1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Authors: Lotsa people, from code originally in tcp
8 */
9
10#ifndef _INET6_HASHTABLES_H
11#define _INET6_HASHTABLES_H
12
13
14#if IS_ENABLED(CONFIG_IPV6)
15#include <linux/in6.h>
16#include <linux/ipv6.h>
17#include <linux/types.h>
18#include <linux/jhash.h>
19
20#include <net/inet_sock.h>
21
22#include <net/ipv6.h>
23#include <net/netns/hash.h>
24
25struct inet_hashinfo;
26
27static inline unsigned int __inet6_ehashfn(const u32 lhash,
28 const u16 lport,
29 const u32 fhash,
30 const __be16 fport,
31 const u32 initval)
32{
33 const u32 ports = (((u32)lport) << 16) | (__force u32)fport;
34 return jhash_3words(a: lhash, b: fhash, c: ports, initval);
35}
36
37/*
38 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
39 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
40 *
41 * The sockhash lock must be held as a reader here.
42 */
43struct sock *__inet6_lookup_established(const struct net *net,
44 const struct in6_addr *saddr,
45 const __be16 sport,
46 const struct in6_addr *daddr,
47 const u16 hnum, const int dif,
48 const int sdif);
49
50typedef u32 (inet6_ehashfn_t)(const struct net *net,
51 const struct in6_addr *laddr, const u16 lport,
52 const struct in6_addr *faddr, const __be16 fport);
53
54inet6_ehashfn_t inet6_ehashfn;
55
56INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
57
58struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
59 struct sk_buff *skb, int doff,
60 const struct in6_addr *saddr,
61 __be16 sport,
62 const struct in6_addr *daddr,
63 unsigned short hnum,
64 inet6_ehashfn_t *ehashfn);
65
66struct sock *inet6_lookup_listener(const struct net *net,
67 struct sk_buff *skb, int doff,
68 const struct in6_addr *saddr,
69 const __be16 sport,
70 const struct in6_addr *daddr,
71 const unsigned short hnum,
72 const int dif, const int sdif);
73
74struct sock *inet6_lookup_run_sk_lookup(const struct net *net,
75 int protocol,
76 struct sk_buff *skb, int doff,
77 const struct in6_addr *saddr,
78 const __be16 sport,
79 const struct in6_addr *daddr,
80 const u16 hnum, const int dif,
81 inet6_ehashfn_t *ehashfn);
82
83static inline struct sock *__inet6_lookup(const struct net *net,
84 struct sk_buff *skb, int doff,
85 const struct in6_addr *saddr,
86 const __be16 sport,
87 const struct in6_addr *daddr,
88 const u16 hnum,
89 const int dif, const int sdif,
90 bool *refcounted)
91{
92 struct sock *sk = __inet6_lookup_established(net, saddr, sport,
93 daddr, hnum,
94 dif, sdif);
95 *refcounted = true;
96 if (sk)
97 return sk;
98 *refcounted = false;
99 return inet6_lookup_listener(net, skb, doff, saddr, sport,
100 daddr, hnum, dif, sdif);
101}
102
103static inline
104struct sock *inet6_steal_sock(struct net *net, struct sk_buff *skb, int doff,
105 const struct in6_addr *saddr, const __be16 sport,
106 const struct in6_addr *daddr, const __be16 dport,
107 bool *refcounted, inet6_ehashfn_t *ehashfn)
108{
109 struct sock *sk, *reuse_sk;
110 bool prefetched;
111
112 sk = skb_steal_sock(skb, refcounted, prefetched: &prefetched);
113 if (!sk)
114 return NULL;
115
116 if (!prefetched || !sk_fullsock(sk))
117 return sk;
118
119 if (sk->sk_protocol == IPPROTO_TCP) {
120 if (sk->sk_state != TCP_LISTEN)
121 return sk;
122 } else if (sk->sk_protocol == IPPROTO_UDP) {
123 if (sk->sk_state != TCP_CLOSE)
124 return sk;
125 } else {
126 return sk;
127 }
128
129 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
130 saddr, sport, daddr, ntohs(dport),
131 ehashfn);
132 if (!reuse_sk)
133 return sk;
134
135 /* We've chosen a new reuseport sock which is never refcounted. This
136 * implies that sk also isn't refcounted.
137 */
138 WARN_ON_ONCE(*refcounted);
139
140 return reuse_sk;
141}
142
143static inline struct sock *__inet6_lookup_skb(struct sk_buff *skb, int doff,
144 const __be16 sport,
145 const __be16 dport,
146 int iif, int sdif,
147 bool *refcounted)
148{
149 struct net *net = skb_dst_dev_net_rcu(skb);
150 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
151 struct sock *sk;
152
153 sk = inet6_steal_sock(net, skb, doff, saddr: &ip6h->saddr, sport, daddr: &ip6h->daddr, dport,
154 refcounted, ehashfn: inet6_ehashfn);
155 if (IS_ERR(ptr: sk))
156 return NULL;
157 if (sk)
158 return sk;
159
160 return __inet6_lookup(net, skb, doff, saddr: &ip6h->saddr, sport,
161 daddr: &ip6h->daddr, ntohs(dport),
162 dif: iif, sdif, refcounted);
163}
164
165struct sock *inet6_lookup(const struct net *net, struct sk_buff *skb, int doff,
166 const struct in6_addr *saddr, const __be16 sport,
167 const struct in6_addr *daddr, const __be16 dport,
168 const int dif);
169
170static inline bool inet6_match(const struct net *net, const struct sock *sk,
171 const struct in6_addr *saddr,
172 const struct in6_addr *daddr,
173 const __portpair ports,
174 const int dif, const int sdif)
175{
176 if (!net_eq(net1: sock_net(sk), net2: net) ||
177 sk->sk_family != AF_INET6 ||
178 sk->sk_portpair != ports ||
179 !ipv6_addr_equal(a1: &sk->sk_v6_daddr, a2: saddr) ||
180 !ipv6_addr_equal(a1: &sk->sk_v6_rcv_saddr, a2: daddr))
181 return false;
182
183 /* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */
184 return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,
185 sdif);
186}
187#endif /* IS_ENABLED(CONFIG_IPV6) */
188
189#endif /* _INET6_HASHTABLES_H */
190

source code of linux/include/net/inet6_hashtables.h