345 lines
9.0 KiB
C
345 lines
9.0 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Generic INET6 transport hashtables
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*
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* Authors: Lotsa people, from code originally in tcp, generalised here
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* by Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <net/inet_connection_sock.h>
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#include <net/inet_hashtables.h>
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#include <net/inet6_hashtables.h>
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#include <net/ip.h>
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void __inet6_hash(struct inet_hashinfo *hashinfo,
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struct sock *sk)
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{
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struct hlist_head *list;
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rwlock_t *lock;
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BUG_TRAP(sk_unhashed(sk));
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if (sk->sk_state == TCP_LISTEN) {
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list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
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lock = &hashinfo->lhash_lock;
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inet_listen_wlock(hashinfo);
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} else {
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unsigned int hash;
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sk->sk_hash = hash = inet6_sk_ehashfn(sk);
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hash &= (hashinfo->ehash_size - 1);
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list = &hashinfo->ehash[hash].chain;
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lock = &hashinfo->ehash[hash].lock;
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write_lock(lock);
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}
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__sk_add_node(sk, list);
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sock_prot_inc_use(sk->sk_prot);
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write_unlock(lock);
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}
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EXPORT_SYMBOL(__inet6_hash);
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/*
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* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
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* we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
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*
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* The sockhash lock must be held as a reader here.
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*/
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struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
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const struct in6_addr *saddr,
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const u16 sport,
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const struct in6_addr *daddr,
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const u16 hnum,
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const int dif)
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{
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struct sock *sk;
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const struct hlist_node *node;
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const __u32 ports = INET_COMBINED_PORTS(sport, hnum);
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/* Optimize here for direct hit, only listening connections can
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* have wildcards anyways.
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*/
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unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
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struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
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prefetch(head->chain.first);
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read_lock(&head->lock);
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sk_for_each(sk, node, &head->chain) {
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/* For IPV6 do the cheaper port and family tests first. */
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if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
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goto hit; /* You sunk my battleship! */
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}
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/* Must check for a TIME_WAIT'er before going to listener hash. */
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sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) {
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const struct inet_timewait_sock *tw = inet_twsk(sk);
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if(*((__u32 *)&(tw->tw_dport)) == ports &&
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sk->sk_family == PF_INET6) {
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const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
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if (ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) &&
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ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) &&
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(!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif))
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goto hit;
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}
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}
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read_unlock(&head->lock);
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return NULL;
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hit:
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sock_hold(sk);
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read_unlock(&head->lock);
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return sk;
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}
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EXPORT_SYMBOL(__inet6_lookup_established);
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struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
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const struct in6_addr *daddr,
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const unsigned short hnum, const int dif)
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{
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struct sock *sk;
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const struct hlist_node *node;
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struct sock *result = NULL;
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int score, hiscore = 0;
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read_lock(&hashinfo->lhash_lock);
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sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
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if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
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const struct ipv6_pinfo *np = inet6_sk(sk);
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score = 1;
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if (!ipv6_addr_any(&np->rcv_saddr)) {
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if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
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continue;
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score++;
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}
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if (sk->sk_bound_dev_if) {
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if (sk->sk_bound_dev_if != dif)
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continue;
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score++;
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}
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if (score == 3) {
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result = sk;
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break;
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}
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if (score > hiscore) {
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hiscore = score;
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result = sk;
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}
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}
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}
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if (result)
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sock_hold(result);
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read_unlock(&hashinfo->lhash_lock);
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return result;
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}
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EXPORT_SYMBOL_GPL(inet6_lookup_listener);
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struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
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const struct in6_addr *saddr, const u16 sport,
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const struct in6_addr *daddr, const u16 dport,
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const int dif)
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{
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struct sock *sk;
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local_bh_disable();
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sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
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local_bh_enable();
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return sk;
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}
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EXPORT_SYMBOL_GPL(inet6_lookup);
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static int __inet6_check_established(struct inet_timewait_death_row *death_row,
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struct sock *sk, const __u16 lport,
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struct inet_timewait_sock **twp)
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{
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struct inet_hashinfo *hinfo = death_row->hashinfo;
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struct inet_sock *inet = inet_sk(sk);
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const struct ipv6_pinfo *np = inet6_sk(sk);
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const struct in6_addr *daddr = &np->rcv_saddr;
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const struct in6_addr *saddr = &np->daddr;
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const int dif = sk->sk_bound_dev_if;
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const u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
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const unsigned int hash = inet6_ehashfn(daddr, inet->num, saddr,
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inet->dport);
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struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
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struct sock *sk2;
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const struct hlist_node *node;
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struct inet_timewait_sock *tw;
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prefetch(head->chain.first);
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write_lock(&head->lock);
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/* Check TIME-WAIT sockets first. */
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sk_for_each(sk2, node, &(head + hinfo->ehash_size)->chain) {
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const struct inet6_timewait_sock *tw6 = inet6_twsk(sk2);
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tw = inet_twsk(sk2);
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if(*((__u32 *)&(tw->tw_dport)) == ports &&
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sk2->sk_family == PF_INET6 &&
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ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) &&
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ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) &&
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sk2->sk_bound_dev_if == sk->sk_bound_dev_if) {
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if (twsk_unique(sk, sk2, twp))
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goto unique;
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else
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goto not_unique;
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}
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}
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tw = NULL;
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/* And established part... */
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sk_for_each(sk2, node, &head->chain) {
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if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif))
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goto not_unique;
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}
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unique:
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/* Must record num and sport now. Otherwise we will see
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* in hash table socket with a funny identity. */
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inet->num = lport;
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inet->sport = htons(lport);
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BUG_TRAP(sk_unhashed(sk));
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__sk_add_node(sk, &head->chain);
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sk->sk_hash = hash;
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sock_prot_inc_use(sk->sk_prot);
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write_unlock(&head->lock);
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if (twp != NULL) {
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*twp = tw;
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NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
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} else if (tw != NULL) {
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/* Silly. Should hash-dance instead... */
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inet_twsk_deschedule(tw, death_row);
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NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
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inet_twsk_put(tw);
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}
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return 0;
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not_unique:
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write_unlock(&head->lock);
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return -EADDRNOTAVAIL;
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}
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static inline u32 inet6_sk_port_offset(const struct sock *sk)
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{
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const struct inet_sock *inet = inet_sk(sk);
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const struct ipv6_pinfo *np = inet6_sk(sk);
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return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
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np->daddr.s6_addr32,
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inet->dport);
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}
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int inet6_hash_connect(struct inet_timewait_death_row *death_row,
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struct sock *sk)
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{
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struct inet_hashinfo *hinfo = death_row->hashinfo;
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const unsigned short snum = inet_sk(sk)->num;
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struct inet_bind_hashbucket *head;
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struct inet_bind_bucket *tb;
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int ret;
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if (snum == 0) {
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const int low = sysctl_local_port_range[0];
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const int high = sysctl_local_port_range[1];
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const int range = high - low;
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int i, port;
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static u32 hint;
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const u32 offset = hint + inet6_sk_port_offset(sk);
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struct hlist_node *node;
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struct inet_timewait_sock *tw = NULL;
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local_bh_disable();
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for (i = 1; i <= range; i++) {
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port = low + (i + offset) % range;
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head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
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spin_lock(&head->lock);
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/* Does not bother with rcv_saddr checks,
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* because the established check is already
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* unique enough.
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*/
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inet_bind_bucket_for_each(tb, node, &head->chain) {
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if (tb->port == port) {
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BUG_TRAP(!hlist_empty(&tb->owners));
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if (tb->fastreuse >= 0)
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goto next_port;
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if (!__inet6_check_established(death_row,
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sk, port,
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&tw))
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goto ok;
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goto next_port;
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}
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}
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tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
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head, port);
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if (!tb) {
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spin_unlock(&head->lock);
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break;
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}
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tb->fastreuse = -1;
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goto ok;
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next_port:
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spin_unlock(&head->lock);
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}
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local_bh_enable();
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return -EADDRNOTAVAIL;
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ok:
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hint += i;
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/* Head lock still held and bh's disabled */
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inet_bind_hash(sk, tb, port);
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if (sk_unhashed(sk)) {
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inet_sk(sk)->sport = htons(port);
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__inet6_hash(hinfo, sk);
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}
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spin_unlock(&head->lock);
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if (tw) {
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inet_twsk_deschedule(tw, death_row);
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inet_twsk_put(tw);
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}
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ret = 0;
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goto out;
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}
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head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
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tb = inet_csk(sk)->icsk_bind_hash;
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spin_lock_bh(&head->lock);
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if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
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__inet6_hash(hinfo, sk);
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spin_unlock_bh(&head->lock);
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return 0;
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} else {
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spin_unlock(&head->lock);
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/* No definite answer... Walk to established hash table */
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ret = __inet6_check_established(death_row, sk, snum, NULL);
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out:
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local_bh_enable();
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return ret;
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}
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}
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EXPORT_SYMBOL_GPL(inet6_hash_connect);
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