1 /* Copyright (C) 2011-2015 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/byteorder/generic.h>
23 #include <linux/errno.h>
24 #include <linux/etherdevice.h>
26 #include <linux/if_arp.h>
27 #include <linux/if_ether.h>
28 #include <linux/if_vlan.h>
30 #include <linux/jiffies.h>
31 #include <linux/kernel.h>
32 #include <linux/list.h>
33 #include <linux/rculist.h>
34 #include <linux/rcupdate.h>
35 #include <linux/seq_file.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/spinlock.h>
39 #include <linux/stddef.h>
40 #include <linux/string.h>
41 #include <linux/workqueue.h>
44 #include "hard-interface.h"
46 #include "originator.h"
48 #include "translation-table.h"
50 static void batadv_dat_purge(struct work_struct *work);
53 * batadv_dat_start_timer - initialise the DAT periodic worker
54 * @bat_priv: the bat priv with all the soft interface information
56 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
58 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
59 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
60 msecs_to_jiffies(10000));
64 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
66 * @dat_entry: the entry to free
68 static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
70 if (atomic_dec_and_test(&dat_entry->refcount))
71 kfree_rcu(dat_entry, rcu);
75 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
76 * @dat_entry: the entry to check
78 * Returns true if the entry has to be purged now, false otherwise.
80 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
82 return batadv_has_timed_out(dat_entry->last_update,
83 BATADV_DAT_ENTRY_TIMEOUT);
87 * __batadv_dat_purge - delete entries from the DAT local storage
88 * @bat_priv: the bat priv with all the soft interface information
89 * @to_purge: function in charge to decide whether an entry has to be purged or
90 * not. This function takes the dat_entry as argument and has to
91 * returns a boolean value: true is the entry has to be deleted,
94 * Loops over each entry in the DAT local storage and deletes it if and only if
95 * the to_purge function passed as argument returns true.
97 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
98 bool (*to_purge)(struct batadv_dat_entry *))
100 spinlock_t *list_lock; /* protects write access to the hash lists */
101 struct batadv_dat_entry *dat_entry;
102 struct hlist_node *node_tmp;
103 struct hlist_head *head;
106 if (!bat_priv->dat.hash)
109 for (i = 0; i < bat_priv->dat.hash->size; i++) {
110 head = &bat_priv->dat.hash->table[i];
111 list_lock = &bat_priv->dat.hash->list_locks[i];
113 spin_lock_bh(list_lock);
114 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
116 /* if a helper function has been passed as parameter,
117 * ask it if the entry has to be purged or not
119 if (to_purge && !to_purge(dat_entry))
122 hlist_del_rcu(&dat_entry->hash_entry);
123 batadv_dat_entry_free_ref(dat_entry);
125 spin_unlock_bh(list_lock);
130 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
132 * @work: kernel work struct
134 static void batadv_dat_purge(struct work_struct *work)
136 struct delayed_work *delayed_work;
137 struct batadv_priv_dat *priv_dat;
138 struct batadv_priv *bat_priv;
140 delayed_work = container_of(work, struct delayed_work, work);
141 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
142 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
144 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
145 batadv_dat_start_timer(bat_priv);
149 * batadv_compare_dat - comparing function used in the local DAT hash table
150 * @node: node in the local table
151 * @data2: second object to compare the node to
153 * Returns 1 if the two entries are the same, 0 otherwise.
155 static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
157 const void *data1 = container_of(node, struct batadv_dat_entry,
160 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
164 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
166 * @hdr_size: size of the possible header before the ARP packet
168 * Returns the value of the hw_src field in the ARP packet.
170 static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
174 addr = (uint8_t *)(skb->data + hdr_size);
175 addr += ETH_HLEN + sizeof(struct arphdr);
181 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
183 * @hdr_size: size of the possible header before the ARP packet
185 * Returns the value of the ip_src field in the ARP packet.
187 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
189 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
193 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
195 * @hdr_size: size of the possible header before the ARP packet
197 * Returns the value of the hw_dst field in the ARP packet.
199 static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
201 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
205 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
207 * @hdr_size: size of the possible header before the ARP packet
209 * Returns the value of the ip_dst field in the ARP packet.
211 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
213 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
217 * batadv_hash_dat - compute the hash value for an IP address
218 * @data: data to hash
219 * @size: size of the hash table
221 * Returns the selected index in the hash table for the given data.
223 static uint32_t batadv_hash_dat(const void *data, uint32_t size)
226 const struct batadv_dat_entry *dat = data;
227 const unsigned char *key;
230 key = (const unsigned char *)&dat->ip;
231 for (i = 0; i < sizeof(dat->ip); i++) {
233 hash += (hash << 10);
237 key = (const unsigned char *)&dat->vid;
238 for (i = 0; i < sizeof(dat->vid); i++) {
240 hash += (hash << 10);
245 hash ^= (hash >> 11);
246 hash += (hash << 15);
252 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
254 * @bat_priv: the bat priv with all the soft interface information
256 * @vid: VLAN identifier
258 * Returns the dat_entry if found, NULL otherwise.
260 static struct batadv_dat_entry *
261 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
264 struct hlist_head *head;
265 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
266 struct batadv_hashtable *hash = bat_priv->dat.hash;
275 index = batadv_hash_dat(&to_find, hash->size);
276 head = &hash->table[index];
279 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
280 if (dat_entry->ip != ip)
283 if (!atomic_inc_not_zero(&dat_entry->refcount))
286 dat_entry_tmp = dat_entry;
291 return dat_entry_tmp;
295 * batadv_dat_entry_add - add a new dat entry or update it if already exists
296 * @bat_priv: the bat priv with all the soft interface information
297 * @ip: ipv4 to add/edit
298 * @mac_addr: mac address to assign to the given ipv4
299 * @vid: VLAN identifier
301 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
302 uint8_t *mac_addr, unsigned short vid)
304 struct batadv_dat_entry *dat_entry;
307 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
308 /* if this entry is already known, just update it */
310 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
311 ether_addr_copy(dat_entry->mac_addr, mac_addr);
312 dat_entry->last_update = jiffies;
313 batadv_dbg(BATADV_DBG_DAT, bat_priv,
314 "Entry updated: %pI4 %pM (vid: %d)\n",
315 &dat_entry->ip, dat_entry->mac_addr,
316 BATADV_PRINT_VID(vid));
320 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
325 dat_entry->vid = vid;
326 ether_addr_copy(dat_entry->mac_addr, mac_addr);
327 dat_entry->last_update = jiffies;
328 atomic_set(&dat_entry->refcount, 2);
330 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
331 batadv_hash_dat, dat_entry,
332 &dat_entry->hash_entry);
334 if (unlikely(hash_added != 0)) {
335 /* remove the reference for the hash */
336 batadv_dat_entry_free_ref(dat_entry);
340 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
341 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
345 batadv_dat_entry_free_ref(dat_entry);
348 #ifdef CONFIG_BATMAN_ADV_DEBUG
351 * batadv_dbg_arp - print a debug message containing all the ARP packet details
352 * @bat_priv: the bat priv with all the soft interface information
355 * @hdr_size: size of the possible header before the ARP packet
356 * @msg: message to print together with the debugging information
358 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
359 uint16_t type, int hdr_size, char *msg)
361 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
362 struct batadv_bcast_packet *bcast_pkt;
364 __be32 ip_src, ip_dst;
367 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
369 ip_src = batadv_arp_ip_src(skb, hdr_size);
370 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
371 batadv_dbg(BATADV_DBG_DAT, bat_priv,
372 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
373 batadv_arp_hw_src(skb, hdr_size), &ip_src,
374 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
379 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
381 switch (unicast_4addr_packet->u.packet_type) {
383 batadv_dbg(BATADV_DBG_DAT, bat_priv,
384 "* encapsulated within a UNICAST packet\n");
386 case BATADV_UNICAST_4ADDR:
387 batadv_dbg(BATADV_DBG_DAT, bat_priv,
388 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
389 unicast_4addr_packet->src);
390 switch (unicast_4addr_packet->subtype) {
391 case BATADV_P_DAT_DHT_PUT:
392 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
394 case BATADV_P_DAT_DHT_GET:
395 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
397 case BATADV_P_DAT_CACHE_REPLY:
398 batadv_dbg(BATADV_DBG_DAT, bat_priv,
399 "* type: DAT_CACHE_REPLY\n");
402 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
405 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
406 unicast_4addr_packet->u.packet_type);
410 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
411 orig_addr = bcast_pkt->orig;
412 batadv_dbg(BATADV_DBG_DAT, bat_priv,
413 "* encapsulated within a BCAST packet (src: %pM)\n",
417 batadv_dbg(BATADV_DBG_DAT, bat_priv,
418 "* encapsulated within an unknown packet type (0x%x)\n",
419 unicast_4addr_packet->u.packet_type);
425 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
426 uint16_t type, int hdr_size, char *msg)
430 #endif /* CONFIG_BATMAN_ADV_DEBUG */
433 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
434 * @res: the array with the already selected candidates
435 * @select: number of already selected candidates
436 * @tmp_max: address of the currently evaluated node
437 * @max: current round max address
438 * @last_max: address of the last selected candidate
439 * @candidate: orig_node under evaluation
440 * @max_orig_node: last selected candidate
442 * Returns true if the node has been elected as next candidate or false
445 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
446 int select, batadv_dat_addr_t tmp_max,
447 batadv_dat_addr_t max,
448 batadv_dat_addr_t last_max,
449 struct batadv_orig_node *candidate,
450 struct batadv_orig_node *max_orig_node)
455 /* check if orig node candidate is running DAT */
456 if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
459 /* Check if this node has already been selected... */
460 for (j = 0; j < select; j++)
461 if (res[j].orig_node == candidate)
463 /* ..and possibly skip it */
466 /* sanity check: has it already been selected? This should not happen */
467 if (tmp_max > last_max)
469 /* check if during this iteration an originator with a closer dht
470 * address has already been found
474 /* this is an hash collision with the temporary selected node. Choose
475 * the one with the lowest address
477 if ((tmp_max == max) && max_orig_node &&
478 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
487 * batadv_choose_next_candidate - select the next DHT candidate
488 * @bat_priv: the bat priv with all the soft interface information
489 * @cands: candidates array
490 * @select: number of candidates already present in the array
491 * @ip_key: key to look up in the DHT
492 * @last_max: pointer where the address of the selected candidate will be saved
494 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
495 struct batadv_dat_candidate *cands,
496 int select, batadv_dat_addr_t ip_key,
497 batadv_dat_addr_t *last_max)
499 batadv_dat_addr_t max = 0, tmp_max = 0;
500 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
501 struct batadv_hashtable *hash = bat_priv->orig_hash;
502 struct hlist_head *head;
505 /* if no node is eligible as candidate, leave the candidate type as
508 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
510 /* iterate over the originator list and find the node with the closest
511 * dat_address which has not been selected yet
513 for (i = 0; i < hash->size; i++) {
514 head = &hash->table[i];
517 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
518 /* the dht space is a ring using unsigned addresses */
519 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
522 if (!batadv_is_orig_node_eligible(cands, select,
524 *last_max, orig_node,
528 if (!atomic_inc_not_zero(&orig_node->refcount))
533 batadv_orig_node_free_ref(max_orig_node);
534 max_orig_node = orig_node;
539 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
540 cands[select].orig_node = max_orig_node;
541 batadv_dbg(BATADV_DBG_DAT, bat_priv,
542 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
543 select, max_orig_node->orig, max_orig_node->dat_addr,
550 * batadv_dat_select_candidates - select the nodes which the DHT message has to
552 * @bat_priv: the bat priv with all the soft interface information
553 * @ip_dst: ipv4 to look up in the DHT
555 * An originator O is selected if and only if its DHT_ID value is one of three
556 * closest values (from the LEFT, with wrap around if needed) then the hash
557 * value of the key. ip_dst is the key.
559 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
561 static struct batadv_dat_candidate *
562 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
565 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
566 struct batadv_dat_candidate *res;
568 if (!bat_priv->orig_hash)
571 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
576 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
577 BATADV_DAT_ADDR_MAX);
579 batadv_dbg(BATADV_DBG_DAT, bat_priv,
580 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
583 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
584 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
591 * batadv_dat_send_data - send a payload to the selected candidates
592 * @bat_priv: the bat priv with all the soft interface information
593 * @skb: payload to send
595 * @packet_subtype: unicast4addr packet subtype to use
597 * This function copies the skb with pskb_copy() and is sent as unicast packet
598 * to each of the selected candidates.
600 * Returns true if the packet is sent to at least one candidate, false
603 static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
604 struct sk_buff *skb, __be32 ip,
610 struct batadv_neigh_node *neigh_node = NULL;
611 struct sk_buff *tmp_skb;
612 struct batadv_dat_candidate *cand;
614 cand = batadv_dat_select_candidates(bat_priv, ip);
618 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
620 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
621 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
624 neigh_node = batadv_orig_router_get(cand[i].orig_node,
629 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
630 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
637 send_status = batadv_send_skb_packet(tmp_skb,
638 neigh_node->if_incoming,
640 if (send_status == NET_XMIT_SUCCESS) {
641 /* count the sent packet */
642 switch (packet_subtype) {
643 case BATADV_P_DAT_DHT_GET:
644 batadv_inc_counter(bat_priv,
645 BATADV_CNT_DAT_GET_TX);
647 case BATADV_P_DAT_DHT_PUT:
648 batadv_inc_counter(bat_priv,
649 BATADV_CNT_DAT_PUT_TX);
653 /* packet sent to a candidate: return true */
657 batadv_neigh_node_free_ref(neigh_node);
659 batadv_orig_node_free_ref(cand[i].orig_node);
668 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
670 * @bat_priv: the bat priv with all the soft interface information
672 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
676 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
680 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
683 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
690 * batadv_dat_status_update - update the dat tvlv container after dat
692 * @net_dev: the soft interface net device
694 void batadv_dat_status_update(struct net_device *net_dev)
696 struct batadv_priv *bat_priv = netdev_priv(net_dev);
698 batadv_dat_tvlv_container_update(bat_priv);
702 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
703 * @bat_priv: the bat priv with all the soft interface information
704 * @orig: the orig_node of the ogm
705 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
706 * @tvlv_value: tvlv buffer containing the gateway data
707 * @tvlv_value_len: tvlv buffer length
709 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
710 struct batadv_orig_node *orig,
713 uint16_t tvlv_value_len)
715 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
716 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
718 orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
722 * batadv_dat_hash_free - free the local DAT hash table
723 * @bat_priv: the bat priv with all the soft interface information
725 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
727 if (!bat_priv->dat.hash)
730 __batadv_dat_purge(bat_priv, NULL);
732 batadv_hash_destroy(bat_priv->dat.hash);
734 bat_priv->dat.hash = NULL;
738 * batadv_dat_init - initialise the DAT internals
739 * @bat_priv: the bat priv with all the soft interface information
741 int batadv_dat_init(struct batadv_priv *bat_priv)
743 if (bat_priv->dat.hash)
746 bat_priv->dat.hash = batadv_hash_new(1024);
748 if (!bat_priv->dat.hash)
751 batadv_dat_start_timer(bat_priv);
753 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
754 NULL, BATADV_TVLV_DAT, 1,
755 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
756 batadv_dat_tvlv_container_update(bat_priv);
761 * batadv_dat_free - free the DAT internals
762 * @bat_priv: the bat priv with all the soft interface information
764 void batadv_dat_free(struct batadv_priv *bat_priv)
766 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
767 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
769 cancel_delayed_work_sync(&bat_priv->dat.work);
771 batadv_dat_hash_free(bat_priv);
775 * batadv_dat_cache_seq_print_text - print the local DAT hash table
776 * @seq: seq file to print on
779 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
781 struct net_device *net_dev = (struct net_device *)seq->private;
782 struct batadv_priv *bat_priv = netdev_priv(net_dev);
783 struct batadv_hashtable *hash = bat_priv->dat.hash;
784 struct batadv_dat_entry *dat_entry;
785 struct batadv_hard_iface *primary_if;
786 struct hlist_head *head;
787 unsigned long last_seen_jiffies;
788 int last_seen_msecs, last_seen_secs, last_seen_mins;
791 primary_if = batadv_seq_print_text_primary_if_get(seq);
795 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
796 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
797 "MAC", "VID", "last-seen");
799 for (i = 0; i < hash->size; i++) {
800 head = &hash->table[i];
803 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
804 last_seen_jiffies = jiffies - dat_entry->last_update;
805 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
806 last_seen_mins = last_seen_msecs / 60000;
807 last_seen_msecs = last_seen_msecs % 60000;
808 last_seen_secs = last_seen_msecs / 1000;
810 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
811 &dat_entry->ip, dat_entry->mac_addr,
812 BATADV_PRINT_VID(dat_entry->vid),
813 last_seen_mins, last_seen_secs);
820 batadv_hardif_free_ref(primary_if);
825 * batadv_arp_get_type - parse an ARP packet and gets the type
826 * @bat_priv: the bat priv with all the soft interface information
827 * @skb: packet to analyse
828 * @hdr_size: size of the possible header before the ARP packet in the skb
830 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
832 static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
833 struct sk_buff *skb, int hdr_size)
835 struct arphdr *arphdr;
836 struct ethhdr *ethhdr;
837 __be32 ip_src, ip_dst;
838 uint8_t *hw_src, *hw_dst;
841 /* pull the ethernet header */
842 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
845 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
847 if (ethhdr->h_proto != htons(ETH_P_ARP))
850 /* pull the ARP payload */
851 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
852 arp_hdr_len(skb->dev))))
855 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
857 /* check whether the ARP packet carries a valid IP information */
858 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
861 if (arphdr->ar_pro != htons(ETH_P_IP))
864 if (arphdr->ar_hln != ETH_ALEN)
867 if (arphdr->ar_pln != 4)
870 /* Check for bad reply/request. If the ARP message is not sane, DAT
871 * will simply ignore it
873 ip_src = batadv_arp_ip_src(skb, hdr_size);
874 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
875 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
876 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
877 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
878 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
881 hw_src = batadv_arp_hw_src(skb, hdr_size);
882 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
885 /* don't care about the destination MAC address in ARP requests */
886 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
887 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
888 if (is_zero_ether_addr(hw_dst) ||
889 is_multicast_ether_addr(hw_dst))
893 type = ntohs(arphdr->ar_op);
899 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
900 * @skb: the buffer containing the packet to extract the VID from
901 * @hdr_size: the size of the batman-adv header encapsulating the packet
903 * If the packet embedded in the skb is vlan tagged this function returns the
904 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
906 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
910 vid = batadv_get_vid(skb, *hdr_size);
912 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
913 * If the header contained in the packet is a VLAN one (which is longer)
914 * hdr_size is updated so that the functions will still skip the
915 * correct amount of bytes.
917 if (vid & BATADV_VLAN_HAS_TAG)
918 *hdr_size += VLAN_HLEN;
924 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
926 * @bat_priv: the bat priv with all the soft interface information
927 * @skb: packet to check
929 * Returns true if the message has been sent to the dht candidates, false
930 * otherwise. In case of a positive return value the message has to be enqueued
931 * to permit the fallback.
933 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
937 __be32 ip_dst, ip_src;
940 struct batadv_dat_entry *dat_entry = NULL;
941 struct sk_buff *skb_new;
945 if (!atomic_read(&bat_priv->distributed_arp_table))
948 vid = batadv_dat_get_vid(skb, &hdr_size);
950 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
951 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
952 * message to the selected DHT candidates
954 if (type != ARPOP_REQUEST)
957 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
958 "Parsing outgoing ARP REQUEST");
960 ip_src = batadv_arp_ip_src(skb, hdr_size);
961 hw_src = batadv_arp_hw_src(skb, hdr_size);
962 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
964 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
966 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
968 /* If the ARP request is destined for a local client the local
969 * client will answer itself. DAT would only generate a
972 * Moreover, if the soft-interface is enslaved into a bridge, an
973 * additional DAT answer may trigger kernel warnings about
974 * a packet coming from the wrong port.
976 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
981 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
982 bat_priv->soft_iface, ip_dst, hw_src,
983 dat_entry->mac_addr, hw_src);
987 if (vid & BATADV_VLAN_HAS_TAG)
988 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
989 vid & VLAN_VID_MASK);
991 skb_reset_mac_header(skb_new);
992 skb_new->protocol = eth_type_trans(skb_new,
993 bat_priv->soft_iface);
994 bat_priv->stats.rx_packets++;
995 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
996 bat_priv->soft_iface->last_rx = jiffies;
999 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1002 /* Send the request to the DHT */
1003 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
1004 BATADV_P_DAT_DHT_GET);
1008 batadv_dat_entry_free_ref(dat_entry);
1013 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
1014 * answer using the local DAT storage
1015 * @bat_priv: the bat priv with all the soft interface information
1016 * @skb: packet to check
1017 * @hdr_size: size of the encapsulation header
1019 * Returns true if the request has been answered, false otherwise.
1021 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1022 struct sk_buff *skb, int hdr_size)
1025 __be32 ip_src, ip_dst;
1027 struct sk_buff *skb_new;
1028 struct batadv_dat_entry *dat_entry = NULL;
1033 if (!atomic_read(&bat_priv->distributed_arp_table))
1036 vid = batadv_dat_get_vid(skb, &hdr_size);
1038 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1039 if (type != ARPOP_REQUEST)
1042 hw_src = batadv_arp_hw_src(skb, hdr_size);
1043 ip_src = batadv_arp_ip_src(skb, hdr_size);
1044 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1046 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1047 "Parsing incoming ARP REQUEST");
1049 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1051 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1055 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1056 bat_priv->soft_iface, ip_dst, hw_src,
1057 dat_entry->mac_addr, hw_src);
1062 /* the rest of the TX path assumes that the mac_header offset pointing
1063 * to the inner Ethernet header has been set, therefore reset it now.
1065 skb_reset_mac_header(skb_new);
1067 if (vid & BATADV_VLAN_HAS_TAG)
1068 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1069 vid & VLAN_VID_MASK);
1071 /* To preserve backwards compatibility, the node has choose the outgoing
1072 * format based on the incoming request packet type. The assumption is
1073 * that a node not using the 4addr packet format doesn't support it.
1075 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1076 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1077 BATADV_P_DAT_CACHE_REPLY,
1080 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1082 if (err != NET_XMIT_DROP) {
1083 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1088 batadv_dat_entry_free_ref(dat_entry);
1095 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1096 * @bat_priv: the bat priv with all the soft interface information
1097 * @skb: packet to check
1099 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1100 struct sk_buff *skb)
1103 __be32 ip_src, ip_dst;
1104 uint8_t *hw_src, *hw_dst;
1108 if (!atomic_read(&bat_priv->distributed_arp_table))
1111 vid = batadv_dat_get_vid(skb, &hdr_size);
1113 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1114 if (type != ARPOP_REPLY)
1117 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1118 "Parsing outgoing ARP REPLY");
1120 hw_src = batadv_arp_hw_src(skb, hdr_size);
1121 ip_src = batadv_arp_ip_src(skb, hdr_size);
1122 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1123 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1125 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1126 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1128 /* Send the ARP reply to the candidates for both the IP addresses that
1129 * the node obtained from the ARP reply
1131 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1132 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1136 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1138 * @bat_priv: the bat priv with all the soft interface information
1139 * @skb: packet to check
1140 * @hdr_size: size of the encapsulation header
1142 * Returns true if the packet was snooped and consumed by DAT. False if the
1143 * packet has to be delivered to the interface
1145 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1146 struct sk_buff *skb, int hdr_size)
1149 __be32 ip_src, ip_dst;
1150 uint8_t *hw_src, *hw_dst;
1151 bool dropped = false;
1154 if (!atomic_read(&bat_priv->distributed_arp_table))
1157 vid = batadv_dat_get_vid(skb, &hdr_size);
1159 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1160 if (type != ARPOP_REPLY)
1163 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1164 "Parsing incoming ARP REPLY");
1166 hw_src = batadv_arp_hw_src(skb, hdr_size);
1167 ip_src = batadv_arp_ip_src(skb, hdr_size);
1168 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1169 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1171 /* Update our internal cache with both the IP addresses the node got
1172 * within the ARP reply
1174 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1175 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1177 /* if this REPLY is directed to a client of mine, let's deliver the
1178 * packet to the interface
1180 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1182 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1183 * packet because the client will reply by itself
1185 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1189 /* if dropped == false -> deliver to the interface */
1194 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1195 * (because the node has already obtained the reply via DAT) or not
1196 * @bat_priv: the bat priv with all the soft interface information
1197 * @forw_packet: the broadcast packet
1199 * Returns true if the node can drop the packet, false otherwise.
1201 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1202 struct batadv_forw_packet *forw_packet)
1206 struct batadv_dat_entry *dat_entry = NULL;
1208 int hdr_size = sizeof(struct batadv_bcast_packet);
1211 if (!atomic_read(&bat_priv->distributed_arp_table))
1214 /* If this packet is an ARP_REQUEST and the node already has the
1215 * information that it is going to ask, then the packet can be dropped
1217 if (forw_packet->num_packets)
1220 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1222 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1223 if (type != ARPOP_REQUEST)
1226 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1227 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1228 /* check if the node already got this entry */
1230 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1231 "ARP Request for %pI4: fallback\n", &ip_dst);
1235 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1236 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1241 batadv_dat_entry_free_ref(dat_entry);