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 <linux/if_ether.h>
19 #include <linux/if_arp.h>
20 #include <linux/if_vlan.h>
25 #include "distributed-arp-table.h"
26 #include "hard-interface.h"
27 #include "originator.h"
30 #include "translation-table.h"
32 static void batadv_dat_purge(struct work_struct *work);
35 * batadv_dat_start_timer - initialise the DAT periodic worker
36 * @bat_priv: the bat priv with all the soft interface information
38 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
40 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
41 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
42 msecs_to_jiffies(10000));
46 * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
48 * @dat_entry: the entry to free
50 static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
52 if (atomic_dec_and_test(&dat_entry->refcount))
53 kfree_rcu(dat_entry, rcu);
57 * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
58 * @dat_entry: the entry to check
60 * Returns true if the entry has to be purged now, false otherwise.
62 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
64 return batadv_has_timed_out(dat_entry->last_update,
65 BATADV_DAT_ENTRY_TIMEOUT);
69 * __batadv_dat_purge - delete entries from the DAT local storage
70 * @bat_priv: the bat priv with all the soft interface information
71 * @to_purge: function in charge to decide whether an entry has to be purged or
72 * not. This function takes the dat_entry as argument and has to
73 * returns a boolean value: true is the entry has to be deleted,
76 * Loops over each entry in the DAT local storage and deletes it if and only if
77 * the to_purge function passed as argument returns true.
79 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
80 bool (*to_purge)(struct batadv_dat_entry *))
82 spinlock_t *list_lock; /* protects write access to the hash lists */
83 struct batadv_dat_entry *dat_entry;
84 struct hlist_node *node_tmp;
85 struct hlist_head *head;
88 if (!bat_priv->dat.hash)
91 for (i = 0; i < bat_priv->dat.hash->size; i++) {
92 head = &bat_priv->dat.hash->table[i];
93 list_lock = &bat_priv->dat.hash->list_locks[i];
95 spin_lock_bh(list_lock);
96 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
98 /* if a helper function has been passed as parameter,
99 * ask it if the entry has to be purged or not
101 if (to_purge && !to_purge(dat_entry))
104 hlist_del_rcu(&dat_entry->hash_entry);
105 batadv_dat_entry_free_ref(dat_entry);
107 spin_unlock_bh(list_lock);
112 * batadv_dat_purge - periodic task that deletes old entries from the local DAT
114 * @work: kernel work struct
116 static void batadv_dat_purge(struct work_struct *work)
118 struct delayed_work *delayed_work;
119 struct batadv_priv_dat *priv_dat;
120 struct batadv_priv *bat_priv;
122 delayed_work = container_of(work, struct delayed_work, work);
123 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
124 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
126 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
127 batadv_dat_start_timer(bat_priv);
131 * batadv_compare_dat - comparing function used in the local DAT hash table
132 * @node: node in the local table
133 * @data2: second object to compare the node to
135 * Returns 1 if the two entries are the same, 0 otherwise.
137 static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
139 const void *data1 = container_of(node, struct batadv_dat_entry,
142 return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
146 * batadv_arp_hw_src - extract the hw_src field from an ARP packet
148 * @hdr_size: size of the possible header before the ARP packet
150 * Returns the value of the hw_src field in the ARP packet.
152 static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
156 addr = (uint8_t *)(skb->data + hdr_size);
157 addr += ETH_HLEN + sizeof(struct arphdr);
163 * batadv_arp_ip_src - extract the ip_src field from an ARP packet
165 * @hdr_size: size of the possible header before the ARP packet
167 * Returns the value of the ip_src field in the ARP packet.
169 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
171 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
175 * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
177 * @hdr_size: size of the possible header before the ARP packet
179 * Returns the value of the hw_dst field in the ARP packet.
181 static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
183 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
187 * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
189 * @hdr_size: size of the possible header before the ARP packet
191 * Returns the value of the ip_dst field in the ARP packet.
193 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
195 return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
199 * batadv_hash_dat - compute the hash value for an IP address
200 * @data: data to hash
201 * @size: size of the hash table
203 * Returns the selected index in the hash table for the given data.
205 static uint32_t batadv_hash_dat(const void *data, uint32_t size)
208 const struct batadv_dat_entry *dat = data;
210 hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip));
211 hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid));
214 hash ^= (hash >> 11);
215 hash += (hash << 15);
221 * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
223 * @bat_priv: the bat priv with all the soft interface information
225 * @vid: VLAN identifier
227 * Returns the dat_entry if found, NULL otherwise.
229 static struct batadv_dat_entry *
230 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
233 struct hlist_head *head;
234 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
235 struct batadv_hashtable *hash = bat_priv->dat.hash;
244 index = batadv_hash_dat(&to_find, hash->size);
245 head = &hash->table[index];
248 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
249 if (dat_entry->ip != ip)
252 if (!atomic_inc_not_zero(&dat_entry->refcount))
255 dat_entry_tmp = dat_entry;
260 return dat_entry_tmp;
264 * batadv_dat_entry_add - add a new dat entry or update it if already exists
265 * @bat_priv: the bat priv with all the soft interface information
266 * @ip: ipv4 to add/edit
267 * @mac_addr: mac address to assign to the given ipv4
268 * @vid: VLAN identifier
270 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
271 uint8_t *mac_addr, unsigned short vid)
273 struct batadv_dat_entry *dat_entry;
276 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
277 /* if this entry is already known, just update it */
279 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
280 ether_addr_copy(dat_entry->mac_addr, mac_addr);
281 dat_entry->last_update = jiffies;
282 batadv_dbg(BATADV_DBG_DAT, bat_priv,
283 "Entry updated: %pI4 %pM (vid: %d)\n",
284 &dat_entry->ip, dat_entry->mac_addr,
285 BATADV_PRINT_VID(vid));
289 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
294 dat_entry->vid = vid;
295 ether_addr_copy(dat_entry->mac_addr, mac_addr);
296 dat_entry->last_update = jiffies;
297 atomic_set(&dat_entry->refcount, 2);
299 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
300 batadv_hash_dat, dat_entry,
301 &dat_entry->hash_entry);
303 if (unlikely(hash_added != 0)) {
304 /* remove the reference for the hash */
305 batadv_dat_entry_free_ref(dat_entry);
309 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
310 &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
314 batadv_dat_entry_free_ref(dat_entry);
317 #ifdef CONFIG_BATMAN_ADV_DEBUG
320 * batadv_dbg_arp - print a debug message containing all the ARP packet details
321 * @bat_priv: the bat priv with all the soft interface information
324 * @hdr_size: size of the possible header before the ARP packet
325 * @msg: message to print together with the debugging information
327 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
328 uint16_t type, int hdr_size, char *msg)
330 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
331 struct batadv_bcast_packet *bcast_pkt;
333 __be32 ip_src, ip_dst;
336 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
338 ip_src = batadv_arp_ip_src(skb, hdr_size);
339 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
340 batadv_dbg(BATADV_DBG_DAT, bat_priv,
341 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
342 batadv_arp_hw_src(skb, hdr_size), &ip_src,
343 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
348 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
350 switch (unicast_4addr_packet->u.packet_type) {
352 batadv_dbg(BATADV_DBG_DAT, bat_priv,
353 "* encapsulated within a UNICAST packet\n");
355 case BATADV_UNICAST_4ADDR:
356 batadv_dbg(BATADV_DBG_DAT, bat_priv,
357 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
358 unicast_4addr_packet->src);
359 switch (unicast_4addr_packet->subtype) {
360 case BATADV_P_DAT_DHT_PUT:
361 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
363 case BATADV_P_DAT_DHT_GET:
364 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
366 case BATADV_P_DAT_CACHE_REPLY:
367 batadv_dbg(BATADV_DBG_DAT, bat_priv,
368 "* type: DAT_CACHE_REPLY\n");
371 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
374 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
375 unicast_4addr_packet->u.packet_type);
379 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
380 orig_addr = bcast_pkt->orig;
381 batadv_dbg(BATADV_DBG_DAT, bat_priv,
382 "* encapsulated within a BCAST packet (src: %pM)\n",
386 batadv_dbg(BATADV_DBG_DAT, bat_priv,
387 "* encapsulated within an unknown packet type (0x%x)\n",
388 unicast_4addr_packet->u.packet_type);
394 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
395 uint16_t type, int hdr_size, char *msg)
399 #endif /* CONFIG_BATMAN_ADV_DEBUG */
402 * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
403 * @res: the array with the already selected candidates
404 * @select: number of already selected candidates
405 * @tmp_max: address of the currently evaluated node
406 * @max: current round max address
407 * @last_max: address of the last selected candidate
408 * @candidate: orig_node under evaluation
409 * @max_orig_node: last selected candidate
411 * Returns true if the node has been elected as next candidate or false
414 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
415 int select, batadv_dat_addr_t tmp_max,
416 batadv_dat_addr_t max,
417 batadv_dat_addr_t last_max,
418 struct batadv_orig_node *candidate,
419 struct batadv_orig_node *max_orig_node)
424 /* check if orig node candidate is running DAT */
425 if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
428 /* Check if this node has already been selected... */
429 for (j = 0; j < select; j++)
430 if (res[j].orig_node == candidate)
432 /* ..and possibly skip it */
435 /* sanity check: has it already been selected? This should not happen */
436 if (tmp_max > last_max)
438 /* check if during this iteration an originator with a closer dht
439 * address has already been found
443 /* this is an hash collision with the temporary selected node. Choose
444 * the one with the lowest address
446 if ((tmp_max == max) && max_orig_node &&
447 (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
456 * batadv_choose_next_candidate - select the next DHT candidate
457 * @bat_priv: the bat priv with all the soft interface information
458 * @cands: candidates array
459 * @select: number of candidates already present in the array
460 * @ip_key: key to look up in the DHT
461 * @last_max: pointer where the address of the selected candidate will be saved
463 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
464 struct batadv_dat_candidate *cands,
465 int select, batadv_dat_addr_t ip_key,
466 batadv_dat_addr_t *last_max)
468 batadv_dat_addr_t max = 0, tmp_max = 0;
469 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
470 struct batadv_hashtable *hash = bat_priv->orig_hash;
471 struct hlist_head *head;
474 /* if no node is eligible as candidate, leave the candidate type as
477 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
479 /* iterate over the originator list and find the node with the closest
480 * dat_address which has not been selected yet
482 for (i = 0; i < hash->size; i++) {
483 head = &hash->table[i];
486 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
487 /* the dht space is a ring using unsigned addresses */
488 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
491 if (!batadv_is_orig_node_eligible(cands, select,
493 *last_max, orig_node,
497 if (!atomic_inc_not_zero(&orig_node->refcount))
502 batadv_orig_node_free_ref(max_orig_node);
503 max_orig_node = orig_node;
508 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
509 cands[select].orig_node = max_orig_node;
510 batadv_dbg(BATADV_DBG_DAT, bat_priv,
511 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
512 select, max_orig_node->orig, max_orig_node->dat_addr,
519 * batadv_dat_select_candidates - select the nodes which the DHT message has to
521 * @bat_priv: the bat priv with all the soft interface information
522 * @ip_dst: ipv4 to look up in the DHT
524 * An originator O is selected if and only if its DHT_ID value is one of three
525 * closest values (from the LEFT, with wrap around if needed) then the hash
526 * value of the key. ip_dst is the key.
528 * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
530 static struct batadv_dat_candidate *
531 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
534 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
535 struct batadv_dat_candidate *res;
537 if (!bat_priv->orig_hash)
540 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
545 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
546 BATADV_DAT_ADDR_MAX);
548 batadv_dbg(BATADV_DBG_DAT, bat_priv,
549 "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
552 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
553 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
560 * batadv_dat_send_data - send a payload to the selected candidates
561 * @bat_priv: the bat priv with all the soft interface information
562 * @skb: payload to send
564 * @packet_subtype: unicast4addr packet subtype to use
566 * This function copies the skb with pskb_copy() and is sent as unicast packet
567 * to each of the selected candidates.
569 * Returns true if the packet is sent to at least one candidate, false
572 static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
573 struct sk_buff *skb, __be32 ip,
579 struct batadv_neigh_node *neigh_node = NULL;
580 struct sk_buff *tmp_skb;
581 struct batadv_dat_candidate *cand;
583 cand = batadv_dat_select_candidates(bat_priv, ip);
587 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
589 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
590 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
593 neigh_node = batadv_orig_router_get(cand[i].orig_node,
598 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
599 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
606 send_status = batadv_send_skb_packet(tmp_skb,
607 neigh_node->if_incoming,
609 if (send_status == NET_XMIT_SUCCESS) {
610 /* count the sent packet */
611 switch (packet_subtype) {
612 case BATADV_P_DAT_DHT_GET:
613 batadv_inc_counter(bat_priv,
614 BATADV_CNT_DAT_GET_TX);
616 case BATADV_P_DAT_DHT_PUT:
617 batadv_inc_counter(bat_priv,
618 BATADV_CNT_DAT_PUT_TX);
622 /* packet sent to a candidate: return true */
626 batadv_neigh_node_free_ref(neigh_node);
628 batadv_orig_node_free_ref(cand[i].orig_node);
637 * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
639 * @bat_priv: the bat priv with all the soft interface information
641 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
645 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
649 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
652 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
659 * batadv_dat_status_update - update the dat tvlv container after dat
661 * @net_dev: the soft interface net device
663 void batadv_dat_status_update(struct net_device *net_dev)
665 struct batadv_priv *bat_priv = netdev_priv(net_dev);
667 batadv_dat_tvlv_container_update(bat_priv);
671 * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
672 * @bat_priv: the bat priv with all the soft interface information
673 * @orig: the orig_node of the ogm
674 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
675 * @tvlv_value: tvlv buffer containing the gateway data
676 * @tvlv_value_len: tvlv buffer length
678 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
679 struct batadv_orig_node *orig,
682 uint16_t tvlv_value_len)
684 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
685 orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
687 orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
691 * batadv_dat_hash_free - free the local DAT hash table
692 * @bat_priv: the bat priv with all the soft interface information
694 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
696 if (!bat_priv->dat.hash)
699 __batadv_dat_purge(bat_priv, NULL);
701 batadv_hash_destroy(bat_priv->dat.hash);
703 bat_priv->dat.hash = NULL;
707 * batadv_dat_init - initialise the DAT internals
708 * @bat_priv: the bat priv with all the soft interface information
710 int batadv_dat_init(struct batadv_priv *bat_priv)
712 if (bat_priv->dat.hash)
715 bat_priv->dat.hash = batadv_hash_new(1024);
717 if (!bat_priv->dat.hash)
720 batadv_dat_start_timer(bat_priv);
722 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
723 NULL, BATADV_TVLV_DAT, 1,
724 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
725 batadv_dat_tvlv_container_update(bat_priv);
730 * batadv_dat_free - free the DAT internals
731 * @bat_priv: the bat priv with all the soft interface information
733 void batadv_dat_free(struct batadv_priv *bat_priv)
735 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
736 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
738 cancel_delayed_work_sync(&bat_priv->dat.work);
740 batadv_dat_hash_free(bat_priv);
744 * batadv_dat_cache_seq_print_text - print the local DAT hash table
745 * @seq: seq file to print on
748 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
750 struct net_device *net_dev = (struct net_device *)seq->private;
751 struct batadv_priv *bat_priv = netdev_priv(net_dev);
752 struct batadv_hashtable *hash = bat_priv->dat.hash;
753 struct batadv_dat_entry *dat_entry;
754 struct batadv_hard_iface *primary_if;
755 struct hlist_head *head;
756 unsigned long last_seen_jiffies;
757 int last_seen_msecs, last_seen_secs, last_seen_mins;
760 primary_if = batadv_seq_print_text_primary_if_get(seq);
764 seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
765 seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
766 "MAC", "VID", "last-seen");
768 for (i = 0; i < hash->size; i++) {
769 head = &hash->table[i];
772 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
773 last_seen_jiffies = jiffies - dat_entry->last_update;
774 last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
775 last_seen_mins = last_seen_msecs / 60000;
776 last_seen_msecs = last_seen_msecs % 60000;
777 last_seen_secs = last_seen_msecs / 1000;
779 seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
780 &dat_entry->ip, dat_entry->mac_addr,
781 BATADV_PRINT_VID(dat_entry->vid),
782 last_seen_mins, last_seen_secs);
789 batadv_hardif_free_ref(primary_if);
794 * batadv_arp_get_type - parse an ARP packet and gets the type
795 * @bat_priv: the bat priv with all the soft interface information
796 * @skb: packet to analyse
797 * @hdr_size: size of the possible header before the ARP packet in the skb
799 * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
801 static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
802 struct sk_buff *skb, int hdr_size)
804 struct arphdr *arphdr;
805 struct ethhdr *ethhdr;
806 __be32 ip_src, ip_dst;
807 uint8_t *hw_src, *hw_dst;
810 /* pull the ethernet header */
811 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
814 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
816 if (ethhdr->h_proto != htons(ETH_P_ARP))
819 /* pull the ARP payload */
820 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
821 arp_hdr_len(skb->dev))))
824 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
826 /* check whether the ARP packet carries a valid IP information */
827 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
830 if (arphdr->ar_pro != htons(ETH_P_IP))
833 if (arphdr->ar_hln != ETH_ALEN)
836 if (arphdr->ar_pln != 4)
839 /* Check for bad reply/request. If the ARP message is not sane, DAT
840 * will simply ignore it
842 ip_src = batadv_arp_ip_src(skb, hdr_size);
843 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
844 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
845 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
846 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
847 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
850 hw_src = batadv_arp_hw_src(skb, hdr_size);
851 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
854 /* don't care about the destination MAC address in ARP requests */
855 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
856 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
857 if (is_zero_ether_addr(hw_dst) ||
858 is_multicast_ether_addr(hw_dst))
862 type = ntohs(arphdr->ar_op);
868 * batadv_dat_get_vid - extract the VLAN identifier from skb if any
869 * @skb: the buffer containing the packet to extract the VID from
870 * @hdr_size: the size of the batman-adv header encapsulating the packet
872 * If the packet embedded in the skb is vlan tagged this function returns the
873 * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
875 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
879 vid = batadv_get_vid(skb, *hdr_size);
881 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
882 * If the header contained in the packet is a VLAN one (which is longer)
883 * hdr_size is updated so that the functions will still skip the
884 * correct amount of bytes.
886 if (vid & BATADV_VLAN_HAS_TAG)
887 *hdr_size += VLAN_HLEN;
893 * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
895 * @bat_priv: the bat priv with all the soft interface information
896 * @skb: packet to check
898 * Returns true if the message has been sent to the dht candidates, false
899 * otherwise. In case of a positive return value the message has to be enqueued
900 * to permit the fallback.
902 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
906 __be32 ip_dst, ip_src;
909 struct batadv_dat_entry *dat_entry = NULL;
910 struct sk_buff *skb_new;
914 if (!atomic_read(&bat_priv->distributed_arp_table))
917 vid = batadv_dat_get_vid(skb, &hdr_size);
919 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
920 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
921 * message to the selected DHT candidates
923 if (type != ARPOP_REQUEST)
926 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
927 "Parsing outgoing ARP REQUEST");
929 ip_src = batadv_arp_ip_src(skb, hdr_size);
930 hw_src = batadv_arp_hw_src(skb, hdr_size);
931 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
933 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
935 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
937 /* If the ARP request is destined for a local client the local
938 * client will answer itself. DAT would only generate a
941 * Moreover, if the soft-interface is enslaved into a bridge, an
942 * additional DAT answer may trigger kernel warnings about
943 * a packet coming from the wrong port.
945 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
950 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
951 bat_priv->soft_iface, ip_dst, hw_src,
952 dat_entry->mac_addr, hw_src);
956 if (vid & BATADV_VLAN_HAS_TAG)
957 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
958 vid & VLAN_VID_MASK);
960 skb_reset_mac_header(skb_new);
961 skb_new->protocol = eth_type_trans(skb_new,
962 bat_priv->soft_iface);
963 bat_priv->stats.rx_packets++;
964 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
965 bat_priv->soft_iface->last_rx = jiffies;
968 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
971 /* Send the request to the DHT */
972 ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
973 BATADV_P_DAT_DHT_GET);
977 batadv_dat_entry_free_ref(dat_entry);
982 * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
983 * answer using the local DAT storage
984 * @bat_priv: the bat priv with all the soft interface information
985 * @skb: packet to check
986 * @hdr_size: size of the encapsulation header
988 * Returns true if the request has been answered, false otherwise.
990 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
991 struct sk_buff *skb, int hdr_size)
994 __be32 ip_src, ip_dst;
996 struct sk_buff *skb_new;
997 struct batadv_dat_entry *dat_entry = NULL;
1002 if (!atomic_read(&bat_priv->distributed_arp_table))
1005 vid = batadv_dat_get_vid(skb, &hdr_size);
1007 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1008 if (type != ARPOP_REQUEST)
1011 hw_src = batadv_arp_hw_src(skb, hdr_size);
1012 ip_src = batadv_arp_ip_src(skb, hdr_size);
1013 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1015 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1016 "Parsing incoming ARP REQUEST");
1018 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1020 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1024 skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
1025 bat_priv->soft_iface, ip_dst, hw_src,
1026 dat_entry->mac_addr, hw_src);
1031 /* the rest of the TX path assumes that the mac_header offset pointing
1032 * to the inner Ethernet header has been set, therefore reset it now.
1034 skb_reset_mac_header(skb_new);
1036 if (vid & BATADV_VLAN_HAS_TAG)
1037 skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
1038 vid & VLAN_VID_MASK);
1040 /* To preserve backwards compatibility, the node has choose the outgoing
1041 * format based on the incoming request packet type. The assumption is
1042 * that a node not using the 4addr packet format doesn't support it.
1044 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1045 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1046 BATADV_P_DAT_CACHE_REPLY,
1049 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1051 if (err != NET_XMIT_DROP) {
1052 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1057 batadv_dat_entry_free_ref(dat_entry);
1064 * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
1065 * @bat_priv: the bat priv with all the soft interface information
1066 * @skb: packet to check
1068 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1069 struct sk_buff *skb)
1072 __be32 ip_src, ip_dst;
1073 uint8_t *hw_src, *hw_dst;
1077 if (!atomic_read(&bat_priv->distributed_arp_table))
1080 vid = batadv_dat_get_vid(skb, &hdr_size);
1082 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1083 if (type != ARPOP_REPLY)
1086 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1087 "Parsing outgoing ARP REPLY");
1089 hw_src = batadv_arp_hw_src(skb, hdr_size);
1090 ip_src = batadv_arp_ip_src(skb, hdr_size);
1091 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1092 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1094 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1095 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1097 /* Send the ARP reply to the candidates for both the IP addresses that
1098 * the node obtained from the ARP reply
1100 batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
1101 batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
1105 * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
1107 * @bat_priv: the bat priv with all the soft interface information
1108 * @skb: packet to check
1109 * @hdr_size: size of the encapsulation header
1111 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1112 struct sk_buff *skb, int hdr_size)
1115 __be32 ip_src, ip_dst;
1116 uint8_t *hw_src, *hw_dst;
1120 if (!atomic_read(&bat_priv->distributed_arp_table))
1123 vid = batadv_dat_get_vid(skb, &hdr_size);
1125 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1126 if (type != ARPOP_REPLY)
1129 batadv_dbg_arp(bat_priv, skb, type, hdr_size,
1130 "Parsing incoming ARP REPLY");
1132 hw_src = batadv_arp_hw_src(skb, hdr_size);
1133 ip_src = batadv_arp_ip_src(skb, hdr_size);
1134 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1135 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1137 /* Update our internal cache with both the IP addresses the node got
1138 * within the ARP reply
1140 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1141 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1143 /* if this REPLY is directed to a client of mine, let's deliver the
1144 * packet to the interface
1146 ret = !batadv_is_my_client(bat_priv, hw_dst, vid);
1150 /* if ret == false -> packet has to be delivered to the interface */
1155 * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
1156 * (because the node has already obtained the reply via DAT) or not
1157 * @bat_priv: the bat priv with all the soft interface information
1158 * @forw_packet: the broadcast packet
1160 * Returns true if the node can drop the packet, false otherwise.
1162 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1163 struct batadv_forw_packet *forw_packet)
1167 struct batadv_dat_entry *dat_entry = NULL;
1169 int hdr_size = sizeof(struct batadv_bcast_packet);
1172 if (!atomic_read(&bat_priv->distributed_arp_table))
1175 /* If this packet is an ARP_REQUEST and the node already has the
1176 * information that it is going to ask, then the packet can be dropped
1178 if (forw_packet->num_packets)
1181 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1183 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1184 if (type != ARPOP_REQUEST)
1187 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1188 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1189 /* check if the node already got this entry */
1191 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1192 "ARP Request for %pI4: fallback\n", &ip_dst);
1196 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1197 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1202 batadv_dat_entry_free_ref(dat_entry);