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[INET]: Drop the inet_inherit_port() call.
[mirror_ubuntu-bionic-kernel.git] / include / net / inet_hashtables.h
CommitLineData
304a1618
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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 * Authors: Lotsa people, from code originally in tcp
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14#ifndef _INET_HASHTABLES_H
15#define _INET_HASHTABLES_H
16
8feaf0c0 17
2d8c4ce5 18#include <linux/interrupt.h>
33b62231 19#include <linux/ipv6.h>
77d8bf9c
ACM
20#include <linux/list.h>
21#include <linux/slab.h>
33b62231 22#include <linux/socket.h>
77d8bf9c 23#include <linux/spinlock.h>
304a1618 24#include <linux/types.h>
f3f05f70 25#include <linux/wait.h>
9e4505c4 26#include <linux/vmalloc.h>
304a1618 27
463c84b9 28#include <net/inet_connection_sock.h>
14c85021 29#include <net/inet_sock.h>
2d8c4ce5 30#include <net/sock.h>
c752f073 31#include <net/tcp_states.h>
2d8c4ce5 32
f3f05f70 33#include <asm/atomic.h>
e48c414e 34#include <asm/byteorder.h>
f3f05f70 35
77d8bf9c 36/* This is for all connections with a full identity, no wildcards.
dbca9b27
ED
37 * One chain is dedicated to TIME_WAIT sockets.
38 * I'll experiment with dynamic table growth later.
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39 */
40struct inet_ehash_bucket {
77d8bf9c 41 struct hlist_head chain;
dbca9b27 42 struct hlist_head twchain;
6d255361 43};
77d8bf9c
ACM
44
45/* There are a few simple rules, which allow for local port reuse by
46 * an application. In essence:
47 *
48 * 1) Sockets bound to different interfaces may share a local port.
49 * Failing that, goto test 2.
50 * 2) If all sockets have sk->sk_reuse set, and none of them are in
51 * TCP_LISTEN state, the port may be shared.
52 * Failing that, goto test 3.
53 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
54 * address, and none of them are the same, the port may be
55 * shared.
56 * Failing this, the port cannot be shared.
57 *
58 * The interesting point, is test #2. This is what an FTP server does
59 * all day. To optimize this case we use a specific flag bit defined
60 * below. As we add sockets to a bind bucket list, we perform a
61 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
62 * As long as all sockets added to a bind bucket pass this test,
63 * the flag bit will be set.
64 * The resulting situation is that tcp_v[46]_verify_bind() can just check
65 * for this flag bit, if it is set and the socket trying to bind has
66 * sk->sk_reuse set, we don't even have to walk the owners list at all,
67 * we return that it is ok to bind this socket to the requested local port.
68 *
69 * Sounds like a lot of work, but it is worth it. In a more naive
70 * implementation (ie. current FreeBSD etc.) the entire list of ports
71 * must be walked for each data port opened by an ftp server. Needless
72 * to say, this does not scale at all. With a couple thousand FTP
73 * users logged onto your box, isn't it nice to know that new data
74 * ports are created in O(1) time? I thought so. ;-) -DaveM
75 */
76struct inet_bind_bucket {
941b1d22 77 struct net *ib_net;
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78 unsigned short port;
79 signed short fastreuse;
80 struct hlist_node node;
81 struct hlist_head owners;
82};
83
84#define inet_bind_bucket_for_each(tb, node, head) \
85 hlist_for_each_entry(tb, node, head, node)
86
87struct inet_bind_hashbucket {
88 spinlock_t lock;
89 struct hlist_head chain;
90};
91
92/* This is for listening sockets, thus all sockets which possess wildcards. */
93#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
94
95struct inet_hashinfo {
96 /* This is for sockets with full identity only. Sockets here will
97 * always be without wildcards and will have the following invariant:
98 *
99 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
100 *
dbca9b27 101 * TIME_WAIT sockets use a separate chain (twchain).
77d8bf9c
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102 */
103 struct inet_ehash_bucket *ehash;
230140cf
ED
104 rwlock_t *ehash_locks;
105 unsigned int ehash_size;
106 unsigned int ehash_locks_mask;
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107
108 /* Ok, let's try this, I give up, we do need a local binding
109 * TCP hash as well as the others for fast bind/connect.
110 */
111 struct inet_bind_hashbucket *bhash;
112
cfcabdcc 113 unsigned int bhash_size;
230140cf 114 /* Note : 4 bytes padding on 64 bit arches */
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115
116 /* All sockets in TCP_LISTEN state will be in here. This is the only
117 * table where wildcard'd TCP sockets can exist. Hash function here
118 * is just local port number.
119 */
120 struct hlist_head listening_hash[INET_LHTABLE_SIZE];
121
122 /* All the above members are written once at bootup and
123 * never written again _or_ are predominantly read-access.
124 *
125 * Now align to a new cache line as all the following members
126 * are often dirty.
127 */
128 rwlock_t lhash_lock ____cacheline_aligned;
129 atomic_t lhash_users;
130 wait_queue_head_t lhash_wait;
e18b890b 131 struct kmem_cache *bind_bucket_cachep;
77d8bf9c
ACM
132};
133
81c3d547
ED
134static inline struct inet_ehash_bucket *inet_ehash_bucket(
135 struct inet_hashinfo *hashinfo,
136 unsigned int hash)
137{
138 return &hashinfo->ehash[hash & (hashinfo->ehash_size - 1)];
304a1618
ACM
139}
140
230140cf
ED
141static inline rwlock_t *inet_ehash_lockp(
142 struct inet_hashinfo *hashinfo,
143 unsigned int hash)
144{
145 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
146}
147
148static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
149{
150 unsigned int i, size = 256;
151#if defined(CONFIG_PROVE_LOCKING)
152 unsigned int nr_pcpus = 2;
153#else
154 unsigned int nr_pcpus = num_possible_cpus();
155#endif
156 if (nr_pcpus >= 4)
157 size = 512;
158 if (nr_pcpus >= 8)
159 size = 1024;
160 if (nr_pcpus >= 16)
161 size = 2048;
162 if (nr_pcpus >= 32)
163 size = 4096;
164 if (sizeof(rwlock_t) != 0) {
165#ifdef CONFIG_NUMA
166 if (size * sizeof(rwlock_t) > PAGE_SIZE)
167 hashinfo->ehash_locks = vmalloc(size * sizeof(rwlock_t));
168 else
169#endif
170 hashinfo->ehash_locks = kmalloc(size * sizeof(rwlock_t),
171 GFP_KERNEL);
172 if (!hashinfo->ehash_locks)
173 return ENOMEM;
174 for (i = 0; i < size; i++)
175 rwlock_init(&hashinfo->ehash_locks[i]);
176 }
177 hashinfo->ehash_locks_mask = size - 1;
178 return 0;
179}
180
181static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
182{
183 if (hashinfo->ehash_locks) {
184#ifdef CONFIG_NUMA
185 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
186 sizeof(rwlock_t);
187 if (size > PAGE_SIZE)
188 vfree(hashinfo->ehash_locks);
189 else
230140cf 190#endif
218ad12f 191 kfree(hashinfo->ehash_locks);
230140cf
ED
192 hashinfo->ehash_locks = NULL;
193 }
194}
195
77d8bf9c 196extern struct inet_bind_bucket *
e18b890b 197 inet_bind_bucket_create(struct kmem_cache *cachep,
941b1d22 198 struct net *net,
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199 struct inet_bind_hashbucket *head,
200 const unsigned short snum);
e18b890b 201extern void inet_bind_bucket_destroy(struct kmem_cache *cachep,
77d8bf9c
ACM
202 struct inet_bind_bucket *tb);
203
204static inline int inet_bhashfn(const __u16 lport, const int bhash_size)
205{
206 return lport & (bhash_size - 1);
207}
208
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209extern void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
210 const unsigned short snum);
211
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212/* These can have wildcards, don't try too hard. */
213static inline int inet_lhashfn(const unsigned short num)
214{
215 return num & (INET_LHTABLE_SIZE - 1);
216}
217
218static inline int inet_sk_listen_hashfn(const struct sock *sk)
219{
220 return inet_lhashfn(inet_sk(sk)->num);
221}
222
2d8c4ce5 223/* Caller must disable local BH processing. */
ab1e0a13 224static inline void __inet_inherit_port(struct sock *sk, struct sock *child)
2d8c4ce5 225{
39d8cda7 226 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
2d8c4ce5
ACM
227 const int bhash = inet_bhashfn(inet_sk(child)->num, table->bhash_size);
228 struct inet_bind_hashbucket *head = &table->bhash[bhash];
229 struct inet_bind_bucket *tb;
230
231 spin_lock(&head->lock);
463c84b9 232 tb = inet_csk(sk)->icsk_bind_hash;
2d8c4ce5 233 sk_add_bind_node(child, &tb->owners);
463c84b9 234 inet_csk(child)->icsk_bind_hash = tb;
2d8c4ce5
ACM
235 spin_unlock(&head->lock);
236}
237
ab1e0a13 238extern void inet_put_port(struct sock *sk);
2d8c4ce5 239
f3f05f70
ACM
240extern void inet_listen_wlock(struct inet_hashinfo *hashinfo);
241
242/*
243 * - We may sleep inside this lock.
244 * - If sleeping is not required (or called from BH),
245 * use plain read_(un)lock(&inet_hashinfo.lhash_lock).
246 */
247static inline void inet_listen_lock(struct inet_hashinfo *hashinfo)
248{
249 /* read_lock synchronizes to candidates to writers */
250 read_lock(&hashinfo->lhash_lock);
251 atomic_inc(&hashinfo->lhash_users);
252 read_unlock(&hashinfo->lhash_lock);
253}
254
255static inline void inet_listen_unlock(struct inet_hashinfo *hashinfo)
256{
257 if (atomic_dec_and_test(&hashinfo->lhash_users))
258 wake_up(&hashinfo->lhash_wait);
259}
260
ab1e0a13
ACM
261extern void __inet_hash_nolisten(struct sock *sk);
262extern void inet_hash(struct sock *sk);
263extern void inet_unhash(struct sock *sk);
33b62231 264
c67499c0
PE
265extern struct sock *__inet_lookup_listener(struct net *net,
266 struct inet_hashinfo *hashinfo,
fb99c848 267 const __be32 daddr,
8f491069
HX
268 const unsigned short hnum,
269 const int dif);
270
c67499c0
PE
271static inline struct sock *inet_lookup_listener(struct net *net,
272 struct inet_hashinfo *hashinfo,
273 __be32 daddr, __be16 dport, int dif)
8f491069 274{
c67499c0 275 return __inet_lookup_listener(net, hashinfo, daddr, ntohs(dport), dif);
8f491069 276}
8feaf0c0
ACM
277
278/* Socket demux engine toys. */
4f765d84
AV
279/* What happens here is ugly; there's a pair of adjacent fields in
280 struct inet_sock; __be16 dport followed by __u16 num. We want to
281 search by pair, so we combine the keys into a single 32bit value
282 and compare with 32bit value read from &...->dport. Let's at least
283 make sure that it's not mixed with anything else...
284 On 64bit targets we combine comparisons with pair of adjacent __be32
285 fields in the same way.
286*/
287typedef __u32 __bitwise __portpair;
8feaf0c0
ACM
288#ifdef __BIG_ENDIAN
289#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 290 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
8feaf0c0
ACM
291#else /* __LITTLE_ENDIAN */
292#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 293 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
8feaf0c0
ACM
294#endif
295
296#if (BITS_PER_LONG == 64)
4f765d84 297typedef __u64 __bitwise __addrpair;
8feaf0c0
ACM
298#ifdef __BIG_ENDIAN
299#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
300 const __addrpair __name = (__force __addrpair) ( \
301 (((__force __u64)(__be32)(__saddr)) << 32) | \
302 ((__force __u64)(__be32)(__daddr)));
8feaf0c0
ACM
303#else /* __LITTLE_ENDIAN */
304#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
305 const __addrpair __name = (__force __addrpair) ( \
306 (((__force __u64)(__be32)(__daddr)) << 32) | \
307 ((__force __u64)(__be32)(__saddr)));
8feaf0c0 308#endif /* __BIG_ENDIAN */
c67499c0 309#define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
3b1e0a65 310 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
4f765d84
AV
311 ((*((__addrpair *)&(inet_sk(__sk)->daddr))) == (__cookie)) && \
312 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 313 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
c67499c0 314#define INET_TW_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
3b1e0a65 315 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
4f765d84
AV
316 ((*((__addrpair *)&(inet_twsk(__sk)->tw_daddr))) == (__cookie)) && \
317 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
318 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
319#else /* 32-bit arch */
320#define INET_ADDR_COOKIE(__name, __saddr, __daddr)
c67499c0 321#define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif) \
3b1e0a65 322 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
81c3d547 323 (inet_sk(__sk)->daddr == (__saddr)) && \
8feaf0c0 324 (inet_sk(__sk)->rcv_saddr == (__daddr)) && \
4f765d84 325 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 326 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
c67499c0 327#define INET_TW_MATCH(__sk, __net, __hash,__cookie, __saddr, __daddr, __ports, __dif) \
3b1e0a65 328 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
81c3d547 329 (inet_twsk(__sk)->tw_daddr == (__saddr)) && \
8feaf0c0 330 (inet_twsk(__sk)->tw_rcv_saddr == (__daddr)) && \
4f765d84 331 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
332 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
333#endif /* 64-bit arch */
e48c414e
ACM
334
335/*
336 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
337 * not check it for lookups anymore, thanks Alexey. -DaveM
338 *
339 * Local BH must be disabled here.
340 */
c67499c0
PE
341extern struct sock * __inet_lookup_established(struct net *net,
342 struct inet_hashinfo *hashinfo,
77a5ba55
PE
343 const __be32 saddr, const __be16 sport,
344 const __be32 daddr, const u16 hnum, const int dif);
e48c414e 345
8f491069 346static inline struct sock *
c67499c0 347 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
fb99c848
AV
348 const __be32 saddr, const __be16 sport,
349 const __be32 daddr, const __be16 dport,
8f491069
HX
350 const int dif)
351{
c67499c0 352 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
8f491069
HX
353 ntohs(dport), dif);
354}
355
c67499c0
PE
356static inline struct sock *__inet_lookup(struct net *net,
357 struct inet_hashinfo *hashinfo,
fb99c848
AV
358 const __be32 saddr, const __be16 sport,
359 const __be32 daddr, const __be16 dport,
e48c414e
ACM
360 const int dif)
361{
8f491069 362 u16 hnum = ntohs(dport);
c67499c0
PE
363 struct sock *sk = __inet_lookup_established(net, hashinfo,
364 saddr, sport, daddr, hnum, dif);
365
366 return sk ? : __inet_lookup_listener(net, hashinfo, daddr, hnum, dif);
e48c414e
ACM
367}
368
c67499c0
PE
369static inline struct sock *inet_lookup(struct net *net,
370 struct inet_hashinfo *hashinfo,
fb99c848
AV
371 const __be32 saddr, const __be16 sport,
372 const __be32 daddr, const __be16 dport,
e48c414e
ACM
373 const int dif)
374{
375 struct sock *sk;
376
377 local_bh_disable();
c67499c0 378 sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
379 local_bh_enable();
380
381 return sk;
382}
a7f5e7f1 383
5ee31fc1 384extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
5d8c0aa9 385 struct sock *sk, u32 port_offset,
5ee31fc1
PE
386 int (*check_established)(struct inet_timewait_death_row *,
387 struct sock *, __u16, struct inet_timewait_sock **),
ab1e0a13 388 void (*hash)(struct sock *sk));
a7f5e7f1
ACM
389extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
390 struct sock *sk);
304a1618 391#endif /* _INET_HASHTABLES_H */