diff options
Diffstat (limited to 'kernel/net/ipv6/inet6_hashtables.c')
| -rw-r--r-- | kernel/net/ipv6/inet6_hashtables.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/kernel/net/ipv6/inet6_hashtables.c b/kernel/net/ipv6/inet6_hashtables.c new file mode 100644 index 000000000..871641bc1 --- /dev/null +++ b/kernel/net/ipv6/inet6_hashtables.c @@ -0,0 +1,275 @@ +/* + * 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/secure_seq.h> +#include <net/ip.h> + +u32 inet6_ehashfn(const struct net *net, + const struct in6_addr *laddr, const u16 lport, + const struct in6_addr *faddr, const __be16 fport) +{ + static u32 inet6_ehash_secret __read_mostly; + static u32 ipv6_hash_secret __read_mostly; + + u32 lhash, fhash; + + net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret)); + net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret)); + + lhash = (__force u32)laddr->s6_addr32[3]; + fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret); + + return __inet6_ehashfn(lhash, lport, fhash, fport, + inet6_ehash_secret + net_hash_mix(net)); +} + +/* + * 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_mask; + struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; + + + rcu_read_lock(); +begin: + sk_nulls_for_each_rcu(sk, node, &head->chain) { + if (sk->sk_hash != hash) + continue; + if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif)) + continue; + if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) + goto out; + + if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) { + sock_gen_put(sk); + goto begin; + } + goto found; + } + if (get_nulls_value(node) != slot) + goto begin; +out: + sk = NULL; +found: + rcu_read_unlock(); + return sk; +} +EXPORT_SYMBOL(__inet6_lookup_established); + +static inline int 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)->inet_num == hnum && + sk->sk_family == PF_INET6) { + + score = 1; + if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) { + if (!ipv6_addr_equal(&sk->sk_v6_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 *saddr, + const __be16 sport, 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, matches = 0, reuseport = 0; + u32 phash = 0; + unsigned int hash = inet_lhashfn(net, hnum); + struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; + + rcu_read_lock(); +begin: + result = NULL; + hiscore = 0; + sk_nulls_for_each(sk, node, &ilb->head) { + score = compute_score(sk, net, hnum, daddr, dif); + if (score > hiscore) { + hiscore = score; + result = sk; + reuseport = sk->sk_reuseport; + if (reuseport) { + phash = inet6_ehashfn(net, daddr, hnum, + saddr, sport); + matches = 1; + } + } else if (score == hiscore && reuseport) { + matches++; + if (reciprocal_scale(phash, matches) == 0) + result = sk; + phash = next_pseudo_random32(phash); + } + } + /* + * 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 in6_addr *daddr = &sk->sk_v6_rcv_saddr; + const struct in6_addr *saddr = &sk->sk_v6_daddr; + const int dif = sk->sk_bound_dev_if; + const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); + struct net *net = sock_net(sk); + const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr, + inet->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 = NULL; + int twrefcnt = 0; + + spin_lock(lock); + + sk_nulls_for_each(sk2, node, &head->chain) { + if (sk2->sk_hash != hash) + continue; + + if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) { + if (sk2->sk_state == TCP_TIME_WAIT) { + tw = inet_twsk(sk2); + if (twsk_unique(sk, sk2, twp)) + break; + } + goto not_unique; + } + } + + /* Must record num and sport now. Otherwise we will see + * in hash table socket with a funny identity. + */ + inet->inet_num = lport; + inet->inet_sport = htons(lport); + sk->sk_hash = hash; + WARN_ON(!sk_unhashed(sk)); + __sk_nulls_add_node_rcu(sk, &head->chain); + if (tw) { + twrefcnt = inet_twsk_unhash(tw); + NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED); + } + spin_unlock(lock); + if (twrefcnt) + inet_twsk_put(tw); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + + if (twp) { + *twp = tw; + } else if (tw) { + /* Silly. Should hash-dance instead... */ + inet_twsk_deschedule(tw); + + 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); + + return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32, + sk->sk_v6_daddr.s6_addr32, + inet->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); +} +EXPORT_SYMBOL_GPL(inet6_hash_connect); |