X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=net%2Fnetfilter%2Fnf_conntrack_core.c;h=b77eb56a87e33a7ec85bd351e5b6d512922ebbc3;hb=1ca721cdb748ba72c47e9c661d54696db3cde796;hp=000c2fb462d07996106270e33eadc72fb07718e6;hpb=95b00786f3b8fa99f53931361beeb4c10504ad87;p=linux-2.6-omap-h63xx.git

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 000c2fb462d..b77eb56a87e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -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 */
@@ -73,15 +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)
@@ -166,8 +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);
@@ -199,7 +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,
@@ -213,7 +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);
@@ -236,31 +240,35 @@ 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)) {
+	/* Disable BHs the entire time since we normally need to disable them
+	 * at least once for the stats anyway.
+	 */
+	local_bh_disable();
+	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);
+			local_bh_enable();
 			return h;
 		}
 		NF_CT_STAT_INC(searched);
 	}
+	local_bh_enable();
 
 	return NULL;
 }
@@ -271,12 +279,16 @@ 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;
 }
@@ -286,10 +298,10 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 				       unsigned int hash,
 				       unsigned int repl_hash)
 {
-	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)
@@ -299,9 +311,9 @@ 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);
 
@@ -338,7 +350,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	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
@@ -364,7 +376,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	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, skb);
@@ -379,7 +391,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 
 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);
@@ -391,12 +403,25 @@ 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);
+	/* Disable BHs the entire time since we need to disable them at
+	 * least once for the stats anyway.
+	 */
+	rcu_read_lock_bh();
+	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_bh();
+			return 1;
+		}
+		NF_CT_STAT_INC(searched);
+	}
+	rcu_read_unlock_bh();
 
-	return h != NULL;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 
@@ -404,7 +429,7 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 
 /* There's a small race here where we may free a just-assured
    connection.  Too bad: we're in trouble anyway. */
-static int early_drop(unsigned int hash)
+static noinline int early_drop(unsigned int hash)
 {
 	/* Use oldest entry, which is roughly LRU */
 	struct nf_conntrack_tuple_hash *h;
@@ -413,21 +438,23 @@ 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;
@@ -444,7 +471,7 @@ static int early_drop(unsigned int hash)
 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 				   const struct nf_conntrack_tuple *repl)
 {
-	struct nf_conn *conntrack = NULL;
+	struct nf_conn *ct = NULL;
 
 	if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 		get_random_bytes(&nf_conntrack_hash_rnd, 4);
@@ -454,8 +481,8 @@ struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 	/* We don't want any race condition at early drop stage */
 	atomic_inc(&nf_conntrack_count);
 
-	if (nf_conntrack_max
-	    && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
+	if (nf_conntrack_max &&
+	    unlikely(atomic_read(&nf_conntrack_count) > nf_conntrack_max)) {
 		unsigned int hash = hash_conntrack(orig);
 		if (!early_drop(hash)) {
 			atomic_dec(&nf_conntrack_count);
@@ -467,30 +494,37 @@ struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 		}
 	}
 
-	conntrack = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC);
-	if (conntrack == NULL) {
+	ct = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC);
+	if (ct == NULL) {
 		pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 		atomic_dec(&nf_conntrack_count);
 		return ERR_PTR(-ENOMEM);
 	}
 
-	atomic_set(&conntrack->ct_general.use, 1);
-	conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
-	conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
+	atomic_set(&ct->ct_general.use, 1);
+	ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
+	ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 	/* Don't set timer yet: wait for confirmation */
-	setup_timer(&conntrack->timeout, death_by_timeout,
-		    (unsigned long)conntrack);
+	setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
+	INIT_RCU_HEAD(&ct->rcu);
 
-	return conntrack;
+	return ct;
 }
 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 *ct)
+{
+	call_rcu(&ct->rcu, nf_conntrack_free_rcu);
+}
 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 
 /* Allocate a new conntrack: we return -ENOMEM if classification
@@ -502,7 +536,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 	       struct sk_buff *skb,
 	       unsigned int dataoff)
 {
-	struct nf_conn *conntrack;
+	struct nf_conn *ct;
 	struct nf_conn_help *help;
 	struct nf_conntrack_tuple repl_tuple;
 	struct nf_conntrack_expect *exp;
@@ -512,46 +546,46 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 		return NULL;
 	}
 
-	conntrack = nf_conntrack_alloc(tuple, &repl_tuple);
-	if (conntrack == NULL || IS_ERR(conntrack)) {
+	ct = nf_conntrack_alloc(tuple, &repl_tuple);
+	if (ct == NULL || IS_ERR(ct)) {
 		pr_debug("Can't allocate conntrack.\n");
-		return (struct nf_conntrack_tuple_hash *)conntrack;
+		return (struct nf_conntrack_tuple_hash *)ct;
 	}
 
-	if (!l4proto->new(conntrack, skb, dataoff)) {
-		nf_conntrack_free(conntrack);
+	if (!l4proto->new(ct, skb, dataoff)) {
+		nf_conntrack_free(ct);
 		pr_debug("init conntrack: can't track with proto module\n");
 		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",
-			 conntrack, exp);
+			 ct, exp);
 		/* Welcome, Mr. Bond.  We've been expecting you... */
-		__set_bit(IPS_EXPECTED_BIT, &conntrack->status);
-		conntrack->master = exp->master;
+		__set_bit(IPS_EXPECTED_BIT, &ct->status);
+		ct->master = exp->master;
 		if (exp->helper) {
-			help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
+			help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 			if (help)
 				rcu_assign_pointer(help->helper, exp->helper);
 		}
 
 #ifdef CONFIG_NF_CONNTRACK_MARK
-		conntrack->mark = exp->master->mark;
+		ct->mark = exp->master->mark;
 #endif
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
-		conntrack->secmark = exp->master->secmark;
+		ct->secmark = exp->master->secmark;
 #endif
-		nf_conntrack_get(&conntrack->master->ct_general);
+		nf_conntrack_get(&ct->master->ct_general);
 		NF_CT_STAT_INC(expect_new);
 	} else {
 		struct nf_conntrack_helper *helper;
 
 		helper = __nf_ct_helper_find(&repl_tuple);
 		if (helper) {
-			help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
+			help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 			if (help)
 				rcu_assign_pointer(help->helper, helper);
 		}
@@ -559,18 +593,17 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 	}
 
 	/* Overload tuple linked list to put us in unconfirmed list. */
-	hlist_add_head(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
-		       &unconfirmed);
+	hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, &unconfirmed);
 
-	write_unlock_bh(&nf_conntrack_lock);
+	spin_unlock_bh(&nf_conntrack_lock);
 
 	if (exp) {
 		if (exp->expectfn)
-			exp->expectfn(conntrack, exp);
+			exp->expectfn(ct, exp);
 		nf_ct_expect_put(exp);
 	}
 
-	return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
+	return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 }
 
 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
@@ -729,7 +762,6 @@ 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));
 
@@ -738,8 +770,9 @@ 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)
@@ -757,7 +790,7 @@ 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);
 
@@ -773,13 +806,11 @@ 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)) {
@@ -799,6 +830,7 @@ void __nf_ct_refresh_acct(struct nf_conn *ct,
 		}
 	}
 
+acct:
 #ifdef CONFIG_NF_CT_ACCT
 	if (do_acct) {
 		ct->counters[CTINFO2DIR(ctinfo)].packets++;
@@ -811,7 +843,7 @@ 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)
@@ -831,10 +863,8 @@ EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 			       const struct nf_conntrack_tuple *tuple)
 {
-	NLA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
-		&tuple->src.u.tcp.port);
-	NLA_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;
 
 nla_put_failure:
@@ -854,8 +884,8 @@ int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 	if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 		return -EINVAL;
 
-	t->src.u.tcp.port = *(__be16 *)nla_data(tb[CTA_PROTO_SRC_PORT]);
-	t->dst.u.tcp.port = *(__be16 *)nla_data(tb[CTA_PROTO_DST_PORT]);
+	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;
 }
@@ -863,7 +893,7 @@ 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;
@@ -880,15 +910,6 @@ 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,
-	int (*iter)(struct nf_conn *i, void *data),
-	void *data)
-{
-	return iter(nf_ct_tuplehash_to_ctrack(i), data);
-}
 
 /* Bring out ya dead! */
 static struct nf_conn *
@@ -899,7 +920,7 @@ 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);
@@ -912,11 +933,11 @@ 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;
 }
 
@@ -942,7 +963,7 @@ 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);
@@ -991,7 +1012,7 @@ 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;
@@ -1016,10 +1037,10 @@ 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;
@@ -1028,7 +1049,7 @@ 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;
 
@@ -1040,12 +1061,17 @@ 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]);
 		}
@@ -1058,13 +1084,14 @@ 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)
@@ -1123,7 +1150,7 @@ 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: