1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2011-2018 B.A.T.M.A.N. contributors:
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include "distributed-arp-table.h"
22 #include <linux/atomic.h>
23 #include <linux/bitops.h>
24 #include <linux/byteorder/generic.h>
25 #include <linux/errno.h>
26 #include <linux/etherdevice.h>
27 #include <linux/gfp.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_ether.h>
30 #include <linux/if_vlan.h>
32 #include <linux/jiffies.h>
33 #include <linux/kernel.h>
34 #include <linux/kref.h>
35 #include <linux/list.h>
36 #include <linux/netlink.h>
37 #include <linux/rculist.h>
38 #include <linux/rcupdate.h>
39 #include <linux/seq_file.h>
40 #include <linux/skbuff.h>
41 #include <linux/slab.h>
42 #include <linux/spinlock.h>
43 #include <linux/stddef.h>
44 #include <linux/string.h>
45 #include <linux/workqueue.h>
47 #include <net/genetlink.h>
48 #include <net/netlink.h>
50 #include <uapi/linux/batman_adv.h>
52 #include "bridge_loop_avoidance.h"
53 #include "hard-interface.h"
57 #include "originator.h"
59 #include "soft-interface.h"
60 #include "translation-table.h"
63 static void batadv_dat_purge(struct work_struct *work);
66 * batadv_dat_start_timer() - initialise the DAT periodic worker
67 * @bat_priv: the bat priv with all the soft interface information
69 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
71 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
72 msecs_to_jiffies(10000));
76 * batadv_dat_entry_release() - release dat_entry from lists and queue for free
77 * after rcu grace period
78 * @ref: kref pointer of the dat_entry
80 static void batadv_dat_entry_release(struct kref *ref)
82 struct batadv_dat_entry *dat_entry;
84 dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
86 kfree_rcu(dat_entry, rcu);
90 * batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly
92 * @dat_entry: dat_entry to be free'd
94 static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry)
96 kref_put(&dat_entry->refcount, batadv_dat_entry_release);
100 * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not
101 * @dat_entry: the entry to check
103 * Return: true if the entry has to be purged now, false otherwise.
105 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
107 return batadv_has_timed_out(dat_entry->last_update,
108 BATADV_DAT_ENTRY_TIMEOUT);
112 * __batadv_dat_purge() - delete entries from the DAT local storage
113 * @bat_priv: the bat priv with all the soft interface information
114 * @to_purge: function in charge to decide whether an entry has to be purged or
115 * not. This function takes the dat_entry as argument and has to
116 * returns a boolean value: true is the entry has to be deleted,
119 * Loops over each entry in the DAT local storage and deletes it if and only if
120 * the to_purge function passed as argument returns true.
122 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
123 bool (*to_purge)(struct batadv_dat_entry *))
125 spinlock_t *list_lock; /* protects write access to the hash lists */
126 struct batadv_dat_entry *dat_entry;
127 struct hlist_node *node_tmp;
128 struct hlist_head *head;
131 if (!bat_priv->dat.hash)
134 for (i = 0; i < bat_priv->dat.hash->size; i++) {
135 head = &bat_priv->dat.hash->table[i];
136 list_lock = &bat_priv->dat.hash->list_locks[i];
138 spin_lock_bh(list_lock);
139 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
141 /* if a helper function has been passed as parameter,
142 * ask it if the entry has to be purged or not
144 if (to_purge && !to_purge(dat_entry))
147 hlist_del_rcu(&dat_entry->hash_entry);
148 batadv_dat_entry_put(dat_entry);
150 spin_unlock_bh(list_lock);
155 * batadv_dat_purge() - periodic task that deletes old entries from the local
157 * @work: kernel work struct
159 static void batadv_dat_purge(struct work_struct *work)
161 struct delayed_work *delayed_work;
162 struct batadv_priv_dat *priv_dat;
163 struct batadv_priv *bat_priv;
165 delayed_work = to_delayed_work(work);
166 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
167 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
169 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
170 batadv_dat_start_timer(bat_priv);
174 * batadv_compare_dat() - comparing function used in the local DAT hash table
175 * @node: node in the local table
176 * @data2: second object to compare the node to
178 * Return: true if the two entries are the same, false otherwise.
180 static bool batadv_compare_dat(const struct hlist_node *node, const void *data2)
182 const void *data1 = container_of(node, struct batadv_dat_entry,
185 return memcmp(data1, data2, sizeof(__be32)) == 0;
189 * batadv_arp_hw_src() - extract the hw_src field from an ARP packet
191 * @hdr_size: size of the possible header before the ARP packet
193 * Return: the value of the hw_src field in the ARP packet.
195 static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
199 addr = (u8 *)(skb->data + hdr_size);
200 addr += ETH_HLEN + sizeof(struct arphdr);
206 * batadv_arp_ip_src() - extract the ip_src field from an ARP packet
208 * @hdr_size: size of the possible header before the ARP packet
210 * Return: the value of the ip_src field in the ARP packet.
212 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
214 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
218 * batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet
220 * @hdr_size: size of the possible header before the ARP packet
222 * Return: the value of the hw_dst field in the ARP packet.
224 static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
226 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
230 * batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet
232 * @hdr_size: size of the possible header before the ARP packet
234 * Return: the value of the ip_dst field in the ARP packet.
236 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
238 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
242 * batadv_hash_dat() - compute the hash value for an IP address
243 * @data: data to hash
244 * @size: size of the hash table
246 * Return: the selected index in the hash table for the given data.
248 static u32 batadv_hash_dat(const void *data, u32 size)
251 const struct batadv_dat_entry *dat = data;
252 const unsigned char *key;
256 key = (const unsigned char *)&dat->ip;
257 for (i = 0; i < sizeof(dat->ip); i++) {
259 hash += (hash << 10);
263 vid = htons(dat->vid);
264 key = (__force const unsigned char *)&vid;
265 for (i = 0; i < sizeof(dat->vid); i++) {
267 hash += (hash << 10);
272 hash ^= (hash >> 11);
273 hash += (hash << 15);
279 * batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash
281 * @bat_priv: the bat priv with all the soft interface information
283 * @vid: VLAN identifier
285 * Return: the dat_entry if found, NULL otherwise.
287 static struct batadv_dat_entry *
288 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
291 struct hlist_head *head;
292 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
293 struct batadv_hashtable *hash = bat_priv->dat.hash;
302 index = batadv_hash_dat(&to_find, hash->size);
303 head = &hash->table[index];
306 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
307 if (dat_entry->ip != ip)
310 if (!kref_get_unless_zero(&dat_entry->refcount))
313 dat_entry_tmp = dat_entry;
318 return dat_entry_tmp;
322 * batadv_dat_entry_add() - add a new dat entry or update it if already exists
323 * @bat_priv: the bat priv with all the soft interface information
324 * @ip: ipv4 to add/edit
325 * @mac_addr: mac address to assign to the given ipv4
326 * @vid: VLAN identifier
328 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
329 u8 *mac_addr, unsigned short vid)
331 struct batadv_dat_entry *dat_entry;
334 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
335 /* if this entry is already known, just update it */
337 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
338 ether_addr_copy(dat_entry->mac_addr, mac_addr);
339 dat_entry->last_update = jiffies;
340 batadv_dbg(BATADV_DBG_DAT, bat_priv,
341 "Entry updated: %pI4 %pM (vid: %d)\n",
342 &dat_entry->ip, dat_entry->mac_addr,
343 batadv_print_vid(vid));
347 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
352 dat_entry->vid = vid;
353 ether_addr_copy(dat_entry->mac_addr, mac_addr);
354 dat_entry->last_update = jiffies;
355 kref_init(&dat_entry->refcount);
357 kref_get(&dat_entry->refcount);
358 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
359 batadv_hash_dat, dat_entry,
360 &dat_entry->hash_entry);
362 if (unlikely(hash_added != 0)) {
363 /* remove the reference for the hash */
364 batadv_dat_entry_put(dat_entry);
368 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
369 &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid));
373 batadv_dat_entry_put(dat_entry);
376 #ifdef CONFIG_BATMAN_ADV_DEBUG
379 * batadv_dbg_arp() - print a debug message containing all the ARP packet
381 * @bat_priv: the bat priv with all the soft interface information
383 * @hdr_size: size of the possible header before the ARP packet
384 * @msg: message to print together with the debugging information
386 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
387 int hdr_size, char *msg)
389 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
390 struct batadv_bcast_packet *bcast_pkt;
392 __be32 ip_src, ip_dst;
395 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
397 ip_src = batadv_arp_ip_src(skb, hdr_size);
398 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
399 batadv_dbg(BATADV_DBG_DAT, bat_priv,
400 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
401 batadv_arp_hw_src(skb, hdr_size), &ip_src,
402 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
404 if (hdr_size < sizeof(struct batadv_unicast_packet))
407 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
409 switch (unicast_4addr_packet->u.packet_type) {
411 batadv_dbg(BATADV_DBG_DAT, bat_priv,
412 "* encapsulated within a UNICAST packet\n");
414 case BATADV_UNICAST_4ADDR:
415 batadv_dbg(BATADV_DBG_DAT, bat_priv,
416 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
417 unicast_4addr_packet->src);
418 switch (unicast_4addr_packet->subtype) {
419 case BATADV_P_DAT_DHT_PUT:
420 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
422 case BATADV_P_DAT_DHT_GET:
423 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
425 case BATADV_P_DAT_CACHE_REPLY:
426 batadv_dbg(BATADV_DBG_DAT, bat_priv,
427 "* type: DAT_CACHE_REPLY\n");
430 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
433 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
434 unicast_4addr_packet->u.packet_type);
438 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
439 orig_addr = bcast_pkt->orig;
440 batadv_dbg(BATADV_DBG_DAT, bat_priv,
441 "* encapsulated within a BCAST packet (src: %pM)\n",
445 batadv_dbg(BATADV_DBG_DAT, bat_priv,
446 "* encapsulated within an unknown packet type (0x%x)\n",
447 unicast_4addr_packet->u.packet_type);
453 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
454 int hdr_size, char *msg)
458 #endif /* CONFIG_BATMAN_ADV_DEBUG */
461 * batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate
462 * @res: the array with the already selected candidates
463 * @select: number of already selected candidates
464 * @tmp_max: address of the currently evaluated node
465 * @max: current round max address
466 * @last_max: address of the last selected candidate
467 * @candidate: orig_node under evaluation
468 * @max_orig_node: last selected candidate
470 * Return: true if the node has been elected as next candidate or false
473 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
474 int select, batadv_dat_addr_t tmp_max,
475 batadv_dat_addr_t max,
476 batadv_dat_addr_t last_max,
477 struct batadv_orig_node *candidate,
478 struct batadv_orig_node *max_orig_node)
483 /* check if orig node candidate is running DAT */
484 if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
487 /* Check if this node has already been selected... */
488 for (j = 0; j < select; j++)
489 if (res[j].orig_node == candidate)
491 /* ..and possibly skip it */
494 /* sanity check: has it already been selected? This should not happen */
495 if (tmp_max > last_max)
497 /* check if during this iteration an originator with a closer dht
498 * address has already been found
502 /* this is an hash collision with the temporary selected node. Choose
503 * the one with the lowest address
505 if (tmp_max == max && max_orig_node &&
506 batadv_compare_eth(candidate->orig, max_orig_node->orig))
515 * batadv_choose_next_candidate() - select the next DHT candidate
516 * @bat_priv: the bat priv with all the soft interface information
517 * @cands: candidates array
518 * @select: number of candidates already present in the array
519 * @ip_key: key to look up in the DHT
520 * @last_max: pointer where the address of the selected candidate will be saved
522 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
523 struct batadv_dat_candidate *cands,
524 int select, batadv_dat_addr_t ip_key,
525 batadv_dat_addr_t *last_max)
527 batadv_dat_addr_t max = 0;
528 batadv_dat_addr_t tmp_max = 0;
529 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
530 struct batadv_hashtable *hash = bat_priv->orig_hash;
531 struct hlist_head *head;
534 /* if no node is eligible as candidate, leave the candidate type as
537 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
539 /* iterate over the originator list and find the node with the closest
540 * dat_address which has not been selected yet
542 for (i = 0; i < hash->size; i++) {
543 head = &hash->table[i];
546 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
547 /* the dht space is a ring using unsigned addresses */
548 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
551 if (!batadv_is_orig_node_eligible(cands, select,
553 *last_max, orig_node,
557 if (!kref_get_unless_zero(&orig_node->refcount))
562 batadv_orig_node_put(max_orig_node);
563 max_orig_node = orig_node;
568 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
569 cands[select].orig_node = max_orig_node;
570 batadv_dbg(BATADV_DBG_DAT, bat_priv,
571 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
572 select, max_orig_node->orig, max_orig_node->dat_addr,
579 * batadv_dat_select_candidates() - select the nodes which the DHT message has
581 * @bat_priv: the bat priv with all the soft interface information
582 * @ip_dst: ipv4 to look up in the DHT
583 * @vid: VLAN identifier
585 * An originator O is selected if and only if its DHT_ID value is one of three
586 * closest values (from the LEFT, with wrap around if needed) then the hash
587 * value of the key. ip_dst is the key.
589 * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM.
591 static struct batadv_dat_candidate *
592 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst,
596 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
597 struct batadv_dat_candidate *res;
598 struct batadv_dat_entry dat;
600 if (!bat_priv->orig_hash)
603 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
610 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
611 BATADV_DAT_ADDR_MAX);
613 batadv_dbg(BATADV_DBG_DAT, bat_priv,
614 "%s(): IP=%pI4 hash(IP)=%u\n", __func__, &ip_dst,
617 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
618 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
625 * batadv_dat_send_data() - send a payload to the selected candidates
626 * @bat_priv: the bat priv with all the soft interface information
627 * @skb: payload to send
629 * @vid: VLAN identifier
630 * @packet_subtype: unicast4addr packet subtype to use
632 * This function copies the skb with pskb_copy() and is sent as unicast packet
633 * to each of the selected candidates.
635 * Return: true if the packet is sent to at least one candidate, false
638 static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
639 struct sk_buff *skb, __be32 ip,
640 unsigned short vid, int packet_subtype)
645 struct batadv_neigh_node *neigh_node = NULL;
646 struct sk_buff *tmp_skb;
647 struct batadv_dat_candidate *cand;
649 cand = batadv_dat_select_candidates(bat_priv, ip, vid);
653 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
655 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
656 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
659 neigh_node = batadv_orig_router_get(cand[i].orig_node,
664 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
665 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
672 send_status = batadv_send_unicast_skb(tmp_skb, neigh_node);
673 if (send_status == NET_XMIT_SUCCESS) {
674 /* count the sent packet */
675 switch (packet_subtype) {
676 case BATADV_P_DAT_DHT_GET:
677 batadv_inc_counter(bat_priv,
678 BATADV_CNT_DAT_GET_TX);
680 case BATADV_P_DAT_DHT_PUT:
681 batadv_inc_counter(bat_priv,
682 BATADV_CNT_DAT_PUT_TX);
686 /* packet sent to a candidate: return true */
690 batadv_neigh_node_put(neigh_node);
692 batadv_orig_node_put(cand[i].orig_node);
701 * batadv_dat_tvlv_container_update() - update the dat tvlv container after dat
703 * @bat_priv: the bat priv with all the soft interface information
705 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
709 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
713 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
716 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
723 * batadv_dat_status_update() - update the dat tvlv container after dat
725 * @net_dev: the soft interface net device
727 void batadv_dat_status_update(struct net_device *net_dev)
729 struct batadv_priv *bat_priv = netdev_priv(net_dev);
731 batadv_dat_tvlv_container_update(bat_priv);
735 * batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container
736 * @bat_priv: the bat priv with all the soft interface information
737 * @orig: the orig_node of the ogm
738 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
739 * @tvlv_value: tvlv buffer containing the gateway data
740 * @tvlv_value_len: tvlv buffer length
742 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
743 struct batadv_orig_node *orig,
745 void *tvlv_value, u16 tvlv_value_len)
747 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
748 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
750 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
754 * batadv_dat_hash_free() - free the local DAT hash table
755 * @bat_priv: the bat priv with all the soft interface information
757 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
759 if (!bat_priv->dat.hash)
762 __batadv_dat_purge(bat_priv, NULL);
764 batadv_hash_destroy(bat_priv->dat.hash);
766 bat_priv->dat.hash = NULL;
770 * batadv_dat_init() - initialise the DAT internals
771 * @bat_priv: the bat priv with all the soft interface information
773 * Return: 0 in case of success, a negative error code otherwise
775 int batadv_dat_init(struct batadv_priv *bat_priv)
777 if (bat_priv->dat.hash)
780 bat_priv->dat.hash = batadv_hash_new(1024);
782 if (!bat_priv->dat.hash)
785 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
786 batadv_dat_start_timer(bat_priv);
788 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
789 NULL, BATADV_TVLV_DAT, 1,
790 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
791 batadv_dat_tvlv_container_update(bat_priv);
796 * batadv_dat_free() - free the DAT internals
797 * @bat_priv: the bat priv with all the soft interface information
799 void batadv_dat_free(struct batadv_priv *bat_priv)
801 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
802 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
804 cancel_delayed_work_sync(&bat_priv->dat.work);
806 batadv_dat_hash_free(bat_priv);
809 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
811 * batadv_dat_cache_seq_print_text() - print the local DAT hash table
812 * @seq: seq file to print on
817 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
819 struct net_device *net_dev = (struct net_device *)seq->private;
820 struct batadv_priv *bat_priv = netdev_priv(net_dev);
821 struct batadv_hashtable *hash = bat_priv->dat.hash;
822 struct batadv_dat_entry *dat_entry;
823 struct batadv_hard_iface *primary_if;
824 struct hlist_head *head;
825 unsigned long last_seen_jiffies;
826 int last_seen_msecs, last_seen_secs, last_seen_mins;
829 primary_if = batadv_seq_print_text_primary_if_get(seq);
833 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
835 " IPv4 MAC VID last-seen\n");
837 for (i = 0; i < hash->size; i++) {
838 head = &hash->table[i];
841 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
842 last_seen_jiffies = jiffies - dat_entry->last_update;
843 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
844 last_seen_mins = last_seen_msecs / 60000;
845 last_seen_msecs = last_seen_msecs % 60000;
846 last_seen_secs = last_seen_msecs / 1000;
848 seq_printf(seq, " * %15pI4 %pM %4i %6i:%02i\n",
849 &dat_entry->ip, dat_entry->mac_addr,
850 batadv_print_vid(dat_entry->vid),
851 last_seen_mins, last_seen_secs);
858 batadv_hardif_put(primary_if);
864 * batadv_dat_cache_dump_entry() - dump one entry of the DAT cache table to a
866 * @msg: buffer for the message
867 * @portid: netlink port
868 * @seq: Sequence number of netlink message
869 * @dat_entry: entry to dump
871 * Return: 0 or error code.
874 batadv_dat_cache_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
875 struct batadv_dat_entry *dat_entry)
880 hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
881 NLM_F_MULTI, BATADV_CMD_GET_DAT_CACHE);
885 msecs = jiffies_to_msecs(jiffies - dat_entry->last_update);
887 if (nla_put_in_addr(msg, BATADV_ATTR_DAT_CACHE_IP4ADDRESS,
889 nla_put(msg, BATADV_ATTR_DAT_CACHE_HWADDRESS, ETH_ALEN,
890 dat_entry->mac_addr) ||
891 nla_put_u16(msg, BATADV_ATTR_DAT_CACHE_VID, dat_entry->vid) ||
892 nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) {
893 genlmsg_cancel(msg, hdr);
897 genlmsg_end(msg, hdr);
902 * batadv_dat_cache_dump_bucket() - dump one bucket of the DAT cache table to
904 * @msg: buffer for the message
905 * @portid: netlink port
906 * @seq: Sequence number of netlink message
907 * @head: bucket to dump
908 * @idx_skip: How many entries to skip
910 * Return: 0 or error code.
913 batadv_dat_cache_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
914 struct hlist_head *head, int *idx_skip)
916 struct batadv_dat_entry *dat_entry;
920 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
924 if (batadv_dat_cache_dump_entry(msg, portid, seq,
941 * batadv_dat_cache_dump() - dump DAT cache table to a netlink socket
942 * @msg: buffer for the message
943 * @cb: callback structure containing arguments
945 * Return: message length.
947 int batadv_dat_cache_dump(struct sk_buff *msg, struct netlink_callback *cb)
949 struct batadv_hard_iface *primary_if = NULL;
950 int portid = NETLINK_CB(cb->skb).portid;
951 struct net *net = sock_net(cb->skb->sk);
952 struct net_device *soft_iface;
953 struct batadv_hashtable *hash;
954 struct batadv_priv *bat_priv;
955 int bucket = cb->args[0];
956 struct hlist_head *head;
957 int idx = cb->args[1];
961 ifindex = batadv_netlink_get_ifindex(cb->nlh,
962 BATADV_ATTR_MESH_IFINDEX);
966 soft_iface = dev_get_by_index(net, ifindex);
967 if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
972 bat_priv = netdev_priv(soft_iface);
973 hash = bat_priv->dat.hash;
975 primary_if = batadv_primary_if_get_selected(bat_priv);
976 if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
981 while (bucket < hash->size) {
982 head = &hash->table[bucket];
984 if (batadv_dat_cache_dump_bucket(msg, portid,
985 cb->nlh->nlmsg_seq, head,
993 cb->args[0] = bucket;
1000 batadv_hardif_put(primary_if);
1003 dev_put(soft_iface);
1009 * batadv_arp_get_type() - parse an ARP packet and gets the type
1010 * @bat_priv: the bat priv with all the soft interface information
1011 * @skb: packet to analyse
1012 * @hdr_size: size of the possible header before the ARP packet in the skb
1014 * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
1016 static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
1017 struct sk_buff *skb, int hdr_size)
1019 struct arphdr *arphdr;
1020 struct ethhdr *ethhdr;
1021 __be32 ip_src, ip_dst;
1022 u8 *hw_src, *hw_dst;
1025 /* pull the ethernet header */
1026 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
1029 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
1031 if (ethhdr->h_proto != htons(ETH_P_ARP))
1034 /* pull the ARP payload */
1035 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
1036 arp_hdr_len(skb->dev))))
1039 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
1041 /* check whether the ARP packet carries a valid IP information */
1042 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1045 if (arphdr->ar_pro != htons(ETH_P_IP))
1048 if (arphdr->ar_hln != ETH_ALEN)
1051 if (arphdr->ar_pln != 4)
1054 /* Check for bad reply/request. If the ARP message is not sane, DAT
1055 * will simply ignore it
1057 ip_src = batadv_arp_ip_src(skb, hdr_size);
1058 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1059 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
1060 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
1061 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
1062 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
1065 hw_src = batadv_arp_hw_src(skb, hdr_size);
1066 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
1069 /* don't care about the destination MAC address in ARP requests */
1070 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
1071 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1072 if (is_zero_ether_addr(hw_dst) ||
1073 is_multicast_ether_addr(hw_dst))
1077 type = ntohs(arphdr->ar_op);
1083 * batadv_dat_get_vid() - extract the VLAN identifier from skb if any
1084 * @skb: the buffer containing the packet to extract the VID from
1085 * @hdr_size: the size of the batman-adv header encapsulating the packet
1087 * Return: If the packet embedded in the skb is vlan tagged this function
1088 * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
1091 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
1095 vid = batadv_get_vid(skb, *hdr_size);
1097 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
1098 * If the header contained in the packet is a VLAN one (which is longer)
1099 * hdr_size is updated so that the functions will still skip the
1100 * correct amount of bytes.
1102 if (vid & BATADV_VLAN_HAS_TAG)
1103 *hdr_size += VLAN_HLEN;
1109 * batadv_dat_arp_create_reply() - create an ARP Reply
1110 * @bat_priv: the bat priv with all the soft interface information
1111 * @ip_src: ARP sender IP
1112 * @ip_dst: ARP target IP
1113 * @hw_src: Ethernet source and ARP sender MAC
1114 * @hw_dst: Ethernet destination and ARP target MAC
1115 * @vid: VLAN identifier (optional, set to zero otherwise)
1117 * Creates an ARP Reply from the given values, optionally encapsulated in a
1120 * Return: An skb containing an ARP Reply.
1122 static struct sk_buff *
1123 batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src,
1124 __be32 ip_dst, u8 *hw_src, u8 *hw_dst,
1127 struct sk_buff *skb;
1129 skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface,
1130 ip_src, hw_dst, hw_src, hw_dst);
1134 skb_reset_mac_header(skb);
1136 if (vid & BATADV_VLAN_HAS_TAG)
1137 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
1138 vid & VLAN_VID_MASK);
1144 * batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to
1146 * @bat_priv: the bat priv with all the soft interface information
1147 * @skb: packet to check
1149 * Return: true if the message has been sent to the dht candidates, false
1150 * otherwise. In case of a positive return value the message has to be enqueued
1151 * to permit the fallback.
1153 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
1154 struct sk_buff *skb)
1157 __be32 ip_dst, ip_src;
1160 struct batadv_dat_entry *dat_entry = NULL;
1161 struct sk_buff *skb_new;
1162 struct net_device *soft_iface = bat_priv->soft_iface;
1166 if (!atomic_read(&bat_priv->distributed_arp_table))
1169 vid = batadv_dat_get_vid(skb, &hdr_size);
1171 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1172 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
1173 * message to the selected DHT candidates
1175 if (type != ARPOP_REQUEST)
1178 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REQUEST");
1180 ip_src = batadv_arp_ip_src(skb, hdr_size);
1181 hw_src = batadv_arp_hw_src(skb, hdr_size);
1182 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1184 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1186 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1188 /* If the ARP request is destined for a local client the local
1189 * client will answer itself. DAT would only generate a
1192 * Moreover, if the soft-interface is enslaved into a bridge, an
1193 * additional DAT answer may trigger kernel warnings about
1194 * a packet coming from the wrong port.
1196 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
1201 /* If BLA is enabled, only send ARP replies if we have claimed
1202 * the destination for the ARP request or if no one else of
1203 * the backbone gws belonging to our backbone has claimed the
1206 if (!batadv_bla_check_claim(bat_priv,
1207 dat_entry->mac_addr, vid)) {
1208 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1209 "Device %pM claimed by another backbone gw. Don't send ARP reply!",
1210 dat_entry->mac_addr);
1215 skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
1216 dat_entry->mac_addr,
1221 skb_new->protocol = eth_type_trans(skb_new, soft_iface);
1223 batadv_inc_counter(bat_priv, BATADV_CNT_RX);
1224 batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
1225 skb->len + ETH_HLEN + hdr_size);
1228 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1231 /* Send the request to the DHT */
1232 ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid,
1233 BATADV_P_DAT_DHT_GET);
1237 batadv_dat_entry_put(dat_entry);
1242 * batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to
1243 * answer using the local DAT storage
1244 * @bat_priv: the bat priv with all the soft interface information
1245 * @skb: packet to check
1246 * @hdr_size: size of the encapsulation header
1248 * Return: true if the request has been answered, false otherwise.
1250 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1251 struct sk_buff *skb, int hdr_size)
1254 __be32 ip_src, ip_dst;
1256 struct sk_buff *skb_new;
1257 struct batadv_dat_entry *dat_entry = NULL;
1262 if (!atomic_read(&bat_priv->distributed_arp_table))
1265 vid = batadv_dat_get_vid(skb, &hdr_size);
1267 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1268 if (type != ARPOP_REQUEST)
1271 hw_src = batadv_arp_hw_src(skb, hdr_size);
1272 ip_src = batadv_arp_ip_src(skb, hdr_size);
1273 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1275 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST");
1277 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1279 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1283 skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
1284 dat_entry->mac_addr, hw_src, vid);
1288 /* To preserve backwards compatibility, the node has choose the outgoing
1289 * format based on the incoming request packet type. The assumption is
1290 * that a node not using the 4addr packet format doesn't support it.
1292 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1293 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1294 BATADV_P_DAT_CACHE_REPLY,
1297 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1299 if (err != NET_XMIT_DROP) {
1300 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1305 batadv_dat_entry_put(dat_entry);
1312 * batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT
1313 * @bat_priv: the bat priv with all the soft interface information
1314 * @skb: packet to check
1316 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1317 struct sk_buff *skb)
1320 __be32 ip_src, ip_dst;
1321 u8 *hw_src, *hw_dst;
1325 if (!atomic_read(&bat_priv->distributed_arp_table))
1328 vid = batadv_dat_get_vid(skb, &hdr_size);
1330 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1331 if (type != ARPOP_REPLY)
1334 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REPLY");
1336 hw_src = batadv_arp_hw_src(skb, hdr_size);
1337 ip_src = batadv_arp_ip_src(skb, hdr_size);
1338 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1339 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1341 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1342 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1344 /* Send the ARP reply to the candidates for both the IP addresses that
1345 * the node obtained from the ARP reply
1347 batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT);
1348 batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT);
1352 * batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the
1353 * local DAT storage only
1354 * @bat_priv: the bat priv with all the soft interface information
1355 * @skb: packet to check
1356 * @hdr_size: size of the encapsulation header
1358 * Return: true if the packet was snooped and consumed by DAT. False if the
1359 * packet has to be delivered to the interface
1361 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1362 struct sk_buff *skb, int hdr_size)
1364 struct batadv_dat_entry *dat_entry = NULL;
1366 __be32 ip_src, ip_dst;
1367 u8 *hw_src, *hw_dst;
1368 bool dropped = false;
1371 if (!atomic_read(&bat_priv->distributed_arp_table))
1374 vid = batadv_dat_get_vid(skb, &hdr_size);
1376 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1377 if (type != ARPOP_REPLY)
1380 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REPLY");
1382 hw_src = batadv_arp_hw_src(skb, hdr_size);
1383 ip_src = batadv_arp_ip_src(skb, hdr_size);
1384 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1385 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1387 /* If ip_dst is already in cache and has the right mac address,
1388 * drop this frame if this ARP reply is destined for us because it's
1389 * most probably an ARP reply generated by another node of the DHT.
1390 * We have most probably received already a reply earlier. Delivering
1391 * this frame would lead to doubled receive of an ARP reply.
1393 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid);
1394 if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) {
1395 batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n",
1396 hw_src, &ip_src, hw_dst, &ip_dst,
1397 dat_entry->mac_addr, &dat_entry->ip);
1401 /* Update our internal cache with both the IP addresses the node got
1402 * within the ARP reply
1404 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1405 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1410 /* If BLA is enabled, only forward ARP replies if we have claimed the
1411 * source of the ARP reply or if no one else of the same backbone has
1412 * already claimed that client. This prevents that different gateways
1413 * to the same backbone all forward the ARP reply leading to multiple
1414 * replies in the backbone.
1416 if (!batadv_bla_check_claim(bat_priv, hw_src, vid)) {
1417 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1418 "Device %pM claimed by another backbone gw. Drop ARP reply.\n",
1424 /* if this REPLY is directed to a client of mine, let's deliver the
1425 * packet to the interface
1427 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1429 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1430 * packet because the client will reply by itself
1432 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1437 batadv_dat_entry_put(dat_entry);
1438 /* if dropped == false -> deliver to the interface */
1443 * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be
1444 * dropped (because the node has already obtained the reply via DAT) or not
1445 * @bat_priv: the bat priv with all the soft interface information
1446 * @forw_packet: the broadcast packet
1448 * Return: true if the node can drop the packet, false otherwise.
1450 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1451 struct batadv_forw_packet *forw_packet)
1455 struct batadv_dat_entry *dat_entry = NULL;
1457 int hdr_size = sizeof(struct batadv_bcast_packet);
1460 if (!atomic_read(&bat_priv->distributed_arp_table))
1463 /* If this packet is an ARP_REQUEST and the node already has the
1464 * information that it is going to ask, then the packet can be dropped
1466 if (batadv_forw_packet_is_rebroadcast(forw_packet))
1469 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1471 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1472 if (type != ARPOP_REQUEST)
1475 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1476 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1477 /* check if the node already got this entry */
1479 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1480 "ARP Request for %pI4: fallback\n", &ip_dst);
1484 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1485 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1490 batadv_dat_entry_put(dat_entry);