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 struct inet_hashinfo *hashinfo,
45 const struct in6_addr *saddr,
46 const __be16 sport,
47 const struct in6_addr *daddr,
48 const u16 hnum, const int dif,
49 const int sdif);
50
51typedef u32 (inet6_ehashfn_t)(const struct net *net,
52 const struct in6_addr *laddr, const u16 lport,
53 const struct in6_addr *faddr, const __be16 fport);
54
55inet6_ehashfn_t inet6_ehashfn;
56
57INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
58
59struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
60 struct sk_buff *skb, int doff,
61 const struct in6_addr *saddr,
62 __be16 sport,
63 const struct in6_addr *daddr,
64 unsigned short hnum,
65 inet6_ehashfn_t *ehashfn);
66
67struct sock *inet6_lookup_listener(const struct net *net,
68 struct inet_hashinfo *hashinfo,
69 struct sk_buff *skb, int doff,
70 const struct in6_addr *saddr,
71 const __be16 sport,
72 const struct in6_addr *daddr,
73 const unsigned short hnum,
74 const int dif, const int sdif);
75
76struct sock *inet6_lookup_run_sk_lookup(const struct net *net,
77 int protocol,
78 struct sk_buff *skb, int doff,
79 const struct in6_addr *saddr,
80 const __be16 sport,
81 const struct in6_addr *daddr,
82 const u16 hnum, const int dif,
83 inet6_ehashfn_t *ehashfn);
84
85static inline struct sock *__inet6_lookup(const struct net *net,
86 struct inet_hashinfo *hashinfo,
87 struct sk_buff *skb, int doff,
88 const struct in6_addr *saddr,
89 const __be16 sport,
90 const struct in6_addr *daddr,
91 const u16 hnum,
92 const int dif, const int sdif,
93 bool *refcounted)
94{
95 struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr,
96 sport, daddr, hnum,
97 dif, sdif);
98 *refcounted = true;
99 if (sk)
100 return sk;
101 *refcounted = false;
102 return inet6_lookup_listener(net, hashinfo, skb, doff, saddr, sport,
103 daddr, hnum, dif, sdif);
104}
105
106static inline
107struct sock *inet6_steal_sock(struct net *net, struct sk_buff *skb, int doff,
108 const struct in6_addr *saddr, const __be16 sport,
109 const struct in6_addr *daddr, const __be16 dport,
110 bool *refcounted, inet6_ehashfn_t *ehashfn)
111{
112 struct sock *sk, *reuse_sk;
113 bool prefetched;
114
115 sk = skb_steal_sock(skb, refcounted, prefetched: &prefetched);
116 if (!sk)
117 return NULL;
118
119 if (!prefetched || !sk_fullsock(sk))
120 return sk;
121
122 if (sk->sk_protocol == IPPROTO_TCP) {
123 if (sk->sk_state != TCP_LISTEN)
124 return sk;
125 } else if (sk->sk_protocol == IPPROTO_UDP) {
126 if (sk->sk_state != TCP_CLOSE)
127 return sk;
128 } else {
129 return sk;
130 }
131
132 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
133 saddr, sport, daddr, ntohs(dport),
134 ehashfn);
135 if (!reuse_sk)
136 return sk;
137
138 /* We've chosen a new reuseport sock which is never refcounted. This
139 * implies that sk also isn't refcounted.
140 */
141 WARN_ON_ONCE(*refcounted);
142
143 return reuse_sk;
144}
145
146static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
147 struct sk_buff *skb, int doff,
148 const __be16 sport,
149 const __be16 dport,
150 int iif, int sdif,
151 bool *refcounted)
152{
153 struct net *net = dev_net_rcu(dev: skb_dst(skb)->dev);
154 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
155 struct sock *sk;
156
157 sk = inet6_steal_sock(net, skb, doff, saddr: &ip6h->saddr, sport, daddr: &ip6h->daddr, dport,
158 refcounted, ehashfn: inet6_ehashfn);
159 if (IS_ERR(ptr: sk))
160 return NULL;
161 if (sk)
162 return sk;
163
164 return __inet6_lookup(net, hashinfo, skb,
165 doff, saddr: &ip6h->saddr, sport,
166 daddr: &ip6h->daddr, ntohs(dport),
167 dif: iif, sdif, refcounted);
168}
169
170struct sock *inet6_lookup(const struct net *net, struct inet_hashinfo *hashinfo,
171 struct sk_buff *skb, int doff,
172 const struct in6_addr *saddr, const __be16 sport,
173 const struct in6_addr *daddr, const __be16 dport,
174 const int dif);
175
176int inet6_hash(struct sock *sk);
177
178static inline bool inet6_match(const struct net *net, const struct sock *sk,
179 const struct in6_addr *saddr,
180 const struct in6_addr *daddr,
181 const __portpair ports,
182 const int dif, const int sdif)
183{
184 if (!net_eq(net1: sock_net(sk), net2: net) ||
185 sk->sk_family != AF_INET6 ||
186 sk->sk_portpair != ports ||
187 !ipv6_addr_equal(a1: &sk->sk_v6_daddr, a2: saddr) ||
188 !ipv6_addr_equal(a1: &sk->sk_v6_rcv_saddr, a2: daddr))
189 return false;
190
191 /* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */
192 return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,
193 sdif);
194}
195#endif /* IS_ENABLED(CONFIG_IPV6) */
196
197#endif /* _INET6_HASHTABLES_H */
198

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