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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/addrconf.h>
21#include <net/inet_connection_sock.h>
22#include <net/inet_hashtables.h>
23#include <net/inet6_hashtables.h>
24#include <net/secure_seq.h>
25#include <net/ip.h>
26#include <net/sock_reuseport.h>
27
28u32 inet6_ehashfn(const struct net *net,
29 const struct in6_addr *laddr, const u16 lport,
30 const struct in6_addr *faddr, 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
47/*
48 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
49 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
50 *
51 * The sockhash lock must be held as a reader here.
52 */
53struct sock *__inet6_lookup_established(struct net *net,
54 struct inet_hashinfo *hashinfo,
55 const struct in6_addr *saddr,
56 const __be16 sport,
57 const struct in6_addr *daddr,
58 const u16 hnum,
59 const int dif)
60{
61 struct sock *sk;
62 const struct hlist_nulls_node *node;
63 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
64 /* Optimize here for direct hit, only listening connections can
65 * have wildcards anyways.
66 */
67 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
68 unsigned int slot = hash & hashinfo->ehash_mask;
69 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
70
71
72 rcu_read_lock();
73begin:
74 sk_nulls_for_each_rcu(sk, node, &head->chain) {
75 if (sk->sk_hash != hash)
76 continue;
77 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif))
78 continue;
79 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
80 goto out;
81
82 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
83 sock_gen_put(sk);
84 goto begin;
85 }
86 goto found;
87 }
88 if (get_nulls_value(node) != slot)
89 goto begin;
90out:
91 sk = NULL;
92found:
93 rcu_read_unlock();
94 return sk;
95}
96EXPORT_SYMBOL(__inet6_lookup_established);
97
98static inline int compute_score(struct sock *sk, struct net *net,
99 const unsigned short hnum,
100 const struct in6_addr *daddr,
101 const int dif)
102{
103 int score = -1;
104
105 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
106 sk->sk_family == PF_INET6) {
107
108 score = 1;
109 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
110 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
111 return -1;
112 score++;
113 }
114 if (sk->sk_bound_dev_if) {
115 if (sk->sk_bound_dev_if != dif)
116 return -1;
117 score++;
118 }
119 if (sk->sk_incoming_cpu == raw_smp_processor_id())
120 score++;
121 }
122 return score;
123}
124
125struct sock *inet6_lookup_listener(struct net *net,
126 struct inet_hashinfo *hashinfo,
127 struct sk_buff *skb, int doff,
128 const struct in6_addr *saddr,
129 const __be16 sport, const struct in6_addr *daddr,
130 const unsigned short hnum, const int dif)
131{
132 struct sock *sk;
133 const struct hlist_nulls_node *node;
134 struct sock *result;
135 int score, hiscore, matches = 0, reuseport = 0;
136 bool select_ok = true;
137 u32 phash = 0;
138 unsigned int hash = inet_lhashfn(net, hnum);
139 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
140
141 rcu_read_lock();
142begin:
143 result = NULL;
144 hiscore = 0;
145 sk_nulls_for_each(sk, node, &ilb->head) {
146 score = compute_score(sk, net, hnum, daddr, dif);
147 if (score > hiscore) {
148 hiscore = score;
149 result = sk;
150 reuseport = sk->sk_reuseport;
151 if (reuseport) {
152 phash = inet6_ehashfn(net, daddr, hnum,
153 saddr, sport);
154 if (select_ok) {
155 struct sock *sk2;
156 sk2 = reuseport_select_sock(sk, phash,
157 skb, doff);
158 if (sk2) {
159 result = sk2;
160 goto found;
161 }
162 }
163 matches = 1;
164 }
165 } else if (score == hiscore && reuseport) {
166 matches++;
167 if (reciprocal_scale(phash, matches) == 0)
168 result = sk;
169 phash = next_pseudo_random32(phash);
170 }
171 }
172 /*
173 * if the nulls value we got at the end of this lookup is
174 * not the expected one, we must restart lookup.
175 * We probably met an item that was moved to another chain.
176 */
177 if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
178 goto begin;
179 if (result) {
180found:
181 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
182 result = NULL;
183 else if (unlikely(compute_score(result, net, hnum, daddr,
184 dif) < hiscore)) {
185 sock_put(result);
186 select_ok = false;
187 goto begin;
188 }
189 }
190 rcu_read_unlock();
191 return result;
192}
193EXPORT_SYMBOL_GPL(inet6_lookup_listener);
194
195struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
196 struct sk_buff *skb, int doff,
197 const struct in6_addr *saddr, const __be16 sport,
198 const struct in6_addr *daddr, const __be16 dport,
199 const int dif)
200{
201 struct sock *sk;
202
203 local_bh_disable();
204 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
205 ntohs(dport), dif);
206 local_bh_enable();
207
208 return sk;
209}
210EXPORT_SYMBOL_GPL(inet6_lookup);
211
212static int __inet6_check_established(struct inet_timewait_death_row *death_row,
213 struct sock *sk, const __u16 lport,
214 struct inet_timewait_sock **twp)
215{
216 struct inet_hashinfo *hinfo = death_row->hashinfo;
217 struct inet_sock *inet = inet_sk(sk);
218 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
219 const struct in6_addr *saddr = &sk->sk_v6_daddr;
220 const int dif = sk->sk_bound_dev_if;
221 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
222 struct net *net = sock_net(sk);
223 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
224 inet->inet_dport);
225 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
226 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
227 struct sock *sk2;
228 const struct hlist_nulls_node *node;
229 struct inet_timewait_sock *tw = NULL;
230
231 spin_lock(lock);
232
233 sk_nulls_for_each(sk2, node, &head->chain) {
234 if (sk2->sk_hash != hash)
235 continue;
236
237 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) {
238 if (sk2->sk_state == TCP_TIME_WAIT) {
239 tw = inet_twsk(sk2);
240 if (twsk_unique(sk, sk2, twp))
241 break;
242 }
243 goto not_unique;
244 }
245 }
246
247 /* Must record num and sport now. Otherwise we will see
248 * in hash table socket with a funny identity.
249 */
250 inet->inet_num = lport;
251 inet->inet_sport = htons(lport);
252 sk->sk_hash = hash;
253 WARN_ON(!sk_unhashed(sk));
254 __sk_nulls_add_node_rcu(sk, &head->chain);
255 if (tw) {
256 sk_nulls_del_node_init_rcu((struct sock *)tw);
257 NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
258 }
259 spin_unlock(lock);
260 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
261
262 if (twp) {
263 *twp = tw;
264 } else if (tw) {
265 /* Silly. Should hash-dance instead... */
266 inet_twsk_deschedule_put(tw);
267 }
268 return 0;
269
270not_unique:
271 spin_unlock(lock);
272 return -EADDRNOTAVAIL;
273}
274
275static u32 inet6_sk_port_offset(const struct sock *sk)
276{
277 const struct inet_sock *inet = inet_sk(sk);
278
279 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
280 sk->sk_v6_daddr.s6_addr32,
281 inet->inet_dport);
282}
283
284int inet6_hash_connect(struct inet_timewait_death_row *death_row,
285 struct sock *sk)
286{
287 u32 port_offset = 0;
288
289 if (!inet_sk(sk)->inet_num)
290 port_offset = inet6_sk_port_offset(sk);
291 return __inet_hash_connect(death_row, sk, port_offset,
292 __inet6_check_established);
293}
294EXPORT_SYMBOL_GPL(inet6_hash_connect);
295
296int inet6_hash(struct sock *sk)
297{
298 if (sk->sk_state != TCP_CLOSE) {
299 local_bh_disable();
300 __inet_hash(sk, NULL, ipv6_rcv_saddr_equal);
301 local_bh_enable();
302 }
303
304 return 0;
305}
306EXPORT_SYMBOL_GPL(inet6_hash);
307
308/* match_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
309 * only, and any IPv4 addresses if not IPv6 only
310 * match_wildcard == false: addresses must be exactly the same, i.e.
311 * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
312 * and 0.0.0.0 equals to 0.0.0.0 only
313 */
314int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
315 bool match_wildcard)
316{
317 const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
318 int sk2_ipv6only = inet_v6_ipv6only(sk2);
319 int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
320 int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
321
322 /* if both are mapped, treat as IPv4 */
323 if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
324 if (!sk2_ipv6only) {
325 if (sk->sk_rcv_saddr == sk2->sk_rcv_saddr)
326 return 1;
327 if (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr)
328 return match_wildcard;
329 }
330 return 0;
331 }
332
333 if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
334 return 1;
335
336 if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
337 !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
338 return 1;
339
340 if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
341 !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
342 return 1;
343
344 if (sk2_rcv_saddr6 &&
345 ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
346 return 1;
347
348 return 0;
349}
350EXPORT_SYMBOL_GPL(ipv6_rcv_saddr_equal);