1 /* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
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.
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.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 #include "distributed-arp-table.h"
21 #include <linux/atomic.h>
22 #include <linux/bitops.h>
23 #include <linux/byteorder/generic.h>
24 #include <linux/errno.h>
25 #include <linux/etherdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/if_ether.h>
29 #include <linux/if_vlan.h>
31 #include <linux/jiffies.h>
32 #include <linux/kernel.h>
33 #include <linux/kref.h>
34 #include <linux/list.h>
35 #include <linux/rculist.h>
36 #include <linux/rcupdate.h>
37 #include <linux/seq_file.h>
38 #include <linux/skbuff.h>
39 #include <linux/slab.h>
40 #include <linux/spinlock.h>
41 #include <linux/stddef.h>
42 #include <linux/string.h>
43 #include <linux/workqueue.h>
46 #include "hard-interface.h"
48 #include "originator.h"
50 #include "translation-table.h"
52 static void batadv_dat_purge(struct work_struct *work);
55 * batadv_dat_start_timer - initialise the DAT periodic worker
56 * @bat_priv: the bat priv with all the soft interface information
58 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
60 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
61 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
62 msecs_to_jiffies(10000));
66 * batadv_dat_entry_release - release dat_entry from lists and queue for free
67 * after rcu grace period
68 * @ref: kref pointer of the dat_entry
70 static void batadv_dat_entry_release(struct kref *ref)
72 struct batadv_dat_entry *dat_entry;
74 dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
76 kfree_rcu(dat_entry, rcu);
80 * batadv_dat_entry_put - decrement the dat_entry refcounter and possibly
82 * @dat_entry: dat_entry to be free'd
84 static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry)
86 kref_put(&dat_entry->refcount, batadv_dat_entry_release);
90 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
91 * @dat_entry: the entry to check
93 * Return: true if the entry has to be purged now, false otherwise.
95 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
97 return batadv_has_timed_out(dat_entry->last_update,
98 BATADV_DAT_ENTRY_TIMEOUT);
102 * __batadv_dat_purge - delete entries from the DAT local storage
103 * @bat_priv: the bat priv with all the soft interface information
104 * @to_purge: function in charge to decide whether an entry has to be purged or
105 * not. This function takes the dat_entry as argument and has to
106 * returns a boolean value: true is the entry has to be deleted,
109 * Loops over each entry in the DAT local storage and deletes it if and only if
110 * the to_purge function passed as argument returns true.
112 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
113 bool (*to_purge)(struct batadv_dat_entry *))
115 spinlock_t *list_lock; /* protects write access to the hash lists */
116 struct batadv_dat_entry *dat_entry;
117 struct hlist_node *node_tmp;
118 struct hlist_head *head;
121 if (!bat_priv->dat.hash)
124 for (i = 0; i < bat_priv->dat.hash->size; i++) {
125 head = &bat_priv->dat.hash->table[i];
126 list_lock = &bat_priv->dat.hash->list_locks[i];
128 spin_lock_bh(list_lock);
129 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
131 /* if a helper function has been passed as parameter,
132 * ask it if the entry has to be purged or not
134 if (to_purge && !to_purge(dat_entry))
137 hlist_del_rcu(&dat_entry->hash_entry);
138 batadv_dat_entry_put(dat_entry);
140 spin_unlock_bh(list_lock);
145 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
147 * @work: kernel work struct
149 static void batadv_dat_purge(struct work_struct *work)
151 struct delayed_work *delayed_work;
152 struct batadv_priv_dat *priv_dat;
153 struct batadv_priv *bat_priv;
155 delayed_work = container_of(work, struct delayed_work, work);
156 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
157 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
159 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
160 batadv_dat_start_timer(bat_priv);
164 * batadv_compare_dat - comparing function used in the local DAT hash table
165 * @node: node in the local table
166 * @data2: second object to compare the node to
168 * Return: 1 if the two entries are the same, 0 otherwise.
170 static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
172 const void *data1 = container_of(node, struct batadv_dat_entry,
175 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
179 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
181 * @hdr_size: size of the possible header before the ARP packet
183 * Return: the value of the hw_src field in the ARP packet.
185 static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
189 addr = (u8 *)(skb->data + hdr_size);
190 addr += ETH_HLEN + sizeof(struct arphdr);
196 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
198 * @hdr_size: size of the possible header before the ARP packet
200 * Return: the value of the ip_src field in the ARP packet.
202 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
204 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
208 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
210 * @hdr_size: size of the possible header before the ARP packet
212 * Return: the value of the hw_dst field in the ARP packet.
214 static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
216 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
220 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
222 * @hdr_size: size of the possible header before the ARP packet
224 * Return: the value of the ip_dst field in the ARP packet.
226 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
228 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
232 * batadv_hash_dat - compute the hash value for an IP address
233 * @data: data to hash
234 * @size: size of the hash table
236 * Return: the selected index in the hash table for the given data.
238 static u32 batadv_hash_dat(const void *data, u32 size)
241 const struct batadv_dat_entry *dat = data;
242 const unsigned char *key;
245 key = (const unsigned char *)&dat->ip;
246 for (i = 0; i < sizeof(dat->ip); i++) {
248 hash += (hash << 10);
252 key = (const unsigned char *)&dat->vid;
253 for (i = 0; i < sizeof(dat->vid); i++) {
255 hash += (hash << 10);
260 hash ^= (hash >> 11);
261 hash += (hash << 15);
267 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
269 * @bat_priv: the bat priv with all the soft interface information
271 * @vid: VLAN identifier
273 * Return: the dat_entry if found, NULL otherwise.
275 static struct batadv_dat_entry *
276 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
279 struct hlist_head *head;
280 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
281 struct batadv_hashtable *hash = bat_priv->dat.hash;
290 index = batadv_hash_dat(&to_find, hash->size);
291 head = &hash->table[index];
294 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
295 if (dat_entry->ip != ip)
298 if (!kref_get_unless_zero(&dat_entry->refcount))
301 dat_entry_tmp = dat_entry;
306 return dat_entry_tmp;
310 * batadv_dat_entry_add - add a new dat entry or update it if already exists
311 * @bat_priv: the bat priv with all the soft interface information
312 * @ip: ipv4 to add/edit
313 * @mac_addr: mac address to assign to the given ipv4
314 * @vid: VLAN identifier
316 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
317 u8 *mac_addr, unsigned short vid)
319 struct batadv_dat_entry *dat_entry;
322 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
323 /* if this entry is already known, just update it */
325 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
326 ether_addr_copy(dat_entry->mac_addr, mac_addr);
327 dat_entry->last_update = jiffies;
328 batadv_dbg(BATADV_DBG_DAT, bat_priv,
329 "Entry updated: %pI4 %pM (vid: %d)\n",
330 &dat_entry->ip, dat_entry->mac_addr,
331 BATADV_PRINT_VID(vid));
335 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
340 dat_entry->vid = vid;
341 ether_addr_copy(dat_entry->mac_addr, mac_addr);
342 dat_entry->last_update = jiffies;
343 kref_init(&dat_entry->refcount);
344 kref_get(&dat_entry->refcount);
346 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
347 batadv_hash_dat, dat_entry,
348 &dat_entry->hash_entry);
350 if (unlikely(hash_added != 0)) {
351 /* remove the reference for the hash */
352 batadv_dat_entry_put(dat_entry);
356 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
357 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
361 batadv_dat_entry_put(dat_entry);
364 #ifdef CONFIG_BATMAN_ADV_DEBUG
367 * batadv_dbg_arp - print a debug message containing all the ARP packet details
368 * @bat_priv: the bat priv with all the soft interface information
371 * @hdr_size: size of the possible header before the ARP packet
372 * @msg: message to print together with the debugging information
374 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
375 u16 type, int hdr_size, char *msg)
377 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
378 struct batadv_bcast_packet *bcast_pkt;
380 __be32 ip_src, ip_dst;
383 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
385 ip_src = batadv_arp_ip_src(skb, hdr_size);
386 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
387 batadv_dbg(BATADV_DBG_DAT, bat_priv,
388 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
389 batadv_arp_hw_src(skb, hdr_size), &ip_src,
390 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
395 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
397 switch (unicast_4addr_packet->u.packet_type) {
399 batadv_dbg(BATADV_DBG_DAT, bat_priv,
400 "* encapsulated within a UNICAST packet\n");
402 case BATADV_UNICAST_4ADDR:
403 batadv_dbg(BATADV_DBG_DAT, bat_priv,
404 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
405 unicast_4addr_packet->src);
406 switch (unicast_4addr_packet->subtype) {
407 case BATADV_P_DAT_DHT_PUT:
408 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
410 case BATADV_P_DAT_DHT_GET:
411 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
413 case BATADV_P_DAT_CACHE_REPLY:
414 batadv_dbg(BATADV_DBG_DAT, bat_priv,
415 "* type: DAT_CACHE_REPLY\n");
418 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
421 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
422 unicast_4addr_packet->u.packet_type);
426 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
427 orig_addr = bcast_pkt->orig;
428 batadv_dbg(BATADV_DBG_DAT, bat_priv,
429 "* encapsulated within a BCAST packet (src: %pM)\n",
433 batadv_dbg(BATADV_DBG_DAT, bat_priv,
434 "* encapsulated within an unknown packet type (0x%x)\n",
435 unicast_4addr_packet->u.packet_type);
441 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
442 u16 type, int hdr_size, char *msg)
446 #endif /* CONFIG_BATMAN_ADV_DEBUG */
449 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
450 * @res: the array with the already selected candidates
451 * @select: number of already selected candidates
452 * @tmp_max: address of the currently evaluated node
453 * @max: current round max address
454 * @last_max: address of the last selected candidate
455 * @candidate: orig_node under evaluation
456 * @max_orig_node: last selected candidate
458 * Return: true if the node has been elected as next candidate or false
461 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
462 int select, batadv_dat_addr_t tmp_max,
463 batadv_dat_addr_t max,
464 batadv_dat_addr_t last_max,
465 struct batadv_orig_node *candidate,
466 struct batadv_orig_node *max_orig_node)
471 /* check if orig node candidate is running DAT */
472 if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
475 /* Check if this node has already been selected... */
476 for (j = 0; j < select; j++)
477 if (res[j].orig_node == candidate)
479 /* ..and possibly skip it */
482 /* sanity check: has it already been selected? This should not happen */
483 if (tmp_max > last_max)
485 /* check if during this iteration an originator with a closer dht
486 * address has already been found
490 /* this is an hash collision with the temporary selected node. Choose
491 * the one with the lowest address
493 if ((tmp_max == max) && max_orig_node &&
494 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
503 * batadv_choose_next_candidate - select the next DHT candidate
504 * @bat_priv: the bat priv with all the soft interface information
505 * @cands: candidates array
506 * @select: number of candidates already present in the array
507 * @ip_key: key to look up in the DHT
508 * @last_max: pointer where the address of the selected candidate will be saved
510 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
511 struct batadv_dat_candidate *cands,
512 int select, batadv_dat_addr_t ip_key,
513 batadv_dat_addr_t *last_max)
515 batadv_dat_addr_t max = 0;
516 batadv_dat_addr_t tmp_max = 0;
517 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
518 struct batadv_hashtable *hash = bat_priv->orig_hash;
519 struct hlist_head *head;
522 /* if no node is eligible as candidate, leave the candidate type as
525 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
527 /* iterate over the originator list and find the node with the closest
528 * dat_address which has not been selected yet
530 for (i = 0; i < hash->size; i++) {
531 head = &hash->table[i];
534 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
535 /* the dht space is a ring using unsigned addresses */
536 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
539 if (!batadv_is_orig_node_eligible(cands, select,
541 *last_max, orig_node,
545 if (!kref_get_unless_zero(&orig_node->refcount))
550 batadv_orig_node_put(max_orig_node);
551 max_orig_node = orig_node;
556 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
557 cands[select].orig_node = max_orig_node;
558 batadv_dbg(BATADV_DBG_DAT, bat_priv,
559 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
560 select, max_orig_node->orig, max_orig_node->dat_addr,
567 * batadv_dat_select_candidates - select the nodes which the DHT message has to
569 * @bat_priv: the bat priv with all the soft interface information
570 * @ip_dst: ipv4 to look up in the DHT
572 * An originator O is selected if and only if its DHT_ID value is one of three
573 * closest values (from the LEFT, with wrap around if needed) then the hash
574 * value of the key. ip_dst is the key.
576 * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM.
578 static struct batadv_dat_candidate *
579 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
582 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
583 struct batadv_dat_candidate *res;
584 struct batadv_dat_entry dat;
586 if (!bat_priv->orig_hash)
589 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
596 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
597 BATADV_DAT_ADDR_MAX);
599 batadv_dbg(BATADV_DBG_DAT, bat_priv,
600 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
603 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
604 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
611 * batadv_dat_send_data - send a payload to the selected candidates
612 * @bat_priv: the bat priv with all the soft interface information
613 * @skb: payload to send
615 * @packet_subtype: unicast4addr packet subtype to use
617 * This function copies the skb with pskb_copy() and is sent as unicast packet
618 * to each of the selected candidates.
620 * Return: true if the packet is sent to at least one candidate, false
623 static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
624 struct sk_buff *skb, __be32 ip,
630 struct batadv_neigh_node *neigh_node = NULL;
631 struct sk_buff *tmp_skb;
632 struct batadv_dat_candidate *cand;
634 cand = batadv_dat_select_candidates(bat_priv, ip);
638 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
640 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
641 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
644 neigh_node = batadv_orig_router_get(cand[i].orig_node,
649 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
650 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
657 send_status = batadv_send_unicast_skb(tmp_skb, neigh_node);
658 if (send_status == NET_XMIT_SUCCESS) {
659 /* count the sent packet */
660 switch (packet_subtype) {
661 case BATADV_P_DAT_DHT_GET:
662 batadv_inc_counter(bat_priv,
663 BATADV_CNT_DAT_GET_TX);
665 case BATADV_P_DAT_DHT_PUT:
666 batadv_inc_counter(bat_priv,
667 BATADV_CNT_DAT_PUT_TX);
671 /* packet sent to a candidate: return true */
675 batadv_neigh_node_put(neigh_node);
677 batadv_orig_node_put(cand[i].orig_node);
686 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
688 * @bat_priv: the bat priv with all the soft interface information
690 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
694 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
698 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
701 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
708 * batadv_dat_status_update - update the dat tvlv container after dat
710 * @net_dev: the soft interface net device
712 void batadv_dat_status_update(struct net_device *net_dev)
714 struct batadv_priv *bat_priv = netdev_priv(net_dev);
716 batadv_dat_tvlv_container_update(bat_priv);
720 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
721 * @bat_priv: the bat priv with all the soft interface information
722 * @orig: the orig_node of the ogm
723 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
724 * @tvlv_value: tvlv buffer containing the gateway data
725 * @tvlv_value_len: tvlv buffer length
727 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
728 struct batadv_orig_node *orig,
730 void *tvlv_value, u16 tvlv_value_len)
732 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
733 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
735 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
739 * batadv_dat_hash_free - free the local DAT hash table
740 * @bat_priv: the bat priv with all the soft interface information
742 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
744 if (!bat_priv->dat.hash)
747 __batadv_dat_purge(bat_priv, NULL);
749 batadv_hash_destroy(bat_priv->dat.hash);
751 bat_priv->dat.hash = NULL;
755 * batadv_dat_init - initialise the DAT internals
756 * @bat_priv: the bat priv with all the soft interface information
758 * Return: 0 in case of success, a negative error code otherwise
760 int batadv_dat_init(struct batadv_priv *bat_priv)
762 if (bat_priv->dat.hash)
765 bat_priv->dat.hash = batadv_hash_new(1024);
767 if (!bat_priv->dat.hash)
770 batadv_dat_start_timer(bat_priv);
772 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
773 NULL, BATADV_TVLV_DAT, 1,
774 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
775 batadv_dat_tvlv_container_update(bat_priv);
780 * batadv_dat_free - free the DAT internals
781 * @bat_priv: the bat priv with all the soft interface information
783 void batadv_dat_free(struct batadv_priv *bat_priv)
785 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
786 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
788 cancel_delayed_work_sync(&bat_priv->dat.work);
790 batadv_dat_hash_free(bat_priv);
794 * batadv_dat_cache_seq_print_text - print the local DAT hash table
795 * @seq: seq file to print on
800 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
802 struct net_device *net_dev = (struct net_device *)seq->private;
803 struct batadv_priv *bat_priv = netdev_priv(net_dev);
804 struct batadv_hashtable *hash = bat_priv->dat.hash;
805 struct batadv_dat_entry *dat_entry;
806 struct batadv_hard_iface *primary_if;
807 struct hlist_head *head;
808 unsigned long last_seen_jiffies;
809 int last_seen_msecs, last_seen_secs, last_seen_mins;
812 primary_if = batadv_seq_print_text_primary_if_get(seq);
816 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
817 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
818 "MAC", "VID", "last-seen");
820 for (i = 0; i < hash->size; i++) {
821 head = &hash->table[i];
824 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
825 last_seen_jiffies = jiffies - dat_entry->last_update;
826 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
827 last_seen_mins = last_seen_msecs / 60000;
828 last_seen_msecs = last_seen_msecs % 60000;
829 last_seen_secs = last_seen_msecs / 1000;
831 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
832 &dat_entry->ip, dat_entry->mac_addr,
833 BATADV_PRINT_VID(dat_entry->vid),
834 last_seen_mins, last_seen_secs);
841 batadv_hardif_put(primary_if);
846 * batadv_arp_get_type - parse an ARP packet and gets the type
847 * @bat_priv: the bat priv with all the soft interface information
848 * @skb: packet to analyse
849 * @hdr_size: size of the possible header before the ARP packet in the skb
851 * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
853 static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
854 struct sk_buff *skb, int hdr_size)
856 struct arphdr *arphdr;
857 struct ethhdr *ethhdr;
858 __be32 ip_src, ip_dst;
862 /* pull the ethernet header */
863 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
866 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
868 if (ethhdr->h_proto != htons(ETH_P_ARP))
871 /* pull the ARP payload */
872 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
873 arp_hdr_len(skb->dev))))
876 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
878 /* check whether the ARP packet carries a valid IP information */
879 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
882 if (arphdr->ar_pro != htons(ETH_P_IP))
885 if (arphdr->ar_hln != ETH_ALEN)
888 if (arphdr->ar_pln != 4)
891 /* Check for bad reply/request. If the ARP message is not sane, DAT
892 * will simply ignore it
894 ip_src = batadv_arp_ip_src(skb, hdr_size);
895 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
896 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
897 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
898 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
899 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
902 hw_src = batadv_arp_hw_src(skb, hdr_size);
903 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
906 /* don't care about the destination MAC address in ARP requests */
907 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
908 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
909 if (is_zero_ether_addr(hw_dst) ||
910 is_multicast_ether_addr(hw_dst))
914 type = ntohs(arphdr->ar_op);
920 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
921 * @skb: the buffer containing the packet to extract the VID from
922 * @hdr_size: the size of the batman-adv header encapsulating the packet
924 * Return: If the packet embedded in the skb is vlan tagged this function
925 * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
928 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
932 vid = batadv_get_vid(skb, *hdr_size);
934 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
935 * If the header contained in the packet is a VLAN one (which is longer)
936 * hdr_size is updated so that the functions will still skip the
937 * correct amount of bytes.
939 if (vid & BATADV_VLAN_HAS_TAG)
940 *hdr_size += VLAN_HLEN;
946 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
948 * @bat_priv: the bat priv with all the soft interface information
949 * @skb: packet to check
951 * Return: true if the message has been sent to the dht candidates, false
952 * otherwise. In case of a positive return value the message has to be enqueued
953 * to permit the fallback.
955 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
959 __be32 ip_dst, ip_src;
962 struct batadv_dat_entry *dat_entry = NULL;
963 struct sk_buff *skb_new;
967 if (!atomic_read(&bat_priv->distributed_arp_table))
970 vid = batadv_dat_get_vid(skb, &hdr_size);
972 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
973 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
974 * message to the selected DHT candidates
976 if (type != ARPOP_REQUEST)
979 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
980 "Parsing outgoing ARP REQUEST");
982 ip_src = batadv_arp_ip_src(skb, hdr_size);
983 hw_src = batadv_arp_hw_src(skb, hdr_size);
984 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
986 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
988 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
990 /* If the ARP request is destined for a local client the local
991 * client will answer itself. DAT would only generate a
994 * Moreover, if the soft-interface is enslaved into a bridge, an
995 * additional DAT answer may trigger kernel warnings about
996 * a packet coming from the wrong port.
998 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
1003 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1004 bat_priv->soft_iface, ip_dst, hw_src,
1005 dat_entry->mac_addr, hw_src);
1009 if (vid & BATADV_VLAN_HAS_TAG)
1010 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1011 vid & VLAN_VID_MASK);
1013 skb_reset_mac_header(skb_new);
1014 skb_new->protocol = eth_type_trans(skb_new,
1015 bat_priv->soft_iface);
1016 bat_priv->stats.rx_packets++;
1017 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
1018 bat_priv->soft_iface->last_rx = jiffies;
1021 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1024 /* Send the request to the DHT */
1025 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
1026 BATADV_P_DAT_DHT_GET);
1030 batadv_dat_entry_put(dat_entry);
1035 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1036 * answer using the local DAT storage
1037 * @bat_priv: the bat priv with all the soft interface information
1038 * @skb: packet to check
1039 * @hdr_size: size of the encapsulation header
1041 * Return: true if the request has been answered, false otherwise.
1043 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1044 struct sk_buff *skb, int hdr_size)
1047 __be32 ip_src, ip_dst;
1049 struct sk_buff *skb_new;
1050 struct batadv_dat_entry *dat_entry = NULL;
1055 if (!atomic_read(&bat_priv->distributed_arp_table))
1058 vid = batadv_dat_get_vid(skb, &hdr_size);
1060 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1061 if (type != ARPOP_REQUEST)
1064 hw_src = batadv_arp_hw_src(skb, hdr_size);
1065 ip_src = batadv_arp_ip_src(skb, hdr_size);
1066 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1068 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1069 "Parsing incoming ARP REQUEST");
1071 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1073 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1077 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1078 bat_priv->soft_iface, ip_dst, hw_src,
1079 dat_entry->mac_addr, hw_src);
1084 /* the rest of the TX path assumes that the mac_header offset pointing
1085 * to the inner Ethernet header has been set, therefore reset it now.
1087 skb_reset_mac_header(skb_new);
1089 if (vid & BATADV_VLAN_HAS_TAG)
1090 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1091 vid & VLAN_VID_MASK);
1093 /* To preserve backwards compatibility, the node has choose the outgoing
1094 * format based on the incoming request packet type. The assumption is
1095 * that a node not using the 4addr packet format doesn't support it.
1097 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1098 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1099 BATADV_P_DAT_CACHE_REPLY,
1102 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1104 if (err != NET_XMIT_DROP) {
1105 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1110 batadv_dat_entry_put(dat_entry);
1117 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1118 * @bat_priv: the bat priv with all the soft interface information
1119 * @skb: packet to check
1121 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1122 struct sk_buff *skb)
1125 __be32 ip_src, ip_dst;
1126 u8 *hw_src, *hw_dst;
1130 if (!atomic_read(&bat_priv->distributed_arp_table))
1133 vid = batadv_dat_get_vid(skb, &hdr_size);
1135 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1136 if (type != ARPOP_REPLY)
1139 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1140 "Parsing outgoing ARP REPLY");
1142 hw_src = batadv_arp_hw_src(skb, hdr_size);
1143 ip_src = batadv_arp_ip_src(skb, hdr_size);
1144 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1145 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1147 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1148 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1150 /* Send the ARP reply to the candidates for both the IP addresses that
1151 * the node obtained from the ARP reply
1153 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1154 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1158 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1160 * @bat_priv: the bat priv with all the soft interface information
1161 * @skb: packet to check
1162 * @hdr_size: size of the encapsulation header
1164 * Return: true if the packet was snooped and consumed by DAT. False if the
1165 * packet has to be delivered to the interface
1167 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1168 struct sk_buff *skb, int hdr_size)
1171 __be32 ip_src, ip_dst;
1172 u8 *hw_src, *hw_dst;
1173 bool dropped = false;
1176 if (!atomic_read(&bat_priv->distributed_arp_table))
1179 vid = batadv_dat_get_vid(skb, &hdr_size);
1181 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1182 if (type != ARPOP_REPLY)
1185 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1186 "Parsing incoming ARP REPLY");
1188 hw_src = batadv_arp_hw_src(skb, hdr_size);
1189 ip_src = batadv_arp_ip_src(skb, hdr_size);
1190 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1191 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1193 /* Update our internal cache with both the IP addresses the node got
1194 * within the ARP reply
1196 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1197 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1199 /* if this REPLY is directed to a client of mine, let's deliver the
1200 * packet to the interface
1202 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1204 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1205 * packet because the client will reply by itself
1207 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1211 /* if dropped == false -> deliver to the interface */
1216 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1217 * (because the node has already obtained the reply via DAT) or not
1218 * @bat_priv: the bat priv with all the soft interface information
1219 * @forw_packet: the broadcast packet
1221 * Return: true if the node can drop the packet, false otherwise.
1223 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1224 struct batadv_forw_packet *forw_packet)
1228 struct batadv_dat_entry *dat_entry = NULL;
1230 int hdr_size = sizeof(struct batadv_bcast_packet);
1233 if (!atomic_read(&bat_priv->distributed_arp_table))
1236 /* If this packet is an ARP_REQUEST and the node already has the
1237 * information that it is going to ask, then the packet can be dropped
1239 if (forw_packet->num_packets)
1242 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1244 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1245 if (type != ARPOP_REQUEST)
1248 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1249 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1250 /* check if the node already got this entry */
1252 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1253 "ARP Request for %pI4: fallback\n", &ip_dst);
1257 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1258 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1263 batadv_dat_entry_put(dat_entry);