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"
49 #include "originator.h"
51 #include "translation-table.h"
54 static void batadv_dat_purge(struct work_struct *work);
57 * batadv_dat_start_timer - initialise the DAT periodic worker
58 * @bat_priv: the bat priv with all the soft interface information
60 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
62 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
63 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
64 msecs_to_jiffies(10000));
68 * batadv_dat_entry_release - release dat_entry from lists and queue for free
69 * after rcu grace period
70 * @ref: kref pointer of the dat_entry
72 static void batadv_dat_entry_release(struct kref *ref)
74 struct batadv_dat_entry *dat_entry;
76 dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
78 kfree_rcu(dat_entry, rcu);
82 * batadv_dat_entry_put - decrement the dat_entry refcounter and possibly
84 * @dat_entry: dat_entry to be free'd
86 static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry)
88 kref_put(&dat_entry->refcount, batadv_dat_entry_release);
92 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
93 * @dat_entry: the entry to check
95 * Return: true if the entry has to be purged now, false otherwise.
97 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
99 return batadv_has_timed_out(dat_entry->last_update,
100 BATADV_DAT_ENTRY_TIMEOUT);
104 * __batadv_dat_purge - delete entries from the DAT local storage
105 * @bat_priv: the bat priv with all the soft interface information
106 * @to_purge: function in charge to decide whether an entry has to be purged or
107 * not. This function takes the dat_entry as argument and has to
108 * returns a boolean value: true is the entry has to be deleted,
111 * Loops over each entry in the DAT local storage and deletes it if and only if
112 * the to_purge function passed as argument returns true.
114 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
115 bool (*to_purge)(struct batadv_dat_entry *))
117 spinlock_t *list_lock; /* protects write access to the hash lists */
118 struct batadv_dat_entry *dat_entry;
119 struct hlist_node *node_tmp;
120 struct hlist_head *head;
123 if (!bat_priv->dat.hash)
126 for (i = 0; i < bat_priv->dat.hash->size; i++) {
127 head = &bat_priv->dat.hash->table[i];
128 list_lock = &bat_priv->dat.hash->list_locks[i];
130 spin_lock_bh(list_lock);
131 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
133 /* if a helper function has been passed as parameter,
134 * ask it if the entry has to be purged or not
136 if (to_purge && !to_purge(dat_entry))
139 hlist_del_rcu(&dat_entry->hash_entry);
140 batadv_dat_entry_put(dat_entry);
142 spin_unlock_bh(list_lock);
147 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
149 * @work: kernel work struct
151 static void batadv_dat_purge(struct work_struct *work)
153 struct delayed_work *delayed_work;
154 struct batadv_priv_dat *priv_dat;
155 struct batadv_priv *bat_priv;
157 delayed_work = to_delayed_work(work);
158 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
159 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
161 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
162 batadv_dat_start_timer(bat_priv);
166 * batadv_compare_dat - comparing function used in the local DAT hash table
167 * @node: node in the local table
168 * @data2: second object to compare the node to
170 * Return: true if the two entries are the same, false otherwise.
172 static bool batadv_compare_dat(const struct hlist_node *node, const void *data2)
174 const void *data1 = container_of(node, struct batadv_dat_entry,
177 return memcmp(data1, data2, sizeof(__be32)) == 0;
181 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
183 * @hdr_size: size of the possible header before the ARP packet
185 * Return: the value of the hw_src field in the ARP packet.
187 static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
191 addr = (u8 *)(skb->data + hdr_size);
192 addr += ETH_HLEN + sizeof(struct arphdr);
198 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
200 * @hdr_size: size of the possible header before the ARP packet
202 * Return: the value of the ip_src field in the ARP packet.
204 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
206 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
210 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
212 * @hdr_size: size of the possible header before the ARP packet
214 * Return: the value of the hw_dst field in the ARP packet.
216 static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
218 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
222 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
224 * @hdr_size: size of the possible header before the ARP packet
226 * Return: the value of the ip_dst field in the ARP packet.
228 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
230 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
234 * batadv_hash_dat - compute the hash value for an IP address
235 * @data: data to hash
236 * @size: size of the hash table
238 * Return: the selected index in the hash table for the given data.
240 static u32 batadv_hash_dat(const void *data, u32 size)
243 const struct batadv_dat_entry *dat = data;
244 const unsigned char *key;
248 key = (const unsigned char *)&dat->ip;
249 for (i = 0; i < sizeof(dat->ip); i++) {
251 hash += (hash << 10);
255 vid = htons(dat->vid);
256 key = (__force const unsigned char *)&vid;
257 for (i = 0; i < sizeof(dat->vid); i++) {
259 hash += (hash << 10);
264 hash ^= (hash >> 11);
265 hash += (hash << 15);
271 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
273 * @bat_priv: the bat priv with all the soft interface information
275 * @vid: VLAN identifier
277 * Return: the dat_entry if found, NULL otherwise.
279 static struct batadv_dat_entry *
280 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
283 struct hlist_head *head;
284 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
285 struct batadv_hashtable *hash = bat_priv->dat.hash;
294 index = batadv_hash_dat(&to_find, hash->size);
295 head = &hash->table[index];
298 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
299 if (dat_entry->ip != ip)
302 if (!kref_get_unless_zero(&dat_entry->refcount))
305 dat_entry_tmp = dat_entry;
310 return dat_entry_tmp;
314 * batadv_dat_entry_add - add a new dat entry or update it if already exists
315 * @bat_priv: the bat priv with all the soft interface information
316 * @ip: ipv4 to add/edit
317 * @mac_addr: mac address to assign to the given ipv4
318 * @vid: VLAN identifier
320 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
321 u8 *mac_addr, unsigned short vid)
323 struct batadv_dat_entry *dat_entry;
326 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
327 /* if this entry is already known, just update it */
329 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
330 ether_addr_copy(dat_entry->mac_addr, mac_addr);
331 dat_entry->last_update = jiffies;
332 batadv_dbg(BATADV_DBG_DAT, bat_priv,
333 "Entry updated: %pI4 %pM (vid: %d)\n",
334 &dat_entry->ip, dat_entry->mac_addr,
335 BATADV_PRINT_VID(vid));
339 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
344 dat_entry->vid = vid;
345 ether_addr_copy(dat_entry->mac_addr, mac_addr);
346 dat_entry->last_update = jiffies;
347 kref_init(&dat_entry->refcount);
349 kref_get(&dat_entry->refcount);
350 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
351 batadv_hash_dat, dat_entry,
352 &dat_entry->hash_entry);
354 if (unlikely(hash_added != 0)) {
355 /* remove the reference for the hash */
356 batadv_dat_entry_put(dat_entry);
360 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
361 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
365 batadv_dat_entry_put(dat_entry);
368 #ifdef CONFIG_BATMAN_ADV_DEBUG
371 * batadv_dbg_arp - print a debug message containing all the ARP packet details
372 * @bat_priv: the bat priv with all the soft interface information
375 * @hdr_size: size of the possible header before the ARP packet
376 * @msg: message to print together with the debugging information
378 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
379 u16 type, int hdr_size, char *msg)
381 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
382 struct batadv_bcast_packet *bcast_pkt;
384 __be32 ip_src, ip_dst;
387 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
389 ip_src = batadv_arp_ip_src(skb, hdr_size);
390 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
391 batadv_dbg(BATADV_DBG_DAT, bat_priv,
392 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
393 batadv_arp_hw_src(skb, hdr_size), &ip_src,
394 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
396 if (hdr_size < sizeof(struct batadv_unicast_packet))
399 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
401 switch (unicast_4addr_packet->u.packet_type) {
403 batadv_dbg(BATADV_DBG_DAT, bat_priv,
404 "* encapsulated within a UNICAST packet\n");
406 case BATADV_UNICAST_4ADDR:
407 batadv_dbg(BATADV_DBG_DAT, bat_priv,
408 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
409 unicast_4addr_packet->src);
410 switch (unicast_4addr_packet->subtype) {
411 case BATADV_P_DAT_DHT_PUT:
412 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
414 case BATADV_P_DAT_DHT_GET:
415 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
417 case BATADV_P_DAT_CACHE_REPLY:
418 batadv_dbg(BATADV_DBG_DAT, bat_priv,
419 "* type: DAT_CACHE_REPLY\n");
422 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
425 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
426 unicast_4addr_packet->u.packet_type);
430 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
431 orig_addr = bcast_pkt->orig;
432 batadv_dbg(BATADV_DBG_DAT, bat_priv,
433 "* encapsulated within a BCAST packet (src: %pM)\n",
437 batadv_dbg(BATADV_DBG_DAT, bat_priv,
438 "* encapsulated within an unknown packet type (0x%x)\n",
439 unicast_4addr_packet->u.packet_type);
445 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
446 u16 type, int hdr_size, char *msg)
450 #endif /* CONFIG_BATMAN_ADV_DEBUG */
453 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
454 * @res: the array with the already selected candidates
455 * @select: number of already selected candidates
456 * @tmp_max: address of the currently evaluated node
457 * @max: current round max address
458 * @last_max: address of the last selected candidate
459 * @candidate: orig_node under evaluation
460 * @max_orig_node: last selected candidate
462 * Return: true if the node has been elected as next candidate or false
465 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
466 int select, batadv_dat_addr_t tmp_max,
467 batadv_dat_addr_t max,
468 batadv_dat_addr_t last_max,
469 struct batadv_orig_node *candidate,
470 struct batadv_orig_node *max_orig_node)
475 /* check if orig node candidate is running DAT */
476 if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
479 /* Check if this node has already been selected... */
480 for (j = 0; j < select; j++)
481 if (res[j].orig_node == candidate)
483 /* ..and possibly skip it */
486 /* sanity check: has it already been selected? This should not happen */
487 if (tmp_max > last_max)
489 /* check if during this iteration an originator with a closer dht
490 * address has already been found
494 /* this is an hash collision with the temporary selected node. Choose
495 * the one with the lowest address
497 if ((tmp_max == max) && max_orig_node &&
498 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
507 * batadv_choose_next_candidate - select the next DHT candidate
508 * @bat_priv: the bat priv with all the soft interface information
509 * @cands: candidates array
510 * @select: number of candidates already present in the array
511 * @ip_key: key to look up in the DHT
512 * @last_max: pointer where the address of the selected candidate will be saved
514 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
515 struct batadv_dat_candidate *cands,
516 int select, batadv_dat_addr_t ip_key,
517 batadv_dat_addr_t *last_max)
519 batadv_dat_addr_t max = 0;
520 batadv_dat_addr_t tmp_max = 0;
521 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
522 struct batadv_hashtable *hash = bat_priv->orig_hash;
523 struct hlist_head *head;
526 /* if no node is eligible as candidate, leave the candidate type as
529 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
531 /* iterate over the originator list and find the node with the closest
532 * dat_address which has not been selected yet
534 for (i = 0; i < hash->size; i++) {
535 head = &hash->table[i];
538 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
539 /* the dht space is a ring using unsigned addresses */
540 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
543 if (!batadv_is_orig_node_eligible(cands, select,
545 *last_max, orig_node,
549 if (!kref_get_unless_zero(&orig_node->refcount))
554 batadv_orig_node_put(max_orig_node);
555 max_orig_node = orig_node;
560 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
561 cands[select].orig_node = max_orig_node;
562 batadv_dbg(BATADV_DBG_DAT, bat_priv,
563 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
564 select, max_orig_node->orig, max_orig_node->dat_addr,
571 * batadv_dat_select_candidates - select the nodes which the DHT message has to
573 * @bat_priv: the bat priv with all the soft interface information
574 * @ip_dst: ipv4 to look up in the DHT
575 * @vid: VLAN identifier
577 * An originator O is selected if and only if its DHT_ID value is one of three
578 * closest values (from the LEFT, with wrap around if needed) then the hash
579 * value of the key. ip_dst is the key.
581 * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM.
583 static struct batadv_dat_candidate *
584 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst,
588 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
589 struct batadv_dat_candidate *res;
590 struct batadv_dat_entry dat;
592 if (!bat_priv->orig_hash)
595 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
602 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
603 BATADV_DAT_ADDR_MAX);
605 batadv_dbg(BATADV_DBG_DAT, bat_priv,
606 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
609 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
610 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
617 * batadv_dat_send_data - send a payload to the selected candidates
618 * @bat_priv: the bat priv with all the soft interface information
619 * @skb: payload to send
621 * @vid: VLAN identifier
622 * @packet_subtype: unicast4addr packet subtype to use
624 * This function copies the skb with pskb_copy() and is sent as unicast packet
625 * to each of the selected candidates.
627 * Return: true if the packet is sent to at least one candidate, false
630 static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
631 struct sk_buff *skb, __be32 ip,
632 unsigned short vid, int packet_subtype)
637 struct batadv_neigh_node *neigh_node = NULL;
638 struct sk_buff *tmp_skb;
639 struct batadv_dat_candidate *cand;
641 cand = batadv_dat_select_candidates(bat_priv, ip, vid);
645 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
647 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
648 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
651 neigh_node = batadv_orig_router_get(cand[i].orig_node,
656 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
657 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
664 send_status = batadv_send_unicast_skb(tmp_skb, neigh_node);
665 if (send_status == NET_XMIT_SUCCESS) {
666 /* count the sent packet */
667 switch (packet_subtype) {
668 case BATADV_P_DAT_DHT_GET:
669 batadv_inc_counter(bat_priv,
670 BATADV_CNT_DAT_GET_TX);
672 case BATADV_P_DAT_DHT_PUT:
673 batadv_inc_counter(bat_priv,
674 BATADV_CNT_DAT_PUT_TX);
678 /* packet sent to a candidate: return true */
682 batadv_neigh_node_put(neigh_node);
684 batadv_orig_node_put(cand[i].orig_node);
693 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
695 * @bat_priv: the bat priv with all the soft interface information
697 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
701 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
705 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
708 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
715 * batadv_dat_status_update - update the dat tvlv container after dat
717 * @net_dev: the soft interface net device
719 void batadv_dat_status_update(struct net_device *net_dev)
721 struct batadv_priv *bat_priv = netdev_priv(net_dev);
723 batadv_dat_tvlv_container_update(bat_priv);
727 * batadv_dat_tvlv_ogm_handler_v1 - process incoming dat tvlv container
728 * @bat_priv: the bat priv with all the soft interface information
729 * @orig: the orig_node of the ogm
730 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
731 * @tvlv_value: tvlv buffer containing the gateway data
732 * @tvlv_value_len: tvlv buffer length
734 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
735 struct batadv_orig_node *orig,
737 void *tvlv_value, u16 tvlv_value_len)
739 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
740 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
742 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
746 * batadv_dat_hash_free - free the local DAT hash table
747 * @bat_priv: the bat priv with all the soft interface information
749 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
751 if (!bat_priv->dat.hash)
754 __batadv_dat_purge(bat_priv, NULL);
756 batadv_hash_destroy(bat_priv->dat.hash);
758 bat_priv->dat.hash = NULL;
762 * batadv_dat_init - initialise the DAT internals
763 * @bat_priv: the bat priv with all the soft interface information
765 * Return: 0 in case of success, a negative error code otherwise
767 int batadv_dat_init(struct batadv_priv *bat_priv)
769 if (bat_priv->dat.hash)
772 bat_priv->dat.hash = batadv_hash_new(1024);
774 if (!bat_priv->dat.hash)
777 batadv_dat_start_timer(bat_priv);
779 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
780 NULL, BATADV_TVLV_DAT, 1,
781 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
782 batadv_dat_tvlv_container_update(bat_priv);
787 * batadv_dat_free - free the DAT internals
788 * @bat_priv: the bat priv with all the soft interface information
790 void batadv_dat_free(struct batadv_priv *bat_priv)
792 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
793 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
795 cancel_delayed_work_sync(&bat_priv->dat.work);
797 batadv_dat_hash_free(bat_priv);
800 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
802 * batadv_dat_cache_seq_print_text - print the local DAT hash table
803 * @seq: seq file to print on
808 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
810 struct net_device *net_dev = (struct net_device *)seq->private;
811 struct batadv_priv *bat_priv = netdev_priv(net_dev);
812 struct batadv_hashtable *hash = bat_priv->dat.hash;
813 struct batadv_dat_entry *dat_entry;
814 struct batadv_hard_iface *primary_if;
815 struct hlist_head *head;
816 unsigned long last_seen_jiffies;
817 int last_seen_msecs, last_seen_secs, last_seen_mins;
820 primary_if = batadv_seq_print_text_primary_if_get(seq);
824 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
826 " IPv4 MAC VID last-seen\n");
828 for (i = 0; i < hash->size; i++) {
829 head = &hash->table[i];
832 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
833 last_seen_jiffies = jiffies - dat_entry->last_update;
834 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
835 last_seen_mins = last_seen_msecs / 60000;
836 last_seen_msecs = last_seen_msecs % 60000;
837 last_seen_secs = last_seen_msecs / 1000;
839 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
840 &dat_entry->ip, dat_entry->mac_addr,
841 BATADV_PRINT_VID(dat_entry->vid),
842 last_seen_mins, last_seen_secs);
849 batadv_hardif_put(primary_if);
855 * batadv_arp_get_type - parse an ARP packet and gets the type
856 * @bat_priv: the bat priv with all the soft interface information
857 * @skb: packet to analyse
858 * @hdr_size: size of the possible header before the ARP packet in the skb
860 * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
862 static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
863 struct sk_buff *skb, int hdr_size)
865 struct arphdr *arphdr;
866 struct ethhdr *ethhdr;
867 __be32 ip_src, ip_dst;
871 /* pull the ethernet header */
872 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
875 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
877 if (ethhdr->h_proto != htons(ETH_P_ARP))
880 /* pull the ARP payload */
881 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
882 arp_hdr_len(skb->dev))))
885 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
887 /* check whether the ARP packet carries a valid IP information */
888 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
891 if (arphdr->ar_pro != htons(ETH_P_IP))
894 if (arphdr->ar_hln != ETH_ALEN)
897 if (arphdr->ar_pln != 4)
900 /* Check for bad reply/request. If the ARP message is not sane, DAT
901 * will simply ignore it
903 ip_src = batadv_arp_ip_src(skb, hdr_size);
904 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
905 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
906 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
907 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
908 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
911 hw_src = batadv_arp_hw_src(skb, hdr_size);
912 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
915 /* don't care about the destination MAC address in ARP requests */
916 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
917 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
918 if (is_zero_ether_addr(hw_dst) ||
919 is_multicast_ether_addr(hw_dst))
923 type = ntohs(arphdr->ar_op);
929 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
930 * @skb: the buffer containing the packet to extract the VID from
931 * @hdr_size: the size of the batman-adv header encapsulating the packet
933 * Return: If the packet embedded in the skb is vlan tagged this function
934 * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
937 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
941 vid = batadv_get_vid(skb, *hdr_size);
943 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
944 * If the header contained in the packet is a VLAN one (which is longer)
945 * hdr_size is updated so that the functions will still skip the
946 * correct amount of bytes.
948 if (vid & BATADV_VLAN_HAS_TAG)
949 *hdr_size += VLAN_HLEN;
955 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
957 * @bat_priv: the bat priv with all the soft interface information
958 * @skb: packet to check
960 * Return: true if the message has been sent to the dht candidates, false
961 * otherwise. In case of a positive return value the message has to be enqueued
962 * to permit the fallback.
964 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
968 __be32 ip_dst, ip_src;
971 struct batadv_dat_entry *dat_entry = NULL;
972 struct sk_buff *skb_new;
976 if (!atomic_read(&bat_priv->distributed_arp_table))
979 vid = batadv_dat_get_vid(skb, &hdr_size);
981 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
982 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
983 * message to the selected DHT candidates
985 if (type != ARPOP_REQUEST)
988 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
989 "Parsing outgoing ARP REQUEST");
991 ip_src = batadv_arp_ip_src(skb, hdr_size);
992 hw_src = batadv_arp_hw_src(skb, hdr_size);
993 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
995 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
997 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
999 /* If the ARP request is destined for a local client the local
1000 * client will answer itself. DAT would only generate a
1003 * Moreover, if the soft-interface is enslaved into a bridge, an
1004 * additional DAT answer may trigger kernel warnings about
1005 * a packet coming from the wrong port.
1007 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
1012 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1013 bat_priv->soft_iface, ip_dst, hw_src,
1014 dat_entry->mac_addr, hw_src);
1018 if (vid & BATADV_VLAN_HAS_TAG) {
1019 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1020 vid & VLAN_VID_MASK);
1025 skb_reset_mac_header(skb_new);
1026 skb_new->protocol = eth_type_trans(skb_new,
1027 bat_priv->soft_iface);
1028 batadv_inc_counter(bat_priv, BATADV_CNT_RX);
1029 batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
1030 skb->len + ETH_HLEN + hdr_size);
1031 bat_priv->soft_iface->last_rx = jiffies;
1034 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1037 /* Send the request to the DHT */
1038 ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid,
1039 BATADV_P_DAT_DHT_GET);
1043 batadv_dat_entry_put(dat_entry);
1048 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1049 * answer using the local DAT storage
1050 * @bat_priv: the bat priv with all the soft interface information
1051 * @skb: packet to check
1052 * @hdr_size: size of the encapsulation header
1054 * Return: true if the request has been answered, false otherwise.
1056 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1057 struct sk_buff *skb, int hdr_size)
1060 __be32 ip_src, ip_dst;
1062 struct sk_buff *skb_new;
1063 struct batadv_dat_entry *dat_entry = NULL;
1068 if (!atomic_read(&bat_priv->distributed_arp_table))
1071 vid = batadv_dat_get_vid(skb, &hdr_size);
1073 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1074 if (type != ARPOP_REQUEST)
1077 hw_src = batadv_arp_hw_src(skb, hdr_size);
1078 ip_src = batadv_arp_ip_src(skb, hdr_size);
1079 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1081 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1082 "Parsing incoming ARP REQUEST");
1084 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1086 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1090 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1091 bat_priv->soft_iface, ip_dst, hw_src,
1092 dat_entry->mac_addr, hw_src);
1097 /* the rest of the TX path assumes that the mac_header offset pointing
1098 * to the inner Ethernet header has been set, therefore reset it now.
1100 skb_reset_mac_header(skb_new);
1102 if (vid & BATADV_VLAN_HAS_TAG) {
1103 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1104 vid & VLAN_VID_MASK);
1109 /* To preserve backwards compatibility, the node has choose the outgoing
1110 * format based on the incoming request packet type. The assumption is
1111 * that a node not using the 4addr packet format doesn't support it.
1113 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1114 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1115 BATADV_P_DAT_CACHE_REPLY,
1118 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1120 if (err != NET_XMIT_DROP) {
1121 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1126 batadv_dat_entry_put(dat_entry);
1133 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1134 * @bat_priv: the bat priv with all the soft interface information
1135 * @skb: packet to check
1137 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1138 struct sk_buff *skb)
1141 __be32 ip_src, ip_dst;
1142 u8 *hw_src, *hw_dst;
1146 if (!atomic_read(&bat_priv->distributed_arp_table))
1149 vid = batadv_dat_get_vid(skb, &hdr_size);
1151 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1152 if (type != ARPOP_REPLY)
1155 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1156 "Parsing outgoing ARP REPLY");
1158 hw_src = batadv_arp_hw_src(skb, hdr_size);
1159 ip_src = batadv_arp_ip_src(skb, hdr_size);
1160 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1161 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1163 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1164 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1166 /* Send the ARP reply to the candidates for both the IP addresses that
1167 * the node obtained from the ARP reply
1169 batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT);
1170 batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT);
1174 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1176 * @bat_priv: the bat priv with all the soft interface information
1177 * @skb: packet to check
1178 * @hdr_size: size of the encapsulation header
1180 * Return: true if the packet was snooped and consumed by DAT. False if the
1181 * packet has to be delivered to the interface
1183 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1184 struct sk_buff *skb, int hdr_size)
1187 __be32 ip_src, ip_dst;
1188 u8 *hw_src, *hw_dst;
1189 bool dropped = false;
1192 if (!atomic_read(&bat_priv->distributed_arp_table))
1195 vid = batadv_dat_get_vid(skb, &hdr_size);
1197 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1198 if (type != ARPOP_REPLY)
1201 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1202 "Parsing incoming ARP REPLY");
1204 hw_src = batadv_arp_hw_src(skb, hdr_size);
1205 ip_src = batadv_arp_ip_src(skb, hdr_size);
1206 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1207 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1209 /* Update our internal cache with both the IP addresses the node got
1210 * within the ARP reply
1212 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1213 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1215 /* if this REPLY is directed to a client of mine, let's deliver the
1216 * packet to the interface
1218 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1220 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1221 * packet because the client will reply by itself
1223 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1227 /* if dropped == false -> deliver to the interface */
1232 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1233 * (because the node has already obtained the reply via DAT) or not
1234 * @bat_priv: the bat priv with all the soft interface information
1235 * @forw_packet: the broadcast packet
1237 * Return: true if the node can drop the packet, false otherwise.
1239 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1240 struct batadv_forw_packet *forw_packet)
1244 struct batadv_dat_entry *dat_entry = NULL;
1246 int hdr_size = sizeof(struct batadv_bcast_packet);
1249 if (!atomic_read(&bat_priv->distributed_arp_table))
1252 /* If this packet is an ARP_REQUEST and the node already has the
1253 * information that it is going to ask, then the packet can be dropped
1255 if (forw_packet->num_packets)
1258 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1260 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1261 if (type != ARPOP_REQUEST)
1264 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1265 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1266 /* check if the node already got this entry */
1268 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1269 "ARP Request for %pI4: fallback\n", &ip_dst);
1273 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1274 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1279 batadv_dat_entry_put(dat_entry);