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 = skb_steal_sock(skb);
100 
101 	if (sk)
102 		return sk;
103 
104 	return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
105 			      &ipv6_hdr(skb)->saddr, sport,
106 			      &ipv6_hdr(skb)->daddr, ntohs(dport),
107 			      inet6_iif(skb));
108 }
109 
110 extern struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
111 				 const struct in6_addr *saddr, const __be16 sport,
112 				 const struct in6_addr *daddr, const __be16 dport,
113 				 const int dif);
114 #endif /* IS_ENABLED(CONFIG_IPV6) */
115 #endif /* _INET6_HASHTABLES_H */
116