[NETFILTER]: nf_conntrack: introduce expectation classes and policies

Introduce expectation classes and policies. An expectation class
is used to distinguish different types of expectations by the
same helper (for example audio/video/t.120). The expectation
policy is used to hold the maximum number of expectations and
the initial timeout for each class.

The individual classes are isolated from each other, which means
that for example an audio expectation will only evict other audio
expectations.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

15 files changed, 166 insertions, 77 deletions

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 90b3e7f5df5..92287713359 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -75,6 +75,9 @@ do {									\
 
 struct nf_conntrack_helper;
 
+/* Must be kept in sync with the classes defined by helpers */
+#define NF_CT_MAX_EXPECT_CLASSES	1
+
 /* nf_conn feature for connections that have a helper */
 struct nf_conn_help {
 	/* Helper. if any */
@@ -85,7 +88,7 @@ struct nf_conn_help {
 	struct hlist_head expectations;
 
 	/* Current number of expected connections */
-	unsigned int expecting;
+	u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
 };
 
 
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 47c28dd0789..dfdf4b45947 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -41,6 +41,9 @@ struct nf_conntrack_expect
 	/* Flags */
 	unsigned int flags;
 
+	/* Expectation class */
+	unsigned int class;
+
 #ifdef CONFIG_NF_NAT_NEEDED
 	__be32 saved_ip;
 	/* This is the original per-proto part, used to map the
@@ -53,6 +56,14 @@ struct nf_conntrack_expect
 	struct rcu_head rcu;
 };
 
+struct nf_conntrack_expect_policy
+{
+	unsigned int	max_expected;
+	unsigned int	timeout;
+};
+
+#define NF_CT_EXPECT_CLASS_DEFAULT	0
+
 #define NF_CT_EXPECT_PERMANENT	0x1
 #define NF_CT_EXPECT_INACTIVE	0x2
 
@@ -75,7 +86,7 @@ void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
 /* Allocate space for an expectation: this is mandatory before calling
    nf_ct_expect_related.  You will have to call put afterwards. */
 struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me);
-void nf_ct_expect_init(struct nf_conntrack_expect *, int,
+void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, int,
 		       const union nf_inet_addr *,
 		       const union nf_inet_addr *,
 		       u_int8_t, const __be16 *, const __be16 *);
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index 4ca125e9b3c..f8060ab5a08 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -20,9 +20,7 @@ struct nf_conntrack_helper
 
 	const char *name;		/* name of the module */
 	struct module *me;		/* pointer to self */
-	unsigned int max_expected;	/* Maximum number of concurrent 
-					 * expected connections */
-	unsigned int timeout;		/* timeout for expecteds */
+	const struct nf_conntrack_expect_policy *expect_policy;
 
 	/* Tuple of things we will help (compared against server response) */
 	struct nf_conntrack_tuple tuple;
@@ -37,6 +35,7 @@ struct nf_conntrack_helper
 	void (*destroy)(struct nf_conn *ct);
 
 	int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
+	unsigned int expect_class_max;
 };
 
 extern struct nf_conntrack_helper *
diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c
index 540ce6ae887..000e080bac5 100644
--- a/net/ipv4/netfilter/nf_nat_snmp_basic.c
+++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c
@@ -50,6 +50,7 @@
 #include <net/udp.h>
 
 #include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_conntrack_expect.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_nat_helper.h>
 
@@ -1267,11 +1268,15 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 	return ret;
 }
 
+static const struct nf_conntrack_expect_policy snmp_exp_policy = {
+	.max_expected	= 0,
+	.timeout	= 180,
+};
+
 static struct nf_conntrack_helper snmp_helper __read_mostly = {
-	.max_expected		= 0,
-	.timeout		= 180,
 	.me			= THIS_MODULE,
 	.help			= help,
+	.expect_policy		= &snmp_exp_policy,
 	.name			= "snmp",
 	.tuple.src.l3num	= AF_INET,
 	.tuple.src.u.udp.port	= __constant_htons(SNMP_PORT),
@@ -1279,10 +1284,9 @@ static struct nf_conntrack_helper snmp_helper __read_mostly = {
 };
 
 static struct nf_conntrack_helper snmp_trap_helper __read_mostly = {
-	.max_expected		= 0,
-	.timeout		= 180,
 	.me			= THIS_MODULE,
 	.help			= help,
+	.expect_policy		= &snmp_exp_policy,
 	.name			= "snmp_trap",
 	.tuple.src.l3num	= AF_INET,
 	.tuple.src.u.udp.port	= __constant_htons(SNMP_TRAP_PORT),
diff --git a/net/netfilter/nf_conntrack_amanda.c b/net/netfilter/nf_conntrack_amanda.c
index 7b8239c0cd5..d14585a19b7 100644
--- a/net/netfilter/nf_conntrack_amanda.c
+++ b/net/netfilter/nf_conntrack_amanda.c
@@ -148,7 +148,8 @@ static int amanda_help(struct sk_buff *skb,
 			goto out;
 		}
 		tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
-		nf_ct_expect_init(exp, family, &tuple->src.u3, &tuple->dst.u3,
+		nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, family,
+				  &tuple->src.u3, &tuple->dst.u3,
 				  IPPROTO_TCP, NULL, &port);
 
 		nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
@@ -164,26 +165,29 @@ out:
 	return ret;
 }
 
+static const struct nf_conntrack_expect_policy amanda_exp_policy = {
+	.max_expected		= 3,
+	.timeout		= 180,
+};
+
 static struct nf_conntrack_helper amanda_helper[2] __read_mostly = {
 	{
 		.name			= "amanda",
-		.max_expected		= 3,
-		.timeout		= 180,
 		.me			= THIS_MODULE,
 		.help			= amanda_help,
 		.tuple.src.l3num	= AF_INET,
 		.tuple.src.u.udp.port	= __constant_htons(10080),
 		.tuple.dst.protonum	= IPPROTO_UDP,
+		.expect_policy		= &amanda_exp_policy,
 	},
 	{
 		.name			= "amanda",
-		.max_expected		= 3,
-		.timeout		= 180,
 		.me			= THIS_MODULE,
 		.help			= amanda_help,
 		.tuple.src.l3num	= AF_INET6,
 		.tuple.src.u.udp.port	= __constant_htons(10080),
 		.tuple.dst.protonum	= IPPROTO_UDP,
+		.expect_policy		= &amanda_exp_policy,
 	},
 };
 
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 882602f1c0e..e31beeb33b2 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -54,7 +54,7 @@ void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
 	nf_ct_expect_count--;
 
 	hlist_del(&exp->lnode);
-	master_help->expecting--;
+	master_help->expecting[exp->class]--;
 	nf_ct_expect_put(exp);
 
 	NF_CT_STAT_INC(expect_delete);
@@ -171,7 +171,7 @@ void nf_ct_remove_expectations(struct nf_conn *ct)
 	struct hlist_node *n, *next;
 
 	/* Optimization: most connection never expect any others. */
-	if (!help || help->expecting == 0)
+	if (!help)
 		return;
 
 	hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) {
@@ -205,7 +205,7 @@ static inline int expect_clash(const struct nf_conntrack_expect *a,
 static inline int expect_matches(const struct nf_conntrack_expect *a,
 				 const struct nf_conntrack_expect *b)
 {
-	return a->master == b->master
+	return a->master == b->master && a->class == b->class
 		&& nf_ct_tuple_equal(&a->tuple, &b->tuple)
 		&& nf_ct_tuple_mask_equal(&a->mask, &b->mask);
 }
@@ -240,7 +240,8 @@ struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me)
 }
 EXPORT_SYMBOL_GPL(nf_ct_expect_alloc);
 
-void nf_ct_expect_init(struct nf_conntrack_expect *exp, int family,
+void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class,
+		       int family,
 		       const union nf_inet_addr *saddr,
 		       const union nf_inet_addr *daddr,
 		       u_int8_t proto, const __be16 *src, const __be16 *dst)
@@ -253,6 +254,7 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, int family,
 		len = 16;
 
 	exp->flags = 0;
+	exp->class = class;
 	exp->expectfn = NULL;
 	exp->helper = NULL;
 	exp->tuple.src.l3num = family;
@@ -309,19 +311,21 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_put);
 static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
 {
 	struct nf_conn_help *master_help = nfct_help(exp->master);
+	const struct nf_conntrack_expect_policy *p;
 	unsigned int h = nf_ct_expect_dst_hash(&exp->tuple);
 
 	atomic_inc(&exp->use);
 
 	hlist_add_head(&exp->lnode, &master_help->expectations);
-	master_help->expecting++;
+	master_help->expecting[exp->class]++;
 
 	hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]);
 	nf_ct_expect_count++;
 
 	setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
 		    (unsigned long)exp);
-	exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
+	p = &master_help->helper->expect_policy[exp->class];
+	exp->timeout.expires = jiffies + p->timeout * HZ;
 	add_timer(&exp->timeout);
 
 	atomic_inc(&exp->use);
@@ -329,35 +333,41 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
 }
 
 /* Race with expectations being used means we could have none to find; OK. */
-static void evict_oldest_expect(struct nf_conn *master)
+static void evict_oldest_expect(struct nf_conn *master,
+				struct nf_conntrack_expect *new)
 {
 	struct nf_conn_help *master_help = nfct_help(master);
-	struct nf_conntrack_expect *exp = NULL;
+	struct nf_conntrack_expect *exp, *last = NULL;
 	struct hlist_node *n;
 
-	hlist_for_each_entry(exp, n, &master_help->expectations, lnode)
-		; /* nothing */
+	hlist_for_each_entry(exp, n, &master_help->expectations, lnode) {
+		if (exp->class == new->class)
+			last = exp;
+	}
 
-	if (exp && del_timer(&exp->timeout)) {
-		nf_ct_unlink_expect(exp);
-		nf_ct_expect_put(exp);
+	if (last && del_timer(&last->timeout)) {
+		nf_ct_unlink_expect(last);
+		nf_ct_expect_put(last);
 	}
 }
 
 static inline int refresh_timer(struct nf_conntrack_expect *i)
 {
 	struct nf_conn_help *master_help = nfct_help(i->master);
+	const struct nf_conntrack_expect_policy *p;
 
 	if (!del_timer(&i->timeout))
 		return 0;
 
-	i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
+	p = &master_help->helper->expect_policy[i->class];
+	i->timeout.expires = jiffies + p->timeout * HZ;
 	add_timer(&i->timeout);
 	return 1;
 }
 
 int nf_ct_expect_related(struct nf_conntrack_expect *expect)
 {
+	const struct nf_conntrack_expect_policy *p;
 	struct nf_conntrack_expect *i;
 	struct nf_conn *master = expect->master;
 	struct nf_conn_help *master_help = nfct_help(master);
@@ -386,9 +396,15 @@ int nf_ct_expect_related(struct nf_conntrack_expect *expect)
 		}
 	}
 	/* Will be over limit? */
-	if (master_help->helper->max_expected &&
-	    master_help->expecting >= master_help->helper->max_expected)
-		evict_oldest_expect(master);
+	p = &master_help->helper->expect_policy[expect->class];
+	if (p->max_expected &&
+	    master_help->expecting[expect->class] >= p->max_expected) {
+		evict_oldest_expect(master, expect);
+		if (master_help->expecting[expect->class] >= p->max_expected) {
+			ret = -EMFILE;
+			goto out;
+		}
+	}
 
 	if (nf_ct_expect_count >= nf_ct_expect_max) {
 		if (net_ratelimit())
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 6770baf2e84..7eff876bb8b 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -483,7 +483,7 @@ static int help(struct sk_buff *skb,
 		daddr = &cmd.u3;
 	}
 
-	nf_ct_expect_init(exp, cmd.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, cmd.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, daddr,
 			  IPPROTO_TCP, NULL, &cmd.u.tcp.port);
 
@@ -517,6 +517,11 @@ out_update_nl:
 static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly;
 static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")] __read_mostly;
 
+static const struct nf_conntrack_expect_policy ftp_exp_policy = {
+	.max_expected	= 1,
+	.timeout	= 5 * 60,
+};
+
 /* don't make this __exit, since it's called from __init ! */
 static void nf_conntrack_ftp_fini(void)
 {
@@ -556,8 +561,7 @@ static int __init nf_conntrack_ftp_init(void)
 		for (j = 0; j < 2; j++) {
 			ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]);
 			ftp[i][j].tuple.dst.protonum = IPPROTO_TCP;
-			ftp[i][j].max_expected = 1;
-			ftp[i][j].timeout = 5 * 60;	/* 5 Minutes */
+			ftp[i][j].expect_policy = &ftp_exp_policy;
 			ftp[i][j].me = THIS_MODULE;
 			ftp[i][j].help = help;
 			tmpname = &ftp_names[i][j][0];
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 898f1922b5b..505052d495c 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -277,7 +277,8 @@ static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 	/* Create expect for RTP */
 	if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(rtp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  IPPROTO_UDP, NULL, &rtp_port);
@@ -287,7 +288,8 @@ static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 		nf_ct_expect_put(rtp_exp);
 		return -1;
 	}
-	nf_ct_expect_init(rtcp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  IPPROTO_UDP, NULL, &rtcp_port);
@@ -344,7 +346,8 @@ static int expect_t120(struct sk_buff *skb,
 	/* Create expect for T.120 connections */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  IPPROTO_TCP, NULL, &port);
@@ -612,13 +615,17 @@ static int h245_help(struct sk_buff *skb, unsigned int protoff,
 }
 
 /****************************************************************************/
+static const struct nf_conntrack_expect_policy h245_exp_policy = {
+	.max_expected	= H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
+	.timeout	= 240,
+};
+
 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 	.name			= "H.245",
 	.me			= THIS_MODULE,
-	.max_expected		= H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
-	.timeout		= 240,
 	.tuple.dst.protonum	= IPPROTO_UDP,
-	.help			= h245_help
+	.help			= h245_help,
+	.expect_policy		= &h245_exp_policy,
 };
 
 /****************************************************************************/
@@ -676,7 +683,8 @@ static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 	/* Create expect for h245 connection */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  IPPROTO_TCP, NULL, &port);
@@ -792,7 +800,8 @@ static int expect_callforwarding(struct sk_buff *skb,
 	/* Create expect for the second call leg */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
 			  IPPROTO_TCP, NULL, &port);
 	exp->helper = nf_conntrack_helper_q931;
@@ -1156,28 +1165,30 @@ static int q931_help(struct sk_buff *skb, unsigned int protoff,
 }
 
 /****************************************************************************/
+static const struct nf_conntrack_expect_policy q931_exp_policy = {
+	/* T.120 and H.245 */
+	.max_expected		= H323_RTP_CHANNEL_MAX * 4 + 4,
+	.timeout		= 240,
+};
+
 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
 	{
 		.name			= "Q.931",
 		.me			= THIS_MODULE,
-					  /* T.120 and H.245 */
-		.max_expected		= H323_RTP_CHANNEL_MAX * 4 + 4,
-		.timeout		= 240,
 		.tuple.src.l3num	= AF_INET,
 		.tuple.src.u.tcp.port	= __constant_htons(Q931_PORT),
 		.tuple.dst.protonum	= IPPROTO_TCP,
-		.help			= q931_help
+		.help			= q931_help,
+		.expect_policy		= &q931_exp_policy,
 	},
 	{
 		.name			= "Q.931",
 		.me			= THIS_MODULE,
-					  /* T.120 and H.245 */
-		.max_expected		= H323_RTP_CHANNEL_MAX * 4 + 4,
-		.timeout		= 240,
 		.tuple.src.l3num	= AF_INET6,
 		.tuple.src.u.tcp.port	= __constant_htons(Q931_PORT),
 		.tuple.dst.protonum	= IPPROTO_TCP,
-		.help			= q931_help
+		.help			= q931_help,
+		.expect_policy		= &q931_exp_policy,
 	},
 };
 
@@ -1261,7 +1272,8 @@ static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
 	/* Create expect for Q.931 */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  gkrouted_only ? /* only accept calls from GK? */
 				&ct->tuplehash[!dir].tuple.src.u3 : NULL,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
@@ -1332,7 +1344,8 @@ static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
 	/* Need new expect */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
 			  IPPROTO_UDP, NULL, &port);
 	exp->helper = nf_conntrack_helper_ras;
@@ -1536,7 +1549,8 @@ static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
 	/* Need new expect */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
 			  IPPROTO_TCP, NULL, &port);
 	exp->flags = NF_CT_EXPECT_PERMANENT;
@@ -1589,7 +1603,8 @@ static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
 	/* Need new expect for call signal */
 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 		return -1;
-	nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[!dir].tuple.src.l3num,
 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
 			  IPPROTO_TCP, NULL, &port);
 	exp->flags = NF_CT_EXPECT_PERMANENT;
@@ -1728,26 +1743,29 @@ static int ras_help(struct sk_buff *skb, unsigned int protoff,
 }
 
 /****************************************************************************/
+static const struct nf_conntrack_expect_policy ras_exp_policy = {
+	.max_expected		= 32,
+	.timeout		= 240,
+};
+
 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
 	{
 		.name			= "RAS",
 		.me			= THIS_MODULE,
-		.max_expected		= 32,
-		.timeout		= 240,
 		.tuple.src.l3num	= AF_INET,
 		.tuple.src.u.udp.port	= __constant_htons(RAS_PORT),
 		.tuple.dst.protonum	= IPPROTO_UDP,
 		.help			= ras_help,
+		.expect_policy		= &ras_exp_policy,
 	},
 	{
 		.name			= "RAS",
 		.me			= THIS_MODULE,
-		.max_expected		= 32,
-		.timeout		= 240,
 		.tuple.src.l3num	= AF_INET6,
 		.tuple.src.u.udp.port	= __constant_htons(RAS_PORT),
 		.tuple.dst.protonum	= IPPROTO_UDP,
 		.help			= ras_help,
+		.expect_policy		= &ras_exp_policy,
 	},
 };
 
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index b1fd21cc1db..e350f56d43c 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -110,7 +110,8 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
 {
 	unsigned int h = helper_hash(&me->tuple);
 
-	BUG_ON(me->timeout == 0);
+	BUG_ON(me->expect_policy == NULL);
+	BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES);
 
 	mutex_lock(&nf_ct_helper_mutex);
 	hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index c336b07a0d4..02f21cbe5ae 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -187,7 +187,8 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 			}
 			tuple = &ct->tuplehash[!dir].tuple;
 			port = htons(dcc_port);
-			nf_ct_expect_init(exp, tuple->src.l3num,
+			nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+					  tuple->src.l3num,
 					  NULL, &tuple->dst.u3,
 					  IPPROTO_TCP, NULL, &port);
 
@@ -210,6 +211,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 
 static struct nf_conntrack_helper irc[MAX_PORTS] __read_mostly;
 static char irc_names[MAX_PORTS][sizeof("irc-65535")] __read_mostly;
+static struct nf_conntrack_expect_policy irc_exp_policy;
 
 static void nf_conntrack_irc_fini(void);
 
@@ -223,6 +225,9 @@ static int __init nf_conntrack_irc_init(void)
 		return -EINVAL;
 	}
 
+	irc_exp_policy.max_expected = max_dcc_channels;
+	irc_exp_policy.timeout = dcc_timeout;
+
 	irc_buffer = kmalloc(65536, GFP_KERNEL);
 	if (!irc_buffer)
 		return -ENOMEM;
@@ -235,8 +240,7 @@ static int __init nf_conntrack_irc_init(void)
 		irc[i].tuple.src.l3num = AF_INET;
 		irc[i].tuple.src.u.tcp.port = htons(ports[i]);
 		irc[i].tuple.dst.protonum = IPPROTO_TCP;
-		irc[i].max_expected = max_dcc_channels;
-		irc[i].timeout = dcc_timeout;
+		irc[i].expect_policy = &irc_exp_policy;
 		irc[i].me = THIS_MODULE;
 		irc[i].help = help;
 
diff --git a/net/netfilter/nf_conntrack_netbios_ns.c b/net/netfilter/nf_conntrack_netbios_ns.c
index 60dedaded84..08404e6755f 100644
--- a/net/netfilter/nf_conntrack_netbios_ns.c
+++ b/net/netfilter/nf_conntrack_netbios_ns.c
@@ -86,6 +86,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 
 	exp->expectfn             = NULL;
 	exp->flags                = NF_CT_EXPECT_PERMANENT;
+	exp->class		  = NF_CT_EXPECT_CLASS_DEFAULT;
 	exp->helper               = NULL;
 
 	nf_ct_expect_related(exp);
@@ -96,19 +97,23 @@ out:
 	return NF_ACCEPT;
 }
 
+static struct nf_conntrack_expect_policy exp_policy = {
+	.max_expected	= 1,
+};
+
 static struct nf_conntrack_helper helper __read_mostly = {
 	.name			= "netbios-ns",
 	.tuple.src.l3num	= AF_INET,
 	.tuple.src.u.udp.port	= __constant_htons(NMBD_PORT),
 	.tuple.dst.protonum	= IPPROTO_UDP,
-	.max_expected		= 1,
 	.me			= THIS_MODULE,
 	.help			= help,
+	.expect_policy		= &exp_policy,
 };
 
 static int __init nf_conntrack_netbios_ns_init(void)
 {
-	helper.timeout = timeout;
+	exp_policy.timeout = timeout;
 	return nf_conntrack_helper_register(&helper);
 }
 
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index b5cb8e83123..8fd83470d1b 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -208,7 +208,8 @@ static int exp_gre(struct nf_conn *ct, __be16 callid, __be16 peer_callid)
 
 	/* original direction, PNS->PAC */
 	dir = IP_CT_DIR_ORIGINAL;
-	nf_ct_expect_init(exp_orig, ct->tuplehash[dir].tuple.src.l3num,
+	nf_ct_expect_init(exp_orig, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[dir].tuple.src.l3num,
 			  &ct->tuplehash[dir].tuple.src.u3,
 			  &ct->tuplehash[dir].tuple.dst.u3,
 			  IPPROTO_GRE, &peer_callid, &callid);
@@ -216,7 +217,8 @@ static int exp_gre(struct nf_conn *ct, __be16 callid, __be16 peer_callid)
 
 	/* reply direction, PAC->PNS */
 	dir = IP_CT_DIR_REPLY;
-	nf_ct_expect_init(exp_reply, ct->tuplehash[dir].tuple.src.l3num,
+	nf_ct_expect_init(exp_reply, NF_CT_EXPECT_CLASS_DEFAULT,
+			  ct->tuplehash[dir].tuple.src.l3num,
 			  &ct->tuplehash[dir].tuple.src.u3,
 			  &ct->tuplehash[dir].tuple.dst.u3,
 			  IPPROTO_GRE, &callid, &peer_callid);
@@ -575,17 +577,21 @@ conntrack_pptp_help(struct sk_buff *skb, unsigned int protoff,
 	return ret;
 }
 
+static const struct nf_conntrack_expect_policy pptp_exp_policy = {
+	.max_expected	= 2,
+	.timeout	= 5 * 60,
+};
+
 /* control protocol helper */
 static struct nf_conntrack_helper pptp __read_mostly = {
 	.name			= "pptp",
 	.me			= THIS_MODULE,
-	.max_expected		= 2,
-	.timeout		= 5 * 60,
 	.tuple.src.l3num	= AF_INET,
 	.tuple.src.u.tcp.port	= __constant_htons(PPTP_CONTROL_PORT),
 	.tuple.dst.protonum	= IPPROTO_TCP,
 	.help			= conntrack_pptp_help,
 	.destroy		= pptp_destroy_siblings,
+	.expect_policy		= &pptp_exp_policy,
 };
 
 static int __init nf_conntrack_pptp_init(void)
diff --git a/net/netfilter/nf_conntrack_sane.c b/net/netfilter/nf_conntrack_sane.c
index a70051d741a..7542e25eede 100644
--- a/net/netfilter/nf_conntrack_sane.c
+++ b/net/netfilter/nf_conntrack_sane.c
@@ -143,7 +143,8 @@ static int help(struct sk_buff *skb,
 	}
 
 	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
-	nf_ct_expect_init(exp, family, &tuple->src.u3, &tuple->dst.u3,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, family,
+			  &tuple->src.u3, &tuple->dst.u3,
 			  IPPROTO_TCP, NULL, &reply->port);
 
 	pr_debug("nf_ct_sane: expect: ");
@@ -163,6 +164,11 @@ out:
 static struct nf_conntrack_helper sane[MAX_PORTS][2] __read_mostly;
 static char sane_names[MAX_PORTS][2][sizeof("sane-65535")] __read_mostly;
 
+static const struct nf_conntrack_expect_policy sane_exp_policy = {
+	.max_expected	= 1,
+	.timeout	= 5 * 60,
+};
+
 /* don't make this __exit, since it's called from __init ! */
 static void nf_conntrack_sane_fini(void)
 {
@@ -200,8 +206,7 @@ static int __init nf_conntrack_sane_init(void)
 		for (j = 0; j < 2; j++) {
 			sane[i][j].tuple.src.u.tcp.port = htons(ports[i]);
 			sane[i][j].tuple.dst.protonum = IPPROTO_TCP;
-			sane[i][j].max_expected = 1;
-			sane[i][j].timeout = 5 * 60;	/* 5 Minutes */
+			sane[i][j].expect_policy = &sane_exp_policy;
 			sane[i][j].me = THIS_MODULE;
 			sane[i][j].help = help;
 			tmpname = &sane_names[i][j][0];
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index c521c891d35..0021d5b60ce 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -380,7 +380,7 @@ static int set_expected_rtp(struct sk_buff *skb,
 	exp = nf_ct_expect_alloc(ct);
 	if (exp == NULL)
 		return NF_DROP;
-	nf_ct_expect_init(exp, family,
+	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, family,
 			  &ct->tuplehash[!dir].tuple.src.u3, addr,
 			  IPPROTO_UDP, NULL, &port);
 
@@ -476,6 +476,11 @@ out:
 static struct nf_conntrack_helper sip[MAX_PORTS][2] __read_mostly;
 static char sip_names[MAX_PORTS][2][sizeof("sip-65535")] __read_mostly;
 
+static const struct nf_conntrack_expect_policy sip_exp_policy = {
+	.max_expected	= 2,
+	.timeout	= 3 * 60,
+};
+
 static void nf_conntrack_sip_fini(void)
 {
 	int i, j;
@@ -505,8 +510,7 @@ static int __init nf_conntrack_sip_init(void)
 		for (j = 0; j < 2; j++) {
 			sip[i][j].tuple.dst.protonum = IPPROTO_UDP;
 			sip[i][j].tuple.src.u.udp.port = htons(ports[i]);
-			sip[i][j].max_expected = 2;
-			sip[i][j].timeout = 3 * 60; /* 3 minutes */
+			sip[i][j].expect_policy = &sip_exp_policy;
 			sip[i][j].me = THIS_MODULE;
 			sip[i][j].help = sip_help;
 
diff --git a/net/netfilter/nf_conntrack_tftp.c b/net/netfilter/nf_conntrack_tftp.c
index bd2e800f23c..a28341b30f2 100644
--- a/net/netfilter/nf_conntrack_tftp.c
+++ b/net/netfilter/nf_conntrack_tftp.c
@@ -63,7 +63,8 @@ static int tftp_help(struct sk_buff *skb,
 		if (exp == NULL)
 			return NF_DROP;
 		tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
-		nf_ct_expect_init(exp, family, &tuple->src.u3, &tuple->dst.u3,
+		nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, family,
+				  &tuple->src.u3, &tuple->dst.u3,
 				  IPPROTO_UDP, NULL, &tuple->dst.u.udp.port);
 
 		pr_debug("expect: ");
@@ -92,6 +93,11 @@ static int tftp_help(struct sk_buff *skb,
 static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
 static char tftp_names[MAX_PORTS][2][sizeof("tftp-65535")] __read_mostly;
 
+static const struct nf_conntrack_expect_policy tftp_exp_policy = {
+	.max_expected	= 1,
+	.timeout	= 5 * 60,
+};
+
 static void nf_conntrack_tftp_fini(void)
 {
 	int i, j;
@@ -118,8 +124,7 @@ static int __init nf_conntrack_tftp_init(void)
 		for (j = 0; j < 2; j++) {
 			tftp[i][j].tuple.dst.protonum = IPPROTO_UDP;
 			tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
-			tftp[i][j].max_expected = 1;
-			tftp[i][j].timeout = 5 * 60; /* 5 minutes */
+			tftp[i][j].expect_policy = &tftp_exp_policy;
 			tftp[i][j].me = THIS_MODULE;
 			tftp[i][j].help = tftp_help;