l2tp: use add READ_ONCE() to fetch sk->sk_bound_dev_if
[linux-block.git] / net / ipv6 / inet6_hashtables.c
CommitLineData
2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
5324a040
ACM
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 *
d8313f5c 9 * Authors: Lotsa people, from code originally in tcp, generalised here
67ba4152 10 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
5324a040
ACM
11 */
12
5324a040 13#include <linux/module.h>
d8313f5c 14#include <linux/random.h>
5324a040 15
c125e80b 16#include <net/addrconf.h>
5324a040
ACM
17#include <net/inet_connection_sock.h>
18#include <net/inet_hashtables.h>
19#include <net/inet6_hashtables.h>
6e5714ea 20#include <net/secure_seq.h>
d8313f5c 21#include <net/ip.h>
c125e80b 22#include <net/sock_reuseport.h>
5324a040 23
1122702f
JS
24extern struct inet_hashinfo tcp_hashinfo;
25
d1e559d0
ED
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)
b50026b5 29{
1bbdceef
HFS
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
b50026b5 41 return __inet6_ehashfn(lhash, lport, fhash, fport,
1bbdceef 42 inet6_ehash_secret + net_hash_mix(net));
b50026b5
HFS
43}
44
b1a7ffcb
DV
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 */
d86e0dac
PE
51struct sock *__inet6_lookup_established(struct net *net,
52 struct inet_hashinfo *hashinfo,
b1a7ffcb 53 const struct in6_addr *saddr,
d2ecd9cc 54 const __be16 sport,
b1a7ffcb
DV
55 const struct in6_addr *daddr,
56 const u16 hnum,
4297a0ef 57 const int dif, const int sdif)
b1a7ffcb
DV
58{
59 struct sock *sk;
3ab5aee7 60 const struct hlist_nulls_node *node;
4f765d84 61 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
b1a7ffcb
DV
62 /* Optimize here for direct hit, only listening connections can
63 * have wildcards anyways.
64 */
33de014c 65 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
f373b53b 66 unsigned int slot = hash & hashinfo->ehash_mask;
3ab5aee7 67 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
b1a7ffcb 68
3ab5aee7 69
3ab5aee7
ED
70begin:
71 sk_nulls_for_each_rcu(sk, node, &head->chain) {
ce43b03e
ED
72 if (sk->sk_hash != hash)
73 continue;
4297a0ef 74 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
efe4208f 75 continue;
41c6d650 76 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
05dbc7b5
ED
77 goto out;
78
4297a0ef 79 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
efe4208f
ED
80 sock_gen_put(sk);
81 goto begin;
3ab5aee7 82 }
efe4208f 83 goto found;
b1a7ffcb 84 }
3ab5aee7
ED
85 if (get_nulls_value(node) != slot)
86 goto begin;
3ab5aee7 87out:
05dbc7b5
ED
88 sk = NULL;
89found:
b1a7ffcb
DV
90 return sk;
91}
92EXPORT_SYMBOL(__inet6_lookup_established);
93
42b16b3f 94static inline int compute_score(struct sock *sk, struct net *net,
c25eb3bf
ED
95 const unsigned short hnum,
96 const struct in6_addr *daddr,
3f7d820b 97 const int dif, const int sdif)
c25eb3bf
ED
98{
99 int score = -1;
100
c720c7e8 101 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
c25eb3bf 102 sk->sk_family == PF_INET6) {
0ee58dad
PO
103 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
104 return -1;
c25eb3bf 105
0ee58dad 106 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
e7819058 107 return -1;
4297a0ef 108
8d6c414c 109 score = sk->sk_bound_dev_if ? 2 : 1;
7170a977 110 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
70da268b 111 score++;
c25eb3bf
ED
112 }
113 return score;
114}
115
5df65312
JS
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
3b24d854 133/* called with rcu_read_lock() */
61b7c691
MKL
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{
61b7c691 141 struct sock *sk, *result = NULL;
cae3873c 142 struct hlist_nulls_node *node;
61b7c691 143 int score, hiscore = 0;
61b7c691 144
cae3873c 145 sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
3f7d820b 146 score = compute_score(sk, net, hnum, daddr, dif, sdif);
61b7c691 147 if (score > hiscore) {
5df65312
JS
148 result = lookup_reuseport(net, sk, skb, doff,
149 saddr, sport, daddr, hnum);
150 if (result)
151 return result;
152
61b7c691
MKL
153 result = sk;
154 hiscore = score;
155 }
156 }
157
158 return result;
159}
160
1122702f
JS
161static inline struct sock *inet6_lookup_run_bpf(struct net *net,
162 struct inet_hashinfo *hashinfo,
163 struct sk_buff *skb, int doff,
164 const struct in6_addr *saddr,
165 const __be16 sport,
166 const struct in6_addr *daddr,
f8931565 167 const u16 hnum, const int dif)
1122702f
JS
168{
169 struct sock *sk, *reuse_sk;
170 bool no_reuseport;
171
172 if (hashinfo != &tcp_hashinfo)
173 return NULL; /* only TCP is supported */
174
f8931565
MP
175 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_TCP, saddr, sport,
176 daddr, hnum, dif, &sk);
1122702f
JS
177 if (no_reuseport || IS_ERR_OR_NULL(sk))
178 return sk;
179
180 reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
181 if (reuse_sk)
182 sk = reuse_sk;
183 return sk;
184}
185
d86e0dac 186struct sock *inet6_lookup_listener(struct net *net,
a583636a
CG
187 struct inet_hashinfo *hashinfo,
188 struct sk_buff *skb, int doff,
189 const struct in6_addr *saddr,
5ba24953 190 const __be16 sport, const struct in6_addr *daddr,
4297a0ef 191 const unsigned short hnum, const int dif, const int sdif)
5324a040 192{
61b7c691 193 struct inet_listen_hashbucket *ilb2;
0ee58dad 194 struct sock *result = NULL;
61b7c691 195 unsigned int hash2;
61b7c691 196
1122702f
JS
197 /* Lookup redirect from BPF */
198 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
199 result = inet6_lookup_run_bpf(net, hashinfo, skb, doff,
f8931565 200 saddr, sport, daddr, hnum, dif);
1122702f
JS
201 if (result)
202 goto done;
203 }
204
61b7c691
MKL
205 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
206 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
61b7c691
MKL
207
208 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
209 saddr, sport, daddr, hnum,
210 dif, sdif);
211 if (result)
8217ca65 212 goto done;
61b7c691
MKL
213
214 /* Lookup lhash2 with in6addr_any */
61b7c691
MKL
215 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
216 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
61b7c691 217
8217ca65 218 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
0ee58dad 219 saddr, sport, &in6addr_any, hnum,
8217ca65 220 dif, sdif);
8217ca65 221done:
26f8113c 222 if (IS_ERR(result))
8217ca65 223 return NULL;
5324a040
ACM
224 return result;
225}
5324a040
ACM
226EXPORT_SYMBOL_GPL(inet6_lookup_listener);
227
d86e0dac 228struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
a583636a 229 struct sk_buff *skb, int doff,
d2ecd9cc
AV
230 const struct in6_addr *saddr, const __be16 sport,
231 const struct in6_addr *daddr, const __be16 dport,
5324a040
ACM
232 const int dif)
233{
234 struct sock *sk;
3b24d854 235 bool refcounted;
5324a040 236
a583636a 237 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
4297a0ef 238 ntohs(dport), dif, 0, &refcounted);
41c6d650 239 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
3b24d854 240 sk = NULL;
5324a040
ACM
241 return sk;
242}
5324a040 243EXPORT_SYMBOL_GPL(inet6_lookup);
d8313f5c
ACM
244
245static int __inet6_check_established(struct inet_timewait_death_row *death_row,
246 struct sock *sk, const __u16 lport,
247 struct inet_timewait_sock **twp)
248{
249 struct inet_hashinfo *hinfo = death_row->hashinfo;
3759fa9c 250 struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
251 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
252 const struct in6_addr *saddr = &sk->sk_v6_daddr;
d8313f5c 253 const int dif = sk->sk_bound_dev_if;
33de014c 254 struct net *net = sock_net(sk);
4297a0ef
DA
255 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
256 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
33de014c 257 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
c720c7e8 258 inet->inet_dport);
d8313f5c 259 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
9db66bdc 260 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
d8313f5c 261 struct sock *sk2;
3ab5aee7 262 const struct hlist_nulls_node *node;
05dbc7b5 263 struct inet_timewait_sock *tw = NULL;
d8313f5c 264
9db66bdc 265 spin_lock(lock);
d8313f5c 266
05dbc7b5 267 sk_nulls_for_each(sk2, node, &head->chain) {
ce43b03e
ED
268 if (sk2->sk_hash != hash)
269 continue;
d8313f5c 270
4297a0ef
DA
271 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
272 dif, sdif))) {
efe4208f 273 if (sk2->sk_state == TCP_TIME_WAIT) {
05dbc7b5
ED
274 tw = inet_twsk(sk2);
275 if (twsk_unique(sk, sk2, twp))
efe4208f 276 break;
05dbc7b5 277 }
d8313f5c 278 goto not_unique;
efe4208f 279 }
d8313f5c
ACM
280 }
281
3759fa9c 282 /* Must record num and sport now. Otherwise we will see
efe4208f
ED
283 * in hash table socket with a funny identity.
284 */
c720c7e8
ED
285 inet->inet_num = lport;
286 inet->inet_sport = htons(lport);
13475a30 287 sk->sk_hash = hash;
547b792c 288 WARN_ON(!sk_unhashed(sk));
3ab5aee7 289 __sk_nulls_add_node_rcu(sk, &head->chain);
13475a30 290 if (tw) {
fc01538f 291 sk_nulls_del_node_init_rcu((struct sock *)tw);
02a1d6e7 292 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
13475a30 293 }
9db66bdc 294 spin_unlock(lock);
c29a0bc4 295 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
d8313f5c 296
13475a30 297 if (twp) {
d8313f5c 298 *twp = tw;
13475a30 299 } else if (tw) {
d8313f5c 300 /* Silly. Should hash-dance instead... */
dbe7faa4 301 inet_twsk_deschedule_put(tw);
d8313f5c
ACM
302 }
303 return 0;
304
305not_unique:
9db66bdc 306 spin_unlock(lock);
d8313f5c
ACM
307 return -EADDRNOTAVAIL;
308}
309
b2d05756 310static u64 inet6_sk_port_offset(const struct sock *sk)
d8313f5c
ACM
311{
312 const struct inet_sock *inet = inet_sk(sk);
efe4208f
ED
313
314 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
315 sk->sk_v6_daddr.s6_addr32,
c720c7e8 316 inet->inet_dport);
d8313f5c
ACM
317}
318
319int inet6_hash_connect(struct inet_timewait_death_row *death_row,
320 struct sock *sk)
321{
b2d05756 322 u64 port_offset = 0;
e2baad9e
ED
323
324 if (!inet_sk(sk)->inet_num)
325 port_offset = inet6_sk_port_offset(sk);
326 return __inet_hash_connect(death_row, sk, port_offset,
b4d6444e 327 __inet6_check_established);
d8313f5c 328}
d8313f5c 329EXPORT_SYMBOL_GPL(inet6_hash_connect);
496611d7
CG
330
331int inet6_hash(struct sock *sk)
332{
e4cabca5
CG
333 int err = 0;
334
4f9bf2a2 335 if (sk->sk_state != TCP_CLOSE)
fe38d2a1 336 err = __inet_hash(sk, NULL);
496611d7 337
e4cabca5 338 return err;
496611d7
CG
339}
340EXPORT_SYMBOL_GPL(inet6_hash);