IABSD.fr/src/sys/net/toeplitz.h

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• Author : dlg
  Date : 2023-05-17 10:22:17
  Hash : 2c85293c
  Message : fix stoeplitz_hash_h32. discussed with and ok tb@

• sys/net/toeplitz.h

• /*	$OpenBSD: toeplitz.h,v 1.11 2023/05/17 10:22:17 dlg Exp $ */
  
  /*
   * Copyright (c) 2019 David Gwynne <dlg@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #ifndef _SYS_NET_TOEPLITZ_H_
  #define _SYS_NET_TOEPLITZ_H_
  
  #include <sys/endian.h>
  
  /*
   * symmetric toeplitz
   */
  
  typedef uint16_t stoeplitz_key;
  
  struct stoeplitz_cache {
  	uint16_t	bytes[256];
  };
  
  static __unused inline uint16_t
  stoeplitz_cache_entry(const struct stoeplitz_cache *scache, uint8_t byte)
  {
  	return (scache->bytes[byte]);
  }
  
  void		stoeplitz_cache_init(struct stoeplitz_cache *, stoeplitz_key);
  
  uint16_t	stoeplitz_hash_ip4(const struct stoeplitz_cache *,
  		    uint32_t, uint32_t);
  uint16_t	stoeplitz_hash_ip4port(const struct stoeplitz_cache *,
  		    uint32_t, uint32_t, uint16_t, uint16_t);
  
  #ifdef INET6
  struct in6_addr;
  uint16_t	stoeplitz_hash_ip6(const struct stoeplitz_cache *,
  		    const struct in6_addr *, const struct in6_addr *);
  uint16_t	stoeplitz_hash_ip6port(const struct stoeplitz_cache *,
  		    const struct in6_addr *, const struct in6_addr *,
  		    uint16_t, uint16_t);
  #endif
  
  uint16_t	stoeplitz_hash_eaddr(const struct stoeplitz_cache *,
  		    const uint8_t *);
  
  /* hash a uint16_t in network byte order */
  static __unused inline uint16_t
  stoeplitz_hash_n16(const struct stoeplitz_cache *scache, uint16_t n16)
  {
  	uint16_t hi, lo;
  
  	hi = stoeplitz_cache_entry(scache, n16 >> 8);
  	lo = stoeplitz_cache_entry(scache, n16);
  
  	return (hi ^ swap16(lo));
  }
  
  /* hash a uint32_t in network byte order */
  static __unused inline uint16_t
  stoeplitz_hash_n32(const struct stoeplitz_cache *scache, uint32_t n32)
  {
  	return (stoeplitz_hash_n16(scache, n32 ^ (n32 >> 16)));
  }
  
  /* hash a uint16_t in host byte order */
  static __unused inline uint16_t
  stoeplitz_hash_h16(const struct stoeplitz_cache *scache, uint16_t h16)
  {
  	uint16_t lo, hi;
  
  	lo = stoeplitz_cache_entry(scache, h16);
  	hi = stoeplitz_cache_entry(scache, h16 >> 8);
  
  #if _BYTE_ORDER == _BIG_ENDIAN
  	return (hi ^ swap16(lo));
  #else
  	return (swap16(hi) ^ lo);
  #endif
  }
  
  static __unused inline uint16_t
  stoeplitz_hash_h32(const struct stoeplitz_cache *scache, uint32_t h32)
  {
  	return (stoeplitz_hash_h16(scache, h32 ^ (h32 >> 16)));
  }
  
  static __unused inline uint16_t
  stoeplitz_hash_h64(const struct stoeplitz_cache *scache, uint64_t h64)
  {
  	return (stoeplitz_hash_h32(scache, h64 ^ (h64 >> 32)));
  }
  
  /*
   * system provided symmetric toeplitz
   */
  
  #define STOEPLITZ_KEYSEED	0x6d5a
  
  void		stoeplitz_init(void);
  
  void		stoeplitz_to_key(void *, size_t)
  		    __bounded((__buffer__, 1, 2));
  
  extern const struct stoeplitz_cache *const stoeplitz_cache;
  
  #define stoeplitz_n16(_n16) \
  	stoeplitz_hash_n16(stoeplitz_cache, (_n16))
  #define stoeplitz_n32(_n32) \
  	stoeplitz_hash_n32(stoeplitz_cache, (_n32))
  #define stoeplitz_h16(_h16) \
  	stoeplitz_hash_h16(stoeplitz_cache, (_h16))
  #define stoeplitz_h32(_h32) \
  	stoeplitz_hash_h32(stoeplitz_cache, (_h32))
  #define stoeplitz_h64(_h64) \
  	stoeplitz_hash_h64(stoeplitz_cache, (_h64))
  #define stoeplitz_port(_p)	stoeplitz_n16((_p))
  #define stoeplitz_ip4(_sa4, _da4) \
  	stoeplitz_hash_ip4(stoeplitz_cache, (_sa4), (_da4))
  #define stoeplitz_ip4port(_sa4, _da4, _sp, _dp) \
  	stoeplitz_hash_ip4port(stoeplitz_cache, (_sa4), (_da4), (_sp), (_dp))
  #ifdef INET6
  #define stoeplitz_ip6(_sa6, _da6) \
  	stoeplitz_hash_ip6(stoeplitz_cache, (_sa6), (_da6))
  #define stoeplitz_ip6port(_sa6, _da6, _sp, _dp) \
  	stoeplitz_hash_ip6port(stoeplitz_cache, (_sa6), (_da6), (_sp), (_dp))
  #endif
  #define stoeplitz_eaddr(_ea) \
  	stoeplitz_hash_eaddr(stoeplitz_cache, (_ea))
  
  #endif /* _SYS_NET_TOEPLITZ_H_ */