net 04/05: fib_rules: allow to delete local rule
[safe/jmp/linux-2.6] / net / ipv6 / inet6_hashtables.c
index 01d5f46..00c6a3e 100644 (file)
@@ -5,7 +5,8 @@
  *
  *             Generic INET6 transport hashtables
  *
- * Authors:    Lotsa people, from code originally in tcp
+ * 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
  *      2 of the License, or (at your option) any later version.
  */
 
-#include <linux/config.h>
-
 #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>
 
-struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
-                                  const struct in6_addr *daddr,
-                                  const unsigned short hnum, const int dif)
+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_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++;
+       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) {
+               /* 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;
                        }
-                       if (score == 3) {
-                               result = sk;
-                               break;
+               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 (score > hiscore) {
-                               hiscore = score;
-                               result = sk;
+                       if (!INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) {
+                               sock_put(sk);
+                               goto begintw;
                        }
+                       goto out;
                }
        }
-       if (result)
-               sock_hold(result);
-       read_unlock(&hashinfo->lhash_lock);
+       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)->inet_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 inet_hashinfo *hashinfo,
-                         const struct in6_addr *saddr, const u16 sport,
-                         const struct in6_addr *daddr, const u16 dport,
+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(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
+       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->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;
+
+       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->inet_num = lport;
+       inet->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(net, LINUX_MIB_TIMEWAITRECYCLED);
+       } else if (tw != NULL) {
+               /* Silly. Should hash-dance instead... */
+               inet_twsk_deschedule(tw, death_row);
+               NET_INC_STATS_BH(net, 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->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);