#include <linux/if_ether.h>
#include <linux/if_arp.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"
#include "unicast.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 - decrements the dat_entry refcounter and possibly
+ * free it
+ * @dat_entry: the oentry 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 - checks 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 delete 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, *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, node_tmp, head,
+ hash_entry) {
+ /* if an 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(node);
+ 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 entry 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
}
/**
+ * batadv_dat_entry_hash_find - looks for a given dat_entry in the local hash
+ * table
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip: search key
+ *
+ * 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)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL;
+ struct batadv_hashtable *hash = bat_priv->dat.hash;
+ uint32_t index;
+
+ if (!hash)
+ return NULL;
+
+ index = batadv_hash_dat(&ip, hash->size);
+ head = &hash->table[index];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, node, 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
+ */
+static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
+ uint8_t *mac_addr)
+{
+ struct batadv_dat_entry *dat_entry;
+ int hash_added;
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip);
+ /* if this entry is already known, just update it */
+ if (dat_entry) {
+ if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
+ memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
+ dat_entry->last_update = jiffies;
+ batadv_dbg(BATADV_DBG_DAT, bat_priv,
+ "Entry updated: %pI4 %pM\n", &dat_entry->ip,
+ dat_entry->mac_addr);
+ goto out;
+ }
+
+ dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
+ if (!dat_entry)
+ goto out;
+
+ dat_entry->ip = ip;
+ memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
+ 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->ip,
+ &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\n",
+ &dat_entry->ip, dat_entry->mac_addr);
+
+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;
+
+ /* if the ARP packet is encapsulated in a batman packet, let's print
+ * some debug messages
+ */
+ unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
+
+ switch (unicast_4addr_packet->u.header.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.header.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.header.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
kfree(cand);
return ret;
}
+
+/**
+ * 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);
+
+ 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)
+{
+ 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_node *node;
+ 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 %-13s %5s\n", "IPv4", "MAC",
+ "last-seen");
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(dat_entry, node, 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 %6i:%02i\n",
+ &dat_entry->ip, dat_entry->mac_addr,
+ 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;
+ 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))
+ goto out;
+
+ type = ntohs(arphdr->ar_op);
+out:
+ return type;
+}
+
+/**
+ * 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 true 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;
+ struct batadv_hard_iface *primary_if = NULL;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ type = batadv_arp_get_type(bat_priv, skb, 0);
+ /* 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, 0, "Parsing outgoing ARP REQUEST");
+
+ ip_src = batadv_arp_ip_src(skb, 0);
+ hw_src = batadv_arp_hw_src(skb, 0);
+ ip_dst = batadv_arp_ip_dst(skb, 0);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ if (dat_entry) {
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ primary_if->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+ if (!skb_new)
+ goto out;
+
+ skb_reset_mac_header(skb_new);
+ skb_new->protocol = eth_type_trans(skb_new,
+ primary_if->soft_iface);
+ bat_priv->stats.rx_packets++;
+ bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
+ primary_if->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 on 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);
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ 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_hard_iface *primary_if = NULL;
+ struct batadv_dat_entry *dat_entry = NULL;
+ bool ret = false;
+ int err;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ 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);
+
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ if (!dat_entry)
+ goto out;
+
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
+ primary_if->soft_iface, ip_dst, hw_src,
+ dat_entry->mac_addr, hw_src);
+
+ if (!skb_new)
+ goto out;
+
+ /* to preserve backwards compatibility, here the node has to answer
+ * using the same packet type it received for the request. This is due
+ * to that if a node is not using the 4addr packet format it may not
+ * support it.
+ */
+ if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
+ err = batadv_unicast_4addr_send_skb(bat_priv, skb_new,
+ BATADV_P_DAT_CACHE_REPLY);
+ else
+ err = batadv_unicast_send_skb(bat_priv, skb_new);
+
+ if (!err)
+ ret = true;
+out:
+ if (dat_entry)
+ batadv_dat_entry_free_ref(dat_entry);
+ if (primary_if)
+ batadv_hardif_free_ref(primary_if);
+ 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;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ return;
+
+ type = batadv_arp_get_type(bat_priv, skb, 0);
+ if (type != ARPOP_REPLY)
+ return;
+
+ batadv_dbg_arp(bat_priv, skb, type, 0, "Parsing outgoing ARP REPLY");
+
+ hw_src = batadv_arp_hw_src(skb, 0);
+ ip_src = batadv_arp_ip_src(skb, 0);
+ hw_dst = batadv_arp_hw_dst(skb, 0);
+ ip_dst = batadv_arp_ip_dst(skb, 0);
+
+ batadv_dat_entry_add(bat_priv, ip_src, hw_src);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
+
+ /* Send the ARP reply to the candidates for both the IP addresses that
+ * the node got within 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: siaze 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;
+
+ if (!atomic_read(&bat_priv->distributed_arp_table))
+ goto out;
+
+ 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);
+ batadv_dat_entry_add(bat_priv, ip_dst, hw_dst);
+
+ /* 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);
+out:
+ /* 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 got 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;
+ const size_t bcast_len = sizeof(struct batadv_bcast_packet);
+
+ 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;
+
+ type = batadv_arp_get_type(bat_priv, forw_packet->skb, bcast_len);
+ if (type != ARPOP_REQUEST)
+ goto out;
+
+ ip_dst = batadv_arp_ip_dst(forw_packet->skb, bcast_len);
+ dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
+ /* 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;
+}
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff