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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Authors: Lotsa people, from code originally in tcp
8 */
9
10#ifndef _INET_HASHTABLES_H
11#define _INET_HASHTABLES_H
12
13
14#include <linux/interrupt.h>
15#include <linux/ip.h>
16#include <linux/ipv6.h>
17#include <linux/list.h>
18#include <linux/slab.h>
19#include <linux/socket.h>
20#include <linux/spinlock.h>
21#include <linux/types.h>
22#include <linux/wait.h>
23
24#include <net/inet_connection_sock.h>
25#include <net/inet_sock.h>
26#include <net/ip.h>
27#include <net/sock.h>
28#include <net/route.h>
29#include <net/tcp_states.h>
30#include <net/netns/hash.h>
31
32#include <linux/refcount.h>
33#include <asm/byteorder.h>
34
35/* This is for all connections with a full identity, no wildcards.
36 * The 'e' prefix stands for Establish, but we really put all sockets
37 * but LISTEN ones.
38 */
39struct inet_ehash_bucket {
40 struct hlist_nulls_head chain;
41};
42
43/* There are a few simple rules, which allow for local port reuse by
44 * an application. In essence:
45 *
46 * 1) Sockets bound to different interfaces may share a local port.
47 * Failing that, goto test 2.
48 * 2) If all sockets have sk->sk_reuse set, and none of them are in
49 * TCP_LISTEN state, the port may be shared.
50 * Failing that, goto test 3.
51 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
52 * address, and none of them are the same, the port may be
53 * shared.
54 * Failing this, the port cannot be shared.
55 *
56 * The interesting point, is test #2. This is what an FTP server does
57 * all day. To optimize this case we use a specific flag bit defined
58 * below. As we add sockets to a bind bucket list, we perform a
59 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
60 * As long as all sockets added to a bind bucket pass this test,
61 * the flag bit will be set.
62 * The resulting situation is that tcp_v[46]_verify_bind() can just check
63 * for this flag bit, if it is set and the socket trying to bind has
64 * sk->sk_reuse set, we don't even have to walk the owners list at all,
65 * we return that it is ok to bind this socket to the requested local port.
66 *
67 * Sounds like a lot of work, but it is worth it. In a more naive
68 * implementation (ie. current FreeBSD etc.) the entire list of ports
69 * must be walked for each data port opened by an ftp server. Needless
70 * to say, this does not scale at all. With a couple thousand FTP
71 * users logged onto your box, isn't it nice to know that new data
72 * ports are created in O(1) time? I thought so. ;-) -DaveM
73 */
74#define FASTREUSEPORT_ANY 1
75#define FASTREUSEPORT_STRICT 2
76
77struct inet_bind_bucket {
78 possible_net_t ib_net;
79 int l3mdev;
80 unsigned short port;
81 signed char fastreuse;
82 signed char fastreuseport;
83 kuid_t fastuid;
84#if IS_ENABLED(CONFIG_IPV6)
85 struct in6_addr fast_v6_rcv_saddr;
86#endif
87 __be32 fast_rcv_saddr;
88 unsigned short fast_sk_family;
89 bool fast_ipv6_only;
90 struct hlist_node node;
91 struct hlist_head bhash2;
92};
93
94struct inet_bind2_bucket {
95 possible_net_t ib_net;
96 int l3mdev;
97 unsigned short port;
98#if IS_ENABLED(CONFIG_IPV6)
99 unsigned short addr_type;
100 struct in6_addr v6_rcv_saddr;
101#define rcv_saddr v6_rcv_saddr.s6_addr32[3]
102#else
103 __be32 rcv_saddr;
104#endif
105 /* Node in the bhash2 inet_bind_hashbucket chain */
106 struct hlist_node node;
107 struct hlist_node bhash_node;
108 /* List of sockets hashed to this bucket */
109 struct hlist_head owners;
110};
111
112static inline struct net *ib_net(const struct inet_bind_bucket *ib)
113{
114 return read_pnet(&ib->ib_net);
115}
116
117static inline struct net *ib2_net(const struct inet_bind2_bucket *ib)
118{
119 return read_pnet(&ib->ib_net);
120}
121
122#define inet_bind_bucket_for_each(tb, head) \
123 hlist_for_each_entry(tb, head, node)
124
125struct inet_bind_hashbucket {
126 spinlock_t lock;
127 struct hlist_head chain;
128};
129
130/* Sockets can be hashed in established or listening table.
131 * We must use different 'nulls' end-of-chain value for all hash buckets :
132 * A socket might transition from ESTABLISH to LISTEN state without
133 * RCU grace period. A lookup in ehash table needs to handle this case.
134 */
135#define LISTENING_NULLS_BASE (1U << 29)
136struct inet_listen_hashbucket {
137 spinlock_t lock;
138 struct hlist_nulls_head nulls_head;
139};
140
141/* This is for listening sockets, thus all sockets which possess wildcards. */
142#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
143
144struct inet_hashinfo {
145 /* This is for sockets with full identity only. Sockets here will
146 * always be without wildcards and will have the following invariant:
147 *
148 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
149 *
150 */
151 struct inet_ehash_bucket *ehash;
152 spinlock_t *ehash_locks;
153 unsigned int ehash_mask;
154 unsigned int ehash_locks_mask;
155
156 /* Ok, let's try this, I give up, we do need a local binding
157 * TCP hash as well as the others for fast bind/connect.
158 */
159 struct kmem_cache *bind_bucket_cachep;
160 /* This bind table is hashed by local port */
161 struct inet_bind_hashbucket *bhash;
162 struct kmem_cache *bind2_bucket_cachep;
163 /* This bind table is hashed by local port and sk->sk_rcv_saddr (ipv4)
164 * or sk->sk_v6_rcv_saddr (ipv6). This 2nd bind table is used
165 * primarily for expediting bind conflict resolution.
166 */
167 struct inet_bind_hashbucket *bhash2;
168 unsigned int bhash_size;
169
170 /* The 2nd listener table hashed by local port and address */
171 unsigned int lhash2_mask;
172 struct inet_listen_hashbucket *lhash2;
173
174 bool pernet;
175} ____cacheline_aligned_in_smp;
176
177static inline struct inet_hashinfo *tcp_or_dccp_get_hashinfo(const struct sock *sk)
178{
179#if IS_ENABLED(CONFIG_IP_DCCP)
180 return sk->sk_prot->h.hashinfo ? :
181 sock_net(sk)->ipv4.tcp_death_row.hashinfo;
182#else
183 return sock_net(sk)->ipv4.tcp_death_row.hashinfo;
184#endif
185}
186
187static inline struct inet_listen_hashbucket *
188inet_lhash2_bucket(struct inet_hashinfo *h, u32 hash)
189{
190 return &h->lhash2[hash & h->lhash2_mask];
191}
192
193static inline struct inet_ehash_bucket *inet_ehash_bucket(
194 struct inet_hashinfo *hashinfo,
195 unsigned int hash)
196{
197 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
198}
199
200static inline spinlock_t *inet_ehash_lockp(
201 struct inet_hashinfo *hashinfo,
202 unsigned int hash)
203{
204 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
205}
206
207int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo);
208
209static inline void inet_hashinfo2_free_mod(struct inet_hashinfo *h)
210{
211 kfree(h->lhash2);
212 h->lhash2 = NULL;
213}
214
215static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
216{
217 kvfree(hashinfo->ehash_locks);
218 hashinfo->ehash_locks = NULL;
219}
220
221struct inet_hashinfo *inet_pernet_hashinfo_alloc(struct inet_hashinfo *hashinfo,
222 unsigned int ehash_entries);
223void inet_pernet_hashinfo_free(struct inet_hashinfo *hashinfo);
224
225struct inet_bind_bucket *
226inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
227 struct inet_bind_hashbucket *head,
228 const unsigned short snum, int l3mdev);
229void inet_bind_bucket_destroy(struct kmem_cache *cachep,
230 struct inet_bind_bucket *tb);
231
232bool inet_bind_bucket_match(const struct inet_bind_bucket *tb,
233 const struct net *net, unsigned short port,
234 int l3mdev);
235
236struct inet_bind2_bucket *
237inet_bind2_bucket_create(struct kmem_cache *cachep, struct net *net,
238 struct inet_bind_hashbucket *head,
239 struct inet_bind_bucket *tb,
240 const struct sock *sk);
241
242void inet_bind2_bucket_destroy(struct kmem_cache *cachep,
243 struct inet_bind2_bucket *tb);
244
245struct inet_bind2_bucket *
246inet_bind2_bucket_find(const struct inet_bind_hashbucket *head,
247 const struct net *net,
248 unsigned short port, int l3mdev,
249 const struct sock *sk);
250
251bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb,
252 const struct net *net, unsigned short port,
253 int l3mdev, const struct sock *sk);
254
255static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
256 const u32 bhash_size)
257{
258 return (lport + net_hash_mix(net)) & (bhash_size - 1);
259}
260
261static inline struct inet_bind_hashbucket *
262inet_bhashfn_portaddr(const struct inet_hashinfo *hinfo, const struct sock *sk,
263 const struct net *net, unsigned short port)
264{
265 u32 hash;
266
267#if IS_ENABLED(CONFIG_IPV6)
268 if (sk->sk_family == AF_INET6)
269 hash = ipv6_portaddr_hash(net, &sk->sk_v6_rcv_saddr, port);
270 else
271#endif
272 hash = ipv4_portaddr_hash(net, sk->sk_rcv_saddr, port);
273 return &hinfo->bhash2[hash & (hinfo->bhash_size - 1)];
274}
275
276struct inet_bind_hashbucket *
277inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, int port);
278
279/* This should be called whenever a socket's sk_rcv_saddr (ipv4) or
280 * sk_v6_rcv_saddr (ipv6) changes after it has been binded. The socket's
281 * rcv_saddr field should already have been updated when this is called.
282 */
283int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family);
284void inet_bhash2_reset_saddr(struct sock *sk);
285
286void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
287 struct inet_bind2_bucket *tb2, unsigned short port);
288
289/* Caller must disable local BH processing. */
290int __inet_inherit_port(const struct sock *sk, struct sock *child);
291
292void inet_put_port(struct sock *sk);
293
294void inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
295 unsigned long numentries, int scale,
296 unsigned long low_limit,
297 unsigned long high_limit);
298int inet_hashinfo2_init_mod(struct inet_hashinfo *h);
299
300bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk);
301bool inet_ehash_nolisten(struct sock *sk, struct sock *osk,
302 bool *found_dup_sk);
303int __inet_hash(struct sock *sk, struct sock *osk);
304int inet_hash(struct sock *sk);
305void inet_unhash(struct sock *sk);
306
307struct sock *__inet_lookup_listener(const struct net *net,
308 struct inet_hashinfo *hashinfo,
309 struct sk_buff *skb, int doff,
310 const __be32 saddr, const __be16 sport,
311 const __be32 daddr,
312 const unsigned short hnum,
313 const int dif, const int sdif);
314
315static inline struct sock *inet_lookup_listener(struct net *net,
316 struct inet_hashinfo *hashinfo,
317 struct sk_buff *skb, int doff,
318 __be32 saddr, __be16 sport,
319 __be32 daddr, __be16 dport, int dif, int sdif)
320{
321 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr, sport,
322 daddr, ntohs(dport), dif, sdif);
323}
324
325/* Socket demux engine toys. */
326/* What happens here is ugly; there's a pair of adjacent fields in
327 struct inet_sock; __be16 dport followed by __u16 num. We want to
328 search by pair, so we combine the keys into a single 32bit value
329 and compare with 32bit value read from &...->dport. Let's at least
330 make sure that it's not mixed with anything else...
331 On 64bit targets we combine comparisons with pair of adjacent __be32
332 fields in the same way.
333*/
334#ifdef __BIG_ENDIAN
335#define INET_COMBINED_PORTS(__sport, __dport) \
336 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
337#else /* __LITTLE_ENDIAN */
338#define INET_COMBINED_PORTS(__sport, __dport) \
339 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
340#endif
341
342#ifdef __BIG_ENDIAN
343#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
344 const __addrpair __name = (__force __addrpair) ( \
345 (((__force __u64)(__be32)(__saddr)) << 32) | \
346 ((__force __u64)(__be32)(__daddr)))
347#else /* __LITTLE_ENDIAN */
348#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
349 const __addrpair __name = (__force __addrpair) ( \
350 (((__force __u64)(__be32)(__daddr)) << 32) | \
351 ((__force __u64)(__be32)(__saddr)))
352#endif /* __BIG_ENDIAN */
353
354static inline bool inet_match(const struct net *net, const struct sock *sk,
355 const __addrpair cookie, const __portpair ports,
356 int dif, int sdif)
357{
358 if (!net_eq(sock_net(sk), net) ||
359 sk->sk_portpair != ports ||
360 sk->sk_addrpair != cookie)
361 return false;
362
363 /* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */
364 return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,
365 sdif);
366}
367
368/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
369 * not check it for lookups anymore, thanks Alexey. -DaveM
370 */
371struct sock *__inet_lookup_established(const struct net *net,
372 struct inet_hashinfo *hashinfo,
373 const __be32 saddr, const __be16 sport,
374 const __be32 daddr, const u16 hnum,
375 const int dif, const int sdif);
376
377typedef u32 (inet_ehashfn_t)(const struct net *net,
378 const __be32 laddr, const __u16 lport,
379 const __be32 faddr, const __be16 fport);
380
381inet_ehashfn_t inet_ehashfn;
382
383INDIRECT_CALLABLE_DECLARE(inet_ehashfn_t udp_ehashfn);
384
385struct sock *inet_lookup_reuseport(const struct net *net, struct sock *sk,
386 struct sk_buff *skb, int doff,
387 __be32 saddr, __be16 sport,
388 __be32 daddr, unsigned short hnum,
389 inet_ehashfn_t *ehashfn);
390
391struct sock *inet_lookup_run_sk_lookup(const struct net *net,
392 int protocol,
393 struct sk_buff *skb, int doff,
394 __be32 saddr, __be16 sport,
395 __be32 daddr, u16 hnum, const int dif,
396 inet_ehashfn_t *ehashfn);
397
398static inline struct sock *
399 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
400 const __be32 saddr, const __be16 sport,
401 const __be32 daddr, const __be16 dport,
402 const int dif)
403{
404 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
405 ntohs(dport), dif, 0);
406}
407
408static inline struct sock *__inet_lookup(struct net *net,
409 struct inet_hashinfo *hashinfo,
410 struct sk_buff *skb, int doff,
411 const __be32 saddr, const __be16 sport,
412 const __be32 daddr, const __be16 dport,
413 const int dif, const int sdif,
414 bool *refcounted)
415{
416 u16 hnum = ntohs(dport);
417 struct sock *sk;
418
419 sk = __inet_lookup_established(net, hashinfo, saddr, sport,
420 daddr, hnum, dif, sdif);
421 *refcounted = true;
422 if (sk)
423 return sk;
424 *refcounted = false;
425 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr,
426 sport, daddr, hnum, dif, sdif);
427}
428
429static inline struct sock *inet_lookup(struct net *net,
430 struct inet_hashinfo *hashinfo,
431 struct sk_buff *skb, int doff,
432 const __be32 saddr, const __be16 sport,
433 const __be32 daddr, const __be16 dport,
434 const int dif)
435{
436 struct sock *sk;
437 bool refcounted;
438
439 sk = __inet_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
440 dport, dif, 0, &refcounted);
441
442 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
443 sk = NULL;
444 return sk;
445}
446
447static inline
448struct sock *inet_steal_sock(struct net *net, struct sk_buff *skb, int doff,
449 const __be32 saddr, const __be16 sport,
450 const __be32 daddr, const __be16 dport,
451 bool *refcounted, inet_ehashfn_t *ehashfn)
452{
453 struct sock *sk, *reuse_sk;
454 bool prefetched;
455
456 sk = skb_steal_sock(skb, refcounted, &prefetched);
457 if (!sk)
458 return NULL;
459
460 if (!prefetched || !sk_fullsock(sk))
461 return sk;
462
463 if (sk->sk_protocol == IPPROTO_TCP) {
464 if (sk->sk_state != TCP_LISTEN)
465 return sk;
466 } else if (sk->sk_protocol == IPPROTO_UDP) {
467 if (sk->sk_state != TCP_CLOSE)
468 return sk;
469 } else {
470 return sk;
471 }
472
473 reuse_sk = inet_lookup_reuseport(net, sk, skb, doff,
474 saddr, sport, daddr, ntohs(dport),
475 ehashfn);
476 if (!reuse_sk)
477 return sk;
478
479 /* We've chosen a new reuseport sock which is never refcounted. This
480 * implies that sk also isn't refcounted.
481 */
482 WARN_ON_ONCE(*refcounted);
483
484 return reuse_sk;
485}
486
487static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
488 struct sk_buff *skb,
489 int doff,
490 const __be16 sport,
491 const __be16 dport,
492 const int sdif,
493 bool *refcounted)
494{
495 struct net *net = dev_net(skb_dst(skb)->dev);
496 const struct iphdr *iph = ip_hdr(skb);
497 struct sock *sk;
498
499 sk = inet_steal_sock(net, skb, doff, iph->saddr, sport, iph->daddr, dport,
500 refcounted, inet_ehashfn);
501 if (IS_ERR(sk))
502 return NULL;
503 if (sk)
504 return sk;
505
506 return __inet_lookup(net, hashinfo, skb,
507 doff, iph->saddr, sport,
508 iph->daddr, dport, inet_iif(skb), sdif,
509 refcounted);
510}
511
512static inline void sk_daddr_set(struct sock *sk, __be32 addr)
513{
514 sk->sk_daddr = addr; /* alias of inet_daddr */
515#if IS_ENABLED(CONFIG_IPV6)
516 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_daddr);
517#endif
518}
519
520static inline void sk_rcv_saddr_set(struct sock *sk, __be32 addr)
521{
522 sk->sk_rcv_saddr = addr; /* alias of inet_rcv_saddr */
523#if IS_ENABLED(CONFIG_IPV6)
524 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_rcv_saddr);
525#endif
526}
527
528int __inet_hash_connect(struct inet_timewait_death_row *death_row,
529 struct sock *sk, u64 port_offset,
530 int (*check_established)(struct inet_timewait_death_row *,
531 struct sock *, __u16,
532 struct inet_timewait_sock **));
533
534int inet_hash_connect(struct inet_timewait_death_row *death_row,
535 struct sock *sk);
536#endif /* _INET_HASHTABLES_H */
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
17
18#include <linux/interrupt.h>
19#include <linux/ip.h>
20#include <linux/ipv6.h>
21#include <linux/list.h>
22#include <linux/slab.h>
23#include <linux/socket.h>
24#include <linux/spinlock.h>
25#include <linux/types.h>
26#include <linux/wait.h>
27
28#include <net/inet_connection_sock.h>
29#include <net/inet_sock.h>
30#include <net/sock.h>
31#include <net/route.h>
32#include <net/tcp_states.h>
33#include <net/netns/hash.h>
34
35#include <linux/atomic.h>
36#include <asm/byteorder.h>
37
38/* This is for all connections with a full identity, no wildcards.
39 * The 'e' prefix stands for Establish, but we really put all sockets
40 * but LISTEN ones.
41 */
42struct inet_ehash_bucket {
43 struct hlist_nulls_head chain;
44};
45
46/* There are a few simple rules, which allow for local port reuse by
47 * an application. In essence:
48 *
49 * 1) Sockets bound to different interfaces may share a local port.
50 * Failing that, goto test 2.
51 * 2) If all sockets have sk->sk_reuse set, and none of them are in
52 * TCP_LISTEN state, the port may be shared.
53 * Failing that, goto test 3.
54 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
55 * address, and none of them are the same, the port may be
56 * shared.
57 * Failing this, the port cannot be shared.
58 *
59 * The interesting point, is test #2. This is what an FTP server does
60 * all day. To optimize this case we use a specific flag bit defined
61 * below. As we add sockets to a bind bucket list, we perform a
62 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
63 * As long as all sockets added to a bind bucket pass this test,
64 * the flag bit will be set.
65 * The resulting situation is that tcp_v[46]_verify_bind() can just check
66 * for this flag bit, if it is set and the socket trying to bind has
67 * sk->sk_reuse set, we don't even have to walk the owners list at all,
68 * we return that it is ok to bind this socket to the requested local port.
69 *
70 * Sounds like a lot of work, but it is worth it. In a more naive
71 * implementation (ie. current FreeBSD etc.) the entire list of ports
72 * must be walked for each data port opened by an ftp server. Needless
73 * to say, this does not scale at all. With a couple thousand FTP
74 * users logged onto your box, isn't it nice to know that new data
75 * ports are created in O(1) time? I thought so. ;-) -DaveM
76 */
77struct inet_bind_bucket {
78 possible_net_t ib_net;
79 unsigned short port;
80 signed char fastreuse;
81 signed char fastreuseport;
82 kuid_t fastuid;
83 int num_owners;
84 struct hlist_node node;
85 struct hlist_head owners;
86};
87
88static inline struct net *ib_net(struct inet_bind_bucket *ib)
89{
90 return read_pnet(&ib->ib_net);
91}
92
93#define inet_bind_bucket_for_each(tb, head) \
94 hlist_for_each_entry(tb, head, node)
95
96struct inet_bind_hashbucket {
97 spinlock_t lock;
98 struct hlist_head chain;
99};
100
101/*
102 * Sockets can be hashed in established or listening table
103 */
104struct inet_listen_hashbucket {
105 spinlock_t lock;
106 struct hlist_head head;
107};
108
109/* This is for listening sockets, thus all sockets which possess wildcards. */
110#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
111
112struct inet_hashinfo {
113 /* This is for sockets with full identity only. Sockets here will
114 * always be without wildcards and will have the following invariant:
115 *
116 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
117 *
118 */
119 struct inet_ehash_bucket *ehash;
120 spinlock_t *ehash_locks;
121 unsigned int ehash_mask;
122 unsigned int ehash_locks_mask;
123
124 /* Ok, let's try this, I give up, we do need a local binding
125 * TCP hash as well as the others for fast bind/connect.
126 */
127 struct inet_bind_hashbucket *bhash;
128
129 unsigned int bhash_size;
130 /* 4 bytes hole on 64 bit */
131
132 struct kmem_cache *bind_bucket_cachep;
133
134 /* All the above members are written once at bootup and
135 * never written again _or_ are predominantly read-access.
136 *
137 * Now align to a new cache line as all the following members
138 * might be often dirty.
139 */
140 /* All sockets in TCP_LISTEN state will be in here. This is the only
141 * table where wildcard'd TCP sockets can exist. Hash function here
142 * is just local port number.
143 */
144 struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE]
145 ____cacheline_aligned_in_smp;
146};
147
148static inline struct inet_ehash_bucket *inet_ehash_bucket(
149 struct inet_hashinfo *hashinfo,
150 unsigned int hash)
151{
152 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
153}
154
155static inline spinlock_t *inet_ehash_lockp(
156 struct inet_hashinfo *hashinfo,
157 unsigned int hash)
158{
159 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
160}
161
162int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo);
163
164static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
165{
166 kvfree(hashinfo->ehash_locks);
167 hashinfo->ehash_locks = NULL;
168}
169
170struct inet_bind_bucket *
171inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
172 struct inet_bind_hashbucket *head,
173 const unsigned short snum);
174void inet_bind_bucket_destroy(struct kmem_cache *cachep,
175 struct inet_bind_bucket *tb);
176
177static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
178 const u32 bhash_size)
179{
180 return (lport + net_hash_mix(net)) & (bhash_size - 1);
181}
182
183void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
184 const unsigned short snum);
185
186/* These can have wildcards, don't try too hard. */
187static inline u32 inet_lhashfn(const struct net *net, const unsigned short num)
188{
189 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
190}
191
192static inline int inet_sk_listen_hashfn(const struct sock *sk)
193{
194 return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num);
195}
196
197/* Caller must disable local BH processing. */
198int __inet_inherit_port(const struct sock *sk, struct sock *child);
199
200void inet_put_port(struct sock *sk);
201
202void inet_hashinfo_init(struct inet_hashinfo *h);
203
204bool inet_ehash_insert(struct sock *sk, struct sock *osk);
205bool inet_ehash_nolisten(struct sock *sk, struct sock *osk);
206int __inet_hash(struct sock *sk, struct sock *osk,
207 int (*saddr_same)(const struct sock *sk1,
208 const struct sock *sk2,
209 bool match_wildcard));
210int inet_hash(struct sock *sk);
211void inet_unhash(struct sock *sk);
212
213struct sock *__inet_lookup_listener(struct net *net,
214 struct inet_hashinfo *hashinfo,
215 struct sk_buff *skb, int doff,
216 const __be32 saddr, const __be16 sport,
217 const __be32 daddr,
218 const unsigned short hnum,
219 const int dif);
220
221static inline struct sock *inet_lookup_listener(struct net *net,
222 struct inet_hashinfo *hashinfo,
223 struct sk_buff *skb, int doff,
224 __be32 saddr, __be16 sport,
225 __be32 daddr, __be16 dport, int dif)
226{
227 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr, sport,
228 daddr, ntohs(dport), dif);
229}
230
231/* Socket demux engine toys. */
232/* What happens here is ugly; there's a pair of adjacent fields in
233 struct inet_sock; __be16 dport followed by __u16 num. We want to
234 search by pair, so we combine the keys into a single 32bit value
235 and compare with 32bit value read from &...->dport. Let's at least
236 make sure that it's not mixed with anything else...
237 On 64bit targets we combine comparisons with pair of adjacent __be32
238 fields in the same way.
239*/
240#ifdef __BIG_ENDIAN
241#define INET_COMBINED_PORTS(__sport, __dport) \
242 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
243#else /* __LITTLE_ENDIAN */
244#define INET_COMBINED_PORTS(__sport, __dport) \
245 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
246#endif
247
248#if (BITS_PER_LONG == 64)
249#ifdef __BIG_ENDIAN
250#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
251 const __addrpair __name = (__force __addrpair) ( \
252 (((__force __u64)(__be32)(__saddr)) << 32) | \
253 ((__force __u64)(__be32)(__daddr)))
254#else /* __LITTLE_ENDIAN */
255#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
256 const __addrpair __name = (__force __addrpair) ( \
257 (((__force __u64)(__be32)(__daddr)) << 32) | \
258 ((__force __u64)(__be32)(__saddr)))
259#endif /* __BIG_ENDIAN */
260#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
261 (((__sk)->sk_portpair == (__ports)) && \
262 ((__sk)->sk_addrpair == (__cookie)) && \
263 (!(__sk)->sk_bound_dev_if || \
264 ((__sk)->sk_bound_dev_if == (__dif))) && \
265 net_eq(sock_net(__sk), (__net)))
266#else /* 32-bit arch */
267#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
268 const int __name __deprecated __attribute__((unused))
269
270#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif) \
271 (((__sk)->sk_portpair == (__ports)) && \
272 ((__sk)->sk_daddr == (__saddr)) && \
273 ((__sk)->sk_rcv_saddr == (__daddr)) && \
274 (!(__sk)->sk_bound_dev_if || \
275 ((__sk)->sk_bound_dev_if == (__dif))) && \
276 net_eq(sock_net(__sk), (__net)))
277#endif /* 64-bit arch */
278
279/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
280 * not check it for lookups anymore, thanks Alexey. -DaveM
281 */
282struct sock *__inet_lookup_established(struct net *net,
283 struct inet_hashinfo *hashinfo,
284 const __be32 saddr, const __be16 sport,
285 const __be32 daddr, const u16 hnum,
286 const int dif);
287
288static inline struct sock *
289 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
290 const __be32 saddr, const __be16 sport,
291 const __be32 daddr, const __be16 dport,
292 const int dif)
293{
294 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
295 ntohs(dport), dif);
296}
297
298static inline struct sock *__inet_lookup(struct net *net,
299 struct inet_hashinfo *hashinfo,
300 struct sk_buff *skb, int doff,
301 const __be32 saddr, const __be16 sport,
302 const __be32 daddr, const __be16 dport,
303 const int dif,
304 bool *refcounted)
305{
306 u16 hnum = ntohs(dport);
307 struct sock *sk;
308
309 sk = __inet_lookup_established(net, hashinfo, saddr, sport,
310 daddr, hnum, dif);
311 *refcounted = true;
312 if (sk)
313 return sk;
314 *refcounted = false;
315 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr,
316 sport, daddr, hnum, dif);
317}
318
319static inline struct sock *inet_lookup(struct net *net,
320 struct inet_hashinfo *hashinfo,
321 struct sk_buff *skb, int doff,
322 const __be32 saddr, const __be16 sport,
323 const __be32 daddr, const __be16 dport,
324 const int dif)
325{
326 struct sock *sk;
327 bool refcounted;
328
329 sk = __inet_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
330 dport, dif, &refcounted);
331
332 if (sk && !refcounted && !atomic_inc_not_zero(&sk->sk_refcnt))
333 sk = NULL;
334 return sk;
335}
336
337static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
338 struct sk_buff *skb,
339 int doff,
340 const __be16 sport,
341 const __be16 dport,
342 bool *refcounted)
343{
344 struct sock *sk = skb_steal_sock(skb);
345 const struct iphdr *iph = ip_hdr(skb);
346
347 *refcounted = true;
348 if (sk)
349 return sk;
350
351 return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo, skb,
352 doff, iph->saddr, sport,
353 iph->daddr, dport, inet_iif(skb),
354 refcounted);
355}
356
357u32 sk_ehashfn(const struct sock *sk);
358u32 inet6_ehashfn(const struct net *net,
359 const struct in6_addr *laddr, const u16 lport,
360 const struct in6_addr *faddr, const __be16 fport);
361
362static inline void sk_daddr_set(struct sock *sk, __be32 addr)
363{
364 sk->sk_daddr = addr; /* alias of inet_daddr */
365#if IS_ENABLED(CONFIG_IPV6)
366 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_daddr);
367#endif
368}
369
370static inline void sk_rcv_saddr_set(struct sock *sk, __be32 addr)
371{
372 sk->sk_rcv_saddr = addr; /* alias of inet_rcv_saddr */
373#if IS_ENABLED(CONFIG_IPV6)
374 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_rcv_saddr);
375#endif
376}
377
378int __inet_hash_connect(struct inet_timewait_death_row *death_row,
379 struct sock *sk, u32 port_offset,
380 int (*check_established)(struct inet_timewait_death_row *,
381 struct sock *, __u16,
382 struct inet_timewait_sock **));
383
384int inet_hash_connect(struct inet_timewait_death_row *death_row,
385 struct sock *sk);
386#endif /* _INET_HASHTABLES_H */