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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.
77d8bf9c
ACM
42 */
43struct inet_ehash_bucket {
3ab5aee7
ED
44 struct hlist_nulls_head chain;
45 struct hlist_nulls_head twchain;
6d255361 46};
77d8bf9c
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
77d8bf9c 83 unsigned short port;
da5e3630
TH
84 signed char fastreuse;
85 signed char fastreuseport;
86 kuid_t fastuid;
a9d8f911 87 int num_owners;
77d8bf9c
ACM
88 struct hlist_node node;
89 struct hlist_head owners;
90};
91
7a9546ee
ED
92static inline struct net *ib_net(struct inet_bind_bucket *ib)
93{
94 return read_pnet(&ib->ib_net);
95}
96
b67bfe0d
SL
97#define inet_bind_bucket_for_each(tb, head) \
98 hlist_for_each_entry(tb, head, node)
77d8bf9c
ACM
99
100struct inet_bind_hashbucket {
101 spinlock_t lock;
102 struct hlist_head chain;
103};
104
c25eb3bf
ED
105/*
106 * Sockets can be hashed in established or listening table
107 * We must use different 'nulls' end-of-chain value for listening
108 * hash table, or we might find a socket that was closed and
109 * reallocated/inserted into established hash table
110 */
111#define LISTENING_NULLS_BASE (1U << 29)
5caea4ea
ED
112struct inet_listen_hashbucket {
113 spinlock_t lock;
c25eb3bf 114 struct hlist_nulls_head head;
5caea4ea
ED
115};
116
77d8bf9c
ACM
117/* This is for listening sockets, thus all sockets which possess wildcards. */
118#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
119
120struct inet_hashinfo {
121 /* This is for sockets with full identity only. Sockets here will
122 * always be without wildcards and will have the following invariant:
123 *
124 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
125 *
dbca9b27 126 * TIME_WAIT sockets use a separate chain (twchain).
77d8bf9c
ACM
127 */
128 struct inet_ehash_bucket *ehash;
9db66bdc 129 spinlock_t *ehash_locks;
f373b53b 130 unsigned int ehash_mask;
230140cf 131 unsigned int ehash_locks_mask;
77d8bf9c
ACM
132
133 /* Ok, let's try this, I give up, we do need a local binding
134 * TCP hash as well as the others for fast bind/connect.
135 */
136 struct inet_bind_hashbucket *bhash;
137
cfcabdcc 138 unsigned int bhash_size;
24dd1fa1 139 /* 4 bytes hole on 64 bit */
77d8bf9c 140
5caea4ea 141 struct kmem_cache *bind_bucket_cachep;
77d8bf9c
ACM
142
143 /* All the above members are written once at bootup and
144 * never written again _or_ are predominantly read-access.
145 *
146 * Now align to a new cache line as all the following members
5caea4ea
ED
147 * might be often dirty.
148 */
149 /* All sockets in TCP_LISTEN state will be in here. This is the only
150 * table where wildcard'd TCP sockets can exist. Hash function here
151 * is just local port number.
77d8bf9c 152 */
5caea4ea
ED
153 struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE]
154 ____cacheline_aligned_in_smp;
155
24dd1fa1 156 atomic_t bsockets;
77d8bf9c
ACM
157};
158
81c3d547
ED
159static inline struct inet_ehash_bucket *inet_ehash_bucket(
160 struct inet_hashinfo *hashinfo,
161 unsigned int hash)
162{
f373b53b 163 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
304a1618
ACM
164}
165
9db66bdc 166static inline spinlock_t *inet_ehash_lockp(
230140cf
ED
167 struct inet_hashinfo *hashinfo,
168 unsigned int hash)
169{
170 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
171}
172
173static inline int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
174{
175 unsigned int i, size = 256;
176#if defined(CONFIG_PROVE_LOCKING)
177 unsigned int nr_pcpus = 2;
178#else
179 unsigned int nr_pcpus = num_possible_cpus();
180#endif
181 if (nr_pcpus >= 4)
182 size = 512;
183 if (nr_pcpus >= 8)
184 size = 1024;
185 if (nr_pcpus >= 16)
186 size = 2048;
187 if (nr_pcpus >= 32)
188 size = 4096;
94cd3e6c 189 if (sizeof(spinlock_t) != 0) {
230140cf 190#ifdef CONFIG_NUMA
9db66bdc
ED
191 if (size * sizeof(spinlock_t) > PAGE_SIZE)
192 hashinfo->ehash_locks = vmalloc(size * sizeof(spinlock_t));
230140cf
ED
193 else
194#endif
9db66bdc 195 hashinfo->ehash_locks = kmalloc(size * sizeof(spinlock_t),
230140cf
ED
196 GFP_KERNEL);
197 if (!hashinfo->ehash_locks)
198 return ENOMEM;
199 for (i = 0; i < size; i++)
9db66bdc 200 spin_lock_init(&hashinfo->ehash_locks[i]);
230140cf
ED
201 }
202 hashinfo->ehash_locks_mask = size - 1;
203 return 0;
204}
205
206static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
207{
208 if (hashinfo->ehash_locks) {
209#ifdef CONFIG_NUMA
210 unsigned int size = (hashinfo->ehash_locks_mask + 1) *
9db66bdc 211 sizeof(spinlock_t);
230140cf
ED
212 if (size > PAGE_SIZE)
213 vfree(hashinfo->ehash_locks);
214 else
230140cf 215#endif
218ad12f 216 kfree(hashinfo->ehash_locks);
230140cf
ED
217 hashinfo->ehash_locks = NULL;
218 }
219}
220
77d8bf9c 221extern struct inet_bind_bucket *
e18b890b 222 inet_bind_bucket_create(struct kmem_cache *cachep,
941b1d22 223 struct net *net,
77d8bf9c
ACM
224 struct inet_bind_hashbucket *head,
225 const unsigned short snum);
e18b890b 226extern void inet_bind_bucket_destroy(struct kmem_cache *cachep,
77d8bf9c
ACM
227 struct inet_bind_bucket *tb);
228
7f635ab7
PE
229static inline int inet_bhashfn(struct net *net,
230 const __u16 lport, const int bhash_size)
77d8bf9c 231{
0b441916 232 return (lport + net_hash_mix(net)) & (bhash_size - 1);
77d8bf9c
ACM
233}
234
2d8c4ce5
ACM
235extern void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
236 const unsigned short snum);
237
77d8bf9c 238/* These can have wildcards, don't try too hard. */
2086a650 239static inline int inet_lhashfn(struct net *net, const unsigned short num)
77d8bf9c 240{
0b441916 241 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
77d8bf9c
ACM
242}
243
244static inline int inet_sk_listen_hashfn(const struct sock *sk)
245{
c720c7e8 246 return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num);
77d8bf9c
ACM
247}
248
2d8c4ce5 249/* Caller must disable local BH processing. */
093d2823 250extern int __inet_inherit_port(struct sock *sk, struct sock *child);
2d8c4ce5 251
ab1e0a13 252extern void inet_put_port(struct sock *sk);
2d8c4ce5 253
5caea4ea 254void inet_hashinfo_init(struct inet_hashinfo *h);
f3f05f70 255
9327f705 256extern int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw);
ab1e0a13
ACM
257extern void inet_hash(struct sock *sk);
258extern void inet_unhash(struct sock *sk);
33b62231 259
c67499c0
PE
260extern struct sock *__inet_lookup_listener(struct net *net,
261 struct inet_hashinfo *hashinfo,
da5e3630
TH
262 const __be32 saddr,
263 const __be16 sport,
fb99c848 264 const __be32 daddr,
8f491069
HX
265 const unsigned short hnum,
266 const int dif);
267
c67499c0
PE
268static inline struct sock *inet_lookup_listener(struct net *net,
269 struct inet_hashinfo *hashinfo,
da5e3630 270 __be32 saddr, __be16 sport,
c67499c0 271 __be32 daddr, __be16 dport, int dif)
8f491069 272{
da5e3630
TH
273 return __inet_lookup_listener(net, hashinfo, saddr, sport,
274 daddr, ntohs(dport), dif);
8f491069 275}
8feaf0c0
ACM
276
277/* Socket demux engine toys. */
4f765d84
AV
278/* What happens here is ugly; there's a pair of adjacent fields in
279 struct inet_sock; __be16 dport followed by __u16 num. We want to
280 search by pair, so we combine the keys into a single 32bit value
281 and compare with 32bit value read from &...->dport. Let's at least
282 make sure that it's not mixed with anything else...
283 On 64bit targets we combine comparisons with pair of adjacent __be32
284 fields in the same way.
285*/
8feaf0c0
ACM
286#ifdef __BIG_ENDIAN
287#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 288 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
8feaf0c0
ACM
289#else /* __LITTLE_ENDIAN */
290#define INET_COMBINED_PORTS(__sport, __dport) \
4f765d84 291 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
8feaf0c0
ACM
292#endif
293
294#if (BITS_PER_LONG == 64)
295#ifdef __BIG_ENDIAN
296#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
297 const __addrpair __name = (__force __addrpair) ( \
298 (((__force __u64)(__be32)(__saddr)) << 32) | \
299 ((__force __u64)(__be32)(__daddr)));
8feaf0c0
ACM
300#else /* __LITTLE_ENDIAN */
301#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
4f765d84
AV
302 const __addrpair __name = (__force __addrpair) ( \
303 (((__force __u64)(__be32)(__daddr)) << 32) | \
304 ((__force __u64)(__be32)(__saddr)));
8feaf0c0 305#endif /* __BIG_ENDIAN */
ce43b03e
ED
306#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
307 ((inet_sk(__sk)->inet_portpair == (__ports)) && \
308 (inet_sk(__sk)->inet_addrpair == (__cookie)) && \
309 (!(__sk)->sk_bound_dev_if || \
310 ((__sk)->sk_bound_dev_if == (__dif))) && \
311 net_eq(sock_net(__sk), (__net)))
312#define INET_TW_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif)\
313 ((inet_twsk(__sk)->tw_portpair == (__ports)) && \
314 (inet_twsk(__sk)->tw_addrpair == (__cookie)) && \
315 (!(__sk)->sk_bound_dev_if || \
316 ((__sk)->sk_bound_dev_if == (__dif))) && \
317 net_eq(sock_net(__sk), (__net)))
8feaf0c0
ACM
318#else /* 32-bit arch */
319#define INET_ADDR_COOKIE(__name, __saddr, __daddr)
ce43b03e
ED
320#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
321 ((inet_sk(__sk)->inet_portpair == (__ports)) && \
322 (inet_sk(__sk)->inet_daddr == (__saddr)) && \
323 (inet_sk(__sk)->inet_rcv_saddr == (__daddr)) && \
324 (!(__sk)->sk_bound_dev_if || \
325 ((__sk)->sk_bound_dev_if == (__dif))) && \
326 net_eq(sock_net(__sk), (__net)))
327#define INET_TW_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
328 ((inet_twsk(__sk)->tw_portpair == (__ports)) && \
329 (inet_twsk(__sk)->tw_daddr == (__saddr)) && \
330 (inet_twsk(__sk)->tw_rcv_saddr == (__daddr)) && \
331 (!(__sk)->sk_bound_dev_if || \
332 ((__sk)->sk_bound_dev_if == (__dif))) && \
333 net_eq(sock_net(__sk), (__net)))
8feaf0c0 334#endif /* 64-bit arch */
e48c414e
ACM
335
336/*
337 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
338 * not check it for lookups anymore, thanks Alexey. -DaveM
339 *
340 * Local BH must be disabled here.
341 */
c67499c0
PE
342extern struct sock * __inet_lookup_established(struct net *net,
343 struct inet_hashinfo *hashinfo,
77a5ba55
PE
344 const __be32 saddr, const __be16 sport,
345 const __be32 daddr, const u16 hnum, const int dif);
e48c414e 346
8f491069 347static inline struct sock *
c67499c0 348 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
fb99c848
AV
349 const __be32 saddr, const __be16 sport,
350 const __be32 daddr, const __be16 dport,
8f491069
HX
351 const int dif)
352{
c67499c0 353 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
8f491069
HX
354 ntohs(dport), dif);
355}
356
c67499c0
PE
357static inline struct sock *__inet_lookup(struct net *net,
358 struct inet_hashinfo *hashinfo,
fb99c848
AV
359 const __be32 saddr, const __be16 sport,
360 const __be32 daddr, const __be16 dport,
e48c414e
ACM
361 const int dif)
362{
8f491069 363 u16 hnum = ntohs(dport);
c67499c0
PE
364 struct sock *sk = __inet_lookup_established(net, hashinfo,
365 saddr, sport, daddr, hnum, dif);
366
da5e3630
TH
367 return sk ? : __inet_lookup_listener(net, hashinfo, saddr, sport,
368 daddr, hnum, dif);
e48c414e
ACM
369}
370
c67499c0
PE
371static inline struct sock *inet_lookup(struct net *net,
372 struct inet_hashinfo *hashinfo,
fb99c848
AV
373 const __be32 saddr, const __be16 sport,
374 const __be32 daddr, const __be16 dport,
e48c414e
ACM
375 const int dif)
376{
377 struct sock *sk;
378
379 local_bh_disable();
c67499c0 380 sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif);
e48c414e
ACM
381 local_bh_enable();
382
383 return sk;
384}
a7f5e7f1 385
9a1f27c4
ACM
386static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
387 struct sk_buff *skb,
388 const __be16 sport,
389 const __be16 dport)
390{
41063e9d 391 struct sock *sk = skb_steal_sock(skb);
9a1f27c4
ACM
392 const struct iphdr *iph = ip_hdr(skb);
393
41063e9d 394 if (sk)
23542618
KK
395 return sk;
396 else
adf30907 397 return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
23542618
KK
398 iph->saddr, sport,
399 iph->daddr, dport, inet_iif(skb));
9a1f27c4
ACM
400}
401
5ee31fc1 402extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
9327f705
ED
403 struct sock *sk,
404 u32 port_offset,
5ee31fc1
PE
405 int (*check_established)(struct inet_timewait_death_row *,
406 struct sock *, __u16, struct inet_timewait_sock **),
9327f705
ED
407 int (*hash)(struct sock *sk, struct inet_timewait_sock *twp));
408
a7f5e7f1
ACM
409extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
410 struct sock *sk);
304a1618 411#endif /* _INET_HASHTABLES_H */