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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, bool exact_dif)
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 = 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 bool exact_dif = inet6_exact_dif_match(net, skb);
142 struct inet_connection_sock *icsk;
143 struct sock *sk, *result = NULL;
144 int score, hiscore = 0;
145
146 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
147 sk = (struct sock *)icsk;
148 score = compute_score(sk, net, hnum, daddr, dif, sdif,
149 exact_dif);
150 if (score > hiscore) {
151 result = lookup_reuseport(net, sk, skb, doff,
152 saddr, sport, daddr, hnum);
153 if (result)
154 return result;
155
156 result = sk;
157 hiscore = score;
158 }
159 }
160
161 return result;
162}
163
164static inline struct sock *inet6_lookup_run_bpf(struct net *net,
165 struct inet_hashinfo *hashinfo,
166 struct sk_buff *skb, int doff,
167 const struct in6_addr *saddr,
168 const __be16 sport,
169 const struct in6_addr *daddr,
170 const u16 hnum)
171{
172 struct sock *sk, *reuse_sk;
173 bool no_reuseport;
174
175 if (hashinfo != &tcp_hashinfo)
176 return NULL; /* only TCP is supported */
177
178 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_TCP,
179 saddr, sport, daddr, hnum, &sk);
180 if (no_reuseport || IS_ERR_OR_NULL(sk))
181 return sk;
182
183 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
184 if (reuse_sk)
185 sk = reuse_sk;
186 return sk;
187}
188
189struct sock *inet6_lookup_listener(struct net *net,
190 struct inet_hashinfo *hashinfo,
191 struct sk_buff *skb, int doff,
192 const struct in6_addr *saddr,
193 const __be16 sport, const struct in6_addr *daddr,
194 const unsigned short hnum, const int dif, const int sdif)
195{
196 struct inet_listen_hashbucket *ilb2;
197 struct sock *result = NULL;
198 unsigned int hash2;
199
200 /* Lookup redirect from BPF */
201 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
202 result = inet6_lookup_run_bpf(net, hashinfo, skb, doff,
203 saddr, sport, daddr, hnum);
204 if (result)
205 goto done;
206 }
207
208 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
209 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
210
211 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
212 saddr, sport, daddr, hnum,
213 dif, sdif);
214 if (result)
215 goto done;
216
217 /* Lookup lhash2 with in6addr_any */
218 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
219 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
220
221 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
222 saddr, sport, &in6addr_any, hnum,
223 dif, sdif);
224done:
225 if (IS_ERR(result))
226 return NULL;
227 return result;
228}
229EXPORT_SYMBOL_GPL(inet6_lookup_listener);
230
231struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
232 struct sk_buff *skb, int doff,
233 const struct in6_addr *saddr, const __be16 sport,
234 const struct in6_addr *daddr, const __be16 dport,
235 const int dif)
236{
237 struct sock *sk;
238 bool refcounted;
239
240 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
241 ntohs(dport), dif, 0, &refcounted);
242 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
243 sk = NULL;
244 return sk;
245}
246EXPORT_SYMBOL_GPL(inet6_lookup);
247
248static int __inet6_check_established(struct inet_timewait_death_row *death_row,
249 struct sock *sk, const __u16 lport,
250 struct inet_timewait_sock **twp)
251{
252 struct inet_hashinfo *hinfo = death_row->hashinfo;
253 struct inet_sock *inet = inet_sk(sk);
254 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
255 const struct in6_addr *saddr = &sk->sk_v6_daddr;
256 const int dif = sk->sk_bound_dev_if;
257 struct net *net = sock_net(sk);
258 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
259 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
260 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
261 inet->inet_dport);
262 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
263 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
264 struct sock *sk2;
265 const struct hlist_nulls_node *node;
266 struct inet_timewait_sock *tw = NULL;
267
268 spin_lock(lock);
269
270 sk_nulls_for_each(sk2, node, &head->chain) {
271 if (sk2->sk_hash != hash)
272 continue;
273
274 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
275 dif, sdif))) {
276 if (sk2->sk_state == TCP_TIME_WAIT) {
277 tw = inet_twsk(sk2);
278 if (twsk_unique(sk, sk2, twp))
279 break;
280 }
281 goto not_unique;
282 }
283 }
284
285 /* Must record num and sport now. Otherwise we will see
286 * in hash table socket with a funny identity.
287 */
288 inet->inet_num = lport;
289 inet->inet_sport = htons(lport);
290 sk->sk_hash = hash;
291 WARN_ON(!sk_unhashed(sk));
292 __sk_nulls_add_node_rcu(sk, &head->chain);
293 if (tw) {
294 sk_nulls_del_node_init_rcu((struct sock *)tw);
295 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
296 }
297 spin_unlock(lock);
298 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
299
300 if (twp) {
301 *twp = tw;
302 } else if (tw) {
303 /* Silly. Should hash-dance instead... */
304 inet_twsk_deschedule_put(tw);
305 }
306 return 0;
307
308not_unique:
309 spin_unlock(lock);
310 return -EADDRNOTAVAIL;
311}
312
313static u32 inet6_sk_port_offset(const struct sock *sk)
314{
315 const struct inet_sock *inet = inet_sk(sk);
316
317 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
318 sk->sk_v6_daddr.s6_addr32,
319 inet->inet_dport);
320}
321
322int inet6_hash_connect(struct inet_timewait_death_row *death_row,
323 struct sock *sk)
324{
325 u32 port_offset = 0;
326
327 if (!inet_sk(sk)->inet_num)
328 port_offset = inet6_sk_port_offset(sk);
329 return __inet_hash_connect(death_row, sk, port_offset,
330 __inet6_check_established);
331}
332EXPORT_SYMBOL_GPL(inet6_hash_connect);
333
334int inet6_hash(struct sock *sk)
335{
336 int err = 0;
337
338 if (sk->sk_state != TCP_CLOSE) {
339 local_bh_disable();
340 err = __inet_hash(sk, NULL);
341 local_bh_enable();
342 }
343
344 return err;
345}
346EXPORT_SYMBOL_GPL(inet6_hash);