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2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
5324a040
ACM
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 *
d8313f5c 9 * Authors: Lotsa people, from code originally in tcp, generalised here
67ba4152 10 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
5324a040
ACM
11 */
12
5324a040 13#include <linux/module.h>
d8313f5c 14#include <linux/random.h>
5324a040 15
c125e80b 16#include <net/addrconf.h>
5324a040
ACM
17#include <net/inet_connection_sock.h>
18#include <net/inet_hashtables.h>
19#include <net/inet6_hashtables.h>
6e5714ea 20#include <net/secure_seq.h>
d8313f5c 21#include <net/ip.h>
c125e80b 22#include <net/sock_reuseport.h>
5324a040 23
d1e559d0
ED
24u32 inet6_ehashfn(const struct net *net,
25 const struct in6_addr *laddr, const u16 lport,
26 const struct in6_addr *faddr, const __be16 fport)
b50026b5 27{
1bbdceef
HFS
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
b50026b5 39 return __inet6_ehashfn(lhash, lport, fhash, fport,
1bbdceef 40 inet6_ehash_secret + net_hash_mix(net));
b50026b5
HFS
41}
42
b1a7ffcb
DV
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 */
d86e0dac
PE
49struct sock *__inet6_lookup_established(struct net *net,
50 struct inet_hashinfo *hashinfo,
b1a7ffcb 51 const struct in6_addr *saddr,
d2ecd9cc 52 const __be16 sport,
b1a7ffcb
DV
53 const struct in6_addr *daddr,
54 const u16 hnum,
4297a0ef 55 const int dif, const int sdif)
b1a7ffcb
DV
56{
57 struct sock *sk;
3ab5aee7 58 const struct hlist_nulls_node *node;
4f765d84 59 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
b1a7ffcb
DV
60 /* Optimize here for direct hit, only listening connections can
61 * have wildcards anyways.
62 */
33de014c 63 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
f373b53b 64 unsigned int slot = hash & hashinfo->ehash_mask;
3ab5aee7 65 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
b1a7ffcb 66
3ab5aee7 67
3ab5aee7
ED
68begin:
69 sk_nulls_for_each_rcu(sk, node, &head->chain) {
ce43b03e
ED
70 if (sk->sk_hash != hash)
71 continue;
4297a0ef 72 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
efe4208f 73 continue;
41c6d650 74 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
05dbc7b5
ED
75 goto out;
76
4297a0ef 77 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
efe4208f
ED
78 sock_gen_put(sk);
79 goto begin;
3ab5aee7 80 }
efe4208f 81 goto found;
b1a7ffcb 82 }
3ab5aee7
ED
83 if (get_nulls_value(node) != slot)
84 goto begin;
3ab5aee7 85out:
05dbc7b5
ED
86 sk = NULL;
87found:
b1a7ffcb
DV
88 return sk;
89}
90EXPORT_SYMBOL(__inet6_lookup_established);
91
42b16b3f 92static inline int compute_score(struct sock *sk, struct net *net,
c25eb3bf
ED
93 const unsigned short hnum,
94 const struct in6_addr *daddr,
4297a0ef 95 const int dif, const int sdif, bool exact_dif)
c25eb3bf
ED
96{
97 int score = -1;
98
c720c7e8 99 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
c25eb3bf 100 sk->sk_family == PF_INET6) {
0ee58dad
PO
101 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
102 return -1;
c25eb3bf 103
0ee58dad 104 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
e7819058 105 return -1;
4297a0ef 106
0ee58dad 107 score = 1;
71115222 108 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
70da268b 109 score++;
c25eb3bf
ED
110 }
111 return score;
112}
113
3b24d854 114/* called with rcu_read_lock() */
61b7c691
MKL
115static 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
d86e0dac 149struct sock *inet6_lookup_listener(struct net *net,
a583636a
CG
150 struct inet_hashinfo *hashinfo,
151 struct sk_buff *skb, int doff,
152 const struct in6_addr *saddr,
5ba24953 153 const __be16 sport, const struct in6_addr *daddr,
4297a0ef 154 const unsigned short hnum, const int dif, const int sdif)
5324a040 155{
61b7c691 156 struct inet_listen_hashbucket *ilb2;
0ee58dad 157 struct sock *result = NULL;
61b7c691 158 unsigned int hash2;
61b7c691
MKL
159
160 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
161 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
61b7c691
MKL
162
163 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
164 saddr, sport, daddr, hnum,
165 dif, sdif);
166 if (result)
8217ca65 167 goto done;
61b7c691
MKL
168
169 /* Lookup lhash2 with in6addr_any */
61b7c691
MKL
170 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
171 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
61b7c691 172
8217ca65 173 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
0ee58dad 174 saddr, sport, &in6addr_any, hnum,
8217ca65 175 dif, sdif);
8217ca65 176done:
26f8113c 177 if (IS_ERR(result))
8217ca65 178 return NULL;
5324a040
ACM
179 return result;
180}
5324a040
ACM
181EXPORT_SYMBOL_GPL(inet6_lookup_listener);
182
d86e0dac 183struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
a583636a 184 struct sk_buff *skb, int doff,
d2ecd9cc
AV
185 const struct in6_addr *saddr, const __be16 sport,
186 const struct in6_addr *daddr, const __be16 dport,
5324a040
ACM
187 const int dif)
188{
189 struct sock *sk;
3b24d854 190 bool refcounted;
5324a040 191
a583636a 192 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
4297a0ef 193 ntohs(dport), dif, 0, &refcounted);
41c6d650 194 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
3b24d854 195 sk = NULL;
5324a040
ACM
196 return sk;
197}
5324a040 198EXPORT_SYMBOL_GPL(inet6_lookup);
d8313f5c
ACM
199
200static 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;
3759fa9c 205 struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
206 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
207 const struct in6_addr *saddr = &sk->sk_v6_daddr;
d8313f5c 208 const int dif = sk->sk_bound_dev_if;
33de014c 209 struct net *net = sock_net(sk);
4297a0ef
DA
210 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
211 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
33de014c 212 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
c720c7e8 213 inet->inet_dport);
d8313f5c 214 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
9db66bdc 215 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
d8313f5c 216 struct sock *sk2;
3ab5aee7 217 const struct hlist_nulls_node *node;
05dbc7b5 218 struct inet_timewait_sock *tw = NULL;
d8313f5c 219
9db66bdc 220 spin_lock(lock);
d8313f5c 221
05dbc7b5 222 sk_nulls_for_each(sk2, node, &head->chain) {
ce43b03e
ED
223 if (sk2->sk_hash != hash)
224 continue;
d8313f5c 225
4297a0ef
DA
226 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
227 dif, sdif))) {
efe4208f 228 if (sk2->sk_state == TCP_TIME_WAIT) {
05dbc7b5
ED
229 tw = inet_twsk(sk2);
230 if (twsk_unique(sk, sk2, twp))
efe4208f 231 break;
05dbc7b5 232 }
d8313f5c 233 goto not_unique;
efe4208f 234 }
d8313f5c
ACM
235 }
236
3759fa9c 237 /* Must record num and sport now. Otherwise we will see
efe4208f
ED
238 * in hash table socket with a funny identity.
239 */
c720c7e8
ED
240 inet->inet_num = lport;
241 inet->inet_sport = htons(lport);
13475a30 242 sk->sk_hash = hash;
547b792c 243 WARN_ON(!sk_unhashed(sk));
3ab5aee7 244 __sk_nulls_add_node_rcu(sk, &head->chain);
13475a30 245 if (tw) {
fc01538f 246 sk_nulls_del_node_init_rcu((struct sock *)tw);
02a1d6e7 247 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
13475a30 248 }
9db66bdc 249 spin_unlock(lock);
c29a0bc4 250 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
d8313f5c 251
13475a30 252 if (twp) {
d8313f5c 253 *twp = tw;
13475a30 254 } else if (tw) {
d8313f5c 255 /* Silly. Should hash-dance instead... */
dbe7faa4 256 inet_twsk_deschedule_put(tw);
d8313f5c
ACM
257 }
258 return 0;
259
260not_unique:
9db66bdc 261 spin_unlock(lock);
d8313f5c
ACM
262 return -EADDRNOTAVAIL;
263}
264
e2baad9e 265static u32 inet6_sk_port_offset(const struct sock *sk)
d8313f5c
ACM
266{
267 const struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
268
269 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
270 sk->sk_v6_daddr.s6_addr32,
c720c7e8 271 inet->inet_dport);
d8313f5c
ACM
272}
273
274int inet6_hash_connect(struct inet_timewait_death_row *death_row,
275 struct sock *sk)
276{
e2baad9e
ED
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,
b4d6444e 282 __inet6_check_established);
d8313f5c 283}
d8313f5c 284EXPORT_SYMBOL_GPL(inet6_hash_connect);
496611d7
CG
285
286int inet6_hash(struct sock *sk)
287{
e4cabca5
CG
288 int err = 0;
289
496611d7
CG
290 if (sk->sk_state != TCP_CLOSE) {
291 local_bh_disable();
fe38d2a1 292 err = __inet_hash(sk, NULL);
496611d7
CG
293 local_bh_enable();
294 }
295
e4cabca5 296 return err;
496611d7
CG
297}
298EXPORT_SYMBOL_GPL(inet6_hash);