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e1a5382f97
The rcu protected macros rcu_dereference() and rcu_assign_pointer() for the orig_node->router need to be used, as well as spin/rcu locking. Otherwise we might end up using a router pointer pointing to already freed memory. Therefore this commit introduces the safe getter method orig_node_get_router(). Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
104 lines
2.9 KiB
C
104 lines
2.9 KiB
C
/*
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* Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
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*
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* Marek Lindner, Simon Wunderlich
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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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*/
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#ifndef _NET_BATMAN_ADV_ORIGINATOR_H_
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#define _NET_BATMAN_ADV_ORIGINATOR_H_
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#include "hash.h"
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int originator_init(struct bat_priv *bat_priv);
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void originator_free(struct bat_priv *bat_priv);
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void purge_orig_ref(struct bat_priv *bat_priv);
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void orig_node_free_ref(struct orig_node *orig_node);
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struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr);
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struct neigh_node *create_neighbor(struct orig_node *orig_node,
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struct orig_node *orig_neigh_node,
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uint8_t *neigh,
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struct hard_iface *if_incoming);
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void neigh_node_free_ref(struct neigh_node *neigh_node);
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struct neigh_node *orig_node_get_router(struct orig_node *orig_node);
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int orig_seq_print_text(struct seq_file *seq, void *offset);
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int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
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int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num);
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/* returns 1 if they are the same originator */
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static inline int compare_orig(struct hlist_node *node, void *data2)
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{
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void *data1 = container_of(node, struct orig_node, hash_entry);
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return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
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}
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/* hashfunction to choose an entry in a hash table of given size */
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/* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
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static inline int choose_orig(void *data, int32_t size)
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{
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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 < 6; 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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static inline struct orig_node *orig_hash_find(struct bat_priv *bat_priv,
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void *data)
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{
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struct hashtable_t *hash = bat_priv->orig_hash;
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struct hlist_head *head;
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struct hlist_node *node;
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struct orig_node *orig_node, *orig_node_tmp = NULL;
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int index;
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if (!hash)
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return NULL;
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index = choose_orig(data, 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(orig_node, node, head, hash_entry) {
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if (!compare_eth(orig_node, data))
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continue;
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if (!atomic_inc_not_zero(&orig_node->refcount))
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continue;
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orig_node_tmp = orig_node;
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break;
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}
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rcu_read_unlock();
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return orig_node_tmp;
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}
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#endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */
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