Commit | Line | Data |
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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> |
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 | */ |
43 | struct inet_ehash_bucket { | |
3ab5aee7 | 44 | struct hlist_nulls_head chain; |
6d255361 | 45 | }; |
77d8bf9c 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 | */ | |
78 | struct inet_bind_bucket { | |
7a9546ee | 79 | #ifdef CONFIG_NET_NS |
941b1d22 | 80 | struct net *ib_net; |
7a9546ee | 81 | #endif |
77d8bf9c | 82 | unsigned short port; |
da5e3630 TH |
83 | signed char fastreuse; |
84 | signed char fastreuseport; | |
85 | kuid_t fastuid; | |
a9d8f911 | 86 | int num_owners; |
77d8bf9c ACM |
87 | struct hlist_node node; |
88 | struct hlist_head owners; | |
89 | }; | |
90 | ||
7a9546ee ED |
91 | static inline struct net *ib_net(struct inet_bind_bucket *ib) |
92 | { | |
93 | return read_pnet(&ib->ib_net); | |
94 | } | |
95 | ||
b67bfe0d SL |
96 | #define inet_bind_bucket_for_each(tb, head) \ |
97 | hlist_for_each_entry(tb, head, node) | |
77d8bf9c ACM |
98 | |
99 | struct inet_bind_hashbucket { | |
100 | spinlock_t lock; | |
101 | struct hlist_head chain; | |
102 | }; | |
103 | ||
c25eb3bf ED |
104 | /* |
105 | * Sockets can be hashed in established or listening table | |
106 | * We must use different 'nulls' end-of-chain value for listening | |
107 | * hash table, or we might find a socket that was closed and | |
108 | * reallocated/inserted into established hash table | |
109 | */ | |
110 | #define LISTENING_NULLS_BASE (1U << 29) | |
5caea4ea ED |
111 | struct inet_listen_hashbucket { |
112 | spinlock_t lock; | |
c25eb3bf | 113 | struct hlist_nulls_head head; |
5caea4ea ED |
114 | }; |
115 | ||
77d8bf9c ACM |
116 | /* This is for listening sockets, thus all sockets which possess wildcards. */ |
117 | #define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */ | |
118 | ||
119 | struct inet_hashinfo { | |
120 | /* This is for sockets with full identity only. Sockets here will | |
121 | * always be without wildcards and will have the following invariant: | |
122 | * | |
123 | * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE | |
124 | * | |
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; |
77d8bf9c ACM |
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; |
77d8bf9c ACM |
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 |
157 | static 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 | 164 | static 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 | ||
171 | static 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 | ||
204 | static 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 | ||
1fd51155 JP |
219 | struct inet_bind_bucket * |
220 | inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net, | |
221 | struct inet_bind_hashbucket *head, | |
222 | const unsigned short snum); | |
223 | void inet_bind_bucket_destroy(struct kmem_cache *cachep, | |
224 | struct inet_bind_bucket *tb); | |
225 | ||
226 | static inline int inet_bhashfn(struct net *net, const __u16 lport, | |
227 | const int bhash_size) | |
77d8bf9c | 228 | { |
0b441916 | 229 | return (lport + net_hash_mix(net)) & (bhash_size - 1); |
77d8bf9c ACM |
230 | } |
231 | ||
1fd51155 JP |
232 | void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, |
233 | const unsigned short snum); | |
2d8c4ce5 | 234 | |
77d8bf9c | 235 | /* These can have wildcards, don't try too hard. */ |
2086a650 | 236 | static inline int inet_lhashfn(struct net *net, const unsigned short num) |
77d8bf9c | 237 | { |
0b441916 | 238 | return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1); |
77d8bf9c ACM |
239 | } |
240 | ||
241 | static inline int inet_sk_listen_hashfn(const struct sock *sk) | |
242 | { | |
c720c7e8 | 243 | return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num); |
77d8bf9c ACM |
244 | } |
245 | ||
2d8c4ce5 | 246 | /* Caller must disable local BH processing. */ |
1fd51155 | 247 | int __inet_inherit_port(struct sock *sk, struct sock *child); |
2d8c4ce5 | 248 | |
1fd51155 | 249 | void inet_put_port(struct sock *sk); |
2d8c4ce5 | 250 | |
5caea4ea | 251 | void inet_hashinfo_init(struct inet_hashinfo *h); |
f3f05f70 | 252 | |
1fd51155 JP |
253 | int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw); |
254 | void inet_hash(struct sock *sk); | |
255 | void inet_unhash(struct sock *sk); | |
33b62231 | 256 | |
1fd51155 JP |
257 | struct sock *__inet_lookup_listener(struct net *net, |
258 | struct inet_hashinfo *hashinfo, | |
259 | const __be32 saddr, const __be16 sport, | |
260 | const __be32 daddr, | |
261 | const unsigned short hnum, | |
262 | const int dif); | |
8f491069 | 263 | |
c67499c0 PE |
264 | static inline struct sock *inet_lookup_listener(struct net *net, |
265 | struct inet_hashinfo *hashinfo, | |
da5e3630 | 266 | __be32 saddr, __be16 sport, |
c67499c0 | 267 | __be32 daddr, __be16 dport, int dif) |
8f491069 | 268 | { |
da5e3630 TH |
269 | return __inet_lookup_listener(net, hashinfo, saddr, sport, |
270 | daddr, ntohs(dport), dif); | |
8f491069 | 271 | } |
8feaf0c0 ACM |
272 | |
273 | /* Socket demux engine toys. */ | |
4f765d84 AV |
274 | /* What happens here is ugly; there's a pair of adjacent fields in |
275 | struct inet_sock; __be16 dport followed by __u16 num. We want to | |
276 | search by pair, so we combine the keys into a single 32bit value | |
277 | and compare with 32bit value read from &...->dport. Let's at least | |
278 | make sure that it's not mixed with anything else... | |
279 | On 64bit targets we combine comparisons with pair of adjacent __be32 | |
280 | fields in the same way. | |
281 | */ | |
8feaf0c0 ACM |
282 | #ifdef __BIG_ENDIAN |
283 | #define INET_COMBINED_PORTS(__sport, __dport) \ | |
4f765d84 | 284 | ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport))) |
8feaf0c0 ACM |
285 | #else /* __LITTLE_ENDIAN */ |
286 | #define INET_COMBINED_PORTS(__sport, __dport) \ | |
4f765d84 | 287 | ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport))) |
8feaf0c0 ACM |
288 | #endif |
289 | ||
290 | #if (BITS_PER_LONG == 64) | |
291 | #ifdef __BIG_ENDIAN | |
292 | #define INET_ADDR_COOKIE(__name, __saddr, __daddr) \ | |
4f765d84 AV |
293 | const __addrpair __name = (__force __addrpair) ( \ |
294 | (((__force __u64)(__be32)(__saddr)) << 32) | \ | |
c7228317 | 295 | ((__force __u64)(__be32)(__daddr))) |
8feaf0c0 ACM |
296 | #else /* __LITTLE_ENDIAN */ |
297 | #define INET_ADDR_COOKIE(__name, __saddr, __daddr) \ | |
4f765d84 AV |
298 | const __addrpair __name = (__force __addrpair) ( \ |
299 | (((__force __u64)(__be32)(__daddr)) << 32) | \ | |
c7228317 | 300 | ((__force __u64)(__be32)(__saddr))) |
8feaf0c0 | 301 | #endif /* __BIG_ENDIAN */ |
ce43b03e | 302 | #define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \ |
50805466 ED |
303 | (((__sk)->sk_portpair == (__ports)) && \ |
304 | ((__sk)->sk_addrpair == (__cookie)) && \ | |
ce43b03e ED |
305 | (!(__sk)->sk_bound_dev_if || \ |
306 | ((__sk)->sk_bound_dev_if == (__dif))) && \ | |
307 | net_eq(sock_net(__sk), (__net))) | |
8feaf0c0 | 308 | #else /* 32-bit arch */ |
c7228317 JP |
309 | #define INET_ADDR_COOKIE(__name, __saddr, __daddr) \ |
310 | const int __name __deprecated __attribute__((unused)) | |
311 | ||
ce43b03e | 312 | #define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \ |
50805466 ED |
313 | (((__sk)->sk_portpair == (__ports)) && \ |
314 | ((__sk)->sk_daddr == (__saddr)) && \ | |
315 | ((__sk)->sk_rcv_saddr == (__daddr)) && \ | |
ce43b03e ED |
316 | (!(__sk)->sk_bound_dev_if || \ |
317 | ((__sk)->sk_bound_dev_if == (__dif))) && \ | |
318 | net_eq(sock_net(__sk), (__net))) | |
8feaf0c0 | 319 | #endif /* 64-bit arch */ |
e48c414e ACM |
320 | |
321 | /* | |
322 | * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need | |
323 | * not check it for lookups anymore, thanks Alexey. -DaveM | |
324 | * | |
325 | * Local BH must be disabled here. | |
326 | */ | |
1fd51155 JP |
327 | struct sock *__inet_lookup_established(struct net *net, |
328 | struct inet_hashinfo *hashinfo, | |
329 | const __be32 saddr, const __be16 sport, | |
330 | const __be32 daddr, const u16 hnum, | |
331 | const int dif); | |
e48c414e | 332 | |
8f491069 | 333 | static inline struct sock * |
c67499c0 | 334 | inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo, |
fb99c848 AV |
335 | const __be32 saddr, const __be16 sport, |
336 | const __be32 daddr, const __be16 dport, | |
8f491069 HX |
337 | const int dif) |
338 | { | |
c67499c0 | 339 | return __inet_lookup_established(net, hashinfo, saddr, sport, daddr, |
8f491069 HX |
340 | ntohs(dport), dif); |
341 | } | |
342 | ||
c67499c0 PE |
343 | static inline struct sock *__inet_lookup(struct net *net, |
344 | struct inet_hashinfo *hashinfo, | |
fb99c848 AV |
345 | const __be32 saddr, const __be16 sport, |
346 | const __be32 daddr, const __be16 dport, | |
e48c414e ACM |
347 | const int dif) |
348 | { | |
8f491069 | 349 | u16 hnum = ntohs(dport); |
c67499c0 PE |
350 | struct sock *sk = __inet_lookup_established(net, hashinfo, |
351 | saddr, sport, daddr, hnum, dif); | |
352 | ||
da5e3630 TH |
353 | return sk ? : __inet_lookup_listener(net, hashinfo, saddr, sport, |
354 | daddr, hnum, dif); | |
e48c414e ACM |
355 | } |
356 | ||
c67499c0 PE |
357 | static 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 | { | |
363 | struct sock *sk; | |
364 | ||
365 | local_bh_disable(); | |
c67499c0 | 366 | sk = __inet_lookup(net, hashinfo, saddr, sport, daddr, dport, dif); |
e48c414e ACM |
367 | local_bh_enable(); |
368 | ||
369 | return sk; | |
370 | } | |
a7f5e7f1 | 371 | |
9a1f27c4 ACM |
372 | static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo, |
373 | struct sk_buff *skb, | |
374 | const __be16 sport, | |
375 | const __be16 dport) | |
376 | { | |
41063e9d | 377 | struct sock *sk = skb_steal_sock(skb); |
9a1f27c4 ACM |
378 | const struct iphdr *iph = ip_hdr(skb); |
379 | ||
41063e9d | 380 | if (sk) |
23542618 KK |
381 | return sk; |
382 | else | |
adf30907 | 383 | return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo, |
23542618 KK |
384 | iph->saddr, sport, |
385 | iph->daddr, dport, inet_iif(skb)); | |
9a1f27c4 ACM |
386 | } |
387 | ||
1fd51155 JP |
388 | int __inet_hash_connect(struct inet_timewait_death_row *death_row, |
389 | struct sock *sk, u32 port_offset, | |
390 | int (*check_established)(struct inet_timewait_death_row *, | |
391 | struct sock *, __u16, | |
392 | struct inet_timewait_sock **), | |
393 | int (*hash)(struct sock *sk, | |
394 | struct inet_timewait_sock *twp)); | |
9327f705 | 395 | |
1fd51155 JP |
396 | int inet_hash_connect(struct inet_timewait_death_row *death_row, |
397 | struct sock *sk); | |
304a1618 | 398 | #endif /* _INET_HASHTABLES_H */ |