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+/**
+ * @file IxEthDBLearning.c
+ *
+ * @par
+ * IXP400 SW Release version 2.0
+ *
+ * -- Copyright Notice --
+ *
+ * @par
+ * Copyright 2001-2005, Intel Corporation.
+ * All rights reserved.
+ *
+ * @par
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * @par
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @par
+ * -- End of Copyright Notice --
+ */
+
+#include "IxEthDB_p.h"
+
+/**
+ * @brief hashes the mac address in a mac descriptor with a XOR function
+ *
+ * @param entry pointer to a mac descriptor to be hashed
+ *
+ * This function only extracts the mac address and employs ixEthDBKeyXORHash()
+ * to do the actual hashing.
+ * Used only to add a whole entry to a hash table, as opposed to searching which
+ * takes only a key and uses the key hashing directly.
+ *
+ * @see ixEthDBKeyXORHash()
+ *
+ * @return the hash value
+ *
+ * @internal
+ */
+UINT32 ixEthDBEntryXORHash(void *entry)
+{
+ MacDescriptor *descriptor = (MacDescriptor *) entry;
+
+ return ixEthDBKeyXORHash(descriptor->macAddress);
+}
+
+/**
+ * @brief hashes a mac address
+ *
+ * @param key pointer to a 6 byte structure (typically an IxEthDBMacAddr pointer)
+ * to be hashed
+ *
+ * Given a 6 bytes MAC address, the hash used is:
+ *
+ * hash(MAC[0:5]) = MAC[0:1] ^ MAC[2:3] ^ MAC[4:5]
+ *
+ * Used by the hash table to search and remove entries based
+ * solely on their keys (mac addresses).
+ *
+ * @return the hash value
+ *
+ * @internal
+ */
+UINT32 ixEthDBKeyXORHash(void *key)
+{
+ UINT32 hashValue;
+ UINT8 *value = (UINT8 *) key;
+
+ hashValue = (value[5] << 8) | value[4];
+ hashValue ^= (value[3] << 8) | value[2];
+ hashValue ^= (value[1] << 8) | value[0];
+
+ return hashValue;
+}
+
+/**
+ * @brief mac descriptor match function
+ *
+ * @param reference mac address (typically an IxEthDBMacAddr pointer) structure
+ * @param entry pointer to a mac descriptor whose key (mac address) is to be
+ * matched against the reference key
+ *
+ * Used by the hash table to retrieve entries. Hashing entries can produce
+ * collisions, i.e. descriptors with different mac addresses and the same
+ * hash value, where this function is used to differentiate entries.
+ *
+ * @retval TRUE if the entry matches the reference key (equal addresses)
+ * @retval FALSE if the entry does not match the reference key
+ *
+ * @internal
+ */
+BOOL ixEthDBAddressMatch(void *reference, void *entry)
+{
+ return (ixEthDBAddressCompare(reference, ((MacDescriptor *) entry)->macAddress) == 0);
+}
+
+/**
+ * @brief compares two mac addresses
+ *
+ * @param mac1 first mac address to compare
+ * @param mac2 second mac address to compare
+ *
+ * This comparison works in a similar way to strcmp, producing similar results.
+ * Used to insert values keyed on mac addresses into binary search trees.
+ *
+ * @retval -1 if mac1 < mac2
+ * @retval 0 if ma1 == mac2
+ * @retval 1 if mac1 > mac2
+ */
+UINT32 ixEthDBAddressCompare(UINT8 *mac1, UINT8 *mac2)
+{
+ UINT32 local_index;
+
+ for (local_index = 0 ; local_index < IX_IEEE803_MAC_ADDRESS_SIZE ; local_index++)
+ {
+ if (mac1[local_index] > mac2[local_index])
+ {
+ return 1;
+ }
+ else if (mac1[local_index] < mac2[local_index])
+ {
+ return -1;
+ }
+ }
+
+ return 0;
+}
+