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Commit 0ffa9e8d authored by Antonio Quartulli's avatar Antonio Quartulli Committed by Antonio Quartulli
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batman-adv: use vid when computing local and global TT CRC 



now that each TT entry is characterised by a VLAN ID, the
latter has to be taken into consideration when computing the
local/global table CRC as it would be theoretically possible
to have the same client in two different VLANs

Signed-off-by: default avatarAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
parent c018ad3d

net/batman-adv/translation-table.c

+31 −4
Original line number Diff line number Diff line
@@ -1506,6 +1506,24 @@ struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv, 
 * batadv_tt_global_crc - calculates the checksum of the local table belonging

 *  to the given orig_node

 * @bat_priv: the bat priv with all the soft interface information

 * @orig_node: originator for which the CRC should be computed

 *

 * This function computes the checksum for the global table corresponding to a

 * specific originator. In particular, the checksum is computed as follows: For

 * each client connected to the originator the CRC32C of the MAC address and the

 * VID is computed and then all the CRC32Cs of the various clients are xor'ed

 * together.

 *

 * The idea behind is that CRC32C should be used as much as possible in order to

 * produce a unique hash of the table, but since the order which is used to feed

 * the CRC32C function affects the result and since every node in the network

 * probably sorts the clients differently, the hash function cannot be directly

 * computed over the entire table. Hence the CRC32C is used only on

 * the single client entry, while all the results are then xor'ed together

 * because the XOR operation can combine them all while trying to reduce the

 * noise as much as possible.

 *

 * Returns the checksum of the global table of a given originator.

 */

static uint32_t batadv_tt_global_crc(struct batadv_priv *bat_priv,

				     struct batadv_orig_node *orig_node)
@@ -1514,7 +1532,7 @@ static uint32_t batadv_tt_global_crc(struct batadv_priv *bat_priv, 
	struct batadv_tt_common_entry *tt_common;

	struct batadv_tt_global_entry *tt_global;

	struct hlist_head *head;

	uint32_t i, crc = 0;

	uint32_t i, crc_tmp, crc = 0;



	for (i = 0; i < hash->size; i++) {

		head = &hash->table[i];
@@ -1545,7 +1563,9 @@ static uint32_t batadv_tt_global_crc(struct batadv_priv *bat_priv, 
							     orig_node))

				continue;



			crc ^= crc32c(0, tt_common->addr, ETH_ALEN);

			crc_tmp = crc32c(0, &tt_common->vid,

					 sizeof(tt_common->vid));

			crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);

		}

		rcu_read_unlock();

	}
@@ -1556,13 +1576,18 @@ static uint32_t batadv_tt_global_crc(struct batadv_priv *bat_priv, 
/**

 * batadv_tt_local_crc - calculates the checksum of the local table

 * @bat_priv: the bat priv with all the soft interface information

 *

 * For details about the computation, please refer to the documentation for

 * batadv_tt_global_crc().

 *

 * Returns the checksum of the local table

 */

static uint32_t batadv_tt_local_crc(struct batadv_priv *bat_priv)

{

	struct batadv_hashtable *hash = bat_priv->tt.local_hash;

	struct batadv_tt_common_entry *tt_common;

	struct hlist_head *head;

	uint32_t i, crc = 0;

	uint32_t i, crc_tmp, crc = 0;



	for (i = 0; i < hash->size; i++) {

		head = &hash->table[i];
@@ -1575,7 +1600,9 @@ static uint32_t batadv_tt_local_crc(struct batadv_priv *bat_priv) 
			if (tt_common->flags & BATADV_TT_CLIENT_NEW)

				continue;



			crc ^= crc32c(0, tt_common->addr, ETH_ALEN);

			crc_tmp = crc32c(0, &tt_common->vid,

					 sizeof(tt_common->vid));

			crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);

		}

		rcu_read_unlock();

	}