Merge tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
[linux-2.6-microblaze.git] / net / ipv6 / inet6_hashtables.c
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  *              Generic INET6 transport hashtables
8  *
9  * Authors:     Lotsa people, from code originally in tcp, generalised here
10  *              by Arnaldo Carvalho de Melo <acme@mandriva.com>
11  */
12
13 #include <linux/module.h>
14 #include <linux/random.h>
15
16 #include <net/addrconf.h>
17 #include <net/inet_connection_sock.h>
18 #include <net/inet_hashtables.h>
19 #include <net/inet6_hashtables.h>
20 #include <net/secure_seq.h>
21 #include <net/ip.h>
22 #include <net/sock_reuseport.h>
23
24 u32 inet6_ehashfn(const struct net *net,
25                   const struct in6_addr *laddr, const u16 lport,
26                   const struct in6_addr *faddr, const __be16 fport)
27 {
28         static u32 inet6_ehash_secret __read_mostly;
29         static u32 ipv6_hash_secret __read_mostly;
30
31         u32 lhash, fhash;
32
33         net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
34         net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
35
36         lhash = (__force u32)laddr->s6_addr32[3];
37         fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
38
39         return __inet6_ehashfn(lhash, lport, fhash, fport,
40                                inet6_ehash_secret + net_hash_mix(net));
41 }
42
43 /*
44  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
45  * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
46  *
47  * The sockhash lock must be held as a reader here.
48  */
49 struct sock *__inet6_lookup_established(struct net *net,
50                                         struct inet_hashinfo *hashinfo,
51                                            const struct in6_addr *saddr,
52                                            const __be16 sport,
53                                            const struct in6_addr *daddr,
54                                            const u16 hnum,
55                                            const int dif, const int sdif)
56 {
57         struct sock *sk;
58         const struct hlist_nulls_node *node;
59         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
60         /* Optimize here for direct hit, only listening connections can
61          * have wildcards anyways.
62          */
63         unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
64         unsigned int slot = hash & hashinfo->ehash_mask;
65         struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
66
67
68 begin:
69         sk_nulls_for_each_rcu(sk, node, &head->chain) {
70                 if (sk->sk_hash != hash)
71                         continue;
72                 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
73                         continue;
74                 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
75                         goto out;
76
77                 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
78                         sock_gen_put(sk);
79                         goto begin;
80                 }
81                 goto found;
82         }
83         if (get_nulls_value(node) != slot)
84                 goto begin;
85 out:
86         sk = NULL;
87 found:
88         return sk;
89 }
90 EXPORT_SYMBOL(__inet6_lookup_established);
91
92 static inline int compute_score(struct sock *sk, struct net *net,
93                                 const unsigned short hnum,
94                                 const struct in6_addr *daddr,
95                                 const int dif, const int sdif, bool exact_dif)
96 {
97         int score = -1;
98
99         if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
100             sk->sk_family == PF_INET6) {
101                 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
102                         return -1;
103
104                 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
105                         return -1;
106
107                 score = 1;
108                 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
109                         score++;
110         }
111         return score;
112 }
113
114 /* called with rcu_read_lock() */
115 static struct sock *inet6_lhash2_lookup(struct net *net,
116                 struct inet_listen_hashbucket *ilb2,
117                 struct sk_buff *skb, int doff,
118                 const struct in6_addr *saddr,
119                 const __be16 sport, const struct in6_addr *daddr,
120                 const unsigned short hnum, const int dif, const int sdif)
121 {
122         bool exact_dif = inet6_exact_dif_match(net, skb);
123         struct inet_connection_sock *icsk;
124         struct sock *sk, *result = NULL;
125         int score, hiscore = 0;
126         u32 phash = 0;
127
128         inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
129                 sk = (struct sock *)icsk;
130                 score = compute_score(sk, net, hnum, daddr, dif, sdif,
131                                       exact_dif);
132                 if (score > hiscore) {
133                         if (sk->sk_reuseport) {
134                                 phash = inet6_ehashfn(net, daddr, hnum,
135                                                       saddr, sport);
136                                 result = reuseport_select_sock(sk, phash,
137                                                                skb, doff);
138                                 if (result)
139                                         return result;
140                         }
141                         result = sk;
142                         hiscore = score;
143                 }
144         }
145
146         return result;
147 }
148
149 struct sock *inet6_lookup_listener(struct net *net,
150                 struct inet_hashinfo *hashinfo,
151                 struct sk_buff *skb, int doff,
152                 const struct in6_addr *saddr,
153                 const __be16 sport, const struct in6_addr *daddr,
154                 const unsigned short hnum, const int dif, const int sdif)
155 {
156         struct inet_listen_hashbucket *ilb2;
157         struct sock *result = NULL;
158         unsigned int hash2;
159
160         hash2 = ipv6_portaddr_hash(net, daddr, hnum);
161         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
162
163         result = inet6_lhash2_lookup(net, ilb2, skb, doff,
164                                      saddr, sport, daddr, hnum,
165                                      dif, sdif);
166         if (result)
167                 goto done;
168
169         /* Lookup lhash2 with in6addr_any */
170         hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
171         ilb2 = inet_lhash2_bucket(hashinfo, hash2);
172
173         result = inet6_lhash2_lookup(net, ilb2, skb, doff,
174                                      saddr, sport, &in6addr_any, hnum,
175                                      dif, sdif);
176 done:
177         if (IS_ERR(result))
178                 return NULL;
179         return result;
180 }
181 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
182
183 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
184                           struct sk_buff *skb, int doff,
185                           const struct in6_addr *saddr, const __be16 sport,
186                           const struct in6_addr *daddr, const __be16 dport,
187                           const int dif)
188 {
189         struct sock *sk;
190         bool refcounted;
191
192         sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
193                             ntohs(dport), dif, 0, &refcounted);
194         if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
195                 sk = NULL;
196         return sk;
197 }
198 EXPORT_SYMBOL_GPL(inet6_lookup);
199
200 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
201                                      struct sock *sk, const __u16 lport,
202                                      struct inet_timewait_sock **twp)
203 {
204         struct inet_hashinfo *hinfo = death_row->hashinfo;
205         struct inet_sock *inet = inet_sk(sk);
206         const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
207         const struct in6_addr *saddr = &sk->sk_v6_daddr;
208         const int dif = sk->sk_bound_dev_if;
209         struct net *net = sock_net(sk);
210         const int sdif = l3mdev_master_ifindex_by_index(net, dif);
211         const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
212         const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
213                                                 inet->inet_dport);
214         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
215         spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
216         struct sock *sk2;
217         const struct hlist_nulls_node *node;
218         struct inet_timewait_sock *tw = NULL;
219
220         spin_lock(lock);
221
222         sk_nulls_for_each(sk2, node, &head->chain) {
223                 if (sk2->sk_hash != hash)
224                         continue;
225
226                 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
227                                        dif, sdif))) {
228                         if (sk2->sk_state == TCP_TIME_WAIT) {
229                                 tw = inet_twsk(sk2);
230                                 if (twsk_unique(sk, sk2, twp))
231                                         break;
232                         }
233                         goto not_unique;
234                 }
235         }
236
237         /* Must record num and sport now. Otherwise we will see
238          * in hash table socket with a funny identity.
239          */
240         inet->inet_num = lport;
241         inet->inet_sport = htons(lport);
242         sk->sk_hash = hash;
243         WARN_ON(!sk_unhashed(sk));
244         __sk_nulls_add_node_rcu(sk, &head->chain);
245         if (tw) {
246                 sk_nulls_del_node_init_rcu((struct sock *)tw);
247                 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
248         }
249         spin_unlock(lock);
250         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
251
252         if (twp) {
253                 *twp = tw;
254         } else if (tw) {
255                 /* Silly. Should hash-dance instead... */
256                 inet_twsk_deschedule_put(tw);
257         }
258         return 0;
259
260 not_unique:
261         spin_unlock(lock);
262         return -EADDRNOTAVAIL;
263 }
264
265 static u32 inet6_sk_port_offset(const struct sock *sk)
266 {
267         const struct inet_sock *inet = inet_sk(sk);
268
269         return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
270                                           sk->sk_v6_daddr.s6_addr32,
271                                           inet->inet_dport);
272 }
273
274 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
275                        struct sock *sk)
276 {
277         u32 port_offset = 0;
278
279         if (!inet_sk(sk)->inet_num)
280                 port_offset = inet6_sk_port_offset(sk);
281         return __inet_hash_connect(death_row, sk, port_offset,
282                                    __inet6_check_established);
283 }
284 EXPORT_SYMBOL_GPL(inet6_hash_connect);
285
286 int inet6_hash(struct sock *sk)
287 {
288         int err = 0;
289
290         if (sk->sk_state != TCP_CLOSE) {
291                 local_bh_disable();
292                 err = __inet_hash(sk, NULL);
293                 local_bh_enable();
294         }
295
296         return err;
297 }
298 EXPORT_SYMBOL_GPL(inet6_hash);