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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> |
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 | */ |
40 | struct 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 | */ | |
76 | struct 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 | ||
86 | struct 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 | ||
94 | struct 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 |
133 | static 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 |
140 | static 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 | ||
147 | static 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 | ||
180 | static 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 | 195 | extern 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 | 199 | extern void inet_bind_bucket_destroy(struct kmem_cache *cachep, |
77d8bf9c ACM |
200 | struct inet_bind_bucket *tb); |
201 | ||
202 | static inline int inet_bhashfn(const __u16 lport, const int bhash_size) | |
203 | { | |
204 | return lport & (bhash_size - 1); | |
205 | } | |
206 | ||
2d8c4ce5 ACM |
207 | extern 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. */ |
211 | static inline int inet_lhashfn(const unsigned short num) | |
212 | { | |
213 | return num & (INET_LHTABLE_SIZE - 1); | |
214 | } | |
215 | ||
216 | static 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. */ |
222 | static 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 | ||
236 | static 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 | ||
244 | extern void inet_put_port(struct inet_hashinfo *table, struct sock *sk); | |
245 | ||
f3f05f70 ACM |
246 | extern 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 | */ | |
253 | static 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 | ||
261 | static 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 |
267 | extern void __inet_hash(struct inet_hashinfo *hashinfo, struct sock *sk); |
268 | extern void __inet_hash_nolisten(struct inet_hashinfo *hinfo, struct sock *sk); | |
81849d10 ACM |
269 | |
270 | static 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 | ||
279 | static 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); |
298 | out: | |
299 | if (sk->sk_state == TCP_LISTEN) | |
300 | wake_up(&hashinfo->lhash_wait); | |
301 | } | |
33b62231 | 302 | |
8f491069 | 303 | extern 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 | ||
308 | static 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 | */ | |
323 | typedef __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 | 333 | typedef __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 |
377 | extern 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 |
381 | static 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 | 391 | static 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 | ||
402 | static 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 |
416 | extern 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 |
421 | extern int inet_hash_connect(struct inet_timewait_death_row *death_row, |
422 | struct sock *sk); | |
304a1618 | 423 | #endif /* _INET_HASHTABLES_H */ |