--- /dev/null
+/* Copyright (C) 2011-2014 B.A.T.M.A.N. contributors:
+ *
+ * Antonio Quartulli
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <linux/if_vlan.h>
+#include <net/arp.h>
+
+#include "main.h"
+#include "hash.h"
+#include "distributed-arp-table.h"
+#include "hard-interface.h"
+#include "originator.h"
+#include "send.h"
+#include "types.h"
+#include "translation-table.h"
+
+static void batadv_dat_purge(struct work_struct *work);
+
+/**
+ * batadv_dat_start_timer - initialise the DAT periodic worker
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
+{
+ INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
+ queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
+ msecs_to_jiffies(10000));
+}
+
+/**
+ * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly
+ * free it
+ * @dat_entry: the entry to free
+ */
+static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
+{
+ if (atomic_dec_and_test(&dat_entry->refcount))
+ kfree_rcu(dat_entry, rcu);
+}
+
+/**
+ * batadv_dat_to_purge - check whether a dat_entry has to be purged or not
+ * @dat_entry: the entry to check
+ *
+ * Returns true if the entry has to be purged now, false otherwise.
+ */
+static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
+{
+ return batadv_has_timed_out(dat_entry->last_update,
+ BATADV_DAT_ENTRY_TIMEOUT);
+}
+
+/**
+ * __batadv_dat_purge - delete entries from the DAT local storage
+ * @bat_priv: the bat priv with all the soft interface information
+ * @to_purge: function in charge to decide whether an entry has to be purged or
+ * not. This function takes the dat_entry as argument and has to
+ * returns a boolean value: true is the entry has to be deleted,
+ * false otherwise
+ *
+ * Loops over each entry in the DAT local storage and deletes it if and only if
+ * the to_purge function passed as argument returns true.
+ */
+static void __batadv_dat_purge(struct batadv_priv *bat_priv,
+ bool (*to_purge)(struct batadv_dat_entry *))
+{
+ spinlock_t *list_lock; /* protects write access to the hash lists */
+ struct batadv_dat_entry *dat_entry;
+ struct hlist_node *node_tmp;
+ struct hlist_head *head;
+ uint32_t i;
+
+ if (!bat_priv->dat.hash)
+ return;
+
+ for (i = 0; i < bat_priv->dat.hash->size; i++) {
+ head = &bat_priv->dat.hash->table[i];
+ list_lock = &bat_priv->dat.hash->list_locks[i];
+
+ spin_lock_bh(list_lock);
+ hlist_for_each_entry_safe(dat_entry, node_tmp, head,
+ hash_entry) {
+ /* if a helper function has been passed as parameter,
+ * ask it if the entry has to be purged or not
+ */
+ if (to_purge && !to_purge(dat_entry))
+ continue;
+
+ hlist_del_rcu(&dat_entry->hash_entry);
+ batadv_dat_entry_free_ref(dat_entry);
+ }
+ spin_unlock_bh(list_lock);
+ }
+}
+
+/**
+ * batadv_dat_purge - periodic task that deletes old entries from the local DAT
+ * hash table
+ * @work: kernel work struct
+ */
+static void batadv_dat_purge(struct work_struct *work)
+{
+ struct delayed_work *delayed_work;
+ struct batadv_priv_dat *priv_dat;
+ struct batadv_priv *bat_priv;
+
+ delayed_work = container_of(work, struct delayed_work, work);
+ priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
+ bat_priv = container_of(priv_dat, struct batadv_priv, dat);
+
+ __batadv_dat_purge(bat_priv, batadv_dat_to_purge);
+ batadv_dat_start_timer(bat_priv);
+}
+
+/**
+ * batadv_compare_dat - comparing function used in the local DAT hash table
+ * @node: node in the local table
+ * @data2: second object to compare the node to
+ *
+ * Returns 1 if the two entries are the same, 0 otherwise.
+ */
+static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
+{
+ const void *data1 = container_of(node, struct batadv_dat_entry,
+ hash_entry);
+
+ return memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0;
+}
+
+/**
+ * batadv_arp_hw_src - extract the hw_src field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the hw_src field in the ARP packet.
+ */
+static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
+{
+ uint8_t *addr;
+
+ addr = (uint8_t *)(skb->data + hdr_size);
+ addr += ETH_HLEN + sizeof(struct arphdr);
+
+ return addr;
+}
+
+/**
+ * batadv_arp_ip_src - extract the ip_src field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the ip_src field in the ARP packet.
+ */
+static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
+{
+ return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
+}
+
+/**
+ * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the hw_dst field in the ARP packet.
+ */
+static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
+{
+ return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
+}
+
+/**
+ * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
+ * @skb: ARP packet
+ * @hdr_size: size of the possible header before the ARP packet
+ *
+ * Returns the value of the ip_dst field in the ARP packet.
+ */
+static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
+{
+ return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
+}
+
+/**
+ * batadv_hash_dat - compute the hash value for an IP address
+ * @data: data to hash
+ * @size: size of the hash table
+ *
+ * Returns the selected index in the hash table for the given data.
+ */
+static uint32_t batadv_hash_dat(const void *data, uint32_t size)
+{
+ uint32_t hash = 0;
+ const struct batadv_dat_entry *dat = data;
+
+ hash = batadv_hash_bytes(hash, &dat->ip, sizeof(dat->ip));
+ hash = batadv_hash_bytes(hash, &dat->vid, sizeof(dat->vid));
+
+ hash += (hash << 3);
+ hash ^= (hash >> 11);
+ hash += (hash << 15);
+
+ return hash % size;
+}
+
+/**
+ * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash
+ * table
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip: search key
+ * @vid: VLAN identifier
+ *
+ * Returns the dat_entry if found, NULL otherwise.
+ */
+static struct batadv_dat_entry *
+batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
+ unsigned short vid)
+{
+ struct hlist_head *head;
+ struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
+ struct batadv_hashtable *hash = bat_priv->dat.hash;
+ uint32_t index;
+
+ if (!hash)
+ return NULL;
+
+ to_find.ip = ip;
+ to_find.vid = vid;
+
+ index = batadv_hash_dat(&to_find, hash->size);
+ head = &hash->table[index];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
+ if (dat_entry->ip != ip)
+ continue;
+
+ if (!atomic_inc_not_zero(&dat_entry->refcount))
+ continue;
+
+ dat_entry_tmp = dat_entry;
+ break;
+ }
+ rcu_read_unlock();
+
+ return dat_entry_tmp;
+}
+
+/**
+ * batadv_dat_entry_add - add a new dat entry or update it if already exists
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip: ipv4 to add/edit
+ * @mac_addr: mac address to assign to the given ipv4
+ * @vid: VLAN identifier
+ */
+static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
+ uint8_t *mac_addr, unsigned short vid)
+{
+ struct batadv_dat_entry *dat_entry;
+ int hash_added;
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
+ /* if this entry is already known, just update it */
+ if (dat_entry) {
+ if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
+ ether_addr_copy(dat_entry->mac_addr, mac_addr);
+ dat_entry->last_update = jiffies;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "Entry updated: %pI4 %pM (vid: %d)\n",
+ &dat_entry->ip, dat_entry->mac_addr,
+ BATADV_PRINT_VID(vid));
+ goto out;
+ }
+
+ dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
+ if (!dat_entry)
+ goto out;
+
+ dat_entry->ip = ip;
+ dat_entry->vid = vid;
+ ether_addr_copy(dat_entry->mac_addr, mac_addr);
+ dat_entry->last_update = jiffies;
+ atomic_set(&dat_entry->refcount, 2);
+
+ hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
+ batadv_hash_dat, dat_entry,
+ &dat_entry->hash_entry);
+
+ if (unlikely(hash_added != 0)) {
+ /* remove the reference for the hash */
+ batadv_dat_entry_free_ref(dat_entry);
+ goto out;
+ }
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
+ &dat_entry->ip, dat_entry->mac_addr, BATADV_PRINT_VID(vid));
+
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUG
+
+/**
+ * batadv_dbg_arp - print a debug message containing all the ARP packet details
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: ARP packet
+ * @type: ARP type
+ * @hdr_size: size of the possible header before the ARP packet
+ * @msg: message to print together with the debugging information
+ */
+static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
+ uint16_t type, int hdr_size, char *msg)
+{
+ struct batadv_unicast_4addr_packet *unicast_4addr_packet;
+ struct batadv_bcast_packet *bcast_pkt;
+ uint8_t *orig_addr;
+ __be32 ip_src, ip_dst;
+
+ if (msg)
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
+
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
+ batadv_arp_hw_src(skb, hdr_size), &ip_src,
+ batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
+
+ if (hdr_size == 0)
+ return;
+
+ unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
+
+ switch (unicast_4addr_packet->u.packet_type) {
+ case BATADV_UNICAST:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a UNICAST packet\n");
+ break;
+ case BATADV_UNICAST_4ADDR:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
+ unicast_4addr_packet->src);
+ switch (unicast_4addr_packet->subtype) {
+ case BATADV_P_DAT_DHT_PUT:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
+ break;
+ case BATADV_P_DAT_DHT_GET:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
+ break;
+ case BATADV_P_DAT_CACHE_REPLY:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* type: DAT_CACHE_REPLY\n");
+ break;
+ case BATADV_P_DATA:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
+ break;
+ default:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
+ unicast_4addr_packet->u.packet_type);
+ }
+ break;
+ case BATADV_BCAST:
+ bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
+ orig_addr = bcast_pkt->orig;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within a BCAST packet (src: %pM)\n",
+ orig_addr);
+ break;
+ default:
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "* encapsulated within an unknown packet type (0x%x)\n",
+ unicast_4addr_packet->u.packet_type);
+ }
+}
+
+#else
+
+static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
+ uint16_t type, int hdr_size, char *msg)
+{
+}
+
+#endif /* CONFIG_BATMAN_ADV_DEBUG */
+
+/**
+ * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
+ * @res: the array with the already selected candidates
+ * @select: number of already selected candidates
+ * @tmp_max: address of the currently evaluated node
+ * @max: current round max address
+ * @last_max: address of the last selected candidate
+ * @candidate: orig_node under evaluation
+ * @max_orig_node: last selected candidate
+ *
+ * Returns true if the node has been elected as next candidate or false
+ * otherwise.
+ */
+static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
+ int select, batadv_dat_addr_t tmp_max,
+ batadv_dat_addr_t max,
+ batadv_dat_addr_t last_max,
+ struct batadv_orig_node *candidate,
+ struct batadv_orig_node *max_orig_node)
+{
+ bool ret = false;
+ int j;
+
+ /* check if orig node candidate is running DAT */
+ if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
+ goto out;
+
+ /* Check if this node has already been selected... */
+ for (j = 0; j < select; j++)
+ if (res[j].orig_node == candidate)
+ break;
+ /* ..and possibly skip it */
+ if (j < select)
+ goto out;
+ /* sanity check: has it already been selected? This should not happen */
+ if (tmp_max > last_max)
+ goto out;
+ /* check if during this iteration an originator with a closer dht
+ * address has already been found
+ */
+ if (tmp_max < max)
+ goto out;
+ /* this is an hash collision with the temporary selected node. Choose
+ * the one with the lowest address
+ */
+ if ((tmp_max == max) && max_orig_node &&
+ (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
+ goto out;
+
+ ret = true;
+out:
+ return ret;
+}
+
+/**
+ * batadv_choose_next_candidate - select the next DHT candidate
+ * @bat_priv: the bat priv with all the soft interface information
+ * @cands: candidates array
+ * @select: number of candidates already present in the array
+ * @ip_key: key to look up in the DHT
+ * @last_max: pointer where the address of the selected candidate will be saved
+ */
+static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
+ struct batadv_dat_candidate *cands,
+ int select, batadv_dat_addr_t ip_key,
+ batadv_dat_addr_t *last_max)
+{
+ batadv_dat_addr_t max = 0, tmp_max = 0;
+ struct batadv_orig_node *orig_node, *max_orig_node = NULL;
+ struct batadv_hashtable *hash = bat_priv->orig_hash;
+ struct hlist_head *head;
+ int i;
+
+ /* if no node is eligible as candidate, leave the candidate type as
+ * NOT_FOUND
+ */
+ cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
+
+ /* iterate over the originator list and find the node with the closest
+ * dat_address which has not been selected yet
+ */
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+ /* the dht space is a ring using unsigned addresses */
+ tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
+ ip_key;
+
+ if (!batadv_is_orig_node_eligible(cands, select,
+ tmp_max, max,
+ *last_max, orig_node,
+ max_orig_node))
+ continue;
+
+ if (!atomic_inc_not_zero(&orig_node->refcount))
+ continue;
+
+ max = tmp_max;
+ if (max_orig_node)
+ batadv_orig_node_free_ref(max_orig_node);
+ max_orig_node = orig_node;
+ }
+ rcu_read_unlock();
+ }
+ if (max_orig_node) {
+ cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
+ cands[select].orig_node = max_orig_node;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
+ select, max_orig_node->orig, max_orig_node->dat_addr,
+ max);
+ }
+ *last_max = max;
+}
+
+/**
+ * batadv_dat_select_candidates - select the nodes which the DHT message has to
+ * be sent to
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip_dst: ipv4 to look up in the DHT
+ *
+ * An originator O is selected if and only if its DHT_ID value is one of three
+ * closest values (from the LEFT, with wrap around if needed) then the hash
+ * value of the key. ip_dst is the key.
+ *
+ * Returns the candidate array of size BATADV_DAT_CANDIDATE_NUM.
+ */
+static struct batadv_dat_candidate *
+batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
+{
+ int select;
+ batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
+ struct batadv_dat_candidate *res;
+
+ if (!bat_priv->orig_hash)
+ return NULL;
+
+ res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
+ GFP_ATOMIC);
+ if (!res)
+ return NULL;
+
+ ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
+ BATADV_DAT_ADDR_MAX);
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "dat_select_candidates(): IP=%pI4 hash(IP)=%u\n", &ip_dst,
+ ip_key);
+
+ for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
+ batadv_choose_next_candidate(bat_priv, res, select, ip_key,
+ &last_max);
+
+ return res;
+}
+
+/**
+ * batadv_dat_send_data - send a payload to the selected candidates
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: payload to send
+ * @ip: the DHT key
+ * @packet_subtype: unicast4addr packet subtype to use
+ *
+ * This function copies the skb with pskb_copy() and is sent as unicast packet
+ * to each of the selected candidates.
+ *
+ * Returns true if the packet is sent to at least one candidate, false
+ * otherwise.
+ */
+static bool batadv_dat_send_data(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, __be32 ip,
+ int packet_subtype)
+{
+ int i;
+ bool ret = false;
+ int send_status;
+ struct batadv_neigh_node *neigh_node = NULL;
+ struct sk_buff *tmp_skb;
+ struct batadv_dat_candidate *cand;
+
+ cand = batadv_dat_select_candidates(bat_priv, ip);
+ if (!cand)
+ goto out;
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
+
+ for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
+ if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
+ continue;
+
+ neigh_node = batadv_orig_router_get(cand[i].orig_node,
+ BATADV_IF_DEFAULT);
+ if (!neigh_node)
+ goto free_orig;
+
+ tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
+ if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
+ cand[i].orig_node,
+ packet_subtype)) {
+ kfree_skb(tmp_skb);
+ goto free_neigh;
+ }
+
+ send_status = batadv_send_skb_packet(tmp_skb,
+ neigh_node->if_incoming,
+ neigh_node->addr);
+ if (send_status == NET_XMIT_SUCCESS) {
+ /* count the sent packet */
+ switch (packet_subtype) {
+ case BATADV_P_DAT_DHT_GET:
+ batadv_inc_counter(bat_priv,
+ BATADV_CNT_DAT_GET_TX);
+ break;
+ case BATADV_P_DAT_DHT_PUT:
+ batadv_inc_counter(bat_priv,
+ BATADV_CNT_DAT_PUT_TX);
+ break;
+ }
+
+ /* packet sent to a candidate: return true */
+ ret = true;
+ }
+free_neigh:
+ batadv_neigh_node_free_ref(neigh_node);
+free_orig:
+ batadv_orig_node_free_ref(cand[i].orig_node);
+ }
+
+out:
+ kfree(cand);
+ return ret;
+}
+
+/**
+ * batadv_dat_tvlv_container_update - update the dat tvlv container after dat
+ * setting change
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
+{
+ char dat_mode;
+
+ dat_mode = atomic_read(&bat_priv->distributed_arp_table);
+
+ switch (dat_mode) {
+ case 0:
+ batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
+ break;
+ case 1:
+ batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
+ NULL, 0);
+ break;
+ }
+}
+
+/**
+ * batadv_dat_status_update - update the dat tvlv container after dat
+ * setting change
+ * @net_dev: the soft interface net device
+ */
+void batadv_dat_status_update(struct net_device *net_dev)
+{
+ struct batadv_priv *bat_priv = netdev_priv(net_dev);
+
+ batadv_dat_tvlv_container_update(bat_priv);
+}
+
+/**
+ * batadv_gw_tvlv_ogm_handler_v1 - process incoming dat tvlv container
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node of the ogm
+ * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
+ * @tvlv_value: tvlv buffer containing the gateway data
+ * @tvlv_value_len: tvlv buffer length
+ */
+static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
+ struct batadv_orig_node *orig,
+ uint8_t flags,
+ void *tvlv_value,
+ uint16_t tvlv_value_len)
+{
+ if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
+ orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
+ else
+ orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
+}
+
+/**
+ * batadv_dat_hash_free - free the local DAT hash table
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
+{
+ if (!bat_priv->dat.hash)
+ return;
+
+ __batadv_dat_purge(bat_priv, NULL);
+
+ batadv_hash_destroy(bat_priv->dat.hash);
+
+ bat_priv->dat.hash = NULL;
+}
+
+/**
+ * batadv_dat_init - initialise the DAT internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+int batadv_dat_init(struct batadv_priv *bat_priv)
+{
+ if (bat_priv->dat.hash)
+ return 0;
+
+ bat_priv->dat.hash = batadv_hash_new(1024);
+
+ if (!bat_priv->dat.hash)
+ return -ENOMEM;
+
+ batadv_dat_start_timer(bat_priv);
+
+ batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
+ NULL, BATADV_TVLV_DAT, 1,
+ BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+ batadv_dat_tvlv_container_update(bat_priv);
+ return 0;
+}
+
+/**
+ * batadv_dat_free - free the DAT internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_dat_free(struct batadv_priv *bat_priv)
+{
+ batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
+ batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
+
+ cancel_delayed_work_sync(&bat_priv->dat.work);
+
+ batadv_dat_hash_free(bat_priv);
+}
+
+/**
+ * batadv_dat_cache_seq_print_text - print the local DAT hash table
+ * @seq: seq file to print on
+ * @offset: not used
+ */
+int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
+{
+ struct net_device *net_dev = (struct net_device *)seq->private;
+ struct batadv_priv *bat_priv = netdev_priv(net_dev);
+ struct batadv_hashtable *hash = bat_priv->dat.hash;
+ struct batadv_dat_entry *dat_entry;
+ struct batadv_hard_iface *primary_if;
+ struct hlist_head *head;
+ unsigned long last_seen_jiffies;
+ int last_seen_msecs, last_seen_secs, last_seen_mins;
+ uint32_t i;
+
+ primary_if = batadv_seq_print_text_primary_if_get(seq);
+ if (!primary_if)
+ goto out;
+
+ seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name);
+ seq_printf(seq, " %-7s %-9s %4s %11s\n", "IPv4",
+ "MAC", "VID", "last-seen");
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
+ last_seen_jiffies = jiffies - dat_entry->last_update;
+ last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
+ last_seen_mins = last_seen_msecs / 60000;
+ last_seen_msecs = last_seen_msecs % 60000;
+ last_seen_secs = last_seen_msecs / 1000;
+
+ seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n",
+ &dat_entry->ip, dat_entry->mac_addr,
+ BATADV_PRINT_VID(dat_entry->vid),
+ last_seen_mins, last_seen_secs);
+ }
+ rcu_read_unlock();
+ }
+
+out:
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ return 0;
+}
+
+/**
+ * batadv_arp_get_type - parse an ARP packet and gets the type
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to analyse
+ * @hdr_size: size of the possible header before the ARP packet in the skb
+ *
+ * Returns the ARP type if the skb contains a valid ARP packet, 0 otherwise.
+ */
+static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ struct arphdr *arphdr;
+ struct ethhdr *ethhdr;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src, *hw_dst;
+ uint16_t type = 0;
+
+ /* pull the ethernet header */
+ if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
+ goto out;
+
+ ethhdr = (struct ethhdr *)(skb->data + hdr_size);
+
+ if (ethhdr->h_proto != htons(ETH_P_ARP))
+ goto out;
+
+ /* pull the ARP payload */
+ if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
+ arp_hdr_len(skb->dev))))
+ goto out;
+
+ arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
+
+ /* check whether the ARP packet carries a valid IP information */
+ if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
+ goto out;
+
+ if (arphdr->ar_pro != htons(ETH_P_IP))
+ goto out;
+
+ if (arphdr->ar_hln != ETH_ALEN)
+ goto out;
+
+ if (arphdr->ar_pln != 4)
+ goto out;
+
+ /* Check for bad reply/request. If the ARP message is not sane, DAT
+ * will simply ignore it
+ */
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+ if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
+ ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
+ ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
+ ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
+ goto out;
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
+ goto out;
+
+ /* don't care about the destination MAC address in ARP requests */
+ if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
+ hw_dst = batadv_arp_hw_dst(skb, hdr_size);
+ if (is_zero_ether_addr(hw_dst) ||
+ is_multicast_ether_addr(hw_dst))
+ goto out;
+ }
+
+ type = ntohs(arphdr->ar_op);
+out:
+ return type;
+}
+
+/**
+ * batadv_dat_get_vid - extract the VLAN identifier from skb if any
+ * @skb: the buffer containing the packet to extract the VID from
+ * @hdr_size: the size of the batman-adv header encapsulating the packet
+ *
+ * If the packet embedded in the skb is vlan tagged this function returns the
+ * VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS is returned.
+ */
+static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
+{
+ unsigned short vid;
+
+ vid = batadv_get_vid(skb, *hdr_size);
+
+ /* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
+ * If the header contained in the packet is a VLAN one (which is longer)
+ * hdr_size is updated so that the functions will still skip the
+ * correct amount of bytes.
+ */
+ if (vid & BATADV_VLAN_HAS_TAG)
+ *hdr_size += VLAN_HLEN;
+
+ return vid;
+}
+
+/**
+ * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
+ * answer using DAT
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ *
+ * Returns true if the message has been sent to the dht candidates, false
+ * otherwise. In case of a positive return value the message has to be enqueued
+ * to permit the fallback.
+ */
+bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ uint16_t type = 0;
+ __be32 ip_dst, ip_src;
+ uint8_t *hw_src;
+ bool ret = false;
+ struct batadv_dat_entry *dat_entry = NULL;
+ struct sk_buff *skb_new;
+ int hdr_size = 0;
+ unsigned short vid;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ vid = batadv_dat_get_vid(skb, &hdr_size);
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
+ * message to the selected DHT candidates
+ */
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing outgoing ARP REQUEST");
+
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
+ if (dat_entry) {
+ /* If the ARP request is destined for a local client the local
+ * client will answer itself. DAT would only generate a
+ * duplicate packet.
+ *
+ * Moreover, if the soft-interface is enslaved into a bridge, an
+ * additional DAT answer may trigger kernel warnings about
+ * a packet coming from the wrong port.
+ */
+ if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
+ ret = true;
+ goto out;
+ }
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ bat_priv->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+ if (!skb_new)
+ goto out;
+
+ if (vid & BATADV_VLAN_HAS_TAG)
+ skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
+ vid & VLAN_VID_MASK);
+
+ skb_reset_mac_header(skb_new);
+ skb_new->protocol = eth_type_trans(skb_new,
+ bat_priv->soft_iface);
+ bat_priv->stats.rx_packets++;
+ bat_priv->stats.rx_bytes += skb->len + ETH_HLEN + hdr_size;
+ bat_priv->soft_iface->last_rx = jiffies;
+
+ netif_rx(skb_new);
+ batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
+ ret = true;
+ } else {
+ /* Send the request to the DHT */
+ ret = batadv_dat_send_data(bat_priv, skb, ip_dst,
+ BATADV_P_DAT_DHT_GET);
+ }
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ return ret;
+}
+
+/**
+ * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to
+ * answer using the local DAT storage
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ * @hdr_size: size of the encapsulation header
+ *
+ * Returns true if the request has been answered, false otherwise.
+ */
+bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src;
+ struct sk_buff *skb_new;
+ struct batadv_dat_entry *dat_entry = NULL;
+ bool ret = false;
+ unsigned short vid;
+ int err;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ vid = batadv_dat_get_vid(skb, &hdr_size);
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing incoming ARP REQUEST");
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
+ if (!dat_entry)
+ goto out;
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ bat_priv->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+
+ if (!skb_new)
+ goto out;
+
+ /* the rest of the TX path assumes that the mac_header offset pointing
+ * to the inner Ethernet header has been set, therefore reset it now.
+ */
+ skb_reset_mac_header(skb_new);
+
+ if (vid & BATADV_VLAN_HAS_TAG)
+ skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
+ vid & VLAN_VID_MASK);
+
+ /* To preserve backwards compatibility, the node has choose the outgoing
+ * format based on the incoming request packet type. The assumption is
+ * that a node not using the 4addr packet format doesn't support it.
+ */
+ if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
+ err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
+ BATADV_P_DAT_CACHE_REPLY,
+ NULL, vid);
+ else
+ err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
+
+ if (err != NET_XMIT_DROP) {
+ batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
+ ret = true;
+ }
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ if (ret)
+ kfree_skb(skb);
+ return ret;
+}
+
+/**
+ * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ */
+void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src, *hw_dst;
+ int hdr_size = 0;
+ unsigned short vid;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ return;
+
+ vid = batadv_dat_get_vid(skb, &hdr_size);
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ if (type != ARPOP_REPLY)
+ return;
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing outgoing ARP REPLY");
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ hw_dst = batadv_arp_hw_dst(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
+
+ /* Send the ARP reply to the candidates for both the IP addresses that
+ * the node obtained from the ARP reply
+ */
+ batadv_dat_send_data(bat_priv, skb, ip_src, BATADV_P_DAT_DHT_PUT);
+ batadv_dat_send_data(bat_priv, skb, ip_dst, BATADV_P_DAT_DHT_PUT);
+}
+
+/**
+ * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local
+ * DAT storage only
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: packet to check
+ * @hdr_size: size of the encapsulation header
+ */
+bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, int hdr_size)
+{
+ uint16_t type;
+ __be32 ip_src, ip_dst;
+ uint8_t *hw_src, *hw_dst;
+ bool ret = false;
+ unsigned short vid;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ vid = batadv_dat_get_vid(skb, &hdr_size);
+
+ type = batadv_arp_get_type(bat_priv, skb, hdr_size);
+ if (type != ARPOP_REPLY)
+ goto out;
+
+ batadv_dbg_arp(bat_priv, skb, type, hdr_size,
+ "Parsing incoming ARP REPLY");
+
+ hw_src = batadv_arp_hw_src(skb, hdr_size);
+ ip_src = batadv_arp_ip_src(skb, hdr_size);
+ hw_dst = batadv_arp_hw_dst(skb, hdr_size);
+ ip_dst = batadv_arp_ip_dst(skb, hdr_size);
+
+ /* Update our internal cache with both the IP addresses the node got
+ * within the ARP reply
+ */
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
+
+ /* if this REPLY is directed to a client of mine, let's deliver the
+ * packet to the interface
+ */
+ ret = !batadv_is_my_client(bat_priv, hw_dst, vid);
+out:
+ if (ret)
+ kfree_skb(skb);
+ /* if ret == false -> packet has to be delivered to the interface */
+ return ret;
+}
+
+/**
+ * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped
+ * (because the node has already obtained the reply via DAT) or not
+ * @bat_priv: the bat priv with all the soft interface information
+ * @forw_packet: the broadcast packet
+ *
+ * Returns true if the node can drop the packet, false otherwise.
+ */
+bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
+ struct batadv_forw_packet *forw_packet)
+{
+ uint16_t type;
+ __be32 ip_dst;
+ struct batadv_dat_entry *dat_entry = NULL;
+ bool ret = false;
+ int hdr_size = sizeof(struct batadv_bcast_packet);
+ unsigned short vid;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ /* If this packet is an ARP_REQUEST and the node already has the
+ * information that it is going to ask, then the packet can be dropped
+ */
+ if (forw_packet->num_packets)
+ goto out;
+
+ vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
+
+ type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
+ /* check if the node already got this entry */
+ if (!dat_entry) {
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP Request for %pI4: fallback\n", &ip_dst);
+ goto out;
+ }
+
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "ARP Request for %pI4: fallback prevented\n", &ip_dst);
+ ret = true;
+
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ return ret;
+}
Code Review / kvmfornfv.git / blobdiff