Merge branch 'master' of git://1984.lsi.us.es/nf-next

Pablo says:

====================
This is the second batch of Netfilter updates for net-next. It contains the
kernel changes for the new user-space connection tracking helper
infrastructure.

More details on this infrastructure are provides here:
http://lwn.net/Articles/500196/

Still, I plan to provide some official documentation through the
conntrack-tools user manual on how to setup user-space utilities for this.
So far, it provides two helper in user-space, one for NFSv3 and another for
Oracle/SQLnet/TNS. Yet in my TODO list.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter.h

@@ -393,6 +393,18 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
 extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
 extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
+
+struct nf_conn;
+struct nlattr;
+
+struct nfq_ct_hook {
+	size_t (*build_size)(const struct nf_conn *ct);
+	int (*build)(struct sk_buff *skb, struct nf_conn *ct);
+	int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
+	void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
+			   u32 ctinfo, int off);
+};
+extern struct nfq_ct_hook *nfq_ct_hook;
 #else
 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
 #endif

include/linux/netfilter/Kbuild

@@ -10,6 +10,7 @@ header-y += nfnetlink.h
 header-y += nfnetlink_acct.h
 header-y += nfnetlink_compat.h
 header-y += nfnetlink_conntrack.h
+header-y += nfnetlink_cthelper.h
 header-y += nfnetlink_cttimeout.h
 header-y += nfnetlink_log.h
 header-y += nfnetlink_queue.h

include/linux/netfilter/nf_conntrack_sip.h

@@ -2,6 +2,8 @@
 #define __NF_CONNTRACK_SIP_H__
 #ifdef __KERNEL__
 
+#include <net/netfilter/nf_conntrack_expect.h>
+
 #define SIP_PORT	5060
 #define SIP_TIMEOUT	3600
 

include/linux/netfilter/nfnetlink.h

@@ -50,7 +50,8 @@ struct nfgenmsg {
 #define NFNL_SUBSYS_IPSET		6
 #define NFNL_SUBSYS_ACCT		7
 #define NFNL_SUBSYS_CTNETLINK_TIMEOUT	8
-#define NFNL_SUBSYS_COUNT		9
+#define NFNL_SUBSYS_CTHELPER		9
+#define NFNL_SUBSYS_COUNT		10
 
 #ifdef __KERNEL__
 

include/linux/netfilter/nfnetlink_conntrack.h

@@ -191,6 +191,7 @@ enum ctattr_expect_nat {
 enum ctattr_help {
 	CTA_HELP_UNSPEC,
 	CTA_HELP_NAME,
+	CTA_HELP_INFO,
 	__CTA_HELP_MAX
 };
 #define CTA_HELP_MAX (__CTA_HELP_MAX - 1)

include/linux/netfilter/nfnetlink_cthelper.h

@@ -0,0 +1,55 @@
+#ifndef _NFNL_CTHELPER_H_
+#define _NFNL_CTHELPER_H_
+
+#define NFCT_HELPER_STATUS_DISABLED	0
+#define NFCT_HELPER_STATUS_ENABLED	1
+
+enum nfnl_acct_msg_types {
+	NFNL_MSG_CTHELPER_NEW,
+	NFNL_MSG_CTHELPER_GET,
+	NFNL_MSG_CTHELPER_DEL,
+	NFNL_MSG_CTHELPER_MAX
+};
+
+enum nfnl_cthelper_type {
+	NFCTH_UNSPEC,
+	NFCTH_NAME,
+	NFCTH_TUPLE,
+	NFCTH_QUEUE_NUM,
+	NFCTH_POLICY,
+	NFCTH_PRIV_DATA_LEN,
+	NFCTH_STATUS,
+	__NFCTH_MAX
+};
+#define NFCTH_MAX (__NFCTH_MAX - 1)
+
+enum nfnl_cthelper_policy_type {
+	NFCTH_POLICY_SET_UNSPEC,
+	NFCTH_POLICY_SET_NUM,
+	NFCTH_POLICY_SET,
+	NFCTH_POLICY_SET1	= NFCTH_POLICY_SET,
+	NFCTH_POLICY_SET2,
+	NFCTH_POLICY_SET3,
+	NFCTH_POLICY_SET4,
+	__NFCTH_POLICY_SET_MAX
+};
+#define NFCTH_POLICY_SET_MAX (__NFCTH_POLICY_SET_MAX - 1)
+
+enum nfnl_cthelper_pol_type {
+	NFCTH_POLICY_UNSPEC,
+	NFCTH_POLICY_NAME,
+	NFCTH_POLICY_EXPECT_MAX,
+	NFCTH_POLICY_EXPECT_TIMEOUT,
+	__NFCTH_POLICY_MAX
+};
+#define NFCTH_POLICY_MAX (__NFCTH_POLICY_MAX - 1)
+
+enum nfnl_cthelper_tuple_type {
+	NFCTH_TUPLE_UNSPEC,
+	NFCTH_TUPLE_L3PROTONUM,
+	NFCTH_TUPLE_L4PROTONUM,
+	__NFCTH_TUPLE_MAX,
+};
+#define NFCTH_TUPLE_MAX (__NFCTH_TUPLE_MAX - 1)
+
+#endif /* _NFNL_CTHELPER_H */

include/linux/netfilter/nfnetlink_queue.h

@@ -42,6 +42,8 @@ enum nfqnl_attr_type {
 	NFQA_IFINDEX_PHYSOUTDEV,	/* __u32 ifindex */
 	NFQA_HWADDR,			/* nfqnl_msg_packet_hw */
 	NFQA_PAYLOAD,			/* opaque data payload */
+	NFQA_CT,			/* nf_conntrack_netlink.h */
+	NFQA_CT_INFO,			/* enum ip_conntrack_info */
 
 	__NFQA_MAX
 };
@@ -92,5 +94,6 @@ enum nfqnl_attr_config {
 
 /* Flags for NFQA_CFG_FLAGS */
 #define NFQA_CFG_F_FAIL_OPEN			(1 << 0)
+#define NFQA_CFG_F_CONNTRACK			(1 << 1)
 
 #endif /* _NFNETLINK_QUEUE_H */

include/linux/netfilter_ipv4.h

@@ -66,6 +66,7 @@ enum nf_ip_hook_priorities {
 	NF_IP_PRI_SECURITY = 50,
 	NF_IP_PRI_NAT_SRC = 100,
 	NF_IP_PRI_SELINUX_LAST = 225,
+	NF_IP_PRI_CONNTRACK_HELPER = 300,
 	NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
 	NF_IP_PRI_LAST = INT_MAX,
 };

include/linux/netfilter_ipv6.h

@@ -71,6 +71,7 @@ enum nf_ip6_hook_priorities {
 	NF_IP6_PRI_SECURITY = 50,
 	NF_IP6_PRI_NAT_SRC = 100,
 	NF_IP6_PRI_SELINUX_LAST = 225,
+	NF_IP6_PRI_CONNTRACK_HELPER = 300,
 	NF_IP6_PRI_LAST = INT_MAX,
 };
 

include/net/netfilter/nf_conntrack.h

@@ -39,36 +39,6 @@ union nf_conntrack_expect_proto {
 	/* insert expect proto private data here */
 };
 
-/* Add protocol helper include file here */
-#include <linux/netfilter/nf_conntrack_ftp.h>
-#include <linux/netfilter/nf_conntrack_pptp.h>
-#include <linux/netfilter/nf_conntrack_h323.h>
-#include <linux/netfilter/nf_conntrack_sane.h>
-#include <linux/netfilter/nf_conntrack_sip.h>
-
-/* per conntrack: application helper private data */
-union nf_conntrack_help {
-	/* insert conntrack helper private data (master) here */
-#if defined(CONFIG_NF_CONNTRACK_FTP) || defined(CONFIG_NF_CONNTRACK_FTP_MODULE)
-	struct nf_ct_ftp_master ct_ftp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_PPTP) || \
-    defined(CONFIG_NF_CONNTRACK_PPTP_MODULE)
-	struct nf_ct_pptp_master ct_pptp_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_H323) || \
-    defined(CONFIG_NF_CONNTRACK_H323_MODULE)
-	struct nf_ct_h323_master ct_h323_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SANE) || \
-    defined(CONFIG_NF_CONNTRACK_SANE_MODULE)
-	struct nf_ct_sane_master ct_sane_info;
-#endif
-#if defined(CONFIG_NF_CONNTRACK_SIP) || defined(CONFIG_NF_CONNTRACK_SIP_MODULE)
-	struct nf_ct_sip_master ct_sip_info;
-#endif
-};
-
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/timer.h>
@@ -89,12 +59,13 @@ struct nf_conn_help {
 	/* Helper. if any */
 	struct nf_conntrack_helper __rcu *helper;
 
-	union nf_conntrack_help help;
-
 	struct hlist_head expectations;
 
 	/* Current number of expected connections */
 	u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
+
+	/* private helper information. */
+	char data[];
 };
 
 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>

include/net/netfilter/nf_conntrack_expect.h

@@ -59,10 +59,12 @@ static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp)
 	return nf_ct_net(exp->master);
 }
 
+#define NF_CT_EXP_POLICY_NAME_LEN	16
+
 struct nf_conntrack_expect_policy {
 	unsigned int	max_expected;
 	unsigned int	timeout;
-	const char	*name;
+	char		name[NF_CT_EXP_POLICY_NAME_LEN];
 };
 
 #define NF_CT_EXPECT_CLASS_DEFAULT	0

include/net/netfilter/nf_conntrack_extend.h

@@ -80,10 +80,13 @@ static inline void nf_ct_ext_free(struct nf_conn *ct)
 }
 
 /* Add this type, returns pointer to data or NULL. */
-void *
-__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
+void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
+			     size_t var_alloc_len, gfp_t gfp);
+
 #define nf_ct_ext_add(ct, id, gfp) \
-	((id##_TYPE *)__nf_ct_ext_add((ct), (id), (gfp)))
+	((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), 0, (gfp)))
+#define nf_ct_ext_add_length(ct, id, len, gfp) \
+	((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), (len), (gfp)))
 
 #define NF_CT_EXT_F_PREALLOC	0x0001
 

include/net/netfilter/nf_conntrack_helper.h

@@ -11,18 +11,27 @@
 #define _NF_CONNTRACK_HELPER_H
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_conntrack_expect.h>
 
 struct module;
 
+enum nf_ct_helper_flags {
+	NF_CT_HELPER_F_USERSPACE	= (1 << 0),
+	NF_CT_HELPER_F_CONFIGURED	= (1 << 1),
+};
+
 #define NF_CT_HELPER_NAME_LEN	16
 
 struct nf_conntrack_helper {
 	struct hlist_node hnode;	/* Internal use. */
 
-	const char *name;		/* name of the module */
+	char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
 	struct module *me;		/* pointer to self */
 	const struct nf_conntrack_expect_policy *expect_policy;
 
+	/* length of internal data, ie. sizeof(struct nf_ct_*_master) */
+	size_t data_len;
+
 	/* Tuple of things we will help (compared against server response) */
 	struct nf_conntrack_tuple tuple;
 
@@ -35,8 +44,12 @@ struct nf_conntrack_helper {
 
 	void (*destroy)(struct nf_conn *ct);
 
+	int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
 	int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
 	unsigned int expect_class_max;
+
+	unsigned int flags;
+	unsigned int queue_num;		/* For user-space helpers. */
 };
 
 extern struct nf_conntrack_helper *
@@ -48,7 +61,7 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
 extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
 
-extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
+extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conntrack_helper *helper, gfp_t gfp);
 
 extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
 				     gfp_t flags);
@@ -60,6 +73,15 @@ static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
 	return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 }
 
+static inline void *nfct_help_data(const struct nf_conn *ct)
+{
+	struct nf_conn_help *help;
+
+	help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+
+	return (void *)help->data;
+}
+
 extern int nf_conntrack_helper_init(struct net *net);
 extern void nf_conntrack_helper_fini(struct net *net);
 
@@ -82,4 +104,7 @@ nf_ct_helper_expectfn_find_by_name(const char *name);
 struct nf_ct_helper_expectfn *
 nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
 
+extern struct hlist_head *nf_ct_helper_hash;
+extern unsigned int nf_ct_helper_hsize;
+
 #endif /*_NF_CONNTRACK_HELPER_H*/

include/net/netfilter/nf_nat_helper.h

@@ -54,4 +54,8 @@ extern void nf_nat_follow_master(struct nf_conn *ct,
 extern s16 nf_nat_get_offset(const struct nf_conn *ct,
 			     enum ip_conntrack_dir dir,
 			     u32 seq);
+
+extern void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
+				  u32 dir, int off);
+
 #endif

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

@@ -95,11 +95,11 @@ static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
 	return NF_ACCEPT;
 }
 
-static unsigned int ipv4_confirm(unsigned int hooknum,
-				 struct sk_buff *skb,
-				 const struct net_device *in,
-				 const struct net_device *out,
-				 int (*okfn)(struct sk_buff *))
+static unsigned int ipv4_helper(unsigned int hooknum,
+				struct sk_buff *skb,
+				const struct net_device *in,
+				const struct net_device *out,
+				int (*okfn)(struct sk_buff *))
 {
 	struct nf_conn *ct;
 	enum ip_conntrack_info ctinfo;
@@ -110,24 +110,38 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
 	/* This is where we call the helper: as the packet goes out. */
 	ct = nf_ct_get(skb, &ctinfo);
 	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
-		goto out;
+		return NF_ACCEPT;
 
 	help = nfct_help(ct);
 	if (!help)
-		goto out;
+		return NF_ACCEPT;
 
 	/* rcu_read_lock()ed by nf_hook_slow */
 	helper = rcu_dereference(help->helper);
 	if (!helper)
-		goto out;
+		return NF_ACCEPT;
 
 	ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
 			   ct, ctinfo);
-	if (ret != NF_ACCEPT) {
+	if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
 		nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
 			      "nf_ct_%s: dropping packet", helper->name);
-		return ret;
 	}
+	return ret;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+				 struct sk_buff *skb,
+				 const struct net_device *in,
+				 const struct net_device *out,
+				 int (*okfn)(struct sk_buff *))
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+		goto out;
 
 	/* adjust seqs for loopback traffic only in outgoing direction */
 	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
@@ -184,13 +198,27 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
 		.hooknum	= NF_INET_LOCAL_OUT,
 		.priority	= NF_IP_PRI_CONNTRACK,
 	},
+	{
+		.hook		= ipv4_helper,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_POST_ROUTING,
+		.priority	= NF_IP_PRI_CONNTRACK_HELPER,
+	},
 	{
 		.hook		= ipv4_confirm,
 		.owner		= THIS_MODULE,
 		.pf		= NFPROTO_IPV4,
 		.hooknum	= NF_INET_POST_ROUTING,
 		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
 	},
+	{
+		.hook		= ipv4_helper,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_CONNTRACK_HELPER,
+	},
 	{
 		.hook		= ipv4_confirm,
 		.owner		= THIS_MODULE,