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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.
05dbc7b5
ED
40 * The 'e' prefix stands for Establish, but we really put all sockets
41 * but LISTEN ones.
77d8bf9c
ACM
42 */
43struct inet_ehash_bucket {
3ab5aee7 44 struct hlist_nulls_head chain;
6d255361 45};
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ACM
46
47/* There are a few simple rules, which allow for local port reuse by
48 * an application. In essence:
49 *
50 * 1) Sockets bound to different interfaces may share a local port.
51 * Failing that, goto test 2.
52 * 2) If all sockets have sk->sk_reuse set, and none of them are in
53 * TCP_LISTEN state, the port may be shared.
54 * Failing that, goto test 3.
55 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
56 * address, and none of them are the same, the port may be
57 * shared.
58 * Failing this, the port cannot be shared.
59 *
60 * The interesting point, is test #2. This is what an FTP server does
61 * all day. To optimize this case we use a specific flag bit defined
62 * below. As we add sockets to a bind bucket list, we perform a
63 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
64 * As long as all sockets added to a bind bucket pass this test,
65 * the flag bit will be set.
66 * The resulting situation is that tcp_v[46]_verify_bind() can just check
67 * for this flag bit, if it is set and the socket trying to bind has
68 * sk->sk_reuse set, we don't even have to walk the owners list at all,
69 * we return that it is ok to bind this socket to the requested local port.
70 *
71 * Sounds like a lot of work, but it is worth it. In a more naive
72 * implementation (ie. current FreeBSD etc.) the entire list of ports
73 * must be walked for each data port opened by an ftp server. Needless
74 * to say, this does not scale at all. With a couple thousand FTP
75 * users logged onto your box, isn't it nice to know that new data
76 * ports are created in O(1) time? I thought so. ;-) -DaveM
77 */
78struct inet_bind_bucket {
0c5c9fb5 79 possible_net_t ib_net;
77d8bf9c 80 unsigned short port;
da5e3630
TH
81 signed char fastreuse;
82 signed char fastreuseport;
83 kuid_t fastuid;
a9d8f911 84 int num_owners;
77d8bf9c
ACM
85 struct hlist_node node;
86 struct hlist_head owners;
87};
88
7a9546ee
ED
89static inline struct net *ib_net(struct inet_bind_bucket *ib)
90{
91 return read_pnet(&ib->ib_net);
92}
93
b67bfe0d
SL
94#define inet_bind_bucket_for_each(tb, head) \
95 hlist_for_each_entry(tb, head, node)
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ACM
96
97struct inet_bind_hashbucket {
98 spinlock_t lock;
99 struct hlist_head chain;
100};
101
c25eb3bf
ED
102/*
103 * Sockets can be hashed in established or listening table
104 * We must use different 'nulls' end-of-chain value for listening
105 * hash table, or we might find a socket that was closed and
106 * reallocated/inserted into established hash table
107 */
108#define LISTENING_NULLS_BASE (1U << 29)
5caea4ea
ED
109struct inet_listen_hashbucket {
110 spinlock_t lock;
c25eb3bf 111 struct hlist_nulls_head head;
5caea4ea
ED
112};
113
77d8bf9c
ACM
114/* This is for listening sockets, thus all sockets which possess wildcards. */
115#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
116
117struct inet_hashinfo {
118 /* This is for sockets with full identity only. Sockets here will
119 * always be without wildcards and will have the following invariant:
120 *
121 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
122 *
77d8bf9c
ACM
123 */
124 struct inet_ehash_bucket *ehash;
9db66bdc 125 spinlock_t *ehash_locks;
f373b53b 126 unsigned int ehash_mask;
230140cf 127 unsigned int ehash_locks_mask;
77d8bf9c
ACM
128
129 /* Ok, let's try this, I give up, we do need a local binding
130 * TCP hash as well as the others for fast bind/connect.
131 */
132 struct inet_bind_hashbucket *bhash;
133
cfcabdcc 134 unsigned int bhash_size;
24dd1fa1 135 /* 4 bytes hole on 64 bit */
77d8bf9c 136
5caea4ea 137 struct kmem_cache *bind_bucket_cachep;
77d8bf9c
ACM
138
139 /* All the above members are written once at bootup and
140 * never written again _or_ are predominantly read-access.
141 *
142 * Now align to a new cache line as all the following members
5caea4ea
ED
143 * might be often dirty.
144 */
145 /* All sockets in TCP_LISTEN state will be in here. This is the only
146 * table where wildcard'd TCP sockets can exist. Hash function here
147 * is just local port number.
77d8bf9c 148 */
5caea4ea
ED
149 struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE]
150 ____cacheline_aligned_in_smp;
151
24dd1fa1 152 atomic_t bsockets;
77d8bf9c
ACM
153};
154
81c3d547
ED
155static inline struct inet_ehash_bucket *inet_ehash_bucket(
156 struct inet_hashinfo *hashinfo,
157 unsigned int hash)
158{
f373b53b 159 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
304a1618
ACM
160}
161
9db66bdc 162static inline spinlock_t *inet_ehash_lockp(
230140cf
ED
163 struct inet_hashinfo *hashinfo,
164 unsigned int hash)
165{
166 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
167}
168
169static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
170{
171 unsigned int i, size = 256;
172#if defined(CONFIG_PROVE_LOCKING)
173 unsigned int nr_pcpus = 2;
174#else
175 unsigned int nr_pcpus = num_possible_cpus();
176#endif
177 if (nr_pcpus >= 4)
178 size = 512;
179 if (nr_pcpus >= 8)
180 size = 1024;
181 if (nr_pcpus >= 16)
182 size = 2048;
183 if (nr_pcpus >= 32)
184 size = 4096;
94cd3e6c 185 if (sizeof(spinlock_t) != 0) {
230140cf 186#ifdef CONFIG_NUMA
9db66bdc
ED
187 if (size * sizeof(spinlock_t) > PAGE_SIZE)
188 hashinfo->ehash_locks = vmalloc(size * sizeof(spinlock_t));
230140cf
ED
189 else
190#endif
9db66bdc 191 hashinfo->ehash_locks = kmalloc(size * sizeof(spinlock_t),
230140cf
ED
192 GFP_KERNEL);
193 if (!hashinfo->ehash_locks)
194 return ENOMEM;
195 for (i = 0; i < size; i++)
9db66bdc 196 spin_lock_init(&hashinfo->ehash_locks[i]);
230140cf
ED
197 }
198 hashinfo->ehash_locks_mask = size - 1;
199 return 0;
200}
201
202static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
203{
204 if (hashinfo->ehash_locks) {
205#ifdef CONFIG_NUMA
206 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
9db66bdc 207 sizeof(spinlock_t);
230140cf
ED
208 if (size > PAGE_SIZE)
209 vfree(hashinfo->ehash_locks);
210 else
230140cf 211#endif
218ad12f 212 kfree(hashinfo->ehash_locks);
230140cf
ED
213 hashinfo->ehash_locks = NULL;
214 }
215}
216
1fd51155
JP
217struct inet_bind_bucket *
218inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
219 struct inet_bind_hashbucket *head,
220 const unsigned short snum);
221void inet_bind_bucket_destroy(struct kmem_cache *cachep,
222 struct inet_bind_bucket *tb);
223
224static inline int inet_bhashfn(struct net *net, const __u16 lport,
225 const int bhash_size)
77d8bf9c 226{
0b441916 227 return (lport + net_hash_mix(net)) & (bhash_size - 1);
77d8bf9c
ACM
228}
229
1fd51155
JP
230void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
231 const unsigned short snum);
2d8c4ce5 232
77d8bf9c 233/* These can have wildcards, don't try too hard. */
2086a650 234static inline int inet_lhashfn(struct net *net, const unsigned short num)
77d8bf9c 235{
0b441916 236 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
77d8bf9c
ACM
237}
238
239static inline int inet_sk_listen_hashfn(const struct sock *sk)
240{
c720c7e8 241 return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num);
77d8bf9c
ACM
242}
243
2d8c4ce5 244/* Caller must disable local BH processing. */
1fd51155 245int __inet_inherit_port(struct sock *sk, struct sock *child);
2d8c4ce5 246
1fd51155 247void inet_put_port(struct sock *sk);
2d8c4ce5 248
5caea4ea 249void inet_hashinfo_init(struct inet_hashinfo *h);
f3f05f70 250
1fd51155
JP
251int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw);
252void inet_hash(struct sock *sk);
253void inet_unhash(struct sock *sk);
33b62231 254
1fd51155
JP
255struct sock *__inet_lookup_listener(struct net *net,
256 struct inet_hashinfo *hashinfo,
257 const __be32 saddr, const __be16 sport,
258 const __be32 daddr,
259 const unsigned short hnum,
260 const int dif);
8f491069 261
c67499c0
PE
262static inline struct sock *inet_lookup_listener(struct net *net,
263 struct inet_hashinfo *hashinfo,
da5e3630 264 __be32 saddr, __be16 sport,
c67499c0 265 __be32 daddr, __be16 dport, int dif)
8f491069 266{
da5e3630
TH
267 return __inet_lookup_listener(net, hashinfo, saddr, sport,
268 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) | \
c7228317 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) | \
c7228317 298 ((__force __u64)(__be32)(__saddr)))
8feaf0c0 299#endif /* __BIG_ENDIAN */
ce43b03e 300#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
50805466
ED
301 (((__sk)->sk_portpair == (__ports)) && \
302 ((__sk)->sk_addrpair == (__cookie)) && \
ce43b03e
ED
303 (!(__sk)->sk_bound_dev_if || \
304 ((__sk)->sk_bound_dev_if == (__dif))) && \
305 net_eq(sock_net(__sk), (__net)))
8feaf0c0 306#else /* 32-bit arch */
c7228317
JP
307#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
308 const int __name __deprecated __attribute__((unused))
309
ce43b03e 310#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
50805466
ED
311 (((__sk)->sk_portpair == (__ports)) && \
312 ((__sk)->sk_daddr == (__saddr)) && \
313 ((__sk)->sk_rcv_saddr == (__daddr)) && \
ce43b03e
ED
314 (!(__sk)->sk_bound_dev_if || \
315 ((__sk)->sk_bound_dev_if == (__dif))) && \
316 net_eq(sock_net(__sk), (__net)))
8feaf0c0 317#endif /* 64-bit arch */
e48c414e
ACM
318
319/*
320 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
321 * not check it for lookups anymore, thanks Alexey. -DaveM
322 *
323 * Local BH must be disabled here.
324 */
1fd51155
JP
325struct sock *__inet_lookup_established(struct net *net,
326 struct inet_hashinfo *hashinfo,
327 const __be32 saddr, const __be16 sport,
328 const __be32 daddr, const u16 hnum,
329 const int dif);
e48c414e 330
8f491069 331static inline struct sock *
c67499c0 332 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
fb99c848
AV
333 const __be32 saddr, const __be16 sport,
334 const __be32 daddr, const __be16 dport,
8f491069
HX
335 const int dif)
336{
c67499c0 337 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
8f491069
HX
338 ntohs(dport), dif);
339}
340
c67499c0
PE
341static inline struct sock *__inet_lookup(struct net *net,
342 struct inet_hashinfo *hashinfo,
fb99c848
AV
343 const __be32 saddr, const __be16 sport,
344 const __be32 daddr, const __be16 dport,
e48c414e
ACM
345 const int dif)
346{
8f491069 347 u16 hnum = ntohs(dport);
c67499c0
PE
348 struct sock *sk = __inet_lookup_established(net, hashinfo,
349 saddr, sport, daddr, hnum, dif);
350
da5e3630
TH
351 return sk ? : __inet_lookup_listener(net, hashinfo, saddr, sport,
352 daddr, hnum, dif);
e48c414e
ACM
353}
354
c67499c0
PE
355static inline struct sock *inet_lookup(struct net *net,
356 struct inet_hashinfo *hashinfo,
fb99c848
AV
357 const __be32 saddr, const __be16 sport,
358 const __be32 daddr, const __be16 dport,
e48c414e
ACM
359 const int dif)
360{
361 struct sock *sk;
362
363 local_bh_disable();
c67499c0 364 sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
365 local_bh_enable();
366
367 return sk;
368}
a7f5e7f1 369
9a1f27c4
ACM
370static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
371 struct sk_buff *skb,
372 const __be16 sport,
373 const __be16 dport)
374{
41063e9d 375 struct sock *sk = skb_steal_sock(skb);
9a1f27c4
ACM
376 const struct iphdr *iph = ip_hdr(skb);
377
41063e9d 378 if (sk)
23542618
KK
379 return sk;
380 else
adf30907 381 return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
23542618
KK
382 iph->saddr, sport,
383 iph->daddr, dport, inet_iif(skb));
9a1f27c4
ACM
384}
385
1fd51155
JP
386int __inet_hash_connect(struct inet_timewait_death_row *death_row,
387 struct sock *sk, u32 port_offset,
388 int (*check_established)(struct inet_timewait_death_row *,
389 struct sock *, __u16,
390 struct inet_timewait_sock **),
391 int (*hash)(struct sock *sk,
392 struct inet_timewait_sock *twp));
9327f705 393
1fd51155
JP
394int inet_hash_connect(struct inet_timewait_death_row *death_row,
395 struct sock *sk);
304a1618 396#endif /* _INET_HASHTABLES_H */