/* * 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 inet_hashinfo *hashinfo, struct sock *sk) { struct hlist_head *list; rwlock_t *lock; BUG_TRAP(sk_unhashed(sk)); if (sk->sk_state == TCP_LISTEN) { list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; lock = &hashinfo->lhash_lock; inet_listen_wlock(hashinfo); } else { unsigned int hash; sk->sk_hash = hash = inet6_sk_ehashfn(sk); hash &= (hashinfo->ehash_size - 1); list = &hashinfo->ehash[hash].chain; lock = &hashinfo->ehash[hash].lock; write_lock(lock); } __sk_add_node(sk, list); sock_prot_inc_use(sk->sk_prot); write_unlock(lock); } 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 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_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(daddr, hnum, saddr, sport); struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash); prefetch(head->chain.first); read_lock(&head->lock); sk_for_each(sk, node, &head->chain) { /* For IPV6 do the cheaper port and family tests first. */ if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif)) goto hit; /* You sunk my battleship! */ } /* Must check for a TIME_WAIT'er before going to listener hash. */ sk_for_each(sk, node, &head->twchain) { const struct inet_timewait_sock *tw = inet_twsk(sk); if(*((__portpair *)&(tw->tw_dport)) == ports && sk->sk_family == PF_INET6) { const struct inet6_timewait_sock *tw6 = inet6_twsk(sk); if (ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) && ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) && (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)) goto hit; } } read_unlock(&head->lock); return NULL; hit: sock_hold(sk); read_unlock(&head->lock); return sk; } EXPORT_SYMBOL(__inet6_lookup_established); struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo, const struct in6_addr *daddr, const unsigned short hnum, const int dif) { struct sock *sk; const struct hlist_node *node; struct sock *result = NULL; int score, hiscore = 0; read_lock(&hashinfo->lhash_lock); sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) { if (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)) continue; score++; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) continue; score++; } if (score == 3) { result = sk; break; } if (score > hiscore) { hiscore = score; result = sk; } } } if (result) sock_hold(result); read_unlock(&hashinfo->lhash_lock); return result; } EXPORT_SYMBOL_GPL(inet6_lookup_listener); struct sock *inet6_lookup(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(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); const unsigned int hash = inet6_ehashfn(daddr, lport, saddr, inet->dport); struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); struct sock *sk2; const struct hlist_node *node; struct inet_timewait_sock *tw; prefetch(head->chain.first); write_lock(&head->lock); /* Check TIME-WAIT sockets first. */ sk_for_each(sk2, node, &head->twchain) { const struct inet6_timewait_sock *tw6 = inet6_twsk(sk2); tw = inet_twsk(sk2); if(*((__portpair *)&(tw->tw_dport)) == ports && sk2->sk_family == PF_INET6 && ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) && ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) && sk2->sk_bound_dev_if == sk->sk_bound_dev_if) { if (twsk_unique(sk, sk2, twp)) goto unique; else goto not_unique; } } tw = NULL; /* And established part... */ sk_for_each(sk2, node, &head->chain) { if (INET6_MATCH(sk2, 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); BUG_TRAP(sk_unhashed(sk)); __sk_add_node(sk, &head->chain); sk->sk_hash = hash; sock_prot_inc_use(sk->sk_prot); write_unlock(&head->lock); if (twp != NULL) { *twp = tw; NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); } else if (tw != NULL) { /* Silly. Should hash-dance instead... */ inet_twsk_deschedule(tw, death_row); NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); inet_twsk_put(tw); } return 0; not_unique: write_unlock(&head->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) { struct inet_hashinfo *hinfo = death_row->hashinfo; const unsigned short snum = inet_sk(sk)->num; struct inet_bind_hashbucket *head; struct inet_bind_bucket *tb; int ret; if (snum == 0) { int i, port, low, high, remaining; static u32 hint; const u32 offset = hint + inet6_sk_port_offset(sk); struct hlist_node *node; struct inet_timewait_sock *tw = NULL; inet_get_local_port_range(&low, &high); remaining = high - low; local_bh_disable(); for (i = 1; i <= remaining; i++) { port = low + (i + offset) % remaining; head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)]; spin_lock(&head->lock); /* Does not bother with rcv_saddr checks, * because the established check is already * unique enough. */ inet_bind_bucket_for_each(tb, node, &head->chain) { if (tb->port == port) { BUG_TRAP(!hlist_empty(&tb->owners)); if (tb->fastreuse >= 0) goto next_port; if (!__inet6_check_established(death_row, sk, port, &tw)) goto ok; goto next_port; } } tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, head, port); if (!tb) { spin_unlock(&head->lock); break; } tb->fastreuse = -1; goto ok; next_port: spin_unlock(&head->lock); } local_bh_enable(); return -EADDRNOTAVAIL; ok: hint += i; /* Head lock still held and bh's disabled */ inet_bind_hash(sk, tb, port); if (sk_unhashed(sk)) { inet_sk(sk)->sport = htons(port); __inet6_hash(hinfo, sk); } spin_unlock(&head->lock); if (tw) { inet_twsk_deschedule(tw, death_row); inet_twsk_put(tw); } ret = 0; goto out; } head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)]; tb = inet_csk(sk)->icsk_bind_hash; spin_lock_bh(&head->lock); if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) { __inet6_hash(hinfo, sk); spin_unlock_bh(&head->lock); return 0; } else { spin_unlock(&head->lock); /* No definite answer... Walk to established hash table */ ret = __inet6_check_established(death_row, sk, snum, NULL); out: local_bh_enable(); return ret; } } EXPORT_SYMBOL_GPL(inet6_hash_connect);