tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include <linux/config.h>
18
19#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
20#include <linux/in6.h>
21#include <linux/ipv6.h>
22#include <linux/types.h>
23
24#include <net/ipv6.h>
25
26struct inet_hashinfo;
27
28/* I have no idea if this is a good hash for v6 or not. -DaveM */
29static inline unsigned int inet6_ehashfn(const struct in6_addr *laddr, const u16 lport,
30 const struct in6_addr *faddr, const u16 fport)
31{
32 unsigned int hashent = (lport ^ fport);
33
34 hashent ^= (laddr->s6_addr32[3] ^ faddr->s6_addr32[3]);
35 hashent ^= hashent >> 16;
36 hashent ^= hashent >> 8;
37 return hashent;
38}
39
40static inline int inet6_sk_ehashfn(const struct sock *sk)
41{
42 const struct inet_sock *inet = inet_sk(sk);
43 const struct ipv6_pinfo *np = inet6_sk(sk);
44 const struct in6_addr *laddr = &np->rcv_saddr;
45 const struct in6_addr *faddr = &np->daddr;
46 const __u16 lport = inet->num;
47 const __u16 fport = inet->dport;
48 return inet6_ehashfn(laddr, lport, faddr, fport);
49}
50
51/*
52 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
53 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
54 *
55 * The sockhash lock must be held as a reader here.
56 */
57static inline struct sock *
58 __inet6_lookup_established(struct inet_hashinfo *hashinfo,
59 const struct in6_addr *saddr,
60 const u16 sport,
61 const struct in6_addr *daddr,
62 const u16 hnum,
63 const int dif)
64{
65 struct sock *sk;
66 const struct hlist_node *node;
67 const __u32 ports = INET_COMBINED_PORTS(sport, hnum);
68 /* Optimize here for direct hit, only listening connections can
69 * have wildcards anyways.
70 */
71 unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
72 struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
73
74 prefetch(head->chain.first);
75 read_lock(&head->lock);
76 sk_for_each(sk, node, &head->chain) {
77 /* For IPV6 do the cheaper port and family tests first. */
78 if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
79 goto hit; /* You sunk my battleship! */
80 }
81 /* Must check for a TIME_WAIT'er before going to listener hash. */
82 sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) {
83 const struct inet_timewait_sock *tw = inet_twsk(sk);
84
85 if(*((__u32 *)&(tw->tw_dport)) == ports &&
86 sk->sk_family == PF_INET6) {
87 const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk);
88
89 if (ipv6_addr_equal(&tcp6tw->tw_v6_daddr, saddr) &&
90 ipv6_addr_equal(&tcp6tw->tw_v6_rcv_saddr, daddr) &&
91 (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif))
92 goto hit;
93 }
94 }
95 read_unlock(&head->lock);
96 return NULL;
97
98hit:
99 sock_hold(sk);
100 read_unlock(&head->lock);
101 return sk;
102}
103
104extern struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
105 const struct in6_addr *daddr,
106 const unsigned short hnum,
107 const int dif);
108
109static inline struct sock *__inet6_lookup(struct inet_hashinfo *hashinfo,
110 const struct in6_addr *saddr,
111 const u16 sport,
112 const struct in6_addr *daddr,
113 const u16 hnum,
114 const int dif)
115{
116 struct sock *sk = __inet6_lookup_established(hashinfo, saddr, sport,
117 daddr, hnum, dif);
118 if (sk)
119 return sk;
120
121 return inet6_lookup_listener(hashinfo, daddr, hnum, dif);
122}
123
124extern struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
125 const struct in6_addr *saddr, const u16 sport,
126 const struct in6_addr *daddr, const u16 dport,
127 const int dif);
128#endif /* defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) */
129#endif /* _INET6_HASHTABLES_H */