include/net/inet6_hashtables.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  * Authors:     Lotsa people, from code originally in tcp
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #ifndef _INET6_HASHTABLES_H
  15 #define _INET6_HASHTABLES_H
  16
  17
  18 #if IS_ENABLED(CONFIG_IPV6)
  19 #include <linux/in6.h>
  20 #include <linux/ipv6.h>
  21 #include <linux/types.h>
  22 #include <linux/jhash.h>
  23
  24 #include <net/inet_sock.h>
  25
  26 #include <net/ipv6.h>
  27 #include <net/netns/hash.h>
  28
  29 struct inet_hashinfo;
  30
  31 /* I have no idea if this is a good hash for v6 or not. -DaveM */
  32 static inline unsigned int inet6_ehashfn(struct net *net,
  33                                 const struct in6_addr *laddr, const u16 lport,
  34                                 const struct in6_addr *faddr, const __be16 fport)
  35 {
  36         u32 ports = (lport ^ (__force u16)fport);
  37
  38         return jhash_3words((__force u32)laddr->s6_addr32[3],
  39                             (__force u32)faddr->s6_addr32[3],
  40                             ports, inet_ehash_secret + net_hash_mix(net));
  41 }
  42
  43 static inline int inet6_sk_ehashfn(const struct sock *sk)
  44 {
  45         const struct inet_sock *inet = inet_sk(sk);
  46         const struct ipv6_pinfo *np = inet6_sk(sk);
  47         const struct in6_addr *laddr = &np->rcv_saddr;
  48         const struct in6_addr *faddr = &np->daddr;
  49         const __u16 lport = inet->inet_num;
  50         const __be16 fport = inet->inet_dport;
  51         struct net *net = sock_net(sk);
  52
  53         return inet6_ehashfn(net, laddr, lport, faddr, fport);
  54 }
  55
  56 extern int __inet6_hash(struct sock *sk, struct inet_timewait_sock *twp);
  57
  58 /*
  59  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
  60  * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
  61  *
  62  * The sockhash lock must be held as a reader here.
  63  */
  64 extern struct sock *__inet6_lookup_established(struct net *net,
  65                                            struct inet_hashinfo *hashinfo,
  66                                            const struct in6_addr *saddr,
  67                                            const __be16 sport,
  68                                            const struct in6_addr *daddr,
  69                                            const u16 hnum,
  70                                            const int dif);
  71
  72 extern struct sock *inet6_lookup_listener(struct net *net,
  73                                           struct inet_hashinfo *hashinfo,
  74                                           const struct in6_addr *daddr,
  75                                           const unsigned short hnum,
  76                                           const int dif);
  77
  78 static inline struct sock *__inet6_lookup(struct net *net,
  79                                           struct inet_hashinfo *hashinfo,
  80                                           const struct in6_addr *saddr,
  81                                           const __be16 sport,
  82                                           const struct in6_addr *daddr,
  83                                           const u16 hnum,
  84                                           const int dif)
  85 {
  86         struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr,
  87                                                 sport, daddr, hnum, dif);
  88         if (sk)
  89                 return sk;
  90
  91         return inet6_lookup_listener(net, hashinfo, daddr, hnum, dif);
  92 }
  93
  94 static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
  95                                               struct sk_buff *skb,
  96                                               const __be16 sport,
  97                                               const __be16 dport)
  98 {
  99         struct sock *sk;
 100
 101         if (unlikely(sk = skb_steal_sock(skb)))
 102                 return sk;
 103         else return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
 104                                    &ipv6_hdr(skb)->saddr, sport,
 105                                    &ipv6_hdr(skb)->daddr, ntohs(dport),
 106                                    inet6_iif(skb));
 107 }
 108
 109 extern struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
 110                                  const struct in6_addr *saddr, const __be16 sport,
 111                                  const struct in6_addr *daddr, const __be16 dport,
 112                                  const int dif);
 113 #endif /* IS_ENABLED(CONFIG_IPV6) */
 114 #endif /* _INET6_HASHTABLES_H */