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.
6 * Generic INET6 transport hashtables
8 * Authors: Lotsa people, from code originally in tcp, generalised here
9 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 #include <linux/module.h>
18 #include <linux/random.h>
20 #include <net/inet_connection_sock.h>
21 #include <net/inet_hashtables.h>
22 #include <net/inet6_hashtables.h>
25 void __inet6_hash(struct inet_hashinfo *hashinfo,
28 struct hlist_head *list;
31 BUG_TRAP(sk_unhashed(sk));
33 if (sk->sk_state == TCP_LISTEN) {
34 list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
35 lock = &hashinfo->lhash_lock;
36 inet_listen_wlock(hashinfo);
39 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
40 list = &inet_ehash_bucket(hashinfo, hash)->chain;
41 lock = inet_ehash_lockp(hashinfo, hash);
45 __sk_add_node(sk, list);
46 sock_prot_inuse_add(sk->sk_prot, 1);
49 EXPORT_SYMBOL(__inet6_hash);
52 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
53 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
55 * The sockhash lock must be held as a reader here.
57 struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
58 const struct in6_addr *saddr,
60 const struct in6_addr *daddr,
65 const struct hlist_node *node;
66 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
67 /* Optimize here for direct hit, only listening connections can
68 * have wildcards anyways.
70 unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
71 struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
72 rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
74 prefetch(head->chain.first);
76 sk_for_each(sk, node, &head->chain) {
77 /* For IPV6 do the cheaper port and family tests first. */
78 if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
79 goto hit; /* You sunk my battleship! */
81 /* Must check for a TIME_WAIT'er before going to listener hash. */
82 sk_for_each(sk, node, &head->twchain) {
83 if (INET6_TW_MATCH(sk, hash, saddr, daddr, ports, dif))
94 EXPORT_SYMBOL(__inet6_lookup_established);
96 struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
97 const struct in6_addr *daddr,
98 const unsigned short hnum, const int dif)
101 const struct hlist_node *node;
102 struct sock *result = NULL;
103 int score, hiscore = 0;
105 read_lock(&hashinfo->lhash_lock);
106 sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
107 if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
108 const struct ipv6_pinfo *np = inet6_sk(sk);
111 if (!ipv6_addr_any(&np->rcv_saddr)) {
112 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
116 if (sk->sk_bound_dev_if) {
117 if (sk->sk_bound_dev_if != dif)
125 if (score > hiscore) {
133 read_unlock(&hashinfo->lhash_lock);
137 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
139 struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
140 const struct in6_addr *saddr, const __be16 sport,
141 const struct in6_addr *daddr, const __be16 dport,
147 sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
153 EXPORT_SYMBOL_GPL(inet6_lookup);
155 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
156 struct sock *sk, const __u16 lport,
157 struct inet_timewait_sock **twp)
159 struct inet_hashinfo *hinfo = death_row->hashinfo;
160 struct inet_sock *inet = inet_sk(sk);
161 const struct ipv6_pinfo *np = inet6_sk(sk);
162 const struct in6_addr *daddr = &np->rcv_saddr;
163 const struct in6_addr *saddr = &np->daddr;
164 const int dif = sk->sk_bound_dev_if;
165 const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
166 const unsigned int hash = inet6_ehashfn(daddr, lport, saddr,
168 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
169 rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
171 const struct hlist_node *node;
172 struct inet_timewait_sock *tw;
174 prefetch(head->chain.first);
177 /* Check TIME-WAIT sockets first. */
178 sk_for_each(sk2, node, &head->twchain) {
181 if (INET6_TW_MATCH(sk2, hash, saddr, daddr, ports, dif)) {
182 if (twsk_unique(sk, sk2, twp))
190 /* And established part... */
191 sk_for_each(sk2, node, &head->chain) {
192 if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif))
197 /* Must record num and sport now. Otherwise we will see
198 * in hash table socket with a funny identity. */
200 inet->sport = htons(lport);
201 BUG_TRAP(sk_unhashed(sk));
202 __sk_add_node(sk, &head->chain);
204 sock_prot_inuse_add(sk->sk_prot, 1);
209 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
210 } else if (tw != NULL) {
211 /* Silly. Should hash-dance instead... */
212 inet_twsk_deschedule(tw, death_row);
213 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
221 return -EADDRNOTAVAIL;
224 static inline u32 inet6_sk_port_offset(const struct sock *sk)
226 const struct inet_sock *inet = inet_sk(sk);
227 const struct ipv6_pinfo *np = inet6_sk(sk);
228 return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
233 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
236 struct inet_hashinfo *hinfo = death_row->hashinfo;
237 const unsigned short snum = inet_sk(sk)->num;
238 struct inet_bind_hashbucket *head;
239 struct inet_bind_bucket *tb;
243 int i, port, low, high, remaining;
245 const u32 offset = hint + inet6_sk_port_offset(sk);
246 struct hlist_node *node;
247 struct inet_timewait_sock *tw = NULL;
249 inet_get_local_port_range(&low, &high);
250 remaining = (high - low) + 1;
253 for (i = 1; i <= remaining; i++) {
254 port = low + (i + offset) % remaining;
255 head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
256 spin_lock(&head->lock);
258 /* Does not bother with rcv_saddr checks,
259 * because the established check is already
262 inet_bind_bucket_for_each(tb, node, &head->chain) {
263 if (tb->port == port) {
264 BUG_TRAP(!hlist_empty(&tb->owners));
265 if (tb->fastreuse >= 0)
267 if (!__inet6_check_established(death_row,
275 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
278 spin_unlock(&head->lock);
285 spin_unlock(&head->lock);
289 return -EADDRNOTAVAIL;
294 /* Head lock still held and bh's disabled */
295 inet_bind_hash(sk, tb, port);
296 if (sk_unhashed(sk)) {
297 inet_sk(sk)->sport = htons(port);
298 __inet6_hash(hinfo, sk);
300 spin_unlock(&head->lock);
303 inet_twsk_deschedule(tw, death_row);
311 head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
312 tb = inet_csk(sk)->icsk_bind_hash;
313 spin_lock_bh(&head->lock);
315 if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
316 __inet6_hash(hinfo, sk);
317 spin_unlock_bh(&head->lock);
320 spin_unlock(&head->lock);
321 /* No definite answer... Walk to established hash table */
322 ret = __inet6_check_established(death_row, sk, snum, NULL);
329 EXPORT_SYMBOL_GPL(inet6_hash_connect);