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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
27void inet6_init_ehash_secret(void);
28
29static inline unsigned int __inet6_ehashfn(const u32 lhash,
30 const u16 lport,
31 const u32 fhash,
32 const __be16 fport,
33 const u32 initval)
34{
35 const u32 ports = (((u32)lport) << 16) | (__force u32)fport;
36 return jhash_3words(lhash, fhash, ports, initval);
37}
38
39/*
40 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
41 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
42 *
43 * The sockhash lock must be held as a reader here.
44 */
45struct sock *__inet6_lookup_established(const struct net *net,
46 const struct in6_addr *saddr,
47 const __be16 sport,
48 const struct in6_addr *daddr,
49 const u16 hnum, const int dif,
50 const int sdif);
51
52typedef u32 (inet6_ehashfn_t)(const struct net *net,
53 const struct in6_addr *laddr, const u16 lport,
54 const struct in6_addr *faddr, const __be16 fport);
55
56inet6_ehashfn_t inet6_ehashfn;
57
58INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
59
60struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
61 struct sk_buff *skb, int doff,
62 const struct in6_addr *saddr,
63 __be16 sport,
64 const struct in6_addr *daddr,
65 unsigned short hnum,
66 inet6_ehashfn_t *ehashfn);
67
68struct sock *inet6_lookup_listener(const struct net *net,
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 sk_buff *skb, int doff,
87 const struct in6_addr *saddr,
88 const __be16 sport,
89 const struct in6_addr *daddr,
90 const u16 hnum,
91 const int dif, const int sdif,
92 bool *refcounted)
93{
94 struct sock *sk = __inet6_lookup_established(net, saddr, sport,
95 daddr, hnum,
96 dif, sdif);
97 *refcounted = true;
98 if (sk)
99 return sk;
100 *refcounted = false;
101 return inet6_lookup_listener(net, skb, doff, saddr, sport,
102 daddr, hnum, dif, sdif);
103}
104
105static inline
106struct sock *inet6_steal_sock(struct net *net, struct sk_buff *skb, int doff,
107 const struct in6_addr *saddr, const __be16 sport,
108 const struct in6_addr *daddr, const __be16 dport,
109 bool *refcounted, inet6_ehashfn_t *ehashfn)
110{
111 struct sock *sk, *reuse_sk;
112 bool prefetched;
113
114 sk = skb_steal_sock(skb, refcounted, &prefetched);
115 if (!sk)
116 return NULL;
117
118 if (!prefetched || !sk_fullsock(sk))
119 return sk;
120
121 if (sk->sk_protocol == IPPROTO_TCP) {
122 if (sk->sk_state != TCP_LISTEN)
123 return sk;
124 } else if (sk->sk_protocol == IPPROTO_UDP) {
125 if (sk->sk_state != TCP_CLOSE)
126 return sk;
127 } else {
128 return sk;
129 }
130
131 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
132 saddr, sport, daddr, ntohs(dport),
133 ehashfn);
134 if (!reuse_sk)
135 return sk;
136
137 /* We've chosen a new reuseport sock which is never refcounted. This
138 * implies that sk also isn't refcounted.
139 */
140 WARN_ON_ONCE(*refcounted);
141
142 return reuse_sk;
143}
144
145static inline struct sock *__inet6_lookup_skb(struct sk_buff *skb, int doff,
146 const __be16 sport,
147 const __be16 dport,
148 int iif, int sdif,
149 bool *refcounted)
150{
151 struct net *net = skb_dst_dev_net_rcu(skb);
152 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
153 struct sock *sk;
154
155 sk = inet6_steal_sock(net, skb, doff, &ip6h->saddr, sport, &ip6h->daddr, dport,
156 refcounted, inet6_ehashfn);
157 if (IS_ERR(sk))
158 return NULL;
159 if (sk)
160 return sk;
161
162 return __inet6_lookup(net, skb, doff, &ip6h->saddr, sport,
163 &ip6h->daddr, ntohs(dport),
164 iif, sdif, refcounted);
165}
166
167struct sock *inet6_lookup(const struct net *net, struct sk_buff *skb, int doff,
168 const struct in6_addr *saddr, const __be16 sport,
169 const struct in6_addr *daddr, const __be16 dport,
170 const int dif);
171
172static inline bool inet6_match(const struct net *net, const struct sock *sk,
173 const struct in6_addr *saddr,
174 const struct in6_addr *daddr,
175 const __portpair ports,
176 const int dif, const int sdif)
177{
178 if (!net_eq(sock_net(sk), net) ||
179 sk->sk_family != AF_INET6 ||
180 READ_ONCE(sk->sk_portpair) != ports ||
181 !ipv6_addr_equal(&sk->sk_v6_daddr, saddr) ||
182 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
183 return false;
184
185 /* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */
186 return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,
187 sdif);
188}
189#endif /* IS_ENABLED(CONFIG_IPV6) */
190
191#endif /* _INET6_HASHTABLES_H */