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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/hotdata.h>
18#include <net/inet_connection_sock.h>
19#include <net/inet_hashtables.h>
20#include <net/inet6_hashtables.h>
21#include <net/secure_seq.h>
22#include <net/ip.h>
23#include <net/sock_reuseport.h>
24
25u32 inet6_ehashfn(const struct net *net,
26 const struct in6_addr *laddr, const u16 lport,
27 const struct in6_addr *faddr, const __be16 fport)
28{
29 u32 lhash, fhash;
30
31 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
32 net_get_random_once(&tcp_ipv6_hash_secret, sizeof(tcp_ipv6_hash_secret));
33
34 lhash = (__force u32)laddr->s6_addr32[3];
35 fhash = __ipv6_addr_jhash(faddr, tcp_ipv6_hash_secret);
36
37 return __inet6_ehashfn(lhash, lport, fhash, fport,
38 inet6_ehash_secret + net_hash_mix(net));
39}
40EXPORT_SYMBOL_GPL(inet6_ehashfn);
41
42/*
43 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
44 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
45 *
46 * The sockhash lock must be held as a reader here.
47 */
48struct sock *__inet6_lookup_established(struct net *net,
49 struct inet_hashinfo *hashinfo,
50 const struct in6_addr *saddr,
51 const __be16 sport,
52 const struct in6_addr *daddr,
53 const u16 hnum,
54 const int dif, const int sdif)
55{
56 struct sock *sk;
57 const struct hlist_nulls_node *node;
58 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
59 /* Optimize here for direct hit, only listening connections can
60 * have wildcards anyways.
61 */
62 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
63 unsigned int slot = hash & hashinfo->ehash_mask;
64 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
65
66
67begin:
68 sk_nulls_for_each_rcu(sk, node, &head->chain) {
69 if (sk->sk_hash != hash)
70 continue;
71 if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
72 continue;
73 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
74 goto out;
75
76 if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
77 sock_gen_put(sk);
78 goto begin;
79 }
80 goto found;
81 }
82 if (get_nulls_value(node) != slot)
83 goto begin;
84out:
85 sk = NULL;
86found:
87 return sk;
88}
89EXPORT_SYMBOL(__inet6_lookup_established);
90
91static inline int compute_score(struct sock *sk, struct net *net,
92 const unsigned short hnum,
93 const struct in6_addr *daddr,
94 const int dif, const int sdif)
95{
96 int score = -1;
97
98 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
99 sk->sk_family == PF_INET6) {
100 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
101 return -1;
102
103 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
104 return -1;
105
106 score = sk->sk_bound_dev_if ? 2 : 1;
107 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
108 score++;
109 }
110 return score;
111}
112
113/**
114 * inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
115 * @net: network namespace.
116 * @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
117 * @skb: context for a potential SK_REUSEPORT program.
118 * @doff: header offset.
119 * @saddr: source address.
120 * @sport: source port.
121 * @daddr: destination address.
122 * @hnum: destination port in host byte order.
123 * @ehashfn: hash function used to generate the fallback hash.
124 *
125 * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
126 * the selected sock or an error.
127 */
128struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,
129 struct sk_buff *skb, int doff,
130 const struct in6_addr *saddr,
131 __be16 sport,
132 const struct in6_addr *daddr,
133 unsigned short hnum,
134 inet6_ehashfn_t *ehashfn)
135{
136 struct sock *reuse_sk = NULL;
137 u32 phash;
138
139 if (sk->sk_reuseport) {
140 phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
141 net, daddr, hnum, saddr, sport);
142 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
143 }
144 return reuse_sk;
145}
146EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
147
148/* called with rcu_read_lock() */
149static struct sock *inet6_lhash2_lookup(struct net *net,
150 struct inet_listen_hashbucket *ilb2,
151 struct sk_buff *skb, int doff,
152 const struct in6_addr *saddr,
153 const __be16 sport, const struct in6_addr *daddr,
154 const unsigned short hnum, const int dif, const int sdif)
155{
156 struct sock *sk, *result = NULL;
157 struct hlist_nulls_node *node;
158 int score, hiscore = 0;
159
160 sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
161 score = compute_score(sk, net, hnum, daddr, dif, sdif);
162 if (score > hiscore) {
163 result = inet6_lookup_reuseport(net, sk, skb, doff,
164 saddr, sport, daddr, hnum, inet6_ehashfn);
165 if (result)
166 return result;
167
168 result = sk;
169 hiscore = score;
170 }
171 }
172
173 return result;
174}
175
176struct sock *inet6_lookup_run_sk_lookup(struct net *net,
177 int protocol,
178 struct sk_buff *skb, int doff,
179 const struct in6_addr *saddr,
180 const __be16 sport,
181 const struct in6_addr *daddr,
182 const u16 hnum, const int dif,
183 inet6_ehashfn_t *ehashfn)
184{
185 struct sock *sk, *reuse_sk;
186 bool no_reuseport;
187
188 no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
189 daddr, hnum, dif, &sk);
190 if (no_reuseport || IS_ERR_OR_NULL(sk))
191 return sk;
192
193 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
194 saddr, sport, daddr, hnum, ehashfn);
195 if (reuse_sk)
196 sk = reuse_sk;
197 return sk;
198}
199EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);
200
201struct sock *inet6_lookup_listener(struct net *net,
202 struct inet_hashinfo *hashinfo,
203 struct sk_buff *skb, int doff,
204 const struct in6_addr *saddr,
205 const __be16 sport, const struct in6_addr *daddr,
206 const unsigned short hnum, const int dif, const int sdif)
207{
208 struct inet_listen_hashbucket *ilb2;
209 struct sock *result = NULL;
210 unsigned int hash2;
211
212 /* Lookup redirect from BPF */
213 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
214 hashinfo == net->ipv4.tcp_death_row.hashinfo) {
215 result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
216 saddr, sport, daddr, hnum, dif,
217 inet6_ehashfn);
218 if (result)
219 goto done;
220 }
221
222 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
223 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
224
225 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
226 saddr, sport, daddr, hnum,
227 dif, sdif);
228 if (result)
229 goto done;
230
231 /* Lookup lhash2 with in6addr_any */
232 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
233 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
234
235 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
236 saddr, sport, &in6addr_any, hnum,
237 dif, sdif);
238done:
239 if (IS_ERR(result))
240 return NULL;
241 return result;
242}
243EXPORT_SYMBOL_GPL(inet6_lookup_listener);
244
245struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
246 struct sk_buff *skb, int doff,
247 const struct in6_addr *saddr, const __be16 sport,
248 const struct in6_addr *daddr, const __be16 dport,
249 const int dif)
250{
251 struct sock *sk;
252 bool refcounted;
253
254 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
255 ntohs(dport), dif, 0, &refcounted);
256 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
257 sk = NULL;
258 return sk;
259}
260EXPORT_SYMBOL_GPL(inet6_lookup);
261
262static int __inet6_check_established(struct inet_timewait_death_row *death_row,
263 struct sock *sk, const __u16 lport,
264 struct inet_timewait_sock **twp)
265{
266 struct inet_hashinfo *hinfo = death_row->hashinfo;
267 struct inet_sock *inet = inet_sk(sk);
268 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
269 const struct in6_addr *saddr = &sk->sk_v6_daddr;
270 const int dif = sk->sk_bound_dev_if;
271 struct net *net = sock_net(sk);
272 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
273 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
274 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
275 inet->inet_dport);
276 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
277 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
278 struct sock *sk2;
279 const struct hlist_nulls_node *node;
280 struct inet_timewait_sock *tw = NULL;
281
282 spin_lock(lock);
283
284 sk_nulls_for_each(sk2, node, &head->chain) {
285 if (sk2->sk_hash != hash)
286 continue;
287
288 if (likely(inet6_match(net, sk2, saddr, daddr, ports,
289 dif, sdif))) {
290 if (sk2->sk_state == TCP_TIME_WAIT) {
291 tw = inet_twsk(sk2);
292 if (twsk_unique(sk, sk2, twp))
293 break;
294 }
295 goto not_unique;
296 }
297 }
298
299 /* Must record num and sport now. Otherwise we will see
300 * in hash table socket with a funny identity.
301 */
302 inet->inet_num = lport;
303 inet->inet_sport = htons(lport);
304 sk->sk_hash = hash;
305 WARN_ON(!sk_unhashed(sk));
306 __sk_nulls_add_node_rcu(sk, &head->chain);
307 if (tw) {
308 sk_nulls_del_node_init_rcu((struct sock *)tw);
309 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
310 }
311 spin_unlock(lock);
312 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
313
314 if (twp) {
315 *twp = tw;
316 } else if (tw) {
317 /* Silly. Should hash-dance instead... */
318 inet_twsk_deschedule_put(tw);
319 }
320 return 0;
321
322not_unique:
323 spin_unlock(lock);
324 return -EADDRNOTAVAIL;
325}
326
327static u64 inet6_sk_port_offset(const struct sock *sk)
328{
329 const struct inet_sock *inet = inet_sk(sk);
330
331 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
332 sk->sk_v6_daddr.s6_addr32,
333 inet->inet_dport);
334}
335
336int inet6_hash_connect(struct inet_timewait_death_row *death_row,
337 struct sock *sk)
338{
339 u64 port_offset = 0;
340
341 if (!inet_sk(sk)->inet_num)
342 port_offset = inet6_sk_port_offset(sk);
343 return __inet_hash_connect(death_row, sk, port_offset,
344 __inet6_check_established);
345}
346EXPORT_SYMBOL_GPL(inet6_hash_connect);
347
348int inet6_hash(struct sock *sk)
349{
350 int err = 0;
351
352 if (sk->sk_state != TCP_CLOSE)
353 err = __inet_hash(sk, NULL);
354
355 return err;
356}
357EXPORT_SYMBOL_GPL(inet6_hash);
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);