nfnetlink.h
#ifndef _NFNETLINK_H
#define _NFNETLINK_H
#include <linux/types.h>
#ifndef __KERNEL__
/* nfnetlink groups: Up to 32 maximum - backwards compatibility for userspace */
#define NF_NETLINK_CONNTRACK_NEW 0x00000001
#define NF_NETLINK_CONNTRACK_UPDATE 0x00000002
#define NF_NETLINK_CONNTRACK_DESTROY 0x00000004
#define NF_NETLINK_CONNTRACK_EXP_NEW 0x00000008
#define NF_NETLINK_CONNTRACK_EXP_UPDATE 0x00000010
#define NF_NETLINK_CONNTRACK_EXP_DESTROY 0x00000020
#endif
enum nfnetlink_groups {
NFNLGRP_NONE,
#define NFNLGRP_NONE NFNLGRP_NONE
NFNLGRP_CONNTRACK_NEW,
#define NFNLGRP_CONNTRACK_NEW NFNLGRP_CONNTRACK_NEW
NFNLGRP_CONNTRACK_UPDATE,
#define NFNLGRP_CONNTRACK_UPDATE NFNLGRP_CONNTRACK_UPDATE
NFNLGRP_CONNTRACK_DESTROY,
#define NFNLGRP_CONNTRACK_DESTROY NFNLGRP_CONNTRACK_DESTROY
NFNLGRP_CONNTRACK_EXP_NEW,
#define NFNLGRP_CONNTRACK_EXP_NEW NFNLGRP_CONNTRACK_EXP_NEW
NFNLGRP_CONNTRACK_EXP_UPDATE,
#define NFNLGRP_CONNTRACK_EXP_UPDATE NFNLGRP_CONNTRACK_EXP_UPDATE
NFNLGRP_CONNTRACK_EXP_DESTROY,
#define NFNLGRP_CONNTRACK_EXP_DESTROY NFNLGRP_CONNTRACK_EXP_DESTROY
__NFNLGRP_MAX,
};
#define NFNLGRP_MAX (__NFNLGRP_MAX - 1)
/* Generic structure for encapsulation optional netfilter information.
* It is reminiscent of sockaddr, but with sa_family replaced
* with attribute type.
* ! This should someday be put somewhere generic as now rtnetlink and
* ! nfnetlink use the same attributes methods. - J. Schulist.
*/
struct nfattr
{
u_int16_t nfa_len;
u_int16_t nfa_type; /* we use 15 bits for the type, and the highest
* bit to indicate whether the payload is nested */
} __attribute__ ((packed));
/* FIXME: Apart from NFNL_NFA_NESTED shamelessly copy and pasted from
* rtnetlink.h, it's time to put this in a generic file */
#define NFNL_NFA_NEST 0x8000
#define NFA_TYPE(attr) ((attr)->nfa_type & 0x7fff)
#define NFA_ALIGNTO 4
#define NFA_ALIGN(len) (((len) + NFA_ALIGNTO - 1) & ~(NFA_ALIGNTO - 1))
#define NFA_OK(nfa,len) ((len) > 0 && (nfa)->nfa_len >= sizeof(struct nfattr) \
&& (nfa)->nfa_len <= (len))
#define NFA_NEXT(nfa,attrlen) ((attrlen) -= NFA_ALIGN((nfa)->nfa_len), \
(struct nfattr *)(((char *)(nfa)) + NFA_ALIGN((nfa)->nfa_len)))
#define NFA_LENGTH(len) (NFA_ALIGN(sizeof(struct nfattr)) + (len))
#define NFA_SPACE(len) NFA_ALIGN(NFA_LENGTH(len))
#define NFA_DATA(nfa) ((void *)(((char *)(nfa)) + NFA_LENGTH(0)))
#define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
#define NFA_NEST(skb, type) \
({ struct nfattr *__start = (struct nfattr *) (skb)->tail; \
NFA_PUT(skb, (NFNL_NFA_NEST | type), 0, NULL); \
__start; })
#define NFA_NEST_END(skb, start) \
({ (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \
(skb)->len; })
#define NFA_NEST_CANCEL(skb, start) \
({ if (start) \
skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
-1; })
/* General form of address family dependent message.
*/
struct nfgenmsg {
u_int8_t nfgen_family; /* AF_xxx */
u_int8_t version; /* nfnetlink version */
u_int16_t res_id; /* resource id */
} __attribute__ ((packed));
#define NFNETLINK_V0 0
#define NFM_NFA(n) ((struct nfattr *)(((char *)(n)) \
+ NLMSG_ALIGN(sizeof(struct nfgenmsg))))
#define NFM_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct nfgenmsg))
/* netfilter netlink message types are split in two pieces:
* 8 bit subsystem, 8bit operation.
*/
#define NFNL_SUBSYS_ID(x) ((x & 0xff00) >> 8)
#define NFNL_MSG_TYPE(x) (x & 0x00ff)
/* No enum here, otherwise __stringify() trick of MODULE_ALIAS_NFNL_SUBSYS()
* won't work anymore */
#define NFNL_SUBSYS_NONE 0
#define NFNL_SUBSYS_CTNETLINK 1
#define NFNL_SUBSYS_CTNETLINK_EXP 2
#define NFNL_SUBSYS_QUEUE 3
#define NFNL_SUBSYS_ULOG 4
#define NFNL_SUBSYS_COUNT 5
#ifdef __KERNEL__
#include <linux/netlink.h>
#include <linux/capability.h>
struct nfnl_callback
{
int (*call)(struct sock *nl, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nfattr *cda[], int *errp);
u_int16_t attr_count; /* number of nfattr's */
};
struct nfnetlink_subsystem
{
const char *name;
__u8 subsys_id; /* nfnetlink subsystem ID */
__u8 cb_count; /* number of callbacks */
struct nfnl_callback *cb; /* callback for individual types */
};
extern void __nfa_fill(struct sk_buff *skb, int attrtype,
int attrlen, const void *data);
#define NFA_PUT(skb, attrtype, attrlen, data) \
({ if (skb_tailroom(skb) < (int)NFA_SPACE(attrlen)) goto nfattr_failure; \
__nfa_fill(skb, attrtype, attrlen, data); })
extern struct semaphore nfnl_sem;
#define nfnl_shlock() down(&nfnl_sem)
#define nfnl_shlock_nowait() down_trylock(&nfnl_sem)
#define nfnl_shunlock() do { up(&nfnl_sem); \
if(nfnl && nfnl->sk_receive_queue.qlen) \
nfnl->sk_data_ready(nfnl, 0); \
} while(0)
extern void nfnl_lock(void);
extern void nfnl_unlock(void);
extern int nfnetlink_subsys_register(struct nfnetlink_subsystem *n);
extern int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n);
extern void nfattr_parse(struct nfattr *tb[], int maxattr,
struct nfattr *nfa, int len);
#define nfattr_parse_nested(tb, max, nfa) \
nfattr_parse((tb), (max), NFA_DATA((nfa)), NFA_PAYLOAD((nfa)))
#define nfattr_bad_size(tb, max, cta_min) \
({ int __i, __res = 0; \
for (__i=0; __i<max; __i++) { \
if (!cta_min[__i]) \
continue; \
if (tb[__i] && NFA_PAYLOAD(tb[__i]) < cta_min[__i]){ \
__res = 1; \
break; \
} \
} \
__res; \
})
extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group,
int echo);
extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);
#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
#endif /* __KERNEL__ */
#endif /* _NFNETLINK_H */