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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/* 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/sock.h>
27#include <net/route.h>
28#include <net/tcp_states.h>
29#include <net/netns/hash.h>
30
31#include <linux/refcount.h>
32#include <asm/byteorder.h>
33
34/* This is for all connections with a full identity, no wildcards.
35 * The 'e' prefix stands for Establish, but we really put all sockets
36 * but LISTEN ones.
37 */
38struct inet_ehash_bucket {
39 struct hlist_nulls_head chain;
40};
41
42/* There are a few simple rules, which allow for local port reuse by
43 * an application. In essence:
44 *
45 * 1) Sockets bound to different interfaces may share a local port.
46 * Failing that, goto test 2.
47 * 2) If all sockets have sk->sk_reuse set, and none of them are in
48 * TCP_LISTEN state, the port may be shared.
49 * Failing that, goto test 3.
50 * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
51 * address, and none of them are the same, the port may be
52 * shared.
53 * Failing this, the port cannot be shared.
54 *
55 * The interesting point, is test #2. This is what an FTP server does
56 * all day. To optimize this case we use a specific flag bit defined
57 * below. As we add sockets to a bind bucket list, we perform a
58 * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
59 * As long as all sockets added to a bind bucket pass this test,
60 * the flag bit will be set.
61 * The resulting situation is that tcp_v[46]_verify_bind() can just check
62 * for this flag bit, if it is set and the socket trying to bind has
63 * sk->sk_reuse set, we don't even have to walk the owners list at all,
64 * we return that it is ok to bind this socket to the requested local port.
65 *
66 * Sounds like a lot of work, but it is worth it. In a more naive
67 * implementation (ie. current FreeBSD etc.) the entire list of ports
68 * must be walked for each data port opened by an ftp server. Needless
69 * to say, this does not scale at all. With a couple thousand FTP
70 * users logged onto your box, isn't it nice to know that new data
71 * ports are created in O(1) time? I thought so. ;-) -DaveM
72 */
73#define FASTREUSEPORT_ANY 1
74#define FASTREUSEPORT_STRICT 2
75
76struct inet_bind_bucket {
77 possible_net_t ib_net;
78 int l3mdev;
79 unsigned short port;
80 signed char fastreuse;
81 signed char fastreuseport;
82 kuid_t fastuid;
83#if IS_ENABLED(CONFIG_IPV6)
84 struct in6_addr fast_v6_rcv_saddr;
85#endif
86 __be32 fast_rcv_saddr;
87 unsigned short fast_sk_family;
88 bool fast_ipv6_only;
89 struct hlist_node node;
90 struct hlist_head owners;
91};
92
93static inline struct net *ib_net(struct inet_bind_bucket *ib)
94{
95 return read_pnet(&ib->ib_net);
96}
97
98#define inet_bind_bucket_for_each(tb, head) \
99 hlist_for_each_entry(tb, head, node)
100
101struct inet_bind_hashbucket {
102 spinlock_t lock;
103 struct hlist_head chain;
104};
105
106/* Sockets can be hashed in established or listening table.
107 * We must use different 'nulls' end-of-chain value for all hash buckets :
108 * A socket might transition from ESTABLISH to LISTEN state without
109 * RCU grace period. A lookup in ehash table needs to handle this case.
110 */
111#define LISTENING_NULLS_BASE (1U << 29)
112struct inet_listen_hashbucket {
113 spinlock_t lock;
114 unsigned int count;
115 union {
116 struct hlist_head head;
117 struct hlist_nulls_head nulls_head;
118 };
119};
120
121/* This is for listening sockets, thus all sockets which possess wildcards. */
122#define INET_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */
123
124struct inet_hashinfo {
125 /* This is for sockets with full identity only. Sockets here will
126 * always be without wildcards and will have the following invariant:
127 *
128 * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
129 *
130 */
131 struct inet_ehash_bucket *ehash;
132 spinlock_t *ehash_locks;
133 unsigned int ehash_mask;
134 unsigned int ehash_locks_mask;
135
136 /* Ok, let's try this, I give up, we do need a local binding
137 * TCP hash as well as the others for fast bind/connect.
138 */
139 struct kmem_cache *bind_bucket_cachep;
140 struct inet_bind_hashbucket *bhash;
141 unsigned int bhash_size;
142
143 /* The 2nd listener table hashed by local port and address */
144 unsigned int lhash2_mask;
145 struct inet_listen_hashbucket *lhash2;
146
147 /* All the above members are written once at bootup and
148 * never written again _or_ are predominantly read-access.
149 *
150 * Now align to a new cache line as all the following members
151 * might be often dirty.
152 */
153 /* All sockets in TCP_LISTEN state will be in listening_hash.
154 * This is the only table where wildcard'd TCP sockets can
155 * exist. listening_hash is only hashed by local port number.
156 * If lhash2 is initialized, the same socket will also be hashed
157 * to lhash2 by port and address.
158 */
159 struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE]
160 ____cacheline_aligned_in_smp;
161};
162
163#define inet_lhash2_for_each_icsk_rcu(__icsk, list) \
164 hlist_for_each_entry_rcu(__icsk, list, icsk_listen_portaddr_node)
165
166static inline struct inet_listen_hashbucket *
167inet_lhash2_bucket(struct inet_hashinfo *h, u32 hash)
168{
169 return &h->lhash2[hash & h->lhash2_mask];
170}
171
172static inline struct inet_ehash_bucket *inet_ehash_bucket(
173 struct inet_hashinfo *hashinfo,
174 unsigned int hash)
175{
176 return &hashinfo->ehash[hash & hashinfo->ehash_mask];
177}
178
179static inline spinlock_t *inet_ehash_lockp(
180 struct inet_hashinfo *hashinfo,
181 unsigned int hash)
182{
183 return &hashinfo->ehash_locks[hash & hashinfo->ehash_locks_mask];
184}
185
186int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo);
187
188static inline void inet_hashinfo2_free_mod(struct inet_hashinfo *h)
189{
190 kfree(h->lhash2);
191 h->lhash2 = NULL;
192}
193
194static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
195{
196 kvfree(hashinfo->ehash_locks);
197 hashinfo->ehash_locks = NULL;
198}
199
200static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
201 int dif, int sdif)
202{
203#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
204 return inet_bound_dev_eq(!!net->ipv4.sysctl_tcp_l3mdev_accept,
205 bound_dev_if, dif, sdif);
206#else
207 return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
208#endif
209}
210
211struct inet_bind_bucket *
212inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,
213 struct inet_bind_hashbucket *head,
214 const unsigned short snum, int l3mdev);
215void inet_bind_bucket_destroy(struct kmem_cache *cachep,
216 struct inet_bind_bucket *tb);
217
218static inline u32 inet_bhashfn(const struct net *net, const __u16 lport,
219 const u32 bhash_size)
220{
221 return (lport + net_hash_mix(net)) & (bhash_size - 1);
222}
223
224void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
225 const unsigned short snum);
226
227/* These can have wildcards, don't try too hard. */
228static inline u32 inet_lhashfn(const struct net *net, const unsigned short num)
229{
230 return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1);
231}
232
233static inline int inet_sk_listen_hashfn(const struct sock *sk)
234{
235 return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num);
236}
237
238/* Caller must disable local BH processing. */
239int __inet_inherit_port(const struct sock *sk, struct sock *child);
240
241void inet_put_port(struct sock *sk);
242
243void inet_hashinfo_init(struct inet_hashinfo *h);
244void inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
245 unsigned long numentries, int scale,
246 unsigned long low_limit,
247 unsigned long high_limit);
248int inet_hashinfo2_init_mod(struct inet_hashinfo *h);
249
250bool inet_ehash_insert(struct sock *sk, struct sock *osk);
251bool inet_ehash_nolisten(struct sock *sk, struct sock *osk);
252int __inet_hash(struct sock *sk, struct sock *osk);
253int inet_hash(struct sock *sk);
254void inet_unhash(struct sock *sk);
255
256struct sock *__inet_lookup_listener(struct net *net,
257 struct inet_hashinfo *hashinfo,
258 struct sk_buff *skb, int doff,
259 const __be32 saddr, const __be16 sport,
260 const __be32 daddr,
261 const unsigned short hnum,
262 const int dif, const int sdif);
263
264static inline struct sock *inet_lookup_listener(struct net *net,
265 struct inet_hashinfo *hashinfo,
266 struct sk_buff *skb, int doff,
267 __be32 saddr, __be16 sport,
268 __be32 daddr, __be16 dport, int dif, int sdif)
269{
270 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr, sport,
271 daddr, ntohs(dport), dif, sdif);
272}
273
274/* Socket demux engine toys. */
275/* What happens here is ugly; there's a pair of adjacent fields in
276 struct inet_sock; __be16 dport followed by __u16 num. We want to
277 search by pair, so we combine the keys into a single 32bit value
278 and compare with 32bit value read from &...->dport. Let's at least
279 make sure that it's not mixed with anything else...
280 On 64bit targets we combine comparisons with pair of adjacent __be32
281 fields in the same way.
282*/
283#ifdef __BIG_ENDIAN
284#define INET_COMBINED_PORTS(__sport, __dport) \
285 ((__force __portpair)(((__force __u32)(__be16)(__sport) << 16) | (__u32)(__dport)))
286#else /* __LITTLE_ENDIAN */
287#define INET_COMBINED_PORTS(__sport, __dport) \
288 ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport)))
289#endif
290
291#if (BITS_PER_LONG == 64)
292#ifdef __BIG_ENDIAN
293#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
294 const __addrpair __name = (__force __addrpair) ( \
295 (((__force __u64)(__be32)(__saddr)) << 32) | \
296 ((__force __u64)(__be32)(__daddr)))
297#else /* __LITTLE_ENDIAN */
298#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
299 const __addrpair __name = (__force __addrpair) ( \
300 (((__force __u64)(__be32)(__daddr)) << 32) | \
301 ((__force __u64)(__be32)(__saddr)))
302#endif /* __BIG_ENDIAN */
303#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \
304 (((__sk)->sk_portpair == (__ports)) && \
305 ((__sk)->sk_addrpair == (__cookie)) && \
306 (((__sk)->sk_bound_dev_if == (__dif)) || \
307 ((__sk)->sk_bound_dev_if == (__sdif))) && \
308 net_eq(sock_net(__sk), (__net)))
309#else /* 32-bit arch */
310#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
311 const int __name __deprecated __attribute__((unused))
312
313#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \
314 (((__sk)->sk_portpair == (__ports)) && \
315 ((__sk)->sk_daddr == (__saddr)) && \
316 ((__sk)->sk_rcv_saddr == (__daddr)) && \
317 (((__sk)->sk_bound_dev_if == (__dif)) || \
318 ((__sk)->sk_bound_dev_if == (__sdif))) && \
319 net_eq(sock_net(__sk), (__net)))
320#endif /* 64-bit arch */
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 */
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, const int sdif);
330
331static inline struct sock *
332 inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
333 const __be32 saddr, const __be16 sport,
334 const __be32 daddr, const __be16 dport,
335 const int dif)
336{
337 return __inet_lookup_established(net, hashinfo, saddr, sport, daddr,
338 ntohs(dport), dif, 0);
339}
340
341static inline struct sock *__inet_lookup(struct net *net,
342 struct inet_hashinfo *hashinfo,
343 struct sk_buff *skb, int doff,
344 const __be32 saddr, const __be16 sport,
345 const __be32 daddr, const __be16 dport,
346 const int dif, const int sdif,
347 bool *refcounted)
348{
349 u16 hnum = ntohs(dport);
350 struct sock *sk;
351
352 sk = __inet_lookup_established(net, hashinfo, saddr, sport,
353 daddr, hnum, dif, sdif);
354 *refcounted = true;
355 if (sk)
356 return sk;
357 *refcounted = false;
358 return __inet_lookup_listener(net, hashinfo, skb, doff, saddr,
359 sport, daddr, hnum, dif, sdif);
360}
361
362static inline struct sock *inet_lookup(struct net *net,
363 struct inet_hashinfo *hashinfo,
364 struct sk_buff *skb, int doff,
365 const __be32 saddr, const __be16 sport,
366 const __be32 daddr, const __be16 dport,
367 const int dif)
368{
369 struct sock *sk;
370 bool refcounted;
371
372 sk = __inet_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
373 dport, dif, 0, &refcounted);
374
375 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
376 sk = NULL;
377 return sk;
378}
379
380static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
381 struct sk_buff *skb,
382 int doff,
383 const __be16 sport,
384 const __be16 dport,
385 const int sdif,
386 bool *refcounted)
387{
388 struct sock *sk = skb_steal_sock(skb, refcounted);
389 const struct iphdr *iph = ip_hdr(skb);
390
391 if (sk)
392 return sk;
393
394 return __inet_lookup(dev_net(skb_dst(skb)->dev), hashinfo, skb,
395 doff, iph->saddr, sport,
396 iph->daddr, dport, inet_iif(skb), sdif,
397 refcounted);
398}
399
400u32 inet6_ehashfn(const struct net *net,
401 const struct in6_addr *laddr, const u16 lport,
402 const struct in6_addr *faddr, const __be16 fport);
403
404static inline void sk_daddr_set(struct sock *sk, __be32 addr)
405{
406 sk->sk_daddr = addr; /* alias of inet_daddr */
407#if IS_ENABLED(CONFIG_IPV6)
408 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_daddr);
409#endif
410}
411
412static inline void sk_rcv_saddr_set(struct sock *sk, __be32 addr)
413{
414 sk->sk_rcv_saddr = addr; /* alias of inet_rcv_saddr */
415#if IS_ENABLED(CONFIG_IPV6)
416 ipv6_addr_set_v4mapped(addr, &sk->sk_v6_rcv_saddr);
417#endif
418}
419
420int __inet_hash_connect(struct inet_timewait_death_row *death_row,
421 struct sock *sk, u32 port_offset,
422 int (*check_established)(struct inet_timewait_death_row *,
423 struct sock *, __u16,
424 struct inet_timewait_sock **));
425
426int inet_hash_connect(struct inet_timewait_death_row *death_row,
427 struct sock *sk);
428#endif /* _INET_HASHTABLES_H */