net: introduce sk_ehashfn() helper
[linux-block.git] / net / ipv6 / inet6_hashtables.c
CommitLineData
5324a040
ACM
1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Generic INET6 transport hashtables
7 *
d8313f5c 8 * Authors: Lotsa people, from code originally in tcp, generalised here
67ba4152 9 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
5324a040
ACM
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
5324a040 17#include <linux/module.h>
d8313f5c 18#include <linux/random.h>
5324a040
ACM
19
20#include <net/inet_connection_sock.h>
21#include <net/inet_hashtables.h>
22#include <net/inet6_hashtables.h>
6e5714ea 23#include <net/secure_seq.h>
d8313f5c 24#include <net/ip.h>
5324a040 25
6eada011
ED
26static u32 inet6_ehashfn(const struct net *net,
27 const struct in6_addr *laddr,
28 const u16 lport,
29 const struct in6_addr *faddr,
30 const __be16 fport)
b50026b5 31{
1bbdceef
HFS
32 static u32 inet6_ehash_secret __read_mostly;
33 static u32 ipv6_hash_secret __read_mostly;
34
35 u32 lhash, fhash;
36
37 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
38 net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
39
40 lhash = (__force u32)laddr->s6_addr32[3];
41 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
42
b50026b5 43 return __inet6_ehashfn(lhash, lport, fhash, fport,
1bbdceef 44 inet6_ehash_secret + net_hash_mix(net));
b50026b5
HFS
45}
46
47static int inet6_sk_ehashfn(const struct sock *sk)
48{
49 const struct inet_sock *inet = inet_sk(sk);
50 const struct in6_addr *laddr = &sk->sk_v6_rcv_saddr;
51 const struct in6_addr *faddr = &sk->sk_v6_daddr;
52 const __u16 lport = inet->inet_num;
53 const __be16 fport = inet->inet_dport;
54 struct net *net = sock_net(sk);
55
56 return inet6_ehashfn(net, laddr, lport, faddr, fport);
57}
58
9327f705 59int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
b1a7ffcb 60{
39d8cda7 61 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
9327f705 62 int twrefcnt = 0;
b1a7ffcb 63
547b792c 64 WARN_ON(!sk_unhashed(sk));
b1a7ffcb
DV
65
66 if (sk->sk_state == TCP_LISTEN) {
5caea4ea 67 struct inet_listen_hashbucket *ilb;
3ab5aee7 68
5caea4ea
ED
69 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
70 spin_lock(&ilb->lock);
c25eb3bf 71 __sk_nulls_add_node_rcu(sk, &ilb->head);
5caea4ea 72 spin_unlock(&ilb->lock);
b1a7ffcb
DV
73 } else {
74 unsigned int hash;
3ab5aee7 75 struct hlist_nulls_head *list;
9db66bdc 76 spinlock_t *lock;
3ab5aee7 77
b1a7ffcb 78 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
230140cf
ED
79 list = &inet_ehash_bucket(hashinfo, hash)->chain;
80 lock = inet_ehash_lockp(hashinfo, hash);
9db66bdc 81 spin_lock(lock);
3ab5aee7 82 __sk_nulls_add_node_rcu(sk, list);
9327f705
ED
83 if (tw) {
84 WARN_ON(sk->sk_hash != tw->tw_hash);
85 twrefcnt = inet_twsk_unhash(tw);
86 }
9db66bdc 87 spin_unlock(lock);
b1a7ffcb
DV
88 }
89
c29a0bc4 90 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
9327f705 91 return twrefcnt;
b1a7ffcb
DV
92}
93EXPORT_SYMBOL(__inet6_hash);
94
95/*
96 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
97 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
98 *
99 * The sockhash lock must be held as a reader here.
100 */
d86e0dac
PE
101struct sock *__inet6_lookup_established(struct net *net,
102 struct inet_hashinfo *hashinfo,
b1a7ffcb 103 const struct in6_addr *saddr,
d2ecd9cc 104 const __be16 sport,
b1a7ffcb
DV
105 const struct in6_addr *daddr,
106 const u16 hnum,
107 const int dif)
108{
109 struct sock *sk;
3ab5aee7 110 const struct hlist_nulls_node *node;
4f765d84 111 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
b1a7ffcb
DV
112 /* Optimize here for direct hit, only listening connections can
113 * have wildcards anyways.
114 */
33de014c 115 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
f373b53b 116 unsigned int slot = hash & hashinfo->ehash_mask;
3ab5aee7 117 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
b1a7ffcb 118
3ab5aee7
ED
119
120 rcu_read_lock();
121begin:
122 sk_nulls_for_each_rcu(sk, node, &head->chain) {
ce43b03e
ED
123 if (sk->sk_hash != hash)
124 continue;
efe4208f
ED
125 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif))
126 continue;
05dbc7b5
ED
127 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
128 goto out;
129
efe4208f
ED
130 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
131 sock_gen_put(sk);
132 goto begin;
3ab5aee7 133 }
efe4208f 134 goto found;
b1a7ffcb 135 }
3ab5aee7
ED
136 if (get_nulls_value(node) != slot)
137 goto begin;
3ab5aee7 138out:
05dbc7b5
ED
139 sk = NULL;
140found:
3ab5aee7 141 rcu_read_unlock();
b1a7ffcb
DV
142 return sk;
143}
144EXPORT_SYMBOL(__inet6_lookup_established);
145
42b16b3f 146static inline int compute_score(struct sock *sk, struct net *net,
c25eb3bf
ED
147 const unsigned short hnum,
148 const struct in6_addr *daddr,
149 const int dif)
150{
151 int score = -1;
152
c720c7e8 153 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
c25eb3bf 154 sk->sk_family == PF_INET6) {
c25eb3bf
ED
155
156 score = 1;
efe4208f
ED
157 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
158 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
c25eb3bf
ED
159 return -1;
160 score++;
161 }
162 if (sk->sk_bound_dev_if) {
163 if (sk->sk_bound_dev_if != dif)
164 return -1;
165 score++;
166 }
167 }
168 return score;
169}
170
d86e0dac 171struct sock *inet6_lookup_listener(struct net *net,
5ba24953
TH
172 struct inet_hashinfo *hashinfo, const struct in6_addr *saddr,
173 const __be16 sport, const struct in6_addr *daddr,
d86e0dac 174 const unsigned short hnum, const int dif)
5324a040
ACM
175{
176 struct sock *sk;
c25eb3bf
ED
177 const struct hlist_nulls_node *node;
178 struct sock *result;
5ba24953
TH
179 int score, hiscore, matches = 0, reuseport = 0;
180 u32 phash = 0;
c25eb3bf
ED
181 unsigned int hash = inet_lhashfn(net, hnum);
182 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
183
184 rcu_read_lock();
185begin:
186 result = NULL;
5ba24953 187 hiscore = 0;
c25eb3bf
ED
188 sk_nulls_for_each(sk, node, &ilb->head) {
189 score = compute_score(sk, net, hnum, daddr, dif);
190 if (score > hiscore) {
191 hiscore = score;
192 result = sk;
5ba24953
TH
193 reuseport = sk->sk_reuseport;
194 if (reuseport) {
195 phash = inet6_ehashfn(net, daddr, hnum,
196 saddr, sport);
197 matches = 1;
198 }
199 } else if (score == hiscore && reuseport) {
200 matches++;
8fc54f68 201 if (reciprocal_scale(phash, matches) == 0)
5ba24953
TH
202 result = sk;
203 phash = next_pseudo_random32(phash);
5324a040
ACM
204 }
205 }
c25eb3bf
ED
206 /*
207 * if the nulls value we got at the end of this lookup is
208 * not the expected one, we must restart lookup.
209 * We probably met an item that was moved to another chain.
210 */
211 if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
212 goto begin;
213 if (result) {
214 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
215 result = NULL;
216 else if (unlikely(compute_score(result, net, hnum, daddr,
217 dif) < hiscore)) {
218 sock_put(result);
219 goto begin;
220 }
221 }
222 rcu_read_unlock();
5324a040
ACM
223 return result;
224}
5324a040
ACM
225EXPORT_SYMBOL_GPL(inet6_lookup_listener);
226
d86e0dac 227struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
d2ecd9cc
AV
228 const struct in6_addr *saddr, const __be16 sport,
229 const struct in6_addr *daddr, const __be16 dport,
5324a040
ACM
230 const int dif)
231{
232 struct sock *sk;
233
234 local_bh_disable();
d86e0dac 235 sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
5324a040
ACM
236 local_bh_enable();
237
238 return sk;
239}
5324a040 240EXPORT_SYMBOL_GPL(inet6_lookup);
d8313f5c
ACM
241
242static int __inet6_check_established(struct inet_timewait_death_row *death_row,
243 struct sock *sk, const __u16 lport,
244 struct inet_timewait_sock **twp)
245{
246 struct inet_hashinfo *hinfo = death_row->hashinfo;
3759fa9c 247 struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
248 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
249 const struct in6_addr *saddr = &sk->sk_v6_daddr;
d8313f5c 250 const int dif = sk->sk_bound_dev_if;
c720c7e8 251 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
33de014c
PE
252 struct net *net = sock_net(sk);
253 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
c720c7e8 254 inet->inet_dport);
d8313f5c 255 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
9db66bdc 256 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
d8313f5c 257 struct sock *sk2;
3ab5aee7 258 const struct hlist_nulls_node *node;
05dbc7b5 259 struct inet_timewait_sock *tw = NULL;
13475a30 260 int twrefcnt = 0;
d8313f5c 261
9db66bdc 262 spin_lock(lock);
d8313f5c 263
05dbc7b5 264 sk_nulls_for_each(sk2, node, &head->chain) {
ce43b03e
ED
265 if (sk2->sk_hash != hash)
266 continue;
d8313f5c 267
efe4208f
ED
268 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) {
269 if (sk2->sk_state == TCP_TIME_WAIT) {
05dbc7b5
ED
270 tw = inet_twsk(sk2);
271 if (twsk_unique(sk, sk2, twp))
efe4208f 272 break;
05dbc7b5 273 }
d8313f5c 274 goto not_unique;
efe4208f 275 }
d8313f5c
ACM
276 }
277
3759fa9c 278 /* Must record num and sport now. Otherwise we will see
efe4208f
ED
279 * in hash table socket with a funny identity.
280 */
c720c7e8
ED
281 inet->inet_num = lport;
282 inet->inet_sport = htons(lport);
13475a30 283 sk->sk_hash = hash;
547b792c 284 WARN_ON(!sk_unhashed(sk));
3ab5aee7 285 __sk_nulls_add_node_rcu(sk, &head->chain);
13475a30
ED
286 if (tw) {
287 twrefcnt = inet_twsk_unhash(tw);
288 NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
289 }
9db66bdc 290 spin_unlock(lock);
13475a30
ED
291 if (twrefcnt)
292 inet_twsk_put(tw);
c29a0bc4 293 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
d8313f5c 294
13475a30 295 if (twp) {
d8313f5c 296 *twp = tw;
13475a30 297 } else if (tw) {
d8313f5c
ACM
298 /* Silly. Should hash-dance instead... */
299 inet_twsk_deschedule(tw, death_row);
d8313f5c
ACM
300
301 inet_twsk_put(tw);
302 }
303 return 0;
304
305not_unique:
9db66bdc 306 spin_unlock(lock);
d8313f5c
ACM
307 return -EADDRNOTAVAIL;
308}
309
310static inline u32 inet6_sk_port_offset(const struct sock *sk)
311{
312 const struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
313
314 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
315 sk->sk_v6_daddr.s6_addr32,
c720c7e8 316 inet->inet_dport);
d8313f5c
ACM
317}
318
319int inet6_hash_connect(struct inet_timewait_death_row *death_row,
320 struct sock *sk)
321{
5d8c0aa9 322 return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
5ee31fc1 323 __inet6_check_established, __inet6_hash);
d8313f5c 324}
d8313f5c 325EXPORT_SYMBOL_GPL(inet6_hash_connect);