1#ifndef _NFNETLINK_H
2#define _NFNETLINK_H
3
4
5#include <linux/netlink.h>
6#include <linux/capability.h>
7#include <net/netlink.h>
8#include <uapi/linux/netfilter/nfnetlink.h>
9
10struct nfnl_callback {
11	int (*call)(struct sock *nl, struct sk_buff *skb,
12		    const struct nlmsghdr *nlh,
13		    const struct nlattr * const cda[]);
14	int (*call_rcu)(struct sock *nl, struct sk_buff *skb,
15		    const struct nlmsghdr *nlh,
16		    const struct nlattr * const cda[]);
17	int (*call_batch)(struct sock *nl, struct sk_buff *skb,
18			  const struct nlmsghdr *nlh,
19			  const struct nlattr * const cda[]);
20	const struct nla_policy *policy;	/* netlink attribute policy */
21	const u_int16_t attr_count;		/* number of nlattr's */
22};
23
24struct nfnetlink_subsystem {
25	const char *name;
26	__u8 subsys_id;			/* nfnetlink subsystem ID */
27	__u8 cb_count;			/* number of callbacks */
28	const struct nfnl_callback *cb;	/* callback for individual types */
29	int (*commit)(struct sk_buff *skb);
30	int (*abort)(struct sk_buff *skb);
31};
32
33int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
34int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
35
36int nfnetlink_has_listeners(struct net *net, unsigned int group);
37struct sk_buff *nfnetlink_alloc_skb(struct net *net, unsigned int size,
38				    u32 dst_portid, gfp_t gfp_mask);
39int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
40		   unsigned int group, int echo, gfp_t flags);
41int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
42int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
43		      int flags);
44
45void nfnl_lock(__u8 subsys_id);
46void nfnl_unlock(__u8 subsys_id);
47#ifdef CONFIG_PROVE_LOCKING
48int lockdep_nfnl_is_held(__u8 subsys_id);
49#else
50static inline int lockdep_nfnl_is_held(__u8 subsys_id)
51{
52	return 1;
53}
54#endif /* CONFIG_PROVE_LOCKING */
55
56/*
57 * nfnl_dereference - fetch RCU pointer when updates are prevented by subsys mutex
58 *
59 * @p: The pointer to read, prior to dereferencing
60 * @ss: The nfnetlink subsystem ID
61 *
62 * Return the value of the specified RCU-protected pointer, but omit
63 * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
64 * caller holds the NFNL subsystem mutex.
65 */
66#define nfnl_dereference(p, ss)					\
67	rcu_dereference_protected(p, lockdep_nfnl_is_held(ss))
68
69#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
70	MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
71
72#endif	/* _NFNETLINK_H */
73