/** * @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;}