Commit | Line | Data |
---|---|---|
77d8bf9c 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 | * Generic INET transport hashtables | |
7 | * | |
8 | * Authors: Lotsa people, from code originally in tcp | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
2d8c4ce5 | 16 | #include <linux/module.h> |
a7f5e7f1 | 17 | #include <linux/random.h> |
f3f05f70 | 18 | #include <linux/sched.h> |
77d8bf9c | 19 | #include <linux/slab.h> |
f3f05f70 | 20 | #include <linux/wait.h> |
77d8bf9c | 21 | |
463c84b9 | 22 | #include <net/inet_connection_sock.h> |
77d8bf9c | 23 | #include <net/inet_hashtables.h> |
a7f5e7f1 | 24 | #include <net/ip.h> |
77d8bf9c ACM |
25 | |
26 | /* | |
27 | * Allocate and initialize a new local port bind bucket. | |
28 | * The bindhash mutex for snum's hash chain must be held here. | |
29 | */ | |
e18b890b | 30 | struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep, |
77d8bf9c ACM |
31 | struct inet_bind_hashbucket *head, |
32 | const unsigned short snum) | |
33 | { | |
54e6ecb2 | 34 | struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC); |
77d8bf9c ACM |
35 | |
36 | if (tb != NULL) { | |
37 | tb->port = snum; | |
38 | tb->fastreuse = 0; | |
39 | INIT_HLIST_HEAD(&tb->owners); | |
40 | hlist_add_head(&tb->node, &head->chain); | |
41 | } | |
42 | return tb; | |
43 | } | |
44 | ||
77d8bf9c ACM |
45 | /* |
46 | * Caller must hold hashbucket lock for this tb with local BH disabled | |
47 | */ | |
e18b890b | 48 | void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) |
77d8bf9c ACM |
49 | { |
50 | if (hlist_empty(&tb->owners)) { | |
51 | __hlist_del(&tb->node); | |
52 | kmem_cache_free(cachep, tb); | |
53 | } | |
54 | } | |
2d8c4ce5 ACM |
55 | |
56 | void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, | |
57 | const unsigned short snum) | |
58 | { | |
463c84b9 | 59 | inet_sk(sk)->num = snum; |
2d8c4ce5 | 60 | sk_add_bind_node(sk, &tb->owners); |
463c84b9 | 61 | inet_csk(sk)->icsk_bind_hash = tb; |
2d8c4ce5 ACM |
62 | } |
63 | ||
2d8c4ce5 ACM |
64 | /* |
65 | * Get rid of any references to a local port held by the given sock. | |
66 | */ | |
67 | static void __inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk) | |
68 | { | |
463c84b9 | 69 | const int bhash = inet_bhashfn(inet_sk(sk)->num, hashinfo->bhash_size); |
2d8c4ce5 ACM |
70 | struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; |
71 | struct inet_bind_bucket *tb; | |
72 | ||
73 | spin_lock(&head->lock); | |
463c84b9 | 74 | tb = inet_csk(sk)->icsk_bind_hash; |
2d8c4ce5 | 75 | __sk_del_bind_node(sk); |
463c84b9 ACM |
76 | inet_csk(sk)->icsk_bind_hash = NULL; |
77 | inet_sk(sk)->num = 0; | |
2d8c4ce5 ACM |
78 | inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); |
79 | spin_unlock(&head->lock); | |
80 | } | |
81 | ||
82 | void inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk) | |
83 | { | |
84 | local_bh_disable(); | |
85 | __inet_put_port(hashinfo, sk); | |
86 | local_bh_enable(); | |
87 | } | |
88 | ||
89 | EXPORT_SYMBOL(inet_put_port); | |
f3f05f70 ACM |
90 | |
91 | /* | |
92 | * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP. | |
93 | * Look, when several writers sleep and reader wakes them up, all but one | |
94 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves | |
95 | * this, _but_ remember, it adds useless work on UP machines (wake up each | |
96 | * exclusive lock release). It should be ifdefed really. | |
97 | */ | |
98 | void inet_listen_wlock(struct inet_hashinfo *hashinfo) | |
9a429c49 | 99 | __acquires(hashinfo->lhash_lock) |
f3f05f70 ACM |
100 | { |
101 | write_lock(&hashinfo->lhash_lock); | |
102 | ||
103 | if (atomic_read(&hashinfo->lhash_users)) { | |
104 | DEFINE_WAIT(wait); | |
105 | ||
106 | for (;;) { | |
107 | prepare_to_wait_exclusive(&hashinfo->lhash_wait, | |
108 | &wait, TASK_UNINTERRUPTIBLE); | |
109 | if (!atomic_read(&hashinfo->lhash_users)) | |
110 | break; | |
111 | write_unlock_bh(&hashinfo->lhash_lock); | |
112 | schedule(); | |
113 | write_lock_bh(&hashinfo->lhash_lock); | |
114 | } | |
115 | ||
116 | finish_wait(&hashinfo->lhash_wait, &wait); | |
117 | } | |
118 | } | |
119 | ||
120 | EXPORT_SYMBOL(inet_listen_wlock); | |
33b62231 ACM |
121 | |
122 | /* | |
123 | * Don't inline this cruft. Here are some nice properties to exploit here. The | |
124 | * BSD API does not allow a listening sock to specify the remote port nor the | |
125 | * remote address for the connection. So always assume those are both | |
126 | * wildcarded during the search since they can never be otherwise. | |
127 | */ | |
8f491069 | 128 | static struct sock *inet_lookup_listener_slow(const struct hlist_head *head, |
fb99c848 | 129 | const __be32 daddr, |
8f491069 HX |
130 | const unsigned short hnum, |
131 | const int dif) | |
33b62231 ACM |
132 | { |
133 | struct sock *result = NULL, *sk; | |
134 | const struct hlist_node *node; | |
135 | int hiscore = -1; | |
136 | ||
137 | sk_for_each(sk, node, head) { | |
138 | const struct inet_sock *inet = inet_sk(sk); | |
139 | ||
140 | if (inet->num == hnum && !ipv6_only_sock(sk)) { | |
fb99c848 | 141 | const __be32 rcv_saddr = inet->rcv_saddr; |
33b62231 ACM |
142 | int score = sk->sk_family == PF_INET ? 1 : 0; |
143 | ||
144 | if (rcv_saddr) { | |
145 | if (rcv_saddr != daddr) | |
146 | continue; | |
147 | score += 2; | |
148 | } | |
149 | if (sk->sk_bound_dev_if) { | |
150 | if (sk->sk_bound_dev_if != dif) | |
151 | continue; | |
152 | score += 2; | |
153 | } | |
154 | if (score == 5) | |
155 | return sk; | |
156 | if (score > hiscore) { | |
157 | hiscore = score; | |
158 | result = sk; | |
159 | } | |
160 | } | |
161 | } | |
162 | return result; | |
163 | } | |
e48c414e | 164 | |
99a92ff5 | 165 | /* Optimize the common listener case. */ |
8f491069 | 166 | struct sock *__inet_lookup_listener(struct inet_hashinfo *hashinfo, |
fb99c848 | 167 | const __be32 daddr, const unsigned short hnum, |
8f491069 | 168 | const int dif) |
99a92ff5 HX |
169 | { |
170 | struct sock *sk = NULL; | |
171 | const struct hlist_head *head; | |
172 | ||
173 | read_lock(&hashinfo->lhash_lock); | |
174 | head = &hashinfo->listening_hash[inet_lhashfn(hnum)]; | |
175 | if (!hlist_empty(head)) { | |
176 | const struct inet_sock *inet = inet_sk((sk = __sk_head(head))); | |
177 | ||
178 | if (inet->num == hnum && !sk->sk_node.next && | |
179 | (!inet->rcv_saddr || inet->rcv_saddr == daddr) && | |
180 | (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) && | |
181 | !sk->sk_bound_dev_if) | |
182 | goto sherry_cache; | |
8f491069 | 183 | sk = inet_lookup_listener_slow(head, daddr, hnum, dif); |
99a92ff5 HX |
184 | } |
185 | if (sk) { | |
186 | sherry_cache: | |
187 | sock_hold(sk); | |
188 | } | |
189 | read_unlock(&hashinfo->lhash_lock); | |
190 | return sk; | |
191 | } | |
8f491069 | 192 | EXPORT_SYMBOL_GPL(__inet_lookup_listener); |
a7f5e7f1 | 193 | |
77a5ba55 PE |
194 | struct sock * __inet_lookup_established(struct inet_hashinfo *hashinfo, |
195 | const __be32 saddr, const __be16 sport, | |
196 | const __be32 daddr, const u16 hnum, | |
197 | const int dif) | |
198 | { | |
199 | INET_ADDR_COOKIE(acookie, saddr, daddr) | |
200 | const __portpair ports = INET_COMBINED_PORTS(sport, hnum); | |
201 | struct sock *sk; | |
202 | const struct hlist_node *node; | |
203 | /* Optimize here for direct hit, only listening connections can | |
204 | * have wildcards anyways. | |
205 | */ | |
206 | unsigned int hash = inet_ehashfn(daddr, hnum, saddr, sport); | |
207 | struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash); | |
208 | rwlock_t *lock = inet_ehash_lockp(hashinfo, hash); | |
209 | ||
210 | prefetch(head->chain.first); | |
211 | read_lock(lock); | |
212 | sk_for_each(sk, node, &head->chain) { | |
213 | if (INET_MATCH(sk, hash, acookie, saddr, daddr, ports, dif)) | |
214 | goto hit; /* You sunk my battleship! */ | |
215 | } | |
216 | ||
217 | /* Must check for a TIME_WAIT'er before going to listener hash. */ | |
218 | sk_for_each(sk, node, &head->twchain) { | |
219 | if (INET_TW_MATCH(sk, hash, acookie, saddr, daddr, ports, dif)) | |
220 | goto hit; | |
221 | } | |
222 | sk = NULL; | |
223 | out: | |
224 | read_unlock(lock); | |
225 | return sk; | |
226 | hit: | |
227 | sock_hold(sk); | |
228 | goto out; | |
229 | } | |
230 | EXPORT_SYMBOL_GPL(__inet_lookup_established); | |
231 | ||
a7f5e7f1 ACM |
232 | /* called with local bh disabled */ |
233 | static int __inet_check_established(struct inet_timewait_death_row *death_row, | |
234 | struct sock *sk, __u16 lport, | |
235 | struct inet_timewait_sock **twp) | |
236 | { | |
237 | struct inet_hashinfo *hinfo = death_row->hashinfo; | |
238 | struct inet_sock *inet = inet_sk(sk); | |
fb99c848 AV |
239 | __be32 daddr = inet->rcv_saddr; |
240 | __be32 saddr = inet->daddr; | |
a7f5e7f1 ACM |
241 | int dif = sk->sk_bound_dev_if; |
242 | INET_ADDR_COOKIE(acookie, saddr, daddr) | |
4f765d84 | 243 | const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport); |
a7f5e7f1 ACM |
244 | unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport); |
245 | struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); | |
230140cf | 246 | rwlock_t *lock = inet_ehash_lockp(hinfo, hash); |
a7f5e7f1 ACM |
247 | struct sock *sk2; |
248 | const struct hlist_node *node; | |
249 | struct inet_timewait_sock *tw; | |
250 | ||
251 | prefetch(head->chain.first); | |
230140cf | 252 | write_lock(lock); |
a7f5e7f1 ACM |
253 | |
254 | /* Check TIME-WAIT sockets first. */ | |
dbca9b27 | 255 | sk_for_each(sk2, node, &head->twchain) { |
a7f5e7f1 ACM |
256 | tw = inet_twsk(sk2); |
257 | ||
258 | if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) { | |
259 | if (twsk_unique(sk, sk2, twp)) | |
260 | goto unique; | |
261 | else | |
262 | goto not_unique; | |
263 | } | |
264 | } | |
265 | tw = NULL; | |
266 | ||
267 | /* And established part... */ | |
268 | sk_for_each(sk2, node, &head->chain) { | |
269 | if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) | |
270 | goto not_unique; | |
271 | } | |
272 | ||
273 | unique: | |
274 | /* Must record num and sport now. Otherwise we will see | |
275 | * in hash table socket with a funny identity. */ | |
276 | inet->num = lport; | |
277 | inet->sport = htons(lport); | |
278 | sk->sk_hash = hash; | |
279 | BUG_TRAP(sk_unhashed(sk)); | |
280 | __sk_add_node(sk, &head->chain); | |
281 | sock_prot_inc_use(sk->sk_prot); | |
230140cf | 282 | write_unlock(lock); |
a7f5e7f1 ACM |
283 | |
284 | if (twp) { | |
285 | *twp = tw; | |
286 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); | |
287 | } else if (tw) { | |
288 | /* Silly. Should hash-dance instead... */ | |
289 | inet_twsk_deschedule(tw, death_row); | |
290 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); | |
291 | ||
292 | inet_twsk_put(tw); | |
293 | } | |
294 | ||
295 | return 0; | |
296 | ||
297 | not_unique: | |
230140cf | 298 | write_unlock(lock); |
a7f5e7f1 ACM |
299 | return -EADDRNOTAVAIL; |
300 | } | |
301 | ||
302 | static inline u32 inet_sk_port_offset(const struct sock *sk) | |
303 | { | |
304 | const struct inet_sock *inet = inet_sk(sk); | |
e905a9ed | 305 | return secure_ipv4_port_ephemeral(inet->rcv_saddr, inet->daddr, |
a7f5e7f1 ACM |
306 | inet->dport); |
307 | } | |
308 | ||
152da81d PE |
309 | void __inet_hash_nolisten(struct inet_hashinfo *hashinfo, struct sock *sk) |
310 | { | |
311 | struct hlist_head *list; | |
312 | rwlock_t *lock; | |
313 | struct inet_ehash_bucket *head; | |
314 | ||
315 | BUG_TRAP(sk_unhashed(sk)); | |
316 | ||
317 | sk->sk_hash = inet_sk_ehashfn(sk); | |
318 | head = inet_ehash_bucket(hashinfo, sk->sk_hash); | |
319 | list = &head->chain; | |
320 | lock = inet_ehash_lockp(hashinfo, sk->sk_hash); | |
321 | ||
322 | write_lock(lock); | |
323 | __sk_add_node(sk, list); | |
324 | sock_prot_inc_use(sk->sk_prot); | |
325 | write_unlock(lock); | |
326 | } | |
327 | EXPORT_SYMBOL_GPL(__inet_hash_nolisten); | |
328 | ||
329 | void __inet_hash(struct inet_hashinfo *hashinfo, struct sock *sk) | |
330 | { | |
331 | struct hlist_head *list; | |
332 | rwlock_t *lock; | |
333 | ||
334 | if (sk->sk_state != TCP_LISTEN) { | |
335 | __inet_hash_nolisten(hashinfo, sk); | |
336 | return; | |
337 | } | |
338 | ||
339 | BUG_TRAP(sk_unhashed(sk)); | |
340 | list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; | |
341 | lock = &hashinfo->lhash_lock; | |
342 | ||
343 | inet_listen_wlock(hashinfo); | |
344 | __sk_add_node(sk, list); | |
345 | sock_prot_inc_use(sk->sk_prot); | |
346 | write_unlock(lock); | |
347 | wake_up(&hashinfo->lhash_wait); | |
348 | } | |
349 | EXPORT_SYMBOL_GPL(__inet_hash); | |
350 | ||
a7f5e7f1 ACM |
351 | /* |
352 | * Bind a port for a connect operation and hash it. | |
353 | */ | |
354 | int inet_hash_connect(struct inet_timewait_death_row *death_row, | |
355 | struct sock *sk) | |
356 | { | |
357 | struct inet_hashinfo *hinfo = death_row->hashinfo; | |
358 | const unsigned short snum = inet_sk(sk)->num; | |
e905a9ed YH |
359 | struct inet_bind_hashbucket *head; |
360 | struct inet_bind_bucket *tb; | |
a7f5e7f1 ACM |
361 | int ret; |
362 | ||
e905a9ed | 363 | if (!snum) { |
227b60f5 | 364 | int i, remaining, low, high, port; |
a7f5e7f1 ACM |
365 | static u32 hint; |
366 | u32 offset = hint + inet_sk_port_offset(sk); | |
367 | struct hlist_node *node; | |
e905a9ed | 368 | struct inet_timewait_sock *tw = NULL; |
a7f5e7f1 | 369 | |
227b60f5 | 370 | inet_get_local_port_range(&low, &high); |
a25de534 | 371 | remaining = (high - low) + 1; |
227b60f5 | 372 | |
e905a9ed | 373 | local_bh_disable(); |
227b60f5 SH |
374 | for (i = 1; i <= remaining; i++) { |
375 | port = low + (i + offset) % remaining; | |
e905a9ed YH |
376 | head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)]; |
377 | spin_lock(&head->lock); | |
a7f5e7f1 | 378 | |
e905a9ed YH |
379 | /* Does not bother with rcv_saddr checks, |
380 | * because the established check is already | |
381 | * unique enough. | |
382 | */ | |
a7f5e7f1 | 383 | inet_bind_bucket_for_each(tb, node, &head->chain) { |
e905a9ed YH |
384 | if (tb->port == port) { |
385 | BUG_TRAP(!hlist_empty(&tb->owners)); | |
386 | if (tb->fastreuse >= 0) | |
387 | goto next_port; | |
388 | if (!__inet_check_established(death_row, | |
a7f5e7f1 ACM |
389 | sk, port, |
390 | &tw)) | |
e905a9ed YH |
391 | goto ok; |
392 | goto next_port; | |
393 | } | |
394 | } | |
395 | ||
396 | tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, head, port); | |
397 | if (!tb) { | |
398 | spin_unlock(&head->lock); | |
399 | break; | |
400 | } | |
401 | tb->fastreuse = -1; | |
402 | goto ok; | |
403 | ||
404 | next_port: | |
405 | spin_unlock(&head->lock); | |
406 | } | |
407 | local_bh_enable(); | |
408 | ||
409 | return -EADDRNOTAVAIL; | |
a7f5e7f1 ACM |
410 | |
411 | ok: | |
412 | hint += i; | |
413 | ||
e905a9ed YH |
414 | /* Head lock still held and bh's disabled */ |
415 | inet_bind_hash(sk, tb, port); | |
a7f5e7f1 | 416 | if (sk_unhashed(sk)) { |
e905a9ed | 417 | inet_sk(sk)->sport = htons(port); |
152da81d | 418 | __inet_hash_nolisten(hinfo, sk); |
e905a9ed YH |
419 | } |
420 | spin_unlock(&head->lock); | |
a7f5e7f1 | 421 | |
e905a9ed YH |
422 | if (tw) { |
423 | inet_twsk_deschedule(tw, death_row); | |
424 | inet_twsk_put(tw); | |
425 | } | |
a7f5e7f1 ACM |
426 | |
427 | ret = 0; | |
428 | goto out; | |
e905a9ed | 429 | } |
a7f5e7f1 | 430 | |
e905a9ed YH |
431 | head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)]; |
432 | tb = inet_csk(sk)->icsk_bind_hash; | |
a7f5e7f1 ACM |
433 | spin_lock_bh(&head->lock); |
434 | if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { | |
152da81d | 435 | __inet_hash_nolisten(hinfo, sk); |
a7f5e7f1 ACM |
436 | spin_unlock_bh(&head->lock); |
437 | return 0; | |
438 | } else { | |
439 | spin_unlock(&head->lock); | |
440 | /* No definite answer... Walk to established hash table */ | |
441 | ret = __inet_check_established(death_row, sk, snum, NULL); | |
442 | out: | |
443 | local_bh_enable(); | |
444 | return ret; | |
445 | } | |
446 | } | |
447 | ||
448 | EXPORT_SYMBOL_GPL(inet_hash_connect); |