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 int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
27 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
30 WARN_ON(!sk_unhashed(sk));
32 if (sk->sk_state == TCP_LISTEN) {
33 struct inet_listen_hashbucket *ilb;
35 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
36 spin_lock(&ilb->lock);
37 __sk_nulls_add_node_rcu(sk, &ilb->head);
38 spin_unlock(&ilb->lock);
41 struct hlist_nulls_head *list;
44 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
45 list = &inet_ehash_bucket(hashinfo, hash)->chain;
46 lock = inet_ehash_lockp(hashinfo, hash);
48 __sk_nulls_add_node_rcu(sk, list);
50 WARN_ON(sk->sk_hash != tw->tw_hash);
51 twrefcnt = inet_twsk_unhash(tw);
56 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
59 EXPORT_SYMBOL(__inet6_hash);
62 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
63 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
65 * The sockhash lock must be held as a reader here.
67 struct sock *__inet6_lookup_established(struct net *net,
68 struct inet_hashinfo *hashinfo,
69 const struct in6_addr *saddr,
71 const struct in6_addr *daddr,
76 const struct hlist_nulls_node *node;
77 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
78 /* Optimize here for direct hit, only listening connections can
79 * have wildcards anyways.
81 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
82 unsigned int slot = hash & hashinfo->ehash_mask;
83 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
88 sk_nulls_for_each_rcu(sk, node, &head->chain) {
89 /* For IPV6 do the cheaper port and family tests first. */
90 if (INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
91 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
93 if (!INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
100 if (get_nulls_value(node) != slot)
104 /* Must check for a TIME_WAIT'er before going to listener hash. */
105 sk_nulls_for_each_rcu(sk, node, &head->twchain) {
106 if (INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
107 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) {
111 if (!INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
118 if (get_nulls_value(node) != slot)
125 EXPORT_SYMBOL(__inet6_lookup_established);
127 static int inline compute_score(struct sock *sk, struct net *net,
128 const unsigned short hnum,
129 const struct in6_addr *daddr,
134 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
135 sk->sk_family == PF_INET6) {
136 const struct ipv6_pinfo *np = inet6_sk(sk);
139 if (!ipv6_addr_any(&np->rcv_saddr)) {
140 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
144 if (sk->sk_bound_dev_if) {
145 if (sk->sk_bound_dev_if != dif)
153 struct sock *inet6_lookup_listener(struct net *net,
154 struct inet_hashinfo *hashinfo, const struct in6_addr *daddr,
155 const unsigned short hnum, const int dif)
158 const struct hlist_nulls_node *node;
161 unsigned int hash = inet_lhashfn(net, hnum);
162 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
168 sk_nulls_for_each(sk, node, &ilb->head) {
169 score = compute_score(sk, net, hnum, daddr, dif);
170 if (score > hiscore) {
176 * if the nulls value we got at the end of this lookup is
177 * not the expected one, we must restart lookup.
178 * We probably met an item that was moved to another chain.
180 if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
183 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
185 else if (unlikely(compute_score(result, net, hnum, daddr,
195 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
197 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
198 const struct in6_addr *saddr, const __be16 sport,
199 const struct in6_addr *daddr, const __be16 dport,
205 sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
211 EXPORT_SYMBOL_GPL(inet6_lookup);
213 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
214 struct sock *sk, const __u16 lport,
215 struct inet_timewait_sock **twp)
217 struct inet_hashinfo *hinfo = death_row->hashinfo;
218 struct inet_sock *inet = inet_sk(sk);
219 const struct ipv6_pinfo *np = inet6_sk(sk);
220 const struct in6_addr *daddr = &np->rcv_saddr;
221 const struct in6_addr *saddr = &np->daddr;
222 const int dif = sk->sk_bound_dev_if;
223 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
224 struct net *net = sock_net(sk);
225 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
227 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
228 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
230 const struct hlist_nulls_node *node;
231 struct inet_timewait_sock *tw;
236 /* Check TIME-WAIT sockets first. */
237 sk_nulls_for_each(sk2, node, &head->twchain) {
240 if (INET6_TW_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) {
241 if (twsk_unique(sk, sk2, twp))
249 /* And established part... */
250 sk_nulls_for_each(sk2, node, &head->chain) {
251 if (INET6_MATCH(sk2, net, hash, saddr, daddr, ports, dif))
256 /* Must record num and sport now. Otherwise we will see
257 * in hash table socket with a funny identity. */
258 inet->inet_num = lport;
259 inet->inet_sport = htons(lport);
261 WARN_ON(!sk_unhashed(sk));
262 __sk_nulls_add_node_rcu(sk, &head->chain);
264 twrefcnt = inet_twsk_unhash(tw);
265 NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
270 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
275 /* Silly. Should hash-dance instead... */
276 inet_twsk_deschedule(tw, death_row);
284 return -EADDRNOTAVAIL;
287 static inline u32 inet6_sk_port_offset(const struct sock *sk)
289 const struct inet_sock *inet = inet_sk(sk);
290 const struct ipv6_pinfo *np = inet6_sk(sk);
291 return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
296 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
299 return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
300 __inet6_check_established, __inet6_hash);
303 EXPORT_SYMBOL_GPL(inet6_hash_connect);