]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - net/netfilter/nf_conntrack_core.c
[NETFILTER]: nf_conntrack: optimize hash_conntrack()
[linux-2.6-omap-h63xx.git] / net / netfilter / nf_conntrack_core.c
index 0fe11889ce141c70f9811a5b8fd89a6e9d267265..4a2cce1e1ced4651679219833c949f477750d646 100644 (file)
@@ -40,7 +40,7 @@
 
 #define NF_CONNTRACK_VERSION   "0.5.0"
 
-DEFINE_RWLOCK(nf_conntrack_lock);
+DEFINE_SPINLOCK(nf_conntrack_lock);
 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
 
 /* nf_conntrack_standalone needs this */
@@ -63,7 +63,6 @@ unsigned int nf_ct_log_invalid __read_mostly;
 HLIST_HEAD(unconfirmed);
 static int nf_conntrack_vmalloc __read_mostly;
 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
-static unsigned int nf_conntrack_next_id;
 
 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
@@ -74,15 +73,19 @@ static unsigned int nf_conntrack_hash_rnd;
 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
                                  unsigned int size, unsigned int rnd)
 {
-       unsigned int a, b;
-
-       a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all),
-                  (tuple->src.l3num << 16) | tuple->dst.protonum);
-       b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
-                  ((__force __u16)tuple->src.u.all << 16) |
-                   (__force __u16)tuple->dst.u.all);
-
-       return jhash_2words(a, b, rnd) % size;
+       unsigned int n;
+       u_int32_t h;
+
+       /* The direction must be ignored, so we hash everything up to the
+        * destination ports (which is a multiple of 4) and treat the last
+        * three bytes manually.
+        */
+       n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
+       h = jhash2((u32 *)tuple, n,
+                  rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
+                         tuple->dst.protonum));
+
+       return ((u64)h * size) >> 32;
 }
 
 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
@@ -167,8 +170,8 @@ static void
 clean_from_lists(struct nf_conn *ct)
 {
        pr_debug("clean_from_lists(%p)\n", ct);
-       hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
-       hlist_del(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
+       hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
+       hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 
        /* Destroy all pending expectations */
        nf_ct_remove_expectations(ct);
@@ -200,7 +203,7 @@ destroy_conntrack(struct nf_conntrack *nfct)
 
        rcu_read_unlock();
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
        /* Expectations will have been removed in clean_from_lists,
         * except TFTP can create an expectation on the first packet,
         * before connection is in the list, so we need to clean here,
@@ -214,7 +217,7 @@ destroy_conntrack(struct nf_conntrack *nfct)
        }
 
        NF_CT_STAT_INC(delete);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
 
        if (ct->master)
                nf_ct_put(ct->master);
@@ -237,26 +240,24 @@ static void death_by_timeout(unsigned long ul_conntrack)
                rcu_read_unlock();
        }
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
        /* Inside lock so preempt is disabled on module removal path.
         * Otherwise we can get spurious warnings. */
        NF_CT_STAT_INC(delete_list);
        clean_from_lists(ct);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
        nf_ct_put(ct);
 }
 
 struct nf_conntrack_tuple_hash *
-__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
-                   const struct nf_conn *ignored_conntrack)
+__nf_conntrack_find(const struct nf_conntrack_tuple *tuple)
 {
        struct nf_conntrack_tuple_hash *h;
        struct hlist_node *n;
        unsigned int hash = hash_conntrack(tuple);
 
-       hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) {
-               if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
-                   nf_ct_tuple_equal(tuple, &h->tuple)) {
+       hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
+               if (nf_ct_tuple_equal(tuple, &h->tuple)) {
                        NF_CT_STAT_INC(found);
                        return h;
                }
@@ -272,12 +273,16 @@ struct nf_conntrack_tuple_hash *
 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
 {
        struct nf_conntrack_tuple_hash *h;
+       struct nf_conn *ct;
 
-       read_lock_bh(&nf_conntrack_lock);
-       h = __nf_conntrack_find(tuple, NULL);
-       if (h)
-               atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
-       read_unlock_bh(&nf_conntrack_lock);
+       rcu_read_lock();
+       h = __nf_conntrack_find(tuple);
+       if (h) {
+               ct = nf_ct_tuplehash_to_ctrack(h);
+               if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
+                       h = NULL;
+       }
+       rcu_read_unlock();
 
        return h;
 }
@@ -287,11 +292,10 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct,
                                       unsigned int hash,
                                       unsigned int repl_hash)
 {
-       ct->id = ++nf_conntrack_next_id;
-       hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
-                      &nf_conntrack_hash[hash]);
-       hlist_add_head(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
-                      &nf_conntrack_hash[repl_hash]);
+       hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
+                          &nf_conntrack_hash[hash]);
+       hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
+                          &nf_conntrack_hash[repl_hash]);
 }
 
 void nf_conntrack_hash_insert(struct nf_conn *ct)
@@ -301,15 +305,15 @@ void nf_conntrack_hash_insert(struct nf_conn *ct)
        hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
        repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
        __nf_conntrack_hash_insert(ct, hash, repl_hash);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 
 /* Confirm a connection given skb; places it in hash table */
 int
-__nf_conntrack_confirm(struct sk_buff **pskb)
+__nf_conntrack_confirm(struct sk_buff *skb)
 {
        unsigned int hash, repl_hash;
        struct nf_conntrack_tuple_hash *h;
@@ -318,7 +322,7 @@ __nf_conntrack_confirm(struct sk_buff **pskb)
        struct hlist_node *n;
        enum ip_conntrack_info ctinfo;
 
-       ct = nf_ct_get(*pskb, &ctinfo);
+       ct = nf_ct_get(skb, &ctinfo);
 
        /* ipt_REJECT uses nf_conntrack_attach to attach related
           ICMP/TCP RST packets in other direction.  Actual packet
@@ -340,7 +344,7 @@ __nf_conntrack_confirm(struct sk_buff **pskb)
        NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
        pr_debug("Confirming conntrack %p\n", ct);
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
 
        /* See if there's one in the list already, including reverse:
           NAT could have grabbed it without realizing, since we're
@@ -366,22 +370,22 @@ __nf_conntrack_confirm(struct sk_buff **pskb)
        atomic_inc(&ct->ct_general.use);
        set_bit(IPS_CONFIRMED_BIT, &ct->status);
        NF_CT_STAT_INC(insert);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
        help = nfct_help(ct);
        if (help && help->helper)
-               nf_conntrack_event_cache(IPCT_HELPER, *pskb);
+               nf_conntrack_event_cache(IPCT_HELPER, skb);
 #ifdef CONFIG_NF_NAT_NEEDED
        if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
            test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
-               nf_conntrack_event_cache(IPCT_NATINFO, *pskb);
+               nf_conntrack_event_cache(IPCT_NATINFO, skb);
 #endif
        nf_conntrack_event_cache(master_ct(ct) ?
-                                IPCT_RELATED : IPCT_NEW, *pskb);
+                                IPCT_RELATED : IPCT_NEW, skb);
        return NF_ACCEPT;
 
 out:
        NF_CT_STAT_INC(insert_failed);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
        return NF_DROP;
 }
 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
@@ -393,12 +397,22 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
                         const struct nf_conn *ignored_conntrack)
 {
        struct nf_conntrack_tuple_hash *h;
+       struct hlist_node *n;
+       unsigned int hash = hash_conntrack(tuple);
 
-       read_lock_bh(&nf_conntrack_lock);
-       h = __nf_conntrack_find(tuple, ignored_conntrack);
-       read_unlock_bh(&nf_conntrack_lock);
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
+               if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
+                   nf_ct_tuple_equal(tuple, &h->tuple)) {
+                       NF_CT_STAT_INC(found);
+                       rcu_read_unlock();
+                       return 1;
+               }
+               NF_CT_STAT_INC(searched);
+       }
+       rcu_read_unlock();
 
-       return h != NULL;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 
@@ -415,21 +429,23 @@ static int early_drop(unsigned int hash)
        unsigned int i, cnt = 0;
        int dropped = 0;
 
-       read_lock_bh(&nf_conntrack_lock);
+       rcu_read_lock();
        for (i = 0; i < nf_conntrack_htable_size; i++) {
-               hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) {
+               hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
+                                        hnode) {
                        tmp = nf_ct_tuplehash_to_ctrack(h);
                        if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
                                ct = tmp;
                        cnt++;
                }
+
+               if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
+                       ct = NULL;
                if (ct || cnt >= NF_CT_EVICTION_RANGE)
                        break;
                hash = (hash + 1) % nf_conntrack_htable_size;
        }
-       if (ct)
-               atomic_inc(&ct->ct_general.use);
-       read_unlock_bh(&nf_conntrack_lock);
+       rcu_read_unlock();
 
        if (!ct)
                return dropped;
@@ -482,17 +498,25 @@ struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
        /* Don't set timer yet: wait for confirmation */
        setup_timer(&conntrack->timeout, death_by_timeout,
                    (unsigned long)conntrack);
+       INIT_RCU_HEAD(&conntrack->rcu);
 
        return conntrack;
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 
-void nf_conntrack_free(struct nf_conn *conntrack)
+static void nf_conntrack_free_rcu(struct rcu_head *head)
 {
-       nf_ct_ext_free(conntrack);
-       kmem_cache_free(nf_conntrack_cachep, conntrack);
+       struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
+
+       nf_ct_ext_free(ct);
+       kmem_cache_free(nf_conntrack_cachep, ct);
        atomic_dec(&nf_conntrack_count);
 }
+
+void nf_conntrack_free(struct nf_conn *conntrack)
+{
+       call_rcu(&conntrack->rcu, nf_conntrack_free_rcu);
+}
 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 
 /* Allocate a new conntrack: we return -ENOMEM if classification
@@ -526,7 +550,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
                return NULL;
        }
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
        exp = nf_ct_find_expectation(tuple);
        if (exp) {
                pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
@@ -564,7 +588,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
        hlist_add_head(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
                       &unconfirmed);
 
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
 
        if (exp) {
                if (exp->expectfn)
@@ -634,7 +658,7 @@ resolve_normal_ct(struct sk_buff *skb,
 }
 
 unsigned int
-nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
+nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff *skb)
 {
        struct nf_conn *ct;
        enum ip_conntrack_info ctinfo;
@@ -646,14 +670,14 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
        int ret;
 
        /* Previously seen (loopback or untracked)?  Ignore. */
-       if ((*pskb)->nfct) {
+       if (skb->nfct) {
                NF_CT_STAT_INC_ATOMIC(ignore);
                return NF_ACCEPT;
        }
 
        /* rcu_read_lock()ed by nf_hook_slow */
        l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
-       ret = l3proto->get_l4proto(*pskb, skb_network_offset(*pskb),
+       ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
                                   &dataoff, &protonum);
        if (ret <= 0) {
                pr_debug("not prepared to track yet or error occured\n");
@@ -668,13 +692,13 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
         * inverse of the return code tells to the netfilter
         * core what to do with the packet. */
        if (l4proto->error != NULL &&
-           (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
+           (ret = l4proto->error(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
                NF_CT_STAT_INC_ATOMIC(error);
                NF_CT_STAT_INC_ATOMIC(invalid);
                return -ret;
        }
 
-       ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto,
+       ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
                               &set_reply, &ctinfo);
        if (!ct) {
                /* Not valid part of a connection */
@@ -688,21 +712,21 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
                return NF_DROP;
        }
 
-       NF_CT_ASSERT((*pskb)->nfct);
+       NF_CT_ASSERT(skb->nfct);
 
-       ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum);
+       ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
        if (ret < 0) {
                /* Invalid: inverse of the return code tells
                 * the netfilter core what to do */
                pr_debug("nf_conntrack_in: Can't track with proto module\n");
-               nf_conntrack_put((*pskb)->nfct);
-               (*pskb)->nfct = NULL;
+               nf_conntrack_put(skb->nfct);
+               skb->nfct = NULL;
                NF_CT_STAT_INC_ATOMIC(invalid);
                return -ret;
        }
 
        if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
-               nf_conntrack_event_cache(IPCT_STATUS, *pskb);
+               nf_conntrack_event_cache(IPCT_STATUS, skb);
 
        return ret;
 }
@@ -731,7 +755,6 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
        struct nf_conn_help *help = nfct_help(ct);
        struct nf_conntrack_helper *helper;
 
-       write_lock_bh(&nf_conntrack_lock);
        /* Should be unconfirmed, so not in hash table yet */
        NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 
@@ -740,8 +763,9 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
 
        ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
        if (ct->master || (help && help->expecting != 0))
-               goto out;
+               return;
 
+       rcu_read_lock();
        helper = __nf_ct_helper_find(newreply);
        if (helper == NULL) {
                if (help)
@@ -759,7 +783,7 @@ void nf_conntrack_alter_reply(struct nf_conn *ct,
 
        rcu_assign_pointer(help->helper, helper);
 out:
-       write_unlock_bh(&nf_conntrack_lock);
+       rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 
@@ -775,13 +799,11 @@ void __nf_ct_refresh_acct(struct nf_conn *ct,
        NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
        NF_CT_ASSERT(skb);
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
 
        /* Only update if this is not a fixed timeout */
-       if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
-               write_unlock_bh(&nf_conntrack_lock);
-               return;
-       }
+       if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
+               goto acct;
 
        /* If not in hash table, timer will not be active yet */
        if (!nf_ct_is_confirmed(ct)) {
@@ -801,6 +823,7 @@ void __nf_ct_refresh_acct(struct nf_conn *ct,
                }
        }
 
+acct:
 #ifdef CONFIG_NF_CT_ACCT
        if (do_acct) {
                ct->counters[CTINFO2DIR(ctinfo)].packets++;
@@ -813,7 +836,7 @@ void __nf_ct_refresh_acct(struct nf_conn *ct,
        }
 #endif
 
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
 
        /* must be unlocked when calling event cache */
        if (event)
@@ -827,48 +850,43 @@ EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 #include <linux/netfilter/nfnetlink_conntrack.h>
 #include <linux/mutex.h>
 
-
 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
  * in ip_conntrack_core, since we don't want the protocols to autoload
  * or depend on ctnetlink */
-int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
+int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
                               const struct nf_conntrack_tuple *tuple)
 {
-       NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
-               &tuple->src.u.tcp.port);
-       NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
-               &tuple->dst.u.tcp.port);
+       NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
+       NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
        return 0;
 
-nfattr_failure:
+nla_put_failure:
        return -1;
 }
-EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr);
+EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 
-static const size_t cta_min_proto[CTA_PROTO_MAX] = {
-       [CTA_PROTO_SRC_PORT-1]  = sizeof(u_int16_t),
-       [CTA_PROTO_DST_PORT-1]  = sizeof(u_int16_t)
+const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
+       [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
+       [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 };
+EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 
-int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
+int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
                               struct nf_conntrack_tuple *t)
 {
-       if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
-               return -EINVAL;
-
-       if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
+       if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
                return -EINVAL;
 
-       t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
-       t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
+       t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
+       t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple);
+EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 #endif
 
 /* Used by ipt_REJECT and ip6t_REJECT. */
-void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
+static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 {
        struct nf_conn *ct;
        enum ip_conntrack_info ctinfo;
@@ -885,7 +903,6 @@ void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
        nskb->nfctinfo = ctinfo;
        nf_conntrack_get(nskb->nfct);
 }
-EXPORT_SYMBOL_GPL(__nf_conntrack_attach);
 
 static inline int
 do_iter(const struct nf_conntrack_tuple_hash *i,
@@ -904,7 +921,7 @@ get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
        struct nf_conn *ct;
        struct hlist_node *n;
 
-       write_lock_bh(&nf_conntrack_lock);
+       spin_lock_bh(&nf_conntrack_lock);
        for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
                hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) {
                        ct = nf_ct_tuplehash_to_ctrack(h);
@@ -917,11 +934,11 @@ get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
                if (iter(ct, data))
                        set_bit(IPS_DYING_BIT, &ct->status);
        }
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
        return NULL;
 found:
        atomic_inc(&ct->ct_general.use);
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
        return ct;
 }
 
@@ -947,7 +964,7 @@ static int kill_all(struct nf_conn *i, void *data)
        return 1;
 }
 
-void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, int size)
+void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 {
        if (vmalloced)
                vfree(hash);
@@ -996,7 +1013,7 @@ void nf_conntrack_cleanup(void)
        nf_conntrack_expect_fini();
 }
 
-struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced)
+struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
 {
        struct hlist_head *hash;
        unsigned int size, i;
@@ -1004,7 +1021,7 @@ struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced)
        *vmalloced = 0;
 
        size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
-       hash = (void*)__get_free_pages(GFP_KERNEL,
+       hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
                                       get_order(sizeof(struct hlist_head)
                                                 * size));
        if (!hash) {
@@ -1021,10 +1038,10 @@ struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced)
 }
 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
 
-int set_hashsize(const char *val, struct kernel_param *kp)
+int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
 {
-       int i, bucket, hashsize, vmalloced;
-       int old_vmalloced, old_size;
+       int i, bucket, vmalloced, old_vmalloced;
+       unsigned int hashsize, old_size;
        int rnd;
        struct hlist_head *hash, *old_hash;
        struct nf_conntrack_tuple_hash *h;
@@ -1033,7 +1050,7 @@ int set_hashsize(const char *val, struct kernel_param *kp)
        if (!nf_conntrack_htable_size)
                return param_set_uint(val, kp);
 
-       hashsize = simple_strtol(val, NULL, 0);
+       hashsize = simple_strtoul(val, NULL, 0);
        if (!hashsize)
                return -EINVAL;
 
@@ -1045,12 +1062,17 @@ int set_hashsize(const char *val, struct kernel_param *kp)
         * use a newrandom seed */
        get_random_bytes(&rnd, 4);
 
-       write_lock_bh(&nf_conntrack_lock);
+       /* Lookups in the old hash might happen in parallel, which means we
+        * might get false negatives during connection lookup. New connections
+        * created because of a false negative won't make it into the hash
+        * though since that required taking the lock.
+        */
+       spin_lock_bh(&nf_conntrack_lock);
        for (i = 0; i < nf_conntrack_htable_size; i++) {
                while (!hlist_empty(&nf_conntrack_hash[i])) {
                        h = hlist_entry(nf_conntrack_hash[i].first,
                                        struct nf_conntrack_tuple_hash, hnode);
-                       hlist_del(&h->hnode);
+                       hlist_del_rcu(&h->hnode);
                        bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
                        hlist_add_head(&h->hnode, &hash[bucket]);
                }
@@ -1063,13 +1085,14 @@ int set_hashsize(const char *val, struct kernel_param *kp)
        nf_conntrack_vmalloc = vmalloced;
        nf_conntrack_hash = hash;
        nf_conntrack_hash_rnd = rnd;
-       write_unlock_bh(&nf_conntrack_lock);
+       spin_unlock_bh(&nf_conntrack_lock);
 
        nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
        return 0;
 }
+EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
 
-module_param_call(hashsize, set_hashsize, param_get_uint,
+module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
                  &nf_conntrack_htable_size, 0600);
 
 int __init nf_conntrack_init(void)
@@ -1128,7 +1151,7 @@ int __init nf_conntrack_init(void)
                goto out_fini_expect;
 
        /* For use by REJECT target */
-       rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach);
+       rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
        rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
 
        /* Set up fake conntrack: