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_free_ref - decrement the dat_entry refcounter and possibly
82 * @dat_entry: dat_entry to be free'd
84 static void batadv_dat_entry_free_ref(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_free_ref(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_free_ref(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_free_ref(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_skb_packet(tmp_skb,
658 neigh_node->if_incoming,
660 if (send_status == NET_XMIT_SUCCESS) {
661 /* count the sent packet */
662 switch (packet_subtype) {
663 case BATADV_P_DAT_DHT_GET:
664 batadv_inc_counter(bat_priv,
665 BATADV_CNT_DAT_GET_TX);
667 case BATADV_P_DAT_DHT_PUT:
668 batadv_inc_counter(bat_priv,
669 BATADV_CNT_DAT_PUT_TX);
673 /* packet sent to a candidate: return true */
677 batadv_neigh_node_put(neigh_node);
679 batadv_orig_node_put(cand[i].orig_node);
688 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
690 * @bat_priv: the bat priv with all the soft interface information
692 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
696 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
700 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
703 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
710 * batadv_dat_status_update - update the dat tvlv container after dat
712 * @net_dev: the soft interface net device
714 void batadv_dat_status_update(struct net_device *net_dev)
716 struct batadv_priv *bat_priv = netdev_priv(net_dev);
718 batadv_dat_tvlv_container_update(bat_priv);
722 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
723 * @bat_priv: the bat priv with all the soft interface information
724 * @orig: the orig_node of the ogm
725 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
726 * @tvlv_value: tvlv buffer containing the gateway data
727 * @tvlv_value_len: tvlv buffer length
729 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
730 struct batadv_orig_node *orig,
732 void *tvlv_value, u16 tvlv_value_len)
734 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
735 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
737 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
741 * batadv_dat_hash_free - free the local DAT hash table
742 * @bat_priv: the bat priv with all the soft interface information
744 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
746 if (!bat_priv->dat.hash)
749 __batadv_dat_purge(bat_priv, NULL);
751 batadv_hash_destroy(bat_priv->dat.hash);
753 bat_priv->dat.hash = NULL;
757 * batadv_dat_init - initialise the DAT internals
758 * @bat_priv: the bat priv with all the soft interface information
760 * Return: 0 in case of success, a negative error code otherwise
762 int batadv_dat_init(struct batadv_priv *bat_priv)
764 if (bat_priv->dat.hash)
767 bat_priv->dat.hash = batadv_hash_new(1024);
769 if (!bat_priv->dat.hash)
772 batadv_dat_start_timer(bat_priv);
774 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
775 NULL, BATADV_TVLV_DAT, 1,
776 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
777 batadv_dat_tvlv_container_update(bat_priv);
782 * batadv_dat_free - free the DAT internals
783 * @bat_priv: the bat priv with all the soft interface information
785 void batadv_dat_free(struct batadv_priv *bat_priv)
787 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
788 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
790 cancel_delayed_work_sync(&bat_priv->dat.work);
792 batadv_dat_hash_free(bat_priv);
796 * batadv_dat_cache_seq_print_text - print the local DAT hash table
797 * @seq: seq file to print on
802 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
804 struct net_device *net_dev = (struct net_device *)seq->private;
805 struct batadv_priv *bat_priv = netdev_priv(net_dev);
806 struct batadv_hashtable *hash = bat_priv->dat.hash;
807 struct batadv_dat_entry *dat_entry;
808 struct batadv_hard_iface *primary_if;
809 struct hlist_head *head;
810 unsigned long last_seen_jiffies;
811 int last_seen_msecs, last_seen_secs, last_seen_mins;
814 primary_if = batadv_seq_print_text_primary_if_get(seq);
818 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
819 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
820 "MAC", "VID", "last-seen");
822 for (i = 0; i < hash->size; i++) {
823 head = &hash->table[i];
826 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
827 last_seen_jiffies = jiffies - dat_entry->last_update;
828 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
829 last_seen_mins = last_seen_msecs / 60000;
830 last_seen_msecs = last_seen_msecs % 60000;
831 last_seen_secs = last_seen_msecs / 1000;
833 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
834 &dat_entry->ip, dat_entry->mac_addr,
835 BATADV_PRINT_VID(dat_entry->vid),
836 last_seen_mins, last_seen_secs);
843 batadv_hardif_put(primary_if);
848 * batadv_arp_get_type - parse an ARP packet and gets the type
849 * @bat_priv: the bat priv with all the soft interface information
850 * @skb: packet to analyse
851 * @hdr_size: size of the possible header before the ARP packet in the skb
853 * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
855 static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
856 struct sk_buff *skb, int hdr_size)
858 struct arphdr *arphdr;
859 struct ethhdr *ethhdr;
860 __be32 ip_src, ip_dst;
864 /* pull the ethernet header */
865 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
868 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
870 if (ethhdr->h_proto != htons(ETH_P_ARP))
873 /* pull the ARP payload */
874 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
875 arp_hdr_len(skb->dev))))
878 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
880 /* check whether the ARP packet carries a valid IP information */
881 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
884 if (arphdr->ar_pro != htons(ETH_P_IP))
887 if (arphdr->ar_hln != ETH_ALEN)
890 if (arphdr->ar_pln != 4)
893 /* Check for bad reply/request. If the ARP message is not sane, DAT
894 * will simply ignore it
896 ip_src = batadv_arp_ip_src(skb, hdr_size);
897 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
898 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
899 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
900 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
901 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
904 hw_src = batadv_arp_hw_src(skb, hdr_size);
905 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
908 /* don't care about the destination MAC address in ARP requests */
909 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
910 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
911 if (is_zero_ether_addr(hw_dst) ||
912 is_multicast_ether_addr(hw_dst))
916 type = ntohs(arphdr->ar_op);
922 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
923 * @skb: the buffer containing the packet to extract the VID from
924 * @hdr_size: the size of the batman-adv header encapsulating the packet
926 * Return: If the packet embedded in the skb is vlan tagged this function
927 * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
930 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
934 vid = batadv_get_vid(skb, *hdr_size);
936 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
937 * If the header contained in the packet is a VLAN one (which is longer)
938 * hdr_size is updated so that the functions will still skip the
939 * correct amount of bytes.
941 if (vid & BATADV_VLAN_HAS_TAG)
942 *hdr_size += VLAN_HLEN;
948 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
950 * @bat_priv: the bat priv with all the soft interface information
951 * @skb: packet to check
953 * Return: true if the message has been sent to the dht candidates, false
954 * otherwise. In case of a positive return value the message has to be enqueued
955 * to permit the fallback.
957 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
961 __be32 ip_dst, ip_src;
964 struct batadv_dat_entry *dat_entry = NULL;
965 struct sk_buff *skb_new;
969 if (!atomic_read(&bat_priv->distributed_arp_table))
972 vid = batadv_dat_get_vid(skb, &hdr_size);
974 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
975 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
976 * message to the selected DHT candidates
978 if (type != ARPOP_REQUEST)
981 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
982 "Parsing outgoing ARP REQUEST");
984 ip_src = batadv_arp_ip_src(skb, hdr_size);
985 hw_src = batadv_arp_hw_src(skb, hdr_size);
986 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
988 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
990 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
992 /* If the ARP request is destined for a local client the local
993 * client will answer itself. DAT would only generate a
996 * Moreover, if the soft-interface is enslaved into a bridge, an
997 * additional DAT answer may trigger kernel warnings about
998 * a packet coming from the wrong port.
1000 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
1005 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1006 bat_priv->soft_iface, ip_dst, hw_src,
1007 dat_entry->mac_addr, hw_src);
1011 if (vid & BATADV_VLAN_HAS_TAG)
1012 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1013 vid & VLAN_VID_MASK);
1015 skb_reset_mac_header(skb_new);
1016 skb_new->protocol = eth_type_trans(skb_new,
1017 bat_priv->soft_iface);
1018 bat_priv->stats.rx_packets++;
1019 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
1020 bat_priv->soft_iface->last_rx = jiffies;
1023 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1026 /* Send the request to the DHT */
1027 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
1028 BATADV_P_DAT_DHT_GET);
1032 batadv_dat_entry_free_ref(dat_entry);
1037 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1038 * answer using the local DAT storage
1039 * @bat_priv: the bat priv with all the soft interface information
1040 * @skb: packet to check
1041 * @hdr_size: size of the encapsulation header
1043 * Return: true if the request has been answered, false otherwise.
1045 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1046 struct sk_buff *skb, int hdr_size)
1049 __be32 ip_src, ip_dst;
1051 struct sk_buff *skb_new;
1052 struct batadv_dat_entry *dat_entry = NULL;
1057 if (!atomic_read(&bat_priv->distributed_arp_table))
1060 vid = batadv_dat_get_vid(skb, &hdr_size);
1062 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1063 if (type != ARPOP_REQUEST)
1066 hw_src = batadv_arp_hw_src(skb, hdr_size);
1067 ip_src = batadv_arp_ip_src(skb, hdr_size);
1068 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1070 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1071 "Parsing incoming ARP REQUEST");
1073 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1075 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1079 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1080 bat_priv->soft_iface, ip_dst, hw_src,
1081 dat_entry->mac_addr, hw_src);
1086 /* the rest of the TX path assumes that the mac_header offset pointing
1087 * to the inner Ethernet header has been set, therefore reset it now.
1089 skb_reset_mac_header(skb_new);
1091 if (vid & BATADV_VLAN_HAS_TAG)
1092 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1093 vid & VLAN_VID_MASK);
1095 /* To preserve backwards compatibility, the node has choose the outgoing
1096 * format based on the incoming request packet type. The assumption is
1097 * that a node not using the 4addr packet format doesn't support it.
1099 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1100 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1101 BATADV_P_DAT_CACHE_REPLY,
1104 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1106 if (err != NET_XMIT_DROP) {
1107 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1112 batadv_dat_entry_free_ref(dat_entry);
1119 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1120 * @bat_priv: the bat priv with all the soft interface information
1121 * @skb: packet to check
1123 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1124 struct sk_buff *skb)
1127 __be32 ip_src, ip_dst;
1128 u8 *hw_src, *hw_dst;
1132 if (!atomic_read(&bat_priv->distributed_arp_table))
1135 vid = batadv_dat_get_vid(skb, &hdr_size);
1137 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1138 if (type != ARPOP_REPLY)
1141 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1142 "Parsing outgoing ARP REPLY");
1144 hw_src = batadv_arp_hw_src(skb, hdr_size);
1145 ip_src = batadv_arp_ip_src(skb, hdr_size);
1146 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1147 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1149 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1150 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1152 /* Send the ARP reply to the candidates for both the IP addresses that
1153 * the node obtained from the ARP reply
1155 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1156 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1160 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1162 * @bat_priv: the bat priv with all the soft interface information
1163 * @skb: packet to check
1164 * @hdr_size: size of the encapsulation header
1166 * Return: true if the packet was snooped and consumed by DAT. False if the
1167 * packet has to be delivered to the interface
1169 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1170 struct sk_buff *skb, int hdr_size)
1173 __be32 ip_src, ip_dst;
1174 u8 *hw_src, *hw_dst;
1175 bool dropped = false;
1178 if (!atomic_read(&bat_priv->distributed_arp_table))
1181 vid = batadv_dat_get_vid(skb, &hdr_size);
1183 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1184 if (type != ARPOP_REPLY)
1187 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1188 "Parsing incoming ARP REPLY");
1190 hw_src = batadv_arp_hw_src(skb, hdr_size);
1191 ip_src = batadv_arp_ip_src(skb, hdr_size);
1192 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1193 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1195 /* Update our internal cache with both the IP addresses the node got
1196 * within the ARP reply
1198 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1199 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1201 /* if this REPLY is directed to a client of mine, let's deliver the
1202 * packet to the interface
1204 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1206 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1207 * packet because the client will reply by itself
1209 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1213 /* if dropped == false -> deliver to the interface */
1218 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1219 * (because the node has already obtained the reply via DAT) or not
1220 * @bat_priv: the bat priv with all the soft interface information
1221 * @forw_packet: the broadcast packet
1223 * Return: true if the node can drop the packet, false otherwise.
1225 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1226 struct batadv_forw_packet *forw_packet)
1230 struct batadv_dat_entry *dat_entry = NULL;
1232 int hdr_size = sizeof(struct batadv_bcast_packet);
1235 if (!atomic_read(&bat_priv->distributed_arp_table))
1238 /* If this packet is an ARP_REQUEST and the node already has the
1239 * information that it is going to ask, then the packet can be dropped
1241 if (forw_packet->num_packets)
1244 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1246 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1247 if (type != ARPOP_REQUEST)
1250 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1251 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1252 /* check if the node already got this entry */
1254 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1255 "ARP Request for %pI4: fallback\n", &ip_dst);
1259 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1260 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1265 batadv_dat_entry_free_ref(dat_entry);