Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NFNETLINK_H
3#define _NFNETLINK_H
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 net *net, struct sock *nl, struct sk_buff *skb,
12 const struct nlmsghdr *nlh,
13 const struct nlattr * const cda[],
14 struct netlink_ext_ack *extack);
15 int (*call_rcu)(struct net *net, struct sock *nl, struct sk_buff *skb,
16 const struct nlmsghdr *nlh,
17 const struct nlattr * const cda[],
18 struct netlink_ext_ack *extack);
19 int (*call_batch)(struct net *net, struct sock *nl, struct sk_buff *skb,
20 const struct nlmsghdr *nlh,
21 const struct nlattr * const cda[],
22 struct netlink_ext_ack *extack);
23 const struct nla_policy *policy; /* netlink attribute policy */
24 const u_int16_t attr_count; /* number of nlattr's */
25};
26
27struct nfnetlink_subsystem {
28 const char *name;
29 __u8 subsys_id; /* nfnetlink subsystem ID */
30 __u8 cb_count; /* number of callbacks */
31 const struct nfnl_callback *cb; /* callback for individual types */
32 int (*commit)(struct net *net, struct sk_buff *skb);
33 int (*abort)(struct net *net, struct sk_buff *skb);
34 void (*cleanup)(struct net *net);
35 bool (*valid_genid)(struct net *net, u32 genid);
36};
37
38int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
39int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
40
41int nfnetlink_has_listeners(struct net *net, unsigned int group);
42int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
43 unsigned int group, int echo, gfp_t flags);
44int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
45int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
46 int flags);
47
48static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
49{
50 return subsys << 8 | msg_type;
51}
52
53void nfnl_lock(__u8 subsys_id);
54void nfnl_unlock(__u8 subsys_id);
55#ifdef CONFIG_PROVE_LOCKING
56bool lockdep_nfnl_is_held(__u8 subsys_id);
57#else
58static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
59{
60 return true;
61}
62#endif /* CONFIG_PROVE_LOCKING */
63
64/*
65 * nfnl_dereference - fetch RCU pointer when updates are prevented by subsys mutex
66 *
67 * @p: The pointer to read, prior to dereferencing
68 * @ss: The nfnetlink subsystem ID
69 *
70 * Return the value of the specified RCU-protected pointer, but omit
71 * the READ_ONCE(), because caller holds the NFNL subsystem mutex.
72 */
73#define nfnl_dereference(p, ss) \
74 rcu_dereference_protected(p, lockdep_nfnl_is_held(ss))
75
76#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
77 MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
78
79#endif /* _NFNETLINK_H */