xref: /linux/include/net/inet6_hashtables.h (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
19 #include <linux/in6.h>
20 #include <linux/ipv6.h>
21 #include <linux/types.h>
22 
23 #include <net/ipv6.h>
24 
25 struct inet_hashinfo;
26 
27 /* I have no idea if this is a good hash for v6 or not. -DaveM */
28 static inline unsigned int inet6_ehashfn(const struct in6_addr *laddr, const u16 lport,
29 				const struct in6_addr *faddr, const __be16 fport)
30 {
31 	unsigned int hashent = (lport ^ (__force u16)fport);
32 
33 	hashent ^= (__force u32)(laddr->s6_addr32[3] ^ faddr->s6_addr32[3]);
34 	hashent ^= hashent >> 16;
35 	hashent ^= hashent >> 8;
36 	return hashent;
37 }
38 
39 static inline int inet6_sk_ehashfn(const struct sock *sk)
40 {
41 	const struct inet_sock *inet = inet_sk(sk);
42 	const struct ipv6_pinfo *np = inet6_sk(sk);
43 	const struct in6_addr *laddr = &np->rcv_saddr;
44 	const struct in6_addr *faddr = &np->daddr;
45 	const __u16 lport = inet->num;
46 	const __be16 fport = inet->dport;
47 	return inet6_ehashfn(laddr, lport, faddr, fport);
48 }
49 
50 extern void __inet6_hash(struct inet_hashinfo *hashinfo, struct sock *sk);
51 
52 /*
53  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
54  * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
55  *
56  * The sockhash lock must be held as a reader here.
57  */
58 extern struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
59 					   const struct in6_addr *saddr,
60 					   const __be16 sport,
61 					   const struct in6_addr *daddr,
62 					   const u16 hnum,
63 					   const int dif);
64 
65 extern struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
66 					  const struct in6_addr *daddr,
67 					  const unsigned short hnum,
68 					  const int dif);
69 
70 static inline struct sock *__inet6_lookup(struct inet_hashinfo *hashinfo,
71 					  const struct in6_addr *saddr,
72 					  const __be16 sport,
73 					  const struct in6_addr *daddr,
74 					  const u16 hnum,
75 					  const int dif)
76 {
77 	struct sock *sk = __inet6_lookup_established(hashinfo, saddr, sport,
78 						     daddr, hnum, dif);
79 	if (sk)
80 		return sk;
81 
82 	return inet6_lookup_listener(hashinfo, daddr, hnum, dif);
83 }
84 
85 extern struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
86 				 const struct in6_addr *saddr, const __be16 sport,
87 				 const struct in6_addr *daddr, const __be16 dport,
88 				 const int dif);
89 #endif /* defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) */
90 #endif /* _INET6_HASHTABLES_H */
91