1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
7 #include "distributed-arp-table.h"
10 #include <asm/unaligned.h>
11 #include <linux/atomic.h>
12 #include <linux/bitops.h>
13 #include <linux/byteorder/generic.h>
14 #include <linux/errno.h>
15 #include <linux/etherdevice.h>
16 #include <linux/gfp.h>
17 #include <linux/if_arp.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_vlan.h>
22 #include <linux/jiffies.h>
23 #include <linux/kernel.h>
24 #include <linux/kref.h>
25 #include <linux/list.h>
26 #include <linux/netlink.h>
27 #include <linux/rculist.h>
28 #include <linux/rcupdate.h>
29 #include <linux/skbuff.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/stddef.h>
33 #include <linux/string.h>
34 #include <linux/udp.h>
35 #include <linux/workqueue.h>
37 #include <net/genetlink.h>
38 #include <net/netlink.h>
40 #include <uapi/linux/batman_adv.h>
42 #include "bridge_loop_avoidance.h"
43 #include "hard-interface.h"
47 #include "originator.h"
49 #include "soft-interface.h"
50 #include "translation-table.h"
57 enum batadv_boothtype {
58 BATADV_HTYPE_ETHERNET = 1,
61 enum batadv_dhcpoptioncode {
62 BATADV_DHCP_OPT_PAD = 0,
63 BATADV_DHCP_OPT_MSG_TYPE = 53,
64 BATADV_DHCP_OPT_END = 255,
67 enum batadv_dhcptype {
71 /* { 99, 130, 83, 99 } */
72 #define BATADV_DHCP_MAGIC 1669485411
74 struct batadv_dhcp_packet {
93 #define BATADV_DHCP_YIADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->yiaddr)
94 #define BATADV_DHCP_CHADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->chaddr)
96 static void batadv_dat_purge(struct work_struct *work);
99 * batadv_dat_start_timer() - initialise the DAT periodic worker
100 * @bat_priv: the bat priv with all the soft interface information
102 static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
104 INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
105 queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
106 msecs_to_jiffies(10000));
110 * batadv_dat_entry_release() - release dat_entry from lists and queue for free
111 * after rcu grace period
112 * @ref: kref pointer of the dat_entry
114 static void batadv_dat_entry_release(struct kref *ref)
116 struct batadv_dat_entry *dat_entry;
118 dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
120 kfree_rcu(dat_entry, rcu);
124 * batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly
126 * @dat_entry: dat_entry to be free'd
128 static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry)
130 kref_put(&dat_entry->refcount, batadv_dat_entry_release);
134 * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not
135 * @dat_entry: the entry to check
137 * Return: true if the entry has to be purged now, false otherwise.
139 static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
141 return batadv_has_timed_out(dat_entry->last_update,
142 BATADV_DAT_ENTRY_TIMEOUT);
146 * __batadv_dat_purge() - delete entries from the DAT local storage
147 * @bat_priv: the bat priv with all the soft interface information
148 * @to_purge: function in charge to decide whether an entry has to be purged or
149 * not. This function takes the dat_entry as argument and has to
150 * returns a boolean value: true is the entry has to be deleted,
153 * Loops over each entry in the DAT local storage and deletes it if and only if
154 * the to_purge function passed as argument returns true.
156 static void __batadv_dat_purge(struct batadv_priv *bat_priv,
157 bool (*to_purge)(struct batadv_dat_entry *))
159 spinlock_t *list_lock; /* protects write access to the hash lists */
160 struct batadv_dat_entry *dat_entry;
161 struct hlist_node *node_tmp;
162 struct hlist_head *head;
165 if (!bat_priv->dat.hash)
168 for (i = 0; i < bat_priv->dat.hash->size; i++) {
169 head = &bat_priv->dat.hash->table[i];
170 list_lock = &bat_priv->dat.hash->list_locks[i];
172 spin_lock_bh(list_lock);
173 hlist_for_each_entry_safe(dat_entry, node_tmp, head,
175 /* if a helper function has been passed as parameter,
176 * ask it if the entry has to be purged or not
178 if (to_purge && !to_purge(dat_entry))
181 hlist_del_rcu(&dat_entry->hash_entry);
182 batadv_dat_entry_put(dat_entry);
184 spin_unlock_bh(list_lock);
189 * batadv_dat_purge() - periodic task that deletes old entries from the local
191 * @work: kernel work struct
193 static void batadv_dat_purge(struct work_struct *work)
195 struct delayed_work *delayed_work;
196 struct batadv_priv_dat *priv_dat;
197 struct batadv_priv *bat_priv;
199 delayed_work = to_delayed_work(work);
200 priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
201 bat_priv = container_of(priv_dat, struct batadv_priv, dat);
203 __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
204 batadv_dat_start_timer(bat_priv);
208 * batadv_compare_dat() - comparing function used in the local DAT hash table
209 * @node: node in the local table
210 * @data2: second object to compare the node to
212 * Return: true if the two entries are the same, false otherwise.
214 static bool batadv_compare_dat(const struct hlist_node *node, const void *data2)
216 const void *data1 = container_of(node, struct batadv_dat_entry,
219 return memcmp(data1, data2, sizeof(__be32)) == 0;
223 * batadv_arp_hw_src() - extract the hw_src field from an ARP packet
225 * @hdr_size: size of the possible header before the ARP packet
227 * Return: the value of the hw_src field in the ARP packet.
229 static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
233 addr = (u8 *)(skb->data + hdr_size);
234 addr += ETH_HLEN + sizeof(struct arphdr);
240 * batadv_arp_ip_src() - extract the ip_src field from an ARP packet
242 * @hdr_size: size of the possible header before the ARP packet
244 * Return: the value of the ip_src field in the ARP packet.
246 static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
248 return *(__force __be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
252 * batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet
254 * @hdr_size: size of the possible header before the ARP packet
256 * Return: the value of the hw_dst field in the ARP packet.
258 static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
260 return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
264 * batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet
266 * @hdr_size: size of the possible header before the ARP packet
268 * Return: the value of the ip_dst field in the ARP packet.
270 static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
272 u8 *dst = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4;
274 return *(__force __be32 *)dst;
278 * batadv_hash_dat() - compute the hash value for an IP address
279 * @data: data to hash
280 * @size: size of the hash table
282 * Return: the selected index in the hash table for the given data.
284 static u32 batadv_hash_dat(const void *data, u32 size)
287 const struct batadv_dat_entry *dat = data;
288 const unsigned char *key;
292 key = (__force const unsigned char *)&dat->ip;
293 for (i = 0; i < sizeof(dat->ip); i++) {
295 hash += (hash << 10);
299 vid = htons(dat->vid);
300 key = (__force const unsigned char *)&vid;
301 for (i = 0; i < sizeof(dat->vid); i++) {
303 hash += (hash << 10);
308 hash ^= (hash >> 11);
309 hash += (hash << 15);
315 * batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash
317 * @bat_priv: the bat priv with all the soft interface information
319 * @vid: VLAN identifier
321 * Return: the dat_entry if found, NULL otherwise.
323 static struct batadv_dat_entry *
324 batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
327 struct hlist_head *head;
328 struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
329 struct batadv_hashtable *hash = bat_priv->dat.hash;
338 index = batadv_hash_dat(&to_find, hash->size);
339 head = &hash->table[index];
342 hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
343 if (dat_entry->ip != ip)
346 if (!kref_get_unless_zero(&dat_entry->refcount))
349 dat_entry_tmp = dat_entry;
354 return dat_entry_tmp;
358 * batadv_dat_entry_add() - add a new dat entry or update it if already exists
359 * @bat_priv: the bat priv with all the soft interface information
360 * @ip: ipv4 to add/edit
361 * @mac_addr: mac address to assign to the given ipv4
362 * @vid: VLAN identifier
364 static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
365 u8 *mac_addr, unsigned short vid)
367 struct batadv_dat_entry *dat_entry;
370 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
371 /* if this entry is already known, just update it */
373 if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
374 ether_addr_copy(dat_entry->mac_addr, mac_addr);
375 dat_entry->last_update = jiffies;
376 batadv_dbg(BATADV_DBG_DAT, bat_priv,
377 "Entry updated: %pI4 %pM (vid: %d)\n",
378 &dat_entry->ip, dat_entry->mac_addr,
379 batadv_print_vid(vid));
383 dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
388 dat_entry->vid = vid;
389 ether_addr_copy(dat_entry->mac_addr, mac_addr);
390 dat_entry->last_update = jiffies;
391 kref_init(&dat_entry->refcount);
393 kref_get(&dat_entry->refcount);
394 hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
395 batadv_hash_dat, dat_entry,
396 &dat_entry->hash_entry);
398 if (unlikely(hash_added != 0)) {
399 /* remove the reference for the hash */
400 batadv_dat_entry_put(dat_entry);
404 batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
405 &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid));
409 batadv_dat_entry_put(dat_entry);
412 #ifdef CONFIG_BATMAN_ADV_DEBUG
415 * batadv_dbg_arp() - print a debug message containing all the ARP packet
417 * @bat_priv: the bat priv with all the soft interface information
419 * @hdr_size: size of the possible header before the ARP packet
420 * @msg: message to print together with the debugging information
422 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
423 int hdr_size, char *msg)
425 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
426 struct batadv_bcast_packet *bcast_pkt;
428 __be32 ip_src, ip_dst;
431 batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
433 ip_src = batadv_arp_ip_src(skb, hdr_size);
434 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
435 batadv_dbg(BATADV_DBG_DAT, bat_priv,
436 "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
437 batadv_arp_hw_src(skb, hdr_size), &ip_src,
438 batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
440 if (hdr_size < sizeof(struct batadv_unicast_packet))
443 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
445 switch (unicast_4addr_packet->u.packet_type) {
447 batadv_dbg(BATADV_DBG_DAT, bat_priv,
448 "* encapsulated within a UNICAST packet\n");
450 case BATADV_UNICAST_4ADDR:
451 batadv_dbg(BATADV_DBG_DAT, bat_priv,
452 "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
453 unicast_4addr_packet->src);
454 switch (unicast_4addr_packet->subtype) {
455 case BATADV_P_DAT_DHT_PUT:
456 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
458 case BATADV_P_DAT_DHT_GET:
459 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
461 case BATADV_P_DAT_CACHE_REPLY:
462 batadv_dbg(BATADV_DBG_DAT, bat_priv,
463 "* type: DAT_CACHE_REPLY\n");
466 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
469 batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
470 unicast_4addr_packet->u.packet_type);
474 bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
475 orig_addr = bcast_pkt->orig;
476 batadv_dbg(BATADV_DBG_DAT, bat_priv,
477 "* encapsulated within a BCAST packet (src: %pM)\n",
481 batadv_dbg(BATADV_DBG_DAT, bat_priv,
482 "* encapsulated within an unknown packet type (0x%x)\n",
483 unicast_4addr_packet->u.packet_type);
489 static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
490 int hdr_size, char *msg)
494 #endif /* CONFIG_BATMAN_ADV_DEBUG */
497 * batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate
498 * @res: the array with the already selected candidates
499 * @select: number of already selected candidates
500 * @tmp_max: address of the currently evaluated node
501 * @max: current round max address
502 * @last_max: address of the last selected candidate
503 * @candidate: orig_node under evaluation
504 * @max_orig_node: last selected candidate
506 * Return: true if the node has been elected as next candidate or false
509 static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
510 int select, batadv_dat_addr_t tmp_max,
511 batadv_dat_addr_t max,
512 batadv_dat_addr_t last_max,
513 struct batadv_orig_node *candidate,
514 struct batadv_orig_node *max_orig_node)
519 /* check if orig node candidate is running DAT */
520 if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
523 /* Check if this node has already been selected... */
524 for (j = 0; j < select; j++)
525 if (res[j].orig_node == candidate)
527 /* ..and possibly skip it */
530 /* sanity check: has it already been selected? This should not happen */
531 if (tmp_max > last_max)
533 /* check if during this iteration an originator with a closer dht
534 * address has already been found
538 /* this is an hash collision with the temporary selected node. Choose
539 * the one with the lowest address
541 if (tmp_max == max && max_orig_node &&
542 batadv_compare_eth(candidate->orig, max_orig_node->orig))
551 * batadv_choose_next_candidate() - select the next DHT candidate
552 * @bat_priv: the bat priv with all the soft interface information
553 * @cands: candidates array
554 * @select: number of candidates already present in the array
555 * @ip_key: key to look up in the DHT
556 * @last_max: pointer where the address of the selected candidate will be saved
558 static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
559 struct batadv_dat_candidate *cands,
560 int select, batadv_dat_addr_t ip_key,
561 batadv_dat_addr_t *last_max)
563 batadv_dat_addr_t max = 0;
564 batadv_dat_addr_t tmp_max = 0;
565 struct batadv_orig_node *orig_node, *max_orig_node = NULL;
566 struct batadv_hashtable *hash = bat_priv->orig_hash;
567 struct hlist_head *head;
570 /* if no node is eligible as candidate, leave the candidate type as
573 cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
575 /* iterate over the originator list and find the node with the closest
576 * dat_address which has not been selected yet
578 for (i = 0; i < hash->size; i++) {
579 head = &hash->table[i];
582 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
583 /* the dht space is a ring using unsigned addresses */
584 tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
587 if (!batadv_is_orig_node_eligible(cands, select,
589 *last_max, orig_node,
593 if (!kref_get_unless_zero(&orig_node->refcount))
598 batadv_orig_node_put(max_orig_node);
599 max_orig_node = orig_node;
604 cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
605 cands[select].orig_node = max_orig_node;
606 batadv_dbg(BATADV_DBG_DAT, bat_priv,
607 "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
608 select, max_orig_node->orig, max_orig_node->dat_addr,
615 * batadv_dat_select_candidates() - select the nodes which the DHT message has
617 * @bat_priv: the bat priv with all the soft interface information
618 * @ip_dst: ipv4 to look up in the DHT
619 * @vid: VLAN identifier
621 * An originator O is selected if and only if its DHT_ID value is one of three
622 * closest values (from the LEFT, with wrap around if needed) then the hash
623 * value of the key. ip_dst is the key.
625 * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM.
627 static struct batadv_dat_candidate *
628 batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst,
632 batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
633 struct batadv_dat_candidate *res;
634 struct batadv_dat_entry dat;
636 if (!bat_priv->orig_hash)
639 res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
646 ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
647 BATADV_DAT_ADDR_MAX);
649 batadv_dbg(BATADV_DBG_DAT, bat_priv,
650 "%s(): IP=%pI4 hash(IP)=%u\n", __func__, &ip_dst,
653 for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
654 batadv_choose_next_candidate(bat_priv, res, select, ip_key,
661 * batadv_dat_forward_data() - copy and send payload to the selected candidates
662 * @bat_priv: the bat priv with all the soft interface information
663 * @skb: payload to send
665 * @vid: VLAN identifier
666 * @packet_subtype: unicast4addr packet subtype to use
668 * This function copies the skb with pskb_copy() and is sent as a unicast packet
669 * to each of the selected candidates.
671 * Return: true if the packet is sent to at least one candidate, false
674 static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,
675 struct sk_buff *skb, __be32 ip,
676 unsigned short vid, int packet_subtype)
681 struct batadv_neigh_node *neigh_node = NULL;
682 struct sk_buff *tmp_skb;
683 struct batadv_dat_candidate *cand;
685 cand = batadv_dat_select_candidates(bat_priv, ip, vid);
689 batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
691 for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
692 if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
695 neigh_node = batadv_orig_router_get(cand[i].orig_node,
700 tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
701 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
708 send_status = batadv_send_unicast_skb(tmp_skb, neigh_node);
709 if (send_status == NET_XMIT_SUCCESS) {
710 /* count the sent packet */
711 switch (packet_subtype) {
712 case BATADV_P_DAT_DHT_GET:
713 batadv_inc_counter(bat_priv,
714 BATADV_CNT_DAT_GET_TX);
716 case BATADV_P_DAT_DHT_PUT:
717 batadv_inc_counter(bat_priv,
718 BATADV_CNT_DAT_PUT_TX);
722 /* packet sent to a candidate: return true */
726 batadv_neigh_node_put(neigh_node);
728 batadv_orig_node_put(cand[i].orig_node);
737 * batadv_dat_tvlv_container_update() - update the dat tvlv container after dat
739 * @bat_priv: the bat priv with all the soft interface information
741 static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
745 dat_mode = atomic_read(&bat_priv->distributed_arp_table);
749 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
752 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
759 * batadv_dat_status_update() - update the dat tvlv container after dat
761 * @net_dev: the soft interface net device
763 void batadv_dat_status_update(struct net_device *net_dev)
765 struct batadv_priv *bat_priv = netdev_priv(net_dev);
767 batadv_dat_tvlv_container_update(bat_priv);
771 * batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container
772 * @bat_priv: the bat priv with all the soft interface information
773 * @orig: the orig_node of the ogm
774 * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
775 * @tvlv_value: tvlv buffer containing the gateway data
776 * @tvlv_value_len: tvlv buffer length
778 static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
779 struct batadv_orig_node *orig,
781 void *tvlv_value, u16 tvlv_value_len)
783 if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
784 clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
786 set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
790 * batadv_dat_hash_free() - free the local DAT hash table
791 * @bat_priv: the bat priv with all the soft interface information
793 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
795 if (!bat_priv->dat.hash)
798 __batadv_dat_purge(bat_priv, NULL);
800 batadv_hash_destroy(bat_priv->dat.hash);
802 bat_priv->dat.hash = NULL;
806 * batadv_dat_init() - initialise the DAT internals
807 * @bat_priv: the bat priv with all the soft interface information
809 * Return: 0 in case of success, a negative error code otherwise
811 int batadv_dat_init(struct batadv_priv *bat_priv)
813 if (bat_priv->dat.hash)
816 bat_priv->dat.hash = batadv_hash_new(1024);
818 if (!bat_priv->dat.hash)
821 batadv_dat_start_timer(bat_priv);
823 batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
824 NULL, BATADV_TVLV_DAT, 1,
825 BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
826 batadv_dat_tvlv_container_update(bat_priv);
831 * batadv_dat_free() - free the DAT internals
832 * @bat_priv: the bat priv with all the soft interface information
834 void batadv_dat_free(struct batadv_priv *bat_priv)
836 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
837 batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
839 cancel_delayed_work_sync(&bat_priv->dat.work);
841 batadv_dat_hash_free(bat_priv);
845 * batadv_dat_cache_dump_entry() - dump one entry of the DAT cache table to a
847 * @msg: buffer for the message
848 * @portid: netlink port
849 * @cb: Control block containing additional options
850 * @dat_entry: entry to dump
852 * Return: 0 or error code.
855 batadv_dat_cache_dump_entry(struct sk_buff *msg, u32 portid,
856 struct netlink_callback *cb,
857 struct batadv_dat_entry *dat_entry)
862 hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
863 &batadv_netlink_family, NLM_F_MULTI,
864 BATADV_CMD_GET_DAT_CACHE);
868 genl_dump_check_consistent(cb, hdr);
870 msecs = jiffies_to_msecs(jiffies - dat_entry->last_update);
872 if (nla_put_in_addr(msg, BATADV_ATTR_DAT_CACHE_IP4ADDRESS,
874 nla_put(msg, BATADV_ATTR_DAT_CACHE_HWADDRESS, ETH_ALEN,
875 dat_entry->mac_addr) ||
876 nla_put_u16(msg, BATADV_ATTR_DAT_CACHE_VID, dat_entry->vid) ||
877 nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) {
878 genlmsg_cancel(msg, hdr);
882 genlmsg_end(msg, hdr);
887 * batadv_dat_cache_dump_bucket() - dump one bucket of the DAT cache table to
889 * @msg: buffer for the message
890 * @portid: netlink port
891 * @cb: Control block containing additional options
892 * @hash: hash to dump
893 * @bucket: bucket index to dump
894 * @idx_skip: How many entries to skip
896 * Return: 0 or error code.
899 batadv_dat_cache_dump_bucket(struct sk_buff *msg, u32 portid,
900 struct netlink_callback *cb,
901 struct batadv_hashtable *hash, unsigned int bucket,
904 struct batadv_dat_entry *dat_entry;
907 spin_lock_bh(&hash->list_locks[bucket]);
908 cb->seq = atomic_read(&hash->generation) << 1 | 1;
910 hlist_for_each_entry(dat_entry, &hash->table[bucket], hash_entry) {
914 if (batadv_dat_cache_dump_entry(msg, portid, cb, dat_entry)) {
915 spin_unlock_bh(&hash->list_locks[bucket]);
924 spin_unlock_bh(&hash->list_locks[bucket]);
930 * batadv_dat_cache_dump() - dump DAT cache table to a netlink socket
931 * @msg: buffer for the message
932 * @cb: callback structure containing arguments
934 * Return: message length.
936 int batadv_dat_cache_dump(struct sk_buff *msg, struct netlink_callback *cb)
938 struct batadv_hard_iface *primary_if = NULL;
939 int portid = NETLINK_CB(cb->skb).portid;
940 struct net *net = sock_net(cb->skb->sk);
941 struct net_device *soft_iface;
942 struct batadv_hashtable *hash;
943 struct batadv_priv *bat_priv;
944 int bucket = cb->args[0];
945 int idx = cb->args[1];
949 ifindex = batadv_netlink_get_ifindex(cb->nlh,
950 BATADV_ATTR_MESH_IFINDEX);
954 soft_iface = dev_get_by_index(net, ifindex);
955 if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
960 bat_priv = netdev_priv(soft_iface);
961 hash = bat_priv->dat.hash;
963 primary_if = batadv_primary_if_get_selected(bat_priv);
964 if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
969 while (bucket < hash->size) {
970 if (batadv_dat_cache_dump_bucket(msg, portid, cb, hash, bucket,
978 cb->args[0] = bucket;
985 batadv_hardif_put(primary_if);
994 * batadv_arp_get_type() - parse an ARP packet and gets the type
995 * @bat_priv: the bat priv with all the soft interface information
996 * @skb: packet to analyse
997 * @hdr_size: size of the possible header before the ARP packet in the skb
999 * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
1001 static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
1002 struct sk_buff *skb, int hdr_size)
1004 struct arphdr *arphdr;
1005 struct ethhdr *ethhdr;
1006 __be32 ip_src, ip_dst;
1007 u8 *hw_src, *hw_dst;
1010 /* pull the ethernet header */
1011 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
1014 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
1016 if (ethhdr->h_proto != htons(ETH_P_ARP))
1019 /* pull the ARP payload */
1020 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
1021 arp_hdr_len(skb->dev))))
1024 arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
1026 /* check whether the ARP packet carries a valid IP information */
1027 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1030 if (arphdr->ar_pro != htons(ETH_P_IP))
1033 if (arphdr->ar_hln != ETH_ALEN)
1036 if (arphdr->ar_pln != 4)
1039 /* Check for bad reply/request. If the ARP message is not sane, DAT
1040 * will simply ignore it
1042 ip_src = batadv_arp_ip_src(skb, hdr_size);
1043 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1044 if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
1045 ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
1046 ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
1047 ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
1050 hw_src = batadv_arp_hw_src(skb, hdr_size);
1051 if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
1054 /* don't care about the destination MAC address in ARP requests */
1055 if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
1056 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1057 if (is_zero_ether_addr(hw_dst) ||
1058 is_multicast_ether_addr(hw_dst))
1062 type = ntohs(arphdr->ar_op);
1068 * batadv_dat_get_vid() - extract the VLAN identifier from skb if any
1069 * @skb: the buffer containing the packet to extract the VID from
1070 * @hdr_size: the size of the batman-adv header encapsulating the packet
1072 * Return: If the packet embedded in the skb is vlan tagged this function
1073 * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
1076 static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
1080 vid = batadv_get_vid(skb, *hdr_size);
1082 /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
1083 * If the header contained in the packet is a VLAN one (which is longer)
1084 * hdr_size is updated so that the functions will still skip the
1085 * correct amount of bytes.
1087 if (vid & BATADV_VLAN_HAS_TAG)
1088 *hdr_size += VLAN_HLEN;
1094 * batadv_dat_arp_create_reply() - create an ARP Reply
1095 * @bat_priv: the bat priv with all the soft interface information
1096 * @ip_src: ARP sender IP
1097 * @ip_dst: ARP target IP
1098 * @hw_src: Ethernet source and ARP sender MAC
1099 * @hw_dst: Ethernet destination and ARP target MAC
1100 * @vid: VLAN identifier (optional, set to zero otherwise)
1102 * Creates an ARP Reply from the given values, optionally encapsulated in a
1105 * Return: An skb containing an ARP Reply.
1107 static struct sk_buff *
1108 batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src,
1109 __be32 ip_dst, u8 *hw_src, u8 *hw_dst,
1112 struct sk_buff *skb;
1114 skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface,
1115 ip_src, hw_dst, hw_src, hw_dst);
1119 skb_reset_mac_header(skb);
1121 if (vid & BATADV_VLAN_HAS_TAG)
1122 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
1123 vid & VLAN_VID_MASK);
1129 * batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to
1131 * @bat_priv: the bat priv with all the soft interface information
1132 * @skb: packet to check
1134 * Return: true if the message has been sent to the dht candidates, false
1135 * otherwise. In case of a positive return value the message has to be enqueued
1136 * to permit the fallback.
1138 bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
1139 struct sk_buff *skb)
1142 __be32 ip_dst, ip_src;
1145 struct batadv_dat_entry *dat_entry = NULL;
1146 struct sk_buff *skb_new;
1147 struct net_device *soft_iface = bat_priv->soft_iface;
1151 if (!atomic_read(&bat_priv->distributed_arp_table))
1154 vid = batadv_dat_get_vid(skb, &hdr_size);
1156 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1157 /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
1158 * message to the selected DHT candidates
1160 if (type != ARPOP_REQUEST)
1163 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REQUEST");
1165 ip_src = batadv_arp_ip_src(skb, hdr_size);
1166 hw_src = batadv_arp_hw_src(skb, hdr_size);
1167 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1169 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1171 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1173 /* If the ARP request is destined for a local client the local
1174 * client will answer itself. DAT would only generate a
1177 * Moreover, if the soft-interface is enslaved into a bridge, an
1178 * additional DAT answer may trigger kernel warnings about
1179 * a packet coming from the wrong port.
1181 if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
1186 /* If BLA is enabled, only send ARP replies if we have claimed
1187 * the destination for the ARP request or if no one else of
1188 * the backbone gws belonging to our backbone has claimed the
1191 if (!batadv_bla_check_claim(bat_priv,
1192 dat_entry->mac_addr, vid)) {
1193 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1194 "Device %pM claimed by another backbone gw. Don't send ARP reply!",
1195 dat_entry->mac_addr);
1200 skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
1201 dat_entry->mac_addr,
1206 skb_new->protocol = eth_type_trans(skb_new, soft_iface);
1208 batadv_inc_counter(bat_priv, BATADV_CNT_RX);
1209 batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
1210 skb->len + ETH_HLEN + hdr_size);
1213 batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
1216 /* Send the request to the DHT */
1217 ret = batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
1218 BATADV_P_DAT_DHT_GET);
1222 batadv_dat_entry_put(dat_entry);
1227 * batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to
1228 * answer using the local DAT storage
1229 * @bat_priv: the bat priv with all the soft interface information
1230 * @skb: packet to check
1231 * @hdr_size: size of the encapsulation header
1233 * Return: true if the request has been answered, false otherwise.
1235 bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
1236 struct sk_buff *skb, int hdr_size)
1239 __be32 ip_src, ip_dst;
1241 struct sk_buff *skb_new;
1242 struct batadv_dat_entry *dat_entry = NULL;
1247 if (!atomic_read(&bat_priv->distributed_arp_table))
1250 vid = batadv_dat_get_vid(skb, &hdr_size);
1252 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1253 if (type != ARPOP_REQUEST)
1256 hw_src = batadv_arp_hw_src(skb, hdr_size);
1257 ip_src = batadv_arp_ip_src(skb, hdr_size);
1258 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1260 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST");
1262 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1264 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1268 skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
1269 dat_entry->mac_addr, hw_src, vid);
1273 /* To preserve backwards compatibility, the node has choose the outgoing
1274 * format based on the incoming request packet type. The assumption is
1275 * that a node not using the 4addr packet format doesn't support it.
1277 if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
1278 err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
1279 BATADV_P_DAT_CACHE_REPLY,
1282 err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
1284 if (err != NET_XMIT_DROP) {
1285 batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
1290 batadv_dat_entry_put(dat_entry);
1297 * batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT
1298 * @bat_priv: the bat priv with all the soft interface information
1299 * @skb: packet to check
1301 void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
1302 struct sk_buff *skb)
1305 __be32 ip_src, ip_dst;
1306 u8 *hw_src, *hw_dst;
1310 if (!atomic_read(&bat_priv->distributed_arp_table))
1313 vid = batadv_dat_get_vid(skb, &hdr_size);
1315 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1316 if (type != ARPOP_REPLY)
1319 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REPLY");
1321 hw_src = batadv_arp_hw_src(skb, hdr_size);
1322 ip_src = batadv_arp_ip_src(skb, hdr_size);
1323 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1324 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1326 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1327 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1329 /* Send the ARP reply to the candidates for both the IP addresses that
1330 * the node obtained from the ARP reply
1332 batadv_dat_forward_data(bat_priv, skb, ip_src, vid,
1333 BATADV_P_DAT_DHT_PUT);
1334 batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
1335 BATADV_P_DAT_DHT_PUT);
1339 * batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the
1340 * local DAT storage only
1341 * @bat_priv: the bat priv with all the soft interface information
1342 * @skb: packet to check
1343 * @hdr_size: size of the encapsulation header
1345 * Return: true if the packet was snooped and consumed by DAT. False if the
1346 * packet has to be delivered to the interface
1348 bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
1349 struct sk_buff *skb, int hdr_size)
1351 struct batadv_dat_entry *dat_entry = NULL;
1353 __be32 ip_src, ip_dst;
1354 u8 *hw_src, *hw_dst;
1355 bool dropped = false;
1358 if (!atomic_read(&bat_priv->distributed_arp_table))
1361 vid = batadv_dat_get_vid(skb, &hdr_size);
1363 type = batadv_arp_get_type(bat_priv, skb, hdr_size);
1364 if (type != ARPOP_REPLY)
1367 batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REPLY");
1369 hw_src = batadv_arp_hw_src(skb, hdr_size);
1370 ip_src = batadv_arp_ip_src(skb, hdr_size);
1371 hw_dst = batadv_arp_hw_dst(skb, hdr_size);
1372 ip_dst = batadv_arp_ip_dst(skb, hdr_size);
1374 /* If ip_dst is already in cache and has the right mac address,
1375 * drop this frame if this ARP reply is destined for us because it's
1376 * most probably an ARP reply generated by another node of the DHT.
1377 * We have most probably received already a reply earlier. Delivering
1378 * this frame would lead to doubled receive of an ARP reply.
1380 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid);
1381 if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) {
1382 batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n",
1383 hw_src, &ip_src, hw_dst, &ip_dst,
1384 dat_entry->mac_addr, &dat_entry->ip);
1388 /* Update our internal cache with both the IP addresses the node got
1389 * within the ARP reply
1391 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1392 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1397 /* If BLA is enabled, only forward ARP replies if we have claimed the
1398 * source of the ARP reply or if no one else of the same backbone has
1399 * already claimed that client. This prevents that different gateways
1400 * to the same backbone all forward the ARP reply leading to multiple
1401 * replies in the backbone.
1403 if (!batadv_bla_check_claim(bat_priv, hw_src, vid)) {
1404 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1405 "Device %pM claimed by another backbone gw. Drop ARP reply.\n",
1411 /* if this REPLY is directed to a client of mine, let's deliver the
1412 * packet to the interface
1414 dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
1416 /* if this REPLY is sent on behalf of a client of mine, let's drop the
1417 * packet because the client will reply by itself
1419 dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
1424 batadv_dat_entry_put(dat_entry);
1425 /* if dropped == false -> deliver to the interface */
1430 * batadv_dat_check_dhcp_ipudp() - check skb for IP+UDP headers valid for DHCP
1431 * @skb: the packet to check
1432 * @ip_src: a buffer to store the IPv4 source address in
1434 * Checks whether the given skb has an IP and UDP header valid for a DHCP
1435 * message from a DHCP server. And if so, stores the IPv4 source address in
1436 * the provided buffer.
1438 * Return: True if valid, false otherwise.
1441 batadv_dat_check_dhcp_ipudp(struct sk_buff *skb, __be32 *ip_src)
1443 unsigned int offset = skb_network_offset(skb);
1444 struct udphdr *udphdr, _udphdr;
1445 struct iphdr *iphdr, _iphdr;
1447 iphdr = skb_header_pointer(skb, offset, sizeof(_iphdr), &_iphdr);
1448 if (!iphdr || iphdr->version != 4 || iphdr->ihl * 4 < sizeof(_iphdr))
1451 if (iphdr->protocol != IPPROTO_UDP)
1454 offset += iphdr->ihl * 4;
1455 skb_set_transport_header(skb, offset);
1457 udphdr = skb_header_pointer(skb, offset, sizeof(_udphdr), &_udphdr);
1458 if (!udphdr || udphdr->source != htons(67))
1461 *ip_src = get_unaligned(&iphdr->saddr);
1467 * batadv_dat_check_dhcp() - examine packet for valid DHCP message
1468 * @skb: the packet to check
1469 * @proto: ethernet protocol hint (behind a potential vlan)
1470 * @ip_src: a buffer to store the IPv4 source address in
1472 * Checks whether the given skb is a valid DHCP packet. And if so, stores the
1473 * IPv4 source address in the provided buffer.
1475 * Caller needs to ensure that the skb network header is set correctly.
1477 * Return: If skb is a valid DHCP packet, then returns its op code
1478 * (e.g. BOOTREPLY vs. BOOTREQUEST). Otherwise returns -EINVAL.
1481 batadv_dat_check_dhcp(struct sk_buff *skb, __be16 proto, __be32 *ip_src)
1483 __be32 *magic, _magic;
1484 unsigned int offset;
1492 if (proto != htons(ETH_P_IP))
1495 if (!batadv_dat_check_dhcp_ipudp(skb, ip_src))
1498 offset = skb_transport_offset(skb) + sizeof(struct udphdr);
1499 if (skb->len < offset + sizeof(struct batadv_dhcp_packet))
1502 dhcp_h = skb_header_pointer(skb, offset, sizeof(_dhcp_h), &_dhcp_h);
1503 if (!dhcp_h || dhcp_h->htype != BATADV_HTYPE_ETHERNET ||
1504 dhcp_h->hlen != ETH_ALEN)
1507 offset += offsetof(struct batadv_dhcp_packet, magic);
1509 magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic);
1510 if (!magic || get_unaligned(magic) != htonl(BATADV_DHCP_MAGIC))
1517 * batadv_dat_get_dhcp_message_type() - get message type of a DHCP packet
1518 * @skb: the DHCP packet to parse
1520 * Iterates over the DHCP options of the given DHCP packet to find a
1521 * DHCP Message Type option and parse it.
1523 * Caller needs to ensure that the given skb is a valid DHCP packet and
1524 * that the skb transport header is set correctly.
1526 * Return: The found DHCP message type value, if found. -EINVAL otherwise.
1528 static int batadv_dat_get_dhcp_message_type(struct sk_buff *skb)
1530 unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
1537 offset += sizeof(struct batadv_dhcp_packet);
1539 while ((tl = skb_header_pointer(skb, offset, sizeof(_tl), &_tl))) {
1540 if (tl->type == BATADV_DHCP_OPT_MSG_TYPE)
1543 if (tl->type == BATADV_DHCP_OPT_END)
1546 if (tl->type == BATADV_DHCP_OPT_PAD)
1549 offset += tl->len + sizeof(_tl);
1552 /* Option Overload Code not supported */
1553 if (!tl || tl->type != BATADV_DHCP_OPT_MSG_TYPE ||
1554 tl->len != sizeof(_type))
1557 offset += sizeof(_tl);
1559 type = skb_header_pointer(skb, offset, sizeof(_type), &_type);
1567 * batadv_dat_dhcp_get_yiaddr() - get yiaddr from a DHCP packet
1568 * @skb: the DHCP packet to parse
1569 * @buf: a buffer to store the yiaddr in
1571 * Caller needs to ensure that the given skb is a valid DHCP packet and
1572 * that the skb transport header is set correctly.
1574 * Return: True on success, false otherwise.
1576 static bool batadv_dat_dhcp_get_yiaddr(struct sk_buff *skb, __be32 *buf)
1578 unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
1581 offset += offsetof(struct batadv_dhcp_packet, yiaddr);
1582 yiaddr = skb_header_pointer(skb, offset, BATADV_DHCP_YIADDR_LEN, buf);
1588 *buf = get_unaligned(yiaddr);
1594 * batadv_dat_get_dhcp_chaddr() - get chaddr from a DHCP packet
1595 * @skb: the DHCP packet to parse
1596 * @buf: a buffer to store the chaddr in
1598 * Caller needs to ensure that the given skb is a valid DHCP packet and
1599 * that the skb transport header is set correctly.
1601 * Return: True on success, false otherwise
1603 static bool batadv_dat_get_dhcp_chaddr(struct sk_buff *skb, u8 *buf)
1605 unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
1608 offset += offsetof(struct batadv_dhcp_packet, chaddr);
1609 chaddr = skb_header_pointer(skb, offset, BATADV_DHCP_CHADDR_LEN, buf);
1615 memcpy(buf, chaddr, BATADV_DHCP_CHADDR_LEN);
1621 * batadv_dat_put_dhcp() - puts addresses from a DHCP packet into the DHT and
1623 * @bat_priv: the bat priv with all the soft interface information
1624 * @chaddr: the DHCP client MAC address
1625 * @yiaddr: the DHCP client IP address
1626 * @hw_dst: the DHCP server MAC address
1627 * @ip_dst: the DHCP server IP address
1628 * @vid: VLAN identifier
1630 * Adds given MAC/IP pairs to the local DAT cache and propagates them further
1633 * For the DHT propagation, client MAC + IP will appear as the ARP Reply
1634 * transmitter (and hw_dst/ip_dst as the target).
1636 static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr,
1637 __be32 yiaddr, u8 *hw_dst, __be32 ip_dst,
1640 struct sk_buff *skb;
1642 skb = batadv_dat_arp_create_reply(bat_priv, yiaddr, ip_dst, chaddr,
1647 skb_set_network_header(skb, ETH_HLEN);
1649 batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid);
1650 batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
1652 batadv_dat_forward_data(bat_priv, skb, yiaddr, vid,
1653 BATADV_P_DAT_DHT_PUT);
1654 batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
1655 BATADV_P_DAT_DHT_PUT);
1659 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1660 "Snooped from outgoing DHCPACK (server address): %pI4, %pM (vid: %i)\n",
1661 &ip_dst, hw_dst, batadv_print_vid(vid));
1662 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1663 "Snooped from outgoing DHCPACK (client address): %pI4, %pM (vid: %i)\n",
1664 &yiaddr, chaddr, batadv_print_vid(vid));
1668 * batadv_dat_check_dhcp_ack() - examine packet for valid DHCP message
1669 * @skb: the packet to check
1670 * @proto: ethernet protocol hint (behind a potential vlan)
1671 * @ip_src: a buffer to store the IPv4 source address in
1672 * @chaddr: a buffer to store the DHCP Client Hardware Address in
1673 * @yiaddr: a buffer to store the DHCP Your IP Address in
1675 * Checks whether the given skb is a valid DHCPACK. And if so, stores the
1676 * IPv4 server source address (ip_src), client MAC address (chaddr) and client
1677 * IPv4 address (yiaddr) in the provided buffers.
1679 * Caller needs to ensure that the skb network header is set correctly.
1681 * Return: True if the skb is a valid DHCPACK. False otherwise.
1684 batadv_dat_check_dhcp_ack(struct sk_buff *skb, __be16 proto, __be32 *ip_src,
1685 u8 *chaddr, __be32 *yiaddr)
1689 type = batadv_dat_check_dhcp(skb, proto, ip_src);
1690 if (type != BATADV_BOOTREPLY)
1693 type = batadv_dat_get_dhcp_message_type(skb);
1694 if (type != BATADV_DHCPACK)
1697 if (!batadv_dat_dhcp_get_yiaddr(skb, yiaddr))
1700 if (!batadv_dat_get_dhcp_chaddr(skb, chaddr))
1707 * batadv_dat_snoop_outgoing_dhcp_ack() - snoop DHCPACK and fill DAT with it
1708 * @bat_priv: the bat priv with all the soft interface information
1709 * @skb: the packet to snoop
1710 * @proto: ethernet protocol hint (behind a potential vlan)
1711 * @vid: VLAN identifier
1713 * This function first checks whether the given skb is a valid DHCPACK. If
1714 * so then its source MAC and IP as well as its DHCP Client Hardware Address
1715 * field and DHCP Your IP Address field are added to the local DAT cache and
1716 * propagated into the DHT.
1718 * Caller needs to ensure that the skb mac and network headers are set
1721 void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv,
1722 struct sk_buff *skb,
1726 u8 chaddr[BATADV_DHCP_CHADDR_LEN];
1727 __be32 ip_src, yiaddr;
1729 if (!atomic_read(&bat_priv->distributed_arp_table))
1732 if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr))
1735 batadv_dat_put_dhcp(bat_priv, chaddr, yiaddr, eth_hdr(skb)->h_source,
1740 * batadv_dat_snoop_incoming_dhcp_ack() - snoop DHCPACK and fill DAT cache
1741 * @bat_priv: the bat priv with all the soft interface information
1742 * @skb: the packet to snoop
1743 * @hdr_size: header size, up to the tail of the batman-adv header
1745 * This function first checks whether the given skb is a valid DHCPACK. If
1746 * so then its source MAC and IP as well as its DHCP Client Hardware Address
1747 * field and DHCP Your IP Address field are added to the local DAT cache.
1749 void batadv_dat_snoop_incoming_dhcp_ack(struct batadv_priv *bat_priv,
1750 struct sk_buff *skb, int hdr_size)
1752 u8 chaddr[BATADV_DHCP_CHADDR_LEN];
1753 struct ethhdr *ethhdr;
1754 __be32 ip_src, yiaddr;
1759 if (!atomic_read(&bat_priv->distributed_arp_table))
1762 if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
1765 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
1766 skb_set_network_header(skb, hdr_size + ETH_HLEN);
1767 proto = ethhdr->h_proto;
1769 if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr))
1772 hw_src = ethhdr->h_source;
1773 vid = batadv_dat_get_vid(skb, &hdr_size);
1775 batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid);
1776 batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
1778 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1779 "Snooped from incoming DHCPACK (server address): %pI4, %pM (vid: %i)\n",
1780 &ip_src, hw_src, batadv_print_vid(vid));
1781 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1782 "Snooped from incoming DHCPACK (client address): %pI4, %pM (vid: %i)\n",
1783 &yiaddr, chaddr, batadv_print_vid(vid));
1787 * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be
1788 * dropped (because the node has already obtained the reply via DAT) or not
1789 * @bat_priv: the bat priv with all the soft interface information
1790 * @forw_packet: the broadcast packet
1792 * Return: true if the node can drop the packet, false otherwise.
1794 bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
1795 struct batadv_forw_packet *forw_packet)
1799 struct batadv_dat_entry *dat_entry = NULL;
1801 int hdr_size = sizeof(struct batadv_bcast_packet);
1804 if (!atomic_read(&bat_priv->distributed_arp_table))
1807 /* If this packet is an ARP_REQUEST and the node already has the
1808 * information that it is going to ask, then the packet can be dropped
1810 if (batadv_forw_packet_is_rebroadcast(forw_packet))
1813 vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
1815 type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
1816 if (type != ARPOP_REQUEST)
1819 ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
1820 dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
1821 /* check if the node already got this entry */
1823 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1824 "ARP Request for %pI4: fallback\n", &ip_dst);
1828 batadv_dbg(BATADV_DBG_DAT, bat_priv,
1829 "ARP Request for %pI4: fallback prevented\n", &ip_dst);
1834 batadv_dat_entry_put(dat_entry);