summaryrefslogtreecommitdiffstats
path: root/net/ipv6/inet6_hashtables.c
blob: 00cf28ad45650c801c90c37fb571acb7d1615183 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Generic INET6 transport hashtables
 *
 * Authors:	Lotsa people, from code originally in tcp, generalised here
 *		by Arnaldo Carvalho de Melo <acme@mandriva.com>
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/random.h>

#include <net/addrconf.h>
#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/inet6_hashtables.h>
#include <net/secure_seq.h>
#include <net/ip.h>
#include <net/sock_reuseport.h>

u32 inet6_ehashfn(const struct net *net,
		  const struct in6_addr *laddr, const u16 lport,
		  const struct in6_addr *faddr, const __be16 fport)
{
	static u32 inet6_ehash_secret __read_mostly;
	static u32 ipv6_hash_secret __read_mostly;

	u32 lhash, fhash;

	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
	net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));

	lhash = (__force u32)laddr->s6_addr32[3];
	fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);

	return __inet6_ehashfn(lhash, lport, fhash, fport,
			       inet6_ehash_secret + net_hash_mix(net));
}

/*
 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
 *
 * The sockhash lock must be held as a reader here.
 */
struct sock *__inet6_lookup_established(struct net *net,
					struct inet_hashinfo *hashinfo,
					   const struct in6_addr *saddr,
					   const __be16 sport,
					   const struct in6_addr *daddr,
					   const u16 hnum,
					   const int dif)
{
	struct sock *sk;
	const struct hlist_nulls_node *node;
	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
	/* Optimize here for direct hit, only listening connections can
	 * have wildcards anyways.
	 */
	unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
	unsigned int slot = hash & hashinfo->ehash_mask;
	struct inet_ehash_bucket *head = &hashinfo->ehash[slot];


begin:
	sk_nulls_for_each_rcu(sk, node, &head->chain) {
		if (sk->sk_hash != hash)
			continue;
		if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif))
			continue;
		if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
			goto out;

		if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
			sock_gen_put(sk);
			goto begin;
		}
		goto found;
	}
	if (get_nulls_value(node) != slot)
		goto begin;
out:
	sk = NULL;
found:
	return sk;
}
EXPORT_SYMBOL(__inet6_lookup_established);

static inline int compute_score(struct sock *sk, struct net *net,
				const unsigned short hnum,
				const struct in6_addr *daddr,
				const int dif)
{
	int score = -1;

	if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
	    sk->sk_family == PF_INET6) {

		score = 1;
		if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
			if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
				return -1;
			score++;
		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
			score++;
		}
		if (sk->sk_incoming_cpu == raw_smp_processor_id())
			score++;
	}
	return score;
}

/* called with rcu_read_lock() */
struct sock *inet6_lookup_listener(struct net *net,
		struct inet_hashinfo *hashinfo,
		struct sk_buff *skb, int doff,
		const struct in6_addr *saddr,
		const __be16 sport, const struct in6_addr *daddr,
		const unsigned short hnum, const int dif)
{
	unsigned int hash = inet_lhashfn(net, hnum);
	struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
	int score, hiscore = 0, matches = 0, reuseport = 0;
	struct sock *sk, *result = NULL;
	u32 phash = 0;

	sk_for_each(sk, &ilb->head) {
		score = compute_score(sk, net, hnum, daddr, dif);
		if (score > hiscore) {
			reuseport = sk->sk_reuseport;
			if (reuseport) {
				phash = inet6_ehashfn(net, daddr, hnum,
						      saddr, sport);
				result = reuseport_select_sock(sk, phash,
							       skb, doff);
				if (result)
					return result;
				matches = 1;
			}
			result = sk;
			hiscore = score;
		} else if (score == hiscore && reuseport) {
			matches++;
			if (reciprocal_scale(phash, matches) == 0)
				result = sk;
			phash = next_pseudo_random32(phash);
		}
	}
	return result;
}
EXPORT_SYMBOL_GPL(inet6_lookup_listener);

struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
			  struct sk_buff *skb, int doff,
			  const struct in6_addr *saddr, const __be16 sport,
			  const struct in6_addr *daddr, const __be16 dport,
			  const int dif)
{
	struct sock *sk;
	bool refcounted;

	sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
			    ntohs(dport), dif, &refcounted);
	if (sk && !refcounted && !atomic_inc_not_zero(&sk->sk_refcnt))
		sk = NULL;
	return sk;
}
EXPORT_SYMBOL_GPL(inet6_lookup);

static int __inet6_check_established(struct inet_timewait_death_row *death_row,
				     struct sock *sk, const __u16 lport,
				     struct inet_timewait_sock **twp)
{
	struct inet_hashinfo *hinfo = death_row->hashinfo;
	struct inet_sock *inet = inet_sk(sk);
	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	const int dif = sk->sk_bound_dev_if;
	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
	struct net *net = sock_net(sk);
	const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
						inet->inet_dport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
	struct sock *sk2;
	const struct hlist_nulls_node *node;
	struct inet_timewait_sock *tw = NULL;

	spin_lock(lock);

	sk_nulls_for_each(sk2, node, &head->chain) {
		if (sk2->sk_hash != hash)
			continue;

		if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) {
			if (sk2->sk_state == TCP_TIME_WAIT) {
				tw = inet_twsk(sk2);
				if (twsk_unique(sk, sk2, twp))
					break;
			}
			goto not_unique;
		}
	}

	/* Must record num and sport now. Otherwise we will see
	 * in hash table socket with a funny identity.
	 */
	inet->inet_num = lport;
	inet->inet_sport = htons(lport);
	sk->sk_hash = hash;
	WARN_ON(!sk_unhashed(sk));
	__sk_nulls_add_node_rcu(sk, &head->chain);
	if (tw) {
		sk_nulls_del_node_init_rcu((struct sock *)tw);
		__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
	}
	spin_unlock(lock);
	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);

	if (twp) {
		*twp = tw;
	} else if (tw) {
		/* Silly. Should hash-dance instead... */
		inet_twsk_deschedule_put(tw);
	}
	return 0;

not_unique:
	spin_unlock(lock);
	return -EADDRNOTAVAIL;
}

static u32 inet6_sk_port_offset(const struct sock *sk)
{
	const struct inet_sock *inet = inet_sk(sk);

	return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
					  sk->sk_v6_daddr.s6_addr32,
					  inet->inet_dport);
}

int inet6_hash_connect(struct inet_timewait_death_row *death_row,
		       struct sock *sk)
{
	u32 port_offset = 0;

	if (!inet_sk(sk)->inet_num)
		port_offset = inet6_sk_port_offset(sk);
	return __inet_hash_connect(death_row, sk, port_offset,
				   __inet6_check_established);
}
EXPORT_SYMBOL_GPL(inet6_hash_connect);

int inet6_hash(struct sock *sk)
{
	if (sk->sk_state != TCP_CLOSE) {
		local_bh_disable();
		__inet_hash(sk, NULL, ipv6_rcv_saddr_equal);
		local_bh_enable();
	}

	return 0;
}
EXPORT_SYMBOL_GPL(inet6_hash);

/* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
 *                          only, and any IPv4 addresses if not IPv6 only
 * match_wildcard == false: addresses must be exactly the same, i.e.
 *                          IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
 *                          and 0.0.0.0 equals to 0.0.0.0 only
 */
int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
			 bool match_wildcard)
{
	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
	int sk2_ipv6only = inet_v6_ipv6only(sk2);
	int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;

	/* if both are mapped, treat as IPv4 */
	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
		if (!sk2_ipv6only) {
			if (sk->sk_rcv_saddr == sk2->sk_rcv_saddr)
				return 1;
			if (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr)
				return match_wildcard;
		}
		return 0;
	}

	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
		return 1;

	if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
		return 1;

	if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
	    !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
		return 1;

	if (sk2_rcv_saddr6 &&
	    ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
		return 1;

	return 0;
}
EXPORT_SYMBOL_GPL(ipv6_rcv_saddr_equal);
OpenPOWER on IntegriCloud