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
25 struct inet_hashinfo;
26
__inet6_ehashfn(const u32 lhash,const u16 lport,const u32 fhash,const __be16 fport,const u32 initval)27 static 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(lhash, fhash, 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 */
43 struct 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
50 typedef 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
54 inet6_ehashfn_t inet6_ehashfn;
55
56 INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
57
58 struct 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
66 struct 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
74 struct 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
__inet6_lookup(const struct net * net,struct sk_buff * skb,int doff,const struct in6_addr * saddr,const __be16 sport,const struct in6_addr * daddr,const u16 hnum,const int dif,const int sdif,bool * refcounted)83 static 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
103 static inline
inet6_steal_sock(struct net * net,struct sk_buff * skb,int doff,const struct in6_addr * saddr,const __be16 sport,const struct in6_addr * daddr,const __be16 dport,bool * refcounted,inet6_ehashfn_t * ehashfn)104 struct 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);
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
__inet6_lookup_skb(struct sk_buff * skb,int doff,const __be16 sport,const __be16 dport,int iif,int sdif,bool * refcounted)143 static 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, &ip6h->saddr, sport, &ip6h->daddr, dport,
154 refcounted, inet6_ehashfn);
155 if (IS_ERR(sk))
156 return NULL;
157 if (sk)
158 return sk;
159
160 return __inet6_lookup(net, skb, doff, &ip6h->saddr, sport,
161 &ip6h->daddr, ntohs(dport),
162 iif, sdif, refcounted);
163 }
164
165 struct 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
inet6_match(const struct net * net,const struct sock * sk,const struct in6_addr * saddr,const struct in6_addr * daddr,const __portpair ports,const int dif,const int sdif)170 static 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(sock_net(sk), net) ||
177 sk->sk_family != AF_INET6 ||
178 READ_ONCE(sk->sk_portpair) != ports ||
179 !ipv6_addr_equal(&sk->sk_v6_daddr, saddr) ||
180 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 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