blob: 83bc1aaf5800cbc68aa8a33f967a2ae5533af801 [file] [log] [blame]
Sven Eckelmann9f6446c2015-04-23 13:16:35 +02001/* Copyright (C) 2011-2015 B.A.T.M.A.N. contributors:
Antonio Quartulli785ea112011-11-23 11:35:44 +01002 *
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
Antonio Quartulliebf38fb2013-11-03 20:40:48 +010015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Antonio Quartulli785ea112011-11-23 11:35:44 +010016 */
17
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020018#include "distributed-arp-table.h"
19#include "main.h"
20
21#include <linux/atomic.h>
Linus Lüssing65d7d4602015-06-16 17:10:22 +020022#include <linux/bitops.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020023#include <linux/byteorder/generic.h>
24#include <linux/errno.h>
25#include <linux/etherdevice.h>
26#include <linux/fs.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010027#include <linux/if_arp.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020028#include <linux/if_ether.h>
Antonio Quartullibe1db4f2013-06-04 12:11:43 +020029#include <linux/if_vlan.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020030#include <linux/in.h>
31#include <linux/jiffies.h>
32#include <linux/kernel.h>
33#include <linux/list.h>
34#include <linux/rculist.h>
35#include <linux/rcupdate.h>
36#include <linux/seq_file.h>
37#include <linux/skbuff.h>
38#include <linux/slab.h>
39#include <linux/spinlock.h>
40#include <linux/stddef.h>
41#include <linux/string.h>
42#include <linux/workqueue.h>
Antonio Quartullic384ea32011-06-26 03:37:18 +020043#include <net/arp.h>
Antonio Quartulli785ea112011-11-23 11:35:44 +010044
Antonio Quartulli785ea112011-11-23 11:35:44 +010045#include "hard-interface.h"
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020046#include "hash.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010047#include "originator.h"
48#include "send.h"
Antonio Quartullic384ea32011-06-26 03:37:18 +020049#include "translation-table.h"
Antonio Quartulli785ea112011-11-23 11:35:44 +010050
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020051static void batadv_dat_purge(struct work_struct *work);
52
53/**
54 * batadv_dat_start_timer - initialise the DAT periodic worker
55 * @bat_priv: the bat priv with all the soft interface information
56 */
57static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
58{
59 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
60 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
61 msecs_to_jiffies(10000));
62}
63
64/**
Marek Lindner93178012013-03-10 19:29:15 +080065 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020066 * free it
Marek Lindner93178012013-03-10 19:29:15 +080067 * @dat_entry: the entry to free
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020068 */
69static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
70{
71 if (atomic_dec_and_test(&dat_entry->refcount))
72 kfree_rcu(dat_entry, rcu);
73}
74
75/**
Marek Lindner93178012013-03-10 19:29:15 +080076 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020077 * @dat_entry: the entry to check
78 *
Marek Lindner93178012013-03-10 19:29:15 +080079 * Returns true if the entry has to be purged now, false otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020080 */
81static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
82{
83 return batadv_has_timed_out(dat_entry->last_update,
84 BATADV_DAT_ENTRY_TIMEOUT);
85}
86
87/**
88 * __batadv_dat_purge - delete entries from the DAT local storage
89 * @bat_priv: the bat priv with all the soft interface information
90 * @to_purge: function in charge to decide whether an entry has to be purged or
91 * not. This function takes the dat_entry as argument and has to
92 * returns a boolean value: true is the entry has to be deleted,
93 * false otherwise
94 *
Marek Lindner93178012013-03-10 19:29:15 +080095 * Loops over each entry in the DAT local storage and deletes it if and only if
96 * the to_purge function passed as argument returns true.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +020097 */
98static void __batadv_dat_purge(struct batadv_priv *bat_priv,
99 bool (*to_purge)(struct batadv_dat_entry *))
100{
101 spinlock_t *list_lock; /* protects write access to the hash lists */
102 struct batadv_dat_entry *dat_entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800103 struct hlist_node *node_tmp;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200104 struct hlist_head *head;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200105 u32 i;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200106
107 if (!bat_priv->dat.hash)
108 return;
109
110 for (i = 0; i < bat_priv->dat.hash->size; i++) {
111 head = &bat_priv->dat.hash->table[i];
112 list_lock = &bat_priv->dat.hash->list_locks[i];
113
114 spin_lock_bh(list_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -0800115 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200116 hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800117 /* if a helper function has been passed as parameter,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200118 * ask it if the entry has to be purged or not
119 */
120 if (to_purge && !to_purge(dat_entry))
121 continue;
122
Sasha Levinb67bfe02013-02-27 17:06:00 -0800123 hlist_del_rcu(&dat_entry->hash_entry);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200124 batadv_dat_entry_free_ref(dat_entry);
125 }
126 spin_unlock_bh(list_lock);
127 }
128}
129
130/**
131 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
132 * hash table
133 * @work: kernel work struct
134 */
135static void batadv_dat_purge(struct work_struct *work)
136{
137 struct delayed_work *delayed_work;
138 struct batadv_priv_dat *priv_dat;
139 struct batadv_priv *bat_priv;
140
141 delayed_work = container_of(work, struct delayed_work, work);
142 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
143 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
144
145 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
146 batadv_dat_start_timer(bat_priv);
147}
148
149/**
150 * batadv_compare_dat - comparing function used in the local DAT hash table
151 * @node: node in the local table
152 * @data2: second object to compare the node to
153 *
Marek Lindner93178012013-03-10 19:29:15 +0800154 * Returns 1 if the two entries are the same, 0 otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200155 */
156static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
157{
158 const void *data1 = container_of(node, struct batadv_dat_entry,
159 hash_entry);
160
Antonio Quartulli36484f82013-11-07 08:02:07 +0100161 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200162}
163
Antonio Quartulli785ea112011-11-23 11:35:44 +0100164/**
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200165 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
166 * @skb: ARP packet
167 * @hdr_size: size of the possible header before the ARP packet
168 *
Marek Lindner93178012013-03-10 19:29:15 +0800169 * Returns the value of the hw_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200170 */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200171static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200172{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200173 u8 *addr;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200174
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200175 addr = (u8 *)(skb->data + hdr_size);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200176 addr += ETH_HLEN + sizeof(struct arphdr);
177
178 return addr;
179}
180
181/**
182 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
183 * @skb: ARP packet
184 * @hdr_size: size of the possible header before the ARP packet
185 *
Marek Lindner93178012013-03-10 19:29:15 +0800186 * Returns the value of the ip_src field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200187 */
188static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
189{
190 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
191}
192
193/**
194 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
195 * @skb: ARP packet
196 * @hdr_size: size of the possible header before the ARP packet
197 *
Marek Lindner93178012013-03-10 19:29:15 +0800198 * Returns the value of the hw_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200199 */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200200static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200201{
202 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
203}
204
205/**
206 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
207 * @skb: ARP packet
208 * @hdr_size: size of the possible header before the ARP packet
209 *
Marek Lindner93178012013-03-10 19:29:15 +0800210 * Returns the value of the ip_dst field in the ARP packet.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200211 */
212static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
213{
214 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
215}
216
217/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100218 * batadv_hash_dat - compute the hash value for an IP address
219 * @data: data to hash
220 * @size: size of the hash table
221 *
Marek Lindner93178012013-03-10 19:29:15 +0800222 * Returns the selected index in the hash table for the given data.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100223 */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200224static u32 batadv_hash_dat(const void *data, u32 size)
Antonio Quartulli785ea112011-11-23 11:35:44 +0100225{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200226 u32 hash = 0;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200227 const struct batadv_dat_entry *dat = data;
Sven Eckelmann36fd61c2015-03-01 09:46:18 +0100228 const unsigned char *key;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200229 u32 i;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100230
Sven Eckelmann36fd61c2015-03-01 09:46:18 +0100231 key = (const unsigned char *)&dat->ip;
232 for (i = 0; i < sizeof(dat->ip); i++) {
233 hash += key[i];
234 hash += (hash << 10);
235 hash ^= (hash >> 6);
236 }
237
238 key = (const unsigned char *)&dat->vid;
239 for (i = 0; i < sizeof(dat->vid); i++) {
240 hash += key[i];
241 hash += (hash << 10);
242 hash ^= (hash >> 6);
243 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100244
245 hash += (hash << 3);
246 hash ^= (hash >> 11);
247 hash += (hash << 15);
248
249 return hash % size;
250}
251
252/**
Marek Lindner93178012013-03-10 19:29:15 +0800253 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200254 * table
255 * @bat_priv: the bat priv with all the soft interface information
256 * @ip: search key
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200257 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200258 *
Marek Lindner93178012013-03-10 19:29:15 +0800259 * Returns the dat_entry if found, NULL otherwise.
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200260 */
261static struct batadv_dat_entry *
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200262batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
263 unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200264{
265 struct hlist_head *head;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200266 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200267 struct batadv_hashtable *hash = bat_priv->dat.hash;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200268 u32 index;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200269
270 if (!hash)
271 return NULL;
272
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200273 to_find.ip = ip;
274 to_find.vid = vid;
275
276 index = batadv_hash_dat(&to_find, hash->size);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200277 head = &hash->table[index];
278
279 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800280 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200281 if (dat_entry->ip != ip)
282 continue;
283
284 if (!atomic_inc_not_zero(&dat_entry->refcount))
285 continue;
286
287 dat_entry_tmp = dat_entry;
288 break;
289 }
290 rcu_read_unlock();
291
292 return dat_entry_tmp;
293}
294
295/**
296 * batadv_dat_entry_add - add a new dat entry or update it if already exists
297 * @bat_priv: the bat priv with all the soft interface information
298 * @ip: ipv4 to add/edit
299 * @mac_addr: mac address to assign to the given ipv4
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200300 * @vid: VLAN identifier
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200301 */
302static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200303 u8 *mac_addr, unsigned short vid)
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200304{
305 struct batadv_dat_entry *dat_entry;
306 int hash_added;
307
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200308 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200309 /* if this entry is already known, just update it */
310 if (dat_entry) {
311 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
Antonio Quartulli8fdd0152014-01-22 00:42:11 +0100312 ether_addr_copy(dat_entry->mac_addr, mac_addr);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200313 dat_entry->last_update = jiffies;
314 batadv_dbg(BATADV_DBG_DAT, bat_priv,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200315 "Entry updated: %pI4 %pM (vid: %d)\n",
316 &dat_entry->ip, dat_entry->mac_addr,
317 BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200318 goto out;
319 }
320
321 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
322 if (!dat_entry)
323 goto out;
324
325 dat_entry->ip = ip;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200326 dat_entry->vid = vid;
Antonio Quartulli8fdd0152014-01-22 00:42:11 +0100327 ether_addr_copy(dat_entry->mac_addr, mac_addr);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200328 dat_entry->last_update = jiffies;
329 atomic_set(&dat_entry->refcount, 2);
330
331 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200332 batadv_hash_dat, dat_entry,
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200333 &dat_entry->hash_entry);
334
335 if (unlikely(hash_added != 0)) {
336 /* remove the reference for the hash */
337 batadv_dat_entry_free_ref(dat_entry);
338 goto out;
339 }
340
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200341 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
342 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200343
344out:
345 if (dat_entry)
346 batadv_dat_entry_free_ref(dat_entry);
347}
348
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200349#ifdef CONFIG_BATMAN_ADV_DEBUG
350
351/**
352 * batadv_dbg_arp - print a debug message containing all the ARP packet details
353 * @bat_priv: the bat priv with all the soft interface information
354 * @skb: ARP packet
355 * @type: ARP type
356 * @hdr_size: size of the possible header before the ARP packet
357 * @msg: message to print together with the debugging information
358 */
359static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200360 u16 type, int hdr_size, char *msg)
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200361{
362 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
363 struct batadv_bcast_packet *bcast_pkt;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200364 u8 *orig_addr;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200365 __be32 ip_src, ip_dst;
366
367 if (msg)
368 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
369
370 ip_src = batadv_arp_ip_src(skb, hdr_size);
371 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
372 batadv_dbg(BATADV_DBG_DAT, bat_priv,
373 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
374 batadv_arp_hw_src(skb, hdr_size), &ip_src,
375 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
376
377 if (hdr_size == 0)
378 return;
379
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200380 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
381
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100382 switch (unicast_4addr_packet->u.packet_type) {
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200383 case BATADV_UNICAST:
384 batadv_dbg(BATADV_DBG_DAT, bat_priv,
385 "* encapsulated within a UNICAST packet\n");
386 break;
387 case BATADV_UNICAST_4ADDR:
388 batadv_dbg(BATADV_DBG_DAT, bat_priv,
389 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
390 unicast_4addr_packet->src);
391 switch (unicast_4addr_packet->subtype) {
392 case BATADV_P_DAT_DHT_PUT:
393 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
394 break;
395 case BATADV_P_DAT_DHT_GET:
396 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
397 break;
398 case BATADV_P_DAT_CACHE_REPLY:
399 batadv_dbg(BATADV_DBG_DAT, bat_priv,
400 "* type: DAT_CACHE_REPLY\n");
401 break;
402 case BATADV_P_DATA:
403 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
404 break;
405 default:
406 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100407 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200408 }
409 break;
410 case BATADV_BCAST:
411 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
412 orig_addr = bcast_pkt->orig;
413 batadv_dbg(BATADV_DBG_DAT, bat_priv,
414 "* encapsulated within a BCAST packet (src: %pM)\n",
415 orig_addr);
416 break;
417 default:
418 batadv_dbg(BATADV_DBG_DAT, bat_priv,
419 "* encapsulated within an unknown packet type (0x%x)\n",
Simon Wunderlicha40d9b02013-12-02 20:38:31 +0100420 unicast_4addr_packet->u.packet_type);
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200421 }
422}
423
424#else
425
426static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200427 u16 type, int hdr_size, char *msg)
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200428{
429}
430
431#endif /* CONFIG_BATMAN_ADV_DEBUG */
432
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200433/**
Antonio Quartulli785ea112011-11-23 11:35:44 +0100434 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
435 * @res: the array with the already selected candidates
436 * @select: number of already selected candidates
437 * @tmp_max: address of the currently evaluated node
438 * @max: current round max address
439 * @last_max: address of the last selected candidate
440 * @candidate: orig_node under evaluation
441 * @max_orig_node: last selected candidate
442 *
Marek Lindner93178012013-03-10 19:29:15 +0800443 * Returns true if the node has been elected as next candidate or false
444 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100445 */
446static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
447 int select, batadv_dat_addr_t tmp_max,
448 batadv_dat_addr_t max,
449 batadv_dat_addr_t last_max,
450 struct batadv_orig_node *candidate,
451 struct batadv_orig_node *max_orig_node)
452{
453 bool ret = false;
454 int j;
455
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800456 /* check if orig node candidate is running DAT */
Linus Lüssing65d7d4602015-06-16 17:10:22 +0200457 if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800458 goto out;
459
Antonio Quartulli785ea112011-11-23 11:35:44 +0100460 /* Check if this node has already been selected... */
461 for (j = 0; j < select; j++)
462 if (res[j].orig_node == candidate)
463 break;
464 /* ..and possibly skip it */
465 if (j < select)
466 goto out;
467 /* sanity check: has it already been selected? This should not happen */
468 if (tmp_max > last_max)
469 goto out;
470 /* check if during this iteration an originator with a closer dht
471 * address has already been found
472 */
473 if (tmp_max < max)
474 goto out;
475 /* this is an hash collision with the temporary selected node. Choose
476 * the one with the lowest address
477 */
Pau Koning816cd5b2013-02-12 00:18:45 +0000478 if ((tmp_max == max) && max_orig_node &&
Antonio Quartulli785ea112011-11-23 11:35:44 +0100479 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
480 goto out;
481
482 ret = true;
483out:
484 return ret;
485}
486
487/**
488 * batadv_choose_next_candidate - select the next DHT candidate
489 * @bat_priv: the bat priv with all the soft interface information
490 * @cands: candidates array
491 * @select: number of candidates already present in the array
492 * @ip_key: key to look up in the DHT
493 * @last_max: pointer where the address of the selected candidate will be saved
494 */
495static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
496 struct batadv_dat_candidate *cands,
497 int select, batadv_dat_addr_t ip_key,
498 batadv_dat_addr_t *last_max)
499{
Sven Eckelmann4f248cf2015-06-09 20:50:49 +0200500 batadv_dat_addr_t max = 0;
501 batadv_dat_addr_t tmp_max = 0;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100502 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
503 struct batadv_hashtable *hash = bat_priv->orig_hash;
Antonio Quartulli785ea112011-11-23 11:35:44 +0100504 struct hlist_head *head;
505 int i;
506
507 /* if no node is eligible as candidate, leave the candidate type as
508 * NOT_FOUND
509 */
510 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
511
Marek Lindner93178012013-03-10 19:29:15 +0800512 /* iterate over the originator list and find the node with the closest
Antonio Quartulli785ea112011-11-23 11:35:44 +0100513 * dat_address which has not been selected yet
514 */
515 for (i = 0; i < hash->size; i++) {
516 head = &hash->table[i];
517
518 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800519 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
Marek Lindner93178012013-03-10 19:29:15 +0800520 /* the dht space is a ring using unsigned addresses */
Antonio Quartulli785ea112011-11-23 11:35:44 +0100521 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
522 ip_key;
523
524 if (!batadv_is_orig_node_eligible(cands, select,
525 tmp_max, max,
526 *last_max, orig_node,
527 max_orig_node))
528 continue;
529
530 if (!atomic_inc_not_zero(&orig_node->refcount))
531 continue;
532
533 max = tmp_max;
534 if (max_orig_node)
535 batadv_orig_node_free_ref(max_orig_node);
536 max_orig_node = orig_node;
537 }
538 rcu_read_unlock();
539 }
540 if (max_orig_node) {
541 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
542 cands[select].orig_node = max_orig_node;
543 batadv_dbg(BATADV_DBG_DAT, bat_priv,
544 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
545 select, max_orig_node->orig, max_orig_node->dat_addr,
546 max);
547 }
548 *last_max = max;
549}
550
551/**
Marek Lindner93178012013-03-10 19:29:15 +0800552 * batadv_dat_select_candidates - select the nodes which the DHT message has to
Antonio Quartulli785ea112011-11-23 11:35:44 +0100553 * be sent to
554 * @bat_priv: the bat priv with all the soft interface information
555 * @ip_dst: ipv4 to look up in the DHT
556 *
557 * An originator O is selected if and only if its DHT_ID value is one of three
558 * closest values (from the LEFT, with wrap around if needed) then the hash
559 * value of the key. ip_dst is the key.
560 *
Marek Lindner93178012013-03-10 19:29:15 +0800561 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100562 */
563static struct batadv_dat_candidate *
564batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
565{
566 int select;
567 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
568 struct batadv_dat_candidate *res;
569
570 if (!bat_priv->orig_hash)
571 return NULL;
572
Antonio Quartulli0185dda2014-05-24 06:43:47 +0200573 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
574 GFP_ATOMIC);
Antonio Quartulli785ea112011-11-23 11:35:44 +0100575 if (!res)
576 return NULL;
577
578 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
579 BATADV_DAT_ADDR_MAX);
580
581 batadv_dbg(BATADV_DBG_DAT, bat_priv,
582 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
583 ip_key);
584
585 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
586 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
587 &last_max);
588
589 return res;
590}
591
592/**
593 * batadv_dat_send_data - send a payload to the selected candidates
594 * @bat_priv: the bat priv with all the soft interface information
595 * @skb: payload to send
596 * @ip: the DHT key
597 * @packet_subtype: unicast4addr packet subtype to use
598 *
Marek Lindner93178012013-03-10 19:29:15 +0800599 * This function copies the skb with pskb_copy() and is sent as unicast packet
600 * to each of the selected candidates.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100601 *
Marek Lindner93178012013-03-10 19:29:15 +0800602 * Returns true if the packet is sent to at least one candidate, false
603 * otherwise.
Antonio Quartulli785ea112011-11-23 11:35:44 +0100604 */
605static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
606 struct sk_buff *skb, __be32 ip,
607 int packet_subtype)
608{
609 int i;
610 bool ret = false;
611 int send_status;
612 struct batadv_neigh_node *neigh_node = NULL;
613 struct sk_buff *tmp_skb;
614 struct batadv_dat_candidate *cand;
615
616 cand = batadv_dat_select_candidates(bat_priv, ip);
617 if (!cand)
618 goto out;
619
620 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
621
622 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
623 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
624 continue;
625
Simon Wunderlich7351a4822013-11-13 19:14:47 +0100626 neigh_node = batadv_orig_router_get(cand[i].orig_node,
627 BATADV_IF_DEFAULT);
Antonio Quartulli785ea112011-11-23 11:35:44 +0100628 if (!neigh_node)
629 goto free_orig;
630
Octavian Purdilabad93e92014-06-12 01:36:26 +0300631 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
Martin Hundebøllf097e252013-05-23 16:53:01 +0200632 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
633 cand[i].orig_node,
634 packet_subtype)) {
Antonio Quartulli785ea112011-11-23 11:35:44 +0100635 kfree_skb(tmp_skb);
636 goto free_neigh;
637 }
638
639 send_status = batadv_send_skb_packet(tmp_skb,
640 neigh_node->if_incoming,
641 neigh_node->addr);
Martin Hundebøll4046b242012-04-20 17:02:45 +0200642 if (send_status == NET_XMIT_SUCCESS) {
643 /* count the sent packet */
644 switch (packet_subtype) {
645 case BATADV_P_DAT_DHT_GET:
646 batadv_inc_counter(bat_priv,
647 BATADV_CNT_DAT_GET_TX);
648 break;
649 case BATADV_P_DAT_DHT_PUT:
650 batadv_inc_counter(bat_priv,
651 BATADV_CNT_DAT_PUT_TX);
652 break;
653 }
654
Antonio Quartulli785ea112011-11-23 11:35:44 +0100655 /* packet sent to a candidate: return true */
656 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +0200657 }
Antonio Quartulli785ea112011-11-23 11:35:44 +0100658free_neigh:
659 batadv_neigh_node_free_ref(neigh_node);
660free_orig:
661 batadv_orig_node_free_ref(cand[i].orig_node);
662 }
663
664out:
665 kfree(cand);
666 return ret;
667}
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200668
669/**
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800670 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
671 * setting change
672 * @bat_priv: the bat priv with all the soft interface information
673 */
674static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
675{
676 char dat_mode;
677
678 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
679
680 switch (dat_mode) {
681 case 0:
682 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
683 break;
684 case 1:
685 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
686 NULL, 0);
687 break;
688 }
689}
690
691/**
692 * batadv_dat_status_update - update the dat tvlv container after dat
693 * setting change
694 * @net_dev: the soft interface net device
695 */
696void batadv_dat_status_update(struct net_device *net_dev)
697{
698 struct batadv_priv *bat_priv = netdev_priv(net_dev);
Antonio Quartullif1386942014-05-10 18:56:37 +0200699
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800700 batadv_dat_tvlv_container_update(bat_priv);
701}
702
703/**
704 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
705 * @bat_priv: the bat priv with all the soft interface information
706 * @orig: the orig_node of the ogm
707 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
708 * @tvlv_value: tvlv buffer containing the gateway data
709 * @tvlv_value_len: tvlv buffer length
710 */
711static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
712 struct batadv_orig_node *orig,
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200713 u8 flags,
714 void *tvlv_value, u16 tvlv_value_len)
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800715{
716 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
Linus Lüssing65d7d4602015-06-16 17:10:22 +0200717 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800718 else
Linus Lüssing65d7d4602015-06-16 17:10:22 +0200719 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800720}
721
722/**
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200723 * batadv_dat_hash_free - free the local DAT hash table
724 * @bat_priv: the bat priv with all the soft interface information
725 */
726static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
727{
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200728 if (!bat_priv->dat.hash)
729 return;
730
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200731 __batadv_dat_purge(bat_priv, NULL);
732
733 batadv_hash_destroy(bat_priv->dat.hash);
734
735 bat_priv->dat.hash = NULL;
736}
737
738/**
739 * batadv_dat_init - initialise the DAT internals
740 * @bat_priv: the bat priv with all the soft interface information
741 */
742int batadv_dat_init(struct batadv_priv *bat_priv)
743{
744 if (bat_priv->dat.hash)
745 return 0;
746
747 bat_priv->dat.hash = batadv_hash_new(1024);
748
749 if (!bat_priv->dat.hash)
750 return -ENOMEM;
751
752 batadv_dat_start_timer(bat_priv);
753
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800754 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
755 NULL, BATADV_TVLV_DAT, 1,
756 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
757 batadv_dat_tvlv_container_update(bat_priv);
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200758 return 0;
759}
760
761/**
762 * batadv_dat_free - free the DAT internals
763 * @bat_priv: the bat priv with all the soft interface information
764 */
765void batadv_dat_free(struct batadv_priv *bat_priv)
766{
Marek Lindner17cf0ea2013-04-23 21:39:59 +0800767 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
768 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
769
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200770 cancel_delayed_work_sync(&bat_priv->dat.work);
771
772 batadv_dat_hash_free(bat_priv);
773}
774
775/**
776 * batadv_dat_cache_seq_print_text - print the local DAT hash table
777 * @seq: seq file to print on
778 * @offset: not used
779 */
780int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
781{
782 struct net_device *net_dev = (struct net_device *)seq->private;
783 struct batadv_priv *bat_priv = netdev_priv(net_dev);
784 struct batadv_hashtable *hash = bat_priv->dat.hash;
785 struct batadv_dat_entry *dat_entry;
786 struct batadv_hard_iface *primary_if;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200787 struct hlist_head *head;
788 unsigned long last_seen_jiffies;
789 int last_seen_msecs, last_seen_secs, last_seen_mins;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200790 u32 i;
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200791
792 primary_if = batadv_seq_print_text_primary_if_get(seq);
793 if (!primary_if)
794 goto out;
795
796 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200797 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
798 "MAC", "VID", "last-seen");
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200799
800 for (i = 0; i < hash->size; i++) {
801 head = &hash->table[i];
802
803 rcu_read_lock();
Sasha Levinb67bfe02013-02-27 17:06:00 -0800804 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200805 last_seen_jiffies = jiffies - dat_entry->last_update;
806 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
807 last_seen_mins = last_seen_msecs / 60000;
808 last_seen_msecs = last_seen_msecs % 60000;
809 last_seen_secs = last_seen_msecs / 1000;
810
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200811 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200812 &dat_entry->ip, dat_entry->mac_addr,
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200813 BATADV_PRINT_VID(dat_entry->vid),
Antonio Quartulli2f1dfbe2012-06-30 20:01:19 +0200814 last_seen_mins, last_seen_secs);
815 }
816 rcu_read_unlock();
817 }
818
819out:
820 if (primary_if)
821 batadv_hardif_free_ref(primary_if);
822 return 0;
823}
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200824
825/**
826 * batadv_arp_get_type - parse an ARP packet and gets the type
827 * @bat_priv: the bat priv with all the soft interface information
828 * @skb: packet to analyse
829 * @hdr_size: size of the possible header before the ARP packet in the skb
830 *
Marek Lindner93178012013-03-10 19:29:15 +0800831 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200832 */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200833static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
834 struct sk_buff *skb, int hdr_size)
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200835{
836 struct arphdr *arphdr;
837 struct ethhdr *ethhdr;
838 __be32 ip_src, ip_dst;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200839 u8 *hw_src, *hw_dst;
840 u16 type = 0;
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200841
842 /* pull the ethernet header */
843 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
844 goto out;
845
846 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
847
848 if (ethhdr->h_proto != htons(ETH_P_ARP))
849 goto out;
850
851 /* pull the ARP payload */
852 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
853 arp_hdr_len(skb->dev))))
854 goto out;
855
856 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
857
Marek Lindner93178012013-03-10 19:29:15 +0800858 /* check whether the ARP packet carries a valid IP information */
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200859 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
860 goto out;
861
862 if (arphdr->ar_pro != htons(ETH_P_IP))
863 goto out;
864
865 if (arphdr->ar_hln != ETH_ALEN)
866 goto out;
867
868 if (arphdr->ar_pln != 4)
869 goto out;
870
871 /* Check for bad reply/request. If the ARP message is not sane, DAT
872 * will simply ignore it
873 */
874 ip_src = batadv_arp_ip_src(skb, hdr_size);
875 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
876 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
Matthias Schiffer757dd822013-01-24 18:18:26 +0100877 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
878 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
879 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200880 goto out;
881
Matthias Schifferb618ad12013-01-24 18:18:27 +0100882 hw_src = batadv_arp_hw_src(skb, hdr_size);
883 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
884 goto out;
885
Marek Lindner93178012013-03-10 19:29:15 +0800886 /* don't care about the destination MAC address in ARP requests */
Matthias Schifferb618ad12013-01-24 18:18:27 +0100887 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
888 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
889 if (is_zero_ether_addr(hw_dst) ||
890 is_multicast_ether_addr(hw_dst))
891 goto out;
892 }
893
Antonio Quartulli5c3a0e52011-06-02 12:29:51 +0200894 type = ntohs(arphdr->ar_op);
895out:
896 return type;
897}
Antonio Quartullic384ea32011-06-26 03:37:18 +0200898
899/**
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200900 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
901 * @skb: the buffer containing the packet to extract the VID from
902 * @hdr_size: the size of the batman-adv header encapsulating the packet
903 *
904 * If the packet embedded in the skb is vlan tagged this function returns the
905 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
906 */
907static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
908{
909 unsigned short vid;
910
911 vid = batadv_get_vid(skb, *hdr_size);
912
913 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
914 * If the header contained in the packet is a VLAN one (which is longer)
915 * hdr_size is updated so that the functions will still skip the
916 * correct amount of bytes.
917 */
918 if (vid & BATADV_VLAN_HAS_TAG)
919 *hdr_size += VLAN_HLEN;
920
921 return vid;
922}
923
924/**
Antonio Quartullic384ea32011-06-26 03:37:18 +0200925 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
926 * answer using DAT
927 * @bat_priv: the bat priv with all the soft interface information
928 * @skb: packet to check
929 *
930 * Returns true if the message has been sent to the dht candidates, false
Marek Lindner93178012013-03-10 19:29:15 +0800931 * otherwise. In case of a positive return value the message has to be enqueued
932 * to permit the fallback.
Antonio Quartullic384ea32011-06-26 03:37:18 +0200933 */
934bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
935 struct sk_buff *skb)
936{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200937 u16 type = 0;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200938 __be32 ip_dst, ip_src;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200939 u8 *hw_src;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200940 bool ret = false;
941 struct batadv_dat_entry *dat_entry = NULL;
942 struct sk_buff *skb_new;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200943 int hdr_size = 0;
944 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200945
Antonio Quartulli33af49a2012-08-08 18:50:57 +0200946 if (!atomic_read(&bat_priv->distributed_arp_table))
947 goto out;
948
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200949 vid = batadv_dat_get_vid(skb, &hdr_size);
950
951 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200952 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
953 * message to the selected DHT candidates
954 */
955 if (type != ARPOP_REQUEST)
956 goto out;
957
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200958 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
959 "Parsing outgoing ARP REQUEST");
Antonio Quartullic384ea32011-06-26 03:37:18 +0200960
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200961 ip_src = batadv_arp_ip_src(skb, hdr_size);
962 hw_src = batadv_arp_hw_src(skb, hdr_size);
963 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200964
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200965 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200966
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200967 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200968 if (dat_entry) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200969 /* If the ARP request is destined for a local client the local
970 * client will answer itself. DAT would only generate a
971 * duplicate packet.
972 *
973 * Moreover, if the soft-interface is enslaved into a bridge, an
974 * additional DAT answer may trigger kernel warnings about
975 * a packet coming from the wrong port.
976 */
Antonio Quartullicc2f3382014-03-29 17:27:38 +0100977 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
Antonio Quartulli88e48d72013-05-09 09:35:45 +0200978 ret = true;
979 goto out;
980 }
981
Antonio Quartullic384ea32011-06-26 03:37:18 +0200982 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +0800983 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +0200984 dat_entry->mac_addr, hw_src);
985 if (!skb_new)
986 goto out;
987
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200988 if (vid & BATADV_VLAN_HAS_TAG)
989 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
990 vid & VLAN_VID_MASK);
991
Antonio Quartullic384ea32011-06-26 03:37:18 +0200992 skb_reset_mac_header(skb_new);
993 skb_new->protocol = eth_type_trans(skb_new,
Marek Lindner736292c2013-01-12 19:19:06 +0800994 bat_priv->soft_iface);
Antonio Quartullic384ea32011-06-26 03:37:18 +0200995 bat_priv->stats.rx_packets++;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +0200996 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
Marek Lindner736292c2013-01-12 19:19:06 +0800997 bat_priv->soft_iface->last_rx = jiffies;
Antonio Quartullic384ea32011-06-26 03:37:18 +0200998
999 netif_rx(skb_new);
1000 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1001 ret = true;
1002 } else {
Marek Lindner93178012013-03-10 19:29:15 +08001003 /* Send the request to the DHT */
Antonio Quartullic384ea32011-06-26 03:37:18 +02001004 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
1005 BATADV_P_DAT_DHT_GET);
1006 }
1007out:
1008 if (dat_entry)
1009 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001010 return ret;
1011}
1012
1013/**
1014 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1015 * answer using the local DAT storage
1016 * @bat_priv: the bat priv with all the soft interface information
1017 * @skb: packet to check
1018 * @hdr_size: size of the encapsulation header
1019 *
Marek Lindner93178012013-03-10 19:29:15 +08001020 * Returns true if the request has been answered, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001021 */
1022bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1023 struct sk_buff *skb, int hdr_size)
1024{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001025 u16 type;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001026 __be32 ip_src, ip_dst;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001027 u8 *hw_src;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001028 struct sk_buff *skb_new;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001029 struct batadv_dat_entry *dat_entry = NULL;
1030 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001031 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001032 int err;
1033
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001034 if (!atomic_read(&bat_priv->distributed_arp_table))
1035 goto out;
1036
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001037 vid = batadv_dat_get_vid(skb, &hdr_size);
1038
Antonio Quartullic384ea32011-06-26 03:37:18 +02001039 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1040 if (type != ARPOP_REQUEST)
1041 goto out;
1042
1043 hw_src = batadv_arp_hw_src(skb, hdr_size);
1044 ip_src = batadv_arp_ip_src(skb, hdr_size);
1045 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1046
1047 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1048 "Parsing incoming ARP REQUEST");
1049
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001050 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001051
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001052 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001053 if (!dat_entry)
1054 goto out;
1055
Antonio Quartullic384ea32011-06-26 03:37:18 +02001056 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
Marek Lindner736292c2013-01-12 19:19:06 +08001057 bat_priv->soft_iface, ip_dst, hw_src,
Antonio Quartullic384ea32011-06-26 03:37:18 +02001058 dat_entry->mac_addr, hw_src);
1059
1060 if (!skb_new)
1061 goto out;
1062
Linus Lüssing927c2ed2014-01-19 22:22:45 +01001063 /* the rest of the TX path assumes that the mac_header offset pointing
1064 * to the inner Ethernet header has been set, therefore reset it now.
1065 */
1066 skb_reset_mac_header(skb_new);
1067
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001068 if (vid & BATADV_VLAN_HAS_TAG)
1069 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1070 vid & VLAN_VID_MASK);
1071
Marek Lindner93178012013-03-10 19:29:15 +08001072 /* To preserve backwards compatibility, the node has choose the outgoing
1073 * format based on the incoming request packet type. The assumption is
1074 * that a node not using the 4addr packet format doesn't support it.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001075 */
1076 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
Linus Lüssinge300d312013-07-03 10:40:00 +02001077 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1078 BATADV_P_DAT_CACHE_REPLY,
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001079 NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001080 else
Antonio Quartulli6c413b12013-11-05 19:31:08 +01001081 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001082
Linus Lüssinge300d312013-07-03 10:40:00 +02001083 if (err != NET_XMIT_DROP) {
Martin Hundebøll4046b242012-04-20 17:02:45 +02001084 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001085 ret = true;
Martin Hundebøll4046b242012-04-20 17:02:45 +02001086 }
Antonio Quartullic384ea32011-06-26 03:37:18 +02001087out:
1088 if (dat_entry)
1089 batadv_dat_entry_free_ref(dat_entry);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001090 if (ret)
1091 kfree_skb(skb);
1092 return ret;
1093}
1094
1095/**
1096 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1097 * @bat_priv: the bat priv with all the soft interface information
1098 * @skb: packet to check
1099 */
1100void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1101 struct sk_buff *skb)
1102{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001103 u16 type;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001104 __be32 ip_src, ip_dst;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001105 u8 *hw_src, *hw_dst;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001106 int hdr_size = 0;
1107 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001108
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001109 if (!atomic_read(&bat_priv->distributed_arp_table))
1110 return;
1111
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001112 vid = batadv_dat_get_vid(skb, &hdr_size);
1113
1114 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001115 if (type != ARPOP_REPLY)
1116 return;
1117
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001118 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1119 "Parsing outgoing ARP REPLY");
Antonio Quartullic384ea32011-06-26 03:37:18 +02001120
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001121 hw_src = batadv_arp_hw_src(skb, hdr_size);
1122 ip_src = batadv_arp_ip_src(skb, hdr_size);
1123 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1124 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001125
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001126 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1127 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001128
1129 /* Send the ARP reply to the candidates for both the IP addresses that
Marek Lindner93178012013-03-10 19:29:15 +08001130 * the node obtained from the ARP reply
Antonio Quartullic384ea32011-06-26 03:37:18 +02001131 */
1132 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1133 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1134}
Antonio Quartulliaa143d22014-09-01 14:37:27 +02001135
Antonio Quartullic384ea32011-06-26 03:37:18 +02001136/**
1137 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1138 * DAT storage only
1139 * @bat_priv: the bat priv with all the soft interface information
1140 * @skb: packet to check
Marek Lindner93178012013-03-10 19:29:15 +08001141 * @hdr_size: size of the encapsulation header
Antonio Quartullif202a662015-06-16 21:06:24 +02001142 *
1143 * Returns true if the packet was snooped and consumed by DAT. False if the
1144 * packet has to be delivered to the interface
Antonio Quartullic384ea32011-06-26 03:37:18 +02001145 */
1146bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1147 struct sk_buff *skb, int hdr_size)
1148{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001149 u16 type;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001150 __be32 ip_src, ip_dst;
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001151 u8 *hw_src, *hw_dst;
Antonio Quartullif202a662015-06-16 21:06:24 +02001152 bool dropped = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001153 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001154
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001155 if (!atomic_read(&bat_priv->distributed_arp_table))
1156 goto out;
1157
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001158 vid = batadv_dat_get_vid(skb, &hdr_size);
1159
Antonio Quartullic384ea32011-06-26 03:37:18 +02001160 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1161 if (type != ARPOP_REPLY)
1162 goto out;
1163
1164 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1165 "Parsing incoming ARP REPLY");
1166
1167 hw_src = batadv_arp_hw_src(skb, hdr_size);
1168 ip_src = batadv_arp_ip_src(skb, hdr_size);
1169 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1170 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1171
1172 /* Update our internal cache with both the IP addresses the node got
1173 * within the ARP reply
1174 */
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001175 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1176 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001177
1178 /* if this REPLY is directed to a client of mine, let's deliver the
1179 * packet to the interface
1180 */
Antonio Quartullif202a662015-06-16 21:06:24 +02001181 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1182
1183 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1184 * packet because the client will reply by itself
1185 */
1186 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001187out:
Antonio Quartullif202a662015-06-16 21:06:24 +02001188 if (dropped)
Matthias Schiffer0d15bec2013-01-23 18:11:53 +01001189 kfree_skb(skb);
Antonio Quartullif202a662015-06-16 21:06:24 +02001190 /* if dropped == false -> deliver to the interface */
1191 return dropped;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001192}
1193
1194/**
1195 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
Marek Lindner93178012013-03-10 19:29:15 +08001196 * (because the node has already obtained the reply via DAT) or not
Antonio Quartullic384ea32011-06-26 03:37:18 +02001197 * @bat_priv: the bat priv with all the soft interface information
1198 * @forw_packet: the broadcast packet
1199 *
Marek Lindner93178012013-03-10 19:29:15 +08001200 * Returns true if the node can drop the packet, false otherwise.
Antonio Quartullic384ea32011-06-26 03:37:18 +02001201 */
1202bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1203 struct batadv_forw_packet *forw_packet)
1204{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +02001205 u16 type;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001206 __be32 ip_dst;
1207 struct batadv_dat_entry *dat_entry = NULL;
1208 bool ret = false;
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001209 int hdr_size = sizeof(struct batadv_bcast_packet);
1210 unsigned short vid;
Antonio Quartullic384ea32011-06-26 03:37:18 +02001211
Antonio Quartulli33af49a2012-08-08 18:50:57 +02001212 if (!atomic_read(&bat_priv->distributed_arp_table))
1213 goto out;
1214
Antonio Quartullic384ea32011-06-26 03:37:18 +02001215 /* If this packet is an ARP_REQUEST and the node already has the
1216 * information that it is going to ask, then the packet can be dropped
1217 */
1218 if (forw_packet->num_packets)
1219 goto out;
1220
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001221 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1222
1223 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001224 if (type != ARPOP_REQUEST)
1225 goto out;
1226
Antonio Quartullibe1db4f2013-06-04 12:11:43 +02001227 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1228 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
Antonio Quartullic384ea32011-06-26 03:37:18 +02001229 /* check if the node already got this entry */
1230 if (!dat_entry) {
1231 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1232 "ARP Request for %pI4: fallback\n", &ip_dst);
1233 goto out;
1234 }
1235
1236 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1237 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1238 ret = true;
1239
1240out:
1241 if (dat_entry)
1242 batadv_dat_entry_free_ref(dat_entry);
1243 return ret;
1244}