powerpc/mm: Introduce MMU features
[deliverable/linux.git] / include / net / inet_hashtables.h
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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>
9a1f27c4 19#include <linux/ip.h>
33b62231 20#include <linux/ipv6.h>
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21#include <linux/list.h>
22#include <linux/slab.h>
33b62231 23#include <linux/socket.h>
77d8bf9c 24#include <linux/spinlock.h>
304a1618 25#include <linux/types.h>
f3f05f70 26#include <linux/wait.h>
9e4505c4 27#include <linux/vmalloc.h>
304a1618 28
463c84b9 29#include <net/inet_connection_sock.h>
14c85021 30#include <net/inet_sock.h>
2d8c4ce5 31#include <net/sock.h>
9a1f27c4 32#include <net/route.h>
c752f073 33#include <net/tcp_states.h>
0b441916 34#include <net/netns/hash.h>
2d8c4ce5 35
f3f05f70 36#include <asm/atomic.h>
e48c414e 37#include <asm/byteorder.h>
f3f05f70 38
77d8bf9c 39/* This is for all connections with a full identity, no wildcards.
dbca9b27
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40 * One chain is dedicated to TIME_WAIT sockets.
41 * I'll experiment with dynamic table growth later.
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42 */
43struct inet_ehash_bucket {
77d8bf9c 44 struct hlist_head chain;
dbca9b27 45 struct hlist_head twchain;
6d255361 46};
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47
48/* There are a few simple rules, which allow for local port reuse by
49 * an application. In essence:
50 *
51 * 1) Sockets bound to different interfaces may share a local port.
52 * Failing that, goto test 2.
53 * 2) If all sockets have sk->sk_reuse set, and none of them are in
54 * TCP_LISTEN state, the port may be shared.
55 * Failing that, goto test 3.
56 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
57 * address, and none of them are the same, the port may be
58 * shared.
59 * Failing this, the port cannot be shared.
60 *
61 * The interesting point, is test #2. This is what an FTP server does
62 * all day. To optimize this case we use a specific flag bit defined
63 * below. As we add sockets to a bind bucket list, we perform a
64 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
65 * As long as all sockets added to a bind bucket pass this test,
66 * the flag bit will be set.
67 * The resulting situation is that tcp_v[46]_verify_bind() can just check
68 * for this flag bit, if it is set and the socket trying to bind has
69 * sk->sk_reuse set, we don't even have to walk the owners list at all,
70 * we return that it is ok to bind this socket to the requested local port.
71 *
72 * Sounds like a lot of work, but it is worth it. In a more naive
73 * implementation (ie. current FreeBSD etc.) the entire list of ports
74 * must be walked for each data port opened by an ftp server. Needless
75 * to say, this does not scale at all. With a couple thousand FTP
76 * users logged onto your box, isn't it nice to know that new data
77 * ports are created in O(1) time? I thought so. ;-) -DaveM
78 */
79struct inet_bind_bucket {
941b1d22 80 struct net *ib_net;
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81 unsigned short port;
82 signed short fastreuse;
83 struct hlist_node node;
84 struct hlist_head owners;
85};
86
87#define inet_bind_bucket_for_each(tb, node, head) \
88 hlist_for_each_entry(tb, node, head, node)
89
90struct inet_bind_hashbucket {
91 spinlock_t lock;
92 struct hlist_head chain;
93};
94
95/* This is for listening sockets, thus all sockets which possess wildcards. */
96#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
97
98struct inet_hashinfo {
99 /* This is for sockets with full identity only. Sockets here will
100 * always be without wildcards and will have the following invariant:
101 *
102 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
103 *
dbca9b27 104 * TIME_WAIT sockets use a separate chain (twchain).
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105 */
106 struct inet_ehash_bucket *ehash;
230140cf
ED
107 rwlock_t *ehash_locks;
108 unsigned int ehash_size;
109 unsigned int ehash_locks_mask;
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110
111 /* Ok, let's try this, I give up, we do need a local binding
112 * TCP hash as well as the others for fast bind/connect.
113 */
114 struct inet_bind_hashbucket *bhash;
115
cfcabdcc 116 unsigned int bhash_size;
230140cf 117 /* Note : 4 bytes padding on 64 bit arches */
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118
119 /* All sockets in TCP_LISTEN state will be in here. This is the only
120 * table where wildcard'd TCP sockets can exist. Hash function here
121 * is just local port number.
122 */
123 struct hlist_head listening_hash[INET_LHTABLE_SIZE];
124
125 /* All the above members are written once at bootup and
126 * never written again _or_ are predominantly read-access.
127 *
128 * Now align to a new cache line as all the following members
129 * are often dirty.
130 */
131 rwlock_t lhash_lock ____cacheline_aligned;
132 atomic_t lhash_users;
133 wait_queue_head_t lhash_wait;
e18b890b 134 struct kmem_cache *bind_bucket_cachep;
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135};
136
81c3d547
ED
137static inline struct inet_ehash_bucket *inet_ehash_bucket(
138 struct inet_hashinfo *hashinfo,
139 unsigned int hash)
140{
141 return &hashinfo->ehash[hash & (hashinfo->ehash_size - 1)];
304a1618
ACM
142}
143
230140cf
ED
144static inline rwlock_t *inet_ehash_lockp(
145 struct inet_hashinfo *hashinfo,
146 unsigned int hash)
147{
148 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
149}
150
151static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
152{
153 unsigned int i, size = 256;
154#if defined(CONFIG_PROVE_LOCKING)
155 unsigned int nr_pcpus = 2;
156#else
157 unsigned int nr_pcpus = num_possible_cpus();
158#endif
159 if (nr_pcpus >= 4)
160 size = 512;
161 if (nr_pcpus >= 8)
162 size = 1024;
163 if (nr_pcpus >= 16)
164 size = 2048;
165 if (nr_pcpus >= 32)
166 size = 4096;
167 if (sizeof(rwlock_t) != 0) {
168#ifdef CONFIG_NUMA
169 if (size * sizeof(rwlock_t) > PAGE_SIZE)
170 hashinfo->ehash_locks = vmalloc(size * sizeof(rwlock_t));
171 else
172#endif
173 hashinfo->ehash_locks = kmalloc(size * sizeof(rwlock_t),
174 GFP_KERNEL);
175 if (!hashinfo->ehash_locks)
176 return ENOMEM;
177 for (i = 0; i < size; i++)
178 rwlock_init(&hashinfo->ehash_locks[i]);
179 }
180 hashinfo->ehash_locks_mask = size - 1;
181 return 0;
182}
183
184static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
185{
186 if (hashinfo->ehash_locks) {
187#ifdef CONFIG_NUMA
188 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
189 sizeof(rwlock_t);
190 if (size > PAGE_SIZE)
191 vfree(hashinfo->ehash_locks);
192 else
230140cf 193#endif
218ad12f 194 kfree(hashinfo->ehash_locks);
230140cf
ED
195 hashinfo->ehash_locks = NULL;
196 }
197}
198
77d8bf9c 199extern struct inet_bind_bucket *
e18b890b 200 inet_bind_bucket_create(struct kmem_cache *cachep,
941b1d22 201 struct net *net,
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202 struct inet_bind_hashbucket *head,
203 const unsigned short snum);
e18b890b 204extern void inet_bind_bucket_destroy(struct kmem_cache *cachep,
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205 struct inet_bind_bucket *tb);
206
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PE
207static inline int inet_bhashfn(struct net *net,
208 const __u16 lport, const int bhash_size)
77d8bf9c 209{
0b441916 210 return (lport + net_hash_mix(net)) & (bhash_size - 1);
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211}
212
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213extern void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
214 const unsigned short snum);
215
77d8bf9c 216/* These can have wildcards, don't try too hard. */
2086a650 217static inline int inet_lhashfn(struct net *net, const unsigned short num)
77d8bf9c 218{
0b441916 219 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
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ACM
220}
221
222static inline int inet_sk_listen_hashfn(const struct sock *sk)
223{
2086a650 224 return inet_lhashfn(sock_net(sk), inet_sk(sk)->num);
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225}
226
2d8c4ce5 227/* Caller must disable local BH processing. */
53083773 228extern void __inet_inherit_port(struct sock *sk, struct sock *child);
2d8c4ce5 229
ab1e0a13 230extern void inet_put_port(struct sock *sk);
2d8c4ce5 231
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ACM
232extern void inet_listen_wlock(struct inet_hashinfo *hashinfo);
233
234/*
235 * - We may sleep inside this lock.
236 * - If sleeping is not required (or called from BH),
237 * use plain read_(un)lock(&inet_hashinfo.lhash_lock).
238 */
239static inline void inet_listen_lock(struct inet_hashinfo *hashinfo)
240{
241 /* read_lock synchronizes to candidates to writers */
242 read_lock(&hashinfo->lhash_lock);
243 atomic_inc(&hashinfo->lhash_users);
244 read_unlock(&hashinfo->lhash_lock);
245}
246
247static inline void inet_listen_unlock(struct inet_hashinfo *hashinfo)
248{
249 if (atomic_dec_and_test(&hashinfo->lhash_users))
250 wake_up(&hashinfo->lhash_wait);
251}
252
ab1e0a13
ACM
253extern void __inet_hash_nolisten(struct sock *sk);
254extern void inet_hash(struct sock *sk);
255extern void inet_unhash(struct sock *sk);
33b62231 256
c67499c0
PE
257extern struct sock *__inet_lookup_listener(struct net *net,
258 struct inet_hashinfo *hashinfo,
fb99c848 259 const __be32 daddr,
8f491069
HX
260 const unsigned short hnum,
261 const int dif);
262
c67499c0
PE
263static inline struct sock *inet_lookup_listener(struct net *net,
264 struct inet_hashinfo *hashinfo,
265 __be32 daddr, __be16 dport, int dif)
8f491069 266{
c67499c0 267 return __inet_lookup_listener(net, hashinfo, daddr, ntohs(dport), dif);
8f491069 268}
8feaf0c0
ACM
269
270/* Socket demux engine toys. */
4f765d84
AV
271/* What happens here is ugly; there's a pair of adjacent fields in
272 struct inet_sock; __be16 dport followed by __u16 num. We want to
273 search by pair, so we combine the keys into a single 32bit value
274 and compare with 32bit value read from &...->dport. Let's at least
275 make sure that it's not mixed with anything else...
276 On 64bit targets we combine comparisons with pair of adjacent __be32
277 fields in the same way.
278*/
279typedef __u32 __bitwise __portpair;
8feaf0c0
ACM
280#ifdef __BIG_ENDIAN
281#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 282 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
8feaf0c0
ACM
283#else /* __LITTLE_ENDIAN */
284#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 285 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
8feaf0c0
ACM
286#endif
287
288#if (BITS_PER_LONG == 64)
4f765d84 289typedef __u64 __bitwise __addrpair;
8feaf0c0
ACM
290#ifdef __BIG_ENDIAN
291#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
292 const __addrpair __name = (__force __addrpair) ( \
293 (((__force __u64)(__be32)(__saddr)) << 32) | \
294 ((__force __u64)(__be32)(__daddr)));
8feaf0c0
ACM
295#else /* __LITTLE_ENDIAN */
296#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
297 const __addrpair __name = (__force __addrpair) ( \
298 (((__force __u64)(__be32)(__daddr)) << 32) | \
299 ((__force __u64)(__be32)(__saddr)));
8feaf0c0 300#endif /* __BIG_ENDIAN */
c67499c0 301#define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
3b1e0a65 302 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
4f765d84
AV
303 ((*((__addrpair *)&(inet_sk(__sk)->daddr))) == (__cookie)) && \
304 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 305 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
c67499c0 306#define INET_TW_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif)\
3b1e0a65 307 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
4f765d84
AV
308 ((*((__addrpair *)&(inet_twsk(__sk)->tw_daddr))) == (__cookie)) && \
309 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
310 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
311#else /* 32-bit arch */
312#define INET_ADDR_COOKIE(__name, __saddr, __daddr)
c67499c0 313#define INET_MATCH(__sk, __net, __hash, __cookie, __saddr, __daddr, __ports, __dif) \
3b1e0a65 314 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
81c3d547 315 (inet_sk(__sk)->daddr == (__saddr)) && \
8feaf0c0 316 (inet_sk(__sk)->rcv_saddr == (__daddr)) && \
4f765d84 317 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports)) && \
8feaf0c0 318 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
c67499c0 319#define INET_TW_MATCH(__sk, __net, __hash,__cookie, __saddr, __daddr, __ports, __dif) \
3b1e0a65 320 (((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net) && \
81c3d547 321 (inet_twsk(__sk)->tw_daddr == (__saddr)) && \
8feaf0c0 322 (inet_twsk(__sk)->tw_rcv_saddr == (__daddr)) && \
4f765d84 323 ((*((__portpair *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) && \
8feaf0c0
ACM
324 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
325#endif /* 64-bit arch */
e48c414e
ACM
326
327/*
328 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
329 * not check it for lookups anymore, thanks Alexey. -DaveM
330 *
331 * Local BH must be disabled here.
332 */
c67499c0
PE
333extern struct sock * __inet_lookup_established(struct net *net,
334 struct inet_hashinfo *hashinfo,
77a5ba55
PE
335 const __be32 saddr, const __be16 sport,
336 const __be32 daddr, const u16 hnum, const int dif);
e48c414e 337
8f491069 338static inline struct sock *
c67499c0 339 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
fb99c848
AV
340 const __be32 saddr, const __be16 sport,
341 const __be32 daddr, const __be16 dport,
8f491069
HX
342 const int dif)
343{
c67499c0 344 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
8f491069
HX
345 ntohs(dport), dif);
346}
347
c67499c0
PE
348static inline struct sock *__inet_lookup(struct net *net,
349 struct inet_hashinfo *hashinfo,
fb99c848
AV
350 const __be32 saddr, const __be16 sport,
351 const __be32 daddr, const __be16 dport,
e48c414e
ACM
352 const int dif)
353{
8f491069 354 u16 hnum = ntohs(dport);
c67499c0
PE
355 struct sock *sk = __inet_lookup_established(net, hashinfo,
356 saddr, sport, daddr, hnum, dif);
357
358 return sk ? : __inet_lookup_listener(net, hashinfo, daddr, hnum, dif);
e48c414e
ACM
359}
360
c67499c0
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361static inline struct sock *inet_lookup(struct net *net,
362 struct inet_hashinfo *hashinfo,
fb99c848
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363 const __be32 saddr, const __be16 sport,
364 const __be32 daddr, const __be16 dport,
e48c414e
ACM
365 const int dif)
366{
367 struct sock *sk;
368
369 local_bh_disable();
c67499c0 370 sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
371 local_bh_enable();
372
373 return sk;
374}
a7f5e7f1 375
9a1f27c4
ACM
376static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
377 struct sk_buff *skb,
378 const __be16 sport,
379 const __be16 dport)
380{
23542618 381 struct sock *sk;
9a1f27c4
ACM
382 const struct iphdr *iph = ip_hdr(skb);
383
23542618
KK
384 if (unlikely(sk = skb_steal_sock(skb)))
385 return sk;
386 else
387 return __inet_lookup(dev_net(skb->dst->dev), hashinfo,
388 iph->saddr, sport,
389 iph->daddr, dport, inet_iif(skb));
9a1f27c4
ACM
390}
391
5ee31fc1 392extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
5d8c0aa9 393 struct sock *sk, u32 port_offset,
5ee31fc1
PE
394 int (*check_established)(struct inet_timewait_death_row *,
395 struct sock *, __u16, struct inet_timewait_sock **),
ab1e0a13 396 void (*hash)(struct sock *sk));
a7f5e7f1
ACM
397extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
398 struct sock *sk);
304a1618 399#endif /* _INET_HASHTABLES_H */
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