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
10 struct 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 net *net, 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
24 struct 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
33 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
34 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
35
36 int nfnetlink_has_listeners(struct net *net, unsigned int group);
37 struct sk_buff *nfnetlink_alloc_skb(struct net *net, unsigned int size,
38 u32 dst_portid, gfp_t gfp_mask);
39 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
40 unsigned int group, int echo, gfp_t flags);
41 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
42 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
43 int flags);
44
45 void nfnl_lock(__u8 subsys_id);
46 void nfnl_unlock(__u8 subsys_id);
47 #ifdef CONFIG_PROVE_LOCKING
48 bool lockdep_nfnl_is_held(__u8 subsys_id);
49 #else
lockdep_nfnl_is_held(__u8 subsys_id)50 static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
51 {
52 return true;
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