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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>
9a1f27c4 19#include <linux/ip.h>
33b62231 20#include <linux/ipv6.h>
77d8bf9c
ACM
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
60063497 36#include <linux/atomic.h>
e48c414e 37#include <asm/byteorder.h>
f3f05f70 38
77d8bf9c 39/* This is for all connections with a full identity, no wildcards.
dbca9b27
ED
40 * One chain is dedicated to TIME_WAIT sockets.
41 * I'll experiment with dynamic table growth later.
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ACM
42 */
43struct inet_ehash_bucket {
3ab5aee7
ED
44 struct hlist_nulls_head chain;
45 struct hlist_nulls_head twchain;
6d255361 46};
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ACM
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 {
7a9546ee 80#ifdef CONFIG_NET_NS
941b1d22 81 struct net *ib_net;
7a9546ee 82#endif
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83 unsigned short port;
84 signed short fastreuse;
a9d8f911 85 int num_owners;
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86 struct hlist_node node;
87 struct hlist_head owners;
88};
89
7a9546ee
ED
90static inline struct net *ib_net(struct inet_bind_bucket *ib)
91{
92 return read_pnet(&ib->ib_net);
93}
94
5256f2ef
LAG
95#define inet_bind_bucket_for_each(tb, pos, head) \
96 hlist_for_each_entry(tb, pos, head, node)
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97
98struct inet_bind_hashbucket {
99 spinlock_t lock;
100 struct hlist_head chain;
101};
102
c25eb3bf
ED
103/*
104 * Sockets can be hashed in established or listening table
105 * We must use different 'nulls' end-of-chain value for listening
106 * hash table, or we might find a socket that was closed and
107 * reallocated/inserted into established hash table
108 */
109#define LISTENING_NULLS_BASE (1U << 29)
5caea4ea
ED
110struct inet_listen_hashbucket {
111 spinlock_t lock;
c25eb3bf 112 struct hlist_nulls_head head;
5caea4ea
ED
113};
114
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115/* This is for listening sockets, thus all sockets which possess wildcards. */
116#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
117
118struct inet_hashinfo {
119 /* This is for sockets with full identity only. Sockets here will
120 * always be without wildcards and will have the following invariant:
121 *
122 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
123 *
dbca9b27 124 * TIME_WAIT sockets use a separate chain (twchain).
77d8bf9c
ACM
125 */
126 struct inet_ehash_bucket *ehash;
9db66bdc 127 spinlock_t *ehash_locks;
f373b53b 128 unsigned int ehash_mask;
230140cf 129 unsigned int ehash_locks_mask;
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130
131 /* Ok, let's try this, I give up, we do need a local binding
132 * TCP hash as well as the others for fast bind/connect.
133 */
134 struct inet_bind_hashbucket *bhash;
135
cfcabdcc 136 unsigned int bhash_size;
24dd1fa1 137 /* 4 bytes hole on 64 bit */
77d8bf9c 138
5caea4ea 139 struct kmem_cache *bind_bucket_cachep;
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140
141 /* All the above members are written once at bootup and
142 * never written again _or_ are predominantly read-access.
143 *
144 * Now align to a new cache line as all the following members
5caea4ea
ED
145 * might be often dirty.
146 */
147 /* All sockets in TCP_LISTEN state will be in here. This is the only
148 * table where wildcard'd TCP sockets can exist. Hash function here
149 * is just local port number.
77d8bf9c 150 */
5caea4ea
ED
151 struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE]
152 ____cacheline_aligned_in_smp;
153
24dd1fa1 154 atomic_t bsockets;
77d8bf9c
ACM
155};
156
81c3d547
ED
157static inline struct inet_ehash_bucket *inet_ehash_bucket(
158 struct inet_hashinfo *hashinfo,
159 unsigned int hash)
160{
f373b53b 161 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
304a1618
ACM
162}
163
9db66bdc 164static inline spinlock_t *inet_ehash_lockp(
230140cf
ED
165 struct inet_hashinfo *hashinfo,
166 unsigned int hash)
167{
168 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
169}
170
171static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
172{
173 unsigned int i, size = 256;
174#if defined(CONFIG_PROVE_LOCKING)
175 unsigned int nr_pcpus = 2;
176#else
177 unsigned int nr_pcpus = num_possible_cpus();
178#endif
179 if (nr_pcpus >= 4)
180 size = 512;
181 if (nr_pcpus >= 8)
182 size = 1024;
183 if (nr_pcpus >= 16)
184 size = 2048;
185 if (nr_pcpus >= 32)
186 size = 4096;
94cd3e6c 187 if (sizeof(spinlock_t) != 0) {
230140cf 188#ifdef CONFIG_NUMA
9db66bdc
ED
189 if (size * sizeof(spinlock_t) > PAGE_SIZE)
190 hashinfo->ehash_locks = vmalloc(size * sizeof(spinlock_t));
230140cf
ED
191 else
192#endif
9db66bdc 193 hashinfo->ehash_locks = kmalloc(size * sizeof(spinlock_t),
230140cf
ED
194 GFP_KERNEL);
195 if (!hashinfo->ehash_locks)
196 return ENOMEM;
197 for (i = 0; i < size; i++)
9db66bdc 198 spin_lock_init(&hashinfo->ehash_locks[i]);
230140cf
ED
199 }
200 hashinfo->ehash_locks_mask = size - 1;
201 return 0;
202}
203
204static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
205{
206 if (hashinfo->ehash_locks) {
207#ifdef CONFIG_NUMA
208 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
9db66bdc 209 sizeof(spinlock_t);
230140cf
ED
210 if (size > PAGE_SIZE)
211 vfree(hashinfo->ehash_locks);
212 else
230140cf 213#endif
218ad12f 214 kfree(hashinfo->ehash_locks);
230140cf
ED
215 hashinfo->ehash_locks = NULL;
216 }
217}
218
77d8bf9c 219extern struct inet_bind_bucket *
e18b890b 220 inet_bind_bucket_create(struct kmem_cache *cachep,
941b1d22 221 struct net *net,
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222 struct inet_bind_hashbucket *head,
223 const unsigned short snum);
e18b890b 224extern void inet_bind_bucket_destroy(struct kmem_cache *cachep,
77d8bf9c
ACM
225 struct inet_bind_bucket *tb);
226
7f635ab7
PE
227static inline int inet_bhashfn(struct net *net,
228 const __u16 lport, const int bhash_size)
77d8bf9c 229{
0b441916 230 return (lport + net_hash_mix(net)) & (bhash_size - 1);
77d8bf9c
ACM
231}
232
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ACM
233extern void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
234 const unsigned short snum);
235
77d8bf9c 236/* These can have wildcards, don't try too hard. */
2086a650 237static inline int inet_lhashfn(struct net *net, const unsigned short num)
77d8bf9c 238{
0b441916 239 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
77d8bf9c
ACM
240}
241
242static inline int inet_sk_listen_hashfn(const struct sock *sk)
243{
c720c7e8 244 return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num);
77d8bf9c
ACM
245}
246
2d8c4ce5 247/* Caller must disable local BH processing. */
093d2823 248extern int __inet_inherit_port(struct sock *sk, struct sock *child);
2d8c4ce5 249
ab1e0a13 250extern void inet_put_port(struct sock *sk);
2d8c4ce5 251
5caea4ea 252void inet_hashinfo_init(struct inet_hashinfo *h);
f3f05f70 253
9327f705 254extern int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw);
ab1e0a13
ACM
255extern void inet_hash(struct sock *sk);
256extern void inet_unhash(struct sock *sk);
33b62231 257
c67499c0
PE
258extern struct sock *__inet_lookup_listener(struct net *net,
259 struct inet_hashinfo *hashinfo,
fb99c848 260 const __be32 daddr,
8f491069
HX
261 const unsigned short hnum,
262 const int dif);
263
c67499c0
PE
264static inline struct sock *inet_lookup_listener(struct net *net,
265 struct inet_hashinfo *hashinfo,
266 __be32 daddr, __be16 dport, int dif)
8f491069 267{
c67499c0 268 return __inet_lookup_listener(net, hashinfo, daddr, ntohs(dport), dif);
8f491069 269}
8feaf0c0
ACM
270
271/* Socket demux engine toys. */
4f765d84
AV
272/* What happens here is ugly; there's a pair of adjacent fields in
273 struct inet_sock; __be16 dport followed by __u16 num. We want to
274 search by pair, so we combine the keys into a single 32bit value
275 and compare with 32bit value read from &...->dport. Let's at least
276 make sure that it's not mixed with anything else...
277 On 64bit targets we combine comparisons with pair of adjacent __be32
278 fields in the same way.
279*/
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)
289#ifdef __BIG_ENDIAN
290#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
291 const __addrpair __name = (__force __addrpair) ( \
292 (((__force __u64)(__be32)(__saddr)) << 32) | \
293 ((__force __u64)(__be32)(__daddr)));
8feaf0c0
ACM
294#else /* __LITTLE_ENDIAN */
295#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
296 const __addrpair __name = (__force __addrpair) ( \
297 (((__force __u64)(__be32)(__daddr)) << 32) | \
298 ((__force __u64)(__be32)(__saddr)));
8feaf0c0 299#endif /* __BIG_ENDIAN */
ce43b03e
ED
300#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
301 ((inet_sk(__sk)->inet_portpair == (__ports)) && \
302 (inet_sk(__sk)->inet_addrpair == (__cookie)) && \
303 (!(__sk)->sk_bound_dev_if || \
304 ((__sk)->sk_bound_dev_if == (__dif))) && \
305 net_eq(sock_net(__sk), (__net)))
306#define INET_TW_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif)\
307 ((inet_twsk(__sk)->tw_portpair == (__ports)) && \
308 (inet_twsk(__sk)->tw_addrpair == (__cookie)) && \
309 (!(__sk)->sk_bound_dev_if || \
310 ((__sk)->sk_bound_dev_if == (__dif))) && \
311 net_eq(sock_net(__sk), (__net)))
8feaf0c0
ACM
312#else /* 32-bit arch */
313#define INET_ADDR_COOKIE(__name, __saddr, __daddr)
ce43b03e
ED
314#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
315 ((inet_sk(__sk)->inet_portpair == (__ports)) && \
316 (inet_sk(__sk)->inet_daddr == (__saddr)) && \
317 (inet_sk(__sk)->inet_rcv_saddr == (__daddr)) && \
318 (!(__sk)->sk_bound_dev_if || \
319 ((__sk)->sk_bound_dev_if == (__dif))) && \
320 net_eq(sock_net(__sk), (__net)))
321#define INET_TW_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
322 ((inet_twsk(__sk)->tw_portpair == (__ports)) && \
323 (inet_twsk(__sk)->tw_daddr == (__saddr)) && \
324 (inet_twsk(__sk)->tw_rcv_saddr == (__daddr)) && \
325 (!(__sk)->sk_bound_dev_if || \
326 ((__sk)->sk_bound_dev_if == (__dif))) && \
327 net_eq(sock_net(__sk), (__net)))
8feaf0c0 328#endif /* 64-bit arch */
e48c414e
ACM
329
330/*
331 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
332 * not check it for lookups anymore, thanks Alexey. -DaveM
333 *
334 * Local BH must be disabled here.
335 */
c67499c0
PE
336extern struct sock * __inet_lookup_established(struct net *net,
337 struct inet_hashinfo *hashinfo,
77a5ba55
PE
338 const __be32 saddr, const __be16 sport,
339 const __be32 daddr, const u16 hnum, const int dif);
e48c414e 340
8f491069 341static inline struct sock *
c67499c0 342 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
fb99c848
AV
343 const __be32 saddr, const __be16 sport,
344 const __be32 daddr, const __be16 dport,
8f491069
HX
345 const int dif)
346{
c67499c0 347 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
8f491069
HX
348 ntohs(dport), dif);
349}
350
c67499c0
PE
351static inline struct sock *__inet_lookup(struct net *net,
352 struct inet_hashinfo *hashinfo,
fb99c848
AV
353 const __be32 saddr, const __be16 sport,
354 const __be32 daddr, const __be16 dport,
e48c414e
ACM
355 const int dif)
356{
8f491069 357 u16 hnum = ntohs(dport);
c67499c0
PE
358 struct sock *sk = __inet_lookup_established(net, hashinfo,
359 saddr, sport, daddr, hnum, dif);
360
361 return sk ? : __inet_lookup_listener(net, hashinfo, daddr, hnum, dif);
e48c414e
ACM
362}
363
c67499c0
PE
364static inline struct sock *inet_lookup(struct net *net,
365 struct inet_hashinfo *hashinfo,
fb99c848
AV
366 const __be32 saddr, const __be16 sport,
367 const __be32 daddr, const __be16 dport,
e48c414e
ACM
368 const int dif)
369{
370 struct sock *sk;
371
372 local_bh_disable();
c67499c0 373 sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
374 local_bh_enable();
375
376 return sk;
377}
a7f5e7f1 378
9a1f27c4
ACM
379static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
380 struct sk_buff *skb,
381 const __be16 sport,
382 const __be16 dport)
383{
41063e9d 384 struct sock *sk = skb_steal_sock(skb);
9a1f27c4
ACM
385 const struct iphdr *iph = ip_hdr(skb);
386
41063e9d 387 if (sk)
23542618
KK
388 return sk;
389 else
adf30907 390 return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
23542618
KK
391 iph->saddr, sport,
392 iph->daddr, dport, inet_iif(skb));
9a1f27c4
ACM
393}
394
5ee31fc1 395extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
9327f705
ED
396 struct sock *sk,
397 u32 port_offset,
5ee31fc1
PE
398 int (*check_established)(struct inet_timewait_death_row *,
399 struct sock *, __u16, struct inet_timewait_sock **),
9327f705
ED
400 int (*hash)(struct sock *sk, struct inet_timewait_sock *twp));
401
a7f5e7f1
ACM
402extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
403 struct sock *sk);
304a1618 404#endif /* _INET_HASHTABLES_H */