/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * Generic INET6 transport hashtables * * Authors: Lotsa people, from code originally in tcp, generalised here * by Arnaldo Carvalho de Melo <acme@mandriva.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/module.h> #include <linux/random.h> #include <net/inet_connection_sock.h> #include <net/inet_hashtables.h> #include <net/inet6_hashtables.h> #include <net/ip.h> void __inet6_hash(struct sock *sk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; WARN_ON(!sk_unhashed(sk)); if (sk->sk_state == TCP_LISTEN) { struct inet_listen_hashbucket *ilb; ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; spin_lock(&ilb->lock); __sk_nulls_add_node_rcu(sk, &ilb->head); spin_unlock(&ilb->lock); } else { unsigned int hash; struct hlist_nulls_head *list; spinlock_t *lock; sk->sk_hash = hash = inet6_sk_ehashfn(sk); list = &inet_ehash_bucket(hashinfo, hash)->chain; lock = inet_ehash_lockp(hashinfo, hash); spin_lock(lock); __sk_nulls_add_node_rcu(sk, list); spin_unlock(lock); } sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); } EXPORT_SYMBOL(__inet6_hash); /* * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM * * The sockhash lock must be held as a reader here. */ struct sock *__inet6_lookup_established(struct net *net, struct inet_hashinfo *hashinfo, const struct in6_addr *saddr, const __be16 sport, const struct in6_addr *daddr, const u16 hnum, const int dif) { struct sock *sk; const struct hlist_nulls_node *node; const __portpair ports = INET_COMBINED_PORTS(sport, hnum); /* Optimize here for direct hit, only listening connections can * have wildcards anyways. */ unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport); unsigned int slot = hash & (hashinfo->ehash_size - 1); struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; rcu_read_lock(); begin: sk_nulls_for_each_rcu(sk, node, &head->chain) { /* For IPV6 do the cheaper port and family tests first. */ if (INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) { if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) goto begintw; if (!INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) { sock_put(sk); goto begin; } goto out; } } if (get_nulls_value(node) != slot) goto begin; begintw: /* Must check for a TIME_WAIT'er before going to listener hash. */ sk_nulls_for_each_rcu(sk, node, &head->twchain) { if (INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) { if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) { sk = NULL; goto out; } if (!INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) { sock_put(sk); goto begintw; } goto out; } } if (get_nulls_value(node) != slot) goto begintw; sk = NULL; out: rcu_read_unlock(); return sk; } EXPORT_SYMBOL(__inet6_lookup_established); static int inline compute_score(struct sock *sk, struct net *net, const unsigned short hnum, const struct in6_addr *daddr, const int dif) { int score = -1; if (net_eq(sock_net(sk), net) && inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) { const struct ipv6_pinfo *np = inet6_sk(sk); score = 1; if (!ipv6_addr_any(&np->rcv_saddr)) { if (!ipv6_addr_equal(&np->rcv_saddr, daddr)) return -1; score++; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) return -1; score++; } } return score; } struct sock *inet6_lookup_listener(struct net *net, struct inet_hashinfo *hashinfo, const struct in6_addr *daddr, const unsigned short hnum, const int dif) { struct sock *sk; const struct hlist_nulls_node *node; struct sock *result; int score, hiscore; unsigned int hash = inet_lhashfn(net, hnum); struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; rcu_read_lock(); begin: result = NULL; hiscore = -1; sk_nulls_for_each(sk, node, &ilb->head) { score = compute_score(sk, net, hnum, daddr, dif); if (score > hiscore) { hiscore = score; result = sk; } } /* * if the nulls value we got at the end of this lookup is * not the expected one, we must restart lookup. * We probably met an item that was moved to another chain. */ if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE) goto begin; if (result) { if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt))) result = NULL; else if (unlikely(compute_score(result, net, hnum, daddr, dif) < hiscore)) { sock_put(result); goto begin; } } rcu_read_unlock(); return result; } EXPORT_SYMBOL_GPL(inet6_lookup_listener); struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo, const struct in6_addr *saddr, const __be16 sport, const struct in6_addr *daddr, const __be16 dport, const int dif) { struct sock *sk; local_bh_disable(); sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif); local_bh_enable(); return sk; } EXPORT_SYMBOL_GPL(inet6_lookup); static int __inet6_check_established(struct inet_timewait_death_row *death_row, struct sock *sk, const __u16 lport, struct inet_timewait_sock **twp) { struct inet_hashinfo *hinfo = death_row->hashinfo; struct inet_sock *inet = inet_sk(sk); const struct ipv6_pinfo *np = inet6_sk(sk); const struct in6_addr *daddr = &np->rcv_saddr; const struct in6_addr *saddr = &np->daddr; const int dif = sk->sk_bound_dev_if; const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport); struct net *net = sock_net(sk); const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr, inet->dport); struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); spinlock_t *lock = inet_ehash_lockp(hinfo, hash); struct sock *sk2; const struct hlist_nulls_node *node; struct inet_timewait_sock *tw; spin_lock(lock); /* Check TIME-WAIT sockets first. */ sk_nulls_for_each(sk2, node, &head->twchain) { tw = inet_twsk(sk2); if (INET6_TW_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) { if (twsk_unique(sk, sk2, twp)) goto unique; else goto not_unique; } } tw = NULL; /* And established part... */ sk_nulls_for_each(sk2, node, &head->chain) { if (INET6_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) goto not_unique; } unique: /* Must record num and sport now. Otherwise we will see * in hash table socket with a funny identity. */ inet->num = lport; inet->sport = htons(lport); WARN_ON(!sk_unhashed(sk)); __sk_nulls_add_node_rcu(sk, &head->chain); sk->sk_hash = hash; spin_unlock(lock); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); if (twp != NULL) { *twp = tw; NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); } else if (tw != NULL) { /* Silly. Should hash-dance instead... */ inet_twsk_deschedule(tw, death_row); NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); inet_twsk_put(tw); } return 0; not_unique: spin_unlock(lock); return -EADDRNOTAVAIL; } static inline u32 inet6_sk_port_offset(const struct sock *sk) { const struct inet_sock *inet = inet_sk(sk); const struct ipv6_pinfo *np = inet6_sk(sk); return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32, np->daddr.s6_addr32, inet->dport); } int inet6_hash_connect(struct inet_timewait_death_row *death_row, struct sock *sk) { return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk), __inet6_check_established, __inet6_hash); } EXPORT_SYMBOL_GPL(inet6_hash_connect);