net/ipv6/inet6_hashtables.c

   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  *              Generic INET6 transport hashtables
   7  *
   8  * Authors:     Lotsa people, from code originally in tcp
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/config.h>
  17
  18 #include <linux/module.h>
  19
  20 #include <net/inet_connection_sock.h>
  21 #include <net/inet_hashtables.h>
  22 #include <net/inet6_hashtables.h>
  23
  24 struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
  25                                    const struct in6_addr *daddr,
  26                                    const unsigned short hnum, const int dif)
  27 {
  28         struct sock *sk;
  29         const struct hlist_node *node;
  30         struct sock *result = NULL;
  31         int score, hiscore = 0;
  32
  33         read_lock(&hashinfo->lhash_lock);
  34         sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
  35                 if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
  36                         const struct ipv6_pinfo *np = inet6_sk(sk);
  37
  38                         score = 1;
  39                         if (!ipv6_addr_any(&np->rcv_saddr)) {
  40                                 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
  41                                         continue;
  42                                 score++;
  43                         }
  44                         if (sk->sk_bound_dev_if) {
  45                                 if (sk->sk_bound_dev_if != dif)
  46                                         continue;
  47                                 score++;
  48                         }
  49                         if (score == 3) {
  50                                 result = sk;
  51                                 break;
  52                         }
  53                         if (score > hiscore) {
  54                                 hiscore = score;
  55                                 result = sk;
  56                         }
  57                 }
  58         }
  59         if (result)
  60                 sock_hold(result);
  61         read_unlock(&hashinfo->lhash_lock);
  62         return result;
  63 }
  64
  65 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
  66
  67 struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
  68                           const struct in6_addr *saddr, const u16 sport,
  69                           const struct in6_addr *daddr, const u16 dport,
  70                           const int dif)
  71 {
  72         struct sock *sk;
  73
  74         local_bh_disable();
  75         sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
  76         local_bh_enable();
  77
  78         return sk;
  79 }
  80
  81 EXPORT_SYMBOL_GPL(inet6_lookup);