1 // SPDX-License-Identifier: GPL-2.0
7 #include "distributed-arp-table.h"
43 #include "hard-interface.h"
49 #include "translation-table.h"
88 	__be32 magic;  member
92 #define BATADV_DHCP_YIADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->yiaddr)
93 #define BATADV_DHCP_CHADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->chaddr)
98  * batadv_dat_start_timer() - initialise the DAT periodic worker
103 	queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,  in batadv_dat_start_timer()
108  * batadv_dat_entry_release() - release dat_entry from lists and queue for free
122  * batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly
131 	kref_put(&dat_entry->refcount, batadv_dat_entry_release);  in batadv_dat_entry_put()
135  * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not
142 	return batadv_has_timed_out(dat_entry->last_update,  in batadv_dat_to_purge()
147  * __batadv_dat_purge() - delete entries from the DAT local storage
166 	if (!bat_priv->dat.hash)  in __batadv_dat_purge()
169 	for (i = 0; i < bat_priv->dat.hash->size; i++) {  in __batadv_dat_purge()
170 		head = &bat_priv->dat.hash->table[i];  in __batadv_dat_purge()
171 		list_lock = &bat_priv->dat.hash->list_locks[i];  in __batadv_dat_purge()
182 			hlist_del_rcu(&dat_entry->hash_entry);  in __batadv_dat_purge()
190  * batadv_dat_purge() - periodic task that deletes old entries from the local
209  * batadv_compare_dat() - comparing function used in the local DAT hash table
224  * batadv_arp_hw_src() - extract the hw_src field from an ARP packet
225  * @skb: ARP packet
226  * @hdr_size: size of the possible header before the ARP packet
228  * Return: the value of the hw_src field in the ARP packet.
234 	addr = (u8 *)(skb->data + hdr_size);  in batadv_arp_hw_src()
241  * batadv_arp_ip_src() - extract the ip_src field from an ARP packet
242  * @skb: ARP packet
243  * @hdr_size: size of the possible header before the ARP packet
245  * Return: the value of the ip_src field in the ARP packet.
253  * batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet
254  * @skb: ARP packet
255  * @hdr_size: size of the possible header before the ARP packet
257  * Return: the value of the hw_dst field in the ARP packet.
265  * batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet
266  * @skb: ARP packet
267  * @hdr_size: size of the possible header before the ARP packet
269  * Return: the value of the ip_dst field in the ARP packet.
279  * batadv_hash_dat() - compute the hash value for an IP address
293 	key = (__force const unsigned char *)&dat->ip;  in batadv_hash_dat()
294 	for (i = 0; i < sizeof(dat->ip); i++) {  in batadv_hash_dat()
300 	vid = htons(dat->vid);  in batadv_hash_dat()
302 	for (i = 0; i < sizeof(dat->vid); i++) {  in batadv_hash_dat()
316  * batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash
330 	struct batadv_hashtable *hash = bat_priv->dat.hash;  in batadv_dat_entry_hash_find()
339 	index = batadv_hash_dat(&to_find, hash->size);  in batadv_dat_entry_hash_find()
340 	head = &hash->table[index];  in batadv_dat_entry_hash_find()
344 		if (dat_entry->ip != ip)  in batadv_dat_entry_hash_find()
347 		if (!kref_get_unless_zero(&dat_entry->refcount))  in batadv_dat_entry_hash_find()
359  * batadv_dat_entry_add() - add a new dat entry or update it if already exists
374 		if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))  in batadv_dat_entry_add()
375 			ether_addr_copy(dat_entry->mac_addr, mac_addr);  in batadv_dat_entry_add()
376 		dat_entry->last_update = jiffies;  in batadv_dat_entry_add()
379 			   &dat_entry->ip, dat_entry->mac_addr,  in batadv_dat_entry_add()
388 	dat_entry->ip = ip;  in batadv_dat_entry_add()
389 	dat_entry->vid = vid;  in batadv_dat_entry_add()
390 	ether_addr_copy(dat_entry->mac_addr, mac_addr);  in batadv_dat_entry_add()
391 	dat_entry->last_update = jiffies;  in batadv_dat_entry_add()
392 	kref_init(&dat_entry->refcount);  in batadv_dat_entry_add()
394 	kref_get(&dat_entry->refcount);  in batadv_dat_entry_add()
395 	hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,  in batadv_dat_entry_add()
397 				     &dat_entry->hash_entry);  in batadv_dat_entry_add()
406 		   &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid));  in batadv_dat_entry_add()
415  * batadv_dbg_arp() - print a debug message containing all the ARP packet
418  * @skb: ARP packet
419  * @hdr_size: size of the possible header before the ARP packet
436 		   "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",  in batadv_dbg_arp()
443 	unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;  in batadv_dbg_arp()
445 	switch (unicast_4addr_packet->u.packet_type) {  in batadv_dbg_arp()
448 			   "* encapsulated within a UNICAST packet\n");  in batadv_dbg_arp()
452 			   "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",  in batadv_dbg_arp()
453 			   unicast_4addr_packet->src);  in batadv_dbg_arp()
454 		switch (unicast_4addr_packet->subtype) {  in batadv_dbg_arp()
470 				   unicast_4addr_packet->u.packet_type);  in batadv_dbg_arp()
475 		orig_addr = bcast_pkt->orig;  in batadv_dbg_arp()
477 			   "* encapsulated within a BCAST packet (src: %pM)\n",  in batadv_dbg_arp()
482 			   "* encapsulated within an unknown packet type (0x%x)\n",  in batadv_dbg_arp()
483 			   unicast_4addr_packet->u.packet_type);  in batadv_dbg_arp()
497  * batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate
520 	if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))  in batadv_is_orig_node_eligible()
542 	    batadv_compare_eth(candidate->orig, max_orig_node->orig))  in batadv_is_orig_node_eligible()
551  * batadv_choose_next_candidate() - select the next DHT candidate
566 	struct batadv_hashtable *hash = bat_priv->orig_hash;  in batadv_choose_next_candidate()
578 	for (i = 0; i < hash->size; i++) {  in batadv_choose_next_candidate()
579 		head = &hash->table[i];  in batadv_choose_next_candidate()
584 			tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +  in batadv_choose_next_candidate()
593 			if (!kref_get_unless_zero(&orig_node->refcount))  in batadv_choose_next_candidate()
607 			   select, max_orig_node->orig, max_orig_node->dat_addr,  in batadv_choose_next_candidate()
614  * batadv_dat_select_candidates() - select the nodes which the DHT message has
635 	if (!bat_priv->orig_hash)  in batadv_dat_select_candidates()
660  * batadv_dat_forward_data() - copy and send payload to the selected candidates
665  * @packet_subtype: unicast4addr packet subtype to use
667  * This function copies the skb with pskb_copy() and is sent as a unicast packet
670  * Return: true if the packet is sent to at least one candidate, false
709 			/* count the sent packet */  in batadv_dat_forward_data()
721 			/* packet sent to a candidate: return true */  in batadv_dat_forward_data()
735  * batadv_dat_tvlv_container_update() - update the dat tvlv container after dat
743 	dat_mode = atomic_read(&bat_priv->distributed_arp_table);  in batadv_dat_tvlv_container_update()
757  * batadv_dat_status_update() - update the dat tvlv container after dat
769  * batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container
782 		clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);  in batadv_dat_tvlv_ogm_handler_v1()
784 		set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);  in batadv_dat_tvlv_ogm_handler_v1()
788  * batadv_dat_hash_free() - free the local DAT hash table
793 	if (!bat_priv->dat.hash)  in batadv_dat_hash_free()
798 	batadv_hash_destroy(bat_priv->dat.hash);  in batadv_dat_hash_free()
800 	bat_priv->dat.hash = NULL;  in batadv_dat_hash_free()
804  * batadv_dat_init() - initialise the DAT internals
811 	if (bat_priv->dat.hash)  in batadv_dat_init()
814 	bat_priv->dat.hash = batadv_hash_new(1024);  in batadv_dat_init()
816 	if (!bat_priv->dat.hash)  in batadv_dat_init()
817 		return -ENOMEM;  in batadv_dat_init()
819 	INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);  in batadv_dat_init()
830  * batadv_dat_free() - free the DAT internals
838 	cancel_delayed_work_sync(&bat_priv->dat.work);  in batadv_dat_free()
844  * batadv_dat_cache_dump_entry() - dump one entry of the DAT cache table to a
861 	hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,  in batadv_dat_cache_dump_entry()
865 		return -ENOBUFS;  in batadv_dat_cache_dump_entry()
869 	msecs = jiffies_to_msecs(jiffies - dat_entry->last_update);  in batadv_dat_cache_dump_entry()
872 			    dat_entry->ip) ||  in batadv_dat_cache_dump_entry()
874 		    dat_entry->mac_addr) ||  in batadv_dat_cache_dump_entry()
875 	    nla_put_u16(msg, BATADV_ATTR_DAT_CACHE_VID, dat_entry->vid) ||  in batadv_dat_cache_dump_entry()
878 		return -EMSGSIZE;  in batadv_dat_cache_dump_entry()
886  * batadv_dat_cache_dump_bucket() - dump one bucket of the DAT cache table to
906 	spin_lock_bh(&hash->list_locks[bucket]);  in batadv_dat_cache_dump_bucket()
907 	cb->seq = atomic_read(&hash->generation) << 1 | 1;  in batadv_dat_cache_dump_bucket()
909 	hlist_for_each_entry(dat_entry, &hash->table[bucket], hash_entry) {  in batadv_dat_cache_dump_bucket()
914 			spin_unlock_bh(&hash->list_locks[bucket]);  in batadv_dat_cache_dump_bucket()
917 			return -EMSGSIZE;  in batadv_dat_cache_dump_bucket()
923 	spin_unlock_bh(&hash->list_locks[bucket]);  in batadv_dat_cache_dump_bucket()
929  * batadv_dat_cache_dump() - dump DAT cache table to a netlink socket
938 	int portid = NETLINK_CB(cb->skb).portid;  in batadv_dat_cache_dump()
942 	int bucket = cb->args[0];  in batadv_dat_cache_dump()
943 	int idx = cb->args[1];  in batadv_dat_cache_dump()
951 	hash = bat_priv->dat.hash;  in batadv_dat_cache_dump()
954 	if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {  in batadv_dat_cache_dump()
955 		ret = -ENOENT;  in batadv_dat_cache_dump()
959 	while (bucket < hash->size) {  in batadv_dat_cache_dump()
968 	cb->args[0] = bucket;  in batadv_dat_cache_dump()
969 	cb->args[1] = idx;  in batadv_dat_cache_dump()
971 	ret = msg->len;  in batadv_dat_cache_dump()
982  * batadv_arp_get_type() - parse an ARP packet and gets the type
984  * @skb: packet to analyse
985  * @hdr_size: size of the possible header before the ARP packet in the skb
987  * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
1002 	ethhdr = (struct ethhdr *)(skb->data + hdr_size);  in batadv_arp_get_type()
1004 	if (ethhdr->h_proto != htons(ETH_P_ARP))  in batadv_arp_get_type()
1009 				    arp_hdr_len(skb->dev))))  in batadv_arp_get_type()
1012 	arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);  in batadv_arp_get_type()
1014 	/* check whether the ARP packet carries a valid IP information */  in batadv_arp_get_type()
1015 	if (arphdr->ar_hrd != htons(ARPHRD_ETHER))  in batadv_arp_get_type()
1018 	if (arphdr->ar_pro != htons(ETH_P_IP))  in batadv_arp_get_type()
1021 	if (arphdr->ar_hln != ETH_ALEN)  in batadv_arp_get_type()
1024 	if (arphdr->ar_pln != 4)  in batadv_arp_get_type()
1043 	if (arphdr->ar_op != htons(ARPOP_REQUEST)) {  in batadv_arp_get_type()
1050 	type = ntohs(arphdr->ar_op);  in batadv_arp_get_type()
1056  * batadv_dat_get_vid() - extract the VLAN identifier from skb if any
1057  * @skb: the buffer containing the packet to extract the VID from
1058  * @hdr_size: the size of the batman-adv header encapsulating the packet
1060  * Return: If the packet embedded in the skb is vlan tagged this function
1071 	 * If the header contained in the packet is a VLAN one (which is longer)  in batadv_dat_get_vid()
1082  * batadv_dat_arp_create_reply() - create an ARP Reply
1102 	skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface,  in batadv_dat_arp_create_reply()
1117  * batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to
1120  * @skb: packet to check
1135 	struct net_device *soft_iface = bat_priv->soft_iface;  in batadv_dat_snoop_outgoing_arp_request()
1139 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_outgoing_arp_request()
1163 		 * duplicate packet.  in batadv_dat_snoop_outgoing_arp_request()
1165 		 * Moreover, if the soft-interface is enslaved into a bridge, an  in batadv_dat_snoop_outgoing_arp_request()
1167 		 * a packet coming from the wrong port.  in batadv_dat_snoop_outgoing_arp_request()
1169 		if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {  in batadv_dat_snoop_outgoing_arp_request()
1180 					    dat_entry->mac_addr, vid)) {  in batadv_dat_snoop_outgoing_arp_request()
1183 				   dat_entry->mac_addr);  in batadv_dat_snoop_outgoing_arp_request()
1189 						      dat_entry->mac_addr,  in batadv_dat_snoop_outgoing_arp_request()
1194 		skb_new->protocol = eth_type_trans(skb_new, soft_iface);  in batadv_dat_snoop_outgoing_arp_request()
1198 				   skb->len + ETH_HLEN + hdr_size);  in batadv_dat_snoop_outgoing_arp_request()
1214  * batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to
1217  * @skb: packet to check
1234 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_incoming_arp_request()
1256 					      dat_entry->mac_addr, hw_src, vid);  in batadv_dat_snoop_incoming_arp_request()
1261 	 * format based on the incoming request packet type. The assumption is  in batadv_dat_snoop_incoming_arp_request()
1262 	 * that a node not using the 4addr packet format doesn't support it.  in batadv_dat_snoop_incoming_arp_request()
1283  * batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT
1285  * @skb: packet to check
1296 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_outgoing_arp_reply()
1325  * batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the
1328  * @skb: packet to check
1331  * Return: true if the packet was snooped and consumed by DAT. False if the
1332  * packet has to be delivered to the interface
1344 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_incoming_arp_reply()
1367 	if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) {  in batadv_dat_snoop_incoming_arp_reply()
1368 … bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI…  in batadv_dat_snoop_incoming_arp_reply()
1370 			   dat_entry->mac_addr,	&dat_entry->ip);  in batadv_dat_snoop_incoming_arp_reply()
1398 	 * packet to the interface  in batadv_dat_snoop_incoming_arp_reply()
1403 	 * packet because the client will reply by itself  in batadv_dat_snoop_incoming_arp_reply()
1410 	/* if dropped == false -> deliver to the interface */  in batadv_dat_snoop_incoming_arp_reply()
1415  * batadv_dat_check_dhcp_ipudp() - check skb for IP+UDP headers valid for DHCP
1416  * @skb: the packet to check
1433 	if (!iphdr || iphdr->version != 4 || iphdr->ihl * 4 < sizeof(_iphdr))  in batadv_dat_check_dhcp_ipudp()
1436 	if (iphdr->protocol != IPPROTO_UDP)  in batadv_dat_check_dhcp_ipudp()
1439 	offset += iphdr->ihl * 4;  in batadv_dat_check_dhcp_ipudp()
1443 	if (!udphdr || udphdr->source != htons(67))  in batadv_dat_check_dhcp_ipudp()
1446 	*ip_src = get_unaligned(&iphdr->saddr);  in batadv_dat_check_dhcp_ipudp()
1452  * batadv_dat_check_dhcp() - examine packet for valid DHCP message
1453  * @skb: the packet to check
1457  * Checks whether the given skb is a valid DHCP packet. And if so, stores the
1462  * Return: If skb is a valid DHCP packet, then returns its op code
1463  * (e.g. BOOTREPLY vs. BOOTREQUEST). Otherwise returns -EINVAL.
1468 	__be32 *magic, _magic;  in batadv_dat_check_dhcp()  local
1478 		return -EINVAL;  in batadv_dat_check_dhcp()
1481 		return -EINVAL;  in batadv_dat_check_dhcp()
1484 	if (skb->len < offset + sizeof(struct batadv_dhcp_packet))  in batadv_dat_check_dhcp()
1485 		return -EINVAL;  in batadv_dat_check_dhcp()
1488 	if (!dhcp_h || dhcp_h->htype != BATADV_HTYPE_ETHERNET ||  in batadv_dat_check_dhcp()
1489 	    dhcp_h->hlen != ETH_ALEN)  in batadv_dat_check_dhcp()
1490 		return -EINVAL;  in batadv_dat_check_dhcp()
1492 	offset += offsetof(struct batadv_dhcp_packet, magic);  in batadv_dat_check_dhcp()
1494 	magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic);  in batadv_dat_check_dhcp()
1495 	if (!magic || get_unaligned(magic) != htonl(BATADV_DHCP_MAGIC))  in batadv_dat_check_dhcp()
1496 		return -EINVAL;  in batadv_dat_check_dhcp()
1498 	return dhcp_h->op;  in batadv_dat_check_dhcp()
1502  * batadv_dat_get_dhcp_message_type() - get message type of a DHCP packet
1503  * @skb: the DHCP packet to parse
1505  * Iterates over the DHCP options of the given DHCP packet to find a
1508  * Caller needs to ensure that the given skb is a valid DHCP packet and
1511  * Return: The found DHCP message type value, if found. -EINVAL otherwise.
1525 		if (tl->type == BATADV_DHCP_OPT_MSG_TYPE)  in batadv_dat_get_dhcp_message_type()
1528 		if (tl->type == BATADV_DHCP_OPT_END)  in batadv_dat_get_dhcp_message_type()
1531 		if (tl->type == BATADV_DHCP_OPT_PAD)  in batadv_dat_get_dhcp_message_type()
1534 			offset += tl->len + sizeof(_tl);  in batadv_dat_get_dhcp_message_type()
1538 	if (!tl || tl->type != BATADV_DHCP_OPT_MSG_TYPE ||  in batadv_dat_get_dhcp_message_type()
1539 	    tl->len != sizeof(_type))  in batadv_dat_get_dhcp_message_type()
1540 		return -EINVAL;  in batadv_dat_get_dhcp_message_type()
1546 		return -EINVAL;  in batadv_dat_get_dhcp_message_type()
1552  * batadv_dat_dhcp_get_yiaddr() - get yiaddr from a DHCP packet
1553  * @skb: the DHCP packet to parse
1556  * Caller needs to ensure that the given skb is a valid DHCP packet and
1579  * batadv_dat_get_dhcp_chaddr() - get chaddr from a DHCP packet
1580  * @skb: the DHCP packet to parse
1583  * Caller needs to ensure that the given skb is a valid DHCP packet and
1606  * batadv_dat_put_dhcp() - puts addresses from a DHCP packet into the DHT and
1653  * batadv_dat_check_dhcp_ack() - examine packet for valid DHCP message
1654  * @skb: the packet to check
1692  * batadv_dat_snoop_outgoing_dhcp_ack() - snoop DHCPACK and fill DAT with it
1694  * @skb: the packet to snoop
1714 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_outgoing_dhcp_ack()
1720 	batadv_dat_put_dhcp(bat_priv, chaddr, yiaddr, eth_hdr(skb)->h_source,  in batadv_dat_snoop_outgoing_dhcp_ack()
1725  * batadv_dat_snoop_incoming_dhcp_ack() - snoop DHCPACK and fill DAT cache
1727  * @skb: the packet to snoop
1728  * @hdr_size: header size, up to the tail of the batman-adv header
1744 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_snoop_incoming_dhcp_ack()
1750 	ethhdr = (struct ethhdr *)(skb->data + hdr_size);  in batadv_dat_snoop_incoming_dhcp_ack()
1752 	proto = ethhdr->h_proto;  in batadv_dat_snoop_incoming_dhcp_ack()
1757 	hw_src = ethhdr->h_source;  in batadv_dat_snoop_incoming_dhcp_ack()
1772  * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be
1775  * @forw_packet: the broadcast packet
1777  * Return: true if the node can drop the packet, false otherwise.
1789 	if (!atomic_read(&bat_priv->distributed_arp_table))  in batadv_dat_drop_broadcast_packet()
1792 	/* If this packet is an ARP_REQUEST and the node already has the  in batadv_dat_drop_broadcast_packet()
1793 	 * information that it is going to ask, then the packet can be dropped  in batadv_dat_drop_broadcast_packet()
1798 	vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);  in batadv_dat_drop_broadcast_packet()
1800 	type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);  in batadv_dat_drop_broadcast_packet()
1804 	ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);  in batadv_dat_drop_broadcast_packet()