FreeBSD/Linux Kernel Cross Reference
sys/net/toeplitz2.h

     /*
      * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
      *
      * This code is derived from software contributed to The DragonFly Project
      * by Sepherosa Ziehau <sepherosa@gmail.com>
      *
      * 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 DragonFly Project nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific, prior written permission.
     *
     * 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 HOLDERS 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.
     */
    
    #ifndef _NET_TOEPLITZ2_H_
    #define _NET_TOEPLITZ2_H_
    
    #ifndef _KERNEL
    #error "kernel only header file"
    #endif
    
    #define TOEPLITZ_KEYSEED_CNT    2
    
    extern uint32_t toeplitz_cache[TOEPLITZ_KEYSEED_CNT][256];
    
    static __inline uint32_t
    toeplitz_rawhash_addrport(in_addr_t _faddr, in_addr_t _laddr,
                              in_port_t _fport, in_port_t _lport)
    {
            uint32_t _res;
    
            _res =  toeplitz_cache[0][_faddr & 0xff];
            _res ^= toeplitz_cache[0][(_faddr >> 16) & 0xff];
            _res ^= toeplitz_cache[0][_laddr & 0xff];
            _res ^= toeplitz_cache[0][(_laddr >> 16) & 0xff];
            _res ^= toeplitz_cache[0][_fport & 0xff];
            _res ^= toeplitz_cache[0][_lport & 0xff];
    
            _res ^= toeplitz_cache[1][(_faddr >> 8) & 0xff];
            _res ^= toeplitz_cache[1][(_faddr >> 24) & 0xff];
            _res ^= toeplitz_cache[1][(_laddr >> 8) & 0xff];
            _res ^= toeplitz_cache[1][(_laddr >> 24) & 0xff];
            _res ^= toeplitz_cache[1][(_fport >> 8) & 0xff];
            _res ^= toeplitz_cache[1][(_lport >> 8) & 0xff];
    
            return _res;
    }
    
    static __inline uint32_t
    toeplitz_rawhash_addr(in_addr_t _faddr, in_addr_t _laddr)
    {
            uint32_t _res;
    
            _res =  toeplitz_cache[0][_faddr & 0xff];
            _res ^= toeplitz_cache[0][(_faddr >> 16) & 0xff];
            _res ^= toeplitz_cache[0][_laddr & 0xff];
            _res ^= toeplitz_cache[0][(_laddr >> 16) & 0xff];
    
            _res ^= toeplitz_cache[1][(_faddr >> 8) & 0xff];
            _res ^= toeplitz_cache[1][(_faddr >> 24) & 0xff];
            _res ^= toeplitz_cache[1][(_laddr >> 8) & 0xff];
            _res ^= toeplitz_cache[1][(_laddr >> 24) & 0xff];
    
            return _res;
    }
    
    static __inline int
    toeplitz_hash(uint32_t _rawhash)
    {
            return (_rawhash & 0xffff);
    }
    
    #endif  /* !_NET_TOEPLITZ2_H_ */

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