forked from Minki/linux
b618ad1103
We never want multicast MAC addresses in the Distributed ARP Table, so it's best to completely ignore ARP packets containing them where we expect unicast addresses. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
1084 lines
30 KiB
C
1084 lines
30 KiB
C
/* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors:
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*
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* Antonio Quartulli
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA
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*/
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#include <linux/if_ether.h>
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#include <linux/if_arp.h>
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#include <net/arp.h>
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#include "main.h"
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#include "hash.h"
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#include "distributed-arp-table.h"
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#include "hard-interface.h"
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#include "originator.h"
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#include "send.h"
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#include "types.h"
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#include "translation-table.h"
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#include "unicast.h"
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static void batadv_dat_purge(struct work_struct *work);
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/**
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* batadv_dat_start_timer - initialise the DAT periodic worker
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* @bat_priv: the bat priv with all the soft interface information
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*/
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static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
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{
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INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
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queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
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msecs_to_jiffies(10000));
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}
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/**
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* batadv_dat_entry_free_ref - decrements the dat_entry refcounter and possibly
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* free it
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* @dat_entry: the oentry to free
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*/
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static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry)
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{
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if (atomic_dec_and_test(&dat_entry->refcount))
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kfree_rcu(dat_entry, rcu);
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}
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/**
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* batadv_dat_to_purge - checks whether a dat_entry has to be purged or not
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* @dat_entry: the entry to check
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*
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* Returns true if the entry has to be purged now, false otherwise
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*/
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static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
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{
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return batadv_has_timed_out(dat_entry->last_update,
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BATADV_DAT_ENTRY_TIMEOUT);
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}
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/**
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* __batadv_dat_purge - delete entries from the DAT local storage
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* @bat_priv: the bat priv with all the soft interface information
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* @to_purge: function in charge to decide whether an entry has to be purged or
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* not. This function takes the dat_entry as argument and has to
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* returns a boolean value: true is the entry has to be deleted,
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* false otherwise
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*
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* Loops over each entry in the DAT local storage and delete it if and only if
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* the to_purge function passed as argument returns true
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*/
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static void __batadv_dat_purge(struct batadv_priv *bat_priv,
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bool (*to_purge)(struct batadv_dat_entry *))
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{
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spinlock_t *list_lock; /* protects write access to the hash lists */
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struct batadv_dat_entry *dat_entry;
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struct hlist_node *node, *node_tmp;
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struct hlist_head *head;
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uint32_t i;
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if (!bat_priv->dat.hash)
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return;
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for (i = 0; i < bat_priv->dat.hash->size; i++) {
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head = &bat_priv->dat.hash->table[i];
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list_lock = &bat_priv->dat.hash->list_locks[i];
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spin_lock_bh(list_lock);
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hlist_for_each_entry_safe(dat_entry, node, node_tmp, head,
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hash_entry) {
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/* if an helper function has been passed as parameter,
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* ask it if the entry has to be purged or not
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*/
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if (to_purge && !to_purge(dat_entry))
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continue;
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hlist_del_rcu(node);
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batadv_dat_entry_free_ref(dat_entry);
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}
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spin_unlock_bh(list_lock);
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}
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}
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/**
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* batadv_dat_purge - periodic task that deletes old entries from the local DAT
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* hash table
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* @work: kernel work struct
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*/
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static void batadv_dat_purge(struct work_struct *work)
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{
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struct delayed_work *delayed_work;
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struct batadv_priv_dat *priv_dat;
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struct batadv_priv *bat_priv;
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delayed_work = container_of(work, struct delayed_work, work);
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priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
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bat_priv = container_of(priv_dat, struct batadv_priv, dat);
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__batadv_dat_purge(bat_priv, batadv_dat_to_purge);
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batadv_dat_start_timer(bat_priv);
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}
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/**
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* batadv_compare_dat - comparing function used in the local DAT hash table
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* @node: node in the local table
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* @data2: second object to compare the node to
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*
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* Returns 1 if the two entry are the same, 0 otherwise
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*/
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static int batadv_compare_dat(const struct hlist_node *node, const void *data2)
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{
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const void *data1 = container_of(node, struct batadv_dat_entry,
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hash_entry);
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return (memcmp(data1, data2, sizeof(__be32)) == 0 ? 1 : 0);
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}
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/**
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* batadv_arp_hw_src - extract the hw_src field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Returns the value of the hw_src field in the ARP packet
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*/
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static uint8_t *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
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{
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uint8_t *addr;
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addr = (uint8_t *)(skb->data + hdr_size);
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addr += ETH_HLEN + sizeof(struct arphdr);
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return addr;
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}
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/**
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* batadv_arp_ip_src - extract the ip_src field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Returns the value of the ip_src field in the ARP packet
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*/
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static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
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{
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return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
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}
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/**
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* batadv_arp_hw_dst - extract the hw_dst field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Returns the value of the hw_dst field in the ARP packet
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*/
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static uint8_t *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
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{
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return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
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}
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/**
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* batadv_arp_ip_dst - extract the ip_dst field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Returns the value of the ip_dst field in the ARP packet
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*/
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static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
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{
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return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4);
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}
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/**
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* batadv_hash_dat - compute the hash value for an IP address
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* @data: data to hash
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* @size: size of the hash table
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*
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* Returns the selected index in the hash table for the given data
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*/
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static uint32_t batadv_hash_dat(const void *data, uint32_t size)
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{
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const unsigned char *key = data;
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uint32_t hash = 0;
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size_t i;
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for (i = 0; i < 4; i++) {
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hash += key[i];
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += (hash << 3);
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hash ^= (hash >> 11);
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hash += (hash << 15);
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return hash % size;
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}
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/**
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* batadv_dat_entry_hash_find - looks for a given dat_entry in the local hash
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* table
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* @bat_priv: the bat priv with all the soft interface information
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* @ip: search key
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*
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* Returns the dat_entry if found, NULL otherwise
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*/
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static struct batadv_dat_entry *
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batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip)
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{
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struct hlist_head *head;
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struct hlist_node *node;
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struct batadv_dat_entry *dat_entry, *dat_entry_tmp = NULL;
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struct batadv_hashtable *hash = bat_priv->dat.hash;
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uint32_t index;
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if (!hash)
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return NULL;
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index = batadv_hash_dat(&ip, hash->size);
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head = &hash->table[index];
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rcu_read_lock();
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hlist_for_each_entry_rcu(dat_entry, node, head, hash_entry) {
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if (dat_entry->ip != ip)
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continue;
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if (!atomic_inc_not_zero(&dat_entry->refcount))
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continue;
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dat_entry_tmp = dat_entry;
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break;
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}
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rcu_read_unlock();
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return dat_entry_tmp;
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}
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/**
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* batadv_dat_entry_add - add a new dat entry or update it if already exists
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* @bat_priv: the bat priv with all the soft interface information
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* @ip: ipv4 to add/edit
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* @mac_addr: mac address to assign to the given ipv4
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*/
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static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
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uint8_t *mac_addr)
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{
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struct batadv_dat_entry *dat_entry;
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int hash_added;
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dat_entry = batadv_dat_entry_hash_find(bat_priv, ip);
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/* if this entry is already known, just update it */
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if (dat_entry) {
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if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
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memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
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dat_entry->last_update = jiffies;
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"Entry updated: %pI4 %pM\n", &dat_entry->ip,
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dat_entry->mac_addr);
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goto out;
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}
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dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
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if (!dat_entry)
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goto out;
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dat_entry->ip = ip;
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memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN);
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dat_entry->last_update = jiffies;
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atomic_set(&dat_entry->refcount, 2);
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hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
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batadv_hash_dat, &dat_entry->ip,
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&dat_entry->hash_entry);
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if (unlikely(hash_added != 0)) {
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/* remove the reference for the hash */
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batadv_dat_entry_free_ref(dat_entry);
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goto out;
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}
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM\n",
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&dat_entry->ip, dat_entry->mac_addr);
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out:
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if (dat_entry)
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batadv_dat_entry_free_ref(dat_entry);
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}
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#ifdef CONFIG_BATMAN_ADV_DEBUG
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/**
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* batadv_dbg_arp - print a debug message containing all the ARP packet details
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: ARP packet
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* @type: ARP type
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* @hdr_size: size of the possible header before the ARP packet
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* @msg: message to print together with the debugging information
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*/
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static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
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uint16_t type, int hdr_size, char *msg)
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{
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struct batadv_unicast_4addr_packet *unicast_4addr_packet;
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struct batadv_bcast_packet *bcast_pkt;
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uint8_t *orig_addr;
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__be32 ip_src, ip_dst;
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if (msg)
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
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ip_src = batadv_arp_ip_src(skb, hdr_size);
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ip_dst = batadv_arp_ip_dst(skb, hdr_size);
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
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batadv_arp_hw_src(skb, hdr_size), &ip_src,
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batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
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if (hdr_size == 0)
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return;
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/* if the ARP packet is encapsulated in a batman packet, let's print
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* some debug messages
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*/
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unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
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switch (unicast_4addr_packet->u.header.packet_type) {
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case BATADV_UNICAST:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within a UNICAST packet\n");
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break;
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case BATADV_UNICAST_4ADDR:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
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unicast_4addr_packet->src);
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switch (unicast_4addr_packet->subtype) {
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case BATADV_P_DAT_DHT_PUT:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
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break;
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case BATADV_P_DAT_DHT_GET:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
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break;
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case BATADV_P_DAT_CACHE_REPLY:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* type: DAT_CACHE_REPLY\n");
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break;
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case BATADV_P_DATA:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
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break;
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default:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
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unicast_4addr_packet->u.header.packet_type);
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}
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break;
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case BATADV_BCAST:
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bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
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orig_addr = bcast_pkt->orig;
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within a BCAST packet (src: %pM)\n",
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orig_addr);
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break;
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default:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within an unknown packet type (0x%x)\n",
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unicast_4addr_packet->u.header.packet_type);
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}
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}
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#else
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static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
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uint16_t type, int hdr_size, char *msg)
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{
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}
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#endif /* CONFIG_BATMAN_ADV_DEBUG */
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/**
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* batadv_is_orig_node_eligible - check whether a node can be a DHT candidate
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* @res: the array with the already selected candidates
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* @select: number of already selected candidates
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* @tmp_max: address of the currently evaluated node
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* @max: current round max address
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* @last_max: address of the last selected candidate
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* @candidate: orig_node under evaluation
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* @max_orig_node: last selected candidate
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*
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* Returns true if the node has been elected as next candidate or false othrwise
|
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*/
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static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
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int select, batadv_dat_addr_t tmp_max,
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batadv_dat_addr_t max,
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batadv_dat_addr_t last_max,
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struct batadv_orig_node *candidate,
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struct batadv_orig_node *max_orig_node)
|
|
{
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bool ret = false;
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int j;
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|
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/* Check if this node has already been selected... */
|
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for (j = 0; j < select; j++)
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if (res[j].orig_node == candidate)
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break;
|
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/* ..and possibly skip it */
|
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if (j < select)
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goto out;
|
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/* sanity check: has it already been selected? This should not happen */
|
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if (tmp_max > last_max)
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goto out;
|
|
/* check if during this iteration an originator with a closer dht
|
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* address has already been found
|
|
*/
|
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if (tmp_max < max)
|
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goto out;
|
|
/* this is an hash collision with the temporary selected node. Choose
|
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* the one with the lowest address
|
|
*/
|
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if ((tmp_max == max) &&
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(batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0))
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goto out;
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ret = true;
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out:
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return ret;
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}
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|
|
/**
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* batadv_choose_next_candidate - select the next DHT candidate
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* @bat_priv: the bat priv with all the soft interface information
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* @cands: candidates array
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* @select: number of candidates already present in the array
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* @ip_key: key to look up in the DHT
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* @last_max: pointer where the address of the selected candidate will be saved
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*/
|
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static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
|
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struct batadv_dat_candidate *cands,
|
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int select, batadv_dat_addr_t ip_key,
|
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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_node *node;
|
|
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 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, node, head, hash_entry) {
|
|
/* the dht space is a ring and addresses are unsigned */
|
|
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 - selects 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(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
|
|
*
|
|
* In this function the skb is copied by means of 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_node_get_router(cand[i].orig_node);
|
|
if (!neigh_node)
|
|
goto free_orig;
|
|
|
|
tmp_skb = pskb_copy(skb, GFP_ATOMIC);
|
|
if (!batadv_unicast_4addr_prepare_skb(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_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;
|
|
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;
|
|
|
|
/* we 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_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) {
|
|
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 (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)
|
|
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 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;
|
|
}
|