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Commit 080774a2 authored by Harald Welte's avatar Harald Welte Committed by David S. Miller
Browse files

[NETFILTER]: Add ctnetlink subsystem 



Add ctnetlink subsystem for userspace-access to ip_conntrack table.
This allows reading and updating of existing entries, as well as
creating new ones (and new expect's) via nfnetlink.

Please note the 'strange' byte order: nfattr (tag+length) are in host
byte order, while the payload is always guaranteed to be in network
byte order.  This allows a simple userspace process to encapsulate netlink
messages into arch-independent udp packets by just processing/swapping the
headers and not knowing anything about the actual payload.

Signed-off-by: default avatarHarald Welte <laforge@netfilter.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6f1cf165

include/linux/netfilter/nfnetlink.h

+2 −1
Original line number Diff line number Diff line
@@ -56,7 +56,7 @@ struct nfgenmsg { 
	u_int16_t res_id;		/* resource id */

} __attribute__ ((packed));



#define NFNETLINK_V1	1

#define NFNETLINK_V0	0



#define NFM_NFA(n)      ((struct nfattr *)(((char *)(n)) \

        + NLMSG_ALIGN(sizeof(struct nfgenmsg))))
@@ -81,6 +81,7 @@ enum nfnl_subsys_id { 


#ifdef __KERNEL__



#include <linux/netlink.h>

#include <linux/capability.h>



struct nfnl_callback

include/linux/netfilter/nfnetlink_conntrack.h

0 → 100644
+123 −0
Original line number Diff line number Diff line 
#ifndef _IPCONNTRACK_NETLINK_H

#define _IPCONNTRACK_NETLINK_H

#include <linux/netfilter/nfnetlink.h>



enum cntl_msg_types {

	IPCTNL_MSG_CT_NEW,

	IPCTNL_MSG_CT_GET,

	IPCTNL_MSG_CT_DELETE,

	IPCTNL_MSG_CT_GET_CTRZERO,



	IPCTNL_MSG_MAX

};



enum ctnl_exp_msg_types {

	IPCTNL_MSG_EXP_NEW,

	IPCTNL_MSG_EXP_GET,

	IPCTNL_MSG_EXP_DELETE,



	IPCTNL_MSG_EXP_MAX

};





enum ctattr_type {

	CTA_UNSPEC,

	CTA_TUPLE_ORIG,

	CTA_TUPLE_REPLY,

	CTA_STATUS,

	CTA_PROTOINFO,

	CTA_HELP,

	CTA_NAT,

	CTA_TIMEOUT,

	CTA_MARK,

	CTA_COUNTERS_ORIG,

	CTA_COUNTERS_REPLY,

	CTA_USE,

	CTA_EXPECT,

	CTA_ID,

	__CTA_MAX

};

#define CTA_MAX (__CTA_MAX - 1)



enum ctattr_tuple {

	CTA_TUPLE_UNSPEC,

	CTA_TUPLE_IP,

	CTA_TUPLE_PROTO,

	__CTA_TUPLE_MAX

};

#define CTA_TUPLE_MAX (__CTA_TUPLE_MAX - 1)



enum ctattr_ip {

	CTA_IP_UNSPEC,

	CTA_IP_V4_SRC,

	CTA_IP_V4_DST,

	CTA_IP_V6_SRC,

	CTA_IP_V6_DST,

	__CTA_IP_MAX

};

#define CTA_IP_MAX (__CTA_IP_MAX - 1)



enum ctattr_l4proto {

	CTA_PROTO_UNSPEC,

	CTA_PROTO_NUM,

	CTA_PROTO_SRC_PORT,

	CTA_PROTO_DST_PORT,

	CTA_PROTO_ICMP_ID,

	CTA_PROTO_ICMP_TYPE,

	CTA_PROTO_ICMP_CODE,

	__CTA_PROTO_MAX

};

#define CTA_PROTO_MAX (__CTA_PROTO_MAX - 1)



enum ctattr_protoinfo {

	CTA_PROTOINFO_UNSPEC,

	CTA_PROTOINFO_TCP_STATE,

	__CTA_PROTOINFO_MAX

};

#define CTA_PROTOINFO_MAX (__CTA_PROTOINFO_MAX - 1)



enum ctattr_counters {

	CTA_COUNTERS_UNSPEC,

	CTA_COUNTERS_PACKETS,

	CTA_COUNTERS_BYTES,

	__CTA_COUNTERS_MAX

};

#define CTA_COUNTERS_MAX (__CTA_COUNTERS_MAX - 1)



enum ctattr_nat {

	CTA_NAT_UNSPEC,

	CTA_NAT_MINIP,

	CTA_NAT_MAXIP,

	CTA_NAT_PROTO,

	__CTA_NAT_MAX

};

#define CTA_NAT_MAX (__CTA_NAT_MAX - 1)



enum ctattr_protonat {

	CTA_PROTONAT_UNSPEC,

	CTA_PROTONAT_PORT_MIN,

	CTA_PROTONAT_PORT_MAX,

	__CTA_PROTONAT_MAX

};

#define CTA_PROTONAT_MAX (__CTA_PROTONAT_MAX - 1)



enum ctattr_expect {

	CTA_EXPECT_UNSPEC,

	CTA_EXPECT_TUPLE,

	CTA_EXPECT_MASK,

	CTA_EXPECT_TIMEOUT,

	CTA_EXPECT_ID,

	__CTA_EXPECT_MAX

};

#define CTA_EXPECT_MAX (__CTA_EXPECT_MAX - 1)



enum ctattr_help {

	CTA_HELP_UNSPEC,

	CTA_HELP_NAME,

	__CTA_HELP_MAX

};

#define CTA_HELP_MAX (__CTA_HELP_MAX - 1)



#define CTA_HELP_MAXNAMESIZE	32



#endif /* _IPCONNTRACK_NETLINK_H */

include/linux/netfilter_ipv4/ip_conntrack.h

+45 −1
Original line number Diff line number Diff line
@@ -209,6 +209,9 @@ struct ip_conntrack 
	/* Current number of expected connections */

	unsigned int expecting;



	/* Unique ID that identifies this conntrack*/

	unsigned int id;



	/* Helper, if any. */

	struct ip_conntrack_helper *helper;
@@ -257,6 +260,9 @@ struct ip_conntrack_expect 
	/* Usage count. */

	atomic_t use;



	/* Unique ID */

	unsigned int id;



#ifdef CONFIG_IP_NF_NAT_NEEDED

	/* This is the original per-proto part, used to map the

	 * expected connection the way the recipient expects. */
@@ -296,7 +302,12 @@ ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo) 
}



/* decrement reference count on a conntrack */

extern void ip_conntrack_put(struct ip_conntrack *ct);

static inline void

ip_conntrack_put(struct ip_conntrack *ct)

{

	IP_NF_ASSERT(ct);

	nf_conntrack_put(&ct->ct_general);

}



/* call to create an explicit dependency on ip_conntrack. */

extern void need_ip_conntrack(void);
@@ -331,6 +342,39 @@ extern void 
ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),

		      void *data);



extern struct ip_conntrack_helper *

__ip_conntrack_helper_find_byname(const char *);

extern struct ip_conntrack_helper *

ip_conntrack_helper_find_get(const struct ip_conntrack_tuple *tuple);

extern void ip_conntrack_helper_put(struct ip_conntrack_helper *helper);



extern struct ip_conntrack_protocol *

__ip_conntrack_proto_find(u_int8_t protocol);

extern struct ip_conntrack_protocol *

ip_conntrack_proto_find_get(u_int8_t protocol);

extern void ip_conntrack_proto_put(struct ip_conntrack_protocol *proto);



extern void ip_ct_remove_expectations(struct ip_conntrack *ct);



extern struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *,

					       struct ip_conntrack_tuple *);



extern void ip_conntrack_free(struct ip_conntrack *ct);



extern void ip_conntrack_hash_insert(struct ip_conntrack *ct);



extern struct ip_conntrack_expect *

__ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);



extern struct ip_conntrack_expect *

ip_conntrack_expect_find_get(const struct ip_conntrack_tuple *tuple);



extern struct ip_conntrack_tuple_hash *

__ip_conntrack_find(const struct ip_conntrack_tuple *tuple,

                    const struct ip_conntrack *ignored_conntrack);



extern void ip_conntrack_flush(void);



/* It's confirmed if it is, or has been in the hash table. */

static inline int is_confirmed(struct ip_conntrack *ct)

{

include/linux/netfilter_ipv4/ip_conntrack_core.h

+5 −0
Original line number Diff line number Diff line
@@ -2,6 +2,9 @@ 
#define _IP_CONNTRACK_CORE_H

#include <linux/netfilter.h>



#define MAX_IP_CT_PROTO 256

extern struct ip_conntrack_protocol *ip_ct_protos[MAX_IP_CT_PROTO];



/* This header is used to share core functionality between the

   standalone connection tracking module, and the compatibility layer's use

   of connection tracking. */
@@ -53,6 +56,8 @@ struct ip_conntrack_ecache; 
extern void __ip_ct_deliver_cached_events(struct ip_conntrack_ecache *ec);

#endif



extern void __ip_ct_expect_unlink_destroy(struct ip_conntrack_expect *exp);



extern struct list_head *ip_conntrack_hash;

extern struct list_head ip_conntrack_expect_list;

extern rwlock_t ip_conntrack_lock;

include/linux/netfilter_ipv4/ip_conntrack_helper.h

+2 −0
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ struct ip_conntrack_helper 
	int (*help)(struct sk_buff **pskb,

		    struct ip_conntrack *ct,

		    enum ip_conntrack_info conntrackinfo);



	int (*to_nfattr)(struct sk_buff *skb, const struct ip_conntrack *ct);

};



extern int ip_conntrack_helper_register(struct ip_conntrack_helper *);