text: /*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  INET is implemented using the BSD Socket
   *		interface as the means of communication with the user level.
   *
   * Authors:	Lotsa people, from code originally in tcp
   *
   *	This program is free software; you can redistribute it and/or
   *      modify it under the terms of the GNU General Public License
   *      as published by the Free Software Foundation; either version
   *      2 of the License, or (at your option) any later version.
   */
  
  #ifndef _INET6_HASHTABLES_H
  #define _INET6_HASHTABLES_H
  
  
  #if IS_ENABLED(CONFIG_IPV6)
  #include <linux/in6.h>
  #include <linux/ipv6.h>
  #include <linux/types.h>
  #include <linux/jhash.h>
  
  #include <net/inet_sock.h>
  
  #include <net/ipv6.h>
  #include <net/netns/hash.h>
  
  struct inet_hashinfo;
  
  static inline unsigned int __inet6_ehashfn(const u32 lhash,
  				    const u16 lport,
  				    const u32 fhash,
  				    const __be16 fport,
  				    const u32 initval)
  {
  	const u32 ports = (((u32)lport) << 16) | (__force u32)fport;
  	return jhash_3words(lhash, fhash, ports, initval);
  }
  
  int __inet6_hash(struct sock *sk, struct inet_timewait_sock *twp);
  
  /*
   * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
   * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
   *
   * The sockhash lock must be held as a reader here.
   */
  struct sock *__inet6_lookup_established(struct net *net,
  					struct inet_hashinfo *hashinfo,
  					const struct in6_addr *saddr,
  					const __be16 sport,
  					const struct in6_addr *daddr,
  					const u16 hnum, const int dif);
  
  struct sock *inet6_lookup_listener(struct net *net,
  				   struct inet_hashinfo *hashinfo,
  				   const struct in6_addr *saddr,
  				   const __be16 sport,
  				   const struct in6_addr *daddr,
  				   const unsigned short hnum, const int dif);
  
  static inline struct sock *__inet6_lookup(struct net *net,
  					  struct inet_hashinfo *hashinfo,
  					  const struct in6_addr *saddr,
  					  const __be16 sport,
  					  const struct in6_addr *daddr,
  					  const u16 hnum,
  					  const int dif)
  {
  	struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr,
  						sport, daddr, hnum, dif);
  	if (sk)
  		return sk;
  
  	return inet6_lookup_listener(net, hashinfo, saddr, sport,
  				     daddr, hnum, dif);
  }
  
  static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
  					      struct sk_buff *skb,
  					      const __be16 sport,
  					      const __be16 dport,
  					      int iif)
  {
  	struct sock *sk = skb_steal_sock(skb);
  
  	if (sk)
  		return sk;
  
  	return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
  			      &ipv6_hdr(skb)->saddr, sport,
  			      &ipv6_hdr(skb)->daddr, ntohs(dport),
  			      iif);
  }
  
  struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
  			  const struct in6_addr *saddr, const __be16 sport,
  			  const struct in6_addr *daddr, const __be16 dport,
  			  const int dif);
  #endif /* IS_ENABLED(CONFIG_IPV6) */
  #endif /* _INET6_HASHTABLES_H */
  