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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 *
8 * Authors: Lotsa people, from code originally in tcp, generalised here
9 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
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
17#include <linux/module.h>
18#include <linux/random.h>
19
20#include <net/inet_connection_sock.h>
21#include <net/inet_hashtables.h>
22#include <net/inet6_hashtables.h>
23#include <net/secure_seq.h>
24#include <net/ip.h>
25
26int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
27{
28 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
29 int twrefcnt = 0;
30
31 WARN_ON(!sk_unhashed(sk));
32
33 if (sk->sk_state == TCP_LISTEN) {
34 struct inet_listen_hashbucket *ilb;
35
36 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
37 spin_lock(&ilb->lock);
38 __sk_nulls_add_node_rcu(sk, &ilb->head);
39 spin_unlock(&ilb->lock);
40 } else {
41 unsigned int hash;
42 struct hlist_nulls_head *list;
43 spinlock_t *lock;
44
45 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
46 list = &inet_ehash_bucket(hashinfo, hash)->chain;
47 lock = inet_ehash_lockp(hashinfo, hash);
48 spin_lock(lock);
49 __sk_nulls_add_node_rcu(sk, list);
50 if (tw) {
51 WARN_ON(sk->sk_hash != tw->tw_hash);
52 twrefcnt = inet_twsk_unhash(tw);
53 }
54 spin_unlock(lock);
55 }
56
57 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
58 return twrefcnt;
59}
60EXPORT_SYMBOL(__inet6_hash);
61
62/*
63 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
64 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
65 *
66 * The sockhash lock must be held as a reader here.
67 */
68struct sock *__inet6_lookup_established(struct net *net,
69 struct inet_hashinfo *hashinfo,
70 const struct in6_addr *saddr,
71 const __be16 sport,
72 const struct in6_addr *daddr,
73 const u16 hnum,
74 const int dif)
75{
76 struct sock *sk;
77 const struct hlist_nulls_node *node;
78 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
79 /* Optimize here for direct hit, only listening connections can
80 * have wildcards anyways.
81 */
82 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
83 unsigned int slot = hash & hashinfo->ehash_mask;
84 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
85
86
87 rcu_read_lock();
88begin:
89 sk_nulls_for_each_rcu(sk, node, &head->chain) {
90 /* For IPV6 do the cheaper port and family tests first. */
91 if (INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
92 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
93 goto begintw;
94 if (!INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
95 sock_put(sk);
96 goto begin;
97 }
98 goto out;
99 }
100 }
101 if (get_nulls_value(node) != slot)
102 goto begin;
103
104begintw:
105 /* Must check for a TIME_WAIT'er before going to listener hash. */
106 sk_nulls_for_each_rcu(sk, node, &head->twchain) {
107 if (INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
108 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) {
109 sk = NULL;
110 goto out;
111 }
112 if (!INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
113 sock_put(sk);
114 goto begintw;
115 }
116 goto out;
117 }
118 }
119 if (get_nulls_value(node) != slot)
120 goto begintw;
121 sk = NULL;
122out:
123 rcu_read_unlock();
124 return sk;
125}
126EXPORT_SYMBOL(__inet6_lookup_established);
127
128static inline int compute_score(struct sock *sk, struct net *net,
129 const unsigned short hnum,
130 const struct in6_addr *daddr,
131 const int dif)
132{
133 int score = -1;
134
135 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
136 sk->sk_family == PF_INET6) {
137 const struct ipv6_pinfo *np = inet6_sk(sk);
138
139 score = 1;
140 if (!ipv6_addr_any(&np->rcv_saddr)) {
141 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
142 return -1;
143 score++;
144 }
145 if (sk->sk_bound_dev_if) {
146 if (sk->sk_bound_dev_if != dif)
147 return -1;
148 score++;
149 }
150 }
151 return score;
152}
153
154struct sock *inet6_lookup_listener(struct net *net,
155 struct inet_hashinfo *hashinfo, const struct in6_addr *daddr,
156 const unsigned short hnum, const int dif)
157{
158 struct sock *sk;
159 const struct hlist_nulls_node *node;
160 struct sock *result;
161 int score, hiscore;
162 unsigned int hash = inet_lhashfn(net, hnum);
163 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
164
165 rcu_read_lock();
166begin:
167 result = NULL;
168 hiscore = -1;
169 sk_nulls_for_each(sk, node, &ilb->head) {
170 score = compute_score(sk, net, hnum, daddr, dif);
171 if (score > hiscore) {
172 hiscore = score;
173 result = sk;
174 }
175 }
176 /*
177 * if the nulls value we got at the end of this lookup is
178 * not the expected one, we must restart lookup.
179 * We probably met an item that was moved to another chain.
180 */
181 if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
182 goto begin;
183 if (result) {
184 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
185 result = NULL;
186 else if (unlikely(compute_score(result, net, hnum, daddr,
187 dif) < hiscore)) {
188 sock_put(result);
189 goto begin;
190 }
191 }
192 rcu_read_unlock();
193 return result;
194}
195
196EXPORT_SYMBOL_GPL(inet6_lookup_listener);
197
198struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
199 const struct in6_addr *saddr, const __be16 sport,
200 const struct in6_addr *daddr, const __be16 dport,
201 const int dif)
202{
203 struct sock *sk;
204
205 local_bh_disable();
206 sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
207 local_bh_enable();
208
209 return sk;
210}
211
212EXPORT_SYMBOL_GPL(inet6_lookup);
213
214static int __inet6_check_established(struct inet_timewait_death_row *death_row,
215 struct sock *sk, const __u16 lport,
216 struct inet_timewait_sock **twp)
217{
218 struct inet_hashinfo *hinfo = death_row->hashinfo;
219 struct inet_sock *inet = inet_sk(sk);
220 const struct ipv6_pinfo *np = inet6_sk(sk);
221 const struct in6_addr *daddr = &np->rcv_saddr;
222 const struct in6_addr *saddr = &np->daddr;
223 const int dif = sk->sk_bound_dev_if;
224 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
225 struct net *net = sock_net(sk);
226 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
227 inet->inet_dport);
228 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
229 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
230 struct sock *sk2;
231 const struct hlist_nulls_node *node;
232 struct inet_timewait_sock *tw;
233 int twrefcnt = 0;
234
235 spin_lock(lock);
236
237 /* Check TIME-WAIT sockets first. */
238 sk_nulls_for_each(sk2, node, &head->twchain) {
239 tw = inet_twsk(sk2);
240
241 if (INET6_TW_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) {
242 if (twsk_unique(sk, sk2, twp))
243 goto unique;
244 else
245 goto not_unique;
246 }
247 }
248 tw = NULL;
249
250 /* And established part... */
251 sk_nulls_for_each(sk2, node, &head->chain) {
252 if (INET6_MATCH(sk2, net, hash, saddr, daddr, ports, dif))
253 goto not_unique;
254 }
255
256unique:
257 /* Must record num and sport now. Otherwise we will see
258 * in hash table socket with a funny identity. */
259 inet->inet_num = lport;
260 inet->inet_sport = htons(lport);
261 sk->sk_hash = hash;
262 WARN_ON(!sk_unhashed(sk));
263 __sk_nulls_add_node_rcu(sk, &head->chain);
264 if (tw) {
265 twrefcnt = inet_twsk_unhash(tw);
266 NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
267 }
268 spin_unlock(lock);
269 if (twrefcnt)
270 inet_twsk_put(tw);
271 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
272
273 if (twp) {
274 *twp = tw;
275 } else if (tw) {
276 /* Silly. Should hash-dance instead... */
277 inet_twsk_deschedule(tw, death_row);
278
279 inet_twsk_put(tw);
280 }
281 return 0;
282
283not_unique:
284 spin_unlock(lock);
285 return -EADDRNOTAVAIL;
286}
287
288static inline u32 inet6_sk_port_offset(const struct sock *sk)
289{
290 const struct inet_sock *inet = inet_sk(sk);
291 const struct ipv6_pinfo *np = inet6_sk(sk);
292 return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
293 np->daddr.s6_addr32,
294 inet->inet_dport);
295}
296
297int inet6_hash_connect(struct inet_timewait_death_row *death_row,
298 struct sock *sk)
299{
300 return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
301 __inet6_check_established, __inet6_hash);
302}
303
304EXPORT_SYMBOL_GPL(inet6_hash_connect);
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 *
8 * Authors: Lotsa people, from code originally in tcp, generalised here
9 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
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
17#include <linux/module.h>
18#include <linux/random.h>
19
20#include <net/inet_connection_sock.h>
21#include <net/inet_hashtables.h>
22#include <net/inet6_hashtables.h>
23#include <net/secure_seq.h>
24#include <net/ip.h>
25
26static unsigned int inet6_ehashfn(struct net *net,
27 const struct in6_addr *laddr,
28 const u16 lport,
29 const struct in6_addr *faddr,
30 const __be16 fport)
31{
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
43 return __inet6_ehashfn(lhash, lport, fhash, fport,
44 inet6_ehash_secret + net_hash_mix(net));
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
59int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
60{
61 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
62 int twrefcnt = 0;
63
64 WARN_ON(!sk_unhashed(sk));
65
66 if (sk->sk_state == TCP_LISTEN) {
67 struct inet_listen_hashbucket *ilb;
68
69 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
70 spin_lock(&ilb->lock);
71 __sk_nulls_add_node_rcu(sk, &ilb->head);
72 spin_unlock(&ilb->lock);
73 } else {
74 unsigned int hash;
75 struct hlist_nulls_head *list;
76 spinlock_t *lock;
77
78 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
79 list = &inet_ehash_bucket(hashinfo, hash)->chain;
80 lock = inet_ehash_lockp(hashinfo, hash);
81 spin_lock(lock);
82 __sk_nulls_add_node_rcu(sk, list);
83 if (tw) {
84 WARN_ON(sk->sk_hash != tw->tw_hash);
85 twrefcnt = inet_twsk_unhash(tw);
86 }
87 spin_unlock(lock);
88 }
89
90 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
91 return twrefcnt;
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 */
101struct sock *__inet6_lookup_established(struct net *net,
102 struct inet_hashinfo *hashinfo,
103 const struct in6_addr *saddr,
104 const __be16 sport,
105 const struct in6_addr *daddr,
106 const u16 hnum,
107 const int dif)
108{
109 struct sock *sk;
110 const struct hlist_nulls_node *node;
111 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
112 /* Optimize here for direct hit, only listening connections can
113 * have wildcards anyways.
114 */
115 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
116 unsigned int slot = hash & hashinfo->ehash_mask;
117 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
118
119
120 rcu_read_lock();
121begin:
122 sk_nulls_for_each_rcu(sk, node, &head->chain) {
123 if (sk->sk_hash != hash)
124 continue;
125 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif))
126 continue;
127 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
128 goto out;
129
130 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
131 sock_gen_put(sk);
132 goto begin;
133 }
134 goto found;
135 }
136 if (get_nulls_value(node) != slot)
137 goto begin;
138out:
139 sk = NULL;
140found:
141 rcu_read_unlock();
142 return sk;
143}
144EXPORT_SYMBOL(__inet6_lookup_established);
145
146static inline int compute_score(struct sock *sk, struct net *net,
147 const unsigned short hnum,
148 const struct in6_addr *daddr,
149 const int dif)
150{
151 int score = -1;
152
153 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
154 sk->sk_family == PF_INET6) {
155
156 score = 1;
157 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
158 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
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
171struct sock *inet6_lookup_listener(struct net *net,
172 struct inet_hashinfo *hashinfo, const struct in6_addr *saddr,
173 const __be16 sport, const struct in6_addr *daddr,
174 const unsigned short hnum, const int dif)
175{
176 struct sock *sk;
177 const struct hlist_nulls_node *node;
178 struct sock *result;
179 int score, hiscore, matches = 0, reuseport = 0;
180 u32 phash = 0;
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;
187 hiscore = 0;
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;
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++;
201 if (((u64)phash * matches) >> 32 == 0)
202 result = sk;
203 phash = next_pseudo_random32(phash);
204 }
205 }
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();
223 return result;
224}
225
226EXPORT_SYMBOL_GPL(inet6_lookup_listener);
227
228struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
229 const struct in6_addr *saddr, const __be16 sport,
230 const struct in6_addr *daddr, const __be16 dport,
231 const int dif)
232{
233 struct sock *sk;
234
235 local_bh_disable();
236 sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
237 local_bh_enable();
238
239 return sk;
240}
241
242EXPORT_SYMBOL_GPL(inet6_lookup);
243
244static int __inet6_check_established(struct inet_timewait_death_row *death_row,
245 struct sock *sk, const __u16 lport,
246 struct inet_timewait_sock **twp)
247{
248 struct inet_hashinfo *hinfo = death_row->hashinfo;
249 struct inet_sock *inet = inet_sk(sk);
250 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
251 const struct in6_addr *saddr = &sk->sk_v6_daddr;
252 const int dif = sk->sk_bound_dev_if;
253 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
254 struct net *net = sock_net(sk);
255 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
256 inet->inet_dport);
257 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
258 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
259 struct sock *sk2;
260 const struct hlist_nulls_node *node;
261 struct inet_timewait_sock *tw = NULL;
262 int twrefcnt = 0;
263
264 spin_lock(lock);
265
266 sk_nulls_for_each(sk2, node, &head->chain) {
267 if (sk2->sk_hash != hash)
268 continue;
269
270 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) {
271 if (sk2->sk_state == TCP_TIME_WAIT) {
272 tw = inet_twsk(sk2);
273 if (twsk_unique(sk, sk2, twp))
274 break;
275 }
276 goto not_unique;
277 }
278 }
279
280 /* Must record num and sport now. Otherwise we will see
281 * in hash table socket with a funny identity.
282 */
283 inet->inet_num = lport;
284 inet->inet_sport = htons(lport);
285 sk->sk_hash = hash;
286 WARN_ON(!sk_unhashed(sk));
287 __sk_nulls_add_node_rcu(sk, &head->chain);
288 if (tw) {
289 twrefcnt = inet_twsk_unhash(tw);
290 NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
291 }
292 spin_unlock(lock);
293 if (twrefcnt)
294 inet_twsk_put(tw);
295 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
296
297 if (twp) {
298 *twp = tw;
299 } else if (tw) {
300 /* Silly. Should hash-dance instead... */
301 inet_twsk_deschedule(tw, death_row);
302
303 inet_twsk_put(tw);
304 }
305 return 0;
306
307not_unique:
308 spin_unlock(lock);
309 return -EADDRNOTAVAIL;
310}
311
312static inline u32 inet6_sk_port_offset(const struct sock *sk)
313{
314 const struct inet_sock *inet = inet_sk(sk);
315
316 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
317 sk->sk_v6_daddr.s6_addr32,
318 inet->inet_dport);
319}
320
321int inet6_hash_connect(struct inet_timewait_death_row *death_row,
322 struct sock *sk)
323{
324 return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
325 __inet6_check_established, __inet6_hash);
326}
327
328EXPORT_SYMBOL_GPL(inet6_hash_connect);