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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// 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
24extern struct inet_hashinfo tcp_hashinfo;
25
26u32 inet6_ehashfn(const struct net *net,
27 const struct in6_addr *laddr, const u16 lport,
28 const struct in6_addr *faddr, const __be16 fport)
29{
30 static u32 inet6_ehash_secret __read_mostly;
31 static u32 ipv6_hash_secret __read_mostly;
32
33 u32 lhash, fhash;
34
35 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
36 net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
37
38 lhash = (__force u32)laddr->s6_addr32[3];
39 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
40
41 return __inet6_ehashfn(lhash, lport, fhash, fport,
42 inet6_ehash_secret + net_hash_mix(net));
43}
44
45/*
46 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
47 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
48 *
49 * The sockhash lock must be held as a reader here.
50 */
51struct sock *__inet6_lookup_established(struct net *net,
52 struct inet_hashinfo *hashinfo,
53 const struct in6_addr *saddr,
54 const __be16 sport,
55 const struct in6_addr *daddr,
56 const u16 hnum,
57 const int dif, const int sdif)
58{
59 struct sock *sk;
60 const struct hlist_nulls_node *node;
61 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
62 /* Optimize here for direct hit, only listening connections can
63 * have wildcards anyways.
64 */
65 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
66 unsigned int slot = hash & hashinfo->ehash_mask;
67 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
68
69
70begin:
71 sk_nulls_for_each_rcu(sk, node, &head->chain) {
72 if (sk->sk_hash != hash)
73 continue;
74 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
75 continue;
76 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
77 goto out;
78
79 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
80 sock_gen_put(sk);
81 goto begin;
82 }
83 goto found;
84 }
85 if (get_nulls_value(node) != slot)
86 goto begin;
87out:
88 sk = NULL;
89found:
90 return sk;
91}
92EXPORT_SYMBOL(__inet6_lookup_established);
93
94static inline int compute_score(struct sock *sk, struct net *net,
95 const unsigned short hnum,
96 const struct in6_addr *daddr,
97 const int dif, const int sdif)
98{
99 int score = -1;
100
101 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
102 sk->sk_family == PF_INET6) {
103 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
104 return -1;
105
106 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
107 return -1;
108
109 score = sk->sk_bound_dev_if ? 2 : 1;
110 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
111 score++;
112 }
113 return score;
114}
115
116static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
117 struct sk_buff *skb, int doff,
118 const struct in6_addr *saddr,
119 __be16 sport,
120 const struct in6_addr *daddr,
121 unsigned short hnum)
122{
123 struct sock *reuse_sk = NULL;
124 u32 phash;
125
126 if (sk->sk_reuseport) {
127 phash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
128 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
129 }
130 return reuse_sk;
131}
132
133/* called with rcu_read_lock() */
134static struct sock *inet6_lhash2_lookup(struct net *net,
135 struct inet_listen_hashbucket *ilb2,
136 struct sk_buff *skb, int doff,
137 const struct in6_addr *saddr,
138 const __be16 sport, const struct in6_addr *daddr,
139 const unsigned short hnum, const int dif, const int sdif)
140{
141 struct inet_connection_sock *icsk;
142 struct sock *sk, *result = NULL;
143 int score, hiscore = 0;
144
145 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
146 sk = (struct sock *)icsk;
147 score = compute_score(sk, net, hnum, daddr, dif, sdif);
148 if (score > hiscore) {
149 result = lookup_reuseport(net, sk, skb, doff,
150 saddr, sport, daddr, hnum);
151 if (result)
152 return result;
153
154 result = sk;
155 hiscore = score;
156 }
157 }
158
159 return result;
160}
161
162static inline struct sock *inet6_lookup_run_bpf(struct net *net,
163 struct inet_hashinfo *hashinfo,
164 struct sk_buff *skb, int doff,
165 const struct in6_addr *saddr,
166 const __be16 sport,
167 const struct in6_addr *daddr,
168 const u16 hnum)
169{
170 struct sock *sk, *reuse_sk;
171 bool no_reuseport;
172
173 if (hashinfo != &tcp_hashinfo)
174 return NULL; /* only TCP is supported */
175
176 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_TCP,
177 saddr, sport, daddr, hnum, &sk);
178 if (no_reuseport || IS_ERR_OR_NULL(sk))
179 return sk;
180
181 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
182 if (reuse_sk)
183 sk = reuse_sk;
184 return sk;
185}
186
187struct sock *inet6_lookup_listener(struct net *net,
188 struct inet_hashinfo *hashinfo,
189 struct sk_buff *skb, int doff,
190 const struct in6_addr *saddr,
191 const __be16 sport, const struct in6_addr *daddr,
192 const unsigned short hnum, const int dif, const int sdif)
193{
194 struct inet_listen_hashbucket *ilb2;
195 struct sock *result = NULL;
196 unsigned int hash2;
197
198 /* Lookup redirect from BPF */
199 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
200 result = inet6_lookup_run_bpf(net, hashinfo, skb, doff,
201 saddr, sport, daddr, hnum);
202 if (result)
203 goto done;
204 }
205
206 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
207 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
208
209 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
210 saddr, sport, daddr, hnum,
211 dif, sdif);
212 if (result)
213 goto done;
214
215 /* Lookup lhash2 with in6addr_any */
216 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
217 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
218
219 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
220 saddr, sport, &in6addr_any, hnum,
221 dif, sdif);
222done:
223 if (IS_ERR(result))
224 return NULL;
225 return result;
226}
227EXPORT_SYMBOL_GPL(inet6_lookup_listener);
228
229struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
230 struct sk_buff *skb, int doff,
231 const struct in6_addr *saddr, const __be16 sport,
232 const struct in6_addr *daddr, const __be16 dport,
233 const int dif)
234{
235 struct sock *sk;
236 bool refcounted;
237
238 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
239 ntohs(dport), dif, 0, &refcounted);
240 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
241 sk = NULL;
242 return sk;
243}
244EXPORT_SYMBOL_GPL(inet6_lookup);
245
246static int __inet6_check_established(struct inet_timewait_death_row *death_row,
247 struct sock *sk, const __u16 lport,
248 struct inet_timewait_sock **twp)
249{
250 struct inet_hashinfo *hinfo = death_row->hashinfo;
251 struct inet_sock *inet = inet_sk(sk);
252 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
253 const struct in6_addr *saddr = &sk->sk_v6_daddr;
254 const int dif = sk->sk_bound_dev_if;
255 struct net *net = sock_net(sk);
256 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
257 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
258 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
259 inet->inet_dport);
260 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
261 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
262 struct sock *sk2;
263 const struct hlist_nulls_node *node;
264 struct inet_timewait_sock *tw = NULL;
265
266 spin_lock(lock);
267
268 sk_nulls_for_each(sk2, node, &head->chain) {
269 if (sk2->sk_hash != hash)
270 continue;
271
272 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
273 dif, sdif))) {
274 if (sk2->sk_state == TCP_TIME_WAIT) {
275 tw = inet_twsk(sk2);
276 if (twsk_unique(sk, sk2, twp))
277 break;
278 }
279 goto not_unique;
280 }
281 }
282
283 /* Must record num and sport now. Otherwise we will see
284 * in hash table socket with a funny identity.
285 */
286 inet->inet_num = lport;
287 inet->inet_sport = htons(lport);
288 sk->sk_hash = hash;
289 WARN_ON(!sk_unhashed(sk));
290 __sk_nulls_add_node_rcu(sk, &head->chain);
291 if (tw) {
292 sk_nulls_del_node_init_rcu((struct sock *)tw);
293 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
294 }
295 spin_unlock(lock);
296 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
297
298 if (twp) {
299 *twp = tw;
300 } else if (tw) {
301 /* Silly. Should hash-dance instead... */
302 inet_twsk_deschedule_put(tw);
303 }
304 return 0;
305
306not_unique:
307 spin_unlock(lock);
308 return -EADDRNOTAVAIL;
309}
310
311static u32 inet6_sk_port_offset(const struct sock *sk)
312{
313 const struct inet_sock *inet = inet_sk(sk);
314
315 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
316 sk->sk_v6_daddr.s6_addr32,
317 inet->inet_dport);
318}
319
320int inet6_hash_connect(struct inet_timewait_death_row *death_row,
321 struct sock *sk)
322{
323 u32 port_offset = 0;
324
325 if (!inet_sk(sk)->inet_num)
326 port_offset = inet6_sk_port_offset(sk);
327 return __inet_hash_connect(death_row, sk, port_offset,
328 __inet6_check_established);
329}
330EXPORT_SYMBOL_GPL(inet6_hash_connect);
331
332int inet6_hash(struct sock *sk)
333{
334 int err = 0;
335
336 if (sk->sk_state != TCP_CLOSE) {
337 local_bh_disable();
338 err = __inet_hash(sk, NULL);
339 local_bh_enable();
340 }
341
342 return err;
343}
344EXPORT_SYMBOL_GPL(inet6_hash);