID last-seen\n"); | |
2f1dfbe1 AQ |
827 | |
828 | for (i = 0; i < hash->size; i++) { | |
829 | head = &hash->table[i]; | |
830 | ||
831 | rcu_read_lock(); | |
b67bfe0d | 832 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
833 | last_seen_jiffies = jiffies - dat_entry->last_update; |
834 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
835 | last_seen_mins = last_seen_msecs / 60000; | |
836 | last_seen_msecs = last_seen_msecs % 60000; | |
837 | last_seen_secs = last_seen_msecs / 1000; | |
838 | ||
cd0edf3a | 839 | seq_printf(seq, " * %15pI4 %pM %4i %6i:%02i\n", |
2f1dfbe1 | 840 | &dat_entry->ip, dat_entry->mac_addr, |
f7a2bd65 | 841 | batadv_print_vid(dat_entry->vid), |
2f1dfbe1 AQ |
842 | last_seen_mins, last_seen_secs); |
843 | } | |
844 | rcu_read_unlock(); | |
845 | } | |
846 | ||
847 | out: | |
848 | if (primary_if) | |
82047ad7 | 849 | batadv_hardif_put(primary_if); |
2f1dfbe1 AQ |
850 | return 0; |
851 | } | |
dc1cbd14 | 852 | #endif |
5c3a0e55 AQ |
853 | |
854 | /** | |
7e9a8c2c | 855 | * batadv_arp_get_type() - parse an ARP packet and gets the type |
5c3a0e55 AQ |
856 | * @bat_priv: the bat priv with all the soft interface information |
857 | * @skb: packet to analyse | |
858 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
859 | * | |
62fe710f | 860 | * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 | 861 | */ |
6b5e971a SE |
862 | static u16 batadv_arp_get_type(struct batadv_priv *bat_priv, |
863 | struct sk_buff *skb, int hdr_size) | |
5c3a0e55 AQ |
864 | { |
865 | struct arphdr *arphdr; | |
866 | struct ethhdr *ethhdr; | |
867 | __be32 ip_src, ip_dst; | |
6b5e971a SE |
868 | u8 *hw_src, *hw_dst; |
869 | u16 type = 0; | |
5c3a0e55 AQ |
870 | |
871 | /* pull the ethernet header */ | |
872 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
873 | goto out; | |
874 | ||
875 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
876 | ||
877 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
878 | goto out; | |
879 | ||
880 | /* pull the ARP payload */ | |
881 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
882 | arp_hdr_len(skb->dev)))) | |
883 | goto out; | |
884 | ||
885 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
886 | ||
93178018 | 887 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
888 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
889 | goto out; | |
890 | ||
891 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
892 | goto out; | |
893 | ||
894 | if (arphdr->ar_hln != ETH_ALEN) | |
895 | goto out; | |
896 | ||
897 | if (arphdr->ar_pln != 4) | |
898 | goto out; | |
899 | ||
900 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
901 | * will simply ignore it | |
902 | */ | |
903 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
904 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
905 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
906 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
907 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
908 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
909 | goto out; |
910 | ||
b618ad11 MS |
911 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
912 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
913 | goto out; | |
914 | ||
93178018 | 915 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
916 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
917 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
918 | if (is_zero_ether_addr(hw_dst) || | |
919 | is_multicast_ether_addr(hw_dst)) | |
920 | goto out; | |
921 | } | |
922 | ||
5c3a0e55 AQ |
923 | type = ntohs(arphdr->ar_op); |
924 | out: | |
925 | return type; | |
926 | } | |
c384ea3e | 927 | |
be1db4f6 | 928 | /** |
7e9a8c2c | 929 | * batadv_dat_get_vid() - extract the VLAN identifier from skb if any |
be1db4f6 AQ |
930 | * @skb: the buffer containing the packet to extract the VID from |
931 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
932 | * | |
62fe710f SE |
933 | * Return: If the packet embedded in the skb is vlan tagged this function |
934 | * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS | |
935 | * is returned. | |
be1db4f6 AQ |
936 | */ |
937 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
938 | { | |
939 | unsigned short vid; | |
940 | ||
941 | vid = batadv_get_vid(skb, *hdr_size); | |
942 | ||
943 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
944 | * If the header contained in the packet is a VLAN one (which is longer) | |
945 | * hdr_size is updated so that the functions will still skip the | |
946 | * correct amount of bytes. | |
947 | */ | |
948 | if (vid & BATADV_VLAN_HAS_TAG) | |
949 | *hdr_size += VLAN_HLEN; | |
950 | ||
951 | return vid; | |
952 | } | |
953 | ||
cbfc16de | 954 | /** |
7e9a8c2c | 955 | * batadv_dat_arp_create_reply() - create an ARP Reply |
cbfc16de LL |
956 | * @bat_priv: the bat priv with all the soft interface information |
957 | * @ip_src: ARP sender IP | |
958 | * @ip_dst: ARP target IP | |
959 | * @hw_src: Ethernet source and ARP sender MAC | |
960 | * @hw_dst: Ethernet destination and ARP target MAC | |
961 | * @vid: VLAN identifier (optional, set to zero otherwise) | |
962 | * | |
963 | * Creates an ARP Reply from the given values, optionally encapsulated in a | |
964 | * VLAN header. | |
965 | * | |
966 | * Return: An skb containing an ARP Reply. | |
967 | */ | |
968 | static struct sk_buff * | |
969 | batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src, | |
970 | __be32 ip_dst, u8 *hw_src, u8 *hw_dst, | |
971 | unsigned short vid) | |
972 | { | |
973 | struct sk_buff *skb; | |
974 | ||
975 | skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface, | |
976 | ip_src, hw_dst, hw_src, hw_dst); | |
977 | if (!skb) | |
978 | return NULL; | |
979 | ||
980 | skb_reset_mac_header(skb); | |
981 | ||
982 | if (vid & BATADV_VLAN_HAS_TAG) | |
983 | skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), | |
984 | vid & VLAN_VID_MASK); | |
985 | ||
986 | return skb; | |
987 | } | |
988 | ||
c384ea3e | 989 | /** |
7e9a8c2c | 990 | * batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to |
c384ea3e AQ |
991 | * answer using DAT |
992 | * @bat_priv: the bat priv with all the soft interface information | |
993 | * @skb: packet to check | |
994 | * | |
62fe710f | 995 | * Return: true if the message has been sent to the dht candidates, false |
93178018 ML |
996 | * otherwise. In case of a positive return value the message has to be enqueued |
997 | * to permit the fallback. | |
c384ea3e AQ |
998 | */ |
999 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
1000 | struct sk_buff *skb) | |
1001 | { | |
6b5e971a | 1002 | u16 type = 0; |
c384ea3e | 1003 | __be32 ip_dst, ip_src; |
6b5e971a | 1004 | u8 *hw_src; |
c384ea3e AQ |
1005 | bool ret = false; |
1006 | struct batadv_dat_entry *dat_entry = NULL; | |
1007 | struct sk_buff *skb_new; | |
ab044f8e | 1008 | struct net_device *soft_iface = bat_priv->soft_iface; |
be1db4f6 AQ |
1009 | int hdr_size = 0; |
1010 | unsigned short vid; | |
c384ea3e | 1011 | |
33af49ad AQ |
1012 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1013 | goto out; | |
1014 | ||
be1db4f6 AQ |
1015 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1016 | ||
1017 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1018 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
1019 | * message to the selected DHT candidates | |
1020 | */ | |
1021 | if (type != ARPOP_REQUEST) | |
1022 | goto out; | |
1023 | ||
843314c9 | 1024 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REQUEST"); |
c384ea3e | 1025 | |
be1db4f6 AQ |
1026 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
1027 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1028 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1029 | |
be1db4f6 | 1030 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1031 | |
be1db4f6 | 1032 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 1033 | if (dat_entry) { |
88e48d7b AQ |
1034 | /* If the ARP request is destined for a local client the local |
1035 | * client will answer itself. DAT would only generate a | |
1036 | * duplicate packet. | |
1037 | * | |
1038 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
1039 | * additional DAT answer may trigger kernel warnings about | |
1040 | * a packet coming from the wrong port. | |
1041 | */ | |
cc2f3386 | 1042 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
1043 | ret = true; |
1044 | goto out; | |
1045 | } | |
1046 | ||
00311de5 AP |
1047 | /* If BLA is enabled, only send ARP replies if we have claimed |
1048 | * the destination for the ARP request or if no one else of | |
1049 | * the backbone gws belonging to our backbone has claimed the | |
1050 | * destination. | |
1051 | */ | |
1052 | if (!batadv_bla_check_claim(bat_priv, | |
1053 | dat_entry->mac_addr, vid)) { | |
1054 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1055 | "Device %pM claimed by another backbone gw. Don't send ARP reply!", | |
1056 | dat_entry->mac_addr); | |
1057 | ret = true; | |
1058 | goto out; | |
1059 | } | |
1060 | ||
cbfc16de LL |
1061 | skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src, |
1062 | dat_entry->mac_addr, | |
1063 | hw_src, vid); | |
c384ea3e AQ |
1064 | if (!skb_new) |
1065 | goto out; | |
1066 | ||
ab044f8e TK |
1067 | skb_new->protocol = eth_type_trans(skb_new, soft_iface); |
1068 | ||
36d4d68c SE |
1069 | batadv_inc_counter(bat_priv, BATADV_CNT_RX); |
1070 | batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES, | |
1071 | skb->len + ETH_HLEN + hdr_size); | |
c384ea3e AQ |
1072 | |
1073 | netif_rx(skb_new); | |
1074 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
1075 | ret = true; | |
1076 | } else { | |
93178018 | 1077 | /* Send the request to the DHT */ |
2871734e | 1078 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid, |
c384ea3e AQ |
1079 | BATADV_P_DAT_DHT_GET); |
1080 | } | |
1081 | out: | |
1082 | if (dat_entry) | |
a6416f9f | 1083 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1084 | return ret; |
1085 | } | |
1086 | ||
1087 | /** | |
7e9a8c2c | 1088 | * batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to |
c384ea3e AQ |
1089 | * answer using the local DAT storage |
1090 | * @bat_priv: the bat priv with all the soft interface information | |
1091 | * @skb: packet to check | |
1092 | * @hdr_size: size of the encapsulation header | |
1093 | * | |
62fe710f | 1094 | * Return: true if the request has been answered, false otherwise. |
c384ea3e AQ |
1095 | */ |
1096 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
1097 | struct sk_buff *skb, int hdr_size) | |
1098 | { | |
6b5e971a | 1099 | u16 type; |
c384ea3e | 1100 | __be32 ip_src, ip_dst; |
6b5e971a | 1101 | u8 *hw_src; |
c384ea3e | 1102 | struct sk_buff *skb_new; |
c384ea3e AQ |
1103 | struct batadv_dat_entry *dat_entry = NULL; |
1104 | bool ret = false; | |
be1db4f6 | 1105 | unsigned short vid; |
c384ea3e AQ |
1106 | int err; |
1107 | ||
33af49ad AQ |
1108 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1109 | goto out; | |
1110 | ||
be1db4f6 AQ |
1111 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1112 | ||
c384ea3e AQ |
1113 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1114 | if (type != ARPOP_REQUEST) | |
1115 | goto out; | |
1116 | ||
1117 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1118 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1119 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1120 | ||
843314c9 | 1121 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST"); |
c384ea3e | 1122 | |
be1db4f6 | 1123 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1124 | |
be1db4f6 | 1125 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1126 | if (!dat_entry) |
1127 | goto out; | |
1128 | ||
cbfc16de LL |
1129 | skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src, |
1130 | dat_entry->mac_addr, hw_src, vid); | |
c384ea3e AQ |
1131 | if (!skb_new) |
1132 | goto out; | |
1133 | ||
93178018 ML |
1134 | /* To preserve backwards compatibility, the node has choose the outgoing |
1135 | * format based on the incoming request packet type. The assumption is | |
1136 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1137 | */ |
1138 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1139 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1140 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1141 | NULL, vid); |
c384ea3e | 1142 | else |
6c413b1c | 1143 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1144 | |
e300d314 | 1145 | if (err != NET_XMIT_DROP) { |
4046b24a | 1146 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1147 | ret = true; |
4046b24a | 1148 | } |
c384ea3e AQ |
1149 | out: |
1150 | if (dat_entry) | |
a6416f9f | 1151 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1152 | if (ret) |
1153 | kfree_skb(skb); | |
1154 | return ret; | |
1155 | } | |
1156 | ||
1157 | /** | |
7e9a8c2c | 1158 | * batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT |
c384ea3e AQ |
1159 | * @bat_priv: the bat priv with all the soft interface information |
1160 | * @skb: packet to check | |
1161 | */ | |
1162 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1163 | struct sk_buff *skb) | |
1164 | { | |
6b5e971a | 1165 | u16 type; |
c384ea3e | 1166 | __be32 ip_src, ip_dst; |
6b5e971a | 1167 | u8 *hw_src, *hw_dst; |
be1db4f6 AQ |
1168 | int hdr_size = 0; |
1169 | unsigned short vid; | |
c384ea3e | 1170 | |
33af49ad AQ |
1171 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1172 | return; | |
1173 | ||
be1db4f6 AQ |
1174 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1175 | ||
1176 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1177 | if (type != ARPOP_REPLY) |
1178 | return; | |
1179 | ||
843314c9 | 1180 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REPLY"); |
c384ea3e | 1181 | |
be1db4f6 AQ |
1182 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1183 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1184 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1185 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1186 | |
be1db4f6 AQ |
1187 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1188 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1189 | |
1190 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1191 | * the node obtained from the ARP reply |
c384ea3e | 1192 | */ |
2871734e AQ |
1193 | batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT); |
1194 | batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); | |
c384ea3e | 1195 | } |
aa143d28 | 1196 | |
c384ea3e | 1197 | /** |
7e9a8c2c SE |
1198 | * batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the |
1199 | * local DAT storage only | |
c384ea3e AQ |
1200 | * @bat_priv: the bat priv with all the soft interface information |
1201 | * @skb: packet to check | |
93178018 | 1202 | * @hdr_size: size of the encapsulation header |
f202a666 | 1203 | * |
62fe710f | 1204 | * Return: true if the packet was snooped and consumed by DAT. False if the |
f202a666 | 1205 | * packet has to be delivered to the interface |
c384ea3e AQ |
1206 | */ |
1207 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1208 | struct sk_buff *skb, int hdr_size) | |
1209 | { | |
9aa5cd79 | 1210 | struct batadv_dat_entry *dat_entry = NULL; |
6b5e971a | 1211 | u16 type; |
c384ea3e | 1212 | __be32 ip_src, ip_dst; |
6b5e971a | 1213 | u8 *hw_src, *hw_dst; |
f202a666 | 1214 | bool dropped = false; |
be1db4f6 | 1215 | unsigned short vid; |
c384ea3e | 1216 | |
33af49ad AQ |
1217 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1218 | goto out; | |
1219 | ||
be1db4f6 AQ |
1220 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1221 | ||
c384ea3e AQ |
1222 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1223 | if (type != ARPOP_REPLY) | |
1224 | goto out; | |
1225 | ||
843314c9 | 1226 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REPLY"); |
c384ea3e AQ |
1227 | |
1228 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1229 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1230 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1231 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1232 | ||
9aa5cd79 AP |
1233 | /* If ip_dst is already in cache and has the right mac address, |
1234 | * drop this frame if this ARP reply is destined for us because it's | |
1235 | * most probably an ARP reply generated by another node of the DHT. | |
1236 | * We have most probably received already a reply earlier. Delivering | |
1237 | * this frame would lead to doubled receive of an ARP reply. | |
1238 | */ | |
1239 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid); | |
1240 | if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) { | |
1241 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n", | |
1242 | hw_src, &ip_src, hw_dst, &ip_dst, | |
1243 | dat_entry->mac_addr, &dat_entry->ip); | |
1244 | dropped = true; | |
1245 | goto out; | |
1246 | } | |
1247 | ||
c384ea3e AQ |
1248 | /* Update our internal cache with both the IP addresses the node got |
1249 | * within the ARP reply | |
1250 | */ | |
be1db4f6 AQ |
1251 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1252 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e | 1253 | |
9aa5cd79 AP |
1254 | /* If BLA is enabled, only forward ARP replies if we have claimed the |
1255 | * source of the ARP reply or if no one else of the same backbone has | |
1256 | * already claimed that client. This prevents that different gateways | |
1257 | * to the same backbone all forward the ARP reply leading to multiple | |
1258 | * replies in the backbone. | |
1259 | */ | |
1260 | if (!batadv_bla_check_claim(bat_priv, hw_src, vid)) { | |
1261 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1262 | "Device %pM claimed by another backbone gw. Drop ARP reply.\n", | |
1263 | hw_src); | |
1264 | dropped = true; | |
1265 | goto out; | |
1266 | } | |
1267 | ||
c384ea3e AQ |
1268 | /* if this REPLY is directed to a client of mine, let's deliver the |
1269 | * packet to the interface | |
1270 | */ | |
f202a666 AQ |
1271 | dropped = !batadv_is_my_client(bat_priv, hw_dst, vid); |
1272 | ||
1273 | /* if this REPLY is sent on behalf of a client of mine, let's drop the | |
1274 | * packet because the client will reply by itself | |
1275 | */ | |
1276 | dropped |= batadv_is_my_client(bat_priv, hw_src, vid); | |
c384ea3e | 1277 | out: |
f202a666 | 1278 | if (dropped) |
0d15bece | 1279 | kfree_skb(skb); |
9aa5cd79 AP |
1280 | if (dat_entry) |
1281 | batadv_dat_entry_put(dat_entry); | |
f202a666 AQ |
1282 | /* if dropped == false -> deliver to the interface */ |
1283 | return dropped; | |
c384ea3e AQ |
1284 | } |
1285 | ||
1286 | /** | |
7e9a8c2c SE |
1287 | * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be |
1288 | * dropped (because the node has already obtained the reply via DAT) or not | |
c384ea3e AQ |
1289 | * @bat_priv: the bat priv with all the soft interface information |
1290 | * @forw_packet: the broadcast packet | |
1291 | * | |
62fe710f | 1292 | * Return: true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1293 | */ |
1294 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1295 | struct batadv_forw_packet *forw_packet) | |
1296 | { | |
6b5e971a | 1297 | u16 type; |
c384ea3e AQ |
1298 | __be32 ip_dst; |
1299 | struct batadv_dat_entry *dat_entry = NULL; | |
1300 | bool ret = false; | |
be1db4f6 AQ |
1301 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1302 | unsigned short vid; | |
c384ea3e | 1303 | |
33af49ad AQ |
1304 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1305 | goto out; | |
1306 | ||
c384ea3e AQ |
1307 | /* If this packet is an ARP_REQUEST and the node already has the |
1308 | * information that it is going to ask, then the packet can be dropped | |
1309 | */ | |
e2d9ba43 | 1310 | if (batadv_forw_packet_is_rebroadcast(forw_packet)) |
c384ea3e AQ |
1311 | goto out; |
1312 | ||
be1db4f6 AQ |
1313 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1314 | ||
1315 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1316 | if (type != ARPOP_REQUEST) |
1317 | goto out; | |
1318 | ||
be1db4f6 AQ |
1319 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1320 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1321 | /* check if the node already got this entry */ |
1322 | if (!dat_entry) { | |
1323 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1324 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1325 | goto out; | |
1326 | } | |
1327 | ||
1328 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1329 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1330 | ret = true; | |
1331 | ||
1332 | out: | |
1333 | if (dat_entry) | |
a6416f9f | 1334 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1335 | return ret; |
1336 | } |