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[INET]: Consolidate inet(6)_hash_connect.
[net-next-2.6.git] / include / net / inet_hashtables.h
CommitLineData
304a1618
ACM
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.
77d8bf9c
ACM
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 {
77 unsigned short port;
78 signed short fastreuse;
79 struct hlist_node node;
80 struct hlist_head owners;
81};
82
83#define inet_bind_bucket_for_each(tb, node, head) \
84 hlist_for_each_entry(tb, node, head, node)
85
86struct inet_bind_hashbucket {
87 spinlock_t lock;
88 struct hlist_head chain;
89};
90
91/* This is for listening sockets, thus all sockets which possess wildcards. */
92#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
93
94struct inet_hashinfo {
95 /* This is for sockets with full identity only. Sockets here will
96 * always be without wildcards and will have the following invariant:
97 *
98 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
99 *
dbca9b27 100 * TIME_WAIT sockets use a separate chain (twchain).
77d8bf9c
ACM
101 */
102 struct inet_ehash_bucket *ehash;
230140cf
ED
103 rwlock_t *ehash_locks;
104 unsigned int ehash_size;
105 unsigned int ehash_locks_mask;
77d8bf9c
ACM
106
107 /* Ok, let's try this, I give up, we do need a local binding
108 * TCP hash as well as the others for fast bind/connect.
109 */
110 struct inet_bind_hashbucket *bhash;
111
cfcabdcc 112 unsigned int bhash_size;
230140cf 113 /* Note : 4 bytes padding on 64 bit arches */
77d8bf9c
ACM
114
115 /* All sockets in TCP_LISTEN state will be in here. This is the only
116 * table where wildcard'd TCP sockets can exist. Hash function here
117 * is just local port number.
118 */
119 struct hlist_head listening_hash[INET_LHTABLE_SIZE];
120
121 /* All the above members are written once at bootup and
122 * never written again _or_ are predominantly read-access.
123 *
124 * Now align to a new cache line as all the following members
125 * are often dirty.
126 */
127 rwlock_t lhash_lock ____cacheline_aligned;
128 atomic_t lhash_users;
129 wait_queue_head_t lhash_wait;
e18b890b 130 struct kmem_cache *bind_bucket_cachep;
77d8bf9c
ACM
131};
132
81c3d547
ED
133static inline struct inet_ehash_bucket *inet_ehash_bucket(
134 struct inet_hashinfo *hashinfo,
135 unsigned int hash)
136{
137 return &hashinfo->ehash[hash & (hashinfo->ehash_size - 1)];
304a1618
ACM
138}
139
230140cf
ED
140static inline rwlock_t *inet_ehash_lockp(
141 struct inet_hashinfo *hashinfo,
142 unsigned int hash)
143{
144 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
145}
146
147static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
148{
149 unsigned int i, size = 256;
150#if defined(CONFIG_PROVE_LOCKING)
151 unsigned int nr_pcpus = 2;
152#else
153 unsigned int nr_pcpus = num_possible_cpus();
154#endif
155 if (nr_pcpus >= 4)
156 size = 512;
157 if (nr_pcpus >= 8)
158 size = 1024;
159 if (nr_pcpus >= 16)
160 size = 2048;
161 if (nr_pcpus >= 32)
162 size = 4096;
163 if (sizeof(rwlock_t) != 0) {
164#ifdef CONFIG_NUMA
165 if (size * sizeof(rwlock_t) > PAGE_SIZE)
166 hashinfo->ehash_locks = vmalloc(size * sizeof(rwlock_t));
167 else
168#endif
169 hashinfo->ehash_locks = kmalloc(size * sizeof(rwlock_t),
170 GFP_KERNEL);
171 if (!hashinfo->ehash_locks)
172 return ENOMEM;
173 for (i = 0; i < size; i++)
174 rwlock_init(&hashinfo->ehash_locks[i]);
175 }
176 hashinfo->ehash_locks_mask = size - 1;
177 return 0;
178}
179
180static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
181{
182 if (hashinfo->ehash_locks) {
183#ifdef CONFIG_NUMA
184 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
185 sizeof(rwlock_t);
186 if (size > PAGE_SIZE)
187 vfree(hashinfo->ehash_locks);
188 else
230140cf 189#endif
218ad12f 190 kfree(hashinfo->ehash_locks);
230140cf
ED
191 hashinfo->ehash_locks = NULL;
192 }
193}
194
77d8bf9c 195extern struct inet_bind_bucket *
e18b890b 196 inet_bind_bucket_create(struct kmem_cache *cachep,
77d8bf9c
ACM
197 struct inet_bind_hashbucket *head,
198 const unsigned short snum);
e18b890b 199extern void inet_bind_bucket_destroy(struct kmem_cache *cachep,
77d8bf9c
ACM
200 struct inet_bind_bucket *tb);
201
202static inline int inet_bhashfn(const __u16 lport, const int bhash_size)
203{
204 return lport & (bhash_size - 1);
205}
206
2d8c4ce5
ACM
207extern void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
208 const unsigned short snum);
209
77d8bf9c
ACM
210/* These can have wildcards, don't try too hard. */
211static inline int inet_lhashfn(const unsigned short num)
212{
213 return num & (INET_LHTABLE_SIZE - 1);
214}
215
216static inline int inet_sk_listen_hashfn(const struct sock *sk)
217{
218 return inet_lhashfn(inet_sk(sk)->num);
219}
220
2d8c4ce5
ACM
221/* Caller must disable local BH processing. */
222static inline void __inet_inherit_port(struct inet_hashinfo *table,
223 struct sock *sk, struct sock *child)
224{
225 const int bhash = inet_bhashfn(inet_sk(child)->num, table->bhash_size);
226 struct inet_bind_hashbucket *head = &table->bhash[bhash];
227 struct inet_bind_bucket *tb;
228
229 spin_lock(&head->lock);
463c84b9 230 tb = inet_csk(sk)->icsk_bind_hash;
2d8c4ce5 231 sk_add_bind_node(child, &tb->owners);
463c84b9 232 inet_csk(child)->icsk_bind_hash = tb;
2d8c4ce5
ACM
233 spin_unlock(&head->lock);
234}
235
236static inline void inet_inherit_port(struct inet_hashinfo *table,
237 struct sock *sk, struct sock *child)
238{
239 local_bh_disable();
240 __inet_inherit_port(table, sk, child);
241 local_bh_enable();
242}
243
244extern void inet_put_port(struct inet_hashinfo *table, struct sock *sk);
245
f3f05f70
ACM
246extern void inet_listen_wlock(struct inet_hashinfo *hashinfo);
247
248/*
249 * - We may sleep inside this lock.
250 * - If sleeping is not required (or called from BH),
251 * use plain read_(un)lock(&inet_hashinfo.lhash_lock).
252 */
253static inline void inet_listen_lock(struct inet_hashinfo *hashinfo)
254{
255 /* read_lock synchronizes to candidates to writers */
256 read_lock(&hashinfo->lhash_lock);
257 atomic_inc(&hashinfo->lhash_users);
258 read_unlock(&hashinfo->lhash_lock);
259}
260
261static inline void inet_listen_unlock(struct inet_hashinfo *hashinfo)
262{
263 if (atomic_dec_and_test(&hashinfo->lhash_users))
264 wake_up(&hashinfo->lhash_wait);
265}
266
152da81d
PE
267extern void __inet_hash(struct inet_hashinfo *hashinfo, struct sock *sk);
268extern void __inet_hash_nolisten(struct inet_hashinfo *hinfo, struct sock *sk);
81849d10
ACM
269
270static inline void inet_hash(struct inet_hashinfo *hashinfo, struct sock *sk)
271{
272 if (sk->sk_state != TCP_CLOSE) {
273 local_bh_disable();
152da81d 274 __inet_hash(hashinfo, sk);
81849d10
ACM
275 local_bh_enable();
276 }
277}
278
279static inline void inet_unhash(struct inet_hashinfo *hashinfo, struct sock *sk)
280{
281 rwlock_t *lock;
282
283 if (sk_unhashed(sk))
284 goto out;
285
286 if (sk->sk_state == TCP_LISTEN) {
287 local_bh_disable();
288 inet_listen_wlock(hashinfo);
289 lock = &hashinfo->lhash_lock;
290 } else {
230140cf 291 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
81c3d547 292 write_lock_bh(lock);
81849d10
ACM
293 }
294
295 if (__sk_del_node_init(sk))
65f76517 296 sock_prot_inuse_add(sk->sk_prot, -1);
81849d10
ACM
297 write_unlock_bh(lock);
298out:
299 if (sk->sk_state == TCP_LISTEN)
300 wake_up(&hashinfo->lhash_wait);
301}
33b62231 302
8f491069 303extern struct sock *__inet_lookup_listener(struct inet_hashinfo *hashinfo,
fb99c848 304 const __be32 daddr,
8f491069
HX
305 const unsigned short hnum,
306 const int dif);
307
308static inline struct sock *inet_lookup_listener(struct inet_hashinfo *hashinfo,
fb99c848 309 __be32 daddr, __be16 dport, int dif)
8f491069
HX
310{
311 return __inet_lookup_listener(hashinfo, daddr, ntohs(dport), dif);
312}
8feaf0c0
ACM
313
314/* Socket demux engine toys. */
4f765d84
AV
315/* What happens here is ugly; there's a pair of adjacent fields in
316 struct inet_sock; __be16 dport followed by __u16 num. We want to
317 search by pair, so we combine the keys into a single 32bit value
318 and compare with 32bit value read from &...->dport. Let's at least
319 make sure that it's not mixed with anything else...
320 On 64bit targets we combine comparisons with pair of adjacent __be32
321 fields in the same way.
322*/
323typedef __u32 __bitwise __portpair;
8feaf0c0
ACM
324#ifdef __BIG_ENDIAN
325#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 326 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
8feaf0c0
ACM
327#else /* __LITTLE_ENDIAN */
328#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 329 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
8feaf0c0
ACM
330#endif
331
332#if (BITS_PER_LONG == 64)
4f765d84 333typedef __u64 __bitwise __addrpair;
8feaf0c0
ACM
334#ifdef __BIG_ENDIAN
335#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
336 const __addrpair __name = (__force __addrpair) ( \
337 (((__force __u64)(__be32)(__saddr)) << 32) | \
338 ((__force __u64)(__be32)(__daddr)));
8feaf0c0
ACM
339#else /* __LITTLE_ENDIAN */
340#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
341 const __addrpair __name = (__force __addrpair) ( \
342 (((__force __u64)(__be32)(__daddr)) << 32) | \
343 ((__force __u64)(__be32)(__saddr)));
8feaf0c0 344#endif /* __BIG_ENDIAN */
81c3d547
ED
345#define INET_MATCH(__sk, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
346 (((__sk)->sk_hash == (__hash)) && \
4f765d84
AV
347 ((*((__addrpair *)&(inet_sk(__sk)->daddr))) == (__cookie)) && \
348 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 349 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
81c3d547
ED
350#define INET_TW_MATCH(__sk, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
351 (((__sk)->sk_hash == (__hash)) && \
4f765d84
AV
352 ((*((__addrpair *)&(inet_twsk(__sk)->tw_daddr))) == (__cookie)) && \
353 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
354 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
355#else /* 32-bit arch */
356#define INET_ADDR_COOKIE(__name, __saddr, __daddr)
81c3d547
ED
357#define INET_MATCH(__sk, __hash, __cookie, __saddr, __daddr, __ports, __dif) \
358 (((__sk)->sk_hash == (__hash)) && \
359 (inet_sk(__sk)->daddr == (__saddr)) && \
8feaf0c0 360 (inet_sk(__sk)->rcv_saddr == (__daddr)) && \
4f765d84 361 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 362 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
81c3d547
ED
363#define INET_TW_MATCH(__sk, __hash,__cookie, __saddr, __daddr, __ports, __dif) \
364 (((__sk)->sk_hash == (__hash)) && \
365 (inet_twsk(__sk)->tw_daddr == (__saddr)) && \
8feaf0c0 366 (inet_twsk(__sk)->tw_rcv_saddr == (__daddr)) && \
4f765d84 367 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
368 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
369#endif /* 64-bit arch */
e48c414e
ACM
370
371/*
372 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
373 * not check it for lookups anymore, thanks Alexey. -DaveM
374 *
375 * Local BH must be disabled here.
376 */
77a5ba55
PE
377extern struct sock * __inet_lookup_established(struct inet_hashinfo *hashinfo,
378 const __be32 saddr, const __be16 sport,
379 const __be32 daddr, const u16 hnum, const int dif);
e48c414e 380
8f491069
HX
381static inline struct sock *
382 inet_lookup_established(struct inet_hashinfo *hashinfo,
fb99c848
AV
383 const __be32 saddr, const __be16 sport,
384 const __be32 daddr, const __be16 dport,
8f491069
HX
385 const int dif)
386{
387 return __inet_lookup_established(hashinfo, saddr, sport, daddr,
388 ntohs(dport), dif);
389}
390
e48c414e 391static inline struct sock *__inet_lookup(struct inet_hashinfo *hashinfo,
fb99c848
AV
392 const __be32 saddr, const __be16 sport,
393 const __be32 daddr, const __be16 dport,
e48c414e
ACM
394 const int dif)
395{
8f491069 396 u16 hnum = ntohs(dport);
e48c414e
ACM
397 struct sock *sk = __inet_lookup_established(hashinfo, saddr, sport, daddr,
398 hnum, dif);
8f491069 399 return sk ? : __inet_lookup_listener(hashinfo, daddr, hnum, dif);
e48c414e
ACM
400}
401
402static inline struct sock *inet_lookup(struct inet_hashinfo *hashinfo,
fb99c848
AV
403 const __be32 saddr, const __be16 sport,
404 const __be32 daddr, const __be16 dport,
e48c414e
ACM
405 const int dif)
406{
407 struct sock *sk;
408
409 local_bh_disable();
8f491069 410 sk = __inet_lookup(hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
411 local_bh_enable();
412
413 return sk;
414}
a7f5e7f1 415
5ee31fc1
PE
416extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
417 struct sock *sk,
418 int (*check_established)(struct inet_timewait_death_row *,
419 struct sock *, __u16, struct inet_timewait_sock **),
420 void (*hash)(struct inet_hashinfo *, struct sock *));
a7f5e7f1
ACM
421extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
422 struct sock *sk);
304a1618 423#endif /* _INET_HASHTABLES_H */